Shen Guoqiang, Liu Minhao, Wang Juan, Qi Zhiqiang, Cao Yaoqi, Jin Zhengshuai, Chen Sheng, Wan Bowen, Gu Jun
The Affiliated Jiangsu Shengze Hospital of Nanjing Medical University, Suzhou, Jiangsu 215228, China.
Department of Orthopedics, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China.
ACS Appl Mater Interfaces. 2025 Aug 13;17(32):45511-45526. doi: 10.1021/acsami.5c09766. Epub 2025 Jul 31.
Spinal cord injury (SCI) lacks effective therapies, and umbilical cord mesenchymal stem cell (UCMSC)-derived exosomes show promise but require efficacy optimization. This study explored tanshinone IIA (TSA)-pretreated UCMSC exosomes (T-Exos) to enhance neuroprotection and functional recovery post-SCI. T-Exos were isolated from the TSA-treated UCMSCs. SCI mice received T-Exos, with motor function assessed behaviorally. In vitro and in vivo, microglial NLRP3 inflammasome activity, polarization (M1/M2), and cytokine release were analyzed. miRNA profiling identified key miRNAs in T-Exos; miR-223-5p's role was validated via inhibition. Mechanistic studies linked miR-223-5p to USP8/NLRP3 using Western blot, qPCR, and co-IP assays. T-Exos improved motor recovery in SCI mice by suppressing NLRP3 inflammasome activation, shifting microglia to anti-inflammatory M2 phenotypes, reducing the level of IL-1β/IL-18, and alleviating oxidative stress. miR-223-5p was highly enriched in T-Exos, and its inhibition reversed therapeutic effects. Mechanistically, miR-223-5p targeted USP8, a deubiquitinase stabilizing NLRP3. By inhibiting USP8, T-Exos reduced NLRP3 levels, dampening neuroinflammation. TSA pretreatment enhances exosomal miR-223-5p, which blocks USP8-mediated NLRP3 stabilization, driving microglial M2 polarization and neuroprotection. These findings highlight T-Exos as a targeted therapy for SCI, offering insights into the exosome-mediated modulation of inflammatory microenvironments for neural repair.
脊髓损伤（SCI）缺乏有效的治疗方法，脐带间充质干细胞（UCMSC）衍生的外泌体显示出一定前景，但需要优化其疗效。本研究探索了丹参酮IIA（TSA）预处理的UCMSC外泌体（T-Exos）以增强SCI后的神经保护和功能恢复。T-Exos从经TSA处理的UCMSCs中分离得到。SCI小鼠接受T-Exos，通过行为学评估运动功能。在体外和体内，分析了小胶质细胞NLRP3炎性小体活性、极化（M1/M2）和细胞因子释放。miRNA谱分析确定了T-Exos中的关键miRNA；通过抑制验证了miR-223-5p的作用。机制研究使用蛋白质免疫印迹、定量聚合酶链反应和免疫共沉淀试验将miR-223-5p与USP8/NLRP3联系起来。T-Exos通过抑制NLRP3炎性小体激活、将小胶质细胞转变为抗炎M2表型、降低IL-1β/IL-18水平和减轻氧化应激，改善了SCI小鼠的运动恢复。miR-223-5p在T-Exos中高度富集，其抑制作用逆转了治疗效果。机制上，miR-223-5p靶向USP8，USP8是一种使NLRP3稳定的去泛素化酶。通过抑制USP8，T-Exos降低了NLRP3水平，减轻了神经炎症。TSA预处理增强了外泌体miR-223-5p，其阻断了USP8介导的NLRP3稳定，促进了小胶质细胞M2极化和神经保护。这些发现突出了T-Exos作为SCI的靶向治疗方法，为外泌体介导的神经修复炎症微环境调节提供了见解。
