Effect of high concentration of glucose on the expression of TGF-β mRNA and its relationship with the effect of angiotensin II in human proximal tubular cells

Objective To observe the effect of high concentration of glucose on transforming growth factor-β(TGF-β)mRNA expression and the influence of Irbesartan in human proximal tubular cells(HPTC).Methods After 24 h of serum depletion,cells were incubated in different concentration of D-glucose(5 5,22 2,30,40 mmol/L)for 48 hours and were incubated in 22 2 mmol/L D-glucose for times up to 72 hours.Growth-arrested HPTC was exposed to serum-free medium containing 22 2 mmol/L D-glucose and different concentrations of Irbesartan(Irb)(10 -3,10 -5,10 -7 mol/L)for 48 hours.Total cellular RNA was isolated from cultured HPTC by TRIzol method,and expression of TGF-βmRNA was assessed by RT-PCR,which was performed by using access RT-PCR kit(Promega).Results D-glucose stimulated the expression of TGF-β mRNA in HPTC in time and dose dependent manner.Irb(10 -3,10 -5,10 -7 mol/L)could dose dependently attenuate the mRNA expression stimulated by D-glucose(22 2 mmol/L)for 48 h.Conclusion Our results suggest that high concentration of glucose may stimulate the expression of TGF-β through activation of the intrarenal rennin angiotensin system.