LncRNA KCNQ1OT1 attenuates osteoarthritic chondrocyte dysfunction via the miR-218-5p/PIK3C2A axis

Expression and clinical significance of LncRNA Kcnq1ot1 in type 2 diabetes mellitus patients with osteoarthritis

OBJECTIVE

We aimed to investigate the expression of lncRNA Kcnq1ot1 in T2DM patients with OA, as well as its correlation with serum inflammatory factors and clinical outcomes of the patients.

METHODS

This prospective observational cohort study included a total of 50 patients with type 2 diabetes mellitus (T2DM), 50 patients with osteoarthritis (OA), and 51 patients with both T2DM and OA between March 2020 and March 2023. The serum TNF-α, interleukin (IL)-6, IL-1β and C-reactive protein (CRP) levels were measured using enzyme-linked immunosorbent assay (ELISA). To determine the expression of LncRNA Kcnq1ot1, RT-qPCR was used. Demographic, clinical statistics, lipid metabolism and nutritional indicators were collected. All data used SPSS 26.0 to statistical analyses.

RESULTS

The T2DM + OA group had significantly higher BMI and LDLC levels compared to the T2DM group (p < 0.05). The serum levels of LncRNA Kcnq1ot1 were significantly higher in the T2DM + OA group compared to the OA group and T2DM group (p < 0.05). Pearson's analysis supported a positive correlation between LncRNA Kcnq1ot1 and IL-6 and IL-1β levels. In addition, LncRNA Kcnq1ot1 could be a potential biomarker for diagnosing the occurrence of T2DM patients with OA. Moreover, LncRNA Kcnq1ot1, BMI, IL-6, Low density lipoprotein cholesterol (LDLC) were the risk factors for T2DM patients with OA.

CONCLUSION

This study showed that the serum LncRNA Kcnq1ot1 levels was remarkably elevated in T2DM patients with OA. This study might provide new targets and a comprehensive approach to treatment in T2DM patients with OA.

Overexpression of miR-23b-3p+miR-218-5p+miR-124-3p differentially modifies the transcriptome of C-33A and CaSki cells and the regulation of cellular processes involved in the progression of cervical cancer

Dysregulation of tumor suppressor miRNAs (tsmiRs) is associated with tumor progression in cancer. miR-23b-3p, miR-218-5p and miR-124-3p are tsmiRs in cervical cancer (CC) and regulate the translation of genes involved in metastasis-related biological processes.

OBJECTIVE

To analyze transcriptome changes in cervical cancer cell lines (C-33A HPV-negative and CaSki HPV-positive) overexpressing miR-23b-3p + miR-218-5p + miR-124-3p, to identify specific target transcripts common to all three miRNAs, as well as signaling pathways and cellular processes related to tumor progression.

METHODS

The transcriptome of C-33A and CaSki cells transfected with miR-23b-3p + miR-218-5p + miR-124-3p was analyzed by RNA-seq. Differentially expressed genes (DEGs) were subjected to Gene Ontology analysis on the DAVID platform. The function of under-regulated genes was analyzed on the GEPIA 2.0, Kaplan-Meier plotter and STRING platforms. On the TargetScanHuman platform it was determined which transcripts have MREs for miR-23b-3p, miR-218-5p and/or miR-124-3p in their 3'UTR region.

RESULTS

Simultaneous overexpression of miR-218-5p, miR-124-3p and miR-23b-3p induced changes in global gene expression in C-33A and CaSki cells. In C-33A cells, DEGs included 45 over- and 172 under-regulated transcripts; in CaSki, 125 transcripts were over- and 84 under-regulated. The under-regulated transcripts enrich proliferation, migration, apoptosis and angiogenesis; 20 of these genes are associated with overall survival (OS) in women with CC, and 18 of the 20 mRNAs have MREs for one, two or all three miRNAs.

CONCLUSIONS

miR-23b-3p + miR-218-5p + miR-124-3p, differentially modify global gene expression in C-33A and CaSki cells. The results indicate that these miRNAs act synergistically and modulate CC progression through individual and shared targets by two or all three miRNAs.

Ion channels in osteoarthritis: emerging roles and potential targets

Osteoarthritis (OA) is a highly prevalent joint disease that causes substantial disability, yet effective approaches to disease prevention or to the delay of OA progression are lacking. Emerging evidence has pinpointed ion channels as pivotal mediators in OA pathogenesis and as promising targets for disease-modifying treatments. Preclinical studies have assessed the potential of a variety of ion channel modulators to modify disease pathways involved in cartilage degeneration, synovial inflammation, bone hyperplasia and pain, and to provide symptomatic relief in models of OA. Some of these modulators are currently being evaluated in clinical trials. This review explores the structures and functions of ion channels, including transient receptor potential channels, Piezo channels, voltage-gated sodium channels, voltage-dependent calcium channels, potassium channels, acid-sensing ion channels, chloride channels and the ATP-dependent P2XR channels in the osteoarthritic joint. The discussion spans channel-targeting drug discovery and potential clinical applications, emphasizing opportunities for further research, and underscoring the growing clinical impact of ion channel biology in OA.

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

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

Epigenetics as a Therapeutic Target in Osteoarthritis

Osteoarthritis (OA) is a heterogenous, complex disease affecting the integrity of diarthrodial joints that, despite its high prevalence worldwide, lacks effective treatment. In recent years it has been discovered that epigenetics may play an important role in OA. Our objective is to review the current knowledge of the three classical epigenetic mechanisms-DNA methylation, histone post-translational modifications (PTMs), and non-coding RNA (ncRNA) modifications, including microRNAs (miRNAs), circular RNAs (circRNAs), and long non-coding RNAs (lncRNAs)-in relation to the pathogenesis of OA and focusing on articular cartilage. The search for updated literature was carried out in the PubMed database. Evidence shows that dysregulation of numerous essential cartilage molecules is caused by aberrant epigenetic regulatory mechanisms, and it contributes to the development and progression of OA. This offers the opportunity to consider new candidates as therapeutic targets with the potential to attenuate OA or to be used as novel biomarkers of the disease.

Salvianolic acid B activates chondrocytes autophagy and reduces chondrocyte apoptosis in obese mice via the KCNQ1OT1/miR-128-3p/SIRT1 signaling pathways

Purpose

Salvianolic acid B (Sal B) possesses strong anti-inflammatory and antioxidant activity. This study aims to explore the underlying mechanism of Sal B to improve the obesity-related osteoarthritis (OA).

Methods

C57BL/6 J male mice were fed with a normal control diet (NCD), a high fat diet (HFD), or HFD with Sal B (25 mg/kg), and mouse body weights and osteoarticular inflammatory factor levels were examined. Mouse chondrogenic cell line ATDC5 were transfected with lncRNA KCNQ1 overlapping transcript 1 small hairpin RNA (KCNQ1OT1 shRNA), miR-128-3p mimic or Sirtuin-1 small interfering RNA (SIRT1 siRNA), then stimulated with Palmitic acid (PA) followed by the treatment of Sal B. Then, inflammatory response, apoptosis, and autophagy of ATDC5 cells in different groups were detected.

Results

Sal B reduced the body weight, decreased the levels of inflammatory markers, and improved cartilage damage in OA mice fed with HFD. KCNQ1OT1 was downregulated in OA mice fed with HFD, and PA-stimulated ATDC5 cells. Sal B protected ATDC5 cells against PA-mediated inflammation, apoptosis, and the inhibition of autophagy, while knockdown of KCNQ1OT1 reversed these results. KCNQ1OT1 was found to be functioned as a ceRNA to bind and downregulate the expression of miR-128-3p that was upregulated in PA-induced cells. Furthermore, SIRT1 was verified as a target of miR-128-3p. MiR-128-3p overexpression reversed the effects of Sal B on inflammatory response, apoptosis, and autophagy in PA-stimulated cells, and knockdown of SIRT1 displayed the similar results.

Conclusion

Sal B exerted a chondroprotective effect by upregulating KCNQ1OT1, which indicates Sal B can used for a therapeutic agent in obesity-related OA.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12986-022-00686-0.

LINC00707 knockdown inhibits IL-1β-induced apoptosis and extracellular matrix degradation of osteoarthritis chondrocytes by the miR-330-5p/FSHR axis

BACKGROUND

Osteoarthritis (OA) is a severe disabling condition that causes major health problems. The roles of lncRNAs in regulating OA progression have been increasingly researched. Based on previously published microarray analysis, LINC00707 is upregulated in OA. This research was done to uncover the function of LINC00707 in IL-1β-induced chondrocyte injury and its possible mechanisms.

METHODS

LINC00707, miR-330-5p, and FSHR expression in OA cartilage tissues were assessed by RT-qPCR. Primary chondrocytes were isolated from OA tissues and treated with IL-1β to establish an in vitro OA model. Under the indicated treatment, chondrocyte apoptosis, senescence, ECM degradation, and inflammation were determined using flow cytometry, TUNEL, SA-β-Gal staining, and ELISA experiments, respectively. Interactions between gene were evaluated using Ago2 RIP and luciferase reporter assays.

RESULTS

LINC00707 and FSHR were elevated, and miR-330-5p was reduced in cartilage tissues of OA patients and in IL-1β-treated primary chondrocytes. Silencing LINC00707 hampered chondrocytes apoptosis, senescence, ECM degradation, and inflammation. LINC00707 acted as a ceRNA to regulate FSHR through controlling miR-330-5p availability. Additionally, both miR-330-5p depletion and FSHR overexpression diminished the effects of silencing LINC00707 in OA progression.

CONCLUSION

Silencing LINC00707 mitigates chondrocyte injury in osteoarthritis via sponging miR-330-5p and inhibiting FSHR.

Regulation of circADAMTS6-miR-324-5p-PIK3R3 ceRNA pathway may be a novel mechanism of IL-1β-induced osteoarthritic chondrocytes

INTRODUCTION

A disintegrin and metallopeptidase with thrombospondin type 1 motif 6 (ADAMTS6)-derived circular RNA (circADAMTS6; hsa_circ_0008667) is a novel regulator in interleukin (IL)-1β-induced apoptosis of human chondrocytes (HCs). Here, we planned to probe into its role and mechanism underlying HCs injury in osteoarthritis.

MATERIALS AND METHODS

Real time-quantitative PCR and immunoblotting estimated the abundance of RNA and protein, respectively. Cell proliferation and apoptosis were measured by WST-8, EdU, fluorescein isothiocyanate, and caspase3/7 activity assays. Levels of inflammatory cytokines (IL-6 and tumor necrosis factor-α), apoptosis-related proteins (Bcl-2 and Bcl-2-associated X protein), extracellular matrix (ECM)-related proteins (matrix metalloproteinase-13 and collagen type II alpha-1), and PI3K/AKT/mTOR signaling pathway-related proteins (AKT, mTOR, phosphorylated-AKT, and phosphorylated-mTOR) were evaluated by enzyme-linked immunosorbent assays and immunoblotting. Target relationship was confirmed by dual-luciferase reporter, Argonaute-2 immunoprecipitation and RNA pull-down assays.

RESULTS

Abundances of circADAMTS6 and phosphoinositide-3-kinase regulatory subunit 3 (PIK3R3) were underexpressed, and microRNA (miR)-324-5p was elevated in human osteoarthritic tissues and IL-1β-induced HCs. Overexpressing circADAMTS6 and inhibiting miR-324-5p enhanced proliferation and ECM synthesis, but suppressed apoptosis and inflammatory response in IL-1β-challenged HCs. Besides, silencing circADAMTS6 caused similar effects of IL-1β stress on HCs. Mechanically, there was a direct interaction between miR-324-5p and circADAMTS6 or PIK3R3, and IL-1β-induced activation of PI3K/AKT/mTOR signaling pathway was suppressed by circADAMTS6 overexpression and miR-324-5p silencing. Furthermore, counteractive effects of miR-324-5p upregulation on circADAMTS6 overexpression and PIK3R3 knockdown on miR-324-5p silencing were observed.

CONCLUSION

CircADAMTS6-miR-324-5p-PIK3R3 axis might participate in IL-1β-induced HCs dysfunction via competing endogenous RNA mechanism and the PI3K/AKT/mTOR signaling pathway.

Kaempferol attenuates the effects of XIST/miR-130a/STAT3 on inflammation and extracellular matrix degradation in osteoarthritis

Aim: To investigate whether kaempferol exhibited protective effects on osteoarthritis chondrocytes by modulating the XIST/miR-130a/STAT3 axis. Methods: qRT-PCR and western blot assays were used for gene and protein determination. Dual luciferase reporter and RNA immunoprecipitation assays were employed to study the interaction between miRNA and lncRNA or genes. Results: Kaempferol decreased proinflammatory cytokine production and extracellular matrix degradation in C28/I2 cells. Additionally, kaempferol ameliorated XIST expression and enhanced miR-130a expression. XIST interacted with miR-130a, and STAT3 was identified as a target of miR-130a. Knockdown of XIST expression suppressed proinflammatory cytokine production and extracellular matrix degradation in C28/I2 cells. Overexpression of STAT3 rescued the effects of XIST knockdown. Conclusion: Kaempferol inhibited inflammation and extracellular matrix degradation by modulating the XIST/miR-130a/STAT3 axis in chondrocytes.