MiR-4303 relieves chondrocyte inflammation by targeting ASPN in osteoarthritis

[miR-515-5p targeting Toll-like receptor 4 regulates myeloid differentiation primary response gene 88/nuclear factor-kappa B pathway to inhibit apoptosis and inflammatory response of osteoarthritis chondrocytes]

Objective

To explore the molecular mechanism of miR-515-5p in inhibiting chondrocyte apoptosis and alleviating inflammatory response in osteoarthritis (OA).

Methods

Human cartilage cell line C28/I2 was cultured in vitro and treated with 10 ng/mL interleukin 1β (IL-1β) for 24 hours to construct an in vitro OA model. C28/I2 cells were transfected with miR mimics, mimics negative control (NC), over expression (oe)-NC, and oe-Toll-like receptor 4 (TLR4), respectively, and then treated with 10 ng/mL IL-1β for 24 hours to establish OA model. Cell proliferation capacity was detected by cell counting kit 8 and 5-Ethynyl-2'-deoxyuridine, cell apoptosis and cell cycle were detected by flow cytometry, and B-cell lymphoma 2 protion (Bcl-2), Bcl-2-associated X protein (Bax), cleaved-Caspase-3, TLR4, myeloid differentiation primary response gene 88 (MyD88), p65 and phosphorylated p65 (p-p65) protein expression levels were detected by Western blot. Real-time fluorescence quantitative PCR was used to detect mRNA expression levels of miR-515-5p and TLR4, and ELISA was used to detect pro-inflammatory factor prostaglandin E2 (PGE2), tumor necrosis factor α (TNF -α), and IL-6 levels in cell supernatant. The potential binding sites between miR-515-5p and TLR4 were predicted by BiBiServ2 database, and the targeting relationship between miR-515-5p and TLR4 was verified by dual luciferase reporting assay.

Results

After the treatment of C28/I2 cells with IL-1β, the expressions of miR-515-5p and Bcl-2 protein and the proliferation ability of C28/I2 cells significantly reduced. The expression levels of Bax and cleaved-Caspase-3 protein, the levels of pro-inflammatory factors (PGE2, TNF-α, IL-6) in the supernatant of C28/I2 cells, and the apoptosis of C28/I2 cells significantly increased. In addition, the proportion of the cells at S phase and G 2 phase decreased significantly, and the proportion of cells at G 1 phase increased significantly, suggesting that the cell cycle was blocked after IL-1β treatment. After transfection with miR mimics, the expression level of miR-515-5p in the cells significantly up-regulated, partially reversing the apoptosis of OA chondrocytes induced by IL-1β, and alleviating the cycle arrest and inflammatory response of OA chondrocytes. After treating C28/I2 cells with IL-1β, the mRNA and protein levels of TLR4 significantly increased. Overexpression of miR-515-5p targeted inhibition of TLR4 expression and blocked activation of MyD88/nuclear factor κB (NF-κB) pathway. Overexpression of TLR4 could partially reverse the effect of miR mimics on IL-1β-induced apoptosis and inflammation of OA chondrocytes.

Conclusion

miR-515-5p negatively regulates the expression of TLR4, inhibits the activation of MyD88/NF-κB pathway and apoptosis of OA chondrocytes, and effectively alleviates the inflammatory response of the cells.

miR-181a-5p targets DDX3X to inhibit the progression of osteoarthritis via NF-ΚB signaling pathway

Osteoarthritis (OA) is the most common age-related joint disease, characterized by chronic inflammation, progressive articular cartilage destruction and subchondral osteosclerosis. More and more evidence showed that microRNAs (miRNAs) play a key role in various diseases, but the specific mechanism of miRNAs in OA is not clear. The purpose of this study was to investigate the expression level and role of miR-181a-5p in OA and its related mechanism. Here we identified the key gene DEAD-box RNA helicase 3X (DDX3X) in the OA dataset by bioinformatics analysis. At the same time, miRNAs targeting DDX3X were screened, and miR-181a-5p was selected as the next research object. Then we used different concentrations of interleukin-1 beta (IL-1β)-induced in vitro model of arthritis, and found that IL-1β can stimulate cells to release nitric oxide. The expression levels of miR-181a-5p and DDX3X in mouse chondrocyte cell line ATDC5 induced by IL-1β at a concentration of 10ug/mL were detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). IL-1β induced a decrease in the expression of miR-181a-5p and an increase in the expression of DDX3X in ATDC5 cells. mimic miR-181a-5p or inhibitor miR-181a-5p were transfected into ATDC5 cells, and the levels of inflammatory mediators in the cells were detected by enzyme-linked immunosorbent assay, and the results showed that miR-181a-5p could reduce the release of tumor necrosis factor-α, IL-1β, IL-6 and inducible nitric oxide nitric oxide synthase in a cellular model of arthritis. Luciferase reporter assays confirmed that the miR-181a-5p binding site was in the DDX3X gene 3'-untranslated region (3'-UTR), and DDX3X was negatively regulated by miR-181a-5p. Rescue assays confirmed that miR-181a-5p reduced the expression of DDX3X by targeting the 3'-UTR region of DDX3X, thereby reducing the release of inflammatory factors. Finally, in this paper, western blot was used to detect the mechanism of miR-181a-5p regulating OA. The results showed that interfering with the expression of miR-181a-5p could up-regulate the expression of DDX3X protein, increase the expression of nuclear factor- kappaB (NF-κB) related proteins, and reduce the inflammatory response of OA, thereby increasing the secretion of the matrix proteinases MMP-3 and MMP-13. Taken together, the results of the study suggested that miR-181a-5p may be a promising therapeutic target for the treatment of human OA.

RNA-Sequence Reveals the Regulatory Mechanism of miR-149 on Osteoblast Skeleton under Mechanical Tension

Objective

Based on RNA-sequencing (RNA-seq), the regulation of miRNAs differentially expressed in dental, periodontal, and alveolar bone tissue of orthodontic tree shrews on osteoblast skeleton under tension was investigated.

Methods

Tree shrews were used to construct orthodontic models. We used RNA-seq to identify differentially expressed miRNAs in periodontal tissues of the treatment group and control group tree shrews. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) were used for enrichment analysis. Human osteoblast MG63 was treated with 5000 U mechanical tension. Real-time quantitative polymerase chain reaction (RT-qPCR) detected the expression of miR-149 and ARFGAP with SH3 domain, Ankyrin repeat, and Ph domain 3 (ASAP3) mRNA. Western blot detected the protein levels of ASAP3, F-actin, osteogenic markers bone morphogenetic protein 2 (BMP2), and runt-related transcription factor 2 (RUNX2). Rhodamine phalloidin was used to observe the fluorescence intensity of F-actin. Validation of the targeting relationship between miR-149 and ASAP3 by dual luciferase reporter gene assay.

Results

By performing miRNA-seq analysis on the dental and periodontal tissue of tree shrews in the treatment group and control group, we identified 51 upregulated miRNAs and 13 downregulated miRNAs. The expression of miR-149 in the dental and periodontal tissue of tree shrew and MG63 cells treated with mechanical tension was decreased, and miR-149 targeted ASAP3. Knockdown of ASAP3 inhibited the fluorescence intensity of F-actin in MG63 cells treated with 5000 U tension for 36 h, and overexpression of ASAP3 promoted the expression of F-actin and osteogenic markers BMP2 and RUNX2.

Conclusions

These findings revealed that miR-149 could modulate osteoblast differentiation under orthodontics mechanical tension through targeting ASAP3.

ASPN Is a Potential Biomarker and Associated with Immune Infiltration in Endometriosis

Objective: Endometriosis is a benign gynecological disease characterized by distant metastasis. Previous studies have discovered abnormal numbers and function of immune cells in endometriotic lesions. We aimed to find potential biomarkers of endometriosis and to explore the relationship between ASPN and the immune microenvironment of endometriosis. Methods: We obtained the GSE141549 and GSE7305 datasets containing endometriosis and normal endometrial samples from the Gene Expression Omnibus database (GEO). In the GSE141549 dataset, differentially expressed genes (DEGs) were found. The Least Absolute Shrinkage and Selection Operator (Lasso) regression and generalized linear models (GLMs) were used to screen new biomarkers. The expression levels and diagnostic utility of biomarkers were assessed in GSE7305, and biomarker expression levels were further validated using qRT-PCR and western blot. We identified DEGs between high and low expression groups of key biomarkers. Enrichment analysis was carried out to discover the target gene’s biological function. We analyzed the relationship between key biomarker expression and patient clinical features. Finally, the immune cells that infiltrate endometriosis were assessed using the Microenvironment Cell Population-Counter (MCP-counter), and the correlation of biomarker expression with immune cell infiltration and immune checkpoints genes was studied. Results: There were a total of 38 DEGs discovered. Two machine learning techniques were used to identify 10 genes. Six biomarkers (SCG2, ASPN, SLIT2, GEM, EGR1, and FOS) had good diagnostic efficiency (AUC > 0.7) by internal and external validation. We excluded previously reported related genes (SLIT2, EGR1, and FOS). ASPN was the most significantly differentially expressed biomarker between normal and ectopic endometrial tissues, as verified by qPCR. The western blot assay revealed a significant upregulation of ASPN expression in endometriotic tissues. The investigation for DEGs in the ASPN high- and low-expression groups revealed that the DEGs were particularly enriched in extracellular matrix tissue, vascular smooth muscle contraction, cytokine interactions, the calcium signaling pathway, and the chemokine signaling pathway. High ASPN expression was related to r-AFS stage (p = 0.006), age (p = 0.03), and lesion location (p < 0.001). Univariate and multivariate logistic regression analysis showed that ASPN expression was an independent influencing factor in patients with endometriosis. Immune cell infiltration analysis revealed a significant increase in T-cell, B-cell, and fibroblast infiltration in endometriosis lesions; cytotoxic lymphocyte, NK-cell, and endothelial cell infiltration were reduced. Additionally, the percentage of T cells, B cells, fibroblasts, and endothelial cells was favorably connected with ASPN expression, while the percentage of cytotoxic lymphocytes and NK cells was negatively correlated. Immune checkpoint gene (CTLA4, LAG3, CD27, CD40, and ICOS) expression and ASPN expression were positively associated. Conclusions: Increased expression of ASPN is associated with immune infiltration in endometriosis, and ASPN can be used as a diagnostic biomarker as well as a potential immunotherapeutic target in endometriosis.