Effect of the interaction between MiR-200b-3p and DNMT3A on cartilage cells of osteoarthritis patients.

The aim of this research is to explore the effect of miR-200b-3p targeting DNMT3A on the proliferation and apoptosis of osteoarthritis (OA) cartilage cells. Quantitative RT-PCR was performed to analyse the expression of miR-200b-3p, DNMT3A, MMP1, MMP3, MMP9, MMP13 and COL II in normal and OA cartilage tissues. The dual-luciferase reporter assay and Western blot assay were conducted to confirm the targeting relationship between miR-200b-3p and DNMT3A. We also constructed eukaryotic expression vector to overexpress miR-200b-3p and DNMT3A. We detected the expression level of MMPs and COL II in stable transfected cartilage cells using RT-PCR and Western blot. Cell proliferation and apoptosis were evaluated using the MTS, pellet culture and Hoechst 33342 staining method. Finally, we explored the effect of miR-200b-3p targeting DNMT3A on the proliferation and apoptosis of OA cartilage cells. The results of RT-PCR indicated that both miR-200b-3p and COL II were down-regulated in OA cartilage tissues, while the expression of DNMT3A and MMPs was up-regulated in OA cartilage tissues. The expressions of DNMT3A, MMPs and COL II detected by Western blot showed the same trend of the results of RT-PCR. The dual-luciferase reporter assay and Western blot assay confirmed the targeting relationship between miR-200b-3p and DNMT3A. In overexpressed miR-200b-3p cartilage cells, DNMT3A and MMPs were significantly down-regulated, COL II was significantly up-regulated, cell viability was enhanced and apoptosis rate was decreased (P < 0.05). In overexpressed DNM3T cartilage cells, MMPs were significantly up-regulated, COL II was significantly down-regulated, cell viability was weakened and apoptosis rate was increased (P < 0.05). MiR-200b-3p inhibited the secretion of MMPs, promoted the synthesis of COL II and enhanced the growth and proliferation of OA cartilage cells through inhibiting the expression of DNMT3A.

Wu J ，Tao Y ，Shang A ，Wang W ，Zhang Y ，Hu L ，Wang J ，Wang Y ，Guo N ... -  《-》

MiR-33b-3p promotes chondrocyte proliferation and inhibits chondrocyte apoptosis and cartilage ECM degradation by targeting DNMT3A in osteoarthritis.

Osteoarthritis (OA) is a common and frequently-occurring disease in middle-aged and older people. A growing number of studies have shown that microRNAs (miRNAs) are involved in the development of OA. However, the role and mechanism of miR-33b-3p in OA remain ill-defined. The levels of miR-33b-3p and DNA methyltransferase 3A (DNMT3A) mRNA were determined by quantitative real-time polymerase chain reaction (qRT-PCR). The levels of DNMT3A protein, matrix metalloprotein 13 (MMP-13), a disintegrin and metalloproteinase with thrombospondin motif-5 (ADAMTS-5), collagen II, aggrecan, cleaved Caspase-3, B-cell lymphoma-2 (Bcl-2) and BCL2-Associated X (Bax) were measured by Western blot assay. Cell proliferation and cell apoptosis were assessed by Cell Counting Kit-8 (CCK-8) assay and flow cytometry analysis, respectively. The targeting relationship between miR-33b-3p and DNMT3A was verified by dual-luciferase reporter assay. The expression of miR-33b-3p was decreased and the expression of DNMT3A was increased in OA cartilage tissues and IL-1β-induced chondrocytes. There was an inverse correlation between miR-33b-3p and DNMT3A in OA cartilage tissues. MiR-33b-3p overexpression or DNMT3A knockdown inhibited extracellular matrix (ECM) degradation and cell apoptosis and promoted cell proliferation in IL-1β-induced chondrocytes. Moreover, DNMT3A was confirmed to be a direct target of miR-33b-3p. Upregulation of DNMT3A weakened the effects of miR-33b-3p overexpression on cartilage ECM degradation, cell proliferation and apoptosis in IL-1β-activated chondrocytes. MiR-33b-3p overexpression suppressed cartilage ECM degradation and cell apoptosis, and promoted cell proliferation by directly targeting DNMT3A in IL-1β-stimulated chondrocytes.

Ma F ，Li G ，Yu Y ，Xu J ，Wu X ... -  《-》

Circ_0116061 regulated the proliferation, apoptosis, and inflammation of osteoarthritis chondrocytes through regulating the miR-200b-3p/SMURF2 axis.

Zheng W ，Hou G ，Li Y 《Journal of Orthopaedic Surgery and Research》

MicroRNA-199-3p up-regulation enhances chondrocyte proliferation and inhibits apoptosis in knee osteoarthritis via DNMT3A repression.

Gu W ，Shi Z ，Song G ，Zhang H ... -  《-》

MiR-337-3p promotes chondrocytes proliferation and inhibits apoptosis by regulating PTEN/AKT axis in osteoarthritis.

Osteoarthritis (OA) is a degenerative disease of articular cartilage and its main pathological feature is cartilage destruction, but its specific pathogenesis is still debatable. The aim of this study was to explore the role of miR-337-3p in OA pathogenesis. The expression of miR-337-3p and PTEN in osteoarthritic cartilage tissues was detected using quantitative real time PCR and western blot, respectively. The regulation of miR-337-3p on PTEN was examined by luciferase reporter gene assays. The manipulation of miR-337-3p and PTEN was mediated by siRNA interference technology. The cell viability was analyzed by MTT assays. MiR-337-3p expression was significantly down-regulated in osteoarthritic cartilage tissues compared with normal cartilage tissues. Further studies confirmed that miR-337-3p overexpression evidently promoted the proliferation and inhibited the apoptosis of OA chondrocytes. PTEN expression was significantly up-regulated in osteoarthritic cartilage tissues and was negatively regulated by miR-337-3p in chondrocytes. PTEN silencing could improve the proliferation of OA chondrocytes and increased pAKT protein expression in OA chondrocytes. MiR-337-3p regulated OA chondrocytes proliferation through PTEN/AKT axis and thus involved in OA.

Huang Z ，Zhang N ，Ma W ，Dai X ，Liu J ... -  《-》