Cardiac Differentiation of Adipose Tissue-Derived Stem Cells Is Driven by BMP4 and bFGF but Counteracted by 5-Azacytidine and Valproic Acid

Document Type : Original Article

Authors

1 Department of Stem Cells and Regenerative Medicine, Institute for Medical Biotechnology, National Institute of Genetic Engineering tyand Biotechnology (NIGEB), Tehran, Iran;Department of Biology, Faculty of Science, University of

2 Department of Stem Cells and Regenerative Medicine, Institute for Medical Biotechnology, National Institute of Genetic Engineering tyand Biotechnology (NIGEB), Tehran, Iran

3 Department of Biology, Faculty of Science, University of Mohaghegh Ardabili, Ardabil, Iran

Abstract

Objective
Bone morphogenetic protein 4 (BMP4) and basic fibroblast growth factor (bFGF) play important roles in embryonic heart development. Also, two epigenetic modifying molecules, 5ˊ-azacytidine (5ˊ-Aza) and valproic acid (VPA) induce cardiomyogenesis in the infarcted heart. In this study, we first evaluated the role of BMP4 and bFGF in cardiac trans-differentiation and then the effectiveness of 5´-Aza and VPA in reprogramming and cardiac differentiation of human adipose tissue-derived stem cells (ADSCs).
Materials and Methods
In this experimental study, human ADSCs were isolated by collagenase I digestion. For cardiac differentiation, third to fifth-passaged ADSCs were treated with BMP4 alone or a combination of BMP4 and bFGF with or without 5ˊ-Aza and VPA pre-treatment. After 21 days, the expression of cardiac-specific markers was evaluated by reverse transcription polymerase chain reaction (RT-PCR), quantitative real-time PCR, immunocytochemistry, flow cytometry and western blot analyses.
Results
BMP4 and more prominently a combination of BMP4 and bFGF induced cardiac differentiation of human ADSCs. Epigenetic modification of the ADSCs by 5ˊ-Aza and VPA significantly upregulated the expression of OCT4A, SOX2, NANOG, Brachyury/T and GATA4 but downregulated GSC and NES mRNAs. Furthermore, pre-treatment with 5ˊ-Aza and VPA upregulated the expression of TBX5, ANF, CX43 and CXCR4 mRNAs in three-week differentiated ADSCs but downregulated the expression of some cardiac-specific genes and decreased the population of cardiac troponin I-expressing cells.
Conclusion
Our findings demonstrated the inductive role of BMP4 and especially BMP4 and bFGF combination in cardiac trans-differentiation of human ADSCs. Treatment with 5ˊ-Aza and VPA reprogrammed ADSCs toward a more pluripotent state and increased tendency of the ADSCs for mesodermal differentiation. Although pre-treatment with 5ˊ-Aza and VPA counteracted the cardiogenic effects of BMP4 and bFGF, it may be in favor of migration, engraftment and survival of the ADSCs after transplantation.

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