Xie Haoyu, Lu Yuheng, Pan Jianying, Zeng Hua, Zhang Zhicheng, Yin Jianbin, Zhu Jinjian, Luo Bingsheng, Guo Dong, Wu Chunyu, Zeng Chun, Shao Yan, Bai Xiaochun, Cai Daozhang, Zhang Haiyan
Department of Joint Surgery, Center for Orthopaedic Surgery, The Third Affiliated Hospital of Southern Medical University, Guangzhou 510630, China.
Department of Orthopedics, Orthopedic Hospital of Guangdong Province, Academy of Orthopedics·Guangdong Province, The Third Affiliated Hospital of Southern Medical University, Guangzhou 510630, China.
Research (Wash D C). 2025 May 8;9:0694. doi: 10.34133/research.0694. eCollection 2025.
Mechanical overload is a critical contributor to cartilage degeneration in osteoarthritis (OA) pathogenesis. Circular RNA (circRNA) is expected to provide a long-lasting therapy for OA. However, the involvement of the circRNA-associated competitive endogenous RNA network in chondrocyte senescence induced by mechanical overloading remains unestablished. A mechanical overloading-induced chondrocyte senescence model in human primary chondrocytes is constructed, and differences in the expression of circRNAs and miRNAs were analyzed. The biological roles of circKIAA0586/miR-335-5p in chondrocyte senescence and OA progression under mechanical overloading and its downstream targets were determined using gain- and loss-of-function experiments in various biochemical assays in human chondrocytes. The in vivo effects of circKIAA0586 overexpression were also determined in destabilization of the medial meniscus (DMM) OA mice and aged spontaneous OA mice. The mechanical overloading-induced chondrocyte senescence was aggravated by miR-335-5p or circKIAA0586 knockdown. Accumulated DNA damage response was observed following mechanical overloading, which reduced after miR-335-5p inhibition or circKIAA0586 supplementation. MiR-335-5p was regulated by circKIA0586 adsorption. HELLS was prominently down-regulated following mechanical overloading treatment. Moreover, miR-335-5p bound to lymphoid-specific helicase (HELLS) mRNA during mechanical overloading was demonstrated to mediate the nonhomologous end joining (NHEJ) pathway, thereby inducing DNA damage and senescence. In addition, the senescence delaying and cartilage protective functions of circKIAA0586 and HELLS were validated in DMM OA mice and aged spontaneous OA mice. Our findings suggest that miR-335-5p, which escapes circKIAA0586 adsorption, facilitates mechanical overloading-induced chondrocyte senescence and OA progression by impairing the NHEJ pathway through HELLS inhibition. Overall, targeting circKIAA0586/miR-335-5p/HELLS signaling provides a novel therapeutic approach for OA.
机械过载是骨关节炎（OA）发病机制中软骨退变的关键因素。环状RNA（circRNA）有望为OA提供持久的治疗方法。然而，circRNA相关的竞争性内源RNA网络在机械过载诱导的软骨细胞衰老中的作用尚未明确。构建了人原代软骨细胞机械过载诱导的软骨细胞衰老模型，并分析了circRNA和miRNA表达的差异。在人软骨细胞的各种生化实验中，通过功能获得和功能丧失实验确定了circKIAA0586/miR-335-5p在机械过载下软骨细胞衰老和OA进展中的生物学作用及其下游靶点。还在内侧半月板不稳定（DMM）OA小鼠和老龄自发性OA小鼠中确定了circKIAA0586过表达的体内效应。miR-335-5p或circKIAA0586敲低会加重机械过载诱导的软骨细胞衰老。机械过载后观察到DNA损伤反应积累，miR-335-5p抑制或circKIAA0586补充后减少。miR-335-5p受circKIA0586吸附调节。机械过载处理后，HELLS显著下调。此外，在机械过载期间，miR-335-5p与淋巴样特异性解旋酶（HELLS）mRNA结合，被证明介导非同源末端连接（NHEJ）途径，从而诱导DNA损伤和衰老。此外，在DMM OA小鼠和老龄自发性OA小鼠中验证了circKIAA0586和HELLS的衰老延迟和软骨保护功能。我们的研究结果表明，逃避circKIAA0586吸附的miR-335-5p通过抑制HELLS损害NHEJ途径，促进机械过载诱导的软骨细胞衰老和OA进展。总体而言，靶向circKIAA0586/miR-335-5p/HELLS信号通路为OA提供了一种新的治疗方法。
