OBJECTIVE Temporomandibular joint osteoarthritis (TMJOA) is a common degenerative disease in jaw joint, accompanied by articular cartilage destruction. Differentiation of stem cells to cartilage has important therapeutic implications in TMJ cartilage repair. Previous studies revealed that lncRNA XIST participated in various biological processes. However, the effect of XIST on chondrogenic differentiation of synovium-derived mesenchymal stem cells (SMSCs) remains unclear. Our study aimed to investigate the function of XIST in chondrogenic differentiation of human SMSCs from TMJ. METHODS Alcian blue staining was performed to determine proteoglycan in SMSCs. qPCR, western blotting and immunofluorescence assays were allowed to assess sex determining region Y-box 9 (SOX9), Collagen type II alpha 1 chain (COL2A1) and Aggrecan (ACAN) expression. The direct interaction between miR-27b-3p and XIST or ADAMTS-5 was confirmed by dual luciferase reporter assay or RNA immunoprecipitation (RIP) assay. RESULTS XIST was remarkably down-regulated in chondrogenic differentiation of SMSCs. Functional analysis demonstrated that XIST silencing promoted chondrogenic differentiation of SMSCs. Dual luciferase reporter and RIP assays identified that XIST acted as a sponge for miR-27b-3p. Moreover, XIST regulated ADAMTS-5 expression by directly binding miR-27b-3p. More importantly, miR-27b-3p/ADAMTS-5 rescued the effects of XIST on chondrogenic differentiation of SMSCs. CONCLUSION The results suggest that XIST modulates SMSCs chondrogenic differentiation via the miR-27b-3p/ADAMTS-5 axis, which provides new targets for TMJOA treatment.

中文翻译：

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长链非编码 RNA XIST 通过 miR-27b-3p/ADAMTS-5 轴调控颞下颌关节滑膜间充质干细胞的软骨分化

目的颞下颌关节骨关节炎（TMJOA）是一种常见的颌关节退行性疾病，伴有关节软骨破坏。干细胞向软骨的分化在 TMJ 软骨修复中具有重要的治疗意义。先前的研究表明，lncRNA XIST 参与了各种生物过程。然而，XIST 对滑膜间充质干细胞 (SMSCs) 软骨分化的影响仍不清楚。我们的研究旨在研究 XIST 在人颞下颌关节软骨分化中的作用。方法 进行阿尔辛蓝染色以测定 SMSCs 中的蛋白多糖。允许 qPCR、蛋白质印迹和免疫荧光测定来评估性别决定区 Y-box 9 (SOX9)、II 型胶原蛋白 1 链 (COL2A1) 和蛋白聚糖 (ACAN) 表达。miR-27b-3p 和 XIST 或 ADAMTS-5 之间的直接相互作用通过双荧光素酶报告基因测定或 RNA 免疫沉淀 (RIP) 测定得到证实。结果 XIST 在 SMSCs 的软骨分化中显着下调。功能分析表明，XIST 沉默促进了 SMSC 的软骨分化。双荧光素酶报告基因和 RIP 分析确定 XIST 充当 miR-27b-3p 的海绵。此外，XIST 通过直接结合 miR-27b-3p 来调节 ADAMTS-5 的表达。更重要的是，miR-27b-3p/ADAMTS-5 挽救了 XIST 对 SMSC 软骨分化的影响。结论 结果表明，XIST 通过 miR-27b-3p/ADAMTS-5 轴调节 SMSCs 的软骨形成分化，这为 TMJOA 治疗提供了新的靶点。