Overexpression Of TIGAR Protects Hippocampal Neuron By Regulating Mitochondrial Fission In A Rat Model Of Hypoxia/Re-oxygenation Injury

Objective: To investigate the effect of TIGAR(TP-53 induced Glycolysis and Apoptosis Regulator)on mitochondrial fission in a rat hypoxia / re-oxygenation injury model of rat hippocampal neurons.Methods: Primary cultured hippocampal neurons obtained from newborn Wistar rats were randomly divided into 6 groups.N group: the hippocampal neurons were cultured in normal medium without any interference;H/R group: the hippocampal neurons were subjected to oxygen-glucose for 6h followed by re-oxygenation for 20h(OGD/R);LV-TIGAR group: the hippocampus neurons were co-cultured with lentivirus of TIGAR overexpression for 3~6 hours,followed by OGD/R;LV-GFP group: the hippocampus neurons were co-cultured with lentivirus of GFP for 3~6 hours,followed by OGD/R;LV-sh_TIGAR group: the hippocampus neurons were co-cultured with lentivirus silencing TIGAR for 3~6 hours,followed by OGD/R;LV-sh_scramble group: the hippocampus neurons were co-cultured with lentivirus silencing scramble gene for 3~6 hours,followed by OGD/R.ROS concentration was detected by Laser scanning confocal microscope.The apoptosis rate was tested by flow cytometry.The expression of TIGAR,apoptosis-inducing factor(AIF),dynamin-related protein 1(Drp1),fission 1(Fis1),and Rho-associated coiled-coil containing protein kinase(ROCK1)was measured by Western blotting.Results: Compared with the H/R group,TIGAR expression was up-regulated in the LV-TIGAR group,while TIGAR expression was decreased in the LV-sh_TIGAR group(P<0.05).The expression of TIGAR was not significantly increased in the LV-GFP group and the LV-sh_Scramble group(P>0.05).Compared with the N Group,intracellular ROS concentration,apoptosis rate,and the expression of mitochondrial division-related proteins AIF,Drp1,Fis1 and ROCK1 are increased in the H/R group,LV-TIGAR group,LV-GFP group,LV-sh_TIGAR group,and LV-sh_Scramble group(P<0.05).Compared with the H/R group,the intracellular ROS concentration,apoptosis rate,and the expression of mitochondrial division-related proteins AIF,Drp1,Fis1 and ROCK of the LV-TIGAR group were significantly decreased(P<0.05),the intracellular ROS concentration,apoptosis rate,and the expression of mitochondrial division-related proteins AIF,Drp1,Fis1 and ROCK in the LV-sh_TIGAR group were significantly higher(P<0.05),but there was no significant difference between LV-GFP group and LV-sh_Scramble group(P>0.05).Conclusion: In the hypoxia-reoxygenation model of hippocampal neurons,Overexpression of TIGAR can protect neurons by regulating mitochondrial fission.This may be related to the inhibition of ROS and calcium overload when TIGAR is overexpressed,and the reduction of mitochondrial-induced apoptosis pathway.