A widely distributed gene cluster compensates for uricase loss in hominids.

Approximately 15% of US adults have circulating levels of uric acid above its solubility limit, which is causally linked to the disease gout. In most mammals, uric acid elimination is facilitated by the enzyme uricase. However, human uricase is a pseudogene, having been inactivated early in hominid evolution. Though it has long been known that uric acid is eliminated in the gut, the role of the gut microbiota in hyperuricemia has not been studied. Here, we identify a widely distributed bacterial gene cluster that encodes a pathway for uric acid degradation. Stable isotope tracing demonstrates that gut bacteria metabolize uric acid to xanthine or short chain fatty acids. Ablation of the microbiota in uricase-deficient mice causes severe hyperuricemia, and anaerobe-targeted antibiotics increase the risk of gout in humans. These data reveal a role for the gut microbiota in uric acid excretion and highlight the potential for microbiome-targeted therapeutics in hyperuricemia.

WWC1 upregulation accelerates hyperuricemia by reduction in renal uric acid excretion through Hippo signaling pathway.

Hyperuricemia (HUA) is a metabolic disorder characterized by elevated serum uric acid (UA), primarily attributed to the hepatic overproduction and renal underexcretion of UA. Despite the elucidation of molecular pathways associated with this underexcretion, the etiology of HUA remains largely unknown. In our study, using by Uox knockout rats, HUA mouse, and cell line models, we discovered that the increased WWC1 levels were associated with decreased renal UA excretion. Additionally, using knockdown and overexpression approaches, we found that WWC1 inhibited UA excretion in renal tubular epithelial cells. Mechanistically, WWC1 activated the Hippo pathway, leading to phosphorylation and subsequent degradation of the downstream transcription factor YAP1, thereby impairing the ABCG2 and OAT3 expression through transcriptional regulation. Consequently, this reduction led to a decrease in UA excretion in renal tubular epithelial cells. In conclusion, our study has elucidated the role of upregulated WWC1 in renal tubular epithelial cells inhibiting the excretion of UA in the kidneys and causing HUA.

Current updates for hyperuricemia and gout in age-related macular degeneration.

The escalating prevalence of metabolic syndrome poses a significant public health challenge, particularly among aging populations, with metabolic dysfunctions contributing to pro-inflammatory states. In this review, we delved into the less recognized association between hyperuricemia (HUA), a manifestation of metabolic syndrome and a primary risk factor for gout, and age-related macular degeneration (AMD), a sight-threatening ailment predominantly affecting the elderly. In recent years, inflammation, particularly its involvement in complement pathway dysregulation, has gained prominence in AMD pathophysiology. The contradictory role of uric acid (UA) in intercellular and intracellular environments was discussed, highlighting its antioxidant properties in plasma and its pro-oxidant effects intracellularly. Emerging evidence suggests a potential link between elevated serum uric acid levels and choroid neovascularization in AMD, providing insights into the role of HUA in retinal pathologies. Various pathways, including crystal-induced and non-crystal-induced mechanisms, were proposed to indicate the need for further research into the precise molecular interactions. The implication of HUA in AMD underscores its potential involvement in retinal pathologies, which entails interdisciplinary collaboration for a comprehensive understanding of its impact on retina and related clinical manifestations.

Crystal Facet Controlled Metal-Support Interaction in Uricase Mimics for Highly Efficient Hyperuricemia Treatment.

The effect of strong metal-support interaction (SMSI) has never been systematically studied in the field of nanozyme-based catalysis before. Herein, by coupling two different Pd crystal facets with MnO2, i.e., (100) by Pd cube (Pdc) and (111) by Pd icosahedron (Pdi), we observed the reconstruction of Pd atomic structure within the Pd-MnO2 interface, with the reconstructed Pdc (100) facet more disordered than Pdi (111), verifying the existence of SMSI in such coupled system. The rearranged Pd atoms in the interface resulted in enhanced uricase-like catalytic activity, with Pdc@MnO2 demonstrating the best catalytic performance. Theoretical calculations suggested that a more disordered Pd interface led to stronger interactions with intermediates during the uricolytic process. In vitro cell experiments and in vivo therapy results demonstrated excellent biocompatibility, therapeutic effect, and biosafety for their potential hyperuricemia treatment. Our work provides a brand-new perspective for the design of highly efficient uricase-mimic catalysts.

Linoleyl acetate and mandenol alleviate HUA-induced ED via NLRP3 inflammasome and JAK2/STAT3 signalling conduction in rats.

Hyperuricemia (HUA) is characterized by elevated blood uric acid levels, which can increase the risk of erectile dysfunction (ED). Clinical studies have demonstrated satisfactory efficacy of a traditional Chinese medicine formula QYHT decoction in improving ED. Furthermore, the main monomeric components of this formula, linoleyl acetate and mandenol, demonstrate promise in the treatment of ED. This study established an ED rat model induced by HUA and the animals were administered with linoleyl acetate and mandenol. HE and TUNEL were performed to detect tissue changes, ELISA to measure the levels of serum testosterone (T), MDA, NO, CRP, and TNF-α and qPCR and WB to assess the expression levels of NLRP3, ASC, Caspase-1, JAK2, and STAT3 in whole blood. The findings showed that linoleyl acetate and mandenol improved kidney tissue morphology, reduced cell apoptosis in penile tissue, significantly increased T and NO levels, while substantially decreasing levels of MDA, CRP, and TNF-α. Meanwhile, the expression of NLRP3, ASC, and Caspase-1 mRNAs and proteins was markedly reduced, and the phosphorylation of JAK2 and STAT3 was inhibited. These findings were further validated through faecal microbiota transplantation results. Taken together, linoleyl acetate and mandenol could inhibit NLRP3 inflammasome activation, reduce inflammatory and oxidative stress responses, suppress the activity of JAK-STAT signalling pathway, ultimately providing a potential treatment for HUA-induced ED.

Downregulation of type I interferon signalling pathway by urate in primary human PBMCs.

Type I interferons (IFN1s) mediate innate responses to microbial stimuli and regulate interleukin (IL)-1 and IL-1 receptor antagonist (Ra) production in human cells. This study explores interferon-stimulated gene (ISG) alterations in the transcriptome of patients with gout and stimulated human primary cells in vitro in relation to serum urate concentrations. Peripheral blood mononuclear cells (PBMCs) and monocytes of patients with gout were primed in vitro with soluble urate, followed by lipopolysaccharide (LPS) stimulation. Separately, PBMCs were stimulated with various toll-like receptor (TLR) ligands. RNA sequencing and IL-1Ra cytokine measurement were performed. STAT1 phosphorylation was assessed in urate-treated monocytes. Cytokine responses to IFN-ß were evaluated in PBMCs cultured with or without urate and restimulated with LPS and monosodium urate (MSU) crystals. Transcriptomics revealed suppressed IFN-related signalling pathways in urate-exposed PBMCs or monocytes which was supported by diminishment of phosphorylated STAT1. The stimulation of PBMCs with IFN-ß did not modify the urate-induced inflammation. Interestingly, in vivo, serum urate concentrations were inversely correlated to in vitro ISG expression upon stimulations with TLR ligands. These findings support a deficient IFN1 signalling in the presence of elevated serum urate concentrations, which could translate to increased susceptibility to infections.

Retinol dehydrogenase 12 (RDH12) knock out may cause hyperuricemia phenotype in mice.

Hyperuricemia is a chronic metabolic disease caused by purine metabolism disorder. And several gene loci and transporter proteins that associated with uric acid transport functions have been identified. Retinol Dehydrogenase 12 (RDH12), recognized for its role in safeguarding photoreceptors, and our study investigated the potential impact of Rdh12 mutations on other organs and diseases, particularly hyperuricemia. We assessed Rdh12 mRNA expression levels in various tissues and conducted serum biochemical analyses in Rdh12-/- mice. Compared with the wild type, significant alterations in serum uric acid levels and kidney-related biochemical indicators have been revealed. Then further analysis, including quantitative RT-PCR of gene expression in the liver and kidney, highlighted variations in the expression levels of specific genes linked to hyperuricemia. And renal histology assessment exposed mild pathological lesions in the kidneys of Rdh12-/- mice. In summary, our study suggests that Rdh12 mutations impact not only retinal function but also contribute to hyperuricemia and renal disease phenotypes in mice. Our finding implies that individuals with Rdh12 mutations may be prone to hyperuricemia and gout, emphasizing the significance of preventive measures and regular examinations in daily life.

Can uric acid affect the immune microenvironment in bladder cancer? A single-center multi-omics study.

Metabolic abnormalities are one of the important factors in bladder cancer (BCa) progression and microenvironmental disturbance. As an important product of purine metabolism, uric acid's (UA) role in BCa metabolism and immunotherapy remains unclear. In this study, we conducted a retrospective analysis of a cohort comprising 39 BCa patients treated with PD-1 and 169 patients who underwent radical cystectomy at Shanghai Tenth People's Hospital. Kaplan-Meier curves and Cox regression analysis showed that the prognosis of patients with high UA is worse (p = 0.007), and high UA is an independent risk factor for cancer specific survival in patients with BCa (p = 0.025). We established a hyperuricemia mouse model with BCa subcutaneous xenografts in vivo. The results revealed that the subcutaneous tumors of hyperuricemia mice had a greater weight and volume in comparison with the control group. Through flow cytometric analysis, the proportion of CD8+ and CD4+ T cells in these subcutaneous tumors was seen to decline significantly. We also evaluated the relationship of UA and BCa by muti-omic analysis. UA related genes were significantly increased in the CD8+ T cell of non-responders to immunotherapy by single-cell sequencing. An 11-gene UA related signature was constructed and the risk score negatively correlated with various immune cells and immune checkpoints. Finally, a nomogram was established using a UA related signature to forecast the survival rate of patients with BCa. Collectively, this study demonstrated that UA was an independent prognostic biomarker for BCa and was associated with worse immunotherapy response.

Hyperuricemia suppresses lumican, exacerbating adverse remodeling after myocardial infarction by promoting fibroblast phenotype transition.

BACKGROUND: Hyperuricemia is independently associated with a poor prognosis in patients with myocardial infarction (MI). Furthermore, MI induces activation of the repair response in local fibroblasts, resulting in extracellular matrix accumulation that generates a stable fibrotic scar in the infarcted area. However, researchers have not determined whether hyperuricemia affects fibroblast activation and its involvement in postinfarction cardiac remodeling. OBJECTIVES: We aimed to trigger hyperuricemia by administering potassium oxonate in a mouse model of MI to evaluate the role of hyperuricemia in MI pathogenesis. METHODS: Microarray datasets and single-cell sequencing data from gout patients, heart failure patients, and model mice were used to identify the underlying mechanisms responsible for the effect of hyperuricemia on MI progression. A hyperuricemia-related MI mouse model was established. Cardiac function was assessed, followed by sample collection and a uric acid assay. We conducted an enzyme-linked immunosorbent assay, histological detection, immunofluorescence, sequencing data processing, single-cell RNA-seq, and functional enrichment analysis. We then isolated and cultured cardiac fibroblasts and performed Western blotting, quantitative real-time polymerase chain reaction, and shRNA-mediated lumican knockdown assays. RESULTS: Hyperuricemia decreased cardiac function, increased mortality, and aggravated adverse fibrosis remodeling in mice after MI. These outcomes were closely related to reduced levels of fibroblast-derived lumican. This reduction activated the TGF-ß/SMAD signaling pathway to induce aberrant myofibroblast activation and extracellular matrix deposition in the infarcted area. Furthermore, lumican supplementation or uric acid-lowering therapy with allopurinol alleviated hyperuricemia-mediated abnormal cardiac remodeling. CONCLUSION: Hyperuricemia aggravates postinfarction cardiac remodeling by reducing lumican expression and promoting fibroblast phenotype transition. We highlight the clinical importance of lowering uric acid levels in hyperuricemia-related MI to prevent adverse ventricular remodeling.

Gut commensal Parabacteroides distasonis exerts neuroprotective effects in acute ischemic stroke with hyperuricemia via regulating gut microbiota-gut-brain axis.

BACKGROUND: Hyperuricemia is considered as an independent risk factor for acute ischemic stroke (AIS), and some AIS patients are accompanied by an increase in serum uric acid. Recent studies have highlighted the important role of gut microbiota in both hyperuricemia and AIS, but there is little available data on the relationship between gut microbiota and the pathogenesis of AIS with hyperuricemia (HAS). METHODS: Here we profiled the gut microbiota composition in 63 HAS patients and 269 non-HAS patients through 16s rRNA sequencing. Male rat with hyperuricemia were subjected to middle cerebral artery occlusion (MCAO) to establish HAS model and were then treated with Parabacteroides distasonis. Subsequently, the neurological deficit, pathological damages and blood-brain barrier disruption were evaluated. Moreover, the levels of ROS, inflammatory cytokines, NF-𝜿B pathway related protein, and vascular density markers were determined. RESULTS: There were significant differences of gut microbiota composition between HAS patients and non-HAS patients, and a significant decrease in the abundance of Parabacteroides in HAS patients compared to non-HAS patients. Animal experiments showed that supplementation with P. distasonis increased beneficial commensal bacteria, significantly improved neurological deficits, pathological damages and BBB disruption, as well as reduced the level of serum uric acid in HAS rats. We further demonstrated that P. distasonis treatment decreased ROS level and increased SOD2 level, thereby reducing oxidative stress. Meanwhile, P. distasonis effectively inhibited NF-𝜿B signal pathway and reduced the production of inflammatory cytokines, including TNF-α and IL-1ß, alleviating the inflammatory response. Notably, P. distasonis treatment increased the levels of vascular density markers including cluster of differentiation 31 (CD31) and alpha-smooth muscle actin (α-SMA), ameliorating vascular damage in HAS rats. CONCLUSIONS: Together, these findings highlighted the important role of P. distasonis in the pathogenesis of HAS, and its mechanism was involved in the regulation of gut microbiota-gut-brain axis, which implied a novel strategy against HAS.

A machine learning-based prediction model for gout in hyperuricemics: a nationwide cohort study.

OBJECTIVE: To develop a machine learning-based prediction model for identifying hyperuricemic participants at risk of developing gout. METHODS: A retrospective nationwide Israeli cohort study used the Clalit Health Insurance database of 473 124 individuals to identify adults 18 years or older with at least two serum urate measurements exceeding 6.8 mg/dl between January 2007 and December 2022. Patients with a prior gout diagnosis or on gout medications were excluded. Patients' demographic characteristics, community and hospital diagnoses, routine medication prescriptions and laboratory results were used to train a risk prediction model. A machine learning model, XGBoost, was developed to predict the risk of gout. Feature selection methods were used to identify relevant variables. The model's performance was evaluated using the receiver operating characteristic area under the curve (ROC AUC) and precision-recall AUC. The primary outcome was the diagnosis of gout among hyperuricemic patients. RESULTS: Among the 301 385 participants with hyperuricemia included in the analysis, 15 055 (5%) were diagnosed with gout. The XGBoost model had a ROC-AUC of 0.781 (95% CI 0.78-0.784) and precision-recall AUC of 0.208 (95% CI 0.195-0.22). The most significant variables associated with gout diagnosis were serum uric acid levels, age, hyperlipidemia, non-steroidal anti-inflammatory drugs and diuretic purchases. A compact model using only these five variables yielded a ROC-AUC of 0.714 (95% CI 0.706-0.723) and a negative predictive value (NPV) of 95%. CONCLUSIONS: The findings of this cohort study suggest that a machine learning-based prediction model had relatively good performance and high NPV for identifying hyperuricemic participants at risk of developing gout.

Systemic Inflammation In Asymptomatic Hyperuricemia With Sonographic Crystal Deposits, Including A Comparison With Normouricemia And Gout.

OBJECTIVE: To describe the inflammatory profile of asymptomatic hyperuricemia (AH) with ultrasound evidence of monosodium urate (MSU) crystals (AH-MSUpos), vs AH without deposits (AH-MSUneg), intercritical gout, and normouricemia. METHODS: Based on serum urate levels, musculoskeletal ultrasound, and history of flares, we divided 122 participants into four groups: normouricemia, AH-MSUneg, AH-MSUpos, and intercritical gout. We tested four ultrasound definitions for MSU deposition in AH: grade 2-3 (G2-3) double contour and/or tophi, G1-3 double contour and/or tophi, G1-3 Stewart scheme (double contour sign in knee cartilage and/or first metatarsophalangeal joint and/or tophi in first metatarsophalangeal joint), and G2-3 Stewart scheme. Serum acute phase reactants, cytokines, pyroptosis derivates, and neutrophil-related proteins were measured and compared between groups. A linear regression model was fitted to correlate crystal and inflammatory burden (measured by ultrasound) with inflammatory markers in hyperuricemics. RESULTS: Rates of MSU deposition in AH ranged from 26.0% to 68.8%, depending on the definition used. Levels of CRP, leukocytes, IL-1RA, IL-6, sIL-6R, IL-18, TNF-α, TGF-ß, and galectin-3 were higher in hyperuricemics vs normouricemics. Sex, obesity, and comorbidity scores influenced some comparisons. We saw no differences comparing AH-MSUpos  vs AH-MSUneg groups, except for higher calprotectin using G1-3 sonographic definitions and higher CRP and TGF-ß when restricted to women and obese participants. CONCLUSIONS: Hyperuricemia is associated with substantial inflammation and some degree of active pyroptosis. Four different ultrasound definitions for AH with MSU deposits yielded similar findings, although we noted some differences in calprotectin, CRP, and TGF-ß. Sex, obesity, and comorbidities influenced some inflammatory responses.

Major cardiovascular events in patients with cardiovascular monosodium urate deposits in atherosclerotic plaques.

OBJECTIVE: To determine the association of cardiovascular atherosclerotic plaque monosodium urate deposits with the occurrence of major cardiovascular events in gout and hyperuricemia patients. METHODS: This retrospective cohort study included patients with clinically suspicion of gout, who performed a dual energy computed tomography of the affected limb and thorax between June 1st, 2012 and December 5th, 2019. Clinical and laboratory parameters were retrieved from patients charts. Established cardiovascular risk factors were evaluated. Medical history review identified the presence of major adverse cardiac events with a median follow up time of 33 months (range 0-108 months) after the performed computed tomography scan. RESULTS: Full data sets were available for 189 patients: 131 (69.3%) gout patients, 40 (21.2%) hyperuricemia patients, and 18 (9.5%) controls. Patients with cardiovascular monosodium urate deposits (n = 85/189, 45%) revealed increased serum acute phase reactants, uric acid levels and calcium scores in computed tomography compared with patients without cardiovascular monosodium urate deposits. Major adverse cardiac events were observed in 35 patients (18.5%) with a higher prevalence in those patients revealing cardiovascular monosodium urate deposits (n = 22/85, 25.9%) compared with those without cardiovascular monosodium urate deposits (n = 13/104, 12.5%, OR 2.4, p= 0.018). CONCLUSION: This is the first study demonstrating the higher hazard of major adverse cardiac events in patients with dual energy computed tomography-verified cardiovascular monosodium urate deposits. The higher prevalence of cardiac events in patients with cardiovascular monosodium urate deposits may facilitate risk stratification of gout patients, as classical cardiovascular risk scores or laboratory markers fail in their proper identification.

Intermittent high altitude hypoxia induced liver and kidney injury leading to hyperuricemia.

About 140 million people worldwide live at an altitude above 2500 m. Studies have showed an increase of the incidence of hyperuricemia among plateau populations, but little is known about the possible mechanisms. This study aims to assess the effects of high altitude on hyperuricemia and explore the corresponding mechanisms at the histological, inflammatory and molecular levels. This study finds that intermittent hypobaric hypoxia (IHH) exposure results in an increase of serum uric acid level and a decrease of uric acid clearance rate. Compared with the control group, the IHH group shows significant increases in hemoglobin concentration (HGB) and red blood cell counts (RBC), indicating that high altitude hyperuricemia is associated with polycythemia. This study also shows that IHH exposure induces oxidative stress, which causes the injury of liver and renal structures and functions. Additionally, altered expressions of organic anion transporter 1 (OAT1) and organic cation transporter 1 (OCT1) of kidney have been detected in the IHH exposed rats. The adenosine deaminase (ADA) expression levels and the xanthione oxidase (XOD) and ADA activity of liver of the IHH exposure group have significantly increased compared with those of the control group. Furthermore, the spleen coefficients, IL-2, IL-1ß and IL-8, have seen significant increases among the IHH exposure group. TLR/MyD88/NF-κB pathway is activated in the process of IHH induced inflammatory response in joints. Importantly, these results jointly show that IHH exposure causes hyperuricemia. IHH induced oxidative stress along with liver and kidney injury, unusual expression of the uric acid synthesis/excretion regulator and inflammatory response, thus suggesting a potential mechanism underlying IHH-induced hyperuricemia.

Hyperuricemia: A key contributor to endothelial dysfunction in cardiovascular diseases.

As an end product of purine metabolism, uric acid (UA) is a major endogenous antioxidant in humans. However, impaired UA synthesis and excretion can lead to hyperuricemia (HUA), which may in turn induce endothelial dysfunction (ED) and contribute to the pathogenesis of cardiovascular diseases (CVDs; e.g., atherosclerosis and hypertension). In this review, we discuss recent advances and novel insights into the effects exerted by HUA conditions in ED and related underlying mechanisms focusing on impaired UA metabolism, reduction in the synthesis and bioavailability of nitric oxide, endothelial cell injury, the endothelial-to-mesenchymal transition, insulin resistance, procoagulant activity, and acquisition of an inflammatory phenotype. We additionally discuss intervention strategies for HUA-induced ED and the paradoxical roles of UA in endothelial function. We summarize major conclusions and perspectives: the deleterious effects of HUA contribute to the initiation and progression of CVD-related ED. However, the treatment strategies (in addition to urate-lowering therapy) for increasing endothelial function are limited because the majority of literature on pharmacological and pathophysiological mechanisms underlying HUA-induced ED solely describes in vitro models. Therefore, a better understanding of the mechanisms involved in HUA-induced ED is critical to the development of novel therapies for preventing and treating CVD-HUA comorbidities.

Hyperuricemia: An Intriguing Connection to Metabolic Syndrome, Diabetes, Kidney Disease, and Hypertension.

PURPOSE OF THE REVIEW: Our review explores the epidemiology, physiology, and clinical data surrounding the connection between hyperuricemia and metabolic syndrome, chronic kidney disease, and hypertension. RECENT FINDINGS: Compelling physiologic mechanisms have been proposed to explain a causal relationship between hyperuricemia and metabolic syndrome, chronic kidney disease, and hypertension but clinical studies have given mixed results in terms of whether intervening with hyperuricemia using urate-lowering therapy has any beneficial effects for patients with these conditions. Despite the large amount of research already put into this topic, more randomized placebo-controlled trials are needed to more firmly establish whether a cause-effect relationship exists and whether lowering uric acid levels in patients with these conditions is beneficial.

Urate-Lowering Therapy Inhibits Thoracic Aortic Aneurysm and Dissection Formation in Mice.

BACKGROUND: Thoracic aortic aneurysm and dissection (TAAD) is a highly lethal vascular disease without effective drug therapy. Whether elevated serum concentrations of uric acid are involved in TAAD development remains unclear. METHODS: Serum uric acid levels were detected in different TAAD mouse models and patients. The urate-lowering drug allopurinol was administered in the drinking water of TAAD mice. Adenine diet-induced mice were established to investigate the role of hyperuricemia in TAAD formation and RNA-sequencing of thoracic aortas from these mice was performed. RESULTS: We found serum uric acid levels were elevated in various mouse TAAD models, including mice fed a ß-aminopropionitrile diet, Marfan mice with fibrillin-1 haploinsufficiency (Fbn1C1041G/+), and ApoE-/- mice infused with Ang II (angiotensin II), as well as in patients with TAAD. Administration of urate-lowering drug allopurinol in the drinking water significantly alleviated TAAD formation in ß-aminopropionitrile-treated mice, Fbn1C1041G/+ mice, and Ang II-infused ApoE-/- mice. Moreover, an adenine diet was used to induce hyperuricemia in mice. Intriguingly, a 4-week adenine diet feeding directly induced TAAD formation characterized by increased maximal thoracic aortic diameters and severe elastin degradation, which were ameliorated by allopurinol. Unbiased RNA-sequencing in mouse thoracic aortas suggested that FcγR (Fc gamma receptor) was upregulated upon adenine diet, but reciprocally repressed by allopurinol. Mechanistically, hyperuricemia activated FcγR-mediated ERK1/2 (extracellular signal-regulated kinase 1/2) phosphorylation to induce macrophage inflammation and TAAD development, which was abrogated by allopurinol or FcγR deficiency. CONCLUSIONS: This study uncovered an important and previously unrecognized role of hyperuricemia in mediating the pathogenesis of TAAD, and uric acid-lowering drug may represent a promising therapeutic approach for TAAD.

Review: The Role of Dual-Energy Computed Tomography in Detecting Monosodium Urate Deposits in Vascular Tissues.

PURPOSE OF REVIEW: To highlight novel findings in the detection of monosodium urate deposits in vessels using dual energy computed tomography, and to discuss the potential clinical implications for gout and hyperuricemia patients. RECENT FINDINGS: Gout is an independent risk factor for cardiovascular disease. However, classical risk calculators do not take into account these hazards, and parameters to identify patients at risk are lacking. Monosodium urate measured by dual energy computed tomography is a well-established technology for the detection and quantification of monosodium urate deposits in peripheral joints and tendons. Recent findings also suggest its applicability to identify vascular urate deposits. Dual energy computed tomography is a promising tool for detection of cardiovascular monosodium urate deposits in gout patients, to better delineate individuals at increased risk for cardiovascular disease.

Pipeline Therapies for Gout.

PURPOSE OF REVIEW: Despite effective available treatments, gout management is often unsuccessful in getting patients to target serum urate goal and in managing flares in the setting of comorbidities. Studies addressing future treatment options for short- and long-term management are reviewed. RECENT FINDINGS: URAT-1 blocking agents have been helpful but have had limitations related to effects on renal function, lack of efficacy with renal impairment, and potential to increase renal stones. Dotinurad may function in the setting of decreased renal function. Arhalofenate has anti-URAT-1 activity and may also blunt gout flares. A new xanthine oxidase inhibitor (XOI), tigulixostat, is under study. New uricase treatments manufactured in combination with agents that can reduce immunogenicity may make uricase treatment simpler. A unique strategy of inhibiting gut uricase may offer the benefits of avoiding systemic absorption. For gout flares, IL-1ß inhibitor studies in progress include different dosing schedules. Dapansutrile, an oral agent under investigation, inhibits activation of the NLRP3 inflammasome and may be an effective anti-inflammatory. New treatments for gout that are under study may work in the setting of comorbidities, simplify management, utilize new mechanisms, or have reduced side effects.

Associations of Bisphenols Exposure and Hyperuricemia Based on Human Investigation and Animal Experiments.

Hyperuricemia is characterized by elevated blood uric acid (UA) levels, which can lead to certain diseases. Epidemiological studies have explored the association between environmental contaminant exposure and hyperuricemia. However, few studies have investigated the role of chemical exposure in the development of hyperuricemia. Here, we sought to investigate the effects of bisphenol exposure on the occurrence of hyperuricemia. Fifteen bisphenol chemicals (BPs) were detected in human serum and urine samples collected from an area with a high incidence of hyperuricemia in China. Serum UA levels positively correlated with urinary bisphenol S (BPS), urinary bisphenol P (BPP), and serum bisphenol F (BPF). The effects of these three chemicals on UA levels in mice were explored at various exposure concentrations. An increase in serum UA levels was observed in BPS- and BPP-exposed mice. The results showed that BPS exposure increased serum UA levels by damaging the structure of the kidneys, whereas BPP exposure increased serum UA levels by disturbing purine metabolism in the liver. Moreover, BPF did not induce an increase in serum UA levels owing to the inhibition of guanine conversion to UA. In summary, we provide evidence of the mechanisms whereby exposure to three BPs disturbs UA homeostasis. These findings provide new insights into the risks of exposure to bisphenol chemicals.