Transcription factors GATA4 and TBX5 promote cardiomyogenic differentiation of rat bone marrow mesenchymal stromal cells.

Bone marrow mesenchymal stromal cells (BMSCs) have potential applications in cell and gene therapies for cardiac disease. The cardiac-specific transcription factors GATA-binding protein 4 (GATA4) and T-Box protein 5 (TBX5) are considered to be pivotal in cardiogenesis. The aim of this study was to investigate the effects of GATA4 and TBX5 on cardiomyogenic differentiation of BMSCs. The BMSCs were initially isolated and identified. Vectors harboring cardiac transcription factor genes GATA4 and TBX5 or empty vectors were transferred into BMSCs. Cardiomyogenic cells differentiated from BMSCs were identified by expression of cardiac-specific markers including cardiac troponin T, connexin 43, β-myosin heavy chain, and myosin light chain-2 using immunocytochemical staining, western blotting, and quantitative real-time PCR. The ultrastructures of the differentiated cells were examined by transmission electron microscopy, which were similar to those of fetal cardiomyocytes. The differentiated cells exhibited L-type calcium current activities reflective of the electrophysiological characteristics of cardiomyocytes. These findings indicate that exogenous expression of cardiac-specific transcription factors GATA4 and TBX5 enhance cardiomyogenic differentiation of BMSCs.