Department of Biomedical Data Sciences, Section Molecular Epidemiology, Leiden University Medical Center, Leiden, The Netherlands.
Experimental Rheumatology, Radboud University Medical Center, Nijmegen, The Netherlands.
J Orthop Res. 2024 Feb;42(2):286-295. doi: 10.1002/jor.25673. Epub 2023 Aug 13.
Dysregulation of Wingless and Int-1 (Wnt) signaling has been strongly associated with development and progression of osteoarthritis (OA). Here, we set out to investigate the independent effects of either mechanical stress (MS) or inflammation on Wnt signaling in human neocartilage pellets, and to relate this Wnt signaling to OA pathophysiology. OA synovium-conditioned media (OAS-CM) was collected after incubating synovium from human end-stage OA joints for 24 h in medium. Cytokine levels in the OAS-CM were determined with a multiplex immunoassay (Luminex). Human neocartilage pellets were exposed to 20% MS, 2% OAS-CM or 1 ng/mL Interleukin-1β (IL-1β). Effects on expression levels of Wnt signaling members were determined by reverse transcription-quantitative polymerase chain reaction. Additionally, the expression of these members in articular cartilage from human OA joints was analyzed in association with joint space narrowing (JSN) and osteophyte scores. Protein levels of IL-1β, IL-6, IL-8, IL-10, tumor necrosis factor α, and granulocyte-macrophage colony-stimulating factor positively correlated with each other. MS increased noncanonical WNT5A and FOS expression. In contrast, these genes were downregulated upon stimulation with OAS-CM or IL-1β. Furthermore, Wnt inhibitors DKK1 and FRZB decreased in response to OAS-CM or IL-1β exposure. Finally, expression of WNT5A in OA articular cartilage was associated with increased JSN scores, but not osteophyte scores. Our results demonstrate that MS and inflammatory stimuli have opposite effects on canonical and noncanonical Wnt signaling in human neocartilage. Considering the extent to which MS and inflammation contribute to OA in individual patients, we hypothesize that targeting specific Wnt pathways offers a more effective, individualized approach.
Wingless 和 Int-1（Wnt）信号的失调与骨关节炎（OA）的发展和进展密切相关。在这里，我们着手研究机械应激（MS）或炎症对人新软骨球状体中 Wnt 信号的独立影响，并将这种 Wnt 信号与 OA 病理生理学联系起来。OA 滑膜条件培养基（OAS-CM）是通过在培养基中孵育来自人类终末期 OA 关节的滑膜 24 小时收集的。使用多重免疫测定法（Luminex）测定 OAS-CM 中的细胞因子水平。将人新软骨球状体暴露于 20% MS、2% OAS-CM 或 1ng/mL 白细胞介素 1β（IL-1β）。通过逆转录定量聚合酶链反应确定 Wnt 信号成员的表达水平。此外，还分析了这些成员在来自人类 OA 关节的关节软骨中的表达与关节间隙变窄（JSN）和骨赘评分的关系。白细胞介素 1β、白细胞介素 6、白细胞介素 8、白细胞介素 10、肿瘤坏死因子α和粒细胞-巨噬细胞集落刺激因子的蛋白水平彼此之间呈正相关。MS 增加了非经典 WNT5A 和 FOS 的表达。相比之下，当用 OAS-CM 或 IL-1β 刺激时，这些基因的表达下调。此外，Wnt 抑制剂 DKK1 和 FRZB 的表达响应 OAS-CM 或 IL-1β 暴露而降低。最后，OA 关节软骨中 WNT5A 的表达与 JSN 评分的增加有关，但与骨赘评分无关。我们的研究结果表明，MS 和炎症刺激对人新软骨中的经典和非经典 Wnt 信号具有相反的作用。考虑到 MS 和炎症在个体患者中对 OA 的贡献程度，我们假设针对特定的 Wnt 途径提供了一种更有效、个体化的方法。
