Résumé
AIM: To investigate the effects of advanced glycation end products on activation of Smad signaling pathway and collagenⅠ synthesis in proximal tubular epithelial cells.METHODS: Advanced glycation end products(AGE-BSA) were prepared by incubation of bovine serum albumin(BSA) with D-glucose.Normal rat proximal tubular epithelial(NRK52E) cells were cultured in RPMI-1640 medium with AGE-BSA.Phosphorylation and nuclear translocation of Smad2/3 were examined by immunocytochemistry.Levels of TGF-?_1 in supernatant of cell culture were measured by enzyme-linked immunosorbent assay(ELISA).Expression of TGF-?_1,Smad2,Smad3 and Smad7 mRNA were detected by RT-PCR.Expression of ?-SMA,E-cadherin and collagenⅠproteins were detected by Western blotting.RESULTS: AGE-BSA induced Smad2/3 phosphorylation and nuclear translocation,two peaks occured at 30 min(68% vs 16%,P