骨髓基质干细胞移植对缺血性卒中大鼠PSD-95表达的影响

目的 应用骨髓基质干细胞（BMSCs）治疗缺血性卒中大鼠,观察BMSCs的治疗效果,检测突触后密度蛋白-95（PSD-95）的表达水平,进而研究BMSCs治疗缺血性卒中的机制.方法 将40只成年雌性SD大鼠制备成大脑中动脉缺血2h再灌注24h动物模型,随机分为梗死对照组和BMSCs组,每组20只.每组再按梗死后3,7d分为2个亚组,每组10只.梗死对照组于缺血再灌注24 h后经尾静脉注射PBS液1ml,BMSCs组同时经尾静脉注射BMSCs 3×106.所有大鼠于梗死后1,3,7d分别进行神经功能评分,应用免疫组化法测定PSD-95表达水平,用TUNEL测定凋亡细胞水平.结果 （1）神经功能评分：梗死后3,7 d BMSCs组神经功能评分明显低于梗死对照组,差异有统计学意义（t分别为2.138,3.417;P＜0.05）.（2） PSD-95表达：BMSCs组在梗死后3d时PSD-95表达较梗死对照组的表达有增多,但差异无统计学意义;BMSCs组在梗死后7d时PSD-95表达明显多于梗死对照组,且差异有统计学意义（t=6.013,P＜0.05）.（3）TUNEL细胞凋亡染色：梗死后3d时梗死对照组大鼠缺血侧可见许多凋亡细胞,显多于BMSCs组,且差异有统计学意义（t=4.978,P＜ 0.05）.结论 BMSCs移植能促进缺血性卒中大鼠的神经功能的恢复.BMSCs移植后能明显增加缺血性卒中大鼠PSD-95的表达,减少细胞的凋亡,对缺血性卒中有保护作用.

Expression of PSD-95 in rats with ischemic stroke treated by bone marrow stromal stem cells

Objective We applied the bone marrow stromal stem cells （BMSCs） to treat rats with ischemic stroke,observed the therapeutic effect while detecting the expression level of PSD-95,and then studied the mechanism of BMSCs to treat ischemic stroke.Methods SD female rats （n =40） were subjected to 2-hour middle cerebral artery occlusion and randomly divided into two groups：control group （n =20） and BMSCs group （n =20）.The groups were divided into two subgroups （n =10） again,according to 3 days and 7 days after reperfusion.Control group：at 24 h after MCAO intravenous injection PBS 1ml.BMSCs group：at 24 h after MCAO intravenous injection BMSCs （3 × 106）.Modified Neurological Severity Scores（mNSS） was performed to examine neurological function on 1 day,3 days and 7 days after reperfusion.Immunohistochemistry of brain sections was used to identify PSD-95 expression level; TUNEL staining was performed to examine cellular apoptosis.Results （1）Scores of neurological function：Neurological function scores of BMSCs groups were lower than control group on 3rd and 7th days after reperfusion （t =2.138,3.417,respectively; P ＜ 0.05）.（2）PSD-95 immunohistochemistry：Compared with infarction control group,the expression of PSD-95 in BMSCs group increased on the 3rd day after reperfusion in the ischemic zone,but had no statistical significance （P ＞ 0.05）.The expression of PSD-95 in BMSCs group was more than infarction control group on the 7th day after reperfusion in the ischemic zone and had statistical significance （t =6.013,P ＜ 0.05）.（3）Apoptosis detection by TUNEL staining：The infarction control group displayed more significant TUNEL-positive cells than BMSCs group on 3rd day （t =4.978,P ＜ 0.05）.Conclusions Transplantation of BMSCs can promote the recovery of neurological function in MCAO rats.The BMSCs treatment can obviously increase the expression of PSD-95 in rats with ischemic stroke,reduce the apoptosis of cells and protect the ischemia brain tissue.