大黄甘草汤通过SIRT3去乙酰化p53改善慢性肾脏病铁死亡的机制OA

Objective:To investigate the mechanisms by which Dahuang Gancaotang(DHGC)alleviates ferroptosis in chronic kidney disease(CKD)via silent information regulator 3(SIRT3)-mediated deacetylation of tumor protein p53(p53).Methods:In vivo,a CKD mouse model was established by feeding a 0.2%adenine-containing diet.Seventy-two C57BL/6 mice were randomly divided into six groups:blank group,model group,DHGC low-,medium-,and high-dose groups(0.975,1.95,3.90 g·kg-1),and valsartan group(0.025 g·kg-1),with 12 mice in each group.Renal function was evaluated by measuring serum blood urea nitrogen(BUN)and creatinine(SCr).Renal pathological changes were assessed using hematoxylin-eosin(HE),periodic acid-Schiff(PAS),and Masson staining.Immunohistochemistry was used to detect the expression of collagen type(Col)Ⅰ,ColⅢ,and α-smooth muscle actin(α-SMA)in renal tissue to evaluate renal fibrosis.Enzyme-linked immunosorbent assay(ELISA)was used to measure serum tumor necrosis factor-α(TNF-α),interleukin-1β(IL-1β),and interleukin-6(IL-6)to assess inflammatory responses.Colorimetric assays were used to determine superoxide dismutase(SOD),malondialdehyde(MDA),glutathione(GSH),and renal total iron content to evaluate lipid peroxidation and iron metabolism.Western blot was used to detect the protein expression of the SIRT3/p53 signaling pathway,acetylated p53(ac-p53),and glutathione peroxidase 4(GPX4)in renal tissue.In vitro,a ferroptosis model of HK-2 cells was induced using erastin.Cells were divided into six groups:blank group,model group,DHGC-containing serum low-,medium-,and high-dose groups(15 rats were randomly divided into three groups,n=5 per group,and gavaged with 0.675,1.35,2.70 g·kg-1 to prepare medicated serum),and ferrostatin-1(Fer-1)group(5 μmol·L-1).The cell counting Kit-8(CCK-8)assay was used to determine cell viability and to screen the optimal concentrations of erastin and DHGC-containing serum.Western blot was used to detect SIRT3/p53 pathway proteins,ac-p53,and GPX4 expression.Immunofluorescence confocal microscopy was used to observe p53 nuclear translocation.Results:In vivo,compared with the blank group,the model group showed significantly increased BUN and SCr levels(P<0.01).Severe renal pathological injury and aggravated renal fibrosis were observed.Lipid peroxidation and iron metabolism disorders were evident,as shown by significantly decreased SOD and GSH levels and significantly increased MDA and renal total iron levels(P<0.05,P<0.01).Compared with the model group,all the above indices were significantly improved after DHGC intervention in a dose-dependent manner(P<0.05,P<0.01).In vitro,compared with the blank group,HK-2 cell viability was significantly decreased in the model group.A concentration of 0.4 μmol·L-1 erastin was identified as the optimal induction dose,and high-dose DHGC-containing serum was identified as the optimal treatment condition.Compared with the model group,cell viability was significantly increased in all DHGC-containing serum groups(P<0.05,P<0.01).Mechanistically,compared with the blank group,protein expression of SIRT3 and GPX4 was significantly decreased in both in vivo and in vitro model groups,while p53 and ac-p53 expression and p53 nuclear translocation were significantly increased(P<0.01).Compared with the model group,these changes were significantly reversed after DHGC intervention(P<0.05,P<0.01).Conclusion:DHGC exerts a protective effect against adenine-induced CKD in mice and erastin-induced ferroptosis in HK-2 cells.The mechanism is associated with its anti-ferroptosis effect mediated via the SIRT3/p53 signaling pathway.