title: The stem cell growth factor receptor KIT is not expressed on interstitial cells in bladder.
abstract: The mast/stem cell growth factor receptor KIT has long been assumed to be a specific marker for interstitial cells of Cajal (ICC) in the bladder, with possible druggable perspectives. However, several authors have challenged the presence of KIT+ICC in recent years. The aim of this study was therefore to attempt to clarify the conflicting reports on KIT expression in the bladder of human beings, rat, mouse and guinea pig and to elucidate the possible role of antibody-related issues and interspecies differences in this matter. Fresh samples were obtained from human, rat, mouse and guinea pig cystectomies and processed for single/double immunohistochemistry/immunofluorescence. Specific antibodies against KIT, mast cell tryptase (MCT), anoctamin-1 (ANO1) and vimentin were used to characterize the cell types expressing KIT. Gut (jejunum) tissue was used as an external antibody control. Our results revealed KIT expression on mast cells but not on ICC in human, rat, mouse and guinea pig bladder. Parallel immunohistochemistry showed KIT expression on ICC in human, rat, mouse and guinea pig gut, which confirmed the selectivity of the KIT antibody clones. In conclusion, we have shown that KIT+cells in human, rat, mouse and guinea pig bladder are mast cells and not ICC. The present report is important as it opposes the idea that KIT+ICC are present in bladder. In this perspective, functional concepts of KIT+ICC being involved in sensory and/or motor aspects of bladder physiology should be revised.
authors.affiliation: Laboratory of Experimental Urology, Organ Systems, KU Leuven, Leuven, Belgium.|Translational Cell and Tissue Research, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium.|Department of Pathology, AZ Klina, Brasschaat, Belgium.
authors.forename: Thomas
authors.initials: T
authors.lastname: Gevaert
authors.affiliation: Laboratory of Experimental Urology, Organ Systems, KU Leuven, Leuven, Belgium.|Department of Urology, UZ Leuven, Leuven, Belgium.
authors.forename: Dirk De
authors.initials: D
authors.lastname: Ridder
authors.affiliation: Rega Institute for Medical Research, KU Leuven, Leuven, Belgium.
authors.forename: Els
authors.initials: E
authors.lastname: Vanstreels
authors.affiliation: Rega Institute for Medical Research, KU Leuven, Leuven, Belgium.
authors.forename: Dirk
authors.initials: D
authors.lastname: Daelemans
authors.affiliation: Laboratory of Experimental Urology, Organ Systems, KU Leuven, Leuven, Belgium.|Department of Urology, UZ Leuven, Leuven, Belgium.
authors.forename: Wouter
authors.initials: W
authors.lastname: Everaerts
authors.affiliation: Laboratory of Experimental Urology, Organ Systems, KU Leuven, Leuven, Belgium.|Department of Urology, UZ Leuven, Leuven, Belgium.
authors.forename: Frank Van Der
authors.initials: FV
authors.lastname: Aa
authors.affiliation: Department of Veterinary Sciences, University of Antwerp, Antwerp, Belgium.
authors.forename: Isabel
authors.initials: I
authors.lastname: Pintelon
authors.affiliation: Department of Veterinary Sciences, University of Antwerp, Antwerp, Belgium.
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Timmermans
authors.affiliation: Translational Cell and Tissue Research, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium.
authors.forename: Tania
authors.initials: T
authors.lastname: Roskams
authors.affiliation: Klinik und Poliklinik für Urologie, University of Leipzig, Leipzig, Germany.
authors.forename: Clara
authors.initials: C
authors.lastname: Steiner
authors.affiliation: Klinik und Poliklinik für Urologie, University of Leipzig, Leipzig, Germany.
authors.forename: Jochen
authors.initials: J
authors.lastname: Neuhaus
mesh_terms: D000818:Animals; D005786:Gene Expression Regulation / Q000235:genetics; D006168:Guinea Pigs; D006801:Humans; D056885:Interstitial Cells of Cajal / Q000166:cytology / Q000378:metabolism; D008407:Mast Cells / Q000378:metabolism; D051379:Mice; D009130:Muscle, Smooth / Q000254:growth & development / Q000378:metabolism; D019009:Proto-Oncogene Proteins c-kit / Q000235:genetics* / Q000378:metabolism; D051381:Rats; D013234:Stem Cells / Q000378:metabolism*; D001743:Urinary Bladder / Q000166:cytology / Q000378:metabolism*
chemical_list: D019009:Proto-Oncogene Proteins c-kit
keywords: KIT; bladder; immunofluorescence; immunohistochemistry; interstitial cells; mast cells