miR-29b1对iPSC来源的心肌细胞在心肌梗死区移动的机制研究

Despite recent advances in pharmacological and surgical approaches to rescue ischemic myocardium, ischemic heart disease remains the leading cause of heart failure and death. Myocardial fibrosis, a key contributor to cardiac dysfunction after myocardial infarction (MI), presents as a secondary response to the pathophysiologic remodeling of longstanding coronary artery disease including ischemia, obstruction, and microvascular abnormalities. iPSC( induced pluripotent stem cell )is an ideal donor cells for tissue repair and replacement therapy. Our early research show that a tricell patch (Tri-P) created from peritoneum seeded and cultured with induced pluripotent stem cell-derived cardiomyocytes, endothelial cells, and mouse embryonic fibroblasts, applied over to repair scarred myocardium. MiR-29b1 involved in myocardial fibrosis after myocardial infarction. MiR-29b1 expression is different in different areas in the early phase of AMI.But the mechanism of iPSC how to move from patch to the infarcted zone remains unclear. Therefore, in this project, we will use lentiviral vectors containing the NCX1 promoter to transfect iPSC and use flow cytometry sorting technology to purify the myocardial cells from iPSC. To observe the iPSC-derived progenitor cell engraftment in mice with acute myocardial infarction, BLI and immunohistochemistry will be performed together. The mechanism of the the role of miR-29b1 on iPSC-derived myocardial cells will be clarify by using vitro experiments and vivo experiments in myocardial infarction area. The results of this project will provide a new target for the cell-patch with iPSC repair of acute myocardial infarction and a theoretical basis and experimental basis for the treatment of acute myocardial infarction in clinical.

心肌梗死目前治疗不能使心肌再生，结果是梗死区心肌纤维组织增生并引起心肌重构。诱导多能干细胞（iPSC）是组织修复和替代治疗的理想供体细胞。我们课题组之前研究发现干细胞生物膜补片贴附在心肌梗死表面修复梗死心肌具有良好效果，miR-29b1参与了心梗后心肌纤维化调节，并且在心梗区及非梗死区表达有明显差异。但干细胞如何向梗死区域移动的机制仍不清楚。因此，本项目首先使用含有NCX1启动子的慢病毒载体转染iPSC并应用流式细胞分选技术纯化iPSC来源的心肌细胞，通过活体生物发光技术及免疫组化的方法观察生物膜补片联合iPSC对小鼠急性心肌梗死的修复作用，并通过体外细胞实验及活体实验阐明miR29b1对梗死区胶原合成的影响及对iPSC来源的心肌细胞在心肌梗死区域移动作用的机制。本项目的研究成果将为生物膜补片联合iPSC对急性心肌梗死修复作用提供理论依据和实验基础，为临床上急性心肌梗死的治疗提供新的靶点。

心肌梗死目前治疗不能使心肌再生，其结果是梗死区心肌纤维组织增生并引起心肌重构。iPSC是进行组织修复和替代治疗的理想供体细胞。我们课题组之前研究发现干细胞生物膜补片贴附在心肌梗死表面修复梗死心肌具有良好效果，但干细胞如何向梗死区域移动的机制仍不清楚。miR-29b1参与了心梗后心肌纤维化调节。因此，本项目首先通过使用含有NCX1启动子的慢病毒载体转染iPSC并应用流式细胞分选技术纯化iPSC来源的心肌细胞，通过活体生物发光技术及免疫组化的方法观察生物膜补片联合iPSC对小鼠急性心肌梗死的修复作用，并通过体外细胞实验及活体实验阐明miR29b1对iPSC来源的心肌细胞在心肌梗死区域移动作用机制。本研究有三个主要的研究发现:.1)miR-29b的过度表达,通过阻断p42/44 MAPK-MRTF信号通路，抑制心肌成纤维细胞形成并减少胶原蛋白合成。.2) miR-29b过表达后在心肌梗死瘢痕组织中能减少胶原蛋白沉积，促进iPSCNCX1+ 从补片中进入入梗塞区域，从而使MI后左室功能恢复。.3)过表达miR-29b能促进的补片中新血管的形成，而这些血管能和原有冠脉循环相连接,形成侧枝循环网。.本项目的研究成果将为生物膜补片联合iPSC对急性心肌梗死修复作用提供理论依据和实验基础，为临床上急性心肌梗死的治疗提供新的靶点。