Department of Orthopedics, The Second Xiangya Hospital of Central South University, Changsha 410011, Hunan, China.
Department of Neonatology, The Hunan Children's Hospital, Changsha 410007, Hunan, China.
Int Immunopharmacol. 2021 Jun;95:107495. doi: 10.1016/j.intimp.2021.107495. Epub 2021 Mar 5.
Osteoarthritis (OA) is characterized by chondrocyte injury and dysfunction, such as excessive apoptosis, inflammatory response and extracellular matrix (ECM) degradation. Circular RNA (circRNA) deregulation is reported to be involved in OA. Our study aimed to explore the role of circ_0134111 in OA.
Human chondrocytes were treated with interleukin-1β (IL-1β) to mimic OA cell model. The expression of circ_0134111, miR-515-5p and suppressor of cytokine signaling 1 (SOCS1) mRNA was measured by real-time quantitative polymerase chain reaction (RT-qPCR), and the protein levels of SOCS1 and apoptosis-/inflammation-/ECM-related markers were determined by western blot. Cell proliferation and cell apoptosis were assessed using cell counting kit-8 (CCK-8) and flow cytometry assay, respectively. For mechanism analysis, the predicted interaction between miR-515-5p and circ_0134111 or SOCS1 was verified by dual-luciferase reporter assay, pull-down assay and RNA immunoprecipitation (RIP) assay. Rescue experiments were performed to explore the interplay between miR-515-5p and circ_0134111 or SOCS1.
Circ_0134111 was overexpressed in OA cartilage tissues and IL-1β-induced chondrocytes. IL-1β-induced chondrocyte apoptosis, inflammatory responses and ECM degradation were alleviated by circ_0134111 knockdown or miR-515-5p restoration. Circ_0134111 acted as miR-515-5p sponge to regulate miR-515-5p expression, and miR-515-5p deficiency reversed the effects of circ_0134111 knockdown in IL-1β-induced chondrocytes. MiR-515-5p directly bound to SOCS1, and circ_0134111 decoyed miR-515-5p to increase SOCS1 level. MiR-515-5p restoration alleviated IL-1β-induced chondrocyte apoptosis, inflammatory responses and ECM degradation, While SOCS1 overexpression partly abolished these effects.
Circ_0134111 knockdown alleviated apoptosis, inflammatory responses and ECM degradation in OA cell model by mediating the miR-515-5p-SOCS1 network, hinting that circ_0134111 was involved in OA progression.
骨关节炎（OA）的特征是软骨细胞损伤和功能障碍，如细胞凋亡过度、炎症反应和细胞外基质（ECM）降解。环状 RNA（circRNA）失调被报道与 OA 有关。我们的研究旨在探讨 circ_0134111 在 OA 中的作用。
用白细胞介素-1β（IL-1β）处理人软骨细胞，模拟 OA 细胞模型。实时定量聚合酶链反应（RT-qPCR）检测 circ_0134111、miR-515-5p 和细胞因子信号转导抑制因子 1（SOCS1）mRNA 的表达水平，Western blot 检测 SOCS1 和凋亡/炎症/ECM 相关标志物的蛋白水平。用细胞计数试剂盒-8（CCK-8）和流式细胞术分别评估细胞增殖和细胞凋亡。为了进行机制分析，通过双荧光素酶报告基因检测、下拉实验和 RNA 免疫沉淀（RIP）实验验证 miR-515-5p 与 circ_0134111 或 SOCS1 的预测相互作用。进行挽救实验以探讨 miR-515-5p 与 circ_0134111 或 SOCS1 之间的相互作用。
OA 软骨组织和 IL-1β诱导的软骨细胞中 circ_0134111 表达上调。circ_0134111 敲低或 miR-515-5p 恢复可减轻 IL-1β诱导的软骨细胞凋亡、炎症反应和 ECM 降解。Circ_0134111 作为 miR-515-5p 的海绵来调节 miR-515-5p 的表达，并且 miR-515-5p 缺失逆转了 IL-1β 诱导的软骨细胞中 circ_0134111 敲低的作用。miR-515-5p 直接结合 SOCS1，而 circ_0134111 诱饵 miR-515-5p 以增加 SOCS1 水平。miR-515-5p 恢复减轻了 IL-1β 诱导的软骨细胞凋亡、炎症反应和 ECM 降解，而 SOCS1 过表达部分消除了这些作用。
Circ_0134111 通过调节 miR-515-5p-SOCS1 网络减轻 OA 细胞模型中的细胞凋亡、炎症反应和 ECM 降解，提示 circ_0134111 参与 OA 进展。
