Cysteine-rich 61 inhibition attenuates hepatic insulin resistance and improves lipid metabolism in high-fat diet fed mice and HepG2 cells

Metabolic dysfunction-associated steatotic liver disease (MASLD) is strongly associated with insulin resistance development. Hepatic lipid accumulation and inflammation are considered the main drivers of hepatic insulin resistance in MASLD. Cysteine-rich 61 (Cyr61 also called CCN1), a novel secretory matricellular protein, is implicated in liver inflammation, and its role in MASLD is not clearly understood. Therefore, we investigated the role of Cyr61 in hepatic insulin resistance and lipid metabolism as major factors in MASLD pathogenesis. In high-fat diet (HFD)-fed C57BL/6J mice, Cyr61 was downregulated or upregulated via viral transduction. Measurements of glucose homeostasis, histological assessment of liver tissues, and gene expression and signaling pathways of lipogenesis, fatty acid oxidation, and inflammation were performed using liver samples from these mice. Cyr61 levels in HepG2 cells were reduced using RNAi-mediated gene knockdown. Inflammation and insulin resistance were evaluated using real-time polymerase chain reaction and western blotting. HFD/AAV-shCyr61 mice exhibited enhanced glucose tolerance via the protein kinase B pathway, reduced hepatic inflammation, decreased lipogenesis, and increased fatty acid oxidation. Notably, HFD/AAV-shCyr61 mice showed elevated protein expression of sirtuin 6 and phosphorylated-AMP-activated protein kinase. In vitro experiments demonstrated that inhibition of Cyr61 downregulated pro-inflammatory cytokines such as interleukin-1 beta, IL-6, and tumor necrosis factor-alpha via the nuclear factor kappa B/c-Jun N-terminal kinase pathway, and alleviated insulin resistance. Cyr61 affected hepatic inflammation, lipid metabolism, and insulin resistance. Inhibition of Cyr61 reduced inflammation, recovered insulin resistance, and altered lipid metabolism in vivo and in vitro. Therefore, Cyr61 is a potential therapeutic target in MASLD.

Chemotherapy-initiated cysteine-rich protein 61 decreases acute B-lymphoblastic leukemia chemosensitivity

PURPOSE

Chemoresistance is a major challenge for acute lymphoblastic leukemia (ALL) treatment. Cysteine-rich protein 61 (Cyr61) plays an important role in drug resistance modulation of tumor cells, and Cyr61 levels are increased in the bone marrow of patients with ALL and contribute to ALL cell survival. However, the effect of Cyr61 on B cell acute lymphoblastic leukemia (B-ALL) cell chemosensitivity and the regulatory mechanisms underlying Cyr61 production in bone marrow remain unknown.

METHODS

Nalm-6 and Reh human B-ALL cell lines were used in this study. Cyr61 levels were assessed using quantitative real-time PCR (qRT-PCR), western blot analysis, and enzyme-linked immunosorbent assay. The effect of Cyr61 on B-ALL cell chemosensitivity to daunorubicin (DNR) was evaluated using cell viability and flow cytometry analyses. The regulatory mechanisms of Cyr61 production in bone marrow were examined using qRT-PCR and western blot analysis.

RESULTS

Cyr61 knockdown and overexpression increased and decreased the chemosensitivity of B-ALL cells to DNR, respectively. Cyr61 attenuated chemotherapeutic drug-induced apoptosis by upregulating B cell lymphoma-2. Notably, DNR induced DNA damage response and increased Cyr61 secretion in B-ALL cells through the ataxia telangiectasia mutated (ATM)-dependent nuclear factor kappa B pathway.

CONCLUSION

DNR induces Cyr61 production in B-ALL cells, and increased Cyr61 levels reduce the chemosensitivity of B-ALL cells. Consequently, targeting Cyr61 or related ATM signaling pathway may present a promising treatment strategy to enhance the chemosensitivity of patients with B-ALL.

METTL14-Mediated m6A Modification of TNFAIP3 Involved in Inflammation in Patients With Active Rheumatoid Arthritis

OBJECTIVE

The aim of the study was to investigate the role of N6 -methyladenosine (m6A) modification in the progression of rheumatoid arthritis (RA).

METHODS

Peripheral blood mononuclear cells (PBMCs) from patients with RA and healthy controls were collected. The expression of m6A modification-related proteins and m6A levels were detected using polymerase chain reaction (PCR), western blot, and m6A enzyme-linked immunosorbent assay (ELISA). The roles of methyltransferase-like 14 (METTL14) in the regulation of inflammation in RA was explored using methylated RNA immunoprecipitation (MeRIP) sequencing and RNA immunoprecipitation assays. Collagen antibody-induced arthritis (CAIA) mice were used as an in vivo model to study the role of METTL14 in the inflammation progression of RA.

RESULTS

We found that m6A writer METTL14 and m6A levels were decreased in PBMCs of patients with active RA and correlated negatively with the disease activity score using 28 joint counts (DAS28). Knockdown of METTL14 downregulated m6A and promoted the secretion of inflammatory cytokines interleukin 6 (IL-6) and IL-17 in PBMCs of patients with RA. Consistently, METTL14 knockdown promoted joint inflammation accompanied by upregulation of IL-6 and IL-17 in CAIA mice. MeRIP sequencing and functional studies confirmed that tumor necrosis factor α induced protein 3 (TNFAIP3), a key suppressor of the nuclear factor-κB inflammatory pathway, was involved in m6A-regulated PBMCs. Mechanistic investigations revealed that m6A affected TNFAIP3 expression by regulation of messenger RNA stability and translocation in TNFAIP3 protein coding sequence.

CONCLUSIONS

Our study highlights the critical roles of m6A on regulation of inflammation in RA progression. Treatment strategies targeting m6A modification may represent a new option for management of RA.

Oral vancomycin treatment suppresses gut trypsin activity and preserves intestinal barrier function during EAE

Studies have reported increased intestinal permeability in multiple sclerosis (MS) patients and its mouse model experimental autoimmune encephalomyelitis (EAE). However, the mechanisms driving increased intestinal permeability that in turn exacerbate neuroinflammation during EAE remain unclear. Here we showed that vancomycin preserved the integrity of the intestinal barrier, while also suppressing gut trypsin activity, enhancing the relative abundance of specific Lactobacilli and ameliorating disease during EAE. Furthermore, Lactobacilli enriched in the gut of vancomycin-treated EAE mice at day 3 post immunization negatively correlated with gut trypsin activity and EAE severity. In untreated EAE mice, we observed increased intestinal permeability and increased intestinal protease activated receptor 2 (PAR2) expression at day 3 post immunization. Prior studies have shown that trypsin increases intestinal permeability by activating PAR2. Our results suggest that the interaction between intestinal PAR2 and trypsin may be a key modulator of intestinal permeability and disease severity during EAE.

CD4+ T-cell subsets in autoimmune hepatitis: A review

Autoimmune hepatitis (AIH) is a chronic autoimmune liver disease that can lead to hepatocyte destruction, inflammation, liver fibrosis, cirrhosis, and liver failure. The diagnosis of AIH requires the identification of lymphoblast cell interface hepatitis and serum biochemical abnormalities, as well as the exclusion of related diseases. According to different specific autoantibodies, AIH can be divided into AIH-1 and AIH-2. The first-line treatment for AIH is a corticosteroid and azathioprine regimen, and patients with liver failure require liver transplantation. However, the long-term use of corticosteroids has obvious side effects, and patients are prone to relapse after drug withdrawal. Autoimmune diseases are characterized by an imbalance in immune tolerance of self-antigens, activation of autoreactive T cells, overactivity of B cells, and increased production of autoantibodies. CD4+ T cells are key players in adaptive immunity and can secrete cytokines, activate B cells to produce antibodies, and influence the cytotoxicity of CD8+ T cells. According to their characteristics, CD4+ T cells can be divided into different subsets. In this review, we discuss the changes in T helper (Th)1, Th2, Th17, Th9, Th22, regulatory T cell, T follicular helper, and T peripheral helper cells and their related factors in AIH and discuss the therapeutic potential of targeting CD4+ T-cell subsets in AIH.

The regulation of self-tolerance and the role of inflammasome molecules

Inflammasome molecules make up a family of receptors that typically function to initiate a proinflammatory response upon infection by microbial pathogens. Dysregulation of inflammasome activity has been linked to unwanted chronic inflammation, which has also been implicated in certain autoimmune diseases such as multiple sclerosis, rheumatoid arthritis, type 1 diabetes, systemic lupus erythematosus, and related animal models. Classical inflammasome activation-dependent events have intrinsic and extrinsic effects on both innate and adaptive immune effectors, as well as resident cells in the target tissue, which all can contribute to an autoimmune response. Recently, inflammasome molecules have also been found to regulate the differentiation and function of immune effector cells independent of classical inflammasome-activated inflammation. These alternative functions for inflammasome molecules shape the nature of the adaptive immune response, that in turn can either promote or suppress the progression of autoimmunity. In this review we will summarize the roles of inflammasome molecules in regulating self-tolerance and the development of autoimmunity.

CCN1 upregulates IL-36 via AKT/NF-κB and ERK/CEBP β-mediated signaling pathways in psoriasis-like models

Psoriasis is a chronic skin disorder characterized by epidermal keratinocyte hyperproliferation and inflammatory infiltration. CCN1 (also termed CYR61 or cysteine-rich angiogenic inducer 61) is an extracellular matrix-associated protein that is involved in multiple physiological functions. In psoriasis, we recently demonstrated that the overexpression of CCN1 promoted keratinocyte proliferation and activation. Furthermore, CCN1 was highly expressed in psoriatic skin lesions from psoriasis vulgaris patients. Here, we dissect the underlying molecular mechanism in imiquimod (IMQ) and interleukin (IL)-23-induced psoriasis-like models. Our results demonstrate that CCN1 can significantly upregulate IL-36 production in the murine skin of IMQ and IL-23-induced psoriasis-like models. Injection of CCN1-neutralizing antibody improved epidermal acanthosis and significantly reduced IL-36 production in vivo. These results suggest that CCN1 can be a critical upstream pro-inflammatory factor in psoriasis. In primary normal human epidermal keratinocytes, we demonstrated that CCN1 can selectively induced the production of IL-36α and IL-36γ through the activation of the protein kinase B (AKT)/nuclear factor kappa light chain enhancer of activated B cells (NF-κB) and extracellular-regulated kinase (ERK)/CCAAT/enhancer binding protein β (CEBPβ) signaling pathways via integrin receptor α6β1 in vitro. Our results suggest that targeting CCN1 can be a potential therapeutic strategy for psoriasis.

Two Main Cellular Components in Rheumatoid Arthritis: Communication Between T Cells and Fibroblast-Like Synoviocytes in the Joint Synovium

Rheumatoid arthritis (RA) is a chronic autoimmune disease that endangers the health of approximately 1% of the global population. Current RA medications on the market mainly include non-steroidal anti-inflammatory drugs, biological agents, and disease-modifying drugs. These drugs aim to inhibit the overactivated immune response or inflammation of RA, but they cannot cure RA. A better understanding of the pathogenesis of RA will provide a new understanding to search for RA targets and for drug development. The infiltration of T cells and hyper-proliferation of fibroblast-like synoviocytes (FLS) in the synovium of patients with RA are significantly upregulated. Furthermore, the abnormal activation of these two types of cells has been confirmed to promote development of the course of A by many studies. This article systematically summarizes the interactions between T cells and FLS in RA synovial tissues, including one-way/mutual regulation and direct/indirect regulation between the two. It further aims to investigate the pathogenesis of RA from the perspective of mutual regulation between T cells and FLS and to provide new insights into RA research.

Inhibitory Effects of Cold Atmospheric Plasma on Inflammation and Tumor-Like Feature of Fibroblast-Like Synoviocytes from Patients with Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic, debilitating systemic disease characterized by chronic inflammation and progressive joint destruction. Fibroblast-like synoviocytes (FLSs) are one of the most important players in the pathophysiology of RA, acting like tumor cells and secreting inflammatory cytokines. Previous research has shown that cold atmospheric plasma (CAP) inhibits cancer cells and may have anti-inflammatory properties. This study examined the effects of argon plasma jet-produced CAP on the suppression of invasion and inflammation caused by cultured RA-FLS. The findings revealed that CAP reduced cell viability and elevated the percentage of apoptotic RA-FLS by producing reactive oxygen species. Carboxyfluorescein diacetate succinimidyl ester (CFSE) staining confirmed that CAP could decrease the proliferation of RA-FLS. Furthermore, CAP effectively reduced the production of inflammatory factors (e.g., NF-κB and IL-6) as well as destructive factors like receptor activator of nuclear factor kappa-B ligand (RANKL) and matrix metalloproteinases-3 (MMP-3). These data suggest that CAP could be a promising treatment for slowing the progression of RA by reducing tumor-like features and inflammation in RA-FLS.

A systematic review of multimodal clinical biomarkers in the management of thyroid eye disease

Thyroid Eye Disease (TED) is an autoimmune disease that affects the extraocular muscles and periorbital fat. It most commonly occurs with Graves' Disease (GD) as an extrathyroidal manifestation, hence, it is also sometimes used interchangeably with Graves' Ophthalmopathy (GO). Well-known autoimmune markers for GD include thyroid stimulating hormone (TSH) receptor antibodies (TSH-R-Ab) which contribute to hyperthyroidism and ocular signs. Currently, apart from radiological investigations, detection of TED is based on clinical signs and symptoms which is largely subjective, with no established biomarkers which could differentiate TED from merely GD. We evaluated a total of 28 studies on potential biomarkers for diagnosis of TED. Articles included were published in English, which investigated clinical markers in tear fluid, orbital adipose-connective tissues, orbital fibroblasts and extraocular muscles, serum, thyroid tissue, as well as imaging biomarkers. Results demonstrated that biomarkers with reported diagnostic power have high sensitivity and specificity for TED, including those using a combination of biomarkers to differentiate between TED and GD, as well as the use of magnetic resonance imaging (MRI). Other biomarkers which were upregulated include cytokines, proinflammatory markers, and acute phase reactants in subjects with TED, which are however, deemed less specific to TED. Further clinical investigations for these biomarkers, scrutinising their specificity and sensitivity on a larger sample of patients, may point towards selection of suitable biomarkers for aiding detection and prognosis of TED in the future.

CCN1 Promotes Inflammation by Inducing IL-6 Production via α6β1/PI3K/Akt/NF-κB Pathway in Autoimmune Hepatitis

Autoimmune hepatitis (AIH) is a chronic inflammatory liver disease with unknown etiology. CCN1, an extracellular matrix-associated protein, is associated with carcinoma, inflammation, liver fibrosis, and even autoimmune diseases. However, the role that CCN1 plays in AIH has remained undetermined. In this study, expression of CCN1 in liver was detected by real-time PCR, western blot and immunohistochemistry (IHC). CCN1 level in serum was detected by ELISA. Diagnostic value of CCN1 was determined by receiver operating characteristic (ROC) curve analysis. CCN1 conditional knockout (CCN1^fl/flCre⁺) mice were generated by mating CCN1^fl/fl C57BL/6J and CAG-Cre-ERT C57BL/6J mice. Autoimmune hepatitis mice model was induced by concanavalin A (ConA). IKKα/β, IκBα, NF-κB p65 and Akt phosphorylation were determined by western blot. NF-κB p65 nuclear translocation was examined by immunofluorescence. Here, we found that CCN1 was over-expressed in hepatocytes of AIH patients. CCN1 level also increased in serum of AIH patients compared to healthy controls (HC). ROC curve analysis results showed that serum CCN1 was able to distinguish AIH patients from HD. In ConA induced hepatitis mice model, CCN1 conditional knockout (CCN1^fl/flCre⁺) attenuated inflammation by reducing ALT/AST level and IL-6 expression. In vitro, CCN1 treatment dramatically induced IL-6 production in LO2 cells. Moreover, the production of IL-6 was attenuated by CCN1 knockdown. Furthermore, we showed that CCN1 could activate IL-6 production via the PI3K/Akt/NF-κB signaling pathway by binding to α6β1 receptor. In summary, our results reveal a novel role of CCN1 in promoting inflammation by upregulation of IL-6 production in AIH. Our study also suggests that targeting of CCN1 may represent a novel strategy in AIH treatment.

Hallmarks of aging-based dual-purpose disease and age-associated targets predicted using PandaOmics AI-powered discovery engine

Aging biology is a promising and burgeoning research area that can yield dual-purpose pathways and protein targets that may impact multiple diseases, while retarding or possibly even reversing age-associated processes. One widely used approach to classify a multiplicity of mechanisms driving the aging process is the hallmarks of aging. In addition to the classic nine hallmarks of aging, processes such as extracellular matrix stiffness, chronic inflammation and activation of retrotransposons are also often considered, given their strong association with aging. In this study, we used a variety of target identification and prioritization techniques offered by the AI-powered PandaOmics platform, to propose a list of promising novel aging-associated targets that may be used for drug discovery. We also propose a list of more classical targets that may be used for drug repurposing within each hallmark of aging. Most of the top targets generated by this comprehensive analysis play a role in inflammation and extracellular matrix stiffness, highlighting the relevance of these processes as therapeutic targets in aging and age-related diseases. Overall, our study reveals both high confidence and novel targets associated with multiple hallmarks of aging and demonstrates application of the PandaOmics platform to target discovery across multiple disease areas.

YAP/TAZ: Key Players for Rheumatoid Arthritis Severity by Driving Fibroblast Like Synoviocytes Phenotype and Fibro-Inflammatory Response

Objective

The role of YAP/TAZ, two transcriptional co-activators involved in several cancers, was investigated in rheumatoid arthritis (RA).

Methods

Fibroblast like synoviocytes (FLS) from patients with RA or osteoarthritis were cultured in 2D or into 3D synovial organoids. Arthritis rat model (n=28) and colitis mouse model (n=21) were used. YAP/TAZ transcriptional activity was inhibited by verteporfin (VP). Multiple techniques were used to assess gene and/or protein expression and/or localization, cell phenotype (invasion, proliferation, apoptosis), bone erosion, and synovial stiffness.

Results

YAP/TAZ were transcriptionally active in arthritis (19-fold increase for CTGF expression, a YAP target gene, in RA vs. OA organoids; p<0.05). Stiff support of culture or pro-inflammatory cytokines further enhanced YAP/TAZ transcriptional activity in RA FLS. Inhibiting YAP/TAZ transcriptional activity with VP restored a common phenotype in RA FLS with a decrease in apoptosis resistance, proliferation, invasion, and inflammatory response. Consequently, VP blunted hyperplasic lining layer formation in RA synovial organoids. In vivo, VP treatment strongly reduced arthritis severity (mean arthritic index at 3.1 in arthritic group vs. 2.0 in VP treated group; p<0.01) by restoring synovial homeostasis and decreasing systemic inflammation. YAP/TAZ transcriptional activity also enhanced synovial membrane stiffening in vivo, thus creating a vicious loop with the maintenance of YAP/TAZ activation over time in FLS. YAP/TAZ inhibition was also effective in another inflammatory model of mouse colitis.

Conclusion

Our work reveals that YAP/TAZ were critical factors during arthritis. Thus, their transcriptional inhibition could be relevant to treat inflammatory related diseases.

Serum CYR61 Is Associated With Airway Inflammation and Is a Potential Biomarker for Severity in Chronic Obstructive Pulmonary Disease

Background: Cysteine-rich 61 (CYR61) and inflammation was upregulated in the lungs of patients with chronic obstructive pulmonary disease (COPD). However, the association between CYR61 and inflammation was unclear in COPD patients. This study aimed to analyze the association of serum CYR61 with pulmonary inflammation and lung function indexes in COPD patients. Methods: One hundred and fifty COPD patients and 150 control subjects were enrolled. Serum and pulmonary CYR61 was detected. Lung function indexes were evaluated in COPD patients. Results: Serum CYR61 level was elevated and pulmonary CYR61 expression was upregulated in COPD patients. An increased CYR61 was associated with decreased pulmonary function indexes in COPD patients. Further analyses showed that nuclear factor-kappa B (NF-κB) p65-positive nuclei was elevated in the lungs of COPD patients with high level of CYR61. Accordingly, serum monocyte chemotactic protein (MCP)-1 and tumor necrosis factor α (TNF-α), two downstream inflammatory cytokines of NF-κB pathway, were increased in parallel with CYR61, among which serum MCP-1 and TNF-α were the highest in COPD patients with high level of CYR61. Moreover, a positive correlation, determined by multivariate regression that excluded the influence of age, gender and smoking, was observed between serum CYR61 and inflammatory cytokines in COPD patients. Conclusion: These results provide evidence that an increased CYR61 is associated with pulmonary inflammation and COPD progression. Inflammatory cytokines may be the mediators between CYR61 elevation and COPD progression.

CCN proteins in the musculoskeletal system: current understanding and challenges in physiology and pathology

The acronym for the CCN family was recently revised to represent “cellular communication network”. These six, small, cysteine-enriched and evolutionarily conserved proteins are secreted matricellular proteins, that convey and modulate intercellular communication by interacting with structural proteins, signalling factors and cell surface receptors. Their role in the development and physiology of musculoskeletal system, constituted by connective tissues where cells are interspersed in the cellular matrix, has been broadly studied. Previous research has highlighted a crucial balance of CCN proteins in mesenchymal stem cell commitment and a pivotal role for CCN1, CCN2 and their alter ego CCN3 in chondrogenesis and osteogenesis; CCN4 plays a minor role and the role of CCN5 and CCN6 is still unclear. CCN proteins also participate in osteoclastogenesis and myogenesis. In adult life, CCN proteins serve as mechanosensory proteins in the musculoskeletal system providing a steady response to environmental stimuli and participating in fracture healing. Substantial evidence also supports the involvement of CCN proteins in inflammatory pathologies, such as osteoarthritis and rheumatoid arthritis, as well as in cancers affecting the musculoskeletal system and bone metastasis. These matricellular proteins indeed show involvement in inflammation and cancer, thus representing intriguing therapeutic targets. This review discusses the current understanding of CCN proteins in the musculoskeletal system as well as the controversies and challenges associated with their multiple and complex roles, and it aims to link the dispersed knowledge in an effort to stimulate and guide readers to an area that the writers consider to have significant impact and relevant potentialities.

TLR2 Regulates Mast Cell IL-6 and IL-13 Production During Listeria monocytogenes Infection

Listeria monocytogenes (L.m) is efficiently controlled by several cells of the innate immunity, including the Mast Cell (MC). MC is activated by L.m inducing its degranulation, cytokine production and microbicidal mechanisms. TLR2 is required for the optimal control of L.m infection by different cells of the immune system. However, little is known about the MC receptors involved in recognizing this bacterium and whether these interactions mediate MC activation. In this study, we analyzed whether TLR2 is involved in mediating different MC activation responses during L.m infection. We found that despite MC were infected with L.m, they were able to clear the bacterial load. In addition, MC degranulated and produced ROS, TNF-α, IL-1β, IL-6, IL-13 and MCP-1 in response to bacterial infection. Interestingly, L.m induced the activation of signaling proteins: ERK, p38 and NF-κB. When TLR2 was blocked, L.m endocytosis, bactericidal activity, ROS production and mast cell degranulation were not affected. Interestingly, only IL-6 and IL-13 production were affected when TLR2 was inhibited in response to L.m infection. Furthermore, p38 activation depended on TLR2, but not ERK or NF-κB activation. These results indicate that TLR2 mediates only some MC activation pathways during L.m infection, mainly those related to IL-6 and IL-13 production.

The p53 status in rheumatoid arthritis with focus on fibroblast-like synoviocytes

P53 is a transcription factor that regulates many signaling pathways like apoptosis, cell cycle, DNA repair, and cellular stress responses. P53 is involved in inflammatory responses through the regulation of inflammatory signaling pathways, induction of cytokines, and matrix metalloproteinase expression. Also, p53 regulates immune responses through modulating Toll-like receptors expression and innate and adaptive immune cell differentiation and maturation. P53 is a modulator of the apoptosis and proliferation processes through regulating multiple anti and pro-apoptotic genes. Rheumatoid arthritis (RA) is categorized as an invasive inflammatory autoimmune disease with irreversible deformity of joints and bone resorption. Different immune and non-immune cells contribute to RA pathogenesis. Fibroblast-like synoviocytes (FLSs) have been recently introduced as a key player in the pathogenesis of RA. These cells in RA synovium produce inflammatory cytokines and matrix metalloproteinases which results in synovitis and joint destruction. Besides, hyper proliferation and apoptosis resistance of FLSs lead to synovial hyperplasia and bone and cartilage destruction. Given the critical role of p53 in inflammation, apoptosis, and cell proliferation, lack of p53 function (due to mutation or low expression) exerts a prominent role for this gene in the pathogenesis of RA. This review focuses on the role of p53 in different mechanisms and cells (specially FLSs) that involved in RA pathogenesis.

Targeting CCN Proteins in Rheumatoid Arthritis and Osteoarthritis

The CCN family of matricellular proteins (CYR61/CCN1, CTGF/CCN2, NOV/CCN3 and WISP1-2-3/CCN4-5-6) are essential players in the key pathophysiological processes of angiogenesis, wound healing and inflammation. These proteins are well recognized for their important roles in many cellular processes, including cell proliferation, adhesion, migration and differentiation, as well as the regulation of extracellular matrix differentiation. Substantial evidence implicates four of the proteins (CCN1, CCN2, CCN3 and CCN4) in the inflammatory pathologies of rheumatoid arthritis (RA) and osteoarthritis (OA). A smaller evidence base supports the involvement of CCN5 and CCN6 in the development of these diseases. This review focuses on evidence providing insights into the involvement of the CCN family in RA and OA, as well as the potential of the CCN proteins as therapeutic targets in these diseases.

Correlation between serum cysteine-rich protein 61 and disease activity of antineutrophil cytoplasmic antibody-associated vasculitis

OBJECTIVES

Cysteine-rich protein 61 (CYR61) stimulates protein kinase B (Akt)-mediated nuclear factor-kappa B (NF-κB) signalling leading to an increase in pro-inflammatory cytokines, which play important roles in the pathogenesis of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). Hence, we investigated whether serum CYR61 was correlated with disease activity of AAV in a single-centre prospective cohort.

METHODS

Seventy-two patients with AAV were randomly selected and included. Serum CYR61, interleukin (IL)-6 and IL-8 levels were quantified with the patients' stored sera, and clinical and laboratory data at the time of blood sampling were collected. Spearman's correlation and linear regression analysis was conducted to analyse the correlation between continuous variables. The optimal cut-off of serum CYR61 for predicting high disease activity was identified using the receiver operator characteristic curve. Birmingham vasculitis activity score (BVAS) was used as a measure to assess disease activity, and high disease activity was defined as BVAS ≥ 12.

RESULTS

Serum CYR61 significantly correlated with BVAS (r = 0.249), erythrocyte sedimentation rate (r = 0.283), C-reactive protein (r = 0.298) and serum IL-6 (r = 0.319). However, a linear association was not found between CYR61 and BVAS (β = 0.102, P = 0.304). The relative risk (RR) for high disease activity in AAV patients with serum CYR61 ≥ 236.2 pg/mL was higher than those with serum CYR61 < 236.2 pg/mL (RR 3.316, P = 0.018).

CONCLUSION

Even though serum CYR61 was not directly proportional to the increase of BVAS, it could be predictive of high disease activity in AAV. Key Points • Serum CYR61 was significantly correlated with BVAS along with ESR, CRP and serum IL-6. • The cut-off of serum CYR61 for high disease activity of AAV was obtained as 236.2 pg/mL. • AAV patients with serum CYR61 ≥ 236.2 pg/mL had increased risk of having higher disease activity than those with serum CYR61 < 236.2 pg/mL (RR 3.316, P = 0.018).

Expression of Cyr61 is associated with clinical course in patients with Crohn's disease

Backgrounds

Cysteine-rich angiogenic inducer 61 (Cyr61) is emerging as an important regulator of tissue homeostasis and wound repair. We aim to explore the colonic mucosal expression of Cyr61 and analyze the association between Cyr61 expression and clinical course in patients with Crohn’s disease (CD).

Methods

Endoscopic samples were identified from 83 CD patients with and 372 controls by searching pathological reports. Among them, age- and sex- matched 43 of each group by a propensity score were selected to compare Cyr61 expression by immunohistochemistry (IHC). IHC scores for Cyr61 expression of CD patients were divided into tertiles to evaluate the association with clinical course. We also measured the level of mRNA for Cyr 61 and proinflammatory genes in inflamed and noninflamed colonic mucosal lesions from CD patients.

Results

The mean IHC scores for Cyr61 expression was higher in CD patients (86.5) than in controls (46.1, P < 0.001). In CD patients, the mean IHC scores for Cyr61 expression (68.3) was lower in patients with clinical recurrence than in patients without recurrence (92.2, P = 0.01). Cyr61 mRNA levels in inflamed mucosa were twofold higher than those in non-inflamed lesion (P > 0.05) and the mRNA levels of IL-6 and TLR-4 in inflamed mucosa were significantly higher than those in non-inflamed mucosa in CD patients (all P < 0.05). When CD patients were stratified into tertile groups according to IHC scores for Cyr61 expression, clinical recurrence rates tended to be lower in patients with high Cyr61 expression (P for trend = 0.02). Compared with tertile 1 of Cyr61 expression, tertile 3 of Cyr 61 expression was associated with reduced risk of clinical recurrence (OR 0.43, 95% CI 0.20–0.92) after adjustment for age, sex and CD activity index at the time of colonoscopy in CD patients (P = 0.03).

Conclusions

Cyr61 mucosal expression in CD patients was inversely associated with clinical course. Future study need to be considered to evaluate whether Cyr 61 may play a role in activating inflammatory responses and contributing to wound healing and tissue repair in patients with CD.

Sesquiterpene lactones; Damsin and neoambrosin suppress cytokine-mediated inflammation in complete Freund's adjuvant rat model via shutting Akt/ERK1/2/STAT3 signaling

ETHNOPHARMACOLOGIAL RELEVANCE

Although Damsissa (Ambrosia maritima) is traditionally used as anti-inflammatory and diuretic, the biological activity and mechanism of action of its major constituents are to be elucidated.

AIM

to decipher the anti-arthritic potential of damsin (DMS) and neoambrosin (NMS) and to unfold their molecular signaling in complete Freund's adjuvant (CFA)-induced arthritis model.

MATERIALS AND METHODS

the right hind paw was inoculated with CFA (0.1 ml) at day 0 and 7 while treatments were started from the 14^th day and continued for 2 weeks. Rats were randomly assigned into 4 groups; normal group (NRML), CFA-induced arthritis group, CFA-induced arthritis treated with DMS and NMS (10 mg/kg/day) as 3^rd and 4^th group; respectively.

RESULTS

Throughout experimental period, treatments ameliorated the increase of paw volume, knee joint diameter and nociception tests as reflected in open field arena. Also, DSM and NMS suppressed phosphorylation of Akt, STAT-3, ERK1/2 which was further mirrored by inactivation of GSK3β and downregulation of MCP-1 together with CCN1 and NF-kβ in hind paw tissue. Concomitantly, inflammation markers; TNF-α, IL-6, -12 were lowered as confirmed microscopically during examination of hind paw tissue.

CONCLUSION

DSM and NMS-induced suppression of NF-kβ subdues clinical features of RA most probably through repression of Akt/ERK1/2/STAT3 pathway. Therefore, DMS and NMS can serve as safe and effective treatment for rheumatoid arthritis, one of the most disabling chronic, inflammatory and painful autoimmune disease.

Simvastatin Inhibits CYR61 Expression in Orbital Fibroblasts in Graves' Ophthalmopathy through the Regulation of FoxO3a Signaling

Graves' ophthalmopathy (GO), which is characterized by orbital tissue inflammation, expansion, and fibrosis, is the ocular manifestation in 25% to 50% of patients with Graves' disease. As the pathology of GO is driven by autoimmune inflammation, many proinflammatory cytokines/chemokines, including TNF-α, IL-1β, IL-6, and CCL20, are crucial in the pathogenesis of GO to activate the orbital fibroblasts. Cysteine-rich protein 61 (CYR61), which is known to regulate cell proliferation, adhesion, and migration, plays a proinflammatory role in the pathogenesis of many inflammatory diseases, such as rheumatoid arthritis. CYR61 was considered a potential biomarker of GO in recent studies. Statins, which are cholesterol-lowering drugs, were found to reduce the risk of GO, probably through their anti-inflammatory and immunomodulatory effects. In this study, we established a link between CYR61 and statins in the pathogenesis and potential treatment for GO. Firstly, our data showed the overexpression of CYR61 in the orbital tissue (n = 4) and serum specimens (n = 6) obtained from the patients with inactive GO. CYR61 could induce the production of IL-6 and CCL20 in cultured GO orbital fibroblasts. The expression of CYR61 in cultured GO orbital fibroblasts was upregulated via TNF-α stimulation. Secondly, we pretreated cultured GO orbital fibroblasts using simvastatin, a statin, followed by TNF-α stimulation. The data revealed that simvastatin could inhibit TNF-α-induced CYR61 expression by modulating the activity of transcription factor FoxO3a. Our results provided insights into some cellular mechanisms that may explain the possible protective effects of simvastatin against the development of GO.

Can Dasatinib Ameliorate the Hepatic changes, Induced by Long Term Western Diet, in Mice?

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a worldwide disease that progresses into steatohepatitis (NASH) that has no current effective treatment. This study aimed, for the first time, to investigate the effect of Dasatinib; a tyrosine kinase inhibitor showing anti-PDGFR activity with a macrophage modulating efficacy, on NASH.

METHODS

NASH was induced, in C57BL/6 mice by western diet (WD). Control groups received either DMSO or Dasatinib. After 12 weeks, WD-fed mice received DMSO, Dasatinib (4 mg/kg) or Dasatinib (8 mg/kg) once daily, for four weeks. Serum was examined for ALT and lipid profile. Immunohistochemical staining for SREBP1 (lipogenesis marker), iNOS, arginase-1, CD68, CD163 (macrophage polarization markers), TGF-β (fibrosis marker) and ASMA (a marker for activated hepatic stellate cell), hepatic mRNA expression for SREBP-1, iNOS, arginase-1, TGF-β and PDGFA genes; and western blotting for phosphorylated PDGFR α and β, SREBP1, iNOS, arginase-1, IL1α, COX2, TGF-β and ASMA were performed. Liver sections were stained also for H & E, Oil red O and Sirius red.

RESULTS

Dasatinib could ameliorate the WD-induced disturbance of serum ALT, lipid profile and significantly reduced hepatic expression of PDGFA, phosphorylated PDGFR α and β, IL1α, COX2, SREBP-1, iNOS, CD68, TGF-β and ASMA but increased expression for arginase-1 and CD163 (M2 macrophage markers). Moreover, Dasatinib reduced the steatosis, inflammation, hepatocellular ballooning, hepatic fibrosis and the high NAFLD activity scoring induced by WD.

CONCLUSION

Dasatinib can prevent the progression of WD-induced NASH by attenuating lipogenesis, and inducing M2 macrophage polarization with antifibrotic activity.

Inhibition of CDC42 reduces macrophage recruitment and suppresses lung tumorigenesis in vivo

BACKGROUND

Cell division control (CDC) 42 has been involved in the regulation of diverse cancers. Macrophage recruitment plays an important role in the pathogenesis and development of tumor. However, it remains unclear whether CDC42 contributes to macrophage recruitment and lung tumorigenesis in vivo.

METHODS

Small interference RNA (siRNA) was used to knock down CDC42 in the Lewis lung carcinoma (LLC)1. The invasion capability of CDC42 knockdown LLC1 cells was evaluated. LLC1 cells with CDC42 targeted small hairpin RNA (shRNA) were inoculated into C57BL/6 mice to establish the tumor-bearing animal model Tumor size and metastasis related proteins were measured. In addition, the invasion of macrophages in the tumor site as well as macrophage chemokine were also determined in the model.

RESULTS

The capacity of invasion and metastasis of LLC1 cells significantly decreased when CDC42 was knocked down. When inoculated with CDC42 knockdown LLC1 cells in vivo, the tumor size and metastasis related proteins levels both decreased. The invasion capacity of macrophages and the associated macrophage chemokine were also significantly down-regulated.

CONCLUSION

Our data suggest that the inhibition of CDC42 expression in lung cancer cells can significantly prevent the pathogenesis and development of tumor in an allograft tumor model in vivo, which might provide a novel therapeutic target and potential strategy for lung cancer treatment in the future.

Cyr61 Promotes Inflammation of a Gouty Arthritis Model in Rats

Background

Cyr61 is considered a novel proinflammatory factor. Gouty arthritis (GA) is a self-limited inflammatory reaction caused by monosodium urate (MSU) crystals. In this study, we assessed the role of Cyr61 in the inflammatory process of GA.

Methods

We investigated the expression of Cyr61 in MSU-induced rat gout models and MSU-stimulated rat fibroblast-like synovial (FLS) cells. After inhibiting the expression of Cyr61, levels of IL-1β, TNF-α, and IL-6 were detected by ELISA, qPCR, western blot, and immunohistochemical methods. We probed the downstream NF-κB signaling pathway using the NF-κB inhibitor PDTC, and levels of NF-κB and p-NF-κB were detected by western blot and qPCR.

Results

Our results demonstrate that Cyr61 plays a potent role in the formation of local inflammation in vitro and in vivo. Cyr61 was highly expressed in synovial tissues of gout models, and the expression of Cyr61 protein was also significantly increased in MSU-stimulated FLS cells. Cyr61 promoted MSU-induced acute inflammation via the NF-κB signaling pathway.

Conclusions

Our study has revealed that Cyr61 is an important regulatory factor for the initiation of inflammation in GA. The high expression of Cyr61 protein can induce synovial cells to produce many inflammatory cytokines, such as IL-1β, TNF-α, and IL-6, partly in an NF-κB-dependent manner. Thus, inhibition of Cyr61 could be a new target and strategy for the prevention and treatment of GA.

In vitro IL-6/IL-6R Trans-Signaling in Fibroblasts Releases Cytokines That May Be Linked to the Pathogenesis of IgG4-Related Disease

Background: The remarkable mechanisms of storiform fibrosis and the formation of high levels of IgG4 with a pathogenic germinal center (GC) in the inflammatory tissue of IgG4-RD remains unknown and may be responsible for the unsatisfactory therapeutic effect on IgG4-related diseases when using conventional therapy.

Objectives: To investigate the mechanisms of interleukin 6 (IL-6) inducing fibroblasts to produce cytokines for pathogenic GC formation in the development of IgG4-related disease (IgG4-RD).

Methods: The clinical data and laboratory examinations of 56 patients with IgG4-RD were collected. IL-6 and IL-6R expression in the serum and tissues of patients with IgG4-RD and healthy controls were detected by ELISA, immunohistochemistry, and immunofluorescence. Human aorta adventitial fibroblasts (AAFs) were cultured and stimulated with IL-6/IL-6 receptor (IL-6R). The effect of IL-6/IL-6R on AAFs was determined by Luminex assays.

Results: The serum IL-6 and IL-6R levels were elevated in active IgG4-RD patients and IL-6 was positively correlated with the disease activity (e.g., erythrocyte sedimentation rate [ESR], C-reactive protein [CRP], and IgG4-RD responder index). IL-6 and IL-6R expression in the tissue lesions of IgG4-related retroperitoneal fibrosis and IgG4-related sialadenitis patients were also significantly higher than that in the normal tissues. In addition, there is a relative abundance of myofibroblasts as well as IgG4⁺ plasma cells in the tissues of IgG4-related retroperitoneal fibrosis. α-SMA and B cell differentiation cytokines (i.e., B cell activating factor), and α-SMA and T follicular helper (Tfh) cell differentiation cytokines (e.g., IL-7, IL-12, and IL-23) were co-expressed in the local lesions. In vitro, IL-6/IL-6R significantly promoted the production of B cell activating factor, IL-7, IL-12, and IL-23 in AAFs in a dose-dependent manner. This effect was partially blocked by JAK1, JAK2, STAT3, and Akt inhibitors, respectively.

Conclusions:In vitro IL-6/IL-6R trans-signaling in fibroblasts releases Tfh and B cell differentiation factors partially via the JAK2/STAT3, JAK1/STAT3, and JAK2/Akt pathways, which may be linked to the pathogenesis of IgG4-RD. This indicated that IL-6 and fibroblasts may be responsible for GC formation and fibrosis in the development of IgG4-RD. Blocking IL-6 with JAK1/2 inhibitors or inhibiting fibroblast proliferation might be beneficial for IgG4-RD treatment.

Huzhang Tongfeng Granule Improves Monosodium Urate-Induced Inflammation of Gouty Arthritis Rat Model by Downregulation of Cyr61 and Related Cytokines

OBJECTIVE

Gouty arthritis (GA) is a noninfectious inflammatory disease characterized by self-limited and severe pain. Huzhang Tongfeng granule is one of the most effective traditional Chinese medicines in the treatment of acute GA. However, its effects on the inflammatory factors in the process of acute gout inflammation remain unknown. In the present study, we aimed to evaluate the effect of Huzhang Tongfeng granule on the expressions of Cyr61 and related inflammatory factors in both experimental gout models in vivo and in vitro.

METHODS

Huzhang Tongfeng granule was provided by the pharmaceutical preparation room of Yueyang Hospital of Integrated Traditional Chinese and Western Medicine. The expressions of Cyr61, IL-1β, TNF-α, and IL-6 in monosodium urate- (MSU-) induced rat models and fibroblast-like synoviocytes (FLSs) were determined by RT-PCR, Western blotting analysis, ELISA, immunohistochemistry, and hematoxylin and eosin staining.

RESULTS

Huzhang Tongfeng granule could downregulate the expressions of IL-1β, TNF-α, and IL-6 to some extent by inhibiting the expression of Cyr61.

CONCLUSIONS

Collectively, our findings indicated that Cyr61 was highly expressed in rat models of gout. By inhibiting the expression of Cyr61, Huzhang Tongfeng granule could partially attenuate the inflammation induced by MSU crystal.

CCN1 promotes hepatic steatosis and inflammation in non-alcoholic steatohepatitis

Non-alcoholic fatty liver disease (NAFLD) is characterized by increased uptake and accumulation of lipids in hepatocytes. Simple steatosis may progress to non-alcoholic steatohepatitis (NASH) with inflammation, hepatocellular injury and fibrosis. CCN1 is an important matrix protein that regulates cell death and promotes immune cell adhesion and may potentially control this process. The role of CCN1 in NASH remains unclear. We investigated the role of CCN1 in the pathogenesis of steatohepatitis. CCN1 upregulation was found to be closely related with steatosis in patients with NASH, obese mice and a FFA-treated hepatocyte model. Controlling the expression of CCN1 in murine NASH models demonstrated that CCN1 increased the severity of steatosis and inflammation. From the sequence results, we found that fatty acid metabolism genes were primarily involved in the MCD mice overexpressing CCN1 compared to the control. Then, the expression of fatty acid metabolism genes was determined using a custom-designed pathway-focused qPCR-based gene expression array. Expression analysis showed that CCN1 overexpression significantly upregulated the expression of fatty acid metabolism-associated genes. In vitro analysis revealed that CCN1 increased the intracellular TG content, the pro-inflammatory cytokines and the expression level of apoptosis-associated proteins in a steatosis model using murine primary hepatocytes. We identified CCN1 as an important positive regulator in NASH.

Cyanidin prevents the hyperproliferative potential of fibroblast-like synoviocytes and disease progression via targeting IL-17A cytokine signalling in rheumatoid arthritis

The hyperplastic phenotype of fibroblast-like synoviocytes (FLSs) plays an important role for synovitis, chronic inflammation and joint destruction in rheumatoid arthritis (RA). Interleukin 17A (IL-17A), a signature pro-inflammatory cytokine effectively influences the hyperplastic transformation of FLS cells and synovial pannus growth. IL-17A cytokine signalling participates in RA pathology by regulating an array of pro-inflammatory mediators and osteoclastogenesis. Cyanidin, a key flavonoid inhibits IL-17A/IL-17 receptor A (IL-17RA) interaction and alleviates progression and disease severity of psoriasis and asthma. However, the therapeutic efficacy of cyanidin on IL-17A cytokine signalling in RA remains unknown. In the present study, cyanidin inhibited IL-17A induced migratory and proliferative capacity of FLS cells derived from adjuvant-induced arthritis (AA) rats. Cyanidin treatment reduced IL-17A mediated reprogramming of AA-FLS cells to overexpress IL-17RA. In addition, significantly decreased expression of IL-17A dependent cyr61, IL-23, GM-CSF, and TLR3 were observed in AA-FLS cells in response to cyanidin. At the molecular level, cyanidin modulated IL-17/IL-17RA dependent JAK/STAT-3 signalling in AA-FLS cells. Importantly, cyanidin activated PIAS3 protein to suppress STAT-3 specific transcriptional activation in AA-FLS cells. Cyanidin treatment to AA rats attenuated clinical symptoms, synovial pannus growth, immune cell infiltration, and bone erosion. Cyanidin reduced serum level of IL-23 and GM-CSF and expression of Cyr 61 and TLR3 in the synovial tissue of AA rats. Notably, the level of p-STAT-3 protein was significantly decreased in the synovial tissue of AA rats treated with cyanidin. This study provides the first evidence that cyanidin can be used as IL-17/17RA signalling targeting therapeutic drug for the treatment of RA and this need to be investigated in RA patients.

Relationship between polymorphisms in -572G/C interleukin 6 promoter gene polymorphisms (rs1800796) and risk of rheumatoid arthritis: A meta-analysis

AIMS

This meta-analysis was aimed to investigate the association between -572G/C interleukin (IL)-6 gene polymorphism and occurrence risk of rheumatoid arthritis (RA).

METHODS

Literature search was conducted in PubMed, Embase, Springer and Google Scholar up to November 2018. The pooled odds ratios (ORs) and 95% confidence interval (CI) were calculated by Revman 5.3.

RESULTS

A total of six case-control studies were included in this meta-analysis. In the allele model (G vs C), homozygous gene model (GG vs CC), recessive gene model (GG vs GC + CC), and dominant gene model (GG + GC vs CC), the pooled estimate indicated there was significant association between -572G/C IL-6 gene polymorphism and risk of RA. However, no significant statistical results were found in meta-analyses of heterozygote gene models.

CONCLUSIONS

The -572G/C IL-6 gene polymorphism is associated with the risk of RA. The GG genotype may be the main contributor in increasing susceptibility to RA.

CYR61, a potential biomarker of tumor inflammatory response in epithelial ovarian cancer microenvironment of tumor progress

Background

Recent studies have found that inflammatory response is involved in the pathogenesis of ovarian cancer. Advanced ovarian cancer is often presented with ascites that is rich in cytokines, inflammatory factors or cancer cells. Therefore, it is important to study the microenvironment of ascites in order to further clarify the occurrence and progression of ovarian cancer. As a pro-inflammatory factor, the Cyr61 expression patterns are inconsistent in human tumors. Although it has been reported that Cyr61 is related to the progression of ovarian cancer, its specific mechanism is not yet clear. This study sought to evaluate the Cyr61 levels of ascites, serum and different tissues of ovarian cancer to explore the potential association of Cyr61with the tumor-associated inflammatory microenvironment of EOC.

Methods

Tumor specimens were procured from patients with ovarian serous cystadenocarcinoma and ovarian serous cystadenoma. Cyr61 and IL-6 levels of serum or ascites were determined by ELISA (Enzyme-Linked ImmunoSorbent Assay), while Cyr61 expressions of different ovarian tumor tissues were evaluated by IHC (Immunohistochemistry). Then the correlation of Cyr61 level in ascites with clinicopathologic features was analyzed. And other laboratory data were obtained from medical records.

Results

Both in ascites and serum, significantly higher Cyr61 levels were found in ovarian serous cystadenocarcinoma. In malignant ascites, higher Cyr61 level of ovarian serous cystadenocarcinoma was more closely associated with FIGO stage, initial tumor size > 10 cm and the residual tumor size. And the increased IL-6 level was linearly related to Cyr61 level. Moreover, the serum levels of Cyr61, IL-6 and CRP in advanced stage of ovarian cancer were much higher than those in early stage. Lastly, the IHC data demonstrate that Cyr61 expression of ovarian serous adenocarcinoma was higher than that of ovarian serous cystadenoma, but it was lower than the paired metastatic lesions.

Conclusions

As a pro-inflammatory factor, increased ascites Cyr61 level is associated with FIGO stage, initial tumor size > 10 cm and the residual tumor size. Moreover, serum Cyr61 may be used as a potential marker for EOC inflammatory response. Finally, Cyr61 may be involved in the process of tumor metastasis and progression by producing IL-6 and CRP in the EOC inflammatory microenvironment.

Cysteine-Rich Angiogenic Inducer 61 Serves as a Potential Serum Biomarker for the Remission of Adult-Onset Still's Disease

Objective: Adult-onset Still's disease (AOSD) is a rare, polygenic, systemic autoinflammatory disease. The aim of this study is to evaluate the serum levels of cysteine-rich angiogenic inducer 61 (Cyr61), a secreted, extracellular protein in AOSD patients.

Methods: A total of 60 AOSD patients (39 of active phase and 21 of inactive phase), 16 rheumatoid arthritis patients as a disease control, and 34 sex- and age-matched healthy control subjects (HC) were enrolled in the study. The data of the clinical manifestations and laboratory examinations were collected. The serum levels of Cyr61, interleukin (IL)-17, and IL-37 were detected by ELISA assay, and the serum levels of IL-10, IL-1β, IL-6, IL-18, and tumor necrosis factor (TNF)-α were examined by electrochemiluminescence assay.

Results: The serum levels of Cyr61 were significantly increased in inactive AOSD than those in active patients and HCs, and the levels of Cyr61 were dramatically increased after treatment. The levels of Cyr61 were inversely correlated with systemic score, the counts of leukocyte and neutrophil, and the levels of inflammatory cytokines (IL-1β, IL-6, and IL-17). Moreover, the levels of Cyr61 were higher in patients without the clinical symptoms of fever, skin rash, sore throat, arthralgia, and lymphadenopathy compared with those in patients with these symptoms.

Conclusion: The serum levels of Cyr61 were inversely correlated with disease activity in AOSD patients; thus, we proposed that Cyr61 was a biomarker for the remission of AOSD.

Cysteine-rich protein 61 regulates the chemosensitivity of chronic myeloid leukemia to imatinib mesylate through the nuclear factor kappa B/Bcl-2 pathway

Although the targeted tyrosine kinase inhibitor imatinib mesylate (IM) has achieved significant responses against CML in the clinical setting, a small proportion of patients fail to respond to IM treatment and their disease continues to progress, indicating resistance to IM therapy. As a secreted extracellular matrix protein, cysteine‐rich protein 61 (Cyr61) plays an important role in the resistance of solid tumors to chemotherapy, but its role in CML is unclear. In the present study, we observed that Cyr61 levels were upregulated in the plasma and bone marrow (BM) of patients with CML as well as in K562 cells. This upregulation of Cyr61 significantly decreased IM‐induced cellular apoptosis of K562 cells through nuclear factor kappa B/B‐cell lymphoma 2 pathways. Inhibition of Cyr61 restored the chemosensitivity of K562 cells to IM both in vitro and in vivo. Thus, our results showed for the first time that Cyr61 plays an important role in regulating the chemosensitivity of CML cells to IM, suggesting that selectively targeting Cyr61 directly or its relevant effector pathways may provide potential value in improving the clinical response of patients with CML to IM treatment.

Cysteine-rich 61 (Cyr61): a biomarker reflecting disease activity in rheumatoid arthritis

Background

Numerous preclinical studies have revealed a critical role of cysteine-rich 61 (Cyr61) in the pathogenesis of rheumatoid arthritis (RA). But there is little literature discussing the clinical value of circulation Cyr61 in RA patients. The aim of our study is to investigate the serum Cyr61 level and its association with disease activity in RA patients.

Methods

A training cohort was derived from consecutive RA patients who visited our clinic from Jun 2014 to Nov 2018. Serum samples were obtained at the enrollment time. To further confirm discovery, an independent validation cohort was set up based on a registered clinical trial. Paired serum samples of active RA patients were respectively collected at baseline and 12 weeks after uniformed treatment. Serum Cyr61 concentration was detected by enzyme-linked immunosorbent assay. The comparison of Cyr61 between RA patients and controls, the correlation between Cyr61 levels with disease activity, and the change of Cyr61 after treatment were analyzed by appropriate statistical analyses.

Results

A total of 177 definite RA patients and 50 age- and gender-matched healthy controls were enrolled in the training cohort. Significantly elevated serum Cyr61 concentration was found in RA patients, demonstrating excellent diagnostic ability to discriminate RA from healthy controls (area under the curve (AUC) = 0.98, P <  0.001). In addition, the Cyr61 level in active RA patients was significantly lower than that in patients in remission/low disease activity, and it was inversely correlated with composite disease activity scores and almost all of the components in statistic. Further study in the validation cohort (n = 77) showed a significant increase of the Cyr61 level at 12 weeks in ACR responders (ACR20/50/70), while no significant change of the Cyr61 level from baseline was observed in non-responders.

Conclusions

Serum Cyr61 levels were remarkably increased in RA patients compared with those in healthy controls. The Cyr61 concentration was inversely correlated with RA disease activity and upregulated in those therapeutic responders.

Trial registration

Combination Therapy Prevents the Relapse of RA, NCT02320630. Registered 19 December 2014,

Electronic supplementary material

The online version of this article (10.1186/s13075-019-1906-y) contains supplementary material, which is available to authorized users.

Differentiating Psoriatic Arthritis From Psoriasis Without Psoriatic Arthritis Using Novel Serum Biomarkers

OBJECTIVE

There is a high prevalence of undiagnosed psoriatic arthritis (PsA) in patients with psoriasis. Identifying soluble biomarkers for PsA will help in screening psoriasis patients for appropriate rheumatology referral. We therefore aimed to investigate whether serum levels of novel markers previously discovered by quantitative mass spectrometric analysis of synovial fluid and skin biopsies performs better than the C-reactive protein (CRP) level in differentiating PsA patients from those with psoriasis without PsA (PsC).

METHODS

In this case-control study, serum samples were obtained from 100 subjects with PsA, 100 with PsC, and 100 healthy controls. Patients with PsA and PsC were group matched for age, sex, psoriasis duration, and Psoriasis Area and Severity Index and were not currently receiving biologic treatment. Using enzyme-linked immunosorbent assay, 4 high-priority markers (Mac-2-binding protein [M2BP], CD5-like protein [CD5L], myeloperoxidase [MPO], and integrin β5 [ITGβ5]), as well as previously established markers (matrix metalloproteinase 3 [MMP-3] and CRP level) were assayed. Data were analyzed using logistic regression. Receiver operating characteristic (ROC) curves were plotted.

RESULTS

In comparisons to controls, CD5L, ITGβ5, M2BP, MPO, MMP-3, and CRP level were independently associated with PsA, while only CD5L, M2BP, and MPO were independently associated with PsC alone. In comparisons to PsC, ITGβ5, M2BP, and CRP level were independently associated with PsA. ROC analysis of this model shows an area under the curve (AUC) of 0.85 (95% confidence interval [95% CI] 0.80-0.90). The model that included CRP level alone had an AUC of 0.71 (95% CI 0.64-0.78).

CONCLUSION

CD5L, ITGβ5, M2BP, MPO, MMP-3, and CRP level are markers for PsA. The combination of ITGβ5, M2BP, and CRP level differentiates PsA from PsC, and performs better than CRP level alone.

SjHSP60 induces CD4+ CD25+ Foxp3+ Tregs via TLR4-Mal-drived production of TGF-β in macrophages

CD4⁺ CD25⁺ Foxp3⁺ regulatory T cells (Tregs) play a pivotal role in limiting immunopathological damage to host organs after schistosome infection. Transforming growth factor-β (TGF-β) is an essential factor for the periphery conversion of CD4⁺ CD25^- T cells into CD4⁺ CD25⁺ Foxp3⁺ Tregs by inducing the key transcription factor Foxp3. Antigen presenting cells (APCs), which highly express TGF-β, are involved in parasite antigen-induced Treg conversion in peripheral. However, the mechanisms underlying high TGF-β induction in APCs by parasite antigens remain to be clarified during schistosome infection. Here, we demonstrated that Schistosoma japonicum stress protein, heat shock protein 60 (SjHSP60), promoted TGF-β production in macrophages (Mφ). Furthermore, we showed that activation of TLR4-Mal (MyD88 adaptor-like protein) signaling by SjHSP60 is necessary for induction of TGF-β expression in Mφ, which subsequently promoted Treg induction. Our results not only demonstrate a novel mechanism of TGF-β production in Mφ for inducing Tregs in mice with schistosomiasis, but also allude to the possibility of targeting parasite stress protein for potential therapeutics.

Amelioration of collagen antibody induced arthritis in mice by an antibody directed against the fibronectin type III repeats of tenascin-C: Targeting fibronectin type III repeats of tenascin-C in rheumatoid arthritis

Tenascin-C (TN-C) levels are elevated in the synovial tissue and fluid, as well as cartilage of rheumatoid arthritis (RA) patients. In addition, the presence of TN-C fragments has also been documented in arthritic cartilage. We have previously shown that a single chain variable fragment antibody (TN64), directed against the fibronectin type III repeats 1-5 (TNfnIII 1-5) of TN-C, effectively inhibits fibrotic pathology. Given that fibrosis results from chronic inflammation, and the fact that increased levels of TN-C in the synovial fluid of patients with RA contributes to synovial inflammation and joint destruction, we aimed to investigate the role of TNfnIII 1-5 region of TN-C in RA pathogenesis. Using either the wild type or variants of the two integrin-binding motifs (RGD and AEIDGIEL) present within the TNfnIII 1-5 polypeptide, we demonstrate that the adhesion and migration of synovial fibroblasts is RGD-dependent. The antibody TN64 is effective in inhibiting migration of cells in response to TnfnIII 1-5, and prevents fibroblast-mediated destruction of cartilage. The TN64 antibody was further tested in collagen antibody induced arthritic (CAIA) mice. Our data shows the efficacy of TN64 in preventing induction of arthritis, with significant downregulation of RA-associated cytokines. This suggests that components of the extracellular matrix such as the TNfnIII 1-5 region of TN-C could be exploited to develop therapies to suppress inflammation seen in RA. The TN64 antibody is one such promising candidate in the development of novel treatments for RA.

Exploring the Psoriatic Arthritis Proteome in Search of Novel Biomarkers

Psoriatic arthritis (PsA) is an inflammatory arthritis which develops in up to one-third of patients suffering from the cutaneous disorder, psoriasis. The complex and heterogeneous nature of PsA renders it difficult to diagnose, leading to poor outcomes and, therefore, warrants an examination into soluble biomarkers, which may facilitate early detection of the disease. Protein biomarkers are a dynamic resource of pathophysiological information able to provide an immediate reflection of pathological changes caused by disease. Investigations of the serum and synovial fluid of PsA patients has provided new insights into the molecular basis of this disease and led to the identification of sensitive diagnostic and prognostic biomarkers. The collection of novel PsA biomarkers identified through proteomic studies has been reviewed below.

Interleukin 17 regulates SHP-2 and IL-17RA/STAT-3 dependent Cyr61, IL-23 and GM-CSF expression and RANKL mediated osteoclastogenesis by fibroblast-like synoviocytes in rheumatoid arthritis

Interleukin (IL)-17 predominately produced by the Th17 cells, plays a crucial role in the fibroblast-like synoviocytes (FLS) mediated disease process of rheumatoid arthritis (RA). IL-17 exerts its pathogenic effects in RA-FLS by IL-17/IL-17RA/STAT-3 signaling. Recent studies have shown that RA-FLS produces SHP-2, Cyr61, IL-23, GM-CSF and RANKL which results in worsening of the disease. However, whether IL-17/IL-17RA/STAT-3 signaling regulates SHP-2, Cyr61, IL-23, GM-CSF and RANKL expressions in RA-FLS remains unknown. In this study, IL-17 treatment dramatically induced the production of Cyr61, IL-23 and GM-CSF in FLS isolated from adjuvant induced arthritis (AA) rats. Conversely, IL-17 mediated production of Cyr61, IL-23 and GM-CSF was abrogated by knockdown of IL-17RA using a small interfering RNA or blockade of STAT-3 activation with S3I-201 in AA-FLS. Interestingly, IL-17 treatment noticeably increased the expression of IL-17RA and SHP-2 in AA-FLS. However, silencing of IL-17RA reversed the effect of IL-17 on the expression of IL-17RA and SHP-2 in AA-FLS. In addition, an increased number of TRAP-positive multinucleated cells were observed in a coculture system consisting of IL-17 treated AA-FLS and rat bone marrow derived monocytes/macrophages. Further, mechanistically we found that IL-17 upregulated RANKL expression in AA-FLS that was dependent on the IL-17/IL-17RA/STAT-3 signaling cascade. Knockdown of IL-17RA or inhibition of STAT-3 activation decreased the IL- 17 induced RANKL expression by AA-FLS and their osteoclastogenic potential. Taken together, our findings demonstrate that IL-17 regulates SHP-2 expression and IL-17RA/STAT-3 dependent production of Cyr61, IL-23, GM-CSF and RANKL in AA-FLS and may reveal a new insight into the pathogenesis of RA.

Cysteine-rich 61 (Cyr61) upregulated in pulmonary arterial hypertension promotes the proliferation of pulmonary artery smooth muscle cells

Background: We aimed to evaluate the expression of cysteine rich 61 (Cyr61) in patients with pulmonary arterial hypertension (PAH) as well as monocrotaline (MCT) induced PAH rat, and further investigate the effects and potential mechanisms of Cyr61 on the proliferation of pulmonary arterial smooth muscle cells (PASMCs). Methods and Results: Plasma samples were collected from 20 patients with idiopathic PAH, 20 connective tissue disease (CTD) associated PAH, 29 age-, gender- and disease matched CTD without PAH patients, and 28 healthy controls. ELISA was used to detect the level of Cyr61 in plasma. MCT-induced PAH (MCT-PAH) rat model was established by a single subcutaneous injection of MCT (60mg·kg-1). Lung tissues and pulmonary arteries of rats were collected, while the PASMCs were dissected and cultivated for in vitro experiments. Expression of Cyr61 in the lung tissues, pulmonary arteries and PASMCs were tested by immunohistochemical staining, western blot and quantitative real-time polymerase chain reaction. PASMCs from PAH rats were stimulated by exogenous recombinant Cyr61 protein and knocked down by small interfering RNA. Cell Counting Kit-8 assay was used to identify cell proliferation and the expression of p-AKT and AKT were analysed by western blot. The results showed plasma level of Cyr61 in PAH patients, especially CTD-PAH patients, were significant higher than that of CTD without PAH patients and healthy controls. Compared with wild rats, Cyr61 was overexpressed in the lung tissue, pulmonary arterial and PASMCs in PAH rats. Exogenous recombinant Cyr61 protein promoted the proliferation of PASMCs in a dose-dependent manner. While the expression of Cyr61 in PASMCs was inhibited by specific siRNA, cell proliferation was restrained and the expression of p-AKT declined. Conclusion: Plasma Cyr61 concentration in PAH patients was highly increased. Cyr61 could promote PASMCs proliferation via AKT pathway, indicating that Cyr61 may play a role in the pathogenesis of PAH.

Lipopolysaccharide-induced CCN1 production enhances interleukin-6 secretion in bronchial epithelial cells

Acute lung injury/acute respiratory distress syndrome (ALI/ARDS) is a clinical complication caused by primary or secondary lung injury, as well as by systemic inflammation. Researches regarding molecular pathophysiology of ALI/ARDS are immerging with an ultimate aim towards developing prognostic molecular biomarkers and molecule-based therapy. However, the molecular mechanisms concerning ALI/ARDS are still not completely understood. The purpose of the present study was to identify a crucial role of CCN1 in inflammatory microenvironment during ALI/ARDS and focus on a potential communication between CCN1 and interleukin-6 (IL-6) in the airway epithelial cells. Our data illustrated that the expression levels of CCN1 and IL-6 in bronchoalveolar lavage fluid (BALF) in a lipopolysaccharide (LPS)-induced ALI mouse model were significantly elevated and the pulmonary expression of CCN1 was restricted to bronchial epithelial cells. Interestingly, both endogenous and exogenous CCN1 stimulated IL-6 production in vitro. Furthermore, LPS-induced IL-6 production in a bronchial epithelial cell line was blocked by CCN siRNA whereas CCN1 induced by LPS was sensitive to PI3K inhibition. Together, our data indicate a linear signal pathway, LPS-CCN1-IL-6, existing in bronchial epithelial cells after LPS exposure. This finding may represent an additional mechanism and a novel target for development of therapy and biomarker on ALI/ARDS.

Molecular basis for the recognition of CCN1 by monoclonal antibody 093G9

CCN1, also named Cyr61 (cysteine-rich protein 61), is the first identified member of the CCN family that is composed of 6 secreted extracellular matrix-associated glycoproteins. CCN1 has been demonstrated to participate in pathogenesis of rheumatoid arthritis through various pathways. A monoclonal antibody, namely, 093G9, is effective to antagonize the effects of CCN1 and hence has potential therapeutic benefits against rheumatoid arthritis. Here, we show that the epitope recognized by 093G9 is mapped to residues 77 to 80 of CCN1, and a cyclic peptide encompassing residues 75 to 81 of CCN1 displays high binding affinity for 093G9. The crystal structure of the 093G9 Fab in complex with the cyclic peptide was determined at 2.7 Å resolution, which reveals the intensive interactions between CCN1 and 093G9. Particularly, residues Asn79 and Phe80 of CCN1 are inserted into cavities mainly formed by residues of complementarity-determining region loop L3 and framework region L2 and by residues of complementarity-determining region loops H2 and H3, respectively, which contribute most of the interactions and therefore are critical for the recognition by 093G9. Together, these findings not only identify the epitope of CCN1 for 093G9 but also reveal the molecular mechanism of recognition and binding of CCN1 by 093G9.

IL-34 Upregulated Th17 Production through Increased IL-6 Expression by Rheumatoid Fibroblast-Like Synoviocytes

Rheumatoid arthritis (RA) is a chronic autoimmune disease which is characterized by synovial inflammation and cartilage damage for which causes articular dysfunction. Activation of fibroblast-like synoviocytes (FLS) is a critical step that promotes disease progression. In this study, we aimed to explore the effect of interleukin-34 (IL-34) on RA FLS as a proinflammatory factor and IL-34-stimulated FLS on the production of Th17. We found that serum IL-34 levels were increased compared to those of the healthy controls and had positive correlations with C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), rheumatoid factor (RF), and anticyclic citrullinated peptide (CCP) antibody accordingly. CSF-1R was also highly expressed on RA FLS. The interaction of IL-34 and CSF-1R promoted a dramatic production of IL-6 by FLS through JNK/P38/NF-κB signaling pathway. Further, the IL-34-stimulated IL-6 secretion by RA FLS was found to upregulate the number of Th17. The treatment of IL-6R antagonist could attenuate the production of Th17 mediated by IL-34-stimulated RA FLS. Our results suggest that the increased IL-34 levels were closely related to the disease activity of RA. Additionally, the overexpression of IL-6 in the IL-34-stimulated FLS promoted the generation of Th17. Therefore, IL-34 was supposed to be involved in the pathogenesis of RA. The inhibition of IL-34 might provide a novel target for therapies of RA.

Serum CYR61 Is Associated with Disease Activity in Graves' Orbitopathy

PURPOSE

To investigate the clinical implications of cysteine-rich angiogenic inducer 61 (CYR61) in Graves' orbitopathy (GO).

METHODS

Sera from 52 GO patients, 23 Graves' disease (GD) patients, and 20 healthy controls, and orbital fat tissue samples from 12 of 52 GO patients and 8 control subjects were included for analysis. Concentrations of CYR61 were measured from sera with an enzyme-linked immunosorbent assay, and CYR61 mRNA expression levels were evaluated from orbital fat tissue with polymerase chain reaction.

RESULTS

Serum CYR61 levels were higher in GO patients than in controls (p = 0.001). Patients with active GO showed higher CYR61 levels than those with inactive GO (p < 0.001) or GD (p = 0.004). Expression of CYR61 mRNA was 7.4-fold higher in patients with GO than in healthy controls (p < 0.001).

CONCLUSIONS

CYR61 could be an adjuvant biomarker associated with the inflammatory activity of GO.

MicroRNA-22-3p as a novel regulator and therapeutic target for autoimmune diseases

MicroRNAs (miRNAs) are a class of noncoding RNAs and have emerged as critical regulators of gene expression. Some miRNAs play important roles in regulating the function of the immune system and are involved in the pathogenesis of autoimmune diseases. Recent studies suggested that microRNA-22-3p (miR-22-3p) was able to regulate the function of several types of immune cells and may be involved in the development of autoimmune diseases. We systematically reviewed relevant literatures to provide a comprehensive review of the possible roles of miR-22-3p in autoimmune diseases. Published studies suggest that miR-22-3p can act as a novel regulator of autoimmune diseases via several pathways. More studies are needed to further elucidate the exact roles of miR-22-3p in autoimmune diseases. Treatment strategy targeting miR-22-3p is also a promising therapy for autoimmune diseases.

Enhancement of CCL2 expression and monocyte migration by CCN1 in osteoblasts through inhibiting miR-518a-5p: implication of rheumatoid arthritis therapy

Cysteine-rich 61 (Cyr61 or CCN1), a secreted protein from the CCN family, is an important proinflammatory cytokine. Migration and infiltration of mononuclear cells to inflammatory sites play a critical role in the pathogenesis of rheumatoid arthritis (RA). Monocyte chemoattractant protein-1 (MCP-1/CCL2) is the key chemokine that regulates migration and infiltration of monocytes. Here, we examined the role of CCN1 in monocyte migration, and CCL2 expression in osteoblasts. We found higher levels of CCN1 and CCL2 in synovial fluid from RA patients compared with levels from non-RA controls. We also found that the CCN1-induced increase in CCL2 expression is mediated by the MAPK signaling pathway and that miR-518a-5p expression was negatively regulated by CCN1 via the MAPK cascade. In contrast, inhibition of CCN1 expression with lentiviral vectors expressing short hairpin RNA ameliorated articular swelling, cartilage erosion, and infiltration of monocytes in the ankle joints of mice with collagen-induced arthritis. Our study describes how CCN1 promotes monocyte migration by upregulating CCL2 expression in osteoblasts in RA disease. CCN1 could serve as a potential target for RA treatment.