Prevention and treatment of gout

Recent advances in the treatment of gout with NLRP3 inflammasome inhibitors

Gout is an autoinflammatory disorder characterized by the accumulation of monosodium urate crystals in joints and other tissues, representing the predominant type of inflammatory arthritis with a notable prevalence and propensity for severe outcomes. The NLRP3 inflammasome, a member of the pyrin domain-containing NOD-like receptor family, exerts a substantial impact on both innate and adaptive immune responses and serves as a pivotal factor in the pathogenesis of gout. In recent years, there has been significant academic and industrial interest in the development of NLRP3-targeted small molecule inhibitors as a promising therapeutic approach for gout. To assess the advancements in NLRP3 inflammasome inhibitors for gout treatment, this review offers a comprehensive analysis and evaluation of current clinical candidates and other inhibitors targeting NLRP3 inflammasome from a chemical structure standpoint, with the goal of identifying more efficacious options for clinical management of gout.

Causal impact of human blood metabolites and metabolic pathways on serum uric acid and gout: a mendelian randomization study

Objective

Hyperuricaemia and gout are common metabolic disorders. However, the causal relationships between blood metabolites and serum urate levels, as well as gout, remain unclear. A systematic evaluation of the causal connections between blood metabolites, hyperuricemia, and gout could enhance early screening and prevention of hyperuricemia and gout in clinical settings, providing novel insights and approaches for clinical treatment.

Methods

In this study, we employed a bidirectional two-sample Mendelian randomization analysis utilizing data from a genome-wide association study involving 7,286 participants, encompassing 486 blood metabolites. Serum urate and gout data were sourced from the Chronic Kidney Disease Genetics consortium, including 288,649 participants for serum urate and 9,819 African American and 753,994 European individuals for gout. Initially, LDSC methodology was applied to identify blood metabolites with a genetic relationship to serum urate and gout. Subsequently, inverse-variance weighting was employed as the primary analysis method, with a series of sensitivity and pleiotropy analyses conducted to assess the robustness of the results.

Results

Following LDSC, 133 blood metabolites exhibited a potential genetic relationship with serum urate and gout. In the primary Mendelian randomization analysis using inverse-variance weighting, 19 blood metabolites were recognized as potentially influencing serum urate levels and gout. Subsequently, the IVW p-values of potential metabolites were corrected using the false discovery rate method. We find leucine (IVW P FDR = 0.00004), N-acetylornithine (IVW P FDR = 0.0295), N1-methyl-3-pyridone-4-carboxamide (IVW P FDR = 0.0295), and succinyl carnitine (IVW P FDR = 0.00004) were identified as significant risk factors for elevated serum urate levels. Additionally, 1-oleoylglycerol (IVW P FDR = 0.0007) may lead to a substantial increase in the risk of gout. Succinyl carnitine exhibited acceptable weak heterogeneity, and the results for other blood metabolites remained robust after sensitivity, heterogeneity, and pleiotropy testing. We conducted an enrichment analysis on potential blood metabolites, followed by a metabolic pathway analysis revealing four pathways associated with serum urate levels.

Conclusion

The identified causal relationships between these metabolites and serum urate and gout offer a novel perspective, providing new mechanistic insights into serum urate levels and gout.

The Clinical Significance of Serum Interleukin-36α Levels in Patients with Gout

BACKGROUND

Gout is a chronic inflammatory diseases caused by monosodium urate crystal deposition. However, the role of interleukin (IL)-36 in gout has not dbeen elucidated.

METHODS

We enrolled 75 subjects, including 20 healthy controls (HC), 30 patients with acute gout attack and 25 patients in remission. Baseline data were obtained through clinical interrogation and laboratory data were obtained through tests of blood samples. Serum levels of IL-36α were detected using enzyme-linked immunosorbent assay. Spearman correlation analysis was used to investigate the correlation of IL-36α with other parameters. The diagnostic value of IL-36α was demonstrated using a receiver operating characteristic curve.

RESULTS

The serum IL-36α level of gout patients in acute attack and remission stage was significantly higher than that of HC. Serum IL-36α was positively correlated with alanine transaminase (ALT) and aspartate transaminase (AST). Serum amyloid A (SAA) levels positively correlated with C-reactive protein levels and erythrocyte sedimentation rates. Glutamyl transpeptidase levels positively correlated with AST and ALT levels.

CONCLUSION

In conclusion, serum IL-36α levels were elevated in patients with gout and correlated with the clinical markers of inflammation. Our findings suggest that IL-36α may be a novel inflammatory indicator for gout.

Identification of Anastatica hierochuntica L. Methanolic-Leaf-Extract-Derived Metabolites Exhibiting Xanthine Oxidase Inhibitory Activities: In Vitro and In Silico Approaches

There is a growing interest in the discovery of novel xanthine oxidase inhibitors for gout prevention and treatment with fewer side effects. This study aimed to identify the xanthine oxidase (XO) inhibitory potential and drug-likeness of the metabolites present in the methanolic leaf extract of Anastatica (A.) hierochuntica L. using in vitro and in silico models. The extract-derived metabolites were identified by liquid-chromatography-quadrupole-time-of-flight-mass-spectrometry (LC-QTOF-MS). Molecular docking predicted the XO inhibitory activity of the identified metabolites and validated the best scored in vitro XO inhibitory activities for experimental verification, as well as predictions of their anticancer, pharmacokinetic, and toxic properties; oral bioavailability; and endocrine disruption using SwissADMET, PASS, ProTox-II, and Endocrine Disruptome web servers. A total of 12 metabolites, with a majority of flavonoids, were identified. Rutin, quercetin, and luteolin flavonoids demonstrated the highest ranked docking scores of -12.39, -11.15, and -10.43, respectively, while the half-maximal inhibitory concentration (IC50) values of these metabolites against XO activity were 11.35 µM, 11.1 µM, and 21.58 µM, respectively. In addition, SwissADMET generated data related to the physicochemical properties and drug-likeness of the metabolites. Similarly, the PASS, ProTox-II, and Endocrine Disruptome prediction models stated the safe and potential use of these natural compounds. However, in vivo studies are necessary to support the development of the prominent and promising therapeutic use of A. hierochuntica methanolic-leaf-extract-derived metabolites as XO inhibitors for the prevention and treatment of hyperuricemic and gout patients. Furthermore, the predicted findings of the present study open a new paradigm for these extract-derived metabolites by revealing novel oncogenic targets for the potential treatment of human malignancies.

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.

Bone and Joint-on-Chip Platforms: Construction Strategies and Applications

Organ-on-a-chip, also known as "tissue chip," is an advanced platform based on microfluidic systems for constructing miniature organ models in vitro. They can replicate the complex physiological and pathological responses of human organs. In recent years, the development of bone and joint-on-chip platforms aims to simulate the complex physiological and pathological processes occurring in human bones and joints, including cell-cell interactions, the interplay of various biochemical factors, the effects of mechanical stimuli, and the intricate connections between multiple organs. In the future, bone and joint-on-chip platforms will integrate the advantages of multiple disciplines, bringing more possibilities for exploring disease mechanisms, drug screening, and personalized medicine. This review explores the construction and application of Organ-on-a-chip technology in bone and joint disease research, proposes a modular construction concept, and discusses the new opportunities and future challenges in the construction and application of bone and joint-on-chip platforms.

Comparison of the therapeutic effects of febuxostat combined with a low-purine diet and allopurinol combined with a low-purine diet on the improvement of gout patients

OBJECTIVE

To compare the clinical efficacy of febuxostat combined with a low-purine diet versus allopurinol combined with a low-purine diet in the treatment of gout.

METHODS

In this prospective controlled trial, 98 gout patients admitted to our hospital from February 2021 to December 2022 were enrolled as study subjects. Patients were randomly assigned to the study group (febuxostat combined with a low-purine diet) and the control group (allopurinol combined with a low-purine diet), with 49 patients in each group. The therapeutic effect was evaluated based on joint function and serum uric acid levels after treatment, and classified into three levels: markedly effective, effective, and ineffective. The levels of inflammatory factors, including tumor necrosis factor-a (TNF-a), cytokine interleukin-1beta (IL-1β), and interleukin (IL)-18 (IL-18), were collected. The Numeric Rating Scale (NRS) was used to assess the degree of pain in patients. Clinical indicators before and 6 months after treatment were compared between the two groups.

RESULTS

There was no statistically significant difference in age and gender between the two groups. After 6 months of treatment, the effective rate in the study group (48 cases, 97.96%) was higher than that in the control group (42 cases, 85.71%), with a statistically significant difference (p = .027). At the same time, the study group had significantly lower levels of serum uric acid (162.39 μmol/L ± 17.23 μmol/L vs. S198.32 μmol/L ± 18.34 μmol/L, p < .001), creatinine (87.39 mmol/L ± 9.76 mmol/L vs. 92.18 mmol/L ± 9.27 mmol/L, p = .014), total cholesterol (3.65 mmol/L ± 0.65 mmol/L vs. 4.76 mmol/L ± 0.73 mmol/L, p < .001), and triglycerides (1.76 mmol/L ± 0.32 mmol/L vs. 2.28 mmol/L ± 0.41 mmol/L, p < .001) compared to the control group, with statistically significant differences (p < .05). After treatment, the levels of inflammatory factors and degree of pain in the study group were significantly lower than those in the control group (all p < .05). During the treatment process, the incidence of adverse reactions in the study group (2 cases, 4.08%) was lower than that in the control group (9 cases, 18.37%), with a statistically significant difference (p = .025).

CONCLUSION

Febuxostat combined with a low-purine diet can reduce inflammatory factors and alleviate the degree of pain in gout patients, significantly improving their clinical symptoms.

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

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

Modified Simiaowan prevents and treats gouty arthritis via the Nrf2/NLRP3 inflammasome signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Modified Simiaowan (MSM) is a six-herb formula that has been shown to be effective in gouty arthritis (GA) has been proven, but its regulatory mechanism has not been fully elucidated.

AIM OF THE STUDY

To investigate the therapeutic effects and mechanism of MSM on gouty arthritis.

MATERIALS AND METHODS

Mouse J774A.1 macrophages were induced with Lipopolysaccharide (LPS) and then stimulated with Adenosine 5'-triphosphate (ATP) or Nigericin (Nig.) in presence or absence of MSM. Expression of key indicators of pro-inflammatory cytokines and the NLRP3 inflammasome signaling pathway were investigated by western blot, ELISA and qRT-PCR. Fluorescence staining and flow cytometry were performed to detect intracellular reactive oxygen species (ROS) production. Another study, the anti-inflammatory and antioxidant activities of MSM were evaluated in rats with monosodium urate (MSU) -induced gouty arthritis using ELISA, hematoxylin-eosin staining (HE) staining, immunohistochemistry, and oxidative stress kits to measure relevant inflammatory markers and oxidative stress-related biomarkers.

RESULTS

ELISA and qRT-PCR results demonstrated that MSM effectively reduced the secretion and the mRNA expression levels of pro-inflammatory cytokines. Western blot results indicated that MSM can suppress the expression of NLRP3, an inflamasomes-related protein. In addition, MSM regulated the transition from M1 to M2 macrophages and upregulated the protein expression of Nrf2 and HO-1. The flow cytometry results and the fluorescence staining result were consistent with hypothesis that a large amount of ROS could be effectively cleared by MSM. However, the anti-inflammatory effect of MSM was attenuated after the use of ML385. In vivo experiments demonstrated that joint swelling was significantly attenuated and knee neutrophil infiltration was alleviated in rats given MSM. SOD and GSH-px levels were elevated significantly, while COX-2 and MDA levels decreased. The immunohistochemical results suggested that MSM could effectively inhibit the activation of the NLRP3 inflammasome and the regulation of macrophage polarization in rat synovial tissue, and remarkably enhance the expression of Nrf2 and HO-1.

CONCLUSION

MSM has potent anti-inflammatory and antioxidant effects on MSU-induced gouty arthritis. MSM alleviates GA through Nrf2/HO-1/ROS/NLRP3 signaling pathway.

Manganese-doped albumin-gelatin composite nanogel loaded with berberine applied to the treatment of gouty arthritis in rats via a SPARC-dependent mechanism

In this study, manganese-doped albumin-gelatin composite nanogels (MAGN) were prepared and used to load berberine (Ber) for the treatment of gouty arthritis (GA). The nanodrug delivery system (Ber-MAGN) can target inflammatory joints due to the intrinsic high affinity of albumin for SPARC, which is overexpressed at the inflammatory site of GA. Characterization of the pharmaceutical properties in vitro showed that Ber-MAGN had good dispersion, and the particle size was 121 ± 10.7 nm. The sustained release effect significantly improved the bioavailability of berberine. In vitro and in vivo experimental results showed that Ber-MAGN has better therapeutic effects in relieving oxidative stress and suppressing inflammation. Therefore, Ber-MAGN, as a potential pharmaceutical preparation for GA, provides a new reference for the clinical treatment plan of GA.

Neutrophil autophagy induced by monosodium urate crystals facilitates neutrophil extracellular traps formation and inflammation remission in gouty arthritis

Neutrophil extracellular traps (NETs) are composed of chromatin filaments coated with granular and cytosolic proteins, which contribute to the pathogenesis and progression of immune-related diseases. NETs are frequently observed in gouty arthritis, but the related mechanisms remain poorly understood. The aim of our study was to systematically elucidate the molecular mechanisms of self-remitting effects in gouty arthritis, and the causative relationship between neutrophil autophagy and NETs. The air pouch and paw edema model were used to simulate gouty arthritis in mice. Neutrophil infiltration and the formation of NETs were found in gouty arthritis. Interestingly, monosodium urate (MSU) crystals could induce the formation of NETs, degrade inflammatory factors, and alleviate the inflammatory response in gouty arthritis. In addition, MSU crystals resulted in profound molecular alterations in neutrophils using RNA-seq analysis, including autophagy activation. MSU crystals could activate neutrophil autophagy in vitro, and autophagy activators and inhibitors could regulate the formation of NETs. Furthermore, we explored the mechanism of autophagy-induced NETs. Autophagy related protein 7 (ATG7) produced by neutrophils stimulated with MSU crystals worked synergistically with p53 to enter the nucleus, promoting peptidyl arginine deiminase 4 (PAD4) expression, and inducing the formation of NETs. Finally, we substantiated that neutrophil autophagy regulates the severity of gouty arthritis via the formation of NETs in PAD4 -/- mice. Our results indicated that the autophagy of neutrophils regulates the formation of NETs and degrades inflammatory factors. Regulating autophagy and interfering with the formation of NETs represents a potential therapeutic approach against gouty arthritis during clinical practice.

Discovery and Characterization of Moracin C as an Anti-Gouty Arthritis/Hyperuricemia Candidate by Docking-Based Virtual Screening and Pharmacological Evaluation

In the present study, a natural product database of compounds associated with herbs traditionally verified to treat gout/hyperuricemia/arthritis was constructed. 3D-shape and docking-based virtual screening was conducted. To identify potential xanthine oxidase (XOD) inhibitors in the database, eight compounds with commercial availability were identified as high 3D-shape similarity with febuxostat (1), a known XOD inhibitor. Docking was used to further predict the possible interactions between XOD and these compounds. Moracin C (2), moracin D (3), and isoformononetin (8) exhibited higher docking scores and binding energies than other compounds. In vitro, 2 inhibited XOD with an IC50 value of 0.25 ± 0.14 μM, which is similar to that of 1 (0.16 ± 0.08 μM). In a hyperuricemic mouse model, 5-20 mg/kg 2 exhibited satisfying urate-lowering and XOD inhibitory effects. Compound 2 also exhibited antiarthritis activities. In RAW264.7 cells, 2 at 1-10 μM inhibited the expression of IL-1β and TNF-α induced by MSU. In an acute gouty arthritis model in SD rats, 5-20 mg/kg 2 significantly alleviated the toe swelling, inflammatory response, and dysfunction disorder caused by monosodium urate (MSU). Compound 2 inhibited serum IL-1β and TNF-α cytokines as well as reduced the expression of the NLRP3/ASC/caspase-1 inflammasome in joints. In summary, 2 was an effective compound for the treatment of hyperuricemia/gouty arthritis.

The nurse's role in managing gout in the modern era: A systematic review of the literature

The current treatment of gout is largely suboptimal, with up to 89% of hospitalizations being preventable due to inadequate care. The present study performed a systematic review in an aim to identify barriers to optimal gout treatment (Q1), understand how frequently nurses are involved in the management of gout (Q2), and examine the role of the nurse in the management of gout (Q3). A systematic review was performed, focusing on studies reporting on the nurse's role in the management of gout and the quality of the gathered items was appraised based on the risk of bias. In total, 15 records fulfilled the eligibility criteria and were used in the present systematic review. The main barriers were attributed to the patient's experiences with gout and lay beliefs, which affected seeking advice and adherence to treatment (Q1). Recently, however, several advances in patient care, including nurse-led clinics, have expanded the nurse's role, accounting for as much as 26% of the annual visits (Q2). Nurse-led interventions, such as education and lifestyle counseling, increased adherence to treatment (Q3). On the whole, nurses are key players in multidisciplinary teams and should be capable of engaging in shared decision-making processes, goal setting, providing patients with education and information, and making appropriate referrals.

Pharmacological evaluation of a novel skeleton compound isobavachin (4',7-dihydroxy-8-prenylflavanone) as a hypouricemic agent: Dual actions of URAT1/GLUT9 and xanthine oxidase inhibitory activity

Previously we discovered a novel natural scaffold compound, isobavachin (4', 7-dihydroxy-8-prenylflavanone), as a potent URAT1 inhibitor by shape and structure based on a virtue screening approach. In this study, further urate-lowering mechanism, pharmacokinetics and toxicities of isobavachin were conducted. Isobavachin inhibited URAT1 with an IC₅₀ value of 0.24 ± 0.06 μM, and residues S35, F365, I481 and R477 of URAT1 contributed to high affinity for isobavachin. Isobavachin also inhibited glucose transporter 9 (GLUT9), another pivotal urate reabsorption transporter, with an IC₅₀ value of 1.12 ± 0.26 μM. Molecular docking and MMGBSA results indicated that isobavachin might compete residues R171, L75 and N333 with uric acid, which leads to inhibition of uric acid transport of GLUT9. Isobavachin weakly inhibited urate secretion transporters OAT1 with an IC₅₀ value of 4.38 ± 1.27 μM, OAT3 with an IC₅₀ of 3.64 ± 0.62 μM, and ABCG2 with an IC₅₀ of 10.45 ± 2.17 μM. Isobavachin also inhibited xanthine oxidase (XOD) activity in vitro with an IC₅₀ value of 14.43 ± 3.56 μM, and inhibited the hepatic XOD activities at 5-20 mg/kg in vivo. Docking and MMGBSA analysis indicated that isobavachin might bind to the Mo-Pt catalyze center of XOD, which leads to inhibition of uric acid production. In vivo, isobavachin exhibited powerful urate-lowering and uricosuric effects at 5-20 mg/kg compared with the positive drugs morin (20 mg/kg) and RDEA3170 (10 mg/kg). Safety assessments revealed that isobavachin was safe and had no obvious toxicities. Isobavachin has little cell toxicity in HK2 cells as indicated by the MTT assay. In vivo, after treatment with 50 mg/kg isobavachin for 14 days, isobavachin had little renal toxicity, as revealed by serum CR/BUN levels, and no hepatotoxicity as revealed by ALT/AST levels. Further HE examination also suggests that isobavachin has no obvious kidney/liver damage. A pharmacokinetic study in SD rats indicated isobavachin had lower bioavailability (12.84 ± 5.13 %) but long half-time (7.04 ± 2.68 h) to maintain a continuous plasma concentration. Collectively, these results indicate that isobavachin deserves further investigation as a candidate anti-hyperuricemic drug with a novel mechanism of action: selective urate reabsorption inhibitor (URAT1/GLUT9) with a moderate inhibitory effect on XOD.

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

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

The combination of molecular docking and network pharmacology reveals the molecular mechanism of Danggui Niantong decoction in treating gout

BACKGROUND

Due to unhealthy diet and living habits, the incidence of gout is on the rise and has become a common disease with a high incidence. Danggui Niantong decoction (DGNTD), as a classic formula composed of 15 common herbs, has been widely used in clinical practice since ancient times to prevent and treat gout. However, the pharmacological mechanism and target of DGNTD are not clear.

METHODS

The potential active compounds and targets of DGNTD were obtained by traditional Chinese medicine systems pharmacology (TCMSP) database, and the differential genes of gout patients and controls were analyzed in gene expression omnibus (GEO) database. GSEA analysis of differential genes with GSEA 4.1.0 software and then the differential genes were intersected with the gout-related disease targets searched by GeneCard, CTD and OMIM disease database to obtain the final disease target. The "Traditional Chinese medicine-Active compounds-Targets" network was constructed by Cytoscape3.7.2 software. The R packet is used for enrichment analysis. The molecular docking between the active compound of DGNTD and the core target was verified by AutoDockTools software.

RESULTS

Two hundred eighty six and 244 targets of DGNTD-related active components and 652 targets of gout were obtained, of which 13 targets were potential targets of DGNTD in the treatment of gout. GSEA analysis showed that the differential genes were mainly involved in apoptosis, inflammatory reaction, and receptor metabolism and so on. Gene ontology (GO) functional enrichment analysis shows that DGNTD regulates many biological processes, such as the response to purine-containing compound and response to lipopolysaccharide, positive regulation of acute inflammatory response and other cellular components. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis shows that DGNTD treatment of gout is mainly related to interleukin-17 (IL-17), Toll-like receptor, rheumatoid arthritis, tumor necrosis factor (TNF) and so on. The results of molecular docking showed that the five active compounds in DGNTD had strong binding activity to core protein receptors.

CONCLUSIONS

The active compounds of DGNTD may achieve the purpose of treating gout by acting on the core target (CASP8, CXCL8, FOS, IL1B, IL6, JUN, PTGS2, STAT1, MMP1, TNF) to regulate cell metabolism, proliferation and apoptosis, and improve inflammatory response, which is the result of multi-component, multi-target and multi-pathway interaction. It provides an idea for the development of new combined drugs for gout.

Regulatory Role of miRNAs and lncRNAs in Gout

Objective

To explore the regulatory functions of ceRNA networks in the nosogenesis of gout and search for potential therapeutic targets.

Methods

We searched the GEO database and downloaded the lncRNA microarray chipset GSE160170. This matrix series was analyzed to yield differentially expressed lncRNAs and mRNAs. Then, the correlations between lncRNAs and miRNAs were obtained by comparing the highly conserved miRNA families. The predicted miRNA-regulating mRNAs were matched to the differentially expressed mRNAs from the chipset analyses to obtain miRNA–mRNA interactions. Next, we used the Cytoscape software to model ceRNA networks and the STRING database to determine their protein–protein interactions. The R software was used to algorithmically screen the functional pathways of key PPI modules in the ceRNA networks.

Results

A total of 354 lncRNAs (140 downregulated and 214 upregulated) and 693 mRNAs (399 downregulated and 294 upregulated) were differentially expressed between the gout group and the healthy group. The ceRNA network of differentially expressed lncRNAs contained 86 lncRNAs (35 downregulated and 51 upregulated), 29 miRNAs, and 57 mRNAs. The processes identified in the GO enrichment analysis included gene transcription, RNA polymerase II transcription, and the regulation of cell growth and apoptosis. The pathways identified in the KEGG enrichment analysis included IL-17, TNF, and MAPK signaling. Nine lncRNAs (AC104024, AC084082, AC083843, FAM182A, AC022819, FAM215B, AP000525, TTTY10, and ZNF346-IT1), eleven miRNAs (hsa-miR-1297, hsa-miR-17-5p, hsa-miR-429, hsa-miR-139-5p, hsa-miR-449c-5p, hsa-miR-125a-5p, hsa-miR-125b-5p, hsa-miR-23b-3p, hsa-miR-217, hsa-miR-363-3p, and hsa-miR-20b-5p), and nine mRNAs (JUN, CASP2, PMAIP1, FOS, TNFAIP3, MAP3K8, BTG2, NR4A2, and DUSP2) were identified in the exploration of the key modules.

Conclusion

Characterization of ceRNA networks could be a promising approach for better understanding the pathogenesis of gout, with the TTTY10/hsa-miR-139-5p/AP-1 axis likely to be of clinical significance.

Efficacy and Safety of Qinpi Tongfeng Formula Combined with Bloodletting Therapy in the Treatment of Acute Gouty Arthritis: A Study Protocol for a Randomized Controlled Trial

Background

Acute gouty arthritis (AGA) is a common arthritis disease, with the characteristics of acute onset, severe condition, and poor prognosis. The conventional treatments have shown certain curative effects but are accompanied with many adverse reactions. The combination of orally taken Qinpi Tongfeng Formula (QPTFF) and bloodletting therapy could effectively alleviate arthralgia and joint swelling in AGA patients. However, there is a lack of high-quality randomized controlled trials (RCTs) to evaluate the clinical efficacy and safety of the combined therapy against AGA.

Methods

This is a prospective, randomized, parallel controlled trial conducted in the First Teaching Hospital of Tianjin University of Traditional Chinese Medicine to explore the efficacy and safety of QPTFF combined with bloodletting therapy in the treatment of AGA. Eighty-six AGA patients meeting the inclusion and exclusion criteria will be randomly divided into the treatment group and control group in a 1 : 1 ratio using a randomization table. The investigators and the patients will not be blinded, while the outcome assessors and statisticians will be blinded to the allocation. Patients in the treatment group will take QPTFF and bloodletting therapy simultaneously, while patients in the control group will be instructed to orally take colchicine tablets. The primary outcome is the total effective rate, and the secondary outcomes are the pain changes after the first treatment, pain scores, complete pain relief time, joint symptom scores, TCM syndrome score, and laboratory test. SPSS22.0 will be used for statistical analysis. Discussion. This study will evaluate the clinical efficacy and safety of QPTFF combined with bloodletting therapy in the treatment of AGA, and the results of this study will provide reliable clinical evidence for the clinical use of QPTFF combined with bloodletting in the treatment of AGA. The trial is registered with ChiCTR2100048836.

Diagnostic model for predicting hyperuricemia based on alterations of the gut microbiome in individuals with different serum uric acid levels

BACKGROUND

We aimed to assess the differences in the gut microbiome among participants with different uric acid levels (hyperuricemia [HUA] patients, low serum uric acid [LSU] patients, and controls with normal levels) and to develop a model to predict HUA based on microbial biomarkers.

METHODS

We sequenced the V3-V4 variable region of the 16S rDNA gene in 168 fecal samples from HUA patients (n=50), LSU patients (n=61), and controls (n=57). We then analyzed the differences in the gut microbiome between these groups. To identify gut microbial biomarkers, the 107 HUA patients and controls were randomly divided (2:1) into development and validation groups and 10-fold cross-validation of a random forest model was performed. We then established three diagnostic models: a clinical model, microbial biomarker model, and combined model.

RESULTS

The gut microbial α diversity, in terms of the Shannon and Simpson indices, was decreased in LSU and HUA patients compared to controls, but only the decreases in the HUA group were significant (P=0.0029 and P=0.013, respectively). The phylum Proteobacteria (P<0.001) and genus Bacteroides (P=0.02) were significantly increased in HUA patients compared to controls, while the genus Ruminococcaceae_Ruminococcus was decreased (P=0.02). Twelve microbial biomarkers were identified. The area under the curve (AUC) for these biomarkers in the development group was 84.9% (P<0.001). Notably, an AUC of 89.1% (P<0.001) was achieved by combining the microbial biomarkers and clinical factors.

CONCLUSIONS

The combined model is a reliable tool for predicting HUA and could be used to assist in the clinical evaluation of patients and prevention of HUA.

NFIL3 Facilitates Neutrophil Autophagy, Neutrophil Extracellular Trap Formation and Inflammation During Gout via REDD1-Dependent mTOR Inactivation

Autophagy pathways play an important role in immunity and inflammation via pathogen clearance mechanisms mediated by immune cells, such as macrophages and neutrophils. In particular, autophagic activity is essential for the release of neutrophil extracellular traps (NETs), a distinct form of active neutrophil death. The current study set out to elucidate the mechanism of the NFIL3/REDD1/mTOR axis in neutrophil autophagy and NET formation during gout inflammation. Firstly, NFIL3 expression patterns were determined in the peripheral blood neutrophils of gout patients and monosodium urate (MSU)-treated neutrophils. Interactions between NFIL3 and REDD1 were identified. In addition, gain- or loss-of-function approaches were used to manipulate NFIL3 and REDD1 in both MSU-induced neutrophils and mice. The mechanism of NFIL3 in inflammation during gout was evaluated both in vivo and in vitro via measurement of cell autophagy, NET formation, MPO activity as well as levels of inflammatory factors. NFIL3 was highly-expressed in both peripheral blood neutrophils from gout patients and MSU-treated neutrophils. NFIL3 promoted the transcription of REDD1 by binding to its promoter. REDD1 augmented neutrophil autophagy and NET formation by inhibiting the mTOR pathway. In vivo experimental results further confirmed that silencing of NFIL3 reduced the inflammatory injury of acute gouty arthritis mice by inhibiting the neutrophil autophagy and NET formation, which was associated with down-regulation of REDD1 and activation of the mTOR pathway. Taken together, NFIL3 can aggravate the inflammatory reaction of gout by stimulating neutrophil autophagy and NET formation via REDD1/mTOR, highlighting NFIL3 as a potential therapeutic target for gout.

Function of Uric Acid Transporters and Their Inhibitors in Hyperuricaemia

Disorders of uric acid metabolism may be associated with pathological processes in many diseases, including diabetes mellitus, cardiovascular disease, and kidney disease. These diseases can further promote uric acid accumulation in the body, leading to a vicious cycle. Preliminary studies have proven many mechanisms such as oxidative stress, lipid metabolism disorders, and rennin angiotensin axis involving in the progression of hyperuricaemia-related diseases. However, there is still lack of effective clinical treatment for hyperuricaemia. According to previous research results, NPT1, NPT4, OAT1, OAT2, OAT3, OAT4, URAT1, GLUT9, ABCG2, PDZK1, these urate transports are closely related to serum uric acid level. Targeting at urate transporters and urate-lowering drugs can enhance our understanding of hyperuricaemia and hyperuricaemia-related diseases. This review may put forward essential references or cross references to be contributed to further elucidate traditional and novel urate-lowering drugs benefits as well as provides theoretical support for the scientific research on hyperuricemia and related diseases.

Design of Bacillus fastidious Uricase Mutants Bearing Long Lagging Phases Before Exponential Decreases of Activities Under Physiological Conditions

Under physiological conditions, Bacillus fastidious uricase (BFU) activity shows negligible lagging phase before the exponential decrease; mutants are thus designed for long lagging phases before exponential activity decreases. On homodimer surface of BFU (4R8X.pdb), the last fragment ANSEYVAL at the C-terminus forms a loop whose Y319 is H-bonded by the buried D257 in the same monomer. Within 1.5 nm from the α-carboxyl group of the last leucine (L322), E30, K26, D257, R258, E311, K312 and E318 from the same monomer plus D126 and K127 from a monomer of the other homodimer generate an electrostatic interaction network. Within 1.5 nm from Y319, D307 and R310 in the same monomer interact with ionized residues around the inter-chain β-sheet in the same homodimer. Mutagenesis of Y319R is designed to strengthen the original interactions and concomitantly generate new electrostatic attractions between homodimers. Under physiological conditions, the mutant V144A/Y319R showed an approximately 4 week lagging phase before the exponential activity decrease, an apparent half-life of activity nearly three folds of mutant V144A, but comparable activity. The introduction of ionizable residues into the C-terminus contacting the other homodimer for additional and/or stronger electrostatic attractions between homodimers may be a universal approach to thermostable mutants of uricases.

Optimization of culture medium for Sanghuangporus vaninii and a study on its therapeutic effects on gout

The increasing incidence of gout poses a very challenging management problem. However, the currently available drugs often have various toxic side effects. As a traditional edible and medicinal macrofungus, Sanghuangporus vaninii presents high medical research value. Therefore, to improve fermentation efficiency and identify novel anti-gout drugs, we optimized the culture medium of S. vaninii with lignin and further investigated its anti-gout effects. The results indicated that 0.06 g/L of lignin was most favorable for S. vaninii growth. In the hyperuricemia cell model, we found that S. vaninii could significantly induce the downregulation of xanthine oxidoreductase and the upregulation of hypoxanthine-guanine phosphoribosyltransferase. Furthermore, following oral administration of the extracts, the serum uric acid levels of mice with hyperuricemia were effectively reduced. In a gouty arthritis rat model, S. vaninii also achieved strong suppression of synovial swelling, indicating its anti-inflammatory activity. In addition, the antioxidant assays suggested that S. vaninii shows a strong free radical scavenging capacity and can effectively alleviate cellular oxidative stress. This activity further enhances its anti-inflammatory activity and reduces the incidence of comorbidities. In summary, our results provide the basis for the utilization of S. vaninii to develop anti-gout drugs.

Effects of external application of compound Qingbi granules on acute gouty arthritis with dampness-heat syndrome: a randomized controlled trial

Background and aim

The use of anti-inflammatory and analgesic drugs such as nonsteroidal anti-inflammatory drugs(NSAIDs) for treating acute gout has limitations, such as adverse reactions in the gastrointestinal tract and toxicity in the liver, kidney, and heart. Hence, a new safe and effective treatment approach needs to be explored to reduce the use of anti-inflammatory and analgesic drugs, incidence of adverse reactions, and patients’ burden. This randomized controlled clinical trial aimed to investigate the clinical efficacy and safety of the external application of compound Qingbi granules (CQBG) in treating acute gouty arthritis(AGA), providing evidence for designing a safe, effective, and optimized protocol for AGA comprehensive treatment.

Methods

A total of 90 patients in line with the diagnostic standard of AGA were recruited and randomly divided into control, T1, and T2 groups (30 in each group). All the participators in the three groups all received Western-medicine-basic treatment (low-purine diet, drinking water more than 2000 mL/days, oral loxoprofen, and NAHCO₃). Besides, the T1 group received an external application of diclofenac diethylamine emulgel, while the T2 group received an external application of CQBG. The participants in the control group received single-use Western-medicine-basic treatment. With a treatment course of 7 days and a follow-up of 7 days, the three groups were compared in terms of primary outcome indicators, including swelling, pain improvement, and change in pain duration and secondary outcome indicators, including serum C-reactive protein (CRP) level, uric acid (UA) level, and change in the thickness of the inflammatory synovium of joints under ultrasound. Meanwhile, the safety of the protocol was evaluated.

Results

The three groups of patients had no apparent differences in age, body mass index, history of gout, complications, and so on before recruitment. A comparison between pretreatment and post-treatment revealed remarkable reductions in the arthralgia visual analog scale score(VAS) and the swelling score in the three groups after the treatment and the improvements in the T2 group were more significant than those in the T1 and control groups (P < 0.05). Regarding the onset time of pain improvement and pain duration, the T2 group had more significant efficacy compared with the other two groups (P < 0.05). The serum CRP and blood UA levels in the three groups significantly decreased after the treatment, but with no significant intergroup difference. The improvement in the thickness of the inflammatory synovium in joints tested by ultrasound was more significant in the T2 group than in the control group (P < 0.05). For safety evaluations, no significant difference in the incidence of adverse events was found.

Conclusions

The external application of CQBG combined with Western-medicine-basic treatment in patients with AGA improved arthralgia and swelling, shortened the period of taking NSAIDs, and reduced the levels of CRP and serum UA. Its therapeutic effect was significantly better than the effect of single-use Western-medicine-basic treatment. The study provided evidence for the clinical application of CQBG combined with Western medicine in treating AGA.

Trial registration: ChiCTR, ChiCTR1800018020. Registered 27 August 2018, https://www.chictr.org.cn/showproj.aspx?proj=27138

Interventions to improve uptake of urate-lowering therapy in patients with gout: a systematic review

BACKGROUND

Gout treatment is suboptimal despite available therapy, with low levels of initiation and persistence of urate-lowering therapy (ULT) in many patients.

AIM

To identify all interventions that have attempted to improve the uptake of ULT and analyse the clinical outcomes.

DESIGN & SETTING

A systematic review of international articles published in English.

METHOD

A systematic search was conducted through MEDLINE, Embase, CINAHL Plus, and Scopus databases to identify all studies on relevant interventions for gout. Interventions were included if they aimed to address patient adherence with serum urate (SU) level as an outcome. This included patient education, practitioner monitoring, medication titration, SU monitoring, and ongoing patient engagement and follow-up. Follow-up studies to original interventions and those with only an abstract available were included.

RESULTS

Twenty articles met the inclusion criteria, describing outcomes of 18 interventions conducted in primary care settings: six nurse-led, five pharmacist-led, and seven multidisciplinary, multifaceted interventions. Improvement in SU levels was observed in all interventions. Nurse-led interventions were effective at empowering patients as they addressed illness perceptions and provided education, advice, and telephone follow-up. Pharmacist-led interventions primarily aimed to monitor patients, alter medication dosage, and provide automated telephone follow-up. Various multifaceted programmes involving a range of providers resulted in increased sustained use of urate-lowering medication.

CONCLUSION

A nurse-led approach focusing on patient understanding about gout is the most effective in achieving improved patient adherence, and lowered SU levels among patients. An intervention should include patient education and follow-up components.