RESUMEN
AIM:To investigate the effects of proteasome inhibitor MG 132 on the expression of SnoN in renal tubule epithelial cells incubated in high glucose , and to explore the possible mechanism and function that MG 132 reduces or slows down renal tubular interstitial injury after incubated in high glucose .METHODS:The NRK-52E cells were divid-ed into normal control group (NG), high glucose group (HG) and high glucose plus pretreatment with different doses of MG132 group (HG+MG132).The immunofluorescence staining was used to detect the protein expression of E-cadherin and α-smooth muscle actin (α-SMA) in NRK-52E cells under different conditions .The relative protein expression levels of SnoN, Smad ubiquitination regulatory factor 2 (Smurf2), Arkadia, E-cadherin, α-SMA and collagen type Ⅰ(Col-Ⅰ) were detected by Western blotting .RESULTS:Compared with NG group , the expression of E-cadherin and SnoN was de-creased (P<0.05), while the expression of α-SMA, Col-Ⅰ, Smurf2 and Arkadia was increased (P<0.05).Compared with HG group, the protein expression of SnoN and E-cadherin was significantly up-regulated in HG+MG132 group ( P<0.05 ) , and the protein expression of α-SMA and Col-Ⅰwas significantly down-regulated in a dose-depended manner ( P<0.05).However, no effect on the protein expression of Smurf2 and Arkadia was observed.CONCLUSION: MG132 in-hibits the degradation of SnoN protein induced by high glucose , thus reducing the renal fibrosis .