Current immunotherapy in rheumatoid arthritis

Identification of diagnostic biomarkers of rheumatoid arthritis based on machine learning-assisted comprehensive bioinformatics and its correlation with immune cells

Background

Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease characterized by inflammatory cell infiltration, which can lead to chronic disability, joint destruction and loss of function. At present, the pathogenesis of RA is still unclear. The purpose of this study is to explore the potential biomarkers and immune molecular mechanisms of rheumatoid arthritis through machine learning-assisted bioinformatics analysis, in order to provide reference for the early diagnosis and treatment of RA disease.

Methods

RA gene chips were screened from the public gene GEO database, and batch correction of different groups of RA gene chips was performed using Strawberry Perl. DEGs were obtained using the limma package of R software, and functional enrichment analysis such as gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), disease ontology (DO), and gene set (GSEA) were performed. Three machine learning methods, least absolute shrinkage and selection operator regression (LASSO), support vector machine recursive feature elimination (SVM-RFE) and random forest tree (Random Forest), were used to identify potential biomarkers of RA. The validation group data set was used to verify and further confirm its expression and diagnostic value. In addition, CIBERSORT algorithm was used to evaluate the infiltration of immune cells in RA and control samples, and the correlation between confirmed RA diagnostic biomarkers and immune cells was analyzed.

Results

Through feature screening, 79 key DEGs were obtained, mainly involving virus response, Parkinson's pathway, dermatitis and cell junction components. A total of 29 hub genes were screened by LASSO regression, 34 hub genes were screened by SVM-RFE, and 39 hub genes were screened by Random Forest. Combined with the three algorithms, a total of 12 hub genes were obtained. Through the expression and diagnostic value verification in the validation group data set, 7 genes that can be used as diagnostic biomarkers for RA were preliminarily confirmed. At the same time, the correlation analysis of immune cells found that γδT cells, CD4+ memory activated T cells, activated dendritic cells and other immune cells were positively correlated with multiple RA diagnostic biomarkers, CD4+ naive T cells, regulatory T cells and other immune cells were negatively correlated with multiple RA diagnostic biomarkers.

Conclusions

The results of novel characteristic gene analysis of RA showed that KYNU, EVI2A, CD52, C1QB, BATF, AIM2 and NDC80 had good diagnostic and clinical value for the diagnosis of RA, and were closely related to immune cells. Therefore, these seven DEGs may become new diagnostic markers and immunotherapy markers for RA.

Effect of Recent Antirheumatic Drug on Features of Rheumatoid Arthritis-Associated Lymphoproliferative Disorders

OBJECTIVE

In this study, we examine how advancements in novel antirheumatic drugs affect the clinicopathologic features of lymphoproliferative disorder (LPD) in patients with rheumatoid arthritis (RA).

METHODS

In this multicenter study across 53 hospitals in Japan, we characterized patients with RA who developed LPDs and visited the hospitals between January 1999 and March 2021. The statistical tools used included Fisher's exact test, the Mann-Whitney U-test, the log-rank test, logistic regression analysis, and Cox proportional hazards models.

RESULTS

Overall, 752 patients with RA-associated LPD (RA-LPD) and 770 with sporadic LPD were included in the study. We observed significant differences in the clinicopathologic features between patients with RA-LPD and those with sporadic LPD. Histopathological analysis revealed a high frequency of LPD-associated immunosuppressive conditions. Furthermore, patients with RA-LPD were evaluated based on the antirheumatic drugs administered. The methotrexate (MTX) plus tacrolimus and MTX plus tumor necrosis factor inhibitor (TNFi) groups had different affected site frequencies and histologic subtypes than the MTX-only group. Moreover, MTX and TNFi may synergistically affect susceptibility to Epstein-Barr virus infection. In case of antirheumatic drugs administered after LPD onset, tocilizumab (TCZ)-only therapy was associated with lower frequency of regrowth after spontaneous regression than other regimens.

CONCLUSION

Antirheumatic drugs administered before LPD onset may influence the clinicopathologic features of RA-LPD, with patterns changing over time. Furthermore, TCZ-only regimens are recommended after LPD onset.

Anti-inflammatory effects of infliximab and methotrexate on peripheral blood and synovial fluid mononuclear cells: ex vivo study

OBJECTIVE

To investigate the effects of methotrexate (MTX) and the tumour necrosis factor inhibitor infliximab (IFX) on immune cells derived from peripheral blood mononuclear cells (PBMCs) and synovial fluid mononuclear cells (SFMCs) of inflammatory arthritis patients.

METHOD

Phytohaemagglutinin (PHA)-induced proliferation of healthy donors' PBMCs and synovial intermediate monocytes (CD14+CD16+ cells) in SFMCs derived from psoriatic arthritis (PsA) and rheumatoid arthritis (RA) patients was determined by flow cytometry following co-culture with IFX and MTX. PHA-induced interferon-γ (IFN-γ) production in PBMCs was measured by enzyme-linked immunosorbent assay. The drugs' effect on mRNA expression in SFMCs was determined by quantitative polymerase chain reaction.

RESULTS

The combination of IFX 10 μg/mL + MTX 0.1 μg/mL had the strongest inhibitory effect on PBMC proliferation (91%), followed by MTX 0.1 μg/mL (86%) and IFX 10 μg/mL (49%). In PHA-stimulated PBMCs, IFN-γ production was reduced by IFX 10 μg/mL, MTX 0.1 μg/mL, and IFX 10 μg/mL + MTX 0.1 μg/mL by 68%, 90%, and 85%, respectively. In SFMCs, IFX 10 µg/mL significantly reduced CD14+CD16+ cells compared to medium (PsA 54%, p < 0.01; RA 46%, p < 0.05), while MTX had no effect on this population. IFX + MTX led to a similar suppression of CD14+CD16+ cells as achieved by IFX alone. The drugs had different impacts on SFMC gene expression.

CONCLUSION

Both IFX and MTX effectively inhibited PBMC proliferation and IFN-γ production, but only IFX reduced synovial monocytes and pro-inflammatory gene expression in SFMCs, suggesting a differential impact of IFX and MTX on critical inflammatory cell populations ex vivo.

Autoimmune rheumatic disease in Australian Aboriginal and Torres Strait Islander Peoples: What do we know?

Autoimmune rheumatic disease (AIRD) is a collective term, which comprises a group of multisystem inflammatory autoimmune diseases, including connective tissue disease, chronic inflammatory arthritis, sarcoidosis and systemic vasculitis. Some AIRD are prevalent in the general population, and all can cause significant morbidity and reduced quality of life, with some increasing the risk of premature mortality, such as systemic lupus erythematosus (SLE), a connective tissue disease that is more prevalent and severe in Australian Aboriginal and Torres Strait Islander Peoples with high mortality rates. To ensure that management of AIRD can be optimised for all Australians, it is important that we understand the prevalence and potential phenotypic variations of AIRD across the Australian population. However, to date there have been few described cases of AIRD other than SLE in Aboriginal and Torres Strait Islander Peoples. In this review, we summarise what is known about AIRD other than SLE in Aboriginal and Torres Strait Islander Peoples, particularly with regards to prevalence, phenotype and disease outcomes, and highlight the current gaps in knowledge.

The aminosalicylate - folate connection

Two aminosalicylate isomers have been found to possess useful pharmacological behavior: p-aminosalicylate (PAS, 4AS) is an anti-tubercular agent that targets M. tuberculosis, and 5-aminosalicylate (5AS, mesalamine, mesalazine) is used in the treatment of ulcerative colitis (UC) and other inflammatory bowel diseases (IBD). PAS, a structural analog of pABA, is biosynthetically incorporated by bacterial dihydropteroate synthase (DHPS), ultimately yielding a dihydrofolate (DHF) analog containing an additional hydroxyl group in the pABA ring: 2'-hydroxy-7,8-dihydrofolate. It has been reported to perturb folate metabolism in M. tuberculosis, and to selectively target M. tuberculosis dihydrofolate reductase (mtDHFR). Studies of PAS metabolism are reviewed, and possible mechanisms for its mtDHFR inhibition are considered. Although 5AS is a more distant structural relative of pABA, multiple lines of evidence suggest a related role as a pABA antagonist that inhibits bacterial folate biosynthesis. Structural data support the likelihood that 5AS is recognized by the DHPS pABA binding site, and its effects probably range from blocking pABA binding to formation of a dead-end dihydropterin-5AS adduct. These studies suggest that mesalamine acts as a gut bacteria-directed antifolate, that selectively targets faster growing, more folate-dependent species.

Adult cervical spine deformity: a state-of-the-art review

Adult cervical deformity is a structural malalignment of the cervical spine that may present with variety of significant symptomatology for patients. There are clear and substantial negative impacts of cervical spine deformity, including the increased burden of pain, limited mobility and functionality, and interference with patients' ability to work and perform everyday tasks. Primary cervical deformities develop as the result of a multitude of different etiologies, changing the normal mechanics and structure of the cervical region. In particular, degeneration of the cervical spine, inflammatory arthritides and neuromuscular changes are significant players in the development of disease. Additionally, cervical deformities, sometimes iatrogenically, may present secondary to malalignment or correction of the thoracic, lumbar or sacropelvic spine. Previously, classification systems were developed to help quantify disease burden and influence management of thoracic and lumbar spine deformities. Following up on these works and based on the relationship between the cervical and distal spine, Ames-ISSG developed a framework for a standardized tool for characterizing and quantifying cervical spine deformities. When surgical intervention is required to correct a cervical deformity, there are advantages and disadvantages to both anterior and posterior approaches. A stepwise approach may minimize the drawbacks of either an anterior or posterior approach alone, and patients should have a surgical plan tailored specifically to their cervical deformity based upon symptomatic and radiographic indications. This state-of-the-art review is based upon a comprehensive overview of literature seeking to highlight the normal cervical spine, etiologies of cervical deformity, current classification systems, and key surgical techniques.

Phytochemical profiling, in vitro analysis for anti-inflammatory, immunomodulatory activities, structural elucidation and in silico evaluation of potential selective COX-2 and TNF-α inhibitor from Hydrilla verticillata (L.f.) Royle

Hydrilla verticillata (L.f.) Royle is a perennial aquatic plant, which exhibits nutritional as well as therapeutic properties. The present study has been carried out to evaluate anti-inflammatory and immunomodulatory activities along with in silico evaluation of potential selective COX-2 and TNF-α inhibitors from methanolic extract of H. verticillata (L.f.) Royle. The potential therapeutic compounds have been identified by high-resolution GC-MS analysis. Its capacity to inhibit inflammatory responses using lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophage cells has been explored. The anti-inflammatory properties of the plant extract were investigated by inhibiting inducible nitric oxide (NO) synthase and reduced NO generation driven by LPS on stimulated RAW 264.7 macrophage cells. Further investigation for the underlying molecular mechanism of the anti-inflammatory activity of plant extract has been carried out by molecular docking and molecular dynamics simulation approaches with COX-2 and TNF-α inhibitors ability against the most potent phytocompound phytol from the plant extract. To evaluate whether the extract causes any toxicity, the cytotoxicity test has been carried out with the Human embryonic kidney cell line (Hek-293), Mouse fibroblast (L929), human mesenchyme stem cells (hMSCs) and human breast epithelial cell line (MCF-10a). Ultimately, our findings suggest that the plant extract have great potential to reduce inflammation without causing any toxicity to normal cell.Communicated by Ramaswamy H. Sarma.

Correlation of anti-TNF-a biological therapy with periodontal conditions and osteonecrosis in autoimmune patients: A systematic review

Objectives

This systematic review aims to investigate the impact of tumor necrotic factor alpha inhibitors in suppressing bone resorption in periodontitis, and its potential to cause osteonecrosis. Extensive electronic research was conducted following the PRISMA guidelines, which connected various aspects of anti-TNF-a (anti-tumor necrosis factor-a) to periodontitis and osteonecrosis patients.

Background

TNF-a inhibitors are broadly indicated in the treatment of autoimmune patients with possible joint resorption and increased inflammatory processes such as rheumatoid arthritis and inflammatory bowel disease, where they reduce bone loss and certain mediators. As rheumatoid arthritis and periodontitis share many characteristics, these medications may also be helpful in the treatment of coexisting periodontitis. However, besides medical benefits, anti-TNF-a also exhibits several adverse effects, ranging from dizziness to tuberculosis. Osteonecrosis is considered a recent adverse impact.

Methods

An extensive electronic systematic review following the PRISMA guidelines was performed for English-language papers using the following databases as sources of information: PubMed, Medline, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), Library Genesis, Worldwide Science, National Rheumatoid Arthritis Society (NRAS), and other related articles. This systematic review is registered on the PROSPERO platform under registration number CRD42022341753.

Results

Twenty articles were identified after the exclusion criteria were applied. These include systematic reviews, case reports, retrospective cohort studies, case report series, meta-analyses, clinical trials, randomised clinical trials, cross-sectional and longitudinal analyses, longitudinal observational studies, and prospective clinical trials. All these were included in the quantitative and qualitative analyses.

Conclusions

Anti-TNF-a drugs show promising results in treating patients with rheumatoid arthritis and periodontitis but could be considered a risk factor for osteonecrosis. Hence, patients receiving such medications should be closely monitored by the dentist and physician before, during, and after administration.

Mechanisms of tissue degeneration mediated by periostin in spinal degenerative diseases and their implications for pathology and diagnosis: a review

Periostin (POSTN) serves a dual role as both a matricellular protein and an extracellular matrix (ECM) protein and is widely expressed in various tissues and cells. As an ECM protein, POSTN binds to integrin receptors, transduces signals to cells, enabling cell activation. POSTN has been linked with various diseases, including atopic dermatitis, asthma, and the progression of multiple cancers. Recently, its association with orthopedic diseases, such as osteoporosis, osteoarthritis resulting from cartilage destruction, degenerative diseases of the intervertebral disks, and ligament degenerative diseases, has also become apparent. Furthermore, POSTN has been shown to be a valuable biomarker for understanding the pathophysiology of orthopedic diseases. In addition to serum POSTN, synovial fluid POSTN in joints has been reported to be useful as a biomarker. Risk factors for spinal degenerative diseases include aging, mechanical stress, trauma, genetic predisposition, obesity, and metabolic syndrome, but the cause of spinal degenerative diseases (SDDs) remains unclear. Studies on the pathophysiological effects of POSTN may significantly contribute toward the diagnosis and treatment of spinal degenerative diseases. Therefore, in this review, we aim to examine the mechanisms of tissue degeneration caused by mechanical and inflammatory stresses in the bones, cartilage, intervertebral disks, and ligaments, which are crucial components of the spine, with a focus on POSTN.

Tackling TNF-α in autoinflammatory disorders and autoimmune diseases: From conventional to cutting edge in biologics and RNA- based nanomedicines

Autoinflammatory disorders and autoimmune diseases result from abnormal deviations of innate and adaptive immunity that heterogeneously affect organs and clinical phenotypes. Despite having etiologic and phenotypic differences, these two conditions share the onset of an aberrant inflammatory process. Targeting the main drivers controlling inflammation is useful to treat both autoimmune and autoinflammatory syndromes. TNF-α is a major player in the inflammatory immune response, and anti-TNF-α antibodies have been a revolutionary treatment in many autoimmune disorders. However, production difficulties and high development costs hinder their implementation, and accessibility to their use is still limited. Innovative strategies aimed at overcoming the limitations associated with anti-TNF-α antibodies are being explored, including RNA-based therapies. Here we summarize the central role of TNF-α in immune disorders and how anti-TNF-based immunotherapies changed the therapeutic landscape, albeit with important limitations related to side effects, tolerance, and resistance to therapies. We then outline how nanotechnology has provided the final momentum for the use of nucleic acids in the treatment of autoimmune and autoinflammatory diseases, with a focus on inflammatory bowel diseases (IBDs). The example of IBDs allows the evaluation and discussion of the nucleic acids-based treatments that have been developed, to identify the role that innovative approaches possess in view of the treatment of autoinflammatory disorders and autoimmune diseases.

A Perspective on Oral Immunotherapeutic Tools and Strategies for Autoimmune Disorders

Oral immune tolerance is a physiological process to achieve tolerance against autoimmunity by oral ingestion of self-antigen(s) or other therapeutics. At the cellular level, oral tolerance suppresses autoimmune diseases by activating FoxP-positive and -negative regulatory T cells (Tregs) and/or causing clonal anergy or deletion of autoreactive T cells, affecting B cell tolerance. However, oral delivery of antigens/biologics is challenging due to their instability in the harsh environment of the gastrointestinal (GI) tract. Several antigen/drug delivery tools and approaches, including micro/nanoparticles and transgenic plant-based delivery systems, have been explored to demonstrate oral immune tolerance for different autoimmune diseases successfully. However, despite the effectiveness, variation in results, dose optimization, and undesirable immune system activation are the limitations of the oral approach to further advancement. From this perspective, the current review discusses the oral tolerance phenomenon, cellular mechanisms, antigen delivery tools and strategies, and its challenges.

Delivery route considerations for designing antigen-specific biomaterial strategies to combat autoimmunity

Disease modifying drugs and biologics used to treat autoimmune diseases, although promising, are non-curative. As the field moves towards development of new approaches to treat autoimmune disease, antigen-specific therapies immunotherapies (ASITs) have emerged. Despite clinical approval of ASITs for allergies, clinical trials using soluble ASITs for autoimmunity have been largely unsuccessful. A major effort to address this shortcoming is the use of biomaterials to harness the features unique to specific delivery routes. This review focuses on biomaterials being developed for delivery route-specific strategies to induce antigen-specific responses in autoimmune diseases such as multiple sclerosis, type 1 diabetes, rheumatoid arthritis, and celiac disease. We first discuss the delivery strategies used in ongoing and completed clinical trials in autoimmune ASITs. Next, we highlight pre-clinical biomaterial approaches from the most recent 3 years in the context of these same delivery route considerations. Lastly, we provide discussion on the gaps remaining in biomaterials development and comment on the need to consider delivery routes in the process of designing biomaterials for ASITs.

Elucidating a fresh perspective on the interplay between exosomes and rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by chronic synovitis and the destruction of bones and joints. Exosomes are nanoscale lipid membrane vesicles originating from multivesicular bodies and are used as a vital means of intercellular communication. Both exosomes and the microbial community are essential in RA pathogenesis. Multiple types of exosomes from different origins have been demonstrated to have effects on various immune cells through distinct mechanisms in RA, which depend on the specific cargo carried by the exosomes. Tens of thousands of microorganisms exist in the human intestinal system. Microorganisms exert various physiological and pathological effects on the host directly or through their metabolites. Gut microbe-derived exosomes are being studied in the field of liver disease; however, information on their role in the context of RA is still limited. Gut microbe-derived exosomes may enhance autoimmunity by altering intestinal permeability and transporting cargo to the extraintestinal system. Therefore, we performed a comprehensive literature review on the latest progress on exosomes in RA and provided an outlook on the potential role of microbe-derived exosomes as emerging players in clinical and translational research on RA. This review aimed to provide a theoretical basis for developing new clinical targets for RA therapy.

3D Cell Culture as Tools to Characterize Rheumatoid Arthritis Signaling and Development of New Treatments

Rheumatoid arthritis (RA) is one of the most common autoimmune disorders affecting 0.5-1% of the population worldwide. As a disease of multifactorial etiology, its constant study has made it possible to unravel the pathophysiological processes that cause the illness. However, efficient and validated disease models are necessary to continue the search for new disease-modulating drugs. Technologies, such as 3D cell culture and organ-on-a-chip, have contributed to accelerating the prospecting of new therapeutic molecules and even helping to elucidate hitherto unknown aspects of the pathogenesis of multiple diseases. These technologies, where medicine and biotechnology converge, can be applied to understand RA. This review discusses the critical elements of RA pathophysiology and current treatment strategies. Next, we discuss 3D cell culture and apply these methodologies for rheumatological diseases and selected models for RA. Finally, we summarize the application of 3D cell culture for RA treatment.

Adipose-Derived Stem Cell Exosomes as a Novel Anti-Inflammatory Agent and the Current Therapeutic Targets for Rheumatoid Arthritis

Patients with rheumatoid arthritis (RA), a chronic inflammatory joint disorder, may not respond adequately to current RA treatments. Mesenchymal stem cells (MSCs) elicit several immunomodulatory and anti-inflammatory effects and, thus, have therapeutic potential. Specifically, adipose-derived stem cell (ADSC)-based RA therapy may have considerable potency in modulating the immune response, and human adipose tissue is abundant and easy to obtain. Paracrine factors, such as exosomes (Exos), contribute to ADSCs’ immunomodulatory function. ADSC-Exo-based treatment can reproduce ADSCs’ immunomodulatory function and overcome the limitations of traditional cell therapy. ADSC-Exos combined with current drug therapies may provide improved therapeutic effects. Using ADSC-Exos, instead of ADSCs, to treat RA may be a promising cell-free treatment strategy. This review summarizes the current knowledge of medical therapies, ADSC-based therapy, and ADSC-Exos for RA and discusses the anti-inflammatory properties of ADSCs and ADSC-Exos. Finally, this review highlights the expanding role and potential immunomodulatory activity of ADSC-Exos in patients with RA.

Marine-derived microbes and molecules for drug discovery

Increasing attention has been paid to marine-derived biomolecules as sources of therapeutics for autoimmune diseases. Nagasaki Prefecture has many islands and is surrounded by seas, straits, gulfs, bays, and coves, giving it the second longest coastline in Japan after Hokkaido. We have collected more than 20,000 marine microbes and have been preparing an original marine microbial extract library, which contains small and mid-size biomolecules that may penetrate cell membranes and interfere with the intracellular protein–protein interaction involved in the development of autoinflammatory diseases such as familial Mediterranean fever. In addition, we have been developing an indoor shark farming system to prepare shark nanobodies that could be developed as potential therapeutic agents for autoimmune diseases. Sharks produce heavy-chain antibodies, called immunoglobulin new antigen receptors (IgNARs), consisting of one variable domain (V_NAR) and five constant domains (C_NAR); of these, V_NAR can recognize a variety of foreign antigens. A V_NAR single domain fragment, called a nanobody, can be expressed in Escherichia coli and has the properties of an ideal therapeutic candidate for autoimmune diseases. Shark nanobodies contain complementarity-determining regions that are formed through the somatic rearrangement of variable, diversity, and joining segments, with the segment end trimming and the N- and P-additions, as found in the variable domains of mammalian antibodies. The affinity and diversity of shark nanobodies are thus expected to be comparable to those of mammalian antibodies. In addition, shark nanobodies are physically robust and can be prepared inexpensively; as such, they may lead to the development of highly specific, stable, effective, and inexpensive biotherapeutics in the future. In this review, we first summarize the history of the development of conventional small molecule drugs and monoclonal antibody therapeutics for autoimmune diseases, and then introduce our drug discovery system at Nagasaki University, including the preparation of an original marine microbial extract library and the development of shark nanobodies.

CaP-based anti-inflammatory HIF-1α siRNA-encapsulating nanoparticle for rheumatoid arthritis therapy

Rheumatoid arthritis (RA) is a common inflammatory disease and its treatment is largely limited by drug ineffectiveness or severe side effects. In RA progression, multiple signalling pathways, such as hypoxia-inducible factor (HIF)-1α, nuclear factor kappa B (NF-κB), and mitogen-activated protein kinase (MAPK) pathways, act synergistically to maintain the inflammatory response. To downregulate HIF-1α, NF-κB, and MAPK expression, we proposed HIF-1α siRNA-loaded calcium phosphate nanoparticles encapsulated in apolipoprotein E3-reconstituted high-density lipoprotein (HIF-CaP-rHDL) for RA therapy. Here, we evaluated the potential of CaP-rHDL nanoparticles in RA therapy using a murine macrophage line (RAW 264.7) and a collagen-induced arthritis (CIA) mouse model. The CaP-rHDL nanoparticles showed significant anti-inflammatory effects along with HIF-1α knockdown and NF-κB and MAPK signalling pathway inhibition in lipopolysaccharide-activated macrophages. Moreover, they inhibited receptor activator of NF-κB ligand (RANKL)-induced osteoclast formation. In CIA mice, their intravenous administration resulted in high accumulation at the arthritic joint sites, and HIF-CaP-rHDL effectively suppressed inflammatory cytokine secretion and relieved bone erosion, cartilage damage, and osteoclastogenesis. Thus, HIF-CaP-rHDL demonstrated great potential in RA precision therapy by inhibiting multiple inflammatory signalling pathways.

Engineering a variant of IL-17RA with high binding affinity to IL-17A for optimized immunotherapy

Immunotherapy is one of the most recently used treatments for numerous cancer types and also some autoimmune and inflammatory diseases. One of the valuable targets for immunotherapy is Interleukin-17A (IL-17A) or its receptor (IL-17RA) because overexpression of IL-17A as a pro-inflammatory cytokine is associated with several inflammatory, autoimmune and cancer diseases. In this study, the extracellular domain of IL-17RA involved in binding to IL-17A was mutated by using R software to achieve a variant with increased binding affinity to IL-17A. The ∆∆G value of -30.89 kcal/mol was calculated for the best variant (385) with point mutations of R265N, N91T, and W31K using the FoldX module. Also, the KD for its interaction with IL-17A was calculated 0.06 nM by surface plasmon resonance (SPR) technique. Our results indicated that variant 385 could bind to IL-17A with higher binding affinity than wild-type one, so, it can be a good therapeutic candidate for blocking IL-17A.

lncRNA GAS5 suppresses rheumatoid arthritis by inhibiting miR-361-5p and increasing PDK4

Rheumatoid arthritis (RA) is an inflammatory disease that causes hyperplasia of synovial tissue and cartilage destruction. This research was to investigate the effects of lncRNA GAS5/miR-361-5p/PDK4 on rheumatoid arthritis. By qRT-PCR, GAS5 and PDK4 were found to be overexpressed in synovial tissue, fibroblast-like synoviocytes of RA patients and LPS-induced chondrocytes, while the miR-361-5p expression was significantly reduced. GAS5 overexpression resulted in a decrease in the proliferation and Bcl-2 protein expression, and an increase in the Bax protein level. On the contrary, miR-361-5p sponged by GAS5 could accelerate chondrocyte proliferation, inhibit apoptosis. PDK4 targeted by miR-361-5p could inhibit RA, and partially eliminated the effect of miR-361-5p on RA. Our study suggested that GAS5 suppressed RA by competitively adsorbing miR-361-5p to modulate PDK4 expression.

Treatment approaches to patients with multiple sclerosis and coexisting autoimmune disorders

The past decades have yielded major therapeutic advances in many autoimmune conditions - such as multiple sclerosis (MS) - and thus ushered in a new era of more targeted and increasingly potent immunotherapies. Yet this growing arsenal of therapeutic immune interventions has also rendered therapy much more challenging for the attending physician, especially when treating patients with more than one autoimmune condition. Importantly, some therapeutic strategies are either approved for several autoimmune disorders or may be repurposed for other conditions, therefore opening new curative possibilities in related fields. In this article, we especially focus on frequent and therapeutically relevant concomitant autoimmune conditions faced by neurologists when treating patients with MS, namely psoriasis, rheumatoid arthritis and inflammatory bowel diseases. We provide an overview of the available disease-modifying therapies, highlight possible contraindications, show pathophysiological overlaps and finally present which therapeutics can be utilized as a combinatory treatment, in order to 'kill two birds with one stone'.

Endothelial cell and T-cell crosstalk: Targeting metabolism as a therapeutic approach in chronic inflammation

The role of metabolic reprogramming in the coordination of the immune response has gained increasing consideration in recent years. Indeed, it has become clear that changes in the metabolic status of immune cells can alter their functional properties. During inflammation, T cells need to generate sufficient energy and biomolecules to support growth, proliferation, and effector functions. Therefore, T cells need to rearrange their metabolism to meet these demands. A similar metabolic reprogramming has been described in endothelial cells, which have the ability to interact with and modulate the function of immune cells. In this overview, we will discuss recent insights in the complex crosstalk between endothelial cells and T cells as well as their metabolic reprogramming following activation. We highlight key components of this metabolic switch that can lead to the development of new therapeutics against chronic inflammatory disorders. LINKED ARTICLES: This article is part of a themed issue on Cellular metabolism and diseases. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v178.10/issuetoc.

Exploring the role of immunotherapeutic drugs in autoimmune diseases: A comprehensive review

Autoimmune diseases are group of disorders where an immune response is mounted against the self. The prevalence and burden of this well established and recognised entity is on the rise. Irrespective of being a systemic or organ specific autoimmune disorder, the common underlying mechanism of action, is the imbalance in immune system resulting in loss of tolerance to self-antigens. The oral cavity is no alien to these disorders or to their influences. Pemphigus group of lesions, systemic lupus erythematosus, psoriasis and even Sjogren's syndrome are some of the established autoimmune disorders with prominent oral manifestations. Though these diseases are well documented and enumerated, however addressing them is where the dilemma lies. Science, research and discoveries are a crucial part of medical discipline which help in looking beyond the horizon. With the introduction of selective targeted immunotherapies for autoimmune diseases as a treatment modality either in solitary or in combination with the conventional immunosuppressive treatments, are emerging as a promising elixir for patients enduring them. However, being unique, exploration of these biologics from its inception, to its mechanism of action, recognition of its application and evaluation of its safety norms are equally vital. Therefore, this review aims to provide a comprehensive particular on the novel biologics, the immunotherapies in autoimmune disorders targeting the different cells, their receptors or cytokines of the immune system.

Immunologically Inert Nanostructures as Selective Therapeutic Tools in Inflammatory Diseases

The current therapies based on immunosuppressant or new biologic drugs often show some limitations in term of efficacy and applicability, mainly because of their inadequate targeting and of unwanted adverse reactions they generate. To overcome these inherent problems, in the last decades, innovative nanocarriers have been developed to encapsulate active molecules and offer novel promising strategies to efficiently modulate the immune system. This review provides an overview of how it is possible, exploiting the favorable features of nanocarriers, especially with regard to their immunogenicity, to improve the bioavailability of novel drugs that selectively target immune cells in the context of autoimmune disorders and inflammatory diseases. A focus is made on nanoparticles that selectively target neutrophils in inflammatory pathologies.

Long non-coding RNA GAS5 suppresses rheumatoid arthritis progression via miR-128-3p/HDAC4 axis

Rheumatoid arthritis (RA) is a highly relevant public health problem. RA fibroblast-like synoviocytes (RAFLSs) play an important role in RA progression. Long non-coding RNA growth arrest-specific transcript 5 (GAS5) could improve RA by inducing RAFLSs apoptosis. However, the mechanism of GAS5 in RA remains unclear. RT-qPCR detected the expressions of GAS5, microRNA-128-3p (miR-128-3p), and histone deacetylase 4 (HDAC4) in RA synovial tissues and RAFLSs. Proliferation, apoptosis, migration, and invasion were measured by Cell Counting Kit-8 assay (CCK-8), flow cytometry, and transwell assays, severally. The protein levels of B-cell lymphoma-2 (Bcl-2), C-caspase 3, Bcl-2 related X protein (Bax), Tumor Necrosis factor-α (TNF-α), Interleukin 6 (IL-6), Interleukin 17 (IL-17), HDAC4, phosphorylation-protein kinase B (p-AKT), AKT, a phosphorylation-mechanistic target of rapamycin (p-mTOR), and mTOR were assessed by western blot assay. The interaction between miR-128-3p and GAS5 or HDAC4 was predicted by ENCORI or TargetScan Human and verified by the dual-luciferase reporter, RNA Immunoprecipitation (RIP), and RNA pull-down assays. GAS5 and HDAC4 were downregulated, and miR-128-3p was upregulated in RA synovial tissues and RAFLSs. Function analysis indicated that GAS5 curbed proliferation, migration, invasion, inflammation, and facilitated apoptosis of RAFLSs. Rescue assay confirmed that miR-128-3p overexpression or HDAC4 knockdown weakened the inhibitory effect of GAS5 or anti-miR-128-3p on RA development. GAS5 acted as a miR-128-3p sponge to upregulate HDAC4 expression. Besides, GAS5/miR-128-3p/HDAC4 axis regulated RA progression partially through the AKT/mTOR pathway. Our studies disclosed that GAS5 restrained inflammation in synovial tissue partly through regulating HDAC4 via miR-128-3p, suggesting a potential lncRNA-targeted therapy for RA treatment.

Mesenchymal stem cell-originated exosomal lncRNA HAND2-AS1 impairs rheumatoid arthritis fibroblast-like synoviocyte activation through miR-143-3p/TNFAIP3/NF-κB pathway

Background

Long non-coding RNA heart and neural crest derivatives expressed 2-antisense RNA 1 (HAND2-AS1) was found to be elevated in rheumatoid arthritis (RA) fibroblast-like synoviocytes (RA-FLSs). However, whether HAND2-AS1 functions as an exosomal lncRNA related to mesenchymal stem cells (MSCs) in RA progression is unknown.

Methods

The expression of HAND2-AS1, microRNA (miR)-143-3p, and tumor necrosis factor alpha-inducible protein 3 (TNFAIP3) was detected using quantitative real-time polymerase chain reaction and Western blot. Cell proliferation, apoptosis, migration, and invasion were detected using cell counting kit-8, flow cytometry, and wound healing and transwell assays. The levels of tumor necrosis factor-α (TNF-α) and interleukins (IL)-6 were analyzed using enzyme-linked immunosorbent assay. The level of phosphorylated-p65 was examined by Western blot. The binding interaction between miR-143-3p and HAND2-AS1 or TNFAIP3 was confirmed by the dual-luciferase reporter and RIP assays. Exosomes were isolated by ultracentrifugation and qualified by transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA), and Western blot.

Results

HAND2-AS1 was lowly expressed in RA synovial tissues, and HAND2-AS1 re-expression suppressed the proliferation, motility, and inflammation and triggered the apoptosis in RA-FLSs via the inactivation of NF-κB pathway. Mechanistically, HAND2-AS1 directly sponged miR-143-3p and positively regulated TNFAIP3 expression, the target of miR-143-3p. Moreover, the effects of HAND2-AS1 on RA-FLSs were partially attenuated by miR-143-3p upregulation or TNFAIP3 knockdown. HAND2-AS1 could be packaged into hMSC-derived exosomes and absorbed by RA-FLSs, and human MSC-derived exosomal HAND2-AS1 also repressed above malignant biological behavior of RA-FLSs.

Conclusion

MSC-derived exosomes participated in the intercellular transfer of HAND2-AS1 and suppressed the activation of RA-FLSs via miR-143-3p/TNFAIP3/NF-κB pathway, which provided a novel insight into the pathogenesis and treatment of RA.

Lysosomal dysfunction in osteoarthritis and aged cartilage triggers apoptosis in chondrocytes through BAX mediated release of Cytochrome c

OBJECTIVE

Lysosomes are the major catabolic organelle of the cell and regulate the macromolecular and organelle turnover and programmed cell death. Here, we investigated the lysosome dysfunction in cartilage and its role in chondrocytes apoptosis and the associated mechanism.

DESIGN

Lysosomal acidification in Osteoarthritis (OA) and aged cartilage was determined by LysoSensor staining. Lysosomal function in chondrocytes was blocked by siRNA mediated depletion of Lysosomal Associated Membrane Protein 2 (LAMP2) or with lysosome inhibitors. Chondrocyte apoptosis was determined by LDH release, Caspase-3/7 activation, TUNEL and PI uptake assays. Loss of mitochondrial membrane potential (MMP/ΔΨM) and mitochondrial superoxide level was determined by JC-1 and MitoSOX staining, respectively. Colocalization of mitochondria with BCL2 associated X (BAX) and Cytochrome c was determined by immunostaining. Destabilization of medial meniscus (DMM) was performed to induce OA in mice.

RESULTS

Lysosomal acidification was found to be significantly decreased in aged mouse and human and mouse OA cartilage which also showed increased chondrocyte apoptosis. Inhibition of lysosomal function resulted in increased oxidative stress, accumulation of dysfunctional mitochondria and apoptosis in chondrocytes in monolayer and in cartilage explant cultures. Depletion of LAMP2 expression or treatment of chondrocytes with lysosomal function inhibitors increased the expression and mitochondrial translocation of BAX leading to Cytochrome c release. Lysosomal dysfunction-induced apoptosis in chondrocytes was not blocked by antioxidants MitoTempo or Diphenyleneiodonium (DPI) but was abrogated by inhibiting BAX.

CONCLUSION

Lysosomal dysfunction induce apoptosis in chondrocytes through BAX-mediated mitochondrial damage and release of Cytochrome c. Our data points to lysosomal function restoration and/or BAX inhibition in chondrocytes as a therapeutic approach for OA.

MicroRNA-140-5p regulates the proliferation, apoptosis and inflammation of RA FLSs by repressing STAT3

Ectopic expression of microRNA (miRNA) in rheumatoid arthritis (RA) fibroblast-like synoviocyte (RA FLS) is associated with the development of rheumatoid arthritis. The present study aimed to evaluate the effects of miRNA-140-5p (miR-140) on the properties of RA FLSs. It was found that miR-140 expression was decreased in 33 RA patients and extracted RA FLS samples, when compared to the corresponding healthy controls. Abnormally increased miR-140 expression in RA FLSs attenuated cell proliferation and increased cell apoptosis. Additionally, reduced pro-inflammatory cytokine production was observed in RA FLSs transfected with a miR-140 precursor. Furthermore, the 3'-UTR of the signal transducer and activator of transcription (STAT) 3 gene was identified as a target of miR-140. Notably, restoration of STAT3 expression rescued the regulatory effect of miR-140 on the proliferation, apoptosis and inflammatory cytokine production of RA FLSs. Therefore, the current findings indicated that miR-140 is a crucial modulator of both proliferation and apoptosis, shedding light on the etiology behind RA FLS viability, which is modulated by an interplay between miR-140 and STAT3 in the context of RA.

Microneedles for painless transdermal immunotherapeutic applications

Immunotherapy has recently garnered plenty of attention to improve the clinical outcomes in the treatment of various diseases. However, owing to the dynamic nature of the immune system, this approach has often been challenged by concerns regarding the lack of adequate long-term responses in patients. The development of microneedles (MNs) has resulted in the improvement and expansion of immuno-reprogramming strategies due to the housing of high accumulation of dendritic cells, macrophages, lymphocytes, and mast cells in the dermis layer of the skin. In addition, MNs possess many outstanding properties, such as the ability for the painless traverse of the stratum corneum, minimal invasiveness, facile fabrication, excellent biocompatibility, convenient administration, and bypassing the first pass metabolism that allows direct translocation of therapeutics into the systematic circulation. These advantages make MNs excellent candidates for the delivery of immunological biomolecules to the dermal antigen-presenting cells in the skin with the aim of vaccinating or treating different diseases, such as cancer and autoimmune disorders, with minimal invasiveness and side effects. This review discusses the recent advances in engineered MNs and tackles limitations relevant to traditional immunotherapy of various hard-to-treat diseases.

Autoantigen-specific immune tolerance in pathological and physiological cell death: Nanotechnology comes into view

Apoptotic cells are tolerogenic and can present self-antigens in the absence of inflammation, to antigen-presenting cells by the process of efferocytosis, resulting in anergy and depletion of immune effector cells. This tolerance is essential to maintain immune homeostasis and prevent systemic autoimmune diseases, such as rheumatoid arthritis and systemic lupus erythematosus. Consequently, effective efferocytosis can result in the induction of immune tolerance mediated via triggering modulatory lymphocytes and anti-inflammatory responses. Furthermore, several distinct soluble factors, receptors and pathways have been found to be involved in the efferocytosis, which are able to regulate immune tolerance by lessening antigen presentation, inhibition of T-cell proliferation and induction of regulatory T-cells. Some newly developed nanotechnology-based approaches can induce antigen-specific immunological tolerance without any systemic immunosuppression. These strategies have been explored to reverse autoimmune responses induced against various protein antigens in different diseases. In this review, we describe some nanotechnology-based approaches for the maintenance of self-tolerance using the apoptotic cell clearance process (efferocytosis) that may be able to induce immune tolerance and treat autoimmune diseases.

New Insight of Circular RNAs in Human Musculoskeletal Diseases

Circular RNAs (circRNAs), a novel group of noncoding RNAs, are present in most eukaryotic cells. Different from messenger RNAs, circRNAs have a covalently closed single-stranded stable structure and often act in cell type and tissue-specific manners, indicating that they can be used as biomarkers. With the advance of high-throughput RNA sequencing technology and bioinformatics, a large number of circRNAs have been identified in association with musculoskeletal diseases, but the functions of most circRNAs have not been clarified. circRNAs regulate biological processes by adsorbing microRNA as "sponges," binding to proteins, acting as transcriptional regulators, and participating in translation of proteins. In this study, we discuss the latest understanding of biogenesis and gene regulatory mechanisms of circRNAs with special emphasis on new targets for musculoskeletal disease diagnosis and clinical treatment.

The Structural Basis for Nonsteroidal Anti-Inflammatory Drug Inhibition of Human Dihydrofolate Reductase

Although nonsteroidal anti-inflammatory drugs (NSAIDs) target primarily cyclooxygenase enzymes, a subset of NSAIDs containing carboxylate groups also has been reported to competitively inhibit dihydrofolate reductase (DHFR). In this study, we have characterized NSAID interactions with human DHFR based on kinetic, NMR, and X-ray crystallographic methods. The NSAIDs target a region of the folate binding site that interacts with the p-aminobenzoyl-l-glutamate (pABG) moiety of folate and inhibit cooperatively with ligands that target the adjacent pteridine-recognition subsite. NSAIDs containing benzoate or salicylate groups were identified as having the highest potency. Among those tested, diflunisal, a salicylate derivative not previously identified to have anti-folate activity, was found to have a K_i of 34 μM, well below peak plasma diflunisal levels reached at typical dosage levels. The potential of these drugs to interfere with the inflammatory process by multiple pathways introduces the possibility of further optimization to design dual-targeted analogs.

Chloroquine as a promising adjuvant therapy for type 1 Diabetes Mellitus

Chloroquine (CQ) and hydroxychloroquine, are promising anti-inflammatory drugs for the treatment of Diabetes mellitus (DM) to prevent associated complications. Therefore, this study evaluated the anti-inflammatory effects of CQ-free and CQ-incorporated polylactic acid nanoparticles (NPs) in the peripheral blood mononuclear cells (PBMCs) of patients with type 1 Diabetes mellitus (T1DM). In total, 25 normoglycemic individuals and 25 patients with T1DM aged 10-16 years were selected and glycemic controls evaluated. After cell viability assessed by MTT assay, T1DM PBMCs were subjected to a CQ concentration of 10 µM in three different conditions: not treated (NT), treated with CQ, and treated with CQ NPs. The cells were incubated for 48 h, and the mRNA expressions of cytokines IL1B, IFNG, TNFA, IL12, and IL10 were determined by relative quantification through real-time PCR at 24 h intervals. IL1B expression decreased in CQ and CQ NP-treated cells after 48 h (p < 0.001) and 24 h (p < 0.05) of treatment, respectively. IFNG and IL12 expressions significantly decreased (p < 0.001) in cells treated with CQ and CQ NPs at 24 and 48 h compared to NT. TNFA and IL10 expressions significantly decreased after 48 h (p < 0.001) and 24 h (p < 0.002), respectively, by both CQ and CQ NPs treatment. Despite being a preliminary in vitro study, CQ has anti-inflammatory activity in the primary cells of T1DM patients and could represent an alternative and adjuvant anti-inflammatory therapy to prevent diabetes complications.

A review of ocular adverse events of biological anti-TNF drugs

The recent introduction of biological agents has revolutionized the treatment of chronic immune-inflammatory diseases; however, this new therapy did not come without significant side effects.Through large controlled studies indicating decrease in the number of uveitis flares, the role of TNF inhibitors therapy for non-infectious uveitis gained more ground. Paradoxically to its therapeutic effect, there are reports associating these drugs with the onset or recurrence of inflammatory eye disease.A number of studies have suggested possible roles for anti-TNF-α agents in precipitating or worsening an underlying inflammatory process, including the hypothesis of a disequilibrium in cytokine balance, but to date the mechanisms responsible for these adverse events are not fully understood.A PubMed literature search was performed using the following terms: ophthalmic complication, uveitis, inflammatory eye disease, optic neuritis, neuropathy, adverse events, anti-TNF, TNF alpha inhibitor, infliximab, etanercept, adalimumab, golimumab, certolizumab, and biologics. The data presented in this study was mainly derived from the use of TNF inhibitors in rheumatology, essentially because these drugs have been used for a longer period in this medical field.Many of the ocular adverse events reported on this review may be considered a paradoxical effect of anti-TNF therapy. We found a variety of data associating new onset of uveitis with anti-TNF therapy for rheumatic conditions, predominantly under etanercept.In conclusion, although there is increasing data on ocular adverse events, it remains to be seen whether the suggested link between TNF inhibitors and the onset of ocular inflammation is substantiated by more quality data. Nevertheless, the awareness of potential treatment side effects with anti-TNF should be highlighted.

Infection risk in patients undergoing treatment for inflammatory arthritis: non-biologics versus biologics

Introduction: Despite the therapeutic effectiveness of biologics targeting immune cells or cytokines in patients with inflammatory arthritis, which reflects their pathogenic roles, an increased infection risk is observed in those undergoing biological treatment. However, there are limited data regarding the comparison of infection risks in inflammatory arthritis patients treated with non-biologics (csDMARDs), biologics (bDMARDs), including tumor necrosis factor (TNF) inhibitors and non-TNF inhibitors, or targeted synthetic (ts)DMARDs.Areas covered: Through a review of English-language literature as of 30 June 2019, we focus on the existing evidence on the risk of infections caused by bacteria, Mycobacterium tuberculosis, and hepatitis virus in inflammatory arthritis patients undergoing treatment with csDMARDs, bDMARDs, or tsDMARDs.Expert opinion: While the risks of bacterial and mycobacterial infection are increased in arthritis patients treated with csDMARDs, the risks are further higher in those receiving bDMARDs therapy, particularly TNF inhibitors. Regarding HBV infection, antiviral therapy may effectively prevent HBV reactivation in patients receiving bDMARDs, especially rituximab. However, more data are needed to establish effective preventive strategies for HBsAg-negative/HBcAb-positive patients. It seems safe to use cyclosporine and TNF inhibitors in patients with HCV infection, while those undergoing rituximab therapies should be frequently monitored for HCV activity.Abbreviations: ABT: abatacept; ADA: adalimumab; AS: ankylosing spondylitis; bDMARDs: biologic disease-modifying anti-rheumatic drugs; CKD: chronic kidney disease; COPD: chronic obstructive pulmonary disease; CS: corticosteroids; CsA: cyclosporine A; csDMARDs: conventional synthetic disease-modifying anti-rheumatic drugs; CZP: certolizumab; DAAs: direct-acting antiviral agents; DM: diabetes mellitus; DOT: directly observed therapy; EIN: Emerging Infections Network; ETN: etanercept; GOL: golimumab; GPRD: General Practice Research Database; HBV: hepatitis B virus; HBVr: HBV reactivation; HBsAg+: HBsAg-positive; HBsAg-/anti-HBc+: HBsAg-negative anti-HBc antibodies-positive; HCV: hepatitis C virus; HCQ: hydroxychloroquine: IFX: infliximab; IL-6: interleukin-6; JAK: Janus kinase; LEF: leflunomide; LTBI: latent tuberculosis infection; mAb: monoclonal antibody; MTX: methotrexate; OR: odds ratio; PsA: psoriatic arthritis; PMS: post-marketing surveillance; RA: rheumatoid arthritis; TNF: tumor necrosis factor; TNFi: tumor necrosis factor inhibitor; SCK: secukinumab; SSZ: sulfasalazine; TOZ: tocilizumab; RCT: randomized controlled trial; RR: relative risk; RTX: rituximab; 3HP: 3-month once-weekly isoniazid plus rifapentine; TB: tuberculosis; tsDMARDs: targeted synthetic disease-modifying anti-rheumatic drugs; UTK: ustekinumab; WHO: World Health Organization.

Long Non-coding RNA HIX003209 Promotes Inflammation by Sponging miR-6089 via TLR4/NF-κB Signaling Pathway in Rheumatoid Arthritis

Accumulating studies have suggested that long non-coding RNAs (lncRNAs) have drawn more and more attention in rheumatoid arthritis (RA), which can function as competitive endogenous RNAs (ceRNAs) in inflammation and immune disorders. Previously, we have found that lncRNA HIX003209 is differentially expressed in RA. However, the precise mechanism of lncRNA HIX003209 in RA is still vague. We aim to elucidate the role and its targeted microRNA of lncRNA HIX003209 in RA as ceRNA. Significantly increased expression of lncRNA HIX003209 was observed in the peripheral blood mononuclear cells (PBMCs) from RA cases. It was positively associated with TLR2 and TLR4 in RA. Besides, peptidoglycan (PGN) and lipopolysaccharide (LPS) could enhance the expression of lncRNA HIX003209, which reversely promoted the proliferation and activation of macrophages through IκBα/NF-κB signaling pathway. Moreover, HIX003209 was involved in TLR4-mediated inflammation via targeting miR-6089 in macrophages. LncRNA HIX003209 functions as a ceRNA and exaggerates inflammation by sponging miR-6089 through TLR4/NF-κB pathway in macrophages, which offers promising therapeutic strategies for RA.

miR-138 activates NF-κB signaling and PGRN to promote rheumatoid arthritis via regulating HDAC4

BACKGROUND

Rheumatoid arthritis (RA) is a common immune-related disease worldwide, which is characterized by impaired fibroblast-like synoviocytes (FLS) proliferation and increased release of inflammatory cytokines. Unfortunately, the detailed mechanism by which miR-138-modulated rheumatoid arthritis has not been fully understood.

METHODS

RT-qPCR was used to examined mRNA level of various genes and western blot was utilized to probe protein level of acetylated H3, p-p62 and IκBα. For cytokines detection, we used ELISA method to measure the extracellular level of these cytokines. Bioinformatic tool and dual-luciferase reporter assay were employed to predict and confirm the downstream target of miR-138.

RESULTS

miR-138 was upregulated in serum and synovial tissues of RA patients. Moreover, Increased miR-138 was observed in LPS-treated FLS cells. HDAC4 was shown as the direct target of miR-138 and could be negatively regulated by miR-138. miR-138 and HDAC4 were involved in RA-related inflammatory cytokines release of FLS cells. Next, we revealed NF-κB and PGRN were significantly modulated by HDAC4 and miR-138 in an acetylation-dependent manner. More importantly, IκBα depletion and PGRN overexpression had the ability to rescue miR-138 inhibitor-attenuated inflammatory cytokines release of FLS cells.

CONCLUSION

Here, we reveal miR-138 regulates RA-related inflammatory cytokines in rheumatoid arthritis through HDAC4/PGRN or HDAC4/NF-κB. Our findings uncover a new molecular mechanism implicated in rheumatoid arthritis, which may accelerate development of therapeutical strategy by targeting this mechanism.

Imported visceral leishmaniasis and immunosuppression in seven Norwegian patients

Background

Visceral leishmaniasis (VL) is a protozoal disease that may be aggravated by immunosuppression. In recent years, a growing number of patients with chronic diseases use biological treatment. When such immunosuppressed patients travel to endemic areas, they are facing the risk of VL. Increased incidence of leishmaniasis is reported in endemic areas like the Mediterranean basin, an area frequently visited by Norwegian tourists. This may lead to an increased number of patients, many presenting to health personnel unfamiliar with the disease, in their home countries.

Methods

We reviewed the files of seven immunosuppressed patients with VL, admitted to Oslo and Haukeland University Hospitals in Norway in the period 2009-2018.

Results

The patients were 41-83 (median 66) years of age; four had rheumatic disease all of whom used methotrexate; one had advanced HIV infection, one had inflammatory bowel disease and one had myelofibrosis. Leishmania infantum was confirmed in five patients by polymerase chain reaction (PCR) and sequencing. In the remaining two patients, a definite Leishmania species could not be identified. All patients had a history of recent recreational travel to Spain. Most patients underwent extensive diagnostic work-up before diagnosed with VL. All received treatment with liposomal amphotericin B and all were cured; albeit two after re-treatment due to relapse.

Conclusions

Visceral leishmaniasis is a potentially life-threatening but usually treatable condition. It is endemic in Southern Europe, including popular tourist destinations such as the Mediterranean basin. It is relatively unknown to most medical practitioners in non-endemic areas and clinical vigilance is required to identify those who are infected.

Risk of tuberculosis reactivation associated with traditional disease modifying anti-rheumatic drugs and non-anti-tumor necrosis factor biologics in patients with rheumatic disorders and suggestion for clinical practice

INTRODUCTION

Two classes of biologics, anti-tumor necrosis factor (TNF) and non-anti-TNF targeted, are currently available for the treatment of rheumatic diseases.

AREAS COVERED

Discussion on the need for LTBI diagnosis in rheumatic patients treated csDMARDs and non-anti-TNFs through a review of the literature. The literature, updated to 15 April 2019, on tuberculosis (TB) reactivation risk in patients exposed to conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) and non-anti-TNF biologics was reviewed.

EXPERT OPINION

An increased risk of TB reactivation in patients receiving csDMARDs (except sulphasalazine) resulted, while a review of clinical trials, and Periodic Safety Update Reports from pharmaceutical Companies evidenced a very low or absent risk for non-anti-TNF biologics. Hence, a contradiction emerges considering that latent TB infection (LTBI) screening is recommended for non-anti-TNF candidates but not for csDMARDs. Concerning the low TB incidence countries, several actions could be undertaken, including to screen all patients independently on the treatment, to omit the procedure in non-anti-TNF candidates, or to perform the LTBI investigations only in high-risk patients. According to WHO guidelines, LTBI screening in low TB risk countries seems unnecessary, except in high TB risk subjects.

MiRNA-506 inhibits rheumatoid arthritis fibroblast-like synoviocytes proliferation and induces apoptosis by targetting TLR4

Fibroblast-like synoviocytes (FLSs) play a crucial role in rheumatoid arthritis (RA) pathogenesis. While miRNA (miR)-506 has been implicated in the progression of multiple diseases, its role in RA remains to be explored. The present study evaluated the function of miR-506 in the regulation of RA-FLSs. FLSs were prepared from RA and healthy synovial tissues. The expression of miR-506 was measured by quantitative real time PCR (qRT-PCR). The effects of miR-506 on RA-FLSs proliferation and apoptosis were detected by cell counting Kit-8 and flow cytometry assays, respectively. The determination of TNF-α, IL-6, and IL-1β concentrations in RA-FLSs supernatant were done by ELISA. The levels of miR-506 were detected to be significantly lower in the synovial tissues and FLSs of RA than in the synovial tissues and FLSs of healthy controls. The miR-506 up-regulation in RA-FLSs significantly inhibited the proliferation and promoted cell cycle arrest at the G₀/G₁ phase. The overexpression of miR-506 induced apoptosis, along with an increase in activities of caspase-3 and -8. A target gene Toll-like receptor 4 (TLR4) under the direct regulation of miR-506 was identified through the luciferase assay, qRT-PCR and western blot analysis. Forced overexpression of TLR4 in the rescue experiments showed that TLR4 effectively reversed the effect on proliferation and apoptosis in miR-506-overexpressing RA-FLSs. Thus, miR-506 may be a potential target for RA prevention and therapy of RA.

Pectolinarin inhibits proliferation, induces apoptosis, and suppresses inflammation in rheumatoid arthritis fibroblast-like synoviocytes by inactivating the phosphatidylinositol 3 kinase/protein kinase B pathway

Rheumatoid arthritis fibroblast-like synoviocytes (RA-FLSs), a pathological hallmark of rheumatoid arthritis (RA), exhibit the characteristics of tumor cells. The extracts of Cirsium japonicum var. ussuriense have been shown to possess antitumor and anti-inflammatory activities. Our study aimed to investigate the effects of pectolinarin, a flavonoid compound isolated from C. japonicum var. ussuriense, on RA. Cell viability was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide assay. Apoptosis was determined by flow cytometry analysis and Western blot analysis of Bax and Bcl-2 levels. Inflammation was assessed by detecting the expressions and secretion of interleukin (IL)-6 and IL-8 using quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. The production of nitric oxide (NO) and prostaglandin E2 (PGE2) was also measured. The effects of pectolinarin on the phosphatidylinositol 3 kinase (PI3K)/protein kinase B (Akt) pathway were examined by Western blot. We found that pectolinarin significantly inhibited cell viability at 24 and 48 hours in a dose-dependently manner in RA-FLSs. Pectolinarin reduced the apoptotic rate, increased Bax level, and decreased Bcl-2 level in RA-FLSs. Pectolinarin inhibited the messenger RNA expression and secretion of IL-6 and IL-8, as well as the production of PGE2 and NO in RA-FLSs. Furthermore, pectolinarin inactivated the phosphatidylinositol 3 kinase/protein kinase B (PI3K/Akt) pathway in RA-FLSs. Activation of the PI3K/Akt pathway by 740Y-P impaired the effects of pectolinarin on cell viability, apoptosis, and inflammation in RA-FLSs. In conclusion, pectolinarin suppressed cell proliferation and inflammatory response and induced apoptosis in RA-FLSs via inactivation of the PI3K/Akt pathway.

MiR-3926 inhibits synovial fibroblasts proliferation and inflammatory cytokines secretion through targeting toll like receptor 5

Rheumatoid arthritis synovial fibroblasts (RASFs) play a key role in the pathogenesis of rheumatoid arthritis (RA). This study was aimed to investigate the effects of miR-3926 on the biological activities of RASFs. The results showed that miR-3926 was significantly down-regulated in RASFs and RA synovial tissue. Overexpression of miR-3926 significantly inhibited RASFs proliferation and decreased the secretion of inflammatory cytokines including TNF-α, IL-1β and IL-6 in RASFs. TLR5 was identified to be a direct target of miR-3926. TLR5 showed an opposite expression trends with miR-3926 in RASFs and RA synovial tissue. Overexpression of miR-3926 led to a reduction of endogenous TLR5 in RASFs, whereas down-regulation of miR-3926 increased TLR5 expression. Knocking down of TLR5 significantly inhibited RASFs proliferation and inflammatory cytokines secretion. Rescue experiments with a miR-3926-resistant variant of TLR5 showed that overexpression of TLR5 restored RASFs proliferation and inflammatory cytokines secretion in miR-3926-overexpressing RASFs. In conclusion, miR-3926 is downregulated in RA synovial tissues and its overexpression caused the inhibitory effects on RASF proliferation and inflammatory cytokines secretion by targeting TLR5. The miR-3926/TLR5 pathway may represent a novel target for prevention and treatment of RA.

Astragalus polysaccharides inhibits cell growth and pro-inflammatory response in IL-1β-stimulated fibroblast-like synoviocytes by enhancement of autophagy via PI3K/AKT/mTOR inhibition

The hyperplastic growth of rheumatoid arthritis (RA) fibroblast-like synoviocytes (FLSs) and inflammatory response are pathological hallmarks of RA. It has been reported that Astragalus polysaccharides (APS) possess appreciable anti-inflammatory activity against adjuvant-induced arthritis. Nevertheless, little is known about the role and detailed mechanism underlying the therapeutic effects of APS in RA. This study demonstrated that administration of APS dose-dependently impaired cell viability, increased cell apoptosis by decreasing Bcl-2 expression, increasing Bax expression and Caspase3 activity in IL-1β-stimulated RSC-364 cells and RA-FLS. Simultaneously, IL-1β-induced production of pro-inflammatory cytokines IL-6 and TNF-α was significantly decreased after APS treatment. Furthermore, preconditioning with APS dramatically enhanced autophagy activity by increasing Beclin-1 and LC3II/LC3I expression coupled with decreasing p62 expression and augmenting the number of LC3 puncta in IL-1β-stimulated RSC-364 cells. More importantly, autophagy inhibitor 3-methyladenine (3-MA) partly abolished APS-triggered inhibitory effects on cell growth and production of pro-inflammatory cytokines. APS also repressed the activation of PI3K/Akt/mTOR signaling pathway in IL-1β-stimulated RSC-364 cells. Moreover, treatment with insulin-like growth factor-1 (IGF-1), an activator of PI3K/Akt signaling, partly reversed the therapeutic effects of APS in IL-1β-stimulated RSC-364 cells. Collectively, we concluded that APS might attenuate the pathological progression of RA by exerting the pro-apoptotic and anti-inflammatory effects in IL-1β-stimulated FLSs by regulating the PI3K/AKT/mTOR-autophagy pathway.

The neurosurgical wound and factors that can affect cosmetic, functional, and neurological outcomes

Surgically accessing pathological lesions located within the central nervous system (CNS) frequently requires creating an incision in cosmetic regions of the head and neck. The biggest factors of surgical success typically tend to focus on the middle portion of the surgery, but a vast majority of surgical complications tend to happen towards the end of a case, during closure of the surgical site incisions. One of the most difficult complications for a surgeon to deal with is having to take a patient back to the operating room for wound breakdowns and, even worse, wound or CNS infections, which can negate all the positive outcomes from the surgery itself. In this paper, we discuss the underlying anatomy, pharmacological considerations, surgical techniques and nutritional needs necessary to help facilitate appropriate wound healing. A successful surgery begins with preoperative planning regarding the placement of the surgical incision, being cognizant of cosmetics, and the effects of possible adjuvant radiation therapy on healing incisions. We need to assess patient's medications and past medical history to make sure we can optimise conditions for proper wound reepithelialisation, such as minimizing the amount of steroids and certain antibiotics. Contrary to harmful medications, it is imperative to optimise nutritional intake with adequate supplementation and vitamin intake. The goals of this paper are to reinforce the mechanisms by which surgical wounds can fail, leading to postoperative complications, and to provide surgeons with the reminder and techniques that can help foster a more successful surgical outcome.

Non-classical monocytes as mediators of tissue destruction in arthritis

Objectives

Bone destruction in rheumatoid arthritis is mediated by osteoclasts (OC), which are derived from precursor cells of the myeloid lineage. The role of the two monocyte subsets, classical monocytes (expressing CD115, Ly6C and CCR2) and non-classical monocytes (which are CD115 positive, but low in Ly6C and CCR2), in serving as precursors for OC in arthritis is still elusive.

Methods

We investigated CCR2^−/− mice, which lack circulating classical monocytes, crossed into hTNFtg mice for the extent of joint damage. We analysed monocyte subsets in hTNFtg and K/BxN serum transfer arthritis by flow cytometry. We sorted monocyte subsets and analysed their potential to differentiate into OC and their transcriptional response in response to RANKL by RNA sequencing. With these data, we performed a gene ontology enrichment analysis and gene set enrichment analysis.

Results

We show that in hTNFtg arthritis local bone erosion and OC generation are even enhanced in the absence of CCR2. We further show the numbers of non-classical monocytes in blood are elevated and are significantly correlated with histological signs of joint destruction. Sorted non-classical monocytes display an increased capacity to differentiate into OCs. This is associated with an increased expression of signal transduction components of RANK, most importantly TRAF6, leading to an increased responsiveness to RANKL.

Conclusion

Therefore, non-classical monocytes are pivotal cells in arthritis tissue damage and a possible target for therapeutically intervention for the prevention of inflammatory joint damage.

Projected Burden of Osteoarthritis and Rheumatoid Arthritis in Australia: A Population-Level Analysis

OBJECTIVE

To forecast the prevalence and direct health care costs of osteoarthritis (OA) and rheumatoid arthritis (RA) in Australia to the year 2030.

METHODS

An epidemiologic model of the Australian population was developed. Data on the national prevalence of OA and RA were obtained from the Australian Bureau of Statistics (ABS) 2014-2015 National Health Survey. Future prevalence was estimated using ABS population projections for 2020, 2025, and 2030. Available government data on direct health care expenditure for OA and RA were modeled to forecast costs (in Australian $) for the years 2020, 2025, and 2030, from the perspective of the Australian public health care system.

RESULTS

The number of people with OA is expected to increase nationally from almost 2.2 million in 2015 to almost 3.1 million Australians in 2030. The number of people with RA is projected to increase from 422,309 in 2015 to 579,915 in 2030. Health care costs for OA were estimated to be over $2.1 billion in 2015; by the year 2030, these are forecast to exceed $2.9 billion ($970 for every person with the condition). Health care costs for RA were estimated to be over $550 million in 2015, including $273 million spent on biologic disease-modifying antirheumatic drugs. Health care costs for RA are projected to rise to over $755 million by the year 2030.

CONCLUSION

OA and RA are costly conditions that will impose an increasing health care burden at the population level. These projections provide tangible data that can be used to map future health service provision to expected need.

Antigen-Specific Tolerization and Targeted Delivery as Therapeutic Strategies for Autoimmune Diseases

The prevalence of autoimmune disorders is increasing steadily and there is no permanent cure available. Immunomodulation through repeated exposure of antigens, known as antigen-specific immune tolerance or antigen-specific immunotherapy (ASI), is a promising approach to treat or prevent autoimmune disorders. Different optimization protocols (immunization routes, delivery systems, and approaches) are being developed to implement ASI against self-proteins. Including appropriate adjuvants, altered peptide ligand, and using multipeptides are approaches that can be used to specifically target autoimmunity. This review explores various ASI application methods, including different routes of antigen-specific sensitization, delivery systems, immunomodulators containing specific antigens, and other targeted approaches that have been successfully demonstrated to have therapeutic effects on autoimmune diseases.

Current status of lupus nephritis

Systemic lupus erythematosus (SLE) is a systemic disease of unknown aetiology with variable course and prognosis. Lupus nephritis (LN) is one of the important disease manifestations of SLE with considerable influence on patient outcomes. Immunosuppression therapy has made it possible to control the disease with improved life expectancy and quality of life. In the last few decades, various studies across the globe have clarified the role, dose and duration of immunosuppression currently in use and also provided evidence for new agents such as mycophenolate mofetil, calcineurin inhibitors and rituximab. However, there is still a need to develop new and specific therapy with less adverse effects. In this review, the current evidence of the treatment of LN and its evolution, and new classification criteria for SLE have been discussed. Also, rationale for low-dose intravenous cyclophosphamide as induction agent followed by azathioprine as maintenance agent has been provided with emphasis on individualized and holistic approach.