Wnt Signaling and Biological Therapy in Rheumatoid Arthritis and Spondyloarthritis

The Traditional Chinese Medicine Compound Huangqin Qingre Chubi Capsule Inhibits the Pathogenesis of Rheumatoid Arthritis Through the CUL4B/Wnt Pathway

The pathogenesis of rheumatoid arthritis (RA) is still not fully clarified, and the development of therapeutic drugs for RA is particularly urgent. Our group studies a possibility that circ_ 0015756/miR-942-5p may participate in the pathogenesis of RA through disordered Cullin 4B (CUL4B) and the traditional Chinese medicine compound Huangqin Qingre Chubi Capsule (HQC) may inhibit the pathogenesis of RA through the CUL4B/Wnt pathway. Data showed that the expression of circ_0015756 increased not only in fibroblast-like synoviocytes (FLS) of RA, but also in synovium and FLS of CIA mice, and the expression of miR-942-5p decreased. Abnormal circ_0015756 up-regulated the CUL4B expression and activated the canonical Wnt signaling pathway by inhibiting the expression of miR-942-5p. Circ_0015756 participated in the pathogenesis of RA and promoted the abnormal proliferation of FLS. Further, circ_0015756 activated the secretion of IL-1 and IL-8 and promoted the production of RA pathological gene MMP3 and fibronectin. Further analysis showed that HQC inhibited the pathogenesis of RA through the CUL4B/Wnt pathway, and the specific target was CUL4B. HQC interfered with the effects of circ_0015756 on the pathogenesis of RA by inhibiting the CUL4B, showing a good therapeutic effect on RA.

Wnt signaling pathway activities may be altered in primary Sjogren’s syndrome

Background/aim

Sjögren’s syndrome (SS) is an autoimmune disease and its pathogenesis is still not completely clear. The wingless (Wnt)/β-catenin pathway has recently been shown to play an important role in inflammation. This study aims to determine the serum and saliva levels of Dickkopf (DKK)1 and sclerostin and to evaluate Wnt-1 and Wnt-3a expression in the salivary gland in patients with primary SS.

Materials and methods

This study included 30 patients diagnosed with SS, 30 patients diagnosed with systemic lupus erythematosus (SLE), and 29 healthy controls. Serum and saliva levels of DKK1 and sclerostin were measured and the expressions of Wnt1 and Wnt3a in the salivary gland were measured immunohistochemically.

Results

Serum DKK1 and sclerostin levels were lower in the SS and SLE groups compared to the control group (both p < 0.001). Saliva DKK1 levels were higher in the SS group compared to the control and SLE groups (p = 0.004 and p = 0.009, respectively). Wnt1 and Wnt3a expression were found in salivary gland tissue samples in 71.4% of primary SS patients and relatively frequent than control group.

Conclusions

Serum DKK1 and sclerostin levels in primary SS and SLE were decreased. Moreover, levels of Wnt1 and Wnt3a expression in the salivary gland were also elevated in primary SS. Therefore, it can be concluded that the Wnt/β-catenin pathway activities may be altered in case of glandular inflammation.

Bone erosions and osteophytes in premenopausal women with long-standing rheumatoid arthritis: association with systemic bone involvement by HR-Pqct

OBJECTIVE

To evaluate premenopausal women with long-standing RA and to explore the relationship between parameters of systemic and localized bone involvement.

METHODS

Eighty consecutive RA premenopausal women were evaluated. Volumetric bone mineral density (vBMD), microarchitecture and finite element analysis were performed using high-resolution peripheral quantitative computed tomography (HR-pQCT) at the distal radius (DR) and tibia (DT) and compared with parameters from 160 female healthy controls matched by age and body mass index. Localized bone involvement was also analyzed using HR-pQCT in the metacarpophalangeal and proximal interphalangeal joints to identify erosions and osteophytes.

RESULTS

The mean age of RA patients was 39.4±6.7years and disease duration 9.8±5.3years. RA patients had impaired trabecular, cortical and bone strength parameters, at DR and DT, compared with healthy controls (p<0.05). Bone erosions and osteophytes were found in 75% and 41.3% of patients, respectively. Comparing patients with and without erosions, at DR and DT, a lower cortical vBMD (DR: 980±72 versus 1021±47mgHA/cm³ , p=0.03; DT:979±47 versus 1003±34 mgHA/cm³ , p=0.04) and higher cortical porosity (DR:2.8±2.5 versus 1.8±1.6%, p=0.04; and DT:3.7±1.6 versus 2.7±1.6%, p=0.01) were observed in patients with erosions. At the DR, osteophyte volume was positively correlated with trabecular vBMD (0.392, p=0.02), trabecular number (0.381, p=0.03) and stiffness (0.411, p=0.02), and negatively with trabecular separation (-0.364, p=0.04).

CONCLUSION

Our findings showed that premenopausal women with long-standing RA had systemic bone fragility at peripheral sites. Moreover, erosions were associated mainly with cortical bone fragility at the DR and DT, and osteophytes correlated with repair of trabecular bone at the radius.

Long noncoding RNA intersectin 1-2 gradually declines during adalimumab treatment, and its reduction correlates with treatment efficacy in patients with ankylosing spondylitis

Previous studies show that long noncoding RNA intersectin 1-2 (lnc-ITSN1-2) promotes the inflammation process and serves as a potential biomarker in autoimmune diseases, except for ankylosing spondylitis (AS). Therefore, this study aimed to explore the correlation of baseline lnc-ITSN1-2 expression with disease risk and activity of AS, and to investigate its longitudinal change with treatment response to a tumour necrosis factor alpha (TNFα) inhibitor in patients with AS. In total, 63 patients with AS receiving 12-week adalimumab treatment were included and their baseline clinical features were collected. Lnc-ITSN1-2 expression in peripheral blood mononuclear cells (PBMC) of patients with AS was detected by reverse transcription quantitative polymerase chain reaction. Meanwhile, Assessment in Spondyloarthritis International Society (ASAS) 40 response was evaluated at week 2 (W2), W4, W8, and W12. According to the ASAS40 response status at W12, patients with AS were classified into responders and non-responders. PBMC lnc-ITSN1-2 expression was also determined in healthy controls (N = 60). Lnc-ITSN1-2 expression was elevated in patients with AS compared to controls (P < 0.001). Baseline lnc-ITSN1-2 expression was positively associated with C-reaction protein (CRP) (P = 0.021), interleukin (IL)-1β (P = 0.020), Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) score (P = 0.040), and Ankylosing Spondylitis Disease Activity score with C-reactive protein (ASDAS_CRP) (P = 0.045) in patients with AS. Furthermore, lnc-ITSN1-2 expression declined during the treatment with adalimumab (P < 0.001). Notably, this reduction was more obvious in responders than non-responders. In conclusion, declined lnc-ITSN1-2 expression during the TNFα inhibitor treatment correlates with good treatment efficacy in patients with AS, suggesting its clinical value for AS management.

Individual functions of the histone acetyl transferases CBP and p300 in regulating the inflammatory response of synovial fibroblasts

Chromatin remodeling, and a persistent histone 3 lysine 27 acetylation (H3K27ac) in particular, are associated with a sustained inflammatory response of synovial fibroblasts (SF) in rheumatoid arthritis (RA). Here we investigated individual functions of the writers of H3K27ac marks, the homologues histone acetyl transferases (HAT) CBP and p300, in controlling the constitutive and inflammatory gene expression in RA SF. We applied a silencing strategy, followed by RNA-sequencing and pathway analysis, complemented with the treatment of SF with inhibitors targeting the HAT (C646) or bromo domains (I-CBP) of CBP and p300. We showed that CBP and p300 undertook overlapping and, in particular at gene levels, distinct regulatory functions in SF. p300 is the major HAT for H3K27ac in SF and regulated more diverse pathways than CBP. Whereas both factors regulated genes associated with extracellular matrix remodeling, adhesion and proliferation, p300 specifically controlled developmental genes associated with limb development. Silencing of CBP specifically down regulated the TNF-induced expression of interferon-signature genes. In contrast, silencing of p300 resulted in anti- and pro-inflammatory effects. Integration of data sets derived from RNA-sequencing and chromatin immunoprecipitation sequencing for H3K27ac revealed that changes in gene expression after CBP or p300 silencing could be only partially explained by changes in levels of H3K27ac. Inhibition of CBP/p300 using HAT and bromo domain inhibitors strongly mirrored effects obtained by silencing of p300, including anti- and pro-inflammatory effects, indicating that such inhibitors are not sufficient to be used as anti-inflammatory drugs.

Association between serum bone biomarker levels and therapeutic response to abatacept in patients with rheumatoid arthritis (RA): a multicenter, prospective, and observational RA ultrasound cohort study in Japan

BACKGROUND

To evaluate the effect of treatment on serum bone biomarkers and explore whether serum bone biomarkers are associated with therapeutic response in rheumatoid arthritis (RA) patients treated with abatacept.

METHODS

We enrolled 59 RA patients treated with abatacept from a multicenter, exploratory, short-term, prospective and observational ultrasound cohort study of patients who received biologic or targeted synthetic disease-modifying antirheumatic drug (DMARD) therapy. We evaluated the patients' clinical disease activity and musculoskeletal ultrasound (MSUS) scores. The serum concentrations of five bone biomarkers were evaluated (dickkopf-1 [Dkk-1], sclerostin [SOST], osteocalcin [OC], osteopontin [OPN], and osteoprotegerin [OPG]) by multiplex bead assays at baseline, 3, and 6 months: the change over 6 months was defined as the Δ value. 'Power Doppler (PD) responder' was defined as a patient whose Δtotal PD score over 6 months was greater than the median change.

RESULTS

Abatacept significantly improved the clinical disease activity and MSUS score over 6 months. Serum OPG was significantly elevated at 6 months after the abatacept introduction (p = 0.016). The ΔSOST and ΔOPG were significantly greater in the PD responders versus the non-PD responders (p = 0.0041 and 0.0073, respectively). The serum Dkk-1 at baseline was significantly lower in the PD responders (n = 30) vs. the non-PD responders (n = 29) (p = 0.026). A multivariate logistic regression analysis showed that the serum Dkk-1 at baseline (odds ratio 0.50, 95% confidence interval [CI] 0.23-0.91, p = 0.043) was an independent predictor of PD responder status.

CONCLUSION

Serum levels of bone biomarkers may be useful for predicting RA patients' therapeutic responses to abatacept.

TRIAL REGISTRATION

Name of the registry: Assessment of therapeutic responsiveness by imaging of the joints in patients with rheumatoid arthritis; A observational cohort study Trial registration number: UMIN000012524 Date of registration: 12/9/2013 URL of trial registry record: https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000014657.

Dickkopf-1 perpetuated synovial fibroblast activation and synovial angiogenesis in rheumatoid arthritis

OBJECTIVE

Dickkopf-1 (Dkk-1), a regulatory molecule of the Wnt pathway, is elevated and leads to bone resorption in patients with RA. This study is aimed to investigate the contribution of Dkk-1 to synovial inflammation and synovial fibroblast-mediated angiogenesis in RA.

METHODS

The expression of Dkk-1 in RA synovial fibroblasts (RASF) and osteoarthritis synovial fibroblasts (OASF) was detected by real-time PCR and ELISA, respectively. RASF were stimulated with different pro-inflammatory factors. The expression of angiogenic factors, pro-inflammatory cytokines, and MMPs in RASF was analyzed by real-time PCR when Dkk-1 was inhibited or overexpressed. Meanwhile, the concentrations of MCP-1, IL-6, IL-8, and MMP-3 in the cell culture supernatant were assessed by ELISA. The effects of Dkk-1 on the MAPK signaling pathway were evaluated by western blot. Matrigel tube formation assay was employed to reveal the direct and indirect effects of Dkk-1 on synovial angiogenesis.

RESULTS

Dkk-1 expression was elevated in synovial fluids and synovial fibroblasts of RA patients. Treatment with various pro-inflammatory cytokines significantly promoted DKK-1 expression in RASF. The production of potent angiogenic factors, pro-inflammatory cytokines, and MMPs in RASF was elevated, whereas the reverse results were found in the inhibitor groups. Silenced Dkk-1expression in RASF dampened capillary tube organization in both direct and indirect manners, resulting in restrained ERK, JNK, and p38 signaling pathway activation.

CONCLUSION

We concluded that Dkk-1 exacerbated the inflammation, cartilage erosion, and angiogenesis mediated by synovial fibroblasts in RA. Modulation of DKK-1 expression may facilitate development of novel strategies to control RA. Key points • Dkk-1 expression was elevated in synovial fluids and synovial fibroblasts of RA patients. • Treatment with various pro-inflammatory cytokines significantly promoted DKK-1 expression. • Silenced Dkk-1expression in RASF dampened capillary tube organization.

Loss of the WNT9a ligand aggravates the rheumatoid arthritis-like symptoms in hTNF transgenic mice

Agonists and antagonists of the canonical Wnt signaling pathway are modulators of pathological aspects of rheumatoid arthritis (RA). Their activity is primarily modifying bone loss and bone formation, as shown in animal models of RA. More recently, modulation of Wnt signaling by the antagonist Sclerostin has also been shown to influence soft-tissue-associated inflammatory aspects of the disease pointing towards a role of Wnt signaling in soft-tissue inflammation as well. Yet, nothing is known experimentally about the role of Wnt ligands in RA. Here we provide evidence that altering Wnt signaling at the level of a ligand affects all aspects of the rheumatoid arthritic disease. WNT9a levels are increased in the pannus tissue of RA patients, and stimulation of synovial fibroblasts (SFB) with tumor necrosis factor (TNF) leads to increased transcription of Wnt9a. Loss of Wnt9a in a chronic TNF-dependent RA mouse model results in an aggravation of disease progression with enhanced pannus formation and joint destruction. Yet, loss of its activity in the acute K/BxN serum-transfer induced arthritis (STIA) mouse model, which is independent of TNF signaling, has no effect on disease severity or progression. Thus, suggesting a specific role for WNT9a in TNF-triggered RA. In synovial fibroblasts, WNT9a can activate the canonical Wnt/β-catenin pathway, but it can also activate P38- and downregulate NFκB signaling. Based on in vitro data, we propose that loss of Wnt9a creates a slight proinflammatory and procatabolic environment that boosts the TNF-mediated inflammatory response.

Lentivirus-Mediated Overexpression or Silencing of Aquaporin 1 Affects the Proliferation, Migration and Invasion of TNF-α-Stimulated Rheumatoid Arthritis Fibroblast-Like Synoviocytes by Wnt/β-Catenin Signaling Pathway

Introduction

Previous studies have confirmed the pathologic role of synovial aquaporin 1 (AQP1) in rheumatoid arthritis (RA), but its associations with the abnormal biologic behaviors of fibroblast-like synoviocytes (FLS) remain unclear. Herein, we examined the roles of AQP1 in the proliferation, migration and invasion of TNF-α-stimulated RA FLS (MH7A cells) and explored the underlying mechanisms.

Materials and Methods

Lentivirus-mediated AQP1 overexpression or silencing MH7A cells was constructed. Assays of MTT, flow cytometry (PI staining and Annexin V-PE/7-AAD staining), TMRM staining, wound-healing, transwell and phalloidin staining were performed to detect cell proliferation, cycle distribution, apoptosis, migration and invasion. The involvement of Wnt/β-catenin pathway was revealed by Western blot and β-catenin immunofluorescence staining.

Results

AQP1 overexpression promoted cell proliferation of TNF-α-stimulated MH7A by facilitating transformation from G0/G1 to S phase and inhibiting cell apoptosis (ie, reduced apoptosis rates, raised mitochondrial membrane potential, increased Bcl-2 protein level and decreased levels of Bax and cleaved caspase 3 protein). Also, AQP1 overexpression increased the migration index as well as the numbers of migrated and invasive cells. Furthermore, AQP1 overexpression promoted the activation of Wnt/β-catenin pathway, and XAV939, an inhibitor of Wnt/β-catenin, canceled the above effects of AQP1 overexpression on MH7A cells. As expected, AQP1 silencing exhibited the opposite effects on TNF-α-stimulated MH7A cells, which could be reversed by LiCl, an activator of Wnt/β-catenin.

Conclusion

AQP1 can affect the proliferation, migration and invasion of MH7A cells by Wnt/β-catenin signaling pathway, and AQP1 can be as a crucial determiner that can regulate RA FLS biologic behaviors.

The Immunomodulatory and Anti-Inflammatory Effect of Curcumin on Immune Cell Populations, Cytokines, and In Vivo Models of Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a widespread chronic autoimmune disorder affecting the joints, causing irreversible cartilage, synovium, and bone degradation. During the course of the disease, many immune and joint cells are activated, causing inflammation. Immune cells including macrophages, lymphocytes, neutrophils, mast cells, natural killer cells, innate lymphoid cells, as well as synovial tissue cells, like fibroblast-like synoviocytes, chondrocytes, and osteoclasts secrete different proinflammatory factors, including many cytokines, angiogenesis-stimulating molecules and others. Recent studies reveal that curcumin, a natural dietary anti-inflammatory compound, can modulate the response of the cells engaging in RA course. This review comprises detailed data about the pathogenesis and inflammation process in rheumatoid arthritis and demonstrates scientific investigations about the molecular interactions between curcumin and immune cells responsible for rheumatoid arthritis development to discuss this herbal drug’s immunoregulatory role in RA treatment.

Dysregulation of lncRNAs in Rheumatoid Arthritis: Biomarkers, Pathogenesis and Potential Therapeutic Targets

Rheumatoid arthritis (RA) is a chronic autoimmune disease of unknown etiology, mainly manifested by persistent abnormal proliferation of fibroblast-like synoviocytes (FLSs), inflammation, synovial hyperplasia and cartilage erosion, accompanied by joint swelling and joint destruction. Abnormal expression or function of long noncoding RNAs (lncRNAs) are closely related to human diseases, including cancers, mental diseases, autoimmune diseases and others. The abnormal sequence and spatial structure of lncRNAs, the disorder expression and the abnormal interaction with the binding protein will lead to the change of gene expression in the way of epigenetic modification. Increasing evidence demonstrated that lncRNAs were involved in the activation of FLSs, which played a key role in the pathogenesis of RA. In this review, the research progress of lncRNAs in the pathogenesis of RA was systematically summarized, including the role of lncRNAs in the diagnosis of RA, the regulatory mechanism of lncRNAs in the pathogenesis of RA, and the intervention role of lncRNAs in the treatment of RA. Furthermore, the activated signal pathways, the role of DNA methylation and other mechanism have also been overview in this review.

Adipokines and Chronic Rheumatic Diseases: from Inflammation to Bone Involvement

Besides its well-known role as energy storage tissue, adipose tissue is a biologically active tissue that can also be considered as an endocrine organ, as it is able to secrete adipokines. These bioactive factors, similar in structure to cytokines, are involved in several physiological and pathological conditions, such as glucose homeostasis, angiogenesis, blood pressure regulation, control of food intake, and also inflammation and bone homeostasis via endocrine, paracrine, and autocrine mechanisms. Given their pleiotropic functions, the role of adipokines has been evaluated in chronic rheumatic osteoarticular inflammatory diseases, particularly focusing on their effects on inflammatory and immune response and on bone alterations. Indeed, these diseases are characterized by different bone complications, such as local and systemic bone loss and new bone formation. The aim of this review is to summarize the role of adipokines in rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis, osteoarthritis, and osteoporosis, especially considering their role in the pathogenesis of bone complications typical of these conditions.

Circulating miR-145 as a marker of therapeutic response to anti-TNF therapy in patients with ankylosing spondylitis

Circulating miRNAs appear promising therapeutic and prognostic biomarkers. We aimed to investigate the predictive value of circulating miRNAs on the disease outcome following anti-TNF therapy in patients with ankylosing spondylitis (AS). Our study included 19 AS patients assessed at baseline (M0), after three (M3) and twelve months (M12) of therapy. Total RNA was isolated from plasma. A comprehensive analysis of 380 miRNAs using TaqMan Low Density Array (TLDA) was followed by a single assay validation of selected miRNAs. All AS patients had high baseline disease activity and an excellent response to anti-TNF therapy at M3 and M12. TLDA analysis revealed the dysregulation of 17 circulating miRNAs, including miR-145. Single assay validation confirmed that miR-145 is significantly downregulated at M3 compared to baseline. The decrease in the levels of miR-145 from M0 to M3 negatively correlated with the change in BASDAI from M0 to M3; and positively correlated with disease activity improvement from M3 to M12 as per BASDAI and ASDAS. The predictive value of the early change in miR-145 and levels of miR-145 at M3 were further validated by Receiver operating curves analysis. We show thatthe early change in circulating miR-145 may be a predictor for the future outcome ofAS patients treated with TNF inhibitors. Patients with a more significant decrease in miR-145 levels may show further significant improvement of disease activity after 12 months. Monitoring the expression of miR-145 in plasma in AS patients may, therefore, influence our therapeutic decision-making.

Food-derived natural compounds in the management of chronic diseases via Wnt signaling pathway

Wnt signaling pathway is an evolutionarily conserved pathway that control embryonic development, adult tissue homeostasis, and pathological processes of organisms throughout life. However, dysregulation of the Wnt signaling is associated with the occurrence of chronic diseases. In comparison with the application of chemical drugs as traditional treatment for chronic diseases, dietary agents have unique advantages, such as less side effects, multiple targets, convenience in accessibility and higher acceptability in long-term intervention. In this review, we summarized current progress in manipulating the Wnt signaling using food components and its benefits in managing chronic diseases. The underlying mechanisms of bioactive food components in the management of the disease progression via the Wnt signaling was illustrated. Then, the review focused on the function of dietary pattern (which might act via combination of foods with multiple nutrients or food ingredients) on targeting Wnt signaling at multiple level. The potential caveats and challenges in developing new strategy via modulating Wnt-associated diseases with food-based agents and appropriate dietary pattern are also discussed in detail. This review shed light on the understanding of the regulatory effect of food bioactive components on chronic diseases management through the Wnt signaling, which can be expanded to other specific signaling pathway associated with disease.

Immunological Insights in Equine Recurrent Uveitis

Horses worldwide suffer from equine recurrent uveitis (ERU), an organ-specific, immune-mediated disease with painful, remitting-relapsing inflammatory attacks alternating with periods of quiescence, which ultimately leads to blindness. In course of disease, both eyes can eventually be affected and since blind horses pose a threat to themselves and their surroundings, these animals have to be killed. Therefore, this disease is highly relevant for veterinary medicine. Additionally, ERU shows strong clinical and pathological resemblance to autoimmune uveitis in man. The exact cause for the onset of ERU is unclear to date. T cells are believed to be the main effector cells in this disease, as they overcome the blood retinal barrier to invade the eye, an organ physiologically devoid of peripheral immune cells. These cells cause severe intraocular inflammation, especially in their primary target, the retina. With every inflammatory episode, retinal degeneration increases until eyesight is completely lost. In ERU, T cells show an activated phenotype, with enhanced deformability and migration ability, which is reflected in the composition of their proteome and downstream interaction pathways even in quiescent stage of disease. Besides the dysregulation of adaptive immune cells, emerging evidence suggests that cells of the innate immune system may also directly contribute to ERU pathogenesis. As investigations in both the target organ and the periphery have rapidly evolved in recent years, giving new insights on pathogenesis-associated processes on cellular and molecular level, this review summarizes latest developments in ERU research.

Acetazolamide ameliorates the severity of collagen-induced arthritis in rats: Involvement of inducing synovial apoptosis and inhibiting Wnt/β-catenin pathway

We previously revealed that the overexpression of synovial aquaporin 1 (AQP1) aggravated collagen-induced arthritis (CIA) in rats via regulating β-catenin signaling. This study was to demonstrate the therapeutic effect of acetazolamide (AZ, an AQP1 inhibitor) on rat CIA and explored its underlying mechanisms. Paw swelling, arthritis index, pathological assessments, and serum levels of collagen type II (Col II) antibody, IL-1β and TNF-α were measured to evaluate the anti-arthritic effect of AZ on rat CIA. Ki67 immunohistochemistry and TUNEL assay were performed to reveal the anti-proliferative and pro-apoptotic effects of AZ on synovial cells in vivo. The protein levels of apoptosis-related genes and Wnt/β-catenin pathway key members were detected by western blot. We found that AZ treatment on CIA rats could inhibit paw swelling, reduce arthritis index, alleviate the pathologic changes of ankle joint and decrease the serum levels of Col II antibody, TNF-α and IL-1β. AZ could reduce Ki67 expression and increase apoptosis index in CIA synovial tissues by reducing Bcl-2 protein level, increasing Bax and caspase 3 protein levels and normalizing Bcl-2/Bax ratio. Moreover, AZ could reduce the protein levels of Wnt1, β-catenin, p-GSK-3β (Ser9), c-myc, cyclin D1 and MMP9, while increase GSK-3β protein level in CIA synovial tissues. Importantly, these mentioned effects of AZ (60 mg/kg) on CIA rats could be reversed by the combined use of lithium chloride (LiCl), an activator of Wnt/β-catenin pathway. In short, AZ exerted potent anti-arthritic effects on CIA rats by inducing synovial apoptosis and inhibiting Wnt/β-catenin pathway.

Aptamers for Proteins Associated with Rheumatic Diseases: Progress, Challenges, and Prospects of Diagnostic and Therapeutic Applications

Nucleic acid aptamers capable of affine and specific binding to their molecular targets have now established themselves as a very promising alternative to monoclonal antibodies for diagnostic and therapeutic applications. Although the main focus in aptamers’ research and development for biomedicine is made on cardiovascular, infectious, and malignant diseases, the use of aptamers as therapeutic or diagnostic tools in the context of rheumatic diseases is no less important. In this review, we consider the main features of aptamers that make them valuable molecular tools for rheumatologists, and summarize the studies on the selection and application of aptamers for protein biomarkers associated with rheumatic diseases. We discuss the progress in the development of aptamer-based diagnostic assays and targeted therapeutics for rheumatic disorders, future prospects in the field, and issues that have yet to be addressed.

Roles of MicroRNAs in Bone Destruction of Rheumatoid Arthritis

As an important pathological result of rheumatoid arthritis (RA), bone destruction will lead to joint injury and dysfunction. The imbalance of bone metabolism caused by increased osteoclast activities and decreased osteoblast activities is the main cause of bone destruction in RA. MicroRNAs (MiRNAs) play an important role in regulating bone metabolic network. Recent studies have shown that miRNAs play indispensable roles in the occurrence and development of bone-related diseases including RA. In this paper, the role of miRNAs in regulating bone destruction of RA in recent years, especially the differentiation and activities of osteoclast and osteoblast, is reviewed. Our results will not only help provide ideas for further studies on miRNAs’ roles in regulating bone destruction, but give candidate targets for miRNAs-based drugs research in bone destruction therapy of RA as well.

Therapeutic Effect of Calcimimetics on Osteoclast-Osteoblast Crosslink in Chronic Kidney Disease and Mineral Bone Disease

We have previously demonstrated calcimimetics optimize the balance between osteoclastic bone resorption and osteoblastic mineralization through upregulating Wingless and int-1 (Wnt) signaling pathways in the mouse and cell model. Nonetheless, definitive human data are unavailable concerning therapeutic effects of Cinacalcet on chronic kidney disease and mineral bone disease (CKD-MBD) and osteoclast-osteoblast interaction. We aim to investigate whether Cinacalcet therapy improves bone mineral density (BMD) through optimizing osteocytic homeostasis in a human model. Hemodialysis patients with persistently high intact parathyroid hormone (iPTH) levels > 300 pg/mL for more than 3 months were included and received fixed dose Cinacalcet (25 mg/day, orally) for 6 months. Bone markers presenting osteoclast-osteoblast communication were evaluated at baseline, the 3rd and the 6th month. Eighty percent of study patients were responding to Cinacalcet treatment, capable of improving BMD, T score and Z score (16.4%, 20.7% and 11.1%, respectively). A significant correlation between BMD improvement and iPTH changes was noted (r = -0.26, p < 0.01). Nonetheless, baseline lower iPTH level was associated with better responsiveness to Cinacalcet therapy. Sclerostin, an inhibitor of canonical Wnt/β-catenin signaling, was decreased from 127.3 ± 102.3 pg/mL to 57.9 ± 33.6 pg/mL. Furthermore, Wnt-10b/Wnt 16 expressions were increased from 12.4 ± 24.2/166.6 ± 73.3 pg/mL to 33.8 ± 2.1/217.3 ± 62.6 pg/mL. Notably, procollagen type I amino-terminal propeptide (PINP), a marker of bone formation and osteoblastic activity, was increased from baseline 0.9 ± 0.4 pg/mL to 91.4 ± 42.3 pg/mL. In contrast, tartrate-resistant acid phosphatase isoform 5b (TRACP-5b), a marker of osteoclast activity, was decreased from baseline 16.5 ± 0.4 mIU/mL to 7.7 ± 2.2 mIU/mL. Moreover, C-reactive protein levels were suppressed from 2.5 ± 0.6 to 0.8 ± 0.5 mg/L, suggesting the systemic inflammatory burden may be benefited after optimizing the parathyroid-bone axis. In conclusion, beyond iPTH suppression, our human model suggests Cinacalcet intensifies BMD through inhibiting sclerostin expression and upregulating Wnt-10b/Wnt 16 signaling that activates osteoblastic bone formation and inhibits osteoclastic bone resorption and inflammation. From the perspective of translation to humans, this research trial brings a meaningful insight into the osteoblast-osteoclast homeostasis in Cinacalcet therapy for CKD-MBD.

Research of Pathogenesis and Novel Therapeutics in Arthritis 2.0

Arthritis has a high prevalence globally and includes over 100 types, the most common of which are rheumatoid arthritis, osteoarthritis, psoriatic arthritis, and inflammatory arthritis. All types of arthritis share common features of disease, including monocyte infiltration, inflammation, synovial swelling, pannus formation, stiffness in the joints and articular cartilage destruction. The exact etiology of arthritis remains unclear, and no cure exists as of yet. Anti-inflammatory drugs (NSAIDs and corticosteroids) are commonly used in the treatment of arthritis. However, these drugs are associated with significant side effects, such as gastric bleeding and an increased risk for heart attack and other cardiovascular problems. It is therefore crucial that we continue to research the pathogenesis of arthritis and seek to discover novel modes of therapy. This editorial summarizes and discusses the themes of the 27 articles published in our Special Issue “Research of Pathogenesis and Novel Therapeutics in Arthritis 2.0”, a continuation of our 2019 Special Issue “Research of Pathogenesis and Novel Therapeutics in Arthritis”. These Special Issues detail important novel research discoveries that contribute to our current understanding of arthritis.

Activated coagulation is associated with the disease activity of axial spondyloarthritis

BACKGROUND

Activation of the coagulation system has been related to disease activity in some inflammatory diseases. Here, we aimed to investigate the relationship between coagulation function and the disease activity of axial spondyloarthritis (axSpA).

METHODS

This study retrospectively recruited 144 axSpA patients and 55 healthy controls. The patients were divided into an active group (Bath Ankylosing Spondylitis Disease Activity Index, BASDAI ≥ 4) and a remission group (BASDAI < 4). The coagulation, inflammatory and clinical parameters were detected. The correlations between these parameters were analyzed with Spearman's correlation analysis. Receiver operating characteristic (ROC) curve analysis was performed to compare the values of these variables in discriminating disease activity. Furthermore, binary logistic regression analysis was used to assess the risk factors for axSpA disease activity.

RESULTS

Fibrinogen (FIB) was increased in the axSpA group compared to healthy controls (P < 0.001). Additionally, FIB and D-dimer were higher in the active group than in the remission group (P < 0.05, respectively). FIB and D-dimer were positively correlated with ESR, CRP, BASDAI, Bath Ankylosing Spondylitis Functional Index (BASFI) and Bath Ankylosing Spondylitis Metrology Index (BASMI) (P < 0.05, respectively). The area under the curve (AUC) of FIB was higher than that of ESR, CRP and D-dimer. The optimal cut-off value of FIB was 3.23 g/L, with a specificity of 62.0% and sensitivity of 75.0%. FIB (OR = 4.335, 95% CI: 1.262-14.888, P = 0.020) and BASFI score (OR = 1.878, 95% CI: 1.441-2.448, P < 0.001) were independent risk factors affecting disease activity.

CONCLUSION

Activated coagulation is closely related to the disease activity of axSpA. FIB and D-dimer might be novel indicators for monitoring the disease activity of axSpA.

Adherence to biologic disease-modifying antirheumatic drugs in adult patients with rheumatic diseases

INTRODUCTION

The emergence of biologics has revolutionized the management of refractory rheumatic diseases (RD) by improving clinical outcomes. Unfortunately, the impact of non-adherence to the emerging therapy can limit their potential benefit. The objective of our study was to evaluate biologics' adherence in Tunisian patients with RD and to assess the determinants of non-adherence.

METHODS

We conducted a cross-sectional study involving patients with rheumatoid arthritis (RA) and spondyloarthritis (SpA) treated with bDMARDs (biologic disease-modifying antirheumatic drugs) for at least three months. Socio-demographic, clinical and biological data were collected. Biologic adherence was assessed using the compliance questionnaire for rheumatology (CQR).

RESULTS

One hundred patients with RD (45 RA and 55 SpA) were collected. Non-adherence to bDMARDs was found in 70% of cases. In univariate analysis, non-adherence to bDMARDs was statistically related to the absence of coxitis (P=0.003), to a low ASDAS-CRP (ankylosing spondylitis disease activity score) prior to the initiation of the bDMARDs (P=0.01), to a rate of administration of bDMARDs less than one injection per month (P=0.01), to the subcutaneous delivery route (P=0.02) as well as to non-adherence to csDMARDs (conventional disease-modifying antirheumatic drugs) (P=0.001). In multivariate analysis, the predictors of non-adherence were the absence of coxitis (OR=6.01; IC 95% [1.88-19.12]; P=0.002], and a rate of administration of bDMARDs less than one injection per month (OR=8.79; IC 95% [2.13-36.22]; P=0.003).

CONCLUSION

This work has revealed the low rate of adherence to biological treatments in Tunisian patient with RD. Predictors of poor adherence were the absence of coxitis and a rate of administration of bDMARDs less than one injection per month. Detection of these factors could help us to adapt our strategies to improve adherence that are essentially based on therapeutic education program.

Wnt Inhibitors and Bone Turnover Markers in Patients With Polymyalgia Rheumatica and Acute Effects of Glucocorticoid Treatment

Background: In polymyalgia rheumatica (PMR), data on bone turnover markers (BTM), on Wnt inhibitors (Dkk-1, sclerostin) and their changes induced by glucocorticoids (GC) are lacking. The aims of our study were to compare the baseline levels of Wnt inhibitors and BTM in PMR patients with healthy controls (HC) and to study their changes over the first 4 weeks of GC treatment.

Materials and Methods: We enrolled 17 treatment-naïve patients affected by PMR and 17 age and sex-matched healthy controls (HC) from retired hospital personnel. PMR patients were administered methylprednisolone 16 mg daily for 4 weeks. Blood samples were taken at baseline and at week 4 for the PMR group, a single sample was taken for HC. N-propeptide of type I collagen (PINP), C-terminal telopeptide of type I collagen (CTX-I), sclerostin, Dkk-1, and C-reactive protein (CRP) were dosed.

Results: At baseline, Dkk-1 was significantly higher in the PMR group as compared to HC (p = 0.002) while PINP, CTX-I and sclerostin levels were comparable between PMR patients and HC, After 4 weeks of GC treatment we found in the PMR group a decrease of PINP (mean ± SD percentage decrement as compared to baseline −40 ± 18.6%, p < 0.001), CTX-I (−23.5 ± 41.3%, p = 0.032), Dkk-1 (−22.4 ± 39.6, p = 0.033), and sclerostin (−32.49 ± 20.47, p < 0.001) as compared to baseline levels.

Conclusions: In treatment-naïve PMR, systemic inflammation is associated with a dysregulation of the Wnt system (increased Dkk-1). Within the 1st month, treatment with GC showed noteworthy effects on bone resorption, formation, and on Wnt pathway modulators.

MicroRNAs target the Wnt/β‑catenin signaling pathway to regulate epithelial‑mesenchymal transition in cancer (Review)

Epithelial‑mesenchymal transition (EMT), during which cancer cells lose the epithelial phenotype and gain the mesenchymal phenotype, has been verified to result in tumor migration and invasion. Numerous studies have shown that dysregulation of the Wnt/β‑catenin signaling pathway gives rise to EMT, which is characterized by nuclear translocation of β‑catenin and E‑cadherin suppression. Wnt/β‑catenin signaling was confirmed to be affected by microRNAs (miRNAs), several of which are down‑ or upregulated in metastatic cancer cells, indicating their complex roles in Wnt/β‑catenin signaling. In this review, we demonstrated the targets of various miRNAs in altering Wnt/β‑catenin signaling to promote or inhibit EMT, which may elucidate the underlying mechanism of EMT regulation by miRNAs and provide evidence for potential therapeutic targets in the treatment of invasive tumors.

WNT Signaling in Melanoma

WNT-signaling controls important cellular processes throughout embryonic development and adult life, so any deregulation of this signaling can result in a wide range of pathologies, including cancer. WNT-signaling is classified into two categories: β-catenin-dependent signaling (canonical pathway) and β-catenin-independent signaling (non-canonical pathway), the latter can be further divided into WNT/planar cell polarity (PCP) and calcium pathways. WNT ligands are considered as unique directional growth factors that contribute to both cell proliferation and polarity. Origin of cancer can be diverse and therefore tissue-specific differences can be found in WNT-signaling between cancers, including specific mutations contributing to cancer development. This review focuses on the role of the WNT-signaling pathway in melanoma. The current view on the role of WNT-signaling in cancer immunity as well as a short summary of WNT pathway-related drugs under investigation are also provided.

Molecular Basis of Bone Aging

A decline in bone mass leading to an increased fracture risk is a common feature of age-related bone changes. The mechanisms underlying bone senescence are very complex and implicate systemic and local factors and are the result of the combination of several changes occurring at the cellular, tissue and structural levels; they include alterations of bone cell differentiation and activity, oxidative stress, genetic damage and the altered responses of bone cells to various biological signals and to mechanical loading. The molecular mechanisms responsible for these changes remain greatly unclear and many data derived from in vitro or animal studies appear to be conflicting and heterogeneous, probably due to the different experimental approaches; nevertheless, understanding the main physio-pathological processes that cause bone senescence is essential for the development of new potential therapeutic options for treating age-related bone loss. This article reviews the current knowledge concerning the molecular mechanisms underlying the pathogenesis of age-related bone changes.

Joint remodeling outcome of serum levels of Dickkopf-1 (DKK1), cartilage oligomeric matrix protein (COMP), and C-telopeptide of type II collagen (CTXII) in rheumatoid arthritis

Introduction

Rheumatoid arthritis (RA) is the most widespread chronic inflammatory rheumatic disease over the world. It is characterized by chronic proliferation of synovium, cartilage destruction, and periarticular erosion/bone loss. We investigated the serum levels of the C-telopeptide of type II collagen (CTX-II), Dickkopf-1 (DKK1), and cartilage oligomeric matrix protein (COMP) in relationship to the disease activity.

Material and methods

Serum COMP, CTX-II, and DKK1 levels were measured in 63 RA patients and 50 person age and gender matched as a healthy controls by ELISA test. Disease activity score (DAS) were calculated.

Results

The mean level of and COMP and CTX-II were significantly higher in patients with RA than in healthy controls (5.71 ±7.04 vs. 2.70 ±1.31 ng/ml, and 0.45 ±0.27 vs. 0.23 ±0.16 ng/ml, respectively; p < 0.001). Also, DKK1 serum levels were significantly higher in patients with RA than in healthy controls (6970.68 ±7566.68 vs. 3276.96 ±1306.77 pg/m; p < 0.001). There was a positive significant correlation between DKK1 and swollen joint (r = 0.42, p < 0.001). There were no significant differences in the number of patients, gender, the duration of RA disease, DAS, and RF. Sensitivity was 58.7% and specificity was 85.7% at a cut-off point (> 3.6 ng/ml) for serum COMP in RA patients, while, sensitivity was 100% and specificity was 52.4% at a cut-off point (> 0.15 ng/ml) for serum CTX-II and sensitivity was 68.3% and specificity was 95.2 % at a cut-off point (> 4876 pg/ml) for serum DKK1.

Conclusions

Measurement of some serological biomarkers such as CTX-II, COMP, and DKK1 that reflect bone and cartilage destruction in RA patients could be used to indicate disease activity and early joint affection.