基于SIRT1/HIF-1α/VLDLr信号通路探讨当归芍药散改善db/db小鼠肾小球硬化的作用机制OA

Objective:To investigate the potential mechanism of Danggui Shaoyaosan(DSS)in ameliorating renal injury in db/db mice.Methods:Thirty 8-week-old specific pathogen-free(SPF)-grade male db/db mice and six db/m mice were acclimated for one week.Urinary microalbumin and blood glucose levels were measured weekly in both db/db and db/m mice.Successful modeling was determined by significantly higher microalbuminuria in db/db mice compared to db/m mice and a fasting blood glucose ≥16.7 mmol·L-1.The 30 db/db mice were randomly divided into five groups:the model group,the irbesartan(IBN)group,and three DSS dose groups(low-,medium-,and high-dose DSS groups,administered at 16.77,33.54,67.08 g·kg-1·d-1,respectively).Additionally,the six db/m mice served as the normal control group.The IBN group received irbesartan at 0.025 g·kg-1·d-1 by gavage,while the three DSS groups received DSS at 16.77,33.54,and 67.08 g·kg-1·d-1 by gavage,respectively.The normal and model groups were administered with an equivalent volume of normal saline by gavage.All interventions lasted for 8 consecutive weeks.After intervention,serum creatinine(SCr),blood urea nitrogen(BUN),urinary total protein(UTP),triglyceride(TG),and low-density lipoprotein cholesterol(LDL-C)were measured to evaluate the therapeutic efficacy of the treatments.Renal histopathological changes were observed with hematoxylin-eosin(HE)staining.Western blot was used to detect the protein expression of silencing information regulator 1(SIRT1),hypoxia-inducible factor-1α(HIF-1α),very low-density lipoprotein receptor(VLDLr),and cluster of differentiation 31(CD31).Real-time fluorescence quantitative polymerase chain reaction(Real-time PCR)was used to detect the mRNA levels of HIF-1α and VLDLr.Immunohistochemistry was used to observe the expression and distribution of HIF-1α and Caspase-3.Results:Compared to the normal group,the model group showed significantly increased SCr,BUN,UTP,TG,and LDL-C.HE staining revealed glomerulosclerosis,mesangial matrix hyperplasia,capillary loop distortion and thickening,with extensive inflammatory cell infiltration.Protein expression of SIRT1 and CD31 significantly decreased(P＜0.05),while HIF-1α and VLDLr protein and mRNA levels increased(P＜0.05).Immunohistochemistry showed increased expression of HIF-1α and Caspase-3(P＜0.05),indicating hypoxia and apoptosis in renal cells.In all treatment groups,SCr,BUN,TG,and LDL-C were significantly reduced compared to the model group(P＜0.05),and UTP was significantly improved in the medium-dose DSS group(P＜0.05).Renal tissue structure and morphology were improved,inflammatory cells were reduced,and no vascular hyaline degeneration was observed.SIRT1 and CD31 protein expression was elevated to varying degrees compared to the model group(P＜0.05),while HIF-1α and VLDLr protein and mRNA levels decreased(P＜0.05).Immunohistochemistry showed reduced expression of HIF-1α and Caspase-3 in all treatment groups(P＜0.05),with the most significant improvement observed in the IBN group and medium-dose DSS group(P＜0.05).Conclusion:DSS can effectively ameliorate glomerulosclerosis and lipid deposition in db/db mice,and its mechanism may involve the SIRT1/HIF-1α/VLDLr signaling pathway.