The aim of this study was to explore the role of hsa_circRNA_0000205 (circ_0000205) in chondrocyte injury in osteoarthritis (OA) and the underlying mechanism. Expression of circ_0000205, microRNA (miR)-766-3p and a disintegrin and metalloproteinase with thrombospondin motif (ADAMTS)-5 was detected by quantitative real time (qRT)-polymerase chain reaction (PCR) and Western blot assays. Cell proliferation, apoptosis, and extracellular matrix (ECM) synthesis were examined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and 5-ethynyl-2-deoxyuridine assays, flow cytometry, and qRT-PCR and Western blot assays. The target relationship between miR-766-3p and circ_0000205 or ADAMTS5 was confirmed by luciferase reporter assay and RNA immunoprecipitation. IL-1β treatment could attenuate cell viability of primary chondrocytes and proliferating cell nuclear antigen (PCNA) and collagen II type alpha-1 (COL2A1) levels, and elevate apoptosis rate and cleaved caspase-3, ADAMTS5 and matrix metalloproteinase-13 (MMP13) levels, suggesting that IL-1β induced chondrocyte apoptosis and ECM degradation. Expression of circ_0000205 was up-regulated in OA tissues and IL-1β-induced primary chondrocytes, accompanied with miR-766-3p down-regulation and ADAMTS5 up-regulation. Knockdown of circ_0000205 could mitigate IL-1β-induced above effects and improve cell proliferation. Moreover, both depleting miR-766-3p and promoting ADAMTS5 could partially counteract circ_0000205 knockdown roles in IL-1β-cultured primary chondrocytes. Notably, circ_0000205 was verified as a sponge for miR-766-3p via targeting, and ADAMTS5 was a direct target for miR-766-3p. Silencing circ_0000205 could protect chondrocytes from IL-1β-induced proliferation reduction, apoptosis, and ECM degradation by targeting miR-766-3p/ADAMTS5 axis.

本研究旨在探讨hsa_circRNA_0000205（circ_0000205）在骨关节炎（OA）软骨细胞损伤中的作用及其潜在机制。通过定量实时 (qRT)-聚合酶链反应 (PCR) 和蛋白质印迹分析检测 circ_0000205、microRNA (miR)-766-3p 和具有血小板反应蛋白基序 (ADAMTS)-5 的去整合素和金属蛋白酶的表达。通过 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide 和 5-ethynyl-2-deoxyuridine 测定、流式细胞术和 qRT 检查细胞增殖、凋亡和细胞外基质 (ECM) 合成-PCR和蛋白质印迹分析。miR-766-3p 与 circ_0000205 或 ADAMTS5 之间的靶标关系通过荧光素酶报告基因测定和 RNA 免疫沉淀得到证实。IL-1β 治疗可降低原代软骨细胞的细胞活力和增殖细胞核抗原 (PCNA) 和胶原 II 型 α-1 (COL2A1) 水平，并提高细胞凋亡率和切割 caspase-3、ADAMTS5 和基质金属蛋白酶-13 (MMP13)水平，表明 IL-1β 诱导软骨细胞凋亡和 ECM 降解。circ_0000205 在 OA 组织和 IL-1β 诱导的原代软骨细胞中表达上调，并伴有 miR-766-3p 下调和 ADAMTS5 上调。敲除 circ_0000205 可以减轻 IL-1β 诱导的上述作用并改善细胞增殖。此外，消耗 miR-766-3p 和促进 ADAMTS5 可以部分抵消 IL-1β 培养的原代软骨细胞中 circ_0000205 的敲低作用。值得注意的是，circ_0000205 通过靶向被验证为 miR-766-3p 的海绵，ADAMTS5 是 miR-766-3p 的直接靶标。沉默 circ_0000205 可以通过靶向 miR-766-3p/ADAMTS5 轴来保护软骨细胞免受 IL-1β 诱导的增殖减少、细胞凋亡和 ECM 降解。