Abstract: AIM: To investigate whether α-ketoglutarate dehydrogenase complex (α-KGDHC) has protective effects on adaptive reperfusion after ischemic stroke in rats, and whether its mechanism is related to inhibition of apoptotic pathways. METHODS: A model of middle cerebral artery occlusion (MCAO) ischemia/reperfusion (I/R) was established, and the volume of cerebral infarction was assessed by TTC staining following computer analysis. The α-KGDHC activity was detected based on chemical reaction, to evaluate the change trend of α-KGDHC activity with cerebral ischemia time, and compare the difference between normal reperfusion group and adaptive reperfusion group; treatment of B35 and SH-SY5Y with CoCl2 to mimic cell hypoxia, and inhibition of α-KGDHC activity with E1K siRNA to detect the expression of apoptosis-related proteins Bcl-2/Bax/Caspase 3 by Western blot. RESULTS: In vivo experiments: In MCAO model, adaptive reperfusion further reduced cerebral infarction volume compared with normal reperfusion (P<0.05), and the expression of Caspase 3 was the lowest; α-KGDHC activity in cerebral cortex and hippocampal brain tissue decreased as ischemic time prolonged (P<0.05), and adaptive reperfusion inhibited the rate of decrease in α-KGDHC activity (P<0.05). In vitro experiments: Inhibiting α-KGDHC activity by interfering E1K expression led to downregulation of Bcl-2 (P<0.05) and upregulation of Bax (P<0.05) and Caspase 3 (P<0.05). CONCLUSION: α-KGDHC is an important factor in the protection of adaptive reperfusion after cerebral ischemia, and it may exert protective effect by inhibiting the activation of apoptotic pathways.

Key words: ischemia stroke, adaptive reperfusion, α-ketoglutarate dehydrogenase complex, apoptosis