Chen 2022 Am J Physiol Cell Physiol: Difference between revisions

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|abstract=Mitochondrial reactive oxygen species (ROS) have emerged as an important mechanism of disease and redox signaling in the cellular system. Under basal or pathological conditions, electron leakage for ROS production is primarily mediated by complexes I and III of the electron transport chain (ETC) and by the proton motive force (PMF), consisting of a membrane potential (ฮ”ฮจ) and a proton gradient (ฮ”pH). Several factors control redox status in mitochondria, including ROS, the PMF, oxidative posttranslational modifications (OPTM) of the ETC subunits, SOD2, and cytochrome ''c'' heme lyase (HCCS). In the mitochondrial PMF, increased ฮ”pH-supported backpressure due to diminishing electron transport and chemiosmosis promotes a more reductive mitochondrial physiological setting. OPTM by protein cysteine sulfonation in complex I and complex III has been shown to affect enzymatic catalysis, the proton gradient, redox status, and enzyme-mediated ROS production. Pathological conditions associated with oxidative or nitrosative stress, such as myocardial ischemia and reperfusion (I/R), increase mitochondrial ROS production and redox dysfunction via oxidative injury to complexes I and III, intensely enhancing protein cysteine sulfonation and impairing heme integrity. The physiological conditions of reductive stress induced by gains in SOD2 function normalize I/R-mediated ROS overproduction and redox dysfunction. Further insight into the cellular mechanisms by which HCCS, biogenesis of c-type cytochrome, and OPTM regulate PMF and ROS production in mitochondria will enrich our understanding of redox signal transduction and identify new therapeutic targets for cardiovascular diseases in which oxidative stress perturbs normal redox signaling.
|abstract=Mitochondrial reactive oxygen species (ROS) have emerged as an important mechanism of disease and redox signaling in the cellular system. Under basal or pathological conditions, electron leakage for ROS production is primarily mediated by complexes I and III of the electron transport chain (ETC) and by the proton motive force (PMF), consisting of a membrane potential (ฮ”ฮจ) and a proton gradient (ฮ”pH). Several factors control redox status in mitochondria, including ROS, the PMF, oxidative posttranslational modifications (OPTM) of the ETC subunits, SOD2, and cytochrome ''c'' heme lyase (HCCS). In the mitochondrial PMF, increased ฮ”pH-supported backpressure due to diminishing electron transport and chemiosmosis promotes a more reductive mitochondrial physiological setting. OPTM by protein cysteine sulfonation in complex I and complex III has been shown to affect enzymatic catalysis, the proton gradient, redox status, and enzyme-mediated ROS production. Pathological conditions associated with oxidative or nitrosative stress, such as myocardial ischemia and reperfusion (I/R), increase mitochondrial ROS production and redox dysfunction via oxidative injury to complexes I and III, intensely enhancing protein cysteine sulfonation and impairing heme integrity. The physiological conditions of reductive stress induced by gains in SOD2 function normalize I/R-mediated ROS overproduction and redox dysfunction. Further insight into the cellular mechanisms by which HCCS, biogenesis of c-type cytochrome, and OPTM regulate PMF and ROS production in mitochondria will enrich our understanding of redox signal transduction and identify new therapeutic targets for cardiovascular diseases in which oxidative stress perturbs normal redox signaling.
}}
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== Correction: FADH<sub>2</sub> and S-pathway ==
:::::: [[File:Chen 2022 Am J Physiol Cell Physiol CORRECTION.png|600px|right]]
::::* [[Complex II ambiguities]]
{{Template:Correction FADH2 and S-pathway}}
ย 
:::: [[File:Chen 2022 Am J Physiol Cell Physiol CORRECTION.png|800px]]
ย 
:::: A commonly found error on FADH<sub>2</sub> in the S-pathway requires correction. For clarification, see page 48 in [[Gnaiger_2020_BEC_MitoPathways |Gnaiger (2020)]]
::::* Quote (p 48): "Theย  substrateย  ofย  CIIย  isย  succinate,ย  whichย  isย  oxidizedย  formingย  fumarateย  while reducing flavin adenine dinucleotide FAD to FADH<sub>2</sub>, with further electron transfer to the quinone pool. Whereas reduced NADH is a substrate of Complex I linked to dehydrogenases of the TCA cycle and mt-matrix upstream of CI,ย  reducedย  FADH<sub>2</sub> is a product of Complex II with downstream electron flow from CII to Q."
ย 
:::::: Gnaiger E (2020) Mitochondrial pathways and respiratory control. An introduction to OXPHOS analysis. 5th ed. Bioenerg Commun 2020.2. https://doi.org/10.26124/bec:2020-0002


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Revision as of 13:29, 19 March 2023

Publications in the MiPMap
Chen CL, Zhang L, Jin Z, Kasumov T, Chen YR (2022) Mitochondrial redox regulation and myocardial ischemia-reperfusion injury. Am J Physiol Cell Physiol 322:C12-23. doi: 10.1152/ajpcell.00131.2021

ยป PMID: 34757853 Open Access

Chen CL, Zhang L, Jin Z, Kasumov T, Chen YR (2022) Am J Physiol Cell Physiol

Abstract: Mitochondrial reactive oxygen species (ROS) have emerged as an important mechanism of disease and redox signaling in the cellular system. Under basal or pathological conditions, electron leakage for ROS production is primarily mediated by complexes I and III of the electron transport chain (ETC) and by the proton motive force (PMF), consisting of a membrane potential (ฮ”ฮจ) and a proton gradient (ฮ”pH). Several factors control redox status in mitochondria, including ROS, the PMF, oxidative posttranslational modifications (OPTM) of the ETC subunits, SOD2, and cytochrome c heme lyase (HCCS). In the mitochondrial PMF, increased ฮ”pH-supported backpressure due to diminishing electron transport and chemiosmosis promotes a more reductive mitochondrial physiological setting. OPTM by protein cysteine sulfonation in complex I and complex III has been shown to affect enzymatic catalysis, the proton gradient, redox status, and enzyme-mediated ROS production. Pathological conditions associated with oxidative or nitrosative stress, such as myocardial ischemia and reperfusion (I/R), increase mitochondrial ROS production and redox dysfunction via oxidative injury to complexes I and III, intensely enhancing protein cysteine sulfonation and impairing heme integrity. The physiological conditions of reductive stress induced by gains in SOD2 function normalize I/R-mediated ROS overproduction and redox dysfunction. Further insight into the cellular mechanisms by which HCCS, biogenesis of c-type cytochrome, and OPTM regulate PMF and ROS production in mitochondria will enrich our understanding of redox signal transduction and identify new therapeutic targets for cardiovascular diseases in which oxidative stress perturbs normal redox signaling.

Chen 2022 Am J Physiol Cell Physiol CORRECTION.png

Correction: FADH2 and Complex II

Ambiguity alert.png
FADH2 is shown as the substrate feeding electrons into Complex II (CII). This is wrong and requires correction - for details see Gnaiger (2024).
Gnaiger E (2024) Complex II ambiguities โ€• FADH2 in the electron transfer system. J Biol Chem 300:105470. https://doi.org/10.1016/j.jbc.2023.105470 - ยปBioblast linkยซ


Labels:

Stress:Ischemia-reperfusion, Oxidative stress;RONS 

Tissue;cell: Heart 


Regulation: Redox state 




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