An Update of the Interstitial Cell Compartment in the Normal Human Bladder

Abstract EN

Aims.

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.