Gout

Rosmarinic acid in Perilla frutescens L. as a potential adenosine deaminase inhibitor: Preparation, machine learning validation and binding mechanism study

Gout, a prevalent arthritic disease, can be mitigated by adenosine deaminase (ADA) inhibitors that reduce uric acid production. In this study, the extraction process of rosmarinic acid (RA) from Perilla frutescens L. (P. frutescens) was optimized, and the best yield was 2.22 mg/g. Quantitative structure-activity relationship (QSAR) model was used to predict ADA inhibitors (ADAIs) in potential foods. The random forest model constructed by ChemoPy descriptor was the best (AUC = 0.9648), and five candidate compounds (including RA) were screened. The inhibitory activity of RA on ADA was confirmed in vitro (IC50 = 55.11 μM). Molecular docking showed that ADAIs and ADA were stably bound through hydrogen bonding and hydrophobic interaction. Molecular dynamics (MD) simulation verified the dynamic stability of ADAIs and ADA complexes. This study provides a theoretical basis for RA from P. frutescens extract as a potential compound for the treatment of gout and for the rapid screening of foodborne ADAIs.

Correlation Between Metabolic Syndrome and Hyperuricemia: A Systematic Review and Meta-analysis

BACKGROUND

The main goal of this study was to conduct a meta-analysis and systematic review to examine the correlation between metabolic syndrome (MetS) and hyperuricemia.

METHODS

All studies available in PubMed, Cochrane Library, Embase, and Web of Science were obtained within the retrieval timeframe ending on 9 December 2023. Utilizing the Agency for Healthcare Research and Quality (AHRQ) and the Newcastle-Ottawa Scale (NOS), the included studies underwent quality appraisal, and Stata v14 software was employed for the subsequent data analysis.

RESULTS

A total of 40 studies, covering 214,091 patients, were selected based on specified inclusion and exclusion criteria. The analysis revealed a substantial association between MetS and hyperuricemia (odds ratio (OR) = 2.25, 95% confidence interval (CI) 1.19-4.26, P < 0.001). The metabolically abnormal overweight/obese group (MUHOWO) exhibited a heightened risk of hyperuricemia (OR = 3.54, 95% CI 2.66-4.71, P = 0.002). Additionally, hyperuricemia increased the likelihood of developing MetS (OR = 2.13, 95% CI 1.63-2.79, P < 0.001). Stratified by gender, hyperuricemia elevated the risk of MetS in both men (OR = 1.92, 95% CI 1.43-2.58, P < 0.001) and women (OR = 2.13, 95% CI 1.62-2.8, P < 0.001).

CONCLUSIONS

This meta-analysis and systematic review robustly affirm a significant bidirectional association between MetS and hyperuricemia. The increased risk observed, especially in MUHOWO and across gender lines, underscores the clinical relevance. Addressing MetS emerges as crucial in preventing and managing hyperuricemia, and vice versa. These findings offer valuable insights, urging further research into underlying mechanisms for more targeted interventions and personalized treatments in clinical practice.

Knowledge, Attitude, and Practice Toward Hyperuricemia Among Patients Diagnosed with Hyperuricemia

Objective

To investigate the knowledge, attitude, and practice (KAP) of patients diagnosed with hyperuricemia toward hyperuricemia.

Methods

This cross-sectional study enrolled patients with hyperuricemia who sought medical care at Taikang Xianlin Drum Tower Hospital between September 15, 2023, and January 11, 2024. A self-administered questionnaire was developed to collect participants' socio-demographic information and KAP scores regarding hyperuricemia. The threshold for sufficient knowledge, positive attitude, and proactive practice was ≥ 70.0% of the total score.

Results

This study included 483 non-problematic valid questionnaires, with a mean age of 41.83±14.13 years. The mean knowledge, attitude, and practice scores were 14.65±3.23 (66.59% of the possible maximum of 22), 40.89±4.32 (74.35% of the possible maximum of 55), and 25.66±4.54 (73.31% of the possible maximum of 35). A master's degree or above education (OR=2.555, 95%CU: 1.059-6.164, P=0.037), an income of 10,000-20,000 CNY (OR=2.216, 95% CI: 1.157-4.244, P=0.016), an income of >20,000 CNY (OR=2.237, 95% CI: 1.091-4.586, P=0.028), last uric acid test within the past year (OR=0.583, 95% CI: 0.341-0.997, P=0.049), and not taking uric acid-lowering medication (OR=0.326, 95% CI: 0.204-0.520, P<0.001) were independently associated with knowledge. The knowledge scores (OR=1.181, 95% CI: 1.100-1.269, P<0.001), attitude scores (OR=1.122, 95% CI: 1.063-1.184, P<0.001), age (OR=1.023, 95% CI: 1.005-1.041, P=0.011), current drinker (OR=0.489, 95% CI: 0.301-0.792, P=0.004), last uric acid test within 1 year (OR=0.488, 95% CI: 0.266-0.894, P=0.020), last uric acid test over 1 year ago (OR=0.297, 95% CI: 0.151-0.585, P<0.001), and high uric acid levels at the last test (OR=0.542, 95% CI: 0.299-0.980, P=0.043) were independently associated with practice. The structured equation model showed that knowledge positively influenced attitude (β=0.676, P<0.001) and practice (β=0.494, P=0.002). Attitude positively influenced practice (β=0.624, P<0.001).

Conclusion

Patients with hyperuricemia have insufficient knowledge but a positive attitude and proactive practice toward hyperuricemia. Educational and motivational interventions should be designed to improve practice.

Galangin Protects against Hyperuricemia via Ameliorating Gut-Kidney Axis Dysfunction in Mice

Hyperuricemia (HUA) is often associated with renal injury and intestinal flora disturbance. Galangin, a polyphenolic compound found in Alpinia officinarum and propolis, has demonstrated the capacity to inhibit xanthine oxidase (XO) activity both in vitro and in silico; however, the precise mechanisms underlying its effects in vivo remain unclear. This study aims to investigate the effect of galangin on uric acid (UA) metabolism as a prospective strategy for lowering UA and further explore the underlying mechanisms. Galangin mitigates kidney tissue injury and fibrosis, reduces the serum UA level via inhibiting UA synthesis in the liver, and promotes UA excretion in the kidney. Molecular docking results also uncovered the structure-activity relationship of galangin and the UA transporters GLUT9, URAT1, ABCG2, and OAT1, implying a potential interaction. Also, galangin mitigated the HUA-activated NF-κB/MAPK signaling pathway in the kidney, as well as colon tissue damage and barrier dysfunction, which are closely linked to deteriorated intestinal permeability. Moreover, galangin remedied the alterations in intestinal microecology caused by HUA, encompassing changes in the structure and composition of gut microbial species as well as the metabolism of SCFAs. Collectively, this study demonstrates that galangin exerted an improvement on HUA by ameliorating gut-kidney axis dysfunction.

Global burden and future projections of geriatric gout (1990-2021): a comprehensive analysis and Bayesian Age-Period-Cohort modeling

Introduction

Gout is increasingly recognized as a major chronic condition among older adults, contributing significantly to global disease burden, healthcare costs, and disability.

Methods

This study utilized data from the Global Burden of Disease (GBD) database, covering 204 countries and regions from 1990 to 2021. We evaluated age-standardized incidence rates, prevalence, and Years Lived with Disability (YLDs) of gout among individuals aged 60 years and older. Inequality and frontier analyses were conducted to explore disparities, and Bayesian Age-Period-Cohort (BAPC) models were applied for future trend projections up to 2036.

Results

All indicators-incidence, prevalence, and YLDs-showed a steady increase across the study period, with particularly rapid growth observed in high Socio-demographic Index (SDI) regions and among older women. Although the burden was concentrated in high SDI countries, increasing trends were also evident in low SDI areas. Significant heterogeneity was found among countries with similar SDI levels.

Discussion

The projected rise in gout burden through 2036 underscores the urgent need for targeted public health strategies. Disparities across SDI groups suggest that medical infrastructure, prevention programs, and cultural contexts play critical roles in disease control. Comprehensive interventions are essential to manage this growing challenge, especially among high-risk older populations.

Mimickers of erysipelas and cellulitis: A narrative review

A diffuse erythematous, edematous tender swelling with a distinct border and local rise in temperature suggest a morphological diagnosis of erysipelas-like eruption. While cellulitis and pseudocellulitis have an ill defined tender erythematous plaque. Erysipelas, and cellulitis are not a straightforward diagnosis as multiple cutaneous eruptions mimic erysipelas. It is important to have comprehensive knowledge about the different causes of erysipelas-like eruptions and pseudocellulitis to reach a diagnosis and treat appropriately. Many infectious diseases such as histoplasmosis, leishmaniasis, dermatophytosis, and infusion of chemotherapeutic agents result in erysipelas-like eruptions and pseudocellulitis. Malignancy-related dermatoses such as carcinoma erysipeloides, erysipeloides melanomatosum, and inflammatory dermatoses such as sweet syndrome, well syndrome, and Crohn's disease present as erysipelas-like eruption.

Infection, inflammation, and sexual function in male and female patients-recommendations from the Fifth International Consultation on Sexual Medicine (ICSM 2024)

INTRODUCTION

Sexual dysfunction in men and women is an important clinical issue; infection and inflammation can cause social, medical, and psychological problems that have a profound impact on sexual and reproductive health worldwide.

OBJECTIVES

We set out to identify sexual dysfunctions in men and women that arise from infection and inflammation and propose meaningful interventions, as evaluated by the Fifth International Consultation on Sexual Medicine (ICSM) held in June 2024 in Madrid (Spain).

METHODS

We searched MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials (CENTRAL) for published peer-reviewed journal articles and ClinicalTrials.gov and the World Health Organization's (WHO's) International Clinical Trials Registry Platform for prospective trials. This manuscript represents the opinions of 10 experts from 6 countries developed in a consensus process after completing the literature review, which produced a list of recommendations graded as weak or strong. This document was presented for peer review and debate in a public forum, and revisions were made based on the recommendations of chairpersons of the 5th ICSM.

RESULTS

Infections, and in particular sexually transmitted infections (STIs), dramatically affect the sexual and reproductive health of individuals and couples, irrespective of sexual orientation and gender. Similarly, non-communicable chronic diseases (NCDs), through the common pathogenetic mechanism of inflammation, can directly impair the ability to copulate, reproduce, and enjoy sexual life.

CONCLUSIONS

This expert consensus recommends prioritizing early detection, comprehensive treatment approaches, and preventive measures to mitigate the effects of infection and inflammation on sexual health, both for the patient and the couple. These insights provide a foundation for improving patient outcomes and fostering global awareness of the interconnections between infection, inflammation, and sexual dysfunction.

Exploring Therapeutic Potential of Bi-Qi Capsules in Treatment of Gout by Discovering Crucial Drug Targets

Objectives: This research aims to explore the therapeutic potential of Bi-Qi capsules in the treatment of gout by identifying crucial drug targets through a multidimensional data analysis strategy. Methods: Bi-Qi capsule drug targets and differentially expressed genes (DEGs) of gout were derived from public databases, such as Swiss Target Prediction, STITCH, and the GEO database. Subsequently, the overlapped targets were analyzed to elucidate the potential therapeutic mechanism and to identify candidate targets of Bi-Qi capsules against gout. Next, Mendelian randomization (MR) analysis was employed to screen and explore the causal relationship between candidate targets and gout. Finally, single-cell RNA sequencing (scRNA-seq), gene set enrichment analysis (GSEA), transcription factor and ceRNA regulatory networks, and molecular docking were performed to validate the role of the crucial targets of Bi-Qi capsules in the treatment of gout. Results: A total of 46 candidate targets were identified, in which KCNA5, PTGS2, and TNF exhibited significant causal relationships with gout (p < 0.05) and were regarded as the crucial targets. Through scRNA-seq and gene labeling, crucial targets were found to be expressed in eighteen cell clusters and eight cell types, which are closely associated with carbohydrate metabolism, nerve conduction, and the innate immunity process. Bi-Qi capsule active compounds such as tanshinone IIA, strychnine, tanshinaldehyde, cryptotanshinone, tumulosic acid, and glycyrrhetic acid exhibit a better binding ability to crucial targets. Conclusions: The results not only elucidate the anti-gout mechanism of Bi-Qi capsules but also provide an insight into multi-target natural medication for metabolic disease treatment, which contributes to guiding the clinical application of Bi-Qi capsules in the future.

Association of Chronic Kidney Disease With Increased Glucose Uptake-Associated Metabolic Activity of Visceral Adipose and Subcutaneous Adipose Tissue in Patients With Gout

OBJECTIVE

We evaluate the 18F-fluorodeoxyglucose positron emission tomography (PET) standardized uptake value (SUV) by PET/computed tomography (CT) scans in visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) in patients with and without gout. Additionally, we investigate whether glucose uptake in these tissues predicts the progression of chronic kidney disease (CKD).

METHODS

We used International Classification of Diseases, Tenth Revision codes from the University of California San Diego patient database to identify patients with gout and controls, forming a cohort of individuals who underwent PET/CT scans. The mean VAT and SAT maximum SUV (SUVmax) were measured using PET/CT scans and adjusted for potential confounders using inverse probability of weighting analysis. We also employed multivariable linear regression to analyze changes in estimated glomerular filtration rate (eGFR) after PET/CT scans.

RESULTS

The study included 221 patients, with 120 diagnosed with gout. After the inverse probability of weighting adjustment, the mean VAT and SAT SUVmax were higher in patients with gout (mean VAT SUVmax: β = 0.09, 95% confidence interval [CI] 0.04-0.15; mean SAT SUVmax: β = 0.06, 95% CI 0.01-0.12). Additionally, in patients with gout with CKD stage ≥3, higher mean VAT and SAT SUVmax were associated with decreased eGFR in the 5 years following PET/CT scans (mean VAT SUVmax: β = -1.76, 95% CI -3.50 to -0.01; mean SAT SUVmax: β = -2.97, 95% CI -5.61 to -0.32).

CONCLUSION

Elevated glucose uptake-associated metabolic activity in both VAT and SAT was observed in patients with gout, which may contribute to CKD progression among patients with both gout and CKD.

Disseminated Varicella-Zoster Virus in a Patient on Pegloticase and Mycophenolate Mofetil for Gout

There are various treatments for managing gout, including combination treatment with immunomodulators. However, these treatments can lead to significant immunosuppression, potentially leading to worse health outcomes, such as the one described in this case. We present the case of a 70-year-old female patient with a past medical history of atrial fibrillation, type 2 diabetes mellitus, and gout, who presented with progressively worsening altered mental status. This ultimately necessitated intubation, as well as the initiation of vasopressor support for new, worsening hypotension. She was noted to have a widespread vesicular pruritic rash present for the past month. Swabs of the vesicular lesions resulted positive for varicella-zoster virus (VZV). Her serum was also VZV positive, with 6,800,000 copies/mL detected. She later developed bilateral patchy infiltrates, and a bronchoscopy showed patchy erythema in multiple proximal airways. A lumbar puncture was performed due to the patient's altered mental status, which showed VZV (<200 copies) in her cerebrospinal fluid (CSF). She was, therefore, started on acyclovir, and she clinically improved. Her final diagnosis was disseminated VZV with multiorgan involvement, including the lung, skin, liver, and CSF. Medication review revealed that the patient was taking mycophenolate mofetil (MMF) and pegloticase for the treatment of gout. It was thus suspected that the MMF led to an immunocompromised state, which predisposed her to disseminated VZV.  Pegloticase is a Food and Drug Administration (FDA)-approved treatment for refractory gout but is known to be highly immunogenic. To reduce pegloticase's immunogenicity, MMF is often co-administered. In this case, our patient became profoundly immunosuppressed with the MMF-pegloticase regimen, which led to disseminated VZV. This case sheds light on the serious risks associated with this drug regimen.

Exploration of the Interrelationship Between Serum Uric Acid, Gout, and Cardiac, Renal, and Metabolic Conditions in Middle Aged and Older People

BACKGROUND

Cardiac, renal, and metabolic (CRM) conditions are major causes of morbidity and mortality globally. This study aims to explore the relationship between serum uric acid (SUA), hyperuricemia, gout, and CRM conditions in middle-aged and elderly populations.

METHODS

Sample 1 included participants from CHARLS (China Health and Retirement Longitudinal Study, n=9341), and Sample 2 from NHANES (National Health and Nutrition Examination Survey, unweighted n=17 913; weighted n=115 646 390). Ordinal logistic regression, Cox regression, and restricted cubic spline analyses were used to assess the relationship between SUA, hyperuricemia, gout, and CRM conditions. A 2-sample Mendelian randomization analysis was conducted to explore causal associations between SUA and CRM conditions.

RESULTS

In both samples, SUA, hyperuricemia, and gout were positively correlated with the risk of CRM conditions. Among participants with 3 or ≥1 CRM condition(s), SUA, asymptomatic hyperuricemia, and gout with poorly controlled hyperuricemia showed significant positive associations with all-cause mortality, whereas these associations were not observed in patients with gout with normal SUA levels. The restricted cubic spline analysis revealed a positive relationship between SUA levels and the risk of all-cause mortality in participants with ≥1 CRM condition(s), demonstrating a nonlinear dose-response relationship across both samples (P for nonlinearity <0.05). Mendelian randomization analysis indicated that SUA was causally associated with cardiovascular disease, chronic kidney disease, and diabetes.

CONCLUSIONS

Hyperuricemia and gout are strong predictors of increased prevalence and mortality of CRM conditions, emphasizing the importance of managing hyperuricemia and gout in these patients.

Metagenome-Based Characterization of the Gut Virome Signatures in Patients With Gout

The gut microbiome has been implicated in the development of autoimmune diseases, including gout. However, the role of the gut virome in gout pathogenesis remains underexplored. We employed a reference-dependent virome approach to analyze fecal metagenomic data from 102 gout patients (77 in the discovery cohort and 25 in the validation cohort) and 86 healthy controls (HCs) (63 and 23 in each cohort). A subset of gout patients in the discovery cohort provided longitudinal samples at Weeks 2, 4, and 24. Our analysis revealed significant alterations in the gut virome of gout patients, including reduced viral richness and shifts in viral family composition. Notably, Siphoviridae, Myoviridae, and Podoviridae were depleted, while Quimbyviridae, Retroviridae, and Schitoviridae were enriched in gout patients. We identified 359 viral operational taxonomic units (vOTUs) associated with gout. Enriched vOTUs in gout patients predominantly consisted of Fusobacteriaceae, Bacteroidaceae, and Selenomonadaceae phages, while control-enriched vOTUs included Ruminococcaceae, Oscillospiraceae, and Enterobacteriaceae phages. Longitudinal analysis revealed that a substantial proportion of these virome signatures remained stable over 6 months. Functional profiling highlighted the enrichment of viral auxiliary metabolic genes, suggesting potential metabolic interactions between viruses and host bacteria. Notably, gut virome signatures effectively discriminated gout patients from HCs, with high classification performance in the validation cohort. This study provides the first comprehensive characterization of the gut virome in gout, revealing its potential role in disease pathogenesis and highlighting virome-based signatures as promising biomarkers for gout diagnosis and future therapeutic strategies.

The exploration of the relationship between hyperuricemia, gout and vitamin D deficiency

Our study aims to provide evidence concerning the relationship between hyperuricemia, gout and Vitamin D deficiency by analyzing data from Peking Union Medical College Hospital (PUMCH), the National Health and Nutrition Examination Survey (NHANES) database, and through Mendelian randomization (MR) analyses. Sample 1 involved patients from PUMCH (n = 13,532), and sample 2 involved participants from NHANES (Unweighted n = 22,860; weight n = 182,829,142). Logistic regression and restricted cubic spline analyses were applied to assess above relationship. A two-sample MR analysis was performed using the genome-wide association study summary statistics to identify the causal association between gout and 25-hydroxyvitamin D (25(OH)D). The results from both samples confirmed a positive correlation among hyperuricemia, gout and risk of Vitamin D deficiency. The restricted cubic spline showed positive dose-response relationship between uric acid and risk of Vitamin D deficiency and the minimal threshold of uric acid at 307.5 umol/L and 316.1 umol/L, respectively. Mediation analysis in the sample 2 found that about 29.4% of the total effect of gout on Vitamin D deficiency were mediated by serum uric acid, and 37.1% of which were mediated by body mass index.The results of our MR analysis supported a causal association between gout (IVW β(SE), -0.843 (0.337); P = .0123) and 25(OH)D. Sensitivity analysis and genetic risk scores approach confirmed the robustness and reliability of the above findings. Hyperuricemia and gout are both strong indicators of increased risk of Vitamin D deficiency. Findings highlight the causal effects of gout-associated genetic variants on 25(OH)D.

Molecular mechanisms of urate transport by the native human URAT1 and its inhibition by anti-gout drugs

Gout, a common and painful disease, stems from hyperuricemia, where elevated blood urate levels lead to urate crystal formation in joints and kidneys. The human urate transporter 1 (hURAT1) plays a critical role in urate homeostasis by facilitating urate reabsorption in the renal proximal tubule, making it a key target for gout therapy. Pharmacological inhibition of hURAT1 with drugs such as dotinurad, benzbromarone, lesinurad, and verinurad promotes urate excretion and alleviates gout symptoms. Here, we present cryo-electron microscopy structures of native hURAT1 bound with these anti-gout drugs in the inward-open state, and with urate in inward-open, outward-open, and occluded states. Complemented by mutagenesis and cell-based assays, these structures reveal the mechanisms of urate reabsorption and hURAT1 inhibition. Our findings elucidate the molecular basis of urate transport and anti-gout medication action and provide a structural framework for the rational design of next-generation therapies for hyperuricemia and gout.

Nonlinear association of cardiometabolic index with hyperuricemia: insights from the NHANES 1999-2018 study

Background

Hyperuricemia, a risk factor for gout and cardiovascular diseases, has been linked to various metabolic disorders. This study investigates the association between the cardiometabolic index (CMI) and hyperuricemia.

Methods

Using the National Health and Nutrition Examination Survey 1999-2018 data from 23,212 participants, we employed survey-weighted logistic regression to quantify the CMI-hyperuricemia relationship. Generalized additive models explored potential nonlinear relationships, with two-piecewise logistic regression identifying inflection points. Stratified analyses across demographic and health subgroups assessed relationship consistency.

Results

We found a significant association between higher CMI and increased hyperuricemia and identified a nonlinear relationship, characterized by a faster risk increase at lower CMI levels and slower at higher levels. This pattern remained consistent across all demographic and health subgroups.

Conclusions

Higher CMI significantly predicts hyperuricemia across diverse populations, with a pronounced nonlinear association. This pattern underscores the importance of early intervention, emphasizing the need for personalized risk assessments and targeted strategies.

Effect of Probiotic Product Containing Heyndrickxia coagulans TBC169 on Hyperuricemia in Rats

Hyperuricemia (HUA) is a metabolic disease characterized by elevated serum uric acid, which is closely related to the gut microbiota. Probiotics have great potential in improving HUA. The purpose of this study was to evaluate the effect and mechanism of probiotic product (SQK) containing Heyndrickxia coagulans TBC169 on HUA rats. Forty SD rats (6 weeks old, 200 ± 20 g) were randomly divided into four groups (Ctrl group, HUA group, SQK1 group, and SQK2 group) of 10 rats each. Rats were given potassium oxonate (100 mg potassium oxonate/100 g BW/day) for 12 weeks to establish HUA model and simultaneously administered with sterile saline (HUA group) or different dose of SQK (SQK1 group, 20.48 mg SQK/100 g BW/day; SQK2 group, 40.95 mg SQK/100 g BW/day) throughout the 12 weeks. The results showed that SQK could degrade uric acid precursors and inhibit the xanthine oxidase (XOD) activity in vitro. Oral supplementation of SQK can reverse the increase of serum uric acid, the increase of the liver and serum XOD activity, and the decrease of ABCG2 expression in the ileum induced by HUA. In addition, SQK could restore the changes in α and β diversity of the ileal microbiota and prevent the increase in pathogenic Helicobacter and Staphylococcus caused by HUA. 16S rRNA sequencing and correlation analysis showed that the chondroitin sulfate (CS) degradation pathway of the gut microbiota played a key role in the prevention of HUA in the SQK group. These findings suggest that SQK may improve HUA by reducing uric acid synthesis and increasing uric acid excretion and provide a basis for its development into a probiotic product to improve HUA.

Molecularly Imprinted Polyaniline-Coated Cu-Zeolitic Imidazolate Framework Nanoparticles: Uricase-Mimicking "Polynanozyme" Catalyzing Uric Acid Oxidation

One of the drawbacks of nanozyme catalytic functions rests in their moderate catalytic activities due to the lack of effective binding sites concentrating the reaction substrate at the nanozyme catalytic interface. Methods to concentrate the substrates at the catalytic interface are essential to improving nanozyme functions. The present study addresses this goal by designing uric acid (UA) molecular-imprinted polyaniline (PAn)-coated Cu-zeolitic imidazolate framework (Cu-ZIF) nanoparticles as superior nanozymes, "polynanozymes", catalyzing the H2O2 oxidation of UA to allantoin (peroxidase activity) or the aerobic, uricase mimicking, oxidation of UA to allantoin (oxidase activity). While bare Cu-ZIF nanoparticles reveal only peroxidase activity and the nonimprinted PAn-coated Cu-ZIF nanoparticles reveal inhibited peroxidase activity, the molecular-imprinted PAn-coated Cu-ZIF nanoparticles reveal a 6.1-fold enhanced peroxidase activity, attributed to the concentration of the UA substrate at the catalytic nanoparticle interface. Moreover, the catalytic aerobic oxidation of UA to allantoin by the imprinted PAn-coated Cu-ZIF nanoparticles is lacking in the bare particles, demonstrating the evolved catalytic functions in the molecularly imprinted polynanozymes. Mechanistic characterization of the system reveals that within the UA molecular imprinting process of the PAn coating, Cu+ reactive units are generated within the Cu-ZIF nanoparticles, and these provide reactive sites for generating O2-• as an intermediate agent guiding the oxidase activities of the nanoparticles. The study highlights the practical utility of molecular-imprinted polynanozymes in catalytic pathways lacking in the bare nanozymes, thus broadening the scope of nanozyme systems.

Oleanolic Acid Alleviates Hyperuricemia via Gut Microbiota Control the Integrity of Gut Barrier and the Expressions of Urate Transporter in Mice

Hyperuricemia (HUA) is a globally prevalent metabolic disorder characterized by an imbalance in uric acid (UA) production and excretion. In this study, we found that oleanolic acid (OA), a natural pentacyclic triterpene, effectively reduced HUA and associated kidney injury in C57BL/6J mice. A 12-week OA treatment significantly and dose-dependently reduced UA and creatinine levels in serum and urine while suppressing hepatic xanthine oxidase activity in HUA mice. Mechanistic analysis revealed that OA modulates the expression of urate transporters including ABCG2, GLUT9, and URAT1 in the kidney and small intestine. Furthermore, OA restored gut microbiota imbalances, increased short-chain fatty acid production, and enhanced the expressions of intestinal tight junction proteins in HUA mice, thereby improving gut barrier integrity in HUA mice. Consequently, fecal microbiota transplantation (FMT) was employed to illustrate the major mediating role of gut microbiota in OA's alleviation of HUA in mice. Recipient HUA mice transplanted with feces from OA-treated HUA mice exhibited significantly lower blood and urinary UA levels, reduced kidney inflammation, and improved gut microbiota balance compared to those receiving feces from untreated HUA mice (p < 0.05). Additionally, FMT normalized urate transporter expression and reinforced intestinal tight junctions in recipient mice. These findings underscore that OA mitigates HUA primarily by modulating gut microbiota, regulating urate transporter expression, and reinforcing gut barrier integrity, offering novel insights into its preventive potential for managing HUA and related complications.

Gut microbiota as a new target for hyperuricemia: A perspective from natural plant products

BACKGROUND

Hyperuricemia, a prevalent chronic metabolic disorder caused by purine metabolism disturbances, is characterized by elevated serum uric acid (UA) levels. Prolonged hyperuricemia can cause severe complications such as gout or kidney damage. However, the toxic side effects of and adverse reactions to UA-lowering drugs are becoming increasingly prominent. Therefore, new targets and drugs for hyperuricemia are needed.

PURPOSE

This review aims to summarize recent research progress on the prevention and treatment mechanisms for gut microbiota-hyperuricemia from the perspective of plant-derived natural products.

METHODS

Data from PubMed, Web of Science, ScienceDirect, and the CNKI databases spanning from January 2020 to December 2024 were reviewed. The aim of this study is to categorize and summarize the relevant mechanisms through which natural products improve hyperuricemia via the gut microbiota. The retrieved data followed PRISMA criteria (Preferred Reporting Items for Systematic reviews and Meta-Analyses).

RESULTS

Regulating gut microbiota as a treatment for hyperuricemia. Targeting the gut microbiota could reduce host UA levels by promoting purine degradation, reducing UA production, and increasing UA excretion. Moreover, the gut microbiota also exerts anti-inflammatory and antioxidant effects that alleviate complications such as renal damage caused by hyperuricemia. Due to their diverse sources, multicomponent synergy, multitarget effects, and minimal side effects, plant-derived natural products have been extensively utilized in the management of hyperuricemia. Especially, utilizing natural products from plants to regulate the gut microbiota has become a new strategy for reducing UA levels.

CONCLUSION

This review comprehensively summarizes recent advances in understanding the preventive and therapeutic mechanisms of plant-derived natural products in ameliorating hyperuricemia and its comorbidities through gut microbiota modulation. This review contributes a novel perspective for the development of safer and more efficacious UA-lowering products.

Impact of gout flare on health-related quality of life: a multi-center cross-sectional study in Thailand

OBJECTIVE

Although the 5-level EQ-5D version (EQ-5D-5L) instrument has been used to determine health-related quality of life and health utility in gout, it is used in comparing health utility among gout flare (GF) and non-gout flare (non-GF) patients is still limited. This study aimed to compare health utility among GF and non-GF patients in Thailand.

METHODS

In this multi-center cross-sectional study, patients with GF and non-GF were interviewed for the EQ-5D5L and EQ-Visual Analog Scale (VAS) instruments by rheumatologists or trained research staffs. Patients with GF were subdivided into 2 subgroups (those who received no treatment and those who received treatment less than 48 h after GF episode).

RESULTS

Two hundred and sixteen patients (108 GF and 108 non-GF patients), males in 90.28%, were included. The gout disease duration was significantly longer in the non-GF than in the GF groups (median, 10 vs 5 years; p = 0.004). There was no difference in the tophi present between the two groups. When compared with the non-GF group, the GF patients significantly had low health utility (0.34 ± 0.36 vs. 0.89 ± 0.15, p < 0.001) and EQ-VAS score (54.73 ± 25.14 vs. 84.06 ± 13.38, p < 0.001). In the subgroup analysis of the non-GF group, there was insignificant health utility and EQ-VAS score between those with tophi and those without tophi (0.87 ± 0.14 vs. 0.90 ± 0.15, p = 0.124 and 83.36 ± 14.92 vs. 84.33 ± 12.83, p = 0.938, respectively).

CONCLUSION

This study found that GF clearly had a substantial impact on patients' quality of life. Targeted interventions in managing GF patients to improve their health outcomes are needed. Key Points • Patients with gout flare had lower health utility than those without gout flare. • The clinical significance of the utility and EQ-VAS was evaluated by the EQ-5D-5L instrument between gout flare and non-gout flare groups in Thai gouty patients. • Regarding the presence of tophi or disease duration, no significant differences in health utility and EQ-VAS were observed in the gout flare or non-gout flare group. • Targeted interventions for management of gout flare are needed to improve the health outcomes of gout flare patients.

Effects and potential pathways of goose astrovirus infection on gosling hepatic lipid metabolism

Introduction

The adverse effects of goose astrovirus (GoAstV) on avian growth and health have been widely reported previously, while the stress reactions and corresponding mechanism of gosling liver responding to GoAstV infection remain not entirely clear.

Methods

One-day-old goslings inoculated subcutaneously with 2 × 10-6 TCID50 of GoAstV were employed as an experimental model, and the potential effects and pathways of GoAstV infection on gosling liver functions were investigated by combining the morphological, biochemical and RNA sequencing (RNA-seq) techniques.

Results

Structural and functional impairments were found in gosling livers post the virus infection, as characterized by the histological alterations in liver index and morphology of hepatic cord and sinuses, as well as the abnormal expression patterns of the cellular antioxidant, inflammation and apoptosis-related genes. RNA sequencing analysis were performed to investigate the underlying mechanism. Results showed that the analysis of screened 1949 differentially expressed genes (DEGs) were mainly enriched in GO terms related to organic immune defense and substance metabolism, and their corresponding KEGG pathways represented by PPAR signaling pathway, intestinal immune network for IgA production, and fatty acid metabolism and degradation, suggesting that the functions of avian immunity and lipid metabolism were greatly changed after the GoAstV infection. Finally, the lipid deposition in gosling hepatocytes were further demonstrated by the subsequent Oil red O staining, biochemical detection of serum TG and HDL-C, and the gene expression analysis including PPARα, PPARγ, ACSBG2, ACSL5, CPT1A and PCK1.

Discussion

Though limitations exist, the findings of this study are helpful to expand our understanding about the negative effects of GoAstV on goslings, and provide us with new clues for the salvaging of GoAstV-induced liver dysfunctions in poultry industry.

Acute Coronary Syndrome and Rheumatic Disease

Patients with rheumatic disease and immune disorders have been noted to show an earlier development of atherosclerosis and to present with acute coronary syndrome. These diseases disproportionately affect women, and patients frequently have a higher number of comorbidities and other risk factors. Inflammation has long been known to play a role in the development of coronary artery disease. Early studies have shown some benefit in treatment targeting inflammation. While this has not been realized for all populations, there remains potential in treatment with targeted and individualized therapies. Especially since these diseases are associated with a worse prognosis, management benefits from the multidisciplinary expertise of cardiologists, rheumatologists, and other providers. However, the prevention and treatment of underlying rheumatic disease remains essential. This review will seek to highlight prior studies and future directions in the treatment of acute coronary syndrome in patients with rheumatologic disease.

J-Shaped Association Between Non-HDL Cholesterol to HDL Cholesterol Ratios and Gout in US Adults With Gout

Background and Aim

This study aims to assess the potential association between NHHR and gout risk among the US adult population.

Methods and Results

Utilizing data from the NHANES spanning from 2007 to 2018, we performed a cross-sectional analysis. A weighted multivariable logistic regression model, generalized additive model (GAM) and a restricted cubic spline model were applied to elucidate the association between NHHR and gout risk. In addition, subgroup and sensitivity analyses were conducted to ensure the stability of our findings. This study cohort included 27,731 participants. Multivariate logistic regression analysis indicated a significant correlation between NHHR and the likelihood of gout. This association was sustained after accounting for a range of potential confounding confounders. The risk of gout was observed to escalate with increasing quartiles of NHHR quartiles, with a 67% increased risk in the fourth quartile. Both RCS and curve fitting results indicated a J-shaped relationship between NHHR and gout. The association remained significant in several subgroup analyses. The interaction test did not yield statistically significant effects on this association.

Conclusion

The NHHR is nonlinearly correlated with the risk of gout in US adults. Further investigation research into the role of NHHR in gout could offer new perspectives on the prevention and treatment of gout. However, additional large-scale prospective studies are necessary to validate and reinforce these results.

Association between mixed venous oxygen saturation and serum uric acid levels in patients with heart failure

Hypoxia leads to increased purine metabolism in tissues, resulting in increased serum uric acid levels, and may also cause impaired uric acid excretion in the kidneys and intestinal tract. However, the relationship between hypoxia and serum uric acid levels in patients with heart failure remains largely unexplored. Because mixed venous oxygen saturation is an acute indicator of systemic oxygenation, in this study, we investigated the relationship between mixed venous oxygen saturation and serum uric acid levels. This retrospective analysis included 386 patients with heart failure who underwent cardiac catheterization at our institution. The relationship between mixed venous oxygen saturation and serum uric acid levels was examined by single regression analysis. Stratified regression analysis, structural equation modeling, and partial correlation analysis were used to examine the effects of eight factors known to influence mixed venous oxygen saturation and serum uric acid levels. The single regression analysis showed a significant negative correlation between mixed venous oxygen saturation and serum uric acid levels (P<0.001). Significant negative correlations were also observed in many subgroups in the stratified analysis, in the path diagram based on structural equation modeling, and in the partial correlation analysis. These results suggest that there may be a direct relationship between mixed venous oxygen saturation and serum uric acid levels that is not mediated by any known factor.

The Role of Purine Metabolism and Uric Acid in Postnatal Neurologic Development

This review explores the essential roles of purine metabolism including the catabolic product, uric acid, in the development of dopaminergic neurons of the substantia nigra pars compacta. The high energy requirements of the substantia nigra pars compacta alongside necessary purinergic neurotransmission and the influence of oxidative stress during development makes these neurons uniquely susceptible to changes in purine metabolism. Uric acid's role as a central nervous system antioxidant may help to ameliorate these effects in utero. Understanding the mechanisms by which purines and uric acid influence development of the substantia nigra pars compacta can help further explain neurologic consequences of inborn errors of purine metabolism, such as Lesch-Nyhan disease.

Microbiota from young mice counteracts susceptibility to age-related gout through modulating butyric acid levels in aged mice

Gout is a prevalent form of inflammatory arthritis that occurs due to high levels of uric acid in the blood leading to the formation of urate crystals in and around the joints, particularly affecting the elderly. Recent research has provided evidence of distinct differences in the gut microbiota of patients with gout and hyperuricemia compared to healthy individuals. However, the link between gut microbiota and age-related gout remained underexplored. Our study found that gut microbiota plays a crucial role in determining susceptibility to age-related gout. Specifically, we observed that age-related gut microbiota regulated the activation of the NLRP3 inflammasome pathway and modulated uric acid metabolism. More scrutiny highlighted the positive impact of 'younger' microbiota on the gut microbiota structure of old or aged mice, enhancing butanoate metabolism and butyric acid content. Experimentation with butyrate supplementation indicated that butyric acid exerts a dual effect, inhibiting inflammation in acute gout and reducing serum uric acid levels. These insights emphasize the potential of gut microbiome rejuvenation in mitigating senile gout, unraveling the intricate dynamics between microbiota, aging, and gout. It potentially serves as a therapeutic target for senile gout-related conditions.

A patent review of xanthine oxidase inhibitors (2021-present)

INTRODUCTION

Xanthine oxidase (XO) catalyzes the oxidation of both hypoxanthine and xanthine in the last two steps of the purine metabolic pathway, serving as a rate-limiting enzyme for uric acid production as well as a key target for the treatment of gout and other hyperuricemia-related conditions.

AREAS COVERED

This paper reviews XO inhibitors in patents from 2021 to the present. We summarize in detail the structural classes and characteristics, in vitro and in vivo biological results, and structure‒activity relationships of synthetic inhibitors, as well as the sources, specific structures, research methods, and biological activities of XO inhibitors from natural products.

EXPERT OPINION

(1) Benefiting from the discovery of many high-affinity inhibitors, the binding modes of small molecules in the active pocket of XO have been further elucidated, and this information will contribute to future development; (2) natural products remain one of the important sources in the discovery of XO inhibitors; (3) with a deeper exploration of XO and URAT1 targets, XO/URAT1 dual target inhibitors may be a future research hotspot; and (4) the search for high-affinity, small-molecule scaffolds remains a key challenge and an important direction for the future development.

Unveiling the Potential of Tetrahedral DNA Frameworks in Clinical Medicine: Mechanisms, Advances, and Future Perspectives

As deoxyribonucleic acis (DNA) nanotechnology advances, DNA, a fundamental biological macromolecule, has been employed to treat various clinical diseases. Among the advancements in this field, tetrahedral frameworks nucleic acids (tFNAs) have gained significant attention due to their straightforward design, structural simplicity, low cost, and high yield since their introduction by Turberfield in the early 2000s. Due to its stable spatial structure, tFNAs can resist the impact of innate immune responses on DNA and nuclease activity. Meanwhile, structural programmability of tFNAs allows for the development of static tFNA-based nanomaterials through the engineering of functional oligonucleotides or therapeutic molecules and dynamic tFNAs through the attachment of stimuli-responsive DNA apparatuses. This review first summarizes the key merits of tFNAs, including natural biocompatibility, biodegradability, structural stability, unparalleled programmability, functional diversity, and efficient cellular internalization. Based on these strengths, this review comprehensively analyzes applications of tFNAs in different clinical settings, including orthopedics, stomatology, urinary system diseases, liver-related diseases, tumors, infection, neural system diseases, ophthalmic diseases, and immunoprophylaxis. We also discuss the limitations of tFNAs and the challenges encountered in preclinical studies. This review provides new perspectives for future research and valuable guidance for researchers working in this field.

Mechanism of Biqi capsules in the treatment of gout based on network pharmacology and experimental verification

ETHNOPHARMACOLOGICAL RELEVANCE

Gout is a crystal-related arthropathy caused by monosodium urate (MSU) deposition, resulting from purine metabolism disorders and hyperuricemia (HUA). Gout belongs to the traditional medicine category of Bi syndrome. Biqi capsules (BQ) is a traditional Chinese medicine formula used to treat Bi syndrome. The BQ prescription is derived from the ancient prescription of Hua Tuo, a famous physician in the Han Dynasty.

AIM OF THE STUDY

To study the effect and mechanism of BQ in treating acute gouty arthritis (AGA) and HUA.

MATERIALS AND METHODS

Analyzing BQ's signaling pathways for gout treatment via network pharmacology. The HUA model was induced orally with adenine and potassium oxonate. The rat AGA model was established by MSU injection. In vitro, MH7A and RAW 246.7 cells were treated with LPS and MSU. Serum uric acid, creatinine, and urea nitrogen levels were evaluated. Kidney and ankle joint pathology was observed via HE staining. Inflammatory signaling pathway proteins, epithelial-mesenchymal transition (EMT) pathway proteins, and uric acid metabolism-related proteins were detected by Western blot.

RESULTS

1780 potential targets for gout treatment were identified, and 1039 target proteins corresponding to BQ's active ingredients were obtained. Pathway enrichment analysis revealed BQ improved gout mainly through inflammatory pathways. Experimental results showed BQ could reduce serum uric acid level and increase uric acid clearance rate by regulating the expression of adenosine deaminase (ADA), and organic anion transporter 1 (OAT1) and glucose transporter 9 (GLUT9) in HUA mice. BQ could improve renal function and injury by inhibiting the NLRP3 pathway in HUA mice' kidneys. Additionally, BQ could alleviate ankle joint swelling and synovial injury, inhibit the TLR4/NLRP3 pathway, and reduce levels of inflammatory factors including interleukin 6 (IL-6), interleukin 1β (IL-1β), and tumor necrosis factor-alpha (TNF-α) in AGA rats. The main component of BQ, brucine, could inhibit the activation of NLRP3/NF-κB pathway induced by MSU and reduce the expression level of inflammatory factors (IL-6, IL-1β, and TNF-α) in macrophages. Brucine could inhibit the activation of the EMT pathway and reduce the expression level of inflammatory factors (IL-6, TNF-α) in human fibroblast-like synoviocytes (MH7A cells) induced by MSU.

CONCLUSIONS

BQ effectively reduced serum uric acid levels, improved kidney and joint damage, and ameliorated the inflammatory response caused by MSU. Its main component, brucine, effectively improved the inflammatory response and reduced the invasive ability of synoviocytes induced by MSU.

A comprehensive analysis of trends in the burden of gout in China and globally from 1990 to 2021

Gout is a prevalent metabolic disorder characterized by urate crystal accumulation in joints, leading to acute arthritis and tophi formation. Despite advancements in management, the incidence and prevalence of gout have been increasing globally, particularly in China. This study analyzed data from the Global Burden of Disease Injuries and Risk Factors Study (GBD) to evaluate trends in gout from 1990 to 2021. Statistical analyses were conducted using R and Joinpoint software, while the ARIMA model was employed for forecasting future trends. Our findings revealed a global increase in gout incidence from 93.097 per 100,000 in 1990 to 109.075 per 100,000 in 2021, with cases rising from 3,983,109 to 9,401,585. In China, incidence increased from 122.522 to 151.612 per 100,000, with cases growing from 1,182,498 to 3,079,836. Similarly, global prevalence rose from 536.545 to 653.816 per 100,000, while in China, it increased from 640.679 to 810.359 per 100,000. Disability metrics, including YLDs and DALYs, also demonstrated significant increases both globally and in China. Our analysis indicated that middle-aged and elderly populations, particularly males, are at higher risk for gout. These findings underscore the urgent need for enhanced prevention and management strategies, specifically targeting high-risk populations. Effective public health policies and interventions are crucial to mitigate the escalating burden of gout and improve the quality of life for affected individuals. This study relied on secondary data from the GBD, which may be subject to biases in data collection and reporting. Additionally, variations in diagnostic practices and healthcare access across regions could influence the accuracy of reported trends. Future research should address these limitations by incorporating primary data and exploring region-specific factors contributing to gout prevalence and incidence.

The role of celastrol in inflammation and diseases

Celastrol is one of the main active ingredients extracted from the plant Tripterygium wilfordii Hook F. A growing number of studies have shown that celastrol has various pharmacological effects, including anti-inflammation, anti-rheumatism, treatment of neurodegenerative diseases, and anti-tumor. This article systematically summarized the mechanism and role of celastrol in lipid metabolism and obesity, rheumatoid arthritis (RA), osteoarthritis (OA), gouty arthritis, inflammatory bowel disease, neurodegenerative diseases, and cancer and other diseases (such as diabetes, respiratory-related diseases, atherosclerosis, psoriasis, hearing loss, etc.). The celastrol played roles in inflammation response, cell apoptosis, autophagy, ferroptosis, and lipid metabolism mainly by acting on chondrocytes, macrophages, mitochondria, and endoplasmic reticulum (ER) through NF-κB, STAT, MAPK, TLR, PI3K-AKT-mTOR, and other signal pathways. This review could provide a reference for the clinical application and further development and utilization of celastrol.

Association between the triglyceride/high-density lipoprotein (TG/HDL) ratio and incidence of gout: A nationwide cohort study

Introduction

The global burden of gout, a severe and painful arthralgia, is of note and is expected to increase in the future. We aimed to investigate the association between the triglyceride/high-density lipoprotein (TG/HDL) ratio, a simple and validated biomarker for insulin resistance, and the incidence of gout in a longitudinal setting in the general population.

Methods

Our study was conducted using the National Health Insurance Service-Health Screening Cohort database of Republic of Korea (2002-2019). We included 300,107 participants who had no previous history of gout and had data for more than three repeated measurements of the triglyceride-glucose (TyG) index. The incidence of gout was determined using at least two or more claims of the ICD-10 code M10.

Results

During a median 9.62 years (interquartile range 8.72-10.53), 14,116 individuals (4.72%) had a reported incidence of gout. In a fully adjusted multivariable time-dependent Cox proportional hazards model with repeated measures of the TyG index, a unit increase in the index significantly increased the risk of gout in the entire cohort (hazard ratio (HR) = 1.150, 95% confidence interval (CI) 1.116-1.184). In a multivariable Cox proportional model of average TyG index quartiles, comparison of the lowest (Q1) and highest quartiles (Q4) indicated a significant positive association with the incidence of gout (HR: 1.326, 95% CI: 1.260-1.397). This association was non-linear (J-shape) when assessing the entire cohort and the diabetes and non-diabetes cohorts.

Conclusion

Our study demonstrated that increased TyG index was associated with an incidence risk of gout in the general population. Additionally, this association was non-linear (J-shape) not only in the entire cohort, but also in diabetes mellitus and non-diabetes mellitus cohorts. The TyG index may be an important predictor of gout.

Current Situation of Goose Astrovirus in China: A Review

Gosling gout disease is an infectious disease caused by goose astrovirus (GAstV), which can result in urate deposition in the internal organs and joints of goslings. Since 2015, outbreaks of gosling gout disease have occurred in several goose-producing areas in China. Subsequently, the disease spread to the vast majority of eastern China, becoming a major threat to goose farms and causing huge economic losses to the goose industry. Meanwhile, GAstV can infect species of birds other than geese. It is worth noting that, as an emerging virus, the research on GAstV is still in the early stages. Therefore, the investigation of GAstV has become an urgent issue, which can improve understanding of GAstV and develop effective measures to control its threat to poultry. The purpose of this review is to summarize the latest research progress on GAstV in recent years, mainly focusing on the genetic evolution, pathogenesis, diagnostic detection, and control strategies of GAstV, aiming to provide a reference for scientific prevention and control of GAstV infection.

Biomimetic bioreactor for potentiated uricase replacement therapy in hyperuricemia and gout

Introduction

Uricase replacement therapy is a promising approach for managing hyperuricemia and gout but is hindered by challenges such as short blood circulation time, reduced catalytic activity, and excessive hydrogen peroxide (H2O2) production. These limitations necessitate innovative strategies to enhance therapeutic efficacy and safety.

Methods

We designed and synthesized RBC@SeMSN@Uri, a red blood cell-coated biomimetic self-cascade bioreactor, which encapsulates uricase (Uri) and a selenium-based nano-scavenger (SeMSN) within RBC membranes. This design aims to reduce immunogenicity, extend systemic circulation, and maintain enzymatic activity. In vitro assays were conducted to evaluate biocompatibility, anti-inflammatory effects, and oxidative stress protection. In vivo experiments in hyperuricemia and gout models assessed therapeutic efficacy, biodistribution, and biosafety.

Results

RBC@SeMSN@Uri effectively degraded uric acid (UA) into allantoin and converted H2O2 into water, preventing oxidative damage and inflammation. In vitro assays demonstrated excellent biocompatibility and reduced H2O2-induced inflammatory responses compared to free uricase. In vivo, the bioreactor prolonged circulation time, significantly reduced uric acid levels, alleviated kidney damage, and mitigated symptoms of hyperuricemia and gout. It also targeted inflamed joints, reducing swelling and inflammation in gouty arthritis models.

Discussion

This study presents RBC@SeMSN@Uri as a novel biomimetic strategy for enzyme replacement therapy in hyperuricemia and gout. By integrating uricase and selenium-based nano-scavenger within RBC membranes, the bioreactor addresses key limitations of traditional therapies, offering enhanced stability, reduced immunogenicity, and superior therapeutic efficacy. This platform holds potential for broader applications in protein or antibody delivery for enzyme replacement therapies in other diseases.

Intestinal FXR deficiency induces dysregulation of xanthine oxidase and accounts for sex difference in hyperuricemia

Overproduction of uric acid caused by increased expression and/or enhanced activity of xanthine oxidase (XO) is one of the major etiologies of hyperuricemia, which had a significant sex differences. As an important enzyme involved in production of reactive oxygen species and uric acid, activity of XO is highly correlated with hyperuricemia and its complications. However, the mechanisms underlying XO dysregulation remain unclear, and sex difference in the prevalence of hyperuricemia has been well known. To explore the potential role of intestinal farnesoid X receptor (FXR) on XO regulation and production, and the mechanisms of sex differences in this pathological process. Two hundred and sixty-one dyslipidemia participants and intestine-specific FXR-knockout mice were used to study the relationship between the intestinal FXR and the serum uric acid level. Western blotting, quantitative real-time PCR, and dual-luciferase reporter assay, were applied to clarify the regulatory role of FXR deficiency on XO. Special inhibitors, agonists, siRNA, sex hormones were used to investigate the mechanism of sex difference in FXR deficiency induced hyperuricemia in cell and animal model. Serum fibroblast growth factor 19 (FGF19) levels were lower in hyperuricemia patients in a sex difference manner. Increased local TNFα level driven by intestinal FXR deficiency/inhibition induced overexpression and hyperactivity of intestinal XO, leading to elevated intestinal uric acid synthesis, and subsequently resulting in hyperuricemia. We found that estrogens inhibited XO expression and activity, whereas androgens enhanced XO activity, leading to the sex difference in FXR deficiency induced hyperuricemia. Infliximab treatment eliminated the sex difference in uric acid levels in intestinal FXR-knockout mice. This study demonstrated the role of intestinal FXR in the pathogenesis of hyperuricemia, and partially elucidated the mechanisms underlying the sex differences of hyperuricemia.

Specific blood metabolite associations with Gout: a Mendelian randomization study

OBJECTIVE

Gout, common metabolic disorders, have poorly understood links with blood metabolites. Exploring these relationships could enhance clinical prevention and treatment strategies.

METHODS

We applied bidirectional two-sample Mendelian randomization (MR) analysis, using data from a genome-wide association (GWAS) study of 486 blood metabolites. Gout data was obtained from FinnGen R8 (7461 gout and 221,323 control cases). We implemented the inverse variance-weighted (IVW) method for main analytical approach. Extensive heterogeneity, pleiotropy tests, leave-one-out analysis, and reverse MR were conducted to validate the robustness of our findings. Both Bonferroni and False Discovery Rate (FDR) corrections were used to adjust for multiple comparisons, ensuring stringent validation of our results.

RESULTS

Initial MR identified 31 candidate metabolites with potential genetic associations to gout. Following rigorous sensitivity analysis, 23 metabolites as potential statistical significance after final confirmation. These included metabolites enhancing gout risk such as X-11529 (OR = 1.225, 95% CI 1.112-1.350, P < 0.001), as well as others like piperine and stachydrine, which appeared to confer protective effects. The analysis was strengthened by reverse MR analysis. Additionally, an enrichment analysis was conducted, suggesting that 1-methylxanthine may be involved in the metabolic process of gout through the caffeine metabolism pathway.

CONCLUSION

Identifying causal metabolites offers new insights into the mechanisms influencing gout, suggesting pathways for future research and potential therapeutic targets.

An update on the pharmacotherapy of gout

INTRODUCTION

Gout is a common form of acute inflammatory arthritis caused by the deposition of monosodium urate crystals within synovium of joints. This leads to severe pain, reducing quality of life for patients with this condition.

AREAS COVERED

This review summarizes the treatment of both acute flares of gout and urate-lowering therapy based on guidance from various major international societies. We have also covered new emerging therapies that have not yet reached clinical practice.

EXPERT OPINION

Standard pharmacotherapies for gout flares include the options of colchicine, NSAIDs and oral or intramuscular corticosteroids, with IL-1 inhibitors newly established as an option for flare refractory to standard therapies. Urate-lowering therapies aim to prevent gout flares, with an emphasis on treat-to-target strategy; the escalation of therapies until the target serum uric acid is reached. Initial treatments include allopurinol and febuxostat, with uricosuric agents, probenecid, sulfinpyrazone and benzbromarone, as adjuncts. There are also emerging therapies in development. However, there is increasing personalization of treatment, adjusting pharmacotherapy depending on comorbidities, such as chronic kidney disease and ischemic heart disease, as well as patient preference.

Monitoring and Management of Uric Acid Therapy in Gout and Chronic Kidney Disease: A Single-Center Retrospective Study

Background Gout commonly coexists with chronic kidney disease (CKD) due to reduced renal excretion of uric acid (UA). Guidelines recommend regular monitoring and dose adjustment of urate-lowering therapy (ULT), but the rate of adherence to these guidelines is not well established. Our study aimed to determine adherence to ULT guidelines in gout patients at our institution. In particular, we sought to assess the effect of CKD as well as other comorbidities on the prevalence of ULT guideline adherence. Methods We conducted a retrospective cohort study of 5,985 gout patients at our institution initiated on allopurinol between 2015 and 2020. Inclusion criteria were age over 18, a gout diagnosis, and a new allopurinol prescription. The primary outcome was UA monitoring within six months of therapy initiation. A secondary outcome was the prevalence of dose adjustments made by providers in response to a UA level above target. Results Only 48.3% (n = 2,889) of patients had UA levels monitored within six months. CKD stage did not significantly impact monitoring rates (p = 0.059). In patients with elevated UA levels (>6 mg/dL), 54.3% (n = 1,011) of patients had no dosage adjustments. Conclusions Significant gaps exist in adherence to ULT guidelines; nearly half of patients did not undergo recommended UA monitoring. Over half of patients with elevated uric levels did not have dosage adjustments. CKD stage did not affect the likelihood of UA monitoring or dose changes in persons with elevated UA levels.

Reducing hyperuricemic events with SGLT2 inhibitors: An updated systematic review with meta-regression

INTRODUCTION

Although sodium-glucose cotransporter-2 inhibitors (SGLT2i) were shown to lower hyperuricemic events in patients with type 2 diabetes mellitus (T2DM), the extent of this effect in the general population is yet to be elucidated. We performed an updated systematic review and meta-analysis on a large sample of patients with and without T2DM to evaluate the influence of SGLT2i therapy on clinically relevant hyperuricemic events, defined as the composite of acute gout flare episodes, acute anti-gout management or urate-lowering therapy initiation. Furthermore, we conducted a multivariate meta-regression to assess the relationship between different covariates and the pooled effect size.

MATERIALS AND METHODS

We systematically searched all reported outcomes of interest in patients on SGLT2i (PROSPERO: CRD42023442077) across PubMed, Scopus and Cochrane databases looking for randomized controlled trials, observational studies and post-hoc analyses since inception until August 2023.

RESULTS

Data from seven randomized controlled trials and seven observational studies were included for a total of 464,009 patients, 13,370 of whom did not have T2DM. A total of 50% of the patients included were on SGLT2i. The pooled analysis demonstrated that SGLT2i reduce clinically relevant hyperuricemic events by 33% (HR, 0.67; 95% CI, 0.59-0.77; I2=83%) regardless of the concomitant diagnosis of T2DM. The multivariate meta-regression on chronic kidney disease (CKD) showed a positive correlation on the pooled effect size.

CONCLUSIONS

SGLT2i reduce the risk of developing hyperuricemic events regardless of the concomitant diagnosis of T2DM. The multivariate meta-regression on CKD showed a significant impact on the main outcome. Further studies are essential to investigate more conclusively the extent of these beneficial effects.

Neutrophil Extracellular Trap Formation Model Induced by Monosodium Urate and Phorbol Myristate Acetate: Involvement in MAPK Signaling Pathways

Neutrophil extracellular traps (NETs) formation is a key process in inflammatory diseases like gout, but the underlying molecular mechanisms remain incompletely understood. This study aimed to establish a model to examine the formation of NETs induced by monosodium urate (MSU) and phorbol 12-myristate 13-acetate (PMA) and to elucidate their molecular pathways. Laser confocal microscopy was used to visualize NET formation, while flow cytometry was employed to detect reactive oxygen species (ROS) production. The microstructure of neutrophils was observed by transmission electron microscopy, and the expression of key proteins was determined by Western blotting. Additionally, the effect of various inhibitors targeting the MAPK signaling pathway on NET formation was evaluated. They include the Ras inhibitor Salirasib, Raf inhibitor Vemurafenib, ERK inhibitor PD98059, and p38 MAPK inhibitor SB203580, as well as NADPH oxidase inhibitor DPI and neutrophil elastase inhibitor Alvelestat. The results showed that MSU and PMA triggered significant NET formation, which was accompanied by increased ROS levels, lactate dehydrogenase release, dsDNA, and IL-8. Notably, selective MAPK pathway inhibitors and DPI and Alvelestat, except for SB203580, effectively down-regulated these indicators. These data indicated that the activation of a signaling pathway involving Ras-Raf-ERK, which is dependent on ROS, is crucial for the induction of NET formation by MSU and PMA. Given the involvement of NETs in multiple pathologies, our findings could potentially serve as molecular targets for the intervention and treatment of crystal-related diseases, especially for gout.

The Association Between Serum Uric Acid Levels and the Risk of Cognitive Dysfunction in Patients With Atrial Fibrillation

Patients with atrial fibrillation (AF) are linked to an increased risk of cognitive dysfunction, and serum uric acid levels play an important factor in cognitive dysfunction. However, the optimal serum uric acid level in patients with AF remains unclear. Therefore, we aimed to explore the relationship between serum uric acid and cognitive dysfunction. 583 patients were conducted in the Affiliated Hospital of Jining Medical University. Cognitive dysfunction was assessed by the Montreal Cognitive Assessment (MoCA). The relationship between serum uric acid levels and the risk of cognitive dysfunction in patients with AF was analyzed using the smoothing spline fitting model and threshold analysis. The average serum uric acid level was (383.26 ± 110.11) μmol/L, and the incidence of cognitive dysfunction was 79.76%. There was a non-linear relationship between serum uric acid levels and the risk of cognitive dysfunction in patients with AF, and the inflection point was 352 μmol/L. At the left of the inflection point, the relationship was significant (OR = 1.02, 95% CI = 1.00-1.04). At the right of the inflection point, there was no statistical difference (p=0.101). When serum uric acid levels are less than 352 μmol/L, the risk of cognitive dysfunction increases by 2% for each unit increase in serum uric acid levels in patients with AF. The study provides evidence for the treatment of serum uric acid levels in patients with AF.

Neutrophil diversity and function in health and disease

Neutrophils, the most abundant type of granulocyte, are widely recognized as one of the pivotal contributors to the acute inflammatory response. Initially, neutrophils were considered the mobile infantry of the innate immune system, tasked with the immediate response to invading pathogens. However, recent studies have demonstrated that neutrophils are versatile cells, capable of regulating various biological processes and impacting both human health and disease. Cytokines and other active mediators regulate the functional activity of neutrophils by activating multiple receptors on these cells, thereby initiating downstream signal transduction pathways. Dysfunctions in neutrophils and disruptions in neutrophil homeostasis have been implicated in the pathogenesis of numerous diseases, including cancer and inflammatory disorders, often due to aberrant intracellular signaling. This review provides a comprehensive synthesis of neutrophil biological functions, integrating recent advancements in this field. Moreover, it examines the biological roles of receptors on neutrophils and downstream signaling pathways involved in the regulation of neutrophil activity. The pathophysiology of neutrophils in numerous human diseases and emerging therapeutic approaches targeting them are also elaborated. This review also addresses the current limitations within the field of neutrophil research, highlighting critical gaps in knowledge that warrant further investigation. In summary, this review seeks to establish a comprehensive and multidimensional model of neutrophil regulation, providing new perspectives for potential clinical applications and further research.

An observational study of ultrasound semiquantitative scoring for predicting the risk of gout flare

OBJECTIVE

An observational study was conducted to determine whether semiquantitative scoring of ultrasound signs of gout predicted flare over 12 months.

METHODS

Gout patients were enrolled consecutively in this 12-month prospective observational single-center study. Ultrasound evaluation and clinical assessment were performed at baseline. All patients were examined bilaterally evaluating 14 joints (knee, ankle, metatarsophalangeal joints 1-5) and 10 tendons (posterior tibial, quadriceps, peroneus longus and brevis scored as one, patellar, and Achilles tendons). The following ultrasound features were examined and semiquantitative scoring was performed: DC sign, aggregates, tophi, bone erosion, synovial hypertrophy, PD activity, and tenosynovitis. Patients were divided into two groups, one with flares during the follow-up period and the other without flares.

RESULTS

A total of 119 participants completed the study; 61 (51.3%) participants experienced at least one flare over 12 months, with a median of 2.0 flares. The ultrasound findings indicative of DC sign, aggregate, tophi, bone erosion, and PD activity at baseline were significantly correlated with the development of gout flares over 12 months. Logistic regression analysis suggested that DC sign score (OR: 2.41, 95% CI: 0.92-4.37; P = 0.02), tophi score (OR: 1.87, 95% CI: 0.65-2.28; P = 0.04), and PD activity score (OR: 1.93, 95% CI: 0.58-3.26; P = 0.03) were independent predictors of flare. ROC curve analysis to assess ultrasound semiquantitative scoring has good sensitivity and specificity for the prediction of gout flares.

CONCLUSION

Ultrasound semiquantitative scoring can predict the risk of flare, and ultrasound findings indicative of DC sign, tophi, and PD activity are independent predictors of gout flares over 12 months.

Exploring genetic links between blood metabolites and gout susceptibility

BACKGROUND

Gout, a prevalent form of inflammatory arthritis, has a complex etiology where the causal relationship between metabolites and the disease remains underexplored. This study aims to elucidate the impact of genetically determined blood metabolites on gout.

METHODS

Employing a two-sample bidirectional Mendelian randomization analysis, we examined the association between 1400 blood metabolites and gout. Causal associations were determined using the inverse variance weighted (IVW) method with false discovery rate (FDR) correction. Sensitivity analyses encompassed weighted models, MR-Egger, weighted median, and MR-PRESSO approaches. MR-pleiotropy and Cochran's Q statistic were utilized to evaluate potential heterogeneity and pleiotropy. Additionally, metabolic pathway analyses were conducted to pinpoint relevant pathways.

RESULTS

Of the initial 4 serum metabolites identified, 3 known metabolites-hexanoylglutamine levels, mannose content, and the phosphate to mannose ratio-were found to be causally associated with gout, along with 55 serum metabolites identified as potential predictors of gout (PIVW < 0.05). Furthermore, we discovered 3 metabolic pathways implicated in gouty attacks.

CONCLUSION

Our findings, derived from Mendelian randomization, indicate that the identified metabolites and pathways may serve as biomarkers for clinical screening and prevention of gout. Additionally, they offer novel insights into the mechanisms of the disease and potential drug targets. Key points • Conducted a comprehensive Mendelian randomization study involving 1400 blood metabolites to explore their genetic impact on gout development and progression • Identified three key metabolites-hexanoylglutamine, mannose, and the phosphate-to-mannose ratio-with causal associations to gout, highlighting their potential use as biomarkers for early detection and risk stratification • Discovered 55 additional serum metabolites as potential predictors of gout, offering new insights into the pathophysiology of the disease and identifying high-risk individuals • Revealed three novel metabolic pathways involved in gout attacks, providing new therapeutic targets for precision medicine in gout treatment.

Biotransformation characteristics of urate-lowering probiotic fermented apple juice and potential regulatory mechanisms for ameliorating hyperuricemia via mediating gut microbiota and metabolic pathways

Hyperuricemia has evolved into a global public health concern, and applying probiotics fermented apple juice holds promise for alleviating this condition. This study aimed to investigate the biotransformation and metabolic features of urate-lowering probiotics sequentially fermented dealcoholized apple juice (PSFA), and assess its ameliorative effects and potential mechanisms on hyperuricemia mice. Results showed that CICC 6074 and 20,292 possessed excellent purine, nucleotide and nucleoside degradation and acid and bile salt resistance; sequential fermentation decreased the fructose in apple juice, and viable counts reached 3.76 × 108 CFU/mL. Histopathological analysis showed that PSFA ameliorated kidney damage in hyperuricemia mice. Furthermore, PSFA significantly reduced Urea, Creatinine and Uric acid levels in hyperuricemia mice; and inhibited xanthine oxidase activity and the expression of pro-inflammatory factors. Importantly, PSFA reversed gut microbiota dysbiosis and raised the abundance of beneficial bacteria (Lactobacillush, Faecalibaculum and Lachnospiraceae_NK4A136_group). KEGG and COG functional prediction results revealed that the potential mechanism of PSFA to ameliorate hyperuricemia may be lipid metabolism and glycolysis pathways.

Post-hoc analysis of two gout remission definitions in a two-year randomized controlled trial of nurse-led versus usual gout care

OBJECTIVE

To compare the performance of the 2016 preliminary gout remission definition and a simplified gout remission definition in a clinical trial of nurse-led gout care.

METHODS

Data from a 2-year parallel arm, non-blinded, randomised controlled trial of 517 community-derived people with gout were analyzed. Participants were assigned 1:1 to receive nurse-led care or general practitioner usual care. Remission was defined using the 2016 preliminary gout remission definition and a simplified gout remission definition without patient reported outcomes. Binary logistic regression was used to compare intervention groups. General linear models were used to compare Gout Impact Scale (GIS) scores between those in remission and those not in remission using either definition.

RESULTS

Participants in the nurse-led care group were more likely to achieve remission using either definition; at Year 2 the odds ratio was 7.92 [95 % CI 4.86-12.92] using the 2016 preliminary definition and 11.88 [95 % CI 7.49-18.84] using the simplified definition. For all participants, the 2016 preliminary definition was fulfilled by 9.9 % at Year 1 and 28.4 % at Year 2, p < 0.001 and the simplified definition was fulfilled by 17.6 % at Year 1 and 42.7 % at Year 2, p < 0.001. People in remission using either definition had better gout outcomes assessed using the GIS, including greater control over their gout.

CONCLUSION

Both definitions discriminated between the intervention groups and showed high construct validity. The simplified definition identified more people as being in gout remission at Year 1 and Year 2. The simplified definition is a feasible and valid option for defining gout remission.

Tryptophan Metabolism-Regulating Probiotics Alleviate Hyperuricemia by Protecting the Gut Barrier Integrity and Enhancing Colonic Uric Acid Excretion

The balance of gut microbiota affects uric acid synthesis and excretion, influencing the development of hyperuricemia. This study aimed to investigate the effects and mechanisms of probiotics on hyperuricemia and adenine- and potassium oxonate-induced colonic damage. After two months of gavage at 109 CFU/day, the probiotic strains Lactobacillus rhamnosus UA260 and Lactobacillus plantarum YU28, identified through in vitro screening, significantly reduced serum uric acid levels in hyperuricemia mice from 109.71 ± 56.33 to 38.76 ± 15.06 and 33.22 ± 6.91 μmol/L, respectively. These strains attenuated inflammatory, repaired gut barrier damage, and enhanced colonic uric acid transporter function, thereby promoting uric acid excretion. Furthermore, the probiotics significantly reshaped gut microbiota by increasing the abundance of beneficial bacteria, including Lactobacillus and Coprococcus, while modulating tryptophan, purine, and riboflavin metabolism. Changes in tryptophan metabolites, specifically indole-3-propionic acid and indole-3-acetic acid, were correlated with xanthine oxidase activity, colonic injury, and the expression of the uric acid transporter protein ABCG2 during treatment. Probiotics intervention activated aryl hydrocarbon receptor pathways. These findings suggest that probiotics alleviate hyperuricemia and colonic inflammatory by regulating gut microbiota composition and tryptophan microbial metabolite pathways. Probiotics that modulate tryptophan microbial metabolism may provide a potential strategy for treating or preventing hyperuricemia.

Research hotspots and trends related to pain in gouty arthritis from 2014 to 2024: A bibliometric analysis

BACKGROUND

Gouty arthritis is a metabolic condition caused by disordered purine metabolism and elevated uric acid levels. This study adopts a bibliometric approach to analyze current research on pain in gouty arthritis and forecast future research trends.

METHODS

Retrieve relevant research on gouty arthritis pain in the Web of Science core collection database, screen literature, and use visualization software such as CiteSpace, Vosviewers, and R package "Bibliometrix" for analysis.

RESULTS

The total number of documents included was 1133, with 909 articles and 224 reviews. Between 2014 and 2024, there was an overall upward trend in the number of publications about pain in gouty arthritis, with the United States of America and China ranking first and second, respectively, in terms of publication volume. The UNIVERSITY OF ALABAMA BIRMINGHAM had the most publications, and Professor DALBETH N played a key role in this field. According to the keyword analysis, disease management and treatment, particularly methods for enhancing patients' quality of life and reducing symptoms, are research hotspots. For a deeper understanding, attention is also being paid to the epidemiology and pathological mechanisms of the disease. Emerging keywords such as "gut microbiota" and "urate-lowering therapies" indicate growing interest in the interrelationship between gut microbiota and gout, and the development of new treatment methods.

CONCLUSION

This bibliometric study reveals that research on gouty arthritis pain is actively developing. Current hot topics reflect investigations into the deeper pathological mechanisms of gouty arthritis and the development of new treatment methods, including urate-lowering therapies. There is also increasing attention on the role of gut microbiota in the disease. Despite limitations such as the preliminary nature of research methods and insufficient interdisciplinary collaboration, future research directions aim to improve the rigor of research design, strengthen international cooperation, promote unified treatment guidelines, and optimize the diagnosis and treatment of gouty arthritis with new technologies like artificial intelligence, precision medicine, and nanomedicine. This will drive the field towards a deeper scientific understanding, more effective treatment methods, and more comprehensive disease management, ultimately improving patients' prognosis and quality of life.

Causal relationship between gout and liver cancer: A Mendelian randomization and transcriptome analysis

Gout is an inflammatory arthritis resulting from urate crystal deposition, now recognized as part of metabolic syndrome. Hyperuricemia, a hallmark of gout, is associated with various health complications, including liver cancer. Observational studies indicate a link between gout and increased cancer incidence. However, the causal relationship between gout and hepatocellular carcinoma remains uncertain. This study utilizes Mendelian randomization (MR) to explore this connection, minimizing confounding factors commonly present in observational studies. Genome-wide association study data for gout and liver cancer were sourced from the UK Biobank. We selected single nucleotide polymorphisms that are strongly associated with gout and liver cancer as instrumental variables for the analysis. We conducted 2-sample MR analysis using multiple MR methods (MR-Egger, weighted median, inverse variance weighting, and weighted mode) to evaluate causality. Co-localization and transcriptomic analyses were employed to identify target genes and assess their expression in hepatocellular carcinoma tissues. The 2-sample MR analysis indicated a significant causal relationship between gout and heightened liver cancer risk (P_IVW = .014). Co-localization analysis identified phosphatidylethanolamine N-methyltransferase (PEMT) as a crucial gene associated with gout (pH4 = 0.990). Transcriptomic data showed that PEMT expression was significantly higher in normal liver tissues compared to malignant samples (P < .001), and higher PEMT levels correlated with improved survival outcomes (P = .045). Immunohistochemical analysis revealed lower PEMT expression in hepatocellular carcinoma from patients with concurrent gout compared to those without (P < .05). The results indicate that gout increases the risk of hepatocellular carcinoma, with PEMT potentially playing a key role. Although this study focused on European populations, indicating a need for further research in diverse groups, the results emphasize the potential for liver cancer screening in newly diagnosed gout patients. Understanding the relationship between these conditions may inform future clinical practices and cancer prevention strategies.