Effect of transforming growth factor beta1 on the differentiation of bone marrow mesenchymal stem cells into cardiomyocyte-like cells in vitro

L Yang; Liu Bo; Wang Hai-ping

doi:10.3969/j.issn.2095-4344.2013.49.016

Abstract：BACKGROUND:Transforming growth factorβ1 is a cytokine that can regulate cellproliferation, differentiation, adhesion and apoptosis and have an important role in developmental biology and tissue repair process. <br> OBJECTIVE:To explore the differentiation of rat bone marrow mesenchymal stem cells into cardiomyocyte-like cells in vitro induced by transforming growth factor beta1. <br> METHODS:Bone marrow mesenchymal stem cells were isolated and cultured from the bone marrow of Sprague-Dawley rats. Then, passage 2 bone marrow mesenchymal stem cells were induced by transforming growth factor beta1. Bone marrow mesenchymal stem cells without induction served as controls. <br> RESULTS AND CONCLUSION:The morphology of bone marrow mesenchymal stem cells after induced by transforming growth factor beta1 for 7 days became larger and extended. Most of induced cells became long shuttle-shaped and paral eled, and a few arranged irregularly. After 14 days, most cells became rod-shape and touched with adjacent cells to form myotube-shape. Up to 28 days, the induced cells became smal er, showed fusiform shape and arranged tightly. After induced by transforming growth factor beta1 for 4 weeks, bone marrow mesenchymal stem cells could be identified by the positive staining for desmin, tropomyosin, connexin 43 and cardiac troponin I. The integral absorbance values in the induction group were significantly higher than those in the control group (al P<0.01). According to the positive rate of cardiac troponin I, the conversion rate of cardiomyocyte-like cells in the induction group was significantly higher than that in the control group (P=0.000). Immunofluorescence double-labeling assay showed that after induced by transforming growth factor beta1 for 4 weeks, desmin and cardiac troponin I proteins were localized in the cytoplasm and showed co-expression. Transmission electron microscope showed that the induced cells had a cardiomyocyte-like ultrastructure:a lot of mitochondria, rough endoplasmic reticula and ribosomes were founded in the cytoplasm, and paral eled myofilaments could be seen in the cytoplasm. It is indicated that bone marrow mesenchymal stem cells can differentiate into cardiomyocytes in vitro after induced by transforming growth factor beta1.