Urate-induced immune programming: Consequences for gouty arthritis and hyperuricemia

M28 family peptidase derived from Peribacillus frigoritolerans initiates trained immunity to prevent MRSA via the complosome-phosphatidylcholine axis

Methicillin-resistant Staphylococcus aureus (MRSA) represents a major global health threat due to its resistance to conventional antibiotics. The commensal microbiota maintains a symbiotic relationship with the host, playing essential roles in metabolism, energy regulation, immune modulation, and pathogen control. Mammals harbor a wide range of commensal bacteria capable of producing unique metabolites with potential therapeutic properties. This study demonstrated that M28 family peptidase (M28), derived from commensal bacteria Peribacillus frigoritolerans (P. f), provided protective effects against MRSA-induced pneumonia. M28 enhanced the phagocytosis and bactericidal activity of macrophages by inducing trained immunity. RNA sequencing and metabolomic analyses identified the CFB-C3a-C3aR-HIF-1α axis-mediated phosphatidylcholine accumulation as the key mechanism for M28-induced trained immunity. Phosphatidylcholine, like M28, also induced trained immunity. To enhance M28-mediated therapeutic potential, it was encapsulated in liposomes (M28-LNPs), which exhibited superior immune-stimulating properties compared to M28 alone. In vivo experiments revealed that M28-LNPs significantly reduced bacterial loads and lung damage following MRSA infection, which also provided enhanced protection against Klebsiella pneumoniae and Candida albicans. We first confirmed a link between complement activation and trained immunity, offering valuable insights into the treatment and prevention of complement-related autoimmune diseases.

The Fifth Element: Is Vascular Dysfunction an Intrinsic Feature of Gout?

Gout, the most common inflammatory arthritis, affects as many as 5.1% of the adult population. Classically, gout is conceived as four sequential phenotypic states: 1) asymptomatic hyperuricemia 2) acute gout flare 3) inter-critical gout (gout between flares); and 4) tophaceous gout. However, these four states are paralleled by a fifth state, consisting of vascular involvement. The mechanisms and consequences of vascular gout are incompletely elucidated. In vitro and animal models indicate that soluble urate adversely affects vascular endothelium and smooth muscle. The recent discovery that soluble urate can be transported intracellularly to alter cell metabolism and epigenetics (trained innate immunity) suggests additional impacts of urate on leukocytes and endothelium. Once gout has progressed to flares, the vasculature is exposed to inflammatory mediators, both during flares and to a lesser but persistent extent inter-critically, suggesting additional mechanisms of gout's effect. We have reported that patients with gout have diminished endothelial function measured by brachial artery flow-mediated dilation. ACR gout guideline-concordant treatment improves endothelial function but is less effective in patients with cardiometabolic comorbidities. Moreover, treatment of gout patients with the anti-inflammatory colchicine and urate lowering therapy improves endothelial function and reduces the risk of both incident coronary artery disease (CAD), and MACE in patients with established CAD.

Clostridium butyricum and its metabolites regulate macrophage polarization through miR-146a to antagonize gouty arthritis

INTRODUCTION

Gut microbiota modulation has recently been identified as a prospective avenue for the exploration of novel therapeutic strategies for the management of gout. Nevertheless, the application of a single specific strain or bacterial metabolite for gout intervention has rarely been explored and the underlying regulatory mechanism remains elusive.

OBJECTIVES

To ascertain the potential role and the molecular mechanism of Clostridium butyricum and butyrate in the management of gouty arthritis.

METHODS

A Uox-KO mouse model of gouty arthritis was developed and the composition of the gut microbiota was analyzed. C. butyricum and butyrate were supplemented to assess functional recovery and intestinal homeostasis. NanoString analysis identified miRNA variations. GC/MS measured butyric acid levels and qPCR detected the abundance of butyrate-producing enzymes and bacteria. Flow cytometry analyzed macrophage polarization and ELISA measured pro-inflammatory cytokine production. Agomir and antagomir were transfected and dual-luciferase reporter assay was adapted for validation of miRNA target binding. siRNA and rescue experiments were performed to validate the role of SOCS7 in macrophage polarization. In addition, a cohort of patients with gouty arthritis were assembled for the purpose of validating the molecular mechanism.

RESULTS

The results of our study demonstrated that a reduction of butyrate levels, resulting from a deficiency of butyrate-producing bacteria, leads to aberrant miR-146a expression. This, in turn, induces an imbalance in macrophage polarization and the onset of gouty arthritis. The administration of C. butyricum and butyrate demonstrated considerable anti-inflammatory efficacy by restoring intestinal homeostasis, modulating miR-146a expression, and skewing macrophage polarization. The SOCS7/JAK2-STAT3 signaling pathway was identified as a pivotal mediator in the skewing of macrophage polarization induced by miR-146a.

CONCLUSION

Our findings enrich the understanding of the regulatory mechanisms underlying macrophage polarization in gouty arthritis and highlight the potential applications of probiotics and their metabolites in clinical gout treatment.

Association between circulating inflammatory proteins and gout: A Mendelian randomization study

Clinical studies have consistently demonstrated that inflammation is a critical factor in the pathophysiology and progression of gout. This study aims to explore the causal relationship between CIPs and gout, utilizing MR in conjunction with meta-analyses. We utilized genetic data pertaining to gout from the GWAS which involved 3576 cases and 147,221 control participants. A total of 132 CIPs were extracted from the GWAS data to identify SNPs associated with gout. The primary analytical approach was the IVW method. Sensitivity analyses indicated no pleiotropy or heterogeneity. The IVW results revealed that several CIPs were associated with gout in European populations. The analysis results indicate that FGF-21, MMP-1, G-CSF, and IFN-γ are involved in the pathogenesis of gout, and gout may influence the expression of CXCL1, IL-1Ra, and TNF-α. Consequently, targeted research focusing on specific CIPs could provide a promising strategy for the treatment and prevention of gout, offering potential therapeutic targets for the underlying inflammatory mechanisms of the disease.

Suppressing chondrocyte cuproptosis by syringaresinol-4-O-β-d-glucoside alleviates gouty arthritis

Background

Gouty arthritis is a rheumatic disease characterized by synovial inflammation and cartilage damage. Current therapeutic options for gouty arthritis, such as colchicine, primarily relieve the symptoms, which makes treatment challenging.

Methods

We employed an in vitro co-culture system of chondrocytes and macrophages to simulate gouty arthritis and screen compounds that can inhibit monosodium urate (MSU) associated macrophage inflammation and chondrocytes degeneration. We further elucidated the cuproptosis mechanism in chondrocytes by qPCR and Western blotting analyses. Both acute and chronic gouty arthritis mouse models were established to evaluate the therapeutic efficacy of candidate drugs against gouty arthritis.

Results

MSU upregulates the expression of inflammatory cytokines in macrophages and simultaneously induces cuproptosis in chondrocytes. By screening 24 compounds, we identified syringaresinol-4-O-β-d-glucoside (SSG), a furanoid lignan, as a potent inhibitor of macrophage-mediated inflammation and chondrocyte cuproptosis. Mechanistically, SSG inhibited MSU-induced activation of the NF-κB and NLRP3 pathways in macrophages. Furthermore, SSG regulated the expression of sulfur-linked mitochondrial enzymes (e.g., DLAT) in the cuproptosis pathway, thereby inhibiting the upstream regulator FDX1 in chondrocytes. SSG not only alleviated inflammatory pain but also protected against cartilage damage and improved motor dysfunction in the mice models of acute and chronic gouty arthritis.

Conclusion

SSG can serve as a promising therapeutic option for gouty arthritis in clinical settings by suppressing inflammation and preserving cartilage integrity.

Non-inflammatory macrophages phagocytose and hydrolyse monosodium urate crystals in different stages of gout

OBJECTIVE

Macrophages play a crucial role in gouty arthritis; however, the relationship between non-inflammatory macrophages (M0) and different stages of gout remains unclear. This study aimed to investigate the phagocytosis, hydrolysis, and subsequent cytokine secretion of monosodium urate (MSU) by non-inflammatory macrophages in patients in different stages of gout.

METHOD

Non-inflammatory macrophages were derived from monocytes through stimulation with macrophage colony-stimulating factor (M-CSF) for a duration of 10 days. The study included patients with asymptomatic hyperuricaemia, intercritical gout, tophaceous gout, and a normal control group. The phagocytic and hydrolytic capabilities of non-inflammatory macrophages were measured using flow cytometry based on the increase in side-scatter area. In addition, to evaluate the relationship between the hydrolysis capability of non-inflammatory macrophages and subsequent inflammation, we cultured them with lipopolysaccharide (LPS) and/or MSU.

RESULTS

We discovered that M0 macrophages were capable of phagocytosing and hydrolysing MSU crystals in various stages of gout, including the control group. Patients with asymptomatic hyperuricaemia exhibited the most pronounced phagocytic and hydrolytic capabilities, surpassing even those of the normal control group. The presence of MSU alone did not induce the secretion of pro-inflammatory cytokines. However, in experiments where M0 macrophages were stimulated with LPS and/or MSU, the phagocytic and hydrolytic abilities of M0 macrophages were correlated with inflammatory cytokine elevation.

CONCLUSION

The efficient phagocytosis and hydrolysis of MSU crystals by M0 macrophages suggest their role in maintaining the non-inflammatory stage of gout. Our findings suggest that non-inflammatory macrophages play a role in gout.

Therapeutic potential and pharmacological mechanisms of Traditional Chinese Medicine in gout treatment

Gout is a systemic metabolic disorder caused by elevated uric acid (UA) levels, affecting over 1% of the population. The most common complication of gout is gouty arthritis (GA), characterized by swelling, pain or tenderness in peripheral joints or bursae, which can lead to the formation of tophi. At present, western medicines like colchicine, febuxostat and allopurinol are the primary treatment strategy to alleviate pain and prevent flare-ups in patients with GA, but they have significant side effects and increased mortality risks. Traditional Chinese medicine (TCM) has been utilized for thousands of years for the prevention and treatment of GA, demonstrating effective control over serum UA (SUA) levels with fewer side effects. Herein we summarized a total of 541 studies published from 2000 to 2023 in sources including PubMed, Web of Science, the Cochrane Library and Embase, highlighting the therapeutic potential of TCM in treating gout and GA, particularly in combination with modern medical strategies. This review focuses on TCM formulas, Chinese herbal extracts, and active compounds derived from TCM, providing an overview of recent clinical application and the pharmacological research based on animal models and cellular systems. Particularly, the current review categorized the clinical and experimental evidence into the strategies for improving hyperuricemia, decreasing the sudden onset of acute GA and retarding chronic GA progression, supplied further coherent reference and enlightenment for clinicians, investigators of natural product chemistry, researchers in TCM and pharmacology. We hope this article will inspire the development of novel formulas and molecular entities for the treatment of gout and GA.

Single-cell transcriptome reveals potential mechanisms for gout in children

Objective

Pediatric gout is a condition that differs from traditional adult gout and has attracted significant attention. This study aims to explore the molecular mechanisms underlying pediatric gout.

Methods

We analyzed peripheral blood samples from pediatric gout patients and healthy controls using single-cell RNA sequencing (scRNA-seq). Statistical tests were employed to analyze the data and identify significant differences between the groups.

Results

Our findings revealed that CD14+ monocytes and DN T cells play crucial roles in pediatric gout. CD14+ monocytes are essential for recognizing and phagocytosing monosodium urate (MSU) crystals, triggering inflammation. DN T cells may be involved in the adaptive immune response within gouty joints. These cells not only contribute to the inflammatory response but also interact with other immune cells, amplifying the inflammatory cascade. Comparative analysis with adult gout studies highlighted both similarities and differences in cellular and molecular mechanisms between children and adults. The CD14+ monocytes may be interact with other immune cells through the TNF-α/NF-κB signaling pathway. Targeting this pathway may offer therapeutic potential for managing pediatric gout.

Conclusion

The results provide a foundation for new diagnostic markers and therapeutic targets for pediatric gout. They also pave the way for future research and the development of targeted therapies that can effectively manage and potentially prevent the debilitating effects of gout in children. Understanding the unique molecular mechanisms in pediatric gout could influence treatment strategies and improve patient outcomes.

Primary cilia and inflammatory response: unveiling new mechanisms in osteoarthritis progression

Osteoarthritis (OA) is a common degenerative joint disease that can lead to chronic pain and disability. The pathogenesis of OA involves chronic low-grade inflammation, characterized by the degradation of chondrocytes, inflammation of the synovium, and systemic low-grade inflammation. This inflammatory response accelerates the progression of OA and contributes to pain and functional impairment. Primary cilia play a crucial role in cellular signal transduction and the maintenance of cartilage matrix homeostasis, and their dysfunction is closely linked to inflammatory responses. Given these roles, primary cilia may significantly contribute to the pathogenesis of OA. This review explores inflammation-associated signaling pathways in OA, including NF-κB, MAPK, JAK/STAT, and PI3K/AKT/mTOR signaling. In addition, we place particular emphasis on cilia-mediated inflammatory modulation in OA. Primary cilia mediate chondrocyte responses to mechanical loading and inflammatory cytokines via pathways including NF-κB, MAPK, TRPV4, and Hedgehog signaling. Notably, alterations in the length and incidence of primary cilia in chondrocytes during OA further underscore their potential role in disease pathogenesis. The identification of biomarkers and therapeutic targets related to primary cilia and inflammatory pathways offers new potential for the treatment and management of OA.

Delineating circulating lymphocyte subsets in the transition from gout remission to recurrence

Objectives

Lymphocytes and their subsets are implicated in both the onset and remission of gout. However, the specific roles in gout recurrence and complete remission remain unclear. This study aimed to characterize lymphocyte immunophenotypes across different stages of gout and developed a predictive model for remission and recurrence of gout.

Methods

Plasma levels of 75 lymphocyte immunophenotypes were determined using multiplex flow cytometry in patients with acute gout flare (AG, n=78), gout remission (RG, n=63), and healthy controls (NC, n=66). Lymphocyte immunophenotyping candidates and significant clinical parameters were subjected to LASSO regression for conducting a predictive model.

Results

Significant variations in lymphocyte profiles were identified among the groups. A combination of T peripheral helper cells, virus-specific cytotoxic natural killer (NK) cells, inhibition of Vδ1 and Vδ2 cells, along with BMI, eGFR, hemoglobin, uric acid, distinguished RG from NC (AUC=0.934). Similarly, inhibition of Vδ2 cells, virus-specific cytotoxic NK cells, inactive and terminally differentiated virus-specific CD8+ T cells, plus hematological parameters, classified RG from AG (AUC = 0.814) and predicted gout recurrence in a one-year follow-up validation cohort (AUC = 0.724). Inhibition of Vδ2 cells and virus-infected specific cytotoxic NK cells are strongly associated with gout recurrence and complete remission.

Conclusion

Significant alterations in lymphocyte immunophenotypes, notably the inhibition of Vδ2 cells and virus-infected specific cytotoxic NK cells during the transition from gout recurrence to complete remission, provide compelling evidence to enhance the clinical delineation of gout stages and propel mechanistic investigations into the progression of gout.

A dynamic study on serum biomarkers and kidney injury in a gosling model of hyperuricemia

Hyperuricemia, a metabolic disorder characterized by elevated serum uric acid levels, poses significant challenges to poultry health and productivity. This study aimed to establish a hyperuricemia model in goslings through a multi-factorial induction approach using a high-purine, high-protein, and high-calcium diet, to investigate its dynamic progression, serological markers, and renal pathology. A total of 160 male Sanhua goslings were randomly assigned to control and model groups and fed either a basal diet or a high-purine, high-protein, and high-calcium diet for 18 days. Key findings revealed significant elevations in serum uric acid, creatinine, and urea nitrogen levels in the model group from day 5 onward, peaking on day 13 (p < 0.01). Activities of xanthine oxidase and adenosine deaminase were consistently higher in the model group, indicating enhanced purine metabolism and oxidative stress. Histopathological analysis showed progressive renal damage, including tubular degeneration, interstitial fibrosis, and glomerular injury, becoming evident by day 7 and severe by day 13. Ultrastructural examination further revealed mitochondrial dysfunction, podocyte effacement, and basement membrane disruption in the model group. Behavioral abnormalities, such as reduced mobility and the "shrinking neck" phenomenon, were observed from day 9, reflecting systemic disease severity. The dynamic expression of fibrosis-related markers, including Col-1, Col-3, and α-SMA, demonstrated the progression of renal fibrosis and extracellular matrix remodeling. These findings identify biomarkers for hyperuricemia progression and suggest potential therapeutic targets. This study establishes a comprehensive framework for understanding hyperuricemia-associated renal pathology and lays the groundwork for developing strategies to mitigate its impact on poultry health and productivity.

Prunus mume Alleviates Hyperuricemic Renal Injury: Insights From Network Pharmacology and Experimental Models

Prunus mume (PM), the dried flower bud of a Rosaceae plant, has a long history of use for its liver-soothing, depression-relieving, and appetite-stimulating effects. Recently, PM has gained attention for its anti-inflammatory, antioxidant, and uric acid-lowering properties. The chemical composition of PM was analyzed using network pharmacology and liquid chromatography-mass spectrometry (LC-MS). The therapeutic potential of PM for hyperuricemia-induced kidney damage was evaluated in a quail model. Antioxidant activity in an HK-2 cell model of hyperuricemia was assessed by measuring the levels of MDA, SOD, and GSH. Additionally, the anti-inflammatory potential was examined using ELISA to measure TNF-α and IL-6 levels. Western blotting was employed to study the effects on URAT1, GLUT9, and the PI3K/AKT pathway. LC-MS identified 284 compounds in PM, with 35 predicted active ingredients. The quail model demonstrated PM's protective effects on the kidneys under hyperuricemic conditions. In vitro, PM reduced oxidative stress and lowered TNF-α and IL-6 levels. It also modulated URAT1 and GLUT9 expression and influenced the PI3K/AKT pathway. PM shows promise in protecting kidneys from hyperuricemia-induced damage, likely through its anti-inflammatory and antioxidant activities, as well as the regulation of urate transport proteins and the PI3K/AKT pathway.

Exploring gene expression, alternative splicing events and RNA-binding proteins changes in PBMC from patients with hyperuricemia

AIM

The objective of this study was to examine the transcriptomic profile changes in hyperuricemia (HUA) and to investigate the pathogenic mechanisms and biomarkers of HUA from a transcriptomic perspective.

METHODS

In this study, three patients with HUA were randomly selected and matched with three healthy controls. Six participants provided peripheral blood mononuclear cells (PBMCs) for analysis. RNA sequencing (RNA-seq) was used to identify differentially expressed genes (DEGs) and alternative splicing events (ASEs). Gene Ontology (GO) biological processes and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed to identify the functions and pathways of the DEGs and ASEs. Additionally, a co-expression network was constructed to analyze the regulation of DEGs and ASEs by RNA-binding protein (RBP) genes. In addition, important DEGs and ASEs were validated using quantitative real-time PCR (qPCR).

RESULTS

There were 633 DEGs identified, 348 up-regulated DEGs and 285 down-regulated DEGs, including RGS18, CAVIN2, GZMH, GNLY and MT-TV, which were mainly enriched in inflammatory and immune-related biological processes. A total of 1542 ASEs were significantly differentially expressed in HUA, of which LTB4R and ENTPD4 were closely associated with the development of HUA. In addition, 15 RBP genes were detected to be differentially expressed in HUA. Three RBP genes (IFIT1, IFFIT2, and IFIT3) were highly associated with immunoinflammation and affected HUA by modulating downstream immune responses, inflammatory response-associated DEGs, and ASEs. The selected five DEGs and two ASEs were verified by qPCR, which was consistent with the results of RNA sequencing.

CONCLUSIONS

In summary, the findings indicate that HUA is associated with significant changes in inflammatory and immune response-related genes (RGS18, CAVIN2, GZMH, GNLY, MT-TV, LTB4R, ENTPD4, IFIT1, IFFIT2, and IFIT3). These findings suggest potential biomarkers and therapeutic targets.

Interleukin-10 inhibits important components of trained immunity in human monocytes

Trained immunity induces antigen-agnostic enhancement of host defense and protection against secondary infections, but inappropriate activation can contribute to the pathophysiology of inflammatory diseases. Tight regulation of trained immunity is therefore needed to avoid pathology, but little is known about the endogenous processes that modulate it. Here, we investigated the potential of interleukin (IL)-10, a prototypical anti-inflammatory cytokine, to inhibit trained immunity. IL-10 induced tolerance and inhibited trained immunity in primary human monocytes at both functional and transcriptional levels. Inhibition of STAT3, a signaling route that mediates IL-10 signals, induced trained immunity. IL-10 downregulated glycolytic and oxidative metabolism in monocytes but did not impact the metabolic effects of β-glucan-induced trained immunity. Furthermore, IL-10 prevented increased reactive oxygen species production in Bacillus Calmette-Guérin (BCG)-induced training but did not influence phagocytosis upregulation. In a cohort study of healthy volunteers vaccinated with BCG, genetic variants that influenced IL-10 or its receptor modulated BCG-induced trained immunity. Furthermore, circulating IL-10 concentrations were negatively correlated with induction of trained immunity after BCG vaccination in a sex-specific manner. In conclusion, IL-10 inhibited several, albeit not all, immunological functions amplified after induction of trained immunity. Follow-up studies should explore the precise molecular mechanism that mediates the effects of IL-10 on trained immunity. Addressing these knowledge gaps is an important step toward optimizing IL-10's potential as a therapeutic target in diseases characterized by inappropriate induction of trained immunity.

Hyperuricemia Exacerbates Psoriatic Inflammation by Inducing M1 Macrophage Activation and Th1 Cell Differentiation

A higher prevalence of hyperuricemia is observed in psoriasis, yet the precise involvement of hyperuricemia in psoriasis remains unclear. Therefore, we investigated the relationship between hyperuricemia and psoriasis, as well as the potential mechanisms through which hyperuricemia may promote psoriatic inflammation. Firstly, a literature review on psoriasis and serum uric acid (SUA) levels and a retrospective analysis on PASI scores and SUA of 147 psoriasis patients at the Dermatology Hospital of Southern Medical University were performed. Then mouse models of hyperuricemia and psoriasis were established to assess the impact of hyperuricemia on psoriasis. Finally, assays examined monosodium urate (MSU) on macrophage M1 polarisation, Th1 differentiation and expressions of NLRP3 and ASC. The literature review indicated inconsistent SUA-psoriasis links; however, our clinical data indicated a positive correlation between PASI scores and SUA. Mouse model results indicated that hyperuricemia exacerbated psoriatic lesions and upregulated the transcription of inflammatory cytokines (IL-17A, IL-17F, IL-23A, IL-8, TNF-α and IL-1β) in skin lesions, effects which were reversed with allopurinol treatment. GO-BP, KEGG and GSEA enrichment analyses of RNA-seq data from mice skin lesions and spleens revealed increased enrichment of Toll-like receptor pathways, TNF-α signalling pathways and innate immune cell migration pathways. CIBERSORTx analysis showed increased M1 cell infiltration in skin lesions and Th1 differentiation in splenic lymphocytes under hyperuricemic conditions. In vitro, MSU enhanced IMQ or LPS-induced macrophage M1 polarisation and Th1 differentiation when co-cultured with M1 cells, which depends on TLR4 expression. In conclusion, hyperuricemia may exacerbate psoriasis by promoting macrophage M1 polarisation, increasing Th1 differentiation and psoriatic inflammation.

Integrative analysis reveals the multilateral inflammatory mechanisms of CD14 monocytes in gout

OBJECTIVES

Gout, prevalent inflammatory arthritis caused by urate crystal deposition, involves immune cell activation, yet the precise role of CD14 monocytes in initiating the inflammatory response is poorly understood. This study aimed to characterise the molecular and cellular landscape of CD14 monocytes in gout using single-cell transcriptomic analysis.

METHODS

Single-cell RNA sequencing was performed on peripheral blood mononuclear cells from 8 gout patients and 6 age- and sex-matched healthy controls. The findings were validated using publicly available datasets. Differential gene expression and pathway enrichment analyses were conducted to identify gout's key molecular regulators and cellular subclusters.

RESULTS

At the molecular level, we identified hypoxia-related pathways, including HIF1A, as key regulators of interleukin-1β production in CD14 monocytes in gout. We also observed significant downregulation of CLEC12A across all CD14 monocyte subclusters. At the cellular level, an S100Ahigh CD14 monocyte subcluster, characterized by high expression of S100A8/A9/A12 and linked to inflammatory and metabolic pathways, was found to drive NLRP3 and CLEC7A inflammasome activation, as well as prostaglandin secretion. In vitro stimulation with monosodium urate crystals revealed that the differentially expressed genes were enriched in S100Ahigh monocytes, highlighting the synergistic role of these pathways in driving gout inflammation. Additionally, gout genome-wide association study-prioritised genes underscored the role of fatty acid metabolism in inflammation, promoting prostaglandin secretion from S100Ahigh monocytes.

CONCLUSIONS

These findings provide new insights into the role of CD14 monocytes in gout pathogenesis, particularly the contribution of hypoxia and fatty acid metabolism pathways, and suggest potential therapeutic targets for precision medicine in gout treatment.

Impact of Dietary Fiber on Inflammation in Humans

Cohort studies consistently show that a high intake of cereal fiber and whole-grain products is associated with a decreased risk of type 2 diabetes (T2DM), cancer, and cardiovascular diseases. Similar findings are also reported for infectious and chronic inflammatory disorders. All these disorders are at least partially caused by inflammaging, a chronic state of inflammation associated with aging and Metabolic Syndrome. Surprisingly, insoluble (cereal) fiber intake consistently shows stronger protective associations with most long-term health outcomes than soluble fiber. Most humans consume soluble fiber mainly from sweet fruits, which usually come with high levels of sugar, counteracting the potentially beneficial effects of fiber. In both observational and interventional studies, high-fiber diets show a beneficial impact on inflammation, which can be attributed to a variety of nutrients apart from dietary fiber. These confounders need to be considered when evaluating the effects of fiber as part of complex dietary patterns. When assessing specific types of fiber, inulin and resistant starch clearly elicit anti-inflammatory short-term effects, while results for pectins, beta-glucans, or psyllium turn out to be less convincing. For insoluble fiber, promising but sparse data have been published so far. Hypotheses on putative mechanisms of anti-inflammatory fiber effects include a direct impact on immune cells (e.g., for pectin), fermentation to pleiotropic short-chain fatty acids (for fermentable fiber only), modulation of the gut microbiome towards higher levels of diversity, changes in bile acid metabolism, a differential release of gut hormones (such as the glucose-dependent insulinotropic peptide (GIP)), and an improvement of insulin resistance via the mTOR/S6K1 signaling cascade. Moreover, the contribution of phytate-mediated antioxidative and immune-modulatory means of action needs to be considered. In this review, we summarize the present knowledge on the impact of fiber-rich diets and dietary fiber on the human inflammatory system. However, given the huge heterogeneity of study designs, cohorts, interventions, and outcomes, definite conclusions on which fiber to recommend to whom cannot yet be drawn.

Oral delivery of therapeutic proteins by engineered bacterial type zero secretion system

Genetically engineered commensal bacteria are promising living drugs, however, their therapeutic molecules are frequently confined to their colonization sites. Herein, we report an oral protein delivery technology utilizing an engineered bacterial type zero secretion system (T0SS) via outer membrane vesicles (OMVs). We find that OMVs produced in situ by Escherichia coli Nissle 1917 (EcN) can penetrate the intact gut epithelial barrier to enter the circulation and that epithelial transcytosis involves pinocytosis and dynamin-dependent pathways. EcN is engineered to endogenously load various enzymes into OMVs, and the secreted enzyme-loaded OMVs are able to stably catalyze diverse detoxification reactions against digestive fluid and even enter the circulation. Using hyperuricemic mice and uricase delivery as a demonstration, we demonstrate that the therapeutic efficacy of our engineered EcN with a modified T0SS outperforms that with a direct protein secretion apparatus. The enzyme-loaded OMVs also effectively detoxify human serum samples, highlighting the potential for the clinical treatment of metabolic disorders.

Purine metabolism-associated key genes depict the immune landscape in gout patients

Gout is the most common form of inflammatory arthritis that affects approximately 1% to 6.8% of the global population. Less than half of gout patients received urate-lowering therapy and compliance to the therapy, along with the climbing prevalence, adds a tight burden to public health, not to mention the potential tumor risk incurred by persistent inflammation in the patients. Thus, the study aimed to explore the links between gout, immune responses, and tumor development in terms of genetic alterations. Using RNA-seq data of peripheral blood mononuclear cells (PBMCs) from gout patients, we screened the differentially expressed genes (DEGs) of gout patients and found that they were closely involved in purine metabolism. We then focused on purine metabolism-related DEGs, and machine learning algorithms validated that these genes can help to discriminate gout from healthy conditions. ssGSEA revealed that these DEGs were significantly linked to immune reprogramming concerning fluctuation in the proportion and activity of various immunocytes. Most importantly, they were also partially dysregulated in a wide range of malignancies and exerted a notable influence on the survival of tumor patients, especially LIHC (Liver hepatocellular carcinoma). Therefore, our study made an urgent appeal to due attention to the underlying crosstalk among purine metabolism, immune responses, and tumor development in gout patients.

Hyperuricemia-induced complications: dysfunctional macrophages serve as a potential bridge

With the changes in modern life, hyperuricemia (HUA) has become a serious universal health issue, leading to rising morbidity and mortality. Characterized by elevated levels of UA, HUA has become an independent risk factor for gout, chronic kidney disease, insulin resistance, cardiovascular disease, nonalcoholic fatty liver disease, etc. As HUA is a metabolic syndrome, the immune response is likely to play an active role throughout the whole process. Moreover, macrophages, as an indispensable component of the immune system, may serve as a promising target for addressing hyperuricemia-induced inflammation. Along with their precursor cells, monocytes, macrophages play a key role in the pathogenesis of HUA, primarily through three specific aspects, all of which are associated with inflammatory cytokines. The first mechanism involves direct action on urate transporters, such as URAT1 and ABCG2. The second mechanism is the modulation of inflammation, including targeting toll-like receptors (TLRs) and the NOD-, LRR-, and pyrin domain-containing protein 3 (NLRP3) inflammasome. The third mechanism pertains to the effects on oxidative stress mediators. In this review, we summarize the underlying mechanisms of hyperuricemia, focusing on the effects of macrophages, therapeutic approaches, and clinical trials addressing hyperuricemia-caused dysfunction. Additionally, we highlight directions for future development, aiming to support future theoretical studies.

Associations between lipid-lowering drugs and urate and gout outcomes: a Mendelian randomization study

Objective

Gout is a common inflammatory arthritis and lipid metabolism plays a crucial role in urate and gout. Potential associations between urate and gout and lipid-lowering drugs have been revealed in observational studies. However, the effects of lipid-lowering drugs on urate and gout remain controversial. The aim of this study was to investigate the genetic association between lipid-lowering drugs and urate and gout.

Methods

In this study, two genetic proxies were employed to approximate lipid-lowering drug exposure: expression quantitative trait loci (eQTL) associated with drug-target genes and genetic variations proximal to or within genes targeted by these drugs, which are linked to low-density lipoprotein cholesterol (LDL-C) levels. The study's exposures encompassed genetic variants within drug target genes (HMGCR, PCSK9, NPC1L1), each representing distinct lipid-lowering mechanisms. Causal effects were estimated using the inverse variance weighting (IVW) method, while the Summary Data-based Mendelian Randomization (SMR) method, leveraging pooled data, was applied to compute effect estimates. These estimates were further refined through various approaches including MR-Egger, the weighted median method, simple and weighted models, and leave-one-out analyses to conduct sensitivity analyses.

Result

The analytical outcomes utilizing the IVW method indicated that inhibitors of HMGCR were correlated with an elevated risk of developing gout (IVW: OR [95%CI] = 1.25 [1.03, 1.46], p=0.0436), while PCSK9 inhibitors were linked to heightened levels of urate (IVW: OR [95%CI] = 1.06 [1.01,1.10], p=0.0167). Conversely, no significant correlation between NPC1L1 inhibitors and the levels of urate or the risk of gout was established. Furthermore, the SMR analysis failed to identify significant associations between the expression levels of the HMGCR, PCSK9, and NPC1L1 genes and the risk of gout or elevated urate levels (SMR method: all P values >0.05). Sensitivity analyses further confirmed the robustness of these results, with no significant heterogeneity or pleiotropy found.

Conclusion

This study furnishes novel causal evidence supporting the potential genetic correlation between the use of lipid-lowering drugs and the incidence of gout as well as urate levels. The findings indicate that inhibitors targeting HMGCR may elevate the risk associated with the development of gout, while inhibitors targeting PCSK9 are likely to increase urate concentrations.

Role of Trained Immunity in Heath and Disease

PURPOSE OF REVIEW

This review aims to explore the role of immune memory and trained immunity, focusing on how innate immune cells like monocytes, macrophages, and natural killer cells undergo long-term epigenetic and metabolic rewiring. Specifically, it examines the mechanisms by which trained immunity, often triggered by infection or vaccination, could impact cardiac processes and contribute to both protective and pathological responses within the cardiovascular system.

RECENT FINDINGS

Recent research demonstrates that vaccination and infection not only activate immune responses in circulating monocytes and tissue macrophages but also affect immune progenitor cells within the bone marrow environment, conferring lasting protection against heterologous infections. These protective effects are attributed to epigenetic and metabolic reprogramming, which enable a heightened immune response upon subsequent encounters with pathogens. However, while trained immunity is beneficial in combating infections, it has been linked to exacerbated inflammation, which may increase susceptibility to cardiovascular diseases, including atherosclerosis and heart failure. Our review highlights the dual nature of trained immunity: while it offers protective advantages against infections, it also poses potential risks for cardiovascular health by promoting chronic inflammation. Understanding the molecular mechanisms underlying immune memory's impact on cardiac processes could lead to new therapeutic strategies to mitigate cardiovascular diseases, such as atherosclerosis, heart failure, and diabetes. These insights build the grounds for future research to balance the benefits of trained immunity with its potential risks in cardiovascular disease management.

From Patents to Progress: Unraveling Gout's Journey Through Clinical Trials and Advancements

Gout, an inflammatory arthritis form, is renowned for its historical association with affluence. This review delves into its pathophysiology, exploring hyperuricemia, urate crystal formation, and the ensuing inflammatory response. The epidemiology of gout is examined, focusing on its rising prevalence and impact on public health. In this study, progress in gout management is discussed, involving pharmacological interventions, dietary changes, and emerging therapies. Genetic predisposition and triggers like alcohol, temperature, and diet are highlighted in this study. Prevention strategies, including serum urate-lowering therapy and lifestyle modifications, aim to reduce recurrent flares and complications. The inflammatory response in acute gout attacks is elucidated, involving immune cells, cytokines, and the NLRP3 inflammasome. Chronic gout manifestations, such as gouty tophus formation, are explored for their destructive impact on surrounding tissues. Recent advancements in gout treatment, including nanotherapies and novel compounds, are discussed, along with promising urate-lowering drugs. Cutting-edge research on zinc ferrite nanoparticles, dimethyl fumarate, and myricetin/nobiletin hybrids addresses oxidative stress and inflammation in gout. Additionally, the potential therapeutic role of methanolic leaf extract of Euphorbia milii and tip-loaded CLC-Soluplus® MAPs is explored as natural and transdermal alternatives for gout management. The review also covers the development status of new urate-lowering drugs, providing insights into promising candidates and their mechanisms. Patents on gout and recent diagnostic advancements using techniques like laser confocal micro Raman spectrometer, FTIR, and THz-TDS offer a more accurate approach for gout stone analysis, enabling early detection and targeted treatment.

Exploring the link between serum uric acid and colorectal cancer: Insights from genetic evidence and observational data

Colorectal cancer (CRC) is a major cause of cancer-related mortality worldwide. Urate, known for its antioxidant properties, may influence CRC risk and prognosis, but research on this is limited. We used Mendelian randomization (MR) analysis to explore the causal relationship between serum urate levels and CRC risk. Additionally, we analyzed National Health and Nutrition Examination Survey data to assess the impact of serum urate on CRC prognosis. MR analysis in the European population indicated that higher serum urate levels are associated with a reduced CRC risk (odds ratios [OR] inverse-variance weighted: 0.90, 95% CI: 0.81-0.99, P = .04; OR MR-Egger: 0.86, 95% CI: 0.75-0.98, P = .03; OR Weighted-Median: 0.85, 95% CI: 0.74-0.96, P = .01; OR Weighted-Mode: 0.83, 95% CI: 0.74-0.94, P = .002). Validation datasets supported this (OR inverse-variance weighted: 0.83, 95% CI: 0.72-0.96, P = .011). However, National Health and Nutrition Examination Survey data showed that higher serum urate levels are linked to poorer CRC outcomes (HR 1.50, 95% CI: 1.08-2.10, P = .02). This study suggests that elevated serum urate levels may reduce CRC risk but are associated with worse prognosis in CRC patients, highlighting its potential as a biomarker for CRC risk and prognosis.

The Therapeutic Management of Chemical and Herbal Medications on Uric Acid Levels and Gout: Modern and Traditional Wisdom

Background: Gout is a chronic inflammatory condition characterized by elevated uric acid levels in the blood, which can precipitate acute gout attacks in individuals with genetic susceptibility, existing medical conditions, and dietary influences. Genetic predispositions, comorbid medical conditions, nutritional choices, and environmental factors increasingly recognize the multifactorial etiology of the disease. Methods: Recent research has highlighted the potential of phytochemicals, particularly flavonoids, saponins, and alkaloids, to manage hyperuricemia (HUA) and its associated complications. Results: Plant's natural compounds have garnered attention for their anti-inflammatory, antioxidant, and uric acid-lowering properties, suggesting their role in alternative and complementary medicine. Phytochemicals have demonstrated promise in mitigating gout symptoms and potentially modifying the disease course by addressing different aspects of hyperuricemia and inflammation. Herbal remedies, with their complex phytochemical profiles, offer a unique advantage by potentially complementing conventional pharmacological treatments. The integration of herbal therapies with standard medications could lead to enhanced therapeutic outcomes through synergistic effects, optimizing disease management, and improving patient quality of life. Conclusions: This review examines the current understanding of the multifaceted etiology of gout, explores the role of phytochemicals in managing hyperuricemia, and discusses the potential benefits of combining herbal remedies with conventional treatments to improve patient care and therapeutic efficacy.

Trained immunity in the bone marrow: Hub of autoimmunity

An inappropriate induction of trained immunity in the bone marrow progenitors of immune cells has been described to underlie chronic inflammatory processes. Mills and colleagues' recently published paper in Cell Stem Cell shows that maladaptive trained immunity drives inflammation in autoimmune processes,1 opening a new area of research in autoimmunity.

Insights into the multifaceted role of interleukin-37 on human immune cell regulation

Autoinflammatory diseases, while having a variety of underlying causes, are mediated by dysfunctional innate immune responses. Therefore, standard treatments target innate cytokines or block their receptors. Despite excellent responses in some patients, first-line treatments fail in others, for reasons which remain to be understood. We studied the effects of IL-37, an anti-inflammatory cytokine, on immune cells using multi-omics profiling of 325 healthy adults. Our findings show that IL-37 is associated with inflammation control and generally reduced immune cell activity. Further, genetic variants in IL37 are associated with impaired trained immunity, a memory phenotype of innate immune cells contributing to autoinflammation. To underpin the medical potential of IL-37, an explorative cohort of seven autoinflammatory disorders was built. In vitro stimulation experiments argue for recombinant IL-37 as a potential therapy in IL-6-, and IL-22-driven conditions. Concluding, IL-37 is highlighted as a cytokine with broad anti-inflammatory functions, implicating its potential as therapeutic intervention.

A genome-wide association analysis reveals new pathogenic pathways in gout

Gout is a chronic disease that is caused by an innate immune response to deposited monosodium urate crystals in the setting of hyperuricemia. Here, we provide insights into the molecular mechanism of the poorly understood inflammatory component of gout from a genome-wide association study (GWAS) of 2.6 million people, including 120,295 people with prevalent gout. We detected 377 loci and 410 genetically independent signals (149 previously unreported loci in urate and gout). An additional 65 loci with signals in urate (from a GWAS of 630,117 individuals) but not gout were identified. A prioritization scheme identified candidate genes in the inflammatory process of gout, including genes involved in epigenetic remodeling, cell osmolarity and regulation of NOD-like receptor protein 3 (NLRP3) inflammasome activity. Mendelian randomization analysis provided evidence for a causal role of clonal hematopoiesis of indeterminate potential in gout. Our study identifies candidate genes and molecular processes in the inflammatory pathogenesis of gout suitable for follow-up studies.

Association of circulating monocyte number and monocyte-lymphocyte ratio with cardiovascular disease in patients with bipolar disorder

BACKGROUND

Cardiovascular disease (CVD) is the leading cause of excessive and premature mortality in patients with bipolar disorder (BD). Despite immune cells participating considerably in the pathogenesis of CVD, limited data are available regarding leukocyte phenotypes in patients with BD and CVD. This study aimed to evaluate associations between circulating leukocyte subset and CVD among patients with BD.

METHODS

A total of 109 patients with BD-I and cardiologist-confirmed CVD diagnosis (i.e., case) were matched with 109 BD-I patients without CVD (i.e., control) according to the age (± 2 years), sex, and date of most recent psychiatric admission because of acute mood episode (± 2 years). Leukocyte subset data were retrieved from complete blood count tests performed on the next morning after the most recent acute psychiatric admission.

RESULTS

During the most recent acute psychiatric hospitalization, circulating monocyte counts in the case group were significantly higher than those in the age- and sex-matched controls (p = 0.020). In addition, monocyte-lymphocyte ratios (MLRs) in the case group were significantly higher than those in the control group (p = 0.032). Multiple logistic regression showed that together with serum levels of uric acid and manic symptoms, circulating monocyte counts (95% CI, OR: 1.01-1.05) and MLRs (95% CI, OR: 1.01-1.09) were significantly associated with CVD in patients with BD, respectively.

CONCLUSIONS

Monocyte activation in an acute manic episode may play a critical role in the pathogenesis of CVD among patients with BD. Future research is required to investigate markers of monocyte activation and indices of cardiovascular structure and function across the different mood states of BD.

The Predictive Value of SII Combined with UHR for Contrast-Induced Acute Kidney Injury in Patients with Acute Myocardial Infarction After Percutaneous Coronary Intervention

Background

Contrast-induced acute kidney injury (CI-AKI) refers to the acute renal dysfunction caused by the injection of contrast agents. CI-AKI is currently a common complication after percutaneous coronary intervention (PCI).

Objective

To investigate the predictive value of the combined systemic inflammatory index (SII) and urate/high-density lipoprotein cholesterol ratio (UHR) for CI-AKI after PCI in patients with AMI.

Methods

A total of 1222 patients with AMI who underwent PCI were randomly divided into a training group and a validation group in an 8:2 ratio. According to the definition of CI-AKI diagnostic criteria, the training group was divided into CI-AKI group and non-CI-AKI group. Collect patient's blood and biochemical data, then calculate SII and UHR. The risk factors for CI-AKI were identified using LASSO and multivariate logistic regression analyses. A predictive column was created by using R language.Evaluate the predictive value of SII, UHR and their combination for CI-AKI after PCI using the area under the ROC curve (AUC).

Results

Diabetes, Cystatin C, Diuretics, UHR, and LnSII were independent risk factors for CI-AKI in AMI patients after PCI. The ROC curve showed that the AUC of UHR and SII combined for predicting CI-AKI in AMI patients after PCI was 0.761 (95% CI: 0.709-0.812), with a sensitivity of 65.20% and a specificity of 76.70%, which was better than the prediction by either factor alone.

Conclusion

High SII and high UHR are risk factors for AMI, and their combination can improve the accuracy of predicting CI-AKI in AMI patients after PCI.The prognosis of CI-AKI in AMI patients is worse than in the general population.

Genetic and epigenetic dysregulation of innate immune mechanisms in autoinflammatory diseases

Dysregulation and hyperactivation of innate immune responses can lead to the onset of systemic autoinflammatory diseases. Monogenic autoinflammatory diseases are caused by inborn genetic errors and based on molecular mechanisms at play, can be divided into inflammasomopathies, interferonopathies, relopathies, protein misfolding, and endogenous antagonist deficiencies. On the other hand, more common autoinflammatory diseases are multifactorial, with both genetic and non-genetic factors playing an important role. During the last decade, long-term memory characteristics of innate immune responses have been described (also called trained immunity) that in physiological conditions provide enhanced host protection from pathogenic re-infection. However, if dysregulated, induction of trained immunity can become maladaptive, perpetuating chronic inflammatory activation. Here, we describe the mechanisms of genetic and epigenetic dysregulation of the innate immune system and maladaptive trained immunity that leads to the onset and perpetuation of the most common and recently described systemic autoinflammatory diseases.

Multimodal smart systems reprogramme macrophages and remove urate to treat gouty arthritis

Gouty arthritis is a chronic and progressive disease characterized by high urate levels in the joints and by an inflammatory immune microenvironment. Clinical data indicate that urate reduction therapy or anti-inflammatory therapy alone often fails to deliver satisfactory outcomes. Here we have developed a smart biomimetic nanosystem featuring a 'shell' composed of a fusion membrane derived from M2 macrophages and exosomes, which encapsulates liposomes loaded with a combination of uricase, platinum-in-hyaluronan/polydopamine nanozyme and resveratrol. The nanosystem targets inflamed joints and promotes the accumulation of anti-inflammatory macrophages locally, while the uricase and the nanozyme reduce the levels of urate within the joints. Additionally, site-directed near-infrared irradiation provides localized mild thermotherapy through the action of platinum and polydopamine, initiating heat-induced tissue repair. Combined use of these components synergistically enhances overall outcomes, resulting in faster recovery of the damaged joint tissue.

Relationship between serum uric acid levels and periodontitis-A cross-sectional study

OBJECTIVES

Whether there is an association between serum uric acid level (sUA) and periodontitis remains unclear. The aim of this study was to investigate the association between moderate/severe periodontitis and sUA in US adults.

MATERIALS AND METHODS

A total of 3398 participants were included in the National Health and Nutrition Examination Survey (NHANES) from 2009 to 2014. The independent variable was sUA and the dependent variable was periodontitis. SUA for continuous variables, periodontitis as classification variables. Covariate including social demographic variables, life style, systemic diseases, etc. Multiple linear regression models were used to investigate the distribution of differences in covariates between different independent groups. To investigate the association between serum uric acid levels and moderate/severe periodontitis, three models were used (Model 1: unadjusted model; Model 2: adjusted for age, sex, and race/ethnicity; Model 3: adjusted for age, sex, race/ethnicity, education, household income/poverty ratio, smoking behavior, alcohol consumption, dental floss frequency, obesity, hypertension, diabetes, high cholesterol, hyperlipidemia, and sleep disorders).

RESULTS

Among the 3398 patients, 42.5% had moderate/severe periodontitis. Multivariate logistic regression analysis showed that sUA was significantly associated with moderate/severe periodontitis (OR = 1.10, 95%CI: (1.03, 1.16), P = 0.0020) after adjusting for potential confounding factors. In addition, it may vary by race/ethnicity and gender. The association between sUA levels and the prevalence ofperiodontitis was U-shaped in women and non-Hispanic blacks.

CONCLUSION

sUA level is associated with moderate to severe periodontitis. However, the association between sUA levels and the occurrence of periodontitis in women and non-Hispanic blacks followed a U-shaped curve.

CLINICAL RELEVANCE

sUA may directly or indirectly contribute to the global burden of periodontal disease, but there is little evidence that sUA is directly related to periodontitis.This study further supports that high uric acid levels are closely related to periodontitis and may contribute to the control of periodontitis. It also provides new insights into whether it can be used as an indicator to assess the risk or progression of periodontitis. More studies are needed to confirm the relationship between sUA and periodontitis.

Food-derived bioactive peptides with anti-hyperuricemic activity: A comprehensive review

Hyperuricemia (HU) is a metabolic disorder caused by the overproduction or underexcretion of uric acid (UA) in the human body. Several approved drugs for the treatment of HU are available in the market; however, all these allopathic drugs exhibit multiple side effects. Therefore, the development of safe and effective anti-HU drugs is an urgent need. Natural compounds derived from foods and plants have the potential to decrease UA levels. Recently, food-derived bioactive peptides (FBPs) have gained attention as a functional ingredient owing to their biological activities. In the current review, we aim to explore the urate-lowering potential and the underlying mechanisms of FBPs. We found that FBPs mitigate HU by reducing blood UA levels through inhibiting key enzymes such as xanthine oxidase, increasing renal UA excretion, inhibiting renal UA reabsorption, increasing anti-oxidant activities, regulating inflammatory mediators, and addressing gut microbiota dysbiosis. In conclusion, FBPs exhibit strong potential to ameliorate HU.

Effects of Colchicine on Major Adverse Limb and Cardiovascular Events in Patients With Peripheral Artery Disease

OBJECTIVE

To assess the effects of colchicine, which has been shown to reduce the risks of coronary artery disease but scarcely studied in peripheral artery disease (PAD), on major adverse limb events (MALE) in patients with PAD.

METHODS

This is a retrospective study based on a nationwide database. Patients who were diagnosed with PAD between 2010 and 2020 and prescribed with colchicine after the diagnosis of PAD were identified. Patients were then categorized into the colchicine or the control group according to drug use. Propensity score matching was performed to mitigate selection bias. Risks of MALE (including lower limb revascularization and nontraumatic amputation) and major adverse cardiovascular events were compared between the two groups.

RESULTS

After patient selection and propensity score matching, there were 60,219 patients in both colchicine and control groups. After a mean follow-up of 4.5 years, the risk of MALE was significantly lower in the colchicine group compared with control (subdistribution HR, 0.75; 95% CI, 0.71 to 0.80), as were the incidence of both components of MALE, lower limb revascularization and major amputations. Colchicine treatment was also associated with lower risk of cardiovascular death. The lower risk of MALE observed with colchicine therapy was accentuated in the subgroup of patients receiving concomitant urate-lowering medications.

CONCLUSION

In patients diagnosed with PAD, the use of colchicine is associated with lower risks of MALE and cardiovascular death. Anti-inflammatory therapy with colchicine may provide benefits in vascular beds beyond the coronary arteries.

Anti-inflammatory Properties of Tongfeng Li'an Granules in an Acute Gouty Arthritis Rat Model

OBJECTIVES

To examine the anti-inflammatory properties and underlying mechanisms of Tongfeng Li'an Granules (TFLA), a traditional medicine, in acute gouty arthritis using a rat model.

MATERIALS AND METHODS

We identified 55 major compounds in TFLA via ultrahigh-performance liquid chromatography connected to quadrupole time-of-flight mass spectrometry (UPLC-TQF-MS/MS). Databases were employed for the prediction of potential targets, followed by PPI network construction as well as GO and KEGG analyses. After network-pharmacology-based analysis, a rat gouty arthritis model was used to validate the anti-inflammatory mechanism of TFLA.

RESULTS

UPLC-TQF-MS/MS and network pharmacology analyses revealed 55 active ingredients and 160 targets of TFLA associated with gouty arthritis, forming an ingredient-target-disease network. The PPI network identified 20 core targets, including TLR2, TLR4, IL6, NFκB, etc. Functional enrichment analyses highlighted the Toll-like receptor signaling pathway as significantly enriched by multiple targets, validated in in vivo experiments. Animal experiments demonstrated that TFLA improved pathological changes in gouty joint synovium, with decreased ankle joint circumference, serum IL6, IL10, and TNFα levels, as well as reduced protein and mRNA expression of NLRP3, TLR2, and TLR4 in ankle joint synovial tissue observed in the middle- and high-dose TFLA and positive control groups compared to the model group (p < 0.05).

CONCLUSION

This research elucidated the pharmacological mechanisms of TFLA against gouty arthritis, implicating various ingredients, targets, and signaling pathways. Animal experiments confirmed TFLA's efficacy in alleviating inflammation in acute gouty arthritis by modulating Toll-like receptor signaling and NLRP3 expression.

Allopurinol is Associated with an Increased Risk of Cerebral Infarction: A Two-Sample Mendelian Randomization Study

OBJECTIVE

Previous studies have reported that the inappropriate use of allopurinol may increase the risk of cerebrovascular accidents, but some studies have also confirmed that allopurinol is a protective factor against stroke. To clarify whether there is a relevant causal relationship between allopurinol and cerebral infarction, we conducted a two-sample Mendelian randomization (MR) study.

METHODS

Data on single nucleotide polymorphisms (SNPs) associated with allopurinol and genome-wide association studies of cerebral infarction were obtained from the genome-wide association study (GWAS) web site. Five basic MR analyses were performed using MR-Egger regression, weighted median (WM1), inverse variance weighting (IVW), weighted mode (WM2), and simple mode. Sensitivity analysis was subsequently performed to detect horizontal pleiotropy, heterogeneity, and potential outliers. The final analysis results were mainly based on the IVW estimates.

RESULTS

A total of 10 SNPs were used as instrumental variables (IVs). MR analysis [(IVW: odds ratio (OR) = 1.053, 95% confidence interval (CI): 1.019-1.088, P = 0.002), (WM1: OR = 1.053, 95% CI: 1.009-1.098, P = 0.017), (WM2: OR = 1.050, 95% CI: 1.008-1.095, P = 0.044), (MR Egger: Q = 4.285, P = 0.830)] showed a positive causal association between allopurinol and the risk of cerebral infarction. Sensitivity analysis such as horizontal pleiotropy and heterogeneity increased the reliability of this result.

CONCLUSION

The results of this study provide direct evidence that there is a causal relationship between allopurinol and cerebral infarction and that allopurinol may increase the risk of cerebral infarction.

The pathogenesis of gout: molecular insights from genetic, epigenomic and transcriptomic studies

The pathogenesis of gout involves a series of steps beginning with hyperuricaemia, followed by the deposition of monosodium urate crystal in articular structures and culminating in an innate immune response, mediated by the NLRP3 inflammasome, to the deposited crystals. Large genome-wide association studies (GWAS) of serum urate levels initially identified the genetic variants with the strongest effects, mapping mainly to genes that encode urate transporters in the kidney and gut. Other GWAS highlighted the importance of uncommon genetic variants. More recently, genetic and epigenetic genome-wide studies have revealed new pathways in the inflammatory process of gout, including genetic associations with epigenomic modifiers. Epigenome-wide association studies are also implicating epigenomic remodelling in gout, which perhaps regulates the responsiveness of the innate immune system to monosodium urate crystals. Notably, genes implicated in gout GWAS do not include those encoding components of the NLRP3 inflammasome itself, but instead include genes encoding molecules involved in its regulation. Knowledge of the molecular mechanisms underlying gout has advanced through the translation of genetic associations into specific molecular mechanisms. Notable examples include ABCG2, HNF4A, PDZK1, MAF and IL37. Current genetic studies are dominated by participants of European ancestry; however, studies focusing on other population groups are discovering informative population-specific variants associated with gout.

Sex-specific epigenetic signatures of circulating urate and its increase after BCG vaccination

Background

Urate concentration and the physiological regulation of urate homeostasis exhibit clear sex differences. DNA methylation has been shown to explain a substantial proportion of serum urate variance, mediate the genetic effect on urate concentration, and co-regulate with cardiometabolic traits. However, whether urate concentration is associated with DNA methylation in a sex-dependent manner is unknown. Additionally, it is worth investigating if urate changes after perturbations, such as vaccination, are associated with DNA methylation in a sex-specific manner.

Methods

We investigated the association between DNA methylation and serum urate concentrations in a Dutch cohort of 325 healthy individuals. Urate concentration and DNA methylation were measured before and after Bacillus Calmette-Guérin (BCG) vaccination, used as a perturbation associated with increased gout flares. The association analysis included united, interaction, and sex-stratified analysis. Validation of the identified CpG sites was conducted using three independent cohorts.

Results

215 CpG sites were associated with serum urate in males, while 5 CpG sites were associated with serum urate in females, indicating sex-specific associations. Circulating urate concentrations significantly increased after BCG vaccination, and baseline DNA methylation was associated with differences in urate concentration before and after vaccination in a sex-specific manner. The CpG sites associated with urate concentration in males were enriched in neuro-protection pathways, whereas in females, the urate change-associated CpG sites were related to lipid and glucose metabolism.

Conclusion

Our study enhances the understanding of how epigenetic factors contribute to regulating serum urate levels in a sex-specific manner. These insights have significant implications for the diagnosis, prevention, and treatment of various urate-related diseases and highlight the importance of personalized and sex-specific approaches in medicine.

Uremic toxin indoxyl sulfate induces trained immunity via the AhR-dependent arachidonic acid pathway in end-stage renal disease (ESRD)

Trained immunity is the long-term functional reprogramming of innate immune cells, which results in altered responses toward a secondary challenge. Despite indoxyl sulfate (IS) being a potent stimulus associated with chronic kidney disease (CKD)-related inflammation, its impact on trained immunity has not been explored. Here, we demonstrate that IS induces trained immunity in monocytes via epigenetic and metabolic reprogramming, resulting in augmented cytokine production. Mechanistically, the aryl hydrocarbon receptor (AhR) contributes to IS-trained immunity by enhancing the expression of arachidonic acid (AA) metabolism-related genes such as arachidonate 5-lipoxygenase (ALOX5) and ALOX5 activating protein (ALOX5AP). Inhibition of AhR during IS training suppresses the induction of IS-trained immunity. Monocytes from end-stage renal disease (ESRD) patients have increased ALOX5 expression and after 6 days training, they exhibit enhanced TNF-α and IL-6 production to lipopolysaccharide (LPS). Furthermore, healthy control-derived monocytes trained with uremic sera from ESRD patients exhibit increased production of TNF-α and IL-6. Consistently, IS-trained mice and their splenic myeloid cells had increased production of TNF-α after in vivo and ex vivo LPS stimulation compared to that of control mice. These results provide insight into the role of IS in the induction of trained immunity, which is critical during inflammatory immune responses in CKD patients.

Association between Uric Acid Levels and the Consumption of Sugar-Sweetened Carbonated Beverages in the Korean Population: The 2016 Korea National Health and Nutrition Examination Survey

Elevated uric acid levels are linked with obesity and diabetes. Existing research mainly examines the relationship between sugar-sweetened carbonated beverage (SSB) consumption and uric acid levels. This study explored the association between the quantity and frequency of SSB consumption and elevated uric acid levels in Korean adults. Data from 2881 participants aged 19-64 years (1066 men and 1815 women) in the 2016 Korea National Health and Nutrition Examination Survey were analyzed. Serum uric acid levels were categorized into quartiles, with the highest defined as high uric acid (men, ≥6.7 mg/dL; women, ≥4.8 mg/dL). SSB consumption was classified into quartiles (almost never, <1 cup (<200 mL), 1-3 cups (200-600 mL), ≥3 cups (≥600 mL)) and frequency into tertiles (almost never, ≤1/week, ≥2/week). Multivariate logistic regression assessed the association, with separate analyses for men and women. Increased daily SSB consumption and frequency were significantly associated with high uric acid levels in men but not in women. After adjusting for sociodemographic and health characteristics, consuming ≥3 cups (≥600 mL) of SSBs per day and SSBs ≥ 2/week were significantly associated with high serum uric acid levels in men, but this association was not observed in women. The study concludes that increased SSB intake is linked to elevated uric acid levels in Korean men, but not in women.

Off-Pump Coronary Artery Bypass Graft (OCABG) Surgery Outcome: AKI Incidence, Serum Uric Acid, and Cut-Offs of Variables

Purpose: One of the most important challenges of the medical community is to find out the success rate of coronary artery bypass surgery and control complications after surgery, including acute kidney injury (AKI). The present study was conducted with the aim of determining the predictive effect of serum uric acid (SUA) (UA) level in patients undergoing off-pump coronary artery bypass (OCABG) surgery. Methods: The present descriptive-analytical study included 144 patients who underwent OCABG and met the inclusion criteria. SUA and related indicators, duration of hospitalization and stay in ICU, AKI and in-hospital mortality, and 6-month follow-up mortality were investigated. Results: Patients were divided into high and normal groups based on SUA levels. The prevalence of postoperative AKI was 20% and was significantly associated with the preoperative UA levels (OR: 2.04; CI: 95%; 1.03-4.20). The mortality rate of patients was between 2% and 9%, which increased to 13% in patients with high SUA (p value ~0.224). The average duration of ICU and hospitalization in patients with high UA was longer than the other group (p value ~0.06 and p value ~0.002, respectively). Conclusion: SUA levels are independently associated with a higher risk of AKI and outcome complications after off-pump CABG, and confounding factors at specific cutoffs affect the odds ratio of UA for AKI occurrence.

Hyperuricemia Subtypes Classified According to Renal Uric Acid Handling Manifesting Distinct Phenotypic and Genetic Profiles in People With Gout

OBJECTIVE

Hyperuricemia can be stratified into four subtypes according to renal uric acid handling. The aim of this study was to comprehensively describe the biologic characteristics (including genetic background) of clinically defined hyperuricemia subtypes in two large geographically independent gout cohorts.

METHODS

Hyperuricemia subtype was defined as renal uric acid overload (ROL), renal uric acid underexcretion (RUE), combined, or renal normal. Twenty single nucleotide polymorphisms (SNPs) previously identified as gout risk loci or associated with serum urate (SU) concentration in the East Asian population were genotyped. Weighted polygenic risk scores were calculated to assess the cumulative effect of genetic risks on the subtypes.

RESULTS

Of the 4,873 participants, 8.8% had an ROL subtype, 60.9% RUE subtype, 23.1% combined subtype, and 7.2% normal subtype. The ROL subtype was independently associated with older age at onset, lower SU, tophi, and diabetes mellitus; RUE was associated with lower body mass index (BMI) and non-diabetes mellitus; the combined subtype was associated with younger age at onset, higher BMI, SU, estimated glomerular filtration rate (eGFR), and smoking; and the normal subtype was independently associated with older age at onset, lower SU, and eGFR. Thirteen SNPs were associated with gout with 6 shared loci and subtype-dependent risk loci patterns. High polygenic risk scores were associated with ROL subtype (odds ratio [OR] = 9.63, 95% confidence interval [95% CI] 4.53-15.12), RUE subtype (OR = 2.18, 95% CI 1.57-3.03), and combined subtype (OR = 6.32, 95% CI 4.22-9.48) compared with low polygenic risk scores.

CONCLUSION

Hyperuricemia subtypes classified according to renal uric acid handling have subtype-specific clinical and genetic features, suggesting subtype-unique pathophysiologic mechanisms.

Association between serum uric acid and colorectal cancer risk in European population: a two-sample Mendelian randomization study

Objectives

This study aimed to explore the potential causal associations between serum uric acid (SUA) and the risk of colorectal cancer, colon cancer and rectal cancer.

Methods

Twenty-six SUA-related single nucleotide polymorphisms which were identified by a large meta-analysis of genome-wide association studies (GWASs) were used as instrumental variables in the two-sample Mendelian randomization (MR) study. Meta-analyses were used to synthesize the results of multiple GWASs which were extracted from the MRC Integrative Epidemiology Unit GWAS database for each type of cancer. The inverse variance weighted (IVW) method was used as the primary MR method to analyze the association between SUA and colorectal cancer risk. Several sensitivity analyses were performed to test the robustness of results.

Results

The IVW method showed that there were no causal relationships between SUA and the risk of colorectal cancer [odds ratio (OR): 1.0015; 95% confidence interval (CI): 0.9975-1.0056] and colon cancer (OR: 1.0015; 95% CI: 0.9974-1.0055). The SUA levels were negative correlated with rectal cancer risk (OR: 0.9984; 95% CI: 0.9971-0.9998). The similar results were observed in both males (OR: 0.9987; 95% CI: 0.9975-0.9998) and females (OR: 0.9985; 95% CI: 0.9971-0.9999). The sensitivity analyses suggested no evidence of heterogeneity or horizontal pleiotropy. The leave-one-out analyses showed that one SNP (rs1471633) significantly drove the causal effect of SUA on rectal cancer risk. The MR-Egger regression and weighted median both showed that there were no causal relationships between SUA and the risk of colorectal cancer and its subtypes.

Conclusion

Overall, there was no linear causal association between SUA and the risk of colorectal cancer. However, further research is needed to investigate the role of higher SUA levels such as hyperuricemia or gout in the occurrence of colorectal cancer.

Plasma Uric Acid, Lactate, and Osmolality in Colorectal Cancer

A complex evaluation of colorectal cancer (CRC) in relation to screening, diagnosis, stage determination, prognosis, and treatment requires valuable biomarkers. The aim of this study was to measure selected biomarkers—uric acid (UA), lactate, Na+, Cl−, and osmolality—in CRC patients and to assess their diagnostic value to distinguish between CRC and healthy controls. Plasma lactate (2.21 ± 0.11 vs. 2.88 ± 0.19, p < 0.01), Na+ (130.79 ± 0.42 vs. 133.23 ± 0.25, p < 0.001), Cl− (102.59 ± 0.45 vs. 103.94 ± 0.23, p < 0.01), and osmolality (266.44 ± 0.86 vs. 271.72 ± 0.62, p < 0.001) were found to be significantly lower in CRC patients as compared to the healthy controls group. Among them, with satisfactory diagnostic potential, were plasma Na+ concentrations and osmolality (AUCNa+ = 0.752, p < 0.0001; AUCosmolality = 0.757, p < 0.05), respectively. UA concentrations were detected at higher concentrations in CRC patients (333.67 ± 13.05 vs. 295.88 ± 13.78, p < 0.05). The results of this study contribute to the elucidation of molecular mechanisms of CRC pathogenesis and the role of studied metabolic parameters in this process. Plasma uric acid, lactate, and osmolality parameters can be used for screening and monitoring colorectal cancer. Further studies are required to elucidate the molecular mechanisms of their action in cancer development. The action of circulating plasma lactate may be different from those locally produced in the tumor microenvironment.

[Uric acid, cognitive disorders, neurodegeneration]

This article examines the role of uric acid (UA) in cognitive changes and neurodegeneration, focusing on its functions as an antioxidant and prooxidant. Research suggests that changes in serum UA levels may be associated with the development or delay of cognitive impairment, especially in the context of neurodegenerative diseases such as Alzheimer's disease. It was revealed that there is a relationship between the level of UA and the dynamics of cognitive functions, indicating the potential neuroprotective properties of UA. Particular attention is paid to the balance between the antioxidant and prooxidant properties of UA, which may play a key role in protecting neurons from damage. However, research results are not clear-cut, highlighting the need for further research to more fully understand the role of UA in cognitive processes. Determining the optimal serum UA level may be an important step in developing strategies for the prevention and treatment of cognitive impairment associated with neurodegeneration. Overall, these studies advance the understanding of the mechanisms underlying the interaction between uric acid metabolism and brain health.

Biomimetic Integrated Nanozyme for Flare and Recurrence of Gouty Arthritis

Flare and multiple recurrences pose significant challenges in gouty arthritis. Traditional treatments provide temporary relief from inflammation but fail to promptly alleviate patient pain or effectively prevent subsequent recurrences. It should also be noted that both anti-inflammation and metabolism of uric acid are necessary for gouty arthritis, calling for therapeutic systems to achieve these two goals simultaneously. In this study, we propose a biomimetic integrated nanozyme, HMPB-Pt@MM, comprising platinum nanozyme and hollow Prussian blue. It demonstrates anti-inflammatory properties by eliminating reactive oxygen species and reducing infiltration of inflammatory macrophages. Additionally, it rapidly targets inflamed ankles through the camouflage of macrophage membranes. Furthermore, HMPB-Pt@MM exhibits urate oxidase-like capabilities, continuously metabolizing locally elevated uric acid concentrations, ultimately inhibiting multiple recurrences of gouty arthritis. In summary, HMPB-Pt@MM integrates ROS clearance with uric acid metabolism, offering a promising platform for the treatment of gouty arthritis.

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.

Dihydroartemisinin is an inhibitor of trained immunity through Akt/mTOR/HIF1α signaling pathway

Trained immunity is mechanistically defined as the metabolically and epigenetically mediated long-term functional adaptation of the innate immune system, characterized by a heightened response to a secondary stimulation. Given appropriate activation, trained immunity represents an attractive anti-infective therapeutic target. Nevertheless, excessive immune response and subsequent inflammatory cascades may contribute to pathological tissue damage, indicating that the negative impacts of trained immunity appear to be significant. In this study, we show that innate immune responses such as the production of extracellular traps, pro-inflammatory cytokines, and autophagy-related proteins were markedly augmented in trained BMDMs. Furthermore, heat-killed C. albicans priming promotes the activation of the AIM2 inflammasome, and AIM2-/- mice exhibit impaired memory response induced by heat-killed C. albicans. Therefore, we establish that the AIM2 inflammasome is involved in trained immunity and emerges as a promising therapeutic target for potentially deleterious effects. Dihydroartemisinin can inhibit the memory response induced by heat-killed C. albicans through modulation of mTOR signaling and the AIM2 inflammasome. The findings suggest that dihydroartemisinin can reduce the induction of trained immunity by heat-killed C. albicans in C57BL/6 mice. Dihydroartemisinin is one such therapeutic intervention that has the potential to treat of diseases characterized by excessive trained immunity.

Regulation of SOCS3-STAT3 in urate-induced cytokine production in human myeloid cells

OBJECTIVE

Hyperuricaemia is necessary for gout. High urate concentrations have been linked to inflammation in mononuclear cells. Here, we explore the role of the suppressor of cytokine signaling 3 (SOCS3) in urate-induced inflammation.

METHODS

Peripheral blood mononuclear cells (PBMCs) from gout patients, hyperuricemic and normouricemic individuals were cultured for 24h with varying concentrations of soluble urate, followed by 24h restimulation with lipopolysaccharides (LPS)±monosodium urate (MSU) crystals. Transcriptomic profiling was performed using RNA-Sequencing. DNA methylation was assessed using Illumina Infinium® MethylationEPIC BeadChip system (EPIC array). Phosphorylation of signal transducer and activator of transcription 3 (STAT3) was determined by flow cytometry. Cytokine responses were also assessed in PBMCs from patients with JAK2 V617F tyrosine kinase mutation.

RESULTS

PBMCs pre-treated with urate produced more interleukin-1beta (IL-1β) and interleukin-6 (IL-6) and less interleukin-1 receptor anatagonist (IL-1Ra) after LPS simulation. In vitro, urate treatment enhanced SOCS3 expression in control monocytes but no DNA methylation changes were observed at the SOCS3 gene. A dose-dependent reduction in phosphorylated STAT3 concomitant with a decrease in IL-1Ra was observed with increasing concentrations of urate. PBMCs with constitutively activated STAT3 (JAK2 V617F mutation) could not be primed by urate.

CONCLUSION

In vitro, urate exposure increased SOCS3 expression, while urate priming, and subsequent stimulation resulted in decreased STAT3 phosphorylation and IL-1Ra production. There was no evidence that DNA methylation constitutes a regulatory mechanism of SOCS3. Elevated SOCS3 and reduced pSTAT3 could play a role in urate-induced hyperinflammation since urate priming had no effect in PBMCs from patients with constitutively activated STAT3.