Expression of Niban in renal interstitial fibrosis.

AIM: Apoptosis is one of the most important mechanisms underlying renal interstitial fibrosis. We identified the role of protein Niban in apoptosis of tumour cells. The purpose of this study was to assess the expression of Niban in renal interstitial fibrosis of humans and rats. METHODS: Immunohistochemistry was used to detect Niban in patients with obstructive nephropathy. Proteomics and gene array analysis were performed to screen different molecules involved in the pathophysiology of unilateral-ureteral obstruction rats. We confirmed Niban using immunohistochemistry and Western blot in renal cortex of UUO rats and HK-2 cells. TUNEL assay and flow cytometry revealed apoptosis of renal tubular cells. siRNA and overexpression plasmid were transfected specifically to study the possible function of Niban. RESULTS: Niban was decreased apparently in renal tubular cells of patients with obstructive nephropathy, compared with controls. Niban decreased in renal cortex of UUO rats and transforming growth factor-ß1 (TGF-ß1)-stimulated HK-2 cells. siRNA of Niban increased apoptosis of HK-2 cells. TGF-ß1 also increased apoptosis of HK-2 cells. Overexpression of Niban failed to diminish apoptosis of HK-2 cells induced by TGF-ß1. CONCLUSIONS: Niban decreased in renal tubular cells of patients of obstructive nephropathy, UUO rats and TGF-ß1 stimulated HK-2 cells. Suppressing Niban increases apoptosis in HK-2 cells. Niban may be associated with apoptosis of HK-2 cells.