Hals 2012 Biochem Biophys Res Commun: Difference between revisions
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{{Publication | {{Publication | ||
|title=Hals IK, Ogata H, Pettersen E, Ma Z, BjΓΆrklund A, Skorpen F, Egeberg KW, Grill V (2012) Marked over expression of uncoupling protein-2 in beta cells exerts minor effects on mitochondrial metabolism. Biochem Biophys Res Commun | |title=Hals IK, Ogata H, Pettersen E, Ma Z, BjΓΆrklund A, Skorpen F, Egeberg KW, Grill V (2012) Marked over expression of uncoupling protein-2 in beta cells exerts minor effects on mitochondrial metabolism. Biochem Biophys Res Commun 423:259-64. | ||
|info=[http://www.ncbi.nlm.nih.gov/pubmed?term=Marked%20over%20expression%20of%20uncoupling%20protein-2%20in%20beta%20cells%20exerts%20minor%20effects%20on%20mitochondrial%20metabolism PMID: 22634308] | |info=[http://www.ncbi.nlm.nih.gov/pubmed?term=Marked%20over%20expression%20of%20uncoupling%20protein-2%20in%20beta%20cells%20exerts%20minor%20effects%20on%20mitochondrial%20metabolism PMID: 22634308] | ||
|authors=Hals IK, Ogata H, Pettersen E, Ma Z, Bjoerklund A, Skorpen F, Egeberg KW, Grill V | |authors=Hals IK, Ogata H, Pettersen E, Ma Z, Bjoerklund A, Skorpen F, Egeberg KW, Grill V | ||
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|journal=Biochem Biophys Res Commun | |journal=Biochem Biophys Res Commun | ||
|abstract=Evidence is conflicting as to the impact of elevated levels of uncoupling protein-2 (UCP-2) on insulin-producing beta cells. Here we investigated effects of a fourfold induction of UCP-2 protein primarily on mitochondrial parameters and tested for replication of positive findings at a lower level of induction. We transfected INS-1 cells to obtain a tet-on inducible cell line. A 48 h exposure to 1 ΞΌg/ml of doxycycline (dox) induced UCP-2 fourfold (424 Β± 113%, mean Β± SEM) and 0.1 ΞΌg/ml twofold (178 Β± 29%, n = 3). Fourfold induced cells displayed normal viability (MTT, apoptosis), normal cellular insulin contents and, glucose-induced insulin secretion (+27 Β± 11%) as well as D-[U-(14)C]-glucose oxidation (+5 Β± 9% at 11 mM glucose). Oxidation of [1-(14)C]-oleate was increased from 4088 to 5797 fmol/ΞΌg prot/2h at 3.3 mM glucose, p< 0.03. Oxidation of L-[(14)C(U)]-glutamine was unaffected. Induction of UCP-2 did not significantly affect measures of mitochondrial membrane potential (Rhodamine 123) or mitochondrial mass (Mitotracker Green) and did not affect ATP levels. Oligomycin-inhibited oxygen consumption (a measure of mitochondrial uncoupling) was marginally increased, the effect being significant in comparison with dox-only treated cells, p< 0.05. Oxygen radicals, assessed by dichlorofluorescin diacetate, were decreased by 30%, p< 0.025.Testing for the lower level of UCP-2 induction did not reproduce any of the positive findings. A fourfold induction of UCP-2 was required to exert minor metabolic effects. These findings question an impact of moderately elevated UCP-2 levels in beta cells as seen in diabetes. | |abstract=Evidence is conflicting as to the impact of elevated levels of uncoupling protein-2 (UCP-2) on insulin-producing beta cells. Here we investigated effects of a fourfold induction of UCP-2 protein primarily on mitochondrial parameters and tested for replication of positive findings at a lower level of induction. We transfected INS-1 cells to obtain a tet-on inducible cell line. A 48 h exposure to 1 ΞΌg/ml of doxycycline (dox) induced UCP-2 fourfold (424 Β± 113%, mean Β± SEM) and 0.1 ΞΌg/ml twofold (178 Β± 29%, n = 3). Fourfold induced cells displayed normal viability (MTT, apoptosis), normal cellular insulin contents and, glucose-induced insulin secretion (+27 Β± 11%) as well as D-[U-(14)C]-glucose oxidation (+5 Β± 9% at 11 mM glucose). Oxidation of [1-(14)C]-oleate was increased from 4088 to 5797 fmol/ΞΌg prot/2h at 3.3 mM glucose, p< 0.03. Oxidation of L-[(14)C(U)]-glutamine was unaffected. Induction of UCP-2 did not significantly affect measures of mitochondrial membrane potential (Rhodamine 123) or mitochondrial mass (Mitotracker Green) and did not affect ATP levels. Oligomycin-inhibited oxygen consumption (a measure of mitochondrial uncoupling) was marginally increased, the effect being significant in comparison with dox-only treated cells, p< 0.05. Oxygen radicals, assessed by dichlorofluorescin diacetate, were decreased by 30%, p< 0.025.Testing for the lower level of UCP-2 induction did not reproduce any of the positive findings. A fourfold induction of UCP-2 was required to exert minor metabolic effects. These findings question an impact of moderately elevated UCP-2 levels in beta cells as seen in diabetes. | ||
|keywords=Uncoupling protein-2, | |keywords=Uncoupling protein-2, Insulin secretion, Fatty acid oxidation, INS-1 cells | ||
|mipnetlab=NO Trondheim Grill V | |||
}} | }} | ||
{{Labeling | {{Labeling | ||
|area=Respiration, Genetic knockout;overexpression | |||
|tissues=Islet cell;pancreas;thymus | |||
|enzymes=Uncoupling protein | |||
|topics=Coupling efficiency;uncoupling, Fatty acid | |||
|couplingstates=LEAK, OXPHOS | |||
|instruments=Oxygraph-2k | |instruments=Oxygraph-2k | ||
}} | }} | ||
Latest revision as of 13:02, 13 March 2015
| Hals IK, Ogata H, Pettersen E, Ma Z, BjΓΆrklund A, Skorpen F, Egeberg KW, Grill V (2012) Marked over expression of uncoupling protein-2 in beta cells exerts minor effects on mitochondrial metabolism. Biochem Biophys Res Commun 423:259-64. |
Hals IK, Ogata H, Pettersen E, Ma Z, Bjoerklund A, Skorpen F, Egeberg KW, Grill V (2012) Biochem Biophys Res Commun
Abstract: Evidence is conflicting as to the impact of elevated levels of uncoupling protein-2 (UCP-2) on insulin-producing beta cells. Here we investigated effects of a fourfold induction of UCP-2 protein primarily on mitochondrial parameters and tested for replication of positive findings at a lower level of induction. We transfected INS-1 cells to obtain a tet-on inducible cell line. A 48 h exposure to 1 ΞΌg/ml of doxycycline (dox) induced UCP-2 fourfold (424 Β± 113%, mean Β± SEM) and 0.1 ΞΌg/ml twofold (178 Β± 29%, n = 3). Fourfold induced cells displayed normal viability (MTT, apoptosis), normal cellular insulin contents and, glucose-induced insulin secretion (+27 Β± 11%) as well as D-[U-(14)C]-glucose oxidation (+5 Β± 9% at 11 mM glucose). Oxidation of [1-(14)C]-oleate was increased from 4088 to 5797 fmol/ΞΌg prot/2h at 3.3 mM glucose, p< 0.03. Oxidation of L-[(14)C(U)]-glutamine was unaffected. Induction of UCP-2 did not significantly affect measures of mitochondrial membrane potential (Rhodamine 123) or mitochondrial mass (Mitotracker Green) and did not affect ATP levels. Oligomycin-inhibited oxygen consumption (a measure of mitochondrial uncoupling) was marginally increased, the effect being significant in comparison with dox-only treated cells, p< 0.05. Oxygen radicals, assessed by dichlorofluorescin diacetate, were decreased by 30%, p< 0.025.Testing for the lower level of UCP-2 induction did not reproduce any of the positive findings. A fourfold induction of UCP-2 was required to exert minor metabolic effects. These findings question an impact of moderately elevated UCP-2 levels in beta cells as seen in diabetes. β’ Keywords: Uncoupling protein-2, Insulin secretion, Fatty acid oxidation, INS-1 cells
β’ O2k-Network Lab: NO Trondheim Grill V
Labels: MiParea: Respiration, Genetic knockout;overexpression
Tissue;cell: Islet cell;pancreas;thymus
Enzyme: Uncoupling protein Regulation: Coupling efficiency;uncoupling, Fatty acid Coupling state: LEAK, OXPHOS
HRR: Oxygraph-2k
