The integrin CD11b inhibits MSU-induced NLRP3 inflammasome activation in macrophages and protects mice against MSU-induced joint inflammation.

OBJECTIVE: In gout, monosodium urate crystals are taken up by macrophages, triggering the activation of the NLRP3 inflammasome and the maturation of IL-1ß. This study aimed to investigate the role of integrin CD11b in inflammasome activation in macrophages stimulated by MSU. METHODS: BMDM from WT and CD11b KO mice were stimulated in vitro with MSU crystals. Cellular supernatants were collected to assess the expression of the inflammatory cytokines by enzyme-linked immunosorbent assay and western blot methods. The role of integrin CD11b in MSU-induced gouty arthritis in vivo was investigated by intra-articular injection of MSU crystals. Real-time extracellular acidification rate and oxygen consumption rate of BMDMs were measured by Seahorse Extracellular Flux Analyzer. RESULTS: We demonstrate that CD11b-deficient mice developed exacerbated gouty arthritis with increased recruitment of leukocytes in the joint and higher IL-1ß levels in the sera. In macrophages, genetic deletion of CD11b induced a shift of macrophage metabolism from oxidative phosphorylation to glycolysis, thus decreasing the overall generation of intracellular ATP. Upon MSU stimulation, CD11b-deficient macrophages showed an exacerbated secretion of IL-1ß. Treating wild-type macrophages with a CD11b agonist, LA1, inhibited MSU-induced release of IL-1ß in vitro and attenuated the severity of experimental gouty arthritis. Importantly, LA1, was also effective in human cells as it inhibited MSU-induced release of IL-1ß by peripheral blood mononuclear cells from healthy donors. CONCLUSION: Our data identified the CD11b integrin as a principal cell membrane receptor that modulates NLRP3 inflammasome activation by MSU crystal in macrophages, which could be a potential therapeutic target to treat gouty arthritis in human patients.

Distinct characteristics of the gut virome in patients with osteoarthritis and gouty arthritis.

BACKGROUND/PURPOSE(S): The gut microbiota and its metabolites play crucial roles in pathogenesis of arthritis, highlighting gut microbiota as a promising avenue for modulating autoimmunity. However, the characterization of the gut virome in arthritis patients, including osteoarthritis (OA) and gouty arthritis (GA), requires further investigation. METHODS: We employed virus-like particle (VLP)-based metagenomic sequencing to analyze gut viral community in 20 OA patients, 26 GA patients, and 31 healthy controls, encompassing a total of 77 fecal samples. RESULTS: Our analysis generated 6819 vOTUs, with a considerable proportion of viral genomes differing from existing catalogs. The gut virome in OA and GA patients differed significantly from healthy controls, showing variations in diversity and viral family abundances. We identified 157 OA-associated and 94 GA-associated vOTUs, achieving high accuracy in patient-control discrimination with random forest models. OA-associated viruses were predicted to infect pro-inflammatory bacteria or bacteria associated with immunoglobulin A production, while GA-associated viruses were linked to Bacteroidaceae or Lachnospiraceae phages. Furthermore, several viral functional orthologs displayed significant differences in frequency between OA-enriched and GA-enriched vOTUs, suggesting potential functional roles of these viruses. Additionally, we trained classification models based on gut viral signatures to effectively discriminate OA or GA patients from healthy controls, yielding AUC values up to 0.97, indicating the clinical utility of the gut virome in diagnosing OA or GA. CONCLUSION: Our study highlights distinctive alterations in viral diversity and taxonomy within gut virome of OA and GA patients, offering insights into arthritis etiology and potential treatment and prevention strategies.

Well-defined alginate oligosaccharides ameliorate joint pain and inflammation in a mouse model of gouty arthritis.

Background: Gouty arthritis causes severe pain and inflammation. Alginate oligosaccharides (AOSs) are natural products derived from alginate and have anti-inflammatory properties. We explored the potential effects of AOSs with different degrees of polymerization (Dp) on gouty arthritis and associated mechanisms. Methods: We established a mouse model of gouty arthritis by injecting monosodium urate (MSU) into ankle joint. Nocifensive behavior, gait and ankle swelling were used to study AOS's effects. Biochemical assays, in vivo imaging, live cell Ca2+ imaging, electrophysiology, RNA-sequencing, etc. were used for mechanism exploration. Results: AOS2 (Dp=2), AOS3 (Dp=3) and AOS4 (Dp=4) all inhibited ankle swelling, whereas AOS2&3 produced the most obvious analgesia on model mice. AOS3, which was picked for further evaluation, produced dose-dependent ameliorative effects on model mice. AOS3 reversed gait impairments but did not alter locomotor activity. AOS3 inhibited NLRP3 inflammasome activation and inflammatory cytokine up-regulation in ankle joint. AOS3 ameliorated MSU-induced oxidative stress and reactive oxygen species (ROS) production both in vivo and in vitro and reversed the impaired mitochondrial bioenergetics. AOS3 activated the Nrf2 pathway and promoted Nrf2 disassociation from Keap1-bound complex and Nrf2 nuclear translocation, thus facilitating antioxidant gene expression via Nrf2-dependent mechanism. Nrf2 gene deficiency abolished AOS3's ameliorative effects on pain, inflammation and oxidative stress in ankle joints of model mice. AOS3 reduced TRPV1 functional enhancement in DRG neurons and constrained neuroactive peptide release. Conclusions: AOS3 ameliorates gouty arthritis via activating Nrf2-dependent antioxidant signaling, resulting in suppression of ROS-mediated NLRP3 inflammasome activation and TRPV1 enhancement. AOS3 may be novel therapeutics for gouty arthritis.

The impact of various antiplatelet strategies on the incidence of gouty arthritis in hospitalized patients with acute cerebral infarction.

OBJECTIVES: 1.To explore the incidence of concurrent gouty arthritis (GA) during hospitalization in patients with different subtypes of acute stroke. 2.To investigate disparities in acute cerebral infarction patients with coexisting GA undergoing various antiplatelet strategies. MATERIALS AND METHODS: Data from acute stroke patients admitted to the Affiliated Panyu Central Hospital of Guangzhou Medical University, from January 2019 to December 2021, underwent screening. The incidence of GA in acute stroke patients of various subtypes were analyzed. Subsequently, we divided cerebral infarction cases into three cohorts based on distinct antiplatelet therapies: the aspirin group, the dual antiplatelet therapy group (DAPT，aspirin plus clopidogrel), and the clopidogrel group. Investigate disparities in acute cerebral infarction patients with coexisting GA undergoing various antiplatelet strategies. RESULTS: A total of 12,381 patients with acute stroke were screened in this study. The incidence of GA in various subtypes of acute stroke was as follows: cerebral infarction (3.56 %, n = 9890), TIA (1.81 %, n = 443), cerebral hemorrhag (0.64 %, n = 1713), and SAH (0.30 %, n = 335). The incidence of GA in patients with ischemic stroke is higher than that of hemorrhagic stroke (χ2 = 49.258, p<0.001). No significant differences were observed in the incidence of GA among three different antiplatelet therapy groups. But there was marginal statistical difference in the incidence of GA between the aspirin group and the DAPT group (P = 0.051), as well as between the clopidogrel group and the DAPT group (P = 0.059). CONCLUSIONS: The incidence of GA in patients with ischemic stroke is higher than that of hemorrhagic stroke. No significant differences were observed in the incidence of GA in acute cerebral infarction across various antiplatelet Strategies. The marginal statistical difference in the incidence of GA between the single antiplatelet group and the DAPT group requires further investigation.

Mechanism of flavonoids in the treatment of gouty arthritis (Review).

The present review expounds the advancements in the application and mechanisms of flavonoids in gouty arthritis, highlighting their significance in managing the disease. Gouty arthritis is among the most common and severe inflammatory diseases, caused by hyperuricemia and the deposition of sodium urate crystals in the joints and surrounding tissues, posing a serious threat to human life and health. Flavonoids, extracted from various herbs, have attracted significant attention due to their efficacy in improving gouty arthritis. The present study systematically reviews the in vivo studies and in vitro animal studies on flavonoids from herbal medicines for the treatment of gouty arthritis that have been previously published in the PubMed, ScienceDirect, Google Scholar and China National Knowledge Infrastructure databases between 2000 and 2023. The review of the literature indicated that flavonoids can improve gouty arthritis through multiple mechanisms. These include lowering xanthine oxidase activity, inhibiting uric acid (UA) synthesis, regulating UA transporters to promote UA excretion, reducing the inflammatory response and improving oxidative stress. These mechanisms predominantly involve regulating the NOD­like receptor 3 inflammasome, the Toll­like receptor 4/myeloid differentiation factor 88/nuclear factor­κB signaling pathway, and the levels of UA transporter proteins, namely recombinant urate transporter 1, glucose transporter 9, organic anion transporter (OAT)1 and OAT3. Various flavonoids used in traditional Chinese medicine hold therapeutic promise for gouty arthritis and are anticipated to pave the way for novel pharmaceuticals and clinical applications.

Astilbin inhibited neutrophil extracellular traps in gouty arthritis through suppression of purinergic P2Y6 receptor.

BACKGROUND: Gouty arthritis (GA), a common inflammatory condition triggered by monosodium urate crystal accumulation, often necessitates safer treatment alternatives due to the limitations of current therapies. Astilbin, a flavonoid from Smilax glabra Roxb, has demonstrated potential in traditional Chinese medicine for its anti-inflammatory properties. However, the anti-GA effect and its underlying mechanism have not been fully elucidated. PURPOSE: This study aimed to investigate the therapeutic potential of astilbin in GA, focusing on its effects on neutrophil extracellular traps (NETs), as well as the potential molecular target of GA both in vitro and in vivo. STUDY DESIGN: Firstly, astilbin inhibited the citrullinated histone H3 (Cit h3) protein levels and reduced the NETs formation in neutrophils stimulated by monosodium urate (MSU). Secondly, we wondered the effect of astilbin on migration of neutrophils and dimethyl-sulfoxide (DMSO)-differentiated HL-60 (dHL-60) cells under the stimulation of MSU. Then, the effect of astilbin on suppressing NETs through purinergic P2Y6 receptor (P2Y6R) and Interlukin-8 (IL-8)/ CXC chemokine receptor 2 (CXCR2) pathway was investigated. Also, the relationship between P2Y6R and IL-8/CXCR2 was explored in dHL-60 cells under stimulation of MSU. Finally, we testified the effect of astilbin on reducing NETs in GA through suppressing P2Y6R and then down-regulating IL-8/CXCR2 pathway. METHODS: MSU was used to induce NETs in neutrophils and dHL-60 cells. Real-time formation of NETs and migration of neutrophils were monitored by cell living imaging with or without MSU. Then, the effect of astilbin on NETs formation, P2Y6R and IL-8/CXCR2 pathway were detected by immunofluorescence (IF) and western blotting. P2Y6R knockdown dHL-60 cells were established by small interfering RNA to investigate the association between P2Y6R and IL-8/CXCR2 pathway. Also, plasmid of P2Y6R was used to overexpress P2Y6R in dHL-60 cells, which was employed to explore the role of P2Y6R in astilbin inhibiting NETs. Within the conditions of knockdown and overexpression of P2Y6R, migration and NETs formation were assessed by transmigration assay and IF staining, respectively. In vivo, MSU-induced GA mice model was established to assess the effect of astilbin on inflammation by haematoxylin-eosin and ELISA. Additionally, the effects of astilbin on neutrophils infiltration, NETs, P2Y6R and IL-8/CXCR2 pathway were analyzed by IF, ELISA, immunohistochemistry (IHC) and western blotting. RESULTS: Under MSU stimulation, astilbin significantly suppressed the level of Cit h3 and NETs formation including the fluorescent expressions of Cit h3, neutrophils elastase, myeloperoxidase, and intra/extracellular DNA. Also, results showed that MSU caused NETs release in neutrophils as well as a trend towards recruitment of dHL-60 cells to MSU. Astilbin could markedly decrease expressions of P2Y6R and IL-8/CXCR2 pathway which were upregulated by MSU. By silencing P2Y6R, the expression of IL-8/CXCR2 pathway and migration of dHL-60 cells were inhibited, leading to the suppression of NETs. These findings indicated the upstream role of P2Y6R in the IL-8/CXCR2 pathway. Moreover, overexpression of P2Y6R was evidently inhibited by astilbin, causing a downregulation in IL-8/CXCR2 pathway, migration of dHL-60 cells and NETs formation. These results emphasized that astilbin inhibited the IL-8/CXCR2 pathway primarily through P2Y6R. In vivo, astilbin administration led to marked reductions in ankle swelling, inflammatory infiltration as well as neutrophils infiltration. Expressions of P2Y6R and IL-8/CXCR2 pathway were evidently decreased by astilbin and P2Y6R inhibitor MRS2578 either alone or in combination. Also, astilbin and MRS2578 showed notable effect on reducing MSU-induced NETs formation and IL-8/CXCR2 pathway whether used alone or in combination, parallelly demonstrating that astilbin decreased NETs formation mainly through P2Y6R. CONCLUSION: This study revealed that astilbin suppressed NETs formation via downregulating P2Y6R and subsequently the IL-8/CXCR2 pathway, which evidently mitigated GA induced by MSU. It also highlighted the potential of astilbin as a promising natural therapeutic for GA.

Antigout effects and mechanisms of total flavonoids from prunus tomentosa.

BACKGROUND: In recent years, hyperuricemia and acute gouty arthritis have become increasingly common, posing a serious threat to public health. Current treatments primarily involve Western medicines with associated toxic side effects. OBJECTIVE: This study aims to investigate the therapeutic effects of total flavones from Prunus tomentosa (PTTF) on a rat model of gout and explore the mechanism of PTTF's anti-gout action through the TLR4/NF-κB signaling pathway. METHODS: We measured serum uric acid (UA), creatinine (Cr), blood urea nitrogen (BUN), tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1ß), and interleukin-6 (IL-6) levels using an enzyme-linked immunosorbent assay (ELISA). Histopathological changes were observed using HE staining, and the expression levels of relevant proteins were detected through Western blotting. RESULTS: After PTTF treatment, all indicators improved significantly. PTTF reduced blood levels of UA, Cr, BUN, IL-1ß, IL-6, and TNF-α, and decreased ankle swelling. CONCLUSIONS: PTTF may have a therapeutic effect on animal models of hyperuricemia and acute gouty arthritis by reducing serum UA levels, improving ankle swelling, and inhibiting inflammation. The primary mechanism involves the regulation of the TLR4/NF-κB signaling pathway to alleviate inflammation. Further research is needed to explore deeper mechanisms.

BRD4 promotes gouty arthritis through MDM2-mediated PPARγ degradation and pyroptosis.

BACKGROUND: Gouty arthritis (GA) is characterized by monosodium urate (MSU) crystal accumulation that instigates NLRP3-mediated pyroptosis; however, the underlying regulatory mechanisms have yet to be fully elucidated. The present research endeavors to elucidate the regulatory mechanisms underpinning this MSU-induced pyroptotic cascade in GA. METHODS: J774 cells were exposed to lipopolysaccharide and MSU crystals to establish in vitro GA models, whereas C57BL/6 J male mice received MSU crystal injections to mimic in vivo GA conditions. Gene and protein expression levels were evaluated using real-time quantitative PCR, Western blotting, and immunohistochemical assays. Inflammatory markers were quantified via enzyme-linked immunosorbent assays. Pyroptosis was evaluated using immunofluorescence staining for caspase-1 and flow cytometry with caspase-1/propidium iodide staining. The interaction between MDM2 and PPARγ was analyzed through co-immunoprecipitation assays, whereas the interaction between BRD4 and the MDM2 promoter was examined using chromatin immunoprecipitation and dual-luciferase reporter assays. Mouse joint tissues were histopathologically evaluated using hematoxylin and eosin staining. RESULTS: In GA, PPARγ was downregulated, whereas its overexpression mitigated NLRP3 inflammasome activation and pyroptosis. MDM2, which was upregulated in GA, destabilized PPARγ through the ubiquitin-proteasome degradation pathway, whereas its silencing attenuated NLRP3 activation by elevating PPARγ levels. Concurrently, BRD4 was elevated in GA and exacerbated NLRP3 activation and pyroptosis by transcriptionally upregulating MDM2, thereby promoting PPARγ degradation. In vivo experiments showed that BRD4 silencing ameliorated GA through this MDM2-PPARγ-pyroptosis axis. CONCLUSION: BRD4 promotes inflammation and pyroptosis in GA through MDM2-mediated PPARγ degradation, underscoring the therapeutic potential of targeting this pathway in GA management.

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-1ß 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.

Correlation analysis of serum TLR4 protein levels and TLR4 gene polymorphisms in gouty arthritis patients.

OBJECTIVE: The Toll-like receptor (TLR) 4-mediated nuclear factor kappa B (NF-κB) signaling pathway regulates the production of inflammatory factors and plays a key role in the pathogenesis of gouty arthritis. The aim of the present study was to investigate the link among TLR4 gene polymorphisms at various loci, protein expression, and gouty arthritis susceptibility. METHODS: Between 2016 and 2021, a case-control study was used to collect a total of 1207 study subjects, including 317 male patients with gouty arthritis (gout group) and 890 healthy males (control group). The association between gout susceptibility and different genetic models was analyzed by typing three loci of the TLR4 gene (rs2149356, rs2737191, and rs10759932) using a multiplex point mutation rapid assay, and the association between protein expression and gout was confirmed by measuring TLR4 protein concentrations using enzyme-linked immunosorbent assays (ELISAs). RESULTS: In a codominant models AA and AG, the rs2737191 polymorphism in the gout group increased the risk of gout compared to the AA genotype (OR = 2.249, 95%CI 1.010~5.008), and the risk of gout was higher for those carrying the G allele compared to the A allele (OR = 2.227, 95%CI 1.006~4.932). TLR4 protein expression was different between the two groups with different locus genotypes. The differences in TLR4 protein expression between the gout group and control group were statistically significant between the following genotypes: the GG and GT genotypes of the rs2149356 polymorphism; the AA and AG genotypes of the rs2737191 polymorphism; and the TT and TC genotypes of the rs10759932 polymorphism(P<0.05). The TLR4 protein level in the gout group (19.19±3.09 ng/ml) was significantly higher than that in the control group (15.85±4.75 ng/ml). CONCLUSION: The AG genotype of the TLR4 gene rs2737191 polymorphism may be correlated with the development of gouty arthritis. The level of TLR4 protein expression is significantly higher in patients with gouty arthritis than in controls, and there is a correlation between high TLR4 protein expression and the development of gouty arthritis.

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.

Prednisolone Versus Colchicine for Acute Gout in Primary Care: statistical analysis plan for the pragmatic, multicenter, randomized, and double-blinded COPAGO non-inferiority trial.

BACKGROUND: To date, colchicine and prednisolone are two effective therapies for the treatment of acute gout but have never been compared directly in a randomized clinical trial. In addition, in previous trials of treating acute gout patients with concomitant comorbidities were often excluded due to contraindications to naproxen. STUDY DESIGN: This pragmatic, prospective, double-blind, double-dummy, parallel-group, randomized, non-inferiority trial compares prednisolone with colchicine in terms of non-inferiority in patients with acute gout. Patients presenting to their general practitioner with acute gout can be included if the gout attack has occurred within the last 2 days. A total of 60 practices in the vicinity of three university medical centers (Greifswald, Göttingen, and Würzburg) participate in the study. The intervention group receives 30 mg prednisolone for 5 days, while the group of standard care receives low-dose colchicine (day 1: 1.5 mg; days 2-5: 1 mg). The first dose of treatment is provided at day 0 when patients present to the general practitioner due to an acute gout attack. From day 0 to day 6, patients will be asked to complete a study diary on daily basis regarding pain quantification. For safety reasons, potential side effects and the course of systolic blood pressure are also assessed. STATISTICAL ANALYSIS PLAN: N = 314 patients have to be recruited to compensate for 10% of dropout and to allow for showing non-inferiority of prednisolone compared to colchicine with a power of 90%. We use permuted block randomization with block sizes of 2, 4, and 6 to avoid imbalanced treatment arms in this multi-center study; patients are randomized in a 1:1 ratio. The absolute level of pain on day 3 (in the last 24 h) is the primary outcome and measured on a numerical rating scale (NRS: 0-10). Using a multiple linear regression model adjusted for age, sex, and pain at baseline, prednisolone is considered non-inferior if the effect estimate including the confidence intervals is lower than a margin of 1 unit on the NRS. Average response to treatment, joint swelling and tenderness, physical function of the joint, and patients' global assessment of treatment success are secondary outcomes. DISCUSSION: The trial will provide evidence from a direct comparison of colchicine and prednisolone regarding their efficacy of pain reduction in acute gout patients of primary care and to indicate possible safety signals. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT05698680 first posted on January 26, 2023 (retrospectively registered).

Traditional herbal medicine: Therapeutic potential in acute gouty arthritis.

ETHNOPHARMACOLOGICAL RELEVANCE: Acute gouty arthritis (AGA) is characterized by a rapid inflammatory reaction caused by the build-up of monosodium urate (MSU) crystals in the tissues surrounding the joints. This condition often associated with hyperuricemia (HUA), is distinguished by its symptoms of intense pain, active inflammation, and swelling of the joints. Traditional approaches in AGA management often fall short of desired outcomes in clinical settings. However, recent ethnopharmacological investigations have been focusing on the potential of Traditional Herbal Medicine (THM) in various forms, exploring their therapeutic impact and targets in AGA treatment. AIM OF THE REVIEW: This review briefly summarizes the current potential pharmacological mechanisms of THMs - including active ingredients, extracts, and prescriptions -in the treatment of AGA, and discusses the relevant potential mechanisms and molecular targets in depth. The objective of this study is to offer extensive information and a reference point for the exploration of targeted AGA treatment using THMs. MATERIALS AND METHODS: This review obtained scientific publications focused on in vitro and in vivo studies of anti-AGA THMs conducted between 2013 and 2023. The literature was collected from various journals and electronic databases, including PubMed, Elsevier, ScienceDirect, Web of Science, and Google Scholar. The retrieval and analysis of relevant articles were guided by keywords such as "acute gouty arthritis and Chinese herbal medicine," "acute gouty arthritis herbal prescription," "acute gouty arthritis and immune cells," "acute gouty arthritis and inflammation," "acute gouty arthritis and NOD-like receptor thermoprotein domain associated protein 3 (NLRP3)," "acute gouty arthritis and miRNA," and "acute gouty arthritis and oxidative stress." RESULTS: We found that AGA has a large number of therapeutic targets, highlighting the effectiveness the potential of THMs in AGA treatment through in vitro and in vivo studies. THMs and their active ingredients can mitigate AGA symptoms through a variety of therapeutic targets, such as influencing macrophage polarization, neutrophils, T cells, natural killer (NK) cells, and addressing factors like inflammation, NLRP3 inflammasome, signaling pathways, oxidative stress, and miRNA multi-target interactions. The anti-AGA properties of THMs, including their active components and prescriptions, were systematically summarized and categorized based on their respective therapeutic targets. CONCLUSION: phenolic, flavonoid, terpenoid and alkaloid compounds in THMs are considered the key ingredients to improve AGA. THMs and their active ingredients achieve enhanced efficacy through interactions with multiple targets, of which NLRP3 is a main therapeutic target. Nonetheless, given the intricate composition of traditional Chinese medicine (TCM), additional research is required to unravel the underlying mechanisms and molecular targets through which THMs alleviate AGA.

Identification of potential biomarkers of gout through weighted gene correlation network analysis.

Background: Although hyperuricemia is not always associated with acute gouty arthritis, uric acid is a significant risk factor for gout. Therefore, we investigated the specific mechanism of uric acid activity. Methods: Using the gout-associated transcriptome dataset GSE160170, we conducted differential expression analysis to identify differentially expressed genes (DEGs). Moreover, we discovered highly linked gene modules using weighted gene coexpression network analysis (WGCNA) and evaluated their intersection. Subsequently, we screened for relevant biomarkers using the cytoHubba and Mcode algorithms in the STRING database, investigated their connection to immune cells and constructed a competitive endogenous RNA (ceRNA) network to identify upstream miRNAs and lncRNAs. We also collected PBMCs from acute gouty arthritis patients and healthy individuals and constructed a THP-1 cell gout inflammatory model, RT-qPCR and western blotting (WB) were used to detect the expression of C-X-C motif ligand 8 (CXCL8), C-X-C motif ligand 2 (CXCL2), and C-X-C motif ligand 1 (CXCL1). Finally, we predicted relevant drug targets through hub genes, hoping to find better treatments. Results: According to differential expression analysis, there were 76 upregulated and 28 downregulated mRNAs in GSE160170. Additionally, WGCNA showed that the turquoise module was most strongly correlated with primary gout; 86 hub genes were eventually obtained upon intersection. IL1ß, IL6, CXCL8, CXCL1, and CXCL2 are the principal hub genes of the protein-protein interaction (PPI) network. Using RT-qPCR and WB, we found that there were significant differences in the expression levels of CXCL8, CXCL1, and CXCL2 between the gouty group and the healthy group, and we also predicted 10 chemicals related to these proteins. Conclusion: In this study, we screened and validated essential genes using a variety of bioinformatics tools to generate novel ideas for the diagnosis and treatment of gout.

Assessment of the efficacy of alkaline water in conjunction with conventional medication for the treatment of chronic gouty arthritis: A randomized controlled study.

BACKGROUND: Chronic gouty arthritis, a prevalent metabolic disorder, has prompted interest in the role of diet and lifestyle in its management. This study examines alkaline water as a non-pharmacological adjunct to traditional medicine, hypothesizing its positive effects on uric acid levels and gout symptoms. METHODS: In this research, 400 chronic arthritis patients from Guangdong Hydropower Hospital (September 2021-September 2023) were randomly assigned to groups receiving varying concentrations of alkaline water alongside conventional Western medicine, or Western medicine alone. A 1-year follow-up involved assessments using visual analogue scales, joint swelling scores, functional assessment scales, and biochemical markers (serum uric acid, creatinine, urea nitrogen) for comprehensive evaluation. RESULTS: Pain relief: High-concentration alkaline water significantly reduced VAS pain scores posttreatment (P < .05). Joint swelling: Greatest improvement observed in high-concentration group (P < .001). Daily activity capability: Notable enhancements in daily activity scores in experimental groups (P < .05). Range of joint motion: All groups showed significant improvement posttreatment (P < .05). Inflammatory markers: Experimental groups experienced a notable decrease in C-reactive protein, especially in the low concentration group (P < .001). Erythrocyte sedimentation rate decreases were marginal and not statistically significant (P > .05). Interleukin-1ß and tumor necrosis factor-α levels significantly decreased, particularly in the low concentration group. Serum uric acid levels: Significant reduction in serum uric acid observed in all alkaline water groups (P < .05), contrasting with the control group. CONCLUSION: Alkaline water, particularly at high concentrations, effectively alleviated pain, reduced joint swelling, enhanced daily activities, and improved joint motion in chronic gouty arthritis treatment. It significantly reduced key inflammatory markers (C-reactive protein, interleukin-1ß, tumor necrosis factor-α) and serum uric acid levels, suggesting its potential as a valuable adjunct in gout management. The limited impact on erythrocyte sedimentation rate warrants further investigation.

The NADase CD38 is a central regulator in gouty inflammation and a novel druggable therapeutic target.

OBJECTIVES: Cellular NAD+ declines in inflammatory states associated with increased activity of the leukocyte-expressed NADase CD38. In this study, we tested the potential role of therapeutically targeting CD38 and NAD+ in gout. METHODS: We studied cultured mouse wild type and CD38 knockout (KO) murine bone marrow derived macrophages (BMDMs) stimulated by monosodium urate (MSU) crystals and used the air pouch gouty inflammation model. RESULTS: MSU crystals induced CD38 in BMDMs in vitro, associated with NAD+ depletion, and IL-1ß and CXCL1 release, effects reversed by pharmacologic CD38 inhibitors (apigenin, 78c). Mouse air pouch inflammatory responses to MSU crystals were blunted by CD38 KO and apigenin. Pharmacologic CD38 inhibition suppressed MSU crystal-induced NLRP3 inflammasome activation and increased anti-inflammatory SIRT3-SOD2 activity in macrophages. BMDM RNA-seq analysis of differentially expressed genes (DEGs) revealed CD38 to control multiple MSU crystal-modulated inflammation pathways. Top DEGs included the circadian rhythm modulator GRP176, and the metalloreductase STEAP4 that mediates iron homeostasis, and promotes oxidative stress and NF-κB activation when it is overexpressed. CONCLUSIONS: CD38 and NAD+ depletion are druggable targets controlling the MSU crystal- induced inflammation program. Targeting CD38 and NAD+ are potentially novel selective molecular approaches to limit gouty arthritis.

Elucidating the mechanism of the Tibetan medicine sanguotang in treating gouty arthritis through network pharmacology and in vivo experiments.

BACKGROUND: We explored the mechanisms of Sanguotang (SGT), a Tibetan medicine, in treating gout arthritis (GA). METHODS: The main active components, action targets, and disease targets of SGT were identified through TCMSP databases. The gene functions were analyzed using protein interaction (PPI) networks, Gene Ontology (GO) enrichment analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, and molecular docking. A GA model induced by monosodium urate was established in rats. The ankle joint swelling was observed. The levels of uric acid (UA) and albumin (ALB) in rat serum were measured. Hematoxylin and eosin (HE) staining was conducted to examine the pathological changes in rat ankle joints. RESULTS: Twenty-nine active components of SGT with proven efficacy and 66 intersection targets were identified, primarily involved in inflammation and immune regulation pathways. The PPI results revealed that the key targets of SGT against GA included ALB, IL6, TNF, TP53, and PTGS. Molecular docking showed favorable binding energy between the ALB protein and the active components. The results from animal experiments demonstrated that SGT effectively alleviated the inflammatory reaction in ankle joints, and decreased UA and ALB levels. Furthermore, SGT effectively inhibited the proliferation of synovial cells in the ankle joint cavity, prevented infiltration of inflammatory cells, and protected synovial tissue, thereby improving GA. CONCLUSIONS: SGT comprehensively contributes to the treatment of GA by regulating UA metabolism, reducing the release of inflammatory factors, and modulating immune and inflammatory pathways.

Osteostatin Mitigates Gouty Arthritis through the Inhibition of Caspase-1 Activation and Upregulation of Nrf2 Expression.

Gouty arthritis results from monosodium urate (MSU) crystal deposition in joints, initiating (pro)-interleukin (IL)-1ß maturation, inflammatory mediator release, and neutrophil infiltration, leading to joint swelling and pain. Parathyroid hormone-related protein (107-111) C-terminal peptide (osteostatin) has shown anti-inflammatory properties in osteoblasts and collagen-induced arthritis in mice, but its impact in gouty arthritis models remains unexplored. We investigated the effect of osteostatin on pyroptosis, inflammation, and oxidation in macrophages, as well as its role in the formation of calcium pyrophosphate dihydrate crystals and MSU-induced gouty arthritis in mice models. Osteostatin ameliorated pyroptosis induced by lipopolysaccharide and adenosine 5'-triphosphate (LPS + ATP) in mice peritoneal macrophages by reducing the expression of caspase-1, lactate dehydrogenase release, and IL-1ß and IL-18 secretion. Additionally, IL-6 and tumor necrosis factor-α (TNF-α) were also decreased due to the reduced activation of the NF-κB pathway. Furthermore, osteostatin displayed antioxidant properties in LPS + ATP-stimulated macrophages, resulting in reduced production of mitochondrial and extracellular reactive oxygen species and enhanced Nrf2 translocation to the nuclei. In both models of gouty arthritis, osteostatin administration resulted in reduced pro-inflammatory cytokine production, decreased leukocyte migration, and reduced caspase-1 and NF-κB activation. These results highlight the potential of osteostatin as a therapeutic option for gouty arthritis.

Tetrandrine alleviates inflammation and promotes macrophage M2 polarization in gouty arthritis by NF-κB-mediated Lcp1.

Gouty arthritis (GA) is an inflammatory disease caused by the deposition of monosodium urate (MSU) crystals into joints. Tetrandrine (TET) is a bisbenzylisoquinoline alkaloid extracted from the root of Stephania tetrandra and can exert an anti-inflammatory function in different diseases. Nevertheless, the specific function of TET in GA remains unclear. We established the GA mouse model by MSU injection into joints of mice. Paw volume and gait score were detected for measuring the degree of joint swelling and the situation of joint dysfunction. Western blot were utilized to test the alterations of M1-related factors (IL-6, IL-1ß, TNF-α, IL-12, and iNOS) and M2-related factors (Mgl1, Mgl2, Pgc1-ß, Arg-1, and IL-10). The activity of NF-κB p65 in tissues was determined. The interaction of NF-κB p65 and Lcp1 was measured by ChIP and luciferase reporter assay. Lcp1 KO mice were utilized to detect the effect of Lcp1 depletion on GA process. TET treatment markedly suppressed MSU-induced joint swelling, joint dysfunction, and joint injury in GA mice. TET can also reduce inflammatory reactions in MUS-induced mice. Furthermore, we proved that TET facilitated M2 macrophage polarization and inhibited M1 macrophage polarization in GA mice. In addition, TET was found to inhibit NF-κB activity and NF-κB-mediated Lcp1 expression. Lcp1 knockdown can improve joint injury and promote M2 macrophage polarization in GA mice, while this effect was further enhanced by TET. TET alleviates inflammation and facilitates macrophage M2 polarization in GA by NF-κB-mediated Lcp1.