成年犬自体骨髓基质干细胞经冠状动脉移植在心梗后心肌组织内分化

目的　探讨经冠状动脉移植成年犬自体骨髓基质干细胞在心梗后心肌组织内的存活、分化情况。方法　结扎犬冠状动脉前降支制备心肌梗死模型 ;细胞移植组将体外培养、诱导的自体骨髓基质干细胞标记后在心肌梗死后 4周经冠状动脉植入心脏 ;对照组植入等量培养基 ;细胞移植 4周后取犬心脏 ,行组织学检查、免疫组织化学检查及电镜检查。结果　细胞移植组植入骨髓基质干细胞在心肌组织内存活 ;免疫组织化学检查结蛋白、肌钙蛋白I染色阳性 ;电镜示心肌疤痕组织中可见胞浆丰富的异源性细胞 ,圆形或椭圆形 ,细胞体积较大 ,核糖体丰富 ,线粒体较丰富 ,有肌丝样结构 ,单核。对照组心脏标本中可见疤痕组织 ;心肌细胞结蛋白染色阴性 ,肌钙蛋白I染色阳性 ;电镜未发现异源性细胞。结论　成年犬骨髓基质干细胞经冠状动脉移植后在心肌组织内存活并分化为肌源性细胞。

Observation of Autologous Canine Bone Marrow Stromal Stem Cells Transplantation via Coronary Artery for Myocardial Infarction

Objective To observe the outcome of transplantation of autologous bone marrow stromal stem cells into myocardium via coronary artery in adult canine.Methods Acute myocardial infarction was induced by ligating the left anterior descending coronary arteries in adult canine. Bone marrow stromal cells aspirated from bone marrow were cultured and induced with 5_aza for 4 weeks. In experimental group cultured cells were transplanted into myocardium via coronary artery and in control group same volume of culture media was injected 4 weeks after myocardial infarction. Pathology, immunohistochemical and electron microscopy examination of heart specimen were carried out 4 weeks after cell transplantation. Results Implanted cells were viable in myocardial scar tissue in experimental group. Immunohistochemical study showed that Desmin and Tropponin I were positive in implanted cells. By electron microscopy,heterogeneous cells with myofilament structure were fownd in scar tissues of myocardium. However, there were no heterogeneous cells in myocardial scar tissues in control group. Immunohistochemical study showed that Desmin was negative and Troponin I was positive in myocardium in control group. Electron microscopy showed no heterogeneous cells in scar tissues of myocardium. Conclusions Adult canine marrow stromal stem cells survived and differentiated into myogenic cells in myocardial scar tissues after transplantation via coronary artery.