Electrophysiological characteristics of cardiomyocyte-like cells from rat bone marrow derived mesenchymal stem cells by four inductors.

Background: Bone marrow derived mesenchymal stem cells (BMdMSCs) can differentiate into cardiomyocyte-like cells induced by different inductors individually or collectively. In this study, by inducing BMdMSCs with p53 inhibitor (p-fifty three inhibitor-alpha, PFT-α), 5-azacytidine (5-AZA), angiotensin-II (Ang-II) and bone morphogenic protein-2 (BMP-2) we compared the influences of four inductors on the differentiation of rat BMdMSCs into caridomyocyte like-cells.

Methods: BMdMSCs were collected from the bone marrow of Sprague Dawley rats and after the fourth generation, the purified cells were divided into five groups: 5-AZA (10 µmol/L), Ang-II (0.1 µmol/L), PFT-α (20 µmol/L), BMP-2 (10 µg/L) and control. The purity of the BMdMSCs and the cardiac differentiation rates were obtained by flow cytometry. The expressions of cTnT in the BMdMSCs after four weeks of induction were detected by immunofluorescence and the expressions of cTnI and Cx43 detected by Western blotting. The green fluorescent levels reflecting intracellular calcium transient function were determined by laser scanning confocal microscopy. The total potassium current levels of cells were measured on patch clamp.

Results: All inductors affected to a different degree the differentiation of BMdMSCs into cardiomyocyte-like cells and the expressions of cTnT, cTnI and Cx43 suggesting that the combination of inductors could be an improved method for cardiac regenerative medicine. In addition, the total potassium current level and calcium transient in PFT-α cardiomyocyte-like cells were higher than other groups.

Conclusions: The cardiac differentiation of BMdMSCs induced by PFT-α, 5-AZA, Ang-II and BMP-2 has been improved at different levels. PFT-α has an advantage of differentiation rate and electrophysiological function over other inductors.