Genetic and Epigenetic Regulation of the Innate Immune Response to Gout

Hyperuricemia Exacerbates Experimental Periodontitis via Uric Acid-Induced Periodontal Inflammation and Oxidative Stress

AIM

To investigate the effects of hyperuricemia on periodontitis and the underlying mechanisms by establishing combined animal and cell models.

METHODS

A hyperuricemia mouse model was established by potassium oxonate injection, with sodium carboxymethylcellulose treatment serving as controls. Both models were treated with or without periodontitis induction (n = 10/group). RAW264.7 macrophages and THP-1-derived macrophages were stimulated with Porphyromonas gingivalis -lipopolysaccharide in the presence of normal or excessive concentrations of uric acid. Allopurinol intervention was applied to both animal and cell models. Periodontal destruction was measured by micro-computed tomography and histology. The immune response and oxidative stress in the periodontium and macrophages were assessed using various methods including immunohistochemistry, quantitative PCR, western blotting, flow cytometry and multiplex cytokine assays.

RESULTS

Potassium oxonate successfully induced hyperuricemia without affecting serum glucose/lipid levels or xanthine oxidoreductase activity. In mice with periodontitis, hyperuricemia exacerbated alveolar bone loss and the presence of osteoclasts and M1 macrophages. Mechanistically, hyperuricemia promoted NLRP3 inflammasome activation, disrupted the inflammatory cytokine response and exacerbated oxidative stress both in the periodontium and in vitro. Allopurinol treatment reversed all relevant changes in both mice and macrophages.

CONCLUSION

Hyperuricemia exacerbates periodontitis possibly via uric acid-induced periodontal inflammation and oxidative stress.

Telocyte-derived exosomes promote angiogenesis and alleviate acute respiratory distress syndrome via JAK/STAT-miR-221-E2F2 axis

Acute respiratory distress syndrome (ARDS) is characterized by severe respiratory failure and significant inflammation, leading to vascular and epithelial cell damage. The absence of effective pharmacologic treatments underscores the need for novel therapeutic approaches. Telocytes (TCs), a newly identified type of interstitial cells, have shown potential in tissue repair and angiogenesis, particularly through the release of exosomal microRNAs (miRNAs). Exosomes were isolated from LPS (lipopolysaccharide)-stimulated TCs and characterized using western blotting and nanoparticle tracking analysis. The role of exosomal miR-221 in angiogenesis was assessed through tube formation, migration, and proliferation assays in mouse vascular endothelial cells (MVECs). The JAK/STAT pathway's involvement in miR-221 regulation was determined using western blotting and qRT-PCR. A dual-luciferase assay confirmed E2F2 as a direct target of miR-221. ARDS mouse model was established via LPS instillation, and the therapeutic effects of TCs-derived exosomes were evaluated by histopathological scoring, cytokine analysis, and endothelial barrier integrity assays. Our findings demonstrated that exosomes from LPS-stimulated TCs significantly promoted angiogenesis, proliferation, and migration in MVECs. These effects were mediated by miR-221, which downregulated E2F2 expression, an important regulator of endothelial cell functions. The JAK/STAT pathway played a crucial role in miR-221 production, with pathway inhibition reducing miR-221 levels and attenuating its pro-angiogenic effects. In vivo, TCs-derived exosomes reduced lung inflammation and tissue damage in ARDS mice, effects that were reversed by miR-221 inhibition. These results suggested that TCs-derived exosomes promoted angiogenesis and alleviated ARDS through the JAK/STAT-miR-221-E2F2 axis.

A novel zinc ferrite nanoparticle protects against MSU-induced gout arthritis via Nrf2/NF-κB/NLRP3 pathway

AIMS

Gouty arthritis (GA), a prevalent and intricate form of inflammatory arthritis, affects individuals across all age groups. Existing therapeutic agents for GA are associated with substantial adverse effects. The overarching objective of this study is to identify an efficacious and biocompatible intervention strategy for GA.

MATERIALS AND METHODS

In this investigation, we developed a zinc ferrite nanoparticle (ZFN) characterized by outstanding catalytic activities in anti-inflammatory and antioxidative processes, along with negligible biotoxicity. ZFN features low-content Zn2+ doping, which effectively overcomes the issue of low biocompatibility commonly encountered in Zn-based nanoparticles. Both in vitro and in vivo experimental models were utilized to comprehensively evaluate the effects of ZFN.

KEY FINDINGS

The experimental results demonstrate that ZFN exhibits remarkable efficacy in alleviating inflammation and oxidative stress both in vitro and in vivo. It exerts its therapeutic effect on GA by modulating the NF-κB signaling pathway, suppressing the activation of the NLRP3 inflammasome, and activating the Nrf2 pathway.

SIGNIFICANCE

The protective effect of ZFN against GA holds great promise for the clinical translation of biocompatible inorganic nanoplatforms in the treatment of GA. This finding offers a potential alternative to the currently available medications, thereby providing new insights and possibilities for the management of GA.

Targeting novel regulated cell death: disulfidptosis in cancer immunotherapy with immune checkpoint inhibitors

The battle against cancer has evolved over centuries, from the early stages of surgical resection to contemporary treatments including chemotherapy, radiation, targeted therapies, and immunotherapies. Despite significant advances in cancer treatment over recent decades, these therapies remain limited by various challenges. Immune checkpoint inhibitors (ICIs), a cornerstone of tumor immunotherapy, have emerged as one of the most promising advancements in cancer treatment. Although ICIs, such as CTLA-4 and PD-1/PD-L1 inhibitors, have demonstrated clinical efficacy, their therapeutic impact remains suboptimal due to patient-specific variability and tumor immune resistance. Cell death is a fundamental process for maintaining tissue homeostasis and function. Recent research highlights that the combination of induced regulatory cell death (RCD) and ICIs can substantially enhance anti-tumor responses across multiple cancer types. In cells exhibiting high levels of recombinant solute carrier family 7 member 11 (SLC7A11) protein, glucose deprivation triggers a programmed cell death (PCD) pathway characterized by disulfide bond formation and REDOX (reduction-oxidation) reactions, termed "disulfidptosis." Studies suggest that disulfidptosis plays a critical role in the therapeutic efficacy of SLC7A11high cancers. Therefore, to investigate the potential synergy between disulfidptosis and ICIs, this study will explore the mechanisms of both processes in tumor progression, with the goal of enhancing the anti-tumor immune response of ICIs by targeting the intracellular disulfidptosis pathway.

Single-Cell Sequencing and Machine Learning Integration to Identify Candidate Biomarkers in Psoriasis: INSIG1

Background

Psoriasis represents a persistent, immune-driven inflammatory condition affecting the skin, characterized by a lack of well-established biologic treatments without adverse events. Consequently, the identification of novel targets and therapeutic agents remains a pressing priority in the field of psoriasis research.

Methods

We collected single-cell RNA sequencing (scRNA-seq) datasets and inferred T cell differentiation trajectories through pseudotime analysis. Bulk transcriptome and scRNA-seq data were integrated to identify differentially expressed genes (DEGs). Machine learning was employed to screen candidate genes. Correlation analysis was used to predict the interactions between cells expressing insulin-induced gene 1 (INSIG1) and other immune cells. Finally, drug docking was performed on INSIG1, and the expression levels of INSIG1 in psoriasis were verified through clinical and in vivo experiments, and further in vivo experiments established the efficacy of tetrandrine in the treatment of psoriasis.

Results

T cells were initially categorized into seven states, with differentially expressed genes in T cells (TDEGs) identified and their functions and signaling pathways. INSIG1 emerged as a characteristic gene for psoriasis and was found to be downregulated in psoriasis and potentially negatively associated with T cells, influencing psoriasis fatty acid metabolism, as inferred from enrichment and immunoinfiltration analyses. In the cellular communication network, cells expressing INSIG1 exhibited close interactions with other immune cells through multiple signaling channels. Furthermore, drug sensitivity showed that tetrandrine stably binds to INSIG1, could be a potential therapeutic agent for psoriasis.

Conclusion

INSIG1 emerges as a specific candidate gene potentially regulating the fatty acid metabolism of patients with psoriasis. In addition, tetrandrine shows promise as a potential treatment for the condition.

Targeting IL-17 and its receptors: A feasible way for natural herbal medicines to modulate fibroblast-like synoviocytes in rheumatoid arthritis

Rheumatoid arthritis (RA) is characterized by processive synovial hyperplasia and abnormal proliferation of fibroblast-like synoviocytes (FLSs), and can eventually lead to progressive joint destruction. Increasing evidence has demonstrated that cytokines play pivotal roles in the pathogenesis of RA. In particular, the production of interleukin (IL)-17 by T helper 17 (Th17) cells is closely associated with the development of RA, and inhibition of IL-17/IL-17R could regulate the production of inflammatory factors by FLSs, which may be a feasible way to reduce inflammation and bone destruction in RA. Currently, accumulating evidence suggests that the utilization of natural herbal medicines is advantageous in the management of RA. In our present paper, a comprehensive reference search was conducted of the classic Materia Medica books, literature, online databases, academic search engines, and MS. or Ph. D theses. In conclusion, natural herbal medicines with antirheumatic activities that modulate FLSs by targeting IL-17/IL-17R were summarized. Furthermore, we also discuss the limitations and potential research directions for the future development of natural herbal medicines as candidate drugs for RA management in the clinic.

Hyperuricemia and elevated uric acid/creatinine ratio are associated with stages III/IV periodontitis: a population-based cross-sectional study (NHANES 2009-2014)

OBJECTIVES

To explore the association between hyperuricemia and having periodontitis.

MATERIALS AND METHODS

A representative cross-sectional dataset of 10,158 adults was extracted from the National Health and Nutrition Examination Survey (NHANES) 2009-2014. The association between hyperuricemia (the primary exposure) and having periodontitis (outcome) were evaluated using weighted logistic regression models. Serum uric acid (UA) levels and the UA to creatinine (UA/Cr) ratio were used as secondary exposures. Their associations with the diagnosis periodontitis were analyzed using weighted logistic regression or restricted cubic spline regression.

RESULTS

The prevalence of Stages III/IV periodontitis was 47.7% among individuals with hyperuricemia and 37.4% among those without. After adjustment, individuals with hyperuricemia had 0.281 times higher odds of developing Stages III/IV periodontitis compared to those without hyperuricemia (adjusted OR = 1.286, 95% CI = 1.040 to 1.591, P = 0.024). The increased odds could be explained by a linear relationship with the serum UA/Cr ratio and a U-shaped relationship with serum UA levels. Each unit increase in the serum UA/Cr ratio was associated with 0.048 times higher odds of developing Stages III/IV periodontitis (adjusted OR = 1.048, 95% CI = 1.008 to 1.088, P = 0.021). Additionally, each 1 mg/dL increase in serum UA was associated with 0.156 times higher odds (adjusted OR = 1.156, 95% CI = 1.009 to 1.323, P = 0.038) of developing Stages III/IV periodontitis when UA levels were greater than 5.9 mg/dL, but 0.118 times lower odds when UA levels were 5.9 mg/dL or lower (adjusted OR = 0.882, 95% CI = 0.790 to 0.984, P = 0.027). Sensitivity analyses validated the robustness of the findings.

CONCLUSIONS

This study provides the first direct evidence that hyperuricemia is associated with Stages III/IV periodontitis.

CLINICAL RELEVANCE

Hyperuricemia may represent a new potential comorbidity of periodontitis, possibly contributing directly or indirectly to the disease burden in patients with periodontitis.

CLINICAL TRIAL NUMBER

Not applicable.

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.

Euphorbia factor L2 alleviated gouty inflammation by specifically suppressing both the priming and activation of NLRP3 inflammasome

Euphorbia L. is a traditionally used herb and contains many newly identified compounds with novel chemical structures. Euphorbia factor L2 (EFL2), a diterpenoid derived from Euphorbia seeds, is reported to alleviate acute lung injury and arthritis by exerting anti-inflammatory effects. In this study, we aimed to test the therapeutic benefit and mechanisms of EFL2 in NLRP3 inflammasome-mediated gouty models and identified the potential molecular mechanism. A cell-based system was used to test the specific inhibitory effect of EFL2 on NLRP3-related inflammation. The gouty arthritis model and an air pouch inflammation model induced by monosodium urate monohydrate (MSU) crystals were used for in vivo experiments. Nlrp3-/- mice and in vitro studies were used for mechanistic exploration. Virtual molecular docking and biophysical assays were performed to identify the direct binding and regulatory target of EFL2. The inhibitory effect of EFL2 on inflammatory cell infiltration was determined by flow cytometry in vivo. The mechanism by which EFL2 activates the NLRP3 inflammasome signaling pathway was evaluated by immunological experiment and transmission electron microscopy. In vitro, EFL2 specifically reduced NLRP3 inflammasome-mediated IL-1β production and alleviated MSU crystal-induced arthritis, as well as inflammatory cell infiltration. EFL2 downregulated NF-κB phosphorylation and NLRP3 inflammasome expression by binding to glucocorticoid receptors. Moreover, EFL2 could specifically suppress the lysosome damage-mediated NLRP3 inflammasome activation process. It is expected that this work may be useful to accelerate the development of anti-inflammatory drugs originated from traditional herbs and improve therapeutics in gout and its complications.

Exosomes derived from miR-146a-overexpressing fibroblast-like synoviocytes in cartilage degradation and macrophage M1 polarization: a novel protective agent for osteoarthritis?

Introduction

Pathological changes in the articular cartilage (AC) and synovium are major manifestations of osteoarthritis (OA) and are strongly associated with pain and functional limitations. Exosome-derived microRNAs (miRNAs) are crucial regulatory factors in intercellular communication and can influence the progression of OA by participating in the degradation of chondrocytes and the phenotypic transformation in the polarization of synovial macrophages. However, the specific relationships and pathways of action of exosomal miRNAs in the pathological progression of OA in both cartilage and synovium remain unclear.

Methods

This study evaluates the effects of fibroblast-like synoviocyte (FLS)-derived exosomes (FLS-Exos), influenced by miR-146a, on AC degradation and synovial macrophage polarization. We investigated the targeted relationship between miR-146a and TRAF6, both in vivo and in vitro, along with the involvement of the NF-κB signaling pathway.

Results

The expression of miR-146a in the synovial exosomes of OA rats was significantly higher than in healthy rats. In vitro, the upregulation of miR-146a reduced chondrocyte apoptosis, whereas its downregulation had the opposite effect. In vivo, exosomes derived from miR-146a-overexpressing FLSs (miR-146a-FLS-Exos) reduced AC injury and chondrocyte apoptosis in OA. Furthermore, synovial proliferation was reduced, and the polarization of synovial macrophages shifted from M1 to M2. Mechanistically, the expression of TRAF6 was inhibited by targeting miR-146a, thereby modulating the Toll-like receptor 4/TRAF6/NF-κB pathway in the innate immune response.

Discussion

These findings suggest that miR-146a, mediated through FLS-Exos, may alleviate OA progression by modulating cartilage degradation and macrophage polarization, implicating the NF-κB pathway in the innate immune response. These insights highlight the therapeutic potential of miR-146a as a protective agent in OA, underscoring the importance of exosomal miRNAs in the pathogenesis and potential treatment of the disease.

The occurrence and development of induced pluripotent stem cells

The ectopic expression of four transcription factors, Oct3/4, Sox2, Klf4, and c-Myc (OSKM), known as "Yamanaka factors," can reprogram or stimulate the production of induced pluripotent stem cells (iPSCs). Although OSKM is still the gold standard, there are multiple ways to reprogram cells into iPSCs. In recent years, significant progress has been made in improving the efficiency of this technology. Ten years after the first report was published, human pluripotent stem cells have gradually been applied in clinical settings, including disease modeling, cell therapy, new drug development, and cell derivation. Here, we provide a review of the discovery of iPSCs and their applications in disease and development.

The interaction of inflammasomes and gut microbiota: novel therapeutic insights

Inflammasomes are complex platforms for the cleavage and release of inactivated IL-1β and IL-18 cytokines that trigger inflammatory responses against damage-associated molecular patterns (DAMPs) or pathogen-associated molecular patterns (PAMPs). Gut microbiota plays a pivotal role in maintaining gut homeostasis. Inflammasome activation needs to be tightly regulated to limit aberrant activation and bystander damage to the host cells. Several types of inflammasomes, including Node-like receptor protein family (e.g., NLRP1, NLRP3, NLRP6, NLRP12, NLRC4), PYHIN family, and pyrin inflammasomes, interact with gut microbiota to maintain gut homeostasis. This review discusses the current understanding of how inflammasomes and microbiota interact, and how this interaction impacts human health. Additionally, we introduce novel biologics and antagonists, such as inhibitors of IL-1β and inflammasomes, as therapeutic strategies for treating gastrointestinal disorders when inflammasomes are dysregulated or the composition of gut microbiota changes.

The intricate dance of tumor evolution: Exploring immune escape, tumor migration, drug resistance, and treatment strategies

Recent research has unveiled fascinating insights into the intricate mechanisms governing tumor evolution. These studies have illuminated how tumors adapt and proliferate by exploiting various factors, including immune evasion, resistance to therapeutic drugs, genetic mutations, and their ability to adapt to different environments. Furthermore, investigations into tumor heterogeneity and chromosomal aberrations have revealed the profound complexity that underlies the evolution of cancer. Emerging findings have also underscored the role of viral influences in the development and progression of cancer, introducing an additional layer of complexity to the field of oncology. Tumor evolution is a dynamic and complex process influenced by various factors, including immune evasion, drug resistance, tumor heterogeneity, and viral influences. Understanding these elements is indispensable for developing more effective treatments and advancing cancer therapies. A holistic approach to studying and addressing tumor evolution is crucial in the ongoing battle against cancer. The main goal of this comprehensive review is to explore the intricate relationship between tumor evolution and critical aspects of cancer biology. By delving into this complex interplay, we aim to provide a profound understanding of how tumors evolve, adapt, and respond to treatment strategies. This review underscores the pivotal importance of comprehending tumor evolution in shaping effective approaches to cancer treatment.

The dysregulation of immune cells induced by uric acid: mechanisms of inflammation associated with hyperuricemia and its complications

Changes in lifestyle induce an increase in patients with hyperuricemia (HUA), leading to gout, gouty arthritis, renal damage, and cardiovascular injury. There is a strong inflammatory response in the process of HUA, while dysregulation of immune cells, including monocytes, macrophages, and T cells, plays a crucial role in the inflammatory response. Recent studies have indicated that urate has a direct impact on immune cell populations, changes in cytokine expression, modifications in chemotaxis and differentiation, and the provocation of immune cells by intrinsic cells to cause the aforementioned conditions. Here we conducted a detailed review of the relationship among uric acid, immune response, and inflammatory status in hyperuricemia and its complications, providing new therapeutic targets and strategies.

Hyperuricemia remodels the serum proteome toward a higher inflammatory state

Gout is an autoinflammatory disease triggered by a complex innate immune response to MSU crystals and inflammatory triggers. While hyperuricemia is an obligatory risk factor for the development of gout, the majority of individuals with hyperuricemia never develop gout but have an increased risk of developing cardiometabolic disorders. Current management of gout aims at MSU crystal dissolution by lowering serum urate. We apply a targeted proteomic analysis, using Olink inflammation panel, to a large group of individuals with gout, asymptomatic hyperuricemia, and normouricemic controls, and we show a urate-driven inflammatory signature. We add in vivo evidence of persistent immune activation linked to urate exposure and describe immune pathways involved in the pathogenesis of gout. Our results support a pro-inflammatory effect of asymptomatic hyperuricemia and pave the way for new research into targetable mechanisms in gout and cardiometabolic complications of asymptomatic hyperuricemia.

An elevated likelihood of stroke, ischemic heart disease, or heart failure in individuals with gout: a longitudinal follow-up study utilizing the National Health Information database in Korea

Objective

Accumulating evidence from other countries indicates potential associations between gout and cardiovascular diseases; however, the associations of gout with cardiovascular diseases, particularly stroke, ischemic heart disease, and heart failure, remain ambiguous in the Korean population. We hypothesized that individuals with gout are at a higher likelihood of stroke, ischemic heart disease, or heart failure. This study expands upon previous research by ensuring a comparable baseline between patient and control groups and analyzing 16 years of data derived from an extensive healthcare database.

Methods

We selected 22,480 patients with gout and 22,480 control individuals from the Korean National Health Insurance Service-Health Screening Cohort database (2002-2019), and matched them at a 1:1 ratio according to sex, age, income, and residence. A Cox proportional hazard model with weighted overlap was employed to examine the relationship between gout and the risk of stroke, ischemic heart disease, or heart failure after adjustment for several covariates.

Results

The incidences of stroke, ischemic heart disease, or heart failure in participants with gout were slightly higher than those in controls (stroke: 9.84 vs. 8.41 per 1000 person-years; ischemic heart disease: 9.77 vs. 7.15 per 1000 person-years; heart failure: 2.47 vs. 1.46 per 1000 person-years). After adjustment, the gout group had an 11% (95% confidence interval [CI] = 1.04-1.19), 28% (95% CI = 1.19-1.37), or 64% (95% CI = 1.41-1.91) higher likelihood of experiencing stroke, ischemic heart disease, or heart failure, respectively, than the control group.

Conclusion

The present findings suggest that individuals with gout in the Korean population, particularly those aged ≥ 60 years, were more likely to have stroke, ischemic heart disease, or heart failure.

Meta-analysis of the Prognostic Value of microRNA-22 in Leukemia Patients

Objective: The pathogenesis of leukemia is complex and there are no effective diagnostic and prognostic indicators. Previous studies showed that microRNA-22 (miR-22) has altered expression level in multiple leukemia subtypes, which is associated with the survival outcomes of leukemia. Methods: According to the constituted retrieval strategy, eligible studies were included from January 2010 to November 2022 by searching database. The pooled Risk Ratio (RR) and 95% confidence intervals (CI) were used to study the relationship between miR-22 and survival. Stata12.0 was used for meta-analysis. Differential expression analysis was conducted based on expression profile of miRNA. Results: Four English articles were included containing a total of 215 leukemia patients. Data showed that the pooled RR for overall survival (OS) was 1.558 (95% CI: 1.197-2.028, P < .01). Subgroup analysis for OS of acute myeloid leukemia patients and the RFS of plasma cell leukemia patients were statistically significant with different expression levels of miR-22 (RR:1.495, 95%CI:1.141-1.958, P < .01 and RR:1.517, 95%CI:1.114-2.065, P < .01, respectively). Moreover, all data included had no significant heterogeneity and publication bias. Conclusions: miR-22 is associated with the survival outcome of leukemia patients suggesting that miR-22 may be a promising prognostic biomarker for this patient population, and the expression level of miR-22 in ALL patients down-regulated.