神经干细胞移植对脑缺血再灌注损伤大鼠CXC趋化因子1和2及其趋化因子受体2表达的影响

目的探讨神经干细胞(NSCs)移植对大鼠脑缺血再灌注损伤梗死区CXC趋化因子1(CXCL1)和CXC趋化因子2(CXCL2)及CXC趋化因子受体2(CXCR2)表达的影响。方法线栓法制作大鼠大脑中动脉缺血2 h再灌注模型,实验动物随机分为假手术组、模型组和NSCs组。NSCs组尾静脉注射PKH26标志的NSCs细胞悬液,缺血72 h后行神经功能损害评分(NSS),2,3,5-氯化三苯基四氮唑(TTC)法检测脑梗死体积,苏木精-伊红(HE)染色观察梗死区病理变化,Western blot和实时荧光定量聚合酶链反应(PCR)检测梗死区CXCL1、CXCL2、CXCR2蛋白和mRNA表达。结果脑缺血后72 h,模型组和NSCs组NSS评分和脑梗死体积高于假手术组(P<0.05);NSCs组NSS评分和脑梗死体积低于模型组(P<0.05)。HE染色可见模型组梗死区大量炎性细胞浸润,而NSCs组梗死区炎性细胞浸润较少;NSCs组在梗死区有红色荧光信号表达,而假手术组和模型组未发现红色荧光信号。模型组CXCL1、CXCL2、CX-CR2蛋白和mRNA相对表达高于假手术组(P<0.05);NSCs组CXCL1、CXCL2、CXCR2蛋白和mRNA相对表达低于模型组(P<0.05)。结论 NSCs移植具有促进脑缺血损伤神经功能恢复和减少脑梗死体积的作用,其机制可能与其下调炎症趋化因子CXCL1、CXCL2及其受体CXCR2表达、进而抑制炎症反应有关。

Effects of neural stem cells transplantation on the expression of CXC chemokine ligand 1,2 and CXC chemokine receptor 2 after cerebral ischemia reperfusion in rats

Objective To investigate the effects of transplantation of neural stem cells(NSCs) on expressions of chemotatic factors CXC chemokine ligand 1(CXCL1),CXC chemokine ligand 2(CXCL2) and CXC chemokine receptor 2(CXCR2) in infarction region after cerebral ischemia reperfusion in rats.Methods The rat model of middle cerebral artery occlusion 2 hours reperfusion was established by line switch method.Rats were randomly divided into sham operation group,model group and NSCs group.NSCs suspension were marked with PKH26 and infused into the caudal vein in the NSCs group.After 72 hours reperfusion,the neurological function was investigated by neurological severity scores(NSS) method,volume of cerebral infarction was investigated by 2,3,5-triphenyltetrazolium chloride(TTC) staining,the pathological change of infarction region was studied by hematoxylin and eosin(HE) staining,the expressions of CXCL1,CXCL2 and CXCR2 in infarction region were detected by using Western blot and real-time fluorescence quantitative polymerase chain reaction(PCR).Results After 72 hours cerebral ischemia,compared with sham operation group,the NSS scores and volume of cerebral infarction were increased in model group and NSCs group(P<0.05);and those in NSCs group were lower than in model group(P<0.05).There were a large of inflammatory cells infiltration in infarction region in model group,but infiltrations of inflammatory cells were reduced in NSCs group by HE staining.Red fluorescence signals were observed in infarction area in NSCs group,however,no red fluorescence signals was found in sham operation group and model group.Compared with sham operation group,the protein and mRNA expressions of CXCL1,CXCL2 and CXCR2 were significantly enhanced in model group(P<0.05).Compared with model group,the protein and mRNA expressions of CXCL1,CXCL2 and CXCR2 in NSCs group were significantly decreased(P<0.05).Conclusion NSCs transplantation could promote cerebral ischemia injury neurological recovery and reduce cerebral infarction volume,which may be related to down-regulating the expressions of CXCL1,CXCL2 and CXCR2 in infarction area,and restrain the inflammatory response.