Increased expression of Toll-like receptor 4 in peripheral blood leucocytes and serum levels of some cytokines in patients with ankylosing spondylitis

Artemisinin Attenuates Amyloid-Induced Brain Inflammation and Memory Impairments by Modulating TLR4/NF-κB Signaling

The abnormal immune response is an early change in the pathogenesis of Alzheimer’s disease (AD). Microglial activation is a crucial regulator of the immune response, which contributes to progressive neuronal injury by releasing neurotoxic products. Therefore, finding effective drugs to regulate microglial homeostasis and neuroinflammation has become a new AD treatment strategy. Artemisinin has potent anti-inflammatory and immune activities. However, it is unclear whether Artemisinin contributes to the regulation of microglial activation, thereby improving AD pathology. This study found that Artemisinin significantly reduced amyloid beta-peptide 1–42 (Aβ_1–42)-induced increases in nitric oxide and reactive oxygen species and inflammatory factors in BV2 cells. In addition, Artemisinin inhibited the migration of microglia and prevented the expansion of the inflammatory cascade. The mechanical studies showed Artemisinin inhibited neuroinflammation and exerted neuroprotective effects by regulating the Toll-like receptor 4 (TLR4)/Nuclear factor-kappa B (NF-κB) signaling pathway. Similar results were obtained in AD model mice, in which Artemisinin administration attenuated Aβ_1–42-induced neuroinflammation and neuronal injury, reversing spatial learning and memory deficits. The anti-inflammatory effect of Artemisinin is also accompanied by the activation of the TLR4/NF-κB signaling pathway in the animal model. Our results indicate that Artemisinin attenuated Aβ_1–42-induced neuroinflammation and neuronal injury by stimulating the TLR4/NF-κB signaling pathway. These findings suggest that Artemisinin is a potential therapeutic agent for AD.

Similarities and Differences Between Juvenile and Adult Spondyloarthropathies

Spondyloarthritis (SpA) encompasses a broad spectrum of conditions occurring from childhood to middle age. Key features of SpA include axial and peripheral arthritis, enthesitis, extra-articular manifestations, and a strong association with HLA-B27. These features are common across the ages but there are important differences between juvenile and adult onset disease. Juvenile SpA predominantly affects the peripheral joints and the incidence of axial arthritis increases with age. Enthesitis is important in early disease. This review article highlights the similarities and differences between juvenile and adult SpA including classification, pathogenesis, clinical features, imaging, therapeutic strategies, and disease outcomes. In addition, the impact of the biological transition from childhood to adulthood is explored including the importance of musculoskeletal and immunological maturation. We discuss how the changes associated with adolescence may be important in explaining age-related differences in the clinical phenotype between juvenile and adult SpA and their implications for the treatment of juvenile SpA.

Associations of toll-like receptor 4 and 2 gene polymorphisms with susceptibility to ankylosing spondylitis: A meta-analysis

BACKGROUND

The published evidences on the correlations of toll-like receptor 4 (TLR4) and TLR9 gene polymorphisms and ankylosing spondylitis (AS) were conflicting. The purpose of this study was to investigate whether TLR4 and TLR9 gene polymorphisms conferred susceptibility to AS through a meta-analysis approach.

METHODS

Databases of PubMed, Web of Science, EMBASE, Cochrane Library, CNKI and Wanfang were retrieved for relevant publications up to 20 June 2020. Study quality was assessed based on Newcastle-Ottawa scale (NOS). Odds ratios (ORs) and 95% confidence intervals (95% CIs) were used to judge the associations.

RESULTS

Totally, 13 articles with 3,055 AS cases and 4,238 controls were incorporated into this meta-analysis, and four most widely reported polymorphisms (TLR4-rs4986790, TLR4-rs4986791, TLR9-rs55704465 and TLR9-rs187084) were analysed. All included studies were in high quality. The pooled data did not support any significant association between the four studied polymorphisms and AS susceptibility.

CONCLUSIONS

The present meta-analysis suggests there is no significant association between TLR4-rs4986790, TLR4-rs4986791, TLR9-rs55704465 and TLR9-rs187084 polymorphisms and AS.

Side Effects of Coronary Stenting such as Severe Coronary Stenosis and Multiple Coronary Chronic Total Occlusions in Elderly Patients via Induced Proinflammatory and Prooxidative Stress

Background

Severe coronary stenosis and multiple coronary chronic total occlusions are serious side effects of coronary stent implantation in elderly patients. This research sought to investigate the side effects of coronary stenting such as severe coronary stenosis and multiple coronary chronic total occlusions in elderly patients via induced proinflammatory and prooxidative stress.

Methods

We evaluated the expression levels of tumor necrosis factor-α (TNF-α), toll-like receptor 4 (TLR4), acrolein (ACR), malondialdehyde (MDA), high-sensitivity C-reactive protein (hs-CRP), stromal cell-derived factor-1α (SDF-1α), superoxide dismutase 3 (SOD3), and endothelial nitric oxide synthase (eNOS) in elderly patients with severe coronary stenosis and multiple coronary chronic total occlusions.

Results

Levels of TNF-α, TLR4, ACR, MDA, and hs-CRP were remarkably increased (P < 0.001), and levels of SDF-1α, SOD3, and eNOS were remarkably lowered (P < 0.001) in elderly patients with severe coronary stenosis and multiple coronary chronic total occlusions. Coronary stenting induced proinflammatory and prooxidant mediator expression and inhibited anti-inflammatory/antioxidant mediators. The proinflammatory and prooxidant mediators may be involved in severe coronary stenosis and multiple coronary chronic total occlusions in elderly patients.

Conclusions

Side effects such as severe coronary stenosis and multiple coronary chronic total occlusions because of coronary stenting in elderly patients were induced by proinflammatory and prooxidative stress. Circulating proinflammatory and prooxidant mediators could predict early severe coronary stenosis and multiple coronary chronic total occlusions in elderly coronary heart disease patients.

TNF-Related Apoptosis-Inducing Ligand Receptor 1 in Patients With Ankylosing Spondylitis

OBJECTIVES

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) belongs to the tumor necrosis factor (TNF) superfamily and is reported to play a role in autoimmune diseases. In this study, we aimed to measure serum TRAIL receptor 1 (TRAIL-R1) concentration and assess any phenotypic relationship in patients with ankylosing spondylitis (AS).

METHODS

Fifty-three patients with AS were recruited from August 2014 to December 2014 cross-sectionally. Fifty-three sex- and age-matched healthy controls were also recruited. Serum TRAIL-R1 concentrations were measured using an enzyme-linked immunosorbent assay. The association between serum TRAIL-R1, TNF-α, disease activity indices, markers of systemic inflammation, and clinical features were evaluated.

RESULTS

Serum TRAIL-R1 and TNF-α levels were increased in patients with AS compared with healthy controls (4.5 ± 2.3 vs 3.5 ± 2.3 pg/mL, p = 0.036; 3.8 [1.6-7.7] vs 2.0 [0.21-5.7] pg/mL, p = 0.048, respectively). Serum TRAIL-R1 displayed a medium positive correlation with serum TNF-α concentrations (r = 0.412; p = 0.002). Serum TRAIL-R1 concentration was higher in human leucocyte antigen (HLA)-B27-positive patients compared with non-HLA-B27 patients (5.5 ± 2.2 vs 3.1 ± 1.6 pg/mL, p < 0.001). No relationship was found between serum TRAIL-R1 concentration and disease activity scores.

CONCLUSIONS

This study confirms that serum TRAIL-R1 levels are higher in AS patients than healthy controls. The persistence of significantly elevated serum TRAIL-R1 levels, even in patients with low disease activity or after excluding biologic treatment, and the association with HLA-B27 positivity, warrants further investigation due to the unclear role of TRAIL-R1 in the pathophysiology of AS.

Role of Stem Cells in Pathophysiology and Therapy of Spondyloarthropathies-New Therapeutic Possibilities?

Considerable progress has been made recently in understanding the complex pathogenesis and treatment of spondyloarthropathies (SpA). Currently, along with traditional disease modifying anti-rheumatic drugs (DMARDs), TNF-α, IL-12/23 and IL-17 are available for treatment of such diseases as ankylosing spondylitis (AS) and psoriatic arthritis (PsA). Although they adequately control inflammatory symptoms, they do not affect the abnormal bone formation processes associated with SpA. However, the traditional therapeutic approach does not cover the regenerative treatment of damaged tissues. In this regards, stem cells may offer a promising, safe and effective therapeutic option. The aim of this paper is to present the role of mesenchymal stromal cells (MSC) in pathogenesis of SpA and to highlight the opportunities for using stem cells in regenerative processes and in the treatment of inflammatory changes in articular structures.

M2 polarization of monocytes in ankylosing spondylitis and relationship with inflammation and structural damage

The aim of this study was to evaluate the polarization of peripheral blood monocytes in the patients with ankylosing spondylitis (AS) and to determine the correlations between monocyte polarization and inflammation and structural damage. A total of 120 AS patients, 50 rheumatoid arthritis (RA) patients and 100 healthy controls were enrolled in the study. M1 (CD68+CD192+) and M2 (CX3CR1+CD163+) monocytes were characterized by flow cytometry. Demographic, clinical, radiographic and laboratory data were collected and analyzed. A large increase in M2 (CX3CR1+CD163+) monocytes was observed in AS, and M2/M1 ratio was 7.18 ± 6.12, 2.54 ± 3.14 and 35.61 ± 20.04 in control, RA and AS, respectively. The M2/M1 ratio correlated with modified Stoke Ankylosing Spondylitis Spine Score (mSASSS) (r = 0.565; p < 0.001), ESR (r = -0.321; p < 0.001, CRP (r = -0.265; p < 0.001) and Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) (r = -0.201; p = 0.028). Anti-TNF-α therapy induced a significant reduction in the percentage of M1 monocyte, ESR, CRP and BASDAI in AS patients. The present results demonstrated that M2 type polarized monocytes are predominant in the peripheral blood in AS and the M2/M1 ratio is correlated with structural damage (mSASSS), inflammatory biomarkers (ESR and CRP) and BASDAI.

The potent suppressive effect of β-d-mannuronic acid (M2000) on molecular expression of the TLR/NF-kB Signaling Pathway in ankylosing spondylitis patients

Ankylosing spondylitis (AS) is a chronic inflammatory rheumatic disease characterized by the inflammation of sacroiliac joints and axial skeleton. A combination of genetic, environmental and immunological factors are involved in AS's pathogenesis. TLRs are type I transmembrane glycoproteins that play a crucial role in the innate immune responses against invading pathogens. Observational studies have demonstrated a possible association between TLR dysregulation and AS. The β-d-mannuronic acid (M2000), as a novel NSAID with immunosuppressive property, has shown an inhibitory effect on Toll-like receptor (TLR) 2, 4 signaling in HEK293 cells. In the present study, we investigated the gene expression of Myd88, IKB-alpha, NF-kB and MAPK14 (genes of the TLR/NF-kB Signaling Pathway) in AS patients in comparison to healthy subjects and also the effect of β-d-mannuronic acid on disease activity and mRNA expression of these molecules in affected patients. We showed for the first time that the gene expression level of Myd88, IKB-alpha, NF-kB and MAPK14 was higher in AS patients in comparison to healthy subjects. Moreover we confirmed that the β-d-mannuronic acid not just reduced significantly the disease activity of AS individuals compared to placebo, but also it could significantly decrease the expression level of genes associated with TLR/NF-kB Signaling Pathway in treated patients with M2000. These results may provide a new therapeutic approach to attenuate inflammatory responses in AS patients, (Identified; IRCT 2013062213739N1).

Involvement of Mucosal-associated Invariant T cells in Ankylosing Spondylitis

Objective.

Ankylosing spondylitis (AS) is characterized by chronic inflammation of the axial and peripheral joints and ligamentous attachments. Gut immunity is thought to be involved in AS, because a prominent coexistence of gut and joint inflammation has been observed in patients with AS. Mucosal-associated invariant T (MAIT) cells are preferentially located in the gut lamina propria and produce inflammatory cytokines such as interleukin 17 (IL-17) and tumor necrosis factor-α (TNF-α), which are therapeutic targets for AS. This study aimed to investigate the involvement of MAIT cells in AS.

Methods.

The frequency of MAIT cells and their cytokine production were determined in patients with AS and healthy controls (HC). The expression of a MAIT cell activation marker (CD69) was analyzed in patients with AS by using flow cytometry.

Results.

The frequency of MAIT cells in the peripheral blood was lower in patients with AS compared with HC. The levels of IL-17 produced by MAIT cells after activation were higher in patients with AS than in the HC. CD69 expression on MAIT cells correlated with the Ankylosing Spondylitis Disease Activity Score in patients with AS.

Conclusion.

These results suggest the involvement of MAIT cells in the pathogenesis of AS.

The role of toll like receptors in giant cell arteritis

GCA is a common primary systemic vasculitis that results in granulomatous inflammation of medium to large arteries. Both innate and adaptive immune mechanisms combine to drive intimal hyperplasia, luminal stenosis and ultimately occlusion. While the pathogenesis of GCA is incompletely understood, the activation of resident adventitial dendritic cells via toll like receptors (TLRs) appears to be a crucial inciting event. Here we explore the role of TLRs in the pathogenesis of GCA, including their effects on dendritic cell and T cell activation and recruitment, putative infectious triggers for GCA and the potential of TLR inhibition as a novel therapeutic strategy in GCA.

The associations between PD-1, CTLA-4 gene polymorphisms and susceptibility to ankylosing spondylitis: a meta-analysis and systemic review

Previous surveys had evaluated the effects of the PD-1, CTLA-4 gene polymorphisms on susceptibility to ankylosing spondylitis (AS), but the results remained controversial. To briefly examine these consequences, a comprehensive meta-analysis was conducted to estimate the relationships between PD-1 rs11568821, rs2227982, rs2227981, CTLA-4 +49 A/G and -318 C/T polymorphisms and AS risk. The available articles dated to December 2014 were searched in the PUBMED, MEDLINE and EMBASE databases. The data of the genotypes and/or alleles for the PD-1 rs11568821, rs2227982, rs2227981, CTLA-4 +49 A/G and -318 C/T polymorphisms in the AS and control subjects were extracted, and statistical analysis was conducted by STATA 11.2 software. Summary odds ratios (ORs) with their 95 % confidence intervals (95 % CIs) were calculated to determine the strength of associations with fixed-effects or random-effects models. A total of eight published studies were finally involved in this meta-analysis. Meta-analysis of PD-1 rs2227982 polymorphism under the T allele versus C allele (OR 1.744, 95 % CI 1.477-2.059, P < 0.0001), TT+TC versus CC (OR 2.292, 95 % CI 1.654-3.175, P < 0.0001), TT versus CC (OR 1.883, 95 % CI 1.299-2.729, P = 0.001) revealed a significant association with AS. Our meta-analysis demonstrated that the rs2227982 polymorphism in the PD-1 gene might contribute to AS susceptibility. However, further studies with large sample sizes and among different ethnicity populations should be required to confirm this association.

Association between ankylosing spondylitis and the miR-146a and miR-499 polymorphisms

miRNAs are small, non-coding RNAs that regulate the expression of multiple target genes at the post-transcriptional level. Single-nucleotide polymorphisms (SNPs) in miRNA sequences may alter miRNA expression and have been implicated in the pathogenesis of multiple forms of arthritis, including rheumatoid arthritis (RA) and osteoarthritis. The present study explored the association between ankylosing spondylitis (AS) and two single nucleotide polymorphisms (SNPs), miR-146a rs2910164G>C and miR-499 rs3746444T>C, in a Han Chinese population. A case-control study consisting of 102 subjects with AS and 105 healthy controls was designed. The two miRNA SNPs were identified by direct sequencing. Subsequently, their gene and genotype frequencies were compared with healthy controls. A significant difference was observed in the miR-146a rs2910164G>C SNP. The frequency of the G allele was markedly higher in the AS patients than in the healthy controls (P = 0.005, Pc = 0.01, OR = 1.787), and the frequency of the GG genotype was higher in AS patients than in controls (P = 0.014, Pc = 0.042, OR = 2.516). However, no significant association was found between the miR-499 rs3746444T>C variant and susceptibility to AS. This is the first study to address the association between the miR-146a rs2910164G>C and miR-499 rs3746444T>C polymorphisms and AS, and it suggests a potential pathogenic factor for AS. Further studies are needed to validate our findings in a larger series, as well as in other ethnic backgrounds.

Aberrant expression of shared master-key genes contributes to the immunopathogenesis in patients with juvenile spondyloarthritis

Association of juvenile spondyloarthritis (jSpA) with the HLA-B27 genotype is well established, but there is little knowledge of other genetic factors with a role in the development of the disease. To date, only a few studies have tried to find those associated genes by obtaining expression profiles, but with inconsistent results due to various patient selection criteria and methodology. The aim of the present study was to identify and confirm gene signatures and novel biomarkers in highly homogeneous cohorts of untreated and treated patients diagnosed with jSpA and other forms of juvenile idiopathic arthritis (JIA) according to ILAR criteria. For the purposes of the research, total RNA was isolated from whole blood of 45 children with jSpA and known HLA genotype, 11 children with oligo- and polyarticular forms of JIA, as well as 12 age and sex matched control participants without diagnosis of inflammatory disease. DNA microarray gene expression was performed in 11 patients with jSpA and in four healthy controls, along with bioinformatical analysis of retrieved data. Carefully selected differentially expressed genes where analyzed by qRT-PCR in all participants of the study. Microarray results and bioinformatical analysis revealed 745 differentially expressed genes involved in various inflammatory processes, while qRT-PCR analysis of selected genes confirmed data universality and specificity of expression profiles in jSpA patients. The present study indicates that jSpA could be a polygenic disease with a possible malfunction in antigen recognition and activation of immunological response, migration of inflammatory cells and regulation of the immune system. Among genes involved in these processes TLR4, NLRP3, CXCR4 and PTPN12 showed almost consistent expression in study patients diagnosed with jSpA. Those genes and their products could therefore potentially be used as novel biomarkers, possibly predictive of disease prognosis and response to therapy, or even as a target for new therapeutic approaches.

Aberrant expression of microRNAs in T cells from patients with ankylosing spondylitis contributes to the immunopathogenesis

Ankylosing spondylitis (AS) is a chronic inflammatory disorder characterized by dysregulated T cells. We hypothesized that the aberrant expression of microRNAs (miRNAs) in AS T cells involved in the pathogenesis of AS. The expression profile of 270 miRNAs in T cells from five AS patients and five healthy controls were analysed by real-time polymerase chain reaction (PCR). Thirteen miRNAs were found potentially differential expression. After validation, we confirmed that miR-16, miR-221 and let-7i were over-expressed in AS T cells and the expression of miR-221 and let-7i were correlated positively with the Bath Ankylosing Spondylitis Radiology Index (BASRI) of lumbar spine in AS patients. The protein molecules regulated by miR-16, miR-221 and let-7i were measured by Western blotting. We found that the protein levels of Toll-like receptor-4 (TLR-4), a target of let-7i, in T cells from AS patients were decreased. In addition, the mRNA expression of interferon (IFN)-γ was elevated in AS T cells. Lipopolysaccharide (LPS), a TLR-4 agonist, inhibited IFN-γ secretion by anti-CD3(+) anti-CD28 antibodies-stimulated normal T cells but not AS T cells. In the transfection studies, we found the increased expression of let-7i enhanced IFN-γ production by anti-CD3(+) anti-CD28(+) lipopolysaccharide (LPS)-stimulated normal T cells. In contrast, the decreased expression of let-7i suppressed IFN-γ production by anti-CD3(+) anti-CD28(+) LPS-stimulated AS T cells. In conclusion, we found that miR-16, miR-221 and let-7i were over-expressed in AS T cells, but only miR-221 and let-7i were associated with BASRI of lumbar spine. In the functional studies, the increased let-7i expression facilitated the T helper type 1 (IFN-γ) immune response in T cells.

How to translate basic knowledge into clinical application of biologic therapy in spondyloarthritis

Spondyloarthritis (SpA) is a family of many diseases, and these diseases share some clinical, genetic, and radiologic features. The disease process in the spine at the beginning is spinal inflammation, in which TNFα is the principal cytokine involved. Therefore, the dramatic clinical and pathologic response of anti-TNFα therapy in SpA is based upon the presence of increased TNFα in synovial tissues and sacroiliac joints, which perpetuates chronic inflammation. The increased Toll-like receptors (TCR) 2 and 4 in the serum, peripheral blood mononuclear cells, or synovial tissues of ankylosing spondyloarthritis (AS) or SpA patients suggest that SpA is highly associated with innate immunity. Any drug including anti-TNFα blocker which can downregulate the TCR, infiltrated neutrophils, or CD163+ macrophages in the synovial tissue is the rationale for the management of SpA. Like rheumatoid arthritis, the increased TH22 and TH17 cells either in blood, synovial fluid, or synovial tissues were also demonstrated in SpA. Thus, TH17 and TH22 may be reasonable cellular targets for therapeutic intervention. Drugs (anti-IL6R or anti-IL6) which can reduce the binding of IL6 and IL6R to the cell surface may be beneficial in SpA. Many proteins are implicated in the new bone formation (syndesmophyte) or ankylosis in AS or SpA. The enhanced BMP and Wnt pathway will activate osteoblasts which promote the new bone formation. However, no drug including anti-TNFα can stop or prevent the syndesmophyte in AS. In summary, looking for new targeting therapies for either anti-inflammation (beyond anti-TNF) or anti-bone formation (including anti-TGFβ or PDGF) is warranted in the future.

Lack of association of TLR4 polymorphisms with susceptibility to rheumatoid arthritis and ankylosing spondylitis: a meta-analysis

OBJECTIVE

The aim of the study was to determine whether polymorphisms of toll-like receptor 4 (TLR4) confer susceptibility to rheumatoid arthritis (RA) and ankylosing spondylitis (AS).

METHODS

A meta-analysis was conducted on the association between the D299G/T399I polymorphisms and RA/AS (when available) using (1) the allelic contrast, (2) the recessive, (3) the dominant, and (4) the additive models.

RESULTS

A total of eleven relevant studies met the inclusion criteria were identified, including RA: D299G (six studies), T399I (three studies); AS: D299G (five studies), T399I (four studies). Meta-analysis was performed with fixed/random effect models. Overall, no significant RA/AS risk was found in all genetic models when all studies were pooled into the meta-analysis (P>0.05).

CONCLUSIONS

The present study might suggest that TLR4 D299G/T399I polymorphisms are not associated with RA/AS susceptibility.

The potential importance of Toll-like receptors in ankylosing spondylitis

Cells involved in innate immunity scan for pathogens via extracellular and intracellular (endosomal) pattern recognition receptors (PRRs). Engagement of PRRs by a specific ligand results in downstream activation of intracellular inflammatory cascades. There is emerging evidence indicating that one class of PRR, the Toll-like receptor (TLR) plays a potential role in the pathogenesis of spondyloarthropathies. Since certain Gram-negative bacteria are known to act as triggers for reactive arthritis, there has been much interest in studying the role of TLRs in spondyloarthropathies. In this article, we introduce the immunology of TLRs followed by a discussion of their potential role in ankylosing spondylitis.

Whole-blood gene expression profiling in ankylosing spondylitis shows upregulation of toll-like receptor 4 and 5

OBJECTIVE

to identify differentially expressed genes in peripheral blood cells (PBC) of patients with ankylosing spondylitis (AS) relative to healthy controls and controls with systemic inflammation.

METHODS

we investigated PBC samples of 16 patients with AS and 14 matched controls, in addition to systemic lupus erythematosus (SLE) and systemic sclerosis (SSc) samples utilizing Illumina Human Ref-8 BeadChips. Candidate genes were confirmed using quantitative PCR. Subsequently, these genes were also validated in a separate sample of 27 patients with AS [before and after anti-tumor necrosis factor (anti-TNF) treatment] and 27 matched controls.

RESULTS

we identified 83 differentially expressed transcripts between AS patients and controls. This gene list was filtered through the lists of differentially expressed transcripts in SLE and SSc, which resulted in identification of 52 uniquely dysregulated transcripts in AS. Many of the differentially expressed genes belonged to Toll-like receptor (TLR) and related pathways. TLR4 and TLR5 were the only dysregulated TLR subtypes among AS patients. We confirmed the overexpression of TLR4 and TLR5 in AS patients in comparison to controls (p = 0.012 and p = 0.006, respectively) and SLE (p = 0.002, p = 0.008) using quantitative PCR in the same sample. Similarly, TLR4 (p = 0.007) and TLR5 (p = 0.012) were significantly upregulated among the AS patients before anti-TNF treatment in the confirmatory sample. TLR4 (p = 0.002) and TLR5 (p = 0.025) decreased significantly after anti-TNF treatment.

CONCLUSION

PBC gene expression profiling in AS shows an upregulation of TLR4 and TLR5. This supports the importance of TLR subtypes in the pathogenesis of AS that are responsible for the immune response to Gram-negative bacteria.

Toll-like receptor expression in monocytes in patients with chronic kidney disease and haemodialysis: relation with inflammation

BACKGROUND

Inflammation is one of the main contributors to atherosclerosis in haemodialysis (HD) patients. Activation of Toll-like receptors (TLRs) leads to inflammatory response. In this study, we aimed to evaluate the expression of TLRs on monocytes and relate their expression with inflammation in chronic kidney disease (CKD) and HD patients.

METHODS

Thirty-four age- and gender-matched controls and stage 3-4 CKD patients and thirty-two HD patients were included in each study group. The effect of HD on the expression of Toll-like receptor-2 (TLR-2) and Toll-like receptor-4 (TLR-4) on CD14( +) monocytes was determined at the beginning (baseline), during (120 min) and following (300 min and 24 h) HD and compared with control and stage 3-4 CKD groups. The HD procedure was performed by using low-flux polysulphone dialysers. In addition, serum IL-6 levels were evaluated in both groups at baseline and after a HD session.

RESULTS

The percentage of CD14( +) monocytes expressing TLR-2 were similar in all of the study groups, whereas the percentage of CD14( +) monocytes expressing TLR-4 were significantly lower in both stage 3-4 CKD and HD patients at baseline than in controls. The mean fluorescence intensities (MFI) of TLR-2 were significantly lower in controls than in stage 3-4 CKD and HD patients at baseline. The MFI of TLR-4 was similar in all of the groups. The percentage of CD14( +) monocytes expressing TLR-2 did not change during and after HD. The MFI of TLR-2 decreased at 120 min of HD compared with baseline (1837 ± 672 vs 1650 ± 578, P < 0.05), and recovered back to baseline values at 300 min and at 24 h post-HD. MFI of TLR-4 increased at 24 h compared with baseline (941 ± 294 vs 1087 ± 441, P < 0.05). Serum IL-6 levels correlated with MFI of TLR-2 and TLR-4 in stage 3-4 CKD patients and in HD patients at baseline and after HD in univariate analysis. Stepwise multiple regression analysis revealed that MFI of TLR-2 was an independent determinant of serum IL-6 concentrations in stage 3-4 CKD and in HD patients at baseline, at 300 min and at 24 h post-HD. Conclusions. Our study demonstrates that TLR-2 is associated with the inflammatory response of non-dialysed and dialysed CKD patients.

Rheumatic manifestations of inflammatory bowel disease

This article reviews the literature concerning rheumatic manifestations of inflammatory bowel disease (IBD), including common immune-mediated pathways, frequency, clinical course and therapy. Musculoskeletal complications are frequent and well-recognized manifestations in IBD, and affect up to 33% of patients with IBD. The strong link between the bowel and the osteo-articular system is suggested by many clinical and experimental observations, notably in HLA-B27 transgenic rats. The autoimmune pathogenic mechanisms shared by IBD and spondyloarthropathies include genetic susceptibility to abnormal antigen presentation, aberrant recognition of self, the presence of autoantibodies against specific antigens shared by the colon and other extra-colonic tissues, and increased intestinal permeability. The response against microorganisms may have an important role through molecular mimicry and other mechanisms. Rheumatic manifestations of IBD have been divided into peripheral arthritis, and axial involvement, including sacroiliitis, with or without spondylitis, similar to idiopathic ankylosing spondylitis. Other periarticular features can occur, including enthesopathy, tendonitis, clubbing, periostitis, and granulomatous lesions of joints and bones. Osteoporosis and osteomalacia secondary to IBD and iatrogenic complications can also occur. The management of the rheumatic manifestations of IBD consists of physical therapy in combination with local injection of corticosteroids and nonsteroidal anti-inflammatory drugs; caution is in order however, because of their possible harmful effects on intestinal integrity, permeability, and even on gut inflammation. Sulfasalazine, methotrexate, azathioprine, cyclosporine and leflunomide should be used for selected indications. In some cases, tumor necrosis factor-α blocking agents should be considered as first-line therapy.

Toll-like receptors, transduction-effector pathways, and disease diversity: evidence of an immunobiological paradigm explaining all human illness?

Membrane-bound Toll-like receptors (TLRs) are frontline guardians in the mammalian innate immune system. They primarily function to recognize pathogen-associated molecular patterns (PAMPs) of invading microorganisms and on activation mount rapid, nonspecific innate responses and trigger sequential delayed specific adaptive cellular responses, which are mediated by complex signal transduction pathways involving adaptor molecules, costimulatory ligands and receptors, kinases, transcription factors, and modulated gene expression. Increasing evidence of multiple functionality and diversity suggests TLRs play critical roles in noninfective medical conditions such as cardiovascular, gastrointestinal, neurologic, musculoskeletal, obstetric, renal, liver, and dermatologic diseases, allergy, autoimmunity, and tissue regeneration. The significance of TLR heterogeneity underscores the possibility for establishing a universal immunobiological model to explain all human disease. Novel immunomodulatory therapies targeting specific or multiple TLRs may in the future offer new tools to combat or eradicate pathogenesis potentially transforming the landscape of current medical treatments.

Increased responsiveness to toll-like receptor 4 stimulation in peripheral blood mononuclear cells from patients with recent onset rheumatoid arthritis

Background. Cell signaling via Toll-like receptors (TLRs) leads to synovial inflammation in rheumatoid arthritis (RA). We aimed to assess effects of TLR2 and TLR4 stimulation on proinflammatory cytokine production by peripheral blood mononuclear cells (PBMCs) from patients with recent-onset RA, osteoarthrosis (OA), and healthy control (HC). Methods. PBMCs were stimulated with LPS, biglycan and cytokine mix. Cytokines were analyzed in supernatants with ELISA. Expression of toll-like receptors mRNA in leukocytes was analyzed using real-time qPCR. Results. PBMCs from RA patients spontaneously produced less IL-6 and TNFα than cells from OA and HC subjects. LPS increased cytokines' production in all groups. In RA patients increase was dramatic (30 to 48-fold and 17 to 31-fold, for respective cytokines) compared to moderate (2 to 8-fold) in other groups. LPS induced 15-HETE generation in PBMCs from RA (mean 251%) and OA patients (mean 43%), although only in OA group, the increase was significant. TLR2 and TLR4 gene expressions decreased in response to cytokine mix, while LPS enhanced TLR2 expression in HC and depressed TLR4 expression in OA patients. Conclusion. PBMCs from recent-onset RA patients are overresponsive to stimulation with bacterial lipopolysaccharide. TLR expression is differentially regulated in healthy and arthritic subjects.

Preliminary clinical measurement of the expression of TNF-related apoptosis inducing ligand in patients with ankylosing spondylitis

It has recently been reported that tumor necrosis factor (TNF)-related apoptosis inducing ligand (TRAIL) plays various roles in such autoimmune diseases as diabetes, multiple sclerosis (MS), and systemic lupus erythematosus (SLE). However, it has still remained unclear whether there is a close relationship between TRAIL and ankylosing spondylitis (AS). In this study, we investigated the association between the expression of TRAIL and AS. The specific messenger ribonucleic acid (mRNA) levels of TRAIL in peripheral blood mononuclear cells (PBMCs), serum sTRAIL, and TNF-alpha concentrations from 60 AS patients, 20 rheumatoid arthritis (RA) patients, and 30 healthy controls were determined by real-time fluorescent quantitative polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA). The results indicated that the expression levels of TRAIL mRNA, and serum sTRAIL were significantly elevated in AS patients, compared with RA patients and healthy controls, and there was a close association between TRAIL mRNA and sTRAIL levels. However, there was no significant difference between human leukocyte antigen (HLA)-B27-positive and -negative AS patients. In HLA-B27-positive patients, TRAIL mRNA and sTRAIL closely correlated with serum TNF-alpha and C-reactive protein (CRP), but did not correlate in HLA-B27-negative patients. In conclusion, upregulated expression of TRAIL might be somewhat specific for evaluation of AS.