ABSTRACT

This study explored the role of MEG3 in the cartilage differentiation of bone marrow mesenchymal stem cells (BMSCs). We investigated the effects of over-expression and knockdown of MEG3 on cell viability, cell differentiation, and the expressions of MEG3, miR-129-5p, COL2, chondrocyte differentiation-related genes (sry-type high-mobility-group box 9 (SOX9), SOX5, Aggrecan, silent information regulator 1 (SIRT1), and Cartilage oligomeric matrix protein (COMP)). The targeting relationship between MEG3 and miR-129-5p and the target gene of miR-129-5p was confirmed through Starbase, TargetScan and luciferase experiments. Finally, a series of rescue experiments were conducted to study the regulatory effects of MEG3 and miR-129-5p. BMSCs were identified as CD29⁺ and CD44⁺ positive, and their differentiation was time-dependent. As BMSCs differentiated, MEG3 expression was up-regulated, but miR-129-5p was down-regulated. Over-expressed MEG3 promoted the viability and differentiation of BMSCs, up-regulated the expressions of COL2 and chondrocyte differentiation-related genes, and inhibited miR-129-5p. Runt-related transcription factor 1 (RUNX1) was negatively regulated as a target gene of miR-129-5p. Results of rescue experiments showed that the inhibitory effect of miR-129-5p mimic on BMSCs could be partially reversed by MEG3. Over-expression of MEG3 regulated the miR-129-5p/RUNX1 axis to promote the differentiation of BMSCs into chondrocytes. This study provides a reliable basis for the application of lncRNA in articular cartilage injury.

摘要

本研究探讨了 MEG3 在骨髓间充质干细胞 (BMSCs) 软骨分化中的作用。我们研究了 MEG3 过表达和敲低对细胞活力、细胞分化以及 MEG3、miR-129-5p、COL2、软骨细胞分化相关基因（sry 型高迁移率组框 9（ SOX9)、SOX5、Aggrecan、沉默信息调节因子 1 (SIRT1) 和软骨寡聚基质蛋白 (COMP)。通过Starbase、TargetScan和荧光素酶实验证实了MEG3和miR-129-5p的靶向关系以及miR-129-5p的靶基因。最后，进行了一系列拯救实验，研究MEG3和miR-129-5p的调控作用。BMSCs 被鉴定为 CD29 ⁺和 CD44 ⁺阳性，并且它们的分化是时间依赖性的。随着 BMSCs 的分化，MEG3 表达上调，但 miR-129-5p 下调。过表达的 MEG3 促进了 BMSCs 的活力和分化，上调了 COL2 和软骨细胞分化相关基因的表达，并抑制了 miR-129-5p。Runt 相关转录因子 1 (RUNX1) 作为 miR-129-5p 的靶基因被负调控。救援实验结果表明，miR-129-5p mimic 对 BMSCs 的抑制作用可被 MEG3 部分逆转。MEG3 的过表达调节 miR-129-5p/RUNX1 轴以促进 BMSCs 向软骨细胞的分化。本研究为lncRNA在关节软骨损伤中的应用提供了可靠依据。