miR-17-5p and miR-19b-3p prevent osteoarthritis progression by targeting EZH2

Targeting EZH2 in autoimmune diseases: unraveling epigenetic regulation and therapeutic potential

Approximately 8-10% of the global population is affected by autoimmune diseases (ADs), which encompass a wide array of idiopathic conditions resulting from dysregulated immune responses. The enzymatic component of the polycomb-repressive complex 2 (PRC2), enhancer of zeste homolog 2 (EZH2, also referred to as KMT6), functions as a methyltransferase possessing a SET domain that plays crucial roles in epigenetic regulation, explicitly facilitating the methylation of histone H3 at lysine 27. Notably, EZH2 is catalytically inactive and requires association with EED and SUZ12 to form an active PRC2 complex. Hyperactivation of EZH2 has been implicated in various malignancies, prompting the development of EZH2 inhibitors as therapeutic agents for several cancers, including lymphoma, prostate, breast, and colon cancer. The application of EZH2-targeting therapies has also been explored in the context of autoimmune diseases. While there have been advancements in certain ADs, responses can vary significantly, as evidenced by mixed outcomes in cases such as inflammatory bowel disease. Consequently, the dual role of EZH2 and the therapeutic potential of its inhibitors in the treatment of ADs remain nascent fields of study. This review will elucidate the interplay between EZH2 and autoimmune diseases, highlighting emerging insights and therapeutic avenues.

MiR-17-5p-engineered sEVs Encapsulated in GelMA Hydrogel Facilitated Diabetic Wound Healing by Targeting PTEN and p21

Delayed wound healing is a major complication of diabetes, and is associated with impaired cellular functions. Current treatments are unsatisfactory. Based on the previous reports on microRNA expression in small extracellular vesicles (sEVs), miR-17-5p-engineered sEVs (sEVs17-OE) and encapsulated them in gelatin methacryloyl (GelMA) hydrogel for diabetic wounds treatment are fabricated. SEVs17-OE are successfully fabricated with a 16-fold increase in miR-17-5p expression. SEVs17-OE inhibited senescence and promoted the proliferation, migration, and tube formation of high glucose-induced human umbilical vein endothelial cells (HG-HUVECs). Additionally, sEVs17-OE also performs a promotive effect on high glucose-induced human dermal fibroblasts (HG-HDFs). Mechanism analysis showed the expressions of p21 and phosphatase and tensin homolog (PTEN), as the target genes of miR-17-5p, are downregulated significantly by sEVs17-OE. Accordingly, the downstream genes and pathways of p21 and PTEN, are activated. Next, sEVs17-OE are loaded in GelMA hydrogel to fabricate a novel bioactive wound dressing and to evaluate their effects on diabetic wound healing. Gel-sEVs17-OE effectively accelerated wound healing by promoting angiogenesis and collagen deposition. The cellular mechanism may be associated with local cell proliferation. Therefore, a novel bioactive wound dressing by loading sEVs17-OE in GelMA hydrogel, offering an option for chronic wound management is successfully fabricated.

Overexpression of Synoviolin and miR-125a-5p, miR-19b-3p in peripheral blood of rheumatoid arthritis patients after treatment with conventional DMARDs and methylprednisolone

PURPOSE

SYVN1 is an endoplasmic reticulum (ER)-resident E3 ubiquitin ligase that has an essential function along with SEL1L in rheumatoid arthritis (RA) pathogenesis. This study aimed to investigate the changes in the expression of peripheral blood ncRNAs and SYVN1-SEL1L affected by DMARDs treatment.

METHODS

Twenty-five newly diagnosed RA patients were randomly assigned to receive conventional DMARDs (csDMARDs) and methylprednisolone for six months. The peripheral blood gene expression of SYVN1 and SEL1L and possible regulatory axes, NEAT1, miR-125a-5p, and miR-19b-3p, were evaluated before and after qRT-PCR. We also compared differences between the patients and healthy controls (HCs), and statistical analyses were performed to determine the correlation between ncRNAs with SYVN1-SEL1L and the clinical parameters of RA.

RESULTS

Expression of NEAT1 (P = 0.0001), miR-19b-3p (P = 0.007), miR-125a-5p (P = 0.005), and SYVN1 (P = 0.036) was significantly increased in newly diagnosed patients compared to HCs; also, miR-125a-5p, miR-19b-3p, and SYVN1 were significantly overexpressed after treatment (P = 0.001, P = 0.001, and P = 0.005, respectively). NEAT1 was positively correlated with SYVN1, and miR-125a-5p had a negative correlation with anti-cyclic citrullinated peptides. The ROC curve analysis showed the potential role of selected ncRNAs in RA pathogenesis.

CONCLUSION

The results indicate the ineffectiveness of the csDMARDs in reducing SYVN1 expression. The difference in expression of ncRNAs might be useful markers for monitoring disease activity and determining therapeutic responses in RA patients. Key Points • The expression of NEAT1 is significantly upregulated in RA patients compared to HC subjects. • miR-19b-3p, miR-125a-5p, and SYVN1 are significantly upregulated in RA patients compared to HC subjects. • The expression of miR-19b-3p and miR-125a-5p is significantly increased in RA patients after treatment with DMARDs and methylprednisolone. • NEAT1 is positively correlated with SYVN1.

Fibroblast growth factor 23 regulates hypoxia‑induced osteoblast apoptosis through the autophagy‑signaling pathway

Hypoxia can lead to programmed osteoblast death. Prevention of osteoblast apoptosis caused by hypoxia is of great significance in the study of the occurrence and development of bone necrosis. The present study aimed to investigate the effects and mechanism of fibroblast growth factor 23 (FGF23) on hypoxia‑induced apoptosis in primary osteoblasts and MC3T3‑E1 cells osteoblasts. Cells were transfected with a plasmid carrying the FGF23 gene and a cell model of hypoxia‑induced apoptosis was established. FGF23 mRNA levels were measured using reverse transcription‑quantitative (RT‑q) PCR and western blotting was used to assess protein levels. Apoptosis was analyzed by MTT assay, fluorescein diacetate and ethidium bromide staining, flow cytometry and RT‑qPCR and western blotting were used to verify the mRNA and protein levels of apoptosis‑ and autophagy‑related gene mRNA. The targeted relationship between miR‑17‑5p and FGF23 was confirmed using the StarBase database, TargetScan database and a luciferase reporter assay. FGF23 decreased cell survival and increased the rate of apoptosis. The mRNA and protein expression of the pro‑apoptotic genes Bax and caspases 3 and 9 increased, whereas that of the anti‑apoptotic Bcl‑2 decreased. The expressions of the autophagy‑associated proteins beclin‑1, light chain 3‑II (LC3‑II) and the LC3‑II/LC3‑I ratio were significantly increased. In addition, a luciferase reporter assay confirmed that FGF23 directly regulated micro RNA (miR)‑17‑5p. The effects of FGF23 silencing were reversed by miR‑17‑5p inhibition. FGF23 may regulate hypoxia‑induced osteoblast apoptosis by targeting miR‑17‑5p through the autophagy‑signaling pathway. This provides a rationale for FGF23 as a potential therapeutic target for osteonecrosis of the femoral head.

The Role of Genetics and Epigenetic Regulation in the Pathogenesis of Osteoarthritis

Osteoarthritis (OA) is progressive disease characterised by cartilage degradation, subchondral bone remodelling and inflammation of the synovium. The disease is associated with obesity, mechanical load and age. However, multiple pro-inflammatory immune mediators regulate the expression of metalloproteinases, which take part in cartilage degradation. Furthermore, genetic factors also contribute to OA susceptibility. Recent studies have highlighted that epigenetic mechanisms may regulate the expression of OA-associated genes. This review aims to present the mechanisms of OA pathogenesis and summarise current evidence regarding the role of genetics and epigenetics in this process.

Exosome-mediated long noncoding RNA (lncRNA) PART1 suppresses malignant progression of oral squamous cell carcinoma via miR-17-5p/SOCS6 axis

BACKGROUND

Exosomes derived from oral squamous cell carcinoma (OSCC) could modulate OSCC development. This study aimed to explore effects of exosome-mediated lncRNA PART1 on OSCC cells.

METHODS

This study was performed in Tianjin Medical University Cancer Institute from February 2021 to March 2022. Bioinformatic analysis was performed on the public database GEPIA (http://gepia.cancer-pku.cn/). Exosomes isolated from cell lines squamous cell carcinoma 9 (SCC9) and Centre Antoine Lacassagne-27 (CAL27) were identified by transmission electron microscope and western blot. Exosome-mediated lncRNA PART1, microRNA-17-5p(miR-17-5p) and suppressor of cytokine signaling 6(SOCS6) RNA expressions were assessed by quantitative reverse transcription polymerase chain reaction (RT-qPCR). Cell counting kit8(CCK-8), caspase-3 activity, and flow cytometry were applied to evaluate OSCC cell viabilities and apoptosis. Meanwhile, OSCC cell migratory ability and invasiveness were evaluated using transwell assay. Bindings between miR-17-5p and lncRNA PART1 or SOCS6 were validated using the luciferase reporter test. Western blot was used for detecting the protein levels of SOCS6, phosphorylated signal transducer and activator of transcription 3 (STAT3) and STAT3.

RESULTS

: According to GEPIA, lncRNA PART1 was downregulated in OSCC tissue samples and cells, and it had a positive correlation with the good prognosis of Head and neck squamous cell cancer (HNSCC) patients. After the exosomes from OSCC cells were isolated and verified, PART1 was then confirmed to be secreted by exosomes. Further, overexpression of exosome-mediated lncRNA PART1 inhibited OSCC cell viabilities, migration, and invasiveness but facilitated OSCC cell apoptosis. PART1 upregulated SOCS6 through sponging miR-17-5p. Moreover, exosome-mediated lncRNA PART1 suppressed the phosphorylation of STAT3.

DISCUSSION

Exosome-mediated lncRNA PART1 could mediate the OSCC progression via miR-17-5p/SOCS6 axis in vitro, suggesting that lncRNA PART1 might be a target for treating OSCC.

circ_0004904 regulates the trophoblast cell in preeclampsia via miR-19b-3p/ARRDC3 axis

Circular RNAs have been demonstrated to act as vital participants in various diseases, including preeclampsia (PE). This study aimed to research the effects of circ_0004904 on PE. The contents of circ_0004904, microRNA-19b-3p (miR-19b-3p) and arrestin domain containing 3 (ARRDC3) were quantified by quantitative real-time PCR and western blot. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and 5-ethynyl-2'-deoxyuridine assays were enforced to assess cell proliferation. The transwell assay and flow cytometry were applied to detect the cell migration, invasion, and apoptosis. The liaison between miR-19b-3p and circ_0004904 or ARRDC3 was demonstrated by dual-luciferase reporter assay. Thereafter, circ_0004904 and ARRDC3 were augmented, and miR-19b-3p was restrained in PE. Circ_0004904 silencing contributed to cell proliferation, migration, and invasion, but restrained cell apoptosis in trophoblast cells. Further, miR-19b-3p was a target of circ_0004904, and miR-19b-3p could target ARRDC3. Additionally, circ_0004904 accelerated PE evolution via changing ARRDC3 level by binding to miR-19b-3p. In all, circ_0004904 encouraged PE progress via miR-19b-3p/ARRDC3 axis.

miR-17-92 cluster in osteoarthritis: Regulatory roles and clinical utility

Osteoarthritis (OA) is the most prevalent articular disease, especially in aged population. Caused by multi-factors (e.g., trauma, inflammation, and overloading), OA leads to pain and disability in affected joints, which decreases patients' quality of life and increases social burden. In pathophysiology, OA is mainly characterized by cartilage hypertrophy or defect, subchondral bone sclerosis, and synovitis. The homeostasis of cell-cell communication is disturbed as well in such pro-inflammatory microenvironment, which provides clues for the diagnosis and treatment of OA. MicoRNAs (miRNAs) are endogenous non-coding RNAs that regulate various processes via post-transcriptional mechanisms. The miR-17-92 cluster is an miRNA polycistron encoded by the host gene called MIR17HG. Mature miRNAs generated from MIR17HG participate in biological activities such as oncogenesis, neurogenesis, and modulation of the immune system. Accumulating evidence also indicates that the expression level of miRNAs in the miR-17-92 cluster is tightly related to the pathological processes of OA, such as chondrocyte apoptosis, extracellular matrix degradation, bone remodeling, and synovitis. In this review, we aim to summarize the roles of the miR-17-92 cluster in the underlying molecular mechanism during the development and progression of OA and shed light on the new avenue of the diagnosis and treatment of OA.

MiR-19b-3p Attenuates Chondrocytes Injury by Inhibiting MAPK/NF-Κb Axis via Targeting SOCS1

In this study, miR-19b-3p was downregulated in osteoarthritic cartilage tissues and IL-1β-stimulated primary chondrocytes, and miR-19b-3p overexpression reversed the inhibitory effect of IL-1β on cell viability, the promotion effects of apoptosis, inflammatory factor secretion and extracellular matrix degradation, whereas the opposite effect was observed with miR-19b-3p inhibitor. Moreover, SOCS1 is a target gene of miR-19b-3p. Furthermore, SOCS1 overexpression enhanced cell injury compared with IL-1β alone treatment, whereas knockdown of SOCS1 restored cell damage caused by IL-1β. Further studies revealed that miR-19b-3p promoted chondrocyte injury repair by suppressing SOCS1 expression, and we found that was mediated by blocking the MAPK/NF-κB axis. Taken together, our findings may provide a new therapeutic strategy for osteoarthritis.

Emerging role of EZH2 in rheumatic diseases: A comprehensive review

Enhancer of zeste homolog 2 (EZH2) is a histone methylated enzyme. It trimethylates histone 3 lysine 27 (H3K27) to regulate epigenetic processes. Recently, studies showed excessive expression of EZH2 in rheumatic diseases, such as systemic lupus erythematosus, rheumatoid arthritis, osteoarthritis, and systemic sclerosis. Moreover, epigenetic modification of EZH2 regulates differentiation and proliferation of different immune cells. Therefore, in this review, we comprehensively discuss the role of EZH2 in rheumatic diseases. Collection of the evidence may provide a basis for further understanding the role of EZH2 and give potential for targeting these diseases.

CircSCAPER contributes to IL-1β-induced osteoarthritis in vitro via miR-140-3p/EZH2 axis

Aims

Circular RNA (circRNA) S-phase cyclin A-associated protein in the endoplasmic reticulum (ER) (circSCAPER, ID: hsa_circ_0104595) has been found to be highly expressed in osteoarthritis (OA) patients and has been associated with the severity of OA. Hence, the role and mechanisms underlying circSCAPER in OA were investigated in this study.

Methods

In vitro cultured human normal chondrocyte C28/I2 was exposed to interleukin (IL)-1β to mimic the microenvironment of OA. The expression of circSCAPER, microRNA (miR)-140-3p, and enhancer of zeste homolog 2 (EZH2) was detected using quantitative real-time polymerase chain reaction and Western blot assays. The extracellular matrix (ECM) degradation, proliferation, and apoptosis of chondrocytes were determined using Western blot, cell counting kit-8, and flow cytometry assays. Targeted relationships were predicted by bioinformatic analysis and verified using dual-luciferase reporter and RNA immunoprecipitation (RIP) assays. The levels of phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) pathway-related protein were detected using Western blot assays.

Results

CircSCAPER was highly expressed in OA cartilage tissues and IL-1β-induced chondrocytes. Knockdown of circSCAPER reduced IL-1β-evoked ECM degradation, proliferation arrest, and apoptosis enhancement in chondrocytes. Mechanistically, circSCAPER directly bound to miR-140-3p, and miR-140-3p inhibition reversed the effects of circSCAPER knockdown on IL-1β-induced chondrocytes. miR-140-3p was verified to target EZH2, and overexpression of miR-140-3p protected chondrocytes against IL-1β-induced dysfunction via targeting EZH2. Additionally, we confirmed that circSCAPER could regulate EZH2 through sponging miR-140-3p, and the circSCAPER/miR-140-3p/EZH2 axis could activate the PI3K/AKT pathway.

Conclusion

CircSCAPER promoted IL-1β-evoked ECM degradation, proliferation arrest, and apoptosis enhancement in chondrocytes via regulating miR-140-3p/EZH2 axis, which gained a new insight into the pathogenesis of OA.

Cite this article: Bone Joint Res 2022;11(2):61–72.

miR-19b-3p relieves intervertebral disc degeneration through modulating PTEN/PI3K/Akt/mTOR signaling pathway

Emerging studies have revealed that non-coding RNAs contribute to regulating intervertebral disc degeneration (IVDD). Here, we intended to probe into the function of miR-19b-3p in IVDD evolvement. The miR-19b-3p level in the intervertebral disc (IVD) tissues of IVDD patients and IL-1β/TNF-α/hydrogen peroxide-treated human nucleus pulposus cells (HNPCs) was determined by quantitative real-time polymerase chain reaction (qRT-PCR). Also, qRT-PCR was conducted to examine the profiles of MMP-3, MMP-9, MMP-13, ADAMTS-4 and ADAMTS-5. The PTEN/PI3K/Akt/mTOR pathway was examined by Western blot (WB). The miR-19b-3p overexpression assay was carried out, and HNPC proliferation and apoptosis were compared by the cell counting kit-8 (CCK-8) assay and flow cytometry (FCM). In addition, the mechanism of action of miR-19b-3p was clarified using the PTEN inhibitor (VO-Ohpic triphosphate) or the mTOR inhibitor (Rapamycin) on the basis of IL-1β intervention and miR-19b-3p mimics transfection. Our results testified that miR-19b-3p expression was curbed in IVD tissues of the IVDD patients (vs. normal IVD tissues) and IL-1β-, TNF-α, or hydrogen peroxide-treated HNPCs. Up-regulating miR-19b-3p enhanced HNPC proliferation and hampered its apoptosis. Moreover, miR-19b-3p dampened the PTEN profile and activated the PI3K/Akt/mTOR pathway. Interestingly, attenuating PTEN reduced IL-1β-, TNF-α-, or hydrogen peroxide-mediated HNPC apoptosis and up-regulated PI3K/Akt/mTOR, while inhibiting the mTOR pathway offset the protective function of miR-19b-3p. Further mechanism studies illustrated that miR-19b-3p targeted the 3'untranslated region (UTR) of PTEN and abated the PTEN level. This research confirmed that miR-19b-3p suppressed HNPC apoptosis in the in-vitro model of IVDD by regulating PTEN/PI3K/Akt/mTOR pathway.

miR-590-5p affects chondrocyte proliferation, apoptosis, and inflammation by targeting FGF18 in osteoarthritis

OBJECTIVE

To investigate the potential miRNA targeting FGF18, and its role in regulating the proliferation, apoptosis and inflammation in human primary chondrocytes.

METHODS

The normal human chondrocytes were induced by IL-1β to mimic OA in vitro. qPCR and Western blotting were performed to evaluate the expression of FGF18. Target Scan analysis was performed to predict the miRNA targeting FGF18. Then, the expression of miR-590-5p was quantified by qPCR in IL-1β-induced chondrocytes. After transfection of miR-590-5p mimics or inhibitors, CCK-8 assay was conducted to determine the cell viability and apoptosis-related proteins, and cartilage degeneration related biomarkers were assayed by qPCR and Western blotting. The levels of tumor necrosis factor (TNF)-α, interleukin (IL)-6 and IL-8 were determined by ELISA. The targeting relationship between miR-590-5p and FGF18 was assayed by luciferase reporter assay in IL-1β-induced chondrocytes.

RESULTS

Target Scan analysis predicted that FGF18 is directly targeted by miR-590-5p. miR-590-5p was up-regulated, whereas FGF18 expression was inhibited in IL-1β-induced chondrocytes. miR-590-5p mimics reduced the expression of FGF18 protein, inhibited the cell viability of chondrocytes, and promoted secretion of inflammatory factors in chondrocytes, while miR-590-5p inhibitors increased FGF18 levels in IL-1β-treated chondrocytes. Furthermore, expression of inflammatory factors in chondrocytes was reduced by miR-590-5p inhibitors. The luciferase reporter assay showed that miR-590-5p could target FGF18.

CONCLUSIONS

miR-590-5p promotes OA progression by targeting FGF18, which serves as a potential therapeutic target for OA.

MiR-17-5p downregulation alleviates apoptosis and fibrosis in high glucose-induced human mesangial cells through inactivation of Wnt/β-catenin signaling by targeting KIF23

Diabetic nephropathy (DN) remains the major cause of end-stage renal disease. MicroRNAs (miRNAs) have been reported to perform biological functions in many diseases. This investigation elucidated the biological role of miR-17-5p in DN. In this study, high glucose-cultured human mesangial cells (HMCs) were used as a cell model of DN. The miR-17-5p and KIF23 expression was measured by RT-qPCR. Cell apoptosis was detected by flow cytometry. The protein levels of apoptosis markers, fibrosis markers, and Wnt/β-catenin signaling-related genes were assessed using western blotting. The interaction of miR-17-5p with KIF23 was tested by a luciferase reporter assay. We found that miR-17-5p was upregulated in both DN patients and high glucose-treated HMCs. Silencing miR-17-5p attenuated the apoptosis and fibrosis in high glucose-treated HMCs. MiR-17-5p binds to KIF23 3'UTR and negatively regulates KIF23 expression. KIF23 knockdown could suppress the role of miR-17-5p inhibition in high glucose-treated HMCs. Additionally, inhibition of miR-17-5p activated Wnt/β-catenin signaling in HMCs through upregulating KIF23 expression. Suppression of Wnt/β-catenin signaling antagonized the effect of miR-17-5p in HMCs. In conclusion, miR-17-5p inhibition alleviates the apoptosis and fibrosis in high glucose-treated HMCs by targeting KIF23 activating Wnt/β-catenin signaling.

Data Integration Reveals the Potential Biomarkers of Circulating MicroRNAs in Osteoarthritis

The abnormal expression of circulating miRNAs (c-miRNAs) has become an emerging field in the development of miRNAs-based diagnostic and therapeutic tools for human diseases, including osteoarthritis (OA). OA is the most common form of arthritis leading to disability and a major socioeconomic burden. The abnormal expression of miRNAs plays important roles in the pathogenesis of OA. Unraveling the role of miRNAs in the pathogenesis of OA will throw light on the potential for the development of miRNAs-based diagnostic and therapeutic tools for OA. This article reviews and highlights recent advances in the study of miRNAs in OA, with specific demonstration of the functions of miRNA, especially c-miRNA, in OA pathogenesis as well as its potential implication in the treatment of OA. Based on a systematic literature search using online databases, we figured out the following main points: (1) the integrative systematic review of c-mRNAs and its target genes related to OA pathogenesis; (2) the potential use of c-miRNAs for OA diagnosis purposes as potential biomarkers; and (3) for therapeutic purposes, and we also highlight certain remedies that regulate microRNA expression based on its target genes.