Moshen granule ameliorates membranous nephropathy by blocking intrarenal renin-angiotensin system signalling via the Wnt1/β-catenin pathway

Diosgenin protects against cationic bovine serum albumin-induced membranous glomerulonephritis by attenuating oxidative stress and renal inflammation via the NF-κB pathway

CONTEXT

Membranous glomerulonephritis (MGN) is a leading cause of nephrotic syndrome in adults. Diosgenin (DG) has been reported to exert antioxidative and anti-inflammatory effects.

OBJECTIVE

To investigate the renoprotective activity of DG in a cationic bovine serum albumin-induced rat model of MGN.

MATERIALS AND METHODS

Fourty male Sprague-Dawley rats were randomized into four groups. The MGN model was established and treated with a DG dose (10 mg/kg) and a positive control (TPCA1, 10 mg/kg), while normal control and MGN groups received distilled water by gavage for four consecutive weeks. At the end of the experiment, 24 h urinary protein, biochemical indices, oxidation and antioxidant levels, inflammatory parameters, histopathological examination, immunohistochemistry and immunoblotting were evaluated.

RESULTS

DG significantly ameliorated kidney dysfunction by decreasing urinary protein (0.56-fold), serum creatinine (SCr) (0.78-fold), BUN (0.71-fold), TC (0.66-fold) and TG (0.73-fold) levels, and increasing ALB (1.44-fold). DG also reduced MDA (0.82-fold) and NO (0.83-fold) levels while increasing the activity of SOD (1.56-fold), CAT (1.25-fold), glutathione peroxidase (GPx) (1.55-fold) and GSH (1.81-fold). Furthermore, DG reduced Keap1 (0.76-fold) expression, Nrf2 nuclear translocation (0.79-fold), and induced NQO1 (1.25-fold) and HO-1 (1.46-fold) expression. Additionally, DG decreased IL-2 (0.55-fold), TNF-α (0.80-fold) and IL-6 (0.75-fold) levels, and reduced protein expression of NF-κB p65 (0.80-fold), IKKβ (0.93-fold), p-IKKβ (0.89-fold), ICAM-1 (0.88-fold), VCAM-1 (0.91-fold), MCP-1 (0.88-fold) and E-selectin (0.87-fold), and also inhibited the nuclear translocation of NF-κB p65 (0.64-fold).

DISCUSSION AND CONCLUSIONS

The results suggest a potential therapeutic benefit of DG against MGN due to the inhibition of the NF-κB pathway, supporting the need for further clinical trials.

Oridonin ameliorates renal fibrosis in diabetic nephropathy by inhibiting the Wnt/β-catenin signaling pathway

Diabetic nephropathy (DN) is one of the most serious and frequent complications among diabetes patients and presently constitutes vast the cases of end-stage renal disease worldwide. Tubulointerstitial fibrosis is a crucial factor related to the occurrence and progression of DN. Oridonin (Ori) is a diterpenoid derived from rubescens that has diverse pharmacological properties. Our previous study showed that Ori can protect against DN by decreasing the inflammatory response. However, whether Ori can alleviate renal fibrosis in DN remains unknown. Here, we investigated the mechanism through which Ori affects the Wnt/β-catenin signaling pathway in diabetic rats and human proximal tubular epithelial cells (HK-2) exposed to high glucose (HG) levels. Our results revealed that Ori treatment markedly decreased urinary protein excretion levels, improved renal function and alleviated renal fibrosis in diabetic rats. In vitro, HG treatment increased the migration of HK-2 cells while reducing their viability and proliferation rate, and treatment with Ori reversed these changes. Additionally, the knockdown of β-catenin arrested cell migration and reduced the expression levels of Wnt/β-catenin signaling-related molecules (Wnt4, p-GSK3β and β-catenin) and fibrosis-related molecules (α-smooth muscle actin, collagen I and fibronectin), and Ori treatment exerted an effect similar to that observed after the knockdown of β-catenin. Furthermore, the combination of Ori treatment and β-catenin downregulation exerted more pronounced biological effects than treatment alone. These findings may provide the first line of evidence showing that Ori alleviates fibrosis in DN by inhibiting the Wnt/β-catenin signaling pathway and thereby reveal a novel therapeutic avenue for treating tubulointerstitial fibrosis.

Geniposidic Acid Attenuates Chronic Tubulointerstitial Nephropathy Through Regulation of the NF-ƙB/Nrf2 Pathway Via Aryl Hydrocarbon Receptor Signaling

Renal fibrosis is an outcome of chronic kidney disease, independent of the underlying etiology. Renal fibrosis is caused primarily by oxidative stress and inflammation. We identified the components of Plantaginis semen and elucidated their anti-fibrotic and anti-inflammatory mechanisms. The renoprotective components and underlying molecular mechanisms of P. semen were investigated in rats with adenine-induced chronic tubulointerstitial nephropathy (TIN) and in idole-3-acetic acid (IAA)-stimulated NRK-52E cells. Acetate and n-butanol extracts were found to be the bioactive fractions of P. semen. A total of 65 compounds including geniposidic acid (GPA), apigenin (APG), and acteoside (ATS) were isolated and identified. Among the seven main extract components, treatment with GPA, APG, and ATS reduced the serum levels of creatinine and urea in TIN rats. Mechanistically, GPA ameliorated renal fibrosis through repressing aryl hydrocarbon receptor (AHR) signaling and regulating redox signaling including inhibiting proinflammatory nuclear factor kappa B (NF-ƙB) and its target gene products as well as activated antioxidative nuclear factor-erythroid-2-related factor 2 (Nrf2) and its downstream target gene products in both TIN rats and IAA-stimulated NRK-52E cells. The inhibitory effect of GPA on AHR, NF-Ƙb, and Nrf2 signaling were partially abolished in IAA-stimulated NRK-52E cells treated with CH223191 compared with untreated IAA-stimulated NRK-52E cells. These data demonstrated that GPA alleviates oxidative stress and inflammation partly by suppressing AHR signaling.

Barleriside A, an aryl hydrocarbon receptor antagonist, ameliorates podocyte injury through inhibiting oxidative stress and inflammation

Introduction

Increasing evidence shows that hyperactive aryl hydrocarbon receptor (AHR) signalling is involved in renal disease. However, no currently available intervention strategy is effective in halting disease progression by targeting the AHR signalling. Our previous study showed that barleriside A (BSA), a major component of Plantaginis semen, exhibits renoprotective effects.

Methods

In this study, we determined the effects of BSA on AHR expression in 5/6 nephrectomized (NX) rats. We further determined the effect of BSA on AHR, nuclear factor kappa B (NF-ƙB), and the nuclear factor erythroid 2-related factor 2 (Nrf2) signalling cascade in zymosan-activated serum (ZAS)-stimulated MPC5 cells.

Results

BSA treatment improved renal function and inhibited intrarenal nuclear AHR protein expression in NX-treated rats. BSA mitigated podocyte lesions and suppressed AHR mRNA and protein expression in ZAS-stimulated MPC5 cells. BSA inhibited inflammation by improving the NF-ƙB and Nrf2 pathways in ZAS-stimulated MPC5 cells. However, BSA did not markedly upregulate the expression of podocyte-specific proteins in the ZAS-mediated MPC5 cells treated with CH223191 or AHR siRNA compared to untreated ZAS-induced MPC5 cells. Similarly, the inhibitory effects of BSA on nuclear NF-ƙB p65, Nrf2, and AHR, as well as cytoplasmic cyclooxygenase-2, heme oxygenase-1, and AHR, were partially abolished in ZAS-induced MPC5 cells treated with CH223191 or AHRsiRNA compared with untreated ZAS-induced MPC5 cells. These results indicated that BSA attenuated the inflammatory response, partly by inhibiting AHR signalling.

Discussion

Both pharmacological and siNRA findings suggested that BSA mitigated podocyte lesions by improving the NF-ƙB and Nrf2 pathways via inhibiting AHR signalling. Therefore, BSA is a high-affinity AHR antagonist that abolishes oxidative stress and inflammation.

Effects of Inonotus obliquus on ameliorating podocyte injury in ORG mice through TNF pathway and prediction of active compounds

Background

Podocyte injury is a common pathologic mechanism in diabetic kidney disease (DKD) and obesity-related glomerulopathy (ORG). Our previous study confirmed that Inonotus obliquus (IO) improved podocyte injury on DKD rats. The current study explored the pharmacological effects, related mechanisms and possible active components of IO on ORG mice.

Methods

Firstly, by combining ultra-high performance liquid chromatography tandem mass spectrometry analysis (UPLC-Q-TOF-MS) with network pharmacology to construct the human protein-protein interaction mechanism and enrich the pathway, which led to discover the crucial mechanism of IO against ORG. Then, ORG mice were established by high-fat diet and biochemical assays, histopathology, and Western blot were used to explore the effects of IO on obesity and podocyte injury. Finally, network pharmacology-based findings were confirmed by immunohistochemistry. The compositions of IO absorbed in mice plasma were analyzed by UPLC-Q-TOF-MS and molecular docking was used to predict the possible active compounds.

Results

The network pharmacology result suggested that IO alleviated the inflammatory response of ORG by modulating TNF signal. The 20-week in vivo experiment confirmed that IO improved glomerular hypertrophy, podocyte injury under electron microscopy, renal nephrin, synaptopodin, TNF-α and IL-6 expressions with Western blotting and immunohistochemical staining. Other indicators of ORG such as body weight, kidney weight, serum total cholesterol, liver triglyceride also improved by IO intervention. The components analysis showed that triterpenoids, including inoterpene F and trametenolic acid, might be the pharmacodynamic basis.

Conclusion

The research based on UPLC-Q-TOF-MS analysis, network pharmacology and in vivo experiment suggested that the amelioration of IO on podocyte injury in ORG mice via its modulation on TNF signal. Triterpenoids were predicated as acting components.

Bile acid metabolism in health and ageing-related diseases

Bile acids (BAs) have surpassed their traditional roles as lipid solubilizers and regulators of BA homeostasis to emerge as important signalling molecules. Recent research has revealed a connection between microbial dysbiosis and metabolism disruption of BAs, which in turn impacts ageing-related diseases. The human BAs pool is primarily composed of primary BAs and their conjugates, with a smaller proportion consisting of secondary BAs. These different BAs exert complex effects on health and ageing-related diseases through several key nuclear receptors, such as farnesoid X receptor and Takeda G protein-coupled receptor 5. However, the underlying molecular mechanisms of these effects are still debated. Therefore, the modulation of signalling pathways by regulating synthesis and composition of BAs represents an interesting and novel direction for potential therapies of ageing-related diseases. This review provides an overview of synthesis and transportion of BAs in the healthy body, emphasizing its dependence on microbial community metabolic capacity. Additionally, the review also explores how ageing and ageing-related diseases affect metabolism and composition of BAs. Understanding BA metabolism network and the impact of their nuclear receptors, such as farnesoid X receptor and G protein-coupled receptor 5 agonists, paves the way for developing therapeutic agents for targeting BA metabolism in various ageing-related diseases, such as metabolic disorder, hepatic injury, cardiovascular disease, renal damage and neurodegenerative disease.

TMEM16A inhibits renal tubulointerstitial fibrosis via Wnt/β-catenin signaling during hypertension nephropathy

BACKGROUND AND OBJECTIVE

Hypertensive nephropathy is the second leading cause of end-stage renal disease, but its underlying pathogenesis remains unclear. Therefore, this study aimed to explore whether transmembrane protein 16 A (TMEM16A), the molecular basis of calcium-activated chloride channels (CaCC), is involved in the development and progression of hypertensive nephropathy.

METHODS

In vivo and in vitro experiments were conducted using a hypertensive murine model and human kidney proximal tubular epithelial cells (HK-2 cells), respectively.

EXPERIMENTAL RESULTS

The expression of TMEM16A was down-regulated in renal samples of hypertensive nephropathy patients and hypertensive model mice, accompanied by excessive deposition of extracellular matrix proteins (ECM) such as Fibronectin, Laminin, Collagen I and Collagen III, the up-regulation of α-smooth muscle actin (α-SMA) expression, and the decrease of E-cadherin. Overexpression of TMEM16A or knockdown of TMEM16A inhibited or promoted the expression of Wnt/β-catenin signaling pathway proteins Wnt3a, LRP5 and active β-catenin in HK-2 cells, preventing the epithelial-to-mesenchymal transition (EMT) of renal tubules, and the synthesis of ECM components.

CONCLUSION

In angiotensin II (Ang II)-induced hypertensive nephropathy, TMEM16A was identified as a key player inhibiting the detrimental changes in renal tubules, suggesting a potential avenue for mitigating renal damage in hypertensive nephropathy.

Traditional Chinese medicine for idiopathic membranous nephropathy: A systematic review and meta-analysis

Background

Idiopathic membranous nephropathy (IMN) is a rare autoimmune disorder that causes nephrotic syndromes in adults. Conventional immunosuppressive therapies often exhibit limited efficacy in achieving remission and may result in notable adverse reactions, warranting the exploration of novel therapeutic approaches for IMN treatment. Traditional Chinese medicine (TCM), which is extensively used for kidney disease management, is a promising alternative.

Objective

This study aimed to examine the safety and efficacy of TCM alone or in combination with Western medicine for the management of patients diagnosed with IMN.

Methods

This study employed a systematic search of English and Chinese electronic databases to identify randomized controlled trials (RCTs) that examined the application of TCM in the treatment of IMN. RCTs that met the predetermined inclusion and exclusion criteria and assessed the safety and efficacy of TCM alone or in combination with Western medicine in patients with IMN were included in the analysis. The methodological quality of the included studies was evaluated by using a risk-of-bias tool. All statistical analyses were performed using the RevMan software (version 5.4.2). The evidence was evaluated on the https://www.gradepro.org/website.

Results

This study included 29 randomized controlled trials (RCTs) involving 1982 patients with moderate methodological quality that met the inclusion criteria. The results showed that, compared to Western medicine alone therapy, the use of TCM alone or in combination with Western medicine significantly improved total remission (TR) rate (risk ratios [RR] 1.38, 95% confidence interval [CI] 1.29-1.46, I2 = 0%, P < 0.00001), complete remission (CR) rate (RR 1.78, 95% CI 1.48-2.15, I2 = 0, P < 0.00001), partial remission (PR) rate (RR 1.27, 95% CI 1.161.40, I2 = 0%, P < 0.00001), and serum albumin (ALB) levels (MD: 4.05, 95% CI: 3.02-5.09, I2 = 91%, P < 0.00001). TCM alone or in combination with Western medicine also reduced proteinuria levels (mean difference [MD]: 1.05, 95% CI: 1.30 to -0.79, I2 = 95%, P < 0.00001), serum creatinine (SCr) levels (MD: 7.47, 95% CI: 13.70 to -1.24, I2 = 97%, P = 0.02), and serum antibodies against M-type phospholipase A2 receptor levels (aPLA2Rab) (MD: 19.24, 95% CI: 33.56 to -4.93, I2 = 87%, P = 0.008). Moreover, the efficacy of combined TCM and Western medicine is superior to that of Western medicine alone in reducing the incidence of infection, hepatotoxicity, and thrombosis. Although the primary and secondary outcomes were consistent, the evidence was generally moderate.

Conclusion

The results of this study suggest that TCM alone or in combination with Western medicine may be a feasible alternative therapeutic approach for the treatment of IMN. Nevertheless, additional, rigorously designed, high-quality, and extensive clinical trials are imperative to provide substantial evidence regarding the effectiveness of TCM in managing IMN.

The nuclear factor kappa B signaling pathway is a master regulator of renal fibrosis

Renal fibrosis is increasingly recognized as a global public health problem. Acute kidney injury (AKI) and chronic kidney disease (CKD) both result in renal fibrosis. Oxidative stress and inflammation play central roles in progressive renal fibrosis. Oxidative stress and inflammation are closely linked and form a vicious cycle in which oxidative stress induces inflammation through various molecular mechanisms. Ample evidence has indicated that a hyperactive nuclear factor kappa B (NF-ƙB) signaling pathway plays a pivotal role in renal fibrosis. Hyperactive NF-ƙB causes the activation and recruitment of immune cells. Inflammation, in turn, triggers oxidative stress through the production of reactive oxygen species and nitrogen species by activating leukocytes and resident cells. These events mediate organ injury through apoptosis, necrosis, and fibrosis. Therefore, developing a strategy to target the NF-ƙB signaling pathway is important for the effective treatment of renal fibrosis. This Review summarizes the effect of the NF-ƙB signaling pathway on renal fibrosis in the context of AKI and CKD (immunoglobulin A nephropathy, membranous nephropathy, diabetic nephropathy, hypertensive nephropathy, and kidney transplantation). Therapies targeting the NF-ƙB signaling pathway, including natural products, are also discussed. In addition, NF-ƙB-dependent non-coding RNAs are involved in renal inflammation and fibrosis and are crucial targets in the development of effective treatments for kidney disease. This Review provides a clear pathophysiological rationale and specific concept-driven therapeutic strategy for the treatment of renal fibrosis by targeting the NF-ƙB signaling pathway.

Lactobacillus species ameliorate membranous nephropathy through inhibiting the aryl hydrocarbon receptor pathway via tryptophan-produced indole metabolites

BACKGROUND AND PURPOSE

Membranous nephropathy (MN) is an immune-mediated glomerular disease in adults. Antibody- and antigen-bonding mechanisms have been largely clarified, but the subepithelium immune complex deposition-mediated downstream molecular mechanisms are currently unresolved. Increasing evidence has suggested that gut microbiota contribute to MN pathogenesis.

EXPERIMENTAL APPROACH

In this study, we identified alterations in faecal gut microbiota and serum metabolites that mediate an aryl hydrocarbon receptor (AhR) mechanism in cationic bovine serum albumin (CBSA)-induced MN rats and in patients with idiopathic MN (IMN).

KEY RESULTS

Impaired renal function correlated with the relative abundance of reduced faecal probiotics, Lactobacillus and Bifidobacterium, and altered serum levels of tryptophan-produced indole derivatives (TPIDs) in MN rats. Further results showed that reduced relative abundance of five probiotics, namely Lactobacillus johnsonii, Lactobacillus murinus, Lactobacillus vaginalis, Lactobacillus reuteri and Bifidobacterium animalis, positively correlated with decreased levels of indole-3-pyruvic acid, indole-3-aldehyde and tryptamine and negatively correlated with increased levels of indole-3-lactic acid and indole-3-acetic acid in serum of MN rats. Altered five probiotics and five TPIDs also were observed in patients with IMN. Further studies showed that MN rats exhibited a significant increase in intrarenal mRNA expression of AhR and its target genes CYP1A1, CYP1A2 and CYP1B1, which were accompanied by protein expression of down-regulated cytoplasmic AhR, but up-regulated nuclear AhR, in MN rats and IMN patients.

CONCLUSION AND IMPLICATIONS

Activation of the intrarenal AhR signalling pathway may involve five TPIDs. These data suggest that gut microbiota could influence MN through TPIDs that engage host receptors.

Sirtuin 6 protects against podocyte injury by blocking the renin-angiotensin system by inhibiting the Wnt1/β-catenin pathway

Sirtuins (Sirts) are a family of nicotinamide adenine dinucleotide-dependent protein deacetylases that share diverse cellular functions. Increasing evidence shows that Sirts play a critical role in podocyte injury, which is a major determinant of proteinuria-associated renal disease. Membranous nephropathy (MN) is a typical glomerular disease in which podocyte damage mediates proteinuria development. In this study we investigated the molecular mechanisms underlying the regulatory roles of Sirt in podocyte injury in MN patients, rats with cationic bovine serum albumin (CBSA)-induced MN and zymosan activation serum (ZAS)-stimulated podocytes. Compared with healthy controls, MN patients showed significant reduction in intrarenal Sirt1 and Sirt6 protein expression. In CBSA-induced MN rats, significant reduction in intrarenal Sirt1, Sirt3 and Sirt6 protein expression was observed. However, only significant decrease in Sirt6 protein expression was found in ZAS-stimulated podocytes. MN patients showed significantly upregulated protein expression of Wnt1 and β-catenin and renin-angiotensin system (RAS) components in glomeruli. CBSA-induced MN rats exhibited significantly upregulated protein expression of intrarenal Wnt1 and β-catenin and their downstream gene products as well as RAS components. Similar results were observed in ZAS-stimulated podocytes. In ZAS-stimulated podocytes, treatment with a specific Sirt6 activator UBCS039 preserved the protein expression of podocin, nephrin and podocalyxin, accompanied by significant inhibition of the protein expression of β-catenin and its downstream gene products, including Snail1 and Twist; treatment with a β-catenin inhibitor ICG-001 significantly preserved the expression of podocyte-specific proteins and inhibited the upregulation of downstream β-catenin gene products accompanied by significant suppression of the protein expression of RAS components. Thus, we demonstrate that Sirt6 ameliorates podocyte injury by blocking RAS signalling via the Wnt1/β-catenin pathway. Sirt6 is a specific therapeutic target for the treatment of podocyte damage-associated renal disease.

Network Pharmacology and Molecular Docking Validation to Explore the Pharmacological Mechanism of Zhuling Decoction against Nephrotic Syndrome

BACKGROUND

In recent years, the incidence and prevalence of Nephrotic Syndrome (NS) have been increasing. Zhuling Decoction (ZLD), a classical Chinese medicine, has been clinically proven to be effective for the treatment of NS. However, its underlying mechanism and pharmacodynamic substances remain unclear.

OBJECTIVE

This study aimed to explore the mechanism of action and chemical components of ZLD against NS using network pharmacology and molecular docking.

METHODS

Traditional Chinese Medicine Systems Pharmacology (TCMSP), Bioinformatics Analysis Tool for Molecular Mechanism of Traditional Chinese Medicines (BATMAN-TCM), and SwissTargetPrediction databases were used to screen the principal ingredients and the associated targets of ZLD. NS-related targets were obtained from the Online Mendelian Inheritance in Man (OMIM), GeneCards, Therapeutic Target Database (TTD), and Drugbank databases. Shared targets were derived by the intersection of ZLD- and NS-associated targets. Protein-interaction relationships were analyzed using the STRING database and Cytoscape. A visualized drug-active compound-target network of ZLD was established using Cytoscape. Analyses of gene enrichment were performed using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) methods by the Database for Annotation, Visualization, and Integrated Discovery (DAVID) database. Molecular docking was performed to assess the binding activity between active components and hub targets.

RESULTS

Polyporusterone E, cerevisterol, alisol B, and alisol B 23-acetate were the primary potential ingredients of ZLD. HMGCR, HSD11B1, NOS2, NR3C1, and NR3C2 were the hub targets of ZLD against NS. Molecular docking showed that polyporusterone E, cerevisterol, and alisol B had high binding activities with targets HMGCR, HSD11B1, and NOS2.

CONCLUSION

In summary, this study suggests that the main active compounds (polyporusterone E, cerevisterol, alisol B) may have important roles for ZLD acting against NS by binding to hub targets (HMGCR, HSD11B1, and NOS2) and modulating PI3K-Akt, Ras, MAPK, and HIF-1 signaling pathways.

Oxidative stress and inflammation are mediated via aryl hydrocarbon receptor signalling in idiopathic membranous nephropathy

Membranous nephropathy (MN) patients are diagnosed by the presence of phospholipase A2 receptor (PLA2R) before they progress to renal failure. However, the subepithelium-like immunocomplex deposit-mediated downstream molecular pathways are poorly understood. The aryl hydrocarbon receptor (AHR), NF-ƙB and Nrf2 pathways play central roles in the pathogenesis and progression of chronic kidney disease. However, their mutual effects on MN require further examination. Thus, we investigated the effect of AHR signalling on the NF-ƙB and Nrf2 pathways in IMN patients, cationic bovine serum albumin (CBSA)-injected rats and zymosan activation serum (ZAS)-treated podocytes. IMN patients show significantly decreased serum total protein and albumin levels, increased urine protein levels and intrarenal IgG4 and PLA2R protein expression in glomeruli compared with controls. IMN patients exhibited increased mRNA expression of intrarenal AHR and its target genes, including CYP1A1, CYP1A2, CYP1B1 and COX-2. This increase was accompanied by significantly upregulated protein expression of CD3, NF-ƙB p65 and COX-2 and significantly downregulated Nrf2 and HO-1 expression. Similarly, CBSA-induced rats showed severe proteinuria and activated intrarenal AHR signalling. This was accompanied by significantly upregulated protein expression of intrarenal p-IκBα, NF-κB p65 and its gene products, including COX-2, MCP-1, iNOS, 12-LOX, p47phox and p67phox, and significantly downregulated protein expression of Nrf2 and its gene products, including HO-1, catalase, GCLC, GCLM, MnSOD and NQO1. These results were further verified in ZAS-induced podocytes. Treatment with the AHR antagonist CH223191 and AHRsiRNA significantly preserved podocyte-specific protein expression and improved the NF-ƙB and Nrf2 pathways in ZAS-induced podocytes. In contrast, similar results were obtained in ZAS-induced podocytes treated with the NF-ƙB inhibitor BAY 11-7082 and NF-κBp65 siRNA. However, neither method had a significant effect on AHR signalling. Collectively, these results indicate that the NF-ƙB pathway is a downstream target of AHR signalling. Our findings suggest that blocking AHR signalling inhibits oxidative stress and inflammation, thereby improving proteinuria and renal injury.

Hexarelin alleviates apoptosis on ischemic acute kidney injury via MDM2/p53 pathway

INTRODUCTION

Hexarelin exhibits significant protection against organ injury in models of ischemia/reperfusion (I/R)-induced injury (IRI). Nevertheless, the impact of Hexarelin on acute kidney injury (AKI) and its underlying mechanism remains unclear. In this study, we investigated the therapeutic potential of Hexarelin in I/R-induced AKI and elucidated its molecular mechanisms.

METHODS

We assessed the protective effects of Hexarelin through both in vivo and in vitro experiments. In the I/R-induced AKI model, rats were pretreated with Hexarelin at 100 μg/kg/d for 7 days before being sacrificed 24 h post-IRI. Subsequently, kidney function, histology, and apoptosis were assessed. In vitro, hypoxia/reoxygenation (H/R)-induced HK-2 cell model was used to investigate the impact of Hexarelin on apoptosis in HK-2 cells. Then, we employed molecular docking using a pharmmapper server and autodock software to identify potential target proteins of Hexarelin.

RESULTS

In this study, rats subjected to I/R developed severe kidney injury characterized by tubular necrosis, tubular dilatation, increased serum creatinine levels, and cell apoptosis. However, pretreatment with Hexarelin exhibited a protective effect by mitigating post-ischemic kidney pathological changes, improving renal function, and inhibiting apoptosis. This was achieved through the downregulation of conventional apoptosis-related genes, such as Caspase-3, Bax and Bad, and the upregulation of the anti-apoptotic protein Bcl-2. Consistent with the in vivo results, Hexarelin also reduced cell apoptosis in post-H/R HK-2 cells. Furthermore, our analysis using GSEA confirmed the essential role of the apoptosis pathway in I/R-induced AKI. Molecular docking revealed a strong binding affinity between Hexarelin and MDM2, suggesting the potential mechanism of Hexarelin's anti-apoptosis effect at least partially through its interaction with MDM2, a well-known negative regulator of apoptosis-related protein that of p53. To validate these findings, we evaluated the relative expression of MDM2 and p53 in I/R-induced AKI with or without Hexarelin pre-administration and observed a significant suppression of MDM2 and p53 by Hexarelin in both in vivo and in vitro experiments.

CONCLUSION

Collectively, Hexarelin was identified as a promising medication in protecting apoptosis against I/R-induced AKI.

High glucose dialysate-induced peritoneal fibrosis: Pathophysiology, underlying mechanisms and potential therapeutic strategies

Peritoneal dialysis is an efficient renal replacement therapy for patients with end-stage kidney disease. However, continuous exposure of the peritoneal membrane to dialysate frequently leads to peritoneal fibrosis, which alters the function of the peritoneal membrane and results in withdrawal from peritoneal dialysis in patients. Among others, high glucose dialysate is considered as a predisposing factor for peritoneal fibrosis in patients on peritoneal dialysis. Glucose-induced inflammation, metabolism disturbance, activation of the renin-angiotensin-aldosterone system, angiogenesis and noninflammation-induced reactive oxygen species are implicated in the pathogenesis of high glucose dialysate-induced peritoneal fibrosis. Specifically, high glucose causes chronic inflammation and recurrent peritonitis, which could cause migration and polarization of inflammatory cells, as well as release of cytokines and fibrosis. High glucose also interferes with lipid metabolism and glycolysis by activating the sterol-regulatory element-binding protein-2/cleavage-activating protein pathway and increasing hypoxia inducible factor-1α expression, leading to angiogenesis and peritoneal fibrosis. Activation of the renin-angiotensin-aldosterone system and Ras-mitogen activated protein kinase signaling pathway is another contributing factor in high glucose dialysate-induced fibrosis. Ultimately, activation of the transforming growth factor-β1/Smad pathway is involved in mesothelial-mesenchymal transition or epithelial-mesenchymal transition, which leads to the development of fibrosis. Although possible intervention strategies for peritoneal dialysate-induced fibrosis by targeting the transforming growth factor-β1/Smad pathway have occasionally been proposed, lack of laboratory evidence renders clinical decision-making difficult. We therefore aim to revisit the upstream pathways of transforming growth factor-beta1/Smad and propose potential therapeutic targets for high glucose-induced peritoneal fibrosis.

Moshen granule ameliorates membranous nephropathy by regulating NF-ƙB/Nrf2 pathways via aryl hydrocarbon receptor signalling

Considerable achievements were realized in illuminating underlying pathological mechanisms of patients with idiopathic membranous nephropathy (IMN). Although IMN patients are well diagnosed before they reach renal failure, no currently available drug intervention is effective in halting IMN progression. In this study, we assess Moshen granule (MSG) effect on IMN patients and cationic bovine serum albumin (CBSA)-induced rats. Increasing studies has indicated that activation of aryl hydrocarbon receptor (AHR) was related to oxidative stress and inflammation. We further determine MSG effect on AHR, nuclear factor ƙB (NF-ƙB) and nuclear factor erythroid 2-related factor 2 (Nrf2) in the CBSA-induced rats. MSG markedly reduces proteinuria and improves kidney function in both IMN patients and rats induced by CBSA. MSG markedly inhibits increased mRNA expressions of intrarenal AHR and its four downstream target genes including CYP1A1, CYP1A2, CYP1B1 and COX-2 compared with untreated CBSA-induced rats. This is accompanied by markedly downregulated protein expressions of p-IƙBα and NF-ƙB p65 and its downstream gene products including MCP-1, COX-2, 12-LOX, iNOS, p47phox and p67phox, while markedly preserves protein expressions of Nrf2 and its downstream gene products including catalase, HO-1, GCLM, GCLC, MnSOD and NQO1 in the kidney tissues. These data suggests MSG blunts podocyte damage through inhibiting activation of NF-ƙB/Nrf2 pathway via AHR signaling. This finding may provide a promising therapy for treatment of IMN through oxidative stress and inflammation.

Novel therapeutic approaches in the management of chronic kidney disease: a narrative review

Chronic kidney disease (CKD) remains a pathologic entity with constantly rising incidence and high rates of morbidity and mortality, which are associated with serious cardiovascular complications. Moreover, the incidence of end-stage renal disease tends to increase. The epidemiological trends of CKD warrant the development of novel therapeutic approaches aiming to prevent its development or retard its progression through the control of major risk factors: type 2 diabetes mellitus, arterial hypertension, and dyslipidemia. Contemporary therapeutics such as sodium-glucose cotransporter-2 inhibitors and second-generation mineralocorticoid receptor antagonists are utilized in this direction. Additionally, experimental and clinical studies present novel drug categories that could be employed in managing CKD, such as aldosterone synthesis inhibitors or activators guanylate cyclase, while the role of melatonin should be further tested in the clinical setting. Finally, in this patient population, the use of hypolipidemic agents may provide incremental benefits.

Membranous nephropathy: Mechanistic insights and therapeutic perspectives

Membranous nephropathy (MN) is one of the most common causes of non-diabetic nephrotic syndrome in adults. About 80% of cases are renal limited (primary MN) and 20% are associated with other systemic diseases or exposures (secondary MN). Autoimmune reaction is the main pathogenic factor of MN, and the discovery of autoantigens including the phospholipase A₂ receptor and thrombospondin type-1 domain-containing protein 7A has led to new insights into the pathogenesis, they can induce humoral immune responses led by IgG₄ makes them suitable for the diagnosis and monitoring of MN. In addition, complement activation, genetic susceptibility genes and environmental pollution are also involved in MN immune response. In clinical practice, due to the spontaneous remission of MN, the combination of supportive therapy and pharmacological treatment is widely used. Immunosuppressive drugs are the cornerstone of MN treatment, and the dangers and benefits of this approach vary from person to person. In summary, this review provides a more comprehensive review of the immune pathogenesis, interventions and unresolved issues of MN in the hope of providing some new ideas for clinical and scientific researchers in the treatment of MN.