Syzygium cumini (L.) skeels mitigate diabetic nephropathy by regulating Nrf2 pathway and mitocyhondrial dysfunction: In vitro and in vivo studies.

ETHNOPHARMACOLOGICAL PREVALENCE: Hyperglycemia in diabetes increases the generation of advanced glycation end products (AGEs) through non-enzymatic reactions. The interaction between AGEs and their receptors (RAGE) leads to oxidative and inflammatory stress, which plays a pivotal role in developing diabetic nephropathy. Syzygium cumini (SC) L. (DC.) homeopathic preparations viz. 200C, 30C, and mother tincture [MT] are used to treat diabetes. This study aimed to elucidate the regulatory effects of SC preparations (200C, 30C, and MT) on the nuclear factor erythroid 2-related factor 2 (Nrf2) - nuclear factor-κB (NF-κB) pathways and mitochondrial dysfunction in mitigating diabetic nephropathy (DN). MATERIALS AND METHODS: Streptozotocin-induced diabetic rats were treated with SC preparations (200C, 30C, MT; 1:20 dilution in distilled water; 600 µL/kg body weight) and metformin (45 mg/kg body weight) twice daily for 40 days. DN was evaluated through biochemical parameters and histological examination. Renal tissue lysates were analyzed for glycation markers. Protein and gene levels of Nrf2, NF-κB, and mitochondrial dysfunctional signaling were determined via western blotting and RT-qPCR. An immunohistochemical analysis of the kidneys was performed. In vitro, human serum albumin (HSA - 10 mg/ml) was glycated with methylglyoxal (MGO - 55 mM) in the presence of SC preparations (200C, 30C, MT) for eight days. Glycated samples (400 µg/mL) were incubated with renal cells (HEK-293) for 24 h. Further reactive oxygen species production, Nrf2 nuclear translocation, and protein or gene expression of Nrf2 and apoptosis markers were analyzed by western blotting, RT-qPCR, and flow cytometry. Molecular docking of gallic and ellagic acid with the HSA-MGO complex was performed. RESULT: In vivo experiments using streptozotocin-induced diabetic rats treated with SC preparations exhibited improved biochemical parameters, preserved kidney function, and reduced glycation adduct formation in a dose-dependent manner. Furthermore, SC preparations downregulated inflammatory mediators such as RAGE, NF-κB, vascular endothelial growth factor (VEGF), and Tumor necrosis factor α (TNF-α) while upregulating the Nrf2-dependent antioxidant and detoxification pathways. They downregulated B-cell lymphoma 2 (Bcl-2) associated X-protein (BAX), C/EBP homologous protein (CHOP), Dynamin-related protein 1 (DRP1), and upregulated BCL 2 gene expression. Notably, SC preparations facilitated nuclear translocation of Nrf2, leading to the upregulation of antioxidant enzymes and the downregulation of oxidative stress markers. Molecular docking studies revealed favorable interactions between gallic (-5.26 kcal/mol) and ellagic acid (-4.71 kcal/mol) with the HSA-MGO complex. CONCLUSION: SC preparations mitigate renal cell apoptosis and mitochondrial dysfunction through Nrf2-dependent mechanisms.

Reference gene panel for urinary exosome-based molecular diagnostics in patients with kidney disease.

BACKGROUND: Kidney disease is a severe complication of diabetes that often leads to end-stage renal disease. Early diagnosis is crucial for prevention or delay. However, the current diagnostic methods, with their limitations in detecting the disease in its early stages, underscore the urgency and importance of finding new solutions. miRNAs encapsulated inside urinary exosomes (UEs) have potential as early biomarkers for kidney diseases. The need for reference miRNAs for accurate interpretation currently limits their translational potential. AIM: To identify consistently expressing reference miRNAs from UEs of controls and patients with type 2 diabetesmellitus (T2DM) and biopsy-confirmed kidney diseases. METHODS: miRNA profiling was performed on UEs from 31 human urine samples using a rigorous and unbiased method. The UEs were isolated from urine samples collected from healthy individuals (n = 6), patients with T2DM (n = 13), and T2DM patients who also had kidney diseases (including diabetic nephropathy, n = 5; membranous nephropathy, n = 5; and IgA nephropathy, n = 2) through differential ultracentrifugation. After characterizing the UEs, miRNA expression profiling using microarray technology was conducted. RESULTS: Microarray data analysis identified 14 miRNAs that were consistently expressed in UEs from 31 human samples, representing various kidney conditions: diabetic controls, diabetic nephropathy, membrane nephropathy, IgA nephropathy, and healthy controls. Through in silico analysis, we determined that 10 of these miRNAs had significant potential to serve as reference genes in UEs. CONCLUSION: We identified uniformly expressing UE miRNAs that could serve as reference genes kidney disease biomarkers.

Rutaecarpine alleviates inflammation and fibrosis by targeting CK2α in diabetic nephropathy.

Diabetic nephropathy (DN) is one of the serious microvascular complications of diabetes mellitus. During the progression of DN, the proliferation of glomerular mesangial cells (GMCs) leads to the deposition of excessive extracellular matrix (ECM) in the mesangial region, eventually resulting in glomerulosclerosis. Rutaecarpine (Rut), an alkaloid found in the traditional Chinese medicinal herb Fructus Evodiae (Euodia rutaecarpa (Juss.) Benth.), has many biological activities. However, its mechanism of action in DN remains unknown. This study used db/db mice and high glucose (HG)-treated mouse mesangial cells (SV40 MES-13) to evaluate the protective effects of Rut and underlying mechanisms on GMCs in DN. We found that Rut alleviated urinary albumin and renal function and significantly relieved renal pathological damage. In addition, Rut decreased the ECM production, and renal inflammation and suppressed the activation of TGF-ß1/Smad3 and NF-κB signaling pathways in vitro and in vivo. Protein kinase CK2α (CK2α) was identified as the target of Rut by target prediction, molecular docking, and cellular thermal shift assay (CETSA), and surface plasmon resonance (SPR). Furthermore, Rut could not continue to play a protective role in HG-treated SV40 cells after silencing CK2α. In summary, this study is the first to find that Rut can suppress ECM production and inflammation in HG-treated SV40 cells by inhibiting the activation of TGF-ß1/Smad3 and NF-κB signaling pathways and targeting CK2α. Thus, Rut can potentially become a novel treatment option for DN.

Diminished nuclear-localized ß-adrenoceptor signalling activates YAP to promote kidney fibrosis in diabetic nephropathy.

BACKGROUND AND PURPOSE: Diabetic nephropathy (DN) is a leading cause of chronic kidney disease (CKD), which is characterized by mesangial matrix expansion that involves dysfunctional mesangial cells (MCs). However, the underlying mechanisms remain unclear. This study aims to delineate the spatiotemporal contribution of adrenergic signalling in diabetic kidney fibrosis to reveal potential therapeutic targets. EXPERIMENTAL APPROACH: A model of diabetic nephropathy was induced by in db/db mice. Gene expression in kidneys was profiled by RNA-seq analyses, western blot and immunostaining. Subcellular-localized fluorescence resonance energy transfer (FRET) biosensors determined adrenergic signalling microdomains in MCs. Effects of oral rolipram, a phosphodiesterase 4 (PDE4) inhibitor, on the model were measured. KEY RESULTS: Our model exhibited impaired kidney function with elevated expression of adrenergic and fibrotic genes, including Adrb1, PDEs, Acta2 and Tgfß. RNA-seq analysis revealed that MCs with dysregulated YAP pathway were crucial to the extracellular matrix secretion in kidneys from diabetic nephropathy patients. In cultured MCs, TGF-ß promoted profibrotic gene transcription, which was regulated by nuclear-localized ß-adrenoceptor signalling. Mechanistically, TGF-ß treatment diminished nuclear-specific cAMP signalling in MCs and reduced PKA-dependent phosphorylation of YAP, leading to its activation. In parallel, db/db mouse kidneys showed increased expressions of PDE4B and PDE4D. Treatment with oral rolipram alleviated kidney fibrosis in db/db mice. CONCLUSION AND IMPLICATIONS: Diabetic nephropathy impaired nuclear-localized ß1-adrenoceptor-cAMP signalling microdomain through upregulating PDE4 expression, promoting fibrosis in MCs via PKA dephosphorylation-dependent YAP activation. Our results suggest PDE4 inhibition as a promising strategy for alleviating kidney fibrosis in diabetic nephropathy.

Cost-effectiveness of finerenone added to standard of care for patients with type 2 diabetes-related chronic kidney disease in the United States.

AIM: To examine the cost-effectiveness of adding finerenone to standard of care (SoC) for treating type 2 diabetes mellitus (T2DM)-related chronic kidney disease (CKD) in the United States. MATERIALS AND METHODS: Based on the clinical data analysed by FIDELITY, we referenced the validated FINE-CKD model (Markov model) to evaluate the cost-effectiveness of SoC versus SoC + finerenone from the perspective of US payers. The model was cycled for 35 years in 4-month cycles, with cost and utility values derived from the published literature. The primary outcomes were incremental cost-effectiveness ratio (ICER) and quality-adjusted life years (QALYs). Deterministic and probabilistic sensitivity analyses were conducted to assess the robustness of the base-case results. RESULTS: The treatment strategy of finerenone plus SoC led to gains of 6.95 QALYs and had a lifetime cost of $491 745.31. Compared to SoC, that strategy yielded 0.48 more QALYs at an added cost of $65 305.72. The ICER for finerenone was $135 257.06 per QALY, which is below the willingness-to-pay threshold of United States ($150 000/QALY). The results were sensitive to the hazard ratios associated with the efficacy of finerenone and its cost. Probabilistic sensitivity analyses showed that the probability that finerenone plus SoC would be cost-effective was 57.6%. CONCLUSIONS: For patients with T2DM-related CKD, adding finerenone to SoC may be a cost-effective option in the United States. Reasonable price reductions for finerenone could potentially benefit more patients.

Integrated approach of machine learning, Mendelian randomization and experimental validation for biomarker discovery in diabetic nephropathy.

AIM: To identify potential biomarkers and explore the mechanisms underlying diabetic nephropathy (DN) by integrating machine learning, Mendelian randomization (MR) and experimental validation. METHODS: Microarray and RNA-sequencing datasets (GSE47184, GSE96804, GSE104948, GSE104954, GSE142025 and GSE175759) were obtained from the Gene Expression Omnibus database. Differential expression analysis identified the differentially expressed genes (DEGs) between patients with DN and controls. Diverse machine learning algorithms, including least absolute shrinkage and selection operator, support vector machine-recursive feature elimination, and random forest, were used to enhance gene selection accuracy and predictive power. We integrated summary-level data from genome-wide association studies on DN with expression quantitative trait loci data to identify genes with potential causal relationships to DN. The predictive performance of the biomarker gene was validated using receiver operating characteristic (ROC) curves. Gene set enrichment and correlation analyses were conducted to investigate potential mechanisms. Finally, the biomarker gene was validated using quantitative real-time polymerase chain reaction in clinical samples from patients with DN and controls. RESULTS: Based on identified 314 DEGs, seven characteristic genes with high predictive performance were identified using three integrated machine learning algorithms. MR analysis revealed 219 genes with significant causal effects on DN, ultimately identifying one co-expressed gene, carbonic anhydrase II (CA2), as a key biomarker for DN. The ROC curves demonstrated the excellent predictive performance of CA2, with area under the curve values consistently above 0.878 across all datasets. Additionally, our analysis indicated a significant association between CA2 and infiltrating immune cells in DN, providing potential mechanistic insights. This biomarker was validated using clinical samples, confirming the reliability of our findings in clinical practice. CONCLUSION: By integrating machine learning, MR and experimental validation, we successfully identified and validated CA2 as a promising biomarker for DN with excellent predictive performance. The biomarker may play a role in the pathogenesis and progression of DN via immune-related pathways. These findings provide important insights into the molecular mechanisms underlying DN and may inform the development of personalized treatment strategies for this disease.

Glucagon-like peptide-1 receptor agonists and kidney outcomes.

Glucagon-like peptide-1 receptor agonists (GLP-1RAs) have gained increasing attention for their potential benefits in people with type 2 diabetes mellitus (T2DM) with chronic kidney disease (CKD). Most supportive evidence of a kidney-protective effect of the GLP-1RA class of medications has been derived from kidney-related outcomes reported from cardiovascular outcome trials (CVOTs). GLP-1RAs have been shown to reduce albuminuria, mitigate cardiovascular risk, and possibly attenuate estimated glomerular filtration rate (eGFR) decline. The kidney-protective effects of GLP-1RAs are thought to be attributed to their anti-inflammatory, antioxidant, and vasodilatory properties. Despite these promising findings, the use of GLP-RAs has yet to be definitively shown to slow progression to chronic kidney failure in people with T2DM. The Research Study to See How Semaglutide Works Compared to Placebo in People With Type 2 Diabetes and Chronic Kidney Disease (FLOW trial) is the first major trial assessing the potential of a GLP-1RA to slow progression of kidney disease in people with established CKD to clinically important kidney end points. On March 5, 2024, the top line result from FLOW was announced with semaglutide 1.0 mg being reported to reduce the primary end point of the trial by a significant 24% compared with placebo. Here, we summarize the kidney outcomes reported from CVOTs for the GLP-1RA class of medication and briefly describe kidney outcomes from other major GLP-1RAs trials. We also discuss a potential role of the dual GLP-1/glucose-dependent insulinotropic polypeptide (GIP) receptor agonist, tirzepatide, as a kidney-protective agent.

NSUN2 knockdown inhibits macrophage infiltration in diabetic nephropathy via reducing N5-methylcytosine methylation of SOCS1.

OBJECTIVE: N5-methylcytosine (m5C) methylation is involved in various disease progression; however, its role in diabetic nephropathy (DN) has not been studied. The aim of this study was to investigate the role of NSUN2 in DN and the underlying mechanism. METHODS: Streptozotocin-induced experimental mouse model was generated to analyze the role of NSUN2 in vivo, and high glucose (HG)-treated Raw264.7 cells were used to assess the effect of NSUN2 on macrophage infiltration in vitro. The regulation of NSUN2 on SOCS1 m5C methylation was evaluated using m5C methylated RNA immunoprecipitation, luciferase reporter analysis, and RNA stability determination assay. RESULTS: The results indicated that NSUN2 was highly expressed in the blood and kidney of DN mice. Knockdown of NSUN2 alleviated kidney damage, reduced blood glucose and urine albumin, and suppressed macrophage infiltration in DN mice. Moreover, NSUN2 interacted with SOCS1, and silenced NSUN2 inhibited m5C levels of SOCS1 to reduce SOCS1 mRNA stability. Additionally, interference with NSUN2 suppressed macrophage migration, invasion, and infiltration by positively regulating SOCS1 expression under HG conditions. CONCLUSION: In conclusion, silencing of NSUN2 inhibits macrophage infiltration by reducing m5C modification of SOCS1, and thereby attenuates renal injury. The findings suggest a novel regulatory mechanism between NSUN2-mediated m5C modification and DN.

The effect and mechanism of freeze-dried powder of Poecilobdella manillensis on improving inflammatory injury of rat glomerular mesangial cells through TXNIP / NLRP3 pathway.

Objective: Diabetic kidney disease (DKD) is a common complication of diabetes mellitus. The pathophysiological changes in platelet function and the hypercoagulable state associated with DKD are closely linked to inflammatory processes. Poecilobdella manillensis (PM), a type of leech known for its anticoagulant and antithrombotic properties, has the potential to modulate the inflammatory response in DKD. This study aims to investigate the effect of freeze-dried powder of PM on improving inflammatory injury in rat glomerular mesangial cells and to explore its underlying mechanism. Methods: Lipopolysaccharide (LPS) stimulated HBZY-1 rat mesangial cells to establish an in vitro DKD inflammation model. After the intervention with the water extract of freeze-dried powder of PM (FDPM), cell viability, NO content, and the levels of inflammatory factors such as IL-1ß, IL-18, and TNF-α were assessed. Finally, utilizing transcriptomics technology, RT-qPCR, and Western blot methods, the mechanism by which FDPM improves inflammatory injury in rat glomerular mesangial cells was explored and preliminarily validated. Results: FDPM effectively enhances cell viability and inhibits the production of NO and related inflammatory factors. Transcriptomic analysis suggests that FDPM may exert these effects by regulating the TXNIP/NLRP3 signaling pathway. The mRNA and protein expressions of TXNIP, NLRP3, and MCP-1 in the model cells were reversed by FDPM. Conclusion: FDPM may improve the micro-inflammatory state of DKD and slow the progression of the disease by regulating the TXNIP/NLRP3 signaling pathway. This study provides a scientific basis for the clinical application of PM DKD treatment.

Clinical Profile, Risk Factors, and Complications in Young-Onset Type 2 Diabetes Mellitus.

Background Young-onset type 2 diabetes mellitus (T2DM), defined as a diagnosis before the age of 45, is an increasingly common and aggressive form of diabetes. This population is at a heightened risk of developing complications earlier in life due to longer disease duration and often suboptimal glycemic control. Complications such as diabetic neuropathy, retinopathy, and nephropathy are significant concerns, leading to reduced quality of life and increased morbidity. Objective To investigate the clinical profile and risk factors associated with complications of young-onset T2DM and to analyze the correlation between the age of onset and other parameters and the development of these complications. Methods We conducted a cross-sectional study on young-onset T2DM patients (<45 years) to investigate the prevalence and associated factors of diabetic complications. Variables analyzed included age, gender, BMI, waist-hip ratio, duration of diabetes, age at diagnosis, proteinuria, and glycosuria, along with biochemical markers such as HbA1C (glycated hemoglobin), serum cholesterol, triglycerides, and C-peptide levels. Results The average age of participants in our study was 34.76 ± 6.91 years. The mean BMI was 26.68 ± 3.35, with a mean cholesterol level of 169.84 ± 55.64 and a mean triglyceride level of 205.79 ± 67.49. The average HbA1c level was 9.82 ± 2.44. Diabetic neuropathy was found to increase significantly with advancing age (p < 0.001), longer duration of diabetes (p < 0.001), higher mean levels of HbA1C (p < 0.001), serum cholesterol (p = 0.006), and serum triglycerides (p = 0.010), as well as with lower levels of serum C-peptide (p = 0.025). The severity of kidney damage showed a significant association with older age (p = 0.049), longer diabetes duration (p < 0.01), elevated mean levels of HbA1C (p = 0.0002), and serum cholesterol (p = 0.0310). Diabetic retinopathy increased significantly with advancing age (p < 0.001), longer diabetes duration (p < 0.001), higher mean levels of HbA1C (p < 0.001), and serum triglycerides (p = 0.013). Conclusion Young-onset T2DM is associated with significant risks for neuropathy, retinopathy, and nephropathy, particularly with increasing age and longer disease duration. Higher HbA1C, serum cholesterol, and triglyceride levels are prevalent among those with complications. These findings underscore the need for early intervention and targeted management strategies to mitigate complications in this high-risk population.

Co-regulation and synteny of GFM2 and NSA2 links ribosomal function in mitochondria and the cytosol with chronic kidney disease.

BACKGROUND: We previously reported aberrant expression of the cytosolic ribosomal biogenesis factor Nop-7-associated 2 (NSA2) in diabetic nephropathy, the latter also known to involve mitochondrial dysfunction, however the connections between NSA2, mitochondria and renal disease were unclear. In the current paper, we show that NSA2 expression is co-regulated with the GTP-dependent ribosome recycling factor mitochondrial 2 (GFM2) and provide a molecular link between cytosolic and mitochondrial ribosomal biogenesis with mitochondrial dysfunction in chronic kidney disease (CKD). METHODS: Human renal tubular cells (HK-2) were cultured (+/- zinc, or 5mM/20mM glucose). mRNA levels were quantified using real-time qPCR. Transcriptomics data were retrieved and analysed from Nakagawa chronic kidney disease (CKD) Dataset (GSE66494) and Kidney Precision Medicine Project (KPMP) ( https://atlas.kpmp.org/ ). Protein levels were determined by immunofluorescence and Western blotting. Cellular respiration was measured using Agilent Seahorse XF Analyzer. Data were analysed using one-way ANOVA, Students' t-test and Pearson correlation. RESULTS: The NSA2 gene, on human chromosome 5q13 was next to GFM2. The two genes were syntenic on opposite strands and orientation in multiple species. Their common 381 bp 5' region contained multiple transcription factor binding sites (TFBS) including the zinc-responsive transcription factor MTF1. NSA2 and GFM2 mRNAs showed a dose-dependent increase to zinc in-vitro and were highly expressed in proximal tubular cells in renal biopsies. CKD patients showed higher renal NSA2/GFM2 expression. In HK-2 cells, hyperglycaemia led to increased expression of both genes. The total cellular protein content remained unchanged, but GFM2 upregulation resulted in increased levels of several mitochondrial oxidative phosphorylation (OXPHOS) subunits. Furthermore, increased GFM2 expression, via transient transfection or hyperglycemia, correlated with decrease cellular respiration. CONCLUSION: The highly conserved synteny of NSA2 and GFM2, their shared 5' region, and co-expression in-vitro and in CKD, shows they are co-regulated. Increased GFM2 affects mitochondrial function with a disconnect between an increase in certain mitochondrial respiratory proteins but a decrease in cellular respiration. These data link the regulation of 2 highly conserved genes, NSA2 and GFM2, connected to ribosomes in two different cellular compartments, cytosol and mitochondria, to kidney disease and shows that their dysregulation may be involved in mitochondrial dysfunction.

Insights into the Novel Biomarkers Expressed in Diabetic Nephropathy: Potential Clinical Applications.

Diabetic nephropathy (DN) is increasing worldwide in parallel with type 2 diabetes mellitus. Identifying diagnostic biomarkers for DN at an early stage is crucial due to the considerable societal and economic burden associated with diabetes mellitus (DM) and its risk factors. In the past, early indicators of microvascular problems, such as microalbuminuria (MA), have been used to predict the possibility of developing advanced chronic kidney disease (CKD). However, because of the incapacity of MA to appropriately estimate DN, particularly, non-albuminuric DN, additional markers have been suggested for recognizing the early renal abnormalities and structural lesions, even before MA. This study aims to assess the existing and future biomarkers used to diagnose or predict early DN. This review provides comprehensive insight into diagnostic approaches for early detection of CKD, addressing the following areas: (i) markers of glomerular damage, (ii) markers of tubular damage, (iii) oxidative stress biomarkers, (iv) inflammatory biomarkers and (v) futuristic biomarkers such as micro-ribonucleic acids (miRNAs), proteomics, metabolomics and genomics and gut microbiota. Early detection of DN may lead to improvement in clinical management and quality of life, emphasizing the importance of identifying a specific and reliable predictive biomarker. Emerging serum and urinary biomarkers offer promise for early DN diagnosis, potentially reducing prevalence and preventing progression to end-stage renal disease (ESRD). Further advancements in miRNAs, proteomics, metabolomics genomics and gut microbiota offer prospects for even earlier and more precise DN diagnosis.

Gallic Acid Alleviates Glucolipotoxicity-Induced Nephropathy by miR-709-NFE2L2 Pathway in db/db Mice on a High-Fat Diet.

BACKGROUND: Type 2 diabetes mellitus (T2DM) has become a major global issue, with diabetic nephropathy (DN) ranking as one of its most serious complications. The involvement of microRNAs (miRNAs) in the progression of T2DM and DN is an area of active research, yet the molecular mechanisms remain only partially elucidated. Gallic acid (GA), a naturally occurring polyphenolic compound found in various plants such as bearberry leaves, pomegranate root bark, tea leaves, and oak bark, has demonstrated antioxidant properties that may offer therapeutic benefits in DN. METHODS AND RESULTS: The study aimed to investigate the therapeutic potential of GA in mitigating kidney fibrosis, oxidative stress and inflammation, within a glucolipotoxicity-induced diabetic model using db/db mice. The mice were subjected to a high-fat diet to induce glucolipotoxicity, a condition that mimics the metabolic stress experienced in T2DM. Through microarray data analysis, we identified a significant upregulation of renal miR-709a-5p in the diabetic mice, linking this miRNA to the pathological processes underlying DN. GA treatment was shown to boost the activity of including catalase, essential antioxidant enzymes, glutathione peroxidase and superoxide dismutase, while also reducing lipid accumulation in the kidneys, indicating a protective effect against HFD-induced steatosis. In vitro experiments further revealed that silencing miR-709a-5p in MES-13 renal cells led to a reduction in oxidative stress markers, notably lowering lipid peroxidation markers, and significantly boosting the activity of antioxidant defenses. Additionally, NFE2L2, a crucial transcription factor involved in the antioxidant response, was identified as a direct target of miR-709a-5p. The downregulation of miR-709a-5p by GA suggests that this polyphenol mitigates glucolipotoxicity-induced lipogenesis and oxidative stress, potentially offering a novel therapeutic avenue for managing diabetic fatty liver disease and DN. CONCLUSION: Our findings indicate that GA exerts a protective effect in DN by downregulating miR-709a-5p, thereby alleviating oxidative stress through the suppression of NFE2L2. The results highlight the potential of GA and NFE2L2-activating agents as promising therapeutic strategies in the treatment of DN.

High glucose-induced senescence contributes to tubular epithelial cell damage in diabetic nephropathy.

Dysfunctional renal tubular epithelial cells, induced by high glucose, are commonly observed in the kidney tissues of diabetic nephropathy (DN) patients. The epithelial-mesenchymal transition (EMT) of these cells often leads to renal interstitial fibrosis and kidney damage in DN. High glucose also triggers mitochondrial damage and apoptosis, contributing further to the dysfunction of renal tubular epithelial cells. Cellular senescence, a recognized characteristic of DN, is primarily caused by high glucose. However, it remains unclear whether high glucose-induced cellular senescence in DN exacerbates the functional impairment of tubular epithelial cells. In this study, we examined the relationship between EMT and cellular senescence in kidney tissues from streptozotocin (STZ)-induced DN and HK-2 cells treated with high glucose (HG). We also investigated the impact of HG concentrations on tubular epithelial cells, specifically mitochondrial dysfunction, cellular senescence and apoptosis. These damages were primarily associated with the secretion of cytokines (such as IL-6, and TNF-α), production of reactive oxygen species (ROS), and an increase of intracellular Ca2+. Notably, resveratrol, an anti-aging agent, could effectively attenuate the occurrence of EMT, mitochondrial dysfunction, and apoptosis induced by HG. Mechanistically, anti-aging treatment leads to a reduction in cytokine secretion, ROS production, and intracellular Ca2+ levels.

Association between body fat variation rate and risk of diabetic nephropathy - a posthoc analysis based on ACCORD database.

BACKGROUND: Weight control has consistently been regarded as a significant preventive measure against diabetic nephropathy. however, the potential impact of substantial fluctuations in body fat during this process on the risk of diabetic nephropathy remains uncertain. This study aimed to investigate the association between body fat variation rate and diabetic nephropathy incident in American patients with type 2 diabetes. METHODS: The study used data from the Action to Control Cardiovascular Risk in diabetes (ACCORD) trial to calculate body fat variation rates over two years and divided participants into Low and High groups. The hazard ratio and 95% confidence interval were estimated using a Cox proportional hazards model, and confounding variables were addressed using propensity score matching. RESULTS: Four thousand six hundred nine participants with type 2 diabetes were studied, with 1,511 cases of diabetic nephropathy observed over 5 years. High body fat variation rate was linked to a higher risk of diabetic nephropathy compared to low body fat variation rate (HR 1.13, 95% CI 1.01-1.26). Statistically significant interaction was observed between body fat variation rate and BMI (P interaction = 0.008), and high level of body fat variation rate was only associated with increased risk of diabetic nephropathy in participants with BMI > 30 (HR 1.34 and 95% CI 1.08-1.66). CONCLUSIONS: Among participants with Type 2 Diabetes Mellitus, body fat variation rate was associated with increased risk of diabetic nephropathy. Furthermore, the association was modified by BMI, and positive association was demonstrated in obese but not non-obese individuals. Consequently, for obese patients with diabetes, a more gradual weight loss strategy is recommended to prevent drastic fluctuations in body fat. TRIAL REGISTRATION: Clinical Trials. gov, no. NCT000000620 (Registration Date 199909).

Renoprotective effect of liraglutide on diabetic nephropathy by modulation of Krüppel-like transcription factor 5 expression in rats.

OBJECTIVES: Diabetic nephropathy (DN) is a serious consequence of diabetes that can develop through the lysophosphatidic acid axis. The purpose of this study was to determine whether the antidiabetic drug liraglutide can slow the development of diabetic kidney damage by altering the lysophosphatidic acid axis via KLF5. METHODS: Wistar albino rats were divided into nondiabetic and diabetic rats (resulting from an intraperitoneal streptozotocin dose of 30 mg/kg and a high-fat diet). These rats were further divided into four groups: nondiabetic control, liraglutide-treated nondiabetic, diabetic control, and liraglutide-treated diabetic. The nondiabetic and diabetic control groups received normal saline for 42 days, while the liraglutide-treated nondiabetic and diabetic groups received normal saline for 21 days, followed by a subcutaneous dose of liraglutide (200 µg/kg/day) for 21 days. Subsequently, serum levels of DN biomarkers were evaluated, and kidney tissues were histologically examined. The protein expression of PCNA, autotaxin, and KLF5 was detected. KEY FINDINGS: Liraglutide treatment in diabetic rats decreased DN biomarkers, histological abnormalities in kidney tissues, and the protein expression of PCNA, autotaxin, and KLF5. CONCLUSION: Liraglutide can slow the progression of DN by modulating KLF5-related lysophosphatidic acid axis. Thus, liraglutide may be an effective treatment for preventing or mitigating diabetes-related kidney damage.

Near-infrared microscopy reveals diabetic nephropathy in ob/ob mice.

Diabetic nephropathy (DN) is a major cause of global kidney failure. While histological kidney biopsy is the gold standard for diagnosis, it primarily reveals tissue morphology. In contrast, near-infrared (NIR) microscopy offers a label-free method for detailed molecular characterization of kidney tissue. Hematoxylin and eosin-stained kidney tissue samples from 17 ob/ob mice with DN and 14 healthy mice were examined using Fourier transform-NIR microscopy. Four different spectra were obtained from both the mesangium and tubulus. NIR spectral analysis unveiled distinct differences in wavenumbers between DN-affected and healthy kidneys, notably in the carbohydrate and protein-associated region (5500-4200 cm-1). In the mesangium, DN tissue samples exhibited higher median values at 4235 cm-1, 4659 cm-1, 4844 cm-1, 4906 cm-1, and 5222 cm-1 compared to controls (P < 0.05, P < 0.01, P < 0.05, P < 0.05 and P < 0.001, respectively). In tubular spectra, higher median values were found at 4258 cm-1, 4659 cm-1, 5222 cm-1, and 5346 cm-1 in the DN group (P < 0.01, P < 0.05, P < 0.05 and P < 0.01, respectively). These spectral differences strongly correlated with metabolic, histologic, and urinary parameters, providing valuable DN progression insights. The classification model achieved a visible clustering between the control and DN group for both the mesangial and tubular measurements. NIR microscopy demonstrated significant spectral differences between DN and healthy kidney tissues in mice, hinting at its potential for providing chemical insights, aiding in more accurate diagnoses, and offering a foundation for further clinical exploration and potential therapeutic advancements in DN.

Suppression of aldehyde dehydrogenase 2 in kidney proximal tubules contributes to kidney fibrosis through Transforming Growth Factor-ß signaling.

Chronic kidney disease (CKD) is an increasingly prevalent disorder that poses a significant global health and socioeconomic burden. East Asian countries such as China, Taiwan, Japan, and South Korea have a higher incidence and prevalence of kidney failure when compared to Western nations, and the reasons for this discrepancy remain unclear. Aldehyde dehydrogenase 2 (ALDH2) is an essential detoxifying enzyme for exogenous and endogenous aldehyde metabolism in mitochondria. Inactivating mutations at E504K and E487K are found in 35-45% of East Asian populations and has been linked to a higher risk of various disorders, including cardiovascular diseases and cancer. However, little is known about the role of ALDH2 in CKD. Here, we characterized the expression pattern of ALDH2 in normal and CKD human and mouse kidneys and demonstrated that ALDH2 expression was significantly reduced, and that the protein level was inversely correlated with the degree of CKD and fibrosis. Further, we treated ALDH2*2 knock-in mice, a loss of ALDH2 function model, with aristolochic acid and found that these mice showed enhanced fibrosis. Moreover, ALDH2 deficiency was associated with kidney fibrosis involving epithelial cell differentiation process in vivo and in vitro. However, ALDH2 overexpression protected proximal tubule epithelial cells from transforming growth factor-ß-induced dedifferentiation or partial epithelial-mesenchymal transdifferentiation in vitro. Thus, our findings yield important clinical information regarding the development and progression of CKD involving ALDH2, especially among East Asian populations.

Association between gut microbiota and diabetic nephropathy: a two-sample mendelian randomization study.

BACKGROUND: Observational studies have demonstrated the alterations of gut microbiota composition in diabetic nephropathy (DN), however, the correlation between gut microbiota and DN remains unclear. METHODS: A two-sample Mendelian randomization (MR) analysis was designed to estimate the association between gut microbiota and DN. The summary statistics of gut microbiota from phylum level to genus level were obtained from a large-scale, genome-wide association study involving 18,340 individuals, and the data at the species level was derived from the study of TwinsUK Registry, including 1126 twin pairs. The summary statistics of DN were originated from the latest release data of FinnGen (R7, 299623 participants). The MR estimation was calculated using inverse variance weighted, weighted median, MR-Egger regression, and MR-PRESSO. Heterogeneity was assessed using Cochrane's Q test. RESULTS: Inverse variance weighted results indicated that the order Bacteroidetes and its corresponding class and phylum [odds ratio (OR), 1.58; 95% confidence interval (CI), 1.15-2.17], the family Verrucomicrobiaceae and its corresponding class and order (OR, 1.46; 95% CI, 1.14-1.87), the genera Akkermansia (OR, 1.46; 95% CI, 1.14-1.87) and Catenibacterium (OR, 1.33; 95% CI, 1.07-1.66) might be associated with a higher risk of DN; whereas the genera Coprococcus2 (OR, 0.68; 95% CI, 0.51-0.91) and Eubacterium_coprostanoligenes_group (OR, 0.69; 95% CI, 0.52-0.92) might play protective roles in DN. CONCLUSIONS: This MR study suggested that several gut bacteria were potentially associated with DN, further studies are required to validate these findings.

Effects of APOE isoforms in diabetic nephropathy patients of South India.

BACKGROUND: Diabetic nephropathy (DN) is a grave complication and the most common renal dysfunction of diabetes mellitus. Genetic factors, including Apolipoprotein E (APOE) isoforms, have been implicated in the pathogenesis of DN. METHODS: A total of 577 type 2 Diabetes mellitus subjects were categorized into diabetes non-nephropathic (Controls: n = 321), diabetes nephropathic (DN: n = 256) groups. Demographic, clinical, and biochemical parameters including age, BMI, lipid profiles (TC, LDL-C, HDL-C, TG), glucose metabolism (plasma glucose, HbA1c, serum insulin), renal function (UACR, PCR), and blood pressure (SBP, DBP) were assessed. APOE variant frequencies were determined using restriction fragment length polymorphism (RFLP) analysis, validated against Hardy-Weinberg equilibrium (HWE), and statistically correlated with each clinical and biochemical parameter. RESULTS: The DN group had an increased prevalence of hypertension, fatty liver, and dyslipidemia compared to the Control group. Biochemical analyses revealed elevated levels of TC (213.41 mg/dL vs. 189.32 mg/dL), LDL-C (134.46 mg/dL vs. 107.56 mg/dL), and reduced HDL-C (58.13 mg/dL vs. 65.32 mg/dL) in DN cases compared to Controls (all p < 0.0001). The APOE variants distribution showed a significant increase in E2 allele frequency (69.1% vs. 15.3%) and corresponding homozygous genotype (E2/2: 42.2% vs. 5.6%) in DN cohorts. CONCLUSION: The study found a higher frequency of E2 allele in the DN group compared to Controls, though no statistically significant risk of DN was linked to this allele. The results suggest a potential association for APOE polymorphisms, requiring broader studies to clarify the role of APOE polymorphisms in DN susceptibility.