The Effects Of Inhibition Of AMPK Activity On The Morphology And Function Of Microglia After Cerebral Ischemia/Reperfusion Injury In Mice

Objective: To observe the effects of Compound C, an AMPK inhibition, on themorphology and function of microglia after cerebral ischemia/reperfusion injury in mice,to explain the neuroprotection mechanism of inhibiting AMPK activity. Methods：Seventy-two male kunming mice were randomly divided into sham group、saline groupand Compound C treated group (24mice for each group). Kunming mice were subjectedto middle cerebral artery occlusion (MCAO). Each mouse in Compound C treated groupand saline group was respectively intraperitoneal inject with the AMPK inhibitorcompound C (20mg/kg) and equal volume of0.9%saline affter occlusion, and in the shamgroup nothing was injected. The neurological deficit was evaluated at24h reperfusion inevery group. After cerebral ischemia/reperfusion for24h, the infarct volume was observedby TTC staining, the pathology variety was observed by HE staining, the expression ofmicroglia-specific Iba1and iNOS was detected by immunohistochemistry, and theexpression of nicotinamide adenine dinucleotide phosphate oxidase2mRNA wasdetermined by RT-PCR. Results: After cerebral ischemia/reperfusion for24h, comparedwith the saline group, neurological deficit and infarct volume was decreased significantlyin Compound C treated group（P﹤0.05）, and nerve injury was significantly attenuated incortical area.Immunocytochemistry staining revealed Iba1-positive microglia weredetected at the cortical area in sham group, The number of Iba1-positive microglia wasincrease significantly after cerebral ischemia/reperfusion for24h（P﹤0.05）, comparedwith the saline group, Iba1-positive microglia wae significantly reduced in Compound Ctreated group（P﹤0.05）. iNOS-positive cells were detected at the cortical area in shamgroup, The number of iNOS-positive cells was significantly increased in saline group（P﹤0.05）,compared with the saline group, the number of iNOS-positive cells wassignificantly reduced in the Compound C treated group（P﹤0.05）. RT-PCR analysisshowed that the expression of gp91phoxmRNA in sham group,The expression of gp91phoxmRNA significantly increased after cerebral ischemia/reperfusion for24h(P﹤0.01), compared with the saline group,the expression of gp91phoxmRNA was reduced inCompound C treated group, but these differences were not statistically significant（P=0.15）.Conclusion: Compound C, an AMPK inhibition, could have someneuroprotection effects in the brain ischemia/reperfusion of mice. Its mechanism maybecome effective through inhibition the active microglia and reduce the expression ofiNOS and gp91phox.