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Harari 2015 Vintage + (''Homo deus'' shows us where we're going. … ''Homo deus'' shows us where we're going. Yuval Harari envisions a near future in sihch we face a new set of challenges. ''Homo deus'' exlores the projects, dreams and nightmares that will shape the twendty-first century and beyond - from overcoming death to creating artificial life. It asks the fundamental questions: how can we protect this fragile world from our own desctructive power? And what does our future hold?tive power? And what does our future hold?)
McMurray 2019 FASEB J + (''In utero'' overnutrition can predispose … ''In utero'' overnutrition can predispose offspring to metabolic disease. Although the mechanisms are unclear, increased oxidative stress accelerating cellular aging has been shown to play a role. Mitochondria are the main site of reactive oxygen species (ROS) production in most cell types. Levels of ROS and the risk for oxidative damage are dictated by the balance between ROS production and antioxidant defense mechanisms. Originally considered as toxic species, physiologic levels of ROS are now known to be essential cell signaling molecules. Using a model of maternal overnutrition in C57BL6N mice, we investigate the mechanisms involved in the development of insulin resistance (IR) in muscle. In red and white gastrocnemius muscles of offspring, we are the first to report characteristics of oxidative phosphorylation, H2O2 production, activity of mitoflashes, and electron transport chain supercomplex formation. Results demonstrate altered mitochondrial function with reduced response to glucose in offspring of mice fed a high-fat and high-sucrose diet, increases in mitochondrial leak respiration, and a reduction in ROS production in red gastrocnemius in response to palmitoyl carnitine. We also demonstrate differences in supercomplex formation between red and white gastrocnemius, which may be integral to fiber-type specialization. We conclude that in this model of maternal overnutrition, mitochondrial alterations occur before the development of IR.ion, mitochondrial alterations occur before the development of IR.)
Holt 1988 Nature + (''In vitro'' studies of muscle mitochondri … ''In vitro'' studies of muscle mitochondrial metabolism in patients with mitochondrial myopathy have identified a variety of functional defects of the mitochondrial respiratory chain, predominantly affecting complex I (NADH-CoQ reductase) or complex III (ubiquinol-cytochrome c reductase) in adult cases. These two enzymes consist of approximately 36 subunits, eight of which are encoded by mitochondrial DNA (mtDNA). The increased incidence of maternal, as opposed to paternal, transmission in familial mitochondrial myopathy suggests that these disorders may be caused by mutations of mtDNA. Multiple restriction endonuclease analysis of leukocyte mtDNA from patients with the disease, and their relatives, showed no differences in cleavage patterns between affected and unaffected individuals in any single maternal line. When muscle mtDNA was studied, nine of 25 patients were found to have two populations of muscle mtDNA, one of which had deletions of up to 7 kilobases in length. These observations demonstrate that mtDNA heteroplasmy can occur in man and that human disease may be associated with defects of the mitochondrial genome. with defects of the mitochondrial genome.)
JanssenDuijghuijsen 2017 Front Physiol + (''In vivo'' studies suggest that intestina … ''In vivo'' studies suggest that intestinal barrier integrity is dependent on mitochondrial ATP production. Here, we aim to provide mechanistic support, using an ''in vitro'' model mimicking the oxidative ''in vivo'' situation.Human Caco-2 cells were cultured for 10 days in culture flasks orfor 14 days on transwell inserts in either glucose-containing or galactose-containingmedium. Mitochondria were visualized and cellular respiration and levels of oxidativephosphorylation (OXPHOS) proteins were determined. Mitochondrial ATP depletionwas induced using CCCP, rotenone, or piericidin A (PA). Monolayer permeability wasassessed using transepithelial electrical resistance (TEER) and fluorescein flux. Geneexpression and cellular distribution of tight junction proteins were analyzed.Caco-2 cells cultured in galactose-containing, but not in glucose-containing,medium showed increased mitochondrial connectivity, oxygen consumption rates andlevels of OXPHOS proteins. Inhibition of mitochondrial ATP production using CCCP,rotenone or PA resulted in a dose-dependent increase in Caco-2 monolayer permeability.In-depth studies with PA showed a six fold decrease in cellular ATP and revealedincreased gene expression of tight junction proteins (TJP) 1 and 2, occludin, and claudin1, but decreased gene expression of claudin 2 and 7. Of these, claudin 7 was clearlyredistributed from the cellular membrane into the cytoplasm, while the others were not(TJP1, occludin) or slightly (claudin 2, actin) affected. ''In vivo'' studies suggest that intestinal barrier integrity is dependent on mitochondrial ATP production. Here, we aim to providemechanistic support, using an ''in vitro'' model mimicking the oxidative ''in vivo'' situation.Well-functioning mitochondria are essential for maintaining cellularenergy status and monolayer integrity of galactose grown Caco-2 cells. Energydepletion-induced Caco-2 monolayer permeability may be facilitated by changes in thedistribution of claudin 7. changes in the distribution of claudin 7.)
Wagner 1998 Plant Physiol + (''In vivo'' ubiquinone (UQ) reduction leve … ''In vivo'' ubiquinone (UQ) reduction levels were measured during the development of the inflorescences of ''Arum maculatum'' and ''Amorphophallus krausei''. Thermogenesis in ''A. maculatum'' spadices appeared not to be confined to a single developmental stage, but occurred during various stages. The UQ pool in both ''A. maculatum'' and ''A. krausei'' appendices was approximately 90% reduced during thermogenesis. Respiratory characteristics of isolated appendix mitochondria did not change in the period around thermogenesis. Apparently, synthesis of the required enzyme capacity is regulated via a coarse control upon which a fine control of metabolism that regulates the onset of thermogenesis is imposed.tes the onset of thermogenesis is imposed.)
Rocco-Machado 2019 Free Radic Biol Med + (''Leishmania amazonensis'' is one of leish … ''Leishmania amazonensis'' is one of leishmaniasis' causative agents, a disease that has no cure and leads to the appearance of cutaneous lesions. Recently, our group showed that heme activates a Na+/K+ ATPase in these parasites through a signaling cascade involving hydrogen peroxide (H2O2) generation. Heme has a pro-oxidant activity and signaling capacity, but the mechanism by which this molecule increases H2O2 levels in ''L. amazonensis'' has not been elucidated. Here we investigated the source of H2O2 stimulated by heme, ruling out the participation of mitochondria and raising the possibility of a role for a NADPH oxidase (Nox) activity. Despite the absence of a classical Nox sequence in trypanosomatid genomes, ''L. amazonensis'' expresses a surface ferric iron reductase (LFR1). Interestingly, Nox enzymes are thought to have evolved from ferric iron reductases because they share same core domain and are very similar in structure. The main difference is that Nox catalyses electron flow from NADPH to oxygen, generating reactive oxygen species (ROS), while ferric iron reductase promotes electron flow to ferric iron, generating ferrous iron. Using ''L. amazonensis'' overexpressing or knockout for LFR1 and heterologous expression of LFR1 in mammalian embryonic kidney (HEK 293) cells, we show that this enzyme is bifunctional, being able to generate both ferrous iron and H2O2. It was previously described that protozoans knockout for LFR1 have their differentiation to virulent forms (amastigote and metacyclic promastigote) impaired. In this work, we observed that LFR1 overexpression stimulates protozoan differentiation to amastigote forms, reinforcing the importance of this enzyme in ''L. amazonensis'' life cycle regulation. Thus, we not only identified a new source of ROS production in Leishmania, but also described, for the first time, an enzyme with both ferric iron reductase and Nox activities.Copyright © 2019 Elsevier Inc. All rights reserved.o described, for the first time, an enzyme with both ferric iron reductase and Nox activities. Copyright © 2019 Elsevier Inc. All rights reserved.)
Pinho 2020 PLoS Negl Trop Dis + (''Leishmania'' species are responsible for … ''Leishmania'' species are responsible for a broad spectrum of diseases, denominated Leishmaniasis, affecting over 12 million people worldwide. During the last decade, there have been impressive efforts for sequencing the genome of most of the pathogenic ''Leishmania'' spp. as well as hundreds of strains, but large-scale proteomics analyses did not follow these achievements and the ''Leishmania'' proteome remained mostly uncharacterized. Here, we report a comprehensive comparative study of the proteomes of strains representing ''L. braziliensis'', ''L. panamensis'' and ''L. guyanensis'' species. Proteins extracted by SDS-mediated lysis were processed following the multi-enzyme digestion-filter aided sample preparation (FASP) procedure and analysed by high accuracy mass spectrometry. "Total Protein Approach" and "Proteomic Ruler" were applied for absolute quantification of proteins. Principal component analysis demonstrated very high reproducibility among biological replicates and a very clear differentiation of the three species. Our dataset comprises near 7000 proteins, representing the most complete ''Leishmania'' proteome yet known, and provides a comprehensive quantitative picture of the proteomes of the three species in terms of protein concentration and copy numbers. Analysis of the abundance of proteins from the major energy metabolic processes allow us to highlight remarkably differences among the species and suggest that these parasites depend on distinct energy substrates to obtain ATP. Whereas ''L. braziliensis'' relies the more on glycolysis, ''L. panamensis'' and ''L. guyanensis'' seem to depend mainly on mitochondrial respiration. These results were confirmed by biochemical assays showing opposite profiles for glucose uptake and O2 consumption in these species. In addition, we provide quantitative data about different membrane proteins, transporters, and lipids, all of which contribute for significant species-specific differences and provide rich substrate for explore new molecules for diagnosing purposes. Data are available via ProteomeXchange with identifier PXD017696.ailable via ProteomeXchange with identifier PXD017696.)
MitoCom2014 + (''MitoCom'' closing event and perspectives. Innsbruck, Austria; 2014 October 16)
Barsottini 2020 Commun Biol + (''Moniliophthora perniciosa'' is a fungal … ''Moniliophthora perniciosa'' is a fungal pathogen and causal agent of the witches' broom disease of cocoa, a threat to the chocolate industry and to the economic and social security in cocoa-planting countries. The membrane-bound enzyme alternative oxidase (MpAOX) is crucial for pathogen survival; however a lack of information on the biochemical properties of MpAOX hinders the development of novel fungicides. In this study, we purified and characterised recombinant MpAOX in dose-response assays with activators and inhibitors, followed by a kinetic characterization both in an aqueous environment and in physiologically-relevant proteoliposomes. We present structure-activity relationships of AOX inhibitors such as colletochlorin B and analogues which, aided by an MpAOX structural model, indicates key residues for protein-inhibitor interaction. We also discuss the importance of the correct hydrophobic environment for MpAOX enzymatic activity. We envisage that such results will guide the future development of AOX-targeting antifungal agents against ''M. perniciosa'', an important outcome for the chocolate industry.ortant outcome for the chocolate industry.)
Yurre 2020 Arq Bras Cardiol + (''Moringa oleifera'' seeds, which are used … ''Moringa oleifera'' seeds, which are used for water clarification, contain a lectin named WSMoL which has shown ''in vitro'' antibacterial and immunomodulatory activity. Due to their nutritional value and therapeutic potential, the leaves and seeds of this tree are eaten in some communities. Some plant lectins are non-toxic to mammals, but others have been reported to be harmful when ingested or administered by other means. As one of the steps needed to define the safety of WSMoL, we evaluated possible cardiotoxic effects of this purified protein. WSMoL was administered for 21 consecutive days to mice by gavage. Electrophysiological, mechanical, and metabolic cardiac functions were investigated by ''in vivo'' and ''ex vivo'' electrocardiographic recordings, nuclear magnetic resonance, and high-resolution respirometry. The treatment with WSMoL did not induce changes in blood glucose levels or body weight in comparison with control group. Moreover, the heart weight/body weight and heart weight/tibia length ratios were similar in both groups. Lectin ingestion also did not modify glucose tolerance or insulin resistance. No alterations were observed in electrocardiographic parameters or cardiac action potential duration. The heart of mice from the control and WSMoL groups showed preserved left ventricular function. Furthermore, WSMoL did not induce changes in mitochondrial function (in all cases, p > 0.05). The administration of WSMoL demonstrated a cardiac safety profile. These results contribute to the safety evaluation of using ''M. oleifera'' seeds to treat water, since this lectin is present in the preparation employed by some populations to this end.ion employed by some populations to this end.)
Pelaez Coyotl 2020 Pharmaceutics + (''Mycobacterium tuberculosis'' (MTB) is th … ''Mycobacterium tuberculosis'' (MTB) is the principal cause of human tuberculosis (TB), which is a serious health problem worldwide. The development of innovative therapeutic modalities to treat TB is mainly due to the emergence of multi drug resistant (MDR) TB. Autophagy is a cell-host defense process. Previous studies have reported that autophagy-activating agents eliminate intracellular MDR MTB. Thus, combining a direct antibiotic activity against circulating bacteria with autophagy activation to eliminate bacteria residing inside cells could treat MDR TB. We show that the synthetic peptide, IP-1 (KFLNRFWHWLQLKPGQPMY), induced autophagy in HEK293T cells and macrophages at a low dose (10 μM), while increasing the dose (50 μM) induced cell death; IP-1 induced the secretion of TNFα in macrophages and killed Mtb at a dose where macrophages are not killed by IP-1. Moreover, IP-1 showed significant therapeutic activity in a mice model of progressive pulmonary TB. In terms of the mechanism of action, IP-1 sequesters ATP ''in vitro'' and inside living cells. Thus, IP-1 is the first antimicrobial peptide that eliminates MDR MTB infection by combining four activities: reducing ATP levels, bactericidal activity, autophagy activation, and TNFα secretion. autophagy activation, and TNFα secretion.)
Iqbal 2018 Pathogens + (''Mycobacterium tuberculosis'' (Mtb) exhib … ''Mycobacterium tuberculosis'' (Mtb) exhibits remarkable metabolic flexibility that enables it to survive a plethora of host environments during its life cycle. With the advent of bedaquiline for treatment of multidrug-resistant tuberculosis, oxidative phosphorylation has been validated as an important target and a vulnerable component of mycobacterial metabolism. Exploiting the dependence of Mtb on oxidative phosphorylation for energy production, several components of this pathway have been targeted for the development of new antimycobacterial agents. This includes targeting NADH dehydrogenase by phenothiazine derivatives, menaquinone biosynthesis by DG70 and other compounds, terminal oxidase by imidazopyridine amides and ATP synthase by diarylquinolines. Importantly, oxidative phosphorylation also plays a critical role in the survival of persisters. Thus, inhibitors of oxidative phosphorylation can synergize with frontline TB drugs to shorten the course of treatment. In this review, we discuss the oxidative phosphorylation pathway and development of its inhibitors in detail.d development of its inhibitors in detail.)
Franco 2020 bioRxiv + (''Mycobacterium tuberculosis'' (Mtb) regul … ''Mycobacterium tuberculosis'' (Mtb) regulates the macrophage metabolic state to thrive in the host. Yet, the responsible mechanisms remain elusive. Macrophage activation towards the microbicidal (M1) program depends on the HIF-1 α-mediated metabolic shift from oxidative phosphorylation towards glycolysis. Here, we asked whether a tuberculosis (TB) microenvironment changes the M1 macrophage metabolic state. We exposed M1 macrophages to the acellular fraction of tuberculous pleural effusions (TB-PE), and found lower glycolytic activity, accompanied by elevated levels of oxidative phosphorylation and bacillary load, compared to controls. The host-derived lipid fraction of TB-PE drove these metabolic alterations. HIF-1α stabilization reverted the effect of TB-PE by restoring M1 metabolism. As a proof-of-concept, Mtb-infected mice with stabilized HIF-1α displayed lower bacillary loads and a pronounced M1-like metabolic profile in alveolar macrophages. Collectively, we demonstrate that host-derived lipids from a TB-associated microenvironment alter the M1 macrophage metabolic reprogramming by hampering HIF-1α functions, thereby impairing control of Mtb infection.hereby impairing control of Mtb infection.)
Baines 2020 Biochim Biophys Acta Bioenerg + (''No abstract available'')
Coen 2013 Obesity (Silver Spring) + (''OBJECTIVE'': The link between a reduced … ''OBJECTIVE'': The link between a reduced capacity for skeletal muscle mitochondrial fatty acid oxidation (FAO) and lipotoxicity in human insulin resistance has been the subject of intense debate. The objective of this study was to investigate whether reduced FAO is associated with elevated acyl CoA, ceramide, and diacylglycerol (DAG) in severely obese insulin resistant subjects.''DESIGN AND METHODS'': Muscle biopsies were conducted in lean (L, 22.6 ± 0.5 kg/m2, ''n'' = 8), Class I (CI, 32.1 ± 0.4 kg/m2, ''n'' = 7) and Class II&III obese (CII&III, 45.6 ± 1.1 kg/m2, ''n'' = 15) women for acyl CoA, sphingolipid and DAG profiling. Intramyocellular triglyceride (IMTG) content was determined by histology. FAO was assessed by incubating muscle homogenates with [1-C]palmitate and measuring CO2 production. Cardiolipin content was quantified as an index of mitochondrial content. Lipid metabolism proteins, DGAT1, PLIN5, and PNPLA2 were quantified in biopsy samples by western blot.''RESULTS'': CII&III were more insulin resistant (HOMA-IR: 4.5 ± 0.5 vs. 1.1 ± 0.1, ''P'' < 0.001), and had lower FAO (∼58%, ''P'' = 0.007) and cardiolipin content (∼31%, ''P'' = 0.013) compared to L. IMTG was elevated in CI (''P'' = 0.04) and CII&III (''P'' = 0.04) compared to L. Sphingolipid content was higher in CII&III compared to L (13.6 ± 1.1 vs. 10.3 ± 0.5 pmol/mg, ''P'' = 0.031) whereas DAG content was not different among groups. DGAT1 was elevated in CII&III, and PLIN5 was elevated in CI compared to L.''CONCLUSION'': Severe obesity is associated with reduced muscle oxidative capacity and occurs concomitantly with elevated IMTG, ceramide and insulin resistance.rs concomitantly with elevated IMTG, ceramide and insulin resistance.)
Ceusters 2012 Am J Vet Res + (''Objective'' To culture equine myoblasts … ''Objective'' To culture equine myoblasts from muscle microbiopsy specimens, examine myoblast production of reactive oxygen species (ROS) in conditions of anoxia followed by reoxygenation, and assess the effects of horseradish peroxidase (HRP) and myeloperoxidase (MPO) on ROS production.''Animals'' 5 healthy horses (5 to 15 years old).''Procedures'' Equine skeletal myoblast cultures were derived from 1 or 2 microbiopsy specimens obtained from a triceps brachii muscle of each horse. Cultured myoblasts were exposed to conditions of anoxia followed by reoxygenation or to conditions of normoxia (control cells). Cell production of ROS in the presence or absence of HRP or MPO was assessed by use of a gas chromatography method, after which cells were treated with a 3,3′-diaminobenzidine chromogen solution to detect peroxidase binding.''Results'' Equine skeletal myoblasts were successfully cultured from microbiopsy specimens. In response to anoxia and reoxygenation, ROS production of myoblasts increased by 71%, compared with that of control cells. When experiments were performed in the presence of HRP or MPO, ROS production in myoblasts exposed to anoxia and reoxygenation was increased by 228% and 183%, respectively, compared with findings for control cells. Chromogen reaction revealed a close adherence of peroxidases to cells, even after several washes.''Conclusions and Clinical Relevance'' Results indicated that equine skeletal myoblast cultures can be generated from muscle microbiopsy specimens. Anoxia-reoxygenationtreated myoblasts produced ROS, and production was enhanced in the presence of peroxidases. This experimental model could be used to study the damaging effect of exercise on muscles in athletic horses.of exercise on muscles in athletic horses.)
Fecker 2020 Biomolecules + (''Oenothera biennis'' L. (OB), also common … ''Oenothera biennis'' L. (OB), also commonly known as evening primrose, belongs to the Onagraceae family and has the best studied biological activity of all the members in the family. In therapy, the most frequently used type of extracts are from the aerial part, which are the fatty oils obtained from the seeds and have a wide range of medicinal properties. The aim of this study was to evaluate the phytochemical composition and biological activity of OB hydroalcoholic extract and to provide directions for the antimicrobial effect, antiproliferative and pro-apoptotic potential against A375 melanoma cell line, and anti-angiogenic and anti-inflammatory capacity. The main polyphenols and flavonoids identified were gallic acid, caffeic acid, epicatechin, coumaric acid, ferulic acid, rutin and rosmarinic acid. The total phenolic content was 631.496 µgGAE/mL of extract and the antioxidant activity was 7258.67 μmolTrolox/g of extract. The tested extract had a mild bacteriostatic effect on the tested bacterial strains. It was bactericidal only against ''Candida spp.'' and ''S. aureus''. In the set of experimental conditions, the OB extract only manifested significant antiproliferative and pro-apoptotic activity against the A375 human melanoma cell line at the highest tested concentration, namely 60 μg/mL. The migration potential of A375 cells was hampered by the OB extract in a concentration-dependent manner. Furthermore, at the highest tested concentration, the OB extract altered the mitochondrial function ''in vitro'', while reducing the angiogenic reaction, hindering compact tumor formation in the chorioallantoic membrane assay. Moreover, the OB extract elicited an anti-inflammatory effect on the experimental animal model of ear inflammation.rimental animal model of ear inflammation.)
Verma 2023 Int J Mol Sci + (''Porphyromonas gingivalis'' (''P. gingiva … ''Porphyromonas gingivalis'' (''P. gingivalis''), a key pathogen in periodontitis, is associated with neuroinflammation. Periodontal disease increases with age; 70.1% of adults 65 years and older have periodontal problems. However, the ''P. gingivalis''- lipopolysaccharide (LPS)induced mitochondrial dysfunction in neurodegenerative diseases remains elusive. In this study, we investigated the possible role of ''P. gingivalis''-LPS in mitochondrial dysfunction during neurodegeneration. We found that ''P. gingivalis''-LPS treatment activated toll-like receptor (TLR) 4 signaling and upregulated the expression of Alzheimer's disease-related dementia and neuroinflammatory markers. Furthermore, the LPS treatment significantly exacerbated the production of reactive oxygen species and reduced the mitochondrial membrane potential. Our study highlighted the pivotal role of ''P. gingivalis''-LPS in the repression of serum response factor (SRF) and its co-factor p49/STRAP that regulate the actin cytoskeleton. The LPS treatment repressed the genes involved in mitochondrial function and biogenesis. ''P. gingivalis''-LPS negatively altered oxidative phosphorylation and glycolysis and reduced total adenosine triphosphate (ATP) production. Additionally, it specifically altered the mitochondrial functions in complexes I, II, and IV of the mitochondrial electron transport chain. Thus, it is conceivable that ''P. gingivalis''-LPS causes mitochondrial dysfunction through oxidative stress and inflammatory events in neurodegenerative diseases.tory events in neurodegenerative diseases.)
Lee 2012 Invest Ophthalmol Vis Sci + (''Purpose'': Following the recent demonstr … ''Purpose'': Following the recent demonstration of increased mitochondrial DNA mutations in lymphocytes of POAG patients, the authors sought to characterize mitochondrial function in a separate cohort of POAG.''Methods'': Using similar methodology to that previous applied to Leber's hereditary optic neuropathy (LHON) patients, maximal adenosine triphosphate (ATP) synthesis and cellular respiration rates, as well as cell growth rates in glucose and galactose media, were assessed in transformed lymphocytes from POAG patients (n = 15) and a group of age- and sex-matched controls (n = 15).''Results'': POAG lymphoblasts had significantly lower rates of complex-I-driven ATP synthesis, with preserved complex-II-driven ATP synthesis. Complex-I driven maximal respiration was also significantly decreased in patient cells. Growth in galactose media, where cells are forced to rely on mitochondrial ATP production, revealed no significant differences between the control and POAG cohort.''Conclusions'': POAG lymphoblasts in the study cohort exhibited a defect in complex-I of the oxidative phosphorylation pathway, leading to decreased rates of respiration and ATP production. Studies in LHON and other diseases have established that lymphocyte oxidative phosphorylation measurement is a reliable indicator of systemic dysfunction of this pathway. While these defects did not impact lymphoblast growth when the cells were forced to rely on oxidative ATP supply, the authors suggest that in the presence of a multitude of cellular stressors as seen in the early stages of POAG, these defects may lead to a bioenergetic crisis in retinal ganglion cells and an increased susceptibility to cell death.an increased susceptibility to cell death.)
Li 2018 Gene + (''SURF1'' is an assembly factor of mitocho … ''SURF1'' is an assembly factor of mitochondrial complex IV, and its mutations are the primary cause of Leigh syndrome in infants. To date, over 100 ''SURF1'' mutations have been reported worldwide, but the spectrum of the ''SURF1'' mutations in China remains unclear. Here, using next-generation sequencing targeting mitochondrial protein-coding sequences, we sequenced 178 patients suspected to have mitochondrial diseases. Fifteen ''SURF1'' mutations were identified in 12 Leigh syndrome patients, of which three, c.465_466delAA, c.532A > T, and c.826_827ins AGCATCTGCAGTACATCG, were newly described. The percentage of ''SURF1'' frameshift mutations (6/28, 21.4%) we detected in Chinese population is higher than other studies (21/106, 19.8%) with different populations, however, the percentage of missense mutations is lower in this study than others (4/28, 14.3% VS. 25/106, 23.6%). Since complex IV can be detected in cells carrying missense mutations (3/8) but not in cells carrying null mutations (0/4) by using cell model-based complementation assay, our results indicate that ''SURF1'' mutations may be associated with worse clinical outcome in Chinese patients than other populations. However, studies with larger sample size are needed to verify this conclusion. Additionally, we found that the frameshift mutations resulting in protein truncation closer to the C-terminus are not associated with better disease prognosis. Lastly, we found that determining the levels of complex IV assembly using cell models or lymphocyte analysis rather than invasive muscle and skin fibroblast biopsy, may help predict disease progression in Leigh syndrome patients.sease progression in Leigh syndrome patients.)
Rosenfeld 2003 Yeast + (''Saccharomyces cerevisiae'' is a facultat … ''Saccharomyces cerevisiae'' is a facultative anaerobe devoid of mitochondrial alternative oxidase. In this yeast, the structure and biogenesis of the respiratory chain, on the one hand, and the functional interactions of oxidative phosphorylation with the cellular energetic metabolism, on the other, are well documented. However, to our knowledge, the molecular aspects and the physiological roles of the non-respiratory pathways that utilize molecular oxygen have not yet been reviewed. In this paper, we review the various non-respiratory pathways in a global context of utilization of molecular oxygen in S. cerevisiae. The roles of these pathways are examined as a function of environmental conditions, using either physiological, biochemical or molecular data. Special attention is paid to the characterization of the so-called 'cyanide-resistant respiration' that is induced by respiratory deficiency, catabolic repression and oxygen limitation during growth. Finally, several aspects of oxygen sensing are discussed.l aspects of oxygen sensing are discussed.)
Oliveira 2016 PLOS ONE + (''Schistosoma mansoni'', one of the causat … ''Schistosoma mansoni'', one of the causative agents of human schistosomiasis, has a unique antioxidant network that is key to parasite survival and a valuable chemotherapeutic target. The ability to detoxify and tolerate reactive oxygen species increases along ''S. mansoni'' development in the vertebrate host, suggesting that adult parasites are more exposed to redox challenges than young stages. Indeed, adult parasites are exposed to multiple redox insults generated from blood digestion, activated immune cells, and, potentially, from their own parasitic aerobic metabolism. However, it remains unknown how reactive oxygen species are produced by ''S. mansoni'' metabolism, as well as their biological effects on adult worms. Here, we assessed the contribution of nutrients and parasite gender to oxygen utilization pathways, and reactive oxygen species generation in whole unpaired adult ''S. mansoni'' worms. We also determined the susceptibilities of both parasite sexes to a pro-oxidant challenge. We observed that glutamine and serum importantly contribute to both respiratory and non-respiratory oxygen utilization in adult worms, but with different proportions among parasite sexes. Analyses of oxygen utilization pathways revealed that respiratory rates were high in male worms, which contrast with high non-respiratory rates in females, regardless nutritional sources. Interestingly, mitochondrial complex I-III activity was higher than complex IV specifically in females. We also observed sexual preferences in substrate utilization to sustain hydrogen peroxide production towards glucose in females, and glutamine in male worms. Despite strikingly high oxidant levels and hydrogen peroxide production rates, female worms were more resistant to a pro-oxidant challenge than male parasites. The data presented here indicate that sexual preferences in nutrient metabolism in adult ''S. mansoni'' worms regulate oxygen utilization and reactive oxygen species production, which may differently contribute to redox biology among parasite sexes.ute to redox biology among parasite sexes.)
Konickova 2014 Annals Hepatol + (''Spirulina platensis'' is a blue-green al … ''Spirulina platensis'' is a blue-green alga used as a dietary supplement because of its hypocholesterolemic properties. Among other bioactive substances, it is also rich in tetrapyrrolic compounds closely related to bilirubin molecule, a potent antioxidant and anti-proliferative agent. The aim of our study was to evaluate possible anticancer effects of ''S. platensis'' and ''S. platensis''-derived tetrapyrroles using an experimental model of pancreatic cancer. The anti-proliferative effects of ''S. platensis'' and its tetrapyrrolic components [phycocyanobilin (PCB) and chlorophyllin, a surrogate molecule for chlorophyll A] were tested on several human pancreatic cancer cell lines and xenotransplanted nude mice. The effects of experimental therapeutics on mitochondrial reactive oxygen species (ROS) production and glutathione redox status were also evaluated. Compared to untreated cells, experimental therapeutics significantly decreased proliferation of human pancreatic cancer cell lines ''in vitro'' in a dose-dependent manner (from 0.16 g•L-1 [''S. platensis''], 60 μM [PCB], and 125 μM [chlorophyllin], ''p''<0.05). The anti-proliferative effects of ''S. platensis'' were also shown ''in vivo'', where inhibition of pancreatic cancer growth was evidenced since the third day of treatment (''p''<0.05). All tested compounds decreased generation of mitochondrial ROS and glutathione redox status (''p''=0.0006; 0.016; and 0.006 for ''S. platensis'', PCB, and chlorophyllin, respectively). In conclusion, ''S. platensis'' and its tetrapyrrolic components substantially decreased the proliferation of experimental pancreatic cancer. These data support a chemopreventive role of this edible alga. Furthermore, it seems that dietary supplementation with this alga might enhance systemic pool of tetrapyrroles, known to be higher in subjects with Gilbert syndrome.roles, known to be higher in subjects with Gilbert syndrome.)
Uribe-Alvarez 2016 Abstract MitoFit Science Camp 2016 + (''Staphylcoccus epidermidis'' does not inv … ''Staphylcoccus epidermidis'' does not invade healthy tissues, however, it has been identified as a cause of nosocomial infections due to its ability to form biofilms on polymer surfaces [1]. ''S. epidermidis'' can be grown at different oxygen concentrations ([O2]), including mammalian skin where [O2] ranges from 3-5% and in anaerobic altered tissues [2,3]. Biofilm formation of ''S. epidermidis'' and its respiratory chain components grown in aerobic, microaerobic and anaerobic conditions were evaluated by in-gel activities, enzymatic activities, spectrophotometry and oxymetry. Varying [O2] modified both biofilm formation and the components in the respiratory chain: At high [O2], little tendency to form biofilms was observed. ''S. epidermidis'' expressed glycerol-3-phosphate, pyruvate, ethanol and succinate dehydrogenases; and cyt bo and aa3. Under micro-aerobiosis, biofilm formation increased slightly; pyruvate, ethanol, glycerol-3-phosphate and succinate dehydrogenase decreased; aa3 cyt was not detected; Under anaerobiosis high biofilm-formation and low ethanol and pyruvate dehydrogenase activities were found; anaerobic nitrate dehydrogenase activity was detected. Aerobic-grown cells with cyanide increased biofilm formation. Anaerobic-grown cells with methylamine decreased biofilm formation. Thus, either a decrease in [O2] or the inhibition of the aerobic chain led ''S. epidermidis'' to associate into biofilms. In contrast, high [O2] or inhibition of the anaerobic nitrate reductase prevented biofilm formation suggesting that the enzymes expressed at low to null [O2] are therapeutic targets against biofilm formation by ''S. epidermidis''. expressed at low to null [O2] are therapeutic targets against biofilm formation by ''S. epidermidis''.)
Snow 2015 PLoS One + (''Trichodesmium'' is a biogeochemically im … ''Trichodesmium'' is a biogeochemically important marine cyanobacterium, responsible for a significant proportion of the annual 'new' nitrogen introduced into the global ocean. These non-heterocystous filamentous diazotrophs employ a potentially unique strategy of near-concurrent nitrogen fixation and oxygenic photosynthesis, potentially burdening Trichodesmium with a particularly high iron requirement due to the iron-binding proteins involved in these processes. Iron availability may therefore have a significant influence on the biogeography of Trichodesmium. Previous investigations of molecular responses to iron stress in this keystone marine microbe have largely been targeted. Here a holistic approach was taken using a label-free quantitative proteomics technique (MSE) to reveal a sophisticated multi-faceted proteomic response of Trichodesmium erythraeum IMS101 to iron stress. Increased abundances of proteins known to be involved in acclimation to iron stress and proteins known or predicted to be involved in iron uptake were observed, alongside decreases in the abundances of iron-binding proteins involved in photosynthesis and nitrogen fixation. Preferential loss of proteins with a high iron content contributed to overall reductions of 55-60% in estimated proteomic iron requirements. Changes in the abundances of iron-binding proteins also suggested the potential importance of alternate photosynthetic pathways as Trichodesmium reallocates the limiting resource under iron stress. ''Trichodesmium'' therefore displays a significant and integrated proteomic response to iron availability that likely contributes to the ecological success of this species in the ocean.ical success of this species in the ocean.)
Subrtova 2013 Abstract MiP2013 + (''Trypanosoma brucei'' is a parasitic flag … ''Trypanosoma brucei'' is a parasitic flagellate that causes devastating diseases of humans and lifestock. The infective form dwells in the glucose rich environment of mammalian blood and generate energy solely via glycolysis. In consequence, the bloodstream stage single mitochondrion is highly reduced lacking key Krebs cycle enzymes and traditional cytochrome mediated respiratory chain. Interestingly, the essential mitochondrial membrane potential (Δ''ψ''mt) is maintained by hydrolytic activity of the unique FoF1-ATPase, which contains several trypanosoma specific subunits of unknown function [1].We determined that one of the largest novel subunit, Tb2930 (43 kDa), is membrane-bound and localizes into monomeric and multimeric assemblies of the FoF1-ATPase. RNAi silencing of Tb2930 led to a significant decrease of Δ''ψ''mt and consequently to ''T. brucei'' growth inhibition, indicating that the FoF1-ATPase is not functioning properly even though its structural intergrity seems to be almost unchanged. To further explore the function of this protein, we employed naturally occuring trypanosoma strain that lacks mtDNA (dyskinetoplastic, Dk) including subunit a, an essential component of the Fo-moiety and proton pore. These Dk cells maintain Δ''ψ''mt by electrogenic exchange of ATP4-/ADP3- by the ATP/ADP carrier (AAC) and hydrolytic activity of the soluble F1-ATPase [2]. So far, it has been assumed that only the F1-moiety subunits are present and will be essential for these parasites. Interestingly, glycerol gradient sedimentation and native electrophoresis of Dk mitochondria revealed the presence of high molecular weight ATPase complexes that correspond to the bloodstream stage monomeric and multimeric FoF1-ATPase. Furthermore, the Tb2930 subunit is expressed in Dk cells and co-sediments with these high molecular weight membrane bound complexes. The RNAi study demonstrated that Tb2930 subunit is essential for Dk trypanosoma cells and crucial for maintaining Δ''ψ''mt. Importantly, upon ablation of Tb2930 we observed a shift of the FoF1-ATPase complexes to the lower S-values on glycerol gradient, where the free F1-ATPase sediments, indicating changes in the structural integrity of the Dk FoF1-ATPase. In conclusion, we propose that Tb2930 is responsible for connecting the Dk F1-ATPase to the mitochondrial membrane in the absence of subunit a of the Fo-moiety, thus increasing the efficiency of the functional association between F1-ATPase and AAC.y, thus increasing the efficiency of the functional association between F1-ATPase and AAC.)
Dolezelova 2017 Abstract IOC122 + (''Trypanosoma brucei'' undergoes a complex … ''Trypanosoma brucei'' undergoes a complex life cycle as it alternates between a mammalian host and the blood-feeding insect vector, a tsetse fly. Due to the different environments, the distinct life stages differ in their energy metabolism, i.e. insect stage (procyclic cells, PS) depends on mitochondrial oxidative phosphorylation (OXPHOS) for ATP production while the bloodstream stage (BS) gains energy by aerobic glycolysis. The dramatic switch from the OXPHOS to glycolysis happens during the complex development of the PS in the tsetse fly. This development differentiation is characterized by extensive remodeling of mitochondrion structure and changes in mitochondrial bioenergetics. Importantly, the molecular mechanism behind this process is completely unknown. We have established the ''in vitro'' differentiation system, in which the transition from PS to epimastigotes followed by differentiation to transmission-ready metacylic trypanosomes is triggered by RNA binding protein 6 (RBP6) expression. This ''in vitro'' induced differentiation of PF cells takes 8 days. The appearance of epimastigotes and metacyclic trypanosomes in the culture was mapped using light and fluorescent microscopy. The whole cell proteome of cell culture harvested every day after the RBP6 induction was identified by label-free quantitative mass spectrometry. This proteomic data serves as a resource for further detailed characterization of changes happening in the parasite mitochondrion as well as identification of possible candidates involved in the PS differentiation.idates involved in the PS differentiation.)
Paes 2014 Abstract IOC 2014-04 Schroecken + (''Trypanosoma cruzi'' has a single mitocho … ''Trypanosoma cruzi'' has a single mitochondrion, the main site of reactive oxygen species (ROS) production. Moreover, ''T. cruzi'' epimastigotes proliferate in the presence of heme, which induces ROS formation (Nogueira et al 2011; Lara et al 2007). Therefore, we evaluated heme effect upon mitochondrial ROS formation and mitochondrial membrane potential (ΔΨmt). For that, epimastigotes were incubated with DHE or TMRM with or without heme. After this, FCCP and antymicin A (Ama) were added. Mitochondrial ROS production and ΔΨmt were analyzed by flow cytometry. Our results showed that heme duplicated ROS production and induced a 4-fold increase of ΔΨmt. The FCCP addition reversed heme effects upon ROS generation and ΔΨm. Additionally, Ama induced a 2-fold increase of ROS production and 46% increment in ΔΨmt, while co-incubation with heme and AA presented a 3-fold increase upon ROS formation and increase ΔΨmt in 70%. In order to corroborate the involvement of heme in mitochondrial ROS, we incubated the parasites with heme, in the absence or in the presence of mitoTEMPO, a mitochondrial antioxidant. Our results showed that in the presence of this antioxidant greatly decreased heme induced ROS generation. Afterwards, we incubated epimastigotes with heme for 30 min and then, performed a substrate-uncoupler-inhibitor-tritation protocol with rotenone, succinate, ADP, cytocrome c, FCCP and Ama. We were able to detect a decrease in several states, mainly ROUTINE, OXPHOS and reserve capacity, compared to control cells. Finally, we evaluated epimastigotes proliferation with or without heme, H2O2, FCCP, Ama or mitoTEMPO. We observed that low concentrations of H2O2 increased proliferation, while higher concentrations showed deleterious effects upon the cells. FCCP and mitoTEMPO also reversed heme-induced proliferation, whereas, Ama promoted a tripanostatic effect. Taken together, our results strongly suggest that heme modulates ''T. cruzi'' mitochondrial physiology since it promotes mitochondrial ROS production, decreasing mitochondrial states, and enhances the ΔΨmt.tochondrial states, and enhances the ΔΨmt.)
Goncalves 2011 Abstract IOC65 + (''Trypanosoma cruzi'' is a hemoflagellate … ''Trypanosoma cruzi'' is a hemoflagellate protozoan that causes Chagas’ disease. ''T. cruzi'' life-cycle is complex involving different evolutive forms that experience striking differences in their environmental condition. Here we carried out a functional assessment of mitochondrial function in two distinct ''T. cruzi'' forms: the insect stage, epimastigote and the freshly isolated bloodstream trypomastigote. We observed that in comparison to epimastigotes, bloodstream trypomastigotes facilitate electrons entry into the electron transport chain increasing Complex II-III activity. Curiously, cytochrome c oxidase (CIV) activity and the expression of CIV subunit IV were reduced in bloodstream forms, creating an “electron bottleneck” that favored increased electron leak and H2O2 formation. We propose that the oxidative preconditioning provided by this mechanism would confer a protection to the bloodstream trypomastigotes against host immune response. Thus, mitochondrial remodeling during the ''T. cruzi'' life-cycle can represent a key metabolic adaptation for parasite survival in different environments.rasite survival in different environments.)
Santos Bertolini 2018 Thesis + (''Trypanosoma cruzi'' is the etiologic age … ''Trypanosoma cruzi'' is the etiologic agent of Chagas disease, a disorder affecting thousands of people, for which an effective treatment is not available for the chronic phase. Calcium signaling is important for host cell invasion, differentiation, osmoregulation, cell death and flagellar function in trypanosomatids. The influx of calcium into the mitochondria, which is important for intracellular calcium homeostasis, occurs through a mitochondrial calcium uniporter complex (MCUC) and this complex consists of several components, including two regulatory proteins named mitochondrial calcium uptake 1 and 2 (MICU1 and MICU2). In mammalian cells, these proteins are located in the mitochondrial intermembrane space and play a role in sensing cytosolic calcium levels and regulating the MCU opening. Although several MCUC components have been identified in trypanosomes, the mechanism by which it is regulated is still unknown. In this work, we aimed at studying the role of MICU1 and MICU2 in the mitochondrial calcium uptake of ''T. cruzi''. The predicted TcMICU1 and TcMICU2 proteins displayed a mitochondrial targeting signal and EF-hands domains that could be sensitive to changes in cytosolic calcium. We obtained TcMICU1 (MICU1-KO) and TcMICU2 (MICU2-KO) knockout cell lines using the CRISPR/Cas9 system by co-transfecting ''T. cruzi'' epimastigotes with the Cas9/pTREX-n vector (containing a specific sgRNA) and a DNA donor cassette with a blasticidin resistance marker to induce the DNA double-strand break repair by homologous recombination. Additionally, we generated a cell line of ''T. cruzi'' epimastigotes overexpressing TcMICU2 tagged with 2xHA (MICU2-OE) using pTREX-n vector. Such molecular constructs were used to analyze the mutant phenotypes and indicate the functions of these proteins. Our results show that MICU1-KO and MICU2-KO have a significant decrease in the capacity to take up calcium, showing a different regulation when we compared to what has already been described previously in mammals. In the absence of these proteins there is a decrease in the growth rate and respiration rates of epimastigotes, showing how important these two proteins are to this stage of ''T. cruzi''. In addition, MICU1-KO epimastigotes are able to differentiate to metacyclic trypomastigotes in a greater proportion than the control cells while the metacyclogenesis capacity was reduced in MICU2-KO cells. Using the MICU2-OE cell line we demonstrated by immunofluorescence microscopy the mitochondrial localization of MICU2 and that its overexpression does not alter the capacity to take up calcium, besides that it does not affect the mitochondrial membrane potential and parasite growth. We can conclude that the TcMICU1 and TcMICU2 proteins are essential for the regulation of mitochondrial calcium uptake by MCU in ''T. cruzi''. Likewise, the results suggest that both proteins play an important role in the growth and differentiation of epimastigotes.owth and differentiation of epimastigotes.)
Barison 2016 J Bioenerg Biomembr + (''Trypanosoma cruzi'', the aetiological ag … ''Trypanosoma cruzi'', the aetiological agent of Chagas's disease, metabolizes glucose, and after its exhaustion, degrades amino acids as energy source. Here, we investigate histidine uptake and its participation in energy metabolism. No putative genes for the histidine biosynthetic pathway have been identified in genome databases of ''T. cruzi'', suggesting that its uptake from extracellular medium is a requirement for the viability of the parasite. From this assumption, we characterized the uptake of histidine in ''T. cruzi'', showing that this amino acid is incorporated through a single and saturable active system. We also show that histidine can be completely oxidised to CO2. This finding, together with the fact that genes encoding the putative enzymes for the histidine - glutamate degradation pathway were annotated, led us to infer its participation in the energy metabolism of the parasite. Here, we show that His is capable of restoring cell viability after long-term starvation. We confirm that as an energy source, His provides electrons to the electron transport chain, maintaining mitochondrial inner membrane potential and O2 consumption in a very efficient manner. Additionally, ATP biosynthesis from oxidative phosphorylation was found when His was the only oxidisable metabolite present, showing that this amino acid is involved in bioenergetics and parasite persistence within its invertebrate host.oenergetics and parasite persistence within its invertebrate host.)
Saraiva 2022 Pathogens + (''Trypanosoma cruzi'', the causative agent … ''Trypanosoma cruzi'', the causative agent of Chagas disease, faces changes in redox status and nutritional availability during its life cycle. However, the influence of oxygen fluctuation upon the biology of ''T. cruzi'' is unclear. The present work investigated the response of ''T. cruzi'' epimastigotes to hypoxia. The parasites showed an adaptation to the hypoxic condition, presenting an increase in proliferation and a reduction in metacyclogenesis. Additionally, parasites cultured in hypoxia produced more reactive oxygen species (ROS) compared to parasites cultured in normoxia. The analyses of the mitochondrial physiology demonstrated that hypoxic condition induced a decrease in both oxidative phosphorylation and mitochondrial membrane potential (ΔΨm) in epimastigotes. In spite of that, ATP levels of parasites cultivated in hypoxia increased. The hypoxic condition also increased the expression of the hexokinase and NADH fumarate reductase genes and reduced NAD(P)H, suggesting that this increase in ATP levels of hypoxia-challenged parasites was a consequence of increased glycolysis and fermentation pathways. Taken together, our results suggest that decreased oxygen levels trigger a shift in the bioenergetic metabolism of ''T. cruzi'' epimastigotes, favoring ROS production and fermentation to sustain ATP production, allowing the parasite to survive and proliferate in the insect vector.vive and proliferate in the insect vector.)
Souza 2021 PLoS Pathog + (''Trypanosoma cruzi'', the parasite causin … ''Trypanosoma cruzi'', the parasite causing Chagas disease, is a digenetic flagellated protistthat infects mammals (including humans) and reduviid insect vectors. Therefore, ''T. cruzi''must colonize different niches in order to complete its life cycle in both hosts. This fact determines the need of adaptations to face challenging environmental cues. The primary environmental challenge, particularly in the insect stages, is poor nutrient availability. In this regard,it is well known that ''T. cruzi'' has a flexible metabolism able to rapidly switch from carbohydrates (mainly glucose) to amino acids (mostly proline) consumption. Also established hasbeen the capability of ''T. cruzi'' to use glucose and amino acids to support the differentiationprocess occurring in the insect, from replicative non-infective epimastigotes to non-replicative infective metacyclic trypomastigotes. However, little is known about the possibilities ofusing externally available and internally stored fatty acids as resources to survive in nutrient-poor environments, and to sustain metacyclogenesis. In this study, we revisit the metabolic fate of fatty acid breakdown in ''T. cruzi''. Herein, we show that during parasiteproliferation, the glucose concentration in the medium can regulate the fatty acid metabolism. At the stationary phase, the parasites fully oxidize fatty acids. [U-14C]-palmitate can betaken up from the medium, leading to CO2 production. Additionally, we show that electronsare fed directly to oxidative phosphorylation, and acetyl-CoA is supplied to the tricarboxylicacid (TCA) cycle, which can be used to feed anabolic pathways such as the ''de novo'' biosynthesis of fatty acids. Finally, we show as well that the inhibition of fatty acids mobilization intothe mitochondrion diminishes the survival to severe starvation, and impairsmetacyclogenesis.s the survival to severe starvation, and impairs metacyclogenesis.)
Uribe-Alvarez 2018 Microbiologyopen + (''Wolbachia sp.'' has colonized over 70% o … ''Wolbachia sp.'' has colonized over 70% of insect species, successfully manipulatinghost fertility, protein expression, lifespan, and metabolism. Understanding and engineeringthe biochemistry and physiology of ''Wolbachia'' holds great promise for insectvector-borne disease eradication. ''Wolbachia'' is cultured in cell lines, which have longduplication times and are difficult to manipulate and study. The yeast strain''Saccharomyces cerevisiae'' W303 was used successfully as an artificial host for''Wolbachia'' wAlbB. As compared to controls, infected yeast lost viability early, probablyas a result of an abnormally high mitochondrial oxidative phosphorylation activityobserved at late stages of growth. No respiratory chain proteins from ''Wolbachia''were detected, while several ''Wolbachia'' F1F0-ATPasesubunits were revealed. After 5 days outside the cell, Wolbachia remained fully infective against insect cells.the cell, Wolbachia remained fully infective against insect cells.)
38th Mahabaleshwar Seminar + ('Mitochondria, Metabolism and Energetics': [[Media:MiPNet18.14 IOC85 Mahabaleshwar.pdf|'''38th Mahabaleshwar Seminar''']], [http://www.tifr.res.in/~dbsconf/mito2014/Home.html mito2014], including '''[[MiPNet18.14 | 85th OROBOROS O2k-Workshop]]'''.)
Paeaebo 2014 Basic Books + ('The Neanderthals live on in many of us to … 'The Neanderthals live on in many of us today' (p 199).Neanderthal Man tells the story of geneticist Svante Pääbo's mission to answer this question, and recounts his ultimately successful efforts to genetically define what makes us different from our Neanderthal cousins. Beginning with the study of DNA in Egyptian mummies in the early 1980s and culminating in the sequencing of the Neanderthal genome in 2010, Neanderthal Man describes the events, intrigues, failures, and triumphs of these scientifically rich years through the lens of the pioneer and inventor of the field of ancient DNA.We learn that Neanderthal genes offer a unique window into the lives of our hominin relatives and may hold the key to unlocking the mystery of why humans survived while Neanderthals went extinct. Drawing on genetic and fossil clues, Pääbo explores what is known about the origin of modern humans and their relationship to the Neanderthals and describes the fierce debate surrounding the nature of the two species' interactions. His findings have not only redrawn our family tree, but recast the fundamentals of human history—the biological beginnings of fully modern ''Homo sapiens'', the direct ancestors of all people alive today.A riveting story about a visionary researcher and the nature of scientific inquiry, Neanderthal Man offers rich insight into the fundamental question of who we are.to the fundamental question of who we are.)
Sipos 2005 Cell Mol Neurobiol + ((1) Endothelial cells are permanently chal … (1) Endothelial cells are permanently challenged by altering pH in the blood, and oxidative damage could also influence the intracellular pH (pH(i)) of the endothelium. Cerebral microvascular endothelial cells form the blood-brain barrier (BBB) and pH(i) regulation of brain capillary endothelial cells is important for the maintenance of BBB integrity. The aim of this study was to address the pH regulatory mechanisms and the effect of an acute exposure to hydrogen peroxide (H2O2) on the pH regulation in primary rat brain capillary endothelial (RBCE) cells The RBCE monolayers were loaded with the fluorescent pH indicator BCECF and pH(i) was monitored by detecting the fluorescent changes. (2) The steady-state pH(i) of RBCE cells in HEPES-buffer (6.83 +/- 0.1) did not differ significantly from that found in bicarbonate-buffered medium (6.90 +/- 0.08). Cells were exposed to NH4CI to induce intracellular acidification and then the recovery to resting pH was studied. Half-recovery time after NH4Cl prepulse-induced acid load was significantly less in the bicarbonate-buffered medium than in the HEPES-medium, suggesting that in addition to the Na+ / H+ exchanger, HCO3- / Cl- exchange mechanism is also involved in the restoration of pH(i) after an intracellular acid load in primary RBCE cells. We used RT-PCR-reactions to detect the isoforms of Na+ / H+ exchanger gene family (NHE). NHE-1 -2, -3 and -4 were equally present, and there was no significant difference in the relative abundance of the four transcripts in these cells. (3) No pH(i) recovery was detected when the washout after an intracellular acid load occurred in nominally Na+ -free HEPES-buffered medium or in the presence of 10 microM 5-(N-ethyl-N-isopropyl)amiloride (EIPA), a specific inhibitor of Na+ / H+ exchanger. The new steady-state pH(i) were 6.37 +/- 0.02 and 6.60 +/- 0.02, respectively. (4) No detectable change was observed in the steady-state pH(i) in the presence of 100 microM H2O2; however, recovery from NH4Cl prepulse-induced intracellular acid load was inhibited when H2O2 was present in 50 or 100 microM concentration in the HEPES-buffered medium during NH4Cl washout. These data suggest that H2O2 is without effect on the activity of Na+ / H+ exchanger at rest, but could inhibit the function of the exchanger after an intracellular acid load.xchanger after an intracellular acid load.)
MiPNet25.14 TPP Analysis Template + ((2020) Excel template for TPP data analys … (2020) Excel template for TPP data analysis. Mitochondr Physiol Network 25.14(01):1-8. <div style="padding:0px;border: 1px solid #aaaaaa;margin-bottom:0px;margin-right:10px"><div style="font-size:100%;font-weight:bold;padding:0.2em;padding-right: 0.4em;padding-left: 0.4em;background-color:#eeeeee;border-bottom:1px solid #aaaaaa;text-align:left;">[[Image:O2k-support system.jpg|right|150px|link=http://wiki.oroboros.at/index.php/O2k-technical_support_and_open_innovation|O2k-technical support and open innovation]]: <big>Open the '''pdf document''' above.</big></div><div style="background-color:#ffffff;padding-top:0.2em;padding-right: 0.4em;padding-bottom: 0.2em;padding-left: 0.4em;">::::» Current O2k-series: '''[https://www.oroboros.at/index.php/product-category/products/o2k-packages/ NextGen-O2k Series XB and O2k Series J]'''::::» Current software versions DatLab 8.0: [[MitoPedia: DatLab]]::::* ''Further details:'' '''» [[MitoPedia: O2k-Open Support]]'''</div></div>:» Product: [[DatLab]], [[Oroboros O2k]], [[Oroboros O2k-Catalogue |O2k-Catalogue]]oboros O2k-Catalogue |O2k-Catalogue]])
Kagawa 1971 J Biol Chem + ( * Amorphous membrane fragments depleted i … * Amorphous membrane fragments depleted in P-lipids and cytochrome oxidase were isolated from bovine heart mitochondria and were reconstituted with P-lipids and coupling factors to yield vesicular structures. These vesicles catalyzed a 32Pi—ATP exchange and showed an induced enhancement of anilinonaphthalene sulfonate fluorescence on addition of ATP* 32Pi—ATP exchange and fluorescence enhancement were abolished by uncouplers of oxidative phosphorylation and by energy transfer inhibitors. The ATPase activity was inhibited by energy transfer inhibitors, but stimulated by uncouplers or by the combined action of nigericin and valinomycin in the presence of K+. Both ATPase activity and 32Pi—ATP exchange were inhibited by a specific antibody against coupling factor 1.* It was shown that the reconstitution of vesicular structures with functional activity required several hours. Rapid reconstitution resulted in inactive vesicles. Evidence for the formation of new vesicles from solubilized P-lipids was obtained by demonstrating inclusion of macromolecules such as 14C-labeled inulin or ferritin which could not be removed by washing.itin which could not be removed by washing. )
Cannon 2015 Fatty Acid Oxidation O2k-Network Discussion Forum + ( *Saponin permeabilized skeletal muscle fi … *Saponin permeabilized skeletal muscle fiber bundles*'''Protocol''':#0.5mM Malate#50 µM palmitoyl-CoA + 2mM carnitine#5mM ADP#From here on out, various combinations for titration protocol*Coupling states:#LEAK_M+Palmitoylcarnitine#P_M+Palmitoylcarnitine#P_M+Palmitoylcarnitine+S#E_O+CCCP titrations#E_S+Rot#ROX_AntimycinA_O+CCCP titrations #E_S+Rot #ROX_AntimycinA )
Nernst 1921 Nobel Lecture + (.. From the start of my scientific career … .. From the start of my scientific career the galvanic cell, the first form of which, the Volta pile, popularized physics in a single stroke and at the same time presented us with so many problems, appeared to me to merit especially further study. ..It was particularly disillusioning to find a man like Helmholtz returning repeatedly throughout his scientific career to his first love, the galvanic cell, which he had courted in his great youthful work "Erhaltung der Kraft" (The conservation of energy), without however succeeding in finding a satisfactory solution.As often in natural science the picture changed quite suddenly. New fruitful concepts appeared, through the interplay and extension of which most of the darkness has been to a large extent dispelled in a single stroke. Such means were Van ’t Hoff’s theory of osmotic pressure, Arrhenius’ theory of electrolytic dissociation, and finally many new approaches to the treatment of chemical equilibria, which, brilliantly presented, are to be found scattered throughout the first edition of Ostwald’s "Lehrbuch der Allgemeinen Chemie" (Textbook of general chemistry). So there arose in 1889 the osmotic theory of galvanic current generation, which has not been seriously challenged since it was put forward more than thirty years ago and has undergone no appreciable elaboration since its acceptance, surely a clear sign that it has so far satisfied scientific needs. ..The osmotic theory of current generation stipulates moreover that when a metal ion concentration is higher than consistent with the solution tension of the particular metal, on immersion of the metal, ions of the relevant metal electrode must go into solution, while conversely they must settle on the electrode when the reverse is the case.he electrode when the reverse is the case.)
Estabrook 1967 Methods Enzymol + (.. The convenience and simplicity of the p … .. The convenience and simplicity of the polarographic 'oxygen electrode' technique for measuring rapid changes in the rate of oxygen utilization by cellular and subcellular systems is now leading to its more general application in many laboratories. The types and design of oxygen electrodes vary, depending on the invetigator's ingenuity and specific requirements of the system under investigation.rements of the system under investigation.)
Gnaiger 1997 Transplant Proc + (0RGAN PRESERVATION under hypothermic ische … 0RGAN PRESERVATION under hypothermic ischemia is enhanced by storage solutions that protect the vascular endothelium from ischemia-reperfusion injury. Ischemia-reperfusion injury leads to primary graft failure and chronic rejection, and is commonly assessed by measuring endothelial activation and damage of the endothelial plasma membrane. However, corresponding primary intracellular events are little understood compared with the secondary cytokine/adhesion molecule cascade and inflammatory responses.1, 2 Because protection of intracellular and cell membrane function is fundamental for further improvement of organ preservation, we developed highresolution respirometry as a sensitive diagnostic test for mitochondrial and plasma membrane competence.3 Whereas the plasma membrane remained impermeable after clinically relevant cold storage times of 8 hours and 20 to 60 minutes of reoxygenation, mitochondrial function was impaired at several steps of the respiratory chain.l function was impaired at several steps of the respiratory chain.)
Majiene 2019 Nutrients + (1,4-naphthoquinones, especially juglone, a … 1,4-naphthoquinones, especially juglone, are known for their anticancer activity. However, plumbagin, lawsone, and menadione have been less investigated for these properties. Therefore, we aimed to determine the effects of plumbagin, lawsone, and menadione on C6 glioblastoma cell viability, ROS production, and mitochondrial function.Cell viability was assessed spectrophotometrically using metabolic activity method, and by fluorescent Hoechst/propidium iodide nuclear staining. ROS generation was measured fluorometrically using DCFH-DA. Oxygen uptake rates were recorded by the high-resolution respirometer Oxygraph-2k.Plumbagin and menadione displayed highly cytotoxic activity on C6 cells (IC50 is 7.7 ± 0.28 μM and 9.6 ± 0.75 μM, respectively) and caused cell death by necrosis. Additionally, they increased the amount of intracellular ROS in a concentration-dependent manner. Moreover, even at very small concentrations (1-3 µM), these compounds significantly uncoupled mitochondrial oxidation from phosphorylation impairing energy production in cells. Lawsone had significantly lower viability decreasing and mitochondria-uncoupling effect, and exerted strong antioxidant activity.Plumbagin and menadione exhibit strong prooxidant, mitochondrial oxidative phosphorylation uncoupling and cytotoxic activity. In contrast, lawsone demonstrates a moderate effect on C6 cell viability and mitochondrial functions, and possesses strong antioxidant properties.unctions, and possesses strong antioxidant properties.)
Leyssens 1996 J Physiol + (1. As ATP has a higher affinity for Mg2+ t … 1. As ATP has a higher affinity for Mg2+ than ADP, the cytosolic magnesium concentration rises upon ATP hydrolysis. We have therefore used the Mg(2+)-sensitive fluorescent indicator Magnesium Green (MgG) to provide an index of changing ATP concentration in single rat cardiomyocytes in response to altered mitochondrial state. 2. In response to FCCP, [Mg2+]i rose towards a plateau coincident with the progression to rigor, which signals ATP depletion. Contamination of the MgG signal by changes in intracellular free Ca2+ concentration (the KD of MgG for Ca2+ is 4.7 microM) was excluded by simultaneous measurement of [Ca2+]i and [Mg2+]i in cells dual loaded with fura-2 and MgG. The response to FCCP was independent of external Mg2+, confirming an intracellular source for the rise in [Mg2+]i. 3. Simultaneous measurements of mitochondrial NAD(P)H autofluorescence and mitochondrial potential (delta psi m; .-1 fluorescence) and of autofluorescence and MgG allowed closer study of the relationship between [Mg2+]i and mitochondrial state. Oligomycin abolished the FCCP-induced rise in [Mg2+]i without altering the change in autofluorescence. Thus, the rise in [Mg2+]i in response to FCCP is consistent with the release of intracellular Mg2+ following ATP hydrolysis by the mitochondrial F1F0-ATPase. 4. The rise in [Mg2+]i was correlated with cell-attached recordings of ATP-sensitive K+ channel (KATP) activity. In response to FCCP, an increase in KATP channel activity was seen only as [Mg2+]i reached a plateau. In response to blockade of mitochondrial respiration and glycolysis with cyanide (CN-) and 2-deoxyglucose (DOG), [Mg2+]i rose more slowly but again KATP channel opening increased only when [Mg2+]i reached a plateau and the cells shortened. 5. Oligomycin decreased the rate of rise of [Mg2+]i delayed the onset of rigor and increased the rate of mitochondrial depolarization in response to CN-_DOG. Thus, with blockade of mitochondrial respiration delta psi m is maintained by the mitochondrial F1F0-ATPase at the expense of ATP reserves. 6. In response to CN-_DOG, the initial rise in [Mg2+]i was accompanied by a small rise in [Ca2+]i. After [Mg2+]i reached a plateau and rigor developed, [Ca2+]i rose progressively. On reperfusion, in hypercontracted cells, [Ca2+]i recovered before [Mg2+]i and [ca2+]i oscillations were sustained while [Mg2+]i decreased. Thus on reperfusion, full recovery of [ATP]i is slow, but the activation of contractile elements and the restoration of [Ca2+]i does not require the re-establishment of millimolar concentrations of ATP.hment of millimolar concentrations of ATP.)
Satoh 1995 Br J Pharmacol + (1. Effects of 3-hydroxy-3-methylglutaryl c … 1. Effects of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, pravastatin and simvastatin, on the myocardial level of coenzyme Q10, and on mitochondrial respiration were examined in dogs. 2. Either vehicle (control), pravastatin (4 mg kg-1 day-1), or simvastatin (2 mg kg-1 day-1) was administered orally for 3 weeks. First, the myocardial tissue level of coenzyme Q10 was determined in the 3 groups. Second, ischaemia was induced by ligating the left anterior descending coronary artery (LAD) in anaesthetized open chest dogs, pretreated with the inhibitors. After 30 min of ischaemia, nonischaemic and ischaemic myocardium were removed from the left circumflex and LAD regions, respectively, and immediately used for isolation of mitochondria. The mitochondrial respiration was determined by polarography, with glutamate and succinate used as substrates. 3. Simvastatin significantly decreased the myocardial level of coenzyme Q10, but pravastatin did not. 4. Ischaemia decreased the mitochondrial respiratory control index (RCI) in both groups. Significant differences in RCI between nonischaemic and ischaemic myocardium were observed in the control and simvastatin-treated groups. 5. Only in the simvastatin-treated group did ischaemia significantly decrease the ADP/O ratio, determined with succinate. 6. The present results indicate that simvastatin but not pravastatin may cause worsening of the myocardial mitochondrial respiration during ischaemia, probably because of reduction of the myocardial coenzyme Q10 level.tion of the myocardial coenzyme Q10 level.)
Chance 1962 J Biol Chem + (1. In succinate oxidation reactivated by a … 1. In succinate oxidation reactivated by a low concentration of adenosine triphosphate, addition of small amounts of adenosine diphosphatc will lead to reestablishment of the inhibited state of succinate oxidation after a short burst of respiration.2. The inhibited state is not relieved by either phosphate or phosphate acceptors. 3. The inhibition is closely correlated with a high degree of oxidation of mitochondrial reduced diphosphopyridine nucleotide, which occurs immediately on addition of adenosine diphosphate and is followed by the inhibition of succinate oxidation after the oxidation or rather small amounts of succinate. 4. Oxidation of more than approximately two-thirds of the total diphosphopyridinc nuclcotide (DPN) reducible by succinate and adenosine triphosphate eventually leads to inhibition of succinate oxidation. 5. Based on independent evidence for a compartmentation of mitochondrial pyridine nucleotide (approximately one-third available to DPN-linked substrates), it is proposed that inhibi- tion occurs when oxidation of DPN in the compartment available to malate causes oxaloacetate formation sufficient to inhibit succinate oxidation. 6. The general possibility of DPN control of malate oxidation is considered with respect to the whole question of oxaloacetate regulation of the citric acid cycle.etate regulation of the citric acid cycle.)
Hatefi 1962 J Biol Chem-XLII + (1. It has been shown that the electron tra … 1. It has been shown that the electron transfer system in beef heart mitochondria may be reconstituted either totally or in any desired sequential segment by appropriate combinations of two or more of the four primary complexes that have been isolated in highly purified form in this laboratory. 2. The four enzyme systems that collectively comprise the complete machinery for transfer of electrons from reduced diphosphopyridine nucleotide (DPNH; =NADH) and succinate to oxygen re: I, DPNH-coenzyme Q reductase; II, succinic-coenzyme Q reductase; III, QH2-cytochrome ''c'' reductase; and IV, cytochrome ''c'' reductase. The specific inhibitors of each complex have been studied. 3. By appropriate combinations of the primary complexes the following secondary activities have been reconstituted: V, DPNH-cytochrome ''c'' reductase; VI, succinic-cytochrome ''c'' reductase; VII, DPNH, succinic-cytochrome c reductase; VIII, DPNH oxidase; IX, succinic oxidase; and X, DPNH, succinic oxidase activity. The general oxidation-reduction properties of the reconstituted systems, both in the presence and the absence of the usual specific inhibitors of the electron transfer system, are essentially the same as those found for the same activities in the intact mitochondria and in the integrated particles derived therefrom. 4. The reconstituted activities are quite stable to repeated freezing, thawing, and storage at -2O °C, and for the most part, when once formed, are not dissociated by dilution of the mixture or by centrifugation. The evidence supporting the conclusion that reconstitution necessarily involves a particle-particle interaction is discussed.article-particle interaction is discussed.)
Opalka 2004 Br Poult Sci + (1. M. iliotibialis (MIT) and M. pectoralis … 1. M. iliotibialis (MIT) and M. pectoralis (MP) of the BUT Big 6 and Kelly BBB turkey were characterised with respect to physical properties, mitochondrial function, metabolic state, morphology and meat quality.2. Mitochondrial enzyme activity and respiration rates in MP declined with increasing age while glycolytic enzyme activity remained nearly constant.3. There were no major differences between BUT Big 6 and Kelly BBB with respect to histological, histochemical or biochemical variables. In spite of the greater adult weight of BUT Big 6, body proportion was equal in both strains.4. In agreement with the histochemical findings MIT showed higher oxidative capacities, while glycolytic enzyme activity was higher in MP.5. Pyruvate was the best substrate for oxidative phosphorylation in MIT, but not in MP. Pyruvate dehydrogenase (PDH) activity was up to 15 times less in MP and blood lactate was correlated with intramuscular pH.6. Turkey breast muscle was restricted in its ability to oxidise pyruvate, especially in those animals that tended to develop intramuscular acidosis post mortem.7. It is concluded that the ''in vivo'' metabolic environment results in acidosis and impaired meat quality, at least in turkey M. pectoralis.quality, at least in turkey M. pectoralis.)
Claude 1946 J Exp Med + (1. Materials and technical procedures invo … 1. Materials and technical procedures involved in the preparation of liver suspensions have been described and discussed. 2. Liver extracts prepared by the present method appear to contain almost exclusively elements of cytoplasmic origin and can be considered to represent, on a large scale, the cytoplasm of liver cells.large scale, the cytoplasm of liver cells.)
Wilson 1970 Biochim Biophys Acta + (1. Oxidation of NADH by fumarate coupled t … 1. Oxidation of NADH by fumarate coupled to synthesis of ATP was found to occur in cyanide-poisoned rat heart submitochondrial particles. The reaction was inhibited by amytal, thenoyltrifluoroacetone and malonate, indicating the involvement of a portion of the electron transfer chain.2. Cytochrome b became oxidized (while the other cytochromes remained reduced) during the oxidation of NADH by fumarate, suggesting that cytochrome b is part of the reaction pathway.3. Succinate was recovered as the reaction product and accounted for the NADH oxidized.4. The P/2e ratios indicate that one ATP was produced for each pair of electrons transferred to fumarate.5. The reaction was also demonstrated to be present in liver and gastrocnemius muscle of rat. The reaction rate in heart was 2.0 times that of gastrocnemius and 3.3 times that of liver. These differences are not related to the activities of NADH or succinate dehydrogenase.6. The ubiquitous nature of this reaction suggests that it could serve as an important physiological mechanism for generating extra glycolytic energy during periods of anoxia.lycolytic energy during periods of anoxia.)
Boveris 1973 Biochem J + (1. Pigeon heart mitochondria produce H(2)O … 1. Pigeon heart mitochondria produce H(2)O(2) at a maximal rate of about 20 nmol/min per mg of protein. 2. Succinate-glutamate and malate-glutamate are substrates which are able to support maximal H(2)O(2) production rates. With malate-glutamate, H(2)O(2) formation is sensitive to rotenone. Endogenous substrate, octanoate, stearoyl-CoA and palmitoyl-carnitine are by far less efficient substrates. 3. Antimycin A exerts a very pronounced effect in enhancing H(2)O(2) production in pigeon heart mitochondria; 0.26 nmol of antimycin A/mg of protein and the addition of an uncoupler are required for maximal H(2)O(2) formation. 4. In the presence of endogenous substrate and of antimycin A, ATP decreases and uncoupler restores the rates of H(2)O(2) formation. 5. Reincorporation of ubiquinone-10 and ubiquinone-3 to ubiquinone-depleted pigeon heart mitochondria gives a system in which H(2)O(2) production is linearly related to the incorporated ubiquinone. 6. The generation of H(2)O(2) by pigeon heart mitochondria in the presence of succinate-glutamate and in metabolic [[State 4]] has an optimum pH value of 7.5. In States 1 and 3u, and in the presence of antimycin A and uncoupler, the optimum pH value is shifted towards more alkaline values. 7. With increase of the partial pressure of O(2) to the hyperbaric region the formation of H(2)O(2) is markedly increased in pigeon heart mitochondria and in rat liver mitochondria. With rat liver mitochondria and succinate as substrate in State 4, an increase in the ''p''O(2) up to 1.97 MPa (19.5 atm) increases H(2)O(2) formation 10-15-fold. Similar ''p''O(2) profiles were observed when rat liver mitochondria were supplemented either with antimycin A or with antimycin A and uncoupler. No saturation of the system with O(2) was observed up to 1.97 MPa (19.5 atm). By increasing the ''p''O(2) to 1.97 MPa (19.5atm), H(2)O(2) formation in pigeon heart mitochondria with succinate as substrate increased fourfold in metabolic State 4, with antimycin A added the increase was threefold and with antimycin A and uncoupler it was 2.5-fold. In the last two saturation of the system with oxygen was observed, with an apparent ''K''(m) of about 71 kPa (0.7-0.8 atm) and a ''V''(max) of 12 and 20 nmol of H(2)O(2)/min per mg of protein. 8. It is postulated that in addition to the well-known flavin reaction, formation of H(2)O(2) may be due to interaction with an energy-dependent component of the respiratory chain at the cytochrome ''b'' level.atory chain at the cytochrome ''b'' level.)
Mitchell 1967 Biochem J + (1. Pulses of acidity of the outer aqueous … 1. Pulses of acidity of the outer aqueous phase of rat liver mitochondrial suspensions induced by pulses of respiration are due to the translocation of H(+) (or OH(-)) ions across the osmotic barrier (M phase) of the cristae membrane and cannot be attributed to the formation (with acid production) of a chemical intermediate that subsequently decomposes. 2. The effective quantity of protons translocated per bivalent reducing equivalent passing through the succinate-oxidizing and beta-hydroxybutyrate-oxidizing spans of the respiratory chain are very close to 4 and 6 respectively. These quotients are constant between pH5.5 and 8.5 and are independent of changes in the ionic composition of the mitochondrial suspension medium provided that the conditions permit the accurate experimental measurement of the proton translocation. 3. Apparent changes in the -->H(+)/O quotients may be induced by conditions preventing the occurrence of the usual backlash; these apparent changes of -->H(+)/O are attributable to a very fast electrically driven component of the decay of the acid pulses that is not included in the experimental extrapolations. 4. Apparent changes in the -->H(+)/O quotients may also be induced by the presence of anions, such as succinate, malonate and phosphate, or by cations such as Na(+). These apparent changes of -->H(+)/O are due to an increase in the rate of the pH-driven decay of the acid pulses. 5. The uncoupling agents, 2,4-dinitrophenol, carbonyl cyanide p-trifluoromethoxyphenylhydrazone and gramicidin increase the effective proton conductance of the M phase and thus increase the rate of decay of the respiration-driven acid pulses, but do not change the initial -->H(+)/O quotients. The increase in effective proton conductance of the M phase caused by these uncouplers accounts quantitatively for their uncoupling action; and the fact that the initial -->H(+)/O quotients are unchanged shows that uncoupler-sensitive chemical intermediates do not exist between the respiratory-chain system and the effective proton-translocating mechanism. 6. Stoicheiometric acid-base changes associated with the activity of the regions of the respiratory chain on the oxygen side of the rotenone- and antimycin A-sensitive sites gives experimental support for a suggested configuration of loop 3.xperimental support for a suggested configuration of loop 3.)
Claude 1944 J Exp Med + (1. Rat tumor extracts, containing chiefly … 1. Rat tumor extracts, containing chiefly the cytoplasmic constituents of leukemic cells, were fractionated into three main portions, the different components separating in the centrifuge according to size. 2. Mitochondria were isolated by centrifugation at relatively low speed. Elementary composition of purified mitochondria was found to correspond to about 11.5 per cent nitrogen, 1.6 per cent phosphorus, and 27 per cent lipids. Phosphorus and nitrogen content of the lipid portion suggests that as much as 75 to 80 per cent of the lipids of mitochondria is represented by phospholipids. Tests for ribose nucleic acid were positive. 3. Microsomes were separated by means of centrifugation at 18,000 x g. A relation between the high phosphorus content of the microsomes and the marked basophilia of the cytoplasm of leukemic cells is suggested. 4. Phosphorus distribution in the tumor extract, and light absorption analysis of the third fraction, seem to demonstrate that nucleic acid was not present either in a free condition, or in the form of nucleoprotein of relatively low molecular weight. The nature of the results suggests that ribose nucleic acid occurs in the cytoplasm of leukemic cells only in association with formed elements of relatively large size, namely microsomes, and mitochondria.size, namely microsomes, and mitochondria.)
Ernster 1969 Eur J Biochem + (1. Submitochondrial particles were prepare … 1. Submitochondrial particles were prepared from beef‐heart mitochondria by sonication in the presence of EDTA. The particles were lyophilized and repeatedly extracted with pentane until no ubiquinone was found in the extract. Treatment of the ubiquinone‐depleted particles with pentane containing a suitable concentration of ubiquinone (ubiquinone‐50) and subsequent quick washing with ubiquinone‐free pentane resulted in a “re‐incorporation” of ubiquinone in an amount similar to that present in the original particles (3–6 nmoles/mg protein).2. The ubiquinone‐depleted particles exhibited very low or no succinate and NADH oxidase activities, which were restored upon the re‐incorporation of ubiquinone to the levels found in the lyophilized particles before extraction with pentane. Partial (about 50 %) extraction of ubiquinone resulted in markedly decreased succinate and NADH oxidase activities.3. Added cytochrome ''c'' did not replace ubiquinone in restoring the succinate or NADH oxidase activity of ubiquinone‐depleted particles. It stimulated the NADH oxidase, but not the succinate oxidase, activity of the “ubiquinone‐incorporated” particles, but the same stimulation occurred with the lyophilized particles before ubiquinone extraction. The normal, lyophilized, and “ubiquinone‐incorporated” particles contained equal amounts of both total and enzymatically reducible cytochromes.4. In the presence of KCN, NADH reduced the cytochromes, including cytochrome ''b'', only at insignificant rates in the ubiquinone‐depleted particles as compared to the normal and lyophilized preparations, and these rates were greatly stimulated upon the re‐incorporation of ubiquinone. Succinate caused a rapid partial (about 25 %) reduction of cytochrome ''b'', but not of the rest of the cytochromes, in the ubiquinone‐depleted particles. This reduction occurred also in the absence of KCN, and the fraction of cytochrome ''b'', so reduced was not reoxidized when succinate oxidation was inhibited by malonate. Evidence for the occurrence of such an enzymatically non‐oxidizable form of cytochrome ''b'' was also obtained in the normal, lyophilized and “ubiquinone‐incorporated” particles, but, in those cases, this cytochrome ''b'' was reduced by both succinate and NADH. In the presence of antimycin A, all cytochrome ''b'' in the ubiquinone‐depleted particles was rapidly reduced by succinate but not by NADH.5. The normal and lyophilized particles catalyzed a rotenone‐sensitive oxidation of NADH by fumarate. This reaction was completely absent from the ubiquinone‐depleted particles and was restored upon the re‐incorporation of ubiquinone.6. N,N,N′,N′‐Tetramethyl‐p‐phenylenediamine catalyzed an NADH and succinate oxidase activity in antimycin A‐inhibited particles. This NADH oxidase activity was partially sensitive to rotenone in the normal, lyophilized and “ubiquinone‐incorporated” particles, but completely rotenone‐insensitive in the ubiquinone‐depleted particles. All four types of particles were active in catalyzing the antimycin A‐sensitive oxidation of menadiol.7. It is concluded that uniquinone is essential for the interaction of succinate dehydrogenase, NADH dehydrogenase and cytochrome ''b'', and that this interaction is a requisite for the normal function of the respiratory chain. Functionally modified forms of cytochrome ''b'', arising as a consequence of structural damage or antimycin A treatment, are discussed in relation to existing information and proposals concerning the role of cytochrome ''b'' and ubiquinone in electron transport.'b'' and ubiquinone in electron transport.)
Henderson 1969 Biochem J + (1. The action of the antibiotics enniatin … 1. The action of the antibiotics enniatin A, valinomycin, the actin homologues, gramicidin, nigericin and dianemycin on mitochondria, erythrocytes and smectic mesophases of lecithin-dicetyl hydrogen phosphate was studied. 2. These antibiotics induced permeability to alkali-metal cations on all three membrane systems. 3. The ion specificity on each membrane system was the same. 4. Enniatin A, valinomycin and the actins did not induce permeability to protons, whereas nigericin and dianemycin rendered all three membrane systems freely permeable to protons. 5. Several differences were noted between permeability induced by nigericin and that induced by gramicidin. 6. The action of all these antibiotics on mitochondrial respiration could be accounted for by changes in passive ion permeability of the mitochondrial membrane similar to those induced in erythrocytes and phospholipid membranes, if it is assumed that a membrane potential is present in respiring mitochondria.tial is present in respiring mitochondria.)
Harafuji 1980 J Biochem + (1. The apparent binding constant (Kapp(Ca- … 1. The apparent binding constant (Kapp(Ca-G)) for GEDTA (ethylene glycol bis(β-aminoethyl ether)-N, N, N', N'-tetraacetic acid, EGTA) to calcium was determined under conditions of biological significance in the presence of various kinds of pH-buffering agents, using murexide or tetramethylmurexide as a Ca indicator.2. The value of Kapp(Ca-G) at pH 6.80 was 1.0×106M-1 at an ionic strength of 0.114 at 20°C, irrespective of the type of pH-buffering ions. This value is similar to that of Allen, Blinks and Prendergast (1977) (Science 196, 996-998), but still half that calculated from the results of Schwarzenbach, Senn and Anderegg (1957) (Helv. Chim. Acta 40, 1886-1900).3. The value of Kapp(Ca-G) varied according to the following equation as the ionic strength (I) was varied from 0.039 to 0.264:log Kapp(Ca-G)=6.460-[2_??_I/(1+_??_I)-0.4×I] (pH 6.80, 20°C)4. The discrepancy between the present results and previous ones (Ogawa, Y. (1968) J. Biochem. 64, 255-257) may have been due to inadequate regulation of the temperature of the reaction medium in the previous determinations, during which an increase in the temperature of the solution may have occurred.An increase of temperature causes a decrease in the pH of the solution in the presence of histidine, imidazole or Tris-maleate, but causes very little change of pH in the presence of phosphate or maleate.5. The association rate constant for GEDTA with calcium was determined by the stoppedflow method in solutions containing 100mM KCl and 20mM pH-buffering ions at 20°C: the values obtained were 1.4×106M-1s-1 in the presence of MOPS-KOH at pH 6.80; 3.0×106M-1s-1 with imidazole at pH 6.80; 1.0×106M-1s-1 with Tris-maleate at pH 6.80..0×106M-1s-1 with Tris-maleate at pH 6.80.)
Harris 1968 Biochem J + (1. The concentration-dependence of the int … 1. The concentration-dependence of the intramitochondrial accumulation of l-malate and succinate was measured and expressed in the form of adsorption isotherms. The accumulation, however, may arise because of an internal positive potential. 2. The competition for accumulation offered by some other anions, including phosphate, was measured and is expressed conventionally by additional terms in the adsorption equation. 3. The interactions between anions were also studied when one was acting as oxidized substrate. 4. In some examples there is a parallel between the effects of an added anion on both accumulation and oxidation; in other cases chemical participation of the added substance in metabolism is presumed to remove the correlation. 5. It is suggested that by combining kinetic data on penetration with stoicheiometric data on accumulation and specific reaction rates it may be possible to account for the rates of respiration obtained with intact mitochondria. 6. It is possible to show that there is a certain phosphate/substrate ratio for maximum phosphorylation rate with some substrates. This is to be expected when phosphate and substrate compete for accumulation.te and substrate compete for accumulation.)
Koenig 1969 Biochem J + (1. The effects of succinate oxidation on p … 1. The effects of succinate oxidation on pyruvate and also isocitrate oxidation by rat liver mitochondria were studied. 2. Succinate oxidation was without effect on pyruvate and isocitrate oxidation when respiration was maximally activated with ADP. 3. When respiration was partially inhibited by atractylate, succinate oxidation severely inhibited the oxidation of pyruvate and isocitrate. 4. This inhibitory effect of succinate was associated with a two- to three-fold increase in the reduction of mitochondrial NAD(+) but no change in the reduction of cytochrome b. 5. It is concluded that, in the partially energy-controlled state, respiration is more severely inhibited at the first phosphorylating site than at the other two. 6. The effects of succinate oxidation are compared with those of palmitoylcarnitine oxidation. It is concluded that a rapid flow of electrons directly into the respiratory chain at the level of cytochrome b is in itself inadequate to inhibit the oxidation of intramitochondrial NADH. 7. The effects of succinate oxidation on pyruvate oxidation were similar in rat heart and liver mitochondria.milar in rat heart and liver mitochondria.)
Hoek 1970 Biochim Biophys Acta + (1. The kinetics of the efflux of Pi and ma … 1. The kinetics of the efflux of Pi and malate as well as the relationship between Pi transport and intra- and extramitochondrial pH changes were studied in rat-liver mitochondria in the presence of rotenone and oligomycin at different pH's.2. At high pH a fast efflux of Pi from the mitochondria occurs in the first few seconds, followed by a slow re-entry of Pi into the mitochondria. Under the same conditions the exit of malate shows a time lag of 2–4 sec. The exit of malate coincides with the re-entry of Pi.3. In the presence of butylmalonate the exit of endogenous Pi is coupled with a concomitant alkalinization of the mitochondrial matrix space, as calculated from the distribution of 5,5-[14C]dimethyloxazolidine-2,4-dione.4. The stoicheiometry of the Pi-hydroxyl exchange was found to be 1:1.5. The kinetics of Pi transport are consistent with previous observations that there is a direct exchange between OH− and Pi, but not between OH− and malate. The equilibrium distribution of H2PO4− and OH− deviates from the Donnan distribution. This may be explained by assuming a pH-dependent binding of Pi in the mitochondria.pendent binding of Pi in the mitochondria.)
Claude 1945 J Exp Med + (1. The present paper constitutes a prelimi … 1. The present paper constitutes a preliminary study of the morphology of mitochondria by means of electron microscopy.2. The mitochondria that were the subject of this investigation were obtained from a lymphosarcoma of the rat. They were separated from the other components of the leukemic cells by a method of differential centrifugation, and thus made available for direct examination in the electron microscope.3. In the purified form the mitochondria appeared as spherical bodies, the majority of them varying in size approximately from 0.6 to 1.3 µ in diameter.4. Certain aspects of mitochondria in the electron microscope suggest that these elements are surrounded by a differentiated membrane. In some cases the limiting membrane seemed to be responsible for maintaining the general shape of the mitochondria, even when most of the mitochondrial substance had been lost.5. By means of the electron microscope, it is possible to distinguish small elements, 80 to 100 mµ in diameter, within the body of certain mitochondria. Further work is suggested to establish whether these small granules are normal constituents of mitochondria, and what relation may exist between them and ordinary microsomes.6. The nature of mitochondria as morphological units is discussed. Present evidence indicates that mitochondria constitute definite physical entities which can persist in the absence of the cytoplasm.n persist in the absence of the cytoplasm.)
Griffiths 1995 Biochem J + (1. The yield of mitochondria isolated from … 1. The yield of mitochondria isolated from perfused hearts subjected to 30 min ischaemia followed by 15 min reperfusion was significantly less than that for control hearts, and this was associated with a decrease in the rates of ADP-stimulated respiration. 2. The presence of 0.2 microM cyclosporin A (CsA) in the perfusion medium during ischaemia and reperfusion caused mitochondrial recovery to return to control values, but did not reverse the inhibition of respiration. 3. A technique has been devised to investigate whether the Ca(2+)-induced non-specific pore of the mitochondrial inner membrane opens during ischaemia and/or reperfusion of the isolated rat heart. The protocol involved loading the heart with 2-deoxy[3H]glucose ([3H]DOG), which will only enter mitochondria when the pore opens. Subsequent isolation of mitochondria demonstrated that [3H]DOG did not enter mitochondria during global isothermic ischaemia, but did enter during the reperfusion period. 4. The amount of [3H]DOG that entered mitochondria increased with the time of ischaemia, and reached a maximal value after 30-40 min of ischaemia. 5. CsA at 0.2 microM did not prevent [3H]DOG becoming associated with the mitochondria, but rather increased it; this was despite CsA having a protective effect on heart function similar to that shown previously [Griffiths and Halestrap (1993) J. Mol. Cell. Cardiol. 25, 1461-1469]. 6. The non-immunosuppressive CsA analogue [MeAla6]cyclosporin was shown to have a similar Ki to CsA on purified mitochondrial peptidyl-prolyl cis-trans-isomerase and mitochondrial pore opening, and also to have a similar protective effect against reperfusion injury. 7. Using isolated heart mitochondria, it was demonstrated that pore opening could become CsA-insensitive under conditions of adenine nucleotide depletion and high matrix [Ca2+] such as may occur during the initial phase of reperfusion. The apparent increase in mitochondrial [3H]DOG in the CsA-perfused hearts is explained by the ability of the drug to stabilize pore closure and so decrease the loss of [3H]DOG from the mitochondria during their preparation.the mitochondria during their preparation.)
Kearney 1960 J Biol Chem + (1. Unlike other known flavoproteins, in wh … 1. Unlike other known flavoproteins, in which the flavin is relatively loosely bound and is easily liberated by suitable methods of denaturation, in succinic dehydrogenase from beef heart the flavin component is so tightly held that neither treatment with strong acids nor thermal denaturation separates it from the protein.2. Extensive digestion of the purified dehydrogenase with suitable proteolytic enzymes liberates the flavin in an acid-soluble form, which is not, however, identical with known derivatives of riboflavin. The flavin appears in the digest in several chromatographically distinct forms, which may be separated from each other by purification on ion exchange resins or by chromatography on filter paper.3. The main flavin components have been extensively purified and degraded to the mononucleotide and dephosphorylated flavin levels. The dinucleotide contains 1 mole of 5’-adenylic acid, 2 atoms of phosphorus bound in pyrophosphate linkage and 1 mole of ribose. It differs from authentic flavin adenine dinucleotide (FAD) in numerous regards, including its inactivity in the n-amino acid oxidase test, shifted absorption spectrum, shifted pH-fluorescence curve, and in the presence of cationic group(s). After degradation to the mononucleotide and dephosphorylated flavin level, similar differences exist between the resulting compounds and authentic riboflavin 5’-phosphate and riboflavin, respectively. Irradiation in alkali degrades the flavin further, but the resulting compound is not identical with lumiflavin.4. These differences and the greater water solubility of the unphosphorylated compound as compared with riboflavin are best explained by the hypothesis that the flavin in the dehydrogenase is held to a peptide chain by a covalent linkage which survives proteolytic digestion. The compounds in the digest, therefore, would be peptides of FAD, representing fragments of the original enzyme.5. Evidence for the flavin peptide hypothesis has come from the finding that throughout very extensive purification by a variety of methods the flavin is always accompanied by peptide material. In the most purified fraction, believed to be free of contaminating peptides, alanine, serine, threonine, glutamic acid, and valine were present in molar ratio to the flavin and an additional mole of serine was present as N-terminal group. Similar amino acid compositions were found in 2 other samples, purified by different procedures.6. Evidence pertaining to the flavin peptide hypothesis and the possible structure of the flavin is discussed.ible structure of the flavin is discussed.)
Gnaiger 2013 Abstract MiP2013 + (10 years ago the uncoupling hypothesis was … 10 years ago the uncoupling hypothesis was presented for mitochondrial haplogroups of arctic populations suggesting that lower coupling of mitochondrial respiration to ATP production was selected for in favor of higher heat dissipation as an adaptation to cold climates [1,2]. Up to date no actual tests have been published to compare mitochondrial coupling in tissues obtained from human populations with regional mtDNA variations. Analysis of oxidative phosphorylation (OXPHOS) is a major component of mitochondrial phenotyping [3]. We studied mitochondrial coupling in small biopsies of arm and leg muscle of Inuit of the Thule and Dorset haplogroups in northern Greenland compared to Danes from western Europe haplogroups. Inuit had a higher capacity to oxidize fat substrate in leg and arm muscle, yet mitochondrial respiration compensating for proton leak was proportionate with OXPHOS capacity. Biochemical coupling efficiency was preserved across variations in muscle fiber type and uncoupling protein-3 content. After 42 days of skiing on the sea ice in northern Greenland, Danes demonstrated adaptive substrate control through an increase in fatty acid oxidation approaching the level of the Inuit, yet coupling control of oxidative phosphorylation was conserved. Our findings reveal that coupled ATP production is of primary evolutionary significance for muscle tissue independent of adaptations to the cold.ue independent of adaptations to the cold.)
ASMRM 2013 Seoul KR + (10th Conference of the Asian Society of Mitochondrial Research and Medicine - [http://asmrm2013.com/common_files/mess.asp ASMRM 2013], Seoul KR)
MiP2014 + (10th MiP''conference'': Joint IUBMB/MiP Symposium on Mitochondrial Physiology - a Point/Counterpoint Meeting, Obergurgl, Austria; with post-conference workshop '''[[MiPNet19.10 | 95th Oroboros O2k-Workshop]]'''.)
10th Conference of the International Coenzyme Q10 Association 2022 Hamburg DE + (10th Conference of the International Coenzyme Q10 Association, Hamburg, 2022)
10th European Algae Industry Summit 2020 Reykjavik IS + (10th European Algae Industry Summit, Reykjavik, Iceland, 2020)
10th Int CeBiTec Research Conference 2021 Bielefeld DE + (10th Int. CeBiTec Research Conference, Bielefeld, Germany, 2021)
10th International Luebeck Conference on the Pathophysiology and Pharmacology of Erythropoietin and other Hemopoietic Growth Factors + (10th International Luebeck Conference on the Pathophysiology and Pharmacology of Erythropoietin and other Hemopoietic Growth Factors, Lübeck, DE, [https://www.physio.uni-luebeck.de/index.php?id=162 10th International Luebeck Conference])
10th Italian Meeting on Mitochondrial Disease 2020 IT + (10th Italian Meeting on Mitochondrial Diseases , Virtual, 2020)
TriMAD Conference 2023 Pennsylvania US + (10th Translational Research in Mitochondri … 10th Translational Research in Mitochondria/Metabolism, Aging, and Disease (TRiMAD) Conference, Pennsylvania, United States, 2023 == General information ==:::: TRiMAD is a collaborative venture between The Pennsylvania State University, University of Pittsburgh Medical Center, The Children’s Hospital of Philadelphia (CHoP) Research Institute, and The University of Pennsylvania Perelman School of Medicine ([https://www.huck.psu.edu/node/15830 Website])== Venue == :::: University of Pittsburgh:::: Bridgeside Point 1, 5th Floor:::: 100 Technology Drive:::: Pittsburgh, PA 15219== Organizers ==:::: University of Pittsburgh:::: Aging Institute:::: Center for Metabolism & Mitochondrial Medicine== Program ==:::: Please find the programme [https://aging.pitt.edu/event/trimad-2023/ here]== Registration ==:::: [https://forms.office.com/pages/responsepage.aspx?id=ifT5nqDg606HzDpSYRL9DXg8U8hQ84RKssucFsBERrBURTU2T1lFR01DS0hYNlZGRjNDTzg2QVJRSC4u Register here] == Lecturers and tutors ==:::: The list of speakers can be found [https://aging.pitt.edu/event/trimad-2023/ here]ttps://aging.pitt.edu/event/trimad-2023/ here])
Targeting Mitochondria World Congress 2019 Berlin DE + (10th World Congress on Targeting Mitochond … 10th World Congress on Targeting Mitochondria, Berlin, Germany, 2019 == General information == :::: Flyer available for [http://wiki.oroboros.at/images/7/7f/Berlin_2019.pdf download]== Venue == :::: INTERCONINENTAL BERLIN HOTEL:::: Budapester Str. 2, 10787:::: Berlin, Germany::::[https://targeting-mitochondria.com/venue Hotel and Travel]== Programme ==:::: [https://targeting-mitochondria.com/preliminary-program here]== Speakers == :::: List of speakers can be found [https://targeting-mitochondria.com/speakers-2019 here]== Registration ==:::: [https://targeting-mitochondria.com/registration Registration and more information]tration Registration and more information])
115th International Titisee Conferences Titisee DE + (115th ITC: Evolutionary mitochondrial biology: molecular, biochemical, and metabolic diversity, Titisee, Germany.)
11th Annual Congress of Cardiology 2019 Suzhou CN + (11th Annual Congress of Cardiology, Suzhou, China, 2019)
MiP2015 + (11th Conference on Mitochondrial Physiology, 2015 Sep 07-11, Luční Bouda, Czech Republic.)
Targeting Mitochondria World Congress 2020 Virtual + (11th World Congress on Targeting Mitochond … 11th World Congress on Targeting Mitochondria, Virtual, 2020 == General information == :::: After a long and thorough discussion among the scientific and organizing committees, we have decided to organize our 11th Conference of Targeting Mitochondria, on October 29-30, 2020 as an ONLY Virtual Congress.== Programme ==:::: [https://targeting-mitochondria.com/preliminary-program here]== Speakers == :::: List of speakers can be found [https://targeting-mitochondria.com/speakers here]== Registration ==:::: [https://targeting-mitochondria.com/registration Registration and more information]tration Registration and more information])
11th ÖGMBT Annual Meeting 2019 Salzburg AT + (11th ÖGMBT Annual Meeting - Inside the world of biomolecules, Salzburg, Austria, 2019)
ASMRM 2015 Hangzhou CN + (12th Conference of the Asian Society of Mitochondrial Research and Medicine - [http://www.ig.zju.edu.cn/ASMRM/EN/ ASMRM 2015], Hangzhou CN)
12th International Conference on Obesity and Eating Disorders 2023 Vienna AT + (12th International Conference on Obesity a … 12th International Conference on Obesity and Eating Disorders, Vienna, Austria, 2023 == General Information == :::: The theme of the conference is "New Emerging Challenges in Obesity and their Prevention"== Venue ==:::: [https://obesity.euroscicon.com/ How to get there]== Program ==:::: Program available [https://obesity.euroscicon.com/program-schedule here]== Organizers ==:::: The list of organizers can be found [https://obesity.euroscicon.com/organizing-committee here]== Registration ==:::: [https://obesity.euroscicon.com/registration Registration and more information]:::: Early registration deadline: 203-01-27:::: Late registration deadline: 2023-04-10::: Late registration deadline: 2023-04-10)
IPC2021 Puerto Varas CL + (12th International Phycological Congress - … 12th International Phycological Congress - IPC2021, Puerte Varas, Chile, 2021 == Venue == ::::[https://ipc2021.com/logistic-information/ Venue and how to get there]== Programme ==:::: [https://ipc2021.com/scientific-program/ here]== Speakers == :::: List of speakers can be found [https://ipc2021.com/invited-speakers/ here]== Organizers ==:::: The list of organizers can be found [https://ipc2021.com/local-organizing-committee-scientific-committee/ here]== Registration ==:::: [https://ipc2021.com/registration-and-registration-fees-submission-of-abstracts/ Registration and more information]tracts/ Registration and more information])
12th ÖGMBT Annual Meeting 2020 Virtual Event + (12th ÖGMBT Annual Meeting - Biomolecules in/for 21st century, Virtual Event, 2020 '''''- Conference will be held via a virtual interactive meeting. Oroboros Instruments will be present with a virtual booth.''''')
Life Sciences Meeting 2018 Innsbruck AT + (13th Life Sciences Meeting, Innsbruck, Aus … 13th Life Sciences Meeting, Innsbruck, Austria, 2018 __TOC__== General information== :::: The coming meeting will take place on the 5th and 6th of April, 2018 in the CCB (Center for Chemistry and Biomedicine) and offers all participants and young researchers the possibility to present their research work in the form of a posters or a short talk. At the end of the event the best presentation will be selected by a professional jury consisting of professors of the Medical University of Innsbruck and the winners will be awarded with a prize. The closure of the meeting will be made by the famous scientist Prof. Jannie Cracking of the Netherland Cancer Institute. The Medical University of Innsbruck is looking forward to welcoming Prof. Cracking as a „Key Note Speaker“. == Venue == :::: Center for Chemistry and Biomedicine (CCB):::: Innrain 80, 6020 Innsbruck:::: [http://biocenter.i-med.ac.at/ Location]== Organizers ==:::: Medical University of Innsbruck==Oroboros presentation ==:::: TALK: Marie Skłodowska-Curie Project '''[[TRANSMIT]]''' [[Bastos Sant'Anna Silva AC|Bastos Sant'Anna Silva Ana Carolina]]: [[Bastos Sant'Anna Silva AC 2018 Life Sciences Meeting 2018 Innsbruck AT|Effect of cell-permeable succinate and malonate prodrugs on mitochondrial respiration in prostate cancer cells]]:::: POSTER: Marie Skłodowska-Curie Project '''[[TRACT]]''' [[Chang Shao-Chiang]]: [[Chang 2018 Life Sciences Meeting 2018 Innsbruck AT|pH dependence of mitochondrial respiration and H2O2 production in oral cancer cells – a pilot study.]]:::: POSTER: K-Regio Project '''[[K-Regio_MitoFit|MitoFit]]''' [[Garcia-Souza LF|Garcia-Souza Luiz]]: [[Garcia-Souza 2018 Life Sciences Meeting 2018 Innsbruck AT|A respirometric cell viability test for peripheral-blood mononuclear cells and platelets]]-Souza 2018 Life Sciences Meeting 2018 Innsbruck AT|A respirometric cell viability test for peripheral-blood mononuclear cells and platelets]])
13th Targeting Mitochondria Congress 2022 Berlin DE + (13th Targeting Mitochondria Congress, Berlin, 2022)
EBSA2021 Vienna AT + (13th congress of EBSA, Vienna, Austria, 2021)
13th ÖGMBT Annual Meeting 2021 Innsbruck AT + (13th ÖGMBT Annual Meeting, Virtual, 2021)
FAOBMB 2015 Hyderabad IN + (14th Congress of the Federation of Asian and Oceanian Biochemists and Molecular Biologists (FAOBMB) - [http://www.ccmb.res.in/faobmb2015/ FAOBMB 2015], Hyderabad IN)
EBSA 2023 Stockholm SE + (14th congress of EBSA, Stockholm, Sweden, 2023)
The Power of Metabolism Linking energy supply and demand with contractile function 2017 Weimar DE + (15th Annual Meeting: The Power of Metabolism - Linking energy supply and demand with contractile function, Weimar,)
ASMRM 2018 Busan KR + (15th Conference of the Asian Society of Mitochondrial Research and Medicine, Busan, South Korea, 2018.)
16th Chinese Biophysics Congress 2018 Chengdu CH + (16th Chinese Biophysics Congress - Biophysics and human health , Chengdu, China, 2018)
J-mit 2017 Kyoto JP + (17th Annual Conference of Janpanese Society of Mitochondrial Research and Medicine, Kyoto, Japan)
17th Chinese Biophysics Congress 2019 Tianjin CN + (17th Chinese Biophysics Congress, Tianjin , China, 2019)
17th International Biochemistry of Exercise Conference 2018 Beijing CN + (17th International Biochemistry of Exercise Conference, Beijing, China, 2018)
The 18th Annual Meeting of the Japan Mitochondrial Association 2018 Kurume JP + (18th Annual Meeting of the Japan Mitochondrial Association, Kurume, 2018)
KSMRM2014 + (19th Annual Scientific Meeting of KSMRM , Seoul, Republic of Korea; [http://2014.ksmrm.org/congress/invitation.php KSMRM2014])
SHVM 2022 Seoul KR + (19th Annual Meeting of the Society for Heart and Vascular Metabolism (SHVM), Seoul , South Korea, 2022)
19th Beijing Conference and Exhibition on Instrumental Analysis 2021 Beijing CN + (19th Beijing Conference and Exhibition on Instrumental Analysis, Beijing, China, 2021)
19th Chinese Biophysics congress 2021 Anhui CN + (19th Chinese Biophysics congress, Anhui Province, China, 2021)
ESP2021 Salzburg AT + (19th Congress of the European Society for … 19th Congress of the European Society for Photobiology - ESP2021, Salzburg, Austria, 2021 == Venue == :::: Faculty of Natural Sciences (NAWI) of the Paris Lodron University Salzburg (PLUS):::: Venue address: Hellbrunnerstrasse 34, 5020 Salzburg, Austria.:::: [http://salzburg2021.photobiology.eu/congress-venue more information]== Program ==:::: [http://salzburg2021.photobiology.eu/ here]== Speakers == :::: List of speakers can be found [http://salzburg2021.photobiology.eu/ here]== Organizers ==:::: The list of organizers can be found [http://salzburg2021.photobiology.eu/organizing-committee here]== Registration ==:::: [http://salzburg2021.photobiology.eu/ Registration and more information]ogy.eu/ Registration and more information])
Chlamy 2021 Ile des Embiez FR + (19th International Conference on the Cell and Molecular Biology of Chlamydomonas, Ile des Embiez, France, 2021)
FEBS 2023 Luso PT + (1st 1st FEBS Workshop “Redox Medicine Workshop, Luso, Portugal, 2023)
MiPschool Schroecken AT 2007 + (1st MiP''summer school'' on Mitochondrial Respiratory Physiology, 2007 July 12-18, Schroecken, AT.)
1st Myocardial Function Symposium 2020 Graz AT + (1st Myocardial Function Symposium: “Targets in cardiometabolic disease”, Graz, Austria, 2020)
SHVM 2021 Virtual + (1st virtual meeting of the Society for Heart and Vascular Metabolism (SHVM), Virtual, 2021)
Goncalves 2017 J Cell Commun Signal + (1α,25-Dihydroxyvitamin D3</s … 1α,25-Dihydroxyvitamin D3 (1,25-D3) is critical for the maintenance of normal male reproduction since reduced fertility is observed in vitamin D-deficient rats. Gamma-glutamyl transpeptidase (GGT) is a membrane-bound enzyme that is localized on Sertoli cells and catalyses the transfer of the gamma-glutamyl residues to an amino acid or peptide acceptor. Sertoli cells are also responsible for providing nutrients, as lactate, to the development of germ cells. The aim of this study was to investigate the effect and the mechanism of action of 1,25-D3 on GGT on Sertoli cell functions from 30-day-old immature rat testis. Results demonstrated that 1,25-D3 stimulates GGT activity at Sertoli cells plasma membrane through a PKA-dependent mechanism of action, which was not dependent of active ''de novo'' protein synthesis. The hormone increases glucose uptake, as well as lactate production and release by Sertoli cells without altering the reactive oxygen species (ROS) generation. In addition, 1,25-D3 did not change reduced glutathione (GSH) amount or oxygen consumption, and diminished Sertoli cell death. These findings demonstrate that 1,25-D3 stimulatory effect on GGT activity, glucose uptake, LDH activity and lactate production seem to be an important contribution of Sertoli cells for germ cells nutrition and for a full and active ongoing spermatogenesis.mportant contribution of Sertoli cells for germ cells nutrition and for a full and active ongoing spermatogenesis.)
Royall 1993 Arch Biochem Biophys + (2',7'-Dichlorofluorescein and dihydrorhoda … 2',7'-Dichlorofluorescein and dihydrorhodamine 123 were evaluated as probes for detecting changes in intracellular H2O2 in cultured endothelial cells. Stable intracellular levels of these probes were established within 15 min of exposure to the probe in culture medium. With continued presence of the probe in the medium, intracellular levels were unchanged for 1 h. However, if medium without the probes was used after intracellular loading had occurred, there was a greater than 90% loss of intracellular dichlorofluorescin, dichlorofluorescein, and dihydrorhodamine 123 while intracellular rhodamine 123 decreased by only 15%. Exposure of endothelial cells to exogenous 100 microM H2O2 for 1 h increased intracellular rhodamine 123 by 83%, but there was a reproducible decrease of 53% in intracellular dichlorofluorescein. Exposure to 0.05 mM BCNU plus 10 mM aminotriazole for 2 h increased intracellular rhodamine 123 by 111%. In vitro studies of dihydrorhodamine 123 oxidation were similar to previous reports of dichlorofluorescin oxidation. Oxidation of dihydrorhodamine 123 does not occur with H2O2 alone, but is mediated by a variety of secondary H2O2-dependent intracellular reactions including H2O2-cytochrome c and H2O2-Fe2+. Our results suggest that detection of increased oxidation of these probes in endothelial cells is most useful as a marker of a change in general cellular oxidant production.ge in general cellular oxidant production.)
Lardy 1953 J Biol Chem + (2,4-Dinitrophenol greatly enhanced the … 2,4-Dinitrophenol greatly enhanced the liberation of inorganic phosphate from ATP by the nuclear and mitochondrial fraction of rat liver. The microsomal and supernatant fractions did not exhibit this effect. With mitochondria (Mw) the rate of phosphate liberation was proportional to the DNP concentration up to 6 X 10-5 M In the presence of excess DNP the rate was proportional to the quantity of Mw nd to time. With both fresh and preaged Mw, the response to DNP was much greater in mediums containing salt (either NaCl or KCl) than in isotonic sucrose. Magnesium salts in appreciable concentrations depressed the response of fresh Mw to DNP, but enhanced the response in preaged Mw. Calcium salts, which activate ATP hydrolysis by fresh Mw in the absence of DNP, also depressed the effect of DNP on phosphate liberation. Magnesium salts enhanced phosphate liberation by preaged Mw both in the presence and absence of DNP. Calcium was virtually without effect in preaged Mw. Oxalacetate enhanced phosphate liberation from ATP by fresh Mw. This dicarboxylic acid as well as succinate and L-malate depressed the effect of DNP on phosphate liberation. Fatty acids also depressed the effect of DNP. Caprylate enhanced phosphate liberation, probably be- cause of its surface activity. The thiol inhibitor, p-chloromercuribenzoate, strongly depressed the effect of DNP; iodoacetate and o-iodosobenzoate did not.''Continued in Free Text''ate did not. ''Continued in Free Text'')
Freitas-Correa 2013 Stem Cell Res + (2,4-Dinitrophenol (DNP) is a neuroprotecti … 2,4-Dinitrophenol (DNP) is a neuroprotective compound previously shown to promote neuronal differentiation in a neuroblastoma cell line and neurite outgrowth in primary neurons. Here, we tested the hypothesis that DNP could induce neurogenesis in embryonic stem cells (ESCs). Murine ESCs, grown as embryoid bodies (EBs), were exposed to 20μM DNP (or vehicle) for 4days. Significant increases in the proportion of nestin- and β-tubulin III-positive cells were detected after EB exposure to DNP, accompanied by enhanced glial fibrillary acidic protein (GFAP), phosphorylated extracellular signal-regulated kinase (p-ERK) and ATP-linked oxygen consumption, thought to mediate DNP-induced neural differentiation. DNP further protected ESCs from cell death, as indicated by reduced caspase-3 positive cells, and increased proliferation. Cell migration from EBs was significantly higher in DNP-treated EBs, and migrating cells were positive for nestin, ß-tubulin III and MAP2, similar to that observed with retinoic acid (RA)-treated EBs. Compared to RA, however, DNP exerted a marked neuritogenic effect on differentiating ESCs, increasing the average length and number of neurites per cell. Results establish that DNP induces neural differentiation of ESCs, accompanied by cell proliferation, migration and neuritogenesis, suggesting that DNP may be a novel tool to induce neurogenesis in embryonic stem cells.duce neurogenesis in embryonic stem cells.)
Sebollela 2010 Neurotox Res + (2,4-Dinitrophenol (DNP) is classically kno … 2,4-Dinitrophenol (DNP) is classically known as a mitochondrial uncoupler and, at high concentrations, is toxic to a variety of cells. However, it has recently been shown that, at subtoxic concentrations, DNP protects neurons against a variety of insults and promotes neuronal differentiation and neuritogenesis. The molecular and cellular mechanisms underlying the beneficial neuroactive properties of DNP are still largely unknown. We have now used DNA microarray analysis to investigate changes in gene expression in rat hippocampal neurons in culture treated with low micromolar concentrations of DNP. Under conditions that did not affect neuronal viability, high-energy phosphate levels or mitochondrial oxygen consumption, DNP induced up-regulation of 275 genes and down-regulation of 231 genes. Significantly, several up-regulated genes were linked to intracellular cAMP signaling, known to be involved in neurite outgrowth, synaptic plasticity, and neuronal survival. Differential expression of specific genes was validated by quantitative RT-PCR using independent samples. Results shed light on molecular mechanisms underlying neuroprotection by DNP and point to possible targets for development of novel therapeutics for neurodegenerative disorders.rapeutics for neurodegenerative disorders.)
2014 Mitochondrial Disease Clinical Conference + (2014 Mitochondrial Disease Clinical Conference, Los Angeles, Ca US; [http://www.mitoaction.org/laconference 2014 Mitochondrial Disease Clinical Conference])
2015 Spring PaduaMuscleDays + (2015 Spring PaduaMuscleDays: Translational Myology in Aging and Neuromuscular Disorders, Padova, IT; [http://www.pagepressjournals.org/index.php/bam/announcement/view/176 2015 Spring PaduaMuscleDays].)
2016 Spring PaduaMuscleDays Padua IT + (2016 Spring PaduaMuscleDays: Muscle Decline in Aging and Neuromuscular Disorders - Mechanisms and Countermeasures, Padua, IT)
JSBBA 2017 Kyoto JP + (2017 Annual Meeting of the Japan Society for Bioscience, Biotechnology, and Agrochemistry (JSBBA), Kyoto, Japan)
Movement and Cognition 2018 MA US + (2018 world conference on Movement and Cognition, Boston, Massachusetts, USA, 2018)
Movement and Cognition 2019 Tel-Aviv IL + (2019 World conference on Movement and Cognition, Tel-Aviv, Israel, 2019)
2020 PaduaMuscleDays Padua IT + (2020 PaduaMuscleDays - 30 years of translational research, Vitual Event, 2020)
Movement and Cognition 2020 Paris FR + (2020 World conference on Movement and Cognition, Paris, France, 2020)
EBEC2018 Budapest HU + (20th European Bioenergetics Conference 2018, Budapest, Hungary, 2018)
SHVM 2023 Graz AT + (20th Annual Meeting of the Society for Heart and Vascular Metabolism (SHVM), Graz, Austria, 2023)
SFRR 2021 Virtual + (20th Biennial Meeting of SFRR International, Virtual, 2021)
International Botanical Congress 2024 Madrid ES + (20th International Botanical Congress (IBC), Madrid, ES, 2024)
EBEC2022 Aix-en-Provence FR + (21st European Bioenergetics Conference 2022, Aix-en-Provence, France, 2022.)
EBEC2024 Innsbruck AT + (22st European Bioenergetics Conference 2024, Innsbruck, Austria, 2024)
GFB 2023 Bedoin FR + (22nd GFB conference, Bedoin, France, 2023)

24th Kalorimetrietage 2021 Braunschweig DE + (24th Kalorimetrietage, Braunschweig, Germany, 2021.)

25th Krakow Conference on Endothelium 2017 PL + (25th Krakow Conference on Endothelium, Krakow, Poland.)
SFRR 2018 Auckland NZ + (26th Meeting for the Society for Free Radical Research Australasia SFRR(A), Auckland, New Zeland, 2018)
ECSS 2023 Paris FR + (28th ECSS Congress, Paris, France, 2023)
28th Congress of the Polish Physiological Society 2021 Virtual + (28th Congress of the Polish Physiological Society, Virtual, 2021)
FEBS 2022 Mutters AT + (2nd FEBS Workshop on Ageing and Regeneration, Mutters, Austria, 2022)
Cardiovascular Metabolic Disease 2015 + (2nd Annual Conference of the Prevention and Control of Cardiovascular Metabolic Disease, Wuhan, CN; post-conference workshop '''[[MiPNet20.11_IOC102_Wuhan | 102nd Oroboros O2k-Workshop]]'''.)
Mitochondria-Targeted Drug Development 2022 Boston US + (2nd Annual Mitochondria-Targeted Drug Development, Boston MA, US, 2022.)
2nd International Munich ROS Meeting 2018 Munich DE + (2nd International Munich ROS Meeting, Munich, Germany, 2018)
2nd Mitochondria Conference 2023 Lisbon PT + (2nd Mitochondria Conference, Lisbon, Portugal, 2023.)
Pereira 2009 Biochem J + (3-BrPA (3-bromopyruvate) is an alkylating … 3-BrPA (3-bromopyruvate) is an alkylating agent with antitumoral activity on hepatocellular carcinoma. This compound inhibits cellular ATP production owing to its action on glycolysis and oxidative phosphorylation; however, the specific metabolic steps and mechanisms of 3-BrPA action in human hepatocellularcarcinomas, particularly its effects on mitochondrial energetics, are poorly understood. In the present study it was found that incubation of HepG2 cells with a low concentration of 3-BrPA for a short period (150 μMfor 30 min) significantly affected both glycolysis and mitochondrial respiratory functions. The activity of mitochondrial hexokinase was not inhibited by 150 μM 3-BrPA, but this concentration caused more than 70% inhibition of GAPDH (glyceraldehyde-3-phosphate dehydrogenase) and 3-phosphoglycerate kinase activities. Additionally, 3-BrPA treatment significantly impaired lactate production by HepG2 cells, even when glucose was withdrawn from the incubation medium.Oxygen consumption of HepG2 cells supported by either pyruvate/malate or succinate was inhibited when cells were preincubated with 3-BrPA in glucose-free medium. On the other hand, when cells were pre-incubated in glucose-supplemented medium, oxygen consumption was affected only when succinatewas used as the oxidizable substrate. An increase in oligomycinindependentrespiration was observed in HepG2 cells treated with 3-BrPA only when incubated in glucose-supplemented medium, indicating that 3-BrPA induces mitochondrial proton leakage as well as blocking the electron transport system. The activityof succinate dehydrogenase was inhibited by 70% by 3-BrPA treatment. These results suggest that the combined action of 3- BrPA on succinate dehydrogenase and on glycolysis, inhibiting steps downstream of the phosphorylation of glucose, play an important role in HepG2 cell death.lay an important role in HepG2 cell death.)
Jardim-Messeder 2012 Int J Biochem Cell Biol + (3-Bromopyruvate (3BrPA) is an antitumor ag … 3-Bromopyruvate (3BrPA) is an antitumor agent that alkylates the thiol groups of enzymes and has been proposed as a treatment for neoplasias because of its specific reactivity with metabolic energy transducing enzymes in tumor cells. In this study, we show that the sarco/endoplasmic reticulum calcium (Ca2+) ATPase (SERCA) type 1 is one of the target enzymes of 3BrPA activity. Sarco/endoplasmic reticulum vesicles (SRV) were incubated in the presence of 1mM 3BrPA, which was unable to inhibit the ATPase activity of SERCA. However, Ca2+-uptake activity was significantly inhibited by 80% with 150μM 3BrPA. These results indicate that 3BrPA has the ability to uncouple the ATP hydrolysis from the calcium transport activities. In addition, we observed that the inclusion of 2mM reduced glutathione (GSH) in the reaction medium with different 3BrPA concentrations promoted an increase in 40% in ATPase activity and protects the inhibition promoted by 3BrPA in calcium uptake activity. This derivatization is accompanied by a decrease of reduced cysteine (Cys), suggesting that GSH and 3BrPA increases SERCA activity and transport by pyruvylation and/or S-glutathiolation mediated by GSH at a critical Cys residues of the SERCA.hiolation mediated by GSH at a critical Cys residues of the SERCA.)
Jardim-Messeder 2016 Anticancer Res + (3-bromopyruvate (3BrPA) is an antitumor ag … 3-bromopyruvate (3BrPA) is an antitumor agent able to inhibit aerobic glycolysis and oxidative phosphorylation, therefore inducing cell death. However, cancer cells are also highly dependent of glutaminolysis and tricarboxylic acid cycle (TCA) regarding survival and 3BrPA action in these metabolic routes is poorly understood.The effect of 3BrPA was characterized in mice liver and kidney mitochondria, as well as in human HepG2 cells.Low concentration of 3-BrPA significantly affected both glutaminolysis and TCA cycle functions, through inhibition of isocitrate dehydrogenase, α-ketoglutarate dehydrogenase and succinate dehydrogenase. Additionally, 3-BrPA treatment significantly decreased the reduced status of thiol groups in HepG2 cells without proportional increase of oxidizing groups, suggesting that these chemical groups are the target of alkylation reactions induced by 3-BrPA.This work demonstrates, for the first time, the effect of 3-BrPA in glutaminolysis and TCA cycle. Our results suggest that the combined action of 3-BrPA in glutaminolysis, TCA and glycolysis, inhibiting steps downstream of the glucose and glutamine metabolism, has an antitumor effect.Copyright© 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.John G. Delinassios), All rights reserved.)
Vevera 2016 Physiol Res + (3-hydroxy-3-methylglutaryl-coenzyme A (HMG … 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors (statins) are widely used drugs for lowering blood lipid levels and preventing cardiovascular diseases. However, statins can have serious adverse effects, which may be related to development of mitochondrial dysfunctions. The aim of study was to demonstrate the ''in vivo'' effect of high and therapeutic doses of statins on mitochondrial respiration in blood platelets. Model approach was used model in the study. Simvastatin was administered to rats at a high dose for 4 weeks. Humans were treated with therapeutic doses of rosuvastatin or atorvastatin for 6 weeks. Platelet mitochondrial respiration was measured using high-resolution respirometry. In rats, a significantly lower physiological respiratory rate was found in intact platelets of simvastatin-treated rats compared to controls. In humans, no significant changes in mitochondrial respiration were detected in intact platelets; however, decreased complex I-linked respiration was observed after statin treatment in permeabilized platelets. We propose that the small ''in vivo'' effect of statins on platelet energy metabolism can be attributed to drug effects on complex I of the electron transport system. Both intact and permeabilized platelets can be used as a readily available biological model to study changes in cellular energy metabolism in patients treated with statins.tabolism in patients treated with statins.)
JACBS Taipei TW + (32th Joint Annual Conference of Biomedical Science, Taipei, Taiwan.)
APS2020 Chicago US + (32nd APS Annual Convention, Chicago, USA, 2020)
36th Congress Czech Nutrition Society 2020 Hradec Kralove CZ + (36th annual international congress of Czech Nutrition Society, Hradec Kralove, Czech Republic, 2020)
37th Annual Meeting of the ISHR-ES 2023 Porto PT + (37th Annual Meeting of the ISHR-ES, Porto, Portugal, 2023)
MiPschool Baton Rouge LA US 2009 + (3rd MiP''summer school'' on Mitochondrial Respiratory Physiology, 2009 June 17-23, Baton Rouge, Louisiana US.)
Eugeny I. Schwartz Conference 2015 + (3rd Russian Congress with International Participation “Molecular Basis of Clinical Medicine: State-of-the-Art and Perspectives” dedicated to the memory of Eugeny I. Schwartz, St. Petersburg , Russia;)
Ophthalmology Conference 2018 Rome IT + (3rd Edition of International Conference on Eye and Vision, Rome, Italy; 2018)
METABO & Cancer 2019 Marseille FR + (3rd edition - Metabolism and Cancer Meeting, Marseille, France, 2019)
MacDonald 2014 Abstract MiP2014 + (4-hydroxy-2-oxoglutarate aldolase (HOGA) i … 4-hydroxy-2-oxoglutarate aldolase (HOGA) is a bi-functional mitochondrial enzyme, expressed predominantly in liver and kidney. HOGA is involved in the hydroxyproline degradation pathway (HOGglyoxylate+pyruvate), and mutations in HOGA result in primary Hyperoxaluria Type III, characterized by excessive oxalate production and kidney stone deposition [1]. We hypothesized that HOGA may also be involved in the TCA cycle as an oxaloacetate decarboxylase (oxaloacetatepyruvate; Fig. 1), which may allow the TCA cycle to turnover in the absence of pyruvate and/or excess oxaloacetate. The kinetics of HOGA with substrates HOG and oxaloacetate were investigated by measuring the ''K''’m and ''k''cat of recombinant human HOGA, using an LDH-coupled microplate assay. The role of HOGA in the TCA cycle was investigated using mitochondria, isolated from rat liver and kidney, where HOGA is highly expressed, and brain and heart, where expression is lower. ADP-stimulated malate respiration was measured relative to ADP-malate + pyruvate (M:PM), using oxygraphy (Oroboros Oxygraph-2k, note malate was used as oxaloacetate cannot cross the inner mitochondrial membrane). While HOGA was 75% less efficient at cleaving oxaloacetate than its other substrate, HOG (''K''’m/''k''cat), the ''K''’m for oxaloacetate was within range of that estimated for TCA intermediates (''K''’m,ox=129±8 µM, ''k''cat,ox=0.52±0.01 s-1; ''K''’m,HOG=55±5 µM, ''k''cat,HOG=1.01±0.03 s-1). Overall, HOGA appears to use the same catalytic mechanism to cleave both HOG and oxaloacetate substrates. Interestingly, the TCA cycle intermediate a-ketoglutarate was found to be a competitive inhibitor of HOGA oxaloacetate decarboxylase activity (''K''i=2.8 mM). Mitochondria from rat liver had the highest M:PM respiration relative to all other organs (0.46±0.05, ''P''<0.05). Though kidney had a higher M:PM respiration than heart (0.27±0.02 vs 0.15±0.02, ''P''<0.05 in kidney and heart, respectively), brain respired as well as kidney (0.33±0.04). In summary, HOGA cleaves oxaloacetate and HOG using the same catalytic mechanism but was less efficient with oxaloacetate. Liver and kidney have high HOGA expression, and mitochondria from both respire significantly better on malate relative to PM than heart mitochondria. The brain respires just as well with malate compared to kidney, and this may be due to high expression of malic enzyme, which can convert malate directly to pyruvate (Fig. 1). Malate supported respiration in HOGA overexpressing cells will confirm the direct role of HOGA in the TCA cycle.ession of malic enzyme, which can convert malate directly to pyruvate (Fig. 1). Malate supported respiration in HOGA overexpressing cells will confirm the direct role of HOGA in the TCA cycle.)
MBSJ 2018 Yokohama JP + (41st Annual Meeting of the Molecular Biology Society of Japan, Yokohama, Japan, 2018.)
The 42nd Annual Meeting of The Molecular Biology Society of Japan + (42nd Annual Meeting of The Molecular Biology Society of Japan, Kurume, 2018)
ISOTT 2015 + (43rd Annual Meeting of the International Society on Oxygen Transport to Tissue (ISOTT))
AICBC 2024 Navi Mumbai IN + (46th All India Cell Biology Conference, Navi Mumbai, India, 2024)
46th ISOBM Congress 2019 Athens GR + (46th annual congres of the International Society of Oncology and Biomarkers, Athens, Greece, 2019)
ESCI 2015 + (49th Annual Scientific Meeting of the European Society for Clinical Investigation, Cluj-Napoca, Romania; [http://www.esci.eu.com/meetings/ ESCI 2015])
SMRM2014 Manipal IN + (4th Annual Conference of the Society for Mitochondrial Research and Medicine, Kolkata, India.)
MiPschool Druskininkai LT 2010 + (4th MiP''summer school'' on Mitochondrial Respiratory Physiology, 2010 June 10-16, Druskininkai, Lithuania.)
TrMAD2014 + (4th Regional Translational Research in Mitochondria, Aging, and Disease Symposium, Pittsburgh, PA, US. [http://www.upci.upmc.edu/trmad/ TrMAD2014])
4th Global Chinese Symposium & The 8th Symposium for Cross-straits on Free Radical Biology and Medicine 2018 Macao CN + (4th Global Chinese Symposium & The 8th Symposium for Cross-straits, Hong Kong and Macao on Free Radical Biology and Medicine, Macao, China, 2018)
4th edition Metabolism & Cancer 2021 Virtual + (4th edition Metabolism & Cancer, Virtu … 4th edition Metabolism & Cancer, Virtual, 2021 == Program ==:::: [https://www.metabolism-cancer.com/program/ here]== Organizers ==:::: The list of organizers can be found [https://www.metabolism-cancer.com/under-construction/ here]== Registration ==:::: [https://www.metabolism-cancer.com/registration/ Registration and more information]== Oroboros at MetaboCancer 2021==:::: [[Gnaiger Erich]]: Oroboros Instruments innovations - NextGen-O2k and Bioenergetics Communications, ''May 28th at 11:25''=== Booth ===:::: The Oroboros team is looking forward to welcome you at our Oroboros booth which will be available at this conference.== Support ==[[File:Template NextGen-O2k.jpg|right|350px|link=NextGen-O2k]][[Category:NextGen-O2k]]:::: Supported by project NextGen-O2k which has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 859770. agreement No. 859770. )
MacPherson 2016 Am J Physiol Cell Physiol + (5'-AMP-activated protein kinase (AMPK) is … 5'-AMP-activated protein kinase (AMPK) is activated as a consequence of lipolysis and has been shown to play a role in regulation of adipose tissue mitochondrial content. Conversely, the inhibition of lipolysis has been reported to potentiate the induction of protein kinase A (PKA)-targeted genes involved in the regulation of oxidative metabolism. The purpose of the current study was to address these apparent discrepancies and to more fully examine the relationship between lipolysis, AMPK, and the β-adrenergic-mediated regulation of gene expression. In 3T3-L1 adipocytes, the adipose tissue triglyceride lipase (ATGL) inhibitor ATGListatin attenuated the Thr(172) phosphorylation of AMPK by a β3-adrenergic agonist (CL 316,243) independent of changes in PKA signaling. Similarly, CL 316,243-induced increases in the Thr(172) phosphorylation of AMPK were reduced in adipose tissue from whole body ATGL-deficient mice. Despite reductions in the activation of AMPK, the induction of PKA-targeted genes was intact or, in some cases, increased. Similarly, markers of mitochondrial content and respiration were increased in adipose tissue from ATGL knockout mice independent of changes in the Thr(172) phosphorylation of AMPK. Taken together, our data provide evidence that AMPK is not required for the regulation of adipose tissue oxidative capacity in conditions of reduced fatty acid release.Copyright © 2016 the American Physiological Society.© 2016 the American Physiological Society.)
Stride 2012 Front Physiol + (5'-adenosine monophosphate-activated prote … 5'-adenosine monophosphate-activated protein kinase (AMPK) is considered central in regulation of energy status and substrate utilization within cells. In heart failure the energetic state is compromised and substrate metabolism is altered. We hypothesized that this could be linked to changes in AMPK activity and we therefore investigated mitochondrial oxidative phosphorylation capacity from the oxidation of long- and medium-chain fatty acids (LCFA and MCFA) in cardiomyocytes from young and old mice expressing a dominant negative AMPKα2 (AMPKα2-KD) construct and their wildtype (WT) littermates. We found a 35-45% (P < 0.05) lower mitochondrial capacity for oxidizing MCFA in AMPKα2-KD of both age-groups, compared to WT. This coincided with marked decreases in protein expression (19/29%, P < 0.05) and activity (14/21%, P < 0.05) of 3-hydroxyacyl-CoA-dehydrogenase (HAD), in young and old AMPKα2-KD mice, respectively, compared to WT. Maximal LCFA oxidation capacity was similar in AMPKα2-KD and WT mice independently of age implying that LCFA-transport into the mitochondria was unaffected by loss of AMPK activity or progressing age. Expression of regulatory proteins of glycolysis and glycogen breakdown showed equivocal effects of age and genotype. These results illustrate that AMPK is necessary for normal mitochondrial function in the heart and that decreased AMPK activity may lead to an altered energetic state as a consequence of reduced capacity to oxidize MCFA. We did not identify any clear aging effects on mitochondrial function. any clear aging effects on mitochondrial function.)
Hanley 2005 J Physiol + (5-Hydroxydecanoate (5-HD) blocks pharmacol … 5-Hydroxydecanoate (5-HD) blocks pharmacological and ischaemic preconditioning, and has been postulated to be a specific inhibitor of mitochondrial ATP-sensitive K+ (KATP) channels. However, recent work has shown that 5-HD is activated to 5-hydroxydecanoyl-CoA (5-HD-CoA), which is a substrate for the first step of β-oxidation. We have now analysed the complete β-oxidation of 5-HD-CoA using specially synthesised (and purified) substrates and enzymes, as well as isolated rat liver and heart mitochondria, and compared it with the metabolism of the physiological substrate decanoyl-CoA. At the second step of β-oxidation, catalysed by enoyl-CoA hydratase, enzyme kinetics were similar using either decenoyl-CoA or 5-hydroxydecenoyl-CoA as substrate. The last two steps were investigated using l-3-hydroxyacyl-CoA dehydrogenase (HAD) coupled to 3-ketoacyl-CoA thiolase. ''V''max for the metabolite of 5-HD (3,5-dihydroxydecanoyl-CoA) was fivefold slower than for the corresponding metabolite of decanoate (l-3-hydroxydecanoyl-CoA). The slower kinetics were not due to accumulation of d-3-hydroxyoctanoyl-CoA since this enantiomer did not inhibit HAD. Molecular modelling of HAD complexed with 3,5-dihydroxydecanoyl-CoA suggested that the 5-hydroxyl group could decrease HAD turnover rate by interacting with critical side chains. Consistent with the kinetic data, 5-hydroxydecanoyl-CoA alone acted as a weak substrate in isolated mitochondria, whereas addition of 100 μm 5-HD-CoA inhibited the metabolism of decanoyl-CoA or lauryl-carnitine. In conclusion, 5-HD is activated, transported into mitochondria and metabolised via β-oxidation, albeit with rate-limiting kinetics at the penultimate step. This creates a bottleneck for β-oxidation of fatty acids. The complex metabolic effects of 5-HD invalidate the use of 5-HD as a blocker of mitochondrial KATP channels in studies of preconditioning.TP channels in studies of preconditioning.)
Mitchell 2011 Biochim Biophys Acta + (50 years ago Peter Mitchell proposed the c … 50 years ago Peter Mitchell proposed the chemiosmotic hypothesis for which he was awarded the Nobel Prize for Chemistry in 1978. His comprehensive review on chemiosmotic coupling known as the first “Grey Book”, has been reprinted here with permission, to offer an electronic record and easy access to this important contribution to the biochemical literature. This remarkable account of Peter Mitchell's ideas originally published in 1966 is a landmark and must-read publication for any scientist in the field of bioenergetics. As far as was possible, the wording and format of the original publication have been retained. Some changes were required for consistency with BBA formats though these do not affect scientific meaning. A scanned version of the original publication is also provided as a downloadable file in Supplementary Information. See also Editorial in this issue by Peter R. Rich. Original title: CHEMIOSMOTIC COUPLING IN OXIDATIVE AND PHOTOSYNTHETIC PHOSPHORYLATION, by Peter Mitchell, Glynn Research Laboratories, Bodmin, Cornwall, England.h Laboratories, Bodmin, Cornwall, England.)
ESCI 2021 Virtual + (55th ESCI meeting, Virtual, 2021)
ESCI 2022 Bari IT + (56th ESCI meeting, Bari, Italy, 2022)
ESCI 2023 Prague CZ + (57th ESCI meeting, Prague, Czech Republic, 2023)
Targeting Mitochondria World Congress 2014 + (5th Targeting Mitochondria World Congress - [http://www.targeting-mitochondria.com/ Targeting Mitochondria], Berlin DE)
5th Academic Symposium of Metabolic Biology Branch of Chinese Biophysical Society 2022 Zunyi CN + (5th Academic Symposium of Metabolic Biology Branch of Chinese Biophysical Society, Zunyi, China, 2022)
5th International Conference of Mitochondrial Medicine + (5th International Mitochondrial Medicine Conference Mitochondrial, Online, 2021)
NHLBI Mitochondrial Biology Symposium 2019 Bethesda US + (5th NHLBI Mitochondrial Biology Symposium, … 5th NHLBI Mitochondrial Biology Symposium, Bethesda, Maryland, USA, 2019 == General information == ::::On September 26-27, 2019, experts from around the world will gather on the NIH Campus in Bethesda, Maryland to review advances in our understanding of how mitochondrial structure, function, and interactions within the cell contribute to diseases and aging; and to highlight recent progress made with animal models and therapeutic interventions.== Venue == :::: William H. Natcher Conference Center – Building 45:::: National Institutes of Health:::: 45 Center Drive:::: Bethesda, MD 20814:::: [https://2019mbs.com/meeting-venue/ How to get there]== Organizer ==:::: [https://2019mbs.com/organizers/ Information available here]== Programme ==:::: [https://2019mbs.com/agenda/ Agenda]== Speakers == :::: List of speakers can be found [https://2019mbs.com/featured-speakers/ here]== Registration ==:::: [https://www.eventbrite.com/e/the-2019-nhlbi-mitochondrial-biology-symposium-registration-54765893261 Registration and more information]:::: The abstracts submission deadline is Friday, June 28, 2019, at 11:59PM EST. :::: All submissions must be made through the abstract submission portal. :::: Abstracts should be no longer than 500 words and include four clearly identifiable components: Background, Methods, Results, and Conclusion. :::: Abstracts will be reviewed by the Organizing Committee. Acceptance will be based on the quality of the abstract and availability of space. Four high-quality abstracts will be selected for oral presentation.ts will be selected for oral presentation.)
5th edition Metabolism & Cancer 2023 Nice FR + (5th edition Metabolism & Cancer, Nice, … 5th edition Metabolism & Cancer, Nice, France, 2023 == Venue ==:::: [https://www.metabolism-cancer.com/?utm_source=altemail&utm_medium=email&utm_campaign=2023-01-04%20METABO%202023%201 How to get there]== Program ==:::: Program available [https://www.metabolism-cancer.com/?utm_source=altemail&utm_medium=email&utm_campaign=2023-01-04%20METABO%202023%201 here]== Organizers ==:::: The list of organizers can be found [https://www.metabolism-cancer.com/?utm_source=altemail&utm_medium=email&utm_campaign=2023-01-04%20METABO%202023%201 here]== Registration ==:::: [https://www.metabolism-cancer.com/?utm_source=altemail&utm_medium=email&utm_campaign=2023-01-04%20METABO%202023%201 Registration and more information]utm_campaign=2023-01-04%20METABO%202023%201 Registration and more information])
BPS19 2019 Baltimore US + (63rd Annual Meeting of the Biophysical Soc … 63rd Annual Meeting of the Biophysical Society, Baltimore, Maryland USA, 2019 == General information==:::: The Biophysical Society meeting is the only major scientific meeting in the United States that routinely includes bioenergetics and mitochondrial topics. The Bioenergetics, Mitochondria, and Metabolism Subgroup has its two symposia on the first day of the meeting, March 2nd, and these two symposia have a distinguished group of speakers who are leaders in the field of bioenergetics. == Venue == :::: Baltimore Convention Center:::: 1 W. Pratt Street:::: Baltimore, Maryland 21201::::[https://www.biophysics.org/2019meeting/hotel-travel Hotel and Travel]== Programme ==:::: [https://www.biophysics.org/2019meeting/program here]== Registration ==:::: [https://www.biophysics.org/2019meeting/registration Registration and more information]tration Registration and more information])
AMI 2023 Jhansi IN + (64th Annual International Conference of the Associate of Microbiologists of India, Jhansi, India, 2023)
BPS2023 San Diego US + (67th Annual Meeting of the Biophysical Society, San Diego, California, USA, 2023)
ISOTT 2017 Halle/Saale DE + (6th 45th Annual Meeting of the International Society on Oxygen Transport to Tissue (ISOTT), Halle/Saale, Germany.)
6th Annual Conference of Chinese Society for Neurobiological Control of Metabolism 2024 Quanzhou CN + (6th Annual Conference of Chinese Society for Neurobiological Control of Metabolism, Quanzhou, China, 2024)
SMRM2017 New Delhi IN + (6th Annual Conference of the Society for Mitochondrial Research and Medicine, New Delhi, India.)
MiPschool Copenhagen DK 2013 + (6th MiP''summer school'' on Mitochondrial Physiology, 2013 August 26-30, Copenhagen, Denmark.)
6th Biannual Meeting on Mitochondria Apoptosis & Cancer 2019 Prague CZ + (6th Biannual Meeting on Mitochondria Apoptosis & Cancer, Prague, Czech Republic, 2019)
6th EU-Cardioprotection Meeting 2021 Riga LV + (6th EU-Cardioprotection WG Meeting CA16625 on mito and metabolism as targets for cardioprotection., Virtual Event, 2021)
6th International Conference on Tumor Microenvironment and Cellular Stress 2019 Crete GR + (6th International Conference on Tumor Microenvironment and Cellular Stress: Signaling, Metabolism, Imaging and Therapeutic Targets, Chania, Crete, Greece, 2019)
6th Research Day Innsbruck AT + (6th Research Day, Innsbruck, Austria, 2023)
77th Annual Meeting of the JCA 2018 Osaka JP + (77th Annual Meeting of the Japanese Cancer Association at the Osaka International Convention Center and RIHGA, Osaka, Japan, 2018)
The 77th Japanese Society of Physical Fitness and Sports Medicine 2022 Tochigi JP + (77th Japanese Society of Physical Fitness and Sports Medicine, Tochigi, 2022)
ISOTT 2018 Seoul KR + (7th 46th Annual Meeting of the International Society on Oxygen Transport to Tissue (ISOTT). Seoul, South Korea, 2018)
ISAP 2021 Virtual + (7th Conference of the International Society for Applied Phycology - ISAP2021, Tsukuba, Japan, 2021)
7th European Phycological Congress 2019 Zagreb HR + (7th European Phycological Congress, Zagreb, Croatia, 2019)
7th Molecular Mechanisms of Axon Degeneration Meeting Loch Lomond GB + (7th Molecular Mechanisms of Axon Degeneration Meeting, Loch Lomond, Scotland, Great Britain, 2019)
7th World Congress on Targeting Microbiota 2019 Krakow PL + (7th World Congress on Targeting Microbiota … 7th World Congress on Targeting Microbiota, Krakow, Poland, 2019 == Venue == :::: Park Inn by Radisson Krakow Hotel:::: Ul. Monte Cassino 2 PL:::: 30337 - Krakow - Poland:::: [https://www.microbiota-site.com/venue.html More information]== Organizer ==:::: [https://www.microbiota-site.com/committee.html Information available here]== Programme ==:::: [https://www.microbiota-site.com/images/2019/PDF/Targeting_Microbiota_2019_Agenda_-_V7.pdf Agenda]== Speakers == :::: List of speakers can be found [https://www.microbiota-site.com/microbiota-2019-speakers.html here]== Registration ==:::: [https://www.microbiota-site.com/registrations.html Registration and more information]ns.html Registration and more information])
MiPschool London 2015 + (8th MiP''school'' on Mitochondrial Physiology, 2015 Apr 20-24, London, UK.)
SMRM2020 Virtual + (8th Annual Meeting of the Society for Mitochondria Research and Medicine-India , Virtual.)
8th SMRM and Mitochondria-Metabolism Network Meeting 2020 Pune IN + (8th SMRM and Mitochondria-Metabolism Netwo … 8th SMRM and Mitochondria-Metabolism Network Meeting, Pune, India, 2020 == General information == :::: Flyer available for [https://www.mitoeagle.org/images/b/b2/8th_SMRM_and_Mitochondria-Metabolism_Network_Meeting_Poster.pdf download]== Venue == :::: Indian Institute of Science Education and Research (ISER Pune):::: Dr. Homi Bhabha Road:::: Pashan, Pune 411 008:::: INDIA::::[http://www.iiserpune.ac.in/facilities/guesthouse-cum-convention-centre Hotel and Travel]== Programme ==:::: [https://indico.tifr.res.in/indico/internalPage.py?pageId=12&confId=7288 here]== Speakers == :::: List of speakers can be found [https://indico.tifr.res.in/indico/internalPage.py?pageId=0&confId=7288 here]== Organizers ==:::: The list of organizers can be found [https://indico.tifr.res.in/indico/internalPage.py?pageId=9&confId=7288 here]== Registration ==:::: [https://indico.tifr.res.in/indico/internalPage.py?pageId=6&confId=7288 Registration and more information]ageId=6&confId=7288 Registration and more information])
TriMAD Sysposium 2018 Pennsylvania US + (8th Translational Research in Mitochondria … 8th Translational Research in Mitochondria, Aging, and Disease (TRiMAD) Symposium, Pennsylvania, United States, 2018 == General information ==:::: TRiMAD is a collaborative venture between The Pennsylvania State University, University of Pittsburgh Medical Center, The Children’s Hospital of Philadelphia (CHoP) Research Institute, and The University of Pennsylvania Perelman School of Medicine ([https://www.huck.psu.edu/node/15830 Website])== Venue == :::: The Pennsylvania State University:::: 100 Huck Life Sciences Building:::: University Park, Pennsylvania 16802:::: [http://www.cvent.com/events/8th-regional-translational-research-in-mitochondria-aging-and-disease-symposium/directions-16730cf0fe2c47a1b79f1a3b9ab0b364.aspx directions]== Organizers ==:::: Kateryna Makova, PhD - Penn State, University Park:::: Donna Korzick, PhD - Penn State, University Park[[File:Image001.jpg|right|550px]]== Programme ==:::: Please find the programme [http://www.cvent.com/events/8th-regional-translational-research-in-mitochondria-aging-and-disease-symposium/agenda-16730cf0fe2c47a1b79f1a3b9ab0b364.aspx here]== Registration ==:::: [https://www.cvent.com/events/8th-regional-translational-research-in-mitochondria-aging-and-disease-symposium/registration-16730cf0fe2c47a1b79f1a3b9ab0b364.aspx?fqp=true Register here] == Lecturers and tutors ==:::: The list of speakers can be found [http://www.cvent.com/events/8th-regional-translational-research-in-mitochondria-aging-and-disease-symposium/custom-18-16730cf0fe2c47a1b79f1a3b9ab0b364.aspx here]6730cf0fe2c47a1b79f1a3b9ab0b364.aspx here])
SBC 2023 Goa IN + (92nd Annual Meet of The Society of Biological Chemists, Goa, India, 2023)
Annual Meeting of the DPG 2016 Luebeck DE + (95th Annual Meeting of the DPG, [http://www.dpg2016.de/ DPG 2016], Luebeck, DE)
ASMRM 2012 Bejing CN + (9th Conference of t … 9th Conference of the Asian Society of Mitochondrial Research and Medicine and 5th Conference of Chinese Society of Mitochondrial Research and Medicine (Chinese-Mit), [http://asmrm2012.csp.escience.cn/dct/page/65540 ASMRM 2012], Bejing CN://asmrm2012.csp.escience.cn/dct/page/65540 ASMRM 2012], Bejing CN)
DNA Forensics 2014 + (9th International Y-chromosome workshop & 6th International EMPOP meeting, Brussels, Belgium; DNA Forensics 2014)
MiPschool Greenville 2015 + (9th MiP''school'' f … 9th MiP''school'' for cellular bioenergetics and mitochondrial physiology students, 2015 Aug 10-14, Greenville, US.» [http://www.ecu.edu/cs-admin/news/mip.cfm '''Global conference highlights mitochondria expertise at ECU'''], by Kathryn Kennedy ECU News Services.tise at ECU'''], by Kathryn Kennedy ECU News Services.)
SMRM2023 Hyderabad IN + (9th Annual Conference of the SMRM, Hyderabad, India.)
9th ÖGMBT Annual Meeting & 8th Life Science Meeting 2017 Innsbruck AT + (9th ÖGMBT Annual Meeting & 8th Life Science Meeting, Innsbruck, Austria)
Crispim 2019 MitoFit Preprint Arch EA + ( ::: Version 2 ('''v2''') '' … ::: Version 2 ('''v2''') '''2019-06-27''' [https://www.mitofit.org/images/6/68/Crispim_2019_MitoFit_Preprint_Arch_doi_10.26124mitofitea19.MiPSchool.0007.v2.pdf doi:10.26124/mitofit:ea19.MiPSchool.0007.v2]; v1 2019-06-17 [https://wiki.oroboros.at/images/8/81/Crispim_2019_MitoFit_Preprint_Arch_doi_10.26124mitofitea19.MiPSchool.0007.pdf doi:10.26124/mitofit:ea19.MiPSchool.0007]::: Version 1 (v1) [https://wiki.oroboros.at/images/8/81/Crispim_2019_MitoFit_Preprint_Arch_doi_10.26124mitofitea19.MiPSchool.0007.pdf doi:10.26124/mitofit:ea19.MiPSchool.0007]== Although atovaquone is one of the newest antimalarial compounds discovered, resistant parasites have already been reported1. Atovaquone mechanism of action is established to be the competition with ubiquinol (UQH2) for the bc1 union at mitochondrial cytochrome bc1 complex and preventing the parasite from maintaining an oxidized ubiquinone (UQ) pool, essential for the DHODH activity and consequently for the pyrimidine's biosynthesis. In this sense, possible inhibitors of the ubiquinone biosynthesis pathway would be candidates by stimulating the effects of atovaquone. 4-nitrobenzoate (4-NB) is a well-known inhibitor of 4HPT (4-hydroxybenzoate polyprenyltransferase), the first enzyme of UQ biosynthesis. 4-NB also showed an important effect on reducing the UQs pool in P. falciparum. Herein is presenting the effect of atovaquone and 4-NB on parasitic respiration UQ biosynthesis. The purpose of this study was to better understand the atovaquone mechanism of action in a molecular scale, drug target potential of UQ biosynthesis. Oxygen consumption assays revealed 4-NB potentiates atovaquone mitochondrial effects and showed itself the ability to decrease the respiration rate. ==- ''Extended abstract''crease the respiration rate. == - ''Extended abstract'' )
Gnaiger 2019 MitoFit Preprints Editorial + ( ::: Version 2 ('''v2''') ''' … ::: Version 2 ('''v2''') '''2019-04-24''' [http://www.mitofit.org/images/d/d3/Gnaiger_2019_MitoFit_Preprint_Arch_doi_10.26124_mitofit_190002.v2.pdf doi:10.26124/mitofit:190002.v2]::: Version 1 (v1) 2019-04-01 [http://www.mitofit.org/images/archive/d/d3/20190424180311%21Gnaiger_2019_MitoFit_Preprint_Arch_doi_10.26124_mitofit_190002.v2.pdf doi:10.26124/mitofit:190002] - [http://www.mitofit.org/index.php/File:Gnaiger_2019_MitoFit_Preprint_Arch_doi_10.26124_mitofit_190002.v2.pdf#Links_to_all_versions »Link to all versions«]A manuscript in preparation for publication on ‘Mitochondrial states and rates’ is the first preprint posted on ''[[MitoFit Preprints]]'' (Gnaiger ''et al'' 2019). It actually triggered the initiation of a preprint server for mitochondrial physiology and bioenergetics. This editorial presents the story behind starting ''MitoFit Preprints'', to develop a vision of science communication beyond traditional journal and preprint publication. This is an open invitation to scientists of mitochondrial physiology and bioenergetics to join the preprint community by submitting manuscripts as preprints. We face the ''reproducibility crisis'' in the battle to separate doubtful data from relevant information. This is linked to the ''inflation crisis'' emanating from an exponential increase of scientific articles published per day. Unsustainable exponential growth leads to the ''value-impact crisis'' in the struggle to forge scientific innovation into knowledge and community benefits. forge scientific innovation into knowledge and community benefits. )
Gnaiger 2020 MitoFit x + ( ::: Version 2 ('''v2''') ''' … ::: Version 2 ('''v2''') '''2021-09-06''' [https://www.mitofit.org/images/4/4a/Gnaiger_MitoFit_Preprint_Arch_2020.4_doi_10.26214mitofit.200004.pdf doi:10.26124/mitofit:200004.v2]::: Version 1 ('''v1''') 2020-08-11 [https://wiki.oroboros.at/images/archive/4/4a/20210906072525%21Gnaiger_MitoFit_Preprint_Arch_2020.4_doi_10.26214mitofit.200004.pdf doi:10.26124/mitofit:200004] — [https://www.mitofit.org/index.php/File:Gnaiger_MitoFit_Preprint_Arch_2020.4_doi_10.26214mitofit.200004.pdf »Link to all versions«]“The International System of Units, the SI, has been used around the world as the preferred system of units, the basic language for science, technology, industry and trade since it was established in 1960.” This statement heralds the 9th edition of the SI released on 2019-May-20. An new approach was introduced by defining the SI base units ― and thus the abstract SI units in general ― by their relation to fixed numerical values of fundamental constants of nature. Previous definitions of abstract units relied on a reference to concrete individual things realized as material artefacts, such as the International Prototype of the Kilogram (IPK). The (general) abstract unit ‘kilogram’ had to be calibrated in balance against an (individual) ‘entetic’ unit defining “1 kg” as a reference for the unit of mass and the mole [mol] as the unit of amount. Now the SI defines the mole as the fixed number of entities given by the Avogadro constant ''N''A. The elementary charge ''e'' is a fixed number of charges per proton. Amount and charge are thus in a fixed relation to the count of elementary entities ''U''''X'' [x]. Count, amount, and charge are isomorphic elementary quantities. Amount and charge are linked to the count ''N''''X'' = ''N''∙''U''''X'' with elementary unit x by fixed conversion constants ''N''A-1 [mol∙x−1] and ''e'' [C∙x−1], respectively. The SI does not use the elementary unit x. This causes a number of formal inconsistencies as discussed in the present communication on Euclid’s unit, which is ''U''''X'', and Euclid’s number, which is a count ''N''''X''.sistencies as discussed in the present communication on Euclid’s unit, which is ''U''''X'', and Euclid’s number, which is a count ''N''''X''. )
Baglivo 2022 MitoFit-QC + ( ::: Version 2 ('''v2''') ''' … ::: Version 2 ('''v2''') '''2022-05-09''' [https://wiki.oroboros.at/images/c/c8/Baglivo_2022_MitoFit-QC.pdf doi:10.26124/mitofit:2022-0018.v2]::: Version 1 (v1) 2022-05-05 [https://wiki.oroboros.at/images/archive/c/c8/20220506062726%21Baglivo_2022_MitoFit-QC.pdf doi:10.26124/mitofit:2022-0018.v1] - [https://wiki.oroboros.at/index.php/File:Baglivo_2022_MitoFit-QC.pdf »Link to all versions«][[File:Baglivo 2022 MitoFit QC graphical-abstract.png|right|300px|Graphical abstract]][[Baglivo 2022 Abstract Bioblast]]: Evaluation of instrumental reproducibility is a primary component of quality control to quantify the precision and limit of detection of analytical procedures. A pre-analytical instrumental standard operating procedure (SOP) is implemented in high-resolution respirometry consisting of: (''1'') a daily SOP-POS for air calibration of the polarographic oxygen sensor (POS) in terms of oxygen concentration ''c''O2 [µM]. This is part of the ''sensor test'' to evaluate POS performance; (''2'') a monthly SOP-BG starting with the SOP-POS followed by the ''chamber test'' quantifying the instrumental O2 background. The chamber test focuses on the slope d''c''O2/d''t'' [pmol∙s−1∙mL−1] to determine O2 consumption by the POS and O2 backdiffusion into the chamber as a function of ''c''O2 in the absence of sample. Finally, zero O2 calibration completes the sensor test. We applied this SOP in a 3-year study using 48 Oroboros O2k chambers. Stability of air and zero O2 calibration signals was monitored throughout intervals of up to 8 months without sensor service. Maximum drift over 1 to 3 days was 0.06 pmol∙s−1∙mL−1, without persistence over time since drift was <0.004 pmol∙s−1∙mL−1 for time intervals of one month, corresponding to a drift per day of 0.2 % of the signal at air saturation. Instrumental O2 background -d''c''O2/d''t'' was stable within ±1 pmol∙s−1∙mL−1 when measured at monthly intervals. These results confirm the instrumental limit of detection of volume-specific O2 flux at ±1 pmol∙s−1∙mL−1. The instrumental SOP applied in the present study contributes to the generally applicable internal quality control management ensuring the unique reproducibility in high-resolution respirometry. These results confirm the instrumental limit of detection of volume-specific O2 flux at ±1 pmol∙s−1∙mL−1. The instrumental SOP applied in the present study contributes to the generally applicable internal quality control management ensuring the unique reproducibility in high-resolution respirometry. )
Gainutdinov 2022 MitoFit + ( ::: Version 2 ('''v2''') ''' … ::: Version 2 ('''v2''') '''2022-08-16''' [https://wiki.oroboros.at/images/5/5a/Gainutdinov_2022_MitoFit.pdf https://doi.org/10.26124/mitofit:2022-0015.v2]::: Version 1 (v1) 2022-04-21 [https://wiki.oroboros.at/images/archive/5/5a/20220816100352%21Gainutdinov_2022_MitoFit.pdf https://doi.org/10.26124/mitofit:2022-0015]- [https://wiki.oroboros.at/index.php/File:Gainutdinov_2022_MitoFit.pdf »Link to all versions«]Amyotrophic lateral sclerosis (ALS) is a progressive, devastating, neurodegenerative disorder affecting upper and lower motor neurons. Common mechanisms of ALS pathogenesis are believed to be the disturbance of calcium homeostasis in the cell and dysfunction of mitochondria. Both factors mutually influence each other. As a result, chronic mitochondrial energy stress impairs fine cellular signaling and transport processes, leading to degeneration of motor neurons. In the current study we comparatively evaluated the cytosolic Ca2+ in healthy and ALS fibroblasts. We found that the mitochondrial calcium capacity in fibroblasts obtained from patients with sporadic (sALS) and familial (fALS) ALS differs between two subtypes and from that in healthy individuals. The changes of [Ca2+]cyt dynamics in ALS fibroblasts could be almost completely rescued by treatment with antioxidants (Trolox and CoQ10). These data confirm an important role of oxidative stress as a causative factor of mitochondrial dysfunction in ALS.portant role of oxidative stress as a causative factor of mitochondrial dysfunction in ALS. )
Alencar 2022 MitoFit + ( ::: Version 2 ('''v2''') ''' … ::: Version 2 ('''v2''') '''2022-07-07''' [https://wiki.oroboros.at/images/5/54/Alencar_2022_MitoFit.pdf doi:10.26124/mitofit:2022-0009.v2]::: Version 1 (v1) 2022-04-07 [https://wiki.oroboros.at/images/archive/5/54/20220707123437%21Alencar_2022_MitoFit.pdf doi:10.26124/mitofit:2022-0009.v1] - [https://wiki.oroboros.at/index.php/File:Alencar_2022_MitoFit.pdf »Link to all versions«][[Oliveira 2022 Abstract Bioblast]]: The parasite ''Trypanosoma brucei'' is the causative agent of sleeping sickness and involves an insect vector and a mammalian host through its complex life-cycle. ''T. brucei'' mammalian bloodstream forms (BSF) exhibit unique metabolic features including: ''i)'' reduced expression and activity of mitochondrial enzymes; ''ii)'' respiration mediated by the glycerol phosphate shuttle (GPSh) and the ''Trypanosome'' alternative oxidase (TAO) that is intrinsically uncoupled from generation of mitochondrial membrane potential; ''iii)'' maintenance of mitochondrial membrane potential by ATP hydrolysis through the reversal of F1Fo ATP synthase activity; ''iv)'' strong reliance on glycolysis to meet their energy demands; ''v)'' high susceptibility to oxidants. Here, we critically review the main metabolic features of BSF and provide a hypothesis to explain the unusual metabolic network and its biological significance for this parasite form. We postulate that intrinsically uncoupled respiration provided by GPSh-TAO system would act as a preventive antioxidant defense by limiting mitochondrial superoxide production and complementing the NADPH-dependent scavenging antioxidant defenses to maintain parasite redox balance. Given the uncoupled nature of the GPSh-TAO system, BSF would avoid programmed cell death processes by maintaining mitochondrial membrane potential through the reversal of ATP synthase activity using the ATP generated by glycolysis. This unique “metabolic design” in BSF has no biological parallel outside of Trypanosomatids and highlights the enormous diversity of the parasite mitochondrial processes to adapt to distinct environments.parasite mitochondrial processes to adapt to distinct environments. )
Ganguly 2022 MitoFit + ( ::: Version 2 ('''v2''') ''' … ::: Version 2 ('''v2''') '''2022-11-10''' [https://wiki.oroboros.at/images/6/64/Ganguly_2022_MitoFit.pdf https://doi.org/10.26124/mitofit:2022-0013.v2]::: Version 1 (v1) 2022-04-19 [https://wiki.oroboros.at/images/archive/6/64/20221110103433%21Ganguly_2022_MitoFit.pdf https://doi.org/10.26124/mitofit:2022-0013]- [https://wiki.oroboros.at/index.php/File:Ganguly_2022_MitoFit.pdf »Link to all versions«]Ferroptosis has been identified as a type of regulated cell death triggered by a diverse set of agents with implications in various diseases like cancer and neurodegenerative diseases. Ferroptosis is iron-dependent and accompanied by an accumulation of reactive oxygen species (ROS) and lipid oxidation products, a depletion of reduced glutathione, mitochondrial morphological alterations and the rupture of cell membrane; the process is inhibited by specific antioxidants like ferrostatin-1 and liproxstatin-1 and by other general antioxidants like the iron-chelator deferoxamine, vitamin E and N-acetylcysteine. However, the mechanism of cell death in ferroptosis subsequent to the accumulation of ROS and lipid oxidation products is not clearly established. We show here that the classical mitochondrial Complex I inhibitor rotenone (0.5 µM) causes death of SH-SY5Y cells (a human neuroblastoma cell line) over a period of 48 h accompanied by mitochondrial membrane depolarization and intracellular ATP depletion. This is associated with an intracellular accumulation of ROS and the lipid oxidation product malondialdehyde or MDA and a decrease in reduced glutathione content. All these processes are inhibited very conspicuously by specific inhibitors of ferroptosis such as ferrostatin-1 and liproxstatin-1. However, the decrease in Complex I activity upon rotenone-treatment of SH-SY5Y cells is not significantly recovered by ferrostatin-1 and liproxstatin-1. When the rotenone-treated cells are analyzed morphologically by Hoechst 33258 and propidium iodide (PI) staining, a mixed picture is noticed with densely fluorescent and condensed nuclei indicating apoptotic death of cells (Hoechst 33258) and also significant numbers of necrotic cells with bright red nuclei (PI staining).ant numbers of necrotic cells with bright red nuclei (PI staining). )
Roach 2022 MitoFit + ( ::: Version 2 ('''v2''') ''' … ::: Version 2 ('''v2''') '''2022-07-19''' [https://wiki.oroboros.at/images/d/d6/Roach_2022_MitoFit.pdf doi:10.26124/mitofit:2022-0023.v2]::: Version 1 (v1) 2022-06-03 [https://wiki.oroboros.at/images/archive/d/d6/20220719153447%21Roach_2022_MitoFit.pdf doi:10.26124/mitofit:2022-0023.v1] - [https://wiki.oroboros.at/index.php/File:Roach_2022_MitoFit.pdf »Link to all versions«][[Roach 2022 Abstract Bioblast]]: Tolerance of rapid changes in light intensity by photosynthetic organisms is facilitated by non-photochemical quenching (NPQ), a term with reference to quenching of chlorophyll fluorescence, the technique used in its discovery. Mechanisms of NPQ include dissipating excess light energy to heat (qE), the reversible attachment of light-harvesting complexes (LHC) to photosystems (state transition / qT) and photoinhibition (qI). Chlorophyll is a ubiquitous pigment of photosynthetic organisms, found in LHC and the reaction centres of photosystem II and I (PSII; PSI). At room temperature, pulse-amplitude modulated (PAM) chlorophyll fluorescence protocols provide insights into PSII efficiency, thus a reasonable proxy for photosynthetic activity (carbon fixation), at least under optimal conditions. NPQ has a major impact on chlorophyll fluorescence intensity and is also quantified by PAM. Since NPQ mechanisms can occur simultaneously, they cause complexities in deciphering the signal. In algae, the ability for chlorophyll fluorescence in determining photosynthetic rates is not perfect, but it can still provide valuable information of processes affecting light harvesting. The aim of this report is to provide an overview of how various NPQ mechanisms in the model unicellular chlorophyte alga, ''Chlamydomonas reinhardtii'', as well as environmental conditions, affect chlorophyll fluorescence. I also propose a PAM protocol enabling the kinetics associated with each of the NPQ phases to be semi-quantified in under 20 min. h of the NPQ phases to be semi-quantified in under 20 min. )
Di Marcello 2019 MitoFit Preprint Arch EA + ( ::: Version 3 ('"v3"') '''20 … ::: Version 3 ('"v3"') '''2019-07-03''' [https://www.mitofit.org/images/1/15/Di_Marcello_2019_MitoFit_Preprint_Arch_doi_10.26214mitofitea19.MiPSchool.0005.v2.pdf doi:10.26124/mitofit:ea19.MiPSchool.0005.v2.pdf]::: Version 2 (v2) 2019-06-27 [https://www.mitofit.org/images/1/15/Di_Marcello_2019_MitoFit_Preprint_Arch_doi_10.26214mitofitea19.MiPSchool.0005.v2.pdf doi:10.26124/mitofit:ea19.MiPSchool.0005.v2.pdf]::: Version 1 (v1) 2019-06-15 [http://www.mitofit.org/images/0/09/Di_Marcello_2019_MitoFit_Preprint_Arch.pdf doi:10.26124/mitofit:ea19.MiPSchool.0005]Bioenergetics is the study of how living organisms acquire and transform energy to perform biological work. Energetic coupling between chloroplasts and mitochondria has been described in algae, demonstrating the good functionality and interaction between both organelles is necessary to maintain metabolic integrity. High-resolution respirometry (HRR) is widely used to assess mitochondrial respiration and other bioenergetics parameters in the biomedical field of mitochondrial research and its clinical applications. In our interdisciplinary study, we adapted the multimodal approach of the Oroboros O2k high-resolution respirometer to investigate algal bioenergetics for biotechnological purposes. - ''Extended abstract''gate algal bioenergetics for biotechnological purposes. - ''Extended abstract'' )
Pallag 2022 MitoFit Proline + ( ::: Version 3 ('''v3''') ''' … ::: Version 3 ('''v3''') '''2022-03-07''' [https://wiki.oroboros.at/images/4/42/Pallag_2022_MitoFit_Proline.pdf doi:10.26124/mitofit:2022-0001.v3]::: Version 2 (v2) 2022-03-03 [https://wiki.oroboros.at/images/archive/4/42/20220307085642%21Pallag_2022_MitoFit_Proline.pdf doi:10.26124/mitofit:2022-0001.v2]::: Version 1 (v1) 2022-03-02 [https://wiki.oroboros.at/images/archive/4/42/20220303104356%21Pallag_2022_MitoFit_Proline.pdf doi:10.26124/mitofit:2022-0001] - [https://wiki.oroboros.at/index.php/File:Pallag_2022_MitoFit_Proline.pdf »Link to all versions«]In mitochondria expressing proline dehydrogenase (ProDH), oxidation of proline to pyrroline-5-carboxylate (P5C) leads to transfer of electrons to ubiquinone supporting Complexes CIII and CIV, in turn generating the protonmotive force. Further catabolism of P5C forms glutamate that fuels the citric acid cycle yielding reducing equivalents sustaining oxidative phosphorylation. However, P5C and glutamate catabolism depend on CI activity due to NAD+ requirement. The extent of proline oxidation was established in isolated mitochondria of various mouse tissues by means of simultaneously measuring oxygen consumption, membrane potential, NADH and ubiquinone redox state using the NextGen-O2k (Oroboros Instruments) and correlated to ProDH activity and F1FO-ATPase directionality. In CI-inhibited mouse liver and kidney mitochondria exhibiting high levels of proline oxidation and ProDH activity, catabolism of proline generated a sufficiently high membrane potential maintaining F1FO-ATPase operation in forward mode. This was not observed when either CIII or CIV was inhibited, nor during anoxia. Fueling CIII and CIV with duroquinone partially reproduced the effects of proline. Excess glutamate could not reproduce the effects of proline, arguing that they are due to processes upstream of glutamate conversion from proline. The ProDH inhibitors L-tetrahydro-2-furoic acid and to lesser extent S-5-oxo-2-tetrahydrofurancarboxylic acid abolished all effects conferred by proline. It is concluded that proline catabolism through ProDH generates sufficient CIII and CIV proton pumping, supporting ATP production by F1FO-ATPase even when CI is inhibited. production by F1FO-ATPase even when CI is inhibited. )
Gnaiger 2021 MitoFit BCA + ( ::: Version 1 ('''v1''') '''2021-09-21''' … ::: Version 1 ('''v1''') '''2021-09-21''' [https://www.mitofit.org/images/1/16/Gnaiger_2021_MitoFit_BCA.pdf doi:10.26124/mitofit:2021-0008][[File:Gnaiger 2021 MitoFit BCA-graphical abstract.png|right|300px|Graphical abstract]]Cell respiration reflects mitochondrial fitness and plays a pivotal role in health and disease. Despite the rapidly increasing number of applications of cell respirometry to address current challenges in biomedical research, cross-references are rare between respirometric projects and platforms. Evaluation of accuracy and reproducibility between laboratories requires presentation of results in a common format independent of the applied method. When cell respiration is expressed as oxygen consumption rate in an experimental chamber, normalization is mandatory for comparability of results. Concept-driven normalization and regression analysis are key towards bioenergetic cluster analysis presented as a graphical tool to identify discrete data populations.In a meta-analysis of human skin fibroblasts, high-resolution respirometry and polarography covering cell senescence and the human age range are compared with multiwell respirometry. The common coupling control protocol measures ROUTINE respiration of living cells followed by sequential titrations of oligomycin, uncoupler, and inhibitors of electron transfer.Bioenergetic cluster analysis increases the resolution of outliers within and differences between groups. An outlier-skewness index is introduced as a guide towards logarithmic transformation for statistical analysis. Isolinear clusters are separated by variations in the extent of a quantity that correlates with the rate, whereas heterolinear clusters fall on different regression lines. Dispersed clusters are clouds of data separated by a critical threshold value. Bioenergetic cluster analysis provides new insights into mitochondrial respiratory control and a guideline for establishing a quality control paradigm for bioenergetics and databases in mitochondrial physiology. bases in mitochondrial physiology. )
Donnelly 2022 MitoFit Hypoxia + ( ::: Version 2 ('''v2''') '''2022-07-15''' … ::: Version 2 ('''v2''') '''2022-07-15''' [https://wiki.oroboros.at/images/4/44/Donnelly_2022_MitoFit_Hypoxia.pdf The ABC of hypoxia – what is the norm https://doi.org/10.26124/mitofit:2022-0025.v2]::: Version 1 (v1) 2022-06-28 - [https://wiki.oroboros.at/index.php/File:Donnelly_2022_MitoFit_Hypoxia.pdf »Link to all versions«][[File:Oxia terms.png|right|250px]][[Donnelly 2022 Abstract Bioblast]]: Hypoxia is a condition of oxygen levels below normoxia and opposite to hyperoxia. We here define the normoxic reference state by three complementary precepts: ('''A''') ambient normoxia at sea level in the contemporary atmosphere and corresponding dissolved O2 concentration at air saturation of aqueous environments; ('''B''') biological compartmental O2 levels at ambient normoxia under physiological activity of healthy organisms in the absence of environmental stress (e.g. in a diving human, a stranded whale, a thermally stressed animal); and ('''C''') O2 levels above the control region, i.e., where the capacity for O2 consumption is not compromised by partial O2 pressure as evaluated by its kinetics. Conversely, the '''abc''' of hypoxia is concerned with deviations from these reference points caused by different mechanisms: ('''a''') ambient alterations of oxygen levels; ('''b''') biological O2 demand exceeding O2 supply under pathological or experimental limitations of convective O2 transport or O2 diffusion; and ('''c''') critical oxygen pressure in oxygen kinetics shifted by pathological and toxicological effects or environmental stress. The ABC of hypoxia may be of help in the design and interpretation of ''in vitro'' and ''in vivo'' experimental studies. ical effects or environmental stress. The ABC of hypoxia may be of help in the design and interpretation of ''in vitro'' and ''in vivo'' experimental studies. )
Cardoso 2021 MitoFit MgG + (<big>'''Journal publication 2021-06- … <big>'''Journal publication 2021-06-30 in [https://www.bioenergetics-communications.org/index.php/bec/article/view/cardoso_2021_mgg »Bioenergetics Communications 2021.1«]'''</big>For the advanced study of mitochondrial function, high-resolution respirometry is extended by fluorometric measurement of ATP production using the fluorophore Magnesium Green™ (MgG). A common problem with several fluorescent dyes is the inhibition of mitochondrial respiration. In the present study, a coupling control protocol was applied in combination with MgG to measure ATP production simultaneously with respiration for calculation of P»/O2 ratios. MgG at 1.1 µM did not affect respiration through the NADH-linked and succinate-linked pathways. Respiration was not inhibited in any of the coupling control states, hence coupling control efficiencies were not affected by MgG.tes, hence coupling control efficiencies were not affected by MgG.)
Krako Jakovljevic 2021 MitoFit PD + (<big>'''Journal publication 2021-10- … <big>'''Journal publication 2021-10-06 in [https://www.bioenergetics-communications.org/index.php/bec/article/view/krako_jakovljevic_2021_pd »Bioenergetics Communications 2021.2«]'''</big>Mitochondrial function is known to be an important factor in maintaining cellular homeostasis and its dysregulation has become a hallmark for multiple disease conditions. This review aims to synthesise the extent of this knowledge by analysing changes of mitochondrial physiology parameters in Parkinson’s disease (PD) and to evaluate the contribution of cellular models of PD in the field. The analysis provided here constitutes a platform for further elucidation of mitochondrial function parameters relative to factors that may potentiate disease progression.ve to factors that may potentiate disease progression.)
Vernerova 2021 MitoFit PLT + (<big>'''Journal publication 2021-12- … <big>'''Journal publication 2021-12-08 in [[Vernerova 2021 Biomedicines |''Biomedicines'']]'''</big>[[File:Vernerova 2021 Mitofit PLT - graphical abstract.png|right|300px|Graphical abstract]] Multiple non-aggregatory functions of human platelets (PLT) are widely acknowledged, yet their functional examination is limited mainly due to a lack of standardized isolation and analytic methods. Platelet apheresis (PA) is an established clinical method for PLT isolation aiming at the treatment of bleeding diathesis in severe thrombocytopenia. On the other hand, density gradient centrifugation (DC) is an isolation method applied in research for the analysis of the mitochondrial metabolic profile of oxidative phosphorylation (OXPHOS) in PLT obtained from small samples of human blood. We studied PLT obtained from 29 healthy donors by high-resolution respirometry for comparison of PA and DC isolates. ROUTINE respiration and electron transfer capacity of living PLT isolated by PA were significantly higher than in the DC group, whereas plasma membrane permeabilization resulted in a 57 % decrease of succinate oxidation in PA compared to DC. These differences were eliminated after washing the PA cells with phosphate buffer containing 10 mmol·L-1 EGTA, suggesting that several components, particularly Ca2+ and fuel substrates, were carried over into the respiratory assay from the serum in PA. A simple washing step was sufficient to enable functional mitochondrial analysis in subsamples obtained from PA.The combination of the standard clinical PA isolation procedure with PLT quality control and routine mitochondrial OXPHOS diagnostics meets an acute clinical demand in biomedical research of patients suffering from thrombocytopenia and metabolic diseases. h of patients suffering from thrombocytopenia and metabolic diseases. )
Komlodi 2021 MitoFit AmR-O2 + (<big>'''Journal publication 2021-12- … <big>'''Journal publication 2021-12-21 in [https://www.bioenergetics-communications.org/index.php/bec/article/view/komlodi_2021_amr »Bioenergetics Communications 2021.4«]'''</big>[[File:Komlodi 2021 MitoFit AmR-O2 graphical abstract.png|right|300px|Graphical abstract]]The fluorometric Amplex UltraRed AmR assay is frequently used for quantitative assessment of hydrogen peroxide production. It is specific to H2O2, can be calibrated accurately, and allows continuous real-time measurement. Without correction for the background fluorescence slope, however, H2O2-independent formation of the fluorescent product UltroxRed (or resorufin) leads to artefacts.We analysed (''1'') the medium specificity of the background fluorescence slope of the AmR assay, and (''2'') the oxygen dependence of H2O2 flux in baker´s yeast ''Saccharomyces cerevisiae''. Apparent H2O2 flux, O2 concentration and O2 flux were measured simultaneously by high-resolution respirometry equipped with the fluorescence module. The apparent H2O2 flux of yeast showed a maximum under hypoxia when incubated in Dulbecco´s Phosphate Buffered Saline DPBS or KCl-medium. This hypoxic peak increased with the sequential number of normoxic-anoxic transitions. Even in the absence of yeast, the fluorescence slope increased at low O2 levels as a function of fluorescence intensity. The hypoxic peak was not observed in mitochondrial respiration medium MiR05.Therefore, the hypoxic peak was a medium-specific background effect unrelated to cell physiology. In MiR05, H2O2 production of yeast decreased linearly from hyperoxia to hypoxia, with a steep decline towards anoxia. Respiration and oxygen dependence expressed as ''p''50 of yeast were higher in MiR05 than DPBS. Respiration was a hyperbolic function of oxygen concentration in the low-oxygen range. The flux-dependence of oxygen affinity explained the higher ''p''50 in MiR05. /sub> of yeast were higher in MiR05 than DPBS. Respiration was a hyperbolic function of oxygen concentration in the low-oxygen range. The flux-dependence of oxygen affinity explained the higher ''p''50 in MiR05. )
Buck 2013 Abstract MiP2013 + (<big>'''Peter Hochachka lecture'''&l … <big>'''Peter Hochachka lecture'''</big>Earth’s changing environment has been a major evolutionary force shaping the diversity of species both in the past and present. In particular, seasonal ice cover in northern latitudes has selected for hypoxia and anoxia tolerance in some species, such as freshwater turtles. At the northern reaches of their range North American western painted turtles spend 4 months or more buried in the mud bottom of ice covered lakes and ponds [1]. This offers a unique opportunity to understand how a vertebrate brain, an organ extremely sensitive to reduced oxygen availability in mammals, can function without oxygen [2]. Through oxidative phosphorylation mitochondria fuel the inherently high energetic demands of brain and in mammals mitochondria also play a key role in injury from hypoxic stress – including loss of calcium homeostasis and production of reactive oxygen species (ROS) leading to apoptosis and necrosis. Hypoxic or anoxic stress does not signal stress in turtle brain but rather protective mechanisms with the onset of anoxia. Indeed our data show that mitochondria play a key role in low oxygen signaling in turtle brain by a reduction in mitochondrial membrane potential and release of a relatively small but significant amount of calcium. The increase in cytosolic calcium signals a phosphatase based mechanism to decrease whole-cell glutamatergic (NMDA and AMPA) excitatory currents in pyramidal neurons. While in stellate neurons anoxia results in a large reduction in mitochondrial ROS production that increases the magnitude of GABAergic inhibitory neurotransmission. The increased GABA activity produces a chloride based shunting current that “arrests” action potentials in pyramidal cells resulting in metabolic depression and neuroprotection.resulting in metabolic depression and neuroprotection.)
Weber 2013 Abstract MiP2013 + (<big>'''[[Johansen K|Kjell Johansen]] … <big>'''[[Johansen K|Kjell Johansen]] lecture'''</big>Vertebrate hemoglobins (Hb) are exquisitely designed to transport O2 from the respiratory organs to the tissues, thereby safeguarding mitochondrial O2 supply and aerobic metabolism in the face of wide and independent variations in O2 tensions and temperature at the sites for loading and unloading of O2 [1-3]. In transporting O2, vertebrate Hbs (composed of 2 α and 2 β globin chains) switch between the T (tense, low O2-affinity, deoxygenated) structure that predominates in the tissues, and the R (relaxed, high-affinity, oxygenated) structure that predominates in the lungs and gills. The T-R shift is basic to cooperativity between the O2-binding heme groups that increases O2 (un)loading for a given change in O2 tension - and is reflected in the sigmoid shape of O2 binding curves. Hb’s in vivo O2 binding properties are a product of its intrinsic O2 affinity and its interaction with red cell allosteric effectors that decreases Hb-O2 affinity by stabilizing the T-structure. Apart from protons and CO2 (that facilitate O2 unloading in the acid tissues via the “Bohr-effect”) these effectors include chloride ions and organic phosphates [ATP in lower vertebrates, IPP (inositol pentaphosphate) in birds and DPG (diphosphoglycerate) in mammals]. The interaction with effectors varies between and within individual species and plays a key role in adjusting O2 transport in response to changes in environmental conditions, metabolic requirements, and mode of life. The decrease in Hb-O2 affinity with rising temperature mandated by the exothermic nature of heme oxygenation, enhances O2 unloading in warm tissues that require more O2, but may become maladaptive – and thus commonly is reduced - in regional heterothermic species where it may hamper O2 unloading (in cold extremities of arctic mammals) or cause excessive O2 release (in warm muscles, brains or eyes of fast-swimming fish).Based on case studies (Hbs from estivating fish, fast-swimming gamefish, high-altitude Andean frogs, geese that scale the Himalayas, Rocky Mountain Deer mice and Hb recreated from extinct mammoths [4-6]) the treatise analyses the molecular mechanisms for Hb’s role in securing mitochondrial O2 supply under stressful conditions - illustrating the key significance of molecular interactions to understanding physiological ecology. of molecular interactions to understanding physiological ecology.)
Walker 2013 Abstract MiP2013 + (<big>MiP2013 Keynote by Sir John Wal … <big>MiP2013 Keynote by Sir John Walker</big>The lecture will be devoted to the topic of how the biological world supplies itself with energy to make biology work, and what medical consequences ensue when the energy supply chain in our bodies is damaged or defective. We derive our energy from sunlight, which, via photosynthesis in green plants, provides high energy components in the foods that we ingest. We harvest that energy, effectively by “burning” (oxidising) the high energy components, releasing cellular energy in a controlled way to generate the fuel of life, in the form of the molecule known as adenosine triphosphate (or ATP for short). The key steps in this process take place in the mitochondria inside the cells that make up our tissues. They serve as biological “power stations” that contain millions of tiny molecular turbines, the ATP synthase, that rotate rather like man-made turbines churning out the cellular fuel in massive quantities, which is then delivered to all parts of our bodies to provide the energy to make them function. Each of us makes and expends about 60 kg of this fuel every day of our lives. Defects in the fuel supply process are increasingly being recognised as important components of complex human diseases such as cancer, neurodegeneration and neuromuscular diseases, and they may also be part of the process of ageing. The ATP synthases found in mitochondria, eubacteria and chloroplasts have many common features. Their overall architectures are similar, and they all consist of two rotary motors linked by a stator and a flexible rotor. When rotation of the membrane bound rotor is driven by proton motive force, the direction of rotation ensures that ATP is made from ADP and phosphate in the globular catalytic domain. When ATP serves as the source of energy and is hydrolysed in the catalytic domain, the rotor turns in the opposite sense and protons are pumped outwards through the membrane domain, and away from the catalytic domain. The lecture will describe the common features of their catalytic mechanisms. However, the ATP synthase from mitochondria, eubacteria and chloroplasts differ most fundamentally in the energy cost that is paid to make each ATP molecule. The most efficient ATP synthase is found in the mitochondria from multicellular animals. The ATP synthases in unicellular organisms, and chloroplasts, pay various higher costs that seem to reflect the supply of available energy in the biological niches that they inhabit. The ATP synthases also differ significantly in the way they are regulated. Eubacteria have evolved a range of mechanisms of regulation, and the chloroplast enzyme is rendered inactive by a redox mechanism in the hours darkness. Mitochondria contain an inhibitor protein, IF1, that inhibits ATP hydrolysis but not ATP synthesis. Its in vitro mechanism has been studied in great detail, but its in vivo role is mysterious, and suppression of expression of the protein appears not to influence respiration.In mitochondria the ATP synthase is organised in rows of dimers along the edges of the cristae, and as will be discussed, it has been suggested that the permeability transition pore involved in apoptosis resides in the dimeric enzyme.e involved in apoptosis resides in the dimeric enzyme.)
Lemieux 2017 bioRxiv 103457 + ( '''Lemieux H, Blier PU, Gnaig … '''Lemieux H, Blier PU, Gnaiger E (2017) Remodeling pathway control of mitochondrial respiratory capacity by temperature in mouse heart: electron flow through the Q-junction in permeabilized fibers. Sci Rep 7:2840, DOI:10.1038/s41598-017-02789-8.''' - [[Lemieux 2017 Sci Rep |»Bioblast link«]]* Accepted for publication: 2017-04-18* [http://rdcu.be/tgpY Sci Rep Open Access]: 2017-06-06://rdcu.be/tgpY Sci Rep Open Access]: 2017-06-06)
OroDM01 Innsbruck AT + ( '''Oroboros Distributor Meeting'''. Innsbruck, Austria; 2019 Jul 01-03.)
2nd Oroboros distributor training 2023 Innsbruck AT + ( '''Oroboros distributor training'''. Innsbruck, Austria; 2023 Nov 07-09.)
Oroboros distributor training 2023 Innsbruck AT + ( '''Oroboros distributor training'''. Innsbruck, Austria; 2023 Apr 24-25.)
MiP2015 Book of Abstracts Open Access + ( : » [[MiP2015]] - all abstracts in alphabetical order and programme sessions. : » [[MiP2015 Abstracts in the MiPMap]] - sort by MiP''areas'', species, tissues, diseases, ...)
Chung 2005 Am J Physiol Cell Physiol + (1H-NMR experiments … 1H-NMR experiments have determined intracellular O2 consumption (''V''O2) with oxymyoglobin (MbO2) desaturation kinetics in human calf muscle during plantar flexion exercise at 0.75, 0.92, and 1.17 Hz with a constant load. At the onset of muscle contraction, myoglobin (Mb) desaturates rapidly. The desaturation rate constant of approximately 30 s reflects the intracellular ''V''O2. Although Mb desaturates quickly with a similar time constant at all workload levels, its final steady-state level differs. As work increases, the final steady-state cellular ''P''O2 decreases progressively. After Mb desaturation has reached a steady state, however, ''V''O2 continues to rise. On the basis of current respiratory control models, the analysis in the present report reveals two distinct ''V''O2 phases: an ADP-independent phase at the onset of contraction and an ADP-dependent phase after Mb has reached a steady state. In contrast to the accepted view, the initial intracellular ''V''O2 shows that oxidative phosphorylation can support up to 36 % of the energy cost, a significantly higher fraction than expected. Partitioning of the energy flux shows that a 31 % nonoxidative component exists and responds to the dynamic energy utilization-restoration cycle (which lasts for only milliseconds) as postulated in the glycogen shunt theory. The present study offers perspectives on the regulation of respiration, bioenergetics, and Mb function during muscle contraction.ration cycle (which lasts for only milliseconds) as postulated in the glycogen shunt theory. The present study offers perspectives on the regulation of respiration, bioenergetics, and Mb function during muscle contraction.)
Cohn 1953 J Biol Chem + (A new reaction which occurs in oxida … A new reaction which occurs in oxidative phosphorylation associated with the electron transport system has been observed in rat liver mitochondria with α-ketoglutarate, β-hydroxybutyrate, and succinate as substrates. This reaction manifests itself by a replacement of O18 with normal oxygen in inorganic phosphate labeled with O18 and parallels the phosphorylation which is associated with the oxidation. The number of molecules of inorganic phosphate which participate in this reaction, calculated on the basis that a monoester of phosphate is involved, is several times higher than the number of high energy phosphate bonds that can be formed. The reaction does not occur at the substrate level oxidation of α-ketoglutarate and the evidence suggests that it occurs at every step in the electron transport system. This phosphate turnover reaction occurs only when phosphorylation is proceeding. Dinitrophenol suppresses the reaction. The omission of Mg++ or adenylic acid also suppresses the reaction. The reaction is abolished when succinate oxidation is catalyzed by a succinic oxidase preparation containing no phosphorylating system. The possibility that the reaction is due to a direct reaction of ATP, hydrolytic or otherwise, is eliminated. Various mechanisms which are consistent with the findings are discussed.stent with the findings are discussed.)
Kielley 1951 J Biol Chem + (A simplified procedure for preparing … A simplified procedure for preparing mitochondria suspensions from isotonic sucrose homogenates has been described. These preparations exhibit high rates of net 7 minute phosphorus formation from adenylic acid during the oxidation of α-ketoglutarate in the absence of inhibitors such as fluoride, and show very low dephosphorylating activities. It has been possible to study the complete phosphorylation of AMP in this system and to interpret the characteristics of this process on the basis of adenosinediphosphate as primary phosphate acceptor and the presence of a myokinase in mitochondria. The activity of this transphosphorylase has been directly determined and is of considerable magnitude. It has also been demonstrated that probably all of the myokinase is associated with the mitochondrial fraction. The changes in the characteristics of oxidative phosphorylation and adenosinetriphosphatase activity as the result of incubation of the enzyme at 28° in the absence of substrates have been studied. The inactivation of the phosphorylation system by aging has been considered in two phases, an initial lag phase which is completely reversible in short aging experiments and a permanent reduction in activity observed with more severely aged mitochondria. The initial very low ATPase activity of the mitochondria was increased to appreciable magnitudes by aging. All the characteristics of aging were prevented to a large extent by AMP, ADP, or ATP. a large extent by AMP, ADP, or ATP.)
Chance 1961 J Biol Chem-I + (A thermodynamically improbable reductio … A thermodynamically improbable reduction of pyridine nucleotide caused by the addition of succinate to isolated mitochondria has been demonstrated. The material so reduced exhibits kinetic responses, some of which can suggest its consideration as a member of the respiratory chain, but a quantitative examination of the kinetics of oxidation and reduction shows that only a small portion of the total respiratory activity in succinate oxidation passes through the diphosphopyridine nucleotide-linked pathway. The nature of the reduction product has been examined in heart, liver, and guinea pig kidney mitochondria and is found to be material absorbing at 340 mµ and having a fluorescence emission maximum at 440 mµ. Direct chemical assays on kidney mitochondria indicate that the reduced material is diphosphopyridine nucleotide. A preliminary evaluation of various hypotheses to explain this result leads us tentatively to reject hypotheses based upon a single pool of mitochondrial pyridine nucleotide in which diphosphopyridine nucleotide and succinate compete for oxidizing equivalents from the cytochrome chain. Further indication of the complexities of this reaction is that respiration can be initiated by succinate without measurable pyridine nucleotide reduction and that a transition from aerobiosis in state 3 to anaerobiosis (state 5) can lead to a higher oxidation level of pyridine nucleotide than was observed aerobically in state 4. These observations suggest that the presence of adenosine 5’-diphosphate inhibits pyridine nucleotide reduction under both aerobic and anaerobic conditions and support the possibility that an energy-linked reaction may be involved.nergy-linked reaction may be involved.)
Pesta 2011Abstract Mitochondrial Medicine-Diagnosis + (A 28-year-old former amateur cyclist demon … A 28-year-old former amateur cyclist demonstrated a sudden exercise intolerance and impairment in muscle function since March 2008 without clinical explanation. The main symptom was a decreased ergometric aerobic capacity by 50%. A specific defect of mitochondrial glutamate dehydrogenase (GDH) was indicated by lack of ADP stimulation in the presence of glutamate and subsequent rescue of respiration after addition of malate.e of respiration after addition of malate.)
Kancirova 2016 Physiol Res + (A 2×2 factorial design was used to evaluat … A 2×2 factorial design was used to evaluate possible preservation of mitochondrial functions in two cardioprotective experimental models, remote ischemic preconditioning and streptozotocin-induced ''diabetes mellitus'', and their interaction during ischemia/reperfusion injury (I/R) of the heart. Male Wistar rats were randomly allocated into four groups: control (C), streptozotocin-induced diabetic (DM), preconditioned (RPC) and preconditioned streptozotocin-induced diabetic (DM+RPC). RPC was conducted by 3 cycles of 5-min hind-limb ischemia and 5-min reperfusion. DM was induced by a single dose of 65 mg/kg streptozotocin. Isolated hearts were exposed to ischemia/reperfusion test according to Langendorff. Thereafter mitochondria were isolated and the mitochondrial respiration was measured. Additionally, the ATP synthase activity measurements on the same preparations were done. Animals of all groups subjected to I/R exhibited a decreased state 3 respiration with the least change noted in DM+RPC group associated with no significant changes in state 2 respiration. In RPC, DM and DM+RPC group, no significant changes in the activity of ATP synthase were observed after I/R injury. These results suggest that the endogenous protective mechanisms of RPC and DM do preserve the mitochondrial function in heart when they act in combination.ion in heart when they act in combination.)
Gaudo 2019 Neurogenetics + (A 3-year-old girl presented with severe ep … A 3-year-old girl presented with severe epilepsy in the context of ''Borrelia'' infection. After ceftriaxone/lidocaine administration, she showed secondarily generalized focal crises that led to neurological and motor sequelae. Genetic studies identified in the patient two heterozygous POLG mutations (c.2591A>G; p.Asn864Ser and c.3649G>C; p.Ala1217Pro). Through analysis of POLG activity in cultured fibroblasts, we confirmed that the mutations altered the mtDNA turnover. Moreover, patient fibroblasts were more sensitive than controls in the presence of a mitochondrial replication-affecting drug, the antiretroviral azidothymidine. To test if ceftriaxone treatment could worsen the deleterious effect of the patient mutations, toxicity assays were performed. Cell toxicity, without direct effect on mitochondrial respiratory function, was detected at different antibiotic concentrations. The clinical outcome, together with the different ''in vitro'' sensitivity to ceftriaxone among patient and control cells, suggested that the mitochondrial disease symptoms were hastened by the infection and were possibly worsened by the pharmacological treatment. This study underscores the benefit of early genetic diagnosis of the patients with mitochondrial diseases, since they may be a target group of patients especially vulnerable to environmental factors. especially vulnerable to environmental factors.)
Nijholt 2023 Sci Rep + (A Kinase Interacting Protein 1 (AKIP1) is … A Kinase Interacting Protein 1 (AKIP1) is a signalling adaptor that promotes mitochondrial respiration and attenuates mitochondrial oxidative stress in cultured cardiomyocytes. We sought to determine whether AKIP1 influences mitochondrial function and the mitochondrial adaptation in response to exercise ''in vivo''. We assessed mitochondrial respiratory capacity, as well as electron microscopy and mitochondrial targeted-proteomics in hearts from mice with cardiomyocyte-specific overexpression of AKIP1 (AKIP1-TG) and their wild type (WT) littermates. These parameters were also assessed after four weeks of voluntary wheel running. In contrast to our previous ''in vitro'' study, respiratory capacity measured as state 3 respiration on palmitoyl carnitine was significantly lower in AKIP1-TG compared to WT mice, whereas state 3 respiration on pyruvate remained unaltered. Similar findings were observed for maximal respiration, after addition of FCCP. Mitochondrial DNA damage and oxidative stress markers were not elevated in AKIP1-TG mice and gross mitochondrial morphology was similar. Mitochondrial targeted-proteomics did reveal reductions in mitochondrial proteins involved in energy metabolism. Exercise performance was comparable between genotypes, whereas exercise-induced cardiac hypertrophy was significantly increased in AKIP1-TG mice. After exercise, mitochondrial state 3 respiration on pyruvate substrates was significantly lower in AKIP1-TG compared with WT mice, while respiration on palmitoyl carnitine was not further decreased. This was associated with increased mitochondrial fission on electron microscopy, and the activation of pathways associated with mitochondrial fission and mitophagy. This study suggests that AKIP1 regulates the mitochondrial proteome involved in energy metabolism and promotes mitochondrial turnover after exercise. Future studies are required to unravel the mechanistic underpinnings and whether the mitochondrial changes are required for the AKIP1-induced physiological cardiac growth.KIP1-induced physiological cardiac growth.)
MiPNet17.12 Bioblast 2012 + (A Mitochondrial Festival in the Spirit of … A Mitochondrial Festival in the Spirit of [[Gentle Science]] <div style="padding:0px;border: 1px solid #aaaaaa;margin-bottom:0px;margin-right:10px"><div style="font-size:100%;font-weight:bold;padding:0.2em;padding-right: 0.4em;padding-left: 0.4em;background-color:#eeeeee;border-bottom:1px solid #aaaaaa;text-align:left;">[[Image:O2k-support system.jpg|right|150px|link=http://wiki.oroboros.at/index.php/O2k-technical_support_and_open_innovation|O2k-technical support and open innovation]]: <big>Open the '''pdf document''' above.</big></div><div style="background-color:#ffffff;padding-top:0.2em;padding-right: 0.4em;padding-bottom: 0.2em;padding-left: 0.4em;">::::» Current O2k-series: '''[https://www.oroboros.at/index.php/product-category/products/o2k-packages/ NextGen-O2k Series XB and O2k Series J]'''::::» Current software versions DatLab 8.0: [[MitoPedia: DatLab]]::::* ''Further details:'' '''» [[MitoPedia: O2k-Open Support]]'''</div></div>itoPedia: O2k-Open Support]]''' </div> </div>)
WHO Expert Consultation 2004 Lancet + (A WHO expert consultation addressed the de … A WHO expert consultation addressed the debate about interpretation of recommended body-mass index (BMI) cut-off points for determining overweight and obesity in Asian populations, and considered whether population-specific cut-off points for BMI are necessary. They reviewed scientific evidence that suggests that Asian populations have different associations between BMI, percentage of body fat, and health risks than do European populations. The consultation concluded that the proportion of Asian people with a high risk of type 2 diabetes and cardiovascular disease is substantial at BMIs lower than the existing WHO cut-off point for overweight (> or =25 kg/m2). However, available data do not necessarily indicate a clear BMI cut-off point for all Asians for overweight or obesity. The cut-off point for observed risk varies from 22 kg/m2 to 25 kg/m2 in different Asian populations; for high risk it varies from 26 kg/m2 to 31 kg/m2. No attempt was made, therefore, to redefine cut-off points for each population separately. The consultation also agreed that the WHO BMI cut-off points should be retained as international classifications. The consultation identified further potential public health action points (23.0, 27.5, 32.5, and 37.5 kg/m2) along the continuum of BMI, and proposed methods by which countries could make decisions about the definitions of increased risk for their population.tions of increased risk for their population.)
Hall 2019 Methods Mol Biol + (A better understanding of the molecular ba … A better understanding of the molecular basis of polycation-mediated impairment of mitochondrial bioenergetics might improve the design and synthesis of more efficient and safer polymeric transfectants. Here we utilize the phosphorylation control protocol for studying the effect of polycations on mitochondrial respiration in intact mammalian cells using Oxygraph-2k (OROBOROS). The protocol offers an opportunity to comprehensively monitor mitochondrial respiration through consecutive additions of various cell membrane permeable compounds that alter mitochondrial respiration, thus providing useful information on different states of mitochondrial respiration. Furthermore, we demonstrate how to analyze the data obtained with the phosphorylation control protocol and how to calculate the respiratory flux ratios, which can be used as indicators of respiratory functionality and mitochondrial health.ry functionality and mitochondrial health.)
Ritchie 2008 Photosyn Res + (A blue diode PAM (Pulse Amplitude Modulati … A blue diode PAM (Pulse Amplitude Modulation) fluorometer was used to measure rapid Photosynthesis (P) versus Irradiance (E) curves (P vs. E curves) in ''Synechococcus'' (classical cyanobacteria), ''Prochlorothrix'' (prochlorophyta), ''Chlorella'' (chlorophyta), ''Rhodomonas'' (cryptophyta), ''Phaeodactylum'' (bacillariophyta), ''Acaryochloris'' (Chl d/a cyanobacteria) and Subterranean Clover (''Trifolium subterraneum'', Papilionaceae, Angiospermae). Effective quantum yield (Phi(PSII)) versus irradiance curves could be described by a simple exponential decay function (Phi(PSII) = Phi(PSII, maxe(-kE)) although Log/Log transformation was sometimes found to be necessary to obtain the best fits. Photosynthesis was measured as relative Electron Transport Rate (rETR) standardised on a chlorophyll basis. P versus E curves were fitted to the waiting-in-line function (an equation of the form P = P(max) x k x E x e(-kE)) allowing half-saturating and optimal irradiances (E(optimum)) to be estimated. The second differential of the equation shows that at twice optimal light intensities, there is a point of inflection in the P versus E curve. Photosynthesis is inhibited 26.4% at this point of inflection. The waiting-in-line model was found to be a very good descriptor of photosynthetic light saturation curves and superior to hyperbolic functions with an asymptotic saturation point (Michaelis-Menten, exponential saturation and hyperbolic tangent). The exponential constants (k) of the Phi(PSII) versus E and P versus E curves should be equal because rETR is directly proportional to Phi(PSII) x E. The conventionally calculated Non-Photochemical Quenching (NPQ) in Synechococcus was not significantly different to zero but NPQ versus E curves for the other algae could be fitted to an exponential saturation model. The kinetics of NPQ does not appear to be related to the kinetics of Phi(PSII) or rETR.ated to the kinetics of Phi(PSII) or rETR.)
Mitophagy + (A brief accout of '''mitochondrial mitophagy'''.)
Sirtuins + (A brief accout of the '''sirtuin family'''.)
Hanna 2023 Antioxid Redox Signal + (A burgeoning literature has attributed var … A burgeoning literature has attributed varied physiological effects to hydrogen sulfide (H2S), which is a product of eukaryotic sulfur amino acid metabolism. Protein persulfidation represents a major focus of studies elucidating the mechanism underlying H2S signaling. On the contrary, the capacity of H2S to induce reductive stress by targeting the electron transport chain (ETC) and signal by reprogramming redox metabolism has only recently begun to be elucidated. Recent Advances: In contrast to the nonspecific reaction of H2S with oxidized cysteines to form protein persulfides, its inhibition of complex IV represents a specific mechanism of action. Studies on the dual impact of H2S as an ETC substrate and an inhibitor have led to the exciting discovery of ETC plasticity and the use of fumarate as a terminal electron acceptor. H2S oxidation combined with complex IV targeting generates mitochondrial reductive stress, which is signaled through the metabolic network, leading to increased aerobic glycolysis, glutamine-dependent reductive carboxylation, and lipogenesis. Critical Issues: Insights into H2S-induced metabolic reprogramming are ushering in a paradigm shift for understanding the mechanism of its cellular action. It will be critical to reevaluate the physiological effects of H2S, for example, cytoprotection against ischemia-reperfusion injury, through the framework of metabolic reprogramming and ETC remodeling by H2S. Future Directions: The metabolic ramifications of H2S in other cellular compartments, for example, the endoplasmic reticulum and the nucleus, as well as the intersections between hypoxia and H2S signaling are important future directions that merit elucidation. future directions that merit elucidation.)
Okoye 2019 Aquat Toxicol + (A by-product of mitochondrial substrate ox … A by-product of mitochondrial substrate oxidation and electron transfer to generate cellular energy (ATP) is reactive oxygen species (ROS). Superoxide anion radical and hydrogen peroxide (H2O2) are the proximal ROS produced by the mitochondria. Because low levels of ROS serve critical regulatory roles in cell physiology while excessive levels or inappropriately localized ROS result in aberrant physiological states, mitochondrial ROS need to be tightly regulated. While it is known that regulation of mitochondrial ROS involves balancing the rates of production and removal, the effects of stressors on these processes remain largely unknown. To illuminate how stressors modulate mitochondrial ROS homeostasis, we investigated the effects of temperature and cadmium (Cd) on H2O2 emission and consumption in rainbow trout liver mitochondria. We show that H2O2 emission rates increase with temperature and Cd exposure. Energizing mitochondria with malate-glutamate or succinate increased the rate of H2O2 emission; however, Cd exposure imposed different patterns of H2O2 emission depending on the concentration and substrate. Specifically, mitochondria respiring on malate-glutamate exhibited a saturable graded concentration-response curve that plateaued at 5 μM while mitochondria respiring on succinate had a biphasic concentration-response curve characterized by a spike in the emission rate at 1 μM Cd followed by gradual diminution at higher Cd concentrations. To explain the observed substrate- and concentration-dependent effects of Cd, we sequestered specific mitochondrial ROS-emitting sites using blockers of electron transfer and then tested the effect of the metal. The results indicate that the biphasic H2O2 emission response imposed by succinate is due to site IIF but is further modified at sites IQ and IIIQo. Moreover, the saturable graded H2O2 emission response in mitochondria energized with malate-glutamate is consistent with effect of Cd on site IF. Additionally, Cd and temperature acted cooperatively to increase mitochondrial H2O2 emission suggesting that increased toxicity of Cd at high temperature may be due to increased oxidative insult. Surprisingly, despite their clear stimulatory effect on H2O2 emission, Cd, temperature and bioenergetic status did not affect the kinetics of mitochondrial H2O2 consumption; the rate constants and half-lives for all the conditions tested were similar. Overall, our study indicates that the production processes of rainbow trout liver mitochondrial H2O2 metabolism are highly responsive to stressors and bioenergetics while the consumption processes are recalcitrant. The latter denotes the presence of a robust H2O2 scavenging system in liver mitochondria that would maintain H2O2 homeostasis in the face of increased production and reduced scavenging capacity.Copyright © 2019 Elsevier B.V. All rights reserved.The latter denotes the presence of a robust H2O2 scavenging system in liver mitochondria that would maintain H2O2 homeostasis in the face of increased production and reduced scavenging capacity. Copyright © 2019 Elsevier B.V. All rights reserved.)
Zweck 2023 ESC Heart Fail + (A causal link between non-ischaemic heart … A causal link between non-ischaemic heart failure (HF) and humoral autoimmunity against G-protein-coupled receptors (GPCR) remains unclear except for Chagas' cardiomyopathy. Uncertainty arises from ambiguous reports on incidences of GPCR autoantibodies, spurious correlations of autoantibody levels with disease activity, and lack of standardization and validation of measuring procedures for putatively cardio-pathogenic GPCR autoantibodies. Here, we use validated and certified immune assays presenting native receptors as binding targets. We compared candidate GPCR autoantibody species between HF patients and healthy controls and tested associations of serum autoantibody levels with serological, haemodynamic, metabolic, and functional parameters in HF.Ninety-five non-ischaemic HF patients undergoing transcatheter endomyocardial biopsy and 60 healthy controls were included. GPCR autoantibodies were determined in serum by IgG binding to native receptors or a cyclic peptide (for β1AR autoantibodies). In patients, cardiac function, volumes, and myocardial structural properties were assessed by cardiac magnetic resonance imaging; right heart catheterization served for determination of cardiac haemodynamics; endomyocardial biopsies were used for histological assessment of cardiomyopathy and determination of cardiac mitochondrial oxidative function by high-resolution respirometry.Autoantibodies against β1 adrenergic (β1AR) , M5-muscarinic (M5AR), and angiotensin II type 2 receptors (AT2R) were increased in HF (all P < 0.001). Autoantibodies against α1 -adrenergic (α1 AR) and angiotensin II type 1 receptors (AT1R) were decreased in HF (all P < 0.001). Correlation of alterations of GPCR autoantibodies with markers of cardiac or systemic inflammation or cardiac damage, haemodynamics, myocardial histology, or left ventricular inflammation (judged by T2 mapping) were weak, even when corrected for total IgG. β1 AR autoantibodies were related inversely to markers of left ventricular fibrosis indicated by T1 mapping (r = -0.362, P < 0.05) and global longitudinal strain (r = -0.323, P < 0.05). AT2R autoantibodies were associated with improved myocardial mitochondrial coupling as measured by high-resolution respirometry in myocardial biopsies (r = -0.352, P < 0.05). In insulin-resistant HF patients, AT2R autoantibodies were decreased (r = -.240, P < 0.05), and AT1R autoantibodies were increased (r = 0.212, P < 0.05).GPCR autoantibodies are markedly altered in HF. However, they are correlated poorly or even inversely to haemodynamic, metabolic, and functional markers of disease severity, myocardial histology, and myocardial mitochondrial efficiency. These observations do not hint towards a specific cardio-pathogenic role of GPCR autoantibodies and suggest that further investigations are required before specific therapies directed at GPCR autoantibodies can be clinically tested in non-ischaemic HF.rected at GPCR autoantibodies can be clinically tested in non-ischaemic HF.)
Mouithys-Mickalad 2020 Chem Biol Interact + (A cellular model of cardiomyocytes (H9c2 c … A cellular model of cardiomyocytes (H9c2 cell line) and mitochondria isolated from mouse liver were used to understand the drug action of BPDZ490 and BPDZ711, two benzopyran analogues of the reference potassium channel opener cromakalim, on mitochondrial respiratory parameters and swelling, by comparing their effects with those of the parent compound cromakalim. For these three compounds, the oxygen consumption rate (OCR) was determined by high-resolution respirometry (HRR) and their impact on adenosine triphosphate (ATP) production and calcium-induced mitochondrial swelling was investigated. Cromakalim did not modify neither the OCR of H9c2 cells and the ATP production nor the Ca-induced swelling. By contrast, the cromakalim analogue BPDZ490 (1) induced a strong increase of OCR, while the other benzopyran analogue BPDZ711 (2) caused a marked slowdown. For both compounds, 1 displayed a biphasic behavior while 2 still showed an inhibitory effect. Both compounds 1 and 2 were also found to decrease the ATP synthesis, with pronounced effect for 2, while cromakalim remained without effect. Overall, these results indicate that cromakalim, as parent molecule, does not induce per se any direct effect on mitochondrial respiratory function neither on whole cells nor on isolated mitochondria whereas both benzopyran analogues 1 and 2 display totally opposite behavior profiles, suggesting that compound 1, by increasing the maximal respiration capacity, might behave as a mild uncoupling agent and compound 2 is taken as an inhibitor of the mitochondrial electron-transfer chain.the mitochondrial electron-transfer chain.)
Valle-Mendiola 2020 Cancers (Basel) + (A central characteristic of many types of … A central characteristic of many types of cancer is altered energy metabolism processes such as enhanced glucose uptake and glycolysis and decreased oxidative metabolism. The regulation of energy metabolism is an elaborate process involving regulatory proteins such as HIF (pro-metastatic protein), which reduces oxidative metabolism, and some other proteins such as tumour suppressors that promote oxidative phosphorylation. In recent years, it has been demonstrated that signal transducer and activator of transcription (STAT) proteins play a pivotal role in metabolism regulation. STAT3 and STAT5 are essential regulators of cytokine- or growth factor-induced cell survival and proliferation, as well as the crosstalk between STAT signalling and oxidative metabolism. Several reports suggest that the constitutive activation of STAT proteins promotes glycolysis through the transcriptional activation of hypoxia-inducible factors and therefore, the alteration of mitochondrial activity. It seems that STAT proteins function as an integrative centre for different growth and survival signals for energy and respiratory metabolism. This review summarises the functions of STAT3 and STAT5 in the regulation of some metabolism-related genes and the importance of oxygen in the tumour microenvironment to regulate cell metabolism, particularly in the metabolic pathways that are involved in energy production in cancer cells.lved in energy production in cancer cells.)
Palade 1953 J Histochem Cytochem + (A characteristic pattern of organization w … A characteristic pattern of organization was found with the help of the electron microscope in sectioned animal mitochondria irrespective of the species providing the specimen and of the cell type examined.Each mitochondrion was found to possess:# A limiting membrane.# A mitochondrial matrix that appears structureless at present levels of resolution.# A system of internal ridges (cristae mitochondriales) that protrude from the inside surface of the membrane towards the interior of the organelles. In many mitochondria the cristae are perpendicular to the long axis of the organelles and occur in series within which they lie parallel to one another at more or less regular intervals.In favorable electron micrographs the mitochondrial membrane appears to be double and the cristae appear to be folds of a second, internal mitochondrial membrane.a second, internal mitochondrial membrane.)
Zeng 2017 J Biol Chem + (A chronic high fat diet results in hepatic … A chronic high fat diet results in hepatic mitochondrial dysfunction and induction of peroxisomal fatty acid oxidation (FAO); whether specific inhibition of peroxisomal FAO benefits mitochondrial FAO and reactive oxygen species (ROS) metabolism remains unclear. In this study a specific inhibitor for the rate-limiting enzyme involved in peroxisomal FAO, [[acyl-CoA oxidase]]-1 (ACOX1) was developed and used for the investigation of peroxisomal FAO inhibition upon mitochondrial FAO and ROS metabolism. Specific inhibition of ACOX1 by 10,12-tricosadiynoic acid increased hepatic mitochondrial FAO via activation of the SIRT1-AMPK (adenosine 5'-monophosphate-activated protein kinase) pathway and proliferator activator receptor α and reduced hydrogen peroxide accumulation in high fat diet-fed rats, which significantly decreased hepatic lipid and ROS contents, reduced body weight gain, and decreased serum triglyceride and insulin levels. Inhibition of ACOX1 is a novel and effective approach for the treatment of high fat diet- or obesity-induced metabolic diseases by improving mitochondrial lipid and ROS metabolism.ng mitochondrial lipid and ROS metabolism.)
Boczek 2014 Biomed Res Int + (A close link between Ca2+</s … A close link between Ca2+, ATP level, and neurogenesis is apparent; however, the molecular mechanisms of this relationship have not been completely elucidated. Transient elevations of cytosolic Ca2+ may boost ATP synthesis, but ATP is also consumed by ion pumps to maintain a low Ca2+ in cytosol. In differentiation process plasma membrane Ca2+ ATPase (PMCA) is considered as one of the major players for Ca2+ homeostasis. From four PMCA isoforms, the fastest PMCA2 and PMCA3 are expressed predominantly in excitable cells. In the present study we assessed whether PMCA isoform composition may affect energy balance in differentiating PC12 cells. We found that PMCA2-downregulated cells showed higher basal O2 consumption, lower NAD(P)H level, and increased activity of ETC. These changes associated with higher [Ca2+]c resulted in elevated ATP level. Since PMCA2-reduced cells demonstrated greatest sensitivity to ETC inhibition, we suppose that the main source of energy for PMCA isoforms 1, 3, and 4 was oxidative phosphorylation. Contrary, cells with unchanged PMCA2 expression exhibited prevalence of glycolysis in ATP generation. Our results with PMCA2- or PMCA3-downregulated lines provide an evidence of a novel role of PMCA isoforms in regulation of bioenergetic pathways, and mitochondrial activity and maintenance of ATP level during PC12 cells differentiation.soforms in regulation of bioenergetic pathways, and mitochondrial activity and maintenance of ATP level during PC12 cells differentiation.)
Yang 2010 Cancer Biol Ther + (A common metabolic change in cancer is the … A common metabolic change in cancer is the acquisition of glycolytic phenotypes. Increased expression of glycolytic enzymes is considered as one contributing factor. The role of mitochondrial defects in acquisition of glycolytic phenotypes has been postulated but remains controversial. Here we show that functional defects in mitochondrial respiration could be induced by oncogenic H-RasQ61L transformation, even though the mitochondrial contents or mass was not reduced in the transformed cells. First, mitochondrial respiration, as measured by mitochondrial oxygen consumption, was suppressed in NIH-3T3 cells transformed with H-RasQ61L. Second, oligomycin or rotenone did not reduce the cellular ATP levels in the H-RasQ61L transformed cells, suggesting a diminished role of mitochondrial respiration in the cellular energy metabolism. Third, inhibition of glycolysis with iodoacetic acid reduced ATP levels at a much faster rate in H-RasQ61L transformed cells than in the vector control cells. The reduction of cellular ATP levels was reversed by exogenously added pyruvate in the vector control cells but not in H-RasQ61L transformed cells. Finally when compared to the HRasQ61L transformed cells, the vector control cells had increased resistance toward glucose deprivation. The increased resistance was dependent on mitochondrial oxidative phosphorylation since rotenone or oligomycin abolished the increased survival of the vector control cells under glucose deprivation. The results also suggest an inability of the H-RasQ61L transformed cells to reactivate mitochondrial respiration under glucose deprivation. Taken together, the data suggest that mitochondrial respiration can be impaired during transformation of NIH-3T3 cells by oncogeneic H-RasQ61L.can be impaired during transformation of NIH-3T3 cells by oncogeneic H-RasQ61L.)
Jacobus 1982 Arch Biochem Biophys + (A complete kinetic analysis of the forward … A complete kinetic analysis of the forward mitochondrial creatine kinase reaction was conducted to define the mechanism for its rate enhancement when coupled to oxidative phosphorylation. Two experimental systems were employed. In the first, ATP was produced by oxidative phosphorylation. In the second, heart mitochondria were pretreated with rotenone and oligomycin, and ATP was regenerated by a phosphoenolpyruvate-pyruvate kinase system. Product inhibition studies showed that oxidative phosphorylation did not effect the binding of creatine phosphate to the enzyme. Creatine phosphate interacted competitively with both ATP and creatine, and the E · MgATP · CrP dead-end complex was not readily detected. In a similar manner, the dissociation constants for creatine were not influenced by the source of ATP: ''K''ib = 29 mM; ''K''b = 5.3 mM, and the maximum velocity of the reaction was unchanged: ''V''1 = 1 μmol/min/mg. Slight differences were noted for the dissociation constant (''K''ia) of MgATP from the binary enzyme complex, E · MgATP. The values were 0.75 and 0.29 mM in the absence and presence of respiration. However, a 10-fold decrease in the steady-state dissociation constant (''K''a) of MgATP from the ternary complex, E · MgATP · creatine, was documented: 0.15 mM with exogenous ATP and 0.014 mM with oxidative phosphorylation. Since ''K''ia × ''K''b does not equal ''K''a × ''K''ib under respiring conditions, the enzyme appears to be altered from its normal rapid-equilibrium random binding kinetics to some other mechanism by its coupling to oxidative phosphorylation.its coupling to oxidative phosphorylation.)
Bohanon 2017 Shock + (A complete understanding of the role of th … A complete understanding of the role of the liver in burn-induced hypermetabolism is lacking. We investigated the acute effect of severe burn trauma on liver mitochondrial respiratory capacity and coupling control as well as the signaling events underlying these alterations.Male BALB/c mice (8-12 weeks) received full-thickness scald burns on ∼30% of the body surface. Liver tissue was harvested 24 hours post injury. Mitochondrial respiration was determined by high-resolution respirometry. Citrate synthase activity was determined as a proxy of mitochondrial density. Male Sprague-Dawley rats received full-thickness scald burns to ∼60% of the body surface. Serum was collected 24 hours post injury. HepG2 cells were cultured with serum-enriched media from either sham or burn treated rats. Protein levels were analyzed via western blot.Mass-specific (p = 0.01) and mitochondrial-specific (p = 0.01) respiration coupled to ATP production significantly increased in the liver after burn. The respiratory control ratio for ADP (p = 0.04) and the mitochondrial flux control ratio (p = 0.03) were elevated in the liver of burned animals. Complex III and Complex IV protein abundance in the liver increased after burn by 17% and 14%, respectively. Exposure of HepG2 cells to serum from burned rats increased the pAMPKα:AMPKα ratio (p < 0.001) and levels of SIRT1 (p = 0.01), Nrf2 (p < 0.001), and PGC1α (p = 0.02).Severe burn trauma augments respiratory capacity and function of liver mitochondria, adaptations that augment ATP production. This response may be mediated by systemic factors that activate signaling proteins responsible for regulating cellular energy metabolism and mitochondrial biogenesis. energy metabolism and mitochondrial biogenesis.)
Racker 1971 J Biol Chem + (A complex was reconstituted with hydrophob … A complex was reconstituted with hydrophobic proteins from bovine heart mitochondrial membranes, cytochrome c, cytochrome oxidase, phospholipids, and coupling factors. These vesicular structures catalyzed oxidative phosphorylation with reduced N-methylphenazinium methyl sulfate as substrate.ylphenazinium methyl sulfate as substrate.)
Sobotka 2016 J Bioenerg Biomembr + (A compound with promising anticancer prope … A compound with promising anticancer properties, 3-bromopyruvate (3-BP) is a synthetic derivative of a pyruvate molecule; however, its toxicity in non-malignant cells has not yet been fully elucidated. Therefore, we elected to study the effects of 3-BP on primary hepatocytes in monolayer cultures, permeabilized hepatocytes and isolated mitochondria. After a 1-h treatment with 100 μM 3-BP cell viability of rat hepatocytes was decreased by 30 % as measured by the WST-1 test (p < 0.001); after 3-h exposure to ≥200 μM 3-BP lactate dehydrogenase leakage was increased (p < 0.001). Reactive oxygen species production was increased in the cell cultures after a 1-h treatment at concentrations ≥100 μmol/l (p < 0.01), and caspase 3 activity was increased after a 20-h incubation with 150 μM and 200 μM 3-BP (p < 0.001). This toxic effect of 3-BP was also proved using primary mouse hepatocytes. In isolated mitochondria, 3-BP induced a dose- and time-dependent decrease of mitochondrial membrane potential during a 10-min incubation both with Complex I substrates glutamate + malate or Complex II substrate succinate, although this decrease was more pronounced with the latter. We also measured the effect of 3-BP on respiration of isolated mitochondria. ADP-activated respiration was inhibited by 20 μM 3-BP within 10 min. Similar effects were also found in permeabilized hepatocytes of both species.so found in permeabilized hepatocytes of both species.)