This study aims to explore the mechanism through which Yishen Jiangtang Decoction(YSJTD) regulates endoplasmic reticulum stress(ERS)-mediated NOD-like receptor thermal protein domain associated protein 3(NLRP3) inflammasome to improve diabetic nephropathy(DN) in db/db mice. Thirty db/db mice were randomly divided into the model group, YSJTD group, ERS inhibitor 4-phenylbutyric acid(4-PBA) group, with 10 mice in each group. Additionally, 10 db/m mice were selected as the control group. The YSJTD group was orally administered YSJTD at a dose of 0.01 mL·g~(-1), the 4-PBA group was orally administered 4-PBA at a dose of 0.5 mg·g~(-1), and the control and model groups were given an equal volume of carboxylmethyl cellulose sodium. The treatments were administered once daily for 8 weeks. Food intake, water consumption, and body weight were recorded every 2 weeks. After the intervention, fasting blood glucose(FBG), glycosylated hemoglobin(HbA1c), urine microalbumin(U-mALB), 24-hour urine volume, serum creatinine(Scr), and blood urea nitrogen(BUN) were measured. Inflammatory markers interleukin-1β(IL-1β) and interleukin-18(IL-18) were detected using the enzyme-linked immunosorbent assay(ELISA). Renal pathology was assessed through hematoxylin-eosin(HE), periodic acid-Schiff(PAS), and Masson staining, and transmission electron microscopy(TEM). Western blot was used to detect the expression levels of glucose-regulated protein 78(GRP78), C/EBP homologous protein(CHOP), NLRP3, apoptosis-associated speck-like protein containing CARD(ASC), cysteinyl aspartate-specific proteinase(caspase-1), and gasdermin D(GSDMD) in kidney tissues. The results showed that compared to the control group, the model group exhibited poor general condition, increased weight and food and water intake, and significantly higher levels of FBG, HbA1c, U-mALB, kidney index, 24-hour urine volume, IL-1β, and IL-18. Compared to the model group, the YSJTD and 4-PBA groups showed improved general condition, increased body weight, decreased food intake, and lower levels of FBG, U-mALB, kidney index, 24-hour urine volume, and IL-1β. Specifically, the YSJTD group showed a significant reduction in IL-18 levels compared to the model group, while the 4-PBA group exhibited decreased water intake and HbA1c levels compared to the model group. Although there was a decreasing trend in water intake and HbA1c in the YSJTD group, the differences were not statistically significant. No significant differences were observed in BUN, Scr, and kidney weight among the groups. Renal pathology revealed that the model group exhibited more severe renal damage compared to the control group. Kidney sections from the model group showed diffuse mesangial proliferation in the glomeruli, tubular edema, tubular dilation, significant inflammatory cell infiltration in the interstitium, and increased glycogen staining and blue collagen deposition in the basement membrane. In contrast, the YSJTD and 4-PBA groups showed varying degrees of improvement in renal damage, glycogen staining, and collagen deposition, with the YSJTD group showing more significant improvements. TEM analysis indicated that the model group had extensive cytoplasmic edema, homogeneous thickening of the basement membrane, fewer foot processes, and widening of fused foot processes. In the YSJTD and 4-PBA groups, cytoplasmic swelling of renal tissues was reduced, the basement membrane remained intact and uniform, and foot process fusion improved.Western blot results indicated that compared to the control group, the model group showed upregulation of GRP78, CHOP, GSDMD, NLRP3, ASC, and caspase-1 expression. In contrast, both the YSJTD and 4-PBA groups showed downregulation of these markers compared to the model group. These findings suggest that YSJTD exerts a protective effect against DN by alleviating NLRP3 inflammasome activation through the inhibition of ERS, thereby improving the inflammatory response in db/db DN mice.
Animals ; Endoplasmic Reticulum Stress/drug effects* ; Diabetic Nephropathies/metabolism* ; NLR Family, Pyrin Domain-Containing 3 Protein/genetics* ; Drugs, Chinese Herbal/administration & dosage* ; Mice ; Inflammasomes/drug effects* ; Male ; Kidney/pathology* ; Endoplasmic Reticulum Chaperone BiP ; Humans ; Interleukin-18/genetics* ; Mice, Inbred C57BL

Objective To investigate the impact of Qizhi Jiangtang Capsule (QZJT) on renal damage in diabetic nephropathy (DN) mice via NOD like receptors family pyrin domain containing 3/caspase-1/ Gasdermin D (NLRP3/caspase-1/GSDMD) signaling pathway. Methods Mice were randomly allocated into six experimental groups: a normal control group (NC), a diabetic nephropathy model group (DN), a low-dose QZJT treatment group (L-QZJT), a high-dose QZJT treatment group (H-QZJT), a positive control group administered Shenqi Jiangtang Granules (SQJT), and an ML385 group (treated with an inhibitor of nuclear factor erythroid 2-related factor 2, Nrf2). Upon successful model induction, therapeutic interventions were commenced. Renal function impairment in the mice was evaluated through quantification of fasting blood glucose (FBG), 24-hour urinary albumin (UAlb), serum creatinine (SCr), blood urea nitrogen (BUN), and the kidney-to-body mass ratio (K/B). Renal tissue pathology was evaluated using HE and PAS staining. Serum levels of inflammatory cytokines IL-1β and IL-18 were quantified by ELISA. Levels of podocyte markers and proteins involved in relevant pathways were assessed using Western blot analysis. Results Compared with the NC group, FBG, 24 h UAlb, SCr, and BUN were increased in the DN group, and the K/B mass ratio was also increased. In contrast, compared with the DN group, FBG, 24 h UAlb, SCr, and BUN in both the low-dose (L-QZJT) and high-dose Quanzhou Jintang (H-QZJT) groups were decreased, and the K/B mass ratio was decreased as well. The therapeutic efficacy of H-QZJT was comparable to that of Shenqi Jiangtang Granules. QZJT ameliorated renal histopathological injury in DN mouse, increased the protein levels of Nephrin (a podocyte marker), and decreased the protein levels of NLRP3, apoptosis-associated speck-like protein containing CARD (ASC), pro-caspase-1, and GSDMD-N. After ML385 treatment, renal cells exhibited swelling and morphological changes, the inflammatory infiltrate area was enlarged, the protein levels of NLRP3, ASC, pro-caspase-1, and GSDMD-N were up-regulated, and the levels of IL-1β and IL-18 were increased. Conclusion QZJT may inhibit podocyte pyroptosis by acting on the Nrf2 to regulate the NLRP3/caspase-1/GSDMD pathway, thus improving renal damage in DN mouse.
Animals ; Diabetic Nephropathies/pathology* ; Podocytes/pathology* ; NLR Family, Pyrin Domain-Containing 3 Protein/genetics* ; Pyroptosis/drug effects* ; Drugs, Chinese Herbal/administration & dosage* ; Caspase 1/genetics* ; Signal Transduction/drug effects* ; Mice ; Phosphate-Binding Proteins/genetics* ; Male ; Intracellular Signaling Peptides and Proteins/metabolism* ; Mice, Inbred C57BL ; Kidney/pathology* ; Gasdermins

OBJECTIVES: To investigate the protective effect of Yiqi Yangyin Huazhuo Tongluo Formula (YYHT) against high glucose-induced injury in mouse renal podocytes (MPC5 cells) and the possible mechanism. METHODS: Adult Wistar rats were treated with 19, 38, and 76 g/kg YYHT or saline via gavage for 7 days to prepare YYHT-medicated or blank sera for treatment of MPC5 cells cultured in high glucose (30 mmol/L) prior to transfection with a miR-21a-5p inhibitor or a miR-21a-5p mimic. The changes in miR-21a-5p expressions and the mRNA levels of FoxO1, PINK1, and Parkin in the treated cells were detected with qRT-PCR, and the protein levels of nephrin, podocin, FoxO1, PINK1, and Parkin were detected with Western blotting. Autophagic activity in the cells were evaluated with MDC staining. The effect of miR-21a-5p mimic on FoxO1 transcription and the binding of miR-21a-5p to FoxO1 were examined with luciferase reporter gene assay and radioimmunoprecipitation assay. RESULTS: MPC5 cells exposed to high glucose showed significantly increased miR-21a-5p expression, lowered expressions of FoxO1, PINK1, and Parkin1 mRNAs, and reduced levels of FoxO1, PINK1, parkin, nephrin, and podocin proteins and autophagic activity. Treatment of the exposed cells with YYHT-medicated sera and miR-21a-5p inhibitor both significantly enhanced the protein expressions of nephrin and podocin, inhibited the expression of miR-21a-5p, increased the mRNA and protein expressions of FoxO1, PINK1 and Parkin, and upregulated autophagic activity of the cells. Transfection with miR-21a-5p mimic effectively inhibited the transcription of FoxO1 and promoted the binding of miR-21a-5p to FoxO1 in MPC5 cells, and these effects were obviously attenuated by treatment with YYHT-medicated sera. CONCLUSIONS YYHT-medicated sera alleviate high glucose-induced injury in MPC5 cells by regulating miR-21a-5p/FoxO1/PINK1-mediated mitochondrial autophagy.
Animals ; MicroRNAs/genetics* ; Podocytes/pathology* ; Drugs, Chinese Herbal/pharmacology* ; Autophagy/drug effects* ; Rats, Wistar ; Protein Kinases/metabolism* ; Rats ; Forkhead Box Protein O1 ; Mice ; Mitochondria/drug effects* ; Ubiquitin-Protein Ligases/metabolism* ; Glucose ; Diabetic Nephropathies ; Male ; Membrane Proteins/metabolism* ; Intracellular Signaling Peptides and Proteins

OBJECTIVES: To investigate the mechanism by which Guijianyu ameliorates podocyte injury in a mouse model of diabetic kidney disease (DKD) induced by advanced glycation endproducts (AGEs). METHODS: Sixty db/db mouse models of DKD were randomized equally into 5 groups for treatment with saline, Guijianyu extract at 3 doses or irbesartan for 12 weeks, and the changes in renal pathology and structure were observed using transmission electron microscopy, and the expressions of related genes and key proteins were detected using RT-qPCR and immunohistochemistry. In cultured MPC-5 cells incubated with 50 mg/L AGEs-BSA for 24 h, the effect of different concentrations of Guijianyu extract on cell viability was examined with CCK-8 assay; Western blotting was performed to detect the protein expressions of RAGE, VEGFA, TNF-α, NF-κB(p65), IL-6 and caspase-3, and the mRNA expressions of RAGE, NF-κB (p65), VEGFA and IL-6 were detected with RT-qPCR. RESULTS: In mouse models of DKD, treatment with high-dose Guijianyu extract significantly reduced renal expressions of RAGE, VEGFA, NF-κB(p65), and IL-6 proteins and the mRNA expressions of RAGE, NF-κB, and IL-6. In MPC-5 cells, exposure to AGEs significantly reduced cell viability and increased the protein expressions of RAGE, NF‑κB (p65), VEGFA, TNF-α, IL-6 and caspase-3 (P<0.05) and mRNA expressions of RAGE, NF-κB (p65), VEGFA, and IL-6. Treatment with Guijianyu extract obviously improved cell viability and reduced the expressions of RAGE, NF-κB(p65), VEGFA, TNF-α, IL-6, and caspase-3. Furthermore, Guijianyu extract effectively reversed RAGE agonist-induced elevation of protein expressions of RAGE, VEGFA, TNF-α, IL-6, and caspase-3 and mRNA expressions of RAGE, NF-κB (p65), IL-6, and VEGFA in MPC-5 cells. CONCLUSIONS Guijianyu extract ameliorates AGEs-induced mouse renal podocyte injury in DKD by inhibiting the activation of AGEs-RAGE signaling pathway and reducing the expressions of pro-inflammatory cytokines and vascular endothelial growth factors.
Animals ; Glycation End Products, Advanced ; Drugs, Chinese Herbal/pharmacology* ; Mice ; Signal Transduction/drug effects* ; Podocytes/pathology* ; Diabetic Nephropathies/drug therapy* ; Receptor for Advanced Glycation End Products ; Vascular Endothelial Growth Factor A/metabolism* ; Interleukin-6/metabolism* ; Male

OBJECTIVES: To explore the mechanism of transforming growth factor-β1 (TGF-β1) induce renal fibrosis. METHODS: Renal fibroblast NRK-49F cells treated with and without TGF-β1 were subjected to RNA-seq analysis. DESeq2 was used for analysis. Differentially expressed genes were screened with the criteria of false discovery rate<0.05 and l o g 2 F C >1. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed for differentially expressed genes. Genes encoding transcription factors were further screened for differential expression genes. Then, the expression of these genes during renal fibrosis was verified using unilateral ureteral obstruction (UUO)-induced mouse renal fibrosis model and a public gene expression dataset (GSE104954). RESULTS: After TGF-β1 treatment for 6, 12 and 24 h, 552, 1209 and 1028 differentially expressed genes were identified, respectively. GO analysis indicated that these genes were significantly enriched in development, cell death, and cell migration. KEGG pathway analysis showed that in the early stage of TGF-β1 induction (TGF-β1 treatment for 6 h), the changes in Hippo, TGF-β and Wnt signaling pathways were observed, while in the late stage of TGF-β1 induction (TGF-β1 treatment for 24 h), the changes of extracellular matrix-receptor interaction, focal adhesion and adherens junction were mainly enriched. Among the 291 up-regulated differentially expressed genes treated with TGF-β1 for 6 h, 13 genes (Snai1, Irf8, Bhlhe40, Junb, Arid5a, Vdr, Lef1, Ahr, Foxo1, Myc, Tcf7, Foxc2, Glis1) encoded transcription factors. Validation in a cell model showed that TGF-β1 induced expression of 9 transcription factors (encoded by Snai1, Irf8, Bhlhe40, Junb, Arid5a, Vdr, Lef1, Myc, Tcf7), while the expression levels of the other 4 genes did not significantly change after TGF-β1 treatment. Validation results in UUO-induced mouse renal fibrosis model showed that Snai1, Irf8, Bhlhe40, Junb, Arid5a, Myc and Tcf7 were up-regulated after UUO, Vdr was down-regulated and there was no significant change in Lef1. Validation based on the GSE104954 dataset showed that IRF8 was significantly overexpressed in the renal tubulointerstitium of patients with diabetic nephropathy or IgA nephropathy, MYC was highly expressed in diabetic nephropathy, and the expressions of the other 7 genes were not significantly different compared with the control group. CONCLUSIONS TGF-β1 induces differentially expressed genes in renal fibroblasts, among which Irf8 and Myc were identified as potential targets of chronic kidney disease and renal fibrosis.
Mice ; Animals ; Humans ; Transforming Growth Factor beta1/metabolism* ; Diabetic Nephropathies/pathology* ; Transcriptome ; Signal Transduction ; Kidney ; Ureteral Obstruction/pathology* ; Fibrosis ; Interferon Regulatory Factors ; Transforming Growth Factor beta/metabolism* ; DNA-Binding Proteins/metabolism* ; Transcription Factors/metabolism*

Diabetic kidney disease (DKD) is the primary cause of mortality among diabetic patients. With the increasing prevalence of diabetes, it has become a major concern around the world. The therapeutic effect of clinical use of drugs is far from expected, and therapy choices to slow the progression of DKD remain restricted. Therefore, research on new drugs and treatments for DKD has been a hot topic in the medical field. It has been found that rhein has the potential to target the pathogenesis of DKD and has a wide range of pharmacological effects on DKD, such as anti-nephritis, decreasing blood glucose, controlling blood lipids and renal protection. In recent years, the medical value of rhein in the treatment of diabetes, DKD and renal disease has gradually attracted worldwide attention, especially its potential in the treatment of DKD. Currently, DKD can only be treated with medications from a single symptom and are accompanied by adverse effects, while rhein improves DKD with a multi-pathway and multi-target approach. Therefore, this paper reviews the therapeutic effects of rhein on DKD, and proposes solutions to the limitations of rhein itself, in order to provide valuable references for the clinical application of rhein in DKD and the development of new drugs.
Humans ; Diabetic Nephropathies/drug therapy* ; Kidney/pathology* ; Anthraquinones/therapeutic use* ; Diabetes Mellitus

Diabetic kidney disease is an important microvascular complication of diabetes and the leading cause of end-stage renal disease. Its pathological characteristics mainly include epithelial mesenchymal transition(EMT) in glomerulus, podocyte apoptosis and autophagy, and damage of glomerular filtration barrier. Transforming growth factor-β(TGF-β)/Smad signaling pathway is specifically regulated by a variety of mechanisms, and is a classic pathway involved in physiological activities such as apoptosis, proliferation and differentiation. At present, many studies have found that TGF-β/Smad signaling pathway plays a key role in the pathogenesis of diabetic kidney disease. Traditional Chinese medicine has significant advantages in the treatment of diabetic kidney disease for its multi-component, multi-target and multi-pathway characteristics, and some traditional Chinese medicine extracts, traditional Chinese medicines and traditional Chinese medicine compound prescription improve the renal injury of diabetic kidney disease by regulating TGF-β/Smad signaling pathway. This study clarified the mechanism of TGF-β/Smad signaling pathway in diabetic kidney disease by expounding the relationship between the key targets of the pathway and diabetic kidney disease, and summarized the research progress of traditional Chinese medicine in the treatment of diabetic kidney disease by interfering with TGF-β/Smad signaling pathway in recent years, to provide reference for drug research and clinical treatment of diabetic kidney disease in the future.
Humans ; Diabetic Nephropathies/genetics* ; Medicine, Chinese Traditional ; Kidney/pathology* ; Transforming Growth Factor beta/metabolism* ; Signal Transduction ; Epithelial-Mesenchymal Transition ; Smad Proteins/metabolism* ; Transforming Growth Factor beta1/metabolism* ; Diabetes Mellitus/genetics*

Objective To investigate the effect of 1, 25-(OH)₂-VitD3 (VitD3) on renal tubuleinterstitial fibrosis in diabetic kidney disease. Methods NRK-52E renal tubular epithelial cells were divided into control group (5.5 mmol/L glucose medium treatment), high glucose group (25 mmol/L glucose medium treatment) and high glucose with added VitD3 group (25 mmol/L glucose medium combined with 10^-8 mmol/L VitD3). The mRNA and protein expression of Snail1, SMAD3, SMAD4, α-SMA and E-cadherin in NRK-52E cells were detected by real-time quantitative PCR and Western blot analysis respectively. The expression and localization of Snail1, SMAD3 and SMAD4 were detected by immunofluorescence cytochemical staining. The binding of Snail1 with SMAD3/SMAD4 complex to the promoter of Coxsackie-adenovirus receptor (CAR) was detected by chromatin immunoprecipitation. The interaction among Snail1, SMAD3/SMAD4 and E-cadherin were detected by luciferase assay. Small interfering RNA (siRNA) was used to inhibit the expression of Snail1 and SMAD4, and the expression of mRNA of E-cadherin was detected by real-time quantitative PCR. SD rats were randomly divided into control group, DKD group and VitD3-treated group. DKD model was established by injection of streptozotocin (STZ) in DKD group and VitD3-treated group. After DKD modeling, VitD3-treated group was given VitD3 (60 ng/kg) intragastric administration. Control group and DKD group were given normal saline intragastric administration. In the DKD group and VitD3-treated group, insulin (1-2 U/kg) was injected subcutaneously to control blood glucose for 8 weeks. The mRNA and protein levels of Snail1, SMAD3, SMAD4, α-SMA and E-cadherin in renal tissues were detected by real-time quantitative PCR and Western blot analysis respectively. Immunohistochemistry was used to detect the expression and localization of Snail1, SMAD3, SMAD4, α-SMA and E-cadherin in renal tissue. Results Compared with the control group, the mRNA and protein expressions of Snail1, SMAD3, SMAD4 and α-SMA in NRK-52E cells cultured with high glucose and in DKD renal tissues were up-regulated, while E-cadherin expression was down-regulated. After the intervention of VitD3, the expression levels of Snail1, SMAD3, SMAD4, α-SMA and E-cadherin in the DKD model improved to be close to those in the control group. Chromatin immunoprecipitation showed that Snail1 and SMAD3/SMAD4 bound to CAR promoter IV, while VitD3 prevented Snail1 and SMAD3/SMAD4 from binding to CAR promoter IV. Luciferase assay confirmed the interaction among Snail1, SMAD3/SMAD4 and E-cadherin. After the mRNA of Snail1 and SMAD4 was inhibited by siRNA, the expression of E-cadherin induced by high glucose was up-regulated. Conclusion VitD3 could inhibit the formation of Snail1-SMAD3/SMAD4 complex and alleviate the renal tubulointerstitial fibrosis in DKD.
Animals ; Rats ; Cadherins/genetics* ; Diabetes Mellitus/pathology* ; Diabetic Nephropathies/pathology* ; Epithelial-Mesenchymal Transition ; Fibrosis/pathology* ; Glucose/pharmacology* ; Kidney/pathology* ; Rats, Sprague-Dawley ; RNA, Messenger ; RNA, Small Interfering ; Transforming Growth Factor beta1/metabolism* ; Vitamin D/pharmacology*

Humans ; Diabetic Nephropathies/pathology* ; Kidney/pathology* ; Biopsy ; Diabetes Mellitus, Type 2/pathology* ; Retrospective Studies ; Glomerular Filtration Rate ; Disease Progression

Animals ; Cell Line ; Diabetic Nephropathies ; metabolism ; Epithelial-Mesenchymal Transition ; drug effects ; Eukaryotic Initiation Factor-2 ; metabolism ; Glucose ; pharmacology ; Humans ; Kidney ; drug effects ; metabolism ; pathology ; Kidney Tubules, Proximal ; drug effects ; metabolism ; Rats ; Signal Transduction ; drug effects