Positive Feedback Loop LINC00511/miR-150-5p/SP1 Modulates Chondrocyte Apoptosis and Proliferation in Osteoarthritis

Role of Long Intergenic Nonprotein-Coding RNA 00511 in Nod-Like Receptor Protein Pyrin Domain 3-Induced Chondrocyte Pyroptosis via the MicroRNA-9-5p/FUT1 Axis

This study aimed to determine the function of LINC00511 in Nod-Like Receptor Pyrin Domain 3 inflammasome-mediated chondrocyte pyroptosis via the regulation of miR-9-5p and FUT 1. Chondrocyte inflammatory injury was induced by treating chondrocytes with LPS. Afterwards, the levels of IL-1β and IL-18, the expression of NLRP3, ASC, Caspase-1, and GSDMD, cell viability, and LDH activity in chondrocytes were assessed. LINC00511 expression in LPS-treated chondrocytes was detected, and LINC00511 was subsequently silenced to analyse its role in chondrocyte pyroptosis. The subcellular localization of LINC00511 was predicted and verified. Furthermore, the binding relationships between LINC00511 and miR-9-5p and between miR-9-5p and FUT1 were validated. LINC00511 regulated NLRP3 inflammasome-mediated chondrocyte pyroptosis through the miR-9-5p/FUT1 axis. LPS-treated ATDC5 cells exhibited elevated levels of inflammatory injury; increased levels of NLRP3, ASC, Caspase-1, and GSDMD; reduced cell viability; increased LDH activity; and increased LINC00511 expression, while LINC00511 silencing inhibited the NLRP3 inflammasome to restrict LPS-induced chondrocyte pyroptosis. Next, LINC00511 sponged miR-9-5p, which targeted FUT1. Silencing LINC00511 suppressed FUT1 by upregulating miR-9-5p. Additionally, downregulation of miR-9-5p or overexpression of FUT1 neutralized the suppressive effect of LINC00511 knockdown on LPS-induced chondrocyte pyroptosis. Silencing LINC00511 inhibited the NLRP3 inflammasome to quench Caspase-1-dependent chondrocyte pyroptosis in OA by promoting miR-9-5p and downregulating FUT1.

The emerging role of lncRNAs in osteoarthritis development and potential therapy

Osteoarthritis impairs the functions of various joints, such as knees, hips, hands and spine, which causes pain, swelling, stiffness and reduced mobility in joints. Multiple factors, including age, joint injuries, obesity, and mechanical stress, could contribute to osteoarthritis development and progression. Evidence has demonstrated that genetics and epigenetics play a critical role in osteoarthritis initiation and progression. Noncoding RNAs (ncRNAs) have been revealed to participate in osteoarthritis development. In this review, we describe the pivotal functions and molecular mechanisms of numerous lncRNAs in osteoarthritis progression. We mention that long noncoding RNAs (lncRNAs) could be biomarkers for osteoarthritis diagnosis, prognosis and therapeutic targets. Moreover, we highlight the several compounds that alleviate osteoarthritis progression in part via targeting lncRNAs. Furthermore, we provide the future perspectives regarding the potential application of lncRNAs in diagnosis, treatment and prognosis of osteoarthritis.

NEAT1-mediated miR-150-5p downregulation regulates b-catenin expression in OA chondrocytes

We investigated the role of miR-150-5p in osteoarthritic (OA) chondrocytes, as well as the possible regulatory role of long non-coding RNAs (lncRNAs) in miR-150-5p expression. TargetScan, StarBase, DIANA-LncBase, and Open Targets databases were used to predict miR-150-5p target genes, lncRNAs/miR-150-5p interactions, and OA-related genes. Protein-protein interaction (PPI) network was constructed using the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING). Gene ontology (GO) and pathway analysis were performed using Enrichr database. A publicly available RNA-seq dataset was retrieved to identify differentially expressed lncRNAs in damaged vs intact cartilage. We re-analyzed the retrieved RNA-seq data and revealed 177 differentially expressed lncRNAs in damage vs intact cartilage, including Nuclear Paraspeckle Assembly Transcript 1(NEAT1). MiR-150-5p, NEAT1, b-catenin, matrix metallopeptidase 13 (MMP-13), and ADAM metallopeptidase with thrombospondin type 1 motif 5 (ADAMTS-5) expressions were assessed by reverse transcription-quantitative PCR (RT-qPCR) and western blot assay. Knockout and transfection experiments were conducted to investigate the role of NEAT1/miR-150-5p/b-catenin in cartilage degradation. Bioinformatics analysis revealed that b-catenin was an OA-related miR-150-5p target. MiR-150-5p overexpression in OA chondrocytes resulted in decreased expression of b-catenin, as well as MMP-13 and ADAMTS-5, both being Wnt/b-catenin downstream target genes. NEAT1/miR-150-5p interaction was predicted by bioinformatics analysis, while NEAT1 knockout led to increased expression of miR-150-5p in OA chondrocytes. Moreover, inhibition of miR-150-5p reversed the repressive effects of NEAT1 silencing in b-catenin expression in OA chondrocytes. Our results support a possible catabolic role of NEAT1/miR-150-5p interaction in OA progression by regulating b-catenin expression.

Advances in Research on the Regulatory Roles of lncRNAs in Osteoarthritic Cartilage

Osteoarthritis (OA) is the most common degenerative bone and joint disease that can lead to disability and severely affect the quality of life of patients. However, its etiology and pathogenesis remain unclear. It is currently believed that articular cartilage lesions are an important marker of the onset and development of osteoarthritis. Long noncoding RNAs (lncRNAs) are a class of multifunctional regulatory RNAs that are involved in various physiological functions. There are many differentially expressed lncRNAs between osteoarthritic and normal cartilage tissues that play multiple roles in the pathogenesis of OA. Here, we reviewed lncRNAs that have been reported to play regulatory roles in the pathological changes associated with osteoarthritic cartilage and their potential as biomarkers and a therapeutic target in OA to further elucidate the pathogenesis of OA and provide insights for the diagnosis and treatment of OA.

Linc00511 Knockdown Inhibited TGF-β1-Induced Epithelial-Mesenchymal Transition of Bronchial Epithelial Cells by Targeting miR-16-5p/Smad3

BACKGROUND

Airway remodeling in patients with asthma was correlated with induced epithelial-mesenchymal transition (EMT) of bronchial epithelial cells.

OBJECTIVE

This study examined the mechanism of Linc00511 on induced EMT of bronchial epithelial cells after transforming growth factor-β1 (TGF-β1) induction.

METHODS

The human bronchial epithelial cell 16HBE was treated with 10 ng/mL TGF-β1 for 12 h, 24 h, or 48 h to induce EMT. Cell proliferation and migration rate were detected using CCK8 and wound healing assays, respectively. The expression of key markers of EMT (E-cadherin, N-cadherin, Small mothers against decapentaplegic family member 3 [Smad3], and slug) was tested by Western blot.

RESULTS

We found that Linc00511 was time dependently increased in TGF-β-treated 16HBE cells. Silencing Linc00511 reduced 16HBE cell proliferation, migration, and EMT progress. In addition, the dual-luciferase reporter assay showed Linc00511 was a molecular sponge for miR-16-5p. MiR-16-5p decreased the expression of Smad3 by targeting its 3'-untranslated region (3'UTR). After TGF-β1 exposure, miR-16-5p silencing counteracted the decreases of 16HBE cell proliferation, migration, and EMT induced by Linc00511 knockdown. And Smad3 overexpression also reversed the inhibitory effect of Linc00511 knockdown on proliferation, migration, and EMT progression in TGF-β1-induced human bronchial epithelial cells.

CONCLUSION

Linc00511 may be a valuable biomarker for asthma therapy.

miR-150-5p and XIST interaction controls monocyte adherence: Implications for osteoarthritis therapy

Recent literature highlights the importance of microRNAs (miRNAs) functioning as diagnostic biomarkers and therapeutic agents in osteoarthritis (OA) and regulators of gene expression. In OA pathogenesis, cell adhesion molecules (CAMs), especially vascular cell adhesion protein 1 (VCAM-1), recruit monocyte infiltration to inflamed synovial tissues and thus accelerate OA progression. Up until now, little has been known about the regulatory mechanisms between miRNAs, long non-coding RNAs (lncRNAs) and VCAM-1 during OA progression. The evidence in this article emphasizes that the functional feature of miR-150-5p is an interaction with the lncRNA X-inactive specific transcript (XIST), which regulates VCAM-1-dependent monocyte adherence in OA synovial fibroblasts (OASFs). Levels of VCAM-1, CD11b (a monocyte marker) and XIST expression were higher in human synovial tissue samples and OASFs, while levels of miR-150-5p were lower in human OA synovial tissue compared with non-OA specimens. XIST enhanced VCAM-1-dependent monocyte adherence to OASFs. Upregulation of miR-150-5p inhibited the effects of XIST upon monocyte adherence. Administration of miR-150-5p effectively ameliorated OA severity in anterior cruciate ligament transection (ACLT) rats. The interaction of miR-150-5p and XIST regulated VCAM-1-dependent monocyte adherence and attenuated OA progression. Our findings suggest that miR-150-5p is a promising small-molecule therapeutic strategy for OA.

Epigenetic Regulation in Knee Osteoarthritis

Osteoarthritis (OA) is a complicated disease with both hereditary and environmental causes. Despite an increase in reports of possible OA risk loci, it has become clear that genetics is not the sole cause of osteoarthritis. Epigenetics, which can be triggered by environmental influences and result in transcriptional alterations, may have a role in OA pathogenesis. The majority of recent research on the epigenetics of OA has been focused on DNA methylation, histone modification, and non-coding RNAs. However, this study will explore epigenetic regulation in OA at the present stage. How genetics, environmental variables, and epigenetics interact will be researched, shedding light for future studies. Their possible interaction and control processes open up new avenues for the development of innovative osteoarthritis treatment and diagnostic techniques.

LncRNAs in Osteoarthritis

Osteoarthritis (OA) is a progressive joint disease that affects millions of older adults around the world. With increasing rates of incidence and prevalence worldwide, OA has become an enormous global socioeconomic burden on healthcare systems. Long non-coding ribonucleic acids (lncRNAs), essential functional molecules in many biological processes, are a group of non-coding RNAs that are greater than approximately 200 nucleotides in length. Fast-growing and recent developments in lncRNA research are captivating and represent a novel and promising field in understanding the complexity of OA pathogenesis. The involvement of lncRNAs in OA's pathological processes and their altered expressions in joint tissues, blood and synovial fluid make them attractive candidates for the diagnosis and treatment of OA. We focus on the recent advances in major regulator mechanisms of lncRNAs in the pathophysiology of OA and discuss potential diagnostic and therapeutic uses of lncRNAs for OA. We investigate how upregulation or downregulation of lncRNAs influences the pathogenesis of OA and how we can use lncRNAs to elucidate the molecular mechanism of OA. Furthermore, we evaluate how we can use lncRNAs as a diagnostic marker or therapeutic target for OA. Our study not only provides a comprehensive review of lncRNAs regarding OA's pathogenesis but also contributes to the elucidation of its molecular mechanisms and to the development of diagnostic and therapeutic approaches for OA.

Long noncoding RNAs in mesenchymal stromal/stem cells osteogenic differentiation: Implications in osteoarthritis pathogenesis

This letter focuses on a recently published article that provided an exceptional description of the effect of epigenetic modifications on gene expression patterns related to skeletal system remodeling. Specifically, it discusses a novel modality of epigenetic regulation, the long noncoding RNAs (lncRNAs), and provides evidence of their involvement in mesenchymal stromal/stem cells osteo-/adipo-genic differentiation balance. Despite focus on lncRNAs, there is an emerging cross talk between lncRNAs and miRNAs interaction as a novel mechanism in the regulation of the function of the musculoskeletal system, by controlling bone homeostasis and bone regeneration, as well as the osteogenic differentiation of stem cells. Thus, we touched on some examples to demonstrate this interaction. In addition, we believe there is still much to discover from the effects of lncRNAs on progenitor and non-progenitor cell differentiation. We incorporated data from other published articles to review lncRNAs in normal progenitor cell osteogenic differentiation, determined lncRNAs involved in osteoarthritis pathogenesis in progenitor cells, and provided a review of lncRNAs in non-progenitor cells that are differentially regulated in osteoarthritis. In conclusion, we really enjoyed reading this article and with this information we hope to further our understanding of lncRNAs and mesenchymal stromal/stem cells regulation.

Effects of interleukin 1β on long noncoding RNA and mRNA expression profiles of human synovial fluid derived mesenchymal stem cells

Synovial fluid-derived mesenchymal stem cells (SFMSCs) play important regulatory roles in the physiological balance of the temporomandibular joint. Interleukin (IL)-1β regulates the biological behavior of SFMSCs; however, the effects of IL-1β on long noncoding RNA (lncRNA) and mRNA expression in SFMSCs in the temporomandibular joint are unclear. Here, we evaluated the lncRNA and mRNA expression profiles of IL-1β-stimulated SFMSCs. Using microarrays, we identified 264 lncRNAs (203 upregulated, 61 downregulated) and 258 mRNAs (201 upregulated, 57 downregulated) that were differentially expressed after treatment with IL-1β (fold changes ≥ 2, P < 0.05). Kyoto Encyclopedia of Genes and Genomes pathway analysis found that one of the most significantly enriched pathways was the NF-κB pathway. Five paired antisense lncRNAs and mRNAs, eight paired enhancer lncRNAs and mRNAs, and nine paired long intergenic noncoding RNAs and mRNAs were predicted to be co-expressed. A network constructed by the top 30 K-score genes was visualized and evaluated. We found a co-expression relationship between RP3-467K16.4 and IL8 and between LOC541472 and IL6, which are related to NF-κB pathway activation. Overall, our results provide important insights into changes in lncRNA and mRNA expression in IL-1β-stimulated SFMSCs, which can facilitate the identification of potential therapeutic targets.

A Quartet Network Analysis Identifying Mechanically Responsive Long Noncoding RNAs in Bone Remodeling

Mechanical force, being so ubiquitous that it is often taken for granted and overlooked, is now gaining the spotlight for reams of evidence corroborating their crucial roles in the living body. The bone, particularly, experiences manifold extraneous force like strain and compression, as well as intrinsic cues like fluid shear stress and physical properties of the microenvironment. Though sparkled in diversified background, long noncoding RNAs (lncRNAs) concerning the mechanotransduction process that bone undergoes are not yet detailed in a systematic way. Our principal goal in this research is to highlight the potential lncRNA-focused mechanical signaling systems which may be adapted by bone-related cells for biophysical environment response. Based on credible lists of force-sensitive mRNAs and miRNAs, we constructed a force-responsive competing endogenous RNA network for lncRNA identification. To elucidate the underlying mechanism, we then illustrated the possible crosstalk between lncRNAs and mRNAs as well as transcriptional factors and mapped lncRNAs to known signaling pathways involved in bone remodeling and mechanotransduction. Last, we developed combinative analysis between predicted and established lncRNAs, constructing a pathway–lncRNA network which suggests interactive relationships and new roles of known factors such as H19. In conclusion, our work provided a systematic quartet network analysis, uncovered candidate force-related lncRNAs, and highlighted both the upstream and downstream processes that are possibly involved. A new mode of bioinformatic analysis integrating sequencing data, literature retrieval, and computational algorithm was also introduced. Hopefully, our work would provide a moment of clarity against the multiplicity and complexity of the lncRNA world confronting mechanical input.

miR‑150‑5p inhibits osteogenic differentiation of fibroblasts in ankylosing spondylitis by targeting VDR

Dysregulated microRNAs (miRNAs or miRs) serve potential roles in inflammatory systemic disease, including ankylosing spondylitis (AS). The aim of the present study was to investigate the potential function of miR-150-5p in osteogenic differentiation of AS fibroblasts and its underlying mechanism. The expression of miR-150-5p and vitamin D receptor (VDR) in AS joint capsules and fibroblasts was detected by reverse transcription-quantitative (RT-q)PCR and western blotting. Following overexpression of miR-150-5p, the alteration in osteogenic gene expression was detected by RT-qPCR, western blotting and alkaline phosphatase activity assay, as well as alizarin red staining. The association between miR-150-5p and VDR was confirmed by luciferase assay and rescue experiments were performed. Patients with AS exhibited decreased expression of miR-150-5p in joint capsules. Treatment with bone morphogenic protein 2 (BMP-2) and transforming growth factor-β1 (TGF-β1) led to downregulation of miR-150-5p in AS fibroblasts. Enforced expression of miR-150-5p attenuated osteogenic differentiation of AS fibroblasts. These results demonstrated that miR-150-5p inhibited osteogenic differentiation of AS fibroblasts by targeting VDR. miR-150-5p overexpression decreased osteogenic transformation of fibroblasts by decreasing VDR expression in AS.

Crosstalk Among circRNA/lncRNA, miRNA, and mRNA in Osteoarthritis

Osteoarthritis (OA) is a joint disease that is pervasive in life, and the incidence and mortality of OA are increasing, causing many adverse effects on people's life. Therefore, it is very vital to identify new biomarkers and therapeutic targets in the clinical diagnosis and treatment of OA. ncRNA is a nonprotein-coding RNA that does not translate into proteins but participates in protein translation. At the RNA level, it can perform biological functions. Many studies have found that miRNA, lncRNA, and circRNA are closely related to the course of OA and play important regulatory roles in transcription, post-transcription, and post-translation, which can be used as biological targets for the prevention, diagnosis, and treatment of OA. In this review, we summarized and described the various roles of different types of miRNA, lncRNA, and circRNA in OA, the roles of different lncRNA/circRNA-miRNA-mRNA axis in OA, and the possible prospects of these ncRNAs in clinical application.

The Emerging Role of Non-Coding RNAs in Osteoarthritis

Osteoarthritis (OS) is the most frequent degenerative condition in the joints, disabling many adults. Several abnormalities in the articular cartilage, subchondral bone, synovial tissue, and meniscus have been detected in the course of OA. Destruction of articular cartilage, the formation of osteophytes, subchondral sclerosis, and hyperplasia of synovial tissue are hallmarks of OA. More recently, several investigations have underscored the regulatory roles of non-coding RNAs (ncRNAs) in OA development. Different classes of non-coding RNAs, including long ncRNAs (lncRNAs), microRNAs (miRNAs), and circular RNAs (circRNAs), have been reported to affect the development of OA. The expression level of these transcripts has also been used as diagnostic tools in OA. In the present article, we aimed at reporting the role of these transcripts in this process. We need to give a specific angle on the pathology to provide meaningful thoughts on it.

Positive feedback loop of lncRNA FAM201A/miR‑146a‑5p/POU2F1 regulates IL‑1β‑induced chondrocyte injury in vitro

Numerous studies have previously demonstrated that long non-coding RNAs (lncRNAs) serve an important regulatory role in osteoarthritis (OA). In particular, the lncRNA family with sequence similarity 201 member A (FAM201A) was previously found to be downregulated in necrotic femoral head samples. However, the role of FAM201A in IL-1β-induced chondrocyte injury remains unclear. It was hypothesized that FAM201A may exert a protective effect on IL-1β-induced chondrocyte injury in OA by sponging microRNAs (miRNAs/miRs). The purpose of the present study was to explore the role and molecular mechanism of FAM201A in IL-1β-induced chondrocyte injury. A model of OA was established by stimulation C-28/I2 cell with IL-1β in vitro. The expression levels of FAM201A following IL-1β-induced chondrocyte injury were detected via reverse transcription-quantitative PCR. Luciferase reporter assay was used to assess the possible associations among FAM201A, miR-146a-5p and POU class 2 homeobox 1 (POU2F1). Chromatin immunoprecipitation assay was performed to analyze the interaction between POU2F1 and miR-146a-5p. ELISA, TUNEL and western blotting were performed to measure the level of inflammation, lactate dehydrogenase release, apoptosis and the expression of apoptosis-related proteins (Bcl-2, Bax, cleaved caspase 3 and cleaved caspase 9), respectively. The expression levels of FAM201A were found to be downregulated following IL-1β-induced chondrocyte injury. Overexpression of FAM201A exerted a protective effect against IL-1β-induced chondrocyte injury. In addition, FAM201A could upregulate the expression levels of POU2F1 by sponging miR-146a-5p. Further experiments revealed that POU2F1 could bind to the promoter region of FAM201A and subsequently regulate the expression levels of POU2F1, indicating a role for the FAM201A/miR-146a-5p/POU2F1 positive feedback loop in IL-1β-induced chondrocyte injury. The present study revealed the protective effects of the FAM201A/miR-146a-5p/POU2F1 positive feedback loop on IL-1β-induced chondrocyte injury and provided a potential therapeutic target for OA.

Transcription factor Krüppel-like factor 5-regulated N-myc downstream-regulated gene 2 reduces IL-1β-induced chondrocyte inflammatory injury and extracellular matrix degradation

Previous research has identified N-myc downstream-regulated gene 2 (NDRG2) as one of the differentially expressed genes common to rat models of osteoarthritis (OA) and human OA. The purpose of this study was to investigate the role of NDRG2 in OA. In this study, an in vitro OA model was constructed by challenging ATDC5 chondrocytes with 10 ng/ml IL-1β. After transfection of pcDNA3.1(+)/NDRG2, qPCR and western blot were performed to assay NDRG2 expression. The analyses of cell viability, apoptosis and inflammatory molecule expression were employed respectively by CCK-8, TUNEL and ELISA. The protein expression related to apoptosis, inflammation or extracellular matrix (ECM) degradation was detected by western blot. The binding of Krüppel-like factor 5 (KLF5) to NDRG2 promoter was verified by means of dual-luciferase reporter assay. After overexpression of both NDRG2 and KLF5 in IL-1β-stimulated ATDC5 chondrocytes, corresponding assays were performed to examine cell viability, apoptosis, inflammatory response and ECM degradation. In ATDC5 chondrocytes challenged with IL-1β, NDRG2 expression was much lower than that in the control group, whereas it’s overexpression helped restored cell viability and reduce cell apoptosis, inflammatory response and ECM degradation. It was also observed that KLF5 expression was decreased in IL-1β-stimulated ATDC5 chondrocytes, and that KLF5 bound to the NDRG2 promoter. Importantly, overexpressing KLF5 could reverse the protective effect of NDRG2 overexpression on IL-1β-stimulated ATDC5. Overall, NDRG2 could be transcriptionally regulated by transcription factor KLF5 and may play a protective role against chondrocyte the inflammatory response and ECM degradation in OA.

LncRNAs as a new regulator of chronic musculoskeletal disorder

Objectives

In recent years, long non‐coding RNAs (lncRNAs) have been found to play a role in the occurrence, progression and prognosis of chronic musculoskeletal disorders.

Design and methods

Literature exploring on PubMed was conducted using the combination of keywords 'LncRNA' and each of the following: 'osteoarthritis', 'rheumatoid arthritis', 'osteoporosis', 'osteogenesis', 'osteoclastogenesis', 'gout arthritis', 'Kashin‐Beck disease', 'ankylosing spondylitis', 'cervical spondylotic myelopathy', 'intervertebral disc degeneration', 'human muscle disease' and 'muscle hypertrophy and atrophy'. For each disorder, we focused on the publications in the last five years (5/1/2016‐2021/5/1, except for Kashin‐Beck disease). Finally, we excluded publications that had been reported in reviews of various musculoskeletal disorders during the last three years. Here, we summarized the progress of research on the role of lncRNA in multiple pathological processes during musculoskeletal disorders.

Results

LncRNAs play a crucial role in regulating downstream gene expression and maintaining function and homeostasis of cells, especially in chondrocytes, synovial cells, osteoblasts, osteoclasts and skeletal muscle cells.

Conclusions

Understanding the mechanisms of lncRNAs in musculoskeletal disorders may provide promising strategies for clinical practice.