Uremic Toxins Research Articles

Simultaneous removal of endotoxins, inflammatory mediators and uremic toxins in ICU patients with septic shock: a retrospective cohort study

Sepsis, one of the leading causes of death, is still lacking specific treatment. OXIRIS (BAXTER, Deerfield, IL, USA) is the first device allowing combined removal of endotoxins, inflammatory mediators and uremic toxins, alongside fluid balance control. Available data is very limited. This retrospective propensity score-matched cohort study of adult patients with septic shock aimed to evaluate septic shock duration and mortality in patients treated with either standard of care renal replacement therapy (RRT) or RRT with combined hemoadsorption, who were admitted to the interdisciplinary surgical intensive care unit at Heidelberg University Hospital during the years 2018 through 2021. Main outcomes were duration of shock, thirty-day mortality and plasma interleukin-6 levels before and after initiation of hemoadsorption. Included were 117 patients (female, 33%; male 67%); median age: 67 (16) years. After matching: 42 patients (female, 33%; male, 67%); mean age: 59.1 ± 13.8 years. There was no statistically significant difference in septic shock duration (p = 0.94; hazard ratio (HR) 0.97 (95% CI, 0.48–1.97)). Thirty-day survival analysis showed a non-statistically significant survival difference. (p = 0.063; HR 0.43 (95% CI, 0.17–1.09)). A post-hoc 90-day survival analysis revealed statistically significant longer survival and lower death hazard ratio in patients treated with RRT + HA (p = 0.037; HR = 0.42 (95% CI, 0.18–0.99). In conclusion, RRT with combined hemoadsorption of endotoxins, inflammatory mediators and uremic toxins is a modality worth further investigation.

The Effect of Renaltec on Serum Uremic Toxins in Cats with Experimentally Induced Chronic Kidney Disease.

Serum uremic toxins markedly increase in cats with chronic kidney disease (CKD) and have deleterious consequences. Renaltec is an oral adsorbent that binds uremic toxin precursors in the gut. In this prospective cohort study utilizing 13 purpose-bred cats with remnant kidney model-induced CKD (12 IRIS Stage 2, 1 IRIS Stage 3) eating a standardized renal diet, we aimed to assess the effect of Renaltec administration on serum indoxyl sulfate (IDS) and p-cresol sulfate (pCS) concentrations. Cats were sequentially treated with standard of care for 56 days, 500 mg Renaltec orally once daily for 56 days, and then three months later, 500 mg Renaltec orally twice daily for 56 days. Serum IDS and pCS concentrations were measured 28 and 56 days after the administration of Renaltec. Blood pressure and kidney function were measured before and 56 days after the administration of Renaltec. Significant decreases in serum IDS and pCS concentrations were observed for both once- and twice-daily dosing, particularly during the first 28 days of administration. More cats with BID dosing had clinically significant reductions in serum IDS and pCS concentrations than with SID dosing. Renaltec can reduce the serum concentrations of deleterious gut-derived uremic toxins in cats with CKD.

Vascular endothelial dysfunction improvements in patients with uraemia using pentoxifylline-suppressing NLRP3 expressions and HMGB1 release.

This study aimed to investigate the protective effect of pentoxifylline (PTX) on vascular endothelial dysfunction in uraemia. The human aortic endothelial cells (HAECs) required for the experiments were all obtained from the National Collection of Authenticated Cell Cultures (Salisbury, UK). The permeability of HAECs was assessed. Each group had six samples. Compared with the healthy volunteer group, HAEC proliferation in the 20% uraemia group was significantly inhibited after 72 h (p < 0.001), co-localisation of nucleotide-binding domain, leucine-rich repeat-containing receptor family pyrin domain-containing 3 (NLRP3) and apoptosis-associated speck-like (ASC) protein induced by uremic serum was enhanced (p < 0.01) and high mobility group box 1 (HMGB1) release was increased (0.594 ± 0.057, p = 0.03). The co-immunoprecipitation of NLRP3, ASC and HMGB1 induced by uremic toxin was also enhanced (p < 0.01), and PTX inhibited this phenomenon. The expression of NLRP3 (0.810 ± 0.032, p = 0.02) and caspase-1 (0.580 ± 0.041, p = 0.03) was increased, whereas the expression of ZO-1 (0.255 ± 0.038, p = 0.03) and VE-cadherin (0.0546 ± 0.053, p = 0.02) was decreased in the uraemia group; compared with the healthy volunteer group, treated with PTX (NLRP3, 0.298 ± 0.042, p = 0.03; caspase-1, 0.310 ± 0.021, p = 0.03; ZO-1, 0.412 ± 0.028, p = 0.02; VE-cadherin, 0.150 ± 0.034, p = 0.02) and MCC950 (NLRP3, 0.432 ± 0.022, p = 0.03; caspase-1, 0.067 ± 0.031, p > 0.05; ZO-1, 0.457 ± 0.026, p = 0.03; VE-cadherin, 0.286 ± 0.017, p = 0.03) lessened this trend. Pentoxifylline promoted the HAEC permeability mediated by uremic toxins (1.507 ± 0.012, p = 0.02). In conclusion, PTX enhances the release of HMGB1, which is dependent on NLRP3 activation, and consequently exerts positive effects on interconnecting proteins, ultimately leading to an improvement in vascular permeability.

Indole-3-acetic acid exposure leads to cardiovascular inflammation and fibrosis in chronic kidney disease rat model

Indole-3-acetic acid (IAA), a protein-bound uremic toxin, has been linked to cardiovascular morbidity and mortality in chronic kidney disease (CKD) patients. This study explores the influence of IAA (125 mg/kg) on cardiovascular changes in adenine sulfate-induced CKD rats. HPLC analysis revealed that IAA-exposed CKD rats had lower excretion and increased circulation of IAA compared to both CKD and IAA control groups. Moreover, echocardiography indicated that CKD rats exposed to IAA exhibited heart enlargement, thickening of the myocardium, and cardiac hypertrophy in contrast to CKD or IAA control group. Biochemical analyses supported the finding that IAA-induced CKD rats had elevated serum levels of c-Tn-I, CK-MB, and LDH; there was also evidence of oxidative stress in cardiac tissues, with a significant decrease in SOD and CAT levels, as well as an increase in MDA levels. The gene expression analysis found significant increases in ANP, BNP, β-MHC, TNF-α, IL-1β, and NF-κB levels in IAA-exposed CKD groups in contrast to the CKD or IAA control group. In addition, higher cardiac fibrosis markers, including Col-I and Col-III. The findings of this study indicate that IAA could trigger cardiovascular inflammation and fibrosis in CKD conditions.

Indoxyl Sulfate Inhibits Osteogenesis in Bone Marrow Mesenchymal Stem Cells through the AhR/Hes1 Pathway.

Uremic toxins cause bone disorders in patients with chronic kidney disease (CKD). These disorders are characterized by low turnover osteodystrophy and impaired bone formation in the early stages of CKD. Evidence indicates that the aryl hydrocarbon receptor (AhR) mediates signals that suppress early osteogenic differentiation in bone marrow mesenchymal stem cells (BMSCs). However, whether the AhR mediates the effects of indoxyl sulfate (IS), a uremic toxin, on BMSC osteogenesis remains unclear. We investigated whether IS affects osteogenesis through the AhR/Hes1 pathway. Expression levels of osteogenesis genes (Runx2, Bmp2, Alp, and Oc), AhR, and Hes1 were measured in mouse BMSCs (D1 cells). At concentrations of 2-50 μM, IS significantly reduced mineralization, particularly in the early stages of BMSC osteogenesis. Furthermore, IS significantly downregulated the expression of Runx2, Bmp2, Oc, and Alp. Notably, this downregulation could be prevented using an AhR antagonist and through Ahr knockdown. Mechanistically, IS induced the expression of Hes1 through AhR signaling, thereby suppressing the transcription of Runx2 and Bmp2. Our findings suggest that IS inhibits early osteogenesis of BMSCs through the AhR/Hes1 pathway, thus suppressing the transcription of Runx2 and Bmp2. Our findings may guide new therapeutic strategies against CKD-related bone disorders.

Gut Microbiome Is Related to Cognitive Impairment in Peritoneal Dialysis Patients.

Gut microbiota disturbances may influence cognitive function, increasing uremic toxins and inflammation in dialysis patients; therefore, we aimed to evaluate the association of the gut microbiota profile with cognitive impairment (CI) in patients on automated peritoneal dialysis (APD). In a cross-sectional study, cognitive function was evaluated using the Montreal Cognitive Assessment in 39 APD patients and classified as normal cognitive function and CI. The gut microbiota was analyzed using the 16S rRNA gene sequencing approach. All patients had clinical, biochemical and urea clearance evaluations. Eighty-two percent of patients were men, with a mean age of 47 ± 24 years and 11 (7-48) months on PD therapy; 64% had mild CI. Patients with CI were older (53 ± 16 vs. 38 ± 14, p = 0.006) and had a higher frequency of diabetes mellitus (56% vs. 21%, p = 0.04) and constipation (7% vs. 48%, p = 0.04) and lower creatinine concentrations (11.3 ± 3.7 vs. 14.9 ± 5.4, p = 0.02) compared to normal cognitive function patients. Patients with CI showed a preponderance of S24_7, Rikenellaceae, Odoribacteraceae, Odoribacter and Anaerotruncus, while patients without CI had a greater abundance of Dorea, Ruminococcus, Sutterella and Fusobacteria (LDA score (Log10) > 2.5; p < 0.05). After glucose and age adjustment, Odoribacter was still associated with CI. In conclusion, patients with CI had a different gut microbiota characterized by the higher abundance of indole-producing and mucin-fermenting bacteria compared to normal cognitive function patients.

The impact of chronic kidney disease on cognitive function.

The risk of cognitive impairment is higher in people with CKD than in the general population. The complex relationship between CKD and cognitive dysfunction has not been extensively characterized. Here, we review epidemiological associations, specific patterns of CKD-related cognitive impairment, the underlying mechanisms, and recently published data on relevant biomarkers. Despite some discrepancies, recent published studies have confirmed that CKD is associated with cognitive function (e.g. incident cognitive events). Although patients with CKD often exhibit impairments in executive functions and attention, it is noteworthy that other cognitive functions (e.g. memory) can be preserved. The key mechanisms described recently include vascular damage, genetic factors, the accumulation of uremic toxins, disruption of the blood-brain barrier, glymphatic system dysfunction, and changes in the gut-brain axis. Kidney function is increasingly seen as a game changer in the interpretation of biomarkers of cognitive impairment and, especially, hallmarks of Alzheimer disease. The data reviewed here highlight the need for interdisciplinary collaboration between nephrologists and neurologists in the care of patients with CKD at risk of cognitive impairment. In order to further improving diagnosis and therapy, future research must elucidate the mechanisms underlying the CKD-cognitive impairment association and confirm the value of biomarkers.

Adsorption Dynamics of Uremic Toxins to Cyclodextrin-Coated Magnetic Nano-Adsorbents

Chronic kidney disease entails a progressive decline in kidney function, hindering the kidneys' ability to excrete fluid, electrolytes, and metabolites. This dysfunction leads to metabolite accumulation in the bloodstream, which can reach toxic concentrations. Hemodialysis is an effective means of treating patients with kidney failure, but it does not clear all toxins effectively. Engineered nano-adsorbents can potentially improve the removal of retained toxins, particularly protein-bound types. Magnetic nanoparticles coated with α-, β-, and γ-cyclodextrin were synthesized, and physicochemical properties were characterized using thermogravimetric analysis, transmission electron microscopy, dynamic light scattering, and ζ-potential for their physiochemical properties. The effect of surface chemistry and incubation time on toxin adsorption was investigated using quantitative mass spectrometry techniques. All particle types demonstrated toxin adsorption to some level. Overall, the adsorption process was independent of metabolite concentration, suggesting a dynamic interplay between surface properties and solution composition. This insight will contribute to developing innovative adsorbent films designed to remove uremic toxins effectively.

Assessment of Within- and Inter-Patient Variability of Uremic Toxin Concentrations in Children with CKD.

To promote improved trial design in upcoming randomized clinical trials in childhood chronic kidney disease (CKD), insight in the within- and inter-patient variability of uremic toxins with its nutritional, treatment- and patient-related confounding factors is of utmost importance. In this study, the within- and inter-patient variability of a selection of uremic toxins in a longitudinal cohort of children diagnosed with CKD was assessed, using the intraclass correlation coefficient (ICC) and the within-patient coefficient of variation (CV). Subsequently, the contribution of anthropometry, estimated glomerular filtration rate (eGFR), dietary fiber and protein, and use of (prophylactic) antibiotics to uremic toxin variability was evaluated. Based on 403 observations from 62 children (median seven visits per patient; 9.4 ± 5.3 years; 68% males; eGFR 38.5 [23.1; 64.0] mL/min/1.73 m2) collected over a maximum of 2 years, we found that the within-patient variability is high for especially protein-bound uremic toxins (PBUTs) (ICC < 0.7; within-patient CV 37-67%). Moreover, eGFR was identified as a predominant contributor to the within- and inter-patient variability for the majority of solutes, while the impact of the child's anthropometry, fiber and protein intake, and antibiotics on the variability of uremic toxin concentrations was limited. Based on these findings, we would recommend future intervention studies that attempt to decrease uremic toxin levels to select a (non-dialysis) CKD study population with a narrow eGFR range. As the expected effect of the selected intervention should exceed the inter-patient variability of the selected uremic toxins, a narrow eGFR range might aid in improving the trial design.

Non-dialyzable uremic toxins and renal tubular cell damage in CKD patients: a systems biology approach

BackgroundChronic kidney disease presents global health challenges, with hemodialysis as a common treatment. However, non-dialyzable uremic toxins demand further investigation for new therapeutic approaches. Renal tubular cells require scrutiny due to their vulnerability to uremic toxins.MethodsIn this study, a systems biology approach utilized transcriptomics data from healthy renal tubular cells exposed to healthy and post-dialysis uremic plasma.ResultsDifferential gene expression analysis identified 983 up-regulated genes, including 70 essential proteins in the protein–protein interaction network. Modularity-based clustering revealed six clusters of essential proteins associated with 11 pathological pathways activated in response to non-dialyzable uremic toxins.ConclusionsNotably, WNT1/11, AGT, FGF4/17/22, LMX1B, GATA4, and CXCL12 emerged as promising targets for further exploration in renal tubular pathology related to non-dialyzable uremic toxins. Understanding the molecular players and pathways linked to renal tubular dysfunction opens avenues for novel therapeutic interventions and improved clinical management of chronic kidney disease and its complications.

The microbial metabolite p-cresol compromises the vascular barrier and induces endothelial cytotoxicity and inflammation in a 3D human vessel-on-a-chip

Increased protein-bound uremic toxins (PBUTs) in patients with chronic kidney disease (CKD) are associated with cardiovascular diseases (CVDs); however, whether retention of PBUTs causes CVD remains unclear. Previous studies assessing the impacts of PBUTs on the vasculature have relied on 2D cell cultures lacking in vivo microenvironments. Here, we investigated the impact of various PBUTs (p-cresol (PC), indoxyl sulfate (IS), and p-cresyl sulfate (PCS)) on microvascular function using an organ-on-a-chip (OOC). Human umbilical vein endothelial cells were used to develop 3D vessels. Chronic exposure to PC resulted in significant vascular leakage compared with controls, whereas IS or PCS treatment did not alter the permeability of 3D vessels. Increased permeability induced by PC was correlated with derangement of cell adherens junction complex, vascular endothelial (VE)-cadherin and filamentous (F)-actin. Additionally, PC decreased endothelial viability in a concentration-dependent manner with a lower IC50 in 3D vessels than in 2D cultures. IS slightly decreased cell viability, while PCS did not affect viability. PC induced inflammatory responses by increasing monocyte adhesion to endothelial surfaces of 3D vessels and IL-6 production. In conclusion, this study leveraged an OOC to determine the diverse effects of PBUTs, demonstrating that PC accumulation is detrimental to ECs during kidney insufficiency.

A Systematic Review of Uremic Toxin Concentrations and Cardiovascular Risk Markers in Pediatric Chronic Kidney Disease.

Chronic kidney disease (CKD) can lead to cardiac dysfunction in a condition known as cardiorenal syndrome (CRS). It is postulated that the accumulation of uremic toxins in the bloodstream, as a consequence of declining kidney function, may contribute to these adverse cardiac effects. While CRS in adults has been extensively studied, there is a significant knowledge gap with pediatric patients. Uremic toxin levels in children remain inadequately characterized and quantified compared to adults. This review aims to systematically evaluate the association between uremic toxin concentrations and cardiac changes in pediatric CRS and to examine the impact of different dialysis modalities, specifically hemodialysis and peritoneal dialysis, on uremic toxin clearance and cardiovascular parameters. To address this, we conducted a systematic literature search of PubMed, following PRISMA guidelines. We used the terms "uremic toxins" and "cardiorenal syndrome" with variations in syntax to search for studies discussing the relationship between uremic toxin levels in CKD, the subsequent impact on cardiac parameters, and the emergence of cardiac dysfunction. Full-text articles written in English, conducted on humans aged from birth to 18 years, and published until December 2021 were included. A comprehensive literature search yielded six studies, and their risk of bias was assessed using JBI Critical Appraisal Checklists. Our systematic review is registered on PROSPERO, number CRD42023460072. This synthesis intends to provide an understanding of the role of uremic toxins in pediatric CRS. The findings reveal that pediatric patients with end-stage CKD on dialysis exhibit elevated uremic toxin levels, which are significantly associated with cardiovascular disease parameters. Additionally, the severity of CKD correlated with higher uremic toxin levels. No conclusive evidence was found to support the superiority of either hemodialysis or peritoneal dialysis in terms of uremic toxin clearance or cardiovascular outcomes. More pediatric-specific standardized and longitudinal studies are needed to develop targeted treatments and improve clinical outcomes and the quality of life for affected children.

A case report of hemodialysis management of acute kidney injury in a Russell’s viper-envenomed dog

A four-year-old Russell’s viper-envenomed dog presented with severe azotemia and was diagnosed with acute kidney injury (AKI). Russell’s viper envenomation-induced AKI is highly fatal and medical treatment alone was insufficient. In the current case, intermittent hemodialysis (IHD) was implemented and was found to be highly efficient in removing uremic toxins from the bloodstream of the envenomed dog. After two dialysis sessions, the patient’s renal function levels were markedly improved and clinical signs at presentation were resolved. This case report describes the medical treatment and detailed guidelines for the management of IHD in a Russell’s viper-envenomed AKI dog for veterinarians who consider IHD a suitable therapy option for their patients.

Plant-based diets for kidney disease prevention and treatment.

Plant-based diets are associated with a lower risk of hypertension, diabetes, cardiovascular disease, and mortality. Using the most recent evidence, we critically appraised the role of plant-based diets in primary and secondary prevention of chronic kidney disease (CKD) with a focus on key nutritional factors (dietary acid load, phosphorus, potassium, sodium, and fiber). In healthy individuals, observational studies found that greater intake of plant protein and higher adherence to plant-based diets (overall, healthful, and provegetarian) was associated with a lower risk of CKD. In those with CKD, plant-based diets were associated with a lower risk of mortality, improved kidney function, and favorable metabolic profiles (fibroblast growth factor-23, uremic toxins, insulin sensitivity, inflammatory biomarkers). Only few studies reported nutrient content of plant-based diets. These studies found that plant-based diets had lower dietary acid load, lower or no significant difference in phosphorus and sodium, and higher potassium and fiber. One study reported that vegetarian diets were associated with severe vitamin D deficiency compared to nonvegetarian diets. Plant-based diets provide several benefits for prevention and management of CKD, with little risk for individuals with CKD. Incorporation of vitamin D rich foods in plant-based diets may be helpful.

Efficacy of probiotics/synbiotics supplementation in patients with chronic kidney disease: a systematic review and meta-analysis of randomized controlled trials.

Chronic kidney disease (CKD) is a serious and steadily growing health problem worldwide. Probiotic and synbiotic supplementation are expected to improve kidney function in CKD patients by altering imbalanced intestinal flora, regulating microbiota metabolites, modulating the brain-gut axis, and reducing inflammation. Our aim is to report the latest and largest pooled analyses and evidence updates to explore whether probiotic and synbiotic have beneficial effects on renal function and general conditions in patients with CKD. We conducted a systematic literature search using PubMed, Embase, Web of Science, and the Cochrane Central Register of Controlled Trials from inception until 1 December 2023. Eligible literatures were screened according to inclusion and exclusion criteria, data were extracted, and a systematic review and meta-analysis was performed. Measurements included renal function-related markers, inflammatory markers, uremic toxins, lipid metabolism-related markers and electrolytes levels. Twenty-one studies were included. The results showed that probiotic/synbiotic significantly reduced blood urea nitrogen (BUN) (standardized mean difference (SMD), -0.23, 95% confidence interval (CI) -0.41, -0.04; p = 0.02, I2 = 10%) and lowered c-reactive protein level (CRP) (SMD: -0.34; 95% CI: -0.62, -0.07; p = 0.01, I2 = 37%) in CKD patients, compared with the control group. In summary, probiotic/synbiotic supplementation seems to be effective in improving renal function indices and inflammation indices in CKD patients. Subgroup analyses suggested that longer-term supplementation is more favorable for CKD patients, but there is a high degree of heterogeneity in the results of partial subgroup analyses. The efficacy of probiotic/synbiotic in treating CKD needs to be supported by more evidence from large-scale clinical studies. https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42024526836, Unique identifier: CRD42024526836.

Analysis of the microecological mechanism of diabetic kidney disease based on the theory of "gut-kidney axis": A systematic review.

Diabetic kidney disease (DKD) is one of the main microvascular complications of diabetes mellitus, as well as the leading cause of end-stage renal disease. Intestinal microbiota has emerged as a crucial regulator of its occurrence and development. Dysbiosis of the intestinal microbiota can disrupt the intestinal mucosal barrier, abnormal immunological response, reduction in short-chain fatty acid metabolites, and elevation of uremic toxins, all closely related to the occurrence and development of DKD. However, the underlying mechanisms of how intestinal microbiota and its metabolites influence the onset and progression of DKD has not been fully elucidated. In the current review, we will try to summarize the microecological mechanism of DKD by focusing on three aspects: the intestinal microbiota and its associated metabolites, and the "gut-kidney axis," and try to summarize therapies targeted at managing the intestinal microbiota, expecting to provide theoretical basis for the subsequent study of the relationship between intestinal homeostasis and DKD, and will open an emerging perspective and orientation for DKD treatment.

Luteolin Inhibits Indoxyl Sulfate-Induced ICAM-1 and MCP-1 Expression by Inducing HO-1 Expression in EA.hy926 Human Endothelial Cells.

In patients with chronic kidney disease, the uremic toxin indoxyl sulfate (IS) accelerates kidney damage and the progression of cardiovascular disease. IS may contribute to vascular diseases by inducing inflammation in endothelial cells. Luteolin has documented antioxidant and anti-inflammatory properties. This study aimed to investigate the effect of luteolin on IS-mediated reactive oxygen species (ROS) production and intercellular adhesion molecule (ICAM-1) and monocyte chemoattractant protein (MCP-1) expression in EA.hy926 cells and the possible mechanisms involved. IS significantly induced ROS production (by 6.03-fold, p < 0.05), ICAM-1 (by 2.19-fold, p < 0.05) and MCP-1 protein expression (by 2.18-fold, p < 0.05), and HL-60 cell adhesion (by 31%, p < 0.05), whereas, luteolin significantly decreased IS-induced ROS production, ICAM-1 and MCP-1 protein expression, and HL-60 cell adhesion. Moreover, luteolin attenuated IS-induced nuclear accumulation of p65 and c-jun. Luteolin dose-dependently increased heme oxygenase-1 (HO-1) expression and the maximum fold induction of HO-1 by luteolin was 3.68-fold (p < 0.05), whereas, HO-1 knockdown abolished the suppression of ICAM-1 and MCP-1 expression by luteolin. Luteolin may protect against IS-induced vessel damage by inducing HO-1 expression in vascular endothelial cells, which suppresses nuclear factor kappa B (NF-κB) and activator protein 1 (AP-1) mediated ICAM-1 and MCP-1 expression.

Cannabinoid receptor 2 plays a key role in renal fibrosis through inhibiting lipid metabolism in renal tubular cells

AimsRenal fibrosis is a common feature in various chronic kidney diseases (CKD). Tubular cell damage is a main characterization which results from dysregulated fatty acid oxidation (FAO) and lipid accumulation. Cannabinoid Receptor 2 (CB2) contributes to renal fibrosis, however, its role in FAO dysregulation in tubular cells is not clarified. In this study, we found CB2 plays a detrimental role in lipid metabolism in tubular cells. MethodsCB2 knockout mice were adopted to establish a folic acid-induced nephropathy (FAN) model. CB2-induced FAO dysfunction, lipid deposition, and fibrogenesis were assessed in vivo and vitro. To explore molecular mechanisms, β-catenin inhibitors and peroxisome proliferator-activated receptor alpha (PPARα) activators were also used in CB2-overexpressed cells. The mediative role of β-catenin in CB2-inhibited PPARα and peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) activation was analyzed. ResultsCB2 activates β-catenin signaling, resulting in the suppression of PPARα/PGC-1α axis. This decreased FAO functions and led to lipid droplet formation in tubular cells. CB2 gene ablation effectively mitigated FAO dysfunction, lipid deposition and uremic toxins accumulation in FAN mice, consequently retarding renal fibrosis. Additionally, inhibition to β-catenin or PPARα activation could greatly inhibit lipid accumulation and fibrogenesis induced by CB2. ConclusionsThis study highlights CB2 disrupts FAO in tubular cells through β-catenin activation and subsequent inhibition on PPARα/PGC-1α activity. Targeted inhibition on CB2 offers a perspective therapeutic strategy to fight against renal fibrosis.

Total Determination of Nine Uremic Toxins and Choline in Blood Serum by High-Performance Liquid Chromatography with Tandem Mass Spectrometry Detection

Total Determination of Nine Uremic Toxins and Choline in Blood Serum by High-Performance Liquid Chromatography with Tandem Mass Spectrometry Detection

Relationship Between Arterial Stiffness, Measured by Cardio-Ankle Vascular Index, and Uremic Toxins, Vascular Calcification, and Inflammation Markers After Kidney Donation.

This study investigated whether kidney transplant donors experience increased arterial stiffness compared with the general population and how arterial stiffness changes over time. Our study included 59 kidney transplant donors and 27 healthy volunteers. All subjects underwent cardio-ankle vascular index measurements. We studied fibroblast growth factor23, klotho, monocyte chemoattractant protein-1, N-terminal pro-B-type natriuretic peptide, indoxyl sulfate, and p-cresyl sulfate levels. Cardio-ankle vascular index level was higher in donors 6 to 11 years after donation (8.02 ± 0.24 m/s) than in donors 2 to 6 years after donation (7.02 ± 0.27 m/s) and healthy volunteers (6.65 ± 0.22 m/s). Cardioankle vascular index level was positively correlated with age (r = 0.382, P < .001) and levels of triglyceride (r = 0.213, P = .049), blood urea nitrogen (r = 0.263, P = .014), creatinine (r = 0.354, P = .001), calcium (r = 0.228, P = .035), indoxyl sulfate (r = 0.219, P = .042), p-cresyl sulfate (r = 0.676, P ≤ .001), and monocyte chemoattractant protein-1 (r = 0.451, P ≤ .001) and negatively correlated with estimated glomerular filtration rate (r = -0.383, P < .001). Multiple linear regression analysis revealed that age (P = .026, B = 0.244), mean arterial blood pressure (P < .001, B = 0.446), blood urea nitrogen (P = .006, B = 0.302), creatinine (P = .032, B = 0.236), estimated glomerular filtration rate (P = .003, B = -0.323), fibroblast growth factor-23 (P = .007, B = 0.294), N-terminal pro-B-type natriuretic peptide (P = .005, B = 0.304), and monocyte chemoattractant protein-1 (P ≤ .001, B = 0.434) independently predicted cardio-ankle vascular index levels. Even without additional risk factors, kidney donors should be followed closely for arterial stiffness and cardiovascular disease, especially in the long-term (>5 years) after kidney transplant.