myocardin overexpression is sufficient for promoting the development of a mature smooth muscle cell-like phenotype from human embryonic stem cellsmyocardin超表达是促进发展的足够成熟平滑肌细胞样的从人类胚胎干细胞表型.pdfVIP

Myocardin Overexpression Is Sufficient for Promoting the Development of a Mature Smooth Muscle Cell-Like Phenotype from Human Embryonic Stem Cells Linda Raphel , Amarnath Talasila , Christine Cheung, Sanjay Sinha* Anne McLaren Laboratory for Regenerative Medicine, University of Cambridge, Cambridge, United Kingdom Abstract Background: Myocardin is thought to have a key role in smooth muscle cell (SMC) development by acting on CArG- dependent genes. However, it is unclear whether myocardin-induced SMC maturation and increases in agonist-induced calcium signalling are also associated with increases in the expression of non-CArG-dependent SMC-specific genes. Moreover, it is unknown whether myocardin promotes SMC development from human embryonic stem cells. Methodology/Principal: Findings The effects of adenoviral-mediated myocardin overexpression on SMC development in human ESC-derived embryoid bodies were investigated using immunofluorescence, flow cytometry and real time RT-PCR. Myocardin overexpression from day 10 to day 28 of embryoid body differentiation increased the number of smooth muscle a-actin+ and smooth muscle myosin heavy chain+ SMC-like cells and increased carbachol-induced contractile function. However, myocardin was found to selectively regulate only CArG-dependent SMC-specific genes. Nevertheless, myocardin expression appeared to be sufficient to specify the SMC lineage. Conclusions/Significance: Myocardin increases the development and maturation of SMC-like cells from human embryonic stem cells despite not activating the full repertoire of SMC genes. These findings have implications for vascular tissue engineering and other applications requiring large numbers of functional SMCs. Citation: Raphel L,