MicroRNA-127-5p regulates matrix metalloproteinase 13 expression and interleukin-1β-induced catabolic effects in human chondrocytes

Mirabegron, dependent on β3-adrenergic receptor, alleviates mercuric chloride-induced kidney injury by reversing the impact on the inflammatory network, M1/M2 macrophages, and claudin-2

The β3-adrenergic receptor (β3-AR) agonism mirabegron is used to treat overactive urinary bladder syndrome; however, its role against acute kidney injury (AKI) is not unveiled, hence, we aim to repurpose mirabegron in the treatment of mercuric chloride (HgCl2)-induced AKI. Rats were allocated into normal, normal + mirabegron, HgCl2 untreated, HgCl2 + mirabegron, and HgCl2 + the β3-AR blocker SR59230A + mirabegron. The latter increased the mRNA of β3-AR and miR-127 besides downregulating NF-κB p65 protein expression and the contents of its downstream targets iNOS, IL-4, -13, and -17 but increased that of IL-10 to attest its anti-inflammatory capacity. Besides, mirabegron downregulated the protein expression of STAT-6, PI3K, and ERK1/2, the downstream targets of the above cytokines. Additionally, it enhanced the transcription factor PPAR-α but turned off the harmful hub HNF-4α/HNF-1α and the lipid peroxide marker MDA. Mirabegron also downregulated the CD-163 protein expression, which besides the inhibited correlated cytokines of M1 (NF-κB p65, iNOS, IL-17) and M2 (IL-4, IL-13, CD163, STAT6, ERK1/2), inactivated the macrophage phenotypes. The crosstalk between these parameters was echoed in the maintenance of claudin-2, kidney function-related early (cystatin-C, KIM-1, NGAL), and late (creatinine, BUN) injury markers, besides recovering the microscopic structures. Nonetheless, the pre-administration of SR59230A has nullified the beneficial effects of mirabegron on the aforementioned parameters. Here we verified that mirabegron can berepurposedto treat HgCl2-induced AKI by activating the β3-AR. Mirabegron signified its effect by inhibiting inflammation, oxidative stress, and the activated M1/M2 macrophages, events that preserved the proximal tubular tight junction claudin-2 via the intersection of several trajectories.

microRNA-365 attenuated intervertebral disc degeneration through modulating nucleus pulposus cell apoptosis and extracellular matrix degradation by targeting EFNA3

This present study is aimed to investigate the role of microRNA-365 (miR-365) in the development of intervertebral disc degeneration (IDD). Nucleus pulposus (NP) cells were transfected by miR-365 mimic and miR-365 inhibitor, respectively. Concomitantly, the transfection efficiency and the expression level of miRNA were detected by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Meanwhile, NP cells apoptosis was measured through propidium iodide (PI)-AnnexinV-fluorescein isothiocyanate (FITC) apoptosis detection kit. Subsequently, immunofluorescence (IF) staining was performed to assess the expression of collagen II, aggrecan and matrix metalloproteinase 13 (MMP-13). In addition, bioinformatic prediction and Luciferase reporter assay were used to reveal the target gene of miR-365. Finally, we isolated the primary NP cells from rats and injected NP-miR-365 in rat IDD models. The results showed that overexpression of miR-365 could effectively inhibit NP cells apoptosis and MMP-13 expression and upregulate the expression of collagen II and aggrecan. Conversely, suppression of miR-365 enhanced NP cell apoptosis and elevated MMP-13 expression, but decreased the expression of collagen II and aggrecan. Moreover, the further data demonstrated that miR-365 mediated NP cell degradation through targeting ephrin-A3 (EFNA3). In addition, the cells apoptosis and catabolic markers were increased in NP cells when EFNA3 upregulated. More importantly, the vivo data supported that miR-365-NP cells injection ameliorated IDD in rats models. miR-365 could alleviate the development of IDD by regulating NP cell apoptosis and ECM degradation, which is likely mediated by targeting EFNA3. Therefore, miR-365 may be a promising therapeutic avenue for treatment IDD through EFNA3.

MicroRNA expression in osteoarthritis: a meta-analysis

Osteoarthritis (OA) is one of the most prevalent musculoskeletal diseases globally, leading to chronic disability and poor prognosis. One of the approaches for optimizing OA treatment is to find early effective diagnostic biomarkers. The contribution of microRNAs (miRNAs) in OA progression is now being increasingly recognized. This review provides a comprehensive summary on studies reporting the expression profiling of miRNAs in OA and associated signaling pathways. We performed a systematic search of the Embase, Web of Science, PubMed, and Cochrane library databases. This systematic review is reported according to the PRISMA checklist. Studies which identified miRNAs with aberrant expression compared to controls during OA progression were included, and a meta-analysis was performed. Results from the random effects model were provided as log10 odds ratios (logORs) and 95% confidence intervals. Sensitivity analysis was conducted to confirm the accuracy of the results. Subgroup analysis was conducted based on tissue source. The target genes of miRNAs identified in this study were extracted from the MiRWalk database, and these target genes were enriched in Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathways. A total of 191 studies reporting 162 miRNAs were included in our meta-analysis. Among them, 36 miRNAs distributed across 96 studies were expressed in the same direction in at least two studies (13 up-regulated and 23 down-regulated). Subgroup analysis of tissue source revealed that the highest number of studies was conducted using articular cartilage, where the most up-regulated miRNAs were miR-146a-5p (logOR 7.355; P < 0.001) and miR-34a-5p (logOR 6.955; P < 0.001), and the most down-regulated miRNAs were miR-127-5p (logOR 6.586; P < 0.001) and miR-140-5p (logOR 6.373; P < 0.001). Enrichment analysis of 752 downstream target genes of all identified miRNAs was performed, and the regulatory relationships among them were displayed. Mesenchymal stem cells and transforming growth factor-β were found to be the most important downstream effectors regulated by miRNA in OA. This study highlighted the importance of miRNA signaling in OA progression and identified a number of prominent miRNAs including miR-146a-5p, miR-34a-5p, miR-127-5p, and miR-140-5p which might be considered as potential biomarkers for OA.

Exploring the Feasibility of Circulating miRNAs as Diagnostic and Prognostic Biomarkers in Osteoarthritis: Challenges and Opportunities

Osteoarthritis (OA) is a prevalent degenerative joint disease characterized by progressive cartilage degradation and joint inflammation. As the most common aging-related joint disease, OA is marked by inadequate extracellular matrix synthesis and the breakdown of articular cartilage. However, traditional diagnostic methods for OA, relying on clinical assessments and radiographic imaging, often need to catch up in detecting early-stage disease or i accurately predicting its progression. Consequently, there is a growing interest in identifying reliable biomarkers that can facilitate early diagnosis and prognosis of OA. MicroRNAs (miRNAs) have emerged as potential candidates due to their involvement in various cellular processes, including cartilage homeostasis and inflammation. This review explores the feasibility of circulating miRNAs as diagnostic and prognostic biomarkers in OA, focusing on knee OA while shedding light on the challenges and opportunities associated with their implementation in clinical practice.

Host microRNA interactions with the SARS-CoV-2 viral genome 3'-untranslated region

The 2019 pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has marked the spread of a novel human coronavirus. While the viral life cycle is well understood, most of the interactions at the virus-host interface remain elusive. Furthermore, the molecular mechanisms behind disease severity and immune evasion are still largely unknown. Conserved elements of the viral genome such as secondary structures within the 5'- and 3'-untranslated regions (UTRs) serve as attractive targets of interest and could prove crucial in furthering our understanding of virus-host interactions. It has been proposed that microRNA (miR) interactions with viral components could be used by both the virus and host for their own benefit. Analysis of the SARS-CoV-2 viral genome 3'-UTR has revealed the potential for host cellular miR binding sites, providing sites for specific interactions with the virus. In this study, we demonstrate that the SARS-CoV-2 genome 3'-UTR binds the host cellular miRNAs miR-760-3p, miR-34a-5p, and miR-34b-5p, which have been shown to influence translation of interleukin-6 (IL-6), the IL-6 receptor (IL-6R), as well as progranulin (PGRN), respectively, proteins that have roles in the host immune response and inflammatory pathways. Furthermore, recent work suggests the potential of miR-34a-5p and miR-34b-5p to target and inhibit translation of viral proteins. Native gel electrophoresis and steady-state fluorescence spectroscopy were utilized to characterize the binding of these miRs to their predicted sites within the SARS-CoV-2 genome 3'-UTR. Additionally, we investigated 2'-fluoro-D-arabinonucleic acid (FANA) analogs of these miRNAs as competitive binding inhibitors for these miR binding interactions. The mechanisms detailed in this study have the potential to drive the development of antiviral treatments for SARS-CoV-2 infection, and provide a potential molecular basis for cytokine release syndrome and immune evasion which could implicate the host-virus interface.

Circulating miR-146b and miR-27b are efficient biomarkers for early diagnosis of Equidae osteoarthritis

One of the most orthopedic problems seen in the equine is osteoarthritis (OA). The present study tracks some biochemical, epigenetic, and transcriptomic factors along different stages of monoiodoacetate (MIA) induced OA in donkeys in serum and synovial fluid. The aim of the study was the detection of sensitive noninvasive early biomarkers. OA was induced by a single intra-articular injection of 25 mg of MIA into the left radiocarpal joint of nine donkeys. Serum and synovial samples were taken at zero-day and different intervals for assessment of total GAGs and CS levels as well as miR-146b, miR-27b, TRAF-6, and COL10A1 gene expression. The results showed that the total GAGs and CS levels increased in different stages of OA. The level of expression of both miR-146b and miR-27b were upregulated as OA progressed and then downregulated at late stages. TRAF-6 gene was upregulated at the late stage while synovial fluid COL10A1 was over-expressed at the early stage of OA and then decreased at the late stages (P < 0.05). In conclusion, both miR-146b and miR-27b together with COL10A1 could be used as promising noninvasive biomarkers for the very early diagnosis of OA.

Circ_0002715 promotes the development of osteoarthritis through regulating LXN by sponging miR-127-5p

BACKGROUND

Our study aims to investigate the role and mechanism of circular RNA_0002715 (circ_0002715) in osteoarthritis (OA) progression.

METHODS

IL-1β-induced CHON-001 cells were used to mimic OA cell model. Circ_0002715, microRNA (miR)-127-5p and Latexin (LXN) expression was detected by quantitative real-time PCR. Cell functions were determined by MTT assay, flow cytometry and ELISA assay. Protein expression was examined by western blot.

RESULTS

Circ_0002715 was highly expressed in OA cartilage tissues. Circ_0002715 silencing inhibited inflammation, apoptosis, and ECM degradation in IL-1β-interfered CHON-001 cells. Circ_0002715 could sponge miR-127-5p, and miR-127-5p could target LXN. The effect of circ_0002715 down-regulation on chondrocyte injury was partially restored by miR-127-5p inhibitor. MiR-127-5p could suppress chondrocyte injury by inhibiting LXN expression.

CONCLUSION

Circ_0002715 might be a new therapeutic target for OA, which regulated miR-127-5p/LXN axis to promote IL-1β-induced chondrocyte injury.

Integrative analysis of microRNA-320a-related genes in osteoarthritis cartilage

Objectives

To investigate microRNA-320a-related differentially expressed genes (DEGs) and pathways in osteoarthritis (OA) by bioinformatic analysis.

Methods

The target genes of microRNA-320a were searched and collected from MiRTarBase microRNA Targets dataset, the TargetScan Predicted Nonconserved microRNA Targets dataset and the TargetScan Predicted Conserved microRNA Targets dataset. OA-related microRNAs and OA-related target genes were collected from GeneCards databases. The pathway enrichment analysis of miRNAs ware performed by Funrich analysis tool. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis was obtained from Database for Annotation, Visualization and Integrated Discovery (DAVID). GeneMANIA and STRING are used for protein-protein interaction (PPI) network analysis. Module analysis was performed by Cytoscape.

Results

A total of 176 OA related miRNAs were searched and collected for enrichment analysis, and microRNA-320a was one of OA related miRNAs. Enrichment pathway and analysis of 1721 miRNA-320a-related target genes from MiRTarBase and TargetScan were performed using the online tools Metascape. And results shown that the biological processes were remarkably enriched in chromatin organization, cellular response to DNA damage stimuli, mRNA metabolic process, protein ubiquitination, and regulation of cell adhesion. And then we analysed miRNA-320a-targeted OA genes via KEGG, GO enrichment and PPI Network. Our results showed that miRNA-320a played a role in OA through FoxO signaling pathway, PI3K-Akt signaling pathway, focal adhesion, MAPK signaling pathway, HIF-1 signaling pathway and cellular senescence. And we speculate that MAPK signaling pathway plays a key role in the effect of miRNA-320a on OA.

Conclusion

This study implied microRNA-320a-related DEGs and dysregulated pathways in OA. The aim is to screen miRNA-320a-related genes and pathways in OA and, eventually, to improve the understanding of underlying mechanisms of miRNA-320a in OA.

Research progress on the mechanism of interleukin-1β on epiphyseal plate chondrocytes

Epiphyseal plate injury, a common problem in pediatric orthopedics, may result in poor bone repair or growth defects. Epiphyseal plate, also known as growth plate is a layer of hyaline cartilage tissue between the epiphysis and metaphyseal and has the ability to grow longitudinally. Under normal physiological conditions, the epiphyseal plate has a certain axial resistance to stress, but it is fragile in growth phase and can be damaged by excessive stress, leading to detachment or avulsion of the epiphysis, resulting in life-long devastating consequences for patients. There is an obvious inflammatory response in the phase of growth plate injury, the limited physiological inflammatory response locally favors tissue repair and the organism, but uncontrolled chronic inflammation always leads to tissue destruction and disease progression. Interleukin-1β (IL-1β), as representative inflammatory factors, not only affect the inflammatory phase response to bone and soft tissue injury, but have a potentially important role in the later repair phase, though the exact mechanism is not fully understood. At present, epiphyseal plate injuries are mainly treated by corrective and reconstructive surgery, which is highly invasive with limited effectiveness, thus new therapeutic approaches are urgently needed, so a deeper understanding and exploration of the pathological mechanisms of epiphyseal plate injuries at the cellular molecular level is an entry point. In this review, we fully introduced the key role of IL-1 in the progression of epiphyseal plate injury and repair, deeply explored the mechanism of IL-1 on the molecular transcript level and endocrine metabolism of chondrocytes from multiple aspects, and summarized other possible mechanisms to provide theoretical basis for the clinical treatment and in-depth study of epiphyseal plate injury in children.

CircPRKCH modulates extracellular matrix formation and metabolism by regulating the miR-145/HGF axis in osteoarthritis

BACKGROUND

Osteoarthritis (OA) is a chronic degenerative joint disease. Extracellular matrix (ECM) degradation is essential for OA progression. Previous studies have shown that circular RNAs (circRNAs) are involved in the pathological process of OA. CircPRKCH has been shown to be upregulated in OA chondrocytes. The present study was aimed to explore the roles of circPRKCH in vivo and in vitro models of OA and its underlying molecular mechanisms.

METHODS

IL-1β-induced chondrocytes and mice injected with monosodium iodoacetate were used as OA models in vitro and in vivo, respectively. RT-qPCR was performed to measure the expression of circPRKCH, miR-145, and HGF in cartilage tissues and chondrocytes. The interaction between miR-145 and circPRKCH or HGF was verified by a dual-luciferase reporter assay. Chondrocyte apoptosis, viability, and ECM-related proteins were examined by flow cytometry, MTT assay, and Western blotting, respectively. Histopathological changes were detected by HE and Safranin O-fast green staining.

RESULTS

The expression of circPRKCH and HGF was increased in OA cartilage tissues and IL-1β-treated chondrocytes, while miR-145 expression was decreased. IL-1β induced chondrocyte apoptosis and ECM degradation in chondrocytes. Moreover, circPRKCH promoted HGF expression and activated HGF/c-MET by directly binding to miR-145. miR-145 knockdown or HGF overexpression significantly reversed circPRKCH knockdown-mediated inhibition of apoptosis and ECM degradation in IL-1β-induced chondrocytes. Besides, miR-145 overexpression alleviated IL-1β-induced chondrocyte apoptosis and ECM degradation by inhibiting HGF/c-MET. Finally, circPRKCH knockdown reduced ECM degradation by regulating the miR-145/HGF axis in an experimental OA model in mice.

CONCLUSION

Our study demonstrated that circPRKCH promoted chondrocyte apoptosis and ECM degradation via the miR-145/HGF axis in OA, which may provide a novel target for OA treatment.

Isothermal circular strand displacement-based assay for microRNA detection in liquid biopsy

Extracellular miRNAs are promising targets for developing new assays for the early diagnosis and prognosis of diseases based on liquid biopsy. The detection of miRNAs in liquid biopsies is challenged by their short sequence length, low concentration, and interferences with bodily fluid components. Isothermal circular strand displacement polymerization has emerged as a convenient method for nucleic acid amplification and detection. Herein, we describe an innovative strategy for microRNA detection directly from biological fluids based on hairpin probe–assisted isothermal amplification reaction. We designed and optimized the assay to detect target analytes in 1 µL of the complex media’s biological matrix using a microfluidic device for the straightforward analysis of multiple samples. We validated the assay to detect circulating miR-127-5p in synovial fluid, recently indicated as a predictive biomarker for osteoarthritis disease. The combined use of a mutant polymerase operating with high yield and a primer incorporating locked nucleic acid nucleosides allowed detection of miR-127-5p with 34 fmol L⁻¹ LOD. We quantified circulating miR-127-5p directly in synovial fluid, thus demonstrating that the assay may be employed for the convenient detection of 4.3 ± 0.5 pmol L⁻¹ concentrated miRNAs in liquid biopsy samples.

Dual functions of microRNA-17 in maintaining cartilage homeostasis and protection against osteoarthritis

Damaged hyaline cartilage has no capacity for self-healing, making osteoarthritis (OA) "difficult-to-treat". Cartilage destruction is central to OA patho-etiology and is mediated by matrix degrading enzymes. Here we report decreased expression of miR-17 in osteoarthritic chondrocytes and its deficiency contributes to OA progression. Supplementation of exogenous miR-17 or its endogenous induction by growth differentiation factor 5, effectively prevented OA by simultaneously targeting pathological catabolic factors including matrix metallopeptidase-3/13 (MMP3/13), aggrecanase-2 (ADAMTS5), and nitric oxide synthase-2 (NOS2). Single-cell RNA sequencing of hyaline cartilage revealed two distinct superficial chondrocyte populations (C1/C2). C1 expressed physiological catabolic factors including MMP2, and C2 carries synovial features, together with C3 in the middle zone. MiR-17 is highly expressed in both superficial and middle chondrocytes under physiological conditions, and maintains the physiological catabolic and anabolic balance potentially by restricting HIF-1α signaling. Together, this study identified dual functions of miR-17 in maintaining cartilage homeostasis and prevention of OA.

A review of non-coding RNA related to NF-κB signaling pathway in the pathogenesis of osteoarthritis

Osteoarthritis (OA), often called as "wear and tear" arthritis, is the most common form of degenerative joint arthritis and is a leading cause of disability. The nuclear factor-kappaB (NF-κB) transcription factor has long been recognized as a disease-contributing factor for OA. More and more evidences show that targeting NF-κB signaling could offer novel potential therapeutic options for OA damage and reduce the risk of potential side-effects. In recent years, it has been shown that non-coding RNAs(ncRNAs) can trigger the expression of an array of genes and widely activate NF-κB signaling pathway, which induces destruction of the articular joint, leading to OA onset and progression. In this review, we discuss the involvement of NF-κB in OA pathogenesis and how ncRNAs attend and affect OA incidence and evolution, offering novel potential therapeutic options for OA treatment.

The collagenases: are they tractable targets for preventing cartilage destruction in osteoarthritis?

INTRODUCTION

The etiology and pathogenesis of osteoarthritis (OA) have been intensely investigated; however, the disease course and progression are not completely understood. A prominent role for interstitial collagenases is recognized in this degenerative process, hence strategies to target them are of major interest.

AREAS COVERED

The pathogenesis of OA, the role of interstitial collagenases (MMP-1, -8 and -13) and collagenase modifying drugs are examined and discussed. We reviewed relevant papers from PubMed and Google Scholar.

EXPERT OPINION

There is strong evidence for the therapeutic potential of MMP inhibitors in OA; however, they are not expected to impact the inflammatory process. Therefore, there is a need for a relative inhibitor of MMP-13 collagenase which possesses anti-inflammatory properties. The identification of novel broad-spectrum relative multiple peptidase inhibitors could provide desirable tools for the prophylaxis, cure, or treatment of diseases involving articular cartilage (AC) degradation, in particular OA.

Regulation of serum microRNA expression by acupuncture in patients with diarrhea-predominant irritable bowel syndrome

OBJECTIVE

To screen for differentially expressed serum microRNAs (miRNAs) in patients with diarrhea-predominant irritable bowel syndrome (IBS-D) compared with healthy participants and explore the mechanism of acupuncture in the treatment of IBS-D based on miRNAs.

METHODS

IBS-D patients that met the Rome III diagnostic criteria and age- and sex-matched healthy participants were enrolled between April 2017 and December 2017. Serum miRNA levels were initially determined using a TaqMan low-density array (TLDA) in pooled samples. Markedly altered miRNAs in IBS-D patients were subsequently validated using quantitative real-time polymerase chain reaction (qRT-PCR) on individual samples. All IBS-D patients accepted the acupuncture therapy for 6 weeks. The disease severity was assessed using the IBS symptom severity scale (IBS-SSS) questionnaire before and after treatment. After acupuncture, the patients' serum was re-analyzed for altered expression of the miRNAs by qRT-PCR.

RESULTS

TLDA and qRT-PCR analysis revealed six upregulated miRNAs (miR-1305, miR-575, miR-149-5p, miR-190a-5p, miR-135a-5p, and miR-148a-3p; P < 0.05) and two downregulated miRNAs (miR-194-5p, miR-127-5p; P < 0.05) in IBS-D patients compared with healthy controls. Post acupuncture treatment, total IBS-SSS scores, severity of abdominal pain, duration of abdominal pain, severity of abdominal distention, dissatisfaction with bowel habits and disruption in quality of life decreased significantly (P < 0.001). Furthermore, the upregulated miR-148a-3p levels in IBS-D patients also decreased significantly after acupuncture (P < 0.05).

CONCLUSIONS

The over-expression or reduced expression of several miRNAs may contribute to IBS-D pathogenesis. Acupuncture might downregulate miR-148a-3p through multiple pathways to alleviate or relieve IBS-D symptoms.

TRIAL REGISTRATION NUMBER

ChiCTR-IOR-17010860 (Chinese Clinical Trials Registry).

LncRNA DNM3OS regulates GREM2 via miR-127-5p to suppress early chondrogenic differentiation of rat mesenchymal stem cells under hypoxic conditions

Background

Improved chondrogenic differentiation of mesenchymal stem cells (MSCs) by genetic regulation is a potential method for regenerating articular cartilage. MiR-127-5p has been reported to promote cartilage differentiation of rat bone marrow MSCs (rMSCs); however, the regulatory mechanisms underlying hypoxia-stimulated chondrogenic differentiation remain unknown.

Methods

rMSCs were induced to undergo chondrogenic differentiation under normoxic or hypoxic conditions. Expression of lncRNA DNM3OS, miR-127-5p, and GREM2 was detected by quantitative real-time PCR. Proteoglycans were detected by Alcian blue staining. Western blot assays were performed to examine the relative levels of GREM2 and chondrogenic differentiation related proteins. Luciferase reporter assays were performed to assess the association among DNM3OS, miR-127-5p, and GREM2.

Results

MiR-127-5p levels were upregulated, while DNM3OS and GREM2 levels were downregulated in rMSCs induced to undergo chondrogenic differentiation, and those changes were attenuated by hypoxic conditions (1% O₂). Further in vitro experiments revealed that downregulation of miR-127-5p reduced the production of proteoglycans and expression of chondrogenic differentiation markers (COL1A1, COL2A1, SOX9, and ACAN) and osteo/chondrogenic markers (BMP-2, p-SMAD1/2). MiR-127-5p overexpression produced the opposite results in rMSCs induced to undergo chondrogenic differentiation under hypoxic conditions. GREM2 was found to be a direct target of miR-127-5p, which was suppressed in rMSCs undergoing chondrogenic differentiation. Moreover, DNM3OS could directly bind to miR-127-5p and inhibit chondrogenic differentiation of rMSCs via regulating GREM2.

Conclusions

Our study revealed a novel molecular pathway (DNM3OS/miR-127-5p/GREM2) that may be involved in hypoxic chondrogenic differentiation.

Small Noncoding RNAs in Knee Osteoarthritis: The Role of MicroRNAs and tRNA-Derived Fragments

Knee osteoarthritis (OA) is a degenerative knee joint disease that results from the breakdown of joint cartilage and underlying bone, affecting about 3.3% of the world's population. As OA is a multifactorial disease, the underlying pathological process is closely associated with genetic changes in articular cartilage and bone. Many studies have focused on the role of small noncoding RNAs in OA and identified numbers of microRNAs that play important roles in regulating bone and cartilage homeostasis. The connection between other types of small noncoding RNAs, especially tRNA-derived fragments and knee osteoarthritis is still elusive. The observation that there is limited information about small RNAs different than miRNAs in knee OA was very surprising to us, especially given the fact that tRNA fragments are known to participate in a plethora of human diseases and a portion of them are even more abundant than miRNAs. Inspired by these findings, in this review we have summarized the possible involvement of microRNAs and tRNA-derived fragments in the pathology of knee osteoarthritis.

Adipose-Derived Mesenchymal Stromal Cells Treated with Interleukin 1 Beta Produced Chondro-Protective Vesicles Able to Fast Penetrate in Cartilage

The study of the miRNA cargo embedded in extracellular vesicles (EVs) released from adipose-derived mesenchymal stromal cells (ASC) preconditioned with IL-1β, an inflammatory stimulus driving osteoarthritis (OA), along with EVs-cartilage dynamic interaction represent poorly explored fields and are the purpose of the present research. ASCs were isolated from subcutaneous adipose tissue and EVs collected by ultracentrifugation. Shuttled miRNAs were scored by high-throughput screening and analyzed through bioinformatics approach that predicted the potentially modulated OA-related pathways. Fluorescently labeled EVs incorporation into OA cartilage explants was followed in vitro by time-lapse coherent anti-Stokes Raman scattering; second harmonic generation and two-photon excited fluorescence. After IL-1β preconditioning, 7 miRNA were up-regulated, 4 down-regulated, 37 activated and 17 silenced. Bioinformatics allowed to identify miRNAs and target genes mainly involved in Wnt, Notch, TGFβ and Indian hedgehog (IHH) pathways, cartilage homeostasis, immune/inflammatory responses, cell senescence and autophagy. As well, ASC-EVs steadily diffuse in cartilage cells and matrix, reaching a plateau 16 h after administration. Overall, ASCs preconditioned with IL-1β allows secretion of EVs embedded with a chondro-protective miRNA cargo, able to fast penetrate in collagen-rich areas of cartilage with tissue saturation in a day. Further functional studies exploring the EVs dose-effects are needed to achieve clinical relevance.

Circular RNA circ_0128846 promotes the progression of osteoarthritis by regulating miR-127-5p/NAMPT axis

Background

Mounting evidence indicates that circular RNAs (circRNAs) participate in the occurrence and development of various diseases, including osteoarthritis (OA). However, the effects and molecular mechanism of circ_0128846 in OA have not been reported.

Methods

The expression levels of circ_0128846, microRNA-127-5p (miR-127-5p), and nicotinamide phosphoribosyltransferase (NAMPT) were determined by quantitative real-time polymerase chain reaction (qRT-PCR) or western blot assay. Cell viability was determined by Cell Counting Kit-8 (CCK-8) assay. Cell apoptosis was examined by flow cytometry and western blot assay. Inflammatory response and cartilage extracellular matrix (ECM) degradation were evaluated by western blot assay. The relationship between miR-127-5p and circ_0128846 or NAMPT was predicted by bioinformatics tools and verified by dual-luciferase reporter and RNA Immunoprecipitation (RIP) assays.

Results

Circ_0128846 and NAMPT were upregulated and miR-127-5p was downregulated in OA cartilage tissues. Knockdown of circ_0128846 increased cell viability and inhibited apoptosis, inflammation and ECM degradation in OA chondrocytes, while these effects were reversed by downregulating miR-127-5p. Moreover, circ_0128846 positively regulated NAMPT expression by sponging miR-127-5p. Furthermore, miR-127-5p promoted cell viability and suppressed apoptosis, inflammation, and ECM degradation in OA chondrocytes by directly targeting NAMPT.

Conclusion

Circ_0128846 knockdown might inhibit the progression of OA by upregulating miR-127-5p and downregulating NAMPT, offering a new insight into the potential application of circ_0128846 in OA treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13018-021-02428-z.

Weighted gene co expression network analysis (WGCNA) with key pathways and hub-genes related to micro RNAs in ischemic stroke

Ischemic stroke (IS) is one of the major causes of death and disability worldwide. However, the specific mechanism of gene interplay and the biological function in IS are not clear. Therefore, more research into IS is necessary. Dataset GSE110993 including 20 ischemic stroke (IS) and 20 control specimens are used to establish both groups and the raw RNA‐seq data were analysed. Weighted gene co‐expression network analysis (WGCNA) was used to screen the key micro‐RNA modules. The centrality of key genes were determined by module membership (mm) and gene significance (GS). The key pathways were identified by enrichment analysis with Kyoto Protocol Gene and Genome Encyclopedia (KEGG), and the key genes were validated by protein‐protein interactions network. Result: Upon investigation, 1185 up‐ and down‐regulated genes were gathered and distributed into three modules in response to their degree of correlation to clinical traits of IS, among which the turquoise module show a trait‐correlation of 0.77. The top 140 genes were further identified by GS and MM. KEGG analysis showed two pathways may evolve in the progress of IS. Discussion: CXCL12 and EIF2a may be important biomarkers for the accurate diagnosis and treatment in IS.

Overexpression of hsa_circ_0094742 inhibits IL-1β-induced decline in CHON-001 cell viability by targeting microRNA-127-5p

Osteoarthritis (OA) is a public health problem that affects 240 million people globally; however, the current treatment options for OA are not effective. Therefore, there is still an urgent need to identify novel strategies to reduce the incidence and progression of OA. The circular RNA hsa_circ_0094742 was reported to be downregulated in patients with OA. However, the underlying mechanism remains unclear. The levels of hsa_circ_0094742 in CHON-001 were detected by reverse transcription quantitative polymerase chain reaction. Moreover, Cell Counting Kit-8 assay and Ki67 staining were used to determine the cell viability. The protein expression of biomarkers was detected by western blot analysis. In addition, the putative downstream target of hsa_circ_0094742 was predicted using the Circinteractome and TargetScan online databases. The putative targeting relationship was verified by dual luciferase reporter assay and fluorescence in situ hybridization. Next, cell apoptosis was determined by Annexin V/PI staining. hsa_circ_0094742 overexpression (OE) inhibited interleukin (IL)-1β-induced decline in the viability of CHON-001 cells and primary human chondrocytes. Furthermore, IL-1β-induced alterations in aggrecan, matrix metallopeptidase 13, X-linked inhibitor of apoptosis protein (XIAP), Bax and active caspase 3 were reversed by hsa_circ_0094742 OE. Luciferase reporter assay indicated that miR-127-5p was the downstream target of hsa_circ_0094742, and latexin was the target of miR-127-5p. hsa_circ_0094742 OE inhibited IL-1β-induced decline in CHON-001 cell viability by targeting miRNA-127-5p. The findings of the present study revealed the biological rational of the use of hsa_circ_0094742 OE as an anti-IL-1β effector in human chondrocytes. These findings may prompt further research on hsa_circ_0094742 as a potent circRNA target for the treatment of OA.

Overview of MMP-13 as a Promising Target for the Treatment of Osteoarthritis

Osteoarthritis (OA) is a common degenerative disease characterized by the destruction of articular cartilage and chronic inflammation of surrounding tissues. Matrix metalloproteinase-13 (MMP-13) is the primary MMP involved in cartilage degradation through its particular ability to cleave type II collagen. Hence, it is an attractive target for the treatment of OA. However, the detailed molecular mechanisms of OA initiation and progression remain elusive, and, currently, there are no interventions available to restore degraded cartilage. This review fully illustrates the involvement of MMP-13 in the initiation and progression of OA through the regulation of MMP-13 activity at the molecular and epigenetic levels, as well as the strategies that have been employed against MMP-13. The aim of this review is to identify MMP-13 as an attractive target for inhibitor development in the treatment of OA.

Exosome-Encapsulated microRNA-127-3p Released from Bone Marrow-Derived Mesenchymal Stem Cells Alleviates Osteoarthritis Through Regulating CDH11-Mediated Wnt/β-Catenin Pathway

Objective

Exosome-encapsulated microRNAs (miRNAs) are being considered as either diagnostic or predictive markers in different types of diseases. Here, we discussed the effects of exosome-encapsulated miR-127-3p from bone marrow-derived mesenchymal stem cells (BM-MSCs) on osteoarthritis (OA).

Methods

BM-MSCs and primary chondrocytes were isolated from Sprague Dawley rats. IL-1β was utilized to treat chondrocytes to mimic an OA in vitro model, and exosomes extracted from BM-MSCs were utilized to treat chondrocytes so as to verify their protective effects on OA. Through online website prediction and experiments confirmation, we found the most significantly enriched miRNA in exosomes and elucidated the effect of this miRNA on the therapeutic effect of exosomes by interfering with its expression. Also, the genes targeted by the miRNA and the involved pathway were also found through bioinformatics analysis and experimental research, thereby probing into the protective mechanism of exosomes on chondrocytes.

Results

Exosomes derived from BM-MSCs restricted the IL-1β-induced chondrocytes damage. miR-127-3p was found to be enriched in exosomes, and the protective effect of exosomes was reversed by miR-127-3p inhibition. miR-127-3p targeted CDH11, and overexpressed CDH11 in chondrocytes weakened the therapeutic effect of exosomes. IL-1β treatment resulted in the activation of the Wnt/β-catenin pathway in chondrocytes. Exosomes treatment could inhibit the activation of this pathway, and overexpressed CDH11 reversed the inhibitory effect of exosomes on this pathway.

Conclusion

This study suggests that exosomal miR-127-3p derived from BM-MSCs inhibits CDH11 in chondrocytes, thereby blocking the Wnt/β-catenin pathway activation and relieving chondrocyte damage in OA.

Impacts of Green Tea on Joint and Skeletal Muscle Health: Prospects of Translational Nutrition

Osteoarthritis and sarcopenia are two major joint and skeletal muscle diseases prevalent during aging. Osteoarthritis is a multifactorial progressive degenerative and inflammatory disorder of articular cartilage. Cartilage protection and pain management are the two most important strategies in the management of osteoarthritis. Sarcopenia, a condition of loss of muscle mass and strength, is associated with impaired neuromuscular innervation, the transition of skeletal muscle fiber type, and reduced muscle regenerative capacity. Management of sarcopenia requires addressing both skeletal muscle quantity and quality. Emerging evidence suggests that green tea catechins play an important role in maintaining healthy joints and skeletal muscle. This review covers (i) the prevalence and etiology of osteoarthritis and sarcopenia, such as excessive inflammation and oxidative stress, mitochondrial dysfunction, and reduced autophagy; (ii) the effects of green tea catechins on joint health by downregulating inflammatory signaling mediators, upregulating anabolic mediators, and modulating miRNAs expression, resulting in reduced chondrocyte death, collagen degradation, and cartilage protection; (iii) the effects of green tea catechins on skeletal muscle health via maintaining a dynamic balance between protein synthesis and degradation and boosting the synthesis of mitochondrial energy metabolism, resulting in favorable muscle homeostasis and mitigation of muscle atrophy with aging; and (iv) the current study limitations and future research directions.

Knockout of miR-21-5p alleviates cartilage matrix degradation by targeting Gdf5 in temporomandibular joint osteoarthritis

AIMS

The study aimed to determine whether the microRNA miR21-5p (MiR21) mediates temporomandibular joint osteoarthritis (TMJ-OA) by targeting growth differentiation factor 5 (Gdf5).

METHODS

TMJ-OA was induced in MiR21 knockout (KO) mice and wild-type (WT) mice by a unilateral anterior crossbite (UAC) procedure. Mouse tissues exhibited histopathological changes, as assessed by: Safranin O, toluidine blue, and immunohistochemistry staining; western blotting (WB); and quantitative real-time polymerase chain reaction (RT-qPCR). Mouse condylar chondrocytes were transfected with a series of MiR21 mimic, MiR21 inhibitor, Gdf5 siRNA (si-GDF5), and flag-GDF5 constructs. The effects of MiR-21 and Gdf5 on the expression of OA related molecules were evaluated by immunofluorescence, alcian blue staining, WB, and RT-qPCR.

RESULTS

UAC altered the histological structure and extracellular matrix content of cartilage in the temporomandibular joint (TMJ), and KO of MiR21 alleviated this effect (p < 0.05). Upregulation of MiR21 influenced the expression of TMJ-OA related molecules in mandibular condylar chondrocytes via targeting Gdf5 (p < 0.05). Gdf5 overexpression significantly decreased matrix metalloproteinase 13 (MMP13) expression (p < 0.05) and reversed the effects of MiR21 (p < 0.05).

CONCLUSION

MiR21, which acts as a critical regulator of Gdf5 in chondrocytes, regulates TMJ-OA related molecules and is involved in cartilage matrix degradation, contributing to the progression of TMJ-OA. Cite this article: Bone Joint Res 2020;9(10):689-700.

Genetics in Cartilage Lesions: Basic Science and Therapy Approaches

Cartilage lesions have a multifactorial nature, and genetic factors are their strongest determinants. As biochemical and genetic studies have dramatically progressed over the past decade, the molecular basis of cartilage pathologies has become clearer. Several homeostasis abnormalities within cartilaginous tissue have been found, including various structural changes, differential gene expression patterns, as well as altered epigenetic regulation. However, the efficient treatment of cartilage pathologies represents a substantial challenge. Understanding the complex genetic background pertaining to cartilage pathologies is useful primarily in the context of seeking new pathways leading to disease progression as well as in developing new targeted therapies. A technology utilizing gene transfer to deliver therapeutic genes to the site of injury is quickly becoming an emerging approach in cartilage renewal. The goal of this work is to provide an overview of the genetic basis of chondral lesions and the different approaches of the most recent systems exploiting therapeutic gene transfer in cartilage repair. The integration of tissue engineering with viral gene vectors is a novel and active area of research. However, despite promising preclinical data, this therapeutic concept needs to be supported by the growing body of clinical trials.

Epigenetic regulation of matrix metalloproteinases in inflammatory diseases: a narrative review

With the acceleration of urbanization and aging and the change of lifestyle, inflammatory diseases have become one of the important threats to the health of the global population. Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) are involved in the metabolism of extracellular matrix (ECM). They play a key role in inflammation-related diseases. Factors such as inflammation, oxidative stress and growth factors stimulate the production of MMPs with subsequent ECM remodeling. Recently, the studies of epigenetic regulation, including the ability to predict disease progression, important pathophysiological deficiencies as well as treatment methods have been extensively discussed. This article reviews the current studies on epigenetic alterations in MMPs during inflammatory response. It is likely to provide new insights into development of efficient medications of epigenetic therapy for inflammatory diseases.

MicroRNA-365 functions as a mechanosensitive microRNA to inhibit end plate chondrocyte degeneration by targeting histone deacetylase 4

End plate chondrocyte degeneration is a major cause of intervertebral disc degeneration. Mechanical biophysical forces, including intermittent cyclic mechanical tension (ICMT), exacerbate end plate chondrocyte degeneration. However, the underlying molecular mechanism of mechanical stretch-induced end plate chondrocyte degeneration is still unclear. This study sought to determine whether microRNAs (miRNAs) respond to mechanical stretch and play a role in regulating mechanically-induced end plate chondrocyte degeneration. We identified miR-365 as a mechanoresponsive miRNA in primary human end plate chondrocytes after ICMT application by miRNA microarray analysis. The expression of miR-365 was down-regulated in the disc samples obtained from patients with disc degeneration. We also found that the miR-365 stimulates chondrocyte proliferation but does not promote end plate chondrocyte death. Using bioinformatic analyses and subsequent confirmation by real-time RT-PCR, we identified multiple candidate target genes of miR-365 that responded to in vitro mechanical stimulation; among them, HDAC4 was fully characterized. Mutation of putative miR-365 binding sites in HDAC4 mRNA abolished miR-365 mediated repression of HDAC4 3'-untranslated region (3'UTR) luciferase reporter activity, suggesting that miR-365 binds to the HDAC4 3'UTR. Overexpression of miR-365 significantly decreased the HDAC4 protein level, suggesting that miR-365 acts as an endogenous attenuator of HDAC4 in human end plate chondrocytes. Further, perturbation of miR-365 expression also had a significant effect on the expression of COL2A and ACAN and on matrix degeneration. Overexpression of HDAC4 abolished miR-365 rescued end plate chondrocyte degeneration during ICMT application. Furthermore, we found that the wnt/β-catenin signal pathway was related to HDAC4 and promoted end plate chondrocyte degeneration. Overall, our results suggest that miR-365 is a mechanosensitive miRNA that regulates human chondrocyte degeneration by directly targeting HDAC4. We propose that therapeutic regulation of miR-365 may be an efficient anabolic strategy for inhibiting end plate chondrocyte degeneration.

MiR-146b accelerates osteoarthritis progression by targeting alpha-2-macroglobulin

Osteoarthritis (OA) is an aging-related chronic degenerative disease characterized by the degradation of chondrocyte extracellular matrix (ECM). Previous studies have suggested that microRNAs (miRNAs) are associated with OA, but the role of miR-146b in OA remains unclear. The aim of this study was to determine the role of miR-146b in OA progression. The effect of miR-146b on ECM degradation were studied in mouse chondrocytes transfected with miRNA and treated with IL-1β. Cell viability and the expression levels of proteolytic enzymes in the transfected cells were assessed by real-time RT-PCR, ELISA and Western blots. We found downregulation of miR-146b expression in chondrocytes dramatically inhibited IL-1β-induced caspase activation and proteolytic enzyme expression via influencing its targeted Alpha-2-macroglobulin (A2M). Luciferase reporter assays confirmed that A2M mRNA was negatively regulated by miR-146b in chondrocytes. Intra-articular injection of antago-miR-146b against miR-146b effectively protected mice from the progression of DMM-induced osteoarthritis by inhibiting cartilage proteoglycan degradation. Our study indicates that miR-146b plays a critical role in the progression of injury-induced osteoarthritis by directly targeting A2M expression to elevate the proteolytic enzyme production and stimulate chondrocytes apoptosis, and miR-146b as well as A2M could be therapeutic targets.

Circ_0136474 and MMP-13 suppressed cell proliferation by competitive binding to miR-127-5p in osteoarthritis

Osteoarthritis (OA) is a prevalent degenerative joint disease whose pathogenesis remains unclear. The research aims to investigate the roles of Circ_0136474/miR‐127‐5p/MMP‐13 axis in OA. Differentially expressed circRNAs and miRNAs in OA cartilage tissue were screened out and visualized by R project based on RNA‐seq data and microarray data respectively. qRT‐PCR was carried out for detection of relative expression levels of Circ_0136474, miR‐127‐5p, MMP‐13 and other inflammatory factors and Western blot analysis was conducted to detect the protein expression level of MMP‐13. CCK‐8 assay and flow cytometry were conducted to determine cell proliferation and cell apoptotic ability respectively. RNA‐fluorescence in situ hybridization (RNA‐FISH) experiments were conducted to confirm the immune‐localization of the Circ_0136474 and MMP‐13 in human tissues. Targeted relationships were predicted by bioinformatic analysis and verified by dual‐luciferase reporter assay. Our findings revealed that the expression levels of both Circ_0136474 and MMP‐13 in OA cartilage tissue were significantly higher than that in normal cartilage tissue. Circ_0136474 could suppress cell proliferation by facilitating MMP‐13 expression and suppressing miR‐127‐5p expression in OA. Overexpression of miR‐127‐5p negatively regulated MMP‐13 expression to enhance cell proliferation. Our study demonstrated that Circ_0136474 and MMP‐13 suppressed cell proliferation, while enhanced cell apoptosis by competitive binding to miR‐127‐5p in OA, which may well provide us with a new therapeutic strategy for osteoarthritis.

Long non-coding RNA NR2F1-AS1 promoted proliferation and migration yet suppressed apoptosis of thyroid cancer cells through regulating miRNA-338-3p/CCND1 axis

Thyroid cancer (TC) is a prevalent endocrine malignant cancer whose pathogenic mechanism remains unclear. The aim of the study was to investigate the roles of long non‐coding RNA (lncRNA) NR2F1‐AS1/miRNA‐338‐3P/CCND1 axis in TC progression. Differentially expressed lncRNAs and mRNAs in TC tissues were screened out and visualized by R program. Relative expression of NR2F1‐AS1, miRNA‐338‐3p and cyclin D1 (CCND1) was determined by quantitative real time polymerase chain reaction. In addition, Western blot analysis was adopted for evaluation of protein expression of CCND1. Targeted relationships between NR2F1‐AS1 and miRNA‐338‐3p, as well as miRNA‐338‐3p and CCND1 were predicted using bioinformatics analysis and validated by dual‐luciferase reporter gene assay. Besides, tumour xenograft assay was adopted for verification of the role of NR2F1‐AS1 in TC in vivo. NR2F1‐AS1 and CCND1 were overexpressed, whereas miRNA‐338‐3p was down‐regulated in TC tissues and cell lines. Down‐regulation of NR2F1‐AS1 and CCND1 suppressed proliferation and migration of TC cells yet greatly enhanced cell apoptotic rate. Silence of NR2F1‐AS1 significantly suppressed TC tumorigenesis in vivo. NR2F1‐AS1 sponged miRNA‐338‐3p to up‐regulate CCND1 expression to promote TC progression. Our study demonstrated that up‐regulation of NR2F1‐AS1 accelerated TC progression through regulating miRNA‐338‐3P/CCND1 axis.

Myalgic encephalomyelitis or chronic fatigue syndrome: how could the illness develop?

A model of the development and progression of chronic fatigue syndrome (myalgic encephalomyelitis), the aetiology of which is currently unknown, is put forward, starting with a consideration of the post-infection role of damage-associated molecular patterns and the development of chronic inflammatory, oxidative and nitrosative stress in genetically predisposed individuals. The consequences are detailed, including the role of increased intestinal permeability and the translocation of commensal antigens into the circulation, and the development of dysautonomia, neuroinflammation, and neurocognitive and neuroimaging abnormalities. Increasing levels of such stress and the switch to immune and metabolic downregulation are detailed next in relation to the advent of hypernitrosylation, impaired mitochondrial performance, immune suppression, cellular hibernation, endotoxin tolerance and sirtuin 1 activation. The role of chronic stress and the development of endotoxin tolerance via indoleamine 2,3-dioxygenase upregulation and the characteristics of neutrophils, monocytes, macrophages and T cells, including regulatory T cells, in endotoxin tolerance are detailed next. Finally, it is shown how the immune and metabolic abnormalities of chronic fatigue syndrome can be explained by endotoxin tolerance, thus completing the model.

circRNA.33186 Contributes to the Pathogenesis of Osteoarthritis by Sponging miR-127-5p

Osteoarthritis (OA), the most prevalent age-related joint disorder, is characterized by chronic inflammation, progressive articular cartilage destruction, and subchondral bone sclerosis. Accumulating evidences indicate that circular RNAs (circRNAs) play a critical role in various diseases, but the function of circRNAs in OA remains largely unknown. Here we showed that circRNA.33186 was significantly upregulated in IL-1β)-treated chondrocytes and in cartilage tissues of a destabilized medial meniscus (DMM)-induced OA mouse model. Knockdown of circRNA.33186 increased anabolic factor (type II collagen) expression and decreased catabolic factor (MMP-13) expression. Knockdown of circRNA.33186 also promoted proliferation and inhibited apoptosis in IL-1β-treated chondrocytes. Silencing of circRNA.33186 in vivo markedly alleviated DMM-induced OA. Mechanistic study showed that circRNA.33186 directly binds to and inhibits miR-127-5p, thereby increasing MMP-13 expression, and contributes to OA pathogenesis. Taken together, our findings demonstrated a fundamental role of circRNA.33186 in OA progression and provide a potential drug target in OA therapy.

Diagnostic and prognostic role of serum miR-20b, miR-17-3p, HOTAIR, and MALAT1 in diabetic retinopathy

Noncoding RNAs are emerging biomarkers for many diseases including diabetic retinopathy (DR). This study aimed to measure the expression levels of serum miR-20b, miR-17-3p, HOTAIR, and MALAT1 in DR patients. A total of 80 patients diagnosed as type 2 diabetes (T2D) and 81 healthy subjects were recruited in this study. T2D patients were divided into three groups: nondiabetic retinopathy (NDR) group (30 patients), nonproliferative diabetic retinopathy (NPDR) group (30 patients), and proliferative diabetic retinopathy (PDR) group (20 patients). Quantitative real-time polymerase chain reaction (PCR) was used to assess the expression of serum miR-20b, miR-17-3p, HOTAIR, and MALAT1. We found a significant decrease in serum miR-20b and a significant increase in serum HOTAIR and MALAT1 in NDR patients compared to healthy subjects. Also, we revealed a significant decrease in serum miR-20b and miR-17-3p and a significant increase in serum HOTAIR and MALAT1 in each of NPDR and PDR groups when compared with healthy subjects. Furthermore, we reported a significant decrease in miR-20b and miR-17-3p and a significant increase in HOTAIR and MALAT1in DR as well as in PDR patients when compared with NDR patients. However, on comparing NPDR with NDR patients, no significant difference was observed regarding the expression levels of miR-20b and miR-17-3p, in contrast, significant elevation of serum HOTAIR and MALAT1 was found in NPDR. Moreover, we observed a significant decrease in serum miR-20b and miR-17-3p and a significant increase in serum HOTAIR and MALAT1 in PDR group relative to NPDR group. Receiver operating characteristic (ROC) curve was used for evaluating the diagnostic value of the examined serum noncoding RNAs as novel biochemical indicators detecting severity of DR. Our analyses suggested that the examined serum noncoding RNAs may discriminate DR (PDR and NPDR) from NDR. Furthermore, these noncoding RNAs (less importantly miR-17) can be used as promising novel biomarkers for prediction DR severity, distinguishing PDR from NPDR patients. We can conclude that serum miR-20b, miR-17-3p, HOTAIR, and MALAT1 may be used as noninvasive biomarkers for screening of DR and early diagnosis of PDR. © 2018 IUBMB Life, 71(3):310-320, 2019.

miRNA expression profiles of premalignant and malignant arsenic-induced skin lesions

Arsenic, a naturally occurring element, contaminates the drinking water of over 200 million people globally. Chronic arsenic exposure causes multiple cancers including those originating from skin, lung and bladder, and is associated with liver, kidney, and prostate cancers. Skin is the primary target organ for arsenic toxicity; chronic toxicity initially manifests as non-malignant hyperkeratoses (HK) and subsequently advances to malignant lesions, including squamous cell carcinoma (SCC) and basal cell carcinoma (BCC). In this study, we evaluate the miRNA expression profiles of premalignant (3 HK) and malignant (3 BCC and 3 SCC) skin lesions from individuals chronically exposed to high levels of arsenic (59–172 ppb) in their drinking water in West Bengal, India. The lesions were histologically complex requiring histopathologic identification of keratinocytes to be isolated for RNA analyses. Keratinocytes were harvested using Laser Capture Microdissection and miRNA expression profiles were determined using TaqMan® Array Human MiRNA A Card v2.0. Thirty-five miRNAs were differentially expressed among the three lesion types analyzed. Two miRNAs (miR-425-5p and miR-433) were induced in both BCC and SCC relative to HK indicating their association with malignancy. Two other miRNAs (miR-184 and miR-576-3p) were induced in SCC relative to both BCC and HK suggesting selective induction in tumors capable of metastasis. Six miRNAs (miR-29c, miR-381, miR-452, miR-487b, miR-494 and miR-590-5p) were selectively suppressed in BCC relative to both SCC and HK. In conclusion, the differential miRNA expression was both phenotype- and stage-related. These miRNAs are potential biomarkers and may serve as therapy targets for arsenic-induced internal tumors.

Onset and Progression of Human Osteoarthritis-Can Growth Factors, Inflammatory Cytokines, or Differential miRNA Expression Concomitantly Induce Proliferation, ECM Degradation, and Inflammation in Articular Cartilage?

Osteoarthritis (OA) is a degenerative whole joint disease, for which no preventative or therapeutic biological interventions are available. This is likely due to the fact that OA pathogenesis includes several signaling pathways, whose interactions remain unclear, especially at disease onset. Early OA is characterized by three key events: a rarely considered early phase of proliferation of cartilage-resident cells, in contrast to well-established increased synthesis, and degradation of extracellular matrix components and inflammation, associated with OA progression. We focused on the question, which of these key events are regulated by growth factors, inflammatory cytokines, and/or miRNA abundance. Collectively, we elucidated a specific sequence of the OA key events that are described best as a very early phase of proliferation of human articular cartilage (AC) cells and concomitant anabolic/catabolic effects that are accompanied by incipient pro-inflammatory effects. Many of the reviewed factors appeared able to induce one or two key events. Only one factor, fibroblast growth factor 2 (FGF2), is capable of concomitantly inducing all key events. Moreover, AC cell proliferation cannot be induced and, in fact, is suppressed by inflammatory signaling, suggesting that inflammatory signaling cannot be the sole inductor of all early OA key events, especially at disease onset.

Emodin ameliorates cartilage degradation in osteoarthritis by inhibiting NF-κB and Wnt/β-catenin signaling in-vitro and in-vivo

The overproduction of MMPs (matrix metalloproteinases) and members of the ADAMTS (a disintegrin and metalloproteinase with thrombospondin motifs) protein family plays an important role in the pathogenesis of osteoarthritis (OA). The potential of selective MMPs or ADAMTS inhibitors as chemopreventive agents for OA has been demonstrated in several studies. In this study, we investigated the protective effects of emodin (1,3,8-trihydroxy-6-methylanthaquinone), isolated from the root of Rheum palmatum L., in the inhibition of MMP and ADAMTS expression in both rat chondrocytes and an animal model of OA. The expression of MMP-3, MMP-13, ADAMTS-4, ADAMTS-5, aggrecan, and collagen II mRNA and protein in interleukin-1beta (IL-1β)-induced rat chondrocytes was followed by quantitative real-time PCR and western blot. The activation of the NF-κB and Wnt/β-catenin pathways by IL-1β was assessed by western blot. The in vivo effects of emodin were evaluated by intra-articular injection in rats in an experimental model of OA induced by anterior cruciate ligament transection. Emodin dose-dependently down-regulated the expression of MMP-3, MMP-13, ADAMTS-4 and ADAMTS-5 at both the mRNA and protein level in IL-1β-stimulated rat chondrocytes. In addition, the IL-1β-induced activation of NF-κB and Wnt signals was attenuated by emodin, as determined by western blotting. The intra-articular injection of emodin in a rat OA model ameliorated OA progression, as determined in morphological and histological analyses in vivo. Taken together, our findings demonstrate that emodin is a promising therapeutic agent for the prevention and treatment of OA.

MicroRNA-193b-3p regulates matrix metalloproteinase 19 expression in interleukin-1β-induced human chondrocytes

Micro(mi)RNAs are small, non-coding RNA molecules known to play a significant role in osteoarthritis (OA) initiation and development, and similar to matrix metalloproteinases (MMPs), they participate in cartilage degeneration and cleave multiple extracellular matrices. The aim of this study was to determine whether the expression of MMP-19 in interleukin (IL)-1β-induced human chondrocytes is directly regulated by miR-193b-3p. Expression levels of miR-193b-3p and MMP-19 in normal and osteoarthritis (OA) human cartilage, and interleukin-1 β (IL-1β)-induced human chondrocytes were determined by real-time polymerase chain reaction. Additionally, expression level of MMP-19 in IL-1β-induced human chondrocytes was estimated by Western blotting and immunohistochemistry analyses. The effect of miR-193b-3p on MMP-19 expression was evaluated using transient transfection of normal human chondrocytes with miR-193b-3p mimic or its antisense inhibitor (miR-193b-3p inhibitor), and siMMP-19. The putative binding site of miR-193b-3p in the 3'-untranslated region (UTR) of MMP-19 mRNA was validated by luciferase reporter assay. miR-193b-3p expression was reduced in OA cartilage compared to that in normal chondrocytes, while the opposite was observed for MMP-19. Upregulation of MMP-19 expression was correlated with downregulation of miR-193b-3p in IL-1β-stimulated normal chondrocytes. Increase in miR-193b-3p levels was associated with silencing of MMP-19. Overexpression of miR-193b-3p suppressed the activity of the reporter construct containing the 3'-UTR of human MMP-19 mRNA and inhibited the IL-1β-induced expression of MMP-19 and iNOS in chondrocytes, while treatment with miR-193b-3p inhibitor enhanced MMP-19 expression. MiR-193b-3p is an important regulator of MMP-19 in human chondrocytes and may relieve the inflammatory response in OA.

IL-1β-stimulated β-catenin up-regulation promotes angiogenesis in human lung-derived mesenchymal stromal cells through a NF-κB-dependent microRNA-433 induction

Considerable attentions have been focused on the treatment of lung injury using mesenchymal stem cells that can replenish damaged tissues including the blood vessels. In human lung-derived mesenchymal stem cells (hL-MSC), we investigated the potential role of an IL-1β-stimulated miR-433 pathway in angiogenesis in vitro. The expressions of miR-433 and its target genes were examined in cells treated with IL-1β. The angiogenic activity of hL-MSC was studied by cell migration and tube formation assays in which miR-433 levels were manipulated. The reporter assay and chromatin immunoprecipitation (ChIP) were also performed to analyze the underlying regulations. We found that the expression of miR-433 was enhanced in hL-MSC by IL-1β in a NF-κB dependent manner via a NF-κB binding site at its promoter region. The effects of IL-1β on promoting angiogenic activities in hL-MSC can be mimicked by the overexpression of miR-433 and were blocked by anti-miR-433. Mechanistically, our data suggested that miR-433 directly targets the 3'-UTR of Dickkopf Wnt signaling pathway inhibitor 1 (DKK1) mRNA and decreases its expression. Consistently, the expression of β-catenin, the major mediator of canonical Wnt pathway that is capable of inducing endothelial differentiation and angiogenesis, was upregulated by IL-1β through miR-433. Thus, increasing miR-433 expression by IL-1β in mesenchymal stem cells could stimulate their capacity of vascular remodeling for efficient repair processes, which may be utilized as a therapeutic target in patients suffering from severe lung injury.

MicroRNA-365 regulates IL-1β-induced catabolic factor expression by targeting HIF-2α in primary chondrocytes

Endothelial Per-Arnt-Sim domain protein-1/hypoxia-inducible factor-2α (EPAS-1/ HIF-2α) is a catabolic transcription factor that regulates osteoarthritis (OA)-related cartilage destruction. Here, we examined whether microRNA-365 (miR-365) affects interleukin (IL)-1β-induced expression of catabolic factors in chondrocytes via regulation of HIF-2α. MiR-365 levels were significantly decreased in human OA cartilage relative to normal cartilage. Overexpression of miR-365 significantly suppressed IL-1β-induced expression of HIF-2α in human articular chondrocytes. Pharmacological inhibition of various IL-1β-associated signaling pathways revealed mitogen-activated protein kinase and nuclear factor-κB as the primary pathways driving IL-1β-mediated decreases in miR-365 and subsequent increase in HIF-2α expression. Using a luciferase reporter assay encoding the 3′ untranslated region (UTR) of human HIF-2α mRNA, we showed that overexpression of miR-365 significantly suppressed IL-1β-induced up-regulation of HIF-2α. AGO2 RNA-immunoprecipitation (IP) assay demonstrated that miR-365 and HIF-2α mRNA were enriched in the AGO2-IP fraction in miR-365-transfected primary chondrocytes compared to miR-con-transfected cells, indicating that HIF-2α is a target of miR-365. Furthermore, miR-365 overexpression significantly suppressed IL-1β-induced expression of catabolic factors, including cyclooxygenase-2 and matrix metalloproteinase-1, -3 and -13, in chondrocytes. In pellet culture of primary chondrocytes miR-365 prevented IL-1β-stimulated extracellular matrix loss and matrix metalloproteinase-13 expression. MiR-365 regulates IL-1β-stimulated catabolic effects in human chondrocytes by modulating HIF-2α expression.

[Effect of chondrogenesis related miR-4287 on expression of aggrecanase-1 in human chondrocytes]

Objective

To investigate the effect and mechanism of miR-4287, a chondrogenesis associated microRNA, regulated the expression of aggrecanase-1 (a disintegrin and metalloproteinase with thrombospondin motif 4, ADAMTS4) in human chondrocytes.

Methods

First, the voluntarily donated normal and osteoarthritic knee articular cartilages were used to detect the expressions of miR-4287 and ADAMTS4 mRNA by real-time fluorescence quantitative PCR. Then, chondrocytes were isolated from knee articular cartilages. The effect of IL-1β on the expression of miR-4287 and ADAMTS4 mRNA was validated by the first generation of osteoarthritic chondrocytes. To confirm the influence of IL-1β signal pathways on the expression of miR-4287 and ADAMTS4 mRNA, osteoarthritic chondrocytes were pretreated with MAPK signal pathway inhibitor SP600125, NF-κB pathway inhibitor SN50, and finally stimulated with IL-1β. Chondro cytes were transfected with miR-4287 mimics and mimics negative control, inhibitors and inhibitors negative control respectively to value the effect of miR-4287 on ADAMTS4 expression. Luciferase reporter assay was used to verify the direct interaction between miR-4287 and putative site in the 3-untranslated region (3'UTR) of ADAMTS4 mRNA.

Results

Compared with normal knee articular cartilages, the miR-4287 expression was markedly diminished and conversely ADAMTS4 mRNA expression was raised in osteoarthritis cartilages ( P<0.05). Stimulation with IL-1β led to a reduction in miR-4287 expression and upregulation in ADAMTS4 mRNA expression, showing significant difference when compared with the untreated groups ( P<0.05). Pretreatment with IL-1β signal pathway inhibitors induced miR-4287 expression and attenuated ADAMTS4 mRNA expression in human chondrocytes, which were significantly different from that of unstimulated cells ( P<0.05). ADAMTS4 mRNA and protein were suppressed by transfection with miR-4287 mimics ( P<0.05) and elevated by transfection with miR-4287 inhibitors ( P<0.05). As luciferase reporter assay showed, overexpression miR-4287 failed to alter the luciferase activity of a reporter construct containing either wild or mutant 3'UTR of ADAMTS4 mRNA ( P>0.05).

Conclusion

miR-4287, a chondrogenesis associated microRNA, may play an important role in cartilage degeneration. miRNA-4287 is able to regulate ADAMTS4 expression in human chondrocytes, but not by means of directly targeted the ADAMTS4 mRNA 3'UTR. The exact mechanisms need to be further addressed.

MiR-26a and miR-26b mediate osteoarthritis progression by targeting FUT4 via NF-κB signaling pathway

Osteoarthritis (OA) is the most common joint disease, characterized by articular cartilage degradation and changes in all other joint tissues. MicroRNAs (miRNAs) play an important role in mediating the main risk factors for OA. This study aimed to investigate the effect of miR-26a/26b on the proliferation and apoptosis of human chondrocytes by targeting fucosyltransferase 4 (FUT4) through NF-κB signaling pathway. We revealed the differential expression profiles of FUT4 and miR-26a/26b in the articular cartilage tissues of OA patients and normal people. The ability of miR-26a/26b to specifically interact with the 3'UTR of FUT4 was demonstrated via a luciferase reporter assay in chondrocytes. Further results showed altered levels of miR-26a/26b and FUT4 could regulate the process of IL-1β-induced extracellular matrix degradation in chondrocytes. Forced miR-26a/26b expression was able to affect chondrocytes proliferation and apoptosis, while altered expression of FUT4 in chondrocytes modulated progression upon transfection with miR-26a/26b mimic or inhibitor. In OA mice, the overexpression of miR-26a/26b by intra-articular injection significantly attenuated OA progression. In addition, regulating FUT4 expression markedly modulated the activity of NF-κB signaling pathway, and this effect could be reversed by miR-26a/26b. In short, miR-26a/-26b/FUT4/NF-κB axis may serve as a predictive biomarker and a potential therapeutic target in OA treatment.

New insights on the MMP-13 regulatory network in the pathogenesis of early osteoarthritis

Osteoarthritis (OA) is the most common joint disorder and affects approximately half of the aged population. Current treatments for OA are largely palliative until the articular cartilage has been deeply damaged and irreversible morphological changes appear. Thus, effective methods are needed for diagnosing and monitoring the progression of OA during its early stages when therapeutic drugs or biological agents are most likely to be effective. Various proteinases involved in articular cartilage degeneration in pre-OA conditions, which may represent the earliest reversible measurable changes, are considered diagnostic and therapeutic targets for early OA. Of these proteinases, matrix metalloproteinase 13 (MMP-13) has received the most attention, because it is a central node in the cartilage degradation network. In this review, we highlight the main MMP-13-related changes in OA chondrocytes, including alterations in the activity and expression level of MMP-13 by upstream regulatory factors, DNA methylation, various non-coding RNAs (ncRNAs), and autophagy. Because MMP-13 and its regulatory networks are suitable targets for the development of effective early treatment strategies for OA, we discuss the specific targets of MMP-13, including upstream regulatory proteins, DNA methylation, non-coding RNAs, and autophagy-related proteins of MMP-13, and their therapeutic potential to inhibit the development of OA. Moreover, the various entities mentioned in this review might be useful as early biomarkers and for personalized approaches to disease prevention and treatment by improving the phenotyping of early OA patients.

MicroRNA-145 attenuates TNF-α-driven cartilage matrix degradation in osteoarthritis via direct suppression of MKK4

Cartilage dyshomeostasis contributes to osteoarthritis (OA) pathogenesis, and tumor necrosis factor (TNF)-α has critical role in this process by driving inflammatory cascades and cartilage degradation. However, the negative regulation of TNF-α-mediated signaling remains undefined. Here we demonstrate the crucial role of miR-145 in the modulation of TNF-α-mediated signaling and cartilage matrix degradation. MicroRNA (miRNA) expression profiles of TNF-α-stimulated chondrocytes showed that miR-145 expression was rapidly downregulated by TNF-α. Moreover, miR-145 was directly repressed by p65 and was negatively correlated with TNF-α secretion during OA progression. Further, we found that miR-145 directly targeted mitogen-activated protein kinase kinase 4 (MKK4) and broadly restrained the production of several TNF-α-triggered matrix-degrading enzymes (MMP-3, MMP-13, and Adamts-5). Mechanistic studies unveiled that miR-145 negatively regulated TNF-α-mediated JNK and p38 activation, as well as the nuclear accumulation of p-c-Jun and p-ATF2, by inhibiting MKK4 phosphorylation, eventually resulting in the alteration of catabolic genes transcription. Indeed, p-ATF2 interacted with the promoter of Mmp-13, whereas p-c-Jun bound to promoters of Mmp-3 and Adamts-5. MKK4 was significantly elevated in OA cartilage. Eliminating MKK4 by short hairpin RNA resulted in obviously decreased matrix-degrading enzymes production, JNK and p38 inactivation, and an inhibition of cartilage degradation. On the contrary, MKK4 overexpression enhanced TNF-α-mediated signaling activation and transcription of downstream catabolic genes, and consequently worsened cartilage degradation. Moreover, intra-articular (IA) injection of miR-145 agonist to rat with surgery-induced OA alleviated cartilage destruction. Altogether, we elucidate a novel regulatory mechanism underlying TNF-α-triggered cartilage degradation and demonstrate the potential utility of miR-145 and MKK4 as therapy targets for OA.

A bioinformatic analysis of microRNAs role in osteoarthritis

OBJECTIVE

To evaluate the underlying function of microRNAs (miRNAs) in osteoarthritis (OA).

DESIGN

A bioinformatic analysis of miRNAs-OA studies was completed in multiple databases. All identified articles were assessed using specific inclusion and exclusion criteria (Eligible case-control studies for the present study included those which investigated miRNAs differential expression in cartilage tissues and cells of OA and controls. Abstracts, case reports, conference presentations, editorials, and expert opinions were excluded.). We performed bioinformatic analysis and assessed which miRNAs are commonly elevated or decreased in cartilage of OA, and assessed putative targets of these miRNAs using TargetScan, Database for Annotation, Visualization and Integrated Discovery (DAVID), FunRich and String.

RESULTS

Fifty seven studies were included in this study. Our current review has identified 46 differentially expressed miRNAs involved in autophagy, inflammation, chondrocyte apoptosis, chondrocyte differentiation & homeostasis, chondrocyte metabolism and degradation of the extracellular matrix (ECM). Additionally, our literature search identified a wide range of miRNAs that have been shown to be differentially expressed in OA. The function of up-regulated miRNAs primarily target nucleus, whereas the function of down-regulated miRNAs primarily target transcription.

CONCLUSIONS

Comprehensive analysis of all miRNAs studies reveals cooperation in miRNA signatures and suggests that there may be two biologically synergic classes of miRNAs that are associated with OA. This finding suggests that miRNAs may be useful as diagnostic biomarkers and/or may provide new therapeutic targets in OA. Furthermore, a better understanding of the targets of these miRNAs will accelerate biomedical discoveries and improve clinical care based on new knowledge of OA-related disease mechanisms.

miR-127-5p promotes chondrogenic differentiation in rat bone marrow mesenchymal stem cells

The effect and related mechanisms of miR-127-5p on the cartilage differentiation of rat bone marrow mesenchymal stem cells (BMSCs) was investigated. Rat BMSCs were generated and transfected with miR-127-5p, RT-PCR and Safranin O staining were used to detect the effect of miR-127-5p on the cartilage differentiation of rat BMSCs. Western blot analysis was used to detect the related mechanisms of miR-127-5p on the cartilage differentiation of rat BMSCs. Genes related to cartilage differentiation such as Sox9, collagen II and aggrecan were significantly increased in the group which were transfected with miR-127-5p, while collagen X, which was related to cartilage hypertrophy, was decreased in the miR-127-5p transfected group. Safranin O staining revealed that the expression of chondroitin sulfate was significantly increased in the group of miR-127-5p, than the miRNA control group. Western blot analysis showed that miR-127-5p transfection promoted the expression of Sox9, while decreased the expression of Runx2 of rat BMSCs. In conclusion, via increasing the expression of Sox9 and decreasing the expression of Runx2, miR-127-5p could promote cartilage differentiation and decrease cartilage hypertrophy of rat BMSCs.