MicroRNA-137-mediated inhibition of lysine-specific demethylase-1 prevents against rheumatoid arthritis in an association with the REST/mTOR axis

The role of non-coding RNAs in fibroblast-like synoviocytes in rheumatoid arthritis

Rheumatoid arthritis (RA) is an inflammatory autoimmune disease characterized by synovial hyperplasia, and fibroblast-like synoviocytes (FLSs) constitute the majority of cells in the synovial tissue, playing a crucial role in the onset of RA. Dysregulation of FLSs function is a critical strategy in treating joint damage associated with RA. Non-coding RNAs, a class of RNA molecules that do not encode proteins, participate in the development of various diseases. This article aims to review the progress in the study of long non-coding RNAs, microRNAs, and circular RNAs in FLSs. Non-coding RNAs are involved in the pathogenesis of RA, directly or indirectly regulating FLSs' proliferation, migration, invasion, apoptosis, and inflammatory responses. Furthermore, non-coding RNAs also influence DNA methylation and osteogenic differentiation in FLSs. Therefore, non-coding RNAs hold promise as biomarkers for diagnosing RA. Targeting non-coding RNAs in FLSs locally represents a potential strategy for future therapies in RA.

Inhibition of LSD1 via SP2509 attenuated the progression of rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by synovial hyperplasia, pannus formation, and cartilage and bone destruction. Lysine-specific demethylase 1 (LSD1), an enzyme involved in transcriptional regulation, has an unclear role in synovial inflammation, fibroblast-like synoviocytes migration, and invasion during RA pathogenesis. In this study, we observed increased LSD1 expression in RA synovial tissues and in TNF-α-stimulated MH7A cells. SP2509, an LSD1 antagonist, directly reduced LSD1 expression and reversed the elevated levels of proteins associated with inflammation, apoptosis, proliferation, and autophagy induced by TNF-α. Furthermore, SP2509 inhibited the migratory capacity of MH7A cells, which was enhanced by TNF-α. In CIA models, SP2509 treatment ameliorated RA development, reducing the expression of pro-inflammatory cytokines and alleviating joint pathological symptoms. These findings underscore the significance of LSD1 in RA and propose the therapeutic potential of SP2509.

Human umbilical cord mesenchymal stem cell-derived exosomes loaded miR-451a targets ATF2 to improve rheumatoid arthritis

OBJECTIVE

Rheumatoid arthritis (RA) is an autoimmune disease characterized by chronic joint inflammation, with synovial fibroblasts (SFs) playing a pivotal role in its pathogenesis. Dysregulation of microRNA (miRNA) expression in SFs contributes to RA development. Exosomes (Exos) have emerged as effective carriers for therapeutic molecules, facilitating miRNA transfer between cells. This study explores the therapeutic potential of Exos derived from human umbilical cord mesenchymal stem cells (hUCMSCs), loaded with miR-451a, to modulate ATF2 expression, aiming to address RA in both in vivo and in vitro settings.

METHODS

In this study, hUCMSC and RA SFs were isolated and identified, and hUCMSC-Exos were extracted and characterized. The influence of hUCMSC-Exos on RA SFs was detected. And hUCMSC-Exos targeting RA SFs was traced. HUCMSCKD-AGO2 was prepared by knocking down AGO2 in hUCMSC. HUCMSCKD-AGO2-Exos was extracted and characterized,and their influence on RA SFs was detected. The miRNA profiles before and after hUCMSC-Exos intervention in RA SFs were mapped to identify differential miRNAs. RT-qPCR was used to verify the differential miRNAs, with hsa-miR-451a finally selected as the target gene. The effect of miR-451a on SFs was detected. The latent binding of miR-451a to activating transcription factor 2 (ATF2) was analyzed. The effect of hUCMSC-ExosmiR-451a on SFs was detected, and the expression of miR-451a and ATF2 was measured by RT-PCR. In vivo, hUCMSC-ExosmiR-451a was injected into the ankle joint of CIA rats, and arthritis index, joint imaging and synovial pathology were assessed. The expression of miR-451a and ATF2 in synovial tissue was detected. Finally, the safety of hUCMSC-ExosmiR-451a in CIA rats was evaluated.

RESULTS

This study revealed that hUCMSC-Exos can inhibit RA SFs proliferation, migration and invasion through miRNAs. High throughput sequencing detected 13 miRNAs that could be transmitted from hUCMSCs to RA SFs via hUCMSC-Exos. miR-451a inhibited RA SFs proliferation, migration and invasion by regulating ATF2. hUCMSC-Exos loaded with miR-451a targeted ATF2 to inhibit RA SFs proliferation, migration and invasion, and improve joint inflammation and imaging findings in CIA rats.

CONCLUSIONS

This study demonstrates that miR-451a carried by hUCMSC-Exos can play a role in inhibiting RA SFs biological traits and improving arthritis in CIA rats by inhibiting ATF2. The findings suggest a promising treatment for RA and provide insights into the mechanism of action of hUCMSC-Exos in RA. Future research directions will continue to explore the potential in this field.

Early-Stage Application of Agomir-137 Promotes Locomotor Recovery in a Mouse Model of Motor Cortex Injury

Traumatic brain injury (TBI) is a significant risk factor for neurodegenerative disorders, and patients often experience varying degrees of motor impairment. MiR-137, a broadly conserved and brain-enriched miRNA, is a key regulator in neural development and in various neurological diseases. Following TBI, the expression of miR-137 is dramatically downregulated. However, whether miR-137 is a therapeutic target for TBI still remains unknown. Here, for the first time, we demonstrate that intranasal administration of miR-137 agomir (a mimic) in the early stage (0-7 days) of TBI effectively inhibits glial scar formation and improves neuronal survival, while early-stage administration of miR-137 antagomir (an inhibitor) deteriorates motor impairment. This study elucidates the therapeutic potential of miR-137 mimics in improving locomotor recovery following motor cortex injury.

Lysine-Specific Demethylase 1 (LSD1) Inhibitors: Peptides as an Emerging Class of Therapeutics

Aberrant expression of the epigenetic regulator lysine-specific demethylase 1 (LSD1) has been associated with the incidence of many diseases, particularly cancer, and it has evolved as a promising epigenetic target over the years for treatment. The advent of LSD1 inhibitor-based clinical utility began with tranylcypromine, and it is now considered an inevitable scaffold in the search for other irreversible novel LSD1 inhibitors (IMG-7289 or bomedemstat, ORY1001 or iadademstat, ORY-2001 or vafidemstat, GSK2879552, and INCB059872). Moreover, numerous reversible inhibitors for LSD1 have been reported in the literature, including clinical candidates CC-90011 (pulrodemstat) and SP-2577 (seclidemstat). There is parallel mining for peptide-based LSD1 inhibitors, which exploits the opportunities in the LSD1 substrate binding pocket. This Review highlights the research progress on reversible and irreversible peptide/peptide-derived LSD1 inhibitors. For the first time, we comprehensively organized the peptide-based LSD1 inhibitors from the design strategy. Peptide inhibitors of LSD1 are classified as H3 peptide and SNAIL1 peptide derivatives, along with miscellaneous peptides that include naturally occurring LSD1 inhibitors.

The Diagnostic Value of miR-124a Expression in Peripheral Blood and Synovial Fluid of Patients with Rheumatoid Arthritis

INTRODUCTION

Rheumatoid arthritis (RA), a chronic autoimmune disorder, is currently a severe health threat. Previous studies have documented the altered expression of various miRNAs in RA patients. This study determined the expression of miR-124a in RA patients and estimated its diagnostic value for RA.

METHODS

A total of 80 RA patients were enrolled as the study subjects, and 36 patients with osteoarthritis were included, with another 36 healthy people as the controls. miR-124a expression levels in peripheral blood plasma, peripheral blood mononuclear cells (PBMCs), and synovial fluid were measured using reverse transcription quantitative polymerase chain reaction, followed by Pearson correlation analysis. Additionally, the association between miR-124a and major clinical indicators was assessed, such as rheumatoid factor (RF), erythrocyte sedimentation rate (ESR), and disease activity score of 28 joints (DAS28). The diagnostic efficacy of miR-124a expression in plasma, PBMCs, and synovial fluid for RA was evaluated by the receiver operating characteristic curve, and the difference in the area under the curve (AUC) was analyzed.

RESULTS

miR-124a was downregulated in RA patients, and the expression levels of miR-124a in plasma, PBMCs, and synovial fluid showed a certain degree of positive correlation. miR-124a was inversely linked with RF, ESR, and DAS28. For the diagnosis of RA patients, the AUC of plasma miR-124a was 0.899 and the cut-off value was 0.800, with 68.75% sensitivity and 94.44% specificity; the AUC of miR-124a in PBMCs was 0.937 and the cut-off value was 0.805, with 82.50% sensitivity and 91.67% specificity; the AUC of miR-124a in plasma combined with PBMCs was 0.961, with a higher diagnostic value than independent plasma or PBMCs; the AUC of miR-124a in synovial fluid was 0.929 and the cut-off value was 0.835, with 80.00% sensitivity and 88.89% specificity.

CONCLUSION

miR-124a expression is downregulated in the plasma, PBMCs, and synovial fluid of RA patients and has a high diagnostic value for RA.

MicroRNA-345-3p is a potential biomarker and ameliorates rheumatoid arthritis by reducing the release of proinflammatory cytokines

OBJECTIVES

The study was to explore the influence of microRNA (miR)-345-3p on proinflammatory cytokines in patients with rheumatoid arthritis (RA).

METHODS

A total of 32 RA patients and 32 healthy patients were enrolled. Proinflammatory factors in patients' serum were detected by ELISA, and miR-345-3p was detected by RT-qPCR. The correlation between miR-345-3p expression and proinflammatory factors in RA patients was analyzed. The diagnostic value of miR-345-3p and proinflammatory factors in RA patients was analyzed by receiver operating curve diagnosis. The predictive value of miR-345-3p levels and proinflammatory factors in RA patients was analyzed by multivariate Cox regression. HFLS-RA and HFLS cells were cultured, in which miR-345-3p and proinflammatory cytokines were detected by RT-qPCR. Cell proliferation and apoptosis were determined by CCK-8 and flow cytometry, respectively.

RESULTS

MiR-345-3p was lowly expressed in the serum of RA patients. MiR-345-3p and proinflammatory factors were of diagnostic and predictive values in RA. Elevated miR-345-3p restrained the production of proinflammatory factors of HFLS-RA cells, improved cell proliferation, and reduced apoptosis.

CONCLUSION

MiR-345-3p is a potential biomarker and ameliorates RA by reducing the release of proinflammatory cytokines.

Sodium propionate improves rheumatoid arthritis by inhibiting survivin mediated proliferation of fibroblast like synoviocytes by promoting miR-140-5p

BACKGROUND

Increased proliferation and impaired death of fibroblast-like synovial cells play an important role in the development of rheumatoid arthritis (RA). Survivin plays an important role in the prodromal stage and prognosis of RA and has been introduced as a biomarker of joint injury in RA patients. The purpose of this study was to explore whether propionate alleviates RA through miR-140-5p/survivin pathway.

METHODS

The synovial tissues of RA patients were collected to detect the expression levels of miR-140-5p and survivin; normal human fibroblast-like synovial cells (HLSs) and RA fibroblast-like synovial cells (RA-FLSs) were cultured and treated with 10 mM of sodium propionate (SP), then the expressions of miR-140-5p and survivin, cell viability and apoptosis were detected; collagen induced arthritis (CIA) rat model was constructed and treated with SP, then the tissue inflammation level and the expression levels of miR-140-5p and Survivin were detected.

RESULTS

The expression of miR-140-5p decreased in synovial tissues of RA patients and RA-FLSs cells, while the expression of survivin increased significantly in RA patients. SP promoted miR-140-5p expression and apoptosis in RA-FLSs cells and inhibited survivin expression and cell viability of RA-FLSs cells. In addition, miR-140-5p plays a protective role by targeting survivin. Importantly, in the CIA rat model, SP reduced joint inflammatory response, and the miR-140-5p inhibitor weakened the protective effect of SP.

CONCLUSION

SP can alleviate RA by promoting the expression of miR-140-5p and inhibiting the excessive proliferation and death impairment of RA-FLSs cells induced by survivin.

MicroRNAs (miRNAs) in Cardiovascular Complications of Rheumatoid Arthritis (RA): What Is New?

Rheumatoid Arthritis (RA) is among the most prevalent and impactful rheumatologic chronic autoimmune diseases (AIDs) worldwide. Within a framework that recognizes both immunological activation and inflammatory pathways, the exact cause of RA remains unclear. It seems however, that RA is initiated by a combination between genetic susceptibility, and environmental triggers, which result in an auto-perpetuating process. The subsequently, systemic inflammation associated with RA is linked with a variety of extra-articular comorbidities, including cardiovascular disease (CVD), resulting in increased mortality and morbidity. Hitherto, vast evidence demonstrated the key role of non-coding RNAs such as microRNAs (miRNAs) in RA, and in RA-CVD related complications. In this descriptive review, we aim to highlight the specific role of miRNAs in autoimmune processes, explicitly on their regulatory roles in the pathogenesis of RA, and its CV consequences, their main role as novel biomarkers, and their possible role as therapeutic targets.

Circ_0088036 mediated progression and inflammation in fibroblast-like synoviocytes of rheumatoid arthritis by miR-1263/REL-activated NF-κB pathway

BACKGROUND

Rheumatoid arthritis (RA) is a common joint disease with abnormal development of human fibroblast-like synoviocytes (HFLS). Circular RNAs (circRNAs) have essential regulation in the disease progression, and this study was to explore the regulatory mechanism of circ_0088036 in RA.

METHODS

RNA expression analysis was performed through reverse transcription-quantitative polymerase chain reaction assay. Cell experiments were conducted by Cell Counting Kit-8 assay for cell viability, EdU (5-ethynyl-2'-deoxyuridine) assay for proliferation and flow cytometry for cell cycle or apoptosis. The protein detection was conducted using western blot. Enzyme-linked immunosorbent assay (ELISA) was used to examine the inflammatory cytokines. The binding identification was carried out through dual-luciferase reporter assay, RNA immunoprecipitation assay and pull-down assay.

RESULTS

The level of circ_0088036 RNA was significantly upregulated in sera and in HFLS cells of RA patients. Targeted silencing of circ_0088036 restrained proliferation, cell cycle progression and inflammatory reaction through promoted the apoptosis of HFLS-RA cells via inhibiting the NF-κB pathway. The miR-1263 was identified as a target of circ_0088036. MiR-1263 was found to be down-regulated in sera and in HFLS cells of RA patients. The regulatory effects of circ_0088036 on HFLS-RA cells were attributed to inhibit the miR-1263 level. REL is a susceptibility locus for certain autoimmune diseases. MiR-1263 directly targeted REL, which was discovered to be elevated in sera and HFLS cells of RA patients, and circ_0088036 interacted with miR-1263 to affect REL expression. Functionally, overexpression of miR-1263 suppressed the development of HFLS-RA by blocking the NF-κB pathway, and this phenomenon was reversed by the upregulation of REL.

CONCLUSION

These findings suggested that circ_0088036/miR-1263/REL/NF-κB pathway was involved in the functional development of HFLS-RA cells, indicating a novel molecular network in RA progression in vitro.

MicroRNA-Mediated Epigenetic Regulation of Rheumatoid Arthritis Susceptibility and Pathogenesis

MicroRNAs (miRNAs) play crucial roles in regulating the transcriptome and development of rheumatoid arthritis (RA). Currently, a comprehensive map illustrating how miRNAs regulate transcripts, pathways, immune system differentiation, and their interactions with terminal cells such as fibroblast-like synoviocytes (FLS), immune-cells, osteoblasts, and osteoclasts are still laking. In this review, we summarize the roles of miRNAs in the susceptibility, pathogenesis, diagnosis, therapeutic intervention, and prognosis of RA. Numerous miRNAs are abnormally expressed in cells involved in RA and regulate target genes and pathways, including NF-κB, Fas-FasL, JAK-STAT, and mTOR pathways. We outline how functional genetic variants of miR-499 and miR-146a partly explain susceptibility to RA. By regulating gene expression, miRNAs affect T cell differentiation into diverse cell types, including Th17 and Treg cells, thus constituting promising gene therapy targets to modulate the immune system in RA. We summarize the diagnostic and prognostic potential of blood-circulating and cell-free miRNAs, highlighting the opportunity to combine these miRNAs with antibodies to cyclic citrullinated peptide (ACCP) to allow accurate diagnosis and prognosis, particularly for seronegative patients. Furthermore, we review the evidence implicating miRNAs as promising biomarkers of efficiency and response of, and resistance to, disease-modifying anti-rheumatic drugs and immunotherapy. Finally, we discuss the autotherapeutic effect of miRNA intervention as a step toward the development of miRNA-based anti-RA drugs. Collectively, the current evidence supports miRNAs as interesting targets to better understand the pathogenetic mechanisms of RA and design more efficient therapeutic interventions.

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.