LncRNA MCM3AP-AS1 regulates miR-142-3p/HMGB1 to promote LPS-induced chondrocyte apoptosis

Long noncoding RNA MCM3AP-AS1 attenuates sepsis-induced cardiomyopathy by improving inflammation, oxidative stress, and mitochondrial function through mediating the miR-501-3p/CADM1/STAT3 axis

Oxidative stress and inflammation are highly important for sepsis-mediated myocardial damage. The long noncoding RNA (lncRNA) MCM3AP-AS1 is involved in inflammatory diseases, but its function in acute myocardial injury during sepsis has not been fully elucidated. LPS and cecal ligation and puncture (CLP) were used to construct in vitro and in vivo sepsis-induced myocardial damage models, respectively. qRT-PCR was used to evaluate alterations in MCM3AP-AS1 and miR-501-3p alterations. After the MCM3AP-AS1 and miR-501-3p knockdown or overexpression models were established, the viability, apoptosis, inflammation, oxidative stress, and mitochondrial function of the myocardial cells were examined. Dual luciferase activity assay, RNA immunoprecipitation, and fluorescence in situ hybridization (FISH) confirmed the correlation among MCM3AP-AS1, miR-501-3p, and CADM1. Previous studies revealed that MCM3AP-AS1 was downregulated in sepsis patients, myocardial cells treated with LPS, and in the CLP mouse sepsis model, whereas miR-501-3p expression was increased. MCM3AP-AS1 overexpression hampered myocardial damage mediated by LPS and abated inflammation, oxidative stress, and mitochondrial dysfunction in myocardial cells and THP-1 cells. In contrast, MCM3AP-AS1 knockdown or miR-501-3p overexpression promoted all the effects of LPS. In vivo, MCM3AP-AS1 overexpression increased the survival rate of CLP mice; ameliorated myocardial injury; decreased the levels of TNF-α, IL-1β, IL-6, iNOS, COX2, ICAM1, VCAM1, PGE2, and MDA; and increased the levels of SOD, GSH-PX, Nrf2, and HO-1. Mechanistic studies demonstrated that MCM3AP-AS1 acted as a competitive endogenous RNA to repress miR-501-3p, enhance CADM1 expression, and dampen STAT3/nuclear factor-kappaB (NF-κB) activation. MCM3AP-AS1 suppresses myocardial injury elicited by sepsis by mediating the miR-501-3p/CADM1/STAT3/NF-κB axis.

The Role of Alarmins in Osteoarthritis Pathogenesis: HMGB1, S100B and IL-33

Osteoarthritis (OA) is a multifactorial disease in which genetics, aging, obesity, and trauma are well-known risk factors. It is the most prevalent joint disease and the largest disability problem worldwide. Recent findings have described the role of damage-associated molecular patterns (DAMPs) in the course of the disease. In particular, alarmins such as HMGB1, IL-33, and S100B, appear implicated in enhancing articular inflammation and favouring a catabolic switch in OA chondrocytes. The aims of this review are to clarify the molecular signalling of these three molecules in OA pathogenesis, to identify their possible use as staging biomarkers, and, most importantly, to find out whether they could be possible therapeutic targets. Osteoarthritic cartilage expresses increased levels of all three alarmins. HMGB1, in particular, is the most studied alarmin with increased levels in cartilage, synovium, and synovial fluid of OA patients. High levels of HMGB1 in synovial fluid of OA joints are positively correlated with radiological and clinical severity. Counteracting HMGB1 strategies have revealed improving results in articular cells from OA patients and in OA animal models. Therefore, drugs against this alarmin, such as anti-HMGB1 antibodies, could be new treatment possibilities that can modify the disease course since available medications only alleviate symptoms.

The role of apoptosis in the pathogenesis of osteoarthritis

PURPOSE

Apoptosis is an important physiological process, making a great difference to development and tissue homeostasis. Osteoarthritis (OA) is a chronic joint disease characterized by degeneration and destruction of articular cartilage and bone hyperplasia. This purpose of this study is to provide an updated review of the role of apoptosis in the pathogenesis of osteoarthritis.

METHODS

A comprehensive review of the literature on osteoarthritis and apoptosis was performed, which mainly focused on the regulatory factors and signaling pathways associated with chondrocyte apoptosis in osteoarthritis and other pathogenic mechanisms involved in chondrocyte apoptosis.

RESULTS

Inflammatory mediators such as reactive oxygen species (ROS), nitric oxide (NO), IL-1β, tumor necrosis factor-α (TNF-α), and Fas are closely related to chondrocyte apoptosis. NF-κB signaling pathway, Wnt signaling pathway, and Notch signaling pathway activate proteins and gene targets that promote or inhibit the progression of osteoarthritis disease, including chondrocyte apoptosis and ECM degradation. Long non-coding RNAs (LncRNAs) and microRNAs (microRNAs) have gradually replaced single and localized research methods and become the main research approaches. In addition, the relationship between cellular senescence, autophagy, and apoptosis was also briefly explained.

CONCLUSION

This review offers a better molecular delineation of apoptotic processes that may help in designing new therapeutic options for OA treatment.

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.

Research progress on microRNA in gout

Gout is a common form of arthritis caused by the deposition of sodium urate crystals in the joints and tissues around them. MicroRNAs (miRNAs) are noncoding RNAs that have been shown to be involved in regulating the pathogenesis of gout through multiple cellular signaling pathways, which may be potential targets for the treatment of gout. In this review, we systematically discuss the regulatory roles of related miRNAs in gout, which will provide help for the treatment of gout and miRNAs is expected to become a potential biomarker for gout diagnosis.

Long Non-Coding RNA MCM3AP-AS1: A Crucial Role in Human Malignancies

The incidence of cancer continues to grow and is one of the leading causes of death in the world. Long noncoding RNAs (LncRNAs) is a group of RNA transcripts greater than 200 nucleotides in length, and although it cannot encode proteins, it can regulate different biological functions by controlling gene expression, transcription factors, etc. LncRNA micro-chromosome maintenance protein 3-associated protein antisense RNA 1 (MCM3AP-AS1) is involved in RNA processing and cell cycle-related functions, and MCM3AP-AS1 is dysregulated in expression in various types of cancers. This biomarker is involved in many processes related to carcinogens, such as cell proliferation, apoptosis, cell cycle, and migration. In this review, we summarize the roles of MCM3AP-AS1 in different human cancers and its biological functions with a view to providing ideas for future research.

LncRNA LEMD1-AS1 relieves chondrocyte inflammation by targeting miR-944/PGAP1 in osteoarthritis

Osteoarthritis (OA) is a common degenerative disease characterized by reducing articular chondrocytes and destruction of joint matrix, it's detailed pathogenesis remains unclear. Emerging evidences have demonstrated that long non-coding RNAs (lncRNAs) are closely related to the progression of OA. This study aims to explore the expression of long non-coding RNA LEMD1 antisense RNA 1 (LEMD1-AS1) in OA tissues and chondrocytes and investigate the possible mechanisms of LEMD1-AS1 in OA, which will provide a new target for the treatment of OA. In our study, LEMD1-AS1 and post-GPI attachment to protein (PGAP1) were lowly expressed, but miR-944 was highly expressed both in OA tissues and in Lipopolysaccharide (LPS) -treated chondrocytes detected by qRT-PCR. Over-expression of LEMD1-AS1 or down-regulation of miR-944 significantly promoted viability, proliferation and inhibited cell apoptosis, cell cycle arrest and inflammatory responses of chondrocytes treated with LPS by CCK-8, EdU, flow cytometry and an ELISA assay. Over-expression of LEMD1-AS1 or down-regulation of miR-944 remarkably increased the protein levels of PCNA, Ki-67, Cyclin A1, Cyclin B1, Cyclin D2 and Bcl-2, while decreasing the protein levels of p27, Bax, Cleaved-caspase-3 and Cleaved-caspase-9 in chondrocytes treated with LPS. LEMD1-AS1 bound to miR-944 and regulated its expression, and PGAP1 presented as a direct target gene of miR-944, which was confirmed by a dual-luciferase reporter assay. Inhibition of PGAP1 partially restored the effects of LEMD1-AS1/miR-944 on the proliferation, cell apoptosis, cell cycle distribution and inflammatory responses of LPS-treated chondrocytes. To conclude, the LEMD1-AS1/miR-944/PGAP1 axis may be a novel therapeutic candidate to target in OA treatment.

MicroRNA-142-3p facilitates inflammatory response by targeting ZEB2 and activating NF-κB signaling in gouty arthritis

Gouty arthritis (GA) is caused by monosodium urate (MSU) crystal accumulation in the joints. MSU-mediated inflammation is an important inducing factor in gouty arthritis (GA). Recent studies have demonstrated that microRNAs can influence GA progression. Herein, the role and mechanism of miRNA-142-3p in GA were explored. To establish the in vitro and in vivo GA models, MSU was used to induce inflammatory response in human monocyte cell line THP-1 and male C57BL/6 mice. Protein levels, gene expression and proinflammatory cytokine secretion were respectively tested by Western blotting, RT-qPCR, and enzyme-linked immunosorbent assay (ELISA). Pathological changes in sagittal sections of ankle tissues were exhibited by hematoxylin-eosin (HE) staining. Binding relationship between miRNA-142-3p and zinc finger E-box binding homeobox 2 (ZEB2) was predicted and confirmed by bioinformatics analysis and luciferase reporter assay. In this study, MSU induced inflammatory response and upregulated miRNA-142-3p in THP-1 cells. Functionally, miRNA-142-3p knockdown inhibited inflammatory response in MSU-stimulated THP-1 cells and alleviated pathological symptoms of GA mice. Mechanically, miRNA-142-3p targeted ZEB2 in THP-1 cells. ZEB2 expression was elevated in MSU-administrated THP-1 cells and GA mice. ZEB2 downregulation reserved the inhibitory effect of miRNA-142-3p deficiency on inflammatory response in MSU-treated THP-1 cells. In addition, miRNA-142-3p activated NF-κB signaling by binding with ZEB2 in THP-1 cells upon MSU stimulation. Overall, miRNA-142-3p facilitates inflammatory response by targeting ZEB2 and activating NF-κB signaling in GA.

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.

SOX4-activated lncRNA MCM3AP-AS1 aggravates osteoarthritis progression by modulating miR-149-5p/Notch1 signaling

OBJECTIVE

To clarify the expression and underlying network of long non-coding RNA (lncRNA) MCM3AP-AS1 in osteoarthritis (OA).

METHODS

Human articular cartilage samples, OA model rats and IL-1β-treated C28/I2 cells were used in this study. The expression changes of genes and proteins were assessed by real-time quantitative PCR (qRT-PCR) and western blot. Cell viability, apoptosis, autophagy and extracellular matrix (ECM) degradation were assessed by Cell Counting Kit-8 (CCK-8), immunohistochemistry (IHC), flow cytometry, immunofluorescence and western blot assays, respectively. Molecule interactions were validated by dual luciferase and Chromatin immunoprecipitation (ChIP) assays. H&E staining was used to detect the pathological changes of cartilage.

RESULTS

MCM3AP-AS1 was upregulated in OA patients and IL-1β-induced chondrocytes. Knockdown of MCM3AP-AS1 enhanced autophagy, while alleviated ECM degradation and cartilage injury. Mechanistically, overexpression of SOX4 boosted the transcription of MCM3AP-AS1. Moreover, MCM3AP-AS1 functioned as a molecular sponge or epigenetic regulator of miR-149-5p to facilitate Notch1 expression. Functional rescue experiments showed that either inhibition of miR-149-5p nor ectopic expression of Notch1 dramatically weakened the biological impacts of MCM3AP-AS1 silencing.

CONCLUSION

These finding demonstrated that SOX4-activated MCM3AP-AS1 aggravated OA progression by modulating autophagy and ECM degradation via targeting miR-149-5p/Notch1 axis. These data supported that inhibition of MCM3AP-AS1 might be a potential treatment strategy of OA.

Columbianetin alleviates lipopolysaccharides (LPS)-induced inflammation and apoptosis in chondrocyte through activation of autophagy by inhibiting serum and glucocorticoid-induced protein kinase 1 (SGK1) expression

Osteoarthritis (OA) is a degenerative disease of articular cartilage involving the entire joint tissue. Columbianetin (CBT) is a major active compound of radix angelicae pubescentis, which is used in the treatment of OA. This paper attempts to explore the role of CBT in OA. Lipopolysaccharides (LPS) was used to induce mouse chondrocytes ATDC5. The effect of CBT on cell viability in ATDC5 cells with or without LPS induction was determined by CCK-8 and LDH kits. The inflammatory response was evaluated using ELISA kits. Apoptosis in LPS-induced ATDC5 cells were examined by TUNEL staining. The expression of apoptosis and autophagy-related proteins was tested with Western blot. The relationship between CBT and serum and glucocorticoid-induced protein kinase 1 (SGK1) was examined by RT-qPCR, Western blot, and molecular docking. After SGK1 overexpression or addition of the autophagy inhibitor 3-methyladenine (3 MA), the above experiments were done again. Results revealed that CBT increased LPS-induced decrease in ATDC5 cell viability. CBT inhibited inflammation triggered by LPS, evidenced by reduced levels of TNF-α, IL-6 and IL-1β. Cell apoptosis was attenuated following CBT adding in ATDC5 cells exposed to LPS, accompanied by upregulated Bcl-2 expression and downregulated Bax and cleaved caspase 3 expression. In addition, CBT elevated Beclin1 and LC3II/LC3I expression but decreased p62 expression. Additionally, CBT inhibited SGK1 expression. However, SGK1 overexpression or 3 MA reversed the effects of CBT on LPS-induced loss of ATDC5 cell viability, inflammation, apoptosis and autophagy. Collectively, CBT could improve OA through the activation of chondrocyte autophagy by suppressing SGK1 expression.

Long non-coding RNA MCM3AP antisense RNA 1 silencing upregulates microRNA-24-3p to accelerate proliferation and migration of vascular endothelial cells in myocardial infarction rats by reducing EIF4G2

Long non-coding RNAs (lncRNAs) are crucial drivers in the progression of human diseases such as myocardial infarction (MI). However, the impact of lncRNA MCM3AP antisense RNA 1 (MCM3AP-AS1) on MI remains unknown. This research was determined to explore the effect of MCM3AP-AS1 modulating microRNA-24-3p (miR-24-3p) and eukaryotic translation initiation factor 4 gamma 2 (EIF4G2) on MI. The rat MI models were constructed and, respectively, treated with altered MCM3AP-AS1, miR-24-3p or/and EIF4G2. Subsequently, the cardiac function, myocardial pathological injury, malondialdehyde content and superoxide dismutase activity were determined. The vascular endothelial cells (VECs) were isolated and treated severally, and then proliferation and migration of VECs were measured. MCM3AP-AS1, miR-24-3p, EIF4G2 and vascular endothelial growth factor (VEGF) expressions in myocardial tissues and VECs were assessed. MCM3AP-AS1 and EIF4G2 were upregulated while miR-24-3p and VEGF were downregulated in MI rat myocardial tissues. MCM3AP-AS1 silencing or miR-24-3p elevation improved cardiac function and myocardial pathological injury, suppressed malondialdehyde content, and also enhanced VEGF expression and superoxide dismutase activity in MI rats. In VECs, downregulated MCM3AP-AS1 or upregulated miR-24-3p accelerated cell proliferation and migration. These effects of miR-24-3p upregulation were reversed by overexpressed EIF4G2. Our study summarizes that reduced MCM3AP-AS1 elevates miR-24-3p to promote proliferation and migration of MI rat VECs by inhibiting EIF4G2.

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 non-coding RNA interactome in joint health and disease

Non-coding RNAs have distinct regulatory roles in the pathogenesis of joint diseases including osteoarthritis (OA) and rheumatoid arthritis (RA). As the amount of high-throughput profiling studies and mechanistic investigations of microRNAs, long non-coding RNAs and circular RNAs in joint tissues and biofluids has increased, data have emerged that suggest complex interactions among non-coding RNAs that are often overlooked as critical regulators of gene expression. Identifying these non-coding RNAs and their interactions is useful for understanding both joint health and disease. Non-coding RNAs regulate signalling pathways and biological processes that are important for normal joint development but, when dysregulated, can contribute to disease. The specific expression profiles of non-coding RNAs in various disease states support their roles as promising candidate biomarkers, mediators of pathogenic mechanisms and potential therapeutic targets. This Review synthesizes literature published in the past 2 years on the role of non-coding RNAs in OA and RA with a focus on inflammation, cell death, cell proliferation and extracellular matrix dysregulation. Research to date makes it apparent that 'non-coding' does not mean 'non-essential' and that non-coding RNAs are important parts of a complex interactome that underlies OA and RA.

Interactions Among lncRNA/circRNA, miRNA, and mRNA in Musculoskeletal Degenerative Diseases

Musculoskeletal degenerative diseases (MSDDs) are pathological conditions that affect muscle, bone, cartilage, joint and connective tissue, leading to physical and functional impairments in patients, mainly consist of osteoarthritis (OA), intervertebral disc degeneration (IDD), rheumatoid arthritis (RA) and ankylosing spondylitis (AS). Long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) are novel regulators of gene expression that play an important role in biological regulation, involving in chondrocyte proliferation and apoptosis, extracellular matrix degradation and peripheral blood mononuclear cell inflammation. Research on MSDD pathogenesis, especially on RA and AS, is still in its infancy and major knowledge gaps remain to be filled. The effects of lncRNA/circRNA-miRNA-mRNA axis on MSDD progression help us to fully understand their contribution to the dynamic cellular processes, provide the potential OA, IDD, RA and AS therapeutic strategies. Further studies are needed to explore the mutual regulatory mechanisms between lncRNA/circRNA regulation and effective therapeutic interventions in the pathology of MSDD.

Upregulation of miR‑335 exerts protective effects against sepsis‑induced myocardial injury

Septicemia is associated with excessive inflammation, oxidative stress and apoptosis, causing myocardial injury that results in high mortality and disability rates worldwide. The abnormal expression of multiple microRNAs (miRNAs/miRs) is associated with more severe sepsis-induced myocardial injury (SIMI) and miR-335 has been shown to protect cardiomyocytes from oxidative stress. The present study aimed to investigate the role of miR-335 in SIMI. An SIMI model was established by cecal ligation and puncture (CLP) in mice. An miRNA-335 precursor (pre-miR-335) was transfected to accelerate miR-335 expression and an miR-335 inhibitor (anti-miR-335) was used to inhibit miR-335 expression. CLP or sham surgery was performed on pre-miR-335, anti-miR-335 and wild-type mice and miR-335 expression was determined by reverse transcription-quantitative PCR. Inflammatory factors (TNF-α, IL-6 and IL-10) and troponin (cTNI), brain natriuretic peptide (BNP), creatine kinase (CK), lactate dehydrogenase (LDH) and aspartate aminotransferase (AST) were assessed using commercial kits. Apoptosis was detected by flow cytometry and cardiac function was assessed using a Langendorff isolated cardiac perfusion system. miR-335 expression was upregulated and an elevation in inflammatory factors and cTNI, BNP, CK, LDH and AST was observed. Compared with the wild-type control group, pre-miR-335 mice treated with CLP exhibited significantly reduced left ventricular development pressure, maximum pressure increased reduction rates, as well as decreased levels of TNF-α, IL-6 and IL-10, myocardial injury and apoptosis; by contrast, these features were amplified in CLP-treated anti-miR-335 mice. In conclusion, the upregulation of miR-335 exerted ameliorative effects on myocardial injury following sepsis and may indicate a novel therapeutic intervention for SIMI.

MiR-142-3p ameliorates high glucose-induced renal tubular epithelial cell injury by targeting BOD1

BACKGROUND

Tubular injury plays a crucial role in the pathogenesis of diabetic nephropathy (DN). It is well known that many microRNAs (miRNAs) exert crucial effects on tubular injury. This study intends to explore the effect of miR-142-3p on the apoptosis and oxidative stress of high glucose (HG)-treated renal tubular epithelial cells (HK-2) and its underlying mechanism.

MATERIALS AND METHODS

HK-2 cells were exposed to HG to mimic cell injury. MTT assays and flow cytometry analyses were conducted to measure cell viability and cell apoptosis, respectively. RT-qPCR and western blot analyses were carried out to detect RNA and protein levels, respectively. The levels of oxidative stress markers were evaluated by ELISA. The binding between miR-142-3p and biorientation of chromosomes in cell division 1 (BOD1) was validated by a luciferase reporter assay.

RESULT

MiR-142-3p is low-expressed in HG-stimulated HK-2 cells. Functionally, miR-142-3p overexpression attenuates the apoptosis and oxidative stress of HG-stimulated HK-2 cells. Mechanistically, BOD1 was confirmed to be targeted by miR-142-3p in HK-2 cells. Moreover, BOD1 overexpression reversed the suppressive effect of miR-142-3p overexpression on the apoptosis and oxidative stress of HK-2 cells treated with HG.

CONCLUSION

MiR-142-3p ameliorates HG-induced renal tubular epithelial cell injury by targeting BOD1. The finding might provide novel insight into the role of miR-142-3p/BOD1 axis in DN treatment.

Long non-coding RNA MCM3AP-AS1 protects chondrocytes ATDC5 and CHON-001 from IL-1β-induced inflammation via regulating miR-138-5p/SIRT1

Osteoarthritis (OA) is a chronic inflammatory joint disease. Increased apoptosis of chondrocytes contributes to cartilage degradation in OA pathogenesis. The function of lncRNA MCM3AP-AS1 in regulating the viability of chondrocytes still awaits further elaboration. In this work, MCM3AP-AS1, miR-138-5p and SIRT1 mRNA expression levels in OA and normal cartilage tissues were detected by qRT-PCR. Besides, chondrocyte cell lines, CHON-001 and ATDC5 induced by interleukin-1β (IL-1β) were used to initiate the inflammatory response environment of OA. CCK-8 assay was used to examine the cell multiplication; meanwhile, transwell assay was utilized to detect migration. Western blot was adopted to determine SIRT1 expression in chondrocyte. Enzyme-linked immunosorbent assay (ELISA) was performed to evaluate inflammatory factor levels. In addition, the binding sites between MCM3AP-AS1 and miR-138-5p, miR-138-5p and 3'UTR of SIRT1 were validated by dual-luciferase reporter assay, RIP assay or RNA pull-down assay. It was found that MCM3AP-AS1 was declined in OA cartilage tissues, positively interrelated with SIRT1 expression while negatively correlated with miR-138-5p. MCM3AP-AS1 up-regulation enhanced the viability and migration of CHON-001 and ATDC5 cells while restraining the apoptosis and inflammatory response. Additionally, miR-138-5p overexpression counteracted the effects on chondrocytes caused by MCM3AP-AS1 overexpression. MCM3AP-AS1 could adsorb miR-138-5p, and SIRT1 was verified as a target of miR-138-5p, and SIRT1 could be up-regulated by overexpression of MCM3AP-AS1 indirectly. In conclusion, MCM3AP-AS1 has the potential to be the 'ceRNA' to regulate miR-138-5p and SIRT1 in chondrocytes, and to participate in the pathogenesis of OA.

Visfatin Regulates Inflammatory Mediators in Mouse Intestinal Mucosa Through Toll-Like Receptors Signaling Under Lipopolysaccharide Stress

Visfatin is a multifunctional protein involved in inflammatory immune stress. The aim of current study was to explore the role of visfatin in lipopolysaccharide (LPS)-induced intestinal mucosal inflammation and to confirm its cellular effect in inflammatory immune response through silencing of Toll-like receptors (TLRs). We divided Kunming mice into three groups: Saline group, LPS group, and LPS + visfatin group and performed hematoxylin and eosin staining, immunohistochemistry, quantitative polymerase chain reaction, Western blot, enzyme linked immunosorbent assay and RNA-seq analysis. Pretreatment of visfatin improves LPS-stimulated reduction of tight junction protein 1 (ZO-1) and secretory immunoglobulin A, inhibits overexpression of Claudin-1 and vascular endothelial growth factor, and reduces intestinal mucosal damage and inflammation. RNA-seq analysis of cellular transcriptomes indicated that visfatin is involved in down-regulation of mRNA level of TLR4 as well as attenuation of protein levels of TLR8 and nucleotide-binding oligomerization domain-containing protein 2, revealing that visfatin could reduce intestinal mucosal inflammation through TLR signaling pathway in mice ileum. In RAW264.7 cells, the genes silencing of Toll/IL-1R family, such as TLR4, TLR2, and IL-1R1, was accompanied by decreased expressions of inflammatory factors (TNF-α, IL-1β, IL-6 and MCP-1) along with lower cellular visfatin levels. Hence, visfatin maintains the intestinal mucosal barrier structure and attenuates the intestinal mucosal inflammation through the TLR signaling pathway. Likewise, the Toll/IL-1R family regulates the release of visfatin, which can participate in the inflammatory reaction through the regulation of inflammatory factors.

Long noncoding RNA MCM3AP-AS1 enhances cell proliferation and metastasis in colorectal cancer by regulating miR-193a-5p/SENP1

BACKGROUND

Accumulating evidences have shown that long noncoding RNAs (lncRNAs) play key roles in many diseases, including cancer. Several studies reported that MCM3AP antisense RNA 1 (MCM3AP-AS1) was associated with the tumorigenesis and progression. However, the specific function and mechanism of MCM3AP-AS1 in colorectal cancer (CRC) have not been fully understood.

METHODS

The expression of MCM3AP-AS1 was detected by quantitative reverse transcription PCR (RT-qPCR) in CRC tissues and matched noncancerous tissues (NCTs). CCK-8 assay, colony formation assay, transwell assay, xenograft and lung metastasis mouse models were used to examine the tumor-promoting function of MCM3AP-AS1 in vitro and in vivo. The binding relationship between MCM3AP-AS1, miR-193a-5p and sentrin-specific peptidase 1 (SENP1) were screened and identified by databases, RT-qPCR, dual luciferase reporter assay and western blot.

RESULTS

In the present study, we got that the expression of MCM3AP-AS1 was higher in CRC tissues than in paired NCTs, and increased MCM3AP-AS1 expression was associated with adverse outcomes in CRC patients. Functional experiments in vitro revealed that silencing of MCM3AP-AS1 could inhibit the proliferation, colony formation, migratory, and invasive abilities of CRC cells. The mouse models of xenograft and lung metastasis further confirmed that in vivo silencing MCM3AP-AS1 could significantly inhibit the growth and metastasis of CRC. Further mechanism studies indicated that MCM3AP-AS1 could sponge miR-193a-5p and inhibit the activity of it. What is more, SENP1 was proved to be a novel target of miR-193a-5p and could be upregulated by MCM3AP-AS1. At last, we observed that SENP1 overexpression in CRC tissues was closely related to unfavorable prognosis.

CONCLUSION

Taken together, we identified in CRC the MCM3AP-AS1/miR-193a-5p/SENP1 regulatory axis, which affords a therapeutic possibility for CRC.

LncRNA SNHG7 alleviates IL-1β-induced osteoarthritis by inhibiting miR-214-5p-mediated PPARGC1B signaling pathways

BACKGROUND

As a common joint disease, osteoarthritis (OA) is the main cause of limited joint mobility and disability. The role of lncRNAs in the regulation of OA is increasingly discovered. Therefore, further exploring the function of SNHG7 in OA is of great significance for understanding its occurrence and development.

METHODS

We used interleukin-1β (IL-1β) to treat to establish an OA model primary on chondrocytes in vitro, and gain- and loss of function assays of SNHG7 and miR-214-5p were conducted. The cell viability and apoptosis of chondrocytes were detected by CCK8 assay, BrdU assay and flow cytometry. The inflammatory cytokines (IL-1β, IL-6 and TNF-α), NLRP3 inflammasome, protein level of PPARGC1B, PPARγ, P38 and NF-κB were determined by RT-PCR and/or western blot.

RESULTS

The results showed that SNHG7 was distinctly downregulated, while miR-214-5p was significantly upregulated in OA patients and primary chondrocytes treated with IL-1β. In addition, SNHG7 enhanced cell viability, inhibited apoptosis and inflammation of IL-1β-mediated chondrocytes. In contrast, miR-214-5p upregulation reduced viability, promoted apoptosis and inflammation of chondrocytes. Mechanistically, SNHG7 served as a competitive endogenous RNA by sponging miR-214-5p, which targeted PPARGC1B. Besides, the results of the compensation experiment affirmed that miR-214-5p attenuates SNHG7-mediated protective effects on IL-1β-mediated chondrocytes against apoptosis and inflammation, and activating PPARγ pathway markedly dampened the cytotoxic effects of miR-214-5p.

CONCLUSIONS

Collectively, The above results confirmed that SNHG7 prevents IL-1β induced OA by inhibiting NLRP3 inflammasome and apoptosis through miR-214-5p/PPARGC1B axis.

MicroRNA-613 alleviates IL-1β-induced injury in chondrogenic CHON-001 cells by targeting fibronectin 1

BACKGROUND

Osteoarthritis (OA) is an aging-related chronic degenerative joint disease. A number of miRNAs have been found to be involved in the development of OA, but the role of miR-613 in OA remains unclear. Thus, this study aimed to investigate the role of miR-613 during the progression of OA.

METHODS

CHON-001 cells were transfected with miR-613 agonist for 48 h, and then exposed to 10 ng/mL IL-1β for 24 h. Cell viability, cell proliferation and cell apoptosis in CHON-001 cells were assessed by CCK-8, immunofluorescence, and flow cytometry assays, respectively. In addition, the dual luciferase reporter system assay was used to determine the interaction of miR-613 and fibronectin 1 in CHON-001 cells.

RESULTS

The level of miR-613 was significantly decreased in IL-1β-treated CHON-001 cells. Overexpression of miR-613 markedly inhibited IL-1β-induced apoptosis in CHON-001 cells. In addition, upregulation of miR-613 obviously alleviated IL-1β-induced inflammatory response and cartilage matrix degradation in CHON-001 cells. Meanwhile, fibronectin 1 was identified as a direct binding target of miR-613 in CHON-001 cells. Overexpression of miR-613 alleviated IL-1β-induced injury in CHON-001 cells via downregulating the expression of fibronectin 1. Furthermore, overexpression of miR-613 alleviated cartilage degradation, and reduced OARSI scores and subchondral bone thickness in a mouse model of OA.

CONCLUSION

Our data indicated that overexpression of miR-613 could inhibit IL-1β-induced injury in CHON-001 cells via decreasing the level fibronectin 1 in vitro, and alleviate the symptoms of OA in vivo. Therefore, miR-613 might be a potential therapeutic option for the treatment of OA.

The emerging role of lncRNAs in chondrocytes from osteoarthritis patients

Long non-coding RNAs (lncRNAs) play important roles in many physiological and pathological processes, including osteoarthritis (OA). Recent studies have demonstrated that lncRNAs are involved in the pathogenesis of OA by affecting various essential cellular features of chondrocytes, such as proliferation, apoptosis, inflammation, and degradation of the extracellular matrix (ECM). However, there are only a limited number of studies in this area, indicating that the role of lncRNAs in OA may have been overlooked. The aim of this literature review is to summarize the versatile roles and molecular mechanisms of lncRNAs in chondrocytes involved in OA. At the end of this article, the function of the lncRNA HOX transcript antisense RNA (HOTAIR) in chondrocytes in OA is highlighted. Because lncRNAs affect proliferation, apoptosis, inflammatory responses, and ECM degradation by chondrocytes in OA, they may serve as potential biomarkers or therapeutic targets for the diagnosis or treatment of OA. The specific role and related mechanisms of lncRNAs in OA warrants further investigation.

Overexpression of long non-coding RNA MCM3AP-AS1 in breast cancer tissues compared to adjacent non-tumour tissues

BACKGROUND

Altered expression of several long non-coding RNAs (lncRNAs) has been described in numerous malignancies, including breast cancer, and some may have a role in carcinogenesis. We hypothesised differences in the expression of lncRNA MCM3AP-AS1 in breast cancer tissues compared to nearby healthy tissues and potential links with clinical features.

METHODS

We tested our hypothesis in 102 pairs of breast cancer tumours and adjacent non-tumour tissues from female patients. After RNA extraction, cDNA synthesis was performed for all specimens. The differential gene expression was assessed using Quantitative Real-Time PCR Technique.

RESULTS

There was a significant overexpression of the lncRNAs in tumour tissues as compared with their adjacent non-tumour tissues (P < 0.001). Expression was significantly linked with the tumour oestrogen receptor expression (P = 0.023) and tumour progesterone receptor expression (P < 0.001). ROC analysis showed an AUC of 0.67 (95% CI 0.60-0.75) (P < 0.001) with sensitivity and specificity of 58% and 76%, respectively.

CONCLUSION

The lncRNA MCM3AP-AS1 may be a novel breast cancer lncRNA with high expression levels in breast cancer patients' tissue. Further investigations are needed to confirm its uses as a potential molecular marker and therapeutic target.

MiR-505 as an anti-inflammatory regulator suppresses HMGB1/NF-κB pathway in lipopolysaccharide-mediated endometritis by targeting HMGB1

Endometritis is characterized by severe inflammation and tissue damage. It is a common clinical disease that causes infertility due to infectious diseases of the reproductive system. MicroRNAs (miRNAs) are the current focus of research on the regulation of the inflammatory process and play a vital role in various inflammatory diseases. The highly conserved miR-505 regulates the mechanism of lipopolysaccharide (LPS) induced endometritis, but the extent to which pro-inflammatory genes are activated remains unclear. The results of this study showed that the expression of miR-505 was significantly down-regulated in mouse endometritis tissue and LPS-stimulated BEND cells. The study also showed that overexpression of miR-505 significantly suppressed the production of the pro-inflammatory cytokines IL-1β, IL-6 and TNF-α, and this effect was reversed by inhibiting the expression of miR-505. Moreover, miR-505 inhibited the expression of HMGB1 by targeting its 3'-UTR, thereby inhibiting the activation of HMGB1/NF-κB signalling. Taken together, the results of this study further confirmed that miR-505, as an anti-inflammatory agent, regulates the activation of the HMGB1/NF-κB signalling pathway through negative feedback.