title: A novel in vitro model system for smooth muscle differentiation from human embryonic stem cell-derived mesenchymal cells.
abstract: The objective of this study was to develop a novel in vitro model for smooth muscle cell (SMC) differentiation from human embryonic stem cell-derived mesenchymal cells (hES-MCs). We found that hES-MCs were differentiated to SMCs by transforming growth factor-β (TGF-β) in a dose- and time-dependent manner as demonstrated by the expression of SMC-specific genes smooth muscle α-actin, calponin, and smooth muscle myosin heavy chain. Under normal growth conditions, however, the differentiation capacity of hES-MCs was very limited. hES-MC-derived SMCs had an elongated and spindle-shaped morphology and contracted in response to the induction of carbachol and KCl. KCl-induced calcium transient was also evident in these cells. Compared with the parental cells, TGF-β-treated hES-MCs sustained the endothelial tube formation for a longer time due to the sustained SMC phenotype. Mechanistically, TGF-β-induced differentiation was both Smad- and serum response factor/myocardin dependent. TGF-β regulated myocardin expression via multiple signaling pathways including Smad2/3, p38 MAPK, and PI3K. Importantly, we found that a low level of myocardin was present in mesoderm prior to SMC lineage determination, and a high level of myocardin was not induced until the differentiation process was initiated. Taken together, our study characterized a novel SMC differentiation model that can be used for studying human SMC differentiation from mesoderm during vascular development.
authors.affiliation: Department of Physiology and Pharmacology, University of Georgia, Athens, GA 30602, USA.
authors.forename: Xia
authors.initials: X
authors.lastname: Guo
authors.forename: Steven L
authors.initials: SL
authors.lastname: Stice
authors.forename: Nolan L
authors.initials: NL
authors.lastname: Boyd
authors.forename: Shi-You
authors.initials: SY
authors.lastname: Chen
mesh_terms: D000943:Antigens, Differentiation / Q000235:genetics / Q000378:metabolism; D020013:Calcium Signaling; D018929:Cell Culture Techniques; D002454:Cell Differentiation; D048430:Cell Shape; D002478:Cells, Cultured; D018920:Coculture Techniques; D053595:Embryonic Stem Cells / Q000502:physiology*; D042783:Endothelial Cells / Q000502:physiology; D015870:Gene Expression; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000502:physiology*; D009119:Muscle Contraction; D024510:Muscle Development; D009130:Muscle, Smooth / Q000166:cytology*; D032389:Myocytes, Smooth Muscle / Q000378:metabolism* / Q000502:physiology; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D010641:Phenotype; D026362:Serum Response Factor / Q000378:metabolism; D051899:Smad2 Protein / Q000378:metabolism; D051900:Smad3 Protein / Q000378:metabolism; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism; D015533:Transcriptional Activation; D016212:Transforming Growth Factor beta / Q000502:physiology; D000099251:Myocardin
chemical_list: D000943:Antigens, Differentiation; D009687:Nuclear Proteins; D026362:Serum Response Factor; D051899:Smad2 Protein; D051900:Smad3 Protein; D015534:Trans-Activators; D016212:Transforming Growth Factor beta; D000099251:Myocardin; C497782:SMAD2 protein, human; C497790:SMAD3 protein, human; C476858:SRF protein, human