title: Immunocytochemical characterisation of cultures of human bladder mucosal cells.
abstract: BACKGROUND
  The functional role of the bladder urothelium has been the focus of much recent research. The bladder mucosa contains two significant cell types: urothelial cells that line the bladder lumen and suburothelial interstitial cells or myofibroblasts. The aims of this study were to culture these cell populations from human bladder biopsies and to perform immunocytochemical characterisation.
  
  
  METHODS
  Primary cell cultures were established from human bladder biopsies (n = 10). Individual populations of urothelial and myofibroblast-like cells were isolated using magnetic activated cell separation (MACS). Cells were slow growing, needing 3 to 5 weeks to attain confluence.
  
  
  RESULTS
  Cytokeratin 20 positive cells (umbrella cells) were isolated at primary culture and also from patients' bladder washings but these did not proliferate. In primary culture, proliferating cells demonstrated positive immunocytochemical staining to cytokeratin markers (AE1/AE3 and A0575) as well fibroblasts (5B5) and smooth muscle (αSMA) markers. An unexpected finding was that populations of presumptive urothelial and myofibroblast-like cells, isolated using the MACS beads, stained for similar markers. In contrast, staining for cytokeratins and fibroblast or smooth muscle markers was not co-localised in full thickness bladder sections.
  
  
  CONCLUSIONS
  Our results suggest that, in culture, bladder mucosal cells may undergo differentiation into a myoepithelial cell phenotype indicating that urothelial cells have the capacity to respond to environmental changes. This may be important pathologically but also suggests that studies of the physiological function of these cells in culture may not give a reliable indicator of human physiology.
authors.affiliation: Detrusor Muscle Laboratory, The St George Hospital, University of New South Wales, Sydney, NSW 2052, Australia.
authors.forename: Jacqueline R
authors.initials: JR
authors.lastname: Woodman
authors.forename: Kylie J
authors.initials: KJ
authors.lastname: Mansfield
authors.forename: Vittoria A
authors.initials: VA
authors.lastname: Lazzaro
authors.forename: William
authors.initials: W
authors.lastname: Lynch
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Burcher
authors.forename: Kate H
authors.initials: KH
authors.lastname: Moore
mesh_terms: D000368:Aged; D002478:Cells, Cultured; D005260:Female; D006801:Humans; D053554:Keratin-20 / Q000378:metabolism*; D008297:Male; D009092:Mucous Membrane / Q000166:cytology* / Q000378:metabolism*; D014018:Tissue Distribution; D001743:Urinary Bladder / Q000166:cytology* / Q000378:metabolism*
chemical_list: D053554:Keratin-20