Antiapoptotic Effect of Gene Therapy with Recombinant Adenovirus Vector Containing Hypoxia-inducible Factor-1α after Cerebral Ischemia and Reperfusion in Rats

摘要

Background:Mounting evidence has demonstrated that hypoxia-inducible factor-1α (HIF-1α) could attenuate brain injuries after cerebral ischemia and reperfusion (CIR).However,few reports have addressed the therapeutic efficacies of a recombinant adenovirus vector containing HIF-1o (AdHIF-1o) gene after ischemia and reperfusion.The aim of this study was to examine the antiapoptotic and neuroprotective effects ofAdHIF-1o gene for cerebral injuries after ischemia and reperfusion in rats.Methods:From February to December 2016,male Sprague-Dawley rats were randomly divided into normal,sham,CIR,AdHIF-1α,and recombinant adenovirus (Ad) groups.Middle cerebral artery occlusion model was established by Longa's method and reperfusion resumed at 2 h postocclusion.AdHIF-1α solution,Ad solution,and phosphate-buffered saline were injected into the right lateral ventricle of rats in AdHIF-lα,Ad,and CIR groups.Brain tissue sections were observed under fluorescent microscope to confirm the definite expression of recombinant adenovirus in Ad and AdHIF-1o groups.The expressions of HIF-lα protein were analyzed by immunohistochemical staining at 6 h,24 h,and 72 h postreperfusion.Brain water content and neurological deficit scores were evaluated at 6 h,24 h,and 72 h postreperfusion.Pathological brain injuries were examined after hematoxylin and eosin stain and nerve cell apoptosis was measured after terminal-deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) stain at 72 h postreperfusion.Comparisons were conducted with one-way analysis of variance by post hoc Scheffe's test among different experimental groups.Results:Green fluorescent protein was successfully expressed in brain tissue ofAd andAdHIF-1α groups from 24 h to 21 days postinjection.As detected by immunohistochemical staining,the expressions of HIF-lα protein were obviously enhanced in AdHIF-1o group than those in CIR and Ad groups at 24 h and 72 h postreperfusion,respectively.There were significant reductions of brain water content (78.83％ ± 0.34％ vs.83.21％ ± 0.50％ and 83.35％ ± 0.32％;84.13％ ± 0.24％ vs.89.76％ ± 0.34％ and 89.70％ ± 0.18％;respectively;all P ＜ 0.05) and neurological deficit scores (2.90 ± 0.74 vs.3.50 ± 0.52 and 3.60 ± 0.53 at 24 h;2.40 ± 0.84 vs.3.60 ± 0.52 and 3.50 ± 0.53 at 72 h;respectively;all P ＜ 0.05) in AdHIF-1 α group versus CIR and Ad groups at 24 h and 72 h postreperfusion,respectively.The pathologic changes ofAdHIF-1 α group were milder than those in CIR and Ad groups at 72 h postreperfusion.The percentage of TUNEL-positive cells in cerebral subcortex decreased significantly in AdHIF-1α group versus CIR and Ad groups at 72 h postreperfusion (P ＜ 0.05).Conclusion:AdHIF-1α has an obvious neuroprotective effect on ischemia and reperfusion in rat brains possibly through inhibiting the apoptosis of nerve cells.