IL-17 induces the production of IL-16 in rheumatoid arthritis

Exploring the molecular mechanisms of the involvement of GZMB-Caspase-3-GSDME pathway in the progression of rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune disease with an unclear pathogenesis. Granzyme B (GZMB) has been reported as a potential therapeutic target for RA treatment, but its mechanism remains unclear. This study aimed to explore the molecular mechanism of the GZMB-Caspase-3-GSDME pathway in the progression of RA. An SD rat model of RA was constructed, and Western blot analysis was used to verify the high expression of the GZMB gene in RA rats. Functional validation was then performed on two common RA cells, HFLS-RA cells and MH7A cells, by inhibiting the GZMB gene with the GZMB siRNA virus. Cell proliferation function was measured by CCK8 and EDU assays; cell pyroptosis markers were detected by the LDH assay; inflammation factor levels were measured by ELISA; and the expression of GZMB and pathway-related genes and proteins was measured by Western blot. After GZMB silencing, cell proliferation was decreased compared to the control group, and the inflammation factors IL-1b and IL-18, as well as the pyroptosis markers LDH, IL-1b, and IL-18, were all reduced. The GZMB-related proteins GZMB, caspase-3, and Gasdermin E (GSDME) were also decreased. Therefore, GZMB silencing reduces pyroptosis by inhibiting caspase-3 and Gasdermin E decomposition. In summary, GZMB silencing inhibits the activation of caspase-3 and Gasdermin E, thereby delaying inflammation in RA. The GZMB gene may be a potential therapeutic target for RA.

Pathogenesis of Collagen-Induced Arthritis: Role of Immune Cells with Associated Cytokines and Antibodies, Comparison with Rheumatoid Arthritis

Collagen-induced arthritis is the most com-mon in vivo model of rheumatoid arthritis used for investigation of new potential therapies in preclinical research. Rheumatoid arthritis is a systemic inflammatory and autoimmune disease affecting joints, accompanied by significant extra-articular symptoms. The pathogenesis of rheumatoid arthritis and collagen-induced arthritis involves a so far properly unexplored network of immune cells, cytokines, antibodies and other factors. These agents trigger the autoimmune response leading to polyarthritis with cell infiltration, bone and cartilage degeneration and synovial cell proliferation. Our review covers the knowledge about cytokines present in the rat collagen-induced arthritis model and the factors affecting them. In addition, we provide a comparison with rheumatoid arthritis and a description of their important effects on the development of both diseases. We discuss the crucial roles of various immune cells (subtypes of T and B lymphocytes, dendritic cells, monocytes, macrophages), fibroblast-like synoviocy-tes, and their related cytokines (TNF-α, IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12, IL-17, IL-23, GM-CSF, TGF-β). Finally, we also focus on key antibodies (rheu-matoid factor, anti-citrullinated protein antibodies, anti-collagen II antibodies) and tissue-degrading enzymes (matrix metalloproteinases).

Enhanced Anti-Inflammatory Effect of the Combination of Lactiplantibacillus plantarum LS/07 with Methotrexate Compared to Their Monotherapies Studied in Experimental Arthritis

The gut microbiome (GM) of rheumatic arthritis (RA) patients is often altered in composition and function. Moreover, methotrexate (MTX), one of the most frequently used disease-modifying antirheumatic drugs, is known to negatively affect GM composition. The modulation of immune system activity is one of the therapeutic benefits of probiotics. The aim of the current investigation was to determine the impact of MTX therapy combined with one of the Lactobacillus strains, Lactoplantibacillus plantarum LS/07 (LB), on adjuvant arthritis (AA) in rats. Methods focused on biometric and inflammatory parameters in AA, particularly on plasmatic levels of IL-17A, MMP-9, and MCP-1, and the activities of gamma-glutamyl transferase in the spleen and joints were applied. Enhancing the effect of MTX, LB positively influenced all biometric and inflammatory parameters. The findings of the present study may be of help in proposing novel therapeutic strategies for RA patients.

Antibacterial and Anti-Inflammatory Potential of Chinese Medicinal Herbs: Lonicerae flos, Lonicerae japonicae flos, Scutellaria baicalensis Georgi, and Forsythia suspensa

Chinese herbal medicine (CHM) represents a potent, safe, and efficacious reservoir of treatment options against an array of microbial infections and inflammatory diseases. It has a long history of positive clinical outcomes with minimal or no side effects while enhancing and bolstering the host's protection against infections. With its unique ability to prevent, treat, and manage a wide range of diseased conditions, CHM has been successfully practiced in China for thousands of years. In the modern medical era, where harsh therapeutic drugs and antimicrobial resistance (AMR) present a significant challenge, CHM warrants further exploration. The present review highlights and focuses on 4 major CHM-based herbs, that is, ( Lonicerae flos [ LF] , Lonicerae japonicae flos [ LJF] , Scutellaria baicalensis Georgi [ SBG] , and Forsythia suspensa [ FS]) in terms of their antibacterial and anti-inflammatory efficacies. A detailed literature survey was done by the team using a systematic electronic search from PubMed, Science Direct, Google Scholar, Research Gate, books, etc. This was followed by data collecting, pertinent data extraction, in-depth analysis, and composing the final review. Each herb has been discussed in detail describing its mechanism adopted and the bioactive components involved in alleviating bacterial infections and inflammatory damage. Further, proof of efficacy by detailing the major past studies and major findings has been discussed for each of the 4 herbs. This review will give the scientific community the opportunity to update their knowledge on the subject, which is crucial for heralding the process of bringing CHM-based medicines closer to clinical development given the area of alternative medicine's rapid advancements.

Association of a miRNA-binding site polymorphism in IL-16 gene with disease risk and clinical characteristics of rheumatoid arthritis and systemic lupus erythematosus

INTRODUCTION

/objectives. Single nucleotide polymorphisms (SNPs) located at the 3'-UTR region of the target genes of microRNAs (miRNAs) can dysregulate their expression via disrupting the binding site of miRNAs. Interleukin-16 (IL-16) is involved in the pathogenesis of rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). In the current study, we assessed the possible association between rs1131445 polymorphism in IL-16 gene with risk and clinical characteristics of RA and SLE in the Iranian population.

METHODS

In this case-control study, 120 patients with RA, 120 patients with SLE, and 120 unrelated healthy subjects were collected to estimate rs1131445 (T > C) polymorphism in IL-16 gene using real-time PCR high-resolution melting (HRM) method.

RESULTS

Our results demonstrated considerable associations between TC genotype and C allele of rs1131445 with enhanced risk of RA (OR_{for TC genotype} = 3.01; 95%CI [1.667-5.526], P < 0.001; OR_{for C allele} = 1.96; 95%CI [1.314-2.941], P < 0.001). Besides, there was a marginal association between CC genotype and increased risk of RA (P: 0.031). However, there was an insignificant correlation between genotypes and allele frequencies of rs1131445 with incidence risk of SLE (P > 0.05). Moreover, stratification analysis indicated that the C allele in rs1131445 was linked with disease activity-associated laboratory parameters such as CRP and ESR in both RA and SLE patients, as well as the higher incidence of neurological symptoms in SLE subjects (P < 0.05).

CONCLUSION

These results proposed a significant association between IL-16 polymorphism and augmented risk of RA and clinical characteristics of RA and SLE.

A comprehensive profile of chemokines in the peripheral blood and vascular tissue of patients with Takayasu arteritis

Background

Takayasu arteritis (TAK) is a chronic granulomatous large vessel vasculitis with multiple immune cells involved. Chemokines play critical roles in recruitment and activation of immune cells. This study aimed to investigate chemokine profile in the peripheral blood and vascular tissue of patients with TAK.

Methods

A total of 58 patients with TAK and 53 healthy controls were enrolled. Chemokine array assay was performed in five patients with TAK and three controls. Chemokines with higher levels were preliminarily validated in 20 patients and controls. The validated chemokines were further confirmed in another group of samples with 25 patients and 25 controls. Their expression and distribution were also examined in vascular tissue from 8 patients and 5 controls. Correlations between these chemokines and peripheral immune cells, cytokines, and disease activity parameters were analyzed. Their serum changes were also investigated in these 45 patients after glucocorticoids and immunosuppressive treatment.

Results

Patients and controls were age and sex-matched. Twelve higher chemokines and 4 lower chemokines were found based on the chemokine array. After validation, increase of 5 chemokines were confirmed in patients with TAK, including CCL22, RANTES, CXCL16, CXCL11, and IL-16. Their expressions were also increased in vascular tissue of patients with TAK. In addition, levels of RANTES and IL-16 were positively correlated with peripheral CD3⁺CD4⁺ T cell numbers. Close localization of CCL22, CXCL11, or IL-16 with inflammatory cells was also observed in TAK vascular tissue. No correlations were found between these chemokines and cytokines (IL-6, IL-17, IFN-γ) or inflammatory parameters (ESR, CRP). No differences were observed regarding with these chemokines between active and inactive patients. After treatment, increase of CCL22 and decrease of RANTES and CXCL16 were found, while no changes were showed in levels of CXCL11 and IL-16.

Conclusions

CCL22, RANTES, CXCL16, CXCL11, and IL-16 were identified as the major chemokines involved in the recruitment of immune cells in the vascular tissue of patients with TAK. Additionally, the persistently high levels of CCL22, CXCL11, and IL-16 observed after treatment indicate their role in vascular chronic inflammation or fibrosis and demonstrate the need for developing more efficacious treatment options.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-022-02740-x.

TLRs Play Crucial Roles in Regulating RA Synoviocyte

Rheumatoid arthritis (RA) is an autoimmune inflammatory disease comparing the inflammation of synovium. Macrophage-like synoviocytes and fibroblast-like synoviocytes (synoviocytes) are crucial ingredients of synovium. Therein, a lot of research has focused on synoviocytes. Researches demonstrated that TLR1, TLR2, TLR3, TLR4, TLR5, TLR6 TLR7 and TLR9 are expressed in synoviocyte. Additionally, the expression of TLR2, TLR3, TLR4 and TLR5 is increased in RA synoviocyte. In this paper, we review the exact role of TLR2, TLR3, TLR4 and TLR5 participate in regulating the production of inflammatory factors in RA synoviocyte. Furthermore, we discuss the role of vasoactive intestinal peptide (VIP), MicroRNA, Monome of Chinese herb and other cells (Monocyte and T cell) influence the function of synoviocyte by regulating TLRs. The activation of toll-like receptors (TLRs) in synoviocyte leads to the aggravation of arthritis, comparing with angiogenesis and bone destruction. Above all, TLRs are promising targets for managing RA.

Interleukin-18 in Brazilian Rheumatoid Arthritis Patients: Can Leflunomide Reduce It?

OBJECTIVES

Rheumatoid arthritis affects about 1% of the world's population. This is a chronic autoimmune disease. It is predominant in females with progressive joint damage. Immune cells are involved, especially Th1/Th17 lymphocytes and their inflammatory cytokines. These proteins have different functions in the immune system, such as IL-16 is a chemotactic factor; IL-18 can activate NFκB transcription producing inflammatory proteins; IL-31 can activate the JAK/STAT pathway which leads to the production of inflammatory factors in chronic diseases; IL-33 promotes IL-16 secretion which causes lymphocyte recruitment, and IL-32 and IL-34 appear to increase TNF secretion by macrophages activation in AR. The aim of this study was to evaluate serum levels of IL-16, IL-18, IL-31, IL-32, IL-33, and IL-34 and compare them with the severity and treatment of RA patients if there are any correlations.

METHODS

A total of 140 RA patients and 40 healthy donors were recruited from the Department of Rheumatology at Hospital das Clínicas from the Federal University of Pernambuco. 60 AR patients were naïve for any treatment. Serum cytokine levels were determined using an ELISA kit.

RESULTS

Serum IL-16 (p = 0.0491), IL-18 (p < 0.0001), IL-31 (p = 0.0004), and IL-32 (p = 0.0040) levels were significantly increased in RA patients compared with healthy donors. It was observed that patients using leflunomide had the lowest IL-18 levels, close to controls levels (p = 0.0064).

CONCLUSION

IL-16, IL-18, IL-31, and IL-32 are increased in the serum of RA patients. IL-18 is at lower levels in those AR who are taking leflunomide as treatment.

Inhibition of regulator of G protein signaling 10, aggravates rheumatoid arthritis progression by promoting NF-κB signaling pathway

Rheumatoid arthritis (RA) is the most common inflammatory arthropathy, with evidence pointing to an immune-mediated etiology that propagates chronic inflammation. Although targeted immune therapeutics and aggressive treatment strategies have substantially improved, a complete understanding of the associated pathological mechanisms of the disease remains elusive. This study aimed at investigating whether regulator of G protein signaling 10 (RGS10) could affect rheumatoid arthritis (RA) pathology by regulating the immune response. A DBA/J1 mouse model of RA was established and evaluated for disease severity. RGS10 expression was inhibited by adeno-associated virus in vivo. Moreover, small interfering RNA was used to downregulate RGS10 expression in raw 264.7 cells in vitro. Results showed that RGS10 inhibition augmented RA severity, and attenuated the increase in expression of inflammatory factors. Furthermore, activated NF-κB signaling pathways were detected following RGS10 inhibition. These results revealed that RGS10 inhibition directly aggravated the RA pathological process by activating the NF-κB signaling pathway. Therefore, RGS10 is a promising novel therapeutic target for RA treatment with a potential clinical impact.

Serum interleukin-16 significantly correlates with the Vasculitis Damage Index in antineutrophil cytoplasmic antibody-associated vasculitis

Background

Interleukin (IL)-16 is a T cell chemoattractant produced by peripheral mononuclear cells. We investigated whether IL-16 plays a pro- or an anti-inflammatory role in antineutrophil cytoplasmic antibody-associated vasculitis (AAV). Furthermore, we investigated whether the level of IL-16 could predict the activity and extent of organ damage in AAV based on AAV-specific indices.

Methods

Seventy-eight patients with AAV from a prospective observational cohort were included in this analysis. Blood sampling and clinical assessments, including the Birmingham Vasculitis Activity Score (BVAS), Five-Factor Score (FFS), Short Form 36-item Health Survey (SF-36), and Vasculitis Damage Index (VDI), were performed, and laboratory data were collected. Serum IL-16 was measured from stored sera.

Results

The median age was 62.0 years, and 27 patients were male. The median serum IL-16 concentration was 84.1 pg/dL, and the median BVAS, FFS, VDI, and SF-36 scores were 7.0, 1.0, 3.0, and 48.0, respectively. Among the AAV-related indices, the serum IL-16 concentration was correlated with VDI (R² = 0.306, P = 0.006), but not with BVAS (R² = 0.024, P = 0.834), FFS (R² = − 0.069, P = 0.550), or SF-36 (R² = − 0.015, P = 0.898). The serum IL-16 concentration also did not correlate with either the erythrocyte sedimentation rate or the C-reactive protein concentration. Per our analysis based on organ involvement, only patients with ear, nose, and throat manifestations had higher serum IL-16 concentrations relative to those with other conditions (P = 0.030).

Conclusions

This was the first study to elucidate the clinical implication of serum IL-16 in patients with AAV. We found that the serum IL-16 level may reflect the cross-sectional VDI scores among AAV-specific indices. Future studies with larger numbers of patients and serial measurements could provide more reliable data on the clinical implications of serum IL-16 in AAV.

Correlation of myomir-206 and proinflammatory cytokines (IL-16 and IL-17) in patients with rheumatoid arthritis

Introduction

Rheumatoid arthritis (RA) is a persistent autoimmune disease in which the activity of proinflammatory cytokines and the imbalance, related to the inflammatory process, between elements of bone tissue remodeling such as osteoclasts and osteoblasts play a key role in development of erosions and bone destruction. MicroRNAs are important regulators of skeletal remodeling and are involved in RA pathogenesis. Myomir-206 (miR-206) is unrivalled among the myomirRs, where it is expressed in skeletal muscle and either absent or minimally expressed in other tissues

Material and methods

This study was designed to analyze the miR-206 expression pattern in peripheral blood mononuclear cells (PBMCs) using quantitative real time polymerase chain reaction and its correlation with IL-16/IL-17 proinflammatory cytokines in two groups – 20 healthy individuals and 30 patients with RA.

Results

Elevated expression of miR-206 was observed in RA patients compared with healthy controls (p < 0.001). A significant increase in both IL-17 and IL-16 serum levels was found in the RA group (p < 0.01 and p < 0.05; respectively) compared to the control group. miR-206 expression level and IL-17 production were directly positively correlated (r = 0.491; p < 0.01). ROC analysis of miR-206 showed a cutoff value of 2.7 with 70% sensitivity, 85% specificity, and the area under the curve was 0.802 (p < 0.001) with the 95% confidence interval from 0. 676 to 0.927

Conclusions

Taken together, our results indicate the importance of miR-206 expression in patients with RA, as a potential new biomarker that affects bone loss/deformity and its collaborative role with proinflammatory cytokines such as IL-16 and IL-17 in RA bone metabolism. Particular interest should be given to further research to determine the contribution of expression of miR-206 in RA pathogenesis

Repetitive Exposure of IL-17 Into the Murine Air Pouch Favors the Recruitment of Inflammatory Monocytes and the Release of IL-16 and TREM-1 in the Inflammatory Fluids

The infiltration of Th17 cells in tissues and organs during the development of many autoimmune diseases is considered a key step toward the establishment of chronic inflammation. Indeed, the localized and prolonged release of IL-17 in specific tissues has been associated with an increased severity of the inflammatory response that remains sustained over time. The cellular and molecular mechanisms behind these effects are far from being clear. In this study we investigated the effects of two repetitive administration of recombinant IL-17 into the murine air pouch to simulate a scenario where IL-17 is released over time in a pre-inflamed tissue. Consistent with our previous observations, mice receiving a single dose of IL-17 showed a transitory influx of neutrophils into the air pouch that peaked at 24 h and declined at 48 h. Conversely, mice receiving a double dose of the cytokine—one at time 0 and the second after 24 h—showed a more dramatic inflammatory response with almost 2-fold increase in the number of infiltrated leukocytes and significant higher levels of TNF-α and IL-6 in the inflammatory fluids. Further analysis of the exacerbated inflammatory response of double-injected IL-17 mice showed a unique cellular and biochemical profile with inflammatory monocytes as the second main population emigrating to the pouch and IL-16 and TREM-1 as the most upregulated cytokines found in the inflammatory fluids. Most interestingly, mice receiving a double injection of IL-1β did not show any change in the cellular or biochemical inflammatory response compared to those receiving a single injection or just vehicle. Collectively these results shed some light on the function of IL-17 as pro-inflammatory cytokine and provide possible novel ways to target therapeutically the pathogenic effects of IL-17 in autoimmune conditions.

Protective effects of Paederia scandens extract on rheumatoid arthritis mouse model by modulating gut microbiota

ETHNOPHARMACOLOGICAL RELEVANCE

Paederia scandens (Lour.) Merr. (P. scandens) has been traditionally used to treat the pain of rheumatism.

AIM OF THE STUDY

The purpose of this study was to investigate the possible influences of P. scandens on the progression of rheumatoid arthritis (RA), inflammatory responses and gut bacterial communities in RA mouse model.

MATERIALS AND METHODS

collagen-induced arthritis (CIA) mice were orally administered with P. scandens extract (PSE) for 24 days. Then, pro-inflammatory cytokine levels in the serum were measured, and gut microbiota was examined with Illumina HiSeq.

RESULTS

Compared with the vehicle group, PSE significantly inhibited paw swelling and reduced arthritis score. Histological examination of ankle soft tissue of demonstrated PSE effectively inhibited the tissue fibrosis and inflammatory cell infiltration. The increased serum levels of TNF-α, IL-1β, IL-6, IL-7, and IL-23 in RA mice were significantly suppressed by PSE. Moreover, PSE treatment help restore gut microbial ecosystem altered in RA mice including decreasing relative abundance of inflammatory related microorganisms, Desulfovibrio, Mucispirillum, Helicobacter, and Lachnospiraceae.

CONCLUSION

These results suggest that PSE has therapeutic effects in RA mice with CIA, showing the potential as anti-arthritis reagent.

Neutrophil-Derived Interleukin 16 in Premetastatic Lungs Promotes Breast Tumor Cell Seeding

The premetastatic niche in distant organs prior to metastatic cell arrival emerged as an important step in the metastatic cascade. However, molecular mechanisms underlying this process are still poorly understood. In particular, whether neutrophil recruitment at a premetastatic stage promotes or inhibits metastatic cell seeding has to be clarified. We aimed at unraveling how neutrophil infiltration in lung parenchyma induced by the distant primary tumor influences the establishment of lung metastasis. Elevated neutrophil counts and IL-16 levels were found in premetastatic lungs in a syngenic mouse model using 4T1 tumor cells. 4T1 cell-derived soluble factors stimulated IL-16 secretion by neutrophils. The functional contribution of IL-16 is supported by metastasis burden reduction in lungs observed on instillation of an IL-16 neutralizing antibody. Moreover, IL-16 promotes in vitro 4T1 cell adhesiveness, invasiveness, and migration. In conclusion, at a premetastatic stage, neutrophil-derived IL-16 favors tumor cell engraftment in lung parenchyma.

HtrA2 suppresses autoimmune arthritis and regulates activation of STAT3

Rheumatoid arthritis (RA) is an autoimmune disease that is related to the induction of T helper (Th)17 cells, which secrete interleukin-17, and activation of the signal transducer and activator of transcription (STAT) 3. The expression of high-temperature requirement protein A (HtrA) 2, a serine protease involved in apoptosis, was decreased in RA patients nonresponsive to drug treatment of RA. The aim of this study was to determine whether overexpression of HtrA2 has a therapeutic effect on RA. Th17 differentiation, osteoclastogenesis, and lymphocyte activation are increased in motor neuron degeneration (mnd)2 mice, which lack HtrA2 activity because of a missense mutation (Ser276Cys) in the protease domain of HtrA2. The inhibitor of HtrA2 also increased Th17 differentiation. On the other hand, HtrA2 induced cleavage of STAT3 and overexpression of HtrA2 attenuated CIA in a mouse model. HtrA2 overexpression inhibited plaque development as well as the differentiation of Th17 in ApoE^-/- mice after immunization with proteoglycans to induce a hyperlipidemia-based RA animal model. The therapeutic function of HtrA2 in inflammatory diseases is linked with Th17 development and the STAT3 pathway in splenocytes. These results suggest that HtrA2 participates in immunomodulatory activity where the upregulation of HtrA2 may shed light on therapeutic approaches to RA and hyperlipidemia.

Major involvement of bacterial components in rheumatoid arthritis and its accompanying oxidative stress, systemic inflammation and hypercoagulability

We review the evidence that infectious agents, including those that become dormant within the host, have a major role to play in much of the etiology of rheumatoid arthritis and the inflammation that is its hallmark. This occurs in particular because they can produce cross-reactive (auto-)antigens, as well as potent inflammagens such as lipopolysaccharide that can themselves catalyze further inflammagenesis, including via β-amyloid formation. A series of observables coexist in many chronic, inflammatory diseases as well as rheumatoid arthritis. They include iron dysregulation, hypercoagulability, anomalous morphologies of host erythrocytes, and microparticle formation. Iron dysregulation may be responsible for the periodic regrowth and resuscitation of the dormant bacteria, with concomitant inflammagen production. The present systems biology analysis benefits from the philosophical idea of "coherence," that reflects the principle that if a series of ostensibly unrelated findings are brought together into a self-consistent narrative, that narrative is thereby strengthened. As such, we provide a coherent and testable narrative for the major involvement of (often dormant) bacteria in rheumatoid arthritis.

PTEN ameliorates autoimmune arthritis through down-regulating STAT3 activation with reciprocal balance of Th17 and Tregs

PTEN is a tyrosine phosphatase with significant function in inhibiting STAT3 activation. Recently, inactivation of STAT3 has been demonstrated as a therapeutic candidate for autoimmune arthritis. The expression of PTEN controlled by p53 regulates autoimmune arthritis through modulating the balance between Th17 and Treg. We hypothesized that PTEN regulated by p53 might reduce CIA severity and inflammatory response via inhibiting STAT3 activation. Our results revealed that PTEN could ameliorate experimental autoimmune arthritis by reducing STAT3 activity and Th17 differentiation. Systemic infusion of PTEN overexpression downregulated CIA severity. In addition, PTEN overexpression decreased the activation of T cells and modulated reciprocal differentiation of Th17 and Treg cells. We observed that PTEN expression downregulated by p53 deficiency induced the activation of STAT3. Loss of p53 exacerbated autoimmune arthritis and dysregulated the population of Th17 and Treg. These data suggest that induction of STAT3-modulatory activity of PTEN may be a therapeutic target for rheumatoid arthritis therapy.

IL-14 and IL-16 are expressed in the thyroid of patients with either Graves' disease or Hashimoto's thyroiditis

OBJECTIVES

Cytokines have an important role in orchestrating the pathophysiology in autoimmune thyroid disease. The aim of the current study was to analyse the expression of interleukin (IL)-14 and IL-16 in the thyroid tissue of patients with Graves' disease (GD), Hashimoto's thyroiditis (HT) or multinodular goitre (MNG) and in that of normal individuals, in patients' intrathyroidal CD4(+) and CD8(+) T cells, and in patient and normal cultured thyroid follicular cells.

METHODS

The expression of IL-14 and IL-16 mRNA and protein was investigated using reverse transcription-polymerase chain reaction (RT-PCR) amplification, and Western blotting and ELISAs, respectively.

RESULTS

IL-14 mRNA expression was detected in thyroid tissue from 8/9 GD, 3/4 HT and 3/13 MNG patients and 1/6 normal individuals, and IL-16 mRNA expression in thyroid tissue from 9/9 GD, 4/4 HT and 9/13 MNG patients and 4/6 normal individuals. IL-14 mRNA expression was detected in intrathyroidal CD4(+) and CD8(+) T cells from 2/2 GD and 2/2 HT patients, while IL-16 mRNA was detected in samples from 1/2 HT patients but not in those from either patient with GD. IL-14 and IL-16 mRNA expression was found in thyroid follicular cells derived from 2/2 patient with GD and 1/1 normal individual. IL-14 protein was detected in thyroid tissue from 6/6 GD, 1/1 HT and 0/6 MNG patients and 0/6 normal individuals, and IL-16 protein in thyroid tissue from 6/6 GD, 1/1 HT and 1/6 MNG patients and 0/6 normal individuals. Expression of IL-14 protein was stimulated in thyroid follicular cells derived from two patients with GD and one normal individual by peripheral blood mononuclear cell (PBMC)-conditioned medium. Treatment of thyrocytes from two patients with GD and one normal individual with PBMC-conditioned medium and tumour necrosis factor (TNF)-α stimulated IL-16 protein expression. In normal thyrocytes, IL-16 protein synthesis was induced also by IL-1β, IL-17A, IL-4 and transforming growth factor (TGF)-β.

CONCLUSIONS

The data provide evidence that the intrathyroidal production of IL-14 and IL-16 is associated with the pathogenesis of autoimmune thyroid disease. Thyroid follicular cells display the ability to express IL-14 and IL-16 mRNA and can be stimulated to express IL-16 protein, by a panel of cytokines, and IL-14 protein, by as yet unidentified factors.

Pulmonary but Not Subcutaneous Delivery of BCG Vaccine Confers Protection to Tuberculosis-Susceptible Mice by an Interleukin 17-Dependent Mechanism

Some of the most promising novel tuberculosis vaccine strategies currently under development are based on respiratory vaccination, mimicking the natural route of infection. In this work, we have compared pulmonary and subcutaneous delivery of BCG vaccine in the tuberculosis-susceptible DBA/2 mouse strain, a model in which parenterally administered BCG vaccine does not protect against tuberculosis. Our data show that intranasally but not subcutaneously administered BCG confers robust protection against pulmonary tuberculosis challenge. In addition, our results indicate that pulmonary vaccination triggers a Mycobacterium tuberculosis-specific mucosal immune response orchestrated by interleukin 17A (IL-17A). Thus, IL-17A neutralization in vivo reduces protection and abrogates M. tuberculosis-specific immunoglobulin A (IgA) secretion to respiratory airways and lung expression of polymeric immunoglobulin receptor induced following intranasal vaccination. Together, our results demonstrate that pulmonary delivery of BCG can overcome the lack of protection observed when BCG is given parenterally, suggesting that respiratory tuberculosis vaccines could have an advantage in tuberculosis-endemic countries, where intradermally administered BCG has inefficient effectiveness against pulmonary tuberculosis.

IL-12p40 Homodimer Ameliorates Experimental Autoimmune Arthritis

IL-23 is the key cytokine that induces the expansion of Th17 cells. It is composed of p19 and p40 subunits of IL-12. The p40 subunit binds competitively to the receptor of IL-23 and blocks its activity. Our aim was to assess the preventive and therapeutic effect of the IL-12p40 homodimer (p40)2 subunit in autoimmune arthritis animal models. In the current study, using IL-1R antagonist-knockout mice and a collagen-induced arthritis model, we investigated the suppressive effect of (p40)2 on inflammatory arthritis. We demonstrated that the recombinant adenovirus-expressing mouse (p40)2 model prevented the development of arthritis when given before the onset of arthritis. It also decreased the arthritis index and joint erosions in the mouse model if transferred after arthritis was established. (p40)2 inhibited the production of inflammatory cytokines and Ag-specific T cell proliferation. It also induced CD4(+)CD25(+)Foxp3 regulatory T (Treg) cells in vitro and in vivo, whereas the generation of retinoic acid receptor-related organ receptor γt and Th17 cells was suppressed. The induction of Treg cells and the suppression of Th17 cells were mediated via activated STAT5 and suppressed STAT3. Our data suggest that (p40)2 suppressed inflammatory arthritis successfully. This could be a useful therapeutic approach in autoimmune arthritis to regulate the Th17/Treg balance and IL-23 signaling.

S-calprotectin (S100A8/S100A9): a potential marker of inflammation in patients with psoriatic arthritis

OBJECTIVE

To analyse levels of S100A8/S100A9 (calprotectin) and selected cytokines, in blood, in patients with psoriatic arthritis (PsA).

METHODS

Sixty-five patients with PsA were examined for clinical manifestations and laboratory measurements of S-calprotectin, ESR, hs-CRP, and selected cytokines. Thirty-two patients had mono-/oligoarthritis and 33 had polyarthritis. S-calprotectin, hs-CRP, and cytokines were measured using ELISA, immunoturbidimetry, and multiplex technology (Bio-Plex). Patients with PsA were compared with 31 healthy controls.

RESULTS

S-calprotectin and hs-CRP levels were significantly higher in patients with PsA compared with controls (P<0.001 and P<0.001, resp.). Patients suffering a polyarthritic disease pattern presented with significantly higher levels of S-calprotectin compared with controls and patients with mono-/oligoarthritis (P<0.001 and P=0.017, resp.). The levels of S-calprotectin correlated with hs-CRP (P<0.001; rs=0.441), swollen joint count (P=0.002, rs=0.397), and CXCL10 (P=0.046, rs=0.678) but not with any of the other cytokines evaluated. In multiple logistic regression analysis, S-calprotectin was the only variable significantly associated with psoriatic arthritis (P=0.002, OR=1.006, 95% CI=1.002-1.010).

CONCLUSION

S-calprotectin and hs-CRP levels were significantly higher in patients with PsA. A polyarthritic disease pattern showed higher levels of S-calprotectin than mono-/oligoarthritis. S-calprotectin is considered a potential marker of disease activity in patients with PsA.

Interleukin 16 expression changes in association with ovarian malignant transformation

OBJECTIVE

Long-term unresolved inflammation has been suggested as a risk factor for the development of various malignancies. The goal of this study was to examine whether the expression of interleukin (IL)-16, a proinflammatory cytokine, changes in association with ovarian cancer (OVCA) development.

STUDY DESIGN

In an exploratory study, changes in IL-16 expression in association with OVCA development and progression were determined using ovarian tissues and serum samples from healthy subjects (n = 10) and patients with benign (n = 10) and malignant ovarian tumors at early (n = 8) and late (n = 20) stages. In the prospective study, laying hens, a preclinical model of spontaneous OVCA, were monitored (n = 200) for 45 weeks with serum samples collected at 15-week interval. Changes in serum levels of IL-16 relative to OVCA development were examined.

RESULTS

The frequency of IL-16-expressing cells increased significantly in patients with OVCA (P < .001) compared to healthy subjects and patients with benign ovarian tumors. The concentration of serum IL-16 was higher in patients with benign tumors (P < .05) than in healthy subjects and increased further in patients with early-stage (P < .05) and late-stage (P < .03) OVCA. Increase in tissue expression and serum levels of IL-16 in patients with early and late stages of OVCA were positively correlated with the increase in ovarian tumor-associated microvessels. Prospective monitoring showed that serum levels of IL-16 increase significantly (P < .002) even before ovarian tumors become grossly detectable in hens.

CONCLUSION

This study showed that tissue expression and serum levels of IL-16 increase in association with malignant ovarian tumor development and progression.

A candidate gene analysis of canine hypoadrenocorticism in 3 dog breeds

Canine hypoadrenocorticism is believed to be an immune-related condition. It is rare in the overall dog population but shows a breed-related predisposition with Standard poodles and Portuguese water dogs having a greater prevalence of the condition. It shares many similarities with human primary adrenal insufficiency and is believed to be a naturally occurring, spontaneous model for the human condition. Short haplotype blocks and low levels of linkage disequilibrium in the human genome mean that the identification of genetic contributors to the condition requires large sample numbers. Pedigree dogs have high linkage disequilibrium and long haplotypes within a breed, increasing the potential of identifying novel genes that contribute to canine genetic disease. We investigated 222 SNPs from 42 genes that have been associated or may be implicated in human Addison's disease. We conducted case-control analyses in 3 pedigree dog breeds (Labrador retriever: affected n = 30, unaffected = 76; Cocker Spaniel: affected n = 19, unaffected = 53; Springer spaniel: affected n = 26, unaffected = 46) and identified 8 associated alleles in genes COL4A4, OSBPL9, CTLA4, PTPN22, and STXBP5 in 3 pedigree breeds. Association with immune response genes PTPN22 and CTLA4 in certain breeds suggests an underlying immunopathogenesis of the disease. These results suggest that canine hypoadrenocorticism could be a useful model for studying comparative genetics relevant to human Addison's disease.

Combination of MTX and LEF attenuates inflammatory bone erosion by down-regulation of receptor activator of NF-kB ligand and interleukin-17 in type II collagen-induced arthritis rats

The objectives of this study were to determine the effect of combination of methotrexate (MTX) and leflunomide (LEF) on type II collagen-induced arthritis rats and its mechanism. Curative effect was confirmed on CIA rats, which were randomized and divided into model, MTX, LEF and MTX + LEF group. Weights and joint swelling scores of rats were recorded. Interleukin (IL)-17, receptor activator of NF-κB ligand (RANKL) and osteoprotegerin (OPG) concentration in serum were determined by ELISA. H&E dyeing of joint was used to estimate the inflammation and osteoclasia extent. The mechanism was investigated through fibroblast-like synoviocytes isolated from RA patients. The effect of MTX and LEF on cell viability, and RANKL and OPG expression were indicated through MTT and RT-PCR analysis, respectively. Combination therapy would be effective in treating CIA rats. Joint swelling scores and IL-17 and RANKL level in serum were decreased obviously (P < 0.05), while OPG level was elevated (P < 0.05). Anti-inflammatory and anti-osteoclasia effect would be indicated by H&E dyeing results. Moreover, FLS cell viability was inhibited by combination treatment in vitro (P < 0.05), and expression of osteoclasia-related genes (RANKL and OPG) was modified (P < 0.05). Combination therapy would relive the synovium hypertrophy through depressing cell viability and osteoclasia through decreasing RANKL and increasing OPG expression. Otherwise, combination was superior to monotherapy.

IL-32 and IL-17 interact and have the potential to aggravate osteoclastogenesis in rheumatoid arthritis

Introduction

Interleukin (IL)-32 and IL-17 play critical roles in pro-inflammatory responses and are highly expressed in the synovium of patients with rheumatoid arthritis (RA). We investigated the relations between these two cytokines (IL-17 and IL-32) for their ability to induce each other and to stimulate osteoclasts in RA fibroblast-like synoviocytes (FLSs) and T cells.

Methods

FLSs were isolated through surgical synovectomy obtained from patients with RA or osteoarthritis (OA). Real-time PCR were performed to evaluate the expression of IL-32, IL-17 and osteoclast-related genes. Immunohistochemical staining and tartrate-resistant acid phosphatase (TRAP) staining were performed to determine the distribution of inflammatory cytokines and the presence of osteoclastogenesis.

Results

IL-17 induced the expression of IL-32 in the FLSs from RA patients, as assessed by microarray. IL-32 production was increased by IL-17. IL-32 in the FLSs from RA patients induced the production of IL-17 in CD4⁺ T cells. IL-32 and IL-17 were colocalized near TRAP-positive areas in joint specimens. IL-17 and IL-32 synergistically induced the differentiation of osteoclasts, as demonstrated by the expression of osteoclast-related genes. IL-32 and IL-17 also could induce resorption by osteoclasts in a RANKL-dependent manner.

Conclusions

IL-17 affected the expression of IL-32 in FLSs of RA patients and IL-32 induced the production of IL-17 in CD4+ T cells. Both IL-17 and IL-32 cytokines can reciprocally influence each other's production and amplify the function of osteoclastogenesis in the in RA synovium. Separately, IL-17 and IL-32 each stimulated osteoclastogenesis without RANKL. Together, the two cytokines synergistically amplified the differentiation of osteoclasts, independent of RANKL stimulation.

Markers of inflammation and bone remodelling associated with improvement in clinical response measures in psoriatic arthritis patients treated with golimumab

Objective

To determine serum biomarker associations with clinical response to golimumab treatment in patients with psoriatic arthritis (PsA).

Methods

GO–REVEAL was a randomised, placebo-controlled study of golimumab in patients with active PsA. Samples were collected from 100 patients at baseline, week 4 and week 14, and analysed for serum-based biomarkers and protein profiling (total 92 markers); data were correlated with clinical measures at week 14.

Results

Serum levels of a subset of proteins (apolipoprotein C III, ENRAGE, IL-16, myeloperoxidase, vascular endothelial growth factor, pyridinoline, matrix metalloproteinase 3, C-reactive protein (CRP), carcinoembryonic antigen, intercellular adhesion molecule 1 and macrophage inflammatory protein 1α) at baseline or week 4 were strongly associated with American College of Rheumatology 20% improvement (ACR20) response and/or disease activity score in 28 joints (DAS28) at week 14. A smaller subset of proteins was significantly associated with a 75% improvement in the psoriasis area and severity index score (PASI75) at week 14, (adiponectin, apolipoprotein CIII, serum glutamic oxaloacetic transaminase, and tumour necrosis factor α). Subsets of proteins were identified as potentially predictive of clinical response for each of the clinical measures, and the power of these biomarker panels to predict clinical response to golimumab treatment was stronger than for CRP alone.

Conclusions

This analysis provides insight into several panels of markers that may have utility in identifying PsA patients likely to have ACR20, DAS28, or PASI75 responses following golimumab treatment.

Network-based gene expression biomarkers for cold and heat patterns of rheumatoid arthritis in traditional chinese medicine

In Traditional Chinese Medicine (TCM), patients with Rheumatoid Arthritis (RA) can be classified into two main patterns: cold-pattern and heat-pattern. This paper identified the network-based gene expression biomarkers for both cold- and heat-patterns of RA. Gene expression profilings of CD4+ T cells from cold-pattern RA patients, heat-pattern RA patients, and healthy volunteers were obtained using microarray. The differentially expressed genes and related networks were explored using DAVID, GeneSpring software, and the protein-protein interactions (PPI) method. EIF4A2, CCNT1, and IL7R, which were related to the up-regulation of cell proliferation and the Jak-STAT cascade, were significant gene biomarkers of the TCM cold pattern of RA. PRKAA1, HSPA8, and LSM6, which were related to fatty acid metabolism and the I-κB kinase/NF-κB cascade, were significant biomarkers of the TCM heat-pattern of RA. The network-based gene expression biomarkers for the TCM cold- and heat-patterns may be helpful for the further stratification of RA patients when deciding on interventions or clinical trials.

Evaluation of SV40-transformed synovial fibroblasts in the study of rheumatoid arthritis pathogenesis

The SV40 T antigen has been used to generate immortalized cells from rheumatoid arthritis (RA) synovial fibroblasts (RASFs) that are commonly used in lieu of primary RASFs. In the current study, we investigated the effect of stimulation by tissue necrosis factor alpha (TNF-α) and interleukin 17 (IL-17) on primary and immortalized RASFs in order to gauge the appropriateness of the use of immortalized RASFs, the MH7A cell line, in the study of RA pathogenesis. Changes in the levels of secretion and expression of 8 proteins associated with RA upon stimulation were assessed by multiplex immunoassay. IL-17 stimulation had a minimal impact on protein secretion and expression for primary and immortalized cells. Basic fibroblast growth factor (FGF-2) was not detectable for the primary cells but was detectable for the immortalized cells. In contrast, monocyte chemoattractant protein 1 (MCP-1) was detectable for primary cells but was undetectable for immortalized cells. In general, protein expression and secretion by cells stimulated with TNF-α were significantly increased. For primary cells, several proteins were below the limit of detection for unstimulated cells and cells stimulated with IL-17, while levels for TNF-α-stimulated cells were within the detectable range. For the same proteins, expression was observed for immortalized cells, regardless of stimulation, suggestive of constitutive activation of the NF-κB signaling pathway. The current study therefore provides strong evidence that immortalized and primary RASFs differ in regard to protein expression and secretion and therefore may not be appropriate for use in the study of RA pathogenesis.

A pertussis toxin sensitive G-protein-independent pathway is involved in serum amyloid A-induced formyl peptide receptor 2-mediated CCL2 production

Serum amyloid A (SAA) induced CCL2 production via a pertussis toxin (PTX)-insensitive pathway in human umbilical vein endothelial cells (HUVECs). SAA induced the activation of three MAPKs (ERK, p38 MAPK, and JNK), which were completely inhibited by knock-down of formyl peptide receptor 2 (FPR2). Inhibition of p38 MAPK and JNK by their specific inhibitors (SB203580 and SP600125), or inhibition by a dominant negative mutant of p38 MAPK dramatically decreased SAA-induced CCL2 production. Inactivation of G((i)) protein(s) by PTX inhibited the activation of SAA-induced ERK, but not p38 MAPK or JNK. The results indicate that SAA stimulates FPR2-mediated activation of p38 MAPK and JNK, which are independent of a PTX-sensitive G-protein and are essential for SAA-induced CCL2 production.

Overexpression and unique rearrangement of VH2 transcripts in immunoglobulin variable heavy chain genes in ankylosing spondylitis patients

To identify immunoglobulin variable heavy chain (VH) gene usages in Korean ankylosing spondylitis (AS) patients, expression level of VH2 genes from peripheral blood mononuclear cells (PBMCs) of 8 AS patients and 9 healthy donors was analysed by quantitative real-time PCR (Q-PCR). Q-PCR results demonstrated VH2 genes were overexpressed in AS patients (Relative amount of mRNA of VH2 genes to a house-keeping gene, 7.13+/-7.77 vs, 0.68+/-0.55; P<0.0001). The sequence analysis revealed the majority of them contained CDC42 binding protein kinase Beta (CDC42 BPB) genes. The insertion of CDC42 BPB gene was confirmed by PCR with primers corresponding CDC42 BPB and CH genes. Our study revealed VH2 overexpression and unique rearrangement in Ig VH genes from peripheral blood of AS patients. This may imply aberrant immunoglobulin gene rearrangement in B cell occurs in Korean AS patients, which requires further investigation.

Sequential evolution of IL-17 responses in the early period of allograft rejection

In addition to CD4+CD25+Foxp3+ regulatory T (T(reg)) cells which protect against autoimmune tissue injury, IL-17-producing CD4+ T (T(h)17) cells have been recently described and shown to play a crucial role in autoimmune injury. It appears that there is a reciprocal developmental pathway between T(h)17 and T(reg) cells. Although IL-17 is known to be associated with allograft rejection, the cellular source of IL-17 and the nature of T(h)17 in the context of allograft rejection remain unknown. In the current study, the dynamics of T(reg) and IL-17-producing cells after syngeneic and allogeneic transplantation were examined using a wild-type murine cardiac transplantation model. Ly6G+ cells were found to produce IL-17 during the early postoperative period and CD8+ as well as CD4+ T cells were also found to produce IL-17 during alloimmune response. Graft-infiltrating Ly6G+, CD4+, and even CD8+ cells were found to express IL-17 highly compared to those in spleen. Although the frequencies of T(h)17 and T(reg) were found to gradually increase in both syngeneic and allogeneic recipients, T(h)17/T(reg) ratios were significantly higher in recipients with allograft rejection than in syngeneic recipients. In conclusion, IL-17 is produced by neutrophils during the early postoperative period and subsequently by T(h)17 and CD8+ T cells during allograft rejection. T(h)17/T(reg) imbalance is associated with the development of allograft rejection. This study would provide basic information on T(h)17 biology for future investigation in the field of transplantation.

Breaking old paradigms: Th17 cells in autoimmune arthritis

Aberrant helper T cell activation has been implicated in the pathogenesis of an array of autoimmune diseases. In this review, we summarize evidence that suggests the involvement of a novel T cell subset, the Th17 lineage, in rheumatoid arthritis. In particular, we focus on the role of Th17 cells in inducing and perpetuating the chronic inflammation, cartilage damage, and bone erosion that are hallmark phases of joint destruction and consider current and emerging therapies that seek to disrupt the inflammatory Th17 network and shift the immune system back towards homeostasis.