The extracellular matrix proteoglycan versican is strongly expressed in the urothelium of healthy rats

Objective: We have previously demonstrated protein expression of the extracellular matrix degrading protein ADAMTS5 in the nuclei of urothelial cells in healthy rats. The proteoglycan versican constitutes one of the main substrates for this protease. In this follow up study we investigated a potential co-localization of versican and ADAMTS5 in the urinary bladder wall.Material and Methods: The study was conducted with archive material (paraffin embedded bladder tissue from our previous study, i.e., 8 male Sprague-Dawley rats). Protein expression of versican was investigated by immunohistochemistry. Furthermore, the occurrence of versican mRNA was examined by in-situ hybridization.Results: Positive immunoreactivity for versican was evident in the urothelium but also, weakly, in the detrusor. This expression was localized only in the cytoplasm, leaving the nuclei devoid of reactivity. Interestingly, versican mRNA was only sparsely observed in the urothelial cells.Conclusions: We found by immunohistochemistry that the substrate for ADAMTS5, versican, was localized in the cytosol of urothelial cells. This demonstrates a difference regarding the expression of ADAMTS5, which was emphasized in the nuclei. This could imply an additional, non-enzymatic, function of ADAMTS5 in the urothelium.