Adipose tissue derived mesenchymal stem cells are better respondents to TGFβ1 for in vitro generation of cardiomyocyte-like cells

Abstract

Mesenchymal stem cells (MSCs) are multipotent cells which hold immense potential in translational research as a novel treatment modality. In recent years, MSCs isolated from various tissues have been used in several clinical trials for the treatment of cardiac injury caused by permanent myocardial loss. However, a better MSCs source and an optimum inducer for in vitro cardiac differentiation are still far reaching and unexplored. The aim of the study was to compare the ability and efficiency of differentiation of MSCs isolated from bone marrow (BM-MSCs) and adipose tissue (ADSC) into cardiomyocyte-like cells to aid translational research. To fulfill this aim, freshly isolated BM-MSCs and ADSCs were differentiated into cardiomyocytes using 5-Azacytidine (6 μM) and TGF-β1 (25 ng/ml). These two differentiation protocols were compared on the basis of morphological, transcriptional, translational and functionality analysis. Both tissue specific MSCs, ADSCs and BM-MSCs, have similar surface marker profile and population doubling time. In both the treatment regimes, BM-MSCs and ADSCs showed morphological changes like flattening of cells and myotube formation in concurrence with structure and multinucleation, with early sign of differentiation in ADSCs. Further, the expression of cardiac specific markers including myosin light chain-2v (Mlc-2v), cardiac troponin I (cTnI), and sarco/endoplasmic reticulum Ca²⁺-ATPase (SerCa2) were higher in AD-TGFβ1 group, both at transcriptional and translational level. During functionality analysis by KCl stimulation, increased intracellular calcium fluorescence was observed in AD- TGFβ1 group as compared to others. Thus, ADSCs proved to be a better choice for stem cell therapy in cardiovascular diseases when induced with TGF-β1.

Keywords: 5-Azacytidine; Adult stem cells; Cardiomyocyte-like cells; Functionality; TGF-β1.