Synergistic effects of micropatterned substrates and transforming growth factor-β1 on differentiation of human mesenchymal stem cells into vascular smooth muscle cells through modulation of Krϋppel-like factor 4.

The functionality and structural integrity of the cardiovascular system are critically dependent on vascular smooth muscle cells (VSMCs). Human mesenchymal stem cells (hMSCs) have significant potential for differentiating into VSMCs, making them a valuable resource in regenerative medicine and the development of vascular grafts. This study explored the synergistic effects of micropatterned substrates and TGF-β1 on the differentiation of hMSCs into VSMCs. HMSCs were cultured on both micropatterned and flat substrates for a duration of 6 days, with some groups receiving TGF-β1 treatment, after which cell morphology and the expression of specific smooth muscle markers were evaluated through Western blotting, immunofluorescence staining, and RT-qPCR. Results indicated that hMSCs on micropatterned substrates treated with TGF-β1 exhibited significantly elevated protein levels of smooth muscle myosin heavy chain (MYH11) compared with hMSCs on flat substrates without TGF-β1 (p < 0.001). Additionally, MYH11 expression was markedly enhanced in samples cultured on micropatterned substrates with TGF-β1. Furthermore, hMSCs treated with TGF-β1 on flat substrates exhibited increased cadherin-11 mRNA expression compared with both micropatterned and flat substrates lacking TGF-β1 (p < 0.05). Interestingly, KLF4 protein levels were significantly higher in hMSCs on flat substrates without TGF-β1 compared to those cultured on micropatterned substrates with TGF-β1 treatment (p < 0.001). In conclusion, this study demonstrated that the combination of micropatterned substrates and TGF-β1 treatment preferentially enhances MYH11 expression, indicative of advanced smooth muscle cell organization, along with modulating KLF4 levels and upregulating cadherin-11 expression in hMSCs. These findings provide critical insights into the differentiation pathways of MSCs into VSMCs and may inform the design of improved vascular grafts that better replicate the properties of native blood vessels.