The Signaling Pathway of TNF Receptors: Linking Animal Models of Renal Disease to Human CKD

From Liver to Kidney: The Overlooked Burden of Nonalcoholic Fatty Liver Disease in Chronic Kidney Disease

Nonalcoholic fatty liver disease (NAFLD) is increasingly recognized as a contributor to chronic kidney disease (CKD), yet its impact remains underappreciated in clinical practice. Recent studies reveal a strong association between NAFLD and CKD progression, with evidence linking hepatic dysfunction to renal impairment through metabolic and inflammatory pathways. NAFLD not only increases the risk of CKD but also accelerates its progression, leading to worse cardiovascular outcomes and higher mortality, particularly in patients with advanced fibrosis. Despite this growing evidence, NAFLD often goes undiagnosed in CKD patients and routine hepatic evaluation is rarely integrated into nephrology care. Emerging diagnostic tools, including noninvasive biomarkers and imaging techniques, offer potential for earlier detection, yet their clinical implementation remains inconsistent. Although lifestyle modifications remain the foundation of treatment, pharmacotherapeutic strategies, including SGLT2 inhibitors and GLP-1 receptor agonists, have demonstrated potential in mitigating both hepatic and renal impairment. Recognizing the interplay between NAFLD and CKD is essential for improving patient outcomes. A multidisciplinary approach, integrating hepatology and nephrology expertise, is crucial to refining screening strategies, optimizing treatment, and reducing the long-term burden of these coexisting conditions.

Targeting Inflammatory Imbalance in Chronic Kidney Disease: Focus on Anti-Inflammatory and Resolution Mediators

Chronic kidney disease (CKD) is a condition caused by the gradual decline of renal function that approximatively affects 10-12% of the world population, thus representing a public health priority. In CKD patients, chronic and systemic low-grade inflammation is observed, and it significantly contributes to disease development and progression, especially for patients with advanced disease. It also results in CKD-associated complications and increased mortality. The low-grade inflammation is due to different factors, such as the decline of glomerular filtration rate, increased immune system activation, reactive oxygen species release, and intestinal homeostasis. Therefore, the possibility to control chronic low-grade inflammation in CKD deserves great attention. In this review, we will examine the current possible pharmacological approaches to counteract the inflammatory state in CKD, focusing our attention both on the pro-inflammatory factors and the pro-resolving mediators involved in CKD inflammatory state.

Ethnicity-specific associations between the promoter region G-308A polymorphism (rs1800629) of the TNF-α gene and the development of end-stage renal disease: An evidence-based meta-analysis and trial sequential analysis

Tumor necrosis factor-alpha (TNF-α), is partly attributed to pathogenesis of end-stage renal disease (ESRD). Inconsistency of reported associations between TNF-α G-308A polymorphism (rs1800629) and ESRD prompted a meta-analysis to obtain more precise estimates. Eleven case-control studies from 11 articles were included. Pooled odds ratios (OR) and 95% confidence intervals (95% CIs) were estimated to evaluate the association. Subgroup analysis was based on ethnicity (Caucasian and Asian). Multiple comparisons were Bonferroni-corrected. Trial sequential analysis (TSA) was implemented to ascertain the reliability of results. Sensitivity analyses and publication bias tests were performed on significant results. There were no significant association (pa >0.05) in the overall and ethnic subgroup. Indians, three significant pool ORs (pa < 0.01-0.03) showed increased susceptibility to ESRD in homozygous (OR, 6.57; 95% CI, 1.45 to 29.75; pa = 0.01), recessive (OR, 6.75; 95% CI, 1.44 to 31.56; pa = 0.02), and codominant (OR, 2.06; 95% CI, 1.08 to 3.94; pa = 0.03) models. TSA indicated the robustness of such association in the Indian population. The main outcomes were robust without evidence of publication bias. This study showed associations between TNF-α G-308A and ESRD are confined to Indians, which are susceptible to ESRD up to approximately 7 times.

Uncovering the mechanisms of diosmin in treating obesity-related kidney injury based on network pharmacology, molecular docking, and in vitro validation

Obesity increases the risk of kidney injury, involving various pathological events such as inflammation, insulin resistance, lipid metabolism disorders, and hemodynamic changes, making it a significant risk factor for the development and progression of chronic kidney disease. Diosmin, a natural flavonoid glycoside, exhibits anti-inflammatory, antioxidant, anti-lipid, and vasodilatory effects. However, whether diosmin has a protective effect on obesity-related kidney injury remains unclear. The molecular formula of diosmin was obtained, and diosmin and target genes related to obesity-related kidney injury were screened. The interaction between overlapping target genes was analyzed. GO functional enrichment and KEGG pathway enrichment analyses were performed on overlapping target genes. Molecular docking was employed to assess the binding strength between overlapping target genes. Palmitic acid-induced damage to HK-2 cells, which were then treated with diosmin. Subsequently, the expression levels of relevant mRNAs and proteins were measured. Network analysis identified 219 potential diosmin target genes, 6800 potential target genes related to obesity-related kidney injury, and 93 potential overlapping target genes. Protein-protein interaction networks and molecular docking results revealed that AKT1, TNF-α, SRC, EGFR, ESR1, CASP3, MMP9, PPAR-γ, GSK-3β, and MMP2 were identified as key therapeutic targets, and they exhibited stable binding with diosmin. GO analysis indicated that these key targets may participate in inflammation, chemical stress, and protein phosphorylation. KEGG revealed that pathways in cancer, AGE-RAGE signaling pathway, PI3K-AKT signaling pathway, PPAR signaling pathway, and insulin resistance as crucial in treating obesity-related kidney injury. CCK-8 assay showed that diosmin significantly restored the viability of HK-2 cells affected by palmitic acid. Oil Red O staining demonstrated that diosmin significantly improved lipid deposition in HK-2 cells induced by palmitic acid. PCR results showed that diosmin inhibited the mRNA levels of AKT1, TNF-α, EGFR, ESR1, CASP3, MMP9, GSK-3β, and MMP2 while promoting the mRNA level of PPAR-γ. Western blot analysis revealed that diosmin restored PPAR-γ protein expression, inhibited NF-kB p-p65 protein expression, and reduced TNF-α protein expression. Diosmin demonstrated multi-target and multi-pathway effects in the treatment of obesity-associated renal injury, with key targets including AKT1, TNF-α, EGFR, ESR1, CASP3, MMP9, PPAR-γ, GSK-3β, and MMP2. The mechanism may be through the modulation of the PPAR-γ/NF-κB signaling pathway, which can attenuate inflammatory responses and protect the kidney.

Exploring the mechanisms by which common inhalational anesthetics influence malignant tumor metastasis: A data mining study based on comparative toxicogenomic databases

Surgery remains the primary treatment for solid malignant tumors, but controlling postoperative tumor recurrence and metastasis continues to be a major challenge. Understanding the factors that influence tumor recurrence and metastasis after surgery, as well as the underlying biological mechanisms, is critical. Previous studies suggest that anesthetic agents may increase the risk of tumor recurrence and metastasis in patients with cancer, but the mechanisms underlying these findings remain unclear. In this study, we utilized toxicogenomics and comparative toxicogenomic databases to analyze data and explore the potential mechanisms by which three commonly used inhalational anesthetics-sevoflurane, isoflurane, and halothane-might promote malignant tumor metastasis. The results identified 18 genes that may be associated with tumor metastasis. Functional enrichment analysis revealed that these anesthetics could influence tumor cell migration by activating signaling pathways such as the IL-17 and tumor necrosis factor signaling pathways, thereby potentially inducing tumor metastasis. Moreover, by constructing a TF-mRNA network, we predicted several transcription factors that might play key roles in anesthetic-induced tumor metastasis. The analysis revealed a total of 87 regulatory relationships between transcription factors and mRNA. These findings offer new insights for future in vivo or in vitro studies and contribute to a better understanding of the relationship between inhalational anesthetics and tumor metastasis, providing valuable reference points for clinical decision-making. The results of this study also provide a reference for the determination of subsequent clinical treatment targets. Hence, future laboratory studies should prioritize investigating the specific genes and common mechanisms identified in this study.

Chronic Kidney Disease-associated Lung Injury Is Mediated by Phosphate-induced MAPK/AKT Signaling

Chronic kidney disease (CKD) is associated with systemic phosphate elevations, called hyperphosphatemia. Translational studies have shown that hyperphosphatemia contributes to CKD-associated inflammation and injury in various tissues, including the kidney, heart, liver, and parathyroid gland. Mechanisms underlying pathologic actions of elevated phosphate on cells are not well understood but seem to involve uptake of phosphate through sodium phosphate cotransporters and phosphate-induced signaling via FGFR1 (fibroblast growth factor receptor 1). Clinical studies indicate patients with CKD are more likely to develop inflammatory and restrictive lung diseases, such as fibrotic interstitial lung diseases, and here we aimed to determine whether hyperphosphatemia can cause lung injury. We found that a mouse model of CKD and hyperphosphatemia, induced by an adenine-rich diet, develops lung fibrosis and inflammation. Elevation of systemic phosphate concentration by administration of a high-phosphate diet in a mouse model of primary lung inflammation and fibrosis, induced by bleomycin, exacerbated lung injury in the absence of kidney damage. Our in vitro studies identified increases of proinflammatory cytokines in human lung fibroblasts exposed to phosphate elevations. Phosphate activated ERK 1/2 (extracellular signal-related kinase 1/2) and PKB/AKT (protein kinase B) signaling, and pharmacological inhibition of ERK, AKT, FGFR1, or sodium phosphate cotransporters prevented phosphate-induced proinflammatory cytokine upregulation. In addition, inhibition of FGFR1 or sodium phosphate cotransporters decreased the phosphate-induced activation of ERK and AKT. Our study suggests that phosphate can directly target lung fibroblasts and induce an inflammatory response and that hyperphosphatemia in CKD and non-CKD models contributes to lung injury. Phosphate-lowering strategies might protect from CKD-associated lung injury.

Role of baseline soluble tumor necrosis factor receptor 2 as a biomarker in primary podocytopathy: Implications for renal impairment and disease progression

BACKGROUND

Podocytopathies, including minimal change disease (MCD), focal segmental glomerulosclerosis (FSGS), and collapsing glomerulopathy (CG), are kidney diseases that damage glomerular podocytes, leading to heavy proteinuria and nephrotic syndrome (NS). Inflammation plays a critical role in the progression of chronic kidney disease (CKD), with recent studies linking inflammatory biomarkers to declining kidney function. Tumor necrosis factor-alpha (TNF-α), an essential inflammatory cytokine, interacts with its circulating receptors, TNFR1 and TNFR2. The TNF-α pathway has been implicated in the pathogenesis of FSGS and MCD. Increased circulating TNFR2 levels have been associated with worsening renal function in podocytopathies, suggesting that the TNF-α inflammatory pathway significantly contributes to disease progression.

METHODS

We conducted a study involving 53 patients with biopsy-proven MCD or FSGS and 53 healthy, age- and gender-matched controls. All patients were followed for 18 months. We analyzed serum and urine TNFR2 levels and gene expression at baseline and after three months. To assess the ability of TNFR2 to predict persistent decline in estimated glomerular filtration rate (eGFR < 30 mL/min/1.73m2), remission, and relapse, we employed Cox regression analysis. Additionally, we evaluated its prognostic utility for predicting progression to stage 4 CKD using ROC curve analysis.

RESULTS

Serum and urine TNFR2 levels were significantly elevated in patients compared to controls. Serum TNFR2 was a significant predictor in univariate Cox regression analysis for persistent eGFR decline (HR 1.017, 95% CI: 1.003 to 1.032, p = 0.018), remission (HR 0.995, 95% CI: 0.992 to 0.999, p = 0.006), and relapse (HR 1.005, 95% CI: 1.001 to 1.010, p = 0.029). The ROC curve analysis demonstrated that serum TNFR2 levels had a strong prognostic ability for predicting progression to stage 4 CKD, with an AUC of 0.848 (95% CI: 0.737-0.960), sensitivity of 81%, and specificity of 71%.

CONCLUSION

This study underscores the critical role of circulating TNFR2 in kidney injury among patients with primary podocytopathy. Elevated TNFR2 levels are significant predictors of persistent eGFR decline and disease relapse, highlighting their potential as biomarkers for disease progression and prognosis.

Nuclear receptor 4A1 ameliorates UUO-induced renal fibrosis by inhibiting the PI3K/AKT pathway

As an ultra-early response gene, Nuclear receptor 4A1 (NR4A1) has been reported to be involved in the development of various diseases through various pathological pathways, but its specific mechanism in chronic kidney disease (CKD) is unknown currently. Our study showed that the expression of NR4A1 was reduced in unilateral ureteral obstruction (UUO) mice and it could exacerbate UUO-induced renal pathological injury when knocked down NR4A1 in UUO mice. We found that the knockdown of NR4A1 could promote angiogenesis, renal inflammation, and cell apoptosis to aggravate renal fibrosis induced by UUO. As an agonist of NR4A1, Cytosporone B (Csn-B) could inhibit the renal fibrosis by attenuating angiogenesis, renal inflammation and cell apoptosis. In addition, the PI3K/AKT pathway was activated with NR4A1 knockdown in vivo and in vitro experiments. In conclusion, our study demonstrates that NR4A1 can ameliorate renal fibrosis. Furthermore, we speculate that its underlying mechanism may be related to the activation of PI3K/AKT pathway according to our present results.

Biomarkers of chronic kidney disease in older individuals: navigating complexity in diagnosis

Chronic kidney disease (CKD) in older individuals is a matter of growing concern in the field of public health across the globe. Indeed, prevalence of kidney function impairment increases with advancing age and is often exacerbated by age-induced modifications of kidney function, presence of chronic diseases such as diabetes, hypertension, and cardiovascular disorders, and increased burden related to frailty, cognitive impairment and sarcopenia. Accurate assessment of CKD in older individuals is crucial for timely intervention and management and relies heavily on biomarkers for disease diagnosis and monitoring. However, the interpretation of these biomarkers in older patients may be complex due to interplays between CKD, aging, chronic diseases and geriatric syndromes. Biomarkers such as serum creatinine, estimated glomerular filtration rate (eGFR), and albuminuria can be significantly altered by systemic inflammation, metabolic changes, and medication use commonly seen in this population. To overcome the limitations of traditional biomarkers, several innovative proteins have been investigated as potential, in this review we aimed at consolidating the existing data concerning the geriatric aspects of CKD, describing the challenges and considerations in using traditional and innovative biomarkers to assess CKD in older patients, highlighting the need for integration of the clinical context to improve biomarkers' accuracy.

TMAO enhances TNF-α mediated fibrosis and release of inflammatory mediators from renal fibroblasts

Trimethylamine-N-oxide (TMAO) is a gut microbiota-derived metabolite and TNF-α is proinflammatory cytokine, both known to be associated with renal inflammation, fibrosis and chronic kidney disease. However, today there are no data showing the combined effect of TMAO and TNF-α on renal fibrosis-and inflammation. The aim of this study was to investigate whether TMAO can enhance the inflammatory and fibrotic effects of TNF-α on renal fibroblasts. We found that the combination of TNF-α and TMAO synergistically increased fibronectin release and total collagen production from renal fibroblasts. The combination of TMAO and TNF-α also promoted increased cell proliferation. Both renal proliferation and collagen production were mediated through Akt/mTOR/ERK signaling. We also found that TMAO enhanced TNF-α mediated renal inflammation by inducing the release of several cytokines (IL-6, LAP TGF-beta-1), chemokines (CXCL-6, MCP-3), inflammatory-and growth mediators (VEGFA, CD40, HGF) from renal fibroblasts. In conclusion, we showed that TMAO can enhance TNF-α mediated renal fibrosis and release of inflammatory mediators from renal fibroblasts in vitro. Our results can promote further research evaluating the combined effect of TMAO and inflammatory mediators on the development of kidney disease.

Periodontitis deteriorates renal fibrosis and macrophage infiltration in rats with chronic kidney disease

OBJECTIVE

The objective of this study was to examine the effect of periodontitis on renal function and morphology in rats with or without nephrectomy (Nx)-induced chronic kidney disease (CKD).

METHODS

Rats were divided into sham surgery (Sham), Sham with tooth ligation (ShamL), Nx, and NxL groups. Periodontitis was induced by tooth ligation at 16-week olds. Creatinine, alveolar bone area, and renal histopathology were analyzed at 20-week olds.

RESULTS

Creatinine did not differ between the Sham and ShamL groups or between the Nx and NxL groups. The ShamL and NxL groups (both p = 0.002) had less alveolar bone area than the Sham group. The NxL group had fewer glomeruli than the Nx group (p < 0.000). The periodontitis groups demonstrated more tubulointerstitial fibrosis (Sham vs. ShamL p = 0.002, Nx vs. NxL p < 0.000) and macrophage infiltration (Sham vs. ShamL p = 0.002, Nx vs. NxL p = 0.006) than the groups without periodontitis. Only the NxL group had greater renal TNFα expression than the Sham group (p < 0.003).

CONCLUSIONS

These suggest that periodontitis increases renal fibrosis and inflammation in the presence or absence of CKD but does not affect renal function. Periodontitis also increases TNFα expression in the presence of CKD.

Interleukin-10 enhances recruitment of immune cells in the neonatal mouse model of obstructive nephropathy

Urinary tract obstruction during renal development leads to inflammation, leukocyte infiltration, tubular cell death, and interstitial fibrosis. Interleukin-10 (IL-10) is an anti-inflammatory cytokine, produced mainly by monocytes/macrophages and regulatory T-cells. IL-10 inhibits innate and adaptive immune responses. IL-10 has a protective role in the adult model of obstructive uropathy. However, its role in neonatal obstructive uropathy is still unclear which led us to study the role of IL-10 in neonatal mice with unilateral ureteral obstruction (UUO). UUO serves as a model for congenital obstructive nephropathies, a leading cause of kidney failure in children. Newborn Il-10-/- and C57BL/6 wildtype-mice (WT) were subjected to complete UUO or sham-operation on the 2nd day of life. Neonatal kidneys were harvested at day 3, 7, and 14 of life and analyzed for different leukocyte subpopulations by FACS, for cytokines and chemokines by Luminex assay and ELISA, and for inflammation, programmed cell death, and fibrosis by immunohistochemistry and western blot. Compared to WT mice, Il-10-/- mice showed reduced infiltration of neutrophils, CD11bhi cells, conventional type 1 dendritic cells, and T-cells following UUO. Il-10-/- mice with UUO also showed a reduction in pro-inflammatory cytokine and chemokine release compared to WT with UUO, mainly of IP-10, IL-1α, MIP-2α and IL-17A. In addition, Il-10-/- mice showed less necroptosis after UUO while the rate of apoptosis was not different. Finally, α-SMA and collagen abundance as readout for fibrosis were similar in Il-10-/- and WT with UUO. Surprisingly and in contrast to adult Il-10-/- mice undergoing UUO, neonatal Il-10-/- mice with UUO showed a reduced inflammatory response compared to respective WT control mice with UUO. Notably, long term changes such as renal fibrosis were not different between neonatal Il-10-/- and neonatal WT mice with UUO suggesting that IL-10 signaling is different in neonates and adults with UUO.

Full-length transcriptomics study of Ustiloxins-induced hepatocyte injury

Ustiloxins is a mycotoxin produced by the metabolism of Rice false smut. Studies have shown that Ustiloxins may be toxic to animals, but there is still a lack of toxicological evidence. The liver, as the main organ for the biotransformation of foreign chemicals, may be the direct target organ of Ustiloxins toxicity. In this study, we found that cell viability decreased in a dose- and time-dependent manner when BNL CL.2 cells were treated with different concentrations of Ustiloxins (0, 5, 10, 20, 30, 40, 60, 80, 100, 150 and 200 μg/mL) for 24 and 48 h. In addition, scanning electron microscope observation showed that the cell membrane of the experimental group was damaged, with the appearance of apoptotic bodies. Moreover, the ROS and GSH levels were significantly increased in cells exposed to Ustiloxins. We analyzed the key action targets of Ustiloxins on hepatocyte injury using full-length transcriptomics. A total of 1099 differentially expressed genes were screened, of which 473 genes were up-regulated, and 626 genes were down-regulated. Besides, we also found that the expression of MCM7 and CDC45 in BNL CL.2 cells treated with Ustiloxins decreased, and the expression of CCl-2, CYP1b1, CYP4f13, and GSTM1 increased according to qRT-PCR. Ustiloxins might change CYP450 and GST-related genes, affect DNA replication and cell cycle, and lead to oxidative stress and liver cell injury.

Interleukin-6, tumor necrosis factor-α, and high-sensitivity C-reactive protein for optimal immunometabolic profiling of the lifestyle-related cardiorenal risk

OBJECTIVES

The present study aimed to identify optimal inflammatory biomarkers involved in cardiorenal risk in response to major lifestyle factors.

METHODS

One hundred and twenty-nine adults aged 35-77 years participated voluntarily from 2017 to 2019 (Córdoba, Argentina) in a cross-sectional study to collect sociodemographic, clinical, and lifestyle data. Blood biomarkers (different cytokines, monocyte chemoattractant protein-1 [MCP-1], and high-sensitivity C-reactive protein [hs-CRP]) were measured using standard methods and then evaluated by principal component analysis and structural equation modeling (SEM) according to Mediterranean diet adherence, physical activity level, and waist circumference, while cardiorenal risk involved blood diastolic pressure, HDL-cholesterol, triacylglycerols, creatinine, and glycosylated hemoglobin.

RESULTS

A principal component included TNF-α (tumor necrosis factor-alpha), IL-8 (interleukin-8), IL-6 (interleukin-6), hs-CRP, and MCP-1, with absolute rotated factor loadings >0.10. SEM showed that IL-6 (β=0.38, 95 % IC=0.08-0.68), hs-CRP (β=0.33, 95 % IC=0.17-0.48), and TNF-α (β=0.22, 95 % IC=0.11-0.32) were the mediators that better explained an inflammatory profile positively related to waist circumference (β=0.77, 95 % IC=0.61-0.94). Moreover, this profile was associated with an increased cardiorenal risk (β=0.78, 95 % IC=0.61-0.94), which was well-defined by the variable used.

CONCLUSIONS

Immune mediators are key elements in profiling the cardiorenal risk associated with lifestyle factors, for which the combination of hs-CRP, IL-6, and TNF-α has emerged as a robust indicator. This work reaffirms the need for biomarker optimization for early diagnosis and risk assessment.

Natural Polyphenols in Cancer Management: Promising Role, Mechanisms, and Chemistry

BACKGROUND

Although cancers emerge rapidly and cancer cells divide aggressively, which affects our vital organ systems. Recently, cancer treatments are targeted immune systems mediating intrinsic cellular mechanisms. Natural efficacious polyphenols have been exhibited to help prevent most cancers and reverse the progression of cancers.

METHODS

Many resources have been used to know the promising role of polyphenols in preventing and treating cancers. The electronic databases include Science Direct, Google, Google Scholar, PubMed, and Scopus. The search was limited to the English language only.

RESULTS

Polyphenols have been reported as anti-metastatic agents that explore the promising role of these compounds in cancer prevention. Such agents act through many signaling pathways, including PI3K/Akt and TNF-induced signaling pathways. The chemical modifications of polyphenols and the structure-activity relationships (SARs) between polyphenols and anticancer activities have also been discussed.

CONCLUSION

Many research papers were reported to explain the anti-cancer potential of Polyphenols, The SARs between polyphenols and anti-cancer activities, which correlate structures of polyphenols with significant chemotherapeutic action. The mechanism of anti-cancer potential is to be added for searching for new anti-cancer natural products.

Currently Used Methods to Evaluate the Efficacy of Therapeutic Drugs and Kidney Safety

Kidney diseases with kidney failure or damage, such as chronic kidney disease (CKD) and acute kidney injury (AKI), are common clinical problems worldwide and have rapidly increased in prevalence, affecting millions of people in recent decades. A series of novel diagnostic or predictive biomarkers have been discovered over the past decade, enhancing the investigation of renal dysfunction in preclinical studies and clinical risk assessment for humans. Since multiple causes lead to renal failure, animal studies have been extensively used to identify specific disease biomarkers for understanding the potential targets and nephropathy events in therapeutic insights into disease progression. Mice are the most commonly used model to investigate the mechanism of human nephropathy, and the current alternative methods, including in vitro and in silico models, can offer quicker, cheaper, and more effective methods to avoid or reduce the unethical procedures of animal usage. This review provides modern approaches, including animal and nonanimal assays, that can be applied to study chronic nonclinical safety. These specific situations could be utilized in nonclinical or clinical drug development to provide information on kidney disease.

Expression of TNFR1, VEGFA, CD147 and MCT1 as early biomarkers of diabetes complications and the impact of aging on this profile

Hyperglycemia leads to microvascular lesions in various tissues. In diabetic nephropathy-DN, alterations in usual markers reflect an already installed disease. The study of new biomarkers for the early detection of diabetic complications can bring new prevention perspectives. Rats were divided into diabetic adult-DMA-or elderly-DME and control sham adult-CSA-or control sham elderly-CSE. Blood and urine samples were collected for biochemical analysis. Bulbar region, cardiac, hepatic and renal tissues were collected for target gene expression studies. As result, DMA showed decreased TNFR1, MCT1 and CD147 expression in the bulbar region, TNFR1 in the heart, VEGFA and CD147 in the kidney and TNFR1 in blood. Positive correlations were found between TNFR1 and MCT1 in the bulbar region and HbA1c and plasma creatinine, respectively. DME showed positive correlation in the bulbar region between TNFR1 and glycemia, in addition to negative correlations between CD147 in the heart versus glycemia and urea. We concluded that the initial hyperglycemic stimulus already promotes changes in the expression of genes involved in the inflammatory and metabolic pathways, and aging alters this profile. These changes prior to the onset of diseases such as DN, show that they have potential for early biomarkers studies.

Chronic Kidney Disease: Underlying Molecular Mechanisms-A Special Issue Overview

Chronic kidney disease (CKD) is an epidemic health issue that requires global attention [...].

Kidney Damage in Long COVID: Studies in Experimental Mice

Signs and symptoms involving multiple organ systems which persist for weeks or months to years after the initial SARS-CoV-2 infection (also known as PASC or long COVID) are common complications of individuals with COVID-19. We recently reported pathophysiological changes in various organs post-acute infection of mice with mouse hepatitis virus-1 (MHV-1, a coronavirus) (7 days) and after long-term post-infection (12 months). One of the organs severely affected in this animal model is the kidney, which correlated well with human studies showing kidney injury post-SARS-CoV-2 infection. Our long-term post-infection pathological observation in kidneys includes the development of edema and inflammation of the renal parenchyma, severe acute tubular necrosis, and infiltration of macrophages and lymphocytes, in addition to changes observed in both acute and long-term post-infection, which include tubular epithelial cell degenerative changes, peritubular vessel congestion, proximal and distal tubular necrosis, hemorrhage in the interstitial tissue, and vacuolation of renal tubules. These findings strongly suggest the possible development of renal fibrosis, in particular in the long-term post-infection. Accordingly, we investigated whether the signaling system that is known to initiate the above-mentioned changes in kidneys in other conditions is also activated in long-term post-MHV-1 infection. We found increased TGF-β1, FGF23, NGAL, IL-18, HIF1-α, TLR2, YKL-40, and B2M mRNA levels in long-term post-MHV-1 infection, but not EGFR, TNFR1, BCL3, and WFDC2. However, only neutrophil gelatinase-associated lipocalin (NGAL) increased in acute infection (7 days). Immunoblot studies showed an elevation in protein levels of HIF1-α, TLR-2, and EGFR in long-term post-MHV-1 infection, while KIM-1 and MMP-7 protein levels are increased in acute infection. Treatment with a synthetic peptide, SPIKENET (SPK), which inhibits spike protein binding, reduced NGAL mRNA in acute infection, and decreased TGF-β1, BCL3 mRNA, EGFR, HIF1-α, and TLR-2 protein levels long-term post-MHV-1 infection. These findings suggest that fibrotic events may initiate early in SARS-CoV-2 infection, leading to pronounced kidney fibrosis in long COVID. Targeting these factors therapeutically may prevent acute or long-COVID-associated kidney complications.

Deciphering the pharmacological mechanisms of Rostellularia procumbens (L) Nees. Extract alleviates adriamycin-induced nephropathy in vivo and in vitro

BACKGROUND

Rostellularia procumbens (L) Nees. is an effective traditional Chinese herbal medicine for the treatment of patients with chronic glomerulonephritis (CGN) in the clinic. However, the underlying molecular mechanisms need further elucidation.

PURPOSE

This study aims to investigate the renoprotective mechanisms of n-butanol extract from Rostellularia procumbens (L) Nees. (J-NE) in vivo and in vitro.

METHODS

The components of J-NE were analyzed by UPLC-MS/MS. In vivo, the nephropathy model was induced in mice by tail vein injection with adriamycin (10 mg·kg^-1), and mice were treated with vehicle or J-NE or benazepril by daily gavage. In vitro, MPC5 cells exposed to adriamycin (0.3 μg/ml) were treated with J-NE. The effects of J-NE inhibit podocyte apoptosis and protect against adriamycin-induced nephropathy were determined by Network pharmacology, RNA-seq, qPCR, ELISA, immunoblotting, flow cytometry, and TUNEL assay, according to the experimental protocols.

RESULT

The results showed that treatment significantly improved ADR-induced renal pathological changes, and the therapeutic mechanism of J-NE was related to the inhibition of podocyte apoptosis. Further molecular mechanism studies found that J-NE inhibited inflammation, increase the proteins expression levels of Nephrin and Podocin, reduce TRPC6 and Desmin expression levels and calcium ion levels in podocytes, and decrease the proteins expression levels of PI3K, p-PI3K, Akt and p-Akt to attenuated apoptosis. Furthermore, 38 compounds of J-NE were identified.

CONCLUSION

J-NE exerted the renoprotective effects by inhibiting podocyte apoptosis, which provides effective evidence for the treatment of J-NE targeting renal injury in CGN.

Zeb1 facilitates corneal epithelial wound healing by maintaining corneal epithelial cell viability and mobility

The cornea is the outmost ocular tissue and plays an important role in protecting the eye from environmental insults. Corneal epithelial wounding provokes pain and fear and contributes to the most ocular trauma emergency assessments worldwide. ZEB1 is an essential transcription factor in development; but its roles in adult tissues are not clear. We identify Zeb1 is an intrinsic factor that facilitates corneal epithelial wound healing. In this study, we demonstrate that monoallelic deletion of Zeb1 significantly expedites corneal cell death and inhibits corneal epithelial EMT-related cell migration upon an epithelial debridement. We provide evidence that Zeb1-regulation of corneal epithelial wound healing is through the repression of genes required for Tnfa-induced epithelial cell death and the induction of genes beneficial for epithelial cell migration. We suggest utilizing TNF-α antagonists would reduce TNF/TNFR1-induced cell death in the corneal epithelium and inflammation in the corneal stroma to help corneal wound healing.

Lyn attenuates sepsis-associated acute kidney injury by inhibition of phospho-STAT3 and apoptosis

Sepsis-associated acute kidney injury (SA-AKI) is a life-threatening condition associated with high mortality and morbidity. However, the underlying pathogenesis of SA-AKI is still unclear. Lyn belongs to Src family kinases (SFKs), which exert numerous biological functions including modulation in receptor-mediated intracellular signaling and intercellular communication. Previous studies demonstrated that Lyn gene deletion obviously aggravates LPS-induced lung inflammation, but the role and possible mechanism of Lyn in SA-AKI have not been reported yet. Here, we found that Lyn protected against renal tubular injury in cecal ligation and puncture (CLP) induced AKI mouse model by inhibition of signal transducer and activator of transcription 3 (STAT3) phosphorylation and cell apoptosis. Moreover, Lyn agonist MLR-1023 pretreatment improved renal function, inhibited STAT3 phosphorylation and decreased cell apoptosis. Thus, Lyn appears to play a crucial role in orchestrating STAT3-mediated inflammation and cell apoptosis in SA-AKI. Hence, Lyn kinase may be a promising therapeutic target for SA-AKI.

TNFR2 as a Potential Biomarker for Early Detection and Progression of CKD

The inflammatory pathway driven by TNF-α, through its receptors TNFR1 and TNFR2, is a common feature in the pathogenesis of chronic kidney disease (CKD), regardless of the initial disease cause. Evidence correlates the chronic inflammatory status with decreased renal function. Our aim was to evaluate the potential of TNF receptors as biomarkers for CKD diagnosis and staging, as well as their association with the progression of renal lesions, in rat models of early and moderate CKD. We analyzed the circulating levels of inflammatory molecules—tumor necrosis factor-alpha (TNF-α), tumor necrosis factor receptor 1 (TNFR1) and 2 (TNFR2) and tissue inhibitor of metalloproteinase-1 (TIMP-1)—and studied their associations with TNFR1 and TNFR2 renal expression, glomerular and tubulointerstitial lesions, and with biomarkers of renal (dys)function. An increase in all inflammatory markers was observed in moderate CKD, as compared to controls, but only circulating levels of both TNFR1 and TNFR2 were significantly increased in the early disease; TNFR2 serum levels were negatively correlated with eGFR. However, only TNFR2 renal expression increased with CKD severity and showed correlations with the score of mild and advanced tubular lesions. Our findings suggest that renal TNFR2 plays a role in CKD development, and has potential to be used as a biomarker for the early detection and progression of the disease. Still, the potential value of this biomarker in disease progression warrants further investigation.

TNF and IL6/Jak2 signaling pathways are the main contributors of the glia-derived neuroinflammation present in Lafora disease, a fatal form of progressive myoclonus epilepsy

Lafora disease (LD; OMIM#254780) is a rare form of progressive myoclonus epilepsy (prevalence <1:1,000,000) characterized by the accumulation of insoluble deposits of aberrant glycogen (polyglucosans), named Lafora bodies, in the brain but also in peripheral tissues. LD is the most severe form of the group of progressive myoclonus epilepsies, since patients present a rapid deterioration and dementia with amplification of seizures, leading to death after a decade from the onset of the first symptoms. We have recently described that reactive glia-derived neuroinflammation should be considered a novel hallmark of LD since we observed a florid upregulation of differentially expressed genes in both LD mouse lines, which were mainly related to mediators of inflammatory response. In this work, we define an upregulation of the expression of mediators of the TNF and IL6/JAK2 signaling pathways in LD. In addition, we describe the activation of the non-canonical form of the inflammasome. Furthermore, we describe the infiltration of peripheral immune cells in the brain parenchyma, which could aggravate glia-derived neuroinflammation. Finally, we describe CXCL10 and S100b as blood biomarkers of the disease, which will allow the study of the progression of the disease using serum blood samples. We consider that the identification of these initial inflammatory changes in LD will be very important to implement possible anti-inflammatory therapeutic strategies to prevent the development of the disease.