Regulation of inflammatory and catabolic responses to IL-1β in rat articular chondrocytes by microRNAs miR-122 and miR-451

Chemokines in Cartilage Regeneration and Degradation: New Insights

Cartilage plays a crucial role in the human body by forming long bones during development and growth to bear loads on joints and intervertebral discs. However, the increasing prevalence of cartilage degenerative disorders is a growing public health concern, especially due to the poor innate regenerative capacity of cartilage. Chondrocytes are a source of several inflammatory mediators that play vital roles in the pathogenesis of cartilage disorders. Among these mediators, chemokines have been explored as potential contributors to cartilage degeneration and regeneration. Our review focuses on the progress made during the last ten years in identifying the regulators and roles of chemokines and their receptors in different mechanisms related to chondrocytes and cartilage. Recent findings have demonstrated that chemokines influence cartilage both positively and negatively. Their induction and involvement in either process depends on the local molecular environment and is both site- and time-dependent. One of the challenges in defining the role of chemokines in cartilage pathology or regeneration is the apparent redundancy in the interaction of chemokines with their receptors. Hence, it is crucial to determine, for each situation, whether targeting specific chemokines or their receptors will help in developing effective therapeutic strategies for cartilage repair.

Circulating miRNA-122 is associated with knee osteoarthritis progression: A 6-year longitudinal cohort study in the Yakumo study

OBJECTIVE

The association between knee osteoarthritis (OA) and miRNAs has been widely reported. However, the utility of miRNAs as predictors of knee osteoarthritis (KOA) progression in longitudinal studies has not been reported. We aimed to identify circulating miRNAs (c-miRNAs) associated with KOA progression in the general population and to examine their potential use as predictors of KOA progression.

METHODS

In 2012 and 2018, 66 participants (128 knees) took part in a resident health check-up in the Yakumo study. If the KL classification progressed two or more levels, the patient was classified as having progressive OA. Quantitative real-time polymerase chain reaction was used to screen 21 c-miRNAs. The expression levels of those c-miRNAs were compared between the progressive OA group and non-progressive OA group using student-t-test. Logistic analysis was performed in c-miRNAs less than p < 0.10 in univariate analysis.

RESULTS

The progressive OA group consisted of 78 knees. The results of the comparison between the progressive OA group and the non-progressive OA group showed that six c-miRNAs as follows; let7d (p = 0.030), c-miRNA-122 (p < 0.001), 150 (p = 0.070), 199 (p = 0.078), 21 (p = 0.016) and 320 (p = 0.093) were extracted as factors related to the progression of knee OA. In addition, logistic regression analysis identified c-miRNA-122 as an independent factor involved in the progression of knee osteoarthritis (odds ratio: 1.510, 95% confidence interval: 1.060-2.140, p = 0.023). The ROC curve showed by c-miRNA-122 for the progression of OA risk had an area under the curve of 0.702 (95% CI: 0.609-0.795). The threshold of c-miRNA-122 was -4.609.

CONCLUSION

The expression level of c-miRNA-122 was associated with the risk of KOA progression in community dwelling Japanese people.

The role and mechanism of action of microRNA-122 in cancer: Focusing on the liver

microRNA-122 (miR-122) is a highly conserved microRNA that is predominantly expressed in the liver and plays a critical role in the regulation of liver metabolism. Recent studies have shown that miR-122 is involved in the pathogenesis of various types of cancer, particularly liver cancer. In this sense, The current findings highlighted the potential role of miR-122 in regulating many vital processes in cancer pathophysiology, including apoptosis, signaling pathway, cell metabolism, immune system response, migration, and invasion. These results imply that miR-122, which has been extensively studied for its biological functions and potential therapeutic applications, acts as a tumor suppressor or oncogene in cancer development. We first provide an overview and summary of the physiological function and mode of action of miR-122 in liver cancer. We will examine the various signaling pathways and molecular mechanisms through which miR-122 exerts its effects on cancer cells, including the regulation of oncogenic and tumor suppressor genes, the modulation of cell proliferation and apoptosis, and the regulation of metastasis. Most importantly, we will also discuss the potential diagnostic and therapeutic applications of miR-122 in cancer, including the development of miRNA-based biomarkers for cancer diagnosis and prognosis, and the potential use of miR-122 as a therapeutic target for cancer treatment.

Crocus sativus L. Extract (Saffron) Effectively Reduces Arthritic and Inflammatory Parameters in Monotherapy and in Combination with Methotrexate in Adjuvant Arthritis

Rheumatoid arthritis (RA), an autoimmune disease, is characterized by inflammation that affects not only the liver but also other organs and the musculoskeletal system. The standard therapy for RA is methotrexate (MTX), which has safety limitations. The extract from Crocus sativus L. (saffron-SF) is also known for its anti-inflammatory effects. Therefore, we decided to investigate the potential benefit of SF in monotherapy via two doses (SF1-25 mg/kg of b.w.; SF2-50 mg/kg of b.w.) and in combination with MTX (0.3 mg/kg of b.w., twice a week) using adjuvant arthritis in rats. To evaluate these therapeutic settings, we used biometric, immunological, and biochemical parameters, as well as the relative gene expression of the mRNA in the liver. Our results showed a statistically significant increase in the experimental animals' body weight and the arthritic score (AS) on day 14 for monotherapy with SF1 and SF2. The change of hind paw volume (CHPV) was significant only for SF2 monotherapy on the 14th day of the experiment. A combination of SF1 and SF2 with MTX significantly modulated all the biometric parameters during the experimental period. Additionally, AS and CHPV improved considerably compared to MTX monotherapy on day 21. Furthermore, all monotherapies and combination therapies were significant for the biochemical parameter γ-glutamyl transferase (GGT) in the joint. GGT activity in the spleen was less pronounced; only MTX in combination with SF1 significantly modified this parameter. The higher dose of SF monotherapy (SF2) was similarly significant with respect to immunological parameters, such as plasmatic IL-17A, IL-1β, and MMP-9 on day 21. The combination of both doses of SF with MTX significantly improved these immunological parameters, except for C-reactive protein (CRP), which was influenced only by the higher dose of SF2 in combination with MTX in plasma at the end of the experiment. A different effect was found for the relative expression of CD36 mRNA, where only SF1 significantly decreased gene expression in the liver. However, the relative gene mRNA expression of IL-1β in the liver was significantly reduced by the SF monotherapies and the combination of both SF doses with MTX. Our findings showed SF's partial antiarthritic and anti-inflammatory potential in monotherapy, but the effect was stronger in combination with MTX.

Secretive derived from hypoxia preconditioned mesenchymal stem cells promote cartilage regeneration and mitigate joint inflammation via extracellular vesicles

Secretome derived from mesenchymal stem cells (MSCs) have profound effects on tissue regeneration, which could become the basis of future MSCs therapies. Hypoxia, as the physiologic environment of MSCs, has great potential to enhance MSCs paracrine therapeutic effect. In our study, the paracrine effects of secretome derived from MSCs preconditioned in normoxia and hypoxia was compared through both in vitro functional assays and an in vivo rat osteochondral defect model. Specifically, the paracrine effect of total EVs were compared to that of soluble factors to characterize the predominant active components in the hypoxic secretome. We demonstrated that hypoxia conditioned medium, as well as the corresponding EVs, at a relatively low dosage, were efficient in promoting the repair of critical-sized osteochondral defects and mitigated the joint inflammation in a rat osteochondral defect model, relative to their normoxia counterpart. In vitro functional test shows enhancement through chondrocyte proliferation, migration, and matrix deposition, while inhibit IL-1β-induced chondrocytes senescence, inflammation, matrix degradation, and pro-inflammatory macrophage activity. Multiple functional proteins, as well as a change in EVs' size profile, with enrichment of specific EV-miRNAs were detected with hypoxia preconditioning, implicating complex molecular pathways involved in hypoxia pre-conditioned MSCs secretome generated cartilage regeneration.

Micro RNA in meniscal ailments: current concepts

INTRODUCTION

Micro RNAs (miRNAs) are short non-coding RNAs that act primarily in posttranscriptional gene silencing, and are attracting increasing interest in musculoskeletal conditions.

SOURCE OF DATA

Current scientific literature published in PubMed, Google Scholar, Embase and Web of Science databases.

AREAS OF AGREEMENT

Recently, the potential of miRNAs as biomarkers for diagnosis and treatment of meniscal injuries has been postulated.

AREAS OF CONTROVERSY

Evaluation of the role of miRNAs in patients with meniscal tears is still controversial.

GROWING POINTS

A systematic review was conducted to investigate the potential of miRNA in the diagnosis and management of meniscal damage.

AREAS TIMELY FOR DEVELOPING RESEARCH

Intra-articular injection of microRNA-210 in vivo may represent a potential innovative methodology for the management of meniscal injuries. Characterization of the miRNAs expression in the synovial fluid could lead to the development of better early diagnosis and management strategies for meniscal tears.

Dendrobine Alleviates Cellular Senescence and Osteoarthritis via the ROS/NF-κB Axis

Osteoarthritis (OA) is a degenerative joint disease characterized by low-grade inflammation and cartilage degradation. Dendrobine (DEN) is reported to inhibit inflammation and oxidative stress in some diseases, but its role in chondrocyte senescence and OA progress has not yet been elucidated. Our study aimed to explore the protective effects of DEN on OA both in vitro and in vivo. We found that DEN inhibited extracellular matrix (ECM) degradation and promoted ECM synthesis. Meanwhile, DEN inhibited senescence-associated secretory phenotype (SASP) factors expression and senescence phenotype in IL-1β-treated chondrocytes. Furthermore, DEN improved mitochondrial function and reduced the production of intracellular reactive oxygen species (ROS). Also, DEN suppressed IL-1β-induced activation of the NF-κB pathway. Further, using NAC (ROS inhibitor), we found that DEN might inhibit NF-κB cascades by reducing ROS. Additionally, X-ray, micro-CT, and histological analyses in vivo demonstrated that DEN significantly alleviated cartilage inflammation, ECM degradation, and subchondral alterations in OA progression. In conclusion, DEN inhibits SASP factors expression and senescence phenotype in chondrocytes and alleviated the progression of OA via the ROS/NF-κB axis, which provides innovative strategies for the treatment of OA.

Prophylactic administration of miR-451 inhibitor decreases osteoarthritis severity in rats

Transfection of chondrocytes with microRNA-451(miR-451), present in growth zone cartilage of the growth plate, upregulates production of enzymes association with extracellular matrix degradation. miR-451 is also present in articular cartilage and exacerbates IL-1β effects in articular chondrocytes. Moreover, when osteoarthritis (OA) was induced in Sprague Dawley rats via bilateral anterior cruciate ligament transection (ACLT), miR-451 expression was increased in OA cartilage compared to control, suggesting its inhibition might be used to prevent or treat OA. To examine the prophylactic and therapeutic potential of inhibiting miR-451, we evaluated treatment with miR-451 power inhibitor (451-PI) at the onset of joint trauma and treatment after OA had developed. The prophylactic animal cohort received twice-weekly intra-articular injections of either 451-PI or a negative control (NC-PI) beginning on post-surgical day 3. OA was allowed to develop for 24 days in the therapeutic cohort before beginning injections. All rats were killed on day 45. Micro-CT, histomorphometrics, OARSI scoring, and muscle force testing were performed on samples. 451-PI mitigated OA progression compared to NC-PI limbs in the prophylactic cohort based on histomorphometric analysis and OARSI scoring, but no differences were detected by micro-CT. 451-PI treatment beginning 24 days post-surgery was not able to reduce OA severity. Prophylactic administration of 451-PI mitigates OA progression in a post-trauma ACLT rat model supporting its potential to prevent OA development following an ACLT injury clinically.

The Role of Matrix-Bound Extracellular Vesicles in the Regulation of Endochondral Bone Formation

Matrix vesicles are key players in the development of the growth plate during endochondral bone formation. They are involved in the turnover of the extracellular matrix and its mineralization, as well as being a vehicle for chondrocyte communication and regulation. These extracellular organelles are released by the cells and are anchored to the matrix via integrin binding to collagen. The exact function and makeup of the vesicles are dependent on the zone of the growth plate in which they are produced. Early studies defined their role as sites of initial calcium phosphate deposition based on the presence of crystals on the inner leaflet of the membrane and subsequent identification of enzymes, ion transporters, and phospholipid complexes involved in mineral formation. More recent studies have shown that they contain small RNAs, including microRNAs, that are distinct from the parent cell, raising the hypothesis that they are a distinct subset of exosomes. Matrix vesicles are produced under complex regulatory pathways, which include the action of steroid hormones. Once in the matrix, their maturation is mediated by the action of secreted hormones. How they convey information to cells, either through autocrine or paracrine actions, is now being elucidated.

miR-122 and the WNT/β-catenin pathway inhibit effects of both interleukin-1β and tumor necrosis factor-α in articular chondrocytes in vitro

Interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and WNT/β-catenin signaling cause dysregulation of rat primary articular chondrocytes (rArCs), resulting in cartilage extracellular matrix destruction and osteoarthritis (OA) progression. microRNA (miR) miR-122 represses these effects whereas miR-451 exacerbates IL-1β-stimulated matrix metalloproteinase-13 (MMP-13) and prostaglandin E2 (PGE2) production. The goals of this study were to evaluate crosstalk between these signaling pathways and determine if miR-122 and miR-451 exert their protective/destructive effects through these pathways in an in vitro model of OA. Primary rArCs were treated with IL-1β or TNF-α for 24 h and total DNA, MMP-13, and PGE2, as well as expression levels of miR-122 and miR-451 were measured. After 24-h transfection with miR-122, miR-451, miR-122-inhibitor, or miR-451-inhibitor, rArCs were treated with or without TNF-α for 24 h; total DNA, MMP-13, and PGE2 were measured. Similarly, cells were treated with WNT-agonist lithium chloride (LiCl), WNT-antagonist XAV-939 (XAV), or PKF-118-310 (PKF) with and without IL-1β or TNF-α stimulation. Both IL-1β and TNF-α-stimulation increased MMP-13 and PGE2 production. Transfection with miR-122 prevented TNF-α-stimulated increases in MMP-13 and PGE2 whereas transfection with miR-451 did not change these levels. No differences were found in MMP-13 or PGE2 production with miR-122 or miR-451 inhibitors. LiCl treatment decreased PGE2 production in cultures treated with TNF-α, but not MMP-13. XAV increased TNF-α-stimulated increases in PGE2 but not MMP-13. LiCl reduced IL-1β-stimulated increases in MMP-13 and PGE2. XAV and PKF increased IL-1β-stimulated increases in MMP-13 and PGE2. In this in vitro OA model, miR-122 protects against both IL-1β and TNF-α stimulated increases in MMP-13 and PGE2 production. miR-451 does not act through the TNF-α pathway. The WNT/β-catenin pathway regulates the effects of IL-1β and TNF-α stimulation. This study suggests that miR-122 can be used as a treatment or prevention for OA.

Non-coding RNA-based regulation of inflammation

Inflammation is a multifactorial process and various biological mechanisms and pathways participate in its development. The presence of inflammation is involved in pathogenesis of different diseases such as diabetes mellitus, cardiovascular diseases and even, cancer. Non-coding RNAs (ncRNAs) comprise large part of transcribed genome and their critical function in physiological and pathological conditions has been confirmed. The present review focuses on miRNAs, lncRNAs and circRNAs as ncRNAs and their potential functions in inflammation regulation and resolution. Pro-inflammatory and anti-inflammatory factors are regulated by miRNAs via binding to 3'-UTR or indirectly via affecting other pathways such as SIRT1 and NF-κB. LncRNAs display a similar function and they can also affect miRNAs via sponging in regulating levels of cytokines. CircRNAs mainly affect miRNAs and reduce their expression in regulating cytokine levels. Notably, exosomal ncRNAs have shown capacity in inflammation resolution. In addition to pre-clinical studies, clinical trials have examined role of ncRNAs in inflammation-mediated disease pathogenesis and cytokine regulation. The therapeutic targeting of ncRNAs using drugs and nucleic acids have been analyzed to reduce inflammation in disease therapy. Therefore, ncRNAs can serve as diagnostic, prognostic and therapeutic targets in inflammation-related diseases in pre-clinical and clinical backgrounds.

Specific MicroRNAs Found in Extracellular Matrix Vesicles Regulate Proliferation and Differentiation in Growth Plate Chondrocytes

Matrix vesicles (MVs) are extracellular organelles produced by growth plate cartilage cells in a zone-specific manner. MVs are similar in size to exosomes, but they are tethered to the extracellular matrix (ECM) via integrins. Originally associated with matrix calcification, studies now show that they contain matrix processing enzymes and microRNA that are specific to their zone of maturation. MVs produced by costochondral cartilage resting zone (RC) chondrocytes are enriched in microRNA 503 whereas those produced by growth zone (GC) chondrocytes are enriched in microRNA 122. MVs are packaged by chondrocytes under hormonal and factor regulation and release of their contents into the ECM is also under hormonal control, suggesting that their microRNA might have a regulatory role in growth plate proliferation and maturation. To test this, we selected a subset of these enriched microRNAs and transfected synthetic mimics back into RC and GC cells. Transfecting growth plate chondrocytes with select microRNA produced a broad range of phenotypic responses indicating that MV-based microRNAs are involved in the regulation of these cells. Specifically, microRNA 122 drives both RC and GC cells toward a proliferative phenotype, stabilizes the matrix and inhibits differentiation whereas microRNA 22 exerts control over regulatory factor production. This study demonstrates the strong regulatory capability possessed by unique MV enriched microRNAs on growth plate chondrocytes and their potential for use as therapeutic agents.

Overexpression of miR-122 Impairs Intestinal Barrier Function and Aggravates Acute Pancreatitis by Downregulating Occludin Expression

Acute pancreatitis (AP) causes intestinal barrier damage, resulting in systemic inflammatory response syndrome (SIRS) or multiple organ dysfunction syndrome (MODS), which are important factors affecting AP severity and mortality. Here, we studied the mechanism of miR-122 in regulating intestinal barrier function in AP. AP rat model was constructed via intraperitoneal injection of ketamine, and primary intestinal epithelial cells were isolated from rats for in vitro studies. HE staining was used to assess pathological alterations of pancreas and intestines tissues. Inflammatory factors were detected by ELISA assay. qRT-PCR and WB were used to detect the expressions of miR-122 and occluding, respectively. Then dual-luciferase reporter assay, intestinal permeability test, and cell permeability were performed in vivo and in vitro to probe the molecular mechanism of miR-122 in regulating intestinal barrier function in AP. The expression of miR-122 was upregulated in AP rats, while the expression of occludin was downregulated, and the intestinal permeability was increased in AP rats and primary intestinal epithelial cells isolated from rats. Inhibition of miR-122 regulated intestinal barrier function through mediating occludin expression. miR-122 regulated intestinal barrier function to affect AP through mediating occludin expression in vivo. These results provided evidence that miR-122 overexpression impaired intestinal barrier function via regulation of occludin expression, thus promoting AP progression.