The Cytosolic Antioxidant Copper/zinc-superoxide Dismutase Prevents the Early Release of Mitochondrial Cytochrome C in Ischemic Brain After Transient Focal Cerebral Ischemia in Mice
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Release of mitochondrial cytochrome c into the cytosol is a critical step in apoptosis. We have reported that early release of cytochrome c in vivo occurs after permanent focal cerebral ischemia (FCI) and is mediated by the mitochondrial antioxidant manganese superoxide dismutase (SOD). However, the role of reactive oxygen species produced after ischemia-reperfusion in the mitochondrial apoptosis process is still unknown, although overexpression of copper/zinc-SOD (SOD1), a cytosolic isoenzyme, protects against ischemia-reperfusion. We now hypothesize that the overexpression of SOD1 also prevents apoptosis after FCI. To address this issue, we examined the subcellular distribution of the cytochrome c protein in both wild-type mice and in SOD1 transgenic (Tg) mice after transient FCI. Cytosolic cytochrome c was detected as early as 2 hr after reperfusion, and correspondingly, mitochondrial cytochrome c was significantly reduced after FCI. Cytosolic cytochrome c was significantly lower in the SOD1 Tg mice compared with wild types 2 (p < 0.0001) and 4 (p < 0.05) hr after FCI. Apaf-1, which interacts with cytochrome c and activates caspases, was constitutively expressed in both groups of animals, with no alteration after FCI. Double staining with cytochrome c immunohistochemistry and terminal deoxynucleotidyl transferase-mediated uridine 5'-triphosphate-biotin nick end labeling showed a spatial relationship between cytosolic cytochrome c expression and DNA fragmentation. A significant amount of DNA laddering was detected 24 hr after ischemia and was reduced in SOD1 Tg mice. These data suggest that SOD1 blocks cytosolic release of cytochrome c and could thereby reduce apoptosis after transient FCI.
Shao R, Liu L, Xu J, Lan P, Wu G, Shi H Front Neurol. 2023; 13:1077043.
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Jelinek M, Jurajda M, Duris K Antioxidants (Basel). 2021; 10(12).
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Han H, Park S, Kang J, Kim J, Yoo S, Kim D Mar Drugs. 2021; 19(8).
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Proteomic changes in intracranial blood during human ischemic stroke.
Maglinger B, Frank J, McLouth C, Trout A, Roberts J, Grupke S J Neurointerv Surg. 2020; 13(4):395-399.
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