Co-culture with umbilical vein endothelial cells promotes differentiation of epicardial progenitor cells into vascular smooth muscle cells

Abstract

Objective To investigate whether vascular endothelial cells affect the differentiation of epicardial progenitor cells (EpiCs) during coronary development. Methods Highly purified EpiCs were extracted from 30 female and 30 male C57BL/6 mice (7 to 8 weeks old, body weight 25-30 g) and cultured alone or in the presence of human umbilical vein endothelial cells (HUVECs) in a Transwell co-culture system. The expressions of EpiCs markers WT1 and Tbx18 and the smooth muscle cell markers α-SMA and Myh11 were detected using immunofluorescence assay and qRT-PCR. Collagen gel contraction assay was used to assess the contractility of the cultured EpiCs, and ELISA was used to detect the expression of growth factors in the cell culture medium. Results Compared with EpiCs cultured alone, the EpiCs co-cultured with HUVECs exhibited significantly increased expression levels of α-SMA [(1.73±0.85)% vs (34.20±3.38)%, P < 0.01, n=3] and Myh11 [(3.70±1.49)% vs (45.63±4.85)%, P < 0.01, n=3] with obviously enhanced contractile ability. The concentration of basic fibroblast growth factors (bFGFs) in the conditioned medium was also significantly higher in the co-cultured cells than in EpiCs cultured alone (304.96±52.91 vs 87.64±8.78 pg/mL, P < 0.01, n=3). Conclusion In the co-culture system of EpiCs and HUVECs, the production of bFGFs by HUVECs promotes the differentiation of EpiCs into vascular smooth muscle cells, indicating a regulatory mechanism of the development of coronary arteries

Keywords

• epicardial progenitor cells
• co-culture
• cell differentiation