Pathological mechanism of immune disorders in diabetic kidney disease and intervention strategies.

Diabetic kidney disease is one of the most severe chronic microvascular complications of diabetes and a primary cause of end-stage renal disease. Clinical studies have shown that renal inflammation is a key factor determining kidney damage during diabetes. With the development of immunological technology, many studies have shown that diabetic nephropathy is an immune complex disease, and that most patients have immune dysfunction. However, the immune response associated with diabetic nephropathy and autoimmune kidney disease, or caused by ischemia or infection with acute renal injury, is different, and has a com-plicated pathological mechanism. In this review, we discuss the pathogenesis of diabetic nephropathy in immune disorders and the intervention mechanism, to provide guidance and advice for early intervention and treatment of diabetic nephropathy.

Protein glycation products associate with progression of kidney disease and incident cardiovascular events in individuals with type 1 diabetes.

BACKGROUND: Despite improved glycemic treatment, the impact of glycation on pathological consequences may persist and contribute to adverse clinical outcomes in diabetes. In the present study we investigated the association between serum protein glycation products and progression of kidney disease as well as incident major adverse cardiovascular events (MACE) in type 1 diabetes. METHODS: Fructosamine, advanced glycation end products (AGEs), and methylglyoxal-modified hydro-imidazolone (MG-H1) were measured from baseline serum samples in the FinnDiane study (n = 575). Kidney disease progression was defined as steep eGFR decline (> 3 mL/min/1.73 m2/year) or progression of albuminuria (from lower to higher stage of albuminuria). MACE was defined as acute myocardial infarction, coronary revascularization, cerebrovascular event (stroke), and cardiovascular death. RESULTS: Fructosamine was independently associated with steep eGFR decline (OR 2.15 [95% CI 1.16-4.01], p = 0.016) in the fully adjusted model (age, sex, baseline eGFR). AGEs were associated with steep eGFR decline (OR 1.58 per 1 unit of SD [95% CI 1.07-2.32], p = 0.02), progression to end-stage kidney disease (ESKD) (HR 2.09 per 1 unit of SD [95% CI 1.43-3.05], p < 0.001), and pooled progression (to any stage of albuminuria) (HR 2.72 per 1 unit of SD [95% CI 2.04-3.62], p < 0.001). AGEs (HR 1.57 per 1 unit of SD [95% CI 1.23-2.00], p < 0.001) and MG-H1 (HR 4.99 [95% CI 0.98-25.55], p = 0.054) were associated with incident MACE. MG-H1 was also associated with pooled progression (HR 4.19 [95% CI 1.11-15.89], p = 0.035). Most AGEs and MG-H1 associations were no more significant after adjusting for baseline eGFR. CONCLUSIONS: Overall, these findings suggest that protein glycation products are an important risk factor for target organ damage in type 1 diabetes. The data provide further support to investigate a potential causal role of serum protein glycation in the progression of diabetes complications.

Estimated small dense low-density lipoprotein-cholesterol and the risk of kidney and cardiovascular outcomes in diabetic kidney disease.

AIMS: This study aimed to investigate the correlations between estimated small dense low-density lipoprotein-cholesterol (esd-LDL-c) and the development of end-stage kidney disease (ESKD), cardiovascular mortality, and all-cause mortality in individuals with diabetic kidney disease (DKD) or diabetes mellitus (DM) concomitant chronic kidney disease (CKD). METHODS: We analyzed the data from a biopsy-proven DKD cohort conducted at West China Hospital of Sichuan University between 2009 and 2021 (the DKD cohort) and participants with DM and CKD in the National Health and Nutrition Examination Survey (NHANES) 2011-2014 (the NHANES DM-CKD cohort). Cox regression analysis was also used to estimate associations between esd-LDL-c and the incidence of ESKD, cardiovascular mortality, and all-cause mortality. RESULTS: There were 175 ESKD events among 338 participants in the DKD cohort. Patients were divided into three groups based on esd-LDL-c tertiles (T1 < 33.7 mg/dL, T2 ≥ 33.7 mg/dL to <45.9 mg/dL, T3 ≥ 45.9 mg/dL). The highest tertile of esd-LDL-c was associated with ESKD (adjusted HR 2.016, 95% CI 1.144-3.554, p = .015). Furthermore, there were 99 deaths (39 cardiovascular) among 293 participants in the NHANES DM-CKD cohort. Participants were classified into three groups in line with the tertile values of esd-LDL-c in the DKD cohort. The highest tertile of esd-LDL-c was associated with cardiovascular mortality (adjusted HR 3.95, 95% CI 1.3-12, p = .016) and all-cause mortality (adjusted HR 2.37, 95% CI 1.06-5.32, p = .036). CONCLUSIONS: Higher esd-LDL-c was associated with increased risk of ESKD in people with biopsy-proven DKD, and higher cardiovascular and all-cause mortality risk among those with DM-CKD.

Update: The Role of Epigenetics in the Metabolic Memory of Diabetic Complications.

Diabetes, a chronic disease characterized by hyperglycemia, is associated with significantly accelerated complications, including diabetic kidney disease (DKD), which increase morbidity and mortality. Hyperglycemia and other diabetes-related environmental factors such as overnutrition, sedentary lifestyles and hyperlipidemia can induce epigenetic changes. Working alone or with genetic factors, these epigenetic changes, that occur without alterations in the underlying DNA sequence, can alter the expression of pathophysiological genes and impair functions of associated target cells/organs, leading to diabetic complications like DKD. Notably, some hyperglycemia-induced epigenetic changes persist in target cells/tissues even after glucose normalization, leading to sustained complications despite glycemic control, so called metabolic memory. Emerging evidence from in-vitro, in-vivo animal models and clinical trials with diabetes subjects identified clear associations between metabolic memory and epigenetic changes including DNA methylation, histone modifications, chromatin structure, and noncoding RNAs at key loci. Targeting such persistent epigenetic changes and/or molecules regulated by them can serve as valuable opportunities to attenuate, or erase metabolic memory, which is crucial to prevent complication progression. Here, we review these cell/tissue-specific epigenetic changes identified to-date as related to diabetic complications, especially DKD, and the current status on targeting epigenetics to tackle metabolic memory. We also discuss limitations in current studies, including the need for more (epi)genome-wide studies, integrative analysis using multiple epigenetic marks and Omics datasets, and mechanistic evaluation of metabolic memory. Considering the tremendous technological advances in epigenomics, genetics, sequencing, and availability of genomic datasets from clinical cohorts, this field is likely to see considerable progress in the upcoming years.

A Quest for Potential Role of Vitamin D in Type II Diabetes Mellitus Induced Diabetic Kidney Disease.

Diabetes mellitus is a metabolic disorder characterized by high blood sugar levels. In recent years, T2DM has become a worldwide health issue due to an increase in incidence and prevalence. Diabetic kidney disease (DKD) is one of the devastating consequences of diabetes, especially owing to T2DM and the key clinical manifestation of DKD is weakened renal function and progressive proteinuria. DKD affects approximately 1/3rd of patients with diabetes mellitus, and T2DM is the predominant cause of end-stage kidney disease (ESKD). Several lines of studies have observed the association between vitamin D deficiency and the progression and etiology of type II diabetes mellitus. Emerging experimental evidence has shown that T2DM is associated with various kinds of kidney diseases. Recent evidence has also shown that an alteration in VDR (vitamin D receptor) signaling in podocytes leads to DKD. The present review aims to examine vitamin D metabolism and its correlation with T2DM. Furthermore, we discuss the potential role of vitamin D and VDR in diabetic kidney disease.

Finerenone: Who should prescribe it for CKD? The physician associate's perspective.

Diabetic kidney disease (DKD) affects 30-40% of all patients with diabetes and contributes significantly to the cardiovascular burden of chronic kidney disease (CKD). Despite the availability of evidence-based medications like finerenone and simple screening tests such as Urinary Albumin-to-Creatinine Ratio (UACR), more resources are still needed to care for DKD patients. Physician Associates (PAs) play a crucial role in the multidisciplinary team responsible for DKD diagnosis, monitoring, and management. A nonsteroidal mineralocorticoid receptor antagonist, namely finerenone, was approved by the FDA in adults with CKD associated with type 2 diabetes to reduce the risk of renal and cardiovascular outcomes. Finerenone is considered among the pillars of care for DKD, furthermore, the addition of finerenone in combination with renin-angiotensin system inhibitors and/or other renal protective medications may offer additional benefits. Primary care providers prescribe finerenone less frequently than specialized care providers, indicating a need to empower physician associates in medication prescription and other renal protection strategies. As part of a multidisciplinary team, physician associates can play an important role in evaluating risk factors that contribute to heart disease and metabolic health. They can also monitor not only kidney function by ordering tests, such as serum creatinine and urinary albumin-to-creatinine ratio every 3-12 months, but also serum potassium levels. Additionally, physician associates can encourage patients to take responsibility for their health by regularly monitoring their blood pressure, blood glucose levels, and body weight. With early detection and management, kidney failure and cardiovascular events may be preventable. Specialized physician associates also play a significant role in the comprehensive care of DKD patients, especially in the later stages. DKD care can be hindered by numerous factors such as lack of patient engagement during counseling, cost disparities, and a complex referral system that requires multidisciplinary guidelines to improve professional communication. It is necessary to re-envision the physician associates' role in primary care and empower them in goal-directed therapies.

Chlorogenic acid alleviates renal fibrosis by reducing lipid accumulation in diabetic kidney disease through suppressing the Notch1 and Stat3 signaling pathway.

AIMS: Abnormal renal lipid metabolism causes renal lipid deposition, which leads to the development of renal fibrosis in diabetic kidney disease (DKD). The aim of this study was to investigate the effect and mechanism of chlorogenic acid (CA) on reducing renal lipid accumulation and improving DKD renal fibrosis. METHODS: This study evaluated the effects of CA on renal fibrosis, lipid deposition and lipid metabolism by constructing in vitro and in vivo models of DKD, and detected the improvement of Notch1 and Stat3 signaling pathways. Molecular docking was used to predict the binding between CA and the extracellular domain NRR1 of Notch1 protein. RESULTS: In vitro studies have shown that CA decreased the expression of Fibronectin, α-smooth muscle actin (α-SMA), p-smad3/smad3, alleviated lipid deposition, promoted the expression of carnitine palmitoyl transferase 1 A (CPT1A), and inhibited the expression of cholesterol regulatory element binding protein 1c (SREBP1c). The expression of Notch1, Cleaved Notch1, Hes1, and p-stat3/stat3 were inhibited. These results suggested that CA might reduce intercellular lipid deposition in human kidney cells (HK2) by inhibiting Notch1 and stat3 signaling pathways, thereby improving fibrosis. Further, in vivo studies demonstrated that CA improved renal fibrosis and renal lipid deposition in DKD mice by inhibiting Notch1 and stat3 signaling pathways. Finally, molecular docking experiments showed that the binding energy of CA and NRR1 was -6.6 kcal/mol, which preliminarily predicted the possible action of CA on Notch1 extracellular domain NRR1. CONCLUSION: CA reduces renal lipid accumulation and improves DKD renal fibrosis by inhibiting Notch1 and stat3 signaling pathways.

Common Needs of Patients with Diabetic Kidney Disease: Qualitative Analysis Based on Disease-Specific Social Media Platforms.

Background: Diabetic kidney disease (DKD) patients require comprehensive disease education and mutual support to cope with various challenges. Social media platforms provide opportunities for DKD patients to access information and interact with peers. However, qualitative analysis of DKD patients' real-world concerns and needs on social media is lacking. Methods: A qualitative study was conducted to analyze DKD patients' posts on Facebook and Baidu DKD-specific forums from June 2013 to June 2023. Posts were retrieved, and the forum with the most DKD-related posts from each platform was selected using stratified random sampling. Thematic analysis was performed to identify common themes, which were categorized and quantified. Results: In total, 746 DKD-related posts were analyzed, generating 203 keyword categories with 954 tags. Three main themes emerged: Diagnosis and Comorbidities (50.2%), Treatment and Prevention (29.7%), and Lifestyle and Psychology (20.1%). Patients were most concerned about DKD diagnosis, staging, comorbidities, and interpreting diagnostic indicators. They also sought information on treatment advancements, medications, renal replacement therapies, and traditional Chinese medicine. Diet, exercise, work-life balance, family planning, and mental well-being were key lifestyle and psychological concerns. Conclusion: This study reveals DKD patients' primary needs and concerns on social media, which can guide healthcare professionals in providing targeted education and support. Meeting patients' needs through comprehensive education and counseling can improve treatment adherence and prognosis, though challenges remain in addressing all issues in real-world practice.

Intermittent protein restriction before but not after the onset of diabetic kidney disease attenuates disease progression in mice.

Background: High dietary protein intake exacerbates proteinuria in individuals with diabetic kidney disease (DKD). However, studies on the impacts of low protein diet (LPD) on DKD have yielded conflicting results. Furthermore, patient compliance to continuous protein restriction is challenging. Objective: The current study aims to investigate the effects of intermittent protein restriction (IPR) on disease progression of DKD. Methods: Diabetic KK-Ay mice were used in this study. For the IPR treatment, three consecutive days of LPD were followed by four consecutive days of normal protein diet (NPD) within each week. For early intervention, mice received IPR before DKD onset. For late intervention, mice received IPR after DKD onset. In both experiments, age-matched mice fed continuous NPD served as the control group. Kidney morphology, structure and function of mice in different groups were examined. Results: Intermittent protein restriction before DKD onset ameliorated pathological changes in kidney, including nephromegaly, glomerular hyperfiltration, tubular injuries and proteinuria, without improving glycemic control. Meanwhile, IPR initiated after DKD onset showed no renoprotective effects despite improved glucose homeostasis. Conclusion: Intermittent protein restriction before rather than after DKD onset protects kidneys, and the impacts of IPR on the kidneys are independent of glycemic control. IPR shows promise as an effective strategy for managing DKD and improving patient compliance.

Development of a machine learning-based model for the prediction and progression of diabetic kidney disease: A single centred retrospective study.

BACKGROUND: Diabetic kidney disease (DKD) is a diabetic microvascular complication often characterized by an unpredictable progression. Hence, early detection and recognition of patients vulnerable to progression is crucial. OBJECTIVE: To develop a prediction model to identify the stages of DKD and the factors contributing to progression to each stage using machine learning. METHODOLOGY: A retrospective study was conducted in a South Indian tertiary care hospital and collected the details of patients diagnosed with DKD from January 2017 to January 2022. Bayesian optimization-based machine learning techniques such as classification and regression were employed. The model was developed with the help of an optimization framework that effectively balances classification, prediction accuracy, and explainability. RESULTS: Of the 311 patients diagnosed with DKD, 227 were selected for the study. A system for predicting DKD has been created for a patient dataset utilizing a variety of machine-learning approaches. The eXtreme gradient (XG) Boost method excelled, achieving 88.75% accuracy, 88.57% precision, 91.4% sensitivity,100% specificity, and 89.49% F1-score. An interpretable data-driven method highlights significant features for early DKD diagnosis. The best explainable prediction model uses the XG Boost classifier, revealing serum uric acid, urea, phosphorous, red blood cells, calcium, and absolute eosinophil count as the major predictors influencing the progression of DKD. In the case of regression models, the gradient boost regressor performed the best, with an R2 score of 0.97. CONCLUSION: Machine learning algorithms can effectively predict the stages of DKD and thus help physicians in providing patients with personalized care at the right time.

Effect of finerenone on nephrotic syndrome in patients with diabetic kidney disease.

Introduction: Diabetic kidney disease (DKD) is an important complication of diabetes as it results in end-stage renal disease; hence, several drugs have been developed for its treatment. However, even with treatment with renin-angiotensin system inhibitors and sodium-glucose cotransporter-2 inhibitors, the residual risk of DKD remains. While this risk is an issue, the renoprotective effects of finerenone, a novel non-steroidal mineralocorticoid receptor antagonist, are becoming evident. High proteinuria increases the risk of cardiovascular death as well as renal failure. Hence, it is especially important to address cases of urine protein to nephrotic levels in DKD, however, no previous studies have assessed the safety and efficacy of finerenone in patients with DKD and nephrotic syndrome. Therefore, this study aimed to assess whether finerenone has a renoprotective effect in advanced DKD complicated by nephrotic syndrome. Methods: Nine patients with DKD and nephrotic syndrome who received 10-20 mg/day of finerenone were retrospectively analyzed. The average observation period was 9.7 ± 3.4 months. Patients with serum potassium levels greater than 5.0 mEq/L at the start of finelenone were excluded. Changes in urinary protein levels, estimated glomerular filtration rate (eGFR), and serum potassium levels were studied before and after finerenone administration. Results: The mean changes in the urinary protein creatinine ratio (UPCR) at baseline were 6.6 ± 2.0. After finerenone treatment, the mean UPCR decreased to -0.6 ± 3.9; however, this change was not statistically significant.The eGFR decline slope also tended to decrease with finerenone treatment (before vs. after: 3.1 ± 4.9 vs. -1.7 ± 3.2 mL/min/1.73 m2. Furthermore, finerenone did not increase serum potassium levels. Conclusions: Patients treated with finerenone showed decreased UPCR; hence, it is suggested that finerenone may be effective in treating nephrotic syndrome in patients with DKD. These findings may be applicable to real-world clinical settings. Nonetheless, it is important to note that this study was a retrospective analysis of a single-center cohort and had a limited sample size, highlighting the need for additional large-scale investigations.

Dose and Time Effects of Renin-Angiotensin Inhibitors on Patients With Advanced Stages 4 to 5 of Diabetic Kidney Disease.

Context: Limited evidence exists regarding the cumulative dosing and duration impact of renin-angiotensin system inhibitors (RASis) on cardiorenal and mortality outcomes in patients with advanced stages (predominantly in stage 5 and a minority in stage 4) of diabetic kidney disease (DKD). Objective: To retrospectively investigate whether there are dose- and time-dependent relationships between RASis and cardiorenal and mortality outcomes in this population. Methods: Using Taiwan's national health insurance data in 2000-2017, we analyzed 2196 RASi users and 2196 propensity-matched nonusers among 8738 patients living with diabetes and newly diagnosed with advanced chronic kidney disease (23% stage 4, 77% stage 5). Cox proportional hazards regression models were used to estimate adjusted hazard ratios (aHRs) and 95% CI. Results: RASi use was significantly associated with reduced risks of all-cause mortality (aHR, 0.53; 95% CI 0.47-0.60) and cardiovascular mortality (0.68; 0.56-0.83) with the degree of benefit depending on therapeutic dosage and duration, despite a nonsignificant increase in acute kidney injury risk (1.16; 0.98-1.38) and a significant increase in hyperkalemia risk (1.45; 1.19-1.77). Significant differences in proteinuria risk (1.32; 1.21-1.43) were observed, while there were no significant differences in end-stage renal disease risk (1.01; 0.88-1.15) and no dose- or time-response relationships for either end-stage renal disease or proteinuria risks. Sensitivity analyses confirmed cardiovascular and survival benefits, even in patients with stage 5 DKD. Conclusion: This real-world study suggests that RASi use in advanced stages 4 to 5 DKD may provide dose- and time-dependent cardioprotection and improved survival, without excess renal harms.

Krüppel-like Factor 2 is an endo-protective transcription factor in diabetic kidney disease.

Diabetic kidney disease (DKD) is a microvascular complication of diabetes, and glomerular endothelial cell (GEC) injury is a key driver of DKD pathogenesis. Krüppel-like factor 2 (KLF2), a shear stress-induced transcription factor, was identified among the genes that are highly upregulated in early DKD. In the kidney, KLF2 expression is mostly restricted to endothelial cells, but its expression is also found in immune cell subsets. KLF2 expression is upregulated in response to increased shear stress by the activation of mechanosensory receptors, but suppressed by inflammatory cytokines, both of which characterize the early diabetic kidney milieu. KLF2 expression is reduced in progressive DKD and hypertensive nephropathy in humans and mice, likely due to high glucose and inflammatory cytokines such as TNF-α. However, KLF2 expression is increased in settings of glomerular hyperfiltration-induced shear stress without metabolic dysregulation, such as in settings of unilateral nephrectomy. Lower KLF2 expression is associated with CKD progression in patients with unilateral nephrectomy, consistent with its endoprotective role. KLF2 confers endoprotection by inhibition of inflammation, thrombotic activation, and angiogenesis, and thus KLF2 is considered a protective factor for cardiovascular disease (CVD). Based on similar mechanisms, KLF2 also exhibits renoprotection, and its reduced expression in endothelial cells worsens glomerular injury and albuminuria in settings of diabetes or unilateral nephrectomy. Thus, KLF2 confers endo-protective effects in both CVD and DKD, and its agonists could be potentially developed as a novel class of drugs for cardio-renal protection in diabetic patients.

Clinical practice guideline for the management of lipids in adults with diabetic kidney disease: abbreviated summary of the Joint Association of British Clinical Diabetologists and UK Kidney Association (ABCD-UKKA) Guideline 2024.

The contribution of chronic kidney disease (CKD) towards the risk of developing cardiovascular disease (CVD) is magnified with co-existing type 1 or type 2 diabetes. Lipids are a modifiable risk factor and good lipid management offers improved outcomes for people with diabetic kidney disease (DKD).The primary purpose of this guideline, written by the Association of British Clinical Diabetologists (ABCD) and UK Kidney Association (UKKA) working group, is to provide practical recommendations on lipid management for members of the multidisciplinary team involved in the care of adults with DKD.

High levels of high-density lipoprotein cholesterol may increase the risk of diabetic kidney disease in patients with type 2 diabetes.

Studies have indicated that low high-density lipoprotein cholesterol (HDL-C) level is an important risk factor for diabetic kidney disease (DKD) in patients with type 2 diabetes (T2D). However, whether higher HDL-C levels decrease the risk of developing DKD remains unclear. This study aimed to clarify the relationship between HDL-C levels and DKD risk in individuals with T2D in China. In total, 936 patients with T2D were divided into DKD and non-DKD groups. The association between HDL-C levels and DKD risk was evaluated using logistic regression analysis and restricted cubic spline curves adjusted for potential confounders. Threshold effect analysis of HDL-C for DKD risk was also performed. Higher HDL-C levels did not consistently decrease the DKD risk. Furthermore, a nonlinear association with threshold interval effects between HDL-C levels and the incidence of DKD was observed. Patients with HDL-C ≤ 0.94 mmol/L or HDL-C > 1.54 mmol/L had significantly higher DKD risk after adjusting for confounding factors. Interestingly, the association between high HDL-C levels and increased DKD risk was more significant in women. A U-shaped association between HDL-C levels and DKD risk was observed; therefore, low and high HDL-C levels may increase the DKD risk in patients with T2D.

Strategies to address diabetic kidney disease burden in Mexico: a narrative review by the Mexican College of Nephrologists.

Chronic kidney disease (CKD) is a growing global public health challenge worldwide. In Mexico, CKD prevalence is alarmingly high and remains a leading cause of morbidity and mortality. Diabetic kidney disease (DKD), a severe complication of diabetes, is a leading determinant of CKD. The escalating diabetes prevalence and the complex regional landscape in Mexico underscore the pressing need for tailored strategies to reduce the burden of CKD. This narrative review, endorsed by the Mexican College of Nephrologists, aims to provide a brief overview and specific strategies for healthcare providers regarding preventing, screening, and treating CKD in patients living with diabetes in all care settings. The key topics covered in this review include the main cardiometabolic contributors of DKD (overweight/obesity, hyperglycemia, arterial hypertension, and dyslipidemia), the identification of kidney-related damage markers, and the benefit of novel pharmacological approaches based on Sodium-Glucose Co-Transporter-2 Inhibitors (SGLT2i) and Glucagon-Like Peptide-1 Receptor Agonists (GLP-1 RA). We also address the potential use of novel therapies based on Mineralocorticoid Receptor Antagonists (MRAs) and their future implications. Emphasizing the importance of multidisciplinary treatment, this narrative review aims to promote strategies that may be useful to alleviate the burden of DKD and its associated complications. It underscores the critical role of healthcare providers and advocates for collaborative efforts to enhance the quality of life for millions of patients affected by DKD.

Proteomic and lipidomic analysis of the mechanism underlying astragaloside IV in mitigating ferroptosis through hypoxia-inducible factor 1α/heme oxygenase 1 pathway in renal tubular epithelial cells in diabetic kidney disease.

ETHNOPHARMACOLOGICAL RELEVANCE: The limitations of modern medicine in mitigating the pathological process of diabetic kidney disease (DKD) necessitate novel, precise, and effective prevention and treatment methods. Huangqi, the root of Astragalus membranaceus Fisch. ex Bunge has been used in traditional Chinese medicine for various kidney ailments. Astragaloside IV (AS-IV), the primary pharmacologically active compound in A. membranaceus, is involved in lipid metabolism regulation; however, its potential in ameliorating renal damage in DKD remains unexplored. AIM OF THE STUDY: To elucidate the specific mechanism by which AS-IV moderates DKD progression. MATERIALS AND METHODS: A murine model of DKD and high glucose-induced HK-2 cells were treated with AS-IV. Furthermore, multiomics analysis, molecular docking, and molecular dynamics simulations were performed to elucidate the mechanism of action of AS-IV in DKD, which was validated using molecular biological methods. RESULTS: AS-IV regulated glucose and lipid metabolism in DKD, thereby mitigating lipid deposition in the kidneys. Proteomic analysis identified 12 proteins associated with lipid metabolism regulated by AS-IV in the DKD renal tissue. Additionally, lipid metabolomic analysis revealed that AS-IV upregulated and downregulated 4 beneficial and 79 harmful lipid metabolites, respectively. Multiomics analysis further indicated a positive correlation between the top-ranked differential protein heme oxygenase (HMOX)1 and the levels of various harmful lipid metabolites and a negative correlation with the levels of beneficial lipid metabolites. Furthermore, enrichment of both ferroptosis and hypoxia-inducible factor (HIF)-1 signaling pathways during the AS-IV treatment of DKD was observed using proteomic analysis. Validation results showed that AS-IV effectively reduced ferroptosis in DKD-affected renal tubular epithelial cells by inhibiting HIF-1α/HMOX1 pathway activity, upregulating glutathione peroxidase-4 and ferritin heavy chain-1 expression, and downregulating acyl-CoA synthetase long-chain family member-4 and transferrin receptor-1 expression. Our findings demonstrate the potential of AS-IV in mitigating DKD pathology by downregulating the HIF-1α/HMOX1 signaling pathway, thereby averting ferroptosis in renal tubular epithelial cells. CONCLUSIONS: AS-IV is a promising treatment strategy for DKD via the inhibition of ferroptosis in renal tubular epithelial cells. The findings of this study may help facilitate the development of novel therapeutic strategies.

Guidelines for clinical evaluation of chronic kidney disease in early stages : AMED research on regulatory science of pharmaceuticals and medical devices.

BACKGROUND: For the development of pharmaceutical products in kidney field, appropriate surrogate endpoints which can predict long-term prognosis are needed as an alternative to hard endpoints, such as end-stage kidney disease. Though international workshop has proposed estimated glomerular filtration rate (GFR) slope reduction of 0.5-1.0 mL/min/1.73 m /year and 30% decrease in albuminuria/proteinuria as surrogate endpoints in early and advanced chronic kidney disease (CKD), it was not clear whether these are applicable to Japanese patients. METHODS: We analyzed J-CKD-DB and CKD-JAC, Japanese databases/cohorts of CKD patients, and J-DREAMS, a Japanese database of patients with diabetes mellitus to investigate the applicability of eGFR slope and albuminuria/proteinuria to the Japanese population. Systematic review on those endpoints was also conducted including the results of clinical trials published after the above proposal. RESULTS: Our analysis showed an association between eGFR slope and the risk of end-stage kidney disease. A 30% decrease in albuminuria/proteinuria over 2 years corresponded to a 20% decrease in the risk of end-stage kidney disease patients with baseline UACR ≥ 30 mg/gCre or UPCR ≥ 0.15 g/gCre in the analysis of CKD-JAC, though this analysis was not performed on the other database/cohort. Those results suggested similar trends to those of the systematic review. CONCLUSION: The results suggested that eGFR slope and decreased albuminuria/proteinuria may be used as a surrogate endpoint in clinical trials for early CKD (including diabetic kidney disease) in Japanese population, though its validity and cutoff values must be carefully considered based on the latest evidence and other factors.

Renal protective effect of metformin in type 2 diabetes patients.

BACKGROUND: Inhibiting the development and progression of diabetic kidney disease (DKD) is an important issue, but the renoprotective effect of metformin is still controversial. AIMS: To assess the renoprotective effect of metformin in patients with type 2 diabetes. METHODS: This retrospective observational multicenter cohort study included 316,693 patients with type 2 diabetes from seven hospital. After age, gender, medical year, baseline estimated glomerular filtration rate (eGFR), urine protein (dipstick), glycated hemoglobin (HbA1C) and propensity score matching; a total of 13,096 metformin and 13,096 non-metformin patients were included. The main results were doubling of serum creatinine, eGFR ≤ 15 mL/min/1.73 m2 and end stage kidney disease (ESKD). RESULTS: After conducting a multivariable logistic regression analysis on the variables, the metformin group was revealed to have better renal outcomes than non-metformin group, including a lower incidence of doubling of serum creatinine (hazard ratio [HR], 0.71; 95% CI, 0.65-0.77), eGFR ≤ 15 mL/min/1.73 m2 (HR 0.61; 95% CI 0.53-0.71), and ESKD (HR 0.55; 95% CI 0.47-0.66). The subgroup analyses revealed a consistent renoprotective effect across patients with various renal functions. Furthermore, when considering factors such as age, sex, comorbidities, and medications in subgroup analyses, it consistently showed that the metformin group experienced a slower deterioration in renal function across nearly all patient subgroups. CONCLUSIONS: Metformin decreased the risk of renal function deterioration.

A Clinical-radiomic Nomogram for the Non-invasive Evaluation of Glomerular Status in Diabetic Kidney Disease.

OBJECTIVE: Utilizing ultrasound radiomics, we developed a machine learning (ML) model to construct a nomogram for the non-invasive evaluation of glomerular status in diabetic kidney disease (DKD). MATERIALS AND METHODS: Patients with DKD who underwent renal biopsy were retrospectively enrolled between February 2017 and February 2023. The patients were classified into mild or moderate-severe glomerular severity based on pathological findings. All patients were randomly divided into a training (n =79) or testing cohort (n = 35). Radiomic features were extracted from ultrasound images, and a logistic regression ML algorithm was applied to construct an ultrasound radiomic model after selecting the most significant features using univariate analysis and the least absolute shrinkage and selection operator algorithm (LASSO). A clinical model was created following univariate and multivariate logistic regression analyses of the patient's clinical characteristics. Then, the clinical-radiomic model was constructed by combining rad scores and independent clinical characteristics and plotting the nomogram. The receiver operating characteristic curve (ROC) and decision curve analysis (DCA), respectively, were used to evaluate the prediction abilities of the clinical model, ultrasound-radiomics model, and clinical-radiomics model. RESULTS: A total of 114 DKD patients were included in the study, including 43 with mild glomerulopathy and 71 with moderate-severe glomerulopathy. The area under the curve (AUC) for the clinical model based on clinical features and the radiomic model based on 2D ultrasound images in the testing cohort was 0.729 and 0.761, respectively. Further, the AUC for the clinical-radiomic nomogram was constructed by combining clinical features, and the rad score was 0.850 in the testing cohort. The outcomes were better than those of both the radiomic and clinical single-model approaches. CONCLUSION: The nomogram constructed by combining ultrasound radiomics and clinical features has good performance in assessing the glomerular status of patients with DKD and will help clinicians monitor the progression of DKD.