心肌球源性心肌干细胞联合心室肌细胞外基质治疗大鼠急性心肌梗死效果

目的拟研究心室肌细胞外基质（ECM）能否促进植入心肌梗死心肌组织内的心肌球源性心肌干细胞（CDC）向心肌细胞，血管内皮及血管平滑肌细胞分化，改善大鼠心肌梗死后的心脏结构及功能。方法心肌组织块培养法培养CDC，脱细胞法配置ECM，结扎Wistar 大鼠前降支建立急性心肌梗死模型。分别向心肌梗死心肌组织内注入IMDM（I 组），ECM悬液（E组），含106CDCs的IMDM溶液（IC 组），含106CDCs的ECM悬液（EC组），每组心肌梗死大鼠6 只。3 周后心脏彩超评估心脏功能，Masson染色分析心肌纤维化阳性面积百分比，免疫荧光定性分析CDC在体表达vWF，α-SA，α-SMA。结果心肌梗死3周后，EC组左室射血分数及短轴缩率（FS%）最高；EC组心肌梗死后心肌纤维化阳性面积百分比最低；EC组CDC向内皮，心肌及平滑肌细胞的分化阳性面积百分比较高，P<0.05。结论心肌组织源性的ECM能够促进植入心肌梗死组织内的CDC向心肌，内皮及平滑肌细胞分化。联合移植CDC及ECM能够取得最佳的心脏结构及功能上的益处。

Effect of implantation of cardiosphere-derived cells combined with rat heart tissue-derived extracellular matrix on acute myocardial infarction in rats

Objective To investigate whether heart tissue-derived extracellular matrix (ECM) promotes the differentiation of cardiosphere-derived cells (CDCs) implanted in rat infracted myocardium to improve the cardiac structure and function. Methods Rat CDCs were cultured by cardiac explant methods, and ECM was prepared by decelluariztion method. In a Wistar rat model of acute myocardial infarction established by ligating the left anterior descending branch, IMDM solution, ECM suspension, 106 CDCs in IMDM solution, or 106 CDCs in ECM suspension were injected into the infracted rat myocardium (6 rats in each group). The cardiac function of the rats was evaluated by cardiac ultrasonography, and the percentage of positive heart fibrosis area after infarction was determined with Masson staining. The differentiation of implanted CDCs in the infarcted myocardium was detected using immunofluorescence assay for the markers of cardiac muscle cells (α-SA), vascular endothelial cells (vWF) and smooth muscle cells (α-SMA). Results Three weeks after acute myocardial infarction, the rats with injection of CDCs in ECM showed the highest left ventricular ejection fraction (LVEF) and percentage of fraction shortening with the lowest percentage of positive heart fibrosis area; implantation of CDCs with ECM resulted in significantly higher rates of CDC differentiation into cardiac muscle cells, vascular endothelial cells and smooth muscle cell (P<0.05). Conclusion Heart-tissue derived ECM significantly promotes the differentiation of CDCs implanted in the infracted myocardium into cardiac muscle cells, vascular endothelial cells and smooth muscle cells to improve the cardiac structure and cardiac functions in rats.