Update on gout: new therapeutic strategies and options

Development and Validation of an Ultrasound-Based Clinical Radiomics Nomogram for Diagnosing Gouty Arthritis

OBJECTIVE

This study aimed to develop and validate a diagnostic model for gouty arthritis by integrating ultrasonographic radiomic features with clinical parameters.

METHODS

A total of 604 patients suspected of having gouty arthritis were enrolled and randomly divided into a training set (n = 483) and a validation set (n = 121) in a 4:1 ratio. Univariate and multivariate analyses were conducted on the clinical data to identify statistically significant clinical features for constructing an initial diagnostic model. Key radiomic features were identified in the training set using least absolute shrinkage and selection operator (LASSO) regression analysis to establish a radiomic model. A composite clinicoradiomic nomogram was then developed by combining clinical (such as C-reactive protein, erythrocyte sedimentation rate and uric acid level) and radiomic features through logistic regression. The predictive performance of the clinical model, radiomic model and clinicoradiomic nomogram was evaluated in the validation set using receiver operating characteristic curves, calibration curves and decision curve analysis.

RESULTS

The clinicoradiomic nomogram, which integrated imaging features and clinical characteristics via logistic regression, demonstrated superior predictive performance in the validation set, with an area under the curve (AUC) of 0.936 (95% CI: 0.885-0.986), surpassing both clinical (AUC = 0.924; 95% CI: 0.873-0.976) and radiomic models (AUC = 0.828; 95% CI: 0.738-0.918) alone. Decision curve analysis further confirmed the clinical utility of this model, particularly in differentiating between gouty and non-gouty arthritis.

CONCLUSION

Compared with standalone clinical or radiomic models, the ultrasonography-based clinicoradiomic model exhibited enhanced predictive accuracy for diagnosing gouty arthritis, presenting a novel and promising approach for the early diagnosis and management of gouty arthritis.

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.

Exploration of uricase-like activity in Pd@Ir nanosheets and their application in relieving acute gout using self-cascade reaction

Gout, marked by the deposition of sodium urate crystals in joints and peripheral tissues, presents a considerable health challenge. Recent research has shown a growing interest in nanozyme-based treatments for gout. However, literature on nanozymes that combine uricase-like (UOX) activity for uric acid (UA) degradation with catalase (CAT)-like activity for H2O2 elimination through a self-cascade reaction is limited. Herein, we discovered that two-dimensional Pd@Ir nanosheets (NSs) exhibit UOX and CAT activities effectively. Notably, we observed a size-dependent effect of Pd@Ir on activation energy during UA degradation, with the larger Pd@Ir NSs demonstrating a lower energy barrier. The 46-nm Pd@Ir had activation energy as low as 35.9 kJ/mol, surpassing the efficiency of natural bacterial uricase and most reported nanozymes. Through a tandem self-cascade reaction of Pd@Ir, UA was effectively degraded via UOX activity, while the byproduct H2O2 was simultaneously eliminated by CAT-like activity. Cell experiments revealed that Pd@Ir protect normal cells from oxidative stress and promote cell proliferation, demonstrating an excellent self-cascade effect. Additionally, Pd@Ir substantially alleviated gout symptoms in monosodium urate-induced acute gout mice without causing toxic effects on biological organs and tissues. This study opens new avenues for using nanozyme-based cascade reaction systems in the treatment of metabolic diseases.

A Closed-Loop Cascade Strategy for On-Demand Regulation of Uric Acid

Despite that the current anti-hyperuricemia drugs can effectively reduce uric acid (UA) levels, imprecise medication dosage or uncontrolled lowering of UA levels may result in undesired effects. To address this issue, a closed-loop cascade strategy based on a biocompatible network composite, NW-FPNP/uricase (UOX), is proposed for on-demand regulation of UA levels. NW-FPNP/UOX is constructed by encapsulation of UOX) as UA-responsive element and FPNP, a nanoparticle of phenylboronic acid modified xanthine oxidase (XOD) inhibitor febuxostat, as H2O2-sensitive element with AMP/Gd3+ network. It interrelates the UA metabolization and generation processes into a closed loop of cascade reactions involving UOX-catalyzed UA metabolization and H2O2 generation, H2O2-triggered febuxostat regeneration and XOD inhibition, and XOD-catalyzed UA generation. Through UA level-dependent auto-adjustment of XOD activity, specially 6% at 600 × 10-6 m UA compared to 82% at 100 × 10-6 m, UA levels can be regulated to an appropriate range through dynamically balancing UA metabolization and generation. This biocompatible on-demand UA regulation system prevents the overdose of UA-lowering medications and avoids hypouricemia in hyperuricemia treatment, demonstrating great potential in intelligent UA level management. This work also introduces a new concept of a closed-loop cascade strategy for on-demand regulation of biochemical indicators within specific thresholds.

Fe Single-Atom and Fe Cluster-Coupled N, S Co-doped Carbon Nanomaterial-Based Flexible Electrochemical Sweat Biosensor for the Real-Time Analysis of Uric Acid and Tyrosine

Fe single-atom and Fe cluster-coupled N, S co-doped carbon nanomaterials (FeSA-FeONC-NSC) were prepared through a two-step high-temperature pyrolysis process using Gelidium corneum enriched with C, Fe, O, N, and S as precursors. The analysis by aberration-corrected scanning transmission electron microscopy and X-ray absorption spectroscopy revealed the presence of single-atom Fe in Fe-N4 coordination structures, along with small clusters as Fe-O-coordinated Fe2O3. Single-atom Fe in the form of Fe2+/Fe3+ provides more electrocatalytic active sites, which synergistically accelerates the charge migration process in the assembly of FeSA-FeONC-NSC with Fe2O3 clusters. The flexible nonenzymatic sensor, based on FeSA-FeONC-NSC and fabricated using a polydimethylsiloxane substrate, exhibited excellent catalytic activity for both uric acid (UA) and tyrosine (Tyr). Low detection limits for UA (0.14 μmol L-1) and Tyr (0.03 μmol L-1) were observed by using chronoamperometry in artificial sweat. The in situ detection of sweat was performed in combination with an integrated circuit board affixed to human skin, and the results were generally consistent with those of the high-performance liquid chromatography method. Therefore, FeSA-FeONC-NSC serves as a good modifier for wearable electrochemical sweat sensor applications.

Polymeric Microspheres with High Mass Fraction of Therapeutics Enabled by the Manipulation of Kinetics Factor During Emulsion Droplet Solidification

High drug‐loaded polymeric microspheres hold promise in biomedical fields due to reduced excipient administration, minimized side effects, and enhanced therapeutical efficacy. Although thermodynamic factors like drug‐carrier material compatibility are well‐known to influence the drug loading capacity of microspheres, they fail to explain the huge difference in drug loading degree observed for polymers and drugs with similar interactions. Here, based on the droplet microfluidic platform, the single droplet solidification process is investigated. The results indicated that amorphous polymers can hinder drug diffusion during droplet solidification compared to crystalline polymers, resulting in a higher drug loading degree. Next, this principle is applied to improve the drug loading capability of crystalline polymers (polycaprolactone (PCL) and poly(L‐lactide) (PLLA)) by random co‐polymerization (poly(caprolactone‐co‐L‐lactide) (PCL‐PLLA)), achieving 6.2–22.2 times increased drug loading degree. Moreover, PCL‐PLLA microspheres with a high content of indomethacin exhibited superior therapeutical efficacy in the treatment of gout arthritis. Overall, these results offer insights into the impact of polymer crystallization on droplet solidification kinetics, which consequently affects the drug loading capacity. These findings provide guidelines for the development of polymers for efficient drug encapsulation.

Biotechnological applications of purine and pyrimidine deaminases

Deaminases, ubiquitous enzymes found in all living organisms from bacteria to humans, serve diverse and crucial functions. Notably, purine and pyrimidine deaminases, while biologically essential for regulating nucleotide pools, exhibit exceptional versatility in biotechnology. This review systematically consolidates current knowledge on deaminases, showcasing their potential uses and relevance in the field of biotechnology. Thus, their transformative impact on pharmaceutical manufacturing is highlighted as catalysts for the synthesis of nucleic acid derivatives. Additionally, the role of deaminases in food bioprocessing and production is also explored, particularly in purine content reduction and caffeine production, showcasing their versatility in this field. The review also delves into most promising biomedical applications including deaminase-based GDEPT and genome and transcriptome editing by deaminase-based systems. All in all, illustrated with practical examples, we underscore the role of purine and pyrimidine deaminases in advancing sustainable and efficient biotechnological practices. Finally, the review highlights future challenges and prospects in deaminase-based biotechnological processes, encompassing both industrial and medical perspectives.

Transcutaneous auricular vagus nerve stimulation mitigates gouty inflammation by reducing neutrophil infiltration in BALB/c mice

Gouty inflammation, caused by uric acid crystal deposition, primarily affects tissues around the toe joints and triggers potent inflammatory responses. Current treatments focus on alleviating inflammation and pain using pharmaceutical agents, which can lead to side effects and complications. This has generated interest in non-pharmacological interventions, such as non-invasive vagus nerve stimulation (VNS). In this study, we explored the anti-inflammatory mechanisms of transcutaneous auricular vagus nerve stimulation (taVNS) in a mouse model of acute gout. Gouty inflammation was induced by injecting monosodium urate (MSU) crystals into the ankle joints of BALB/c mice. The effects of taVNS on the expression of inflammatory cytokines and chemokines in the ankle joint tissue were assessed using real-time quantitative PCR (qPCR), western blotting, histological assessments (H&E staining), and immunohistochemistry (IHC). The role of α7 nicotinic acetylcholine receptors (α7nAChR) was also evaluated by signal blocking. Our findings revealed that MSU significantly elevated gout-associated inflammatory cascades and mediators in the ankle joint. Notably, taVNS at 200 µA and 25 Hz effectively reduced these inflammatory responses, decreasing neutrophil infiltration and chemoattraction within the tissue. taVNS showed significant anti-inflammatory properties by suppressing neutrophil activity, offering a novel therapeutic approach for gout beyond conventional pharmacological methods. Additionally, taVNS holds potential for managing various chronic joint diseases. These results highlight taVNS as a promising non-pharmacological therapy for chronic inflammation.

Wearable Hydrogel SERS Chip Utilizing Plasmonic Trimers for Uric Acid Analysis in Sweat

Uric acid is typically measured through blood tests, which can be inconvenient and uncomfortable for patients. Herein, we propose a wearable surface-enhanced Raman scattering (SERS) chip, incorporating a hydrogel membrane with integrated plasmonic trimers, for noninvasive monitoring of uric acid in sweat. The plasmonic trimers feature sub 5 nm nanogaps, generating strong electromagnetic fields to boost the Raman signal of surrounding molecules. Simultaneously, the hydrogel membrane pumps sweat through these gaps, efficiently capturing sweat biomarkers for SERS detection. The chip can achieve saturation adsorption of sweat within 5 min, eliminating variations in individual sweat production rates. Dynamic SERS tracking of uric acid and lactic acid levels during anaerobic exercise reveals a temporary suppression of uric acid metabolism, likely due to metabolic competition with lactic acid. Furthermore, long-term monitoring correlates well with blood test results, confirming that regular exercise helps reduce serum uric acid levels and supporting its potential in managing hyperuricemia.

Anti-gouty arthritis and anti-inflammatory effects of curcumin nanoparticles in monosodium urate crystals induced Balb/C mice

Gout is a metabolic condition characterized by the accumulation of urate crystals in the synovial joints. These crystal depositions result in joint swelling and increased concentration of serum uric acid in blood. The commercially available drugs lower serum uric acid levels and reduce inflammation, but these standard therapies have many side effects. This study aimed to investigate anti-gout and anti-inflammatory properties of curcumin nanoparticles (CNPs). For this purpose, CNPs were prepared by dissolving curcumin into dichloromethane. Then, gout was induced by injecting monosodium urate crystals (MSU) in the ankle joint and in the intra-peritoneal cavity which caused ankle swelling and increased blood uric acid levels. CNPs in different concentrations (5, 10, and 20 ppm) and allopurinol were orally administered. The MSU crystals increased the xanthine oxidase levels both in serum and the liver. Moreover, MSU crystals increased the serum levels of interleukin 1β, interleukin-6, tumor necrosis factor-alpha, liver function tests markers, renal function tests markers, and lipid profiles. However, the administration of CNPs decreased the levels of all these variables. CNPs increased the serum high-density lipoprotein and interleukin-10 levels. Moreover, CNPs also reduced ankle swelling significantly. Hence, the levels of xanthine oxidase, uric acid and ankle swelling were reduced significantly by oral administration of CNPs. Our findings indicate that CNPs through their anti-inflammatory properties significantly alleviate gouty arthritis. Thus, the study concluded that CNPs can be developed as an efficient anti-gout agent with minimal side effects.

Diagnostic values of different musculoskeletal ultrasound signs, serum uric acid, and their combined detection for gouty arthritis

Objectives

The study aimed to investigate the diagnostic values of different musculoskeletal ultrasound (MSUS) signs, serum uric acid (SUA), and their combined detection for gouty arthritis (GA).

Patients and methods

In this retrospective study, 70 patients (62 males, 8 females; mean age: 46.1±14.1 years; range, 25 to 86 years) diagnosed with GA (the GA group) between August 2022 and March 2023 and 70 patients (54 females, 16 males; mean age: 49.0±14.1 years; range, 21 to 75 years) diagnosed with rheumatoid arthritis and osteoarthritis during the same period (the non-GA group) were included. The positive rate of MSUS signs and SUA in both groups was recorded to compare the differences. The correlations of MSUS signs and SUA with GA were analyzed using Spearman's rank correlation analysis. The diagnostic values of different MSUS signs, SUA, and their combined detection for GA were analyzed using a receiver operating characteristic, the area under the curve (AUC), sensitivity, specificity, and the Youden index.

Results

The positive rate of the double contour (DC) sign (chi-squared [χ2 ]=102.935, p<0.001), hyperechoic spots (χ2=56.395, p<0.001), bone erosions (χ2 =10.080, p<0.001), and SUA (χ2 =41.117, p <0.001) were higher in the GA group than in the non-GA group. The positive rate of the DC sign (rs=0.829, p=0.001), hyperechoic spots (rs=0.631, p<0.001), bone erosion (rs=0.268, p=0.001), and SUA (rs=0.542, p<0.001) were positively correlated with GA. Among the single-indicator measures, the DC sign exhibited the highest diagnostic value (AUC=0.907, sensitivity=81.4%, specificity=100%, p<0.001). Among the combined-indicator measures, the DC sign combined with SUA exhibited the highest diagnostic value (AUC=0.929, sensitivity=91.4%, specificity=94.3%, p<0.001), higher than DC sign detection alone.

Conclusion

The DC sign combined with SUA yielded a high diagnostic value and can thus provide a reliable basis for effectively and efficiently diagnosing GA.

Analyzing chemical composition of Sargentodoxae caulis water extract and their hypouricemia effect in hyperuricemic mice

Hyperuricemia (HUA) is a metabolic disease characterized by the increase of serum uric acid (UA) level. Sargentodoxae Caulis (SC) is a commonly used herbal medicine for the treatment of gouty arthritis, traumatic swelling, and rheumatic arthritis in clinic. In this study, a total of fifteen compounds were identified in SC water extract using UHPLC-Q-TOF-MS/MS, including three phenolic acids, seven phenolic glycosides, four organic acids, and one lignan. Then, to study the hypouricemia effect of SC, a HUA mouse model was induced using a combination of PO, HX, and 20% yeast feed. After 14 days of treatment with the SC water extract, the levels of serum UA, creatinine (CRE), blood urea nitrogen (BUN) were reduced significantly, and the organ indexes were restored, the xanthine oxidase (XOD) activity were inhibited as well. Meanwhile, SC water extract could ameliorate the pathological status of kidneys and intestine of HUA mice. Additionally, quantitative real-time PCR (qRT-PCR) and western blotting results showed that SC water extract could increase the expression of ATP binding cassette subfamily G member 2 (ABCG2), organic cation transporter 1 (OCT1), organic anion transporter 1 (OAT1) and organic anion transporter 3 (OAT3), whereas decrease the expression of glucose transporter 9 (GLUT9). This study provided a data support for the clinical application of SC in the treatment of HUA.

Signaling pathways in uric acid homeostasis and gout: From pathogenesis to therapeutic interventions

Uric acid is a product of purine degradation, and uric acid may have multiple physiologic roles, including the beneficial effects as an antioxidant and neuroprotector, maintenance of blood pressure during low salt ingestion, and modulation of immunity. However, overproduction of metabolic uric acid, and/or imbalance of renal uric acid secretion and reabsorption, and/or underexcretion of extrarenal uric acid, e.g. gut, will contribute to hyperuricemia, which is a common metabolic disease. Long-lasting hyperuricemia can induce the formation and deposition of monosodium urate (MSU) crystals within the joints and periarticular structures. MSU crystals further induce an acute, intensely painful, and sterile inflammation conditions named as gout by NLRP3 inflammasome-mediated cleavage of pro-IL-1β to bioactive IL-1β. Moreover, hyperuricemia and gout are associated with multiple cardiovascular and renal disorders, e.g., hypertension, myocardial infarction, stroke, obesity, hyperlipidemia, type 2 diabetes mellitus and chronic kidney disease. Although great efforts have been made by scientists of modern medicine, however, modern therapeutic strategies with a single target are difficult to exert long-term positive effects, and even some of these agents have severe adverse effects. The Chinese have used the ancient classic prescriptions of traditional Chinese medicine (TCM) to treat metabolic diseases, including gout, by multiple targets, for more than 2200 years. In this review, we discuss the current understanding of urate homeostasis, the pathogenesis of hyperuricemia and gout, and both modern medicine and TCM strategies for this commonly metabolic disorder. We hope these will provide the good references for treating hyperuricemia and gout.

Deficiency of histone deacetylases 3 in macrophage alleviates monosodium urate crystals-induced gouty inflammation in mice

BACKGROUND

Gout is caused by monosodium urate (MSU) crystals deposition to trigger immune response. A recent study suggested that inhibition of Class I Histone deacetylases (HDACs) can significantly reduce MSU crystals-induced inflammation. However, which one of HDACs members in response to MSU crystals was still unknown. Here, we investigated the roles of HDAC3 in MSU crystals-induced gouty inflammation.

METHODS

Macrophage specific HDAC3 knockout (KO) mice were used to investigate inflammatory profiles of gout in mouse models in vivo, including ankle arthritis, foot pad arthritis and subcutaneous air pouch model. In the in vitro experiments, bone marrow-derived macrophages (BMDMs) from mice were treated with MSU crystals to assess cytokines, potential target gene and protein.

RESULTS

Deficiency of HDAC3 in macrophage not only reduced MSU-induced foot pad and ankle joint swelling but also decreased neutrophils trafficking and IL-1β release in air pouch models. In addition, the levels of inflammatory genes related to TLR2/4/NF-κB/IL-6/STAT3 signaling pathway were significantly decreased in BMDMs from HDAC3 KO mice after MSU treatment. Moreover, RGFP966, selective inhibitor of HDAC3, inhibited IL-6 and TNF-α production in BMDMs treated with MSU crystals. Besides, HDAC3 deficiency shifted gene expression from pro-inflammatory macrophage (M1) to anti-inflammatory macrophage (M2) in BMDMs after MSU challenge.

CONCLUSIONS

Deficiency of HDAC3 in macrophage alleviates MSU crystals-induced gouty inflammation through inhibition of TLR2/4 driven IL-6/STAT3 signaling pathway, suggesting that HDAC3 could contribute to a potential therapeutic target of gout.

Comparison of the efficacy and safety of benzbromarone and febuxostat in gout and hyperuricemia: a systematic review and meta-analysis

OBJECTIVE

Urate-lowering therapy (ULT) is widely recognized as the primary treatment for hyperuricemia and gout. Xanthine oxidase inhibitors (XOI), particularly febuxostat, have gained popularity as a frontline approach. However, the divergent efficacy and safety between febuxostat and the traditional ULT drug, benzbromarone, remain poorly understood. This knowledge gap necessitates a comprehensive analysis and evidence update to guide drug selection for physicians and patients.

METHOD

We conducted a systematic analysis by extracting relevant clinical studies from four medical literature databases. Forest plots, funnel plots, sensitivity analysis, Egger's test, and subgroup analysis were utilized to compare relevant indicators.

RESULTS

The advantages and disadvantages of the two drugs were evaluated based on various indicators such as serum uric acid (SUA), triglyceride (TG), urinary uric acid (UUA), white blood cell count (WBC), total cholesterol (TC), blood urea nitrogen (BUN), alanine aminotransferase (ALT), aspartate aminotransferase (AST), estimated glomerular filtration rate (eGFR), and serum creatinine (SC). Benzbromarone demonstrated better efficacy in rapidly reducing SUA levels and inhibiting inflammation for hyperuricemia and gout patients. Febuxostat was slightly less effective in lowering SUA, but there was no significant difference in its impact on liver and kidney function after long-term use.

CONCLUSION

This study highlights the superiority of benzbromarone in rapidly reducing SUA and inhibiting inflammation. Febuxostat shows comparable effects on liver and kidney function after long-term use. These findings provide valuable insights for clinicians and patients in drug selection. Key Points • Benzbromarone stands out as a highly effective treatment for hyperuricemia and gout, offering rapid reduction of serum uric acid levels and potent anti-inflammatory effects. • When it comes to long-term use, febuxostat demonstrates comparable effects on liver and kidney function. This provides reassurance for patients who require extended treatment duration. • Moreover, our study goes beyond previous research by presenting a more comprehensive and detailed analysis.

CXCL5 activates CXCR2 in nociceptive sensory neurons to drive joint pain and inflammation in experimental gouty arthritis

Gouty arthritis evokes joint pain and inflammation. Mechanisms driving gout pain and inflammation remain incompletely understood. Here we show that CXCL5 activates CXCR2 expressed on nociceptive sensory neurons to drive gout pain and inflammation. CXCL5 expression was increased in ankle joints of gout arthritis model mice, whereas CXCR2 showed expression in joint-innervating sensory neurons. CXCL5 activates CXCR2 expressed on nociceptive sensory neurons to trigger TRPA1 activation, resulting in hyperexcitability and pain. Neuronal CXCR2 coordinates with neutrophilic CXCR2 to contribute to CXCL5-induced neutrophil chemotaxis via triggering CGRP- and substance P-mediated vasodilation and plasma extravasation. Neuronal Cxcr2 deletion ameliorates joint pain, neutrophil infiltration and gait impairment in model mice. We confirmed CXCR2 expression in human dorsal root ganglion neurons and CXCL5 level upregulation in serum from male patients with gouty arthritis. Our study demonstrates CXCL5-neuronal CXCR2-TRPA1 axis contributes to gouty arthritis pain, neutrophil influx and inflammation that expands our knowledge of immunomodulation capability of nociceptive sensory neurons.

Comparison of efficacy of acupuncture-related therapies in treating Acute Gouty Arthritis: A Network Meta-Analysis of Randomized Controlled Trials

Background

and purpose: Acupuncture and moxibustion, as a complementary and alternative therapy, has been widely used in the treatment of acute gouty arthritis (AGA). However, there are various forms of acupuncture and moxibustion, and the curative effect of different forms is different. This study evaluated the clinical efficacy of different acupuncture therapies in treating AGA by network meta-analysis.

Methods

Computer searches of English databases (including PubMed, The Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science, Embase) and Chinese databases (including China National Knowledge Infrastructure (CNKI), VIP Database, Wanfang Database and China Biomedical Literature Database) were conducted for randomized controlled trials (RCTs) of acupuncture therapies in treating AGA. We set the search time from the database establishment to May 2022. Data analysis was performed using Stata14.2 software.

Results

Thirty-two RCTs involving 2434 patients with AGA were screened out. The results showed that in terms of the improvement of pain visual analogue scale (VAS) scores, the top ones were acupoint application (100%), electroacupuncture + Western medicine (73.5%) and acupuncture + Western medicine (69.2%); In terms of total effective rate, acupoint application (85.2%), acupuncture (75.2%) and acupuncture + Western medicine (63%) ranked the top; In terms of reducing serum uric acid (SUA) levels, the top ones were acupoint application (95%), acupuncture + Western medicine (87.5%) and acupuncture (66.2%); In terms of the reduction of erythrocyte sedimentation rate (ESR), acupuncture (95%), acupoint application (84.7%), and electroacupuncture + Western medicine (52.8%) were the most prominent.

Conclusion

The existing evidence shows that acupoint application has more advantages in improving the total effective rate, improving pain and reduce SUA levels, and acupuncture has an advantage in reducing ESR levels and adverse events. However, due to the low qualities of the original studies, the quality of this evidence is poor. Therefore, it is recommended that more scientific research be performed to confirm the efficacy of acupuncture.

Polyvinylpyrrolidone-Coated Cubic Hollow Nanocages of PdPt3 and PdIr3 as Highly Efficient Self-Cascade Uricase/Peroxidase Mimics

Uricase-catalyzed uric acid (UA) degradation has been applied for hyperuricemia therapy, but this medication is limited by H2O2 accumulation, which can cause oxidative stress of cells, resulting in many other health issues. Herein, we report a robust cubic hollow nanocage (HNC) system based on polyvinylpyrrolidone-coated PdPt3 and PdIr3 to serve as highly efficient self-cascade uricase/peroxidase mimics to achieve the desired dual catalysis for both UA degradation and H2O2 elimination. These HNCs have hollow cubic shape with average wall thickness of 1.5 nm, providing desired synergy to enhance catalyst's activity and stability. Density functional theory calculations suggest the PdIr3 HNC surface tend to promote OH*/O* desorption for better peroxidase-like catalysis, while the PdPt3 HNC surface accelerates the UA oxidation by facilitating O2-to-H2O2 conversion. The dual catalysis power demonstrated by these HNCs in cell studies suggests their great potential as a new type of nanozyme for treating hyperuricemia.

Targeting Neutrophil Extracellular Traps in Gouty Arthritis: Insights into Pathogenesis and Therapeutic Potential

Gouty arthritis (GA) is an immune-mediated disorder characterized by severe inflammation due to the deposition of monosodium urate (MSU) crystals in the joints. The pathophysiological mechanisms of GA are not yet fully understood, and therefore, the identification of effective therapeutic targets is of paramount importance. Neutrophil extracellular traps (NETs), an intricate structure of DNA scaffold, encompassing myeloperoxidase, histones, and elastases - have gained significant attention as a prospective therapeutic target for gouty arthritis, due to their innate antimicrobial and immunomodulatory properties. Hence, exploring the therapeutic potential of NETs in gouty arthritis remains an enticing avenue for further investigation. During the process of gouty arthritis, the formation of NETs triggers the release of inflammatory cytokines, thereby contributing to the inflammatory response, while MSU crystals and cytokines are sequestered and degraded by the aggregation of NETs. Here, we provide a concise summary of the inflammatory processes underlying the initiation and resolution of gouty arthritis mediated by NETs. Furthermore, this review presents an overview of the current pharmacological approaches for treating gouty arthritis and summarizes the potential of natural and synthetic product-based inhibitors that target NET formation as novel therapeutic options, alongside elucidating the intrinsic challenges of these inhibitors in NETs research. Lastly, the limitations of HL-60 cell as a suitable substitute of neutrophils in NETs research are summarized and discussed. Series of recommendations are provided, strategically oriented towards guiding future investigations to effectively address these concerns. These findings will contribute to an enhanced comprehension of the interplay between NETs and GA, facilitating the proposition of innovative therapeutic strategies and novel approaches for the management of GA.

A Wearable Electrochemical Biosensor Utilizing Functionalized Ti3C2Tx MXene for the Real-Time Monitoring of Uric Acid Metabolite

Wearable, noninvasive sensors enable the continuous monitoring of metabolites in sweat and provide clinical information related to an individual's health and disease states. Uric acid (UA) is a key indicator highly associated with gout, hyperuricaemia, hypertension, kidney disease, and Lesch-Nyhan syndrome. However, the detection of UA levels typically relies on invasive blood tests. Therefore, developing a wearable device for noninvasive monitoring of UA concentrations in sweat could facilitate real-time personalized disease prevention. Here, we introduce 1,3,6,8-pyrene tetrasulfonic acid sodium salt (PyTS) as a bifunctional molecule functionalized with Ti3C2Tx via π-π conjugation to design nonenzymatic wearable sensors for sensitive and selective detection of UA concentration in human sweat. PyTS@Ti3C2Tx provides many oxidation-reduction active groups to enhance the electrocatalytic ability of the UA oxidation reaction. The PyTS@Ti3C2Tx-based electrochemical sensor demonstrates highly sensitive detection of UA in the concentration range of 5 μM-100 μM, exhibiting a lower detection limit of 0.48 μM compared to the uricase-based sensor (0.84 μM). In volunteers, the PyTS@Ti3C2Tx-based wearable sensor is integrated with flexible microfluidic sweat sampling and wireless electronics to enable real-time monitoring of UA levels during aerobic exercise. Simultaneously, it allows for comparison of blood UA levels via a commercial UA analyzer. Herein, this study provides a promising electrocatalyst strategy for nonenzymatic electrochemical UA sensor, enabling noninvasive real-time monitoring of UA levels in human sweat and personalized disease prevention.

Epidemiology of gout - Global burden of disease research from 1990 to 2019 and future trend predictions

Background

Understanding the global burden of gout in the past and future can provide important references for optimizing prevention and control strategies in healthcare systems.

Objectives

This study aimed to report variations in the global disease burden and risk factors of gout in 204 countries and territories from 1990 to 2019.

Design

We conducted a retrospective analysis of gout based on the latest Global Burden of Disease (GBD) 2019 database.

Methods

We collected data on the prevalence, incidence, and disability-adjusted life years (DALYs) of gout from 1990 to 2019. The data were then stratified by age, sex, and economic development level. Decomposition analysis, frontier analysis, and prediction models were used to analyze the changes and influencing factors influencing each indicator.

Results

Globally, there were 53,871,846.4 [95% uncertainty interval (UI): 43,383,204.6-66,342,327.3] prevalent cases, 92,228,86.8 (95% UI: 7419,132.1-11,521,165) incident cases, and 1673,973.4 (95% UI: 1,068,061.1-2,393,469.2) cases of DALYs of gout in 2019, more than double those in 1990. Moreover, the pace of increase in the age-standardized prevalence rate (ASPR), age-standardized incidence rate (ASIR), and age-standardized DALY rate (ASDR) accelerated during 1990-2019, with estimated annual percentage changes (EAPC) of 0.94 [95% confidence interval (CI): 0.85-1.03], 0.77 (95% CI: 0.69-0.84), and 0.93 (95% CI: 0.84-1.02), respectively, especially among men. The disease burden of gout has increased in all the other 20 GBD regions in the past 30 years, except Western Sub-Saharan Africa. The highest risk of high body mass index (BMI) and kidney dysfunction was in high-income countries such as North America and East Asia. The global prevalence rate, incidence rate, and DALYs rate of gout in 2030 will reach 599.86, 102.96 per 100,000 population, and 20.26 per 100,000 population, respectively, roughly the same as in 2019.

Conclusion

With the development of society, the disease burden of gout will become increasingly severe. It is very important to study the accurate epidemiological data on gout for clinical diagnosis and treatment and health policy.

Association between patient adherence and treat-to-target in gout: A cross-sectional study

The implementation of a treat-to-target (T2T) approach has been widely recommended for achieving optimal outcomes in gout treatment, as substantiated by a wealth of compelling evidence. However, a paucity of knowledge exists regarding the barriers hindering effective T2T management in China. This study seeks to investigate the factors contributing to treatment failure within the context of the T2T strategy. A cross-sectional, multi-center investigation was conducted, involving the completion of electronic questionnaires by outpatients undergoing urate-lowering treatment for a duration exceeding 6 months. These questionnaires encompassed demographic information, disease-related conditions, comorbid conditions, and management. The study analyzed factors associated with serum uric acid levels exceeding 360 µmol/L, poor disease control, and poor medication adherence. A total of 425 valid questionnaires were collected, representing 90.8% of the patients. The T2T implementation rate was 26.82% (n = 114). Factors linked to serum uric acid levels surpassing 360 µmol/L included moderate medication adherence (odds ratio (OR) = 2.35; 95% confidence interval (CI) 1.17-4.77; P = .016), poor medication adherence (OR = 4.63; 95% CI 2.28-9.51; P < .001), and management by general practitioners (OR = 0.60; 95% CI 0.37-0.97; P = .036). The rate of well-controlled patients was 14.35% (n = 61). Predictors of not well controlled encompassed the presence of tophi (OR = 2.48; 95% CI 1.17-5.61; P = .023), general medication adherence (OR = 2.78; 95% CI 1.28-6.05; P = .009), poor medication adherence (OR = 6.23; 95% CI 2.68-14.77; P < .001), and poor patient's perception of gout (OR = 4.07; 95% CI 1.41-13.91; P = .015). A poor medication adherence rate of 55.29% (n = 235) was observed, with lower rates of poor medication adherence associated with the use of febuxostat (OR = 0.35; 95% CI 0.14-0.83; P = .02), uric acid levels exceeding 360 µmol/L (OR = 3.05; 95% CI 1.84-5.12; P = .00), moderate patient education (OR = 2.28; 95% CI 1.29-4.15; P = .01), moderate diet control (OR = 1.98; 95% CI 1.17-3.41; P = .01), and poor diet control (OR = 3.73; 95% CI 1.26-12.83; P = .02). The rate of T2T implementation in China is notably low among patients undergoing urate-lowering treatment of gout beyond 6 months. Importantly, medication adherence demonstrates a significant association with T2T outcomes.

Activation of Nrf2 antioxidant signaling alleviates gout arthritis pain and inflammation

Excessive deposition of monosodium urate (MSU) crystal in the joint results in gout arthritis, which triggers severe pain and affects life quality. Oxidative stress is a pivotal mechanism that contributes to etiology of gout pain and inflammation. Here we investigated whether activating Nrf2, which plays important roles in regulating endogenous antioxidant response, would attenuate gout arthritis via promoting antioxidant signaling in joint tissues. Gout arthritis model was established by intra-articular injection of MSU (500 μg/ankle) into the right ankle joint of mouse. Pharmacologically activating Nrf2 by activator oltipraz (50, 100 or 150 mg/kg, intraperitoneal) at 1 h before and 5, 23, 47 h after model establishment dose-dependently inhibited joint inflammation, mechanical and heat hypersensitivities in model mice. Oltipraz (100 mg/kg) reversed gait impairments without altering locomotor activity and reduced neutrophil infiltrations in ankle joints. In vitro studies revealed oltipraz (25 μM) inhibited MSU-induced ROS production in mouse macrophages and improved mitochondrial bioenergetics impairments caused by MSU. In vivo ROS imaging combined with biochemical assays confirmed the antioxidant effects of oltipraz on model mice. Nrf2 activation inhibited pro-inflammatory cytokine overproduction in ankle joint and attenuated the overexpression and enhancement in TRPV1 channel in DRG neurons innervating hind limb. Therapeutic effects of oltipraz were abolished by inhibiting Nrf2 or in Nrf2 knockout mice. These results suggest pharmacologically activating Nrf2 alleviates gout pain, gait impairments, inflammation and peripheral sensitization via Nrf2-dependent antioxidant mechanism. Targeting Nrf2 may represent a novel treatment option for gout arthritis.

Chemical Comparison and Identification of Xanthine Oxidase Inhibitors of Dioscoreae Hypoglaucae Rhizoma and Dioscoreae Spongiosae Rhizoma by Chemometric Analysis and Spectrum-Effect Relationship

Dioscoreae hypoglaucae Rhizoma (DH) and Dioscoreae spongiosae Rhizoma (DS) are two similar Chinese herbal medicines derived from the Dioscorea family. DH and DS have been used as medicines in China and other Asian countries for a long time, but study on their phytochemicals and bioactive composition is limited. This present study aimed to compare the chemical compositions of DH and DS, and explore the anti-xanthine oxidase components based on chemometric analysis and spectrum-effect relationship. Firstly, an HPLC method was used to establish the chemical fingerprints of DH and DS samples, and nine common peaks were selected. Then, hierarchical clustering analysis, principal component analysis and orthogonal partial least squares discriminant analysis were employed to compare and discriminate DH and DS samples based on the fingerprints data, and four steroidal saponins compounds (protodioscin, protogracillin, dioscin, gracillin) could be chemical markers responsible for the differences between DH and DS. Meanwhile, the anti-xanthine oxidase activities of these two herbal medicines were evaluated by xanthine oxidase inhibitory assay in vitro. Pearson correlation analysis and partial least squares regression analysis were subsequently used to investigate the spectrum-effect relationship between chemical fingerprints and xanthine oxidase inhibitory activities. The results showed that four steroidal saponins, including protodioscin, protogracillin, methyl protodioscin and pseudoprogracillin could be potential anti-xanthine oxidase compounds in DH and DS. Furthermore, the xanthine oxidase inhibitory activities of the four selected inhibitors were validated by anti-xanthine oxidase inhibitory assessment and molecular docking experiments. The present work provided evidence for understanding of the chemical differences and the discovery of the anti-xanthine oxidase constituent of DH and DS, which could be useful for quality evaluation and bioactive components screening of these two herbal medicines.

Articular mobilization promotes improvement in functional and inflammatory parameters in a gouty arthritis model

OBJECTIVE

Gouty arthritis is characterized by painful inflammation due to the deposition of monosodium urate crystals in joint tissues. Despite available treatments, many patients experience ineffective management and adverse effects. This study evaluated a manual therapy protocol involving passive joint mobilization at the peak of inflammation in a gouty arthritis model using functional and inflammatory parameters.

METHODS

Twenty male Wistar rats, 12 weeks old, were divided into two groups (n=10 each): Gouty Arthritis and Control Groups, which were further subdivided into treated and untreated groups (n=5 each). The Gouty Arthritis Group received intraarticular knee injection of 50µL of monosodium urate crystals, while the Control Group received 50µL of phosphate buffered saline. The treatment involved a 9-minutes session of grade III joint mobilization (according to Maitland). Nociception, grip strength, and edema were evaluated before induction (EV0), 7 hours after assessment (EV1), immediately after treatment (EV2), and 1 hour after treatment (EV3). The animals were euthanized, and synovial fluid was collected to analyze leukocyte migration.

RESULTS

The model mimicked the signs of the Gouty Arthritis Group, with a decrease in the threshold of nociception and strength and an increase in edema and leukocyte count. The mobilization protocol significantly increased the nociceptive threshold and grip strength and reduced edema; however, it did not reverse the increase in leukocyte count.

CONCLUSION

Our results suggest that mobilization promotes analgesia and may modulate the inflammatory process owing to reduced edema and subtle attenuation of cell migration, which contributes to strength gain.

Associations of polychlorinated biphenyl and organochlorine pesticide exposure with hyperuricemia: modification by lifestyle factors

Recent research has reported positive associations of exposure to polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) with hyperuricemia. However, most of these studies have primarily focused on the individual effects of PCB/OCP exposure. We aimed to explore the associations of both individual and combined PCB/OCP exposure with hyperuricemia and examine whether such associations could be modified by lifestyle factors. The cross-sectional study recruited 2032 adults between March and May 2019 in Wuhan, China. Logistic regression and weighted quantile sum (WQS) regression were applied to explore the relationship of individual and combined PCB/OCP exposure with hyperuricemia, while considering the modified effects of lifestyle factors. Of the 2032 participants, 522 (25.7%) had hyperuricemia. Compared with the non-detected group, the detected groups of PCB153 and PCB180 exhibited a positive association with hyperuricemia, with OR (95% CIs) of 1.52 (1.22, 1.91) and 1.51 (1.20, 1.90), respectively. WQS regression showed that PCB/OCP mixture was positively associated with hyperuricemia (OR: 1.31, 95% CI: 1.08, 1.58). PCB153/PCB180 exposure, combined with an unhealthy lifestyle, has a significant additive effect on hyperuricemia. Overall, PCB/OCP mixture and individual PCB153/PCB180 exposure were positively associated with hyperuricemia. Adherence to a healthy lifestyle may modify the potential negative impact of PCBs/OCPs on hyperuricemia.

Knowledge and attitudes of gout patients and their perspectives about diagnosis and management: A cross-sectional study in Saudi Arabia

BACKGROUND

Gout is a chronic noncommunicable disease that might lead to multiple systemic complications if it is left untreated. The knowledge, attitudes, and perceptives among patients toward the diagnosis and management of gout are important indicators in determining the prognosis and predicting sequelae of the disease. This cross-sectional survey aimed to assess the knowledge, attitudes, and perspectives of patients diagnosed with gout toward the disease diagnosis and treatment.

METHODOLOGY

An observational cross-sectional study was conducted at university clinics and local health facilities in central Riyadh, Saudi Arabia, for the duration between April and August 2022. Pearson χ2 test was used to determine the difference in the proportion of patients who adapt different attitudes and perspectives in terms of their demographic variables. Statistical significance was defined as a p value less than .05.

RESULTS

Two-hundred thirteen patients were involved in this study. The majority of the patients (84.0%) were diagnosed for more than 1 year. The majority of the patients (76.5%) were aged 25-60 years when they were diagnosed with gout. The most common complaint at the time of the diagnosis was joint pain (73.7%). The most commonly reported gout medication treatment being used was allopurinol accounting for 23.0%. The majority of the patients (83.6%) were satisfied regarding the effects of gout management on their job performance, work life, and careers. The vast majority (97.5%) reported that they are satisfied with the health service provided.

CONCLUSION

The patients diagnosed with gout in Saudi Arabia exhibited a satisfactory level of information, attitude, and perspectives regarding their condition. The participants expressed a significant degree of satisfaction with the impact of gout management on their occupational performance, work-life balance, and professional plans. Additional research is necessary to ascertain the risk factors associated with gout and provide suitable preventative interventions.

Electroacupuncture improves gout arthritis pain via attenuating ROS-mediated NLRP3 inflammasome overactivation

BACKGROUND

Gout results from disturbed uric acid metabolism, which causes urate crystal deposition in joints and surrounding tissues. Gout pain management is largely limited to colchicine and nonsteroidal anti-inflammatory drugs. Constant usage of these medications leads to severe side effects. We previously showed electroacupuncture (EA) is effective for relieving pain in animal model of gout arthritis. Here we continued to study the mechanisms underlying how EA alleviates gout pain.

METHODS

Monosodium urate was injected into ankle joint to establish gout arthritis model in mice. EA or sham EA was applied at ST36 and BL60 acupoints of model animals. Biochemical assays, immunostaining, live cell Ca²⁺ imaging and behavioral assays were applied.

RESULTS

Model mice displayed obvious mechanical allodynia, accompanied with gait impairments. EA attenuated mechanical hypersensitivities and improved gait impairments. EA reduced the overexpression of NLRP3 inflammasome signaling molecules in ankle joints of model animals. EA-induced anti-allodynia, as well as inhibition on NLRP3 inflammasome, were mimicked by antagonizing but abolished by activating NLRP3 inflammasome via pharmacological methods. EA attenuated oxidative stress, an upstream signaling of NLRP3 inflammasome in ankle joints of model mice. Exogenously increasing oxidative stress abolished EA's inhibitory effect on NLRP3 inflammasome and further reversed EA's anti-allodynic effect. EA reduced neutrophil infiltrations in ankle joint synovium, a major mechanism contributing to oxidative stress in gout. Pharmacological blocking NLRP3 inflammasome or EA reduced TRPV1 channel overexpression in dorsal root ganglion (DRG) neurons. Ca²⁺ imaging confirmed that EA could reduce functional enhancement in TRPV1 channel in DRG neurons during gout.

CONCLUSIONS

Our results demonstrate that EA reduces gout pain possibly through suppressing ROS-mediated NLRP3 inflammasome activation in inflamed ankle joints and TRPV1 upregulation in sensory neurons, supporting EA as a treatment option for gout pain.

Rational design of a genome-based insulated system in Escherichia coli facilitates heterologous uricase expression for hyperuricemia treatment

Hyperuricemia is a prevalent disease worldwide that is characterized by elevated urate levels in the blood owing to purine metabolic disorders, which can result in gout and comorbidities. To facilitate the treatment of hyperuricemia through the uricolysis, we engineered a probiotic Escherichia coli Nissle 1917 (EcN) named EcN C6 by inserting an FtsP-uricase cassette into an "insulated site" located between the uspG and ahpF genes. Expression of FtsP-uricase in this insulated region did not influence the probiotic properties or global gene transcription of EcN but strongly increased the enzymatic activity for urate degeneration, suggesting that the genome-based insulated system is an ideal strategy for EcN modification. Oral administration of EcN C6 successfully alleviated hyperuricemia, related symptoms and gut microbiota in a purine-rich food-induced hyperuricemia rat model and a uox-knockout mouse model. Together, our study provides an insulated site for heterologous gene expression in EcN strain and a recombinant EcN C6 strain as a safe and effective therapeutic candidate for hyperuricemia treatment.

Relationship between phthalates exposures and hyperuricemia in U.S. general population, a multi-cycle study of NHANES 2007-2016

BACKGROUND

Phthalates exposure might cause kidney damage and a potential risk for hyperuricemia. However, direct evidence on phthalates and hyperuricemia is somewhat limited.

OBJECTIVE

To examine associations between 10 phthalates metabolites and hyperuricemia in a large-scale representative of the U.S.

METHODS

A cross-sectional study of 6865 participants aged over 20 from NHANES 2007-2016 was performed. All participants had complete data on ten phthalate metabolites (MECPP, MnBP, MEHHP, MEOHP, MiBP, cx-MiNP, MCOP, MCPP, MEP, MBzP), hyperuricemia, and covariates. We used multivariable logistics regression, restricted cubic splines (RCS) model, and Bayesian kernel machine regression (BKMR) models to assess single, nonlinear, and mixed relationships between phthalate metabolites and hyperuricemia. As a complement, we also assessed the relationship between phthalate metabolites and serum uric acid (SUA) levels.

RESULTS

The multivariable logistics regression showed that MECPP, MEOHP, MEHHP, MBzP, and MiBP were generally positively associated with hyperuricemia (P_FDR < 0.05), especially in MiBP (Q3 (OR (95 %): 1.31 (1.02, 1.68)) and Q4 (OR (95 %): 1.68 (1.27, 2.24)), compared to Q1). All ten phthalate metabolites had a linear dose-response relationship with hyperuricemia in the RCS model (P for non-linear >0.05). BKMR showed that mixed phthalate metabolites were associated with a higher risk of hyperuricemia, with MBzP contributing the most (groupPIP = 0.999, condPIP = 1.000). We observed the consistent results between phthalate metabolites and SUA levels in three statistical models. The relationship between phthalate metabolites and hyperuricemia remained in the sensitivity analysis.

CONCLUSIONS

The present study suggests that exposure to phthalates, individually or jointly, might increase the risk of hyperuricemia. Since hyperuricemia influences on the quality of life, more explorations are needed to confirm these findings.

Progressive alignment of crystals: reproducible and efficient assessment of crystal structure similarity

During in silico crystal structure prediction of organic molecules, millions of candidate structures are often generated. These candidates must be compared to remove duplicates prior to further analysis (e.g. optimization with electronic structure methods) and ultimately compared with structures determined experimentally. The agreement of predicted and experimental structures forms the basis of evaluating the results from the Cambridge Crystallographic Data Centre (CCDC) blind assessment of crystal structure prediction, which further motivates the pursuit of rigorous alignments. Evaluating crystal structure packings using coordinate root-mean-square deviation (RMSD) for N molecules (or N asymmetric units) in a reproducible manner requires metrics to describe the shape of the compared molecular clusters to account for alternative approaches used to prioritize selection of molecules. Described here is a flexible algorithm called Progressive Alignment of Crystals (PAC) to evaluate crystal packing similarity using coordinate RMSD and introducing the radius of gyration (R g) as a metric to quantify the shape of the superimposed clusters. It is shown that the absence of metrics to describe cluster shape adds ambiguity to the results of the CCDC blind assessments because it is not possible to determine whether the superposition algorithm has prioritized tightly packed molecular clusters (i.e. to minimize R g) or prioritized reduced RMSD (i.e. via possibly elongated clusters with relatively larger R g). For example, it is shown that when the PAC algorithm described here uses single linkage to prioritize molecules for inclusion in the superimposed clusters, the results are nearly identical to those calculated by the widely used program COMPACK. However, the lower R g values obtained by the use of average linkage are favored for molecule prioritization because the resulting RMSDs more equally reflect the importance of packing along each dimension. It is shown that the PAC algorithm is faster than COMPACK when using a single process and its utility for biomolecular crystals is demonstrated. Finally, parallel scaling up to 64 processes in the open-source code Force Field X is presented.

Asymptomatic Hyperuricemia Is Associated with Achilles Tendon Rupture through Disrupting the Normal Functions of Tendon Stem/Progenitor Cells

Hyperuricemia is a metabolic disorder that is essential to the development of inflammatory gout, with increasing prevalence over recent years. Emerging clinical findings has evidenced remarkable tendon damage in individuals with longstanding asymptomatic hyperuricemia, yet the impact of hyperuricemia on tendon homeostasis and associated repercussions is largely unknown. Here, we investigated whether asymptomatic hyperuricemia was associated with spontaneous ruptures in the Achilles tendon and the pathological effect of hyperuricemia on the tendon stem/progenitor cells (TSPCs). Significantly higher serum uric acid (SUA) levels were found in 648 closed Achilles tendon rupture (ATR) patients comparing to those in 12559 healthy volunteers. In vitro study demonstrated that uric acid (UA) dose dependently reduced rat Achilles TSPC viability, decreased the expressions of tendon collagens, and deformed their structural organization while significantly increased the transcript levels of matrix degradative enzymes and proinflammatory factors. Consistently, marked disruptions in Achilles tendon tissue structural and functional integrity were found in a rat model of hyperuricemia, together with enhanced immune cell infiltration. Transcriptome analysis revealed a significant elevation in genes involved in metabolic stress and tissue degeneration in TSPCs challenged by hyperuricemia. Specifically, reduced activity of the AKT-mTOR pathway with enhanced autophagic signaling was confirmed. Our findings indicate that asymptomatic hyperuricemia may be a predisposition of ATR by impeding the normal functions of TSPCs. This information may provide theoretical and experimental basis for exploring the early prevention and care of ATR.

Dynamin-Related Protein 1 Is Involved in Mitochondrial Damage, Defective Mitophagy, and NLRP3 Inflammasome Activation Induced by MSU Crystals

Excessive generation of reactive oxygen species (ROS) has great impacts on MSU crystal-induced inflammation. Drp1-dependent mitochondrial fission is closely associated with mitochondrial ROS levels. However, whether Drp1 signaling contributes to MSU crystal-induced inflammation remains unclear. Mice bone marrow-derived macrophages (BMDMs) were primed with LPS and then stimulated with MSU suspensions for 12 h. The protein levels associated with mitochondrial dynamics, oxidative stress, and mitophagy were detected by Western blot. BMDMs were loaded with MitoTracker Green probe to detect mitochondrial morphology. To measure mitochondrial reactive oxygen species (ROS) and total ROS levels, cells were loaded, respectively, with MitoSOX and DHE probes. The effects of Mito-TEMPO, an antioxidant that targets the mitochondria or DRP1 inhibitor (Mdivi-1) on MSU crystal-induced peritonitis and arthritis mouse models, were evaluated. Our study revealed that MSU crystal stimulation resulted in elevation of mitochondrial fragmentation of BMDMs. Treatment with Mito-TEMPO or Drp1 knockdown significantly ameliorated the mitochondrial damage induced by MSU crystals. BMDMs exposure to MSU crystals increased the expression of auto/mitophagy marker proteins and promoted the fusion of mitophagosomes with lysosomes, leading to accumulation of mitolysosomes. Drp1 knockdown alleviated defective mitophagy and activation of the NLRP3 inflammasome in MSU crystal-treated BMDMs. This study indicates that there is crosstalk between mitochondrial ROS and Drp1 signaling in MSU crystal-induced inflammation. Drp1 signaling is involved in MSU crystal-induced mitochondrial damage, impaired mitophagy and NLRP3 inflammasome activation.

The Good, the Bad and the New about Uric Acid in Cancer

Simple Summary

The concentration of uric acid in blood is sex-, age- and diet-dependent and is maintained close to its maximal solubility, indicating that it plays some important role. Indeed, it has been demonstrated that, at physiological concentrations, uric acid is a powerful antioxidant and is a scavenger of singlet oxygen and radicals. At high intracellular concentration, uric acid has been demonstrated to act as a pro-oxidant molecule. Recently, uric acid has been reported to affect the properties of several proteins involved in metabolic regulation and signaling, and the relationship between uric acid and cancer has been extensively investigated. In this review, we present the most recent results on the positive and negative effects played by uric acid in cancer and some new findings and hypotheses about the implication of this metabolite in the pathogenesis of several diseases such as metabolic syndrome, diabetes, and inflammation, thus favoring the development of cancer.

Abstract

Uric acid is the final product of purine catabolism in man and apes. The serum concentration of uric acid is sex-, age- and diet-dependent and is maintained close to its maximal solubility, indicating that it plays some important role. Indeed, it has been demonstrated that, at physiological concentrations, uric acid is a powerful antioxidant, while at high intracellular concentrations, it is a pro-oxidant molecule. In this review, we describe the possible causes of uric acid accumulation or depletion and some of the metabolic and regulatory pathways it may impact. Particular attention has been given to fructose, which, because of the complex correlation between carbohydrate and nucleotide metabolism, causes uric acid accumulation. We also present recent results on the positive and negative effects played by uric acid in cancer and some new findings and hypotheses about the implication of this metabolite in a variety of signaling pathways, which can play a role in the pathogenesis of diseases such as metabolic syndrome, diabetes, and inflammation, thus favoring the development of cancer. The loss of uricase in Homo sapiens and great apes, although exposing these species to the potentially adverse effects of uric acid, appears to be associated with evolutionary advantages.

Spectral computed tomography with inorganic nanomaterials: State-of-the-art

Recently, spectral computed tomography (CT) technology has received great interest in the field of radiology. Spectral CT imaging utilizes the distinct, energy-dependent X-ray absorption properties of substances in order to provide additional imaging information. Dual-energy CT and multi-energy CT (Spectral CT) are capable of constructing monochromatic energy images, material separation images, energy spectrum curves, constructing effective atomic number maps, and more. However, poor contrast, due to neighboring X-ray attenuation of organs and tissues, is still a challenge to spectral CT. Hence, contrast agents (CAs) are applied for better differentiation of a given region of interest (ROI). Currently, many different kinds of inorganic nanoparticulate CAs for spectral CT have been developed due to the limitations of clinical iodine (I)-based contrast media, leading to the conclusion that inorganic nanomedicine applied to spectral CT will be a powerful collaboration both in basic research and in clinics. In this review, the underlying principles and types of spectral CT techniques are discussed, and some evolving clinical diagnosis applications of spectral CT techniques are introduced. In particular, recent developments in inorganic CAs used for spectral CT are summarized. Finally, the challenges and future developments of inorganic nanomedicine in spectral CT are briefly discussed.

Lacticaseibacillus rhamnosus Fmb14 prevents purine induced hyperuricemia and alleviate renal fibrosis through gut-kidney axis

Hyperuricemia is a critical threat to human health, and conventional medical treatment only aims to treat acute gouty arthritis. Purine diet-mediated chronic hyperuricemia and related syndromes are neglected in clinical therapeutics. In this study, the prevention ability of Lacticaseibacillus rhamnosus Fmb14, screened from Chinese yogurt, was evaluated in chronic purine-induced hyperuricemia (CPH) mice. After 12 weeks of Fmb14 administration, serum uric acid (SUA) in CPH mice decreased by 36.8 %, from 179.1 to 113.2 µmol/L, and the mortality rate decreased from 30 % to 10 %. The prevention role of Fmb14 in CPH was further investigated, and the reduction of uric acid by Fmb14 was attributed to the reduction of XOD (xanthine oxidase) in the liver and URAT1 in the kidney, as well the promotion of ABCG2 in the colon. Fmb14 administration Increased ZO-1 and Occludin expression in the colon and decreased fibrosis degree in the kidney indicated that Fmb14 administration had preventive effects through the gut-kidney axis in CPH. In specific, Fmb14 administration upregulated the diversity of gut microbiota, increased short-chain fatty acids (SCFA) by 35 % in colon materials and alleviated the inflammatory response by reducing biomarkers levels of IL-1β, IL-18 and TNF-α at 11.6 %, 21.7 % and 26.5 % in serum, compared to CPH group, respectively. Additionally, 16 S rRNA sequencing showed 31.5 % upregulation of Prevotella, 20.5 % and 21.6 % downregulation of Ruminococcus and Suterella at the genus level, which may be a new gut microbial marker in hyperuricemia. In conclusion, Fmb14 ameliorated CPH through the gut-kidney axis, suggesting a new strategy to prevent hyperuricemia.

Taxifolin blocks monosodium urate crystal-induced gouty inflammation by regulating phagocytosis and autophagy

Gout is a chronic disease caused by monosodium urate (MSU) crystal deposition in the joints and surrounding tissues. We examined the effects of Taxifolin, a natural flavonoid mainly existing in vegetables and fruits, on MSU-induced gout. Pretreatment with Taxifolin significantly reduced IL-1β, Caspase-1 and HMGB1 levels, upregulation of autophagy-related protein, LC3, as well as improved phagocytosis of macrophages. This study indicated that Taxifolin-attenuated inflammatory response in MSU-induced acute gout model by decreasing pro-inflammatory cytokine production and promoting the autophagy and phagocytic capacity of macrophages. Dietary supplementation with Taxifolin induces the autophagy and attenuated inflammatory response, which in consequence modulates acute gout. A preventive strategy combining dietary interventions with Taxifolin may offer a potential therapeutic alternative to pharmacological treatment to reduce inflammatory response to gout.

U-shaped association of uric acid to overall-cause mortality and its impact on clinical management of hyperuricemia

Serum uric acid (SUA) is significantly elevated in obesity, gout, type 2 diabetes mellitus, and the metabolic syndrome and appears to contribute to the renal, cardiovascular and pulmonary comorbidities that are associated with these disorders. Most previous studies have focused on the pathophysiologic effects of high levels of uric acid (hyperuricemia). More recently, research has also shifted to the impact of hypouricemia, with multiple studies showing the potentially damaging effects that can be caused by abnormally low levels of SUA. Along with these observations, recent inconclusive data from human studies evaluating the treatment of hyperuricemia with xanthine oxidoreductase (XOR) inhibitors have added to the debate about the causal role of UA in human disease processes. SUA, which is largely derived from hepatic degradation of purines, appears to exert both systemic pro-inflammatory effects that contribute to disease and protective antioxidant properties. XOR, which catalyzes the terminal two steps of purine degradation, is the major source of both reactive oxygen species (O2.-, H2O2) and UA. This review will summarize the evidence that both elevated and low SUA may be risk factors for renal, cardiovascular and pulmonary comorbidities. It will also discuss the mechanisms through which modulation of either XOR activity or SUA may contribute to vascular redox hemostasis. We will address future research studies to better account for the differential effects of high versus low SUA in the hope that this will identify new evidence-based approaches for the management of hyperuricemia.

SLC35E2 promoter mutation as a prognostic marker of esophageal squamous cell carcinoma

AIMS

Esophageal squamous cell carcinoma (ESCC) is one of the deadliest digestive tract cancer with poor prognosis. In our previous comprehensive genomics study, we identified that hotspot mutations in the solute carrier family 35 member E2 (SLC35E2) promoter region was significantly associated with worse prognosis in patients with ESCC. However, the biological function and molecular mechanism of SLC35E2 remains unclear. This study was to investigate the malignant function and mechanism of SLC35E2 in ESCC.

MAIN METHODS

Western blotting and qRT-PCR were used to assess the expression of SLC35E2 in ESCC cell lines. Luciferase assay and chromatin immunoprecipitation (ChIP) assay were used to assess the transcriptional inhibition of KLF4. Incucyte cell proliferation assay, colony formation assay and subcutaneous tumor formation in nude mice were used to assess the malignant function of SLC35E2.

KEY FINDINGS

SLC35E2 can promote ESCC cell proliferation in vitro and in vivo. Krüppel-like factor 4 (KLF4), a transcriptional repressor in ESCC, binds to the SLC35E2 promoter and represses the expression of SLC35E2. The transcriptional suppression of KLF4 can be blocked by the mutation at -118 site of the SLC35E2 promoter. Besides, the accumulation of SLC35E2 expression contributes to the malignant phenotype of ESCC.

SIGNIFICANCE

These results indicate that SLC35E2 may be used as a biomarker for prognosis as well as a therapeutic target for patients with ESCC.

Efficacy of Xanthine Oxidase Inhibitors in Lowering Serum Uric Acid in Chronic Kidney Disease: A Systematic Review and Meta-Analysis

Objective: Current guidelines for gout recommend a treat-to-target approach with serum uric acid (SUA). However, there is little evidence for the dose-dependent effects of urate-lowering therapy (ULT). Herein, we analyzed the reported SUA-lowering effect and SUA target achievement differences for various doses of xanthine oxidase inhibitors. Methods: Approved ULT drugs were selected from the FDA Drug Database. We included prospective randomized controlled trials of ULT drugs from ClinicalTrials.gov, articles published in the journal “Drugs”, and Embase, a literature database. A meta-analysis was performed to determine the ability of different ULT drugs and doses to lower and maintain a target SUA < 6 mg/dL. Results: We identified 35 trials including 8172 patients with a baseline SUA of 8.92 mg/dL. The allopurinol, febuxostat, and topiroxostat showed dose-proportional SUA-lowering responses. Compared with allopurinol 300 mg daily, febuxostat 80 mg daily and 120 mg daily more effectively maintained SUA < 6 mg/dL. Conclusion: Allopurinol, febuxostat, and topiroxostat showed dose-proportional ability to lower and achieve a target SUA < 6 mg/dL. Significance and Innovations. We showed dose-dependent SUA lowering effects of allopurinol, febuxostat, and topiroxostat. Febuxostat is effective at ULT compared to allopurinol and could be potentially offered as an alternative agent when patients (1) have CKD, (2) have the human leukocyte antigen HLA-B*5801 allele, and (3) become refractory to allopurinol. Gradual allopurinol dose increase with a lower starting dose is needed in CKD.

Management and Cure of Gouty Arthritis

Gout is the most common inflammatory arthritis in the United States. Gouty arthritis is associated with significant morbidity and mortality and is the result of chronic hyperuricemia. Gout is effectively managed and potentially cured by decreasing the overall urate burden with serum urate-lowering therapy. When serum urate is maintained at less than 6.0 mg/dL, urate deposition is resolved, and gout can be cured. Unfortunately, because of less than optimal physician monitoring and dose escalation, many patients do not achieve these urate levels.

Specular Microscopic Corneal Endothelial Cell Changes following Uneventful Phacoemulsification in Patients with Gout

Purpose. To assess the effects of phacoemulsification on the corneal endothelium in patients with gout and age-related cataracts. Methods. Eighty-eight patients who underwent uneventful phacoemulsification for age-related cataracts were included in this retrospective comparative study. The patients were divided into two groups: group A included 31 patients with gout and tight control of uric acid levels and group B included 57 patients without gout or any other systemic disease. All patients completed follow-up assessments over 6 months, and the two groups were compared in terms of changes to their specular microscopic values. Results. Both groups showed marked improvement in uncorrected and best-corrected visual acuity at the end of the follow-up period. Corneal endothelial cell loss was more severe in group A than in group B, with a mean difference of 221.35 ± 43.87 in group A and 169.88 ± 52.67 in group B at the sixth month ( $p$  < 0.001). The difference between the two groups in terms of other specular microscopic values did not reach statistical significance. Conclusion. Patients with gout are more prone to corneal endothelial cell damage after phacoemulsification than those without gout. To confirm these results, future studies with a prospective design and longer durations of follow-up are needed.

The Possible Role of Nitric Oxide signaling and NMDA Receptors in Allopurinol effect on Maximal Electroshock- and Pentylenetetrazol-Induced Seizures in Mice

Allopurinol, a uric-acid-lowering medication, has shown its efficacy in several studies suggesting that allopurinol can be prescribed as adjunctive cure meant for intractable epilepsy. The exact mechanism of allopurinol is still unknown. This study evaluates allopurinol's effect on seizure threshold, seizure incidence, and mortality rate in mice models. Moreover, the possible involvement of nitric oxide (NO) pathway and N-methyl-D-aspartate (NMDA) receptors are investigated. To evaluate the effect of allopurinol on seizure, we used the pentylenetetrazole (PTZ)-induced seizure along with maximal electroshock (MES)-induced seizure. To assess the underlying mechanism behind the allopurinol activity, we used nitric oxide synthase (NOS) substrate (L-arginine), NOS inhibitors (L-NAME, aminoguanidine, 7-nitroindazole), and NMDA receptor antagonist (MK-801). Intraperitoneal allopurinol administration at a dose of 50 mg/kg in mice showed a significant (p<0.001) anti-convulsant activity in the PTZ-induced seizure. Even though pre-treatment with L-Arginine (60 mg/kg) potentiates allopurinol's anti-convulsant effect in the PTZ-induced seizure, pre-treatment with L-NAME (10 mg/kg), aminoguanidine (100 mg/kg), and 7-nitroindazole (30 mg/kg) reversed the anti-convulsant effect of allopurinol in the PTZ-induced seizure. In addition, pre-treatment with MK-801 also decreased the anti-convulsant effect of allopurinol in the PTZ-induced seizure. While allopurinol at a dose of 50 mg/kg and 100 mg/kg did not induce protection against seizure incidence in the MES-induced seizure, it revealed a remarkable effect in reducing the mortality rate in the MES-induced seizure. Allopurinol increases the seizure threshold in PTZ-induced seizure and enhances the survival rate in MES-induced seizure. Allopurinol exerts its anti-convulsant effect, possibly through targeting NO pathway and NMDA receptors.

Regulation of TRPV1 channel in monosodium urate-induced gouty arthritis in mice

OBJECTIVE

The transient receptor potential vanilloid subtype 1 (TRPV1) channel is considered to play an important regulatory role in the process of pain. The purpose of this study is to observe the change characteristics of TRPV1 channel in MSU-induced gouty arthritis and to find a new target for clinical treatment of gout pain.

METHODS

Acute gouty arthritis was induced by injection of monosodium urate (MSU) crystals into the ankle joint of mice. The swelling degree was evaluated by measuring the circumference of the ankle joint. Mechanical hyperalgesia was conducted using the electronic von Frey. Calcium fluorescence and TRPV1 current were recorded by applying laser scanning confocal microscope and patch clamp in dorsal root ganglion (DRG) neurons, respectively.

RESULTS

MSU treatment resulted in significant inflammatory response and mechanical hyperalgesia. The peak swelling degree appeared at 12 h, and the minimum pain threshold appeared at 8 h after MSU treatment. The fluorescence intensity of capsaicin-induced calcium response and TRPV1 current were increased in DRG cells from MSU-treated mice. The number of cells that increased calcium response after MSU treatment was mainly distributed in small-diameter DRG cells. However, the action potential was not significantly changed in small-diameter DRG cells after MSU treatment.

CONCLUSIONS

These findings identified an important role of TRPV1 in mediating mechanical hyperalgesia in MSU-induced gouty arthritis and further suggest that TRPV1 can be regarded as a potential new target for the clinical treatment of gouty arthritis.

The potential of probiotics in the amelioration of hyperuricemia

Hyperuricemia is a common disease caused by metabolic disorders or the excessive intake of high-purine foods. Persistent hyperuricemia in extreme cases induces gout, and asymptomatic hyperuricemia is probably linked to other metabolic diseases, such as hypertension. The typical damage caused by asymptomatic hyperuricemia includes inflammation, oxidative stress and gut dysbiosis. Probiotics have broad potential applications as food additives, not as drug therapies, in the amelioration of hyperuricemia. In this review, we describe novel methods for potential hyperuricemia amelioration with probiotics. The pathways through which probiotics may ameliorate hyperuricemia are discussed, including the decrease in uric acid production through purine assimilation and XOD (xanthine oxidase) inhibition as well as enhanced excretion of uric acid production by promoting ABCG2 (ATP binding cassette subfamily G member 2) activity, respectively. Three possible probiotic-related therapeutic pathways for alleviating the syndrome of hyperuricemia are also summarized. The first mechanism is to alleviate the oxidation and inflammation induced by hyperuricemia through the inhibition of NLRP3 inflammasome, the second is to restore damaged intestinal epithelium barriers and prevent gut microbiota dysbiosis, and the third is to enhance the innate immune system by increasing the secretion of immunoglobulin A (sIgA) to resist the stimulus by hyperuricemia. We propose that future research should focus on superior strain resource isolation and insight into the cause-effect mechanisms of probiotics for hyperuricemia amelioration. The safety and effects of the application of probiotics in clinical use also need verification.

Safety and efficacy of SHR4640 combined with febuxostat for primary hyperuricemia: a multicenter, randomized, double-blind, phase II study

Background:

To evaluate the safety, tolerability, and efficacy of SHR4640, a highly selective urate transporter-1 inhibitor, in combination with febuxostat, in patients with primary hyperuricemia.

Methods:

In this randomized, double-blind, parallel-controlled phase II study, patients whose fasting serum uric acid (sUA) levels were ⩾ 480 μmol/L at screening with gout or sUA levels were ⩾ 420 μmol/L lasting for at least 3 months without gout, either with sUA levels ⩾ 540 μmol/L at screening or sUA levels ⩾ 480 μmol/L with comorbidities at screening, were enrolled. Patients were randomized (1:1:1) to receive SHR4640 10 mg plus febuxostat 80 mg, SHR4640 10 mg plus febuxostat 40 mg, and SHR4640 5 mg plus febuxostat 20 mg orally once daily. The primary end point was the incidence of treatment-emergent adverse events (TEAEs).

Results:

A total of 93 patients were randomized and received treatment. TEAEs occurred in 55.9% of patients. The incidence of TEAEs was comparable among all the groups. Serious TEAEs occurred in one patient (1.1%), with no deaths observed. The proportion of patients who achieved the target sUA levels by week 4 was 79.3%, 96.6%, and 75.0% in the SHR4640 10 mg plus febuxostat 80 mg, SHR4640 10 mg plus febuxostat 40 mg, and SHR4640 5 mg plus febuxostat 20 mg groups, respectively. The mean percent reduction of sUA was 59.7%, 63.7%, and 41.8%, respectively.

Conclusion:

SHR4640 plus febuxostat exhibited a tolerable safety profile and substantial sUA lowering activity in patients with primary hyperuricemia.

Registration:

www.chinadrugtrials.org.cn; CTR 20192429

Remission in Gout: Concepts From a Patient Perspective

Any human who has ever experienced an acute gout flare understands how painful and debilitating this condition is. Unfortunately, due to the episodic nature of these acute flares that occur randomly due to transient fluctuations in urate levels, patients often underreport these attacks.