Pro-resolving lipid mediators: regulators of inflammation, metabolism and kidney function

The relationship between dietary inflammatory index (DII) and early renal injury in population with/without hypertension: analysis of the National health and nutrition examination survey 2001-2002

BACKGROUND

Inflammation plays a crucial role in occurrence of kidney injury, and specific dietary patterns can influence systemic inflammation levels. However, the relationship between dietary inflammatory potential and early-stage kidney damage remains unclear.

METHOD

2,108 participants was recruited from 2001-2002 National Health and Nutrition Examination Survey (NHANES). Dietary Inflammatory Index (DII) is utilized to assess dietary inflammatory potential, calculated through a 24-h dietary recall questionnaire. Early renal injury was evaluated using urinary albumin to creatinine (UACR), cystatin C (CysC), β-2 microglobulin (β2M), and estimated glomerular filtration rate (eGFR) based on serum creatinine (eGFRs), cystatin C (eGFRc), and both Scr and CysC (eGFRs&c). Participant characteristics were analyzed, and association between DII, hypertension, and early renal injury markers was explored using multiple linear and logistic regression models.

RESULTS

The average age of participants was 53.9 years. DII exhibited a positive correlation with UACR (β = -0.048[0.017,0.078]), β2M (β = 0.019[0.010,0.027]), CysC (β = 0.012 [0.004,0.021]). Conversely, a negative correlation was observed between DII and eGFRc (β = -1.126[-1.554, -0.699]), eGFRs&c (β=-1.101[-1.653, -0.549]). A significant association was observed between hypertension and abnormality of early kidney damage markers. Subgroup analysis reveals that the positive correlation between DII and the occurrence of abnormal markers of early kidney damage is only observed in individuals with hypertension. Furthermore, an interaction between DII and hypertension was detected in eGFRs&c (OR:1.250[1.042, 1.499], p for interaction = 0.03).

CONCLUSION

Higher levels of DII may be associated with occurrence of early kidney damage. For individuals with hypertension, avoiding excessive consumption of pro-inflammatory foods may reduce the risk of renal injury.

Resolution of inflammation, an active process to restore the immune microenvironment balance: A novel drug target for treating arterial hypertension

The resolution of inflammation, the other side of the inflammatory response, is defined as an active and highly coordinated process that promotes the restoration of immune microenvironment balance and tissue repair. Inflammation resolution involves several key processes, including dampening proinflammatory signaling, specialized proresolving lipid mediator (SPM) production, nonlipid proresolving mediator production, efferocytosis and regulatory T-cell (Treg) induction. In recent years, increasing attention has been given to the effects of inflammation resolution on hypertension. Furthermore, our previous studies reported the antihypertensive effects of SPMs. Therefore, in this review, we aim to summarize and discuss the detailed association between arterial hypertension and inflammation resolution. Additional, the association between gut microbe-mediated immune and hypertension is discussed. This findings suggested that accelerating the resolution of inflammation can have beneficial effects on hypertension and its related organ damage. Exploring novel drug targets by focusing on various pathways involved in accelerating inflammation resolution will contribute to the treatment and control of hypertensive diseases in the future.

Magnoflorine Ameliorates Chronic Kidney Disease in High-Fat and High-Fructose-Fed Mice by Promoting Parkin/PINK1-Dependent Mitophagy to Inhibit NLRP3/Caspase-1-Mediated Pyroptosis

Excessive intake of fat and fructose in Western diets has been confirmed to induce renal lipotoxicity, thereby driving the progression of chronic kidney disease (CKD). This study was conducted to evaluate the efficacy of magnoflorine in a CKD mouse model subjected to high-fat and high-fructose diets. Our results demonstrated that magnoflorine treatment ameliorated abnormal renal function indices (serum creatinine, urea nitrogen, uric acid, and urine protein) in high-fat- and high-fructose-fed mice. Histologically, renal tubular cell steatosis, lipid deposition, tubular dilatation, and glomerular fibrosis were significantly reduced by the magnoflorine treatment in these mice. Mechanistically, magnoflorine promotes Parkin/PINK1-mediated mitophagy, thereby inhibiting NLRP3/Caspase-1-mediated pyroptosis. Consistent findings were observed in the palmitic acid-incubated HK-2 cell model. Notably, both silencing of Parkin and the use of a mitophagy inhibitor reversed the inhibitory effect of magnoflorine on NLRP3 inflammasome activation in vitro. Therefore, the present study provides compelling evidence that magnoflorine improves renal injury in high-fat- and high-fructose-fed mice by promoting Parkin/PINK1-dependent mitophagy to inhibit NLRP3 inflammasome activation and pyroptosis. Our findings suggest that dietary supplementation with magnoflorine and magnoflorine-rich foods (such as magnolia) might be an effective strategy for the prevention of CKD.

The therapeutic potential of isosakuranetin against perfluorooctane sulfonate instigated cardiac toxicity via modulating Nrf-2/Keap-1 pathway, inflammatory, apoptotic, and histological profile

Perfluorooctane sulfonate (PFOS) is a pervasive organic toxicant that damages body organs, including heart. Isosakuranetin (ISN) is a plant-based flavonoid that exhibits a broad range of pharmacological potentials. The current investigation was conducted to evaluate the potential role of ISN to counteract PFOS-induced cardiac damage in rats. Twenty-four albino rats (Rattus norvegicus) were distributed into four groups, including control, PFOS (10 mg/kg) intoxicated, PFOS + ISN (10 mg/kg + 20 mg/kg) treated, and ISN (20 mg/kg) alone supplemented group. It was revealed that PFOS intoxication reduced the expressions of Nrf-2 and its antioxidant genes while escalating the expression of Keap-1. Furthermore, PFOS exposure reduced the activities of glutathione reductase (GSR), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione S-transferase (GST), Heme oxygenase-1 (HO-1) and glutathione (GSH) contents while upregulating the levels of reactive oxygen species (ROS) and malondialdehyde (MDA). Besides, PFOS administration upregulated the levels of creatine kinase-MB (CK-MB), troponin I, creatine phosphokinase (CPK), and lactate dehydrogenase (LDH). Moreover, the levels of tumor necrosis factor-alpha (TNF-α), nuclear factor kappa-B (NF-κB), interleukin-6 (IL-6), and interleukin-1β (IL-1β) were increased after PFOS intoxication. Additionally, PFOS exposure downregulated the expression of Bcl-2 while upregulating the expressions of Bax and Caspase-3. Furthermore, PFOS administration disrupted the normal architecture of cardiac tissues. Nonetheless, ISN treatment remarkably protected the cardiac tissues via regulating aforementioned dysregulations owing to its antioxidative, anti-inflammatory, and antiapoptotic properties.

Causality of Genetically Determined Metabolites on Chronic Kidney Disease: A Two-Sample Mendelian Randomization Study In Silico

Introduction: Chronic kidney disease (CKD) is associated with metabolic disorders. However, the evidence for the causality of circulating metabolites to promote or prevent CKD is still lacking. Methods: The two-sample Mendelian randomization (MR) analysis was conducted to evaluate the latent causal relationship between the genetically proxied 486 blood metabolites and CKD. Genome-wide association study (GWAS) data for exposures were derived from 7824 European GWAS on metabolite levels, which have been extensively utilized in the medical field to elucidate the mechanisms underlying disease onset and progression. The random inverse variance weighted (IVW) is the primary analysis for causality analysis while MR-Egger and weighted median as complementary analyses. For the further identification of metabolites, reverse MR and linkage disequilibrium score regression were performed for further evaluation. The drug target for N-acetylornithine was subsequently supplemented into the analysis, with MR and colocalization analysis being utilized. Key metabolic pathways were identified via MetaboAnalyst 4.0 (https://www.metaboanalyst.ca/) online website. Results: N-acetylornithine was identified as a reliable metabolite that increases the susceptibility to estimated glomerular filtration rate (eGFR) decrease (β = 0.047; 95% confidence interval: -0.068 to -0.026; PIVW = 1.5E-5). The "glyoxylate and dicarboxylate metabolism" pathway showed significant relevance to CKD development (P = 6E-4), whereas the "glycine, serine, and threonine metabolism" pathway was also recognized as associated with CKD by general practitioners (P = 7E-4). Colocalization analysis revealed a robust genetic link between N-acetylornithine and both CKD and eGFR, with 85.1% and 99.4% colocalization rates, respectively. IVW-MR analysis substantiated these findings with a significant positive association for CKD (odds ratio = 1.43, P = 4.7E-5) and a negative correlation with eGFR (b = -0.04, P = 1.13E-31). Conclusions: MR was utilized to explore the potential causal links between 61 genetic serum metabolites and CKD. N-acetylornithine and NAT8 were further explored as a potential therapeutic target for CKD treatment.

The relationship between mean corpuscular hemoglobin concentration and mortality in hypertensive individuals: A population-based cohort study

INTRODUCTION

Hematology is an essential field for investigating the prognostic outcomes of cardiovascular diseases (CVDs). Recent research has suggested that mean corpuscular hemoglobin concentration (MCHC) is associated with a poor prognosis in several CVDs. There is no evidence of a correlation between MCHC and hypertension. Therefore, our study aimed to analyze the association of MCHC with all-cause and cardiovascular mortality in hypertensive patients.

METHODS

We used cohort data from U.S. adults who participated in the National Health and Nutrition Examination Survey from 1999-2014. COX regression was applied to analyze the relationship between MCHC and all-cause and cardiovascular mortality. In addition, three models were adjusted to reduce confounding factors. We reanalyzed the data after propensity score matching (PSM) to inspect the stability of the results. Stratified analysis was additionally adopted to investigate the results of each subgroup.

RESULTS

Our research included 15,154 individuals. During a mean follow-up period of 129 months, 30.6% of the hypertensive population succumbed to mortality. Based on previous studies, we categorized patients with MCHC ≤33mg/dl as the hypochromia group and those with >33mg/dl as the non-hypochromia group. After PSM, the hypochromia group had higher all-cause mortality (adjusted hazard ratio [HR]:1.26, 95% confidence interval [95%CI]:1.11-1.43) and cardiovascular mortality (adjusted HR:1.42, 95%CI:1.12-1.80) than the non-hypochromia group. The results of the COX regression remain stable after matching. Stratified analyses before PSM revealed an interaction of anemia in the relationship between MCHC and mortality, whereas there was no significant interaction after matching.

CONCLUSION

In hypertensive individuals, low MCHC was correlated with a poor prognosis. Further studies on MCHC are necessary to analyze the potential mechanisms of its poor prognosis in hypertensive populations.

Causal association of plasma circulating metabolites with nephritis: a Mendelian randomization study

Background

Nephritis is a pivotal catalyst in chronic kidney disease (CKD) progression. Although epidemiological studies have explored the impact of plasma circulating metabolites and drugs on nephritis, few have harnessed genetic methodologies to establish causal relationships.

Methods

Through Mendelian randomization (MR) in two substantial cohorts, spanning large sample sizes, we evaluated over 100 plasma circulating metabolites and 263 drugs to discern their causal effects on nephritis risk. The primary analytical tool was the inverse variance weighted (IVW) analysis. Our bioinformatic scrutiny of GSE115857 (IgA nephropathy, 86 samples) and GSE72326 (lupus nephritis, 238 samples) unveiled anomalies in lipid metabolism and immunological characteristics in nephritis. Thorough sensitivity analyses (MR-Egger, MR-PRESSO, leave-one-out analysis) were undertaken to verify the instrumental variables' (IVs) assumptions.

Results

Unique lipoprotein-related molecules established causal links with diverse nephritis subtypes. Notably, docosahexaenoic acid (DHA) emerged as a protective factor for acute tubulointerstitial nephritis (ATIN) (OR1 = 0.84, [95% CI 0.78-0.90], p1 = 0.013; OR2 = 0.89, [95% CI 0.82-0.97], p2 = 0.007). Conversely, multivitamin supplementation minus minerals notably increased the risk of ATIN (OR = 31.25, [95% CI 9.23-105.85], p = 0.004). Reduced α-linolenic acid (ALA) levels due to lipid-lowering drugs were linked to both ATIN (OR = 4.88, [95% CI 3.52-6.77], p < 0.001) and tubulointerstitial nephritis (TIN) (OR = 7.52, [95% CI 2.78-20.30], p = 0.042). While the non-renal drug indivina showed promise for TIN treatment, the use of digoxin, hydroxocobalamin, and liothyronine elevated the risk of chronic tubulointerstitial nephritis (CTIN). Transcriptome analysis affirmed that anomalous lipid metabolism and immune infiltration are characteristic of IgA nephropathy and lupus nephritis. The robustness of these causal links was reinforced by sensitivity analyses and leave-one-out tests, indicating no signs of pleiotropy.

Conclusion

Dyslipidemia significantly contributes to nephritis development. Strategies aimed at reducing plasma low-density lipoprotein levels or ALA supplementation may enhance the efficacy of existing lipid-lowering drug regimens for nephritis treatment. Renal functional status should also be judiciously considered with regard to the use of nonrenal medications.

Inulin Reduces Kidney Damage in Type 2 Diabetic Mice by Decreasing Inflammation and Serum Metabolomics

This study is aimed at assessing the impact of soluble dietary fiber inulin on the treatment of diabetes-related chronic inflammation and kidney injury in mice with type 2 diabetes (T2DM). The T2DM model was created by feeding the Institute of Cancer Research (ICR) mice a high-fat diet and intraperitoneally injecting them with streptozotocin (50 mg/kg for 5 consecutive days). The thirty-six ICR mice were divided into three dietary groups: the normal control (NC) group, the T2DM (DM) group, and the DM + inulin diet (INU) group. The INU group mice were given inulin at the dose of 500 mg/kg gavage daily until the end of the 12th week. After 12 weeks, the administration of inulin resulted in decreased serum levels of fasting blood glucose (FBG), low-density lipoprotein cholesterol (LDL-C), blood urea nitrogen (BUN), and creatinine (CRE). The administration of inulin not only ameliorated renal injury but also resulted in a reduction in the mRNA expressions of inflammatory factors in the spleen and serum oxidative stress levels, when compared to the DM group. Additionally, inulin treatment in mice with a T2DM model led to a significant increase in the concentrations of three primary short-chain fatty acids (SCFAs) (acetic acid, propionic acid, and butyric acid), while the concentration of advanced glycation end products (AGEs), a prominent inflammatory factor in diabetes, exhibited a significant decrease. The results of untargeted metabolomics indicate that inulin has the potential to alleviate inflammatory response and kidney damage in diabetic mice. This beneficial effect is attributed to its impact on various metabolic pathways, including glycerophospholipid metabolism, taurine and hypotaurine metabolism, arginine biosynthesis, and tryptophan metabolism. Consequently, oral inulin emerges as a promising treatment option for diabetes and kidney injury.

Association of Chronic Kidney Disease With Dietary Inflammatory Index in Adults Aged 50 Years and Older: Dose-Response Analysis of a Nationally Representative Population-Based Study

OBJECTIVE

Dietary inflammatory index (DII) is associated with systemic inflammatory markers, which have been linked to the development of chronic kidney disease (CKD). However, epidemiological studies on the association of DII scores with CKD are sparse. This study aimed to quantitatively assess the dose-response relationship of DII scores with the prevalence of CKD.

METHODS

Adults (≥50 years) from the 2007 to 2018 National Health and Nutrition Examination Survey (N = 12,090) were included. DII scores were calculated based on 27 nutritional parameters. The outcome of interest is the prevalence of CKD 3-5 stages, which is defined as an estimated glomerular filtration rate <60 mL/min/1.73 m2. The nonlinear dose-response relationship of DII scores with the prevalence of CKD stages 3-5 was assessed with restricted cubic splines. Stratified analyses were conducted by age, sex, and race/ethnicity. Covariates included age, sex, body mass index, race/ethnicity, education, ratio of family income to poverty, smoking, physical activity, hypertension, diabetes, and daily intakes of total plain water, sodium, and energy.

RESULTS

The weighted prevalence of CKD stages 3-5 was 14.77%. The relationship of DII scores with CKD stages 3-5 was linear, and the odds ratios (95% confidence intervals) of CKD stages 3-5 were 0.68 (0.51-0.84) for -2 (DII score), 0.83 (0.74-0.93) for -1, 1.00 for 0 (reference value), 1.20 (1.07-1.32) for 1, 1.41 (1.16-1.66) for 2, 1.63 (1.28-1.98) for 3, 1.84 (1.34-2.34) for 4, and 2.08 (1.30-2.86) for 5. The linear relationship pattern of DII scores with CKD stages 3-5 was observed in stratified analyses by age, sex, and race/ethnicity, respectively.

CONCLUSIONS

Higher DII scores were independently and linearly associated with the odds of CKD stages 3-5, which deserves to be confirmed in further prospective cohort studies.

Klotho exerts protection in chronic kidney disease associated with regulating inflammatory response and lipid metabolism

BACKGROUND

The anti-aging protein Klotho plays a protective role in kidney disease, but its potential as a biomarker for chronic kidney disease (CKD) is controversial. Additionally, the main pathways through which Klotho exerts its effects on CKD remain unclear. Therefore, we used bioinformatics and clinical data analysis to determine its role in CKD.

RESULTS

We analyzed the transcriptomic and clinical data from the Nephroseq v5 database and found that the Klotho gene was mainly expressed in the tubulointerstitium, and its expression was significantly positively correlated with estimated glomerular filtration rate (eGFR) and negatively correlated with blood urea nitrogen (BUN) in CKD. We further found that Klotho gene expression was mainly negatively associated with inflammatory response and positively associated with lipid metabolism in CKD tubulointerstitium by analyzing two large sample-size CKD tubulointerstitial transcriptome datasets. By analyzing 10-year clinical data from the National Health and Nutrition Examination Survey (NHANES) 2007-2016, we also found that Klotho negatively correlated with inflammatory biomarkers and triglyceride and positively correlated with eGFR in the CKD population. Mediation analysis showed that Klotho could improve renal function in the general population by modulating the inflammatory response and lipid metabolism, while in the CKD population, it primarily manifested by mediating the inflammatory response. Restricted cubic spline (RCS) analysis showed that the optimal concentration range for Klotho to exert its biological function was around 1000 pg/ml. Kaplan-Meier curves showed that lower cumulative hazards of all-cause mortality in participants with higher levels of Klotho. We also demonstrated that Klotho could reduce cellular inflammatory response and improve cellular lipid metabolism by establishing an in vitro model similar to CKD.

CONCLUSIONS

Our results suggest that Klotho exerts protection in CKD, which may be mainly related to the regulation of inflammatory response and lipid metabolism, and it can serve as a potential biomarker for CKD.

A Cross-Sectional Pilot Study on Association of Ready-to-Eat and Processed Food Intakes with Metabolic Factors, Serum Trans Fat and Phospholipid Fatty Acid Compositions in Healthy Japanese Adults

Frequently consuming processed and ready-to-eat (RTE) foods is regarded as unhealthy, but evidence on the relationships with circulating metabolic parameters is lacking. Japanese residents of a metropolitan area, 20 to 50 years of age, were studied in terms of anthropometric and biochemical parameters, including circulating trans fat and serum phospholipid fatty acid levels. Processed foods, except drinks and dairy items, were categorized according to requirements for additional ingredients and cooking before eating. Processed and RTE foods were divided according to fat and/or oil content into non-fatty or fatty foods. The participants were grouped into tertiles based on the energy percent (En%) derived from fatty-RTE foods. Fatty-RTE En% showed negative associations with fish, soybean and soybean products, dairy, eggs, vegetables, seaweed/mushrooms/konjac, fruit and non-oily seasonings reflecting lower dietary fiber, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and mineral and vitamin intakes, while the associations with fat/oil, confectionaries, and sweet beverages were positive. Fatty-RTE En% consumption was positively associated with alkaline phosphatase, leucine aminopeptidase, direct bilirubin, elaidic acid, and C18:2 but inversely associated with HDL cholesterol, C15:0, C17:0, EPA, and DHA. A higher fatty-RTE food intake was suggested to contribute to unbalanced nutrient intakes, as reflected in lipid metabolic parameters. Further large-scale studies are needed to evaluate the quality and impacts of RTE foods.

GLP-1 receptor agonist attenuates tubular cell ferroptosis in diabetes via enhancing AMPK-fatty acid metabolism pathway through macropinocytosis

Kidney tubules are mostly responsible for pathogenesis of diabetic kidney disease. Actively reabsorption of iron, high rate of lipid metabolism and exposure to concentrated redox-active compounds constructed the three main pillars of ferroptosis in tubular cells. However, limited evidence has indicated that ferroptosis is indispensable for diabetic tubular injury. Glucagon-like peptide-1 receptor agonist (GLP-1RA) processed strong benefits on kidney outcomes in people with diabetes. Moreover, GLP-1RA may have additive effects by improving dysmetabolism besides glucose control and weight loss. Therefore, the present study aimed at exploring the benefits of exendin-4, a high affinity GLP-1RA on kidney tubular dysregulation in diabetes and the possible mechanisms involved, with focus on ferroptosis and adenosine 5'-monophosphate-activated protein kinase (AMPK)-mitochondrial lipid metabolism pathway. Our data revealed that exendin-4 treatment markedly improved kidney structure and function by reducing iron overload, oxidative stress, and ACSL4-driven lipid peroxidation taken place in diabetic kidney tubules, along with reduced GPX4 expression and GSH content. AMPK signaling was identified as the downstream target of exendin-4, and enhancement of AMPK triggered the transmit of its downstream signal to activate fatty acid oxidation in mitochondria and suppress lipid synthesis and glycolysis, and ultimately alleviated toxic lipid accumulation and ferroptosis. Further study suggested that exendin-4 was taken up by tubular cells via macropinocytosis. The protective effect of exendin-4 on tubular ferroptosis was abolished by macropinocytosis blockade. Taken together, present work demonstrated the beneficial effects of GLP-1RA treatment on kidney tubular protection in diabetes by suppressing ferroptosis through enhancing AMPK-fatty acid metabolic signaling via macropinocytosis.

HMGN1 down-regulation in the diabetic kidney attenuates tubular cells injury and protects against renal inflammation via suppressing MCP-1 and KIM-1 expression through TLR4

BACKGROUND

Renal tubular injury, accompanied by damaging inflammation, has been identified to drive diabetic kidney disease (DKD) toward end-stage renal disease. However, it is unclear how damage-associated molecular patterns (DAMPs) activate innate immunity to mediate tubular epithelial cell (TEC) injury, which in turn causes with subsequent sterile inflammation in diabetic kidneys. High mobility group nucleosome-binding protein 1 (HMGN1) is a novel DAMP that contributes to generating the innate immune response. In this study, we focused on determining whether HMGN1 is involved in DKD progression.

METHODS

Streptozotocin (STZ)-induced diabetic mice model was established. Then we downrergulated HMGN1 expression in kidney with or without HMGN1 administration. The renal dysfunction and morphological lesions in the kidneys were evaluated. The expressions of KIM-1, MCP-1, F4/80, CD68, and HMGN1/TLR4 signaling were examined in the renal tissue. In vitro, HK2 cells were exposed in the high glucose with or without HMGN1, and further pre-incubated with TAK242 was applied to elucidate the underlying mechanism.

RESULTS

We demonstrated that HMGN1 was upregulated in the tubular epithelial cells of streptozotocin (STZ)-induced type 1 and type 2 diabetic mouse kidneys compared to controls, while being positively correlated with increased TLR4, KIM-1, and MCP-1. Down-regulation of renal HMGN1 attenuated diabetic kidney injury, decreased the TLR4, KIM-1, and MCP-1 expression levels, and reduced interstitial infiltrating macrophages. However, these phenotypes were reversed after administration of HMGN1. In HK-2 cells, HMGN1 promoted the expression of KIM-1 and MCP-1 via regulating MyD88/NF-κB pathway; inhibition of TLR4 effectively diminished the in vitro response to HMGN1.

CONCLUSIONS

Our study provides novel insight into HMGN1 signaling mechanisms that contribute to tubular sterile injury and low-grade inflammation in DKD. The study findings may help to develop new HMGN1-targeted approaches as therapy for immune-mediated kidney damage rather than as an anti-infection treatments.

Systemic Inflammatory Response Index (SIRI) is associated with all-cause mortality and cardiovascular mortality in population with chronic kidney disease: evidence from NHANES (2001-2018)

Objective

To examine the correlation between SIRI and the probability of cardiovascular mortality as well as all-cause mortality in individuals with chronic kidney disease.

Methods

A cohort of 3,262 participants from the US National Health and Nutrition Examination Survey (NHANES) database were included in the study. We categorized participants into five groups based on the stage of chronic kidney disease. A weighted Cox regression model was applied to assess the relationship between SIRI and mortality. Subgroup analyses, Kaplan-Meier survival curves, and ROC curves were conducted. Additionally, restricted cubic spline analysis was employed to elucidate the detailed association between SIRI and hazard ratio (HR).

Results

This study included a cohort of 3,262 individuals, of whom 1,535 were male (weighted proportion: 42%), and 2,216 were aged 60 or above (weighted proportion: 59%). Following adjustments for covariates like age, sex, race, and education, elevated SIRI remained a significant independent risk factor for cardiovascular mortality (HR=2.50, 95%CI: 1.62-3.84, p<0.001) and all-cause mortality (HR=3.02, 95%CI: 2.03-4.51, p<0.001) in CKD patients. The restricted cubic spline analysis indicated a nonlinear relationship between SIRI and cardiovascular mortality, with SIRI>1.2 identified as an independent risk factor for cardiovascular mortality in CKD patients.

Conclusion

Heightened SIRI independently poses a risk for both all-cause and cardiovascular mortality in chronic kidney disease patients, with potentially heightened significance in the early stages (Stage I to Stage III) of chronic kidney disease.

Bicyclol alleviates obesity-induced renal injury by inhibiting JNK and NF-κB-mediated inflammation

Obesity is recognized as a major risk factor for chronic kidney disease (CKD), which is accompanied by increased renal lipid build-up, fibrosis, inflammation, apoptosis and pyroptosis. Bicyclol (BIC), a Chinese marketed hepatoprotective drug, has shown excellent anti-inflammatory, anti-fibrosis, anti-apoptotic, and lipid regulation effects in different animal models. In this study, we explored the role and mechanism of BIC in high-fat diet (HFD)-induced obesity-related nephropathy. Mice were fed with HFD for 24 weeks to develop obesity-related nephropathy, while mice in the BIC administration group were treated with BIC (50 mg/kg or 100 mg/kg, once every two days) at the last 12 weeks. We found that BIC treatment relieved the impairment of kidney structure and renal dysfunction caused by HFD. In addition, we found that BIC mitigated HFD-induced renal fibrosis, inflammation, apoptosis and pyroptosis by inhibiting JNK and NF-κB pathways. SV40-MES-13 cells treated with palmitate (PA) were used as the in vitro model. Our data show that BIC pre-administration relieved cellular damage caused by PA through suppressing JNK and NF-κB signaling pathways. In conclusion, we demonstrated that BIC attenuated obesity-induced renal injury by inhibiting chronic inflammation, fibrosis, apoptosis and pyroptosis via targeting JNK and NF-κB pathways. Our data suggested that BIC could be potentially used to prevent obesity-associated nephropathy, which warrants future investigation.

Prediction of immunotherapy response in idiopathic membranous nephropathy using deep learning-pathological and clinical factors

Background

Owing to individual heterogeneity, patients with idiopathic membranous nephropathy (IMN) exhibit varying sensitivities to immunotherapy. This study aimed to establish and validate a model incorporating pathological and clinical features using deep learning training to evaluate the response of patients with IMN to immunosuppressive therapy.

Methods

The 291 patients were randomly categorized into training (n = 219) and validation (n = 72) cohorts. Patch-level convolutional neural network training in a weakly supervised manner was utilized to analyze whole-slide histopathological features. We developed a machine-learning model to assess the predictive value of pathological signatures compared to clinical factors. The performance levels of the models were evaluated using the area under the receiver operating characteristic curve (AUC) on the training and validation tests, and the prediction accuracies of the models for immunotherapy response were compared.

Results

Multivariate analysis indicated that diabetes and smoking were independent risk factors affecting the response to immunotherapy in IMN patients. The model integrating pathologic features had a favorable predictive value for determining the response to immunotherapy in IMN patients, with AUCs of 0.85 and 0.77 when employed in the training and test cohorts, respectively. However, when incorporating clinical features into the model, the predictive efficacy diminishes, as evidenced by lower AUC values of 0.75 and 0.62 on the training and testing cohorts, respectively.

Conclusions

The model incorporating pathological signatures demonstrated a superior predictive ability for determining the response to immunosuppressive therapy in IMN patients compared to the integration of clinical factors.

Research progress in cell therapy for oral diseases: focus on cell sources and strategies to optimize cell function

In recent years, cell therapy has come to play an important therapeutic role in oral diseases. This paper reviews the active role of mesenchymal stem cells, immune cell sources, and other cells in oral disorders, and presents data supporting the role of cell therapy in oral disorders, including bone and tooth regeneration, oral mucosal disorders, oral soft tissue defects, salivary gland dysfunction, and orthodontic tooth movement. The paper will first review the progress of cell optimization strategies for oral diseases, including the use of hormones in combination with stem cells, gene-modified regulatory cells, epigenetic regulation of cells, drug regulation of cells, cell sheets/aggregates, cell-binding scaffold materials and hydrogels, nanotechnology, and 3D bioprinting of cells. In summary, we will focus on the therapeutic exploration of these different cell sources in oral diseases and the active application of the latest cell optimization strategies.

Iron and aluminum ore mining pollution induce oxidative and tissue damage on fruit-eating bats from the Atlantic Forest

Mining, a vital industry for economic growth, poses significant environmental pollution challenges. Failures in tailings dam containment have caused environmental contamination and raised concerns about preserving the globally significant biodiversity in the Atlantic Forest, which is under severe threat. Fruit-eating bats are key for forest regeneration as essential seed dispersers and pollinators. This study focuses on two keystone species, Artibeus lituratus and Sturnira lilium, exploring the effects of iron ore mining area (FEOA) and aluminum ore mining area (ALOA) on these bats, respectively, and comparing to individuals from a preserved Atlantic Forest fragment (FFA). Bats from FEOA showed higher Aluminum (Al), Calcium (Ca), Iron (Fe) and Barium (Ba) liver accumulation, as well as Ca and Fe muscle accumulation. These animals also showed higher liver and kidney oxidative damage associated with liver fibrosis and kidney inflammation. Brain and muscle also showed oxidative stress. Bats from ALOA showed higher Ca and Ba liver accumulation and Ca, Zinc (Zn), and Ba muscle accumulation, along with higher brain oxidative stress, liver fibrosis, and kidney inflammation. Our findings indicate that iron and aluminum ore mining activities cause adverse effects on bat tissues, posing a potential threat to biodiversity maintenance in the Atlantic Forest.

Cardiac Resolvin D2 ameliorates sepsis-induced cardiomyopathy via inhibiting Caspase-11/GSDMD dependent pyroptosis

BACKGROUND

Sepsis-induced cardiomyopathy (SICM) is common complication in septic patients with a high mortality and is characterized by an abnormal inflammation response, which was precisely regulated by endogenous specialized pro-resolving mediators (SPMs). However, the metabolic changes of cardiac SPMs during SICM and the roles of SPMs subset in the development of SICM remain unknown.

METHODS

In this work, the SPMs concentration was assessed using ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) of SICM mice and SICM patients. The cardiac function was measured by echocardiography after the treatment of a SPMs subset, termed Resolvin D2 (RvD2). Caspase-11-/-, GSDMD-/- and double deficient (Caspase-11-/-GSDMD-/-) mice were used to clarify the mechanisms of RvD2 in SICM.

RESULTS

We found that endogenous cardiac SPMs were disorders and RvD2 was decreased significantly and correlated with left ventricular ejection fraction (LVEF) and β-BNP, cTnT in Lipopolysaccharide/Cecum ligation and puncture (CLP) induced SICM models. Treatment with RvD2 attenuated lethality, cardiac dysfunction and cardiomyocytes death during SICM. Mechanistically, RvD2 alleviated SICM via inhibiting Caspase-11/GSDMD-mediated cardiomyocytes pyroptosis. Finally, the plasma levels of RvD2 were also decreased and significantly correlated with IL-1β, β-BNP, cTnT and LVEF in patients with SICM. Of note, plasma RvD2 level is indicator of SICM patients from healthy controls or sepsis patients.

CONCLUSION

These findings suggest that decreased cardiac RvD2 may involve in the pathogenesis of SICM. In addition, treatment with RvD2 represents a novel therapeutic strategy for SICM by inhibiting cardiomyocytes pyroptosis.

Interface between Resolvins and Efferocytosis in Health and Disease

Acute inflammation resolution acts as a vital process for active host response, tissue support, and homeostasis maintenance, during which resolvin D (RvD) and E (RvE) as mediators derived from omega-3 polyunsaturated fatty acids display specific and stereoselective anti-inflammations like restricting neutrophil infiltration and pro-resolving activities. On the other side of the coin, potent macrophage-mediated apoptotic cell clearance, namely efferocytosis, is essential for successful inflammation resolution. Further studies mentioned a linkage between efferocytosis and resolvins. For instance, resolvin D1 (RvD1), which is endogenously formed from docosahexaenoic acid within the inflammation resolution, thereby provoking efferocytosis. There is still limited information regarding the mechanism of action of RvD1-related efferocytosis enhancement at the molecular level. The current review article was conducted to explore recent data on how the efferocytosis process and resolvins relate to each other during the inflammation resolution in illness and health. Understanding different aspects of this connection sheds light on new curative approaches for medical conditions caused by defective efferocytosis and disrupted inflammation resolution.

Multi-omics and imaging mass cytometry characterization of human kidneys to identify pathways and phenotypes associated with impaired kidney function

Despite the recent advances in our understanding of the role of lipids, metabolites, and related enzymes in mediating kidney injury, there is limited integrated multi-omics data identifying potential metabolic pathways driving impaired kidney function. The limited availability of kidney biopsies from living donors with acute kidney injury has remained a major constraint. Here, we validated the use of deceased transplant donor kidneys as a good model to study acute kidney injury in humans and characterized these kidneys using imaging and multi-omics approaches. We noted consistent changes in kidney injury and inflammatory markers in donors with reduced kidney function. Neighborhood and correlation analyses of imaging mass cytometry data showed that subsets of kidney cells (proximal tubular cells and fibroblasts) are associated with the expression profile of kidney immune cells, potentially linking these cells to kidney inflammation. Integrated transcriptomic and metabolomic analysis of human kidneys showed that kidney arachidonic acid metabolism and seven other metabolic pathways were upregulated following diminished kidney function. To validate the arachidonic acid pathway in impaired kidney function we demonstrated increased levels of cytosolic phospholipase A2 protein and related lipid mediators (prostaglandin E2) in the injured kidneys. Further, inhibition of cytosolic phospholipase A2 reduced injury and inflammation in human kidney proximal tubular epithelial cells in vitro. Thus, our study identified cell types and metabolic pathways that may be critical for controlling inflammation associated with impaired kidney function in humans.

Association between systemic inflammation response index and chronic kidney disease: a population-based study

Introduction

Our objective was to explore the potential link between systemic inflammation response index (SIRI) and chronic kidney disease (CKD).

Methods

The data used in this study came from the National Health and Nutrition Examination Survey (NHANES), which gathers data between 1999 and 2020. CKD was diagnosed based on the low estimated glomerular filtration rate (eGFR) of less than 60 mL/min/1.73 m2 or albuminuria (urinary albumin-to-creatinine ratio (ACR) of more than 30 mg/g). Using generalized additive models and weighted multivariable logistic regression, the independent relationships between SIRI and other inflammatory biomarkers (systemic immune-inflammation index (SII), monocyte/high-density lipoprotein ratio (MHR), neutrophil/high-density lipoprotein ratio (NHR), platelet/high-density lipoprotein ratio (PHR), and lymphocyte/high-density lipoprotein ratio (LHR)) with CKD, albuminuria, and low-eGFR were examined.

Results

Among the recruited 41,089 participants, males accounted for 49.77% of the total. Low-eGFR, albuminuria, and CKD were prevalent in 8.30%, 12.16%, and 17.68% of people, respectively. SIRI and CKD were shown to be positively correlated in the study (OR = 1.24; 95% CI: 1.19, 1.30). Furthermore, a nonlinear correlation was discovered between SIRI and CKD. SIRI and CKD are both positively correlated on the two sides of the breakpoint (SIRI = 2.04). Moreover, increased SIRI levels were associated with greater prevalences of low-eGFR and albuminuria (albuminuria: OR = 1.27; 95% CI: 1.21, 1.32; low-eGFR: OR = 1.11; 95% CI: 1.05, 1.18). ROC analysis demonstrated that, compared to other inflammatory indices (SII, NHR, LHR, MHR, and PHR), SIRI exhibited superior discriminative ability and accuracy in predicting CKD, albuminuria, and low-eGFR.

Discussion

When predicting CKD, albuminuria, and low-eGFR, SIRI may show up as a superior inflammatory biomarker when compared to other inflammatory biomarkers (SII, NHR, LHR, MHR, and PHR). American adults with elevated levels of SIRI, SII, NHR, MHR, and PHR should be attentive to the potential risks to their kidney health.

Comprehensive strategy for identifying extracellular vesicle surface proteins as biomarkers for chronic kidney disease

Chronic kidney disease (CKD) poses a significant health burden worldwide. Especially, obesity-induced chronic kidney disease (OCKD) is associated with a lack of accuracy in disease diagnostic methods. The identification of reliable biomarkers for the early diagnosis and monitoring of CKD and OCKD is crucial for improving patient outcomes. Extracellular vesicles (EVs) have emerged as potential biomarkers in the context of CKD. In this review, we focused on the role of EVs as potential biomarkers in CKD and OCKD and developed a comprehensive list of EV membrane proteins that could aid in the diagnosis and monitoring of the disease. To assemble our list, we employed a multi-step strategy. Initially, we conducted a thorough review of the literature on EV protein biomarkers in kidney diseases. Additionally, we explored papers investigating circulating proteins as biomarkers in kidney diseases. To further refine our list, we utilized the EV database Vesiclepedia.org to evaluate the qualifications of each identified protein. Furthermore, we consulted the Human Protein Atlas to assess the localization of these candidates, with a particular focus on membrane proteins. By integrating the information from the reviewed literature, Vesiclepedia.org, and the Human Protein Atlas, we compiled a comprehensive list of potential EV membrane protein biomarkers for CKD and OCKD. Overall, our review underscores the potential of EVs as biomarkers in the field of CKD research, providing a foundation for future studies aimed at improving CKD and OCKD diagnosis and treatment.

Specialized pro-resolving mediators in vascular inflammation and atherosclerotic cardiovascular disease

Timely resolution of the acute inflammatory response (or inflammation resolution) is an active, highly coordinated process that is essential to optimal health. Inflammation resolution is regulated by specific endogenous signalling molecules that function as 'stop signals' to terminate the inflammatory response when it is no longer needed; to actively promote healing, regeneration and tissue repair; and to limit pain. Specialized pro-resolving mediators are a superfamily of signalling molecules that initiate anti-inflammatory and pro-resolving actions. Without an effective and timely resolution response, inflammation can become chronic, a pathological state that is associated with many widely occurring human diseases, including atherosclerotic cardiovascular disease. Uncovering the mechanisms of inflammation resolution failure in cardiovascular diseases and identifying useful biomarkers for non-resolving inflammation are unmet needs. In this Review, we discuss the accumulating evidence that supports the role of non-resolving inflammation in atherosclerosis and the use of specialized pro-resolving mediators as therapeutic tools for the treatment of atherosclerotic cardiovascular disease. We highlight open questions about therapeutic strategies and mechanisms of disease to provide a framework for future studies on the prevention and treatment of atherosclerosis.

Protectin D1 ameliorates non-compressive lumbar disc herniation through SIRT1-mediated CGRP signaling

Background. Neuro-inflammatory response promotes the initiation and sustenance of lumbar disc herniation (LDH). Protectin D1 (PD1), as a new type of specialized pro-resolving mediator (SPM), can improve the prognosis of various inflammatory diseases. Recent studies have shown that over representation of calcitonin gene-related peptides (CGRP) may activate nociceptive signaling following nerve injury. Silent information regulator 1 (SIRT1) is ubiquitously expressed in the dorsal horn of the spinal cord and plays a role in the pathogenesis of LDH. In this study, we investigated the analgesic effects of PD1 and elucidated the impact of neurogenic inflammation in the pathogenesis of neuropathic pain induced by non-compressive lumbar disc herniation (NCLDH) in a rat model. Methods. NCLDH models were established by applying protruding autologous nucleus pulposus to the L5 Dorsal root ganglion (DRG). PD1, SIRT1 antagonist or agonist, CGRP or antagonist were administered as daily intrathecal injections for three consecutive days postoperatively. Behavioral tests were conducted to assess mechanical and thermal hyperalgesia. The ipsilateral lumbar (L4-6) segment of the spinal dorsal horn was isolated for further analysis. Alterations in the release of SIRT1 and CGRP were explored using western blot and immunofluorescence. Results. Application of protruded nucleus (NP) materials to the DRG induced mechanical and thermal allodynia symptoms, and deregulated the expression of pro-inflammatory and anti-inflammatory cytokines in rats. Intrathecal delivery of PD1 significantly reversed the NCLDH-induced imbalance in neuro-inflammatory response and alleviated the symptoms of mechanical and thermal hyperalgesia. In addition, NP application to the DGRs resulted the spinal upregulation of CGRP and SIRT1 expression, which was almost restored by intrathecal injection of PD1 in a dose-dependent manner. SIRT1 antagonist or agonist and CGRP or antagonist treatment further confirmed the result. Conclusion. Our findings indicate PD1 has a potent analgesic effect, and can modulate neuro-inflammation by regulating SIRT1-mediated CGRP signaling in NCLDH.

Predictors of Kidney Function Outcomes and Their Relation to SGLT2 Inhibitor Dapagliflozin in Patients with Type 2 Diabetes Mellitus Who Had Chronic Heart Failure

INTRODUCTION

Sodium-glucose cotransporter 2 inhibitors (SGLT2i) have a favorable impact on the kidney function in patients with heart failure (HF), while there is no clear evidence of what factors predict this effect. The aim of the study was to identify plausible predictors for kidney function outcome among patients with HF and investigate their association with SGLT2i.

METHODS

We prospectively enrolled 480 patients with type 2 diabetes mellitus (T2DM) treated with diet and metformin and concomitant chronic HF and followed them for 52 weeks. In the study, we determined kidney outcome as a composite of ≥ 40% reduced estimated glomerular filtration rate from baseline, newly diagnosed end-stage kidney disease or kidney replacement therapy. The relevant medical information and measurement of the biomarkers (N-terminal natriuretic pro-peptide, irisin, apelin, adropin, C-reactive protein, tumor necrosis factor-alpha) were collected at baseline and at the end of the study.

RESULTS

The composite kidney outcome was detected in 88 (18.3%) patients of the entire population. All patients received guideline-recommended optimal therapy, which was adjusted to phenotype/severity of HF, cardiovascular risk and comorbidity profiles, and fasting glycemia. Levels of irisin, adropin and apelin significantly increased in patients without clinical endpoint, whereas in those with composite endpoint the biomarker levels exhibited a decrease with borderline statistical significance (p = 0.05). We noticed that irisin ≤ 4.50 ng/ml at baseline and a ≤ 15% increase in irisin serum levels added more valuable predictive information than the reference variable. However, the combination of irisin ≤ 4.50 ng/ml at baseline and ≤ 15% increase in irisin serum levels (area under curve = 0.91; 95% confidence interval = 0.87-0.95) improved the discriminative value of each biomarker alone.

CONCLUSION

We suggest that low levels of irisin and its inadequate increase during administration of SGLT2i are promising predictors for unfavorable kidney outcome among patients with T2DM and concomitant HF.

Genetic variants of metabolism and inflammatory pathways, and PCOS risk -Systematic review, meta-analysis, and in-silico analysis

IMPORTANCE

Identification of genetic risk factors for PCOS susceptibility.

OBJECTIVE

To identify genetic risk variants of the genes involved in metabolic or inflammatory pathways.

DATA SOURCES

Relevant literature was identified and extracted from PubMed, Central Cochrane Library, Google Scholar, and Science Direct by using a set of keywords related to pre-determined genes up to 06 May 2023. Study selection and synthesis: PRISMA guidelines were followed to design the protocol which is registered in PROSPERO (CRD42023422501). Pooled odds ratio (OR) and 95% confidence interval (95% CI) for different gene variants were calculated under different genetic models (dominant model, recessive model, additive model, and allele model) by using Review Manager software 4.2.

MAIN OUTCOMES

Metabolic genetic variants FTO rs9939609, IL-6 rs1800795 and CAPN10 rs3842570, rs2975760, and RAB5B rs705702 are associated with PCOS risk.

RESULTS

Forty-four relevant articles have been identified for genes involved in metabolic (n = 23) or inflammatory pathways (n = 21). There is a significant association (p < 0.05) of IL-6 rs1800795 and FTO rs9939609 with increased risk.CAPN10 rs2975760 Ins allele is suggested as a protective factor among only the non-Asian population. Also, a significant association of CAPN10 rs2975760 and RAB5B rs705702 with increased risk among the Asian population is suggested. However, no significant association could be found between CAPN10 rs3792267, rs5030952, and SUMO1P1 rs2272046, and the risk of PCOS in any of the subpopulations analysed. In silico analysis suggests the deleterious effect of IL-6 rs1800795.

CONCLUSION

and relevance: The study suggests the role of various genetic variants for genetic predisposition to PCOS among different subpopulations.

Associations Between Life's Essential 8 and Chronic Kidney Disease

BACKGROUND

Chronic kidney disease (CKD) is closely associated with cardiovascular disease. We aimed to examine the association of Life's Essential 8 (LE8), the recently updated measurement of cardiovascular health, with the prevalence of CKD among US adults.

METHODS AND RESULTS

This population-based cross-sectional study used data from the National Health and Nutrition Examination Survey from 2007 to 2018 and included adults aged ≥20 years. Multivariable logistic and restricted cubic spline models were used to assess the associations between LE8 and CKD. Among 24 960 participants, 4437 were determined to have CKD (weighted percentage, 14.11%). After the adjustment of potential confounders, higher LE8 scores were associated with reduced odds of CKD (odds ratio for each 10-point increase, 0.79 [95% CI, 0.76-0.83]), and a nonlinear dose-response relationship was observed. Similar patterns were also identified in the associations of health behavior and health factor scores with CKD. Meanwhile, higher scores for blood glucose (odds ratio, for each 10-point increase, 0.88 [95% CI, 0.87-0.90]) and blood pressure (odds ratio, for each 10-point increase, 0.92 [95% CI, 0.91-0.94]) in the LE8 component are significantly associated with a lower prevalence of CKD. The inversed association of LE8 score and CKD was significantly stronger among middle-aged, male, and coupled participants.

CONCLUSIONS

LE8 was negatively associated with the prevalence of CKD in a nonlinear fashion. Promoting adherence to optimal cardiovascular health levels may be beneficial to reduce the burden of CKD.

A moderate dosage of prostaglandin E2-mediated annexin A1 upregulation promotes alkali-burned corneal repair

Corneal alkali burn remains a clinical challenge in ocular emergency, necessitating the development of effective therapeutic drugs. Here, we observed the arachidonic acid metabolic disorders of corneas induced by alkali burns and aimed to explore the role of Prostaglandin E2 (PGE2), a critical metabolite of arachidonic acid, in the repair of alkali-burned corneas. We found a moderate dosage of PGE2 promoted the alkali-burned corneal epithelial repair, whereas a high dosage of PGE2 exhibited a contrary effect. This divergent effect is attributed to different dosages of PGE2 regulating ANXA1 expression differently. Mechanically, a high dosage of PGE2 induced higher GATA3 expression, followed by enhanced GATA3 binding to the ANXA1 promoter to inhibit ANXA1 expression. In contrast, a moderate dosage of PGE2 increased CREB1 phosphorylation and reduced GATA3 binding to the ANXA1 promoter, promoting ANXA1 expression. We believe PGE2 and its regulatory target ANXA1 could be potential drugs for alkali-burned corneas.

Effects of Nutrition Education Program for the Japan Diet on Serum Phospholipid Fatty Acid Compositions in Patients with Dyslipidemia: Re-analysis of Data from a Previous Randomized Controlled Trial

AIM

We investigated changes in serum phospholipid fatty acid compositions with intake of the Japan Diet (JD) (higher consumption of fish, soybeans, vegetables, seaweed/mushrooms/konjak, and unrefined cereals with reduced consumption of animal fat, meat and poultry with fat, sweets and alcoholic drinks) recommended by the Japan Atherosclerosis Society.

METHODS

A randomized parallel controlled clinical trial on JD intake was conducted on Japanese patients with dyslipidemia. Nutrition education, based on the JD or partial JD (PJD) at baseline and at 3 months, was provided and the participants were followed up for 6 months. Fatty acids comprising serum phospholipids were measured in the JD (n=44) and PJD (n=44) groups.

RESULTS

Fatty acid intakes of C20:4, C20:5 and C22:6 increased in the JD group as compared with the PJD group. The percentages of serum phospholipid, C22:1 and C20:5 increased, while those of C18:1, C20:3(n-6) and C20:4(n-6) decreased in the JD as compared with the PJD group at 3 months. Changes in the phospholipid concentrations of C20:5, C22:5 and C22:6 reflected those intake volumes. Serum phospholipid C20:5 and C22:6 showed inverse correlations with C18:1, C18:2, and C20:3(n-6) at baseline and the changes at 3 and 6 months. In contrast, no correlation was observed between C20:4(n-6) and those n-3 fatty acids. The ratios of fatty acid concentrations, C16:1/C16:0 and C18:1/C18:0, decreased, but the ratio of C20:4(n-6)/C20:3(n-6) increased in the JD group.

CONCLUSION

Nutrition education on the JD changed serum phospholipid fatty acid profiles in favor to prevent against cardiovascular risk factors in patients with dyslipidemia.

Association of a low ankle brachial index with progression to end-stage kidney disease in patients with advanced-stage diabetic kidney disease

INTRODUCTIONS

The effect of a low ankle-brachial index (ABI) in patients with advanced-stage diabetic kidney disease is not fully understood. This study investigates the prevalence of a low ABI in patients with advanced-stage diabetic kidney disease, which was defined as a urinary albumin-to-creatinine ratio (UACR) ≥300 mg/g and an estimated glomerular filtration rate (eGFR) between 15-60 mL/min/1.73 m². Furthermore, the association between a low ABI and end-stage kidney disease (ESKD) was determined.

METHODS

This single-center, retrospective, cohort study included 529 patients with advanced-stage diabetic kidney disease who were stratified into groups according to the ABI: high (>1.3), normal (0.9-1.3), and low (<0.9). The Kaplan-Meier method and Cox proportional analysis were used to examine the association between the ABI and ESKD.

RESULTS

A total of 42.5% of patients with a low ABI progressed to ESKD. A low ABI was associated with a greater risk of ESKD (hazard ratio (HR): 1.073). After adjusting for traditional chronic kidney disease risk factors, a low ABI remained associated with a greater risk of ESKD (HR: 1.758; 95% confidence interval: 1.243-2.487; p = 0.001).

CONCLUSIONS

These results indicate that patients with a low ABI should be monitored carefully. Furthermore, preventive therapy should be considered to improve the long-term kidney survival of patients with residual kidney function.

Tripterygium glycosides improve abnormal lipid deposition in nephrotic syndrome rat models

OBJECTIVE

The purpose of this study was to determine the effect of tripterygium glycosides (TGs) on regulating abnormal lipid deposition in nephrotic syndrome (NS) rats.

METHODS

Sprague-Dawley (SD) rats were injected with 6 mg/kg doxorubicin to construct nephrotic syndrome models (n = 6 per group), and then administered with TGs (10 mg/kg·d^-1), prednisone (6.3 mg/kg·d^-1), or pure water for 5 weeks. Biomedical indexes, such as urine protein/creatinine ratio (PCR), blood urea nitrogen (BUN), serum creatinine (Scr), serum albumin (SA), triglycerides (TG), total cholesterol (TC)were investigated to evaluate the renal injury of rats. H&E staining experiment was used to assess the pathological alterations. Oil Red O staining was used to assess the level of renal lipid deposition. Malondialdehyde (MDA) and glutathione (GSH) were measured to assess the extent of oxidative damage to the kidney. TUNEL staining was used to assess the status of apoptosis in the kidney. Western blot analysis was performed to examine the levels of relevant intracellular signaling molecules.

RESULTS

After treatment with TGs, those tested biomedical indexes were significantly improved, and the extent of kidney tissue pathological changes and lipid deposition in the kidney was diminished. Treatment with TGs decreased renal oxidative damage and apoptosis. Regarding the molecular mechanism, TGs significantly increased the protein expression levels of Bcl-2 but decreased the levels of CD36, ADFP, Bax, and Cleaved caspase-3.

CONCLUSION

TGs alleviates renal injury and lipid deposition induced by doxorubicin, suggesting that it may be a new strategy for reducing renal lipotoxicity in NS.

From Oxidized Fatty Acids to Dimeric Species: In Vivo Relevance, Generation and Methods of Analysis

The occurrence of free fatty acids (FFAs) and the generation of reactive oxygen species (ROS) such as hydroxyl radicals (HO●) or hypochlorous acid (HOCl) is characteristic of inflammatory diseases, for instance, rheumatoid arthritis. Unsaturated fatty acids react with ROS yielding a variety of important products such as peroxides and chlorohydrins as primary and chain-shortened compounds (e.g., aldehydes and carboxylic acids) as secondary products. These modified fatty acids are either released from phospholipids by phospholipases or oxidatively modified subsequent to their release. There is increasing evidence that oligomeric products are also generated upon these processes. Fatty acid esters of hydroxy fatty acids (FAHFAs) are considered as very important products, but chlorinated compounds may be converted into dimeric and (with smaller yields) oligomeric products, as well. Our review is structured as follows: first, the different types of FFA oligomers known so far and the mechanisms of their putative generation are explained. Industrially relevant products as well as compounds generated from the frying of vegetable oils are also discussed. Second, the different opinions on whether dimeric fatty acids are considered as "friends" or "foes" are discussed.

Lipidomic Analysis Reveals Differences in the Extent of Remyelination in the Brain and Spinal Cord

During demyelination, lipid-rich myelin debris is released in the central nervous system (CNS) and must be phagocytosed and processed before new myelin can form. Although myelin comprises over 70% lipids, relatively little is known about how the CNS lipidome changes during demyelination and remyelination. In this study, we obtained a longitudinal lipidomic profile of the brain, spinal cord, and serum using a genetic mouse model of demyelination, known as Plp1-iCKO-Myrf. The mass spectrometry data is available at the Metabolomics Workbench, where it has been assigned Study ID ST002958. This model has distinct phases of demyelination and remyelination over the course of 24 weeks, in which loss of motor function peaks during demyelination. Using principal component analysis (PCA) and volcano plots, we have demonstrated that the brain and spinal cord have different remyelination capabilities and that this is reflected in different lipidomic profiles over time. We observed that plasmalogens (ether-linked phosphatidylserine and ether-linked phosphatidylcholine) were elevated specifically during the early stages of active demyelination. In addition, we identified lipids in the brain that were altered when mice were treated with a remyelinating drug, which may be CNS biomarkers of remyelination. The results of this study provide new insights into how the lipidome changes in response to demyelination, which will enable future studies to elucidate mechanisms of lipid regulation during demyelination and remyelination.

Association Between Weight Change During Adulthood and Chronic Kidney Disease: Results from a National Survey 2011-2018

Purpose

This study aimed to investigate the intricate relationship between weight change patterns and the onset of chronic kidney disease (CKD). Although obesity is recognized as a predisposing factor for CKD, the dynamics of weight fluctuation and its impact on CKD development are not well-defined. By analyzing data from the National Health and Nutrition Examination Survey (NHANES) spanning 2011 to 2018, we sought to elucidate the association between weight trajectories and CKD risk.

Patients and Methods

We included participants aged ≥40 years, employing body mass index (BMI) measurements at three life stages-baseline, age 25, and a decade preceding baseline-to categorize weight change patterns. Logistic regression was employed to evaluate the association of these patterns with CKD onset, adjusting for potential confounders.

Results

The study encompassed 12,284 participants, with 2893 individuals diagnosed with CKD. Transitioning from normal weight to obesity and staying obese throughout adulthood were found to increase the risk of developing CKD. These associations remained consistent after adjusting for covariates but were statistically insignificant after adjusting for comorbidities. Notably, individuals transitioning from obesity to normal weight from age 25 to baseline and from 10 years before baseline to baseline demonstrated significant correlations with CKD but not between age 25 and 10 years before baseline.

Conclusion

Obesity, weight gain throughout adulthood, and weight loss in middle-to-late adulthood are associated with an increased risk of CKD. This emphasizes the importance of long-term weight change patterns and maintaining a healthy weight throughout adulthood.

An Overview of Chronic Kidney Disease Pathophysiology: The Impact of Gut Dysbiosis and Oral Disease

Chronic kidney disease (CKD) is a severe condition and a significant public health issue worldwide, carrying the burden of an increased risk of cardiovascular events and mortality. The traditional factors that promote the onset and progression of CKD are cardiometabolic risk factors like hypertension and diabetes, but non-traditional contributors are escalating. Moreover, gut dysbiosis, inflammation, and an impaired immune response are emerging as crucial mechanisms in the disease pathology. The gut microbiome and kidney disease exert a reciprocal influence commonly referred to as "the gut-kidney axis" through the induction of metabolic, immunological, and endocrine alterations. Periodontal diseases are strictly involved in the gut-kidney axis for their impact on the gut microbiota composition and for the metabolic and immunological alterations occurring in and reciprocally affecting both conditions. This review aims to provide an overview of the dynamic biological interconnections between oral health status, gut, and renal pathophysiology, spotlighting the dynamic oral-gut-kidney axis and raising whether periodontal diseases and gut microbiota can be disease modifiers in CKD. By doing so, we try to offer new insights into therapeutic strategies that may enhance the clinical trajectory of CKD patients, ultimately advancing our quest for improved patient outcomes and well-being.

Basigin is released in extracellular vesicles derived from the renal tubular epithelium in response to albuminuria

AIM

Irrespective of the cause, albumin/proteinuria induces tubulointerstitial damage and accelerates the progression of kidney diseases. Our series of studies demonstrated that proteinuria, an independent prognostic factor for chronic kidney disease (CKD), is correlated with urinary basigin/CD147 (Bsg) levels. We examined the morphology and origin of Bsg in the tubular lumen through the effects of filtered glucose and protein solutes on the tubules.

METHODS

Diabetic kidney disease (DKD) patients (N = 50) were treated with spironolactone 25 mg for 4 weeks or by conservative treatment. The associations between urinary Bsg values and clinical indicators were examined. Primary-cultured proximal tubular epithelial cells (PTECs) from human adult kidneys were exposed to high glucose or bovine serum albumin (BSA).

RESULTS

In patients with early phase DKD, urinary Bsg levels were closely correlated with proteinuria but not HbA1c. Full-length Bsg on extracellular vesicles (EVs) was investigated primarily in urine collected from DKD patients. EVs obtained from the urine of DKD patients included Bsg and SGLT2 proteins. Notably, spironolactone treatment concomitantly suppressed the release of Bsg-bearing EVs in correlation with decreased albuminuria. Exposure of PTECs to BSA (but not high glucose) enhanced the storage of supernatant Bsg in EVs despite the absence of exposure-specific changes in Bsg transcription.

CONCLUSION

Proteinuria induces the release of Bsg-bearing EVs derived from PTECs into the tubular lumen.

USP25 ameliorates diabetic nephropathy by inhibiting TRAF6-mediated inflammatory responses

Diabetic kidney disease (DKD) is a common diabetic vascular complication affecting nearly 40% of patients with diabetes. The lack of efficacious therapy for DKD necessitates the in-depth investigation of the molecular mechanisms underlying the pathogenesis and progression of DKD, which remain incompletely understood. Here, we discovered that the expression of USP25, a deubiquitinating enzyme, was significantly upregulated in the kidney of diabetic mice. Ablation of USP25 had no influence on glycemic control in type 1 diabetes but significantly aggravated diabetes-induced renal dysfunction and fibrosis by exacerbating inflammation in the kidney. In DKD, USP25 was mainly expressed in glomerular mesangial cells and kidney-infiltrating macrophages. Upon stimulation with advanced glycation end-products (AGEs), USP25 markedly inhibited the production of proinflammatory cytokines in these two cell populations by downregulating AGEs-induced activation of NF-κB and MAPK pathways. Mechanistically, USP25 interacted with TRAF6 and inhibited its K63 polyubiquitination induced by AGEs. Collectively, these findings identify USP25 as a novel regulator of DKD.

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.

Understanding the relationship between circulating lipids and risk of chronic kidney disease: a prospective cohort study and large-scale genetic analyses

BACKGROUND

This study aims to comprehensively investigate the phenotypic and genetic relationships between four common lipids (high-density lipoprotein cholesterol, HDL-C; low-density lipoprotein cholesterol, LDL-C; total cholesterol, TC; and triglycerides, TG), chronic kidney disease (CKD), and estimated glomerular filtration rate (eGFR).

METHODS

We first investigated the observational association of lipids (exposures) with CKD (primary outcome) and eGFR (secondary outcome) using data from UK Biobank. We then explored the genetic relationship using summary statistics from the largest genome-wide association study of four lipids (N = 1,320,016), CKD (Ncase = 41,395, Ncontrol = 439,303), and eGFR(N = 567,460).

RESULTS

There were significant phenotypic associations (HDL-C: hazard ratio (HR) = 0.76, 95%CI = 0.60-0.95; TG: HR = 1.08, 95%CI = 1.02-1.13) and global genetic correlations (HDL-C: [Formula: see text] = - 0.132, P = 1.00 × 10-4; TG: [Formula: see text] = 0.176; P = 2.66 × 10-5) between HDL-C, TG, and CKD risk. Partitioning the whole genome into 2353 LD-independent regions, twelve significant regions were observed for four lipids and CKD. The shared genetic basis was largely explained by 29 pleiotropic loci and 36 shared gene-tissue pairs. Mendelian randomization revealed an independent causal relationship of genetically predicted HDL-C (odds ratio = 0.91, 95%CI = 0.85-0.98), but not for LDL-C, TC, or TG, with the risk of CKD. Regarding eGFR, a similar pattern of correlation and pleiotropy was observed.

CONCLUSIONS

Our work demonstrates a putative causal role of HDL-C in CKD and a significant biological pleiotropy underlying lipids and CKD in populations of European ancestry. Management of low HDL-C levels could potentially benefit in reducing the long-term risk of CKD.

Association between weight-adjusted-waist index and chronic kidney disease: a cross-sectional study

AIMS

We aimed to investigate the potential association between weight-adjusted-waist index (WWI) and chronic kidney disease (CKD).

DESIGN AND METHODS

This research examined data collected from the National Health and Nutrition Examination Survey (NHANES) spanning from 1999 to 2020. CKD was defined as the low estimated glomerular filtration rate (eGFR) or the existence of albuminuria (urinary albumin-to-creatinine ratio (ACR) ≥ 30mg/g). Low-eGFR was described as eGFR < 60 mL/min/1.73m2. The associations between WWI with CKD, albuminuria, and low-eGFR were examined using generalized additive models and weighted multivariable logistic regression models. We also analyzed the associations of other obesity indicators with CKD, albuminuria, and low-eGFR, including body mass index (BMI), waist-to-height ratio (WHtR), waist circumference(WC), height, and weight. The receiver operating characteristic (ROC) curves were used to assess and compare their diagnostic abilities.

RESULTS

Males made up 48.26% of the total 40,421 individuals that were recruited. The prevalences of CKD, albuminuria, and low-eGFR were 16.71%, 10.97%, and 7.63%, respectively. WWI was found to be positively linked with CKD (OR = 1.42; 95% CI: 1.26, 1.60). A nonlinear connection between WWI and CKD was found using smooth curve fitting. Additionally, a higher prevalence of albuminuria is linked to a higher level of WWI (OR = 1.60; 95% CI: 1.40, 1.82). Different stratifications did not substantially influence the connection between WWI and CKD, albuminuria, and low-eGFR, according to subgroup analysis and interaction tests. We observed higher height was related to higher low-eGFR prevalence (OR = 1.05; 95% CI: 1.03, 1.06). ROC analysis revealed that WWI had the best discrimination and accuracy for predicting CKD and albuminuria compared to other obesity indicators (BMI, WHTR, WC, height and weight). In addition, height had the highest area under the curve (AUC) value for predicting low-eGFR.

CONCLUSION

WWI is the best obesity indicator to predict CKD and albuminuria compared to other obesity indicators (BMI, WHTR, WC, height, and weight). WWI and CKD and albuminuria were found to be positively correlated. Furthermore, height had the strongest ability to predict low-eGFR. Therefore, the importance of WWI and height in assessing kidney health in US adults should be emphasized.

Lipidomic analysis reveals differences in the extent of remyelination in the brain and spinal cord

During demyelination, lipid-rich myelin debris is released in the central nervous system (CNS) and must be phagocytosed and processed before new myelin can form. Although myelin comprises over 70% lipids, relatively little is known about how the CNS lipidome changes during demyelination and remyelination. In this study, we obtained a longitudinal lipidomic profile of the brain, spinal cord, and serum using a genetic mouse model of demyelination, known as Plp1 -iCKO- Myrf mice. This model has distinct phases of demyelination and remyelination over the course of 24 weeks, in which loss of motor function peaks during demyelination. Using principal component analysis (PCA) and volcano plots, we have demonstrated that the brain and spinal cord have different remyelination capabilities and that this is reflected in different lipidomic profiles over time. We observed that plasmalogens (ether-linked phosphatidylserine and ether-linked phosphatidylcholine) were elevated specifically during the early stages of active demyelination. In addition, we identified lipids in the brain that were altered when mice were treated with a remyelinating drug, which may be CNS biomarkers of remyelination. The results of this study provide new insights into how the lipidome changes in response to demyelination, which will enable future studies to elucidate mechanisms of lipid regulation during demyelination and remyelination.

Plasma metabolomics by nuclear magnetic resonance reveals biomarkers and metabolic pathways associated with the control of HIV-1 infection/progression

How the human body reacts to the exposure of HIV-1 is an important research goal. Frequently, HIV exposure leads to infection, but some individuals show natural resistance to this infection; they are known as HIV-1-exposed but seronegative (HESN). Others, although infected but without antiretroviral therapy, control HIV-1 replication and progression to AIDS; they are named controllers, maintaining low viral levels and an adequate count of CD4⁺ T lymphocytes. Biological mechanisms explaining these phenomena are not precise. In this context, metabolomics emerges as a method to find metabolites in response to pathophysiological stimuli, which can help to establish mechanisms of natural resistance to HIV-1 infection and its progression. We conducted a cross-sectional study including 30 HESN, 14 HIV-1 progressors, 14 controllers and 30 healthy controls. Plasma samples (directly and deproteinized) were analyzed through Nuclear Magnetic Resonance (NMR) metabolomics to find biomarkers and altered metabolic pathways. The metabolic profile analysis of progressors, controllers and HESN demonstrated significant differences with healthy controls when a discriminant analysis (PLS-DA) was applied. In the discriminant models, 13 metabolites associated with HESN, 14 with progressors and 12 with controllers were identified, which presented statistically significant mean differences with healthy controls. In progressors, the metabolites were related to high energy expenditure (creatinine), mood disorders (tyrosine) and immune activation (lipoproteins), phenomena typical of the natural course of the infection. In controllers, they were related to an inflammation-modulating profile (glutamate and pyruvate) and a better adaptive immune system response (acetate) associated with resistance to progression. In the HESN group, with anti-inflammatory (lactate and phosphocholine) and virucidal (lactate) effects which constitute a protective profile in the sexual transmission of HIV. Concerning the significant metabolites of each group, we identified 24 genes involved in HIV-1 replication or virus proteins that were all altered in progressors but only partially in controllers and HESN. In summary, our results indicate that exposure to HIV-1 in HESN, as well as infection in progressors and controllers, affects the metabolism of individuals and that this affectation can be determined using NMR metabolomics.

Randomized crossover clinical trial of coenzyme Q10 and nicotinamide riboside in chronic kidney disease

BackgroundCurrent studies suggest mitochondrial dysfunction is a major contributor to impaired physical performance and exercise intolerance in chronic kidney disease (CKD). We conducted a clinical trial of coenzyme Q10 (CoQ10) and nicotinamide riboside (NR) to determine their impact on exercise tolerance and metabolic profile in patients with CKD.MethodsWe conducted a randomized, placebo-controlled, double-blind, crossover trial comparing CoQ10, NR, and placebo in 25 patients with an estimated glomerular filtration rate (eGFR) of less than 60mL/min/1.73 m2. Participants received NR (1,000 mg/day), CoQ10 (1,200 mg/day), or placebo for 6 weeks each. The primary outcomes were aerobic capacity measured by peak rate of oxygen consumption (VO2 peak) and work efficiency measured using graded cycle ergometry testing. We performed semitargeted plasma metabolomics and lipidomics.ResultsParticipant mean age was 61.0 ± 11.6 years and mean eGFR was 36.9 ± 9.2 mL/min/1.73 m2. Compared with placebo, we found no differences in VO2 peak (P = 0.30, 0.17), total work (P = 0.47, 0.77), and total work efficiency (P = 0.46, 0.55) after NR or CoQ10 supplementation. NR decreased submaximal VO2 at 30 W (P = 0.03) and VO2 at 60 W (P = 0.07) compared with placebo. No changes in eGFR were observed after NR or CoQ10 treatment (P = 0.14, 0.88). CoQ10 increased free fatty acids and decreased complex medium- and long-chain triglycerides. NR supplementation significantly altered TCA cycle intermediates and glutamate that were involved in reactions that exclusively use NAD+ and NADP+ as cofactors. NR decreased a broad range of lipid groups including triglycerides and ceramides.ConclusionsSix weeks of treatment with NR or CoQ10 improved markers of systemic mitochondrial metabolism and lipid profiles but did not improve VO2 peak or total work efficiency.Trial registrationClinicalTrials.gov NCT03579693.FundingNational Institutes of Diabetes and Digestive and Kidney Diseases (grants R01 DK101509, R03 DK114502, R01 DK125794, and R01 DK101509).

Resolvins and cysteinyl-containing pro-resolving mediators activate resolution of infectious inflammation and tissue regeneration

This review is a synopsis of the main points from the opening presentation by the authors in the Resolution of Inflammation session at the 8th European Workshop on Lipid Mediators held at the Karolinska Institute, Stockholm, Sweden, June 29th, 2022. Specialized pro-resolving mediators (SPM) promote tissue regeneration, control infections and resolution of inflammation. These include resolvins, protectins, maresins and the newly identified conjugates in tissue regeneration (CTRs). We reported mechanisms of CTRs in activating primordial regeneration pathways in planaria using RNA-sequencing. Also, the 4S,5S-epoxy-resolvin intermediate in the biosynthesis of resolvin D3 and resolvin D4 was prepared by total organic synthesis. Human neutrophils convert this to resolvin D3 and resolvin D4, while human M2 macrophages transformed this labile epoxide intermediate to resolvin D4 and a novel cysteinyl-resolvin that is a potent isomer of RCTR1. The novel cysteinyl-resolvin significantly accelerates tissue regeneration with planaria and inhibits human granuloma formation.

Ferroptotic mechanisms and therapeutic targeting of iron metabolism and lipid peroxidation in the kidney

Ferroptosis is a mechanism of regulated necrotic cell death characterized by iron-dependent, lipid peroxidation-driven membrane destruction that can be inhibited by glutathione peroxidase 4. Morphologically, it is characterized by cellular, organelle and cytoplasmic swelling and the loss of plasma membrane integrity, with the release of intracellular components. Ferroptosis is triggered in cells with dysregulated iron and thiol redox metabolism, whereby the initial robust but selective accumulation of hydroperoxy polyunsaturated fatty acid-containing phospholipids is further propagated through enzymatic and non-enzymatic secondary mechanisms, leading to formation of oxidatively truncated electrophilic species and their adducts with proteins. Thus, ferroptosis is dependent on the convergence of iron, thiol and lipid metabolic pathways. The kidney is particularly susceptible to redox imbalance. A growing body of evidence has linked ferroptosis to acute kidney injury in the context of diverse stimuli, such as ischaemia-reperfusion, sepsis or toxins, and to chronic kidney disease, suggesting that ferroptosis may represent a novel therapeutic target for kidney disease. However, further work is needed to address gaps in our understanding of the triggers, execution and spreading mechanisms of ferroptosis.

Factors affecting variability in free oxylipins in mammalian tissues

PURPOSE OF THE REVIEW

Along with the growing interest in oxylipins is an increasing awareness of multiple sources of variability in oxylipin data. This review summarizes recent findings that highlight the experimental and biological sources of variation in free oxylipins.

RECENT FINDINGS

Experimental factors that affect oxylipin variability include different methods of euthanasia, postmortem changes, cell culture reagents, tissue processing conditions and timing, storage losses, freeze-thaw cycles, sample preparation techniques, ion suppression, matrix effects, use and availability of oxylipin standards, and postanalysis procedures. Biological factors include dietary lipids, fasting, supplemental selenium, vitamin A deficiency, dietary antioxidants and the microbiome. Overt, but also more subtle differences in health affect oxylipin levels, including during resolution of inflammation and long-term recovery from disease. Sex, genetic variation, exposure to air pollution and chemicals found in food packaging and household and personal care products, as well as many pharmaceuticals used to treat health conditions also affect oxylipin levels.

SUMMARY

Experimental sources of oxylipin variability can be minimized with proper analytical procedures and protocol standardization. Fully characterizing study parameters will help delineate biological factors of variability, which are rich sources of information that can be used to probe oxylipin mechanisms of action and to investigate their roles in health.

YY1 was indispensable for the alleviation of quercetin on diabetic nephropathy-associated tubulointerstitial inflammation

BACKGROUND

The emergence of tubulointerstitial inflammation (TI) could accelerate the development of tubulointerstitial fibrosis (TIF) of diabetic nephropathy (DN). Yin Yang 1 (YY1) was a new pro-inflammatory mediator and became the important target of DN-related TIF. Quercetin performed an effective role in anti-inflammation and was probable to bind to YY1. However, the role of YY1 in quercetin's anti-inflammatory effect on DN-related TIF was uncovered.

PURPOSE

To investigate the potential effect and mechanism of quercetin against DN-related TI.

STUDY DESIGN AND METHODS

The protein levels of YY1 were examined in the renal tubular epithelial cells (RTECs) of db/db mice and HG-cultured HK-2 cells. Molecular modeling studies and YY1 overexpression lentivirus vector were selected to further confirm the indispensable part of YY1 in quercetin's TI protection in vitro. Luciferase assay and chromatin immunoprecipitation (ChIP) assay were carried out to identify whether YY1 directly regulated IL-6/STAT3 signaling by binding to the IL-6 promoter in quercetin's TI protection in vitro. At last, the important role of YY1-mediated IL-6/STAT3 signaling in quercetin's TIF protection effect was further identified by using of YY1 overexpression lentivirus vector and IL-6 specific inhibitor tocilizumab.

RESULTS

Along with the alleviated tubulointerstitial injury by quercetin in the RTECs of db/db mice and HK-2 cells stimulated by HG, YY1-mediated IL-6/STAT-3 pathway involved in TI protection of quercetin in vivo and in vitro. Quercetin bound to YY1 and decreased its protein expression, and YY1 directly suppressed IL-6 transcription by bounding to its promoter, resulting in the alleviation of inflammation by inactivating of IL-6/STAT-3 pathway in vitro. YY1-mediated IL-6/STAT-3 pathway was also indispensable for the alleviation of quercetin on DN-associated TIF.

CONCLUSION

YY1 could not be absent from quercetin's anti-inflammatory effect on DN-associated TIF via alleviating IL-6/STAT-3 pathway mediated TI.

Pathogenesis of Chronic Kidney Disease Is Closely Bound up with Alzheimer's Disease, Especially via the Renin-Angiotensin System

Chronic kidney disease (CKD) is a clinical syndrome secondary to the definitive change in function and structure of the kidney, which is characterized by its irreversibility and slow and progressive evolution. Alzheimer's disease (AD) is characterized by the extracellular accumulation of misfolded β-amyloid (Aβ) proteins into senile plaques and the formation of neurofibrillary tangles (NFTs) containing hyperphosphorylated tau. In the aging population, CKD and AD are growing problems. CKD patients are prone to cognitive decline and AD. However, the connection between CKD and AD is still unclear. In this review, we take the lead in showing that the development of the pathophysiology of CKD may also cause or exacerbate AD, especially the renin-angiotensin system (RAS). In vivo studies had already shown that the increased expression of angiotensin-converting enzyme (ACE) produces a positive effect in aggravating AD, but ACE inhibitors (ACEIs) have protective effects against AD. Among the possible association of risk factors in CKD and AD, we mainly discuss the RAS in the systemic circulation and the brain.

Eicosanoids and other oxylipins in liver injury, inflammation and liver cancer development

Liver cancer is a malignancy developed from underlying liver disease that encompasses liver injury and metabolic disorders. The progression from these underlying liver disease to cancer is accompanied by chronic inflammatory conditions in which liver macrophages play important roles in orchestrating the inflammatory response. During this process, bioactive lipids produced by hepatocytes and macrophages mediate the inflammatory responses by acting as pro-inflammatory factors, as well as, playing roles in the resolution of inflammation conditions. Here, we review the literature discussing the roles of bioactive lipids in acute and chronic hepatic inflammation and progression to cancer.