Department of Rheumatology, Fuzhou No. 1 Hospital Affiliated with Fujian Medical University, Taijiang District, Fuzhou, 350000, Fujian Province, China.
Department of Medical Technology, Zhangzhou Health Vocational College, Zhangzhou, 363000, Fujian Province, China.
Arthritis Res Ther. 2022 Sep 6;24(1):216. doi: 10.1186/s13075-022-02893-9.
Osteoarthritis (OA) is a chronic degenerative joint disease. Extracellular matrix (ECM) degradation is essential for OA progression. Previous studies have shown that circular RNAs (circRNAs) are involved in the pathological process of OA. CircPRKCH has been shown to be upregulated in OA chondrocytes. The present study was aimed to explore the roles of circPRKCH in vivo and in vitro models of OA and its underlying molecular mechanisms.
IL-1β-induced chondrocytes and mice injected with monosodium iodoacetate were used as OA models in vitro and in vivo, respectively. RT-qPCR was performed to measure the expression of circPRKCH, miR-145, and HGF in cartilage tissues and chondrocytes. The interaction between miR-145 and circPRKCH or HGF was verified by a dual-luciferase reporter assay. Chondrocyte apoptosis, viability, and ECM-related proteins were examined by flow cytometry, MTT assay, and Western blotting, respectively. Histopathological changes were detected by HE and Safranin O-fast green staining.
The expression of circPRKCH and HGF was increased in OA cartilage tissues and IL-1β-treated chondrocytes, while miR-145 expression was decreased. IL-1β induced chondrocyte apoptosis and ECM degradation in chondrocytes. Moreover, circPRKCH promoted HGF expression and activated HGF/c-MET by directly binding to miR-145. miR-145 knockdown or HGF overexpression significantly reversed circPRKCH knockdown-mediated inhibition of apoptosis and ECM degradation in IL-1β-induced chondrocytes. Besides, miR-145 overexpression alleviated IL-1β-induced chondrocyte apoptosis and ECM degradation by inhibiting HGF/c-MET. Finally, circPRKCH knockdown reduced ECM degradation by regulating the miR-145/HGF axis in an experimental OA model in mice.
Our study demonstrated that circPRKCH promoted chondrocyte apoptosis and ECM degradation via the miR-145/HGF axis in OA, which may provide a novel target for OA treatment.
骨关节炎（OA）是一种慢性退行性关节疾病。细胞外基质（ECM）降解对于 OA 的进展至关重要。先前的研究表明，环状 RNA（circRNA）参与 OA 的病理过程。circPRKCH 在 OA 软骨细胞中呈上调表达。本研究旨在探讨 circPRKCH 在 OA 的体内和体外模型中的作用及其潜在的分子机制。
采用白细胞介素 1β（IL-1β）诱导的软骨细胞和注射单碘乙酸盐的小鼠分别作为 OA 的体内和体外模型。采用 RT-qPCR 检测软骨组织和软骨细胞中 circPRKCH、miR-145 和 HGF 的表达。通过双荧光素酶报告基因实验验证 miR-145 与 circPRKCH 或 HGF 的相互作用。采用流式细胞术、MTT 法和 Western blot 分别检测软骨细胞凋亡、活力和细胞外基质相关蛋白。采用 HE 和番红 O-fast 绿染色检测组织病理学变化。
OA 软骨组织和 IL-1β 处理的软骨细胞中 circPRKCH 和 HGF 的表达增加，而 miR-145 的表达降低。IL-1β 诱导软骨细胞凋亡和 ECM 降解。此外，circPRKCH 通过直接结合 miR-145 促进 HGF 表达并激活 HGF/c-MET。circPRKCH 敲低后，miR-145 敲低或 HGF 过表达可显著逆转 IL-1β 诱导的软骨细胞凋亡和 ECM 降解。此外，miR-145 过表达通过抑制 HGF/c-MET 缓解 IL-1β 诱导的软骨细胞凋亡和 ECM 降解。最后，circPRKCH 敲低通过调节 miR-145/HGF 轴减轻实验性 OA 模型中小鼠的 ECM 降解。
本研究表明，circPRKCH 通过 miR-145/HGF 轴促进 OA 中的软骨细胞凋亡和 ECM 降解，这可能为 OA 的治疗提供新的靶点。
