In vitro cardiomyogenic differentiation of adipose-derived stromal cells using transforming growth factor-beta1

Transplanting stem cells differentiated towards a cardiac lineage can regenerate cardiac muscle tissues to treat myocardial infarction. In this study, we tested the hypothesis that transforming growth factor-beta1 (TGF-beta1) induces cardiomyogenic differentiation of adipose- derived stromal cells (ADSCs) in vitro. Rat ADSCs were cultured with TGF-beta1 (10 ng ml(-1)) for 2 weeks in vitro. ADSCs cultured without TGF-beta1 served as a control. The mRNA expression of cardiac-specific gene was induced by TGF-beta1, while the control culture did not show cardiac-specific gene expression. Immunocytochemical analyses showed that a small fraction of ADSCs cultured with TGF-beta1 for 2 weeks stained positively for cardiac myosin heavy chain (MHC) and alpha-sarcomeric actin. Flow cytometric analyses showed that the proportion of cells expressing cardiac MHC increased with TGF-beta1. However, no mesenchymal differentiation (e.g., osteogenic and adipogenic differentiation) was detected other than cardiomyogenic differentiation. These results showed that TGF-beta1 induce ADSC cardiomyogenic differentiation in vitro, which could be useful for myocardial infarction stem cell therapy.