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Morphological and electrophysiologic changes during differentiation of marrow-derived cardiac stem cells induced with bone morphogenetic protein-2 towards cardiomyocytes

WANG Xin-yan1, SUN Ying-gang2, YANG Zhi-fang1   

  1. 1.Department of Anatomy and Physiology, Shanghai Institute of Health Sciences, Shanghai 201318, China; 2.Department of Cardiovascular Diseases, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200092, China
  • Online:2013-07-28 Published:2013-08-22
  • Supported by:

    Shanghai College Young Teacher Cultivation Foundation

Abstract:

Objective To investigate the morphological changes, expression of cardiac specific protein and electrophysiologic changes of the marrow-derived cardiac stem cells (MCSCs) induced with bone morphogenetic protein-2 (BMP-2) during differentiation towards cardiomyocytes. Methods MCSCs were screened from the bone marrow of SD rats, cultured with 10 ng/mL BMP-2 for 24 h, and treated with DMEM containing 10% fetal bovine serum. The morphological changes of cells were observed with phase contrast microscope, and the expression of myocardium-specific protein cTnT of cells was detected with immunocytochemical staining. The ventricular cardiomyocytes of normal rats were served as controls. The action potential and L-type calcium ion current of cells were recorded with the whole cell patch clamp. Results After induction with BMP-2, the morphology and arrangement of MCSCs changed. Four weeks after induction, a few cells were conjunct to form the myotube-like structures, and cTnT exhibited dense and striation-like expression. Three weeks after induction, the action potential of the cells could be recorded, which was similar to that of the ventricular cardiomyocytes, while the plateau of the action potential of the cells was not obvious. Four weeks after induction, the plateau of the action potential was obvious, which was similar to that of the ventricular cardiomyocyte of adult rats. The L-type calcium ion current of the cells could be recorded three weeks after induction, while it was small. The L-type calcium ion current of the cells was increased four weeks after induction, the depolarizing potential was -40 mV, the peak activated potential was 0 mV, and the reversal potential was +60 mV, the characteristics of which were similar to those of ventricular cardiomyocytes of adult rats. Conclusion BMP-2 may induce MCSCs to differentiate into cardiomyocytes. The differentiated cells have the morphological and electrophysiological characteristics of the mature cardiomyocytes.

Key words: bone morphogenetic protein-2, marrow-derived cardiac stem cells, cTnT, action potential, L-type calcium ion current, rats