Icariin Promotes In Vitro Cardiomyocyte Proliferation and Differentiation in Human Bone Marrow-Derived Mesenchymal Stem Cells

Mesenchymal stem cells (MSCs) are the excellent candidates in myocardial regeneration given their easy accessibility, low immunogenicity and high potential for cardiomyocyte differentiation. This work focused on investigating the role of icariin, a main active component of the Traditional Chinese herb epimedium, in human bone marrow-derived MSCs (BMSCs) proliferation and differentiation into cardiomyocytes in vitro, Human BMSCs were cultivated in vitro, and MTT assay was conducted to measure their proliferation. On this basis, we selected the optimal icariin dose for promoting the proliferation to induce cardiomyocyte differentiation of MSCs, which were pretreated with or without 5-azacytidine (5-Aza). Cardiac-specific cardiac troponin I (cTnl) and connexin 43 (Cx43)-positive cells were detected by immunofluorescent staining. The differentiation ratio of MSCs was examined by flow cytometry. This study measured early cardiac transcription factors (TPS) Nkx2.5 and GATA4 levels through RT-PCR and Western blotting (WB). As a result, icariin increased MSC proliferation dependent on its dose, and the optimal dose was determined to be 80 mu g/l. Furthermore, MSCs showed minimal cardiomyogenic differentiation when induced by icariin alone as confirmed by the expression of cardiac-related markers. Moreover, a synergic interaction was observed when icariin and 5-Aza cooperated to induce cardiomyocyte differentiation of MSCs. In conclusion, lcariin stimulates proliferation and facilitates cardiomyocyte differentiation of MSCs in vitro and may be potentially used as a new method for enhancing the MSCs efficacy in cardiovascular disease.