Induction of macrophage migration inhibitory factor in ConA-stimulated rheumatoid arthritis synovial fibroblasts through the P38 map kinase-dependent signaling pathway

Omega-3 long-chain polyunsaturated fatty acids: Metabolism and health implications

Recently, omega-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFAs) have gained substantial interest due to their specific structure and biological functions. Humans cannot naturally produce these fatty acids (FAs), making it crucial to obtain them from our diet. This comprehensive review details n-3 LC-PUFAs and their role in promoting and maintaining optimal health. The article thoroughly analyses several sources of n-3 LC-PUFAs and their respective bioavailability, covering marine, microbial and plant-based sources. Furthermore, we provide an in-depth analysis of the biological impacts of n-3 LC-PUFAs on health conditions, with particular emphasis on cardiovascular disease (CVD), gastrointestinal (GI) cancer, diabetes, depression, arthritis, and cognition. In addition, we highlight the significance of fortification and supplementation of n-3 LC-PUFAs in both functional foods and dietary supplements. Additionally, we conducted a detailed analysis of the several kinds of n-3 LC-PUFAs supplements currently available in the market, including an assessment of their recommended intake, safety, and effectiveness. The dietary guidelines associated with n-3 LC-PUFAs are also highlighted, focusing on the significance of maintaining a well-balanced intake of n-3 PUFAs to enhance health benefits. Lastly, we highlight future directions for further research in this area and their potential implications for public health.

Anti‑inflammatory effects of gambogic acid in murine collagen‑induced arthritis through PI3K/Akt signaling pathway

Garcinia angustifolia is a dry resin secreted by Garcinia cambogia, which has the functions of breaking blood, detoxifying, stopping bleeding and killing insects. It is used for the treatment of cancer and brain edema. Gambogic acid is the primary active ingredient. The present study aimed to investigate the anti‑inflammatory and antiproliferative effects of gambogic acid on arthritis and the possible mechanisms. It was demonstrated that gambogic acid decreased arthritic scores in murine collagen‑induced arthritic mice. The tumor necrosis factor (TNF)‑α, interleukin (IL)‑1β, IL‑6 and IL‑18 concentrations, and caspase‑3 and caspase‑9 were significantly inhibited by gambogic acid in arthritic mice. Gambogic acid decreased matrix metalloproteinases (MMP)‑2, MMP‑9, nuclear factor (NF)‑κB and phosphorylated‑p38 protein expression, and increased tissue inhibitors of matrix metalloproteases‑1 (TIMP‑1) protein expression in arthritic mice. Furthermore, the phosphoinositide 3‑kinase (PI3K)/AKT serine/threonine kinase (Akt) signaling pathway was induced in arthritic mice treated with gambogic acid. The results suggested that gambogic acid induced anti‑inflammatory effects in murine collagen‑induced arthritis, through the PI3K/Akt signaling pathway, and offers future potential for application in arthritis patients.

Vitamin D receptor FokI, BsmI, and TaqI polymorphisms and susceptibility to rheumatoid arthritis : A meta-analysis

OBJECTIVE

The aim of this study was to explore whether vitamin D receptor (VDR) polymorphisms are associated with susceptibility to rheumatoid arthritis (RA).

METHODS

Meta-analyses were conducted on the associations between the VDR FokI, BsmI, and TaqI polymorphisms and RA.

RESULTS

A total of seven studies were considered in the meta-analysis, involving a total of 923 patients and 912 controls. Meta-analysis of the VDR FokI polymorphism showed no association between RA and the F allele in the entire studied cohort (odds ratio, OR = 1.1740, 95 % confidence interval, CI = 0.994-1.387, p = 0.059). However, stratification by ethnicity revealed a significant association between the F allele and RA in Europeans (OR = 1.402, 95 % CI = 1.126-1.746, p = 0.003). Furthermore, an association was found between RA and the VDR FokI polymorphism using both the dominant model and homozygote contrast. Meta-analysis revealed no association between RA and the VDR BsmI B and TaqI T polymorphisms in Europeans (OR for the B allele = 1.065, 95 % CI = 0.911-1.245, p = 0.427; OR for the T allele = 1.065, 95 % CI = 0.834-1.361, p = 0.613).

CONCLUSION

This meta-analysis suggests that the VDR FokI polymorphism is associated with susceptibility to RA in European populations.

Macrophage migration inhibitory factor: a potential therapeutic target for rheumatoid arthritis

Macrophage migration inhibitory factor (MIF) is originally identified in the culture medium of activated T lymphocytes as a soluble factor that inhibits the random migration of macrophages. MIF is now recognized as a multipotent cytokine involved in the regulation of immune and inf lammatory responses. In rheumatoid arthritis (RA), MIF promotes inf lammatory responses by inducing proinflammatory cytokines and tissue-degrading molecules, promoting the proliferation and survival of synovial fibroblasts, stimulating neutrophil chemotaxis, and regulating angiogenesis and osteoclast differentiation. Expression of MIF in synovial tissue and synovial fluid levels of MIF are elevated in RA patients. Specifically, MIF levels correlate with RA disease activity and high levels are associated with bone erosion. In animal models of RA, the genetic and therapeutic inhibition of MIF has been shown to control inflammation and bone destruction. Based on the role of MIF in RA pathogenesis, small molecular inhibitors targeting it or its receptor pathways could provide a new therapeutic option for RA patients.

Meta-analysis reveals PTPN22 1858C/T polymorphism confers susceptibility to rheumatoid arthritis in Caucasian but not in Asian population

The PTPN22 1858C/T polymorphism is associated with rheumatoid arthritis (RA). However, reports from the Asian populations are conflicting in nature and lacks consensus. The aim of our study was to evaluate the association between the PTPN22 1858C/T polymorphism and RA in Asian and Caucasian subjects by carrying out a meta-analysis of Asian and Caucasian data. A total of 27 205 RA cases and 27 677 controls were considered in the present meta-analysis involving eight Asian and 35 Caucasian studies. The pooled odds ratios (ORs) were performed for the allele, dominant, and recessive genetic model. No statistically significant association was found between the PTPN22 1858C/T polymorphism and risk of RA in Asian population (allele genetic model: OR = 1.217, 95% confidence interval (CI) = 0.99-1.496, p value 0.061; dominant genetic model: OR = 1.238, 95% CI = 0.982-1.562, p value 0.071; recessive genetic model: OR = 1.964, 95% CI = 0.678-5.693, p value 0.213). A significant association with risk of RA in Caucasian population suggesting that T-- allele does confer susceptibility to RA in this subgroup was observed (allele genetic model: OR = 1.638, 95% CI = 1.574-1.705, p value < 0.0001; dominant genetic model: OR = 1.67, 95% CI = 1.598-1.745, p value < 0.0001; recessive genetic model: OR = 2.65, 95% CI = 2.273-3.089, p value < 0.0001). The PTPN22 1858C/T polymorphism is not associated with RA risk in Asian populations. However, our meta-analysis confirms that the PTPN22 1858C/T polymorphism is associated with RA susceptibility in Caucasians.

Genome-wide pathway analysis of a genome-wide association study on Alzheimer's disease

The aims of this study were to identify candidate single nucleotide polymorphisms (SNPs) and mechanisms of Alzheimer's disease (AD) and to generate SNP to gene to pathway hypotheses. An AD genome-wide association study (GWAS) dataset that included 370,542 SNPs in 1,000 cases and 1,000 controls of European descent was used in this study. Identify Candidate Causal SNPs and Pathway (ICSNPathway) analysis was applied to the GWAS dataset. ICSNPathway analysis identified 3 candidate SNPs and 2 pathways, which provided 3 hypothetical biological mechanisms. The strongest hypothetical biological mechanism was rs8076604 [non-synonymous coding (deleterious)] to MYO18A to negative regulation of programmed cell death [nominal P < 0.001, false discovery rate (FDR) <0.043]. The second was rs2811226 (regulatory region) to ANXA1 to negative regulation of programmed cell death (nominal P < 0.001, FDR 0.043). The third was rs3734166 (non-synonymous coding) to CDC25C to M phase of the mitotic cell cycle (nominal P < 0.001, FDR 0.049). By applying the ICSNPathway analysis to the AD GWAS meta-analysis data, three candidate SNPs, three genes (MYO18A, ANXA1, CDC25C), 2 pathways involving negative regulation of programmed cell death and 1 pathway involving the M phase of the mitotic cell cycle were identified, which may contribute to AD susceptibility.

Chronic macrophage migration inhibitory factor exposure induces mesenchymal epithelial transition and promotes gastric and colon cancers

Macrophage Migration Inhibitory Factor (MIF) is an inflammatory cytokine that is highly produced in gastrointestinal cancers. Since chronic inflammation is a risk factor for tumorigenesis in these cancers, in this study, the role of MIF in pro-tumorigenic events was examined. MIF and its receptor, CD74, were examined in gastric and colon tumors and found to be increased in most tumors with significantly higher expression in tumors from patients with lymph node metastasis. MIF was also found to be highly produced by cancer associated fibroblasts isolated from human tumors compared to fibroblasts from matched normal tissues from uninvolved areas. Fibroblast-produced MIF highly increased GI cancer cell proliferation, which was decreased upon neutralizing MIF or CD74. Chronic MIF treatment led to sustained proliferation and signaling events in non-transformed GI fibroblast cells, which was maintained upon removing MIF treatment for 8 weeks. Additionally, chronic treatment of normal GI cells expressing fibroblast markers for up to 16 weeks with MIF led to a drastic decrease of fibroblast markers with concurrent increase of epithelial markers. Transformation was examined by telomerase and focus forming assays. These results suggest the MIF promotes mesenchymal epithelial transition, cell transformation and tumorigenesis in GI cancers, and thus may be an important link between chronic inflammation and tumorigenesis.

Gene-environmental interaction between smoking and shared epitope on the development of anti-cyclic citrullinated peptide antibodies in rheumatoid arthritis: a meta-analysis

OBJECTIVE

The aim of this study was to determine the gene-environment interactions of smoking and shared epitope (SE) both separately and combined on anti-cyclic citrullinated peptide (CCP) antibodies in patients with rheumatoid arthritis (RA).

METHODS

The literature was searched using the MEDLINE, EMBASE and Cochrane databases. A meta-analysis on the associations between tobacco exposure (TE) and/or SE and the development of anti-CCP antibodies in patients with RA was performed.

RESULTS

Eight comparison studies with 5317 RA patients were considered in this meta-analysis. The odds ratio (OR) for positive anti-CCP antibodies in TE+/SE- patients with RA was increased compared with TE-/SE- patients (OR = 1.373, 95% CI = 1.111-1.698, P = 0.003). The ORs for positive anti-CCP antibodies in TE-/SE+ patients and TE+/SE+ patients with RA were also increased compared with TE-/SE- patients (OR = 2.678, 95% CI = 2.031-3.532, P < 1.0 × 1(0-9) in TE-/SE+; OR = 4.233, 95% CI = 2.458-7.291, P = 1.9 × 10(-8) in TE+/SE+). Stratification by ethnicity indicated the same pattern as that shown in the overall group. The OR for positive anti-CCP antibodies in TE+/SE+ patients with RA was much higher than in TE-/SE- patients in Europeans and Asians (OR = 3.879, 95% CI = 2.203-6.830, P = 2.6 × 10(-7); OR = 10.504, 95% CI = 3.182-34.67, P = 1.1 × 10(-4)).

CONCLUSIONS

This meta-analysis suggests a gene-environmental interaction between smoking and SE for the development of anti-CCP antibodies.

Associations between TRAF1-C5 gene polymorphisms and rheumatoid arthritis: a meta-analysis

OBJECTIVE

The aim of this study is to determine whether tumor necrosis factor receptor-associated factor 1-complement 5 (TRAF1-C5) polymorphisms are associated with susceptibility to rheumatoid arthritis (RA) in different populations.

METHODS

We conducted a meta-analysis of associations between the TRAF1-C5 polymorphisms and RA susceptibility.

RESULTS

A total of 24 comparative studies were included in this meta-analysis, including 22,682 patients with RA and 23,493 controls. The meta-analysis showed an association between the second allele of rs10818488 and RA in Europeans, but not in Asians (OR 1.229, 95% CI 1.094-1.381, p = 0.001; OR 1.060, 95% CI 0.930-1.335, p = 0.092). The meta-analysis also indicated an association between the second allele of rs3761847 and RA in Europeans, but not in Asians (OR 1.156, 95% CI 1.006-1.327, p = 0.041; OR 1.049, 95% CI 0.952-1.156, p = 0.333). The meta-analysis revealed an association between the second allele of the rs2900180 and rs10760130 polymorphisms and RA risk in Europeans (OR 1.224, 95% CI 1.065-1.405, p = 0.004; OR 1.072, 95% CI 1.002-1.147, p = 0.042).

CONCLUSIONS

This meta-analysis confirms that the TRAF1-C5 rs10818488, rs3761847, rs2900180 and rs10760130 polymorphisms are associated with RA susceptibility in Europeans.

Association between functional Fc receptor-like 3 (FCRL3) -169 C/T polymorphism and susceptibility to seropositive rheumatoid arthritis in Asians: a meta-analysis

OBJECTIVE

The aim of this study was to determine whether the functional Fc receptor like-3 (FCRL3) -169 C/T polymorphism confers susceptibility to rheumatoid arthritis (RA).

METHODS

A meta-analysis was conducted on the associations between the FCRL3 -169 C/T polymorphism and RA.

RESULTS

A total of 17 comparison studies including 11,170 patients and 11,142 controls were considered in the meta-analysis. The meta-analysis showed no association between RA and the FCRL3 -169 C allele in study subjects (OR = 1.046, 95% CI = 0.997-1.098, p = 0.068). Stratification by ethnicity indicated an association between the FCRL3 -169 C allele and RA in Asians (OR = 1.101, 95% CI = 1.035-1.174, p = 0.002), but not in Europeans. Stratification of patients according to the presence of rheumatoid factor (RF) revealed a different significant association between the C allele and RA in RF-positive and RF-negative RA patients. Stratification by ethnicity indicated an association between the FCRL3 -169 C allele and RF-positive RA in Asians (OR = 1.093, 95% CI = 1.004-1.189, p = 0.040), but not in Europeans.

CONCLUSIONS

This meta-analysis demonstrates that the FCRL3 -169 C/T polymorphism may confer susceptibility to seropositive RA in Asians.

The PTPN22 C1858T polymorphism and rheumatoid arthritis: a meta-analysis

The aim of this study was to determine whether the protein tyrosine phosphatase nonreceptor 22 (PTPN22) C1858T polymorphism confers susceptibility to rheumatoid arthritis (RA) in populations with different ethnicities. MEDLINE database and manual search were utilized to identify articles in which the PTPN22 polymorphism was determined in RA patients and controls. A meta-analysis was conducted on the associations between the PTPN22 C1858T polymorphism and RA using (1) allelic contrast and (2) dominant model. A total of 30 separate comparisons involving 17,961 RA patients and 18,611 controls were considered in this meta-analysis. Meta-analysis showed an association between the T allele and RA in all subjects (OR = 1.490, 95% CI = 1.332-1.668, P < 1.0 × 10(-9)). After stratification by ethnicity, analysis indicated that the T allele was significantly associated with RA in Europeans and in Non-Europeans (OR = 1.423, 95% CI = 1.260-1.605, P = 1.0 × 10(-8); OR = 1.902, 95% CI = 1.488-2.430, P = 2.8 × 10(-8)). Meta-analysis of the CT + TT genotype showed the same result patterns as that shown by the PTPN22 C1858T polymorphism T allele. Furthermore, a direct comparison between rheumatoid factor (RF)-positive and RF-negative subjects revealed a significant association with the T allele in RA patients with RF, but not in subjects without RF (OR = 1.561, 95% CI = 1.373-1.775, P < 1.0 × 10(-9)). This meta-analysis confirms that the PTPN22 C1858T polymorphism is associated with RA susceptibility in different ethnic groups, especially in Europeans, and the PTPN22 C1858T polymorphism T allele is significantly more prevalent in RF-positive patents than in RF-negative patients.

Associations between interferon regulatory factor 5 polymorphisms and rheumatoid arthritis: a meta-analysis

The aim of this study was to determine whether interferon regulatory factor 5 (IRF5) polymorphisms confers susceptibility to rheumatoid arthritis (RA) in populations with different ethnicities. We searched the literature using the Pubmed and Embase databases and conducted meta-analyses on associations between the four IRF5 polymorphisms (rs2004640, rs729302, rs752637, and rs2280714) and RA susceptibility, using fixed and random effects models. A total of 12 comparison studies were considered in this meta-analysis, which in total involved 7,916 RA patients and 6,452 controls, and eight European, three Asian, and one Argentinean population. Meta-analysis showed an association between the minor allele of rs2004640 and RA in all subjects (odds ratio [OR] = 0.928, 95 % confidence interval [CI] = 0.865-0.996, P = 0.037). After stratification by ethnicity, analysis indicated that the minor allele was significantly associated with RA in Europeans (OR = 0.889, 95 % CI = 0.839-0.941, P = 5.03 × 10(-6)), but not in Asians (OR = 1.057, 95 % CI = 0.978-1.144, P = 0.164). A direct comparison between anti-citrullinated peptide antibody-positive and -negative patients revealed no difference of the frequency of the rs2004640 minor allele (OR = 1.047, 95 % CI = 0.813-1.348, P = 0.724). Meta-analysis identified a significant association between RA and the minor allele of the rs729302 polymorphism in the overall population (OR = 0.896, 95 % CI = 0.826-0.972, P = 0.009) and in Asians (OR = 0.862, 95 % CI = 0.795-0.935, P = 3.50 × 10(-5)), but not in Europeans (OR = 0.951, 95 % CI = 0.877-1.031, P = 0.225). Meta-analysis showed an association between the minor allele of rs752637 and RA in Europeans (OR = 0.858, 95 % CI = 0.789-0.932, P = 3.03 × 10(-5)), but not in Asians (OR = 1.035, 95 % CI = 0.918-1.168, P = 0.572). No association was found between the rs2280714 polymorphism and RA susceptibility. This meta-analysis confirms that the IRF5 rs2004640, rs729302 and rs752637 polymorphisms are associated with RA susceptibility in different ethnic groups, especially in Europeans and Asians, but further study of this association is required in other ethnic groups.

Associations between interleukin-23 receptor polymorphisms and susceptibility to rheumatoid arthritis: a meta-analysis

The aim of this study was to determine whether interleukin-23 receptor (IL-23R) polymorphisms confer susceptibility to rheumatoid arthritis (RA). A meta-analysis was conducted on the associations between the IL-23R rs1343151, rs10489629, rs7517847, rs11209026, rs1004819, and rs2201841 polymorphisms and RA using (1) allele contrast, (2) the recessive model, (3) the dominant model, and (4) the additive model. A total of 13 studies from eight articles involving 10,016 RA patients and 11,967 controls were considered in the meta-analysis. Meta-analysis identified a significant association between RA and the A allele of the rs1343151 polymorphism in the overall population (OR = 1.110, 95 % CI = 1.056-1.168, p = 4.7 × 10(-6)). Stratification by ethnicity identified a significant association between this polymorphism and RA in Europeans (OR = 1.105, 95 % CI = 1.049-1.163, p = 1.4 × 10(-5)). An association was also found between RA and the A allele carrier of the rs1343151 polymorphism in Europeans (OR = 1.135, 95 % CI = 1.058-1.217, p = 4.0 × 10(-5)). Meta-analysis revealed a significant association between RA and the A allele of the rs10489629 polymorphism in the overall population (OR = 1.079, 95 % CI = 1.029-1.131, p = 0.002) and in Europeans (OR = 1.092, 95 % CI = 1.038-1.149, p = 0.001). Meta-analyses of recessive, dominant, and additive models showed the same pattern as the meta-analysis of the A allele of the rs10489629 polymorphism, that is, a significant association with RA in Europeans. However, no association was found between the IL-23R rs7517847, rs11209026, rs1004819, and rs2201841 polymorphisms and RA susceptibility. This meta-analysis shows that the IL-23R rs1343151 and rs10489629 polymorphisms are associated with the development of RA in Europeans. These findings suggest that the IL-23R genes confer susceptibility to RA in the European population, but further study of this association is required in other ethnic groups.

Association between vitamin D intake and the risk of rheumatoid arthritis: a meta-analysis

The aim of this study was to summarize published results on the association between vitamin D intake and the development of rheumatoid arthritis (RA) and between serum vitamin D levels and RA activity. Evidence of a relationship between vitamin D intake and the development of RA and between serum vitamin D levels and RA activity was studied by summarizing published results using a meta-analysis approach. Three cohort studies including 215,757 participants and 874 incident cases of RA were considered in this meta-analysis, and eight studies on the association between serum vitamin D levels and RA activity involving 2,885 RA patients and 1,084 controls were included. Meta-analysis showed an association between total vitamin D intake and RA incidence (relative risk (RR) of the highest vs. the lowest group = 0.758, 95 % confidence interval (CI) 0.577-0.937, p = 0.047), without between-study heterogeneity (I(2) = 0 %, p = 0.595). Individuals in the highest group for total vitamin D intake were found to have a 24.2 % lower risk of developing RA than those in the lowest group. Subgroup meta-analysis also showed a significant association between vitamin D supplement intake and RA incidence (RR 0.764, 95 % CI 0.628-0.930, p = 0.007), without between-study heterogeneity. All studies, except for one, found that vitamin D levels are inversely associated with RA activity. One study found no correlation between vitamin D levels and disease activity among 85 RA patients, but these patients had a high incidence of vitamin D deficiency, which might have influenced the study outcome. Meta-analysis of 215,757 participants suggests that low vitamin D intake is associated with an elevated risk of RA development. Furthermore, available evidence indicates that vitamin D level is associated with RA activity.

Omega-3 polyunsaturated fatty acids and the treatment of rheumatoid arthritis: a meta-analysis

BACKGROUND AND AIMS

We undertook this study to assess the effects of omega-3 polyunsaturated fatty acids (PUFAs) (administered at ≥2.7 g/day) for a minimum duration of 3 months on clinical outcomes in patients with rheumatoid arthritis (RA).

METHODS

The authors surveyed randomized controlled trials (RCTs) that examined the effects of omega-3 PUFAs on clinical outcomes in RA patients using Medline and the Cochrane Controlled Trials Register and by performing manual searches. Meta-analysis of RCTs was performed using fixed and random effects models. Outcomes are presented as standardized mean differences (SMD).

RESULTS

Ten RCTs involving 183 RA patients and 187 placebo-treated RA controls were included in this meta-analysis. The analysis showed that omega-3 PUFAs clearly reduced nonsteroidal anti-inflammatory drug (NSAID) consumption (SMD -0.518, 95% CI -0.915 to -0.121, p = 0.011) without between-study heterogeneity (I(2) = 0%). Tender joint count (SMD -0.214, 95% CI-0.489-0.062, p = 0.128), swollen joint count (SMD -0.170, 95% CI-0.454-0.114, p = 0.241), morning stiffness (SMD -0.224, 95% CI-0.955-0.212, p = 0.221), and physical function (SMD 0.264, 95% CI-0.232-0.724, p = 0.314) showed a trend to improve more in patients treated with omega-3 PUFAs than in placebo-treated controls, but they did not reach statistical significance.

CONCLUSIONS

This meta-analysis suggests that the use of omega-3 PUFAs at dosages >2.7 g/day for >3 months reduces NSAID consumption by RA patients. Further studies are needed to explore the clinical and NSAID-sparing effects of omega-3 PUFAs in RA.

Association between the chemokine receptor 5 delta32 polymorphism and rheumatoid arthritis: a meta-analysis

OBJECTIVE

The aim of this study was to determine whether the functional chemokine receptor 5 delta32 (CCR5-Δ32) polymorphism confers susceptibility to rheumatoid arthritis (RA) and juvenile idiopathic arthritis (JIA).

METHODS

Meta-analysis was conducted on associations between the CCR5-Δ32 polymorphism and RA and JIA using (1) allele contrast and (2) the recessive, (3) the dominant, and (4) the additive models.

RESULTS

Eleven population comparisons based on the data obtained from nine studies involving 13,412 subjects (RA 3,848, controls 4,095; JIA 1,599, controls 3,870) were considered. In all study subjects, meta-analysis showed a significant negative association between RA and the CCR5-Δ32 allele (OR = 0.771, 95 % CI = 0.694-0.866, p = 6.5 × 10(-7)). Stratification by ethnicity indicated a significant association between the CCR5-Δ32 allele and RA in Europeans (OR = 0.8001, 95 % CI = 0.709-0.904, p = 3.2 × 10(-5)). Meta-analysis showed associations between the CCR5-Δ32 allele and JIA in Europeans and oligoarticular type (OR = 0.797, 95 % CI = 0.690-0.921, p = 0.002; OR = 0.475, 95 % CI = 0.352-0.693, p = 9.5 × 10(-8)).

CONCLUSIONS

This meta-analysis demonstrates that the CCR5-Δ32 polymorphism may confer susceptibility to RA and JIA in Europeans, and suggests that the CCR5-Δ32 allele protects against the development of RA and JIA.

Association of MIF in serum and synovial fluid with severity of knee osteoarthritis

OBJECTIVE

Recent evidences suggest that inflammation contributes to the development and progression of osteoarthritis (OA). This study aims to determine macrophage migration inhibitory factor (MIF) levels in serum and synovial fluid (SF) of patients with knee OA and to analyze the association of MIF levels with the radiographic severity of OA.

DESIGN AND METHODS

224 patients with knee OA and 186 healthy controls were enrolled in this study.

RESULTS

Higher levels of serum MIF were found in knee OA patients compared with healthy controls. Knee OA patients with Kellgren and Lawrence (KL) grade 4 showed significantly elevated MIF levels in serum and SF compared with those with KL grade 2 and 3. MIF levels in serum and SF of knee OA patients were significantly related to disease severity evaluated by KL grading criteria.

CONCLUSION

MIF levels in serum and SF were closely related to the radiographic severity of OA.

New drugs beyond biologics in rheumatoid arthritis: the kinase inhibitors

Orally available small molecule compounds have recently been developed for the treatment of RA, and inhibitors of signalling cascades, specifically inhibitors of kinases, have reached advanced stages of clinical development. The p38 mitogen-activated protein kinase blockers have shown poor clinical response despite encouraging preclinical data. In contrast, inhibitors of the non-receptor tyrosine kinases, spleen tyrosine kinase and janus kinase 3, have demonstrated a significant clinical efficacy together with an acceptable safety profile. We herein present a review on published preclinical and clinical data on these new drugs.

Macrophage migration inhibitory factor enhances osteoclastogenesis through upregulation of RANKL expression from fibroblast-like synoviocytes in patients with rheumatoid arthritis

INTRODUCTION

Macrophage migration inhibitory factor (MIF) is one of key regulators in acute and chronic immune-inflammatory conditions including rheumatoid arthritis (RA). We examined the effect of MIF on osteoclastogenesis, which is known to play a crucial role in bone destruction in RA.

METHODS

The concentration of MIF and receptor activator of nuclear factor-κB ligand (RANKL) in the synovial fluid was measured by ELISA. MIF-induced RANKL expression of RA synovial fibroblasts was determined by real-time PCR and western blot. Osteoclastogenesis was analyzed in culture of human peripheral blood mononuclear cells (PBMC) with MIF. Osteoclastogenesis was also determined after co-cultures of rhMIF-stimulated RA synovial fibroblasts with human PBMC.

RESULTS

Synovial fluid MIF concentration in RA patients was significantly higher than in osteoarthritis (OA) patients. The concentration of RANKL correlated with that of MIF in RA synovial fluids (r = 0.6, P < 0.001). MIF stimulated the expression of RANKL mRNA and protein in RA synovial fibroblasts, which was partially reduced by blocking of interleukin (IL)-1β. Osteoclasts were differentiated from PBMC cultures with MIF and M-CSF, even without RANKL. Osteoclastogenesis was increased after co-culture of MIF-stimulated RA synovial fibroblasts with PBMC and this effect was diminished by RANKL neutralization. Blocking of PI3 kinase, p38 MAP kinase, JAK-2, NF-κB, and AP-1 also led to a marked reduction in RANKL expression and osteoclastogenesis.

CONCLUSIONS

The interactions among MIF, synovial fibroblasts, osteoclasts, RANKL, and IL-1β have a close connection in osteoclastogenesis and they could be a potential gateway leading to new therapeutic approaches in treating bone destruction in RA.