Emerging Concepts and Challenges in Rheumatoid Arthritis Gene Therapy

Therapeutic delivery systems for rheumatoid arthritis based on hydrogel carriers

Rheumatoid arthritis (RA) is an autoimmune disease suffered by millions of people worldwide. It can significantly affect the patient's quality of life by damaging not only the joints but also organs such as the lungs and the heart. RA is normally treated using nonsteroidal anti-inflammatory drugs (NSAIDs), glucocorticoids, disease-modifying antirheumatic drugs (DMARDs), and biologics. These active agents often cause side effects and offer low efficacy due to their lack of specificity and limited retention time. In an attempt to improve RA treatments, hydrogel-based systems have been proposed as drug delivery carriers. Due to their exceptional adaptability and biocompatibility, hydrogels have the potential of enhancing the delivery of RA therapy through different administration routes in an efficient and effective manner. In this review, we explore the application of hydrogel systems as potential carriers in RA treatment. Additionally, we discuss recent work in the field and highlight the required hydrogel properties, depending on the administration route. The outstanding potential of hydrogel systems as carriers for RA was demonstrated; however, there is extensive research yet to be done to improve available treatments for RA.

The Role of MicroRNA in Graft-Versus-Host-Disease: A Review

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a clinically challenging modality for the treatment of many hematologic diseases such as leukemia, lymphoma, and myeloma. Graft-versus-host disease (GVHD) is a common complication after allo-HSCT and remains a major cause of morbidity and mortality, limiting the success of a potentially curative transplant. Several microRNAs (miRNAs) have recently been shown to impact the biology of GVHD. They are molecular regulators involved in numerous processes during T-cell development, homeostasis, and activation, and contribute to the pathological function of T-cells during GvHD. Here, we review the key role of miRNAs contributing to the GvHD; their detection might be an interesting possibility in the early diagnosis and monitoring of disease.

Role of miRNAs in Rheumatoid Arthritis Therapy

Rheumatoid arthritis (RA) is a chronic systemic inflammatory disease characterized by autoimmunity, synovial inflammation and joint destruction. Pannus formation in the synovial cavity can cause irreversible damage to the joint and cartilage and eventually permanent disability. Current conventional treatments for RA have limitations regarding efficacy, safety and cost. microRNA (miRNA) is a type of non-coding RNA (ncRNA) that regulates gene expression at the post-transcriptional level. The dysregulation of miRNA has been observed in RA patients and implicated in the pathogenesis of RA. miRNAs have emerged as potential biomarkers or therapeutic agents. In this review, we explore the role of miRNAs in various aspects of RA pathophysiology, including immune cell imbalance, the proliferation and invasion of fibroblast-like synovial (FLS) cell, the dysregulation of inflammatory signaling and disturbance in angiogenesis. We delve into the regulatory effects of miRNAs on Treg/Th17 and M1/M2 polarization, the activation of the NF-κB/NLRP3 signaling pathway, neovascular formation, energy metabolism induced by FLS-cell-induced energy metabolism, apoptosis, osteogenesis and mobility. These findings shed light on the potential applications of miRNAs as diagnostic or therapeutic biomarkers for RA management. Furthermore, there are some strategies to regulate miRNA expression levels by utilizing miRNA mimics or exosomes and to hinder miRNA activity via competitive endogenous RNA (ceRNA) network-based antagonists. We conclude that miRNAs offer a promising avenue for RA therapy with unlimited potential.

Research Advances in Nucleic Acid Delivery System for Rheumatoid Arthritis Therapy

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease that affects the lives of nearly 1% of the total population worldwide. With the understanding of RA, more and more therapeutic drugs have been developed. However, lots of them possess severe side effects, and gene therapy may be a potential method for RA treatment. A nanoparticle delivery system is vital for gene therapy, as it can keep the nucleic acids stable and enhance the efficiency of transfection in vivo. With the development of materials science, pharmaceutics and pathology, more novel nanomaterials and intelligent strategies are applied to better and safer gene therapy for RA. In this review, we first summarized the existing nanomaterials and active targeting ligands used for RA gene therapy. Then, we introduced various gene delivery systems for RA treatment, which may enlighten the relevant research in the future.

MiR-30e-5p deficiency exerts an inhibitory effect on inflammation in rheumatoid arthritis via regulating Atl2 expression

OBJECTIVES

This study aims to investigate the inflammatory effect of the microRNA (miRNA) miR-30e-5p on rheumatoid arthritis (RA) development in RA mice and fibroblast-like synoviocytes (FLS).

MATERIALS AND METHODS

MiR-30e-5p and atlastin GTPase 2 (Atl2) expression in RA tissues and RA-FLS was evaluated using real-time quantitative polymerase chain reaction. The function of miR-30e-5p in inflammation of RA mice and RA-FLS was analyzed by enzyme-linked immunosorbent assay (ELISA) and Western blotting. 5-ethynyl-2'-deoxyuridine (EdU) assay was used to detect RA-FLS proliferation. Luciferase reporter assay was to confirm the interaction between miR-30e-5p and Atl2.

RESULTS

MiR-30e-5p expression was upregulated in the tissues from RA mice. Silencing miR-30e-5p alleviated inflammation in RA mice and RA-FLS. MiR-30e-5p negatively modulated Atl2 expression. Atl2 knockdown exerted a proinflammatory effect on RA-FLS. Atl2 knockdown rescued the inhibitory effect of miR-30e-5p knockdown on proliferation and inflammatory response of RA-FLS.

CONCLUSION

MiR-30e-5p knockdown inhibited the inflammatory response in RA mice and RA-FLS through Atl2.

Rheumatoid arthritis: advances in treatment strategies

Rheumatoid arthritis (RA) is characterised by severe joint and bone damage due to heightened autoimmune response at the articular sites. Worldwide annual incidence and prevalence rate of RA is 3 cases per 10,000 population and 1%, respectively. Several genetic and environmental (microbiota, smoking, infectious agents) factors contribute to its pathogenesis. Although convention treatment strategies, predominantly Disease Modifying Anti Rheumatic Drugs (DMARDs) and Glucocorticoids (GC), are unchanged as the primary line of treatment; novel strategies consisting of biological DMARDs, are being developed and explored. Personalized approaches using biologicals targetspecific pathways associated with disease progression. However, considering the economic burden and side-effects associated with these, there is an unmet need on strategies for early stratification of the inadequate responders with cDMARDs. As RA is a complex disease with a variable remission rate, it is important not only to evaluate the current status of drugs in clinical practice but also those with the potential of personalised therapeutics. Here, we provide comprehensive data on the treatment strategies in RA, including studies exploring various combination strategies in clinical trials. Our systematic analysis of current literature found that conventional DMARDs along with glucocorticoid may be best suited for early RA cases and a combination of conventional and targeted DMARDs could be effective for treating seronegative patients with moderate to high RA activity. Clinical trials with insufficient responders to Methotrexate suggest that adding biologicals may help in such cases. However, certain adverse events associated with the current therapy advocate exploring novel therapeutic approaches such as gene therapy, mesenchymal stem cell therapy in future.

The effect of long non-coding RNAs in joint destruction of rheumatoid arthritis

Rheumatoid arthritis (RA) is a systemic autoimmune disease accompanied with joint destruction. Serious joint destruction will eventually lead to disability and the decline of life quality in RA patients. At present, the therapeutic effect of drugs to alleviate joint destruction in RA is limited. Recently, accumulating evidences have shown that long non-coding RNAs (lncRNAs) play an important role in the pathogenesis of joint diseases. Therefore, this paper reviews the expression change and the action mechanism of lncRNAs in joint destruction of RA in recent years. A more comprehensive understanding of the role of lncRNAs in joint destruction will help the treatment of RA.

AAV gene therapy vectors in the TMJ

OBJECTIVES

The goal of this project was to evaluate the use of two adeno-associated viral vector serotypes, adeno-associated viral vectors (AAV)-2 and AAV-6, approved for and used for gene therapy in humans, for the delivery of therapeutic genes to the temporomandibular joint (TMJ) and the attendant sensory nerves.

METHODS

Young adult wild-type C57BL/6 mice were intra-articularly inoculated with AAV-2 and AAV-6 encoding the reporter gene gfp, the expression of which was assessed in the TMJ as well as along nerves innervating the TMJ.

RESULTS

AAV-2 and AAV-6 serotypes were characterized by varying levels of tissue tropism demonstrating different efficacy of infection for articular chondrocytes, meniscal fibroblasts, and trigeminal neurons. Specifically, AAV-2 infected both neurons and articular chondrocytes/meniscal fibroblasts, whereas AAV-6 showed selectivity primarily for neurons.

CONCLUSIONS

The results of this study are clinically significant in the successful application of gene therapy vectors for TMJ disorders, as this new knowledge will allow for appropriate targeting of specific therapeutic genes to selective tissues (neurons vs. chondrocytes/fibroblasts) as needed by using specific viral vector serotypes.

Development of pH-sensitive dextran-based methotrexate nanodrug for rheumatoid arthritis therapy through inhibition of JAK-STAT pathways

Rheumatoid arthritis (RA) is a chronic and symmetrical autoimmune disease that primarily characterized with articular synovial hyperplasia, joint swelling, cartilage and bone destruction. The in-depth understanding of the role of immune signaling pathway inhibitors provides inspiration for the construction of new and more effective strategy for RA therapy. In this study, by loading methotrexate (MTX) into an acetalated dextran biopolymer, AcDEX, we developed a pH-sensitive, MTX-loaded and molecularly targeted nanodrug MTX@pH-AcDEX NPs) to decrease the toxicity of MTX and simultaneously enhance its therapeutic effect. The resultant MTX@pH-AcDEX NPs showed the spherical morphology and notable pH-responsiveness with high drug loading of 88.32%. As demonstrated in vitro and in vivo, the reduced cytotoxicity of both RAW264.7 cells and LPS-activated RAW264.7 cells treated with MTX@pH-AcDEX NPs was found compared to free MTX. Upon intravenous administration into adjuvant-induced arthritis (AIA) rat model, the nanodrug had potent pharmacokinetic and pharmacodynamic profiles, which can accumulate in RA lesions and release MTX inhibitors for regulating the JAK-STAT pathways. As a result, the MTX@pH-AcDEX NPs achieved the cartilage and bone protective and a better anti-inflammatory effect with negligible systemic toxicity, suggesting the strong potential of safe and effective nanodrug for RA therapy as well as other autoimmune diseases.

Current approaches in CRISPR-Cas9 mediated gene editing for biomedical and therapeutic applications

A single gene mutation can cause a number of human diseases that affect quality of life. Until the development of clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated protein (Cas) systems, it was challenging to correct a gene mutation to avoid disease by reverting phenotypes. The advent of CRISPR technology has changed the field of gene editing, given its simplicity and intrinsic programmability, surpassing the limitations of both zinc-finger nuclease and transcription activator-like effector nuclease and becoming the method of choice for therapeutic gene editing by overcoming the bottlenecks of conventional gene-editing techniques. Currently, there is no commercially available medicinal cure to correct a gene mutation that corrects and reverses the abnormality of a gene's function. Devising reprogramming strategies for faithful recapitulation of normal phenotypes is a crucial aspect for directing the reprogrammed cells toward clinical trials. The CRISPR-Cas9 system has been promising as a tool for correcting gene mutations in maladies including blood disorders and muscular degeneration as well as neurological, cardiovascular, renal, genetic, stem cell, and optical diseases. In this review, we highlight recent developments and utilization of the CRISPR-Cas9 system in correcting or generating gene mutations to create model organisms to develop deeper insights into diseases, rescue normal gene functionality, and curb the progression of a disease.

Functional Interactions Between lncRNAs/circRNAs and miRNAs: Insights Into Rheumatoid Arthritis

Rheumatoid arthritis (RA) is one of the most common autoimmune diseases that affect synovitis, bone, cartilage, and joint. RA leads to bone and cartilage damage and extra-articular disorders. However, the pathogenesis of RA is still unclear, and the lack of effective early diagnosis and treatment causes severe disability, and ultimately, early death. Accumulating evidence revealed that the regulatory network that includes long non-coding RNAs (lncRNAs)/circular RNAs (circRNAs), micro RNAs (miRNAs), and messenger RNAs (mRNA) plays important roles in regulating the pathological and physiological processes in RA. lncRNAs/circRNAs act as the miRNA sponge and competitively bind to miRNA to regulate the expression mRNA in synovial tissue, FLS, and PBMC, participate in the regulation of proliferation, apoptosis, invasion, and inflammatory response. Thereby providing new strategies for its diagnosis and treatment. In this review, we comprehensively summarized the regulatory mechanisms of lncRNA/circRNA-miRNA-mRNA network and the potential roles of non-coding RNAs as biomarkers and therapeutic targets for the diagnosis and treatment of RA.

MicroRNA-106b Overexpression Suppresses Synovial Inflammation and Alleviates Synovial Damage in Patients with Rheumatoid Arthritis

OBJECTIVES

To explore the effect of miR-106b on synovial inflammation and damage in rheumatoid arthritis (RA) patients, and further to investigate its possible mechanism.

METHODS

: Quantitative real-time polymerase chain reaction (qRT-PCR), immunofluorescence, in situ hybridization and immunohistochemistry assay were separately used to verify the levels of miR-106b and cytokines in the synovial tissues of patients with RA or osteoarthritis (OA). Pearson correlation analysis was conducted to examine the bivariate relationship between miR-106b and cytokines or RANKL. Following the isolation and culture of fibroblast-like synoviocytes (FLS), the cells were transfected with lentivirus-mediated miR-106b mimic, miR-106b inhibitor, and negative control miR-106b mimic, respectively. Thereafter, cell proliferation was measured by Cell Counting Kit-8 assay, and cell invasion and migration capacity was assessed by Transwell assay. Furthermore, concentration and expression of cytokines were separately detected by Enzyme linked immunosorbent assay and Western blot.

RESULTS

Compared with osteoarthritis, validation by qRT-PCR showed that RA patients had a lower level of miR-106b and higher levels of receptor activator of nuclear factor-κ B ligand (RANKL), tumor necrosis factor-a (TNF-a) and interleukin-6 (IL-6). Additionally, the scatter plot showed that the relative transcription of miR-106b level was negatively correlated to the level of TNF-a, IL-6, and RNKAL in the synovial tissues of both RA and OA patients (All P<0.05). Furthermore, miR-106b overexpression suppressed cell proliferation, migration and invasion capacity of human RA-FLS.

CONCLUSIONS

miR-106b overexpression suppresses synovial inflammation and alleviates synovial damage, thus it may be served as a potential therapeutic target for RA patients.

Biomedical nanobubbles and opportunities for microfluidics

The use of bulk nanobubbles in biomedicine is increasing in recent years, which is attributable to the array of therapeutic and diagnostic tools promised by developing bulk nanobubble technologies. From cancer drug delivery and ultrasound contrast enhancement to malaria detection and the diagnosis of acute donor tissue rejection, the potential applications of bulk nanobubbles are broad and diverse. Developing these technologies to the point of clinical use may significantly impact the quality of patient care. This review compiles and summarizes a representative collection of the current applications, fabrication techniques, and characterization methods of bulk nanobubbles in biomedicine. Current state-of-the-art generation methods are not designed to create nanobubbles of high concentration and low polydispersity, both characteristics of which are important for several bulk nanobubble applications. To date, microfluidics has not been widely considered as a tool for generating nanobubbles, even though the small-scale precision and real-time control offered by microfluidics may overcome the challenges mentioned above. We suggest possible uses of microfluidics for improving the quality of bulk nanobubble populations and propose ways of leveraging existing microfluidic technologies, such as organ-on-a-chip platforms, to expand the experimental toolbox of researchers working to develop biomedical nanobubbles.

The use of bulk nanobubbles in biomedicine is increasing in recent years. This translates into new opportunities for microfluidics, which may enable the generation of higher quality nanobubbles that lead to advances in diagnostics and therapeutics.

Therapeutic Approaches for the Management of Autoimmune Disorders via Gene Therapy: Prospects, Challenges, and Opportunities

BACKGROUND

Autoimmune diseases are the diseases that result due to the overactive immune response, and comprise systemic autoimmune diseases like rheumatoid arthritis (RA), sjӧgren's syndrome (SS), and organ-specific autoimmune diseases like type-1 diabetes mellitus (T1DM), myasthenia gravis (MG), and inflammatory bowel disease (IBD). Currently, there is no long-term cure; but, several treatments exist which retard the evolution of the disease, embracing gene therapy, which has been scrutinized to hold immense aptitude for the management of autoimmune diseases.

OBJECTIVE

The review highlights the pathogenic mechanisms and genes liable for the development of autoimmune diseases, namely T1DM, type-2 diabetes mellitus (T2DM), RA, SS, IBD, and MG. Furthermore, the review focuses on investigating the outcomes of delivering the corrective genes with their specific viral vectors in various animal models experiencing these diseases to determine the effectiveness of gene therapy.

METHODS

Numerous review and research articles emphasizing the tremendous potential of gene therapy in the management of autoimmune diseases were procured from PubMed, MEDLINE, Frontier, and other databases and thoroughly studied for writing this review article.

RESULTS

The various animal models that experienced treatment with gene therapy have displayed regulation in the levels of proinflammatory cytokines, infiltration of lymphocytes, manifestations associated with autoimmune diseases, and maintained equilibrium in the immune response, thereby hinder the progression of autoimmune diseases.

CONCLUSION

Gene therapy has revealed prodigious aptitude in the management of autoimmune diseases in various animal studies, but further investigation is essential to combat the limitations associated with it and before employing it on humans.

Recent Advances in Liposomal-Based Anti-Inflammatory Therapy

Liposomes can be seen as ideal carriers for anti-inflammatory drugs as their ability to (passively) target sites of inflammation and release their content to inflammatory target cells enables them to increase local efficacy with only limited systemic exposure and adverse effects. Nonetheless, few liposomal formulations seem to reach the clinic. The current review provides an overview of the more recent innovations in liposomal treatment of rheumatoid arthritis, psoriasis, vascular inflammation, and transplantation. Cutting edge developments include the liposomal delivery of gene and RNA therapeutics and the use of hybrid systems where several liposomal bilayer features, or several drugs, are combined in a single formulation. The majority of the articles reviewed here focus on preclinical animal studies where proof-of-principle of an improved efficacy-safety ratio is observed when using liposomal formulations. A few clinical studies are included as well, which brings us to a discussion about the challenges of clinical translation of liposomal nanomedicines in the field of inflammatory diseases.

Treatment of Rheumatoid Arthritis with Gene Therapy Applications: Biosafety and Bioethical Considerations

Rheumatoid Arthritis (RA) is an autoimmune and inflammatory disease that affects the synovium (lining that surrounds the joints), causing the immune system to attack its own healthy tissues. Treatment options, to the current day, have serious limitations and merely offer short-term alleviation to the pain. Using a theoretical exercise based on literature, a new potentially viable therapy has been proposed. The new therapy focusses on a long-term treatment of RA based on gene therapy, which is only active when inflammation of the joint occurs. This treatment will prevent side effects of systemic application of drugs. Furthermore, the benefits of this treatment for the patient from a socio-economic perspective has been discussed, focusing on the quality of life of the patent and lower costs for the society.

Next Step in Gene Delivery: Modern Approaches and Further Perspectives of AAV Tropism Modification

Today, adeno-associated virus (AAV) is an extremely popular choice for gene therapy delivery. The safety profile and simplicity of the genome organization are the decisive advantages which allow us to claim that AAV is currently among the most promising vectors. Several drugs based on AAV have been approved in the USA and Europe, but AAV serotypes’ unspecific tissue tropism is still a serious limitation. In recent decades, several techniques have been developed to overcome this barrier, such as the rational design, directed evolution and chemical conjugation of targeting molecules with a capsid. Today, all of the abovementioned approaches confer the possibility to produce AAV capsids with tailored tropism, but recent data indicate that a better understanding of AAV biology and the growth of structural data may theoretically constitute a rational approach to most effectively produce highly selective and targeted AAV capsids. However, while we are still far from this goal, other approaches are still in play, despite their drawbacks and limitations.

Characterization of Recombinant Adeno-Associated Viruses (rAAVs) for Gene Therapy Using Orthogonal Techniques

Viruses are increasingly used as vectors for delivery of genetic material for gene therapy and vaccine applications. Recombinant adeno-associated viruses (rAAVs) are a class of viral vector that is being investigated intensively in the development of gene therapies. To develop efficient rAAV therapies produced through controlled and economical manufacturing processes, multiple challenges need to be addressed starting from viral capsid design through identification of optimal process and formulation conditions to comprehensive quality control. Addressing these challenges requires fit-for-purpose analytics for extensive characterization of rAAV samples including measurements of capsid or particle titer, percentage of full rAAV particles, particle size, aggregate formation, thermal stability, genome release, and capsid charge, all of which may impact critical quality attributes of the final product. Importantly, there is a need for rapid analytical solutions not relying on the use of dedicated reagents and costly reference standards. In this study, we evaluate the capabilities of dynamic light scattering, multiangle dynamic light scattering, and SEC–MALS for analyses of rAAV5 samples in a broad range of viral concentrations (titers) at different levels of genome loading, sample heterogeneity, and sample conditions. The study shows that DLS and MADLS^® can be used to determine the size of full and empty rAAV5 (27 ± 0.3 and 33 ± 0.4 nm, respectively). A linear range for rAAV5 size and titer determination with MADLS was established to be 4.4 × 10¹¹–8.7 × 10¹³ cp/mL for the nominally full rAAV5 samples and 3.4 × 10¹¹–7 × 10¹³ cp/mL for the nominally empty rAAV5 samples with 3–8% and 10–37% CV for the full and empty rAAV5 samples, respectively. The structural stability and viral load release were also inferred from a combination of DLS, SEC–MALS, and DSC. The structural characteristics of the rAAV5 start to change from 40 °C onward, with increasing aggregation observed. With this study, we explored and demonstrated the applicability and value of orthogonal and complementary label-free technologies for enhanced serotype-independent characterization of key properties and stability profiles of rAAV5 samples.

Insights Into the Involvement of Circular RNAs in Autoimmune Diseases

Circular RNAs (circRNAs) are single-stranded, endogenous, non-coding RNA (ncRNA) molecules formed by the backsplicing of messenger RNA (mRNA) precursors and have covalently closed circular structures without 5′-end caps and 3′-end polyadenylation [poly(A)] tails. CircRNAs are characterized by abundant species, stable structures, conserved sequences, cell- or tissue-specific expression, and widespread and stable presence in many organisms. Therefore, circRNAs can be used as biomarkers for the prediction, diagnosis, and treatment of a variety of diseases. Autoimmune diseases (AIDs) are caused by defects in immune tolerance or abnormal immune regulation, which leads to damage to host organs. Due to the complexity of the pathophysiological processes of AIDs, clinical therapeutics have been suboptimal. The emergence of circRNAs sheds new light on the treatment of AIDs. In particular, circRNAs mainly participate in the occurrence and development of AIDs by sponging targets. This review systematically explains the formation, function, mechanism, and characteristics of circRNAs in the context of AIDs. With a deeper understanding of the pathophysiological functions of circRNAs in the pathogenesis of AIDs, circRNAs may become reasonable, accurate, and effective biomarkers for the diagnosis and treatment of AIDs in the future.

Long noncoding RNA ZFAS1 silencing alleviates rheumatoid arthritis via blocking miR-296-5p-mediated down-regulation of MMP-15

Rheumatoid arthritis (RA), a chronic inflammatory disease, deprives patients' walking ability and reduces their life quality worldwide. Though recent studies have indicated the role of long noncoding RNA (lncRNA) ZFAS1 in several diseases, however, its role in RA remains uncharacterized. The present study aimed to unravel the the effect of ZFAS1 on RA. Herein, the RA mouse model and the human RA synoviocyte MH7A cell lines stimulated with TNF-α were established. ZFAS1 was next determined to be highly expressed in the mice with RA-like symptoms and TNF-α-stimulated MH7A cells while inhibiting ZFAS1 was demonstrated to promote proliferation and suppress apoptosis of MH7A cells. Furthermore, ZFAS1 knockdown exerted anti-inflammation effect in vitro and in vivo and reduced the arthritis index value. Moreover, RNA immunoprecipitation and dual-luciferase reporter assays identified the binding of ZFAS1 to microRNA (miR)-296-5p as well as the binding of miR-296-5p to matrix metalloproteinase-15 (MMP-15). Of note, ZFAS1 could bind miR-296-5p to up-regulate the expression of MMP-15. Our results from in vitro and in vivo experiments demonstrated silencing ZFAS1 mitigated RA-like symptoms such as inflammation and hyperplasia via miR-296-5p-dependent inhibition of MMP-15. Taken altogether, our study confirmed that ZFAS1 involved in RA progression by competitively binding to miR-296-5p and regulating MMP-15 expression.

The Role of Chronic Inflammatory Bone and Joint Disorders in the Pathogenesis and Progression of Alzheimer's Disease

Late-onset Alzheimer's Disease (LOAD) is a devastating neurodegenerative disorder that causes significant cognitive debilitation in tens of millions of patients worldwide. Throughout disease progression, abnormal secretase activity results in the aberrant cleavage and subsequent aggregation of neurotoxic Aβ plaques in the cerebral extracellular space and hyperphosphorylation and destabilization of structural tau proteins surrounding neuronal microtubules. Both pathologies ultimately incite the propagation of a disease-associated subset of microglia-the principle immune cells of the brain-characterized by preferentially pro-inflammatory cytokine secretion and inhibited AD substrate uptake capacity, which further contribute to neuronal degeneration. For decades, chronic neuroinflammation has been identified as one of the cardinal pathophysiological driving features of AD; however, despite a number of works postulating the underlying mechanisms of inflammation-mediated neurodegeneration, its pathogenesis and relation to the inception of cognitive impairment remain obscure. Moreover, the limited clinical success of treatments targeting specific pathological features in the central nervous system (CNS) illustrates the need to investigate alternative, more holistic approaches for ameliorating AD outcomes. Accumulating evidence suggests significant interplay between peripheral immune activity and blood-brain barrier permeability, microglial activation and proliferation, and AD-related cognitive decline. In this work, we review a narrow but significant subset of chronic peripheral inflammatory conditions, describe how these pathologies are associated with the preponderance of neuroinflammation, and posit that we may exploit peripheral immune processes to design interventional, preventative therapies for LOAD. We then provide a comprehensive overview of notable treatment paradigms that have demonstrated considerable merit toward treating these disorders.

Role of signaling pathway in biological cause of Rheumatoid arthritis

Rheumatoid Arthritis is a chronic progressive inflammatory auto-immune disease in which the immune system of the body attacks its cartilage and joints lining. It not only affects synovial joints but also many other sites including heart, blood vessels, and skins. It is more common in females than in males. The exact cause of rheumatoid arthritis is not well established but the hypothesis reported in the literature is that in the development stage of the disease, both genetics and environmental factors can play an inciting role. Along with these factors alteration in the normal physiology of enzymatic action, acts as a trigger to develop this condition. Numerous signaling pathways involved in the pathogenesis of Rheumatoid Arthritis involves activation of mitogen-activated protein kinase, kinases Janus family, P-38 Mitogen-Activated Protein Kinase, Nuclear Factor-kappa B. Interleukin-1 to play a proinflammatory cytokine that plays an important role in inflammation in RA. These are also associated with an increase in neutrophil, macrophage and lymphocytic chemotaxis, mast cell degranulation, activation, maturation and survival of T-cells and B-cells activated. These signaling pathways also show that p38α downregulation in myeloid cells exacerbates the severity of symptoms of arthritis. Thus, present review carters about the detail of different signaling pathways and their role in rheumatoid arthritis.

Inhibitory role of long non-coding RNA OIP5-AS1 in rheumatoid arthritis progression through the microRNA-448-paraoxonase 1-toll-like receptor 3-nuclear factor κB axis

NEW FINDINGS

What is the central question of this study? What are the functions of long non-coding (lnc) RNA OIP5-AS1 in development of rheumatoid arthritis inflammation and what is the molecular mechanism? What is the main finding and its importance? LncRNA OIP5-AS1 mitigates rheumatoid arthritis progression through the competitive endogenous RNA network involving the miR-448-paraoxonase 1 axis and through the inactivation of the toll-like receptor 3-nuclear factor κB signalling pathway. This study may offer new ideas for molecularly based control of rheumatoid arthritis.

ABSTRACT

Rheumatoid arthritis (RA) is an autoimmune disorder with dysregulation of long non-coding RNAs (lncRNAs) possibly involved. This study aimed to inquire into the roles of lncRNA OIP5-AS1 in RA progression. A rat model of RA was induced. Overexpression of OIP5-AS1 was introduced in the model rats, and the changes in paw swelling, RA severity and the inflammatory factors interleukin (IL)-1β, IL-10, IL-6 and tumour necrosis factor α were measured. Fibroblast-like synoviocytes (FLSs) from RA patients were collected for in vitro experiments. A gain- and loss-of function study of OIP5-AS1, miR-448 and paraoxonase 1 (PON1) was performed to explore their roles in RA-FLS growth, apoptosis and inflammation. A toll-like receptor 3 (TLR3)-specific agonist, polyinosine-polycytidylic acid, or a nuclear factor κB (NF-κB)-specific antagonist, QNZ, was administrated in RA-FLSs. Consequently, overexpression of OIP5-AS1 reduced the symptom severity and the levels of inflammatory factors in RA rats. OIP5-AS1 could bind to miR-448 to up-regulate PON1 expression. Further overexpression of miR-448 reversed the effects of OIP5-AS1, while overexpression of PON1 inhibited RA-FLS growth and inflammation. In addition, TLR3 activation promoted RA progression. To conclude, this study evidenced that lncRNA OIP5-AS1 may mitigate RA progression through the miR-448-PON1 axis and through the inactivation of the TLR3-NF-κB signalling pathway.

lncRNA expression profiles related to apoptosis and autophagy in peripheral blood mononuclear cells of patients with rheumatoid arthritis

Long noncoding RNAs (lncRNAs) are >200-bp molecules that do not generally code for proteins. Human lncRNAs have well-characterized roles in gene expression regulation, particularly with regard to protein-coding genes, and their dysregulation has been linked to disease. Here, we set out to investigate changes in the expression of lncRNAs related to apoptosis and autophagy in the peripheral blood mononuclear cells (PBMCs) of rheumatoid arthritis (RA). In addition, we aimed to correlate lncRNA expression profiles with clinical indexes and self-perception of patients (SPP). To this end, we employed RNA sequencing of lncRNAs in PBMCs from three patients with RA and three healthy controls. We used bioinformatics to screen several dysregulated lncRNAs related to apoptosis and autophagy. To validate key lncRNA candidates, we performed quantitative reverse transcriptase-PCR on 20 patients with RA and 20 healthy controls. We found the expression of seven lncRNAs (MAPKAPK5-AS1, ENST00000619282, C5orf17, LINC01189, LINC01006, DSCR9 and MIR22HG) was significantly altered in PBMCs of patients with RA. Receiver operating characteristic curve analysis suggested that MIR22HG [area under the curve (AUC) = 0.846, P = 0.000], DSCR9 (AUC = 0.783, P = 0.005), LINC01189 (AUC = 0.677, P = 0.034), MAPKAPK5-AS1 (AUC = 0.644, P = 0.025) and ENST00000619282 (AUC = 0.636, P = 0.043) are potential biomarkers of RA. Spearman's correlation analysis revealed selected lncRNAs correlated with clinical indexes and SPP. Therefore, we highlight that some lncRNAs related to apoptosis and autophagy may serve as potential biomarkers for diagnosis and monitoring of RA progression, which also correlate with several clinical indexes and SPP.

Inhibiting role of long non-coding RNA LINC01197 in inflammation in rheumatoid arthritis through the microRNA-150/THBS2 axis

PURPOSE

Rheumatoid arthritis (RA) is a commonly diagnosed systemic autoimmune disease. Aberrant expression of long non-coding RNAs (lncRNAs) is closely linked to the development of RA. This study was conducted to explore the functions of the lncRNA LINC01197 in RA progression.

METHODS

Differentially expressed lncRNAs/microRNAs/mRNAs in patients with RA were analyzed using RNA microarrays. A mouse model with RA was established and RA-fibroblast-like synoviocytes (RA-FLS) were acquired for in vitro experiments. The function of LINC01197 in inflammation and RA progression in mice and its role in the viability of RA-FLS were determined by experiments involving its overexpression or suppression. The sub-cellular localization of LINC01197 was determined and the downstream molecules involved in LINC01197-mediated events were identified.

RESULTS

LINC01197 was poorly expressed in the synovial tissues in the RA model mice. Overexpression of LINC01197 reduced RA severity in mice and inhibited proliferation and inflammatory responses as well as promoted apoptosis in RA-FLS. Online predictions and dual luciferase reporter gene assays suggested that LINC01197 could bind to miR-150 and further regulate THBS2 expression. LINC01197 promoted THBS2 expression through miR-150 sponging and inactivated the TLR4/NF-κB signaling pathway, thus alleviating RA inflammation.

CONCLUSION

The current study suggested that LINC01197 sponged miR-150 to promote THBS2 expression, leading to TLR4/NF-κB inactivation, and ameliorated RA inflammation. These findings may offer new insights into RA treatment.