Abstract:

BACKGROUND: Studies have demonstrated that bone marrow mesenchymal stem cells promote the accumulation of a large number of myofibroblasts in the site of transplantation by paracrine action, secrete much collagen, which contributes to repair of myocardial infaction and improvement of cardiac systolic and diastolic function.
OBJECTIVE: To investigate the role of transforming growth factor β1 during transplantation of rat bone marrow mesenchynmal stem cells for repair of myocardial infarction.
METHODS: (1) In vitro experiments: rat bone marrow mesenchymal stem cells were cultured in simulated micro-environment of myocardial infarction. The levels of tumor necrosis factor α, platelet derived growth factor, and transforming growth factor β1 were detected. (2) In vivo experiments: BrdU-labeled rat bone marrow mesenchymal stem cells, transforming growth factor β1 and PBS were transplanted into the infracted myocardium. The difference of collagen Ⅰ, Ⅲ expression in rat myocardium post-transplantation was determined by immunohistochemical staining, PCR, western blot methods.
RESULTS AND CONCLUSION: After rat bone marrow mesenchymal stem cells were cultured in simulated micro-environment for 14 days, high level of transforming growth factor β1 could be detected. These findings suggest that transplantation of rat bone marrow mesenchymal stem cells into infarct myocardium can promote the generation of collagen Ⅰ, Ⅲ and improve rat cardiac systolic and diastolic function, and transforming growth factor β1 may play an important role.