Inhibition of the tubular epithelial-to-mesenchymal transition in vivo and in vitro by the Uremic Clearance Granule ().

OBJECTIVE: To investigate the effect of the Uremic Clearance Granule (UCG, ), a Chinese patent medicine, on tubular epithelial-to-mesenchymal transition (EMT) in a unilateral ureteral obstruction (UUO) model in vivo and transforming growth factor (TGF)-ß1 induced EMT of HK-2 cells in vitro. METHODS: In vivo study, 50 Sprague Dawley rats were divided into three groups: a sham operation group (n=10), a UUO group (n=20), and a UUO with UCG treatment group (n=20). The UCG was given at a dose of 4.5 g/kg body weight per day by gavage after surgery. In vitro study, HK-2 cells were cultured in 10% fetal bovine serum (FBS), 10% healthy rat serum, 10% FBS and TGF-ß1 (10 ng/mL), 10% healthy rat serum and TGF-ß1, or 10% rat serum containing the uremic clearance granule and TGF-ß1. The expression of the epithelial marker E-cadherin and the mesenchymal markers vimentin and α-smooth muscle actin (α-SMA) in kidney tissues and HK-2 cells were investigated by Western blot analysis and immunofluorescence staining. RESULTS: The rats of the UUO group showed obvious tubulointerstitial fibrosis, compared with the sham operation group rats. Tubulointerstitial fibrosis score was reduced by 17.5%±1.1% at day 7 and by 20.0%±1.2% at day 14 in the UCG-treated group, compared with the UUO group. The UCG could maintained expression of E-cadherin and suppressed expression of vimentin and α-SMA in kidney tissues of UUO rats at days 7 and 14, as determined by Western blot analysis and immunofluorescence staining. Rat serum containing the UCG partially inhibited TGF-ß1-induced fibroblast phenotype of HK-2 cells and maintained the epithelial morphology of HK-2 cells in vitro. This occurred partially through a reduction of vimentin expression and an increase of E-cadherin expression. CONCLUSION: These results suggest that the UCG prevents tubular EMT and may be a promising agent for treating tubulointerstitial fibrosis.

Colon may provide new therapeutic targets for treatment of chronic kidney disease with Chinese medicine.

Chronic kidney disease (CKD) has become a worldwide health and social problem. Retarding its progression to end-stage renal disease is beneficial both to the patients and the healthcare system. Plenty of clinical trials have indicated that enema with Chinese medicine could effectively prevent chronic renal failure, and was widely used in the clinical practice. However, studies on mechanism were still nearly blank, which may prevent further improvement of therapeutic efficacy. Recent studies had discovered that colon was an important organ where uremic toxins were generated. The uremic toxins involved could not only promote CKD progression, but also was closely correlated with CKD mortality. Reducing production and promoting excretion of toxins were confirmed to reduce renal tubule interstitial fibrosis and delay renal progression. On the basis of the theory of gut-kidney axis above, we had conducted pilot clinical researches to evaluate the effect of enema with Chinese medicine on the intestinal flora, gut barrier, enterogenous uremic toxins and renal protection. The preliminary results revealed that rheum enema through colon could accelerate intestinal dynamics, improve intestinal barrier function, regulate intestinal flora and reduce production and absorption of intestine-derived uremic toxins such as indoxyl sulfate, which may reduce renal fibrosis and delay renal progression. Further studies could provide more evidence for colon as a new therapeutic target for the treatment of CKD with Chinese medicine.