Role of NLRP3 in the pathogenesis and treatment of gout arthritis

Anti-inflammatory effect of Plantago asiatica crude extract in rat gout arthritis model

Plantago asiatica L., a perennial herb in the family Plantaginaceae, has been shown to impart several pharmacologic activities, including anti-oxidative, anti-inflammatory, and diuretic effects. In the study here, the anti-gout(y) arthritis (GA) effects of a crude extract from P. asiatica L. (PAE) were investigated in a rat GA model. For this, PAE was prepared by ethanol extraction and analyzed for phytochemicals by RP-HPLC and Q-TOF-MS. Thereafter, potential therapeutic effects of the PAE were investigated in rats; Wistar rats (male, 8 wk-of-age) were randomly allocated into four groups (n = 9/group) and intra-articularly injected with 3 mg monosodium urate (MSU) in saline solution to establish a GA model. For the study, rats received oral dosings of 0.3 mg colchicine/kg or 1 g PAE/kg (w/w) before and after gout was established. At fixed times after the treatments, assessment of joint swelling ratios and pathological changes in the joints, as well as of select cytokine expression in the blood, was done. RP-HPLC results showed the PAE contained at least 8 'active' ingredients, with plantamajoside, verbascoside, and cymaroside being the most abundant. In comparison to in control rats, MSU induced joint space narrowing, ankle joint swelling, and increased levels of pro-inflammatory interleukin (IL)-1β, IL-17a, tumor necrosis factor (TNF)-α, and interferon (IFN)-γ, and reductions in anti-inflammatory IL-10 in the blood. PAE treatment significantly reversed patho- genic joint space narrowing and swelling, reversed the MSU-induced changes in inflammatory factors, and in general imparted effects very similar to those seen with colchicine (COL; known non-steroidal anti-inflammatory drug for clinical treatment of GA). Collectively, these findings provide experimental evidence supporting the potential applicability of PAE to treat gouty arthritis.

Deciphering the role of cell signaling pathways in gout pathogenesis and the therapeutic potential of phytoconstituents in their modulation

PURPOSE

Gout, a type of inflammatory arthritis, arises from the accumulation of monosodium urate crystals in joints, leading to severe pain and inflammation. While conventional treatments, such as uric acid-lowering agents and anti-inflammatory drugs, are effective, they are often associated with adverse effects. This review aims to explore the potential of phytoconstituents as alternative therapeutic agents for gout, focusing on their mechanisms of action and strategies to enhance their clinical efficacy.

METHODS

A comprehensive literature review was conducted to analyze the role of phytochemicals in gout management. Key compounds such as quercetin, curcumin, and resveratrol were examined for their effects on inflammatory pathways, oxidative stress, and uric acid regulation. Furthermore, advancements in drug delivery systems, including nanotechnology-based formulations and CRISPR-mediated pathway modulation, were explored to address the limitations of phytoconstituents.

RESULTS

Phytoconstituents demonstrated significant anti-inflammatory, antioxidant, and xanthine oxidase inhibitory properties. These compounds modulated critical pathways such as NF-κB, NLRP3 inflammasome, and MAPK, reducing inflammation, oxidative stress, and uric acid levels. However, poor bioavailability and rapid metabolism remain key challenges, necessitating advanced formulation strategies to enhance their therapeutic potential.

CONCLUSION

Phytoconstituents offer a promising alternative for gout treatment by targeting multiple pathogenic mechanisms. Integrating nanotechnology and gene-editing approaches may improve their bioavailability and therapeutic efficacy. Further research is warranted to facilitate clinical translation and optimize their application in gout management.

Exploring the Impact of PA and Sedentary Behavior on Gout Risk in Hyperuricemia: Insights From Machine Learning and SHAP Analysis

BACKGROUND

Individuals with hyperuricemia (HUA) are widely recognized as being at increased risk for gout. This study aimed to investigate how physical activity (PA) duration and sedentary duration impact gout risk in individuals with HUA and to develop predictive models to assess their risk of developing gout.

METHODS

We retrospectively collected clinical characteristics of 8057 individuals with HUA from the National Health and Nutrition Examination Survey (NHANES) consortium for the period 2007-2018. By developing and comparing four classic machine learning algorithms, the best-performing Random Forest (RF) model was selected and combined with the SHAP interpreting algorithm to analyze the dose-response relationship between PA duration, sedentary time, and gout risk. Additionally, the RF model was used to identify the most critical factors influencing gout risk and to develop a free online tool for predicting gout risk in HUA individuals.

RESULTS

The RF model outperformed others, achieving a Receiver Operating Characteristic (ROC) of 0.957 in the training cohort and 0.799 in the testing cohort. In the test cohort, it demonstrated an accuracy of 0.778, a Kappa of 0.247, a sensitivity of 0.701, a specificity of 0.785, a positive predictive value of 0.224, a negative predictive value of 0.967, and an F1 score of 0.340. SHAP analysis revealed the following insights: (1) hypertension, serum uric acid, age, gender, and BMI were identified as the top five factors for gout risk; (2) factors such as higher serum uric acid levels, age, BMI, creatinine, sedentary duration, lower PA, hypertension, male sex, and diabetes were associated with an elevated risk of gout; and (3) a PA duration of 1-7 h per week was linked to a lower risk of gout, while sedentary time exceeding 6 h per day increased gout risk, regardless of age, sex, or comorbidities.

CONCLUSION

We encourage individuals with HUA to engage in 1-7 h of PA per week and limit daily sedentary time to less than 6 h to reduce gout risk. The developed prediction model is freely available as a web-based app at: https://sasuki.shinyapps.io/GoutRisk/.

Suppressive effect of curcumin on apoptosis of articular chondrocytes via regulation on NF-κB pathway and NLRP3 inflammasome

Our study probed into how curcumin modulates NF-κB pathway to regulate articular chondrocytes. ATDC5 cells were exposed to varying concentrations of curcumin (0, 10, 20, 50, or 100 μM) for 48 h, followed by an assessment of curcumin's cytotoxicity. Cells were also treated with 10 ng/ml IL-1β, curcumin, 5 μg/L NF-κB inhibitor (PDTC), and 5 μM NLRP3 inflammasome inducer (nigericin) for 48 h, before cell viability, apoptosis, NF-κB pathway-related proteins, NLRP3 inflammasome-related proteins and inflammatory cytokines were detected. IL-1β treatment notably diminished chondrocyte viability and increased apoptosis, evidenced by elevated level of Bax and cleaved caspase-3, and reduced level of Bcl2, while such expression patterns were reversed by curcumin treatment in a concentration-dependent fashion. Additionally, NF-κB pathway and NLRP3 inflammasome in chondrocytes were activated by IL-1β treatment, but can also be suppressed following curcumin intervention. Furthermore, inhibition of NF-κB pathway curtailed the NLRP3 inflammasome activation and chondrocyte apoptosis, while activation of the NLRP3 inflammasome partially reversed the protective impacts of curcumin against chondrocyte apoptosis. Curcumin inhibits NF-κB pathway, thereby preventing the NLRP3 inflammasome activation and ameliorating IL-1β-induced apoptosis in articular chondrocytes.

Gout drives metabolic dysfunction-associated steatotic liver disease through gut microbiota and inflammatory mediators

This study explores the relationship between gout and metabolic dysfunction-associated steatotic liver disease (MASLD), two metabolic conditions linked to worsening health outcomes. While hyperuricemia's association with MASLD is established, the specific connection between gout and MASLD remains less explored. Using data from the UK Biobank, the study employs COX proportional hazard models, multi-state survival analysis, and Mendelian randomization to assess the independent and mutual risks of gout and MASLD. Findings indicate a mutual risk increase: male gout patients, those younger than 60, and those with high BMI are particularly susceptible to MASLD, while female MASLD patients are at heightened risk for gout. Shared risk factors for both conditions include high BMI, hypertension, diabetes, and hyperuricemia. The study further identifies a bidirectional causal link, with gout leading to MASLD, mediated by gut microbiota Ruminococcaceae and proteins like IL-2 and GDF11, implicating specific metabolic pathways. The findings highlight a clinical and mechanistic correlation, emphasizing the need for targeted interventions to address these overlapping metabolic pathways in future treatments.

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.

Value of semi-quantitative scoring based on musculoskeletal ultrasound in diagnosis and disease assessment of gouty arthritis

To explore value of semi-quantitative scoring based on musculoskeletal ultrasound in diagnosis and disease assessment of gouty arthritis (GA). Ninety patients with suspected GA who received in our hospital from January 2022 to December 2023 were retrospectively selected as the study objects. The puncture results of joint synovial fluid or crystal material in the joint cavity were used as the gold standard, and the patients 'joint effusion, synovitis, bone erosion and tenosynovitis were counted. Compare the musculoskeletal ultrasound semi-quantitative score with the puncture results of joint synovial fluid or crystal material in the joint cavity to diagnose different pathological types of GA and evaluate the diagnostic efficiency of musculoskeletal ultrasound semi-quantitative score in diagnosing different pathological types of GA. Use correlation analysis to analyze the correlation between patients with the musculoskeletal ultrasound semi-quantitative score results, IL-6 and DAS28 scores, and typical musculoskeletal ultrasound and MRI examination results. There was no significant difference between the musculoskeletal ultrasound semi-quantitative score and the puncture results of joint synovial fluid or crystal material in the joint cavity. There was no significant difference between the examination results of different lesion types (P > 0.05). The puncture results of joint synovial fluid or crystal material in the joint cavity were used as the gold standard, the sensitivity of musculoskeletal ultrasound semi-quantitative scoring in diagnosing synovial thickening, joint effusion, bone erosion, and tendon/tendon sheath inflammation in GA patients was 92.86% (26/28), 96.00% (24/25), 95.24% (20/21), and 75.00% (12/16), respectively. The specificity values were 93.55% (58/62), 96.92% (63/65), 95.65% (66/69), and 98.65% (73/74) respectively. The accuracy rates were 93.33% (84/90), 96.67% (87/90), 95.56% (86/90), and 94.44% (85/90), respectively. According to Pearson linear correlation analysis, as the semi-quantitative scoring increased, there was a positive correlation with erythrocyte sedimentation rate, IL-6, and DAS28 scores (r = 0.729, 0.584, 0.773, P < 0.001). Observation of their serological indicators showed that there were significant differences in serological indicators between patients with different semi-quantitative scores (P < 0.05). Semi-quantitative scoring based on musculoskeletal ultrasound has high value in the diagnosis and assessment of gouty arthritis, and is worth further use.

Discovery of selective ROCK2 inhibitors with free radical scavenging ability for the treatment of gouty arthritis

ROCK inhibitors can inhibit IL-1β and NLRP3, and their therapeutic potential for osteoarthritis and rheumatoid arthritis has been confirmed, but their impact on gouty arthritis has not been reported yet. By hybridization the structure of Edaravone, a series of ROCK inhibitors with pyrazolone scaffold were designed and synthesized. RM-04 has acceptable selective ROCK2 inhibitory activity with an IC50 of 4.62 µM, and its IC50 values for scavenging DPPH• and ABTS•+ are 16.72 µM and 23.15 µM, respectively, which is equivalent to that of Edaravone. Furthermore, RM-04 exhibits good pharmacokinetic properties and good safety in vivo. Meanwhile, in sodium urate-induced acute gout model, RM-04 at a dose of 5 mg/kg exhibited the alleviating effect approximately equivalent to that of Celecoxib, indicating that ROCKs inhibitors with antioxidation activity could reduce the damage caused by gouty arthritis.

Increased lamina propria B cells play roles in fructose-induced hypertension of Dahl salt-sensitive rats

AIMS

Although the immune system participates in the development of hypertension, the proportional contributions of distinct immune cells remain poorly understood. With the development of transcriptomics, we can profile the transcriptomes of individual immune cells and assess the relative contribution of each immune cell to the development of hypertension. So, we tested the hypothesis that increased lamina propria B cells play roles in fructose-induced hypertension of Dahl salt-sensitive (SS) rats.

MATERIALS AND METHODS

Eight-week-old Dahl SS and Dahl salt-resistant (SR) male rats were divided into four groups; each group received either tap water (TW) or a 20 % fructose solution (HFS) for 4 weeks. Systolic blood pressure was measured using the tail-cuff method. Single-cell RNA sequencing (scRNA-seq) analysis was performed on lamina propria (LP) cells and peripheral blood mononuclear cells (PBMCs) obtained from the SS and SR rats subjected to either TW or HFS.

KEY FINDINGS

Results revealed that high-fructose intake induced hypertension in the SS rats but not in the SR rats. It also increased B cells in LPs but not in PBMCs of the SS rats; their subsets showed increased follicular and naïve B cells. Increased lamina propria B cells play roles in fructose-induced hypertension of SS rats.

SIGNIFICANCE

This finding suggest that targeting B cells could be a potential strategy to mitigate high blood pressure in fructose-induced hypertension.

Current Status of Gout Arthritis: Current Approaches to Gout Arthritis Treatment: Nanoparticles Delivery Systems Approach

The deposition of monosodium urate (MSU) crystals within joint spaces produces a painful inflammatory condition known as gout, a specific form of arthritis. The condition calls for a combined curative and preventive management model. A new development in the approach to gout is that of NLRP3-targeted biologic agents, such as monoclonal therapies, to provide more accurate treatment by blocking specific pro-inflammatory cytokines. Nanoparticle drug delivery enhances biological availability and delivery to targets, which may increase therapeutic efficacy and decrease general toxicity. The preventive approach again cannot be ignored, mainly keeping up certain modifications in diet and weight, along with pharmacological therapies to reduce uric acid (UA) levels and to decrease the frequency of acute attacks. The advancement of genetic profiling of patients and biomarker discoveries drives the trend towards building individualized medicine and care, quickly gaining ground as the most effective method of delivering treatments to individual patients, moving away from one-size-fits-all treatments. The following paper aims to provide an updated account of the management of gout with a focus on recent developments, in order to enhance these approaches, the quality of life for patients with gout, and the standard of gout treatment.

Inflammasomes and idiopathic inflammatory myopathies

Idiopathic inflammatory myopathies (IIM) are a group of systemic autoimmune diseases characterized by muscle weakness and elevated serum creatine kinase levels. Recent research has highlighted the role of the innate immune system, particularly inflammasomes, in the pathogenesis of IIM. This review focuses on the role of inflammasomes, specifically NLRP3 and AIM2, and their associated proteins in the development of IIM. We discuss the molecular mechanisms of pyroptosis, a programmed cell death pathway that triggers inflammation, and its association with IIM. The NLRP3 inflammasome, in particular, has been implicated in muscle fiber necrosis and the subsequent release of damage-associated molecular patterns (DAMPs), leading to inflammation. We also explore the potential therapeutic implications of targeting the NLRP3 inflammasome with inhibitors such as glyburide and MCC950, which have shown promise in reducing inflammation and improving muscle function in preclinical models. Additionally, we discuss the role of caspases, particularly caspase-1, in the canonical pyroptotic pathway associated with IIM. The understanding of these mechanisms offers new avenues for therapeutic intervention and a better comprehension of IIM pathophysiology.

The role of quercetin in NLRP3-associated inflammation

Quercetin is a natural flavonoid that is widely found in fruits and vegetables. As an important flavonoid, it exhibits a wide range of biological activities, including antioxidant, anti-inflammatory, antiviral, immunomodulatory, and analgesic activities. Quercetin exerts powerful antioxidant activity by regulating glutathione, enzyme activity, and the production of reactive oxygen species (ROS). Quercetin exerts powerful anti-inflammatory effects by acting on the Nod-like receptor protein 3 (NLRP3) inflammasome. In diabetes, quercetin has been shown to improve insulin sensitivity and reduce high blood sugar level, while, in neurological diseases, it potentially prevents neuronal degeneration and cognitive decline by regulating neuroinflammation. In addition, in liver diseases, quercetin may improve liver inflammation and fibrosis by regulating the NLRP3 activity. In addition, quercetin may improve inflammation in other diseases based on the NLRP3 inflammasome. With this background, in this review, we have discussed the progress in the study on the mechanism of quercetin toward improving inflammation via NLRP3 inflammasome in the past decade. In addition, from the perspective of quercetin glycoside derivatives, the anti-inflammatory mechanism of hyperoside, rutin, and isoquercetin based on NLRP3 inflammasome has been discussed. Moreover, we have discussed the pharmacokinetics of quercetin and its nanoformulation application, with the aim to provide new ideas for further research on the anti-inflammatory effect of quercetin and its glycoside derivatives based on NLRP3 inflammasome, as well as in drug development and application.

Evidence from Mendelian randomization analysis combined with meta-analysis for the causal validation of the relationship between 91 inflammatory factors and lumbar disc herniation

Lumbar disc herniation (LDH) is a common spinal disease. In recent years, an increasing number of observational studies have reported the impact of inflammatory factors on LDH. By conducting Mendelian randomization (MR) analysis on 91 inflammatory factors, it is possible to reveal their causal relationship with LDH, providing new insights for prevention and treatment strategies. In this study, a two-sample MR analysis was performed, using 91 inflammatory factors as exposure data, and LDH data from 2 different sources as outcome data. Subsequently, the most significant results from the inverse-variance weighted analysis were subjected to meta-analysis, with multiple corrections applied to the thresholds to ensure result accuracy. Finally, reverse causality MR analysis was conducted to validate the causal relationship between the identified positive inflammatory factors and LDH. Ninety-one cytokines were analyzed in relation to LDH using MR with data from the Finngen and UK Biobank databases. The inverse-variance weighted results from both analyses were then meta-analyzed, and multiple corrections were applied to the significance threshold of the meta-analysis results. Ultimately, only 1 cytokine, tumor necrosis factor-beta levels (genome-wide association study ID: GCST90274840), showed a significant association after the combined MR analysis and multiple corrections, with an odds ratio of 1.073 (95% confidence interval: 1.034-1.113, P = .0154). Furthermore, this positive cytokine did not display any reverse causality with LDH from either data source. Tumor necrosis factor-beta levels are a risk factor for LDH, potentially increasing the risk of developing the condition and exacerbating its symptoms.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Type III Secretion System in Intestinal Pathogens and Metabolic Diseases

Modern lifestyle changes, especially the consumption of a diet high in salt, sugar, and fat, have contributed to the increasing incidence and prevalence of chronic metabolic diseases such as diabetes, obesity, and gout. Changing lifestyles continuously shape the gut microbiota which is closely related to the occurrence and development of metabolic diseases due to its specificity of composition and structural diversity. A large number of pathogenic bacteria such as Yersinia, Salmonella, Shigella, and pathogenic E. coli in the gut utilize the type III secretion system (T3SS) to help them resist host defenses and cause disease. Although the T3SS is critical for the virulence of many important human pathogens, its relationship with metabolic diseases remains unknown. This article reviews the structure and function of the T3SS, the disruption of intestinal barrier integrity by the T3SS, the changes in intestinal flora containing the T3SS in metabolic diseases, the possible mechanisms of the T3SS affecting metabolic diseases, and the application of the T3SS in the treatment of metabolic diseases. The aim is to provide insights into metabolic diseases targeting the T3SS, thereby serving as a valuable reference for future research on disease diagnosis, prevention, and treatment.

Versatility of 14-3-3 proteins and their roles in bone and joint-related diseases

Bone and joint-related diseases, including osteoarthritis (OA), rheumatoid arthritis (RA), and bone tumors, pose significant health challenges due to their debilitating effects on the musculoskeletal system. 14-3-3 proteins, a family of conserved regulatory molecules, play a critical role in the pathology of these diseases. This review discusses the intricate structure and multifunctionality of 14-3-3 proteins, their regulation of signaling pathways, and their interactions with other proteins. We underscore the significance of 14-3-3 proteins in the regulation of osteoblasts, osteoclasts, chondrocytes, and bone remodeling, all key factors in the maintenance and dysfunction of bone and joint systems. Specific focus is directed toward elucidating the contribution of 14-3-3 proteins in the pathology of OA, RA, and bone malignancies, where dysregulated 14-3-3-mediated signaling cascades have been implicated in the disease processes. This review illuminates how the perturbation of 14-3-3 protein interactions can lead to the pathological manifestations observed in these disorders, including joint destruction and osteolytic activity. We highlight cutting-edge research that positions 14-3-3 proteins as potential biomarkers for disease progression and as innovative therapeutic targets, offering new avenues for disease intervention and management.

Pathophysiological role and potential drug target of NLRP3 inflammasome in the metabolic disorders

NLRP3 plays a role in the development of autoinflammatory diseases. NLRP3, ASC, and Caspases 1 or 8 make up the NLRP3 inflammasome, which is an important part of innate immune system. The NLRP3 inflammasome-mediated inflammatory cytokines may also participate in metabolic disorders, such as diabetes, hyperlipidemia, atherosclerosis, non-alcoholic fatty liver disease, and gout. Hence, an overview of the NLRP3 regulation in these metabolic diseases and the potential drugs targeting NLRP3 is the focus of this review.

[Bardoxolone methyl alleviates acute liver injury in mice by inhibiting NLRP3 inflammasome activation]

OBJECTIVE

To investigate the inhibitory effect of bardoxolone methyl (CDDO-Me) on activation of NLRP3 inflammasome and its mechanism for alleviating acute liver injury (ALI).

METHODS

Mouse bone marrow-derived macrophages (BMDM) and THP-1 cells were pre-treated with CDDO-Me followed by treatment with Nigericin, ATP, MSU, intracellular LPS transfection for activation of NLRP3 inflammasomes, or poly A: T for activation of AIM2 inflammasomes. The levels of caspase-1 and IL-1β in the cell culture supernatant was determined with Western blotting and ELISA to assess the inhibitory effect of CDDO-Me on NLRP3 inflammasomes and its specificity. In the animal experiment, male C57BL/6J mouse models of acetaminophen-induced ALI were treated with low-dose (20 mg/kg) and high-dose (40 mg/kg) CDDO-Me, and the changes in serum levels of IL-1β, TNF- α, AST and ALT were measured by ELISA and liver tissue pathology was observed using HE staining.

RESULTS

In mouse BMDM and THP-1 cells, CDDO-Me dose-dependently inhibited the activation of NLRP3 inflammasomes without significantly affecting the secretion of non-inflammasome-related inflammatory factors IL-6 and TNF-α or AIM2 inflammasome activation. In the mouse models of ALI, CDDO-Me treatment at both the low and high doses significantly reduced serum levels of IL-1β, AST and ALT, ameliorated histological changes and reduced inflammatory cell infiltration in the liver tissue, and the effects exhibited a distinct dose dependence.

CONCLUSION

CDDO-Me can specifically inhibit the activation of NLRP3 inflammasomes to alleviate acetaminophen-induced ALI in mice.

Euterpe oleracea Mart. Bioactive Molecules: Promising Agents to Modulate the NLRP3 Inflammasome

Inflammation is a vital mechanism that defends the organism against infections and restores homeostasis. However, when inflammation becomes uncontrolled, it leads to chronic inflammation. The NLRP3 inflammasome is crucial in chronic inflammatory responses and has become a focal point in research for new anti-inflammatory therapies. Flavonoids like catechin, apigenin, and epicatechin are known for their bioactive properties (antioxidant, anti-inflammatory, etc.), but the mechanisms behind their anti-inflammatory actions remain unclear. This study aimed to explore the ability of various flavonoids (isolated and combined) to modulate the NLRP3 inflammasome using in silico and in vitro models. Computer simulations, such as molecular docking, molecular dynamics, and MM/GBSA calculations examined the interactions between bioactive molecules and NLRP3 PYD. THP1 cells were treated with LPS + nigericin to activate NLRP3, followed by flavonoid treatment at different concentrations. THP1-derived macrophages were also treated following NLRP3 activation protocols. The assays included colorimetric, fluorometric, microscopic, and molecular techniques. The results showed that catechin, apigenin, and epicatechin had high binding affinity to NLRP3 PYD, similar to the known NLRP3 inhibitor MCC950. These flavonoids, particularly at 1 µg/mL, 0.1 µg/mL, and 0.01 µg/mL, respectively, significantly reduced LPS + nigericin effects in both cell types and decreased pro-inflammatory cytokine, caspase-1, and NLRP3 gene expression, suggesting their potential as anti-inflammatory agents through NLRP3 modulation.

Mesenchymal stem cells and their extracellular vesicles in bone and joint diseases: targeting the NLRP3 inflammasome

The nucleotide-binding oligomerization domain-like-receptor family pyrin domain-containing 3 (NLRP3) inflammasome is a cytosolic multi-subunit protein complex, and recent studies have demonstrated the vital role of the NLRP3 inflammasome in the pathological and physiological conditions, which cleaves gasdermin D to induce inflammatory cell death called pyroptosis and mediates the release of interleukin-1 beta and interleukin-18 in response to microbial infection or cellular injury. Over-activation of the NLRP3 inflammasome is associated with the pathogenesis of many disorders affecting bone and joints, including gouty arthritis, osteoarthritis, rheumatoid arthritis, osteoporosis, and periodontitis. Moreover, mesenchymal stem cells (MSCs) have been discovered to facilitate the inhibition of NLRP3 and maybe ideal for treating bone and joint diseases. In this review, we implicate the structure and activation of the NLRP3 inflammasome along with the detail on the involvement of NLRP3 inflammasome in bone and joint diseases pathology. In addition, we focused on MSCs and MSC-extracellular vesicles targeting NLRP3 inflammasomes in bone and joint diseases. Finally, the existing problems and future direction are also discussed.

Hyperuricemia and its related diseases: mechanisms and advances in therapy

Hyperuricemia, characterized by elevated levels of serum uric acid (SUA), is linked to a spectrum of commodities such as gout, cardiovascular diseases, renal disorders, metabolic syndrome, and diabetes, etc. Significantly impairing the quality of life for those affected, the prevalence of hyperuricemia is an upward trend globally, especially in most developed countries. UA possesses a multifaceted role, such as antioxidant, pro-oxidative, pro-inflammatory, nitric oxide modulating, anti-aging, and immune effects, which are significant in both physiological and pathological contexts. The equilibrium of circulating urate levels hinges on the interplay between production and excretion, a delicate balance orchestrated by urate transporter functions across various epithelial tissues and cell types. While existing research has identified hyperuricemia involvement in numerous biological processes and signaling pathways, the precise mechanisms connecting elevated UA levels to disease etiology remain to be fully elucidated. In addition, the influence of genetic susceptibilities and environmental determinants on hyperuricemia calls for a detailed and nuanced examination. This review compiles data from global epidemiological studies and clinical practices, exploring the physiological processes and the genetic foundations of urate transporters in depth. Furthermore, we uncover the complex mechanisms by which the UA induced inflammation influences metabolic processes in individuals with hyperuricemia and the association with its relative disease, offering a foundation for innovative therapeutic approaches and advanced pharmacological strategies.

Mechanism of Reactive Oxygen Species-Guided Immune Responses in Gouty Arthritis and Potential Therapeutic Targets

Gouty arthritis (GA) is an inflammatory disease caused by monosodium urate (MSU) crystals deposited in the joint tissues causing severe pain. The disease can recur frequently and tends to form tophus in the joints. Current therapeutic drugs for the acute phase of GA have many side effects and limitations, are unable to prevent recurrent GA attacks and tophus formation, and overall efficacy is unsatisfactory. Therefore, we need to advance research on the microscopic mechanism of GA and seek safer and more effective drugs through relevant targets to block the GA disease process. Current research shows that the pathogenesis of GA is closely related to NLRP3 inflammation, oxidative stress, MAPK, NET, autophagy, and Ferroptosis. However, after synthesizing and sorting out the above mechanisms, it is found that the presence of ROS is throughout almost the entire spectrum of micro-mechanisms of the gout disease process, which combines multiple immune responses to form a large network diagram of complex and tight connections involved in the GA disease process. Current studies have shown that inflammation, oxidative stress, cell necrosis, and pathological signs of GA in GA joint tissues can be effectively suppressed by modulating ROS network-related targets. In this article, on the one hand, we investigated the generative mechanism of ROS network generation and its association with GA. On the other hand, we explored the potential of related targets for the treatment of gout and the prevention of tophus formation, which can provide effective reference ideas for the development of highly effective drugs for the treatment of GA.

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

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

Elucidating the molecular landscape of tendinitis: the role of inflammasome-related genes and immune interactions

Tendinitis, characterized by the inflammation of tendons, poses significant challenges in both diagnosis and treatment due to its multifaceted etiology and complex pathophysiology. This study aimed to dissect the molecular mechanisms underlying tendinitis, with a particular focus on inflammasome-related genes and their interactions with the immune system. Through comprehensive gene expression analysis and bioinformatics approaches, we identified distinct expression profiles of inflammasome genes, such as NLRP6, NLRP1, and MEFV, which showed significant correlations with immune checkpoint molecules, indicating a pivotal role in the inflammatory cascade of tendinitis. Additionally, MYD88 and CD36 were found to be closely associated with HLA family molecules, underscoring their involvement in immune response modulation. Contrary to expectations, chemokines exhibited minimal correlation with inflammasome genes, suggesting an unconventional inflammatory pathway in tendinitis. Transcription factors like SP110 and CREB5 emerged as key regulators of inflammasome genes, providing insight into the transcriptional control mechanisms in tendinitis. Furthermore, potential therapeutic targets were identified through the DGidb database, highlighting drugs that could modulate the activity of inflammasome genes, offering new avenues for targeted tendinitis therapy. Our findings elucidate the complex molecular landscape of tendinitis, emphasizing the significant role of inflammasomes and immune interactions, and pave the way for the development of novel diagnostic and therapeutic strategies.

Association of C-reactive protein with all-cause and cause-specific mortality in people with gout

AIMS

To test the association of C-reactive protein (CRP) with all-cause and cause-specific mortality in people with gout.

METHODS

This cohort study included 502 participants with gout from the National Health and Nutrition Examination Survey. Multivariate Cox regression analysis, subgroup analysis, and restricted cubic spline (RCS) analyses were utilized to examine the association of CRP levels with all-cause, cardiovascular, and cancer mortality.

RESULTS

After adjusting for multiple variables, Cox regression analysis showed that compared with individuals in the lowest tertile of CRP levels, those in the middle and highest tertiles experienced increases in all-cause mortality risk of 74.2% and 149.7%, respectively. Similarly, the cancer mortality risk for individuals in the highest tertile of CRP levels increased by 283.9%. In addition, for each standard deviation increase in CRP, the risks of all-cause and cancer mortality increased by 25.9% and 35.4%, respectively (P < 0.05). Subgroup analyses demonstrated that the association between CRP levels and all-cause mortality remained significant across subgroups of age (≤ 60 and > 60 years), gender (male), presence or absence of hypertension, non-diabetes, cardiovascular disease, non-cardiovascular disease and non-cancer. Furthermore, the association with cancer mortality was significant in subgroups including males, those without hypertension and cancer, and those with or without diabetes. However, the association with cardiovascular mortality was only significant in the non-hypertension subgroup (P < 0.05). Nonlinear association of CRP with all-cause mortality and linear association with cancer mortality were also confirmed (P for nonlinearity = 0.008 and 0.135, respectively).

CONCLUSIONS

CRP levels were associated with increased all-cause and cancer mortality among individuals with gout.

CD8 T cell-derived perforin regulates macrophage-mediated inflammation in a murine model of gout

OBJECTIVES

Gout is characterized by hyperuricemia and recurrent inflammatory episodes caused by intra-articular crystal deposition of monosodium urate (MSU). There is a clear relationship between gout and metabolic syndrome. Recent evidence indicates that perforin plays a role in regulating glucose homeostasis and provides protection in diet-induced non-alcoholic steatohepatitis models. However, the impact of perforin on immune inflammation in gout remains unclear.

METHODS

We induced acute gout models in both wild-type (WT) mice and Prf1null mice by administering intra-articular injections of MSU crystals. We compared the ankle joint swelling and the histological score between the two groups. Furthermore, we investigated underlying mechanisms through in vitro co-culture experiments involving CD8 T cells and macrophages.

RESULTS

In this study, Prf1null mice showed significantly more pronounced ankle swelling with increased inflammatory cell infiltrations compared with WT mice 24 h after local MSU injection. Moreover, MSU-induced Prf1null mice exhibited increased accumulation of CD8 T cells but not NK cells. Perforin-deficient CD8 T cells displayed reduced cytotoxicity towards bone marrow-derived M0 and M1 macrophages and promoted TNF-α secretion from macrophage.

CONCLUSIONS

Perforin from CD8 T cells limits joint inflammation in mice with acute gout by downregulating macrophage-mediated inflammation. Key Points • Perforin deficiency increased swelling in the ankle joints of mice upon MSU injection. • Perforin deficiency is associated with increased immune cell recruitment and severe joint damage in gout. • Perforin regulated CD8 T cell accumulation in gout and promoted CD8 T cell cytotoxicity towards M0 and M1 macrophages. • CD8 T cell-derived perforin regulated pro-inflammatory cytokine secretion of macrophage.

Association of Gout with Head and Neck Cancer: Longitudinal Follow-Up Studies Using a National Health Insurance Database in South Korea

Objective: Previous studies have reported controversial results on the association between gout and the risk of cancer. This study aimed to investigate the relationship between gout and the incidence of head and neck cancer (HNC). Methods: The data of participants who underwent health checkups in 2009 were analyzed using the National Health Insurance Database in South Korea. A total of 14,348 HNC patients and 57,392 control participants were analyzed for a prior history of gout. Overlap weighting was applied, and odds ratios (ORs) of gout for HNC patients were analyzed. The overlap-weighted model adjusted for demographic, socioeconomic, and lifestyle factors and comorbidities. HNC sites were classified as oral cavity cancer, oropharyngeal cancer, nasopharyngeal cancer, hypopharyngeal cancer, nasal cavity/sinus cancer, larynx cancer, or salivary gland cancer, and the ORs of gout were estimated for each site. Results: Overall, patients with HNC had 1.12-fold greater odds of having gout (95% confidence intervals [CIs] = 1.04-1.20). According to the site of HNC, oral cavity cancer, oropharynx cancer, and larynx cancer demonstrated high odds of having gout (OR = 1.25, 95% CI = 1.16-1.34 for oral cavity cancer; OR = 1.08, 95% CI = 1.01-1.15 for oropharynx cancer; and OR = 1.12, 95% CI = 1.06-1.20 for larynx cancer). On the other hand, nasal cavity/sinus cancer, nasopharynx cancer, and salivary gland cancer presented low odds of having gout (OR = 0.78, 95% CI = 0.72-0.84 for nasal cavity/sinus cancer; OR = 0.89, 95% CI = 0.83-0.96 for nasopharynx cancer; and OR = 0.88, 95% CI = 0.81-0.96 for salivary gland cancer). Conclusions: A prior history of gout was associated with a high overall incidence of HNC. Oral cavity cancer, oropharynx cancer, and larynx cancer have a high incidence in gout patients. However, nasal cavity/sinus cancer, nasopharyngeal cancer, and salivary gland cancer have low incidences in gout patients. The impact of gout on HNC risk should be specifically considered according to the site of the HNC.

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

BACKGROUND

Gouty arthritis (GA) is characterized by monosodium urate (MSU) crystal accumulation that instigates NLRP3-mediated pyroptosis; however, the underlying regulatory mechanisms have yet to be fully elucidated. The present research endeavors to elucidate the regulatory mechanisms underpinning this MSU-induced pyroptotic cascade in GA.

METHODS

J774 cells were exposed to lipopolysaccharide and MSU crystals to establish in vitro GA models, whereas C57BL/6 J male mice received MSU crystal injections to mimic in vivo GA conditions. Gene and protein expression levels were evaluated using real-time quantitative PCR, Western blotting, and immunohistochemical assays. Inflammatory markers were quantified via enzyme-linked immunosorbent assays. Pyroptosis was evaluated using immunofluorescence staining for caspase-1 and flow cytometry with caspase-1/propidium iodide staining. The interaction between MDM2 and PPARγ was analyzed through co-immunoprecipitation assays, whereas the interaction between BRD4 and the MDM2 promoter was examined using chromatin immunoprecipitation and dual-luciferase reporter assays. Mouse joint tissues were histopathologically evaluated using hematoxylin and eosin staining.

RESULTS

In GA, PPARγ was downregulated, whereas its overexpression mitigated NLRP3 inflammasome activation and pyroptosis. MDM2, which was upregulated in GA, destabilized PPARγ through the ubiquitin-proteasome degradation pathway, whereas its silencing attenuated NLRP3 activation by elevating PPARγ levels. Concurrently, BRD4 was elevated in GA and exacerbated NLRP3 activation and pyroptosis by transcriptionally upregulating MDM2, thereby promoting PPARγ degradation. In vivo experiments showed that BRD4 silencing ameliorated GA through this MDM2-PPARγ-pyroptosis axis.

CONCLUSION

BRD4 promotes inflammation and pyroptosis in GA through MDM2-mediated PPARγ degradation, underscoring the therapeutic potential of targeting this pathway in GA management.

Pathogenesis of gout: Exploring more therapeutic target

Gout is a chronic metabolic and immune disease, and its specific pathogenesis is still unclear. When the serum uric acid exceeds its saturation in the blood or tissue fluid, it is converted to monosodium urate crystals, which lead to acute arthritis of varying degrees, urinary stones, or irreversible peripheral joint damage, and in severe cases, impairment of vital organ function. Gout flare is a clinically significant state of acute inflammation in gout. The current treatment is mostly anti-inflammatory analgesics, which have numerous side effects with limited treatment methods. Gout pathogenesis involves many aspects. Therefore, exploring gout pathogenesis from multiple perspectives is conducive to identifying more therapeutic targets and providing safer and more effective alternative treatment options for patients with gout flare. Thus, this article is of great significance for further exploring the pathogenesis of gout. The author summarizes the pathogenesis of gout from four aspects: signaling pathways, inflammatory factors, intestinal flora, and programmed cell death, focusing on exploring more new therapeutic targets.

Aiouea padiformis extract exhibits anti-inflammatory effects by inhibiting the ATPase activity of NLRP3

Inflammation is implicated as a cause in many diseases. Most of the anti-inflammatory agents in use are synthetic and there is an unmet need for natural substance-derived anti-inflammatory agents with minimal side effects. Aiouea padiformis belongs to the Lauraceae family and is primarily found in tropical regions. While some members of the Aiouea genus are known to possess anti-inflammatory properties, the anti-inflammatory properties of Aiouea padiformis extract (AP) have not been investigated. In this study, we aimed to examine the anti-inflammatory function of AP through the NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasome and elucidate the underlying mechanisms. Treatment with AP inhibited the secretion of interleukin-1 beta (IL-1β) mediated by NLRP3 inflammasome in J774A.1 and THP-1 cells without affecting the viability. In addition, AP treatment did not influence NF-κB signaling, potassium efflux, or intracellular reactive oxygen species (ROS) production-all of which are associated with NLRP3 inflammasome activation. However, intriguingly, AP treatment significantly reduced the ATPase activity of NLRP3, leading to the inhibition of ASC oligomerization and speck formation. Consistent with cellular experiments, the anti-inflammatory property of AP in vivo was also evaluated using an LPS-induced inflammation model in zebrafish, demonstrating that AP hinders NLRP3 inflammasome activation.

Roles of the Caspase-11 Non-Canonical Inflammasome in Rheumatic Diseases

Inflammasomes are intracellular multiprotein complexes that activate inflammatory signaling pathways. Inflammasomes comprise two major classes: canonical inflammasomes, which were discovered first and are activated in response to a variety of pathogen-associated molecular patterns (PAMPs) and danger-associated molecular patterns (DAMPs), and non-canonical inflammasomes, which were discovered recently and are only activated in response to intracellular lipopolysaccharide (LPS). Although a larger number of studies have successfully demonstrated that canonical inflammasomes, particularly the NLRP3 inflammasome, play roles in various rheumatic diseases, including rheumatoid arthritis (RA), infectious arthritis (IR), gouty arthritis (GA), osteoarthritis (OA), systemic lupus erythematosus (SLE), psoriatic arthritis (PA), ankylosing spondylitis (AS), and Sjögren's syndrome (SjS), the regulatory roles of non-canonical inflammasomes, such as mouse caspase-11 and human caspase-4 non-canonical inflammasomes, in these diseases are still largely unknown. Interestingly, an increasing number of studies have reported possible roles for non-canonical inflammasomes in the pathogenesis of various mouse models of rheumatic disease. This review comprehensively summarizes and discusses recent emerging studies demonstrating the regulatory roles of non-canonical inflammasomes, particularly focusing on the caspase-11 non-canonical inflammasome, in the pathogenesis and progression of various types of rheumatic diseases and provides new insights into strategies for developing potential therapeutics to prevent and treat rheumatic diseases as well as associated diseases by targeting non-canonical inflammasomes.

Endovascular Interventional Procedure is a Significant Risk Factor of Postsurgical Gout: A Retrospective Cohort Study

INTRODUCTION

Surgery is a risk factor for flares in people with gout. However, gout flares after endovascular interventional procedures are not well understood. The aim of this study was to evaluate the clinical features and risk factors for gout flare that develop during the postsurgical period including endovascular procedures.

METHODS

We enrolled 222 patients with gout who developed postsurgical gout and 196 controls who had histories of gout but did not develop gout flares after surgery within 20 days. Clinical characteristics of patients who developed a postsurgical gout flare were compared with the controls.

RESULTS

The rate of endovascular interventional procedures was higher (38.74% vs. 13.48%, P < 0.001) in the flare group than in the no-flare group and lower in orthopedic surgery (13.96% vs. 41.84%, P < 0.001). The Cox model showed that endovascular interventional procedures (HR, hazard ratio 1.752; 95% CI, confidence interval 1.126-2.724, P = 0.013) and presurgical uric acid levels of ≥ 7 mg/dl (HR 1.489; 95% CI 1.081-2.051, P = 0.015) were significantly associated with increased risks of postsurgical gout flare, and taking colchicine before surgery were significantly associated with decreased risk of postsurgical gout flare (HR 0.264; 95% CI 0.090-0.774, P = 0.015). There was no significant difference in the types of endovascular interventional procedures between the flare group and the no-flare group.

CONCLUSIONS

Patients with a history of gout should be more alert to recurrence gout flares after endovascular interventional procedures. Adequate presurgical control of serum uric acid levels and/or prophylactic treatment with colchicine will help prevent gout flares during the postsurgical period.

Transcriptomic Analysis of THP-1 Cells Exposed by Monosodium Urate Reveals Key Genes Involved in Gout

BACKGROUND

Gout is a common inflammatory arthritis, which is mainly caused by the deposition of monosodium urate (MSU) in tissues. Transcriptomics was used to explore the pathogenesis and treatment of gout in our work.

OBJECTIVE

The objective of the study was to analyze and validate potential therapeutic targets and biomarkers in THP-1 cells that were exposed to MSU.

METHODS

THP-1 cells were exposed to MSU. The inflammatory effect was characterized, and RNA-Seq analysis was then carried out. The differential genes obtained by RNA-Seq were analyzed with gene expression omnibus (GEO) series 160170 (GSE160170) gout-related clinical samples in the GEO database and gout-related genes in the GeneCards database. From the three analysis approaches, the genes with significant differences were verified by the differential genes' transcription levels. The interaction relationship of long non-coding RNA (lncRNA) was proposed by ceRNA network analysis.

RESULTS

MSU significantly promoted the release of IL-1β and IL-18 in THP-1 cells, which aggravated their inflammatory effect. Through RNA-Seq, 698 differential genes were obtained, including 606 differential mRNA and 92 differential `LncRNA. Cross-analysis of the RNA-Seq differential genes, the GSE160170 differential genes, and the gout-related genes in GeneCards revealed a total of 17 genes coexisting in the tripartite data. Furthermore, seven differential genes-C-X-C motif chemokine ligand 8 (CXCL8), C-X-C motif chemokine ligand 2 (CXCL2), tumor necrosis factor (TNF), C-C motif chemokine ligand 3 (CCL3), suppressor of cytokine signaling 3 (SOCS3), oncostatin M (OSM), and MIR22 host gene (MIR22HG)-were verified as key genes that analyzed the weight of genes in pathways, the enrichment of inflammationrelated pathways, and protein-protein interaction (PPI) nodes combined with the expression of genes in RNA-Seq and GSE160170. It is suggested that MIR22HG may regulate OSM and SOCS3 through microRNA 4271 (miR-4271), OSM, and SOCS3m; CCL3 through microRNA 149-3p (miR-149-3p); and CXCL2 through microRNA 4652-3p (miR-4652-3p).

CONCLUSION

The potential of CXCL8, CXCL2, TNF, CCL3, SOCS3, and OSM as gout biomarkers and MIR22HG as a therapeutic target for gout are proposed, which provide new insights into the mechanisms of gout biomarkers and therapeutic methods.

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.

Emodin, a Natural Anthraquinone, Increases Uric Acid Excretion in Rats with Potassium Oxonate-Induced Hyperuricemia

The treatment of hyperuricemia and gout is mostly based on lowering serum uric acid levels using drugs, such as allopurinol, or increasing urinary excretion of uric acid. However, some patients still experience adverse reactions to allopurinol and turn to Chinese medicine as an alternative. Therefore, it is crucial to design a preclinical study to obtain more convincing data on the treatment of hyperuricemia and gout with Chinese medicine. This study aimed to explore the therapeutic effect of emodin, a Chinese herbal extract, in a rat model of hyperuricemia and gout. In this study, we used 36 Sprague-Dawley rats, which were randomly divided into six groups for experimentation. Hyperuricemia was induced in rats by intraperitoneal injections of potassium oxonate. The efficacy of emodin in reducing serum uric acid levels was demonstrated by comparing the positive control group with groups treated with three different concentrations of emodin. The inflammatory profiles, including interleukin (IL)-1β, IL-6, and tumor necrosis factor-α levels, were unaffected by emodin treatment. In the experimental results, it was observed that the serum uric acid concentration in the vehicle control group was 1.80 ± 1.14, while the concentrations in the moderate and high concentration emodin groups were 1.18 ± 0.23 and 1.12 ± 0.57, resulting in no significant difference in uric acid concentration between these treatment groups and the control group, indicating that emodin has a therapeutic effect on hyperuricemia. The increase in the fractional excretion of uric acid (FEUA) demonstrated that emodin promoted urinary uric acid excretion without significantly affecting the inflammatory profile. Thus, emodin reduced the serum uric acid concentration to achieve effective treatment of hyperuricemia and gout by increasing urinary excretion. These results were supported by the measured serum uric acid and FEUA levels. Our data have potential implications for the treatment of gout and other types of hyperuricemia in clinical practice.