移植的间充质干细胞与宿主心肌匹配整合实验研究

目的 探索间充质干细胞(MSCs)分化的心肌样细胞与宿主心肌匹配的解剖结构基础.方法 采用成年近交系Wistar大鼠,经左冠状动脉前降支结扎1 h建立心肌缺血再灌模型.术后1周,将来自同种供体、经体外扩增和Rt-GFP转染MSCs后植入梗死区.移植后4周测定心脏功能.随后取材、连续冰冻切片,观察心肌组织形态学的变化及MSCs分化的心肌样细胞缝隙连接(Connexin-43)的表达.结果 植入梗死区中的MSCs表达Connexin-43.移植组梗死区面积缩小,左心室壁厚度增加,心脏功能改善.结论 移植的MSCs通过分化为心肌样细胞,并与宿主心肌细胞形成电机械匹配结构即缝隙连接(Connexin-43),使新增加的心肌细胞能够与宿主心肌同步收缩,从而更有效改善心脏功能.

Incorporation and integration of mesenchymal stem cell-derived myocardial cells into host cardiac myocytes: an experimental study in rats

OBJECTIVE: To investigate the anatomical bases for electrical coupling of mesenchymal stem cells (MSCs)-derived myocardial cells with host cardiac myocytes. METHODS: MSCs isolated from adult inbred Wistar rats were cultured and expanded in vitro and labeled with gree fluorescence protein (GFP). The model of acute myocardial infarction (AMI) was established in rats of the same species by occlusion of the left anterior descending arteries (LAD). One week after operation, 1.0x10(7) MSCs were injected into the infarcted area and 4 week after transplantation, the cardiac function of the recipient rats was evaluated. The heart tissues were taken after hemodynamic measurement for histological examination and morphometric measurement using image analysis system, and the expression of connexin-43 in the MSCs was detected by immunofluorescent cytochemistry. RESULTS: Four weeks after transplantation, the transplanted MSCs in the infarcted area showed significantly higher expression rate of connexin-43, and the cell transplantation resulted in decreased infarct size and thickening of the left ventricle wall. CONCLUSION: In a rat AMI model, MSCs differentiate into myocardial cells which can be integrated into host myocardial cells through formation of gap junction, resulting in effective improvement of the cardiac function.