Objective: The effective ability of Danqi mixture to inhibit diabetic nephropathy (DN) has been attested in our previous studies.However

the underlying mechanism remains largely unknown.Smad ubiquitination regulatory factor-2 (Smurf 2) is an E3 ubiqutin ligase that plays a pivotal role in regulating transforming growth factor-β1 (TGF-β1) signaling via selectively targeting Ski related novel protein N (SnoN) for degradation. In this study

we investigated the effect of Danqi mixture on expression of Smurf 2

and discuss Danqi mixture's possible mechanism in rats with DN. Method: The rat model of diabetes was induced by tail vein injection of streptozotocin.The rats were divided into three groups:the normal group

the model group and the Danqi mixture group (1.8 g·kg-1·d-1).They were orally administered once a day for 12 weeks. Result: Smurf 2 was predominantly localized to the renal tubular epithelium and interstitium of the kidney

and Western blot analysis revealed that Smurf 2 was up-regulated specifically in renal tissues from the model rats

the Danqi mixture group was significantly reduce the protein levels of Smurf 2 compared to the model group.Interestingly

Danqi mixture was also able to down-regulate the TGF-β1 and phosphorylated Smad 2 (p-Smad 2)

and up-regulate Smad transcriptional corepressor SnoN

but not phosphorylated Smad 3 (p-Smad 3) in kidney. Conclusion: these results indicate that Danqi mixture can targets Smurf 2

maybe via TGF-β1/Smad 2 signaling

thereby providing the ubiquitination degradation of SnoN

so as to mitigate renal functional disorder in DN and delay its development.