Association of Toll-like receptor 2 polymorphisms with gout

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

OBJECTIVES

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

IL1A regulates the inflammation in gout through the Toll-like receptors pathway

Objective: Gout is a dangerous metabolic condition related to monosodium urate (MSU). Our aim is to study the molecular mechanisms underlying gout and to identify potential clinical biomarkers by bioinformatics analysis and experimental validation. Methods: In this study, we retrieved the overlapping genes between GSE199950-Differential Expressed Genes (DEGs) dataset and key module in Weighted Gene Co-Expression Network Analysis (WGCNA) on GSE199950. These genes were then analyzed by protein-protein interaction (PPI) network, expression and Gene Set Enrichment Analysis to identify the hub gene related to gout. Then, the gene was investigated by peripheral blood mononuclear cells (PBMCs), immunoassay and cell experiments like western blotting to uncover its underlying mechanism in gout cells. Results: From the turquoise module and 83 DEGs, we identified 62 overlapping genes, only 11 genes had mutual interactions in PPI network and these genes were highly expressed in MSU-treated samples. Then, it was found that the IL1A (interleukin 1 alpha) was the only one gene related to Toll-like receptor signaling pathway that was associated with the occurrence of gout. Thus, IL1A was determined as the hub gene in this study. In immunoassay, IL1A was significantly positively correlated with B cells and negatively correlated with macrophages. Moreover, IL1A is highly expressed in gout patients,it has a good clinical diagnostic value. Finally, the results of in vitro experiments showed that after knocking down IL1A, the expressions of pro-inflammatory cytokines and Toll-like receptor signaling pathway-related proteins (TLR2, TLR4, MyD88) were all reduced. Conclusion: It is confirmed that IL1A is a promoting gene in gout with a good diagnostic value, and specifically it affects the inflammation in gout through Toll-like receptor pathway. Our research offers fresh perspectives on the pathophysiology of gout and valuable directions for future diagnosis and treatment.

Toll-like receptor 10 gene polymorphism and risk of multiple sclerosis among Iraqi patients

Background

Toll-like receptors (TLRs) are a family of 10 pattern recognition receptors (TLR1–TLR10) involved in the regulation of inflammatory and immune responses besides their role in the pathogenesis of autoimmune diseases including multiple sclerosis (MS). TLR10 is the least studied TLR in MS, and data for single nucleotide polymorphisms (SNPs) of the TLR10 gene are limited. Therefore, a case–control study was performed on 85 patients with relapsing–remitting MS and 86 healthy controls (HC) to explore SNPs in the promoter region of TLR10 gene. A 927-bp region was amplified, and Sanger sequencing identified 10 SNPs with a minor allele frequency ≥ 10% (rs200395112 T/A, rs201802754 A/T, rs201228097 T/A, rs113588825 G/A, rs10004195 T/A, rs10034903 C/G, rs10012016 G/A/C, rs10012017 G/T, rs33994884 T/Deletion [Del] and rs28393318 A/G).

Results

Del allele and T/Del genotype of rs33994884, as well as AG genotype of rs28393318, showed significantly lower frequencies in MS patients compared to HC. Allele and genotype frequencies of the 10 SNPs showed no significant differences between MS patients classified according to the Expanded Disability Status Scale. Haplotype analysis revealed that haplotype A-T-A-G-A-G-G-T-A showed a significantly increased frequency in MS patients compared to HC (odds ratio [OR] = 9.70; 95% confidence interval [CI] = 1.28–73.31; corrected probability [pc] = 0.03), while frequency of A-T-A-G-T-C-A-T-G haplotype was significantly decreased (OR = 0.10; 95% CI = 0.01–0.85; pc = 0.05).

Conclusions

The study indicated that two SNPs may influence susceptibility to MS (rs33994884 and rs28393318), but haplotype analysis of TLR10 gene SNPs was more informative.

Bioinformatic Analysis and Cellular Assays Identify Substance P Influencing Th17/Treg Differentiation via the MyD88 Pathway as a Potential Contributor to the Progression of Asthma and Allergic Rhinitis

Objective

This study is aimed at investigating the role of substance P (SP) in the development of asthma.

Methods

The Gene Expression Omnibus (GEO) database was used to characterize SP expression in allergic rhinitis (AR) and asthma. Peripheral blood was collected from patients with asthma or AR. The expression of relevant cytokines and neuropeptides was measured. Enzyme-linked immunosorbent assay (ELISA) was also performed. The mast cell line LAD2 and the lung bronchial epithelial cell line BEAS-2B were treated with different concentrations of SP concentration. Then, the qRT-PCR method was used to determine the mRNA expression. Furthermore, p38 and p65 and their associated phosphorylated proteins (p-p38 and p-p65) were further validated by western blotting.

Result

Clinical and GSE75011 data analysis suggested that MyD88 expression was upregulated in AR and asthma. Through the gene set variation analysis (GSVA), MyD88-related pathways were noticed and further investigated. ELISA results suggested that the SP expression was significantly increased in AR and asthma and IL-10 expression was decreased, whereas the expression of IL-6, IL-17A, IL-23, and TGF-β expressions increased. The mast cell line LAD2 was treated with different SP concentrations, and ELISA results showed that the expression of IL-6, IL-17A, IL-23, and TGF-β in the cell supernatant gradually increased with increasing SP concentrations, whereas that of IL-10 decreased. The lung bronchial epithelial cell line BEAS-2B was treated with different SP concentrations, and the expression of myeloid differentiation factor 88 (MyD88) and its related proteins was elevated. The expression of p38 and p-p38 proteins was elevated after SP treatment, and their expression levels elevated as SP concentrations increased. Finally, MyD88 expression at the single-cell level was also demonstrated.

Conclusion

SP may affect the cytokine expression through the MyD88 pathway, thereby influencing Th17/Treg differentiation and eventually participating in the pathological process of asthma and AR. There are many pathological similarities between allergic rhinitis (AR) and bronchial asthma. In the present study, SP was found to possibly activate downstream inflammatory signaling pathways via MyD88, thereby affecting Th17/Treg differentiation and ultimately participating in the pathological process of asthma and AR.

Isovitexin alleviates acute gouty arthritis in rats by inhibiting inflammation via the TLR4/MyD88/NF-κB pathway

CONTEXT

The prevalence of gout has greatly increased, and it has become the most common inflammatory arthritis in men. Isovitexin possesses anti-inflammatory and antioxidant properties.

OBJECTIVE

We explored the effects of isovitexin on rats with acute gouty arthritis (GA).

MATERIALS AND METHODS

Fifty-four Sprague-Dawley rats were assigned to five groups: sham, model, positive (colchicine, 0.3 mg/kg), isovitexin (100 mg/kg), TLR4 inhibitor (TAK-242, 3 mg/kg) and isovitexin + TAK-242. The gait of rats and the ankle joint swelling index were monitored. The levels of tumour necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and IL-6, and pathological changes in the synovial tissues were determined.

RESULTS

Isovitexin significantly reduced the ankle joint swelling index at day 7 compared to that in the model group (4.39 ± 1.01 vs. 6.09 ± 1.31). Moreover, isovitexin alleviated the infiltration of inflammatory cells and ameliorated the proliferation of synovial cells. The levels of TNF-α (93.42 ± 5.02 pg/mL), IL-1β (25.46 ± 1.91 pg/mL) and IL-6 (194.71 ± 7.92 pg/mL) in the isovitexin group were significantly lower than in the model group (129.39 ± 5.43, 39.60 ± 2.71 and 223.77 ± 5.35 pg/mL). The expression of TLR4, MyD88 and p-NF-κB-p65 was remarkably decreased after isovitexin and colchicine treatment. The effect of isovitexin was similar to that colchicine. Furthermore, the combination of isovitexin and TAK-242 had better effect, and there was no significantly difference with colchicine treatment.

DISCUSSION AND CONCLUSIONS

Isovitexin ameliorates joint inflammation in acute GA via the TLR4/MyD88/NF-κB pathway. Isovitexin may be a potential substitute medicine for GA.

The current role of NLRP3 inflammasome polymorphism in gout susceptibility

INTRODUCTION

The NLR family pyrin domain containing 3 (NLRP3) signaling pathway has an important role in inflammation mediated by monosodium urate crystals in gout, and the characterization of single nucleotide polymorphisms (SNPs) have helped to recognize disease susceptibility.

OBJECTIVE

The aim of this review is to provide an overview of the potential role of the inflammasome gene SNPs as a susceptibility factor for gout, discussing the current evidence available.

METHODS

This review analyzes the relevant literature in the field of inflammasome SNPs and gout published in the last 10 years. The systematic research was performed in 16 articles, including both the SNPs associated and those not associated with gout, with the goal to have a complete overview.

RESULTS

Sixty-nine SNPs from 10 different genes have been reported in the literature. Of these, 13 SNPs present association with gout susceptibility in different populations, while 56 have been established as not being associated with the disease.

CONCLUSIONS

This review is a summary of the potential role of inflammasome gene SNPs and their association with gout risk, all of them related with NLRP3 inflammasome signaling, suggesting these polymorphisms are susceptibility candidates and genetic markers for gout. From the 69 SNPs analyzed in the literature, 13 of them have been associated with gout as follows: NLRP3 (rs3806268 and rs10754558), CARD8 (rs2043211), TLR4 (rs2149356), CD14 (rs2569190), IL-1β (rs1143623), P2RX7 (rs2230911, rs1653624, rs7958316 and rs17525809) and PPARGC1B (rs45520937, rs10491360 and rs7712296) in different populations.

PECULIARITIES OF TLR-2 (ARG753GLN) AND TLR-4 (ASP299GLY) POLYMORPHISM PREVALENCE IN PATIENTS WITH ACUTE BRUCELLEIS AND CARDIOVASCULAR SYSTEM DISEASES

Currently, there are single data on the relationship between TLR-2 polymorphisms (Arg753Gln) and TLR-4 (Asp299Gly) polymorphisms and susceptibility to brucellosis. Therefore, the aim of the study was to determine the frequency of TLR-2 (Arg753Gln) and TLR-4 (Asp299Gly) polymorphisms in patients with acute brucellosis with cardiovascular lesions in the Republic of Azerbaijan. Materials and methods: 178 patients with a brucellosis clinic were examined. According to the criteria for inclusion in the study, only 120 people fully met all the criteria, which made up the main group. The control group consisted of 30 healthy individuals. TLR-2 (Arg753Gln) and TLR-4 (Asp299Gly) polymorphisms were also determined for all patients in both groups. In order to assess the state of the cardiovascular system, an electrocardiogram was recorded, blood pressure was measured, and an ultrasound scan of the heart was performed for all patients. Results: it was found that 93 patients (77.50±3.13 %) with acute brucellosis had some or other signs of impairment in the work of the cardiovascular system, identified clinically or as a result of functional examination. Among carriers of the Asp / Gly genotype of the TLR-4 gene, an increased risk of brucellosis with CVS diseases was determined (χ2=30.19; p <0.0001; OR=24.29; 95 % CI [5.45 – 108.37]), while the carriage of the homozygous genotype Asp / Asp, by contrast, had a protective effect on the development of brucellosis (OR=0.06, 95 % CI [0.02 – 0.20]). Among the carriers of the Arg / Gln genotype and the Gln / Gln genotype of the TLR-2 gene, a significantly increased risk of brucellosis with CVS diseases was determined (χ2=5.68; p=0.02; OR=3.10; 95 % CI [0.99 – 9.67]) and (OR=2.48; 95 % CI [0.53 – 11.61]), respectively. While the carriage of the homozygous Arg / Arg genotype, by contrast, was rarely seen in patients with brucellosis (OR=0.28, 95 % CI [0.10 – 0.74]). Conclusions: The Asp / Gly genotype of the TLR-4 gene was 12.7 times more frequently detected in patients with acute brucellosis with CVS diseases than in healthy individuals and 9.5 times more often than in patients without CVS diseases (p<0.05). The Arg / Gln genotype of the TLR-2 gene was 2.4 times more frequently detected in patients with acute brucellosis with CVS diseases than in healthy individuals (p<0.05).

ABCG2 contributes to the development of gout and hyperuricemia in a genome-wide association study

Although many genome-wide association studies (GWASs) of hyperuricemia or gout have been reported, the related genetic factors and the mechanisms from hyperuricemia to gouty attack remain unclear. This study aimed to identify genetic factors and pathogenesis of gout from hyperuricemia by genome-wide association study (GWAS). 747 gout patients, 747 hyperuricemia and 2071 age-matched controls were recruited and analyzed with Affymetrix 650 K chip to find the related genetic variants. The functions of the related genes were investigated in an endothelial cell (EC) with urate crystal stimulation. The GWAS results showed 36 SNPs to be strongly associated with gout compared to controls (all p-values < 10⁻⁷). Whereas the rs2231142 in ABCG2 gene had significant associations between gout and controls, between gout and hyperuricemia, and between hyperuricemia and controls (all p-values < 10⁻⁷), and the ORs were 4.34, 3.37 and 2.15 (all p-values < 0.001) after adjustment of potential confounders, respectively. The cell model showed significantly higher IL-8 release from EC combined with ABCG2 knockdown. We concluded that ABCG2 gene contributed to hyperuricemia but also gout, and that it was involved in the inflammation dysregulation via augmented IL-8 release in EC.

Influence of the total saponin fraction from Dioscorea nipponica Makino on TLR2/4-IL1R receptor singnal pathway in rats of gouty arthritis

ETHNOPHARMACOLOGICAL RELEVANCE

Dioscorea nipponica Makino have been extensively used in traditional medicine for the treatment of arthritic diseases, particularly gouty arthritis (GA).

MATERIALS AND METHODS

Sixty male Wistar rats were divided into six groups: the normal group, model group, colchicine group (COL) and three total saponin groups (RDN) (high dose [160mg/kg], middle dose [80mg/kg] and low dose [40mg/kg]). The mRNA and protein expression levels of TLR2, TLR4, IRAK1, TRAF6, TAK1, IKKα, IκBα and NF-κB in the synovial tissue of joint were detected by realtime PCR and WB methods respectively. The contents of IL-1β, IL-6 and TNF-α in the blood serum were measured by Elisa method. The activation of NF-κB was measured by EMSA method.

RESULTS

Our study showed that RDN decreased both the mRNA and protein expressions of TLR2, TLR4, IRAK1, TRAF6, TAK1, IKKα, IκBα and NF-κB of the synovial tissue of joint of rats induced with monosodium urate crystal (MSU). They could also reduce the levels of IL-1β, IL-6 and TNF-α in the blood serum. Further, EMSA results showed that RDN reduced the DNA binding ability of NF-κB p65 of model group.

CONCLUSION

RDN has the effect of anti-inflammation in MSU-induced GA model. This is realised by influencing an important inflammatory signal pathway which is called TLR2/4-IL1R receptor signal pathway. It highlights the potential utility of RDN for the management of GA.

Clinical significance of the single nucleotide polymorphism TLR2 R753Q in heart transplant recipients at risk for cytomegalovirus disease

BACKGROUND

The toll-like receptor 2 (TLR2) is a significant component of innate immunity against cytomegalovirus (CMV) infection but information on the clinical significance of the single nucleotide polymorphism (SNP) (R753Q) is conflicting.

OBJECTIVES

The inconsistent observations of the immunological and clinical significance of the TLR2 R753Q polymorphism for CMV infection indicates the influence of confounders.

STUDY DESIGN

The presence of the TLR2 polymorphism was determined by a genotyping assay of 175 HTX patients and 281 healthy blood donors and evaluated in relation to selected virological and clinical parameters.

RESULTS

Relative frequency of TLR2 polymorphism was similar in HTX patients and blood donors (homozygous wild-type, 94.3% vs. 94.0%; heterozygous, 5.1% vs. 5.7%; homozygous mutated, <1%). CMV viremia was detectable in 108 (61.7%) of HTX patients. The TLR2 polymorphism was neither associated with occurrence or level of CMV infection nor with survival, graft failure or rejection, or CMV serostatus of patient before transplantation. Nevertheless, CMV viremia occurred in 83.1% of R+/D+, 77.1% of R+/D-, and 64.3% of R-/D+ patients. Time of first CMV viremia was in R-/D+ patients later than in CMV-seropositive patients (median, 182days versus 23 days; P<0.001) corresponding to the duration of antiviral prophylaxis in R-/D+ patients.

CONCLUSIONS

The TLR2 R753Q polymorphism is extremely rare in the general population and HTX patients. Screening for this risk factor of CMV disease may not be cost-effective in contrast to testing for CMV viremia.

Increased Risk of Cancer in relation to Gout: A Review of Three Prospective Cohort Studies with 50,358 Subjects

Gout is a common inflammatory disease characterized by acute arthritis and hyperuricemia. A number of epidemiological studies have suggested the critical role of gout in carcinogenesis. The aim of this study was to estimate the association between gout and cancer risk by meta-analysis of all relevant studies published to date. A comprehensive literature search in PubMed and Embase databases from their inception up to July 1, 2014, was performed to identify eligible studies. The strength for relationship between gout and the risk of different cancers was evaluated by calculating pooled relative risks (RRs) with 95% confidence intervals (95% CIs). All analyses were carried out by STATA 12.0 software. Gout patients were at an increased risk of cancer, particularly urological cancers, digestive system cancers, and lung cancer. No such significant association between gout and the risk of breast or brain cancers was observed. Sensitivity analysis did not materially alter the pooled results. Gout is a risk factor of cancer, particularly that of urological cancers, digestive system cancers, and lung cancer. The pooled data further support the hypothesis of a link between gout and carcinogenesis.

Frequency of P2RX7 A1513C and TLR2 -196 to -174 ins/del in healthy Polish individuals

Polymorphisms within genes coding innate immune response proteins are involved in genetic susceptibility to various conditions. We investigated the frequency of P2RX7 A1513C and TLR2 -196 to -174 ins/del polymorphisms in healthy Polish population. Frequency of minor alleles was relatively similar to the pattern presented by Caucasian populations while it differed significantly when compared to non-European populations, which could be a result of variable selection pressure put upon studied alleles or hindered gene flow between populations.