不同方法诱导的骨髓间充质干细胞移植修复大鼠梗死心肌

目的 探讨将不同方法诱导的骨髓间充质干细胞（MSCs）移植到心肌梗死部位后对梗死心肌的修复作用。方法 自成年大鼠骨髓中分离MSCs，分别以下列方式诱导：A组，用心肌细胞裂解液培养7d后移植；B组，MSCs与心肌细胞按1：4的比例共同培养7d后移植；C组，用5-氮杂胞苷（10μmol／L）诱导24h后，换DMEM培养液培养21d后移植；D组（对照组），用DMEM培养液培养21d后移植。建立大鼠心肌梗死模型，将上述4组MSCs进行DAPI标记后移植于梗死部位。用超声心动图检测移植前和移植30d后心肌功能的改变，苏木精-伊红染色观察移植细胞形态。结果 A、B组移植后大鼠左室舒张末期内径（LVEDD）和收缩末期内径（LVESD）比移植前减小，A、B、C组左室收缩功能指标射血分数（EF）和短轴缩短率（FS）明显比移植前改善。D组移植前后大鼠各指标差异无显著性意义。A、B组移植后镜下可见DAPI标记的MSCs表现为成熟细胞形态，排列在残存的宿主心肌细胞之间，具备与宿主心肌细胞相似排列方向和形态学的特征。C、D组移植后镜下也可见到DAPI标记的细胞，但与宿主心肌细胞形态不同，小部分为成熟心肌细胞形态，大部分为成纤维细胞形态。结论 用与心肌细胞共培养和用心肌细胞裂解液培养两种方法诱导的MSCs移植于心肌梗死部位后，分化为心肌样细胞的效率高，模型鼠心功能恢复显著。

Repair of Infarct Cardiocytes by Transplantation of Bone Marrow Mesenchymal Stem Cells Induced by Different Methods in Rats

Objective To investigate the repair of infarct cardiocytes by transplantation of bone marrow mesenchymal stem cells(MSCs) induced by different methods.Methods MSCs were isolated from bone marrow of adult rats and induced by the following methods:In group A,MSCs were cultured with cardiocyte-lysate medium for 7 days and then transplanted;In group B,MSCs were co-cultured with cardiocytes in a ratio of 1:4 for 7 days and then transplanted;In group C,after induction with 5-azacytidine for 24 h,MSCs were cultured with DMEM medium for 21 days and then transplanted;In group D(control group),the MSCs were cultured with DMEM medium for 21 days and then transplanted.After establishment of myocardial infarction model in rats,the MSCs from the above 4 groups were labeled with DAPI and transplanted into the infarct region.The changes in myocardial functions before and 30 days after transplantation were evaluated by echocardiography and the morphology of the transplanted cells were observed by HE staining.Results Left ventricular end diastolic diameter(LVEDD),left ventricular end systolic diameter(LVESD) in groups A and B after transplantation of MSCs were reduced as compared with those before transplantation of MSCs,and left ventricular systolic function indexes(including EF,FS) in groups A,B and C were significantly improved.However,there was no significant difference in the above indexes before and after transplantation of MSCs in group D.Under the microscopy,the DAPI-labeled MSCs displayed mature cellular morphology and arranged among the residual host cardiocytes,having the similar arrangement and morphology to the host cardiocytes in groups A and B.In groups C and D,although the DAPI-labeled MSCs could be observed after the transplantation of MSCs under the microscopy,they were different from the morphology of the host cardiocytes.Conclusion The differentiation efficacy of MSCs cocultured with cardiocytes or cultured with cardiocyte-lysate system to cardiocytes was high and the recovery of myocardial function after transplantation of MSCs was significant.