All-trans retinoic acid in combination with collagen IV induces the differentiation of mouse embryonic stem cells into smooth muscle cells

All-trans retinoic acid (atRA) and collagen IV (ColIV) have been reported to play key roles in embryogenesis. Differentiation of smooth muscle cells (SMC) plays an important role in human diseases including atherosclerosis, hypertension and neoplasms. Here, atRA and ColIV were applied separately and in combination to investigate the differentiation of mouse embryonic stem cells (ESC) into SMC. The totipotency of ESC was examined by ALP (alkaline phosphatase) staining, SSEA-1 (stage-specific embyronic antigen-1) staining and teratoma formation test in vivo. Real-time Quantitative PCR (qRT-PCR), Western blot and immunofluorescence staining were used to detect a-smooth muscle actin (alpha-SMA) and smooth muscle myosin heavy chain (SM-MHC) expression in differentiation of ESC. We observed that expression of ALP and SSEA-1 was positively localized in ESC. The histochemical staining (HE) showed that ESC had the capacities of totipotency and could differentiate embryoid body. Interesting, we found that pretreatment of ESC with either atRA or ColIV could increase mRNA and protein expression levels of alpha-SMA and SM-MHC in differentiation of ESC at 7 and 14 days. More important, combined treatment with atRA and ColIV resulted in a significant promotion of alpha-SMA and SM-MHC expression compared with atRA or ColIV treated ESC at 7 and 14 days. In conclusion, ESC has the potential to differentiate to SMC. AtRA in combination with ColIV can efficaciously induce the differentiation of mouse ESC into SMC.