Enhancing effect of IL-1, IL-17, and TNF-alpha on macrophage inflammatory protein-3alpha production in rheumatoid arthritis: regulation by soluble receptors and Th2 cytokines

The role of ixekizumab in the treatment of nonradiographic axial spondyloarthritis

Nonradiographic axial spondyloarthritis (nr-axSpA) is a subtype of SpA with undeveloped definite radiographic sacroiliitis. Tumor necrosis factor inhibitors have demonstrated effectiveness in nr-axSpA patients who do not respond to first-line therapy. More recently, accumulated data from genetic, experimental, and clinical studies revealed that IL-17 is a key player in the pathogenesis of SpA, leading to development of new biologics directly inhibiting IL-17. Among them, ixekizumab is a high-affinity monoclonal antibody that selectively targets IL-17A and has exhibited significant efficacy and acceptable safety profiles in the treatment of nr-axSpA. The aim of this paper is to narratively review the recent insights of IL-17 in the pathogenesis of axSpA and discuss the effectiveness and safety of ixekizumab in treatment of nr-axSpA.

Impact of dual neutralization of TNF-α and IL-1β along with Gentamicin treatment on the functions of blood and splenic neutrophils and its role on improvement of S. aureus induced septic arthritis

Researches of recent past years have emphasized potential of antibiotics to improve septic arthritis but as multi-drug resistant strains like MRSA are emerging fast, new alternative therapeutic advances are high in demand. This study aims to figure out the role of neutrophils in regulating inflammatory responses of S. aureus induced septic arthritis while using TNF-α Ab or IL-1β Ab along with antibiotic gentamicin or both in combination. In this study, role of anti-oxidant enzymes were investigated and correlated with generated ROS level. While expression of TLR2, TNFR2, MMP2, RANKL, SAPK/JNK in the spleen were evaluated through western blot. Serum activity of IL-8, IL-10, IL-12, OPG, OPN, CRP was assessed using ELISA. Flow cytometry study evaluated inflamed neutrophil population. Results have shown TNF-α neutralization along with gentamicin was able to reduce arthritic swelling prominently. While combination therapy effectively reduced blood neutrophil ROS activity, arginase activity, MPO activity along with spleen bacterial burden. Serum OPG, CRP, IL-10 level got reduced while serum OPN, IL-8 and IL-12 level enhanced in treatment groups, showing mitigation of inflammatory damage. Overall, it is a novel work that observed how antibiotic and antibody therapy enhanced neutrophil function positively to combat sepsis. This study may not be fully applicable in clinical trials as it is performed with animal model. Clinical trials include crystalline and inflammatory arthritides, trauma, neoplasm. Interdisciplinary collaboration between radiology, orthopaedic surgery and knowledge of animal system responses may give better idea to find proper therapeutic approach in future research works.

Exposure to long wavelength light that improves aged mitochondrial function shifts acute cytokine expression in serum and the retina

Aged mitochondrial function can be improved with long wavelength light exposure. This reduces cellular markers of inflammation and can improve system function from fly through to human. We have previously shown that with age there are increases in cytokine expression in mouse serum. Here, we ask what impact 670nm light has on this expression using a 40 cytokine array in blood serum and retina in C57Bl6 mice. 670nm exposure was delivered daily for a week in 12 month old mice. This shifted patterns of cytokine expression in both serum and retina inducing a selective increase. In serum examples of significant increases were found in IL (interleukins) 1α, IL-7, 10, 16, 17 along with TNF-α and CXCL (chemokines) 9 and 10. In retina the increases were again mainly in some IL's and CXCL's. A few cytokines were reduced by light exposure. Changes in serum cytokines implies that long wavelengths impact systemically even to unexposed tissues deep in the body. In the context of wider literature, increased cytokine expression may be protective. However, their upregulation by light merits further analysis as cytokines upregulation can also be negative and there are probably complex patterns of interaction in the dynamics of their expression.

p-Synephrine ameliorates alloxan-induced diabetes mellitus through inhibiting oxidative stress and inflammation via suppressing the NF-kappa B and MAPK pathways

Oxidative stress and inflammation play important roles in the development of diabetes mellitus. p-Synephrine, the primary pharmacologically active protoalkaloid in Citrus species, has been popularly consumed as a dietary supplement for weight loss management. However, the effects of p-synephrine on diabetes mellitus and the action mechanisms have not been clearly elucidated. In this study, the in vitro antioxidant effects of p-synephrine were evaluated. The data showed that p-synephrine treatment exhibited significant scavenging effects against DPPH, ABTS and OH radicals and showed high reducing power. Diabetic mice were developed by alloxan injection, followed by p-synephrine administration to investigate its hypoglycemic effects in vivo. The results showed that p-synephrine intervention significantly prevented alloxan-induced alteration in body weight, organ indexes, serum uric acid content and serum creatinine content. Meanwhile, p-synephrine application significantly improved the lipid profiles, superoxide dismutase (SOD) and catalase (CAT) activities and glutathione (GSH) contents in the serum and kidneys of diabetic mice and reduced the malondialdehyde (MDA) content in the serum of diabetic mice. Further assays suggested that p-synephrine treatment improved alloxan-induced decreases of glucose tolerance and insulin sensitivity. Also, p-synephrine supplementation altered histopathological changes in the kidneys and interscapular brown adipose tissues in diabetic mice. In addition, p-synephrine administration inhibited renal inflammation through suppressing tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1β (IL-1β) gene expression levels, as well as CD45 expression levels. The anti-inflammatory effects were probably involved in the regulation of nuclear factor-κB (NF-κB) activation and mitogen-activated protein kinase (MAPK) phosphorylation. In conclusion, p-synephrine application significantly ameliorated alloxan-induced diabetes mellitus by inhibiting oxidative stress via suppressing the NF-κB and MAPK pathways.

Crosstalk between fibroblasts and T cells in immune networks

Fibroblasts are primarily considered as cells that support organ structures and are currently receiving attention for their roles in regulating immune responses in health and disease. Fibroblasts are assigned distinct phenotypes and functions in different organs owing to their diverse origins and functions. Their roles in the immune system are multifaceted, ranging from supporting homeostasis to inducing or suppressing inflammatory responses of immune cells. As a major component of immune cells, T cells are responsible for adaptive immune responses and are involved in the exacerbation or alleviation of various inflammatory diseases. In this review, we discuss the mechanisms by which fibroblasts regulate immune responses by interacting with T cells in host health and diseases, as well as their potential as advanced therapeutic targets.

Detection of IL-17A and IL-17F gene polymorphism in recurrent and disseminated pityriasis versicolor: a case-control study

Recurrent and disseminated pityriasis versicolor (RDPV) is a common clinical entity, characterized by its recurrent and disfiguring nature. Studies demonstrated host genetic variations in the immune response, especially the role of IL-17 in antifungal immunity. This study aimed to detect whether IL-17A and F gene polymorphisms are found in cases of RDPV. It included 100 cases of RDPV and 100 age and sex matched controls, from which EDTA blood samples were taken for single-nucleotide polymorphism analysis. IL-17A (rs2275913) and F (rs763780) were associated with a significantly increased incidence of developing RDPV. IL-17A and F gene polymorphism could be implicated as a risk factor for the development of RDPV.

Estimation the relationship between IL-17 and some biochemical parameters in patients with rheumatoid arthritis

Little information is available on the relationship between IL-17 with VD, ESR, MDA and GSH levels for patients with Rheumatoid Arthritis. This study aimed to determine the levels of IL-17, VD, ESR, MDA and GSH, also to determine the relationship between IL -17 with VD, ESR, MDA and GSH. The sample of this study consists of 30 patients and 30 apparently healthy individuals. The results showed that the levels of IL-17, MDA and ESR marked increase in patients group in compare with controls group (P≤0.05).While levels of VD and GSH shows marked decrease in   patients group in comparison with the controls group (P≤0.05). It was found positive relationship between IL-17 and levels of MDA and ESR. Also it was found negative correlation between IL-17 and levels of the VD and GSH.

Impact of Adalimumab Treatment on Interleukin-17 and Interleukin-17 Receptor Expression in Skin and Synovium of Psoriatic Arthritis Patients with Mild Psoriasis

Interleukin (IL)-17 and tumor necrosis factor-alpha (TNF)-α are key players in psoriatic arthritis (PsA) pathogenesis. While both cytokines can be therapeutically targeted with beneficial clinical outcome, it is unclear whether inhibiting one cytokine will affect the other at sites of inflammation. If both act independently, this might provide a rationale for dual or combined inhibition of both cytokines. Here, we evaluated the effect of TNF blockade in PsA patients on IL-17 levels in both skin and synovial tissue biopsies. PsA patients with mild psoriatic skin lesions were randomized to receive either adalimumab or placebo for four weeks. Synovial and skin biopsies were obtained at weeks zero and four. Skin from healthy donors (HDs) was used for comparison. Expression of IL-17A, IL-17F, IL-17RA and IL-17RC was assessed by immunohistochemistry and analyzed with digital image analysis. We found relatively low levels of IL-17 and its receptors in the skin of PsA patients compared to HD, and only IL-17F in the dermis of lesional psoriatic skin was significantly higher compared to HD skin (p = 0.0002). Histologically IL-17A, IL-17F, IL-17RA and IL-17RC in skin and synovial tissue were not downregulated by adalimumab treatment. Thus, in this cohort of PsA patients with mild psoriasis, TNF blockade did not affect the protein levels of IL-17 cytokines and its receptors in skin and synovium, despite reduced cellular inflammation and improved clinical outcome for joint involvement.

Exploring the Diverse Immune and Genetic Landscape of Psoriatic Arthritis

Psoriatic arthritis (PsA) is characterized by delays in diagnosis and modest effect of treatment in terms of joint response. An understanding of molecular pathomechanisms may aid in developing diagnostic and prognostic models. Genetic susceptibility (e.g., HLA class I genes, IL-23-related genes) can be responsible for the pattern of psoriatic manifestations and affinity for tissue involvement. Gene expression analysis indicates an inflammatory profile that is distinct for PsA, but disparate across tissues. This has clinical implications, as for example, dual blockade of IL-17A and IL-17F can lead to superior clinical effects if there is differential expression of IL-17 receptors in tissues. Structural and functional impairment of barrier tissue, including host-microbiome interactions, may be the source of immune activation. Interplay between different cell populations of innate and adaptive immunity is emerging, potentially providing a link between the transition of skin-to-joint disease. Th17 subsets, IL-17A, IL-17F and IL-23 are crucial in PsA pathogenesis, with both clinical and experimental evidence suggesting a differential molecular landscape in cutaneous and articular compartments.

Significance of Interleukin (IL)-4 and IL-13 in Inflammatory Arthritis

Interleukin (IL)-4 and IL-13 belong to the T helper 2 (Th2) cytokine family, along with IL-3, IL-5, and IL-9. These cytokines are key mediators of allergic inflammation. They have important immunomodulatory activities and exert influence on a wide variety of immune cells, such as B cells, eosinophils, basophils, monocytes, fibroblasts, endothelial cells, airway epithelial cells, smooth muscle cells, and keratinocytes. Recent studies have implicated IL-4 and IL-13 in the development of various autoimmune diseases. Additionally, these cytokines have emerged as potential players in pathogenesis of inflammatory arthritis. Recent findings suggest that the IL-4 and IL-13 might play a significant role in the downregulation of inflammatory processes underlying RA pathology, and beneficially modulate the course of the disease. This review summarizes the biological features of the IL-4 and IL-13 and provides current knowledge regarding the role of these cytokines in inflammatory arthritis.

Fibroblast pathology in inflammatory diseases

Fibroblasts are important cells for the support of homeostatic tissue function. In inflammatory diseases such as rheumatoid arthritis and inflammatory bowel disease, fibroblasts take on different roles (a) as inflammatory cells themselves and (b) in recruiting leukocytes, driving angiogenesis, and enabling chronic inflammation in tissues. Recent advances in single-cell profiling techniques have transformed the ability to examine fibroblast states and populations in inflamed tissues, providing evidence of previously underappreciated heterogeneity and disease-associated fibroblast populations. These studies challenge the preconceived notion that fibroblasts are homogeneous and provide new insights into the role of fibroblasts in inflammatory pathology. In addition, new molecular insights into the mechanisms of fibroblast activation reveal powerful cell-intrinsic amplification loops that synergize with primary fibroblast stimuli to result in striking responses. In this Review, we focus on recent developments in our understanding of fibroblast heterogeneity and fibroblast pathology across tissues and diseases in rheumatoid arthritis and inflammatory bowel diseases. We highlight new approaches to, and applications of, single-cell profiling techniques and what they teach us about fibroblast biology. Finally, we address how these insights could lead to the development of novel therapeutic approaches to targeting fibroblasts in disease.

Importance of lymphocyte-stromal cell interactions in autoimmune and inflammatory rheumatic diseases

Interactions between lymphocytes and stromal cells have an important role in immune cell development and responses. During inflammation, stromal cells contribute to inflammation, from induction to chronicity or resolution, through direct cell interactions and through the secretion of pro-inflammatory and anti-inflammatory mediators. Stromal cells are imprinted with tissue-specific phenotypes and contribute to site-specific lymphocyte recruitment. During chronic inflammation, the modified pro-inflammatory microenvironment leads to changes in the stromal cells, which acquire a pathogenic phenotype. At the site of inflammation, infiltrating B cells and T cells interact with stromal cells. These interactions induce a plasma cell-like phenotype in B cells and T cells, associated with secretion of immunoglobulins and inflammatory cytokines, respectively. B cells and T cells also influence the stromal cells, inducing cell proliferation, molecular changes and cytokine production. This positive feedback loop contributes to disease chronicity. This Review describes the importance of these cell interactions in chronic inflammation, with a focus on human disease, using three selected autoimmune and inflammatory diseases: rheumatoid arthritis, psoriatic arthritis (and psoriasis) and systemic lupus erythematosus. Understanding the importance and disease specificity of these interactions could provide new therapeutic options.

T-bet represses collagen-induced arthritis by suppressing Th17 lineage commitment through inhibition of RORγt expression and function

T-bet is a key transcription factor for the T helper 1 lineage and its expression level is negatively correlated to inflammation in patients with rheumatoid arthritis (RA). Our previous study using T-bet transgenic mice revealed over-expression of T-bet completely suppressed collagen-induced arthritis (CIA), a murine model of RA, indicating a potential suppressive role of T-bet in the pathogenesis of autoimmune arthritis. Here, we show T-bet-deficiency exacerbated CIA. T-bet in CD4 + T cells, but not in CD11c + dendritic cells, was critical for regulating the production of IL-17A, IL-17F, IL-22, and TNFα from CD4 + T cells. T-bet-deficient CD4 + T cells showed higher RORγt expression and increased IL-17A production in RORγt-positive cells after CII immunization. In addition, T-bet-deficient naïve CD4 + T cells showed accelerated Th17 differentiation in vitro. CIA induced in CD4-Cre T-bet^fl/fl (cKO) mice was more severe and T-bet-deficient CD4 + T cells in the arthritic joints of cKO mice showed higher RORγt expression and increased IL-17A production. Transcriptome analysis of T-bet-deficient CD4 + T cells revealed that expression levels of Th17-related genes were selectively increased. Our results indicate that T-bet in CD4 + T cells repressed RORγt expression and function resulting in suppression of arthritogenic Th17 cells and CIA.

Rifaximin Prevents T-Lymphocytes and Macrophages Infiltration in Cerebellum and Restores Motor Incoordination in Rats with Mild Liver Damage

In patients with liver cirrhosis, minimal hepatic encephalopathy (MHE) is triggered by a shift in peripheral inflammation, promoting lymphocyte infiltration into the brain. Rifaximin improves neurological function in MHE by normalizing peripheral inflammation. Patients who died with steatohepatitis showed T-lymphocyte infiltration and neuroinflammation in the cerebellum, suggesting that MHE may already occur in these patients. The aims of this work were to assess, in a rat model of mild liver damage similar to steatohepatitis, whether: (1) the rats show impaired motor coordination in the early phases of liver damage; (2) this is associated with changes in the immune system and infiltration of immune cells into the brain; and (3) rifaximin improves motor incoordination, associated with improved peripheral inflammation, reduced infiltration of immune cells and neuroinflammation in the cerebellum, and restoration of the alterations in neurotransmission. Liver damage was induced by carbon tetrachloride (CCl₄) injection over four weeks. Peripheral inflammation, immune cell infiltration, neuroinflammation, and neurotransmission in the cerebellum and motor coordination were assessed. Mild liver damage induces neuroinflammation and altered neurotransmission in the cerebellum and motor incoordination. These alterations are associated with increased TNFa, CCL20, and CX3CL1 in plasma and cerebellum, IL-17 and IL-15 in plasma, and CCL2 in cerebellum. This promotes T-lymphocyte and macrophage infiltration in the cerebellum. Early treatment with rifaximin prevents the shift in peripheral inflammation, immune cell infiltration, neuroinflammation, and motor incoordination. This report provides new clues regarding the mechanisms of the beneficial effects of rifaximin, suggesting that early rifaximin treatment could prevent neurological impairment in patients with steatohepatitis.

A myostatin-CCL20-CCR6 axis regulates Th17 cell recruitment to inflamed joints in experimental arthritis

The interactions of fibroblast-like synoviocyte (FLS)-derived pro-inflammatory cytokines/chemokines and immune cells support the recruitment and activation of inflammatory cells in RA. Here, we show for the first time that the classical myokine myostatin (GDF-8) is involved in the recruitment of Th17 cells to inflammatory sites thereby regulating joint inflammation in a mouse model of TNFalpha-mediated chronic arthritis. Mechanistically, myostatin-deficiency leads to decreased levels of the chemokine CCL20 which is associated with less infiltration of Th17 cells into the inflamed joints. In vitro, myostatin alone or in combination with IL-17A enhances the secretion of CCL20 by FLS whereas myostatin-deficiency reduces CCL20 secretion, associated with an altered transmigration of Th17 cells. Thus, the communication between activated FLS and Th17 cells through myostatin and IL-17A may likely contribute to a vicious cycle of inflammation, accounting for the persistence of joint inflammation in chronic arthritis. Blockade of the CCL20–CCR6 axis by inhibition of myostatin may, therefore, be a promising treatment option for chronic inflammatory diseases such as arthritis.

From Bed to Bench and Back: TNF-α, IL-23/IL-17A, and JAK-Dependent Inflammation in the Pathogenesis of Psoriatic Synovitis

Psoriatic arthritis (PsA) is a chronic inflammatory immune-mediated disease with a burdensome impact on quality of life and substantial healthcare costs. To date, pharmacological interventions with different mechanisms of action, including conventional synthetic (cs), biological (b), and targeted synthetic (ts) disease-modifying antirheumatic drugs (DMARDs), have been proven efficacious, despite a relevant proportion of failures. The current approach in clinical practice and research is typically "predictive": the expected response is based on stratification according to clinical, imaging, and laboratory data, with a "heuristic" approach based on "trial and error". Several available therapeutic options target the TNF-α pathway, while others are directed against the IL-23/IL-17A axis. Janus kinase inhibitors (JAKis), instead, simultaneously block different pathways, endowing these drugs with a potentially "broad-spectrum" mechanism of action. It is not clear, however, whether targeting a specific pathway (e.g., TNF-α or the IL-23/IL-17 axis) could result in discordant effects over other approaches. In particular, in the case of "refractory to a treatment" patients, other pathways might be hyperactivated, with opposing, synergistic, or redundant biological significance. On the contrary, refractory states could be purely resistant to treatment as a whole. Since chronic synovitis is one of the primary targets of inflammation in PsA, synovial biomarkers could be useful in depicting specific biological characteristics of the inflammatory burden at the single-patient level, and despite not yet being implemented in clinical practice, these biomarkers might help in selecting the proper treatment. In this narrative review, we will provide an up-to-date overview of the knowledge in the field of psoriatic synovitis regarding studies investigating the relationships among different activated proinflammatory processes suitable for targeting by different available drugs. The final objective is to clarify the state of the art in the field of personalized medicine for psoriatic disease, aiming at moving beyond the current treatment schedules toward a patient-centered approach.

Local and systemic effects of IL-17 in joint inflammation: a historical perspective from discovery to targeting

The role of IL-17 in many inflammatory and autoimmune diseases is now well established, with three currently registered anti-IL-17-targeted therapies. This story has taken place over a period of 20 years and led to the demonstration that a T cell product could regulate, and often amplify, the inflammatory response. The first results described the contribution of IL-17 to local features in arthritis. Then, understanding was extended to its systemic effects, with a focus on cardiovascular aspects. This review provides a historical perspective of these discoveries focused on arthritis, which started in 1995, followed 10 years later by the description of Th17 cells. Today, IL-17 inhibitors for three chronic inflammatory diseases have been registered. More options are now being tested in ongoing and future clinical trials. Inhibitors of IL-17 family members and Th17 cells ranging from antibodies to small molecules are under active development. The identification of patients with IL-17-driven disease is a key target for the improved selection of patients expected to have a strongly positive response.

Exploring IL-17 in spondyloarthritis for development of novel treatments and biomarkers

Spondyloarthritis (SpA) is an umbrella term describing a family of chronic inflammatory rheumatic diseases. These diseases are characterised by inflammation of the axial skeleton, peripheral joints, and entheseal insertion sites throughout the body which can lead to structural joint damage including formation of axial syndesmophytes and peripheral osteophytes. Genetic evidence, preclinical and clinical studies indicate a clear role of interleukin (IL)- 23 and IL-17 as mediators in SpA pathogenesis. Targeting the IL-23/-17 pathways seems an efficient strategy for treatment of SpA patients, and despite the remaining challenges the pathway holds great promise for further advances and improved therapeutic opportunities. Much research is focusing on serological markers and imaging strategies to correctly diagnose patients in the early stages of SpA. Biomarkers may facilitate personalised medicine tailored to each patient's specific disease to optimise treatment efficacy and to monitor therapeutic response. This narrative review focuses on the IL-17 pathway in SpA-related diseases with emphasis on its role in pathogenesis, current approved IL-17 inhibitors, and the need for biomarkers reflecting core disease pathways for early diagnosis and measurement of disease activity, prognosis, and response to therapy.

Nimbolide exerts protective effects in complete Freund's adjuvant induced inflammatory arthritis via abrogation of STAT-3/NF-κB/Notch-1 signaling

AIM

Activation of transmembrane Notch-1 receptors through inflammatory cytokines is highly regulated by STAT-3 and NF-κB phosphorylation. Nimbolide (NMB) exhibits potent anti-inflammatory, anti-fibrotic, anticancer activities by targeting various pathways. Here, we have investigated the effect of NMB in regulation of STAT-3/NF-κB/Notch-1 axis in complete Freund's adjuvant (CFA) induced inflammatory arthritis (IA) model.

MAIN METHODS

The anti-inflammatory and anti-arthritic activity of NMB was evaluated both in vitro (IL-1β stimulated HIG-82 synovial fibroblasts) and in vivo (CFA induced rat model of IA) models. In vitro anti-arthritic activity was assessed by anti-migratory effect, while in vivo effects were evaluated through radiological and histological analysis. The effect of NMB on STAT-3, NF-κB, Notch-1 signaling pathways and proinflammatory cytokines were studied using western blot, immunohistochemistry and ELISA methods. Key findings NMB attenuated the migration of synovial fibroblasts in vitro. It reduced the progression of arthritis as evidenced from the improved radiological and histological abnormalities in arthritic rats. NMB significantly suppressed the nitrosooxidative stress and levels of pro-inflammatory cytokines. NMB also exhibited remarkable protective activity against upregulation of MAPK, STAT-3 and NF-κB phosphorylation mediated Notch-1 signaling pathway in synovial tissue of arthritic rats.

SIGNIFICANCE

NMB may have clinical therapeutic value in rheumatoid arthritis by inhibiting STAT-3/NF-κB/Notch-1 axis and also by reducing the levels of proinflammatory cytokines.

Interleukin-17 in rheumatoid arthritis: Trials and tribulations

Interleukin-17A (IL-17A) is a pro-inflammatory cytokine with well-characterized biological effects on stromal cell activation, angiogenesis, and osteoclastogenesis. The presence of this cytokine in the inflamed joints of patients with rheumatoid arthritis (RA), together with compelling data from in vitro and experimental arthritis models demonstrating its pro-inflammatory effects, made this cytokine a strong candidate for therapeutic targeting. Clinical trials, however, have shown relatively modest success in RA as compared with other indications. Guided by recent insights in IL-17 biology, this review aims to explore possible reasons for the limited clinical efficacy of IL-17A blockade in RA, and what we can learn from these results going forward.

Pirfenidone and Vitamin D Ameliorate Cardiac Fibrosis Induced by Doxorubicin in Ehrlich Ascites Carcinoma Bearing Mice: Modulation of Monocyte Chemoattractant Protein-1 and Jun N-terminal Kinase-1 Pathways

Treatment of breast cancer with doxorubicin causes numerous side effects, of which cardiac fibrosis is considered the main one. This study was designed to investigate the underlying molecular mechanisms for the potential anti-fibrotic effect of pirfenidone and vitamin D against doxorubicin-induced cardiac fibrosis. Seventy mice carrying solid Ehrlich’s ascites carcinoma (EAC) discs on the ventral side were treated with orally administered pirfenidone (500 mg/kg) and intraperitoneal injection of vitamin D (0.5 µg/kg) either individually or in combination with a doxorubicin (15 mg/kg; i.p.) single dose. All treatments commenced one week post-tumor inoculation and continued for 14 days. Compared to control EAC mice, the doxorubicin group showed a significant increase in heart and left ventricle weights, troponin T, and creatinine kinase serum levels. Furthermore, the doxorubicin group depicts a high expression of monocyte chemoattractant protein (MCP-1), nuclear factor-kappa B (NF-κB), transforming growth factor-beta 1 (TGF-β1), smad3, Jun N-terminal Kinase-1 (JNK1), and alpha-smooth muscle actin (α-SMA). Treatment with pirfenidone or vitamin D significantly decreased all of these parameters. Furthermore, the expression of smad7 was downregulated by doxorubicin and improved by pirfenidone or vitamin D. Furthermore, all treated groups showed a marked decrease in tumor weight and volume. Current data demonstrate that pirfenidone and vitamin D represent an attractive approach to ameliorate the cardiac fibrosis produced by doxorubicin through inhibiting both JNK1 signaling and MCP-1 inflammatory pathways, thus preserving heart function. Further, this combination demonstrated an anti-tumor effect to combat breast cancer.

Discovery of novel immunopharmacological ligands targeting the IL-17 inflammatory pathway

Interleukin 17 (IL-17) is a proinflammatory cytokine that acts as an immune checkpoint for several autoimmune diseases. Therapeutic neutralizing antibodies that target this cytokine have demonstrated clinical efficacy in psoriasis. However, biologics have limitations such as their high cost and their lack of oral bioavailability. Thus, it is necessary to expand the therapeutic options for this IL-17A/IL-17RA pathway, applying novel drug discovery methods to find effective small molecules. In this work, we combined biophysical and cell-based assays with structure-based docking to find novel ligands that target this pathway. First, a virtual screening of our chemical library of 60000 compounds was used to identify 67 potential ligands of IL-17A and IL-17RA. We developed a biophysical label-free binding assay to determine interactions with the extracellular domain of IL-17RA. Two molecules (CBG040591 and CBG060392) with quinazolinone and pyrrolidinedione chemical scaffolds, respectively, were confirmed as ligands of IL-17RA with micromolar affinity. The anti-inflammatory activity of these ligands as cytokine-release inhibitors was evaluated in human keratinocytes. Both ligands inhibited the release of chemokines mediated by IL-17A, with an IC₅₀ of 20.9 ± 12.6 μM and 23.6 ± 11.8 μM for CCL20 and an IC₅₀ of 26.7 ± 13.1 μM and 45.3 ± 13.0 μM for CXCL8. Hence, they blocked IL-17A proinflammatory activity, which is consistent with the inhibition of the signalling of the IL-17A receptor by ligand CBG060392. Therefore, we identified two novel immunopharmacological ligands targeting the IL-17A/IL-17RA pathway with antiinflammatory efficacy that can be promising tools for a drug discovery program for psoriasis.

Circulating IL-17A Levels in Postmenopausal Women with Primary Hyperparathyroidism

Background

Primary hyperparathyroidism (PHPT) is a common cause of secondary osteoporosis in postmenopausal women. Th17 lymphocytes and the released cytokine IL-17A play an important role in bone metabolism. Th17 cells have been shown to be activated by PTH, and peripheral blood T cells from patients affected with PHPT express higher levels of IL-17A mRNA than controls.

Aim

To investigate circulating levels of IL-17A and the ratio RANKL/OPG, as markers of osteoclastogenesis, in 50 postmenopausal PHPT women compared with postmenopausal osteoporotic non-PHPT women (n = 20).

Results

Circulating levels of IL-17A were similarly detectable in most PHPT and non-PHPT osteoporotic women (12.9 (8.4-23.1) vs. 11.3 (8.3-14.3) pg/ml, median (range interquartile), P = 0.759), at variance with premenopausal women where IL-17A was undetectable. In PHPT women, any significant correlations could be detected between circulating IL-17A levels and PTH levels. Nonetheless, significant negative correlations between circulating IL-17A and ionized calcium levels (r = -0.294, P = 0.047) and urine calcium excretions (r = -0.300, P = 0.045) were found. Moreover, PHPT women were characterized by positive correlations between IL-17A levels and femur neck (r = 0.364, P = 0.021) and total hip (r = 0.353, P = 0.015) T-scores. Circulating IL-17A levels did not show any significant correlation with sRANKL, OPG, and sRANKL/OPG ratio in PHPT women.

Conclusions

In postmenopausal PHPT women, circulating IL-17A levels were similar to those detected in postmenopausal non-PHPT women, showing a disruption of the relationship observed in postmenopausal osteoporosis among circulating PTH, sRANKL, OPG, IL-17A, and bone demineralization in postmenopausal PHPT women. The data support an osteogenic effect of IL-17A in postmenopausal PHPT women.

CUX1 and IκBζ (NFKBIZ) mediate the synergistic inflammatory response to TNF and IL-17A in stromal fibroblasts

The role of stromal fibroblasts in chronic inflammation is unfolding. In rheumatoid arthritis, leukocyte-derived cytokines TNF and IL-17A work together, activating fibroblasts to become a dominant source of the hallmark cytokine IL-6. However, IL-17A alone has minimal effect on fibroblasts. To identify key mediators of the synergistic response to TNF and IL-17A in human synovial fibroblasts, we performed time series, dose-response, and gene-silencing transcriptomics experiments. Here we show that in combination with TNF, IL-17A selectively induces a specific set of genes mediated by factors including cut-like homeobox 1 (CUX1) and IκBζ (NFKBIZ). In the promoters of CXCL1, CXCL2, and CXCL3, we found a putative CUX1-NF-κB binding motif not found elsewhere in the genome. CUX1 and NF-κB p65 mediate transcription of these genes independent of LIFR, STAT3, STAT4, and ELF3. Transcription of NFKBIZ, encoding the atypical IκB factor IκBζ, is IL-17A dose-dependent, and IκBζ only mediates the transcriptional response to TNF and IL-17A, but not to TNF alone. In fibroblasts, IL-17A response depends on CUX1 and IκBζ to engage the NF-κB complex to produce chemoattractants for neutrophil and monocyte recruitment.

Expansion of fish CCL20_like chemokines by genome and local gene duplication: Characterisation and expression analysis of 10 CCL20_like chemokines in rainbow trout (Oncorhynchus mykiss)

Mammalian CCL20, or macrophage inflammatory protein-3α, can function as a homeostatic and inflammatory chemokine. In relation to the latter, it is responsible for the chemoattraction of lymphocytes and dendritic cells to mucosal immune sites under inflammatory and pathological conditions. CK1, CK8A and CK8B are rainbow trout (Oncorhynchus mykiss) CC chemokines that were reported previously to be phylogenetically related to mammalian CCL20. In the current study, an additional seven CCL20_L paralogues in rainbow trout are reported, that are divided into three subgroups and have been designated here as: CCL20_L1a (also referred to as CK1), CCL20_L1b1-2, CCL20_L2a (CK8A), CCL20_L2b (CK8B), CCL20_L3a, and CCL20_L3b1-4. Multiple CCL20_L genes were also identified in other salmonids that arose from both whole genome duplication and local gene duplication. Phylogenetic tree, homology and synteny analysis support that CCL20_L1-3 found in salmonids are also present in most teleosts arose from the 3 R whole genome duplication and in some species, local gene duplication. Like mammalian CCL20, rainbow trout CCL20_L molecules possess a high positive net charge with a pI of 9.34-10.16, that is reported to be important for antimicrobial activity. Rainbow trout CCL20_L paralogues are differentially expressed and in general highly expressed in mucosal tissues, such as gills, thymus and intestine. The expression levels of rainbow trout CCL20_L paralogues are increased during development and following PAMP/cytokine stimulation. For example, in RTS-11 cells CCL20_L3b1 and CCL20_L3b2 are highly up-regulated by LPS, Poly I:C, recombinant(r) IFNa and rIL-1β. Trout CCL20_L paralogues are also increased after Yersinia ruckeri infection or Poly I:C stimulation in vivo, with CCL20_L3b1 and CCL20_L3b2 again highly up-regulated. Overall, this is the first report of the complete CCL20 chemokine subfamily in rainbow trout, and the analysis of their expression and modulation in vitro and in vivo. These results suggest that teleosts possess divergent CCL20_L molecules that may have important roles in anti-viral/anti-bacterial defence and in mucosal immunity.

Transcriptome Profiling of Bovine Macrophages Infected by Mycobacterium avium spp. paratuberculosis Depicts Foam Cell and Innate Immune Tolerance Phenotypes

Mycobacterium avium spp. paratuberculosis (MAP) is the causative agent of Johne's disease (JD), also known as paratuberculosis, in ruminants. The mechanisms of JD pathogenesis are not fully understood, but it is known that MAP subverts the host immune system by using macrophages as its primary reservoir. MAP infection in macrophages is often studied in healthy cows or experimentally infected calves, but reports on macrophages from naturally infected cows are lacking. In our study, primary monocyte-derived macrophages (MDMs) from cows diagnosed as positive (+) or negative (–) for JD were challenged in vitro with live MAP. Analysis using next-generation RNA sequencing revealed that macrophages from JD(+) cows did not present a definite pattern of response to MAP infection. Interestingly, a considerable number of genes, up to 1436, were differentially expressed in JD(–) macrophages. The signatures of the infection time course of 1, 4, 8, and 24 h revealed differential expression of ARG2, COL1A1, CCL2, CSF3, IL1A, IL6, IL10, PTGS2, PTX3, SOCS3, TNF, and TNFAIP6 among other genes, with major effects on host signaling pathways. While several immune pathways were affected by MAP, other pathways related to hepatic fibrosis/hepatic stellate cell activation, lipid homeostasis, such as LXR/RXR (liver X receptor/retinoid X receptor) activation pathways, and autoimmune diseases (rheumatoid arthritis or atherosclerosis) also responded to the presence of live MAP. Comparison of the profiles of the unchallenged MDMs from JD(+) vs. JD(–) cows showed that 868 genes were differentially expressed, suggesting that these genes were already affected before monocytes differentiated into macrophages. The downregulated genes predominantly modified the general cell metabolism by downregulating amino acid synthesis and affecting cholesterol biosynthesis and other energy production pathways while introducing a pro-fibrotic pattern associated with foam cells. The upregulated genes indicated that lipid homeostasis was already supporting fat storage in uninfected JD(+) MDMs. For JD(+) MDMs, differential gene expression expounds long-term mechanisms established during disease progression of paratuberculosis. Therefore, MAP could further promote disease persistence by influencing long-term macrophage behavior by using both tolerance and fat-storage states. This report contributes to a better understanding of MAP's controls over the immune cell response and mechanisms of MAP survival.

The CCL20 and CCR6 axis in psoriasis

Psoriasis is a TNF-α/IL-23/IL-17A-mediated inflammatory skin disease that causes a significant socioeconomic burden in afflicted patients. IL-17A-producing immune cells, including Th17 cells, are crucial effector cells in the development of psoriasis. IL-17A stimulates epidermal keratinocytes to produce CCL20, which eventually recruits CCR6 + Th17 cells into the lesional skin. Thus, the CCL20/CCR6 axis works as a driving force that prepares an IL-17A-rich cutaneous milieu. In this review, we summarize the current research topics on the CCL20/CCR6 axis and the therapeutic intervention of this axis for psoriasis.

IL‑1β increases the expression of inflammatory factors in synovial fluid‑derived fibroblast‑like synoviocytes via activation of the NF‑κB‑mediated ERK‑STAT1 signaling pathway

Interleukin (IL)-1β serves a crucial role in the progression of rheumatoid arthritis. Previous studies have indicated that the ERK/STAT1 signaling pathway may be involved in the inflammatory response in synovial fluid-derived fibroblast-like synoviocytes (sfd-FLSs). However, the molecular mechanisms underlying the pathological effects of the inflammatory factors induced by IL-1β in sfd-FLSs remain unclear. The aim of the present study was to investigate the IL-1β-mediated signaling pathways involved in the expression of inflammatory factors in sfd-FLSs and in a rat model of rheumatoid arthritis. Reverse transcription-quantitative PCR, western blotting, and immunohistochemistry were used to analyze the role of IL-1β in the rat model of rheumatoid arthritis. The results suggested that IL-1β administration exacerbated rheumatoid arthritis, bone injury and increased the expression levels of inflammatory factors, such as IL-17 and tumor necrosis factor α (TNF-α), whereas treatment with anti-IL-1β exhibited opposite effects. In vitro experiments in sfd-FLSs further suggested that treatment with IL-1β influenced the expression levels of various inflammatory factors. In specific, IL-1β increased the expression of IL-17 and TNF-α, and decreased the expression of IL-6 and IL-10 in sfd-FLSs. Additionally, treatment with IL-1β increased the mRNA expression and protein phosphorylation of NF-κB, ERK and STAT1 in sfd-FLSs. Treatment with anti-IL-1β exhibited opposite effects on the expression levels of inflammatory factors and suppressed the NF-κB-mediated ERK-STAT1 signaling pathway activation in sfd-FLSs. Finally, treatment with a NF-κB inhibitor suppressed the effects of IL-1β, and NF-κB overexpression reversed the effects of anti-IL-1β on the expression levels of IL-17, TNF-α, NF-κB, ERK and STAT1. In conclusion, the present results demonstrated that treatment with IL-1β increased the expression levels of inflammatory factors in sfd-FLSs via the regulation of the NF-κB-mediated ERK/STAT1 signaling pathway in a rat model of rheumatoid arthritis. Therefore, the NF-κB/ERK/STAT1 signaling pathway may represent a potential target for the development of novel treatments for rheumatoid arthritis.

The connection between the Th17 cell related cytokines and cancer stem cells in cancer: Novel therapeutic targets

Cancer Stem Cells (CSCs) are the subpopulation of cells present in the different types of cancers with capabilities of self-renewal, differentiation, and tumorigenicity when transplanted into an animal host. The research work on the CSC has been providing a promising approach for the improvement of cancer therapies in the future. The CSCs have a close connection with the cytokines related with the T helper 17 (Th17) cell and other factors present in the tumor microenvironment, and these play a pivotal role in tumor progression and metastasis. The properties of CSCs are well defined in various type of tumor which is mainly developed by chemically and spontaneously in murine cancer model but in human defined primarily on acute myeloid leukemia, glioma, and breast cancer. The role of Th1, Th2, Natural Killer cells are well described in the cancer biology, but the Th17 cells are the subset which is recently exploited, and lots of research are going on. In this Review, we summarize current findings of the characteristics and functions of the Th17 cell and its signature cytokines in different cancers and their interconnections with cancer stem cells and with their markers. We have also discussed the functional properties of CSCs and how the CSCs markers can be distinguished from normal stem cells markers. We have also talked about the strategies that are efficiently targeting of CSCs and Th17 cells in different cancers.

Mesenchymal Stem Cells Improve Rheumatoid Arthritis Progression by Controlling Memory T Cell Response

In the last years, mesenchymal stem cell (MSC)-based therapies have become an interesting therapeutic opportunity for the treatment of rheumatoid arthritis (RA) due to their capacity to potently modulate the immune response. RA is a chronic autoimmune inflammatory disorder with an incompletely understood etiology. However, it has been well described that peripheral tolerance defects and the subsequent abnormal infiltration and activation of diverse immune cells into the synovial membrane, are critical for RA development and progression. Moreover, the imbalance between the immune response of pro-inflammatory and anti-inflammatory cells, in particular between memory Th17 and memory regulatory T cells (Treg), respectively, is well admitted to be associated to RA immunopathogenesis. In this context, MSCs, which are able to alter the frequency and function of memory lymphocytes including Th17, follicular helper T (Tfh) cells and gamma delta (γδ) T cells while promoting Treg cell generation, have been proposed as a candidate of choice for RA cell therapy. Indeed, given the plasticity of memory CD4⁺ T cells, it is reasonable to think that MSCs will restore the balance between pro-inflammatory and anti-inflammatory memory T cells populations deregulated in RA leading to prompt their therapeutic function. In the present review, we will discuss the role of memory T cells implicated in RA pathogenesis and the beneficial effects exerted by MSCs on the phenotype and functions of these immune cells abnormally regulated in RA and how this regulation could impact RA progression.

IL-17 in Rheumatoid Arthritis and Precision Medicine: From Synovitis Expression to Circulating Bioactive Levels

Interleukin (IL)-17A has a direct contribution in early induction and late chronic stages of various inflammatory diseases. In vitro and in vivo experiments have first characterized its local effects on different cell types and then its systemic effects. For instance, IL-17 axis is now identified as a key driver of psoriasis through its effects on keratinocytes. Similar observations apply for rheumatoid arthritis (RA) where IL-17A triggers changes in the synovium that lead to synovitis and maintain local inflammation. These results have prompted the development of biologics to target this cytokine. However, while convincing studies are reported on the efficacy of IL-17 inhibitors in psoriasis, there are conflicting results in RA. Patient heterogeneity but also the involvement of mediators that regulate IL-17 function may explain these results. Therefore, new tools and concepts are required to identify patients that could benefit from these IL-17 targeted therapies in RA and the development of predictive biomarkers of response has started with the emergence of various bioassays. Current strategies are also focusing on synovial biopsies that may be used to stratify patients. From local to systemic levels, new approaches are developing and move the field of RA management into the era of precision medicine.

Interleukin-13: A promising therapeutic target for autoimmune disease

Interleukin-13 (IL-13) was previously thought to be a redundant presence of IL-4, but in recent years its role in immunity, inflammation, fibrosis, and allergic diseases has become increasingly prominent. IL-13 can regulate several subtypes of T helper (Th) cells and affect their transformation, including Th1, Th2, T17, etc., thus it may play an important role in immune system. Previous studies have revealed that IL-13 is implicated in the pathogenesis of autoimmune diseases, such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), systemic sclerosis (SSc), ulcerative colitis (UC), type 1 diabetes (T1D), sjogren's syndrome (SS), etc. In this review, we will briefly discuss the biological features of IL-13 and summarize recent advances in the role of IL-13 in the development and pathogenesis of autoimmune diseases. This information may provide new perspectives and suggestions for the selection of therapeutic targets for autoimmune diseases.

Autoimmune Th17 Cells Induced Synovial Stromal and Innate Lymphoid Cell Secretion of the Cytokine GM-CSF to Initiate and Augment Autoimmune Arthritis

Despite the importance of Th17 cells in autoimmune diseases, it remains unclear how they control other inflammatory cells in autoimmune tissue damage. Using a model of spontaneous autoimmune arthritis, we showed that arthritogenic Th17 cells stimulated fibroblast-like synoviocytes via interleukin-17 (IL-17) to secrete the cytokine GM-CSF and also expanded synovial-resident innate lymphoid cells (ILCs) in inflamed joints. Activated synovial ILCs, which expressed CD25, IL-33Ra, and TLR9, produced abundant GM-CSF upon stimulation by IL-2, IL-33, or CpG DNA. Loss of GM-CSF production by either ILCs or radio-resistant stromal cells prevented Th17 cell-mediated arthritis. GM-CSF production by Th17 cells augmented chronic inflammation but was dispensable for the initiation of arthritis. We showed that GM-CSF-producing ILCs were present in inflamed joints of rheumatoid arthritis patients. Thus, a cellular cascade of autoimmune Th17 cells, ILCs, and stromal cells, via IL-17 and GM-CSF, mediates chronic joint inflammation and can be a target for therapeutic intervention.

Deficiency of IL-1 receptor antagonist suppresses IL-10-producing B cells in autoimmune arthritis in an IL-17/Th17-dependent manner

Rheumatoid arthritis (RA) is a systemic autoimmune disease with CD4⁺ T cell infiltration and hyperplasia of synovial tissues leading to progressive destruction of articular cartilage. In addition to the central role of T cells in the pathogenesis of RA, recent reports have suggested that B cells also contribute to RA. To explore the effects of interleukin (IL)-17 on B cell development and response in excess IL-1 signaling, we generated IL-17 and IL-1 receptor antagonist (IL-1Ra) double-deficient mice via backcrossing IL-17 knockout (KO) and IL-1RaKO mice. We studied the effect of IL-17 deficiency on antibody-producing B cells and regulatory B cells in IL-1RaKO mice. Excess IL-1 signal increased the frequency of B220⁺ IgG⁺ cells and plasma cells. It also promoted the production of immunoglobulins in vitro. Moreover, IL-17 deficiency significantly enhanced the frequency of regulatory IL-10-producing regulatory B cells in IL-1RaKO mice. IL-17 deficiency ameliorated disease symptoms of inflammatory arthritis in IL-1RaKO mice by suppressing the frequency of plasma cells and antibody production while enhancing the frequency of IL-10-producing B cells. These findings suggest that IL-17 can trigger an inflammatory immune reaction by activating antibody-producing B cells while suppressing immune regulatory B cells in RA.

Differential effects of TNF-α and IL-1β on the control of metal metabolism and cadmium-induced cell death in chronic inflammation

OBJECTIVE

Interleukin-1-beta (IL-1β) and tumour necrosis factor-alpha (TNF-α) are both monocyte-derived cytokines. Both cytokines have been previously described to exert a role in rheumatoid arthritis (RA) pathogenesis synergizing with other pro-inflammatory mediators, such as interleukin-17 (IL-17) on target cells, for the perpetuation of the inflammatory response (e.g. IL-6 production). In the context of experimental RA, Cd addition has an anti-proliferative and anti-inflammatory effect when associated to IL-17/TNF-α stimulation, due to its accumulation in synoviocytes. The aim of this work was to evaluate if IL-1β interaction with IL-17 also contributes to metal-import mechanisms and its effects on cell viability and inflammation.

METHODS

IL-17 and IL-1β were added to synoviocyte cultures with or without exogenous Cd addition (0.1 ppm, 0.89 μM). IL-6 production, Cd import kinetics, gene expression of ZIP-8 importer and metallothioneins (MTs) and cell viability were evaluated by ELISA, inductively-coupled mass spectrometry (ICP-MS), q-RT-PCR and viability assays (neutral red and annexin V) respectively.

RESULTS

IL-17 and IL-1β acted in synergy on synoviocytes to induce IL-6 production similarly to the IL-17/TNF-α combination. Metal import was lower with IL17/ IL-1β in comparison to IL-17/TNF-α exposed-synoviocytes, as the expression of ZIP-8 and MT-1F was less induced. Monocyte and PBMCs exposure to Cd resulted in a reduced production of IL-1β and an increased production of TNF-α and this result was confirmed in co-cultures of synoviocytes and PBMCs. The IL-17/IL-1β combination with Cd slightly reduced cell viability in comparison to the IL-17/TNF-α combination and resulted in a strong induction of IL-6 production.

CONCLUSION

IL-17/TNF-α combination but not IL-17/IL-1β combination mainly drives the accumulation of Cd in synoviocytes and its effects on cell viability and inflammation.

Interleukin-23 promotes intestinal T helper type17 immunity and ameliorates obesity-associated metabolic syndrome in a murine high-fat diet model

We addressed the role of interleukin-23 (IL-23) in driving the intestinal T helper type 17 (Th17) response during obesity and metabolic syndrome progression induced by a high-fat diet (HFD). Diet-induced obese and lean mice received HFD or control diet (CTD), respectively, for 20 weeks. The nutritional, metabolic and immune parameters were examined at weeks 9 and 20. Gene and protein IL-23p19 and IL-23 receptor expression was increased in the ileum of obese wild-type mice (WT) fed the HFD for 9 weeks. Mice lacking IL-23 and fed the HFD exhibited greater weight gain, higher fat accumulation, adipocyte hypertrophy and hepatic steatosis. Notably, these mice had more glucose intolerance, insulin resistance and associated metabolic alterations, such as hyperinsulinaemia and hyperlipidaemia. IL-23 deficiency also significantly reduced protein levels of IL-17, CCL20 and neutrophil elastase in the ileum and reduced Th17 cell expansion in the mesenteric lymph nodes of the HFD mice. Of importance, IL-23-deficient mice exhibited increased gut permeability and blood bacterial translocation compared with WT mice fed HFD. Finally, metagenomics analysis of gut microbiota revealed a dramatic outgrowth of Bacteroidetes over Firmicutes phylum with the prevalence of Bacteroides genera in the faeces of IL-23-deficient mice after HFD. In summary, IL-23 appears to maintain the Th17 response and neutrophil migration into the intestinal mucosa, minimizing the gut dysbiosis and protecting against obesity and metabolic disease development in mice.

Anti-arthritic properties of crude extract from Chenopodium ambrosioides L. leaves

Objectives

To evaluate the effect of hydroalcoholic crude extract (HCE) from Chenopodium ambrosioides leaves on the development of type II collagen-induced arthritis (CIA) and on pro-inflammatory cytokine balance.

Methods

Collagen-induced arthritis was induced in DBA1/J mice. On the 21st day, the mice were treated orally with HCE or methotrexate, daily. Six weeks after beginning the treatment, the following measures were determined: lymphoid organs cell numbers, percentage of blood cells, IL-6, IFN-γ, TNF-α and IL-17 serum concentrations, activity of hepatic and kidney glutathione S-transferase, hepatic 7-ethoxyresorufin-O-deethylase activity, bone density and histopathology.

Key findings

Treatment of CIA mice with HCE 5 mg/kg (HCE5) reduced the percentage of neutrophils and macrophages and the number of bone marrow cells and increased the lymphocyte numbers and the inguinal lymph node cellularity. This treatment inhibited the serum concentration of IL-6 and TNF-α, which may be related to the preservation of bone density and to the slight thickening of periarticular tissues, with minimal fibrosis and fibroblast proliferation in the joints. The CIA group presented advanced articular erosion and synovial hyperplasia. Phytochemical analysis showed mainly flavonols.

Conclusions

HCE5 presented anti-arthritic potential and reduced IL-6 and TNF-α, which participate directly in the development and maintenance of the inflammatory process in rheumatoid arthritis.

Galectin-3 is an amplifier of the interleukin-1β-mediated inflammatory response in corneal keratinocytes

Interleukin-1β (IL-1β) is a potent mediator of innate immunity commonly up-regulated in a broad spectrum of inflammatory diseases. When bound to its cell surface receptor, IL-1β initiates a signalling cascade that cooperatively induces the expression of canonical IL-1 target genes such as IL-8 and IL-6. Here, we present galectin-3 as a novel regulator of IL-1β responses in corneal keratinocytes. Using the SNAP-tag system and digitonin semi-permeabilization, we show that recombinant exogenous galectin-3 binds to the plasma membrane of keratinocytes and is internalized into cytoplasmic compartments. We find that exogenous galectin-3, but not a dominant negative inhibitor of galectin-3 polymerization lacking the N-terminal domain, exacerbates the response to IL-1β by stimulating the secretion of inflammatory cytokines. The activity of galectin-3 could be reduced by a novel d-galactopyranoside derivative targeting the conserved galactoside-binding site of galectins and did not involve interaction with IL-1 receptor 1 or the induction of endogenous IL-1β. Consistent with these observations, we demonstrate that small interfering RNA-mediated suppression of endogenous galectin-3 expression is sufficient to impair the IL-1β-induced secretion of IL-8 and IL-6 in a p38 mitogen-activated protein kinase-independent manner. Collectively, our findings provide a novel role for galectin-3 as an amplifier of IL-1β responses during epithelial inflammation through an as yet unidentified mechanism.

Rheumatoid arthritis bone marrow environment supports Th17 response

BACKGROUND

Rheumatoid arthritis (RA) is a systemic, autoimmune disease leading to joint destruction and ultimately disability. Bone marrow (BM) is an important compartment in RA, where pathological processes from "outside the joint" can occur. IL-17 is a cytokine that exerts proinflammatory effects and participates in the process of bone destruction. It is believed that IL-17 is involved in pathogenesis of RA. However, little is known about the biology of this cytokine in BM. In the present study we investigated Th17-related cytokines in RA BM.

METHODS

BM samples were obtained from RA and osteoarthritis (OA) patients during total hip replacement surgery. Levels of IL-17AF, IL-17AA, IL-17FF, IL-1β, IL-6, IL-23, TGF-β and CCL20 in BM plasma were determined by specific enzyme-linked immunosorbent assay tests. Percentage of IL-17-producing cells in BM was evaluated by flow cytometry. The effect of IL-15 stimulation on IL-17 production by BM mononuclear cells was examined in vitro.

RESULTS

Increased levels of IL-17AF were observed in BM plasma of RA patients in comparison to OA patients. Increased concentrations of IL-1β, IL-6 and CCL20 were observed in RA compared to OA BM plasma. Concordant with these findings, significantly increased percentages of CD3⁺CD4⁺IL-17⁺ and CD3⁺CD4⁺IL-17⁺IFN-γ⁺ cells were present in RA BM in comparison to OA BM samples. Finally, abundant in RA BM, IL-15 increased IL-17 production by cultured BM mononuclear cells.

CONCLUSIONS

In the course of RA, the BM microenvironment can promote the development of Th17 cell responses and overproduction of IL-17AF that may lead to increased inflammation and tissue destruction in RA BM.

Secukinumab in Active Rheumatoid Arthritis after Anti-TNFα Therapy: A Randomized, Double-Blind Placebo-Controlled Phase 3 Study

Introduction

‘REASSURE’ (NCT01377012), a phase 3 study, evaluated the efficacy and safety of secukinumab in patients with active rheumatoid arthritis (RA) who had an inadequate response to, or intolerance of, tumor necrosis factor inhibitors (TNF-inhibitors).

Methods

A total of 637 patients were randomized (1:1:1) to receive intravenous secukinumab 10 mg/kg (baseline, weeks 2 and 4) followed by subcutaneous secukinumab 150 mg or 75 mg every 4 weeks (starting from week 8) or placebo at the same dosing schedule. The primary endpoint was the American College of Rheumatology 20% improvement criteria (ACR20) at week 24. Other predefined hierarchical endpoints included Health Assessment Questionnaire-Disability Index, van der Heijde modified total Sharp score (vdH-mTSS) at week 24, and major clinical response (MCR; continuous 6 month period of ACR70 response) at 1 year.

Results

The primary efficacy endpoint was met with both secukinumab dose groups: ACR20 response rate at week 24 was 35.2% for both secukinumab dose groups (P = 0.0009) vs 19.6% for placebo. The improvements in secondary endpoints were greater in the secukinumab dose groups vs placebo but did not meet statistical significance. The overall safety profile was similar across all treatment groups.

Conclusion

Secukinumab demonstrated efficacy in reducing disease activity over placebo as measured by ACR20 in patients with active RA who had an inadequate response to TNF-inhibitors. Secukinumab demonstrated a safety profile similar to other biologics currently approved for RA.

Funding

Novartis Pharma AG.

Trial registration

ClinicalTrials.gov identifier: NCT01377012.

Electronic supplementary material

The online version of this article (doi:10.1007/s40744-017-0086-y) contains supplementary material, which is available to authorized users.

Relationship of IL-17A and IL-17F genetic variations to cervical cancer risk: a meta-analysis

Aim: We performed a meta-analysis to determine a more precise relationship of IL-17A and IL-17F polymorphisms with cervical cancer risk. Materials & methods: PubMed, CNKI and Wan Fang databases were searched for studies on these associations using STATA version 10.0 software. Results: Five studies were included. The AG and AA genotypes and A allele of IL-17A rs2275913 were correlated with an elevated risk of cervical cancer. The TT genotype and T allele of IL-17A rs3748067 and the CC genotype and C allele of IL-17F rs763780 carried a moderate risk of cervical cancer, when compared with the wild-type genotype. Conclusion: IL-17A and IL-17F polymorphisms therefore have the potential to act as predictive biomarkers for cervical cancer risk.

Update on interleukin-17: a role in the pathogenesis of inflammatory arthritis and implication for clinical practice

Interleukin-17 (IL-17A) is a cytokine critical for the acute defence against extracellular bacterial and fungal infections. Excess production during chronic inflammation has been associated with many inflammatory and autoimmune disorders. The present review describes the key molecules of the IL-17 pathway, which are or could be targeted for treatment. Since targeting of IL-17A may affect defence mechanisms, the pathogenesis of such possible adverse events is analysed. Then the contributions of IL-17 to bone changes in various forms of arthritis are discussed. Finally, the results of current inhibitors of the IL-17 pathway in clinical trials are detailed. IL-17A inhibition has been first registered for the treatment of psoriasis, psoriatic arthritis and ankylosing spondylitis. Other therapeutic options are now tested in a long list of diseases.

Neurodegeneration Enhances the Development of Arthritis

The prevalence of neurodegenerative disease and arthritis increases with age. Despite both processes being associated with immune activation and inflammation, little is known about the mechanistic interactions between neurodegenerative disease and arthritis. In this article, we show that tau-transgenic (tau-tg) mice that develop neurodegenerative disease characterized by deposition of tau tangles in the brain are highly susceptible to developing arthritis. Already at steady-state conditions, tau-tg mice exhibit peripheral immune activation that is manifested by higher numbers of granulocytes, plasmablasts, and inflammatory Ly6C^hi CCR2⁺ monocytes, as well as increased levels of proinflammatory cytokines, such as TNF-α and IL-17. Upon induction of collagen-induced arthritis (CIA), tau-tg mice displayed an increased incidence and an earlier onset of CIA that was associated with a more pronounced inflammatory cytokine response. Furthermore, induction of CIA led to significantly elevated numbers of Iba-1-expressing cells in the brain, indicative of microglia activation, and the formation of anti-tau Abs in tau-tg mice. These changes were accompanied by the resolution of tau tangles and significantly decreased neurodegenerative pathology. In summary, these data show that neurodegenerative disease enhances the development of arthritis. In addition, arthritis, once induced, triggers innate immune responses in the brain, leading to resolution of neurodegenerative changes.