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Objective To investigate the effect of c-Jun N-terminal kinase(JNK) specific inhibitor SP600125 on Angiotensin Ⅱ(AngⅡ)-induced transforming growth factor-?1(TGF-?1) 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-?1 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 ?mol/L and by 90% at 20 ?mol/L.SP600125 had no effect on AngⅡ-induced ERK1/2 and p38 activity.TGF-?1 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 ?mol/L) significantly inhibited AngⅡ-induced TGF-?1 and FN production during this time period.SP600125 inhibited AngⅡ-induced production of TGF-?1 and FN in a concentration-dependent manner.Conclusion SP600125 inhibited AngⅡ-induced JNK activation and TGF-?1 and FN expression in human MC and may serve as the novel approach for the treatment of patients with chronic kidney disease.
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Objective To explore the inhibitory effect of rosiglitazone of peroxisome proliferator-activated receptor-?(PPAR?) agonist on aldosterone-induced mesangial cell(MC) proliferation.Methods Mouse primary MC were cultured and treated with aldosterone(100 nmol/L) in the presence or absence of rosiglitazone(1.0,2.5,5.0,10.0 ?mol/L).The incorporation of 3H-thymidine(3H-TdR) and cell count were used as the measure of MC proliferation.Cyclin D1 and cyclin A expression,PI3K and Akt phosphorylation were determined by Western blot analysis.Results 1.Aldosterone induced MC proliferation,as assessed by 3H-TdR incorporation and cell number,which were increased by 2.46-and 2.14-fold,respectively,in aldosterone-treated cells.Aldosterone-induced MC proliferation was inhibited by PPAR? agonist rosiglitazone in dose-dependent manner in mouse MC.2.Aldosterone induced cyclin D1 and cyclin A expression.Rosiglitazone reduced aldosterone-induced cyclin D1 and cyclin A expression in dose-dependent manner.3.Aldosterone induced PI3K/Akt activation in dose-dependent manner,incubation with 100 nmol/L aldosterone for 60 min,phosphorylation PI3K and Akt expression increased by above 3.0-fold.4.PI3K inhibitor LY294002 and Akt inhibitor significantly inhibited aldosterone-induced cyclin D1 and cyclin A expression.5.Rosiglitazone significantly inhibited aldosterone-induced PI3K/Akt activation,10 ?mol/L rosiglitazone almost completely blocked aldosterone-induced PI3K/Akt activation.Conclusion Rosiglitazone can block aldosterone-induced MC proliferation via inhibition of PI3K/Akt activation.