中国神经再生研究(英文版) ›› 2023, Vol. 18 ›› Issue (8): 1802-1808.doi: 10.4103/1673-5374.363184

• 原著:脊髓损伤修复保护与再生 • 上一篇    下一篇

巨噬细胞迁移抑制因子诱导脊髓损伤后星形胶质细胞产生趋化因子CCL2

  

  • 出版日期:2023-08-15 发布日期:2023-02-24
  • 基金资助:
    中国博士后科学基金(2020M681689)和南通市基础科学研究项目(JC2020015和JC2020041)

Macrophage migration inhibitory factor facilitates astrocytic production of the CCL2 chemokine following spinal cord injury

Han Zhang1, #, Yu-Ming Hu2, #, Ying-Jie Wang3, Yue Zhou2, Zhen-Jie Zhu2, Min-Hao Chen1, Yong-Jun Wang3, Hua Xu1, *, #br# You-Hua Wang1, *#br#   

  1. 1Department of Orthopedics, Affiliated Hospital of Nantong University, Nantong University, Nantong, Jiangsu Province, China; 2Department of Rehabilitation Medicine, Affiliated Hospital of Nantong University, Nantong, Jiangsu Province, China; 3Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, China
  • Online:2023-08-15 Published:2023-02-24
  • Contact: You-Hua Wang, MD, wangyouhua99@163.com; Hua Xu, MD, xuhua1981111@126.com.
  • Supported by:
    This study was supported by the China Postdoctoral Science Foundation, No. 2020M681689 (to YMH), and the Basic Scientific Research Projects of Nantong, Nos. JC2020015 (to HX) and JC2020041 (to YMH).

摘要:

脊髓损伤总是导致大量炎症细胞在病变部位聚集, 加剧神经炎症的发生。过度产生的趋化因子在相当程度上参与炎症细胞的迁移过程,但对脊髓常驻细胞诱导产生趋化因子的调控机制至今还未完全阐明。实验通过检测了大鼠脊髓挫伤后不同阶段巨噬细胞迁移抑制因子和CC趋化因子配体2(CCL2)的蛋白水平。结果显示,病变部位巨噬细胞迁移抑制因子的升高与星形胶质细胞中CCL2水平的增加是动态一致的。用不同浓度的MIF重组蛋白刺激原代培养的星形胶质细胞,可明显诱导细胞产生CCL2,而加入巨噬细胞迁移抑制因子抑制剂4-IPP则足以削弱这种刺激作用。对巨噬细胞迁移抑制因子介导的星形细胞产生CCL2的基本机制的进一步研究显示,巨噬细胞迁移抑制因子通过与CD74受体的结合明显激活了细胞内的JNK信号传导。在脊髓损伤后给予巨噬细胞迁移抑制因子抑制剂4-IPP,可以减少病变部位的CCL2募集的小胶质细胞/巨噬细胞,并明显改善大鼠的后肢运动功能。实验结果提供了星形胶质细胞激活的趋化因子在招募炎症细胞方面的新线索,并将有利于通过靶向CCL2来干预脊髓损伤后的神经炎症。

https://orcid.org/0000-0002-2100-3046 (You-Hua Wang); https://orcid.org/0000-0002-7969-6033 (Hua Xu)

Abstract: Spinal cord injury causes accumulation of a large number of leukocytes at the lesion site where they contribute to excessive inflammation. Overproduced chemokines are responsible for the migratory process of the leukocytes, but the regulatory mechanism underlying the production of chemokines from resident cells of the spinal cord has not been fully elucidated. We examined the protein levels of macrophage migration inhibitory factor and chemokine C-C motif chemokine ligand 2 in a spinal cord contusion model at different time points following spinal cord injury. The elevation of macrophage migration inhibitory factor at the lesion site coincided with the increase of chemokine C-C motif chemokine ligand 2 abundance in astrocytes. Stimulation of primary cultured astrocytes with different concentrations of macrophage migration inhibitory factor recombinant protein induced chemokine C-C motif chemokine ligand 2 production from the cells, and the macrophage migration inhibitory factor inhibitor 4-iodo-6-phenylpyrimidine attenuated the stimulatory effect. Further investigation into the underlying mechanism on macrophage migration inhibitory factor-mediated astrocytic production of chemokine C-C motif chemokine ligand 2 revealed that macrophage migration inhibitory factor activated intracellular JNK signaling through binding with CD74 receptor. Administration of the macrophage migration inhibitory factor inhibitor 4-iodo-6-phenylpyrimidine following spinal cord injury resulted in the reduction of chemokine C-C motif chemokine ligand 2-recruited microglia/macrophages at the lesion site and remarkably improved the hindlimb locomotor function of rats. Our results have provided insights into the functions of astrocyte-activated chemokines in the recruitment of leukocytes and may be beneficial to develop interventions targeting chemokine C-C motif chemokine ligand 2 for neuroinflammation after spinal cord injury.

Key words: astrocytes, CD74, chemokine, chemokine C-C motif chemokine ligand 2 (CCL2), cytokine, inflammation, leukocyte, MAPKs, migration inhibitory factor, spinal cord injury