Effect of SP600125 on AngII-Induced Transforming Growth Factor-1 and Fibronectin Expression in Human Mesangial Cells

Objective To investigate the effect of c-Jun N-terminal kinase(JNK) specific inhibitor SP600125 on Angiotensin Ⅱ(AngⅡ)-induced transforming growth factor-β1(TGF-β1) and fibronectin (FN) expression in human mesangial cells (MC).Methods Human MC were isolated and cultured in vitro and were treated with AngⅡ in the presence or absence of JNK specific inhibitor SP600125.The protein was isolated or the supernate of medium was collected at the end of experiment.JNK,extracellular signal-regulated kinase(ERK1/2),and p38 mitogen-activated protein kinase(MAPK) activity were determined by Western blot method.TGF-β1 and FN were determined by enzyme linked immunosorbent assay(ELISA).Results SP600125 inhibited AngⅡ-induced Ser63 phosphorylation of c-Jun in a concentration-dependent manner,and JNK activity was reduced by 75% at 10 μmol/L and by 90% at 20 μmol/L.SP600125 had no effect on AngⅡ-induced ERK1/2 and p38 activity.TGF-β1 and FN protein were constitutively produced in MC,and production was significantly stimulated for 8 to 48 h after addition of AngⅡ.Preincubation of cells with SP600125(20 μmol/L) significantly inhibited AngⅡ-induced TGF-β1 and FN production during this time period.SP600125 inhibited AngⅡ-induced production of TGF-β1 and FN in a concentration-dependent manner.Conclusion SP600125 inhibited AngⅡ-induced JNK activation and TGF-β1 and FN expression in human MC and may serve as the novel approach for the treatment of patients with chronic kidney disease.