Effect Of Ginsenoside Rg1on Epithelial-mesenchymal Transition Of Rat Renal Tubular Epithelial Cells Induced By TGF-β1and The Relationship Between The Effect And The Expression Of VEGFR2and EPOR

Objective:Epithelial-to-mesenchymal transition is a critical step in the pathogenesis of tubulointerstitial fibrosis, therefore, it is quite important to prevent or reverse tubular epithelial-to-mesenchymal transition in the therapy of tubulointerstitial fibrosis. It has been proved that transforming growth factor-β1(TGF-β1) induced tubular epithelial-myofibroblasts differentiation, and also can lead to apoptosis of renal tubular epithelial cells, resulting in tubular atrophy. Many researches show that Ginsenoside Rgl can delay the progress of renal interstitial fibrosis, and improve the structure and function of renal tubular epithelial cells. And our research was to examine the effect of Ginsenoside Rgl on epithelial-mesenchymal transition (EMT) of rat renal proximal tubular epithelail cells (NRK52E) cultured in vitro and to elucidate the relationship between EMT and VEGFR2and EPOR of the cells.Methods:NRK52E cells were grown in DMEM medium containing10%fetal bovine serum, and were divided into control group,5μg/L TGF-β1induced group, and NRK52E co-treated with Ginsenoside Rgl (10,20,40mg/L) and TGF-β1(5μg/L). NRK52E cells were incubated72hours, then light microscope was performed to observe the morphology of the cells of each group, CCK8measure was used to detect the effect of Ginsenoside Rgl on the tubular Epithelial-myofibroblast transdifferentiation induced by TGF-β1, the VEGFR2and EPOR protein and gene expression were assessed by immunocytochemistry and Real-time quantitative chain reaction.Results:(1) Compared to control group, after72h exposured to5μg/L TGF-β1, NRK52E cells showed fibroblast-like in morphology under light microscope, and cell proliferation was inhibited measured by CCK8(P<0.05). The collagen I and fibronectin were significantly increased (P<0.05). Real-time PCR showed that VEGFR2and EPOR mRNA were down-regulated (P<0.05), and VEGFR2and EPOR protein expression had no significantly change by immunohistochemistry (P<0.05).(2) Compored to TGF-β1-induced group, Ginsenoside Rgl could inhibit the morphology change by TGF-β1in dose-and time-dependent manner, and significantly down-regulate collagen I and fibronectin protein expression (P<0.05), while the expressions of VEGFR2and EPOR mRNA and protein were significantly increased (P<0.05) in Ginsenoside Rgl (10,20,40mg/L) treated groups. Conclusions:Ginsenoside Rgl may inhibit TGF-β1induced EMT of cultured NRK52E cells in dose-and time-dependent manner. This effect is probably related to up-regulated expression of VEGFR2and EPOR induced by Ginsenoside Rgl.