Objective Inflammation and fibrosis are key features of diabetic nephropathy(DN).Triptolide(TP)exhibits anti-inflammatory and anti-fibrotic properties,though its mechanisms of action in DN remain unclear.CREKA(Cys-Arg-Glu-Lys-Ala)is a pentapeptide that specifically binds to fibronectin(FN),and the CREKA-modified liposome(CREKA-Lip)represents a novel FN-targeted drug delivery system.This study aimed to investigate the role of TP in diabetic db/db mice and determine whether encapsulation within CREKA-Lip enhances therapeutic efficacy while reducing the multi-organ toxicity of TP.Methods Eight-week-old diabetic db/db mice received tail vein injections twice weekly with vehicle,free TP,or CREKA-Lip/TP for 10 weeks.Urine and serum parameters were measured,and kidney,heart,liver,and testis tissues were collected for pathological evaluation.Protein-protein interaction networks were constructed using Cytoscape and its plug-ins to identify core targets and elucidate the therapeutic mechanism of TP against DN.Inflammatory,fibrotic,apoptotic,and lipid metabolism markers were evaluated in the kidneys of diabetic mice with DN and in high glucose-treated mouse mesangial cells and podocytes using qPCR,Western blot,immunohistochemistry,and immunofluorescence assays.Results TP administration reduced fasting blood glucose levels and glomerular mesangial expansion in diabetic mice.TP significantly suppressed renal inflammation,fibrosis,and apoptosis while enhancing lipid metabolism.Integration of network pharmacology,molecular docking,and transcriptomics revealed that TP ameliorated DN by inhibiting the JAK2-STAT1 signaling pathway.In vitro,TP inhibited high glucose-induced phosphorylation of JAK2 and STAT1,reduced collagen production in mesangial cells,decreased apoptosis,and improved lipid metabolism in podocytes.Moreover,CREKA-Lip/TP exhibited superior efficacy compared with free TP,with a more sustained reduction in urine albumin-to-creatinine ratio and greater inhibition of mesangial expansion.Notably,CREKA-Lip/TP treatment did not induce systemic toxicity.Conclusion TP improves renal inflammation,fibrosis,apoptosis,and lipid homeostasis,thereby ameliorating DN by inhibiting JAK2-STAT1 activation.Targeted delivery of TP via FN-binding CREKA-Lip enhances therapeutic efficacy while minimizing multi-organ toxicity.

Ferroptosis is an iron-dependent programmed cell death. Iron overload and lipid reactive oxygen accumulation play a core role in the occurrence and development of ferroptosis. Any factors affecting the balance of iron metabolism and redox system may induce and aggravate ferroptosis. Ferroptosis is involved in the pathological process of acute kidney injury, diabetic nephropathy, renal interstitial fibrosis and some other kidney diseases, and inhibiting ferroptosis has potential renoprotective benefits. This article reviewed the pathophysiological mechanism of ferroptosis and its research progress in renal diseases, and discussed the application prospect of targeted ferroptosis in the treatment of renal diseases.

Objective To investigate the renoprotective effects of a Sichuan dark tea-based medicated dietary formula(alternatively referred to as Qing,or clarity in Chinese)on mice with diet-induced obesity(DIO)and to explore the specific mechanisms involved.Methods Male C57BL/6 mice were randomly assigned to three groups,a control group,a DIO group,and a Qing treatment group,or the Qing group,with 8 mice in each group.The mice in the control group were given normal maintenance feed and purified water,and the other two groups were fed a high-fat diet for 12 weeks to establish the DIO model.After that,high-fat diet continued in the DIO group,while the Qing group was given Qing at the same time for 12 weeks,during which period the weight of the mice was monitored and recorded every week.The mice were sacrificed after 12 weeks.Serum samples were collected and the levels of triglyceride(TG),total cholesterol(TC),alanine aminotransferase(ALT),aspartate aminotransferase(AST),and albumin were measured to evaluate liver function.In addition,renal lipids were extracted to determine the levels of TG and TC in the kidney and periodic acid-Schiff(PAS)and oil red O stainings were performed to evaluate kidney pathological injury.Western blot was performed to determine the phosphorylated AMPK(pAMPK)/AMPK ratio in the kidney tissue.RT-qPCR and Western blot were used to determine the expression of proteins related to fatty acid oxidation,including acetyl-CoA carboxylase 1(ACC1),carnitine acyltransferase 1(CTP1),peroxisome proliferators-activated receptor γ(PPARγ),peroxisome proliferators-activated receptor-1 α(PPAR1α),sterol-regulatory element binding proteins(SREBP-1),and key proteins related to lipid synthesis,including fatty acid synthase(FASN)and stearoyl-coenzyme A desaturase 1(stearoyl-CoA desaturase)in the kidney tissue.16SrRNA and metabolomics were applied to analyze the gut microbiota in the intestinal contents and its metabolites.Results Compared with those of the control group,the levels of liver mass(P=0.000 3),serum ALT(P＜0.000 1)and AST(P=0.0001),and kidney TC(P=0.0191)and TG(P=0.0101)of the DIO group were significantly increased and there was lipid deposition in the kidney.Compared with those of the DIO group,mice in the Qing group showed effective reduction in liver mass(P=0.0316)and improvements in the abnormal serum levels of AST(P=0.0012)and ALT(P=0.002 7)and kidney TC(P=0.0200)and TG(P=0.0499).In addition,mice in the Qing group showed significant improvement in lipid deposition in the kidney.Qing group showed increased pAMPK/AMPK ratio in comparison with that of the DIO group.In comparison with those of the control group,mice in the DIO group had upregulated expression of lipid synthesis-related genes and proteins(SREBP-1,FASN,and SCD1).As for the fatty acid oxidation-related genes and proteins,DIO mice showed upregulated expression of ACC1 and downregulated expression of CPT1A,PPARy,and PGC1α in comparison with those of the control group.In the Qing goup,improvements in regard to all these changes were observed.The Qing group demonstrated improvement in the disrupted homeostasis of the gut microbiota.Short-chain fatty acids in the cecal contents,especially isovaleric acid and propionic acid,were also restored.Conclusion Sichuan dark tea-based medicated dietary formula may improve renal lipid metabolism by regulating gut microbiota and the levels of intestinal short-chain fatty acids,thereby protecting obesity-related kidney injury.Isovaleric acid and propionic acid may be the metabolites key to its regulation of gut microbiota.

Biopsy ; Humans ; Nephrotic Syndrome ; Tibet