Overexpression of MicroRNA-1 improves the efficacy of mesenchymal stem cell transplantation after myocardial infarction.

Background: The aim of this research was to study whether transplantation of mesenchymal stem cells (MSCs) overexpressing microRNA-1 into mouse infarcted myocardium can enhance cardiac myocyte differentiation and improve cardiac function efficiently.

Methods: Eight-week-old female C57BL/6 mice underwent ligation of the left coronary artery to produce models of myocardial infarction. The ligated animals were randomly divided into 4 groups (20 in each). One week later, they were intramyocardially injected at the heart infarcted zone with microRNA-1-transduced MSCs (MSC(miR-1) group), mock-vector-transduced MSCs (MSC(null) group), MSCs (MSC group) or medium (PBS group). At 4 weeks post-transplantation, transthoracic echocardiographic assessment, histological evaluation and Western blot were performed.

Results: The transplanted MSCs were able to differentiate into cardiomyocytes in the infarcted zone. Cardiac function in the MSC, MSC(null) and MSC(miR-1) groups was significantly improved compared to the PBS group (p < 0.01 or p < 0.001). However, treatment of MSCs expressing microRNA-1 was more effective for cardiac repair and improved cardiac function more efficiently by enhancing cell survival and cardiac myocyte differentiation compared to the MSC group or the MSC(null) groups (p < 0.05 or p < 0.01, respectively).

Conclusions: Transplantation of microRNA-1-transfected MSCs was more conducive to repair of infarct injury and improved heart function by enhancing transplanted cells survival and cardiomyogenic differentiation.