| Objective: To investigate the expressions and roles of microRNA-155,VEGF,KDR andCD31in focal cerebral ischemia/reperfusion injury of diabetic in rats.Methods:72male SD rats were randomly divided into3groups: the hyperglycemiacerebral ischemia/reperfusion group (HG group), the normal glucose cerebralischemia/reperfusion group (NG group) and the Sham operation group (Sham group).Thehyperglycemia model was made by intraperitoneal injection of streptozotocin (STZ) andthe cerebral ischemia-reperfusion model was developed by suture-occluded method．Thenthe scores of neurological deficit were estimated, the infarct size was measured by TTCstaining (triphenyltetrazolium chloride staining), the pathological changes were observedby HE staining, the cell apoptotic index of neurons were counted by the TUNEL(terminal-deoxyribonucleotidy transferase mediated dUTP nick end labeling) method andthe expressions of CD31were detected by immunohistochemistry staining, the expressionsof VEGF and KDR were detected by qPCR and western-blot technique in the cerebralischemia2h and reperfusion24h. The expressions of microRNA-155were detected byqPCR in the cerebral ischemia2h and reperfusion24h．Results:(1) The scores of neurological deficit:The scores of neurological deficit was3.83±0.31in HG group, was2.33±0.21in NG group,was0.00±0.00in Shamgroup.Compared with the Sham group,the scores of neurological deficit in HG and NGgroups were significantly higher(P＜0.05) and compared with NG group, the scores ofneurological deficit in HG group were higher significantly (P＜0.05).(2)The averageinfarct size: The infarct size was45.08±1.14in HG group, was26.21±1.37in NG groupand0.00±0.00in Sham group. Compared with the Sham group,the infarct size in HG and NG group were significantly higher(P＜0.05) and compared with NG group, the infarctsize in HG group was higher significantly(P＜0.05).(3)The cell apoptotic index of neurons:The cell apoptotic index of neurons was24.50±1.34in HG group, was13.00±0.37in NGgroup and2.50±0.56in Sham group.Compared with the Sham group,the cell apoptoticindex of neurons in HG and NG group were significantly higher(P＜0.05)and comparedwith the NG group, the cell apoptotic index of neurons in HG group was highersignificantly (P＜0.05).(4) Expressions of CD31: Expressions of CD31by immuno-histochemistry staining were20.83±1.40in HG group, were33.67±1.23in NG group and5.00±0.58in Sham group.Compared with the Sham group，the expressions of CD31in HGand NG group were significantly higher (P＜0.05)and compared with NG group, theexpressions of CD31in HG group were lower significantly (P＜0.05).(5) Expression ofVEGF:Relative expressions level of VEGF was analyzed by Real-time PCR were4.74±0.54in HG group,were6.71±0.91in NG group and1.33±0.09in Shamgroup.Compared with the Sham group，the relative mRNA expressions level of VEGF inHG and NG group were significantly higher (P＜0.05)and compared with NG group, therelative mRNA expressions of VEGF in HG group were lower significantly (P＜0.05).Relative protein expression level of VEGF was analyzed by western-blot technique were0.99±0.13in HG group,were1.55±0.23in NG group and0.36±0.04in Shamgroup.Compared with the Sham group,the relative expressions of VEGF in HG and NGgroup were significantly higher (P＜0.05)and compared with NG group,the relativeexpressions of VEGF in HG group were lower significantly (P＜0.05).(6)Expression ofKDR:Relative expressions level of KDR were analyzed by Real-time PCR were4.06±0.60in HG group,were6.16±0.96in NG group and1.33±0.09in Sham group.Compared withthe Sham group,the relative mRNA expressions level of KDR in HG and NG group weresignificantly higher (P＜0.05)and compared with NG group,the relative mRNAexpressions of KDR in HG group were lower significantly (P＜0.05). Relative proteinexpression level of KDR were analyzed by western-blot technique were0.28±0.01in HGgroup, were0.58±0.08in NG group and0.13±0.03in Sham group．Compared with the Sham group,the relative expressions of KDR in HG and NG group were significantlyhigher (P＜0.05)and compared with NG group,the relative expressions of KDR in HGgroup were lower significantly (P＜0.05).(8)Expressions of microRNA-155: Relativeexpressions level of microRNA-155was analyzed by Real-time PCR were9.38±0.69inHG group,were5.67±0.52in NG group and1.36±0.07in Sham group.Compared with theSham group,the expressions of microRNA-155in HG and NG group were significantlyhigher(P＜0.05)and compared with NG group, the expressions of miR-155in HG groupwere higher significantly (P＜0.05).Conclusion:1. The VEGF signaling pathway participate in the pathology of the diabetes-aggravated cerebral ischemia reperfusion injury and the lower expression of VEGF andKDR may play important roles in that diabetes increased cerebral ischemic reperfusioninjury;2. microRNA-155may be involved in the pathology of the diabetes-aggravatedcerebral ischemia reperfusion injury and play important roles in the regulation ofangiogenesis. |
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