An update of the interstitial cell compartment in the normal human bladder.
OBJECTIVE
Interstitial cells, also called myofibroblasts, most probably play a major role in the pathogenesis of the overactive bladder. However, no specific phenotypic marker has been identified. We investigated whether N-cadherin could play a role as a discriminatory marker for interstitial cells in the human bladder.


METHODS
Bladder biopsies (n = 16) were collected from macroscopically nonpathological locations during cystectomy which was performed because of bladder cancer. Tissue was analyzed for expression of N-cadherin. N-cadherin+ cells were phenotyped using antibodies against PGP9.5, smoothelin, vimentin, and C-kit. Findings were related to bladder tissue histology and ultrastructure of myofibroblastic cells.


RESULTS
N-cadherin+/vimentin+ cells with branched cell bodies were found in the lamina propria and detrusor layer. They were closely associated with neurons and showed no colocalization of PGP9.5 or smoothelin. A second type of N-cadherin+ cells was found at the boundary of detrusor bundles and in the lamina propria. These cells colocalization C-kit. We assumed that N-cadherin+/vimentin+ cells are similar to the ultrastructurally defined myofibroblasts.


CONCLUSIONS
N-cadherin can play a role as a discriminatory marker for interstitial cells in the human bladder, as the interstitial compartment of the human bladder houses a population of cells from mesenchymal origin, immunopositive for N-cadherin, vimentin, and C-kit.
Department of Urology, Radboud University Nijmegen Medical Centre, 267 Nijmegen, The Netherlands.
Kamiel A J
KA
Kuijpers
Department of Urology, Radboud University Nijmegen Medical Centre, 267 Nijmegen, The Netherlands.
John P F A
JP
Heesakkers
Department of Biochemistry, Radboud University Nijmegen Medical Centre, 267 Nijmegen, The Netherlands.
Theo G M
TG
Hafmans
Department of Urology, Radboud University Nijmegen Medical Centre, 267 Nijmegen, The Netherlands.
Jack A
JA
Schalken
D015703:Antigens, CD / Q000096:biosynthesis*; D001706:Biopsy; D015820:Cadherins / Q000096:biosynthesis*; D002451:Cell Compartmentation / Q000235:genetics*; D003598:Cytoskeletal Proteins / Q000096:biosynthesis; D005786:Gene Expression Regulation; D006801:Humans; D009124:Muscle Proteins / Q000096:biosynthesis; D058628:Myofibroblasts / Q000166:cytology* / Q000378:metabolism; D019009:Proto-Oncogene Proteins c-kit / Q000096:biosynthesis; D043222:Ubiquitin Thiolesterase / Q000096:biosynthesis; D001743:Urinary Bladder / Q000166:cytology* / Q000378:metabolism; D014746:Vimentin / Q000096:biosynthesis
D015703:Antigens, CD; C050361:CDH2 protein, human; D015820:Cadherins; D003598:Cytoskeletal Proteins; D009124:Muscle Proteins; C100762:SMTN protein, human; C482860:UCHL1 protein, human; D014746:Vimentin; D019009:Proto-Oncogene Proteins c-kit; D043222:Ubiquitin Thiolesterase