title: Directed differentiation of skin-derived precursors into functional vascular smooth muscle cells.
abstract: OBJECTIVE
  The goal of this study was to characterize the factors and conditions required for smooth muscle cell (SMC)-directed differentiation of Sox2(+) multipotent rat and human skin-derived precursors (SKPs) and to define whether they represent a source of fully functional vascular SMCs for applications in vivo.
  
  
  RESULTS
  We found that rat SKPs can differentiate almost exclusively into SMCs by reducing serum concentrations to 0.5% to 2% and plating them at low density. Human SKPs derived from foreskin required the addition of transforming growth factor-β1 or -β3 to differentiate into SMCs, but they did so even in the absence of serum. SMC formation was confirmed by quantitative reverse transcription-polymerase chain reaction, immunocytochemistry, and fluorescence-activated cell sorting, with increased expression of smoothelin-B and little to no expression of telokin or smooth muscle γ-actin, together indicating that SKPs differentiated into vascular rather than visceral SMCs. Rat and human SKP-derived SMCs were able to contract in vitro and also wrap around and support new capillary and larger blood vessel formation in angiogenesis assays in vivo.
  
  
  CONCLUSIONS
  SKPs are Sox2(+) progenitors that represent an attainable autologous source of stem cells that can be easily differentiated into functional vascular SMCs in defined serum-free conditions without reprogramming. SKPs represent a clinically viable cell source for potential therapeutic applications in neovascularization.
authors.affiliation: McEwen Centre for Regenerative Medicine, Toronto, Ontario, Canada.
authors.forename: Sarah K
authors.initials: SK
authors.lastname: Steinbach
authors.forename: Omar
authors.initials: O
authors.lastname: El-Mounayri
authors.forename: Ralph S
authors.initials: RS
authors.lastname: DaCosta
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Frontini
authors.forename: Zengxuan
authors.initials: Z
authors.lastname: Nong
authors.forename: Azusa
authors.initials: A
authors.lastname: Maeda
authors.forename: J Geoffrey
authors.initials: JG
authors.lastname: Pickering
authors.forename: Freda D
authors.initials: FD
authors.lastname: Miller
authors.forename: Mansoor
authors.initials: M
authors.lastname: Husain
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D003598:Cytoskeletal Proteins / Q000378:metabolism; D006801:Humans; D008297:Male; D023421:Models, Animal; D039902:Multipotent Stem Cells / Q000166:cytology* / Q000187:drug effects; D009124:Muscle Proteins / Q000378:metabolism; D009131:Muscle, Smooth, Vascular / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D009219:Myosin-Light-Chain Kinase / Q000378:metabolism; D018919:Neovascularization, Physiologic / Q000502:physiology; D010446:Peptide Fragments / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012867:Skin / Q000166:cytology*; D053773:Transforming Growth Factor beta1 / Q000494:pharmacology; D053782:Transforming Growth Factor beta3 / Q000494:pharmacology
chemical_list: D000199:Actins; D003598:Cytoskeletal Proteins; D009124:Muscle Proteins; D010446:Peptide Fragments; C491051:Smtn protein, rat; D053773:Transforming Growth Factor beta1; D053782:Transforming Growth Factor beta3; C060640:telokin; D009219:Myosin-Light-Chain Kinase