Inhibition of the tubular epithelial-to-mesenchymal transition in vivo and in vitro by the Uremic Clearance Granule () / 中国结合医学杂志

<p><b>OBJECTIVE</b>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)-β1 induced EMT of HK-2 cells in vitro.</p><p><b>METHODS</b>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-β1 (10 ng/mL), 10% healthy rat serum and TGF-β1, or 10% rat serum containing the uremic clearance granule and TGF-β1. 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.</p><p><b>RESULTS</b>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-β1-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.</p><p><b>CONCLUSION</b>These results suggest that the UCG prevents tubular EMT and may be a promising agent for treating tubulointerstitial fibrosis.</p>

Expression of Robo2 gene during the renal development in mice / 解放军医学杂志

Objective To observe the expression of Robo2 gene, and explore its role during the renal development of mice. Methods Real-time quantitative RT-PCR was used to semi-quantitatively measure the expression level of Robo2 mRNA in the developing murine kidney at fetal age of 12.5, 13.5, 14.5, 15.5, 16.5 and 17.5 days, and also 1 day, 1 week, 5 weeks after birth. Immunofluorescence staining was used to examine the expression location of Robo2 protein at different stages of embryonic and postnatal kidney. Results Real-time quantitative RT-PCR analysis revealed that Robo2 was highly expressed in embryonic kidney at fetal age of 12.5, 13.5 and 14.5 days, while the expression level declined quickly thereafter and maintained at very low level after birth. Immunofluorescence staining showed that the expression of Robo2 protein could be primarily detected in metanephric mesenchyme of the developing kidney, but not in the ureteric bud. With the development of embryonic kidney, Robo2 protein was expressed in cell membrane of metanephric mesenchyme, condensed cap mesenchyme surrounding the tip of the ureteric bud, comma-shaped body, S-shaped body and renal capsule, finally expressed in the podocytes. Besides, Robo2 protein was also weakly expressed in part of the proximal tubular epithelial cells. Absence of Robo2 gene resulted in abnormal development of nephron, and broadening of some renal tubules and collecting ducts. Conclusion Robo2 plays an important role in the nephron development in mice by regulating the interaction of metanephric mesenchyme and ureteric bud.