LAUSR

OBJECTIVE To explore the role of microvesicles (MVs) containing microRNA-21 in myocardial fibrosis and their underlying mechanism. MATERIALS AND METHODS Myocardial ischemia rat model was first constructed for collecting myocardial tissues. Myocardial fibrosis-related indicators and microRNA-21 expression in myocardial tissues of ischemia rats were detected. After in vitro primary rat cardiomyocytes were treated with TGF-β1, myocardial fibrosis-related indicators and microRNA-21 expression in primary rat cardiomyocytes were also detected. Furthermore, AKT (protein kinase B) pathway-related genes were detected by Western blot. Rescue experiments were performed after primary rat cardiomyocytes were transfected with a microRNA-21 inhibitor. RESULTS MVs containing microRNA-21 were overexpressed during the process of myocardial fibrosis. AKT pathway was remarkably activated after TGF-β1 treatment in cardiomyocytes. Meanwhile, myocardial fibrosis was significantly alleviated after microRNA-21 expression was inhibited. CONCLUSIONS Overexpressed MVs containing microRNA-21 promoted myocardial fibrosis via AKT pathway.