Protective Effects Of MAPK Inhibitor U0126 On Glomerular Mesangial Cells In The Presence Of High Glucose

[Objective] To investigate the changes of extracellular matrix synthesized by glomerular mesangial cells in the presence of high glucose, and the possible signal pathway of the cells stimulated by high glucose. Further study of the protective effects of MAPK inhibitor U0126 on glomerular mesangial cells was made.[Methods] 1. Cultured cells are divided into six groups: normal glucose group,high glucose group,high glucose +U0126 2.5umol/L group,high glucose +5umol/L U0126 group,high glucose +10umol/L U0126 group and normal glucose + U0126 10umol/L group. 2. Being cultured for at 24 and 48 hours, the mRNA of fibronectin (FN) and transforming growth factor-β1 (TGF-β1)and phosphorylated ERK1/2 protein were detected by using RT-PCR and western blot, respectively. The amount of total ERK1/2 was also visualized as a control. The ratio of p-ERK1/2 vs. total ERK1/2 was used in the study to evaluate the protective effect of U0126.[Results] 1. The expression of FN and TGF-β1 mRNA were increased after being cultured in high glucose, and the increase was more obvious after 48 hours.2. The up-regution of FN and TGF-β1 mRNA high glucose induced,was inhibited by U0126.The inhibitory effect had dose dependent effect.3. The expression of total ERK protein remained unchanged in high glucose.However,the phosphorylated ERK1/2 protein vs. total ERK1/2 ratio was increased after being cultured in high glucose compared with nomal glucose whatevet at 24 hours or 48 hours.4. The up-regulation of the p-ERK1/2 vs. total ERK1/2 ratio,U0126 can normalize it,hasing a dose dependent effect.5. The p-ERK1/2 vs. total ERK1/2 ratio that intervened by U0126 in normal glucose was no difference from the groups cultured in normal glucose without U0126.[Conclusion] 1. U0126 could inhibit the activation of ERK signaling pathway by high glucose,and it had dose dependent effect. 2. U0126 could inhibit the up-regulation of matrix deposition induced by high glucose,and the hibition had dose dependent effect.3. Normal glucose couldn't active ERK signal pathway.