title: Urine derived cells are a potential source for urological tissue reconstruction.
abstract: OBJECTIVE
  Contemporary approaches to tissue engineering and cell therapy for urinary tract reconstruction require invasive tissue biopsies to obtain autologous cells. However, these procedures are associated with potential complications. We determined whether the cells present in urine have characteristics of normal bladder cells and investigated their potential uses for urological reconstructive procedures.
  
  
  METHODS
  A total of 55 urine samples were collected from 15 healthy individuals and 8 patients with vesicoureteral reflux. Urine derived cells were isolated, expanded and tested for progenitor and differentiated cell specific markers using flow cytometry, immunofluorescence and Western immunoblotting. The chromosomal stability of cultured urine derived cells was determined by karyotype analysis.
  
  
  RESULTS
  Clones were successfully established from primary cultures of urine derived cells. Isolated cells showed 3 phenotypes, including fully differentiated, differentiating and progenitor-like cells. Some urine derived cells stained positive for the surface markers c-Kit, SSEA4, CD105, CD73, CD91, CD133 and CD44. Two to 7 cells per 100 ml urine were multipoint progenitors that could expand extensively in culture. Single progenitor cells had the ability to differentiate into the cell lineages expressing urothelial, smooth muscle, endothelial and interstitial cell markers. The expression of lineage markers was characterized by Western blot and immunofluorescence analysis. Urine derived cells also maintained a normal karyotype after serial culture.
  
  
  CONCLUSIONS
  A subpopulation of cells isolated from urine had progenitor cell features and the potential to differentiate into several bladder cell lineages. Urine derived cells could serve as an alternative cell source for urinary tract tissue engineering and reconstruction.
authors.affiliation: Institute for Regenerative Medicine, School of Medicine, Wake Forest University, Winston-Salem, North Carolina 27157, USA. yzhang@wfubmc.edu
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Elena
authors.initials: E
authors.lastname: McNeill
authors.forename: Hong
authors.initials: H
authors.lastname: Tian
authors.forename: Shay
authors.initials: S
authors.lastname: Soker
authors.forename: Karl-Erik
authors.initials: KE
authors.lastname: Andersson
authors.forename: James J
authors.initials: JJ
authors.lastname: Yoo
authors.forename: Anthony
authors.initials: A
authors.lastname: Atala
mesh_terms: D000293:Adolescent; D000328:Adult; D015153:Blotting, Western; D016022:Case-Control Studies; D049109:Cell Proliferation; D002478:Cells, Cultured; D002648:Child; D005260:Female; D005455:Fluorescent Antibody Technique; D048091:Guided Tissue Regeneration; D006801:Humans; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012494:Sampling Studies; D012680:Sensitivity and Specificity; D013234:Stem Cells / Q000502:physiology*; D023822:Tissue Engineering / Q000379:methods*; D014556:Urine / Q000166:cytology*; D019459:Urothelium / Q000166:cytology / Q000502:physiology; D014718:Vesico-Ureteral Reflux / Q000652:urine