Exosomes derived from hypoxia-preconditioned M2 macrophages alleviate degeneration in knee osteoarthritis through the miR‑124‑3p/STAT3 axis

作者：Hao Li, Yuze Yang, Yuanpeng Gao, Bo Li, Jiaju Yang, Pengyu Liu, Min Zhang, Guangzhi Ning · 发表于：Journal of Translational Medicine · 年份：2025 · DOI：10.1186/s12967-025-06808-5 · 被引用次数：11 · 研究领域：Extracellular vesicles in disease、Osteoarthritis Treatment and Mechanisms、MicroRNA in disease regulation

BACKGROUND: M2 macrophages-derived exosomes (M2φ-Exos) have been demonstrated to effectively alleviate osteoarthritis (OA) in animal models. Hypoxic preconditioning is commonly used to enhance the biological effects of stem cell-derived exosomes, but its impact on M2φ-Exos remains unclear. This study aims to investigate whether hypoxic preconditioning could enhance the biological effects of M2φ-Exos in OA treatment and to explore the underlying molecular mechanisms, with the goal of providing new insights for the development of safe and effective OA therapeutic strategies. METHODS: Exosomes were extracted from the supernatants of M2 macrophages cultured under normoxic or hypoxic conditions using low-temperature differential ultracentrifugation and were designated as Nor-Exos and Hypo-Exos. The exosomes were characterized by transmission electron microscopy, nanoparticle tracking analysis, and Western blotting. To evaluate the impact of hypoxic preconditioning on the biological effects of M2φ-Exos, the therapeutic effects of Nor-Exos and Hypo-Exos were assessed in an IL-1β-induced chondrocyte inflammation model and a rat knee OA model established by surgical intervention. Exosomal miRNAs with differential expression between Nor-Exos and Hypo-Exos were identified through exosomal miRNA sequencing. The miRNA with the highest upregulation in Hypo-Exos was selected for further functional validation. To investigate the role of this miRNA, miRNA inhibitors were used to knock down it...