Department of Spine Surgery, The Affiliated Changsha Central Hospital, Hengyang Medical School, University of South China, Changsha, Hunan, China.
Folia Neuropathol. 2023;61(3):326-335. doi: 10.5114/fn.2023.130455.
As of now, there are no satisfactory treatments for spinal cord injury (SCI), so new therapeutic approaches are necessary to be explored. Adipose-derived mesenchymal stem cell exosomes (ADMSC-Exo), delightfully, show remarkable therapeutic effects. Therefore, we try to investigate the effects and mechanisms of ADMSC-Exo on SCI, as well as to provide novel approaches for the treatment of SCI. Adipose-derived mesenchymal stem cells (ADMSC) were isolated from rats and then exosomes (Exo) were extracted from the cells. The extracted Exo were identified by flow cytometry, transmission electron microscopy and nanoparticle tracking analysis (NTA). Then, the SCI rat model was established by the spinal cord impactor and injected with 200 µl PBS or Exo into their tail veins at 30 min, 24 h, and 48 h after surgery. The rats in the Control group and Exo group only exposed the spine. Motor function recovery was assessed on days 0, 7, 14, 21, and 28; histopathological changes and apoptosis levels in spinal cord tissues were observed by HE staining and TUNEL staining; the levels of inflammatory cytokines TNF-a, IL-6, and MCP-1 in spinal cord tissues were measured by ELISA; the expression levels of iNOS, IL-12, Arg1, and Mrc1 in spinal cord tissues were detected by qRT-PCR; and Nrf2, HO-1, and NQO1 protein expression in spinal cord tissues were detected by Western blot. ADMSC-Exo were successfully isolated and identified. ADMSC-Exo significantly relieved SCI and promoted motor function recovery in SCI rats. Moreover, ADMSC-Exo inhibited the expression of both inflammatory factors in the spinal cord tissues and M1 microglia, promoted the expression of M2 microglia, and activated the Nrf2/HO-1 pathway. Altogether, ADMSC-Exo can not only ameliorate SCI, but also promote the motor function recovery of rats. And the mechanism of ADMSC-Exo improving SCI may be achieved by activating Nrf2/HO-1 pathway and microglial polarization.
目前，脊髓损伤（SCI）尚无满意的治疗方法，因此需要探索新的治疗方法。脂肪间充质干细胞外泌体（ADMSC-Exo）表现出显著的治疗效果。因此，我们试图研究 ADMSC-Exo 对 SCI 的作用及其机制，为 SCI 的治疗提供新的方法。从大鼠中分离脂肪间充质干细胞（ADMSC），然后从细胞中提取外泌体（Exo）。通过流式细胞术、透射电子显微镜和纳米颗粒跟踪分析（NTA）鉴定提取的 Exo。然后，通过脊髓撞击器建立 SCI 大鼠模型，并在手术后 30 分钟、24 小时和 48 小时将 200μl PBS 或 Exo 注入其尾静脉。对照组和 Exo 组的大鼠仅暴露脊柱。在 0、7、14、21 和 28 天评估运动功能恢复情况；通过 HE 染色和 TUNEL 染色观察脊髓组织的组织学变化和细胞凋亡水平；通过 ELISA 测量脊髓组织中炎症细胞因子 TNF-a、IL-6 和 MCP-1 的水平；通过 qRT-PCR 检测脊髓组织中 iNOS、IL-12、Arg1 和 Mrc1 的表达水平；通过 Western blot 检测脊髓组织中 Nrf2、HO-1 和 NQO1 蛋白的表达。成功分离并鉴定 ADMSC-Exo。ADMSC-Exo 显著缓解 SCI 并促进 SCI 大鼠运动功能恢复。此外，ADMSC-Exo 抑制脊髓组织中炎症因子和 M1 小胶质细胞的表达，促进 M2 小胶质细胞的表达，并激活 Nrf2/HO-1 通路。总之，ADMSC-Exo 不仅可以改善 SCI，还可以促进大鼠运动功能的恢复。ADMSC-Exo 改善 SCI 的机制可能是通过激活 Nrf2/HO-1 通路和小胶质细胞极化来实现的。
