Department of Orthopaedic Surgery, The First Affiliated Hospital of Chongqing Medical University, 400016, Chongqing, China.
Orthopaedic Research Laboratory, Chongqing Medical University, 400016, Chongqing, China.
Exp Mol Med. 2022 Nov;54(11):1927-1939. doi: 10.1038/s12276-022-00879-w. Epub 2022 Nov 10.
Despite the high prevalence of osteoarthritis (OA) in older populations, disease-modifying OA drugs (DMOADs) are still lacking. This study was performed to investigate the effects and mechanisms of the small molecular drug salicin (SA) on OA progression. Primary rat chondrocytes were stimulated with TNF-α and treated with or without SA. Inflammatory factors, cartilage matrix degeneration markers, and cell proliferation and apoptosis markers were detected at the mRNA and protein levels. Cell proliferation and apoptosis were evaluated by EdU assays or flow cytometric analysis. RNA sequencing, molecular docking and drug affinity-responsive target stability analyses were used to clarify the mechanisms. The rat OA model was used to evaluate the effect of intra-articular injection of SA on OA progression. We found that SA rescued TNF-α-induced degeneration of the cartilage matrix, inhibition of chondrocyte proliferation, and promotion of chondrocyte apoptosis. Mechanistically, SA directly binds to IRE1α and occupies the IRE1α phosphorylation site, preventing IRE1α phosphorylation and regulating IRE1α-mediated endoplasmic reticulum (ER) stress by IRE1α-IκBα-p65 signaling. Finally, intra-articular injection of SA-loaded lactic-co-glycolic acid (PLGA) ameliorated OA progression by inhibiting IRE1α-mediated ER stress in the OA model. In conclusion, SA alleviates OA by directly binding to the ER stress regulator IRE1α and inhibits IRE1α-mediated ER stress via IRE1α-IκBα-p65 signaling. Topical use of the small molecular drug SA shows potential to modify OA progression.
尽管骨关节炎（OA）在老年人群中普遍存在，但仍缺乏疾病修饰 OA 药物（DMOAD）。本研究旨在探讨小分子药物水杨苷（SA）对 OA 进展的作用及其机制。原代大鼠软骨细胞经 TNF-α刺激后，用或不用 SA 处理。在 mRNA 和蛋白水平检测炎症因子、软骨基质降解标志物、细胞增殖和凋亡标志物。通过 EdU 检测或流式细胞术分析评估细胞增殖和凋亡。采用 RNA 测序、分子对接和药物亲和反应靶标稳定性分析来阐明机制。采用大鼠 OA 模型评估关节内注射 SA 对 OA 进展的影响。我们发现，SA 挽救了 TNF-α诱导的软骨基质退化、抑制软骨细胞增殖和促进软骨细胞凋亡。机制上，SA 直接与 IRE1α结合并占据 IRE1α磷酸化位点，防止 IRE1α磷酸化，并通过 IRE1α-IκBα-p65 信号调节 IRE1α 介导的内质网（ER）应激。最后，关节内注射载有 SA 的聚乳酸-羟基乙酸共聚物（PLGA）通过抑制 OA 模型中 IRE1α 介导的 ER 应激来改善 OA 进展。总之，SA 通过直接与 ER 应激调节剂 IRE1α 结合，并通过 IRE1α-IκBα-p65 信号抑制 IRE1α 介导的 ER 应激，从而缓解 OA。小分子药物 SA 的局部应用显示出改善 OA 进展的潜力。
