title: Characterization of urine-derived stem cells obtained from upper urinary tract for use in cell-based urological tissue engineering.
abstract: BACKGROUND
  The goals of this study were to characterize urine-derived stem cells obtained from the upper urinary tract (uUSC), induce these cells to differentiate into urothelial and smooth muscle cells, and determine whether they could serve as a potential stem cell source for bladder tissue engineering.
  
  
  METHODS
  Urine samples were collected from five patients with normal upper urinary tracts during renal pyeloplasty. Cells were isolated from this urine and extensively expanded in vitro.
  
  
  RESULTS
  The mean population doubling of uUSC was 46.5±7.7. The uUSC expressed surface markers associated with mesenchymal stem cells and pericytes. These cells could differentiate into smooth muscle-like cells that expressed smooth muscle-specific gene transcripts and proteins, including α-smooth muscle actin, desmin, and myosin, when exposed to TGF-β1 and PDGF-BB. In a collagen lattice assay, these myogenic-differentiated uUSC displayed contractile function that was similar to that seen in native smooth muscle cells. Urothelial-differentiated uUSC expressed urothelial-specific genes and proteins such as uroplakin-Ia and -III, cytokeratin (CK)-7, and CK-13.
  
  
  CONCLUSIONS
  uUSC possess expansion and differentiation (urothelial and myogenic) capabilities, and can potentially be used as an alternative cell source in bladder tissue engineering for patients needing cystoplasty.
authors.affiliation: Wake Forest Institute for Regenerative Medicine, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27101, USA.
authors.forename: Shantaram
authors.initials: S
authors.lastname: Bharadwaj
authors.forename: Guihua
authors.initials: G
authors.lastname: Liu
authors.forename: Yingai
authors.initials: Y
authors.lastname: Shi
authors.forename: Chad
authors.initials: C
authors.lastname: Markert
authors.forename: Karl-Erik
authors.initials: KE
authors.lastname: Andersson
authors.forename: Anthony
authors.initials: A
authors.lastname: Atala
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000293:Adolescent; D015415:Biomarkers / Q000378:metabolism; D002454:Cell Differentiation / Q000235:genetics; D049109:Cell Proliferation; D048430:Cell Shape; D002648:Child; D002675:Child, Preschool; D005260:Female; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D020869:Gene Expression Profiling; D006801:Humans; D007223:Infant; D008297:Male; D013234:Stem Cells / Q000166:cytology* / Q000378:metabolism; D023822:Tissue Engineering / Q000379:methods*; D014551:Urinary Tract / Q000166:cytology*; D014556:Urine / Q000166:cytology*
chemical_list: D015415:Biomarkers