中国神经再生研究(英文版) ›› 2024, Vol. 19 ›› Issue (10): 2259-2269.doi: 10.4103/1673-5374.391194

• 原著:脊髓损伤修复保护与再生 • 上一篇    下一篇

低氧预处理小细胞外囊泡调节巨噬细胞极化减轻脊髓损伤

  

  • 出版日期:2024-10-15 发布日期:2024-01-29

Small extracellular vesicles from hypoxia-preconditioned bone marrow mesenchymal stem cells attenuate spinal cord injury via miR-146a-5p-mediated regulation of macrophage polarization

Zeyan Liang1, 2, #, Zhelun Yang1, 2, #, Haishu Xie1, 2, #, Jian Rao1, 2, #, Xiongjie Xu1, 2, Yike Lin1, 2, Chunhua Wang1, 2, *, Chunmei Chen1, 2, *   

  1. 1Department of Neurosurgery, Fujian Medical University Union Hospital, Fuzhou, Fujian Province, China; 2Fujian Neurosurgical Institute, Fuzhou, Fujian Province, China
  • Online:2024-10-15 Published:2024-01-29
  • Contact: Chunmei Chen, MD, PhD, cmchen2009@sina.com; Chunhua Wang, PhD, wchmail@126.com.
  • Supported by:
    This work was supported by the Fujian Minimally Invasive Medical Center Foundation, No. 2128100514 (to CC, CW, and HX) and the Natural Science Foundation of Fujian Province, No. 2023J01640 (to CC, CW, ZL, and HX).

摘要:

有研究表明,骨髓间充质干细胞来源的小细胞外囊泡可通过携带微小核糖核酸(microRNA)诱导巨噬细胞表型的变化,从而减轻炎症。作者课题组在以往研究中,总结了干细胞来源的小细胞外囊泡携带 miRNAs 可调节巨噬细胞极化从而降低组织炎症。因此,实验探讨了低氧预处理的骨髓间充质干细胞来源小细胞外囊泡在大鼠脊髓损伤后巨噬细胞免疫调节中的作用及其在脊髓修复中的意义。通过密度梯度超速离心从骨髓间充质干细胞上清液中分离出小细胞外囊泡或骨髓间充质干细胞来源的小细胞外囊泡。体内实验验证了常氧预处理骨髓间充质干细胞来源的小细胞外囊泡和低氧预处理的骨髓间充质干细胞来源小细胞外囊泡均能减轻脊髓损伤,促进脊髓损伤大鼠的运功功能,这种现象与脊髓中巨噬细胞向 M2 型极化相关;进一步的体外实验结果显示,相较于小细胞外囊泡,低氧预处理的骨髓间充质干细胞来源小细胞外囊泡更有益于促进M2型巨噬细胞极化,减轻脊髓炎症。为了探寻这种疗效差异的原因,实验进一步完成了小细胞外囊泡和低氧预处理的骨髓间充质干细胞来源小细胞外囊泡中的 miRNA高通量测序,结合差异分析结果并查阅miRNA相关数据库(miRBase),确定了 miR-146a-5p 作为骨髓间充质干细胞来源的小细胞外囊泡疗效的关键因子之一。最后的过表达或者抑制miRNA的体外研究表明,miR-146a-5p可以促进M2型巨噬细胞极化,并与下调IRAK1/TRAF6/NF-κB通路相关。该研究成果为低氧预处理的骨髓间充质干细胞来源小细胞外囊泡作为脊髓损伤治疗工具的应用提供了新的见解。

https://orcid.org/0000-0002-4483-7465 (Chunmei Chen); https://orcid.org/0000-0002-4490-0380 (Chunhua Wang)

Abstract: Spinal cord injury is a disabling condition with limited treatment options. Multiple studies have provided evidence suggesting that small extracellular vesicles (SEVs) secreted by bone marrow mesenchymal stem cells (MSCs) help mediate the beneficial effects conferred by MSC transplantation following spinal cord injury. Strikingly, hypoxia-preconditioned bone marrow mesenchymal stem cell-derived SEVs (HSEVs) exhibit increased therapeutic potency. We thus explored the role of HSEVs in macrophage immune regulation after spinal cord injury in rats and their significance in spinal cord repair. SEVs or HSEVs were isolated from bone marrow MSC supernatants by density gradient ultracentrifugation. HSEV administration to rats via tail vein injection after spinal cord injury reduced the lesion area and attenuated spinal cord inflammation. HSEVs regulate macrophage polarization towards the M2 phenotype in vivo and in vitro. MicroRNA sequencing and bioinformatics analyses of SEVs and HSEVs revealed that miR-146a-5p is a potent mediator of macrophage polarization that targets interleukin-1 receptor-associated kinase 1. Reducing miR-146a-5p expression in HSEVs partially attenuated macrophage polarization. Our data suggest that HSEVs attenuate spinal cord inflammation and injury in rats by transporting miR-146a-5p, which alters macrophage polarization. This study provides new insights into the application of HSEVs as a therapeutic tool for spinal cord injury.

Key words: bone marrow mesenchymal stem cells, hypoxia preconditioning, interleukin-1 receptor-associated kinase 1, macrophages, mesenchymal stem cells, small extracellular vesicles, spinal cord injury