Icariin-mediated differentiation of mouse adipose-derived stem cells into cardiomyocytes

In this study, we investigated the ability of mouse adipose-derived stem cells (ADSCs) to differentiate into a cardiac phenotype in vitro. Icariin (ICA) has previously been shown to induce cardiomyocyte (CM) differentiation of murine embryonic stem cells in vitro, but its effect on ADSCs remains unclear. We isolated ADSCs from white adipose tissue and analyzed selected surface antigens using flow cytometry. ADSCs and CMs were co-cultured in transwell plates, with or without the addition of either ICA or ICA plus the extracellular signal-regulated kinase (ERK) inhibitor PD98059. Cardiac-specific gene expression was examined by reverse transcription-polymerase chain reaction and western blotting. ICA facilitated differentiation of ADSCs into CMs that expressed cardiac-specific genes, including the transcription factors NKX-2.5, GATA-4, MLC-2v, alpha-actinin, and cardiac troponin-T. Expression of alpha-actinin, the Z band-constituting protein, was promoted by ICA in a dose- and time-dependent manner. ICA can induce ERK activation and cardiac-specific gene expression was partially inhibited by PD98059 after treatment with ICA. These results suggest that ICA-stimulated CM differentiation of ADSCs, and that it acted partially by activating ERK-dependent signaling pathways in vitro.