Serum-derived exosomes containing NEAT1 promote the occurrence of rheumatoid arthritis through regulation of miR-144-3p/ROCK2 axis

Diagnostic and Therapeutic Roles of Extracellular Vesicles and Their Enwrapped ncRNAs in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a systemic inflammatory disease whose precise pathogenesis remains mysterious. The involvement of epigenetic regulation in the pathogenesis of RA is one of the most anticipated findings, among which non-coding RNAs (ncRNAs) hold great application promise as diagnostic and therapeutic biomarkers for RA. Extracellular vesicles (EVs) are a heterogeneous group of nano-sized, membrane-enclosed vesicles that mediate intercellular communication and substance exchange, especially the transfer of ncRNAs from donor cells, thereby regulating the functional activities and biological processes of recipient cells. In light of the significant correlation between EVs, ncRNAs, and RA, we first documented expression levels of EVs and their-encapsulated ncRNAs in RA individuals, and methodically discussed their-implicated signaling pathways and phenotypic changes. The last but not least, we paied special attention to the therapeutic benefits of gene therapy reagents specifically imitating or silencing candidate ncRNAs with exosomes as carriers on RA animal models, and briefly highlighted their clinical application advantage and foreground. In conclusion, the present review may be conducive to a deeper comprehension of the diagnostic and therapeutic roles of EVs-enwrapped ncRNAs in RA, with special emphasis on exosomal ncRNAs, which may offer hints for the monitoring and treatment of RA.

Characterization of the MicroRNA profile in rheumatoid arthritis plasma exosomes and their roles in B-cell responses

OBJECTIVE

This study aimed to identify differentially expressed microRNAs (miRNAs) in exosomes derived from the blood plasma of Rheumatoid Arthritis (RA) patients and explore their clinical significance and biological roles.

METHODS

Illumina high-throughput sequencing was employed to measure miRNA expression levels in plasma exosomes, followed by validation using qRT-PCR. The correlation between exosomal miRNAs and disease activity was systematically analyzed. Additionally, the pathogenic effects of RA exosomes were investigated through bioinformatics analysis and in vitro experiments.

RESULTS

Significantly reduced levels of exosomal miR-144-3p and miR-30b-5p were observed in RA patients, which were negatively correlated with DAS28 scores and anti-CCP antibody levels. ROC curve analysis showed that miR-144-3p and miR-30b-5p in plasma exosomes could effectively distinguish RA patients from healthy controls, with AUC values of 0.725 and 0.773, respectively. Combining bioinformatics analysis and in vitro experiments, it was demonstrated that plasma exosomes contribute to ongoing autoantibody production in RA by promoting B-cell differentiation and antibody production.

CONCLUSION

The present study indicates that plasma exosomes from RA patients may be potentially pathogenic. Exosomal miR-144-3p and miR-30b-5p exhibit significant decreases in RA patients and are associated with disease activity, suggesting their potential as valuable biomarkers for RA.

Construction of LncRNA-mediated CeRNA network for investigating the immune pathogenesis of myocardial infarction

BACKGROUND

Myocardial infarction (MI) is a cardiovascular disease that seriously threatens human health. However, an immune-related competitive endogenous RNA (ceRNA) network has not been reported in MI.

METHODS

The GSE66360, GSE19339, GSE97320, GSE61741, and GSE168281 datasets were acquired from the Gene Expression Omnibus (GEO) database. The differentially expressed genes (DEGs) and differentially expressed miRNAs (DEmiRNAs) from MI patients and healthy controls were screened and an immune-related ceRNA network was constructed. Furthermore, the key long noncoding RNAs(lncRNAs) highly related to the immune mechanism of MI were identified utilizing the random walk with restart algorithm. Finally, the expression of the hub genes was further verified in the GSE66360, GSE19339, and GSE97320 datasets, and quantitativereal-time polymerase chain reaction (qRT-PCR) was performed for the MI patients and healthy controls.

RESULTS

A total of 184 differentially expressed immune-related genes(DE-IRGs) and 432 DE-miRNAs were obtained, and an immune-related ceRNA network comprising 1421 lncRNAs, 61 DE-miRNAs, and 139 DE-IRGs was constructed. According to the order of stress, betweenness, and closeness, NEAT1, KCNQ1OT1, and XIST were identified as key lncRNAs. Moreover, random walk with restart analysis also suggested that NEAT1, KCNQ1OT1, and XIST are key lncRNAs. Subsequently, a ceRNA network of 10 hub genes and 3 lncRNAs was constructed. Finally, we found that the expression of FCER1G and TYROBP significantly differed between MI patients and control individuals in the GSE66360, GSE19339, and GSE97320 datasets. qRT-PCR revealed that the expression of NEAT1, KCNQ1OT1, XIST, FCER1G, and TYROBP was significantly elevated in MI tissue samples compared to healthy control tissue samples.

CONCLUSION

NEAT1, KCNQ1OT1, XIST, FCER1G, and TYROBP are involved in MI and can be used as molecular biomarkers for the screening and diagnosis of MI. Furthermore, the immune system plays an essential role in the onset and progression of MI.

NEAT1 in inflammatory infectious diseases: An integrated perspective on molecular modulation

The long non-coding RNA (lncRNA), NEAT1, has emerged as a central figure in the intricate network of molecular regulators in inflammatory infectious diseases (IIDs). The review initiates a comprehensive exploration of NEAT1's multifaceted roles and molecular interactions in the context of these complex diseases. The study begins by acknowledging the global health burden of IIDs, underscoring the urgency for innovative insights into their pathogenesis and therapeutic avenues. NEAT1 is introduced as a pivotal lncRNA with growing relevance in immune responses and inflammatory processes. The core of this review unravels the NEAT1 landscape, elucidating its involvement in the modulation of immune signalling pathways, regulation of inflammatory cytokines, and interactions with various immune cells during infection. It explores NEAT1's role in orchestrating immune responses and balancing host defence mechanisms with the risk of immunopathology. Furthermore, the review underscores the clinical significance of NEAT1 in infectious diseases, discussing its associations with disease severity, prognosis, and potential as a diagnostic and therapeutic target. It provides insights into ongoing research endeavours aimed at harnessing NEAT1 for innovative disease management strategies, including developing RNA-based therapeutics. Concluding on a forward-looking note, the review highlights the broader implications of NEAT1 in the context of emerging infectious diseases and the possibility for precision medicine approaches that leverage NEAT1's regulatory capacities. In summary, this review illuminates the pivotal role of NEAT1 in IIDs by navigating its complex landscape, offering profound insights into its implications for disease pathogenesis and the development of targeted therapies.

Exosomal Osteoclast-Derived miRNA in Rheumatoid Arthritis: From Their Pathogenesis in Bone Erosion to New Therapeutic Approaches

Rheumatoid arthritis (RA) is an autoimmune disease that causes inflammation, pain, and ultimately, bone erosion of the joints. The causes of this disease are multifactorial, including genetic factors, such as the presence of the human leukocyte antigen (HLA)-DRB1*04 variant, alterations in the microbiota, or immune factors including increased cytotoxic T lymphocytes (CTLs), neutrophils, or elevated M1 macrophages which, taken together, produce high levels of pro-inflammatory cytokines. In this review, we focused on the function exerted by osteoclasts on osteoblasts and other osteoclasts by means of the release of exosomal microRNAs (miRNAs). Based on a thorough revision, we classified these molecules into three categories according to their function: osteoclast inhibitors (miR-23a, miR-29b, and miR-214), osteoblast inhibitors (miR-22-3p, miR-26a, miR-27a, miR-29a, miR-125b, and miR-146a), and osteoblast enhancers (miR-20a, miR-34a, miR-96, miR-106a, miR-142, miR-199a, miR-324, and miR-486b). Finally, we analyzed potential therapeutic targets of these exosomal miRNAs, such as the use of antagomiRs, blockmiRs, agomiRs and competitive endogenous RNAs (ceRNAs), which are already being tested in murine and ex vivo models of RA. These strategies might have an important role in reestablishing the regulation of osteoclast and osteoblast differentiation making progress in the development of personalized medicine.

Understanding the role of exosomal lncRNAs in rheumatic diseases: a review

Rheumatic diseases, a group of diseases whose etiology is still unclear, are thought to be related to genetic and environmental factors, leading to complex pathogenesis. Based on their multi-system involvement, the diagnosis and treatment continue to face huge challenges. Whole-genome assays provide a distinct direction for understanding the underlying mechanisms of such diseases. Exosomes, nano-sized bilayer membrane vesicles secreted by cells, are mentioned as a key element in the physiological and pathological processes of the body. These exosomes mediate biologically active substances, such as nucleic acids, proteins, and lipids and deliver them to cells. Notably, long non-coding RNAs (lncRNAs), a unique class of non-coding RNAs, have been implicated in the pathogenesis of rheumatic diseases. However, the mechanism needs to be further explored. This article provided a comprehensive review of the findings on exosomal lncRNAs in rheumatic diseases, including rheumatoid arthritis, osteoarthritis, systemic lupus erythematosus, autoimmune liver diseases, primary dermatomyositis, and systemic sclerosis. Through in-depth understanding of these lncRNAs and their involved signaling pathways provide new theoretical supports for the diagnosis and treatment of rheumatic diseases.

Exploring Circulating Long Non-Coding RNAs in Mild Cognitive Impairment Patients' Blood

Mild cognitive impairment (MCI) is a transitional clinical stage prior to dementia. Patients with amnestic MCI have a high risk of progression toward Alzheimer's disease. Both amnestic mild cognitive impairment and sporadic Alzheimer's disease are multifactorial disorders consequential from a multifaceted cross-talk among molecular and biological processes. Non-coding RNAs play an important role in the regulation of gene expression, mainly long non-coding RNAs (lncRNAs), that regulate other RNA transcripts through binding microRNAs. Cross-talk between RNAs, including coding RNAs and non-coding RNAs, produces a significant regulatory network all through the transcriptome. The relationship of genes and non-coding RNAs could improve the knowledge of the genetic factors contributing to the predisposition and pathophysiology of MCI. The objective of this study was to identify the expression patterns and relevant lncRNA-associated miRNA regulatory axes in the blood of MCI patients, which includes lncRNA-SNHG16, lncRNA-H19, and lncRNA-NEAT1. Microarray investigations have demonstrated modifications in the expression of long non-coding RNAs (lncRNA) in the blood of patients with MCI compared with control samples. This is the first study to explore lncRNA profiles in mild cognitive impairment blood. Our study proposes RNAs targets involved in molecular pathways connected to the pathogenesis of MCI.

Comprehensive analysis of serum exosome-derived lncRNAs and mRNAs from patients with rheumatoid arthritis

BACKGROUND

Serum exosomes play important roles in intercellular communication and are promising biomarkers of several autoimmune diseases. However, the biological functions and potential clinical importance of long non-coding RNAs (lncRNAs) and mRNAs from serum exosomes in rheumatoid arthritis (RA) have not yet been studied.

METHODS

Serum exosomal lncRNAs and mRNAs were isolated from patients with RA and osteoarthritis (OA) and healthy controls. The differentially expressed lncRNAs (DE-lncRNAs) and mRNA profiles in the serum exosomes of patients with RA were analysed using high-throughput sequencing, and their functions were predicted using Gene Ontologyenrichment, Kyoto Encyclopedia of Genes and Genomes pathway, and gene set enrichment analysis. We constructed a DE-lncRNA-mRNA network and a protein-protein interaction network of differentially expressed mRNAs (DE-mRNAs) in RA using the Cytoscape software. The expression of several candidate a DE-lncRNAs and DE-mRNAs in the serum of patients with RA, patients with OA, and healthy controls was confirmed by qRT-PCR. We assessed the diagnostic ability of DE-lncRNAs and DE-mRNAs in patients with RA using receiver operating characteristic analysis. Furthermore, we analysed the characteristics of immune cell infiltration in RA by digital cytometry using the CIBERSORT algorithm and determined the correlation between immune cells and several DE-lncRNAs or DE-mRNAs in RA.

RESULTS

The profiles of serum exosomal lncRNAs and mRNAs in patients with RA were different from those in healthy controls and patients with OA. The functions of both DE-lncRNAs and DE-mRNAs in RA are associated with the immune response and cellular metabolic processes. The RT-PCR results show that NONHSAT193357.1, CCL5, and MPIG6B were downregulated in patients with RA. The combination of three DE-mRNAs, CCL5, MPIG6B, and PFKP, had an area under the curve of 0.845 for differentiating RA from OA. Digital cytometry using the CIBERSORT algorithm showed that the neutrophil counts were higher in patients with RA than those in healthy controls and patients with OA.

CONCLUSIONS

These findings help to elucidate the role of serum exosomal lncRNAs and mRNAs in the specific mechanisms underlying RA.

LncRNA Neat1 targets NonO and miR-128-3p to promote antigen-specific Th17 cell responses and autoimmune inflammation

Long non-coding RNAs (lncRNAs) interaction with RNA-Binding proteins (RBPs) plays an important role in immunological processes. The generation of antigen-specific Th17 cells is closely associated with autoimmune pathogenesis. However, the function of lncRNA-RBP interactions in the regulation of pathogenic Th17 cell responses during autoimmunity remains poorly understood. Here, we found that lncRNA Neat1, highly expressed in Th17 cells, promoted antigen-specific Th17 cell responses. Both global and CD4+ T cell-specific knockdown of Neat1 protected mice against the development of experimental autoimmune uveitis (EAU). Mechanistically, Neat1 regulated RNA-Binding protein NonO, thus relieving IL-17 and IL-23R from NonO-mediated transcriptional repression and supporting antigen-specific Th17 cell responses. In addition, Neat1 also modulated miR-128-3p/NFAT5 axis to increase the expression of IL-17 and IL-23R, leading to augmented Th17 cell responses. Our findings elucidate a previously unrecognized mechanistic insight into the action of Neat1 in promoting antigen-specific Th17 responses and autoimmunity, and may facilitate the development of therapeutic targets for T cell-mediated autoimmune diseases.

The impact of exosomes derived from distinct sources on rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune disease that can induce joint deformities and functional impairment, significantly impacting the overall well-being of individuals. Exosomes, which are cellularly secreted vesicles, possess favorable biological traits such as biocompatibility, stability, and minimal toxicity. Additionally, they contain nucleic acids, lipids, proteins, amino acids, and metabolites, serving as mediators in cellular communication and information exchange. Recent studies have demonstrated the association between exosomes and the pathogenesis of RA. Exosomes derived from mesenchymal stem cells, dendritic cells, and neutrophils exert influence on the biological functions of immune cells and joint cells, however, the precise mechanism remains largely unclarified. This comprehensive review systematically analyzes and summarizes the biological characteristics and functionalities of exosomes derived from diverse cellular sources, thus establishing a scientific foundation for the utilization of exosomes as diagnostic targets and therapeutic modalities in the context of RA.

Bioinformatics analysis of ceRNA regulatory network of baicalin in alleviating pathological joint alterations in CIA rats

Rheumatoid arthritis (RA) is an autoimmune disease characterized by chronic inffammation of synovium, leading to cartilage damage, bone erosion,even joint destruction and deformity. The conventional treatment modalities in RA are associated with side effects, emphasizing the need for alternative therapeutic remedies. Baicalin possesses multiple pharmacological effects and the advantage of low toxicity. This study aimed to reveal the potential gene regulatory mechanisms underlying the alleviating effects of baicalin in joint pathological alterations in Collagen-Induced Arthritis (CIA) rat models. At 28 days after the primary immunization, 60mg/kg/d of baicalin was administered via intraperitoneal injection once daily for 40 days, and the pathological alterations of hind paw joints were examined with X-ray imaging. Subsequently, the synovial tissue of knee joints was isolated, from which total RNA was extracted, and mRNA and miRNA sequencing libraries were established. Finally, High-throughput transcriptome sequencing(RNA-seq) technology was performed, and the lncRNAs/miRNAs/mRNAs competing endogenous RNA(ceRNA) regulatory network was analyzed. The CIA model was successfully established, and baicalin treatment significantly alleviated the destruction of distal joints of CIA rat models (p < 0.01). We found that 3 potential ceRNA regulatory networks of baicalin were established, including lncRNA ENSRNOT00000076420/miR-144-3p/Fosb, lncRNA MSTRG.1448.13/miR-144-3p/Atp2b2 and lncRNA MSTRG.1448.13/miR-144-3p/Shanks. The validation results from synovial tissue of CIA rats were consistent with the RNA-Seq results. Overall, this study revealed potentially important genes and ceRNA regulatory network that mediate the alleviating effects of baicalin on joint pathological alterations in CIA rats.

Exosomes as biomarkers and therapeutic delivery for autoimmune diseases: Opportunities and challenges

Exosomes are spherical lipid bilayer vesicles composed of lipids, proteins and nucleic acids that deliver signaling molecules through a vesicular transport system to regulate the function and morphology of target cells, thereby involving in a variety of biological processes, such as cell apoptosis or proliferation, and cytokine production. In the past decades, there are emerging evidence that exosomes play pivotal roles in the pathological mechanisms of several autoimmune diseases (ADs), including rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), type 1 diabetes mellitus (T1DM), Sjogren's syndrome (SS), multiple sclerosis (MS), inflammatory bowel disease (IBD). systemic sclerosis (SSc), etc. Several publications have shown that exosomes are involved in the pathogenesis of ADs mainly through intercellular communication and by influencing the response of immune cells. The level of exosomes and the expression of nucleic acids can reflect the degree of disease progression and are excellent biomarkers for ADs. In addition, exosomes have the potential to be used as drug carriers thanks to their biocompatibility and stability. In this review, we briefly summarized the current researches regarding the biological functions of exosomes in ADs, and provided an insight into the potential of exosomes as biomarkers and therapeutic delivery for these diseases.

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.

lncRNA-mediated synovitis in rheumatoid arthritis: A perspective for biomarker development

Long noncoding RNAs (lncRNAs) are a regulatory class of noncoding RNAs with a wide range of activities such as transcriptional and post-transcriptional regulations. Emerging evidence has demonstrated that various lncRNAs contribute to the initiation and progression of Rheumatoid Arthritis (RA) through distinctive mechanisms. The present study reviews the recent findings on lncRNA role in RA development. It focuses on the involvement of different lncRNAs in the main steps of RA pathogenesis including T cell activation, cytokine dysregulation, fibroblast-like synoviocyte (FLS) activation and joint destruction. Besides, it discusses the current findings on RA diagnosis and the potential of lncRNAs as diagnostic, prognostic and predictive biomarkers in Rheumatology clinic.

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.

The role of long noncoding RNA (lncRNA) nuclear-enriched abundant transcript 1 (NEAT1) in immune diseases

The long noncoding RNA (lncRNA) nuclear-enriched abundant transcript 1 (NEAT1) has been shown to be involved in the pathogenesis of several diseases. Herein, we discuss recent developments and insights into NEAT1 and its contribution to a variety of immune disorders. Our evaluations revealed that NEAT1's function in immune diseases seems to be focused on the modulation of paraspeckle expression and it is primarily associated with the nuclear retention of its mRNA. NEAT1 is also involved in the sequestration of paraspeckle proteins and in affecting the transcriptional expression of specific immune regulators. The expression of NEAT1 may be aberrantly upregulated in several immune pathologies, indicating that it could serve as a potential prognostic biomarker in these conditions. We summarized describing the expression changes and the role of NEAT1 in several immune diseases. We also described the mechanism of its regulation of the immune cell differentiation and function of NEAT1 in different disease.

Long Intergenic Noncoding RNAs Affect Biological Pathways Underlying Autoimmune and Neurodegenerative Disorders

Long intergenic noncoding RNAs (lincRNAs) are a class of independently transcribed molecules longer than 200 nucleotides that do not overlap known protein-coding genes. LincRNAs have diverse roles in gene expression and participate in a spectrum of biological processes. Dysregulation of lincRNA expression can abrogate cellular homeostasis, cell differentiation, and development and can also deregulate the immune and nervous systems. A growing body of literature indicates their important and multifaceted roles in the pathogenesis of several different diseases. Furthermore, certain lincRNAs can be considered potential therapeutic targets and valuable diagnostic or prognostic biomarkers capable of predicting the onset of a disease, its degree of activity, or the progression phase. In this review, we discuss possible mechanisms and molecular functions of lincRNAs in the pathogenesis of selected autoimmune and neurodegenerative disorders: multiple sclerosis, rheumatoid arthritis, systemic lupus erythematosus, Sjögren’s syndrome, Huntington’s disease, Parkinson’s disease, Alzheimer’s disease, and amyotrophic lateral sclerosis. This summary can provide new ideas for future research, diagnosis, and treatment of these highly prevalent and devastating diseases.

LncRNA NEAT1 correlates with Th17 cells and proinflammatory cytokines, also reflects stenosis degree and cholesterol level in coronary heart disease patients

BACKGROUND

Long non-coding RNA nuclear enriched abundant transcript 1 (lnc-NEAT1) regulates endothelial cell functions, CD4+ T cell regulation and chronic inflammation related to coronary heart disease (CHD). Then this case-control study measured lnc-NEAT1 expression in CHD patients, aiming to explore its clinical value in CHD management.

METHODS

Totally, 120 documented CHD patients and 120 suspected subjects without CHD diagnosis as controls were enrolled. Plasma lnc-NEAT1 was detected by RT-qPCR in all participants, plasma inflammatory cytokines were assessed by ELISA, T helper (Th) 1, Th2, Th 17 cell proportions in CD4+ T cells were analyzed by flow cytometric analysis in CHD patients, respectively.

RESULTS

Lnc-NEAT1 was higher in CHD patients than in controls (p < 0.001). In CHD patients, lnc-NEAT1 positively associated with Gensini score (r = 0.323, p < 0.001). Besides, lnc-NEAT1 positively correlated with tumor necrosis factor-α (r = 0.271, p = 0.003), interleukin (IL)-1β (r = 0.216, p = 0.018), IL-6 (r = 0.217, p = 0.018) and IL-17 (r = 0.292, p = 0.001); meanwhile, it was positively associated with the percentage of Th 17 cells (r = 0.384, p = 0.002). However, no correlation was found in lnc-NEAT1 with the percentage of Th1 or Th2 cells (all p > 0.05). Moreover, lnc-NEAT1 was correlated with higher hyperuricemia prevalence (p = 0.028), increased total cholesterol (r = 0.263, p = 0.004) and low-density lipoprotein cholesterol (r = 0.261, p = 0.004), but was not associated with other characteristics (all p > 0.05).

CONCLUSION

Lnc-NEAT1 correlates with Th17 cells and proinflammatory cytokines, also reflects stenosis degree and cholesterol level in CHD patients, which potentially improves the management of CHD patients.

LncRNA OSER1-AS1 regulates the inflammation and apoptosis of rheumatoid arthritis fibroblast like synoviocytes via regulating miR-1298-5p/E2F1 axis

It has been reported that long noncoding RNAs (LncRNAs) take part in the progression and occurrence of rheumatoid arthritis (RA). The current work aimed to dig the effect of lncRNA OSER1-AS1 on RA and the associated mechanism. Quantitative real-time polymerase chain reaction (qRT-PCR) was made to decide that OSER1-AS1 was significantly lowly expressed in synovial tissue and serum of RA patients, which was consistent in RA-FLSs cell lines. The result of ROC curve indicated that OSER1-AS1 could be a diagnostic biomarker for RA patients. Cell Counting Kit-8 assay (CCK-8), EdU staining and flow cytometry were performed to explore the effect of OSER1-AS1 on RA-FLSs in vitro. Relative levels of interleukin-1 (IL-1), interleukin-6 (IL-6), matrix metalloproteinases-3 (MMP-3) were detected by ELISA and the result displayed that overexpression of OSER1-AS1 inhibited RA-induced inflammatory production of IL-1, IL-6 and MMP3. Bioinformatics analysis, luciferase reporter, RNA immunoprecipitation assays (RIP) and RNA pull-down assay were conducted to confirm the binding between microRNA-1298-5p (miR-1298-5p) and OSER1-AS1 or E2F transcription factor 1 (E2F1). Mechanistically, OSER1-AS1 serves as a competing endogenous (ceRNA) in RA-FLSs through the sponge of miR-1298-5p and increase in the expression of E2F1. Further restoration experiments revealed that miR-1298-5p mimics and E2F1 silencing could partially reverse the inhibiting effect of OSER1-AS1 overexpression on propagation and apoptosis in RA-FLSs. The results illustrated the biological mechanism of OSER1-AS1/miR-1298-59/E2F1 axis in RA progression. The outcomes indicated that OSER1-AS1 might be adopted as a hopeful diagnostic and therapeutic objective for RA.

LncRNA Expression Profiles in Systemic Lupus Erythematosus and Rheumatoid Arthritis: Emerging Biomarkers and Therapeutic Targets

Systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) are two common multisystem autoimmune diseases that share, among others, many clinical manifestations and serological features. The role of long non-coding RNAs (lncRNAs) has been of particular interest in the pathogenesis of autoimmune diseases. Here, we aimed to summarize the roles of lncRNAs as emerging novel biomarkers and therapeutic targets in SLE and RA. We conducted a narrative review summarizing original articles on lncRNAs associated with SLE and RA, published until November 1, 2021. Based on the studies on lncRNA expression profiles in samples (including PBMCs, serum, and exosomes), it was noted that most of the current research is focused on investigating the regulatory mechanisms of these lncRNAs in SLE and/or RA. Several lncRNAs have been hypothesized to play key roles in these diseases. In SLE, lncRNAs such as GAS5, NEAT1, TUG1, linc0949, and linc0597 are dysregulated and may serve as emerging novel biomarkers and therapeutic targets. In RA, many validated lncRNAs, such as HOTAIR, GAS5, and HIX003209, have been identified as promising novel biomarkers for both diagnosis and treatment. The shared lncRNAs, for example, GAS5, may participate in SLE pathogenesis through the mitogen-activated protein kinase pathway and trigger the AMP-activated protein kinase pathway in RA. Here, we summarize the data on key lncRNAs that may drive the pathogenesis of SLE and RA and could potentially serve as emerging novel biomarkers and therapeutic targets in the coming future.

Role of Exosomal Non-Coding RNAs in Bone-Related Diseases

Bone-related diseases seriously affect the lives of patients and carry a heavy economic burden on society. Treatment methods cannot meet the diverse clinical needs of affected patients. Exosomes participate in the occurrence and development of many diseases through intercellular communication, including bone-related diseases. Studies have shown that exosomes can take-up and “package” non-coding RNAs and “deliver” them to recipient cells, thereby regulating the function of recipient cells. The exosomal non-coding RNAs secreted by osteoblasts, osteoclasts, chondrocytes, and other cells are involved in the regulation of bone-related diseases by inhibiting osteoclasts, enhancing chondrocyte activity and promoting angiogenesis. Here, we summarize the role and therapeutic potential of exosomal non-coding RNAs in the bone-related diseases osteoporosis, osteoarthritis, and bone-fracture healing, and discuss the clinical application of exosomes in patients with bone-related diseases.

Long non-coding RNA NEAT1 and its targets (microRNA-21 and microRNA-125a) in rheumatoid arthritis: Altered expression and potential to monitor disease activity and treatment outcome

Background

The present study aimed to explore the association of long non‐coding RNA nuclear‐enriched abundant transcript 1 (lnc‐NEAT1) with inflammation, disease activity, treatment outcome, and its targets (microRNA [miR]‐21 and miR‐125a) in patients with rheumatoid arthritis (RA).

Methods

Peripheral blood mononuclear cells were sampled from 130 RA patients at baseline, week (W) 6, and W12, as well as from 60 healthy controls (HCs) after enrollment. Meanwhile, the expressions of lnc‐NEAT1, miR‐21, and miR‐125a were detected by reverse transcription‐quantitative polymerase chain reaction.

Results

lnc‐NEAT1 was elevated, but miR‐21 and miR‐125a were declined in RA patients compared with HCs (all p < 0.001); meanwhile, lnc‐NEAT1 was negatively correlated with miR‐21 and miR‐125a (both p < 0.05) in RA patients. Besides, elevated lnc‐NEAT1 but declined miR‐21 and miR‐125a were correlated with erythrocyte sedimentation rate (ESR) and C‐reactive protein and the 28‐joint Disease Activity‐ESR score (all p < 0.05) in RA patients. Moreover, lnc‐NEAT1 was declined from baseline to W12 in RA patients (p < 0.001). Additionally, lnc‐NEAT1 at W12 was declined in response patients compared with non‐response patients (p = 0.006), and also decreased in remission patients compared with non‐remission patients (p < 0.001).

Conclusion

lnc‐NEAT1 and its targets (miR‐21 and miR‐125a) correlate with RA risk and disease activity, and declined lnc‐NEAT1 associates with better treatment outcome to some extent in RA patients, suggesting that lnc‐NEAT1 might be a potential biomarker to monitor disease activity and treatment outcome in RA.

The Role of Long Non-coding RNA, Nuclear Enriched Abundant Transcript 1 (NEAT1) in Cancer and Other Pathologies

Nuclear enriched abundant transcript 1 (NEAT1), consisting of two kinds of lncRNAs of 3.7 kB NEAT1-1 and 23 kB NEAT1-2, can be highly expressed in organs and tissues such as the ovary, prostate, colon, and pancreas, and is involved in paraspeckle formation and mRNA editing and gene expression. Therefore, NEAT1 is a potential biomarker for the treatment of a variety of diseases, which may be caused by two factors (isoforms of NEAT1 and NEAT1 sponging miRNA as ceRNA). However, there is still much confusion about the mechanism and downstream effector between the abnormal expression of NEAT1 and various diseases. This review summarizes recent research progress on NEAT1 in cancer and other pathologies and provides a more reliable theoretical basis for the treatment of related diseases.

Exosomal lncRNA Nuclear Paraspeckle Assembly Transcript 1 (NEAT1)contributes to the progression of allergic rhinitis via modulating microRNA-511/Nuclear Receptor Subfamily 4 Group A Member 2 (NR4A2) axis

Allergic rhinitis (AR) is a common chronic disease characterized by inflammation of the nasal mucosa. Long non-coding RNA (LncRNA) has been reported to be involved in the pathogenesis of various diseases. However, the biological roles of lncRNA Nuclear Paraspeckle Assembly Transcript 1 (NEAT1) in AR are still unclear. The mRNA levels of NEAT1, miR-511, and Nuclear Receptor Subfamily 4 Group A Member 2 (NR4A2) were detected by RT-qPCR. The protein levels of exosomal markers were examined by western blot. ELISA was used to assess the levels of GM-CSF, eotaxin-1, and MUC5AC. The cell viability and apoptosis were evaluated by CCK-8 and TUNEL assays. In this study, we found that the NEAT1 level was highly expressed in AR and IL-13-treated HNECs. NEAT1 interference significantly suppressed levels of GM-CSF, eotaxin-1, and MUC5AC and apoptosis rate, but promoted the viability of IL-13-treated human nasal epithelial cells (HNECs). Moreover, exosomes containing NEAT1 induced inflammatory cytokine production and apoptosis, while NEAT1 depletion abrogated these effects. In addition, NEAT1 directly interacted with miR-511, and the inhibition of miR-511 partially restored the inhibitory effects of NEAT1 silencing on inflammatory cytokine, mucus production, and apoptosis in IL-13-stimulated HNECs. Furthermore, miR-511 could bind to the 3ʹUTR of NR4A2, and the inhibition of miR-511 increased levels of inflammatory factors and apoptosis rate, which was counteracted by depleting NR4A2. In conclusion, our data revealed that exosomal NEAT1 contributed to the pathogenesis of AR through the miR-511/NR4A2 axis. These findings might offer novel strategies for the prevention and treatment of AR.