Immune responses in diabetic nephropathy: Pathogenic mechanisms and therapeutic target

Integrative analysis of mitochondrial and immune pathways in diabetic kidney disease: identification of AASS and CASP3 as key predictors and therapeutic targets

OBJECTIVES

Diabetic kidney disease (DKD) is driven by mitochondrial dysfunction and immune dysregulation, yet the mechanistic interplay remains poorly defined. This study aimed to identify key molecular networks linking mitochondrial and immune pathways to DKD progression, with a focus on uncovering biomarkers and therapeutic targets.

METHODS

We conducted an integrative analysis of human DKD cohorts (GSE30122, GSE96804) using weighted gene co-expression network analysis (WGCNA) to identify gene modules enriched for immune response genes and mitochondrial pathways (from MitoCarta3.0). Machine learning algorithms were employed to prioritize key biomarkers for further investigation. Experimental validation was performed using a DKD rat model.

RESULTS

WGCNA revealed significant gene modules associated with immune responses and mitochondrial functions. Machine learning analysis highlighted two central biomarkers: aminoadipate-semialdehyde synthase (AASS) and caspase-3 (CASP3). In the DKD rat model, elevated levels of AASS and CASP3 were found to correlate with increased oxidative stress. Mechanistically, AASS was shown to drive mitochondrial damage via lysine metabolism, while CASP3 amplified inflammatory apoptosis pathways.

CONCLUSIONS

Our findings establish AASS and CASP3 as dual biomarkers and therapeutic targets, bridging mitochondrial-immune crosstalk to DKD pathogenesis. This multi-omics framework provides actionable insights for targeting kidney damage in diabetes.

Obacunone inhibits ferroptosis through regulation of Nrf2 homeostasis to treat diabetic nephropathy

Diabetic nephropathy (DN), a prevalent and severe microvascular complication of diabetes, often leads to end‑stage renal disease and poses a threat to patient survival. However, to the best of our knowledge, there are currently no effective strategies available for the treatment of DN. Obacunone (OB), a small‑molecule natural compound derived from Citrus plants, exhibits various pharmacological effects; however, the impact of OB on DN remains to be fully elucidated. Therefore, the present study aimed to explore the effects and potential mechanisms of OB in DN. In the current study, DN models were created in vitro by treating HK‑2 cells with high‑glucose (HG) levels, and in vivo by administering a HG and high‑fat diet along with intraperitoneal injections of streptozotocin to Sprague‑Dawley rats. Subsequently, cell viability was evaluated using the Cell Counting Kit‑8 assay, while ferroptosis‑related marker levels were determined using biochemical kits, immunofluorescence and western blotting. Activation and homeostasis of the nuclear factor erythroid 2‑related factor 2 (Nrf2) signaling pathway were analyzed using western blotting, co‑immunoprecipitation and reverse transcription‑quantitative PCR. In addition, alterations in renal function parameters and the severity of renal pathological injury in rats were examined. The in vitro experiments demonstrated that OB significantly promoted cell viability and inhibited ferroptosis, as evidenced by increased glutathione peroxidase 4 and SLC7A11 expression, and decreased levels of malondialdehyde, ferrous ion and reactive oxygen species (P<0.05). Additionally, OB activated the Nrf2 signaling pathway, blocked the interaction between Nrf2 and Kelch‑like ECH‑associated protein 1, and suppressed Nrf2 ubiquitination and degradation (P<0.05). In vivo, OB administration improved renal function parameters, including serum creatinine and blood urea nitrogen levels (P<0.05), and reduced renal pathological injury, in comparison with the DN group. The results of the present study indicated that OB, a natural small molecule, exhibited significant anti‑DN effects, possibly through the regulation of Nrf2 homeostasis to inhibit ferroptosis. Overall, this study provides new evidence for OB as a potential clinical treatment for DN.

The Role and Mechanisms of Aurora Kinases in Kidney Diseases

Aurora kinases are a family of serine/threonine kinases that includes Aurora kinase A, Aurora kinase B, and Aurora kinase C. These kinases play crucial roles in mitotic spindle formation and cell proliferation. Over the past several decades, extensive research has elucidated the multifaceted roles of Aurora kinases in cancer development and progression. Recent studies have also highlighted the significant involvement of Aurora kinases in various kidney diseases, such as renal cell carcinoma, diabetic nephropathy, chronic kidney disease, and polycystic kidney disease. The mechanisms by which Aurora kinases contribute to renal diseases are complex and influenced by both specific pathological conditions and environmental factors. In this review, we comprehensively summarize the role and mechanisms through which Aurora kinases operate in kidney diseases and discuss the efficacy and application of existing inhibitors targeting these kinases in managing renal disorders in animal models.

The effect of GLP-1 receptor agonists on circulating inflammatory markers in type 2 diabetes patients: A systematic review and meta-analysis

AIM

To investigate whether the antidiabetic agent glucagon-like peptide-1 receptor agonists (GLP-1 RAs) can exert anti-inflammatory effects while lowering blood glucose, we performed a meta-analysis and systematic review.

METHODS

We searched 4 online databases (Medline, Embase, Cochrane Library and the Web of Science) for randomised controlled trials (RCTs) that examined changes after GLP-1RAs intervention in commonly accepted biomarkers of inflammation: C-reactive protein (CRP), tumour necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), interleukin-1β (IL-1β), leptin, adiponectin, plasminogen activator inhibitor-1 (PAI-1), monocyte chemotactic protein-1(MCP-1) and advanced glycation end products (AGEs).

RESULTS

This meta-analysis included 52 eligible RCTs (n = 4734) with a median follow-up of 24 weeks, a mean age of 54.13 years, 44.46% females, body mass index (BMI) 29.80 kg/m2, glycated haemoglobin (HbA1c) 8.28% and diabetes duration 7.27 years. GLP-1 RAs treatment, compared to placebo or conventional diabetes therapies (including oral medicine and insulin), resulted in significant reductions in CRP, TNF-α, IL-6, IL-1β and leptin (standard mean difference [SMD] -0.63 [-1.03, -0.23]; SMD -0.92 [-1.57, -0.27]; SMD -0.76 [-1.32, -0.20], SMD -3.89 [-6.56, -1.22], SMD -0.67 [-1.09, -0.26], respectively), as well as significant increases in adiponectin (SMD 0.69 [0.19, 1.19]).

CONCLUSIONS

Our meta-analysis demonstrates that GLP-1 RAs exert significant anti-inflammatory effects in patients with T2DM. Our findings provide important insights that may guide the therapeutic application of GLP-1 RAs and inform the development of related therapies.

Hyperglycemia and type 2 diabetes mellitus associate with postoperative recurrence in chronic rhinosinusitis patients

OBJECTIVE

To investigate the associations between fasting blood glucose (FBG) and type 2 diabetes mellitus (T2DM) and the risk of postoperative CRS recurrence.

METHODS

A retrospective cohort study was conducted on clinical data of CRS patients who underwent surgery at our center between February 2019 and March 2022 and were followed up until June 2023. All CRS patients were categorized into two subgroups based on the presence of T2DM and postoperative recurrence. The Kaplan-Meier survival curves and binary logistic regression analyses were performed to examine the associations between FBG, T2DM, and the risk of postoperative CRS recurrence.

RESULTS

1163 CRS patients were enrolled, including 134 in the T2DM group and 276 in the recurrent group. The recurrence rate in the T2DM group was significantly higher than that in the non-T2DM group (P < 0.05). T2DM prevalence and FBG levels were higher in the recurrent CRS group than in the non-recurrent CRS group (P < 0.05). The Kaplan-Meier survival curves and unadjusted and adjusted logistic regression models showed that T2DM was an independent risk factor for postoperative CRS recurrence (P < 0.05). Moreover, multivariate logistic regression analysis suggested that FBG, CRS duration, and allergic rhinitis were associated with the risk of postoperative CRS recurrence (P < 0.05).

CONCLUSION

Elevated FBG levels and accompanying T2DM were associated with an increased risk of postoperative CRS recurrence, which was independent of traditional risk factors. CRS duration and accompanying allergic rhinitis were also proven to be potential risk factors for postoperative CRS recurrence.

Diagnostic value of TRIM22 in diabetic kidney disease and its mechanism

PURPOSE

Diabetic kidney disease (DKD) is the primary reason of chronic kidney disease. Our objective was to discover potential autophagy-related biomarkers of tubulointerstitial injury in DKD and assess their clinical value.

METHODS

We retrieved four datasets (GSE104954, GSE30122, GSE30529, and GSE99340) of renal tubule samples from Gene Expression Omnibus (GEO) and used two algorithms (LASSO and SVM-RFE) to screen for autophagy-related differentially expressed genes (ARDEGs) in DKD. Tripartite motif containing 22 (TRIM22) was identified for subsequent validation. Validation of TRIM22 and autophagic indicators expression in clinical samples and HK-2 cells stimulated by high glucose using immunohistochemistry, immunofluorescence, and western blot.

RESULTS

We identified four ARDEGs (TRIM22, PLK2, HTR2B, and FAS) using a diagnostic gene model. ROC curves further confirmed that TRIM22 had the best diagnostic efficacy for DKD. Both clinical samples and HK-2 cells stimulated by high glucose showed high protein expression of TRIM22. The correlation analysis revealed that TRIM22 correlates with SQSTM1, NGAL, and some clinical and pathological indicators in patients with DKD.

CONCLUSION

We identified TRIM22 as a potential diagnostic biomarker for DKD, revealing its high diagnostic value in patients with DKD with moderate-to-severe interstitial fibrosis and tubular atrophy (IFTA). TRIM22 is involved in tubulointerstitial injury and autophagy dysregulation in DKD.

Crosstalk between ferroptosis and innate immune in diabetic kidney disease: mechanisms and therapeutic implications

Diabetic kidney disease (DKD) is a prevalent complication of diabetes mellitus (DM), and its incidence is increasing alongside the number of diabetes cases. Effective treatment and long-term management of DKD present significant challenges; thus, a deeper understanding of its pathogenesis is essential to address this issue. Chronic inflammation and abnormal cell death in the kidney closely associate with DKD development. Recently, there has been considerable attention focused on immune cell infiltration into renal tissues and its inflammatory response's role in disease progression. Concurrently, ferroptosis-a novel form of cell death-has emerged as a critical factor in DKD pathogenesis, leading to increased glomerular filtration permeability, proteinuria, tubular injury, interstitial fibrosis, and other pathological processes. The cardiorenal benefits of SGLT2 inhibitors (SGLT2-i) in DKD patients have been demonstrated through numerous large clinical trials. Moreover, further exploratory experiments indicate these drugs may ameliorate serum and urinary markers of inflammation, such as TNF-α, and inhibit ferroptosis in DKD models. Consequently, investigating the interplay between ferroptosis and innate immune and inflammatory responses in DKD is essential for guiding future drug development. This review presents an overview of ferroptosis within the context of DKD, beginning with its core mechanisms and delving into its potential roles in DKD progression. We will also analyze how aberrant innate immune cells, molecules, and signaling pathways contribute to disease progression. Finally, we discuss the interactions between ferroptosis and immune responses, as well as targeted therapeutic agents, based on current evidence. By analyzing the interplay between ferroptosis and innate immunity alongside its inflammatory responses in DKD, we aim to provide insights for clinical management and drug development in this area.

Stress-Related LncRNAs and Their Roles in Diabetes and Diabetic Complications

Diabetes mellitus (DM) is a chronic metabolic disorder and one of the most significant global health burdens worldwide. Key pathophysiological mechanisms underlying its onset and associated complications include hyperglycemia-related stresses, such as oxidative stress and endoplasmic reticulum stress (ER stress). Long non-coding RNAs (lncRNAs), defined as RNA transcripts longer than 200 nucleotides and lacking protein-coding capacity, play crucial roles in various biological processes and have emerged as crucial regulators in the pathogenesis of diabetes. This review provides a comprehensive overview of lncRNA biogenesis and its functional roles, emphasizing recent findings that link stress-related lncRNAs to diabetic pathology and complications. Also, we discuss how lncRNAs influence diabetes and its complications by modulating pathways involved in cell death, proliferation, inflammation, and fibrosis, which contribute to pancreatic β cell dysfunction, insulin resistance, diabetic nephropathy, and retinopathy. By analyzing current research, we aim to enhance understanding of lncRNA involvement in diabetes while identifying potential therapeutic targets and guiding future research directions to elucidate the complex mechanisms underlying this pervasive condition.

REDD1 expression in podocytes facilitates renal inflammation and pyroptosis in streptozotocin-induced diabetic nephropathy

Sterile inflammation resulting in an altered immune response is a key determinant of renal injury in diabetic nephropathy (DN). In this investigation, we evaluated the hypothesis that hyperglycemic conditions augment the pro-inflammatory immune response in the kidney by promoting podocyte-specific expression of the stress response protein regulated in development and DNA damage response 1 (REDD1). In support of the hypothesis, streptozotocin (STZ)-induced diabetes increased REDD1 protein abundance in the kidney concomitant with renal immune cell infiltration. In diabetic mice, administration of the SGLT2 inhibitor dapagliflozin was followed by reductions in blood glucose concentration, renal REDD1 protein abundance, and immune cell infiltration. In contrast with diabetic REDD1+/+ mice, diabetic REDD1-/- mice did not exhibit albuminuria, increased pro-inflammatory factors, or renal macrophage infiltration. In cultured human podocytes, exposure to hyperglycemic conditions promoted REDD1-dependent activation of NF-κB signaling. REDD1 deletion in podocytes attenuated both the increase in chemokine expression and macrophage chemotaxis under hyperglycemic conditions. Notably, podocyte-specific REDD1 deletion prevented the pro-inflammatory immune cell infiltration in the kidneys of diabetic mice. Furthermore, exposure of podocytes to hyperglycemic conditions promoted REDD1-dependent pyroptotic cell death, evidenced by an NLRP3-mediated increase in caspase-1 activity and LDH release. REDD1 expression in podocytes was also required for an increase in pyroptosis markers in the glomeruli of diabetic mice. The data support that podocyte-specific REDD1 is necessary for chronic NF-κB activation in the context of diabetes and raises the prospect that therapies targeting podocyte-specific REDD1 may be helpful in DN.

Causal role of 731 immune cells in diabetic nephropathy: a bi-directional two-sample Mendelian randomization study

BACKGROUND

The primary cause of end-stage renal disease (ESRD) is diabetic nephropathy (DN), and a growing body of research indicates that immunology plays a part in how DN develops into ESRD. Our objective is to identify causal relationships between various immune invading cells and DN to identify possible targets for immunotherapy.

METHODS

This study used a complete Mendelian randomization (MR) analysis with two samples to identify the underlying mechanism linking immune cell characteristics with DN. Using publicly available genetic data, we investigated the causal link between 731 immune cell profiles and DN risk. Included were four different types of immune systems: morphological parameters (MP), absolute cell (AC), relative cell (RC), and median fluorescence intensities (MFI). The results' robustness, heterogeneity, and horizontal pleiotropy were confirmed through extensive sensitivity analysis.

RESULTS

Following FDR (False Discovery Rate correction method) correction, no statistically significant differences were observed; however, six immunophenotypes were shown to be significantly associated with DN risk at the 0.25 level. Only CD28+ CD4- CD8- T cells were identified as the protective immunophenotype (OR = 0.588, 95% CI 0.437-0.792, P = 4.71 × 10-4). Moreover, DN had no discernible impact on immunophenotyping after FDR correction. Surprisingly, three unadjusted phenotypes with low P values were discovered to be positively correlated with the risk of DN: CD20 on IgD- CD27- B cells (OR = 1.263, 95% CI 1.076-1.482, P = 4.22 × 10-3), CD8 on naive CD8 + T cells with Effector Memory (OR = 1.107, 95% CI 1.013-1.209, P = 2.40 × 10-2), and CD8 on Effector Memory CD8 + T cells (OR = 1.126, 95% CI 1.024-1.239, P = 1.46 × 10-2).

CONCLUSIONS

Our findings provide a genetic basis for the association between immune cells and DN and should inform future clinical research.

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.

Characterization of diabetic kidney disease in 235 patients: clinical and pathological insights with or without concurrent non-diabetic kidney disease

BACKGROUND

This study aimed to explore the clinical and pathological features of patients with diabetic kidney disease (DKD), with and without non-diabetic kidney disease (NDKD), through a retrospective analysis. The objective was to provide clinical insights for accurate identification.

METHODS

A retrospective analysis of 235 patients admitted to the Department of Nephrology at Hangzhou Hospital of Traditional Chinese Medicine was conducted between July 2014 and December 2022. These patients underwent renal biopsy and received a pathology-based diagnosis of DKD. They were categorized into the DKD alone group (93 cases) and the DKD + NDKD group (142 cases).

RESULTS

In the DKD alone group, gender distribution was even, with ages mainly between 50 and 59 years, and a disease duration of less than 5 years, primarily presenting nodular diabetic glomerulosclerosis. In contrast, the DKD + NDKD group had a higher male incidence, a wider age range, longer disease duration, and prevalent diffuse diabetic glomerulosclerosis. Acute and chronic tubulointerstitial lesions and IgA nephropathy were the predominant types of combined NDKD, accounting for 40.14% and 35.21%, respectively. Clinical correlation analysis revealed associations between glomerular grading, tubulointerstitial lesions, renal arteriolar vitelliform lesions, renal vascular atherosclerosis, and clinical parameters such as 24-hour urine protein, hemoglobin, and urinary specific gravity. Multifactorial logistic regression analysis identified independent factors affecting DKD + NDKD, including body mass index, blood creatinine level, microscopic erythrocyte grade, urinary immunoglobulin G/creatinine ratio, and serum immunoglobulin A.

CONCLUSION

The research underscores distinctions in age, gender distribution, disease duration, and renal pathology between DKD alone and DKD + NDKD groups. Additionally, significant discriminative factors including BMI, blood creatinine level, microscopic erythrocyte grade, UIgG/urine creatinine ratio, and serum IgA levels help differentiate DKD from NDKD, thereby enabling personalized treatment approaches. Furthermore, the study highlights the role of RASi as the most commonly used drug in the treatment of both DKD and NDKD, with emerging drugs such as SGLT2 inhibitors showing promising renal protective effects.

IL-33, a neutrophil extracellular trap-related gene involved in the progression of diabetic kidney disease

BACKGROUND

Chronic inflammation is well recognized as a key factor related to renal function deterioration in patients with diabetic kidney disease (DKD). Neutrophil extracellular traps (NETs) play an important role in amplifying inflammation. With respect to NET-related genes, the aim of this study was to explore the mechanism of DKD progression and therefore identify potential intervention targets.

METHODS

Hub NET-related DEGs were screened via differential expression analysis and three machine learning methods, namely, LASSO, SVM-RFE and random forest. Consensus clustering was performed to analyze NET-related subtypes in DKD patients. KEGG enrichment analysis, GSEA, GSVA, ssGSEA and ESTIMATE were conducted to explore the molecular features of DKD patient subtypes. Leveraging single-nucleus RNA-seq datasets, the "scissor" and "bisqueRNA" algorithms were applied to identify the composition of renal cell types in DKD patient subtypes. Soft clustering analysis was performed to obtain gene groups with similar expression patterns during the development and progression of DKD. The correlations between hub NET-related DEGs and clinical parameters were mined from the Nephroseq V5 database. The core gene among the hub NET-related DEGs was selected by calculating semantic similarity. "Cellchat" algorithm, immunostaining, ELISA and flow cytometry were performed to explore the expression and function of the core gene. The Drug-Gene Interaction Database (DGIdb) was searched to identify candidate drugs.

RESULTS

Six hub NET-related DEGs, namely, ACTN1, ITGB2, IL33, HRG, NFIL3 and CLEC4E, were identified. On the basis of these 6 genes, DKD patients were classified into 2 clusters. Cluster 1 patients, with higher NET scores, were evidently more immune-activating than those of cluster 2. Markedly increased numbers of immune cells, fibroblasts and proinflammatory proximal tubular cells were observed in cluster 1 but not in cluster 2. Cluster 1 also represented a more clinically advanced disease state. Among the 6 hub NET-related DEGs, the mRNA expression of ACTN1, ITGB2, IL33 and HRG was correlated with the eGFR. By semantic similarity analysis, IL33 was considered a central gene among the 6 genes. Cell-cell communication analysis further indicated that intercellular interactions via IL-33 were enhanced in DKD. Serum IL-33 concentration was negatively correlated with eGFR. IHC staining revealed that IL-33 expression was upregulated in the tubular epithelium in DKD patients. Supernatants from inflammatory tubular epithelial cells can increase MPO in neutrophils, whereas addition of anti-IL-33 antibody attenuated this phenotype.

CONCLUSIONS

We identified 2 distinct NET-related subtypes in DKD patients, in which one subgroup was apparently more inflammatory and associated with a more severe clinical state. A significantly increased level of IL-33 in this inflammatory patient subgroup may play a role in aggravating inflammation via the IL-33-ST2 axis.

Curcumin nanocrystals ameliorate ferroptosis of diabetic nephropathy through glutathione peroxidase 4

Objective

The aim of this study was to investigate the effect of curcumin nanocrystals (Cur-NCs) on ferroptosis in high-glucose (HG)-induced HK-2 cells and streptozotocin (STZ)-induced diabetic nephropathy model (DN) rats. The purpose is to determine whether Cur NCs can become a promising treatment option for diabetes nephropathy by reducing ferroptosis.

Methods

Cur-NCs were prepared using microfluidic technology and studied using dynamic light scattering and transmission electron microscopy. HK-2 cells were treated with 30 mM HG to create a renal tubule damage cell model. Then, cell viability was evaluated in HK-2 cells treated with varying concentrations of Cur-NCs (0.23, 0.47, 0.94, 1.87, 3.75, 7.5, 15, and 30 μg/mL) using Cell Counting Kit-8 (CCK-8). Furthermore, in vivo experiments were carried out to investigate the roles of Cur-NCs in STZ-induced DN rats.

Results

The results showed that HG treatment greatly enhanced the levels of LDH, MDA, Iron, lipid ROS, apoptosis, NCOA4, TFR-1, while decreasing the expression of GSH, GPX4, SLC7A11, and FTH-1. These effects induced by HG could be attenuated by Cur-NCs. Cur-NCs also reduced the HG-induced decrease in cell viability, as well as the increase in lipid ROS and cell apoptosis, however erastin could inhibit their effects. Furthermore, the in vivo results showed that Cur-NCs reduced ferroptosis and inhibited renal damage in DN rats.

Conclusion

This study demonstrates that Cur-NCs can significantly attenuate ferroptosis in a STZ-induced renal damage model by recovering GPX4, implying that Cur-NCs may be a promising therapy option for DN.

Effect of hybrid blood purification on nutritional status, inflammation, and cardiovascular events in patients with end-stage renal disease

Objective

To explore the effects of hybrid blood purification on nutritional status and cardiovascular events in patients with end-stage renal disease (ESRD).

Methods

A total of 135 patients with ESRD who received treatment in The Affiliated Nanhua Hospital of Hengyang Medical School from March 2021 to June 2023 were included in this retrospective study. Of them, 66 patients were treated with hemodialysis purification (hemodialysis group), and 69 patients underwent hybrid blood purification (hybrid group). Renal function status, inflammatory cytokine levels, nutritional status, and incidence of cardiovascular events in two groups were compared.

Results

After the treatment, levels of urea nitrogen and blood creatinine in both groups decreased compared to before the treatment, and was significantly lower in the hybrid group compared to the hemodialysis group (P<0.05). Serum levels of interleukin 6 (IL-6), high sensitivity C-reactive protein (hs-CRP), and tumor necrosis factor α (TNF-α) in both groups decreased compared to before the treatment, and were significantly lower in the hybrid group (P<0.05). Levels of hemoglobin (Hb), albumin (Alb), and serum ferritin (SF) in both groups increased compared to pretreatment levels, and were significantly higher in the hybrid group (P<0.05). The incidence of cardiovascular events in the hybrid group (2.90%) was lower than that in the hemodialysis group (11.59%) (P<0.05).

Conclusions

Hybrid blood purification can improve nutritional status and renal function of patients with ESRD, downregulate the expression of inflammatory factors, reduce the degree of inflammatory response, and reduce the risk of cardiovascular events.

Investigating the inflammatory mechanism of notoginsenoside R1 in Diabetic nephropathy via ITGB8 based on network pharmacology and experimental validation

BACKGROUND

Diabetes often causes diabetic nephropathy (DN), a serious long-term complication. It is characterized by chronic proteinuria, hypertension, and kidney function decline, can progress to end-stage renal disease, lowering patients' quality of life and lifespan. Inflammation and apoptosis are key to DN development. Network pharmacology, clinical correlation, and basic experimental validation to find out how NGR1 might work to reduce inflammation in DN treatment. The study aims to improve DN treatment with new findings.

METHODS

To determine how NGR1 treats DN, this study used network pharmacology, clinical correlation, and basic experimental validation. Three methods were used to predict NGR1 drug targets: ChEMBL, SuperPred, and Swiss Target Prediction. Drug targets are linked to diseases by molecular docking. A clinical correlation analysis using the Nephroseq Classic (V4) database looked at the strong link between medication targets and the development, progression, and renal function of DN. Additional research showed that NGR1 reduces high blood sugar-induced podocyte inflammation.

RESULTS

The integrin subunit beta 8 (ITGB8) protein is a potential NGR1 therapeutic target for DN. It may be linked to inflammatory proteins like caspase 3 and IL-18. Validation of the molecular docking showed that SER-407, ALA-22, Ala-343, and TYR-406 form hydrogen bonds with NGR1 and ITGB8. These interactions represent pharmacodynamic targets. Clinical correlation showed that DN patients had significantly lower ITGB8 expression levels than healthy individuals. Between 50 and 80 years old, DN patients' ITGB8 expression levels decreased. ITGB8 expression was lowest in renal function conditions, with eGFR values of 15-29 ml/min/1.73 m2. In the db/db mouse model, downregulation of ITGB8 expression in renal tissue was associated with renal inflammatory damage. The hyperglycemic group had significantly lower levels of nephrin and caspase-3 protein, but higher levels of cleaved caspase-1 protein. Giving NGR1 in different amounts (1, 3, 10, and 30 µM) greatly decreased the expression of caspase3, stopped the expression of cleaved caspase1, and lowered the damage caused by NLRP3 in podocytes.

CONCLUSION

We identified several NGR1 pharmacological targets and found that the ITGB8 protein is a key drug target linked to inflammation and DN. ITGB8 is critical for DN development and can help to reduce high blood sugar-induced podocyte inflammation.

Clinical Trial of Autologous Dendritic Cell Administration Effect on Water Molecule Diffusion and Anti-Inflammatory Biomarkers in Diabetic Kidney Disease

Diabetic kidney disease (DKD) significantly increases mortality, with patients facing a fourfold risk of death within ten years. Chronic inflammation, marked by transforming growth factor-β (TGF-β) and intracellular adhesion molecule-1 (ICAM-1) activity, contributes to kidney damage and fibrosis. This study investigates the effect of autologous dendritic cells on inflammation and kidney function, focusing on apparent diffusion coefficient (ADC), TGF-β, and ICAM-1 levels. This quasi-experimental clinical trial involved 22 DKD patients at Gatot Soebroto Army Hospital. Patients received autologous dendritic cell injections. Baseline and post-intervention magnetic resonance imaging (MRI) scans measured ADC values, and ICAM-1 and TGF-β levels were analyzed. Post intervention, the median ADC decreased from 1.75 mm2/s to 1.64 mm2/s (p = 0.223). ICAM-1 levels increased significantly in females (p = 0.04) but not in males (p = 0.35). No significant changes were found in TGF-β levels (p = 0.506). ADC changes were statistically insignificant and did not correlate with CKD severity. ICAM-1 increases in females correlated with improved creatinine levels, suggesting kidney function improvement. Autologous dendritic cell therapy revealed potential gender-specific immune responses but showed limited overall biomarker improvements. Further studies are required to validate its therapeutic value.

Open-Label Clinical Trial on the Impact of Autologous Dendritic Cell Therapy on Albuminuria and Inflammatory Biomarkers (Interleukin-6, Interleukin-10, Tumor Necrosis Factor α) in Diabetic Kidney Disease (DKD)

The prevalence of type 2 diabetes mellitus (T2DM) is increasing worldwide, leading to a higher incidence of diabetic kidney disease (DKD), a major risk factor for end-stage kidney disease (ESKD). This study investigates the effects of autologous dendritic cell (DC) therapy on albuminuria and inflammatory biomarkers (IL-6, IL-10, and TNF-α) in DKD patients. An open-label clinical trial was conducted with 69 DKD outpatients at the Gatot Soebroto Army Central Hospital (RSPAD GS). Each subject received a single DC injection, with evaluations of urinary albumin-creatinine ratio (UACR) and inflammatory biomarkers at baseline and 4 weeks post-intervention. UACR was measured weekly, while eGFR, IL-6, IL-10, and TNF-α levels were assessed at baseline and week 4. Results indicated a significant reduction in median UACR from 250 mg/g at baseline to 153 mg/g in week 1, with sustained lower levels over 4 weeks (p < 0.05). No significant change of eGFR was found (p = 0.478). TNF-α levels also significantly decreased from 2.16 pg/mL to 1.92 pg/mL (p = 0.03), while IL-6 (p = 0.83) and IL-10 (p = 0.11) showed no significant change. The reduction in UACR and TNF-α suggests that DC therapy may alleviate albuminuria through anti-inflammatory mechanisms primarily suppressing TNF-α. No significant change in IL-10 levels implies that the anti-inflammatory effect is not mediated by IL-10 enhancement. This study demonstrates the potential of DC therapy as adjunct therapy to reduce albuminuria in DKD patients, with further research needed to explore long-term efficacy, long-term safety, and dosing strategies.

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.

Causal relationship between 731 immune cells and the risk of diabetic nephropathy: a two‑sample bidirectional Mendelian randomization study

OBJECTIVE

Previous observational studies have indicated associations between various immune cells and diabetic nephropathy (DN). However, the causality remains unclear. We aimed to further evaluate the causal association between immune cells and DN using bidirectional two-sample Mendelian randomization (MR) analysis.

METHOD

The DN data were retrieved from the IEU OpenGWAS Project database, while the data for 731 immune cells were sourced from GWAS summary statistics by Orru ̀ et al. The investigation into the causal relationship between immune cells and DN employed the inverse variance weighted (IVW), weighted median (WME), and MR-Egger methods. The stability and reliability of the findings underwent evaluation through Cochran's Q test, MR-Egger intercept's P-value, MR-PRESSO, and Leave-One-Out (LOO) method.

RESULT

The IVW estimates suggested a positive causal effect of CD25 on IgD-CD38dim B cell, CD25 on naive-mature B cell, CD127 on granulocyte, SSC-A on HLA DR + Natural Killer, HLA DR on plasmacytoid Dendritic Cell, and HLA DR on Dendritic Cell on DN. Conversely, the abundance of Myeloid Dendritic Cell, CD62L- Dendritic Cell %Dendritic Cell, CD86+ myeloid Dendritic Cell %Dendritic Cell, CD14- CD16-, CX3CR1 on CD14- CD16-, and SSC-A on CD4+ T cell had negative causal effects on DN. However, after correcting the P value for significant causality results using the FDR method, it was concluded that only Myeloid Dendritic Cells had a causal relationship with DN (FDR-p = 0.041), while the other immune cells showed no significant association with DN, so their relationship was suggestive. The results were stable with no observed horizontal pleiotropy and heterogeneity. Reverse MR analysis indicated no causal relationship between DN and the increased risk of positively identified immune cells.

CONCLUSION

This study provides an initial insight into the genetic perspective of the causal relationship between immune cells and DN. It establishes a crucial theoretical foundation for future endeavors in precision medicine and individualized treatment.

Association of systemic immune-inflammation index with all-cause and cardio-cerebrovascular mortality in individuals with diabetic kidney disease: evidence from NHANES 1999-2018

Background

Emerging evidence suggests a potential role of immune response and inflammation in the pathogenesis of diabetic kidney disease (DKD). The systemic immune-inflammation index (SII) offers a comprehensive measure of inflammation; however, its relationship with the prognosis of DKD patients remains unclear.

Methods

Using data from the National Health and Nutrition Examination Survey (NHANES) spanning 1999 to 2018, this cross-sectional study involved adults diagnosed with DKD. Cox proportional hazards models were utilized to assess the associations between SII and all-cause or cardio-cerebrovascular disease mortality. Additionally, restricted cubic spline, piecewise linear regression, and subgroup analyses were performed.

Results

Over a median follow-up duration of 6.16 years, 1338 all-cause deaths were recorded. After adjusting for covariates, elevated SII levels were significantly associated with increased risks of all-cause and cardio-cerebrovascular disease mortality. Specifically, per one-unit increment in natural log-transformed SII (lnSII), there was a 29% increased risk of all-cause mortality (P < 0.001) and a 23% increased risk of cardio-cerebrovascular disease mortality (P = 0.01) in the fully adjusted model. Similar results were observed when SII was analyzed as a categorical variable (quartiles). Moreover, nonlinear association was identified between SII and all-cause mortality (P < 0.001) through restricted cubic spline analysis, with threshold value of 5.82 for lnSII. The robustness of these findings was confirmed in subgroup analyses. Likewise, the statistically significant correlation between SII levels and cardio-cerebrovascular disease mortality persisted in individuals with DKD.

Conclusion

Increased SII levels, whether examined as continuous variables or categorized, demonstrate a significant association with elevated risks of all-cause and cardio-cerebrovascular disease mortality among DKD patients. These findings imply that maintaining SII within an optimal range could be crucial in reducing mortality risk.

The systemic immune-inflammation index and systemic inflammation response index are useful for predicting mortality in patients with diabetic nephropathy

BACKGROUND

This study investigated the correlation between the systemic immune-inflammation index (SII) and the systemic inflammation response index (SIRI) and all-cause, cardiovascular, and kidney disease mortality in patients with diabetic nephropathy (DN). It aimed to provide a new predictive assessment tool for the clinic and a scientific basis for managing inflammation in DN.

METHODS

The data utilized in this study were obtained from the National Health and Nutrition Examination Survey (NHANES) database, spanning 1999 to 2018. A total of 2641 patients diagnosed with DN were included in the analysis. The association between SII and SIRI levels and mortality in patients with DN was investigated using multivariate Cox proportional risk regression models. These relationships were further validated by Kaplan-Meier survival curves and restricted cubic spline (RCS) modeling, and subgroup analyses were performed to explore the heterogeneity among different characteristic subgroups.

RESULTS

The multivariate Cox regression analysis indicated that SII and SIRI levels were independently associated with all-cause mortality and cardiovascular mortality in patients with DN. SIRI levels were found to be an independently associated factor with kidney disease mortality in patients with DN. Patients in the highest quartile of SII and SIRI exhibited a 1.49-fold and 1.62-fold increased risk of all-cause mortality, respectively, compared to patients in the lowest quartile. The risk of cardiovascular mortality was 1.31 and 1.73 times higher than that in patients in the lowest quartile, respectively. The risk of kidney disease mortality in patients in the highest quartile of SIRI was 2.74 times higher than that in patients in the lowest quartile. Kaplan-Meier survival curve and RCS analyses further confirmed the positive association between SII and SIRI and mortality and a significant nonlinear relationship between SII and all-cause mortality. The SII and SIRI indices offer incremental value in model predictive power for mortality in patients with DN. Subgroup analyses demonstrated that the correlation between SII and SIRI and mortality risk was stable but heterogeneous across different subgroups.

CONCLUSION

SII and SIRI can be utilized as biomarkers for forecasting the likelihood of all-cause and cardiovascular mortality in patients with DN.

Cinnamaldehyde ameliorates diabetes-induced biochemical impairments and AGEs macromolecules in a pre-clinical model of diabetic nephropathy

PURPOSE

Cinnamaldehyde, has various therapeutic potentials including glucose-lowering effect, and insulinotropic effect; however, its glycation inhibitory mechanism is not known yet. In this study, we explored the effects of cinnamaldehyde for its AGEs inhibitory mechanism in a streptozotocin-complete Freund's adjuvant (STZ-CFA) induced diabetic nephropathy (DN) rat model.

METHODS

Pre-clinical DN model was developed by the administration of multiple low doses of STZ-CFA in rats, mainly characterized by abnormal blood parameters and nephrotic damages. Diabetes-related systemic profile and histopathological hallmarks were evaluated using biochemical assays, microscopic imaging, immunoblot, and real-time PCR analyses, supported by cinnamaldehyde-albumin interaction assessed using STD-NMR and in silico site-directed interactions in the presence of glucose.

RESULTS

Cinnamaldehyde-treatment significantly reversed DN hallmarks, fasting blood glucose (FBG), serum insulin, glycated hemoglobin (HbA1c), urinary microalbumin, and creatinine contrasted to non-treated DN rats and aminoguanidine, a positive reference advanced glycation end products (AGEs) inhibitor. The pathological depositions of AGEs, receptor for advanced glycation end products (RAGE), and carboxymethyl lysine (CML), and transcriptional levels of AGE-RAGE targeted immunomodulatory factors (IL1β, TNF-α, NF-κB, TGF-β) were significantly improved in cinnamaldehyde treated rats as compared to aminoguanidine. Cinnamaldehyde post-treatment improved pancreatic pathology and systemic glycemic index (0.539 ± 0.01 vs. 0.040 ± 0.001, P < 0.001) in DN rats. Subsequently, in silico profiling of cinnamaldehyde defined the competitive binding inhibition with glucose in AGE and RAGE receptors that was further confirmed by in vitro STD-NMR analysis.

CONCLUSION

These findings suggest potential role of cinnamaldehyde in reversing STZ-induced diabetic nephropathic impairments; therefore, appears promising candidate for further pharmacological explorations towards diabetes-associated complications.

Cell Division Cycle 42 Improves Renal Functions, Fibrosis, Th1/Th17 Infiltration and Inflammation to Some Degree in Diabetic Nephropathy

Our two previous studies observed that cell division cycle 42 (CDC42) was lower and correlated with improved renal function and inflammation in diabetic nephropathy (DN) patients, and CDC42 inhibited renal tubular epithelial cell fibrosis and inflammation under high glucose condition. Sequentially, this current study aimed to investigate the effect of CDC42 on improving renal function, fibrosis, and inflammation in DN mice, and its interaction with T cell receptor (TCR) related pathways. Mice were treated by streptozotocin to construct early-stage DN model, then transfected with CDC42 overexpression adenovirus, followed by simultaneous treatment of LY294002 (PI3K/AKT inhibitor) and CI-1040 (ERK inhibitor), respectively. CDC42 reduced blood glucose, creatinine, and 24 h urine protein in DN mice, but only showed a tendency to decrease blood urea nitrogen without statistical significance. Hematoxylin&eosin staining revealed that CDC42 descended the glomerular volume, basement membrane thickness, and inflammatory cell infiltration in kidney. Meanwhile, CDC42 lowered fibronectin, TGF-β1, and Collagen I expressions in kidney, but not decreased α-SMA significantly. Besides, CDC42 decreased T-helper (Th) 1 and Th17 cells in kidney, and reduced serum IFN-γ, IL-1β, IL-17A, and TNF-α but not IL-6. Regarding TCR-related pathways, CDC42 activated AKT and ERK pathways but not JNK pathway. However, the treatment of LY294002 and CI-1040 had limited effect on attenuating CDC42's functions on renal function and fibrotic markers. CDC42 improves renal functions, fibrosis, Th1/Th17 infiltration and inflammation to some degree in DN mice, these functions may be independent to AKT and ERK pathways.

Naringenin - a potential nephroprotective agent for diabetic kidney disease: A comprehensive review of scientific evidence

Diabetes mellitus (DM) is a chronic disease characterized by persistent hyperglycemia, which is a major contributing factor to chronic kidney disease (CKD), end-stage renal disease (ESRD), and cardiovascular-related deaths. There are several mechanisms leading to kidney injury, with hyperglycemia well known to stimulate oxidative stress, inflammation, tissue remodeling, and dysfunction in the vascular system and organs. Increased reactive oxygen species (ROS) decrease the bioavailability of vasodilators while increasing vasoconstrictors, resulting in an imbalance in vascular tone and the development of hypertension. Treatments for diabetes focus on controlling blood glucose levels, but due to the complexity of the disease, multiple drugs are often required to successfully delay the development of microvascular complications, including CKD. In this context, naringenin, a flavonoid found in citrus fruits, has demonstrated anti-inflammatory, anti-fibrotic, and antioxidant effects, suggesting its potential to protect the kidney from deleterious effects of diabetes. This review aims to summarize the scientific evidence of the effects of naringenin as a potential therapeutic option for diabetes-induced CKD.

Relationship between immune cells and diabetic nephropathy: a Mendelian randomization study

OBJECTIVE

Although previous studies have suggested potential correlations between immunocytes and diabetic nephropathy (DN), the causal correlations between them remain unclarified. In this study, we employed Mendelian randomization (MR) to analyze the potential causative correlations between immune 731 cells and DN.

METHODS

We used the Genome-Wide Association Studies (GWAS) database to aggregate signatures of immune cells and DN from European and East Asian populations. Single-nucleotide polymorphisms (SNPs) were used as instrumental variables. MR analysis was conducted using Mendelian randomization-Egger (MR-Egger) regression and the random-effects inverse-variance weighted (IVW) method.

RESULTS

A total of 3,571 SNPs were included as instrumental variables. The MR-Egger regression model indicated no genetic pleiotropy (P = 0.6284). The results of the IVW method indicated a statistically significant causal relationship between immune cell HLA-DR on CD14-CD16- (P = 0.029), CD45RA-CD28-CD8 + T cell% T cells (P = 0.0278), CD11c on myeloid dendritic cells (P = 0.0352), HLA-DR on CD14+ monocytes (P < 0.001), CD27 on CD24 + CD27 + B cells (P = 0.0334), CD27 on IgD + CD24 + B cells (P = 0.0137), CD4 on CD39 + CD4 + T cells (P = 0.0347), CD28 on CD39 + CD4 + T cells (P = 0.0414), CD39 on CD39 + CD4 + T cells (P = 0.0426), and DN. Additionally, there was no heterogeneity in SNPs related HLA-DR on CD14-CD16-cells and DN(I2 = 32%, Cochran's Q = 2.9476, P = 0.2291). Moreover, leave-one-out analysis showed a causal correlation between HLA-DR on CD14-CD16- cells and DN.

CONCLUSION

Higher expression of immune cell HLA-DR on CD14-CD16- cells may indicate a lower risk of DN.

Fiery Connections: Macrophage-Mediated Inflammation, the Journey from Obesity to Type 2 Diabetes Mellitus and Diabetic Kidney Disease

The high prevalence of diabetes mellitus (DM) poses a significant public health challenge, with diabetic kidney disease (DKD) as one of its most serious consequences. It has become increasingly clear that type 2 DM (T2D) and the complications of DKD are not purely metabolic disorders. This review outlines emerging evidence related to the step-by-step contribution of macrophages to the development and progression of DKD in individuals who specifically develop T2D as a result of obesity. The macrophage is a prominent inflammatory cell that contributes to obesity, where adipocyte hypertrophy leads to macrophage recruitment and eventually to the expansion of adipose tissue. The recruited macrophages secrete proinflammatory cytokines, which cause systemic inflammation, glucose dysregulation, and insulin sensitivity, ultimately contributing to the development of T2D. Under such pathological changes, the kidney is susceptible to elevated glucose and thereby activates signaling pathways that ultimately drive monocyte recruitment. In particular, the early recruitment of proinflammatory macrophages in the diabetic kidney produces inflammatory cytokines/chemokines that contribute to inflammation and tissue damage associated with DKD pathology. Macrophage activation and recruitment are crucial inciting factors that also persist as DKD progresses. Thus, targeting macrophage activation and function could be a promising therapeutic approach, potentially offering significant benefits for managing DKD at all stages of progression.

Causal role of immune cells in diabetic nephropathy: a bidirectional Mendelian randomization study

Background

Diabetic nephropathy (DN) stands as a pervasive chronic renal disease worldwide, emerging as the leading cause of renal failure in end-stage renal disease. Our objective is to pinpoint potential immune biomarkers and evaluate the causal effects of prospective therapeutic targets in the context of DN.

Methods

We employed Mendelian randomization (MR) analysis to examine the causal associations between 731 immune cell signatures and the risk of DN. Various analytical methods, including inverse-variance weighted (IVW), MR-Egger, weighted median, simple mode, and weighted mode, were employed for the analysis. The primary analytical approach utilized was the inverse-variance weighted (IVW) method. To ensure the reliability of our findings, we conducted comprehensive sensitivity analyses to assess the robustness, heterogeneity, and presence of horizontal pleiotropy in the results. Statistical powers were also calculated. Ultimately, a reverse Mendelian randomization (MR) analysis was conducted to assess the potential for reverse causation.

Results

After Benjamini & Hochberg (BH) correction, four immunophenotypes were identified to be significantly associated with DN risk: HLA DR on Dendritic Cell (OR=1.4460, 95% CI = 1.2904~1.6205, P=2.18×10-10, P.adjusted= 1.6×10-7), HLA DR on CD14+ CD16- monocyte (OR=1.2396, 95% CI=1.1315~1.3580, P=3.93×10-6, P.adjusted = 0.00143). HLA DR on CD14+ monocyte (OR=1.2411, 95% CI=1.12957~1.3637, P=6.97×10-6, P.adjusted=0.0016), HLA DR on plasmacytoid Dendritic Cell (OR=1.2733, 95% CI= 1.1273~1.4382, P= 0.0001, P.adjusted = 0.0183). Significant heterogeneity of instrumental variables was found in the four exposures, and significant horizontal pleiotropy was only found in HLA DR on Dendritic Cell. The bidirectional effects between the immune cells and DN were not supported.

Conclusion

Our research illustrated the intimate association between immune cells and DN, which may contribute to a deeper understanding of the intricate mechanisms underlying DN and aid in the identification of novel intervention target pathways.

VCAM1: an effective diagnostic marker related to immune cell infiltration in diabetic nephropathy

Introduction

The role of immune cells in the pathogenesis and advancement of diabetic nephropathy (DN) is crucial. The objective of this study was to identify immune-cell-related biomarkers that could potentially aid in the diagnosis and management of DN.

Methods

The GSE96804 dataset was obtained from the Gene Expression Omnibus (GEO) database. Then, screen for intersections between differentially expressed genes (DEGs) and immune-related genes (IRGs). Identify core genes through protein-protein interaction (PPI) networks and the Cytoscape plugin. Subsequently, functional enrichment analysis was conducted. In addition, ROC analysis is performed to accurately identify diagnostic biomarkers. Apply the CIBERSORT algorithm to evaluate the proportion of immune cell infiltration. Finally, the mRNA, protein, and immunofluorescence expression of the biomarker was validated in the DN rat model.

Results

The study yielded 74 shared genes associated with DN. Enrichment analysis indicated significant enrichment of these genes in focal adhesion, the humoral immune response, activation of the immune response, Cytokine-cytokine receptor interaction, and IL-17 signaling pathway. The optimal candidate gene VCAM1 was identified. The presence of VCAM1 in DN was further validated using the ROC curve. Analysis of immune cell infiltration matrices revealed a high abundance of monocytes, naïve B cells, memory B cells, and Macrophages M1/M2 in DN tissues. Correlation analysis identified one hub biomarker associated with immune-infiltrated cells in DN. Furthermore, our findings were validated through in vivo RT qPCR, WB, and IF techniques.

Conclusions

Our research indicates that VCAM1 is a signature gene associated with DN and is linked to the progression, treatment, and prognosis of DN. A comprehensive examination of immune infiltration signature genes may offer new perspectives on the clinical diagnosis and management of DN.

The Potential of Anti-Inflammatory DC Immunotherapy in Improving Proteinuria in Type 2 Diabetes Mellitus

A typical consequence of type 2 diabetes mellitus, diabetic kidney disease (DKD) is a significant risk factor for end-stage renal disease. The pathophysiology of diabetic kidney disease (DKD) is mainly associated with the immune system, which involves adhesion molecules and growth factors disruption, excessive expression of inflammatory mediators, decreased levels of anti-inflammatory mediators, and immune cell infiltration in the kidney. Dendritic cells are professional antigen-presenting cells acting as a bridge connecting innate and adaptive immune responses. The anti-inflammatory subset of DCs is also capable of modulating inflammation. Autologous anti-inflammatory dendritic cells can be made by in vitro differentiation of peripheral blood monocytes and utilized as a cell-based therapy. Treatment with anti-inflammatory cytokines, immunosuppressants, and substances derived from pathogens can induce tolerogenic or anti-inflammatory features in ex vivo-generated DCs. It has been established that targeting inflammation can alleviate the progression of DKD. Recent studies have focused on the potential of dendritic cell-based therapies to modulate immune responses favorably. By inducing a tolerogenic phenotype in dendritic cells, it is possible to decrease the inflammatory response and subsequent kidney damage. This article highlights the possibility of using anti-inflammatory DCs as a cell-based therapy for DKD through its role in controlling inflammation.

Identification of key immune-related genes and potential therapeutic drugs in diabetic nephropathy based on machine learning algorithms

BACKGROUND

Diabetic nephropathy (DN) is a major contributor to chronic kidney disease. This study aims to identify immune biomarkers and potential therapeutic drugs in DN.

METHODS

We analyzed two DN microarray datasets (GSE96804 and GSE30528) for differentially expressed genes (DEGs) using the Limma package, overlapping them with immune-related genes from ImmPort and InnateDB. LASSO regression, SVM-RFE, and random forest analysis identified four hub genes (EGF, PLTP, RGS2, PTGDS) as proficient predictors of DN. The model achieved an AUC of 0.995 and was validated on GSE142025. Single-cell RNA data (GSE183276) revealed increased hub gene expression in epithelial cells. CIBERSORT analysis showed differences in immune cell proportions between DN patients and controls, with the hub genes correlating positively with neutrophil infiltration. Molecular docking identified potential drugs: cysteamine, eltrombopag, and DMSO. And qPCR and western blot assays were used to confirm the expressions of the four hub genes.

RESULTS

Analysis found 95 and 88 distinctively expressed immune genes in the two DN datasets, with 14 consistently differentially expressed immune-related genes. After machine learning algorithms, EGF, PLTP, RGS2, PTGDS were identified as the immune-related hub genes associated with DN. In addition, the mRNA and protein levels of them were obviously elevated in HK-2 cells treated with glucose for 24 h, as well as their mRNA expressions in kidney tissues of mice with DN.

CONCLUSION

This study identified 4 hub immune-related genes (EGF, PLTP, RGS2, PTGDS), as well as their expression profiles and the correlation with immune cell infiltration in DN.

The immune-inflammation factor is associated with diabetic nephropathy: evidence from NHANES 2013-2018 and GEO database

Diabetic nephropathy (DN) is a common secondary kidney disease. Immune and inflammatory responses play an influential role in the development of DN. This study aims to explore the role and mechanisms of immune- and inflammatory-related factors in DN. Participants from the NHANES 2013-2018 were included to evaluate the association between the SII and DN. Considering the skewed distribution of SII, log SII was used for subsequent analysis. Then, the DEGs were extracted from the GSE96804 dataset by the "limma" package of R, which were further screened out genes in the key module based on WGCNA. The intersection genes between DEGs and key module genes were the key genes for the following mechanism exploration. The CyTargetlinker plug-in of Cytoscape software was used to construct the drug-genes network. Molecular docking was used to calculate the binding affinity between potential drugs and the hub genes. Among the 8236 participants from NHANES 2013-2018, Log SII was significantly associated with DN (p < 0.05). DEG and WGCNA revealed 30 DN-related genes, which mainly regulated immune- and inflammation pathways, and the NOD-like receptor signaling pathway was the core pathway highly involved in the DN occurrence. Moreover, NAIP, ZFP36, and DUSP1 were identified as hub genes in DN progression and there was a strong binding interaction between resveratrol and DUSP1.In conclusion, immune inflammation plays an influential role in the occurrence and development of DN. SII is an effective diagnostic marker for DN and resveratrol might have potential value in treating DN.

Luteolin Alleviates Diabetic Nephropathy Fibrosis Involving AMPK/NLRP3/TGF-β Pathway

Purpose

Luteolin is a promising candidate for diabetic nephropathy due to its potential anti-inflammatory and anti-fibrotic properties. This study explored the molecular mechanisms through which luteolin combats fibrosis in DN.

Methods

Potential targets affected by luteolin and genes associated with DN were collected from databases. Overlapping targets between luteolin and diabetic nephropathy were identified through Venn analysis. A protein-protein interaction network was constructed using these common targets, and critical pathways and targets were elucidated through GO and KEGG analysis. These pathways and targets were confirmed using a streptozotocin-induced mouse model. Luteolin was administered at 45 mg/kg and 90 mg/kg. Various parameters were evaluated, including body weight, blood glucose levels, and histopathological examinations. Protein levels related to energy metabolism, inflammation, and fibrosis were quantified.

Results

Fifty-three targets associated with luteolin and 36 genes related to diabetic nephropathy were extracted. The AGE-RAGE signaling pathway was the key pathway impacted by luteolin in diabetic nephropathy. Key molecular targets include TGF-β, IL-1β, and PPARG. Luteolin reduced body weight and blood glucose levels, lowered the left kidney index, and improved insulin and glucose tolerance. Furthermore, luteolin mitigated inflammatory cell infiltration, basement membrane thickening, and collagen deposition in the kidney. Luteolin up-regulated the protein expression of p-AMPKα (Th172) while simultaneously down-regulated the protein expression of p-NF-ĸB (p65), NLRP3, TGF-β1, α-SMA, and Collagen I.

Conclusion

Luteolin mitigated renal fibrosis by alleviating energy metabolism disruptions and inflammation by modulating the AMPK/NLRP3/TGF-β signaling pathway.

The causal role between circulating immune cells and diabetic nephropathy: a bidirectional Mendelian randomization with mediating insights

Diabetic nephropathy (DN) is a critical inflammatory condition linked to diabetes, affecting millions worldwide. This study employs Mendelian randomization (MR) to explore the causal relationship between immune cell signatures and DN, analyzing over 731 immune signatures and incorporating data from 1400 metabolites to investigate potential mediators. Despite no statistically significant influence of DN on immunophenotypes after FDR correction, some phenotypes with unadjusted low P-values warranted mention, including CD34 on Hematopoietic Stem Cell (Myeloid cell Panel), CD45 on CD33- HLA DR- (Myeloid cell Panel). Furthermore, three immunophenotypes were identified to have a significant impact on DN risk: CD16-CD56 on HLA DR+ NK (TBNK Panel), CD45 on HLA DR+ T cell (TBNK Panel), and CD33dim HLA DR+ CD11b+ AC (Myeloid cell Panel). Our findings underscore the critical role of immune cells in DN, highlighting potential mediators and offering new insights into its underlying mechanisms.

Mannan-Binding Lectin Is Associated with Inflammation and Kidney Damage in a Mouse Model of Type 2 Diabetes

Autoreactivity of the complement system may escalate the development of diabetic nephropathy. We used the BTBR OB mouse model of type 2 diabetes to investigate the role of the complement factor mannan-binding lectin (MBL) in diabetic nephropathy. Female BTBR OB mice (n = 30) and BTBR non-diabetic WT mice (n = 30) were included. Plasma samples (weeks 12 and 21) and urine samples (week 19) were analyzed for MBL, C3, C3-fragments, SAA3, and markers for renal function. Renal tissue sections were analyzed for fibrosis, inflammation, and complement deposition. The renal cortex was analyzed for gene expression (complement, inflammation, and fibrosis), and isolated glomerular cells were investigated for MBL protein. Human vascular endothelial cells cultured under normo- and hyperglycemic conditions were analyzed by flow cytometry. We found that the OB mice had elevated plasma and urine concentrations of MBL-C (p < 0.0001 and p < 0.001, respectively) and higher plasma C3 levels (p < 0.001) compared to WT mice. Renal cryosections from OB mice showed increased MBL-C and C4 deposition in the glomeruli and increased macrophage infiltration (p = 0.002). Isolated glomeruli revealed significantly higher MBL protein levels (p < 0.001) compared to the OB and WT mice, and no renal MBL expression was detected. We report that chronic inflammation plays an important role in the development of DN through the binding of MBL to hyperglycemia-exposed renal cells.

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.

Whole transcriptome mapping reveals the lncRNA regulatory network of TFP5 treatment in diabetic nephropathy

BACKGROUND

TFP5 is a Cdk5 inhibitor peptide, which could restore insulin production. However, the role of TFP5 in diabetic nephropathy (DN) is still unclear.

OBJECTIVE

This study aims to characterize the transcriptome profiles of mRNA and lncRNA in TFP5-treated DN mice to mine key lncRNAs associated with TFP5 efficacy.

METHODS

We evaluated the role of TFP5 in DN pathology and performed RNA sequencing in C57BL/6J control mice, C57BL/6J db/db model mice, and TFP5 treatment C57BL/6J db/db model mice. The differentially expressed lncRNAs (DElncRNAs) and mRNAs (DEmRNAs) were analyzed. WGCNA was used to screen hub-gene of TFP5 in treatment of DN.

RESULTS

Our results showed that TFP5 therapy ameliorated renal tubular injury in DN mice. In addition, compared with the control group, the expression profile of lncRNAs in the model group was significantly disordered, while TFP5 alleviated the abnormal expression of lncRNAs. A total of 67 DElncRNAs shared among the three groups, 39 DElncRNAs showed a trend of increasing in the DN group and decreasing after TFP treatment, while the remaining 28 showed the opposite trend. DElncRNAs were enriched in glycosphingolipid biosynthesis signaling pathways, NF-κB signaling pathways, and complement activation signaling pathways. There were 1028 up-regulated and 1117 down-regulated DEmRNAs in the model group compared to control group, and 123 up-regulated and 153 down-regulated DEmRNAs in the TFP5 group compared to the model group. The DEmRNAs were involved in PPAR and MAPK signaling pathway. We confirmed that MSTRG.28304.1 is a key DElncRNA for TFP5 treatment of DN. TFP5 ameliorated DN maybe by inhibiting MSTRG.28304.1 through regulating the insulin resistance and PPAR signaling pathway. The qRT-PCR results confirmed the reliability of the sequencing data through verifying the expression of ENSMUST00000211209, MSTRG.31814.5, MSTRG.28304.1, and MSTRG.45642.14.

CONCLUSION

Overall, the present study provides novel insights into molecular mechanisms of TFP5 treatment in DN.

Macrophage SHP2 Deficiency Alleviates Diabetic Nephropathy via Suppression of MAPK/NF-κB- Dependent Inflammation

Increasing evidence implicates chronic inflammation as the main pathological cause of diabetic nephropathy (DN). Exploration of key targets in the inflammatory pathway may provide new treatment options for DN. We aimed to investigate the role of Src homology 2-containing protein tyrosine phosphatase 2 (SHP2) in macrophages and its association with DN. The upregulated phosphorylation of SHP2 was detected in macrophages in both patients with diabetes and in a mouse model. Using macrophage-specific SHP2-knockout (SHP2-MKO) mice and SHP2fl/fl mice injected with streptozotocin (STZ), we showed that SHP2-MKO significantly attenuated renal dysfunction, collagen deposition, fibrosis, and inflammatory response in mice with STZ-induced diabetes. RNA-sequencing analysis using primary mouse peritoneal macrophages (MPMs) showed that SHP2 deletion mainly affected mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) signaling pathways as well as MAPK/NF-κB-dependent inflammatory cytokine release in MPMs. Further study indicated that SHP2-deficient macrophages failed to release cytokines that induce phenotypic transition and fibrosis in renal cells. Administration with a pharmacological SHP2 inhibitor, SHP099, remarkably protected kidneys in both type 1 and type 2 diabetic mice. In conclusion, these results identify macrophage SHP2 as a new accelerator of DN and suggest that SHP2 inhibition may be a therapeutic option for patients with DN.

ARTICLE HIGHLIGHTS

Identification of common genes and pathways between type 2 diabetes and COVID-19

BACKGROUND

Numerous studies have reported a high incidence and risk of severe illness due to coronavirus disease 2019 (COVID-19) in patients with type 2 diabetes (T2DM). COVID-19 patients may experience elevated or decreased blood sugar levels and may even develop diabetes. However, the molecular mechanisms linking these two diseases remain unclear. This study aimed to identify the common genes and pathways between T2DM and COVID-19.

METHODS

Two public datasets from the Gene Expression Omnibus (GEO) database (GSE95849 and GSE164805) were analyzed to identify differentially expressed genes (DEGs) in blood between people with and without T2DM and COVID-19. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed on the common DEGs. A protein-protein interaction (PPI) network was constructed to identify common genes, and their diagnostic performance was evaluated by receiver operating characteristic (ROC) curve analysis. Validation was performed on the GSE213313 and GSE15932 datasets. A gene co-expression network was constructed using the GeneMANIA database to explore interactions among core DEGs and their co-expressed genes. Finally, a microRNA (miRNA)-transcription factor (TF)-messenger RNA (mRNA) regulatory network was constructed based on the common feature genes.

RESULTS

In the GSE95849 and GSE164805 datasets, 81 upregulated genes and 140 downregulated genes were identified. GO and KEGG enrichment analyses revealed that these DEGs were closely related to the negative regulation of phosphate metabolic processes, the positive regulation of mitotic nuclear division, T-cell co-stimulation, and lymphocyte co-stimulation. Four upregulated common genes (DHX15, USP14, COPS3, TYK2) and one downregulated common feature gene (RIOK2) were identified and showed good diagnostic accuracy for T2DM and COVID-19. The AUC values of DHX15, USP14, COPS3, TYK2, and RIOK2 in T2DM diagnosis were 0.931, 0.917, 0.986, 0.903, and 0.917, respectively. In COVID-19 diagnosis, the AUC values were 0.960, 0.860, 1.0, 0.9, and 0.90, respectively. Validation in the GSE213313 and GSE15932 datasets confirmed these results. The miRNA-TF-mRNA regulatory network showed that TYH2 was targeted by PITX1, PITX2, CRX, NFYA, SREBF1, RELB, NR1L2, and CEBP, whereas miR-124-3p regulates THK2, RIOK2, and USP14.

CONCLUSION

We identified five common feature genes (DHX15, USP14, COPS3, TYK2, and RIOK2) and their co-regulatory pathways between T2DM and COVID-19, which may provide new insights for further molecular mechanism studies.

Co-differential genes between DKD and aging: implications for a diagnostic model of DKD

Objective

Diabetic kidney disease (DKD) is a serious complication of diabetes mellitus (DM) that is closely related to aging. In this study, we found co-differential genes between DKD and aging and established a diagnostic model of DKD based on these genes.

Methods

Differentially expressed genes (DEGs) in DKD were screened using GEO datasets. The intersection of the DEGs of DKD and aging-related genes revealed DKD and aging co-differential genes. Based on this, a genetic diagnostic model for DKD was constructed using LASSO regression. The characteristics of these genes were investigated using consensus clustering, WGCNA, functional enrichment, and immune cell infiltration. Finally, the expression of diagnostic model genes was analyzed using single-cell RNA sequencing (scRNA-seq) in DKD mice (model constructed by streptozotocin (STZ) injection and confirmed by tissue section staining).

Results

First, there were 159 common differential genes between DKD and aging, 15 of which were significant. These co-differential genes were involved in stress, glucolipid metabolism, and immunological functions. Second, a genetic diagnostic model (including IGF1, CETP, PCK1, FOS, and HSPA1A) was developed based on these genes. Validation of these model genes in scRNA-seq data revealed statistically significant variations in FOS, HSPA1A, and PCK1 gene expression between the early DKD and control groups. Validation of these model genes in the kidneys of DKD mice revealed that Igf1, Fos, Pck1, and Hspa1a had lower expression in DKD mice, with Igf1 expression being statistically significant.

Conclusion

Our findings suggest that DKD and aging co-differential genes are significant in DKD diagnosis, providing a theoretical basis for novel research directions on DKD.

New insights into the role of immunity and inflammation in diabetic kidney disease in the omics era

Diabetic kidney disease (DKD) is becoming the leading cause of chronic kidney disease, especially in the industrialized world. Despite mounting evidence has demonstrated that immunity and inflammation are highly involved in the pathogenesis and progression of DKD, the underlying mechanisms remain incompletely understood. Substantial molecules, signaling pathways, and cell types participate in DKD inflammation, by integrating into a complex regulatory network. Most of the studies have focused on individual components, without presenting their importance in the global or system-based processes, which largely hinders clinical translation. Besides, conventional technologies failed to monitor the different behaviors of resident renal cells and immune cells, making it difficult to understand their contributions to inflammation in DKD. Recently, the advancement of omics technologies including genomics, epigenomics, transcriptomics, proteomics, and metabolomics has revolutionized biomedical research, which allows an unbiased global analysis of changes in DNA, RNA, proteins, and metabolites in disease settings, even at single-cell and spatial resolutions. They help us to identify critical regulators of inflammation processes and provide an overview of cell heterogeneity in DKD. This review aims to summarize the application of multiple omics in the field of DKD and emphasize the latest evidence on the interplay of inflammation and DKD revealed by these technologies, which will provide new insights into the role of inflammation in the pathogenesis of DKD and lead to the development of novel therapeutic approaches and diagnostic biomarkers.

Parallelism and non-parallelism in diabetic nephropathy and diabetic retinopathy

Diabetic nephropathy (DN) and diabetic retinopathy (DR), as microvascular complications of diabetes mellitus, are currently the leading causes of end-stage renal disease (ESRD) and blindness, respectively, in the adult working population, and they are major public health problems with social and economic burdens. The parallelism between the two in the process of occurrence and development manifests in the high overlap of disease-causing risk factors and pathogenesis, high rates of comorbidity, mutually predictive effects, and partial concordance in the clinical use of medications. However, since the two organs, the eye and the kidney, have their unique internal environment and physiological processes, each with specific influencing molecules, and the target organs have non-parallelism due to different pathological changes and responses to various influencing factors, this article provides an overview of the parallelism and non-parallelism between DN and DR to further recognize the commonalities and differences between the two diseases and provide references for early diagnosis, clinical guidance on the use of medication, and the development of new drugs.

Comprehensive Analysis of Fatty Acid Metabolism in Diabetic Nephropathy from the Perspective of Immune Landscapes, Diagnosis and Precise Therapy

Objective

Diabetic nephropathy (DN) represents the principal cause of end-stage renal diseases worldwide, lacking effective therapies. Fatty acid (FA) serves as the primary energy source in the kidney and its dysregulation is frequently observed in DN. Nevertheless, the roles of FA metabolism in the occurrence and progression of DN have not been fully elucidated.

Methods

Three DN datasets (GSE96804/GSE30528/GSE104948) were obtained and combined. Differentially expressed FA metabolism-related genes were identified and subjected to DN classification using "ConsensusClusterPlus". DN subtypes-associated modules were discovered by "WGCNA", and module genes underwent functional enrichment analysis. The immune landscapes and potential drugs were analyzed using "CIBERSORT" and "CMAP", respectively. Candidate diagnostic biomarkers of DN were screened using machine learning algorithms. A prediction model was constructed, and the performance was assessed using receiver operating characteristic (ROC) curves, calibration curves, and decision curve analysis (DCA). The online tool "Nephroseq v5" was conducted to reveal the clinical significance of the candidate diagnostic biomarkers in patients with DN. A DN mouse model was established to verify the biomarkers' expression.

Results

According to 39 dysregulated FA metabolism-related genes, DN samples were divided into two molecular subtypes. Patients in Cluster B exhibited worse outcomes with a different immune landscape compared with those in Cluster A. Ten potential small-molecular drugs were predicted to treat DN in Cluster B. The diagnostic model based on PRKAR2B/ANXA1 was created with ideal predictive values in early and advanced stages of DN. The correlation analysis revealed significant association between PRKAR2B/ANXA1 and clinical characteristics. The DN mouse model validated the expression patterns of PRKAR2B/ANXA1.

Conclusion

Our study provides new insights into the role of FA metabolism in the classification, immunological pathogenesis, early diagnosis, and precise therapy of DN.

Single-Cell Sequencing Reveals the Expression of Immune-Related Genes in Macrophages of Diabetic Kidney Disease

Diabetic kidney disease (DKD) is characterized by macrophage infiltration, which requires further investigation. This study aims to identify immune-related genes (IRGs) in macrophage and explore their potential as therapeutic targets. This study analyzed isolated glomerular cells from three diabetic mice and three control mice. A total of 59 glomeruli from normal kidney samples and 66 from DKD samples were acquired from four kidney transcriptomic profiling datasets. Bioinformatics analysis was conducted using both single-cell RNA (scRNA) and bulk RNA sequencing data to investigate inflammatory responses in DKD. Additionally, the "AUCell" function was used to investigate statistically different gene sets. The significance of each interaction pair was determined by assigning a probability using "CellChat." The study also analyzed the biological diagnostic importance of immune hub genes for DKD and validated the expression of these immune genes in mice models. The top 2000 highly variable genes (HVGs) were identified after data normalization. Subsequently, a total of eight clusters were identified. It is worth mentioning that macrophages showed the highest percentage increase among all cell types in the DKD group. Furthermore, the present study observed significant differences in gene sets related to inflammatory responses and complement pathways. The study also identified several receptor-ligand pairs and co-stimulatory interactions between endothelial cells and macrophages. Notably, SYK, ITGB2, FCER1G, and VAV1 were identified as immunological markers of DKD with promising predictive ability. This study identified distinct cell clusters and four marker genes. SYK, ITGB2, FCER1G, and VAV1 may be important roles. Consequently, the present study extends our understanding regarding IRGs in DKD and provides a foundation for future investigations into the underlying mechanisms.

Complement Cascade Proteins Correlate with Fibrosis and Inflammation in Early-Stage Type 1 Diabetic Kidney Disease in the Ins2Akita Mouse Model

Diabetic kidney disease (DKD) is characterized by histological changes including fibrosis and inflammation. Evidence supports that DKD is mediated by the innate immune system and more specifically by the complement system. Using Ins2Akita T1D diabetic mice, we studied the connection between the complement cascade, inflammation, and fibrosis in early DKD. Data were extracted from a previously published quantitative-mass-spectrometry-based proteomics analysis of kidney glomeruli of 2 (early DKD) and 4 months (moderately advanced DKD)-old Ins2Akita mice and their controls A Spearman rho correlation analysis of complement- versus inflammation- and fibrosis-related protein expression was performed. A cross-omics validation of the correlation analyses' results was performed using public-domain transcriptomics datasets (Nephroseq). Tissue sections from 43 patients with DKD were analyzed using immunofluorescence. Among the differentially expressed proteins, the complement cascade proteins C3, C4B, and IGHM were significantly increased in both early and later stages of DKD. Inflammation-related proteins were mainly upregulated in early DKD, and fibrotic proteins were induced in moderately advanced stages of DKD. The abundance of complement proteins with fibrosis- and inflammation-related proteins was mostly positively correlated in early stages of DKD. This was confirmed in seven additional human and mouse transcriptomics DKD datasets. Moreover, C3 and IGHM mRNA levels were found to be negatively correlated with the estimated glomerular filtration rate (range for C3 rs = -0.58 to -0.842 and range for IGHM rs = -0.6 to -0.74) in these datasets. Immunohistology of human kidney biopsies revealed that C3, C1q, and IGM proteins were induced in patients with DKD and were correlated with fibrosis and inflammation. Our study shows for the first time the potential activation of the complement cascade associated with inflammation-mediated kidney fibrosis in the Ins2Akita T1D mouse model. Our findings could provide new perspectives for the treatment of early DKD as well as support the use of Ins2Akita T1D in pre-clinical studies.

Critical role of FGF21 in diabetic kidney disease: from energy metabolism to innate immunity

Diabetic kidney disease (DKD) stands as the predominant cause of chronic kidney disease (CKD) on a global scale, with its incidence witnessing a consistent annual rise, thereby imposing a substantial burden on public health. The pathogenesis of DKD is primarily rooted in metabolic disorders and inflammation. Recent years have seen a surge in studies highlighting the regulatory impact of energy metabolism on innate immunity, forging a significant area of research interest. Within this context, fibroblast growth factor 21 (FGF21), recognized as an energy metabolism regulator, assumes a pivotal role. Beyond its role in maintaining glucose and lipid metabolism homeostasis, FGF21 exerts regulatory influence on innate immunity, concurrently inhibiting inflammation and fibrosis. Serving as a nexus between energy metabolism and innate immunity, FGF21 has evolved into a therapeutic target for diabetes, nonalcoholic steatohepatitis, and cardiovascular diseases. While the relationship between FGF21 and DKD has garnered increased attention in recent studies, a comprehensive exploration of this association has yet to be systematically addressed. This paper seeks to fill this gap by summarizing the mechanisms through which FGF21 operates in DKD, encompassing facets of energy metabolism and innate immunity. Additionally, we aim to assess the diagnostic and prognostic value of FGF21 in DKD and explore its potential role as a treatment modality for the condition.

Myricetin induces M2 macrophage polarization to alleviate renal tubulointerstitial fibrosis in diabetic nephropathy via PI3K/Akt pathway

BACKGROUND

Development of end-stage renal disease is predominantly attributed to diabetic nephropathy (DN). Previous studies have indicated that myricetin possesses the potential to mitigate the pathological alterations observed in renal tissue. Nevertheless, the precise molecular mechanism through which myricetin influences the progression of DN remains uncertain.

AIM

To investigate the effects of myricetin on DN and explore its potential therapeutic mechanism.

METHODS

Db/db mice were administered myricetin intragastrically on a daily basis at doses of 50 mg/kg or 100 mg/kg for a duration of 12 wk. Subsequently, blood and urine indexes were assessed, along with examination of renal tissue pathology. Kidney morphology and fibrosis were evaluated using various staining techniques including hematoxylin and eosin, periodic acid-Schiff, Masson's trichrome, and Sirius-red. Additionally, high-glucose culturing was conducted on the RAW 264.7 cell line, treated with 25 mM myricetin or co-administered with the PI3K/Akt inhibitor LY294002 for a period of 24 h. In both in vivo and in vitro settings, quantification of inflammation factor levels was conducted using western blotting, real-time qPCR and ELISA.

RESULTS

In db/db mice, administration of myricetin led to a mitigating effect on DN-induced renal dysfunction and fibrosis. Notably, we observed a significant reduction in expressions of the kidney injury markers kidney injury molecule-1 and neutrophil gelatinase associated lipocalin, along with a decrease in expressions of inflammatory cytokine-related factors. Furthermore, myricetin treatment effectively inhibited the up-regulation of tumor necrosis factor-alpha, interleukin-6, and interluekin-1β induced by high glucose in RAW 264.7 cells. Additionally, myricetin modulated the M1-type polarization of the RAW 264.7 cells. Molecular docking and bioinformatic analyses revealed Akt as the target of myricetin. The protective effect of myricetin was nullified upon blocking the polarization of RAW 264.7 via inhibition of PI3K/Akt activation using LY294002.

CONCLUSION

This study demonstrated that myricetin effectively mitigates kidney injury in DN mice through the regulation of macrophage polarization via the PI3K/Akt signaling pathway.

The effects of apoptosis inhibitor of macrophage in kidney diseases

Kidney disease is a progressive and irreversible condition in which immunity is a contributing factor that endangers human health. It is widely acknowledged that macrophages play a significant role in developing and causing numerous kidney diseases. The increasing focus on the mechanism by which macrophages express apoptosis inhibitor of macrophages (AIM) in renal diseases has been observed. AIM is an apoptosis inhibitor that stops different things that cause apoptosis from working. This keeps AIM-bound cell types alive. Notably, the maintenance of immune cell viability regulates immunity. As our investigation progressed, we concluded that AIM has two sides when it comes to renal diseases. AIM can modulate renal phagocytosis, expedite the elimination of renal tubular cell fragments, and mitigate tissue injury. AIM can additionally exacerbate the development of renal fibrosis and kidney disease by prolonging inflammation. IgA nephropathy (IgAN) may also worsen faster if more protein is in the urine. This is because IgA and immunoglobulin M are found together and expressed. In the review, we provide a comprehensive overview of prior research and concentrate on the impacts of AIM on diverse subcategories of nephropathies. We discovered that AIM is closely associated with renal diseases by playing a positive or negative role in the onset, progression, or cure of kidney disease. AIM is thus a potentially effective therapeutic target for kidney diseases.

Traditional Chinese medicine for the treatment of immune-related nephropathy: A review

Immune-related nephropathy (IRN) refers to immune-response-mediated glomerulonephritis and is the main cause of end-stage renal failure. The pathogenesis of IRN is not fully understood; therefore, treatment is challenging. Traditional Chinese medicines (TCMs) have potent clinical effects in the treatment of the IRN conditions immunoglobulin A nephropathy, lupus nephropathy, and diabetic nephropathy. The underlying mechanisms mainly include its inhibition of inflammation; improvements to renal interstitial fibrosis, oxidative stress, autophagy, apoptosis; and regulation of immunity. In this review, we summarize the clinical symptoms of the three IRN subtypes and the use of TCM prescriptions, herbs, and bioactive compounds in treating IRN, as well as the potential mechanisms, intending to provide a reference for the future study of TCM as IRN treatments.

Immunological Approaches in the Treatment of Diabetic Nephropathy

Diabetic nephropathy (DN), the leading cause of end-stage renal disease, has no definite treatment so far. In fact, a combination of metabolic, hemodynamic, and immunological factors are involved in the pathogenesis of DN; therefore, effective disease management requires a holistic approach to all predisposing contributors. Due to the recent findings about the role of inflammation in the initiation and progression of kidney injury in diabetic patients and considerable advances in immunotherapy methods, it might be useful to revise and reconsider the current knowledge of the potential of immunomodulation in preventing and attenuating DN. In this review, we have summarized the findings of add-on therapeutic methods that have concentrated on regulating inflammatory responses in diabetic nephropathy, including phosphodiesterase inhibitors, nuclear factor-kB inhibitors, Janus kinase inhibitors, chemokine inhibitors, anti-cytokine antibodies, cell therapy, and vaccination.