中国神经再生研究(英文版) ›› 2023, Vol. 18 ›› Issue (10): 2208-2218.doi: 10.4103/1673-5374.368299

• 原著:脑损伤修复保护与再生 • 上一篇    下一篇

M2型巨噬细胞可调控缺血性脑卒中早期纤维瘢痕的形成

  

  • 出版日期:2023-10-15 发布日期:2023-03-28
  • 基金资助:
    国家自然科学基金项目(82171456,81971229);重庆市自然科学基金项目(cstc2021jcyj-msxmX0263);重庆市研究生研究与创新项目(CYB20151,CYS19182)

M2 macrophages mediate fibrotic scar formation in the early stages after cerebral ischemia in rats

Jia-Gui Huang, Jiang-Xia Ren, Yue Chen, Ming-Fen Tian, Li Zhou, Jun Wen, Xiao-Song Song, You-Lin Wu, Qing-Huan Yang, #br# Pei-Ran Jiang, Jia-Ni Wang, Qin Yang*#br#   

  1. Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
  • Online:2023-10-15 Published:2023-03-28
  • Contact: Qin Yang, MD, PhD, xyqh200@126.com.
  • Supported by:
    This study was supported by the National Natural Science Foundation of China, Nos. 82171456 (to QY), 81971229 (to QY); the Natural Science Foundation of Chongqing, No. cstc2021jcyj-msxmX0263 (to QY); and the Postgraduate Research and Innovation Project of Chongqing, Nos. CYB20151 (to QY), CYS19182 (to YC).

摘要:

中枢神经系统纤维化瘢痕具有抑制轴突再生和促进修复的双重作用,然而对于其形成以及调节机制,尚知之甚少。M2巨噬细胞可调节心脏、肺脏、肾脏以及中枢神经系统损伤后纤维化瘢痕的形成,但调控机制尚不清楚。实验首先在大脑中动脉闭塞再灌注诱导的脑缺血大鼠模型中发现,损伤早期(14d内)缺血核心中出现纤维化形成以及大量巨噬细胞浸润,且二者呈明显正相关。耗竭循环单核细胞来源的巨噬细胞会减弱纤维化瘢痕的形成。此外证实白细胞介素4诱导的M2巨噬细胞能参与缺血损伤后纤维化的形成。同时,巨噬细胞条件培养基可在体外直接促进成纤维细胞增殖以及细胞外基质蛋白的生成。进一步药理学和遗传学结果显示,M2巨噬细胞分泌的Shh蛋白可在体内外通过介导纤维相关调节蛋白转化生长因子β1和基质金属蛋白酶9的分泌,促进纤维化的形成。同时,白细胞介素4诱导的M2巨噬细胞源性Shh信号可促进大鼠缺血核心区的血管生成、减少细胞凋亡和梗死体积,且这些神经保护作用是与纤维化瘢痕形成相向而行的。综上,靶向巨噬细胞的白细胞介素4/Shh/转化生长因子β1轴调节纤维瘢痕的形成将可能成为缺血性脑卒中潜在的靶点。

https://orcid.org/0000-0003-4040-1661 (Qin Yang) 

关键词: 纤维化瘢痕, 巨噬细胞, SHH, 白细胞介素4, 缺血性脑损伤, 中枢神经系统, 神经功能, 转化生长因子β1, 细胞外基质, 纤连蛋白

Abstract: In the central nervous system, the formation of fibrotic scar after injury inhibits axon regeneration and promotes repair. However, the mechanism underlying fibrotic scar formation and regulation remains poorly understood. M2 macrophages regulate fibrotic scar formation after injury to the heart, lung, kidney, and central nervous system. However, it remains to be clarified whether and how M2 macrophages regulate fibrotic scar formation after cerebral ischemia injury. In this study, we found that, in a rat model of cerebral ischemia induced by middle cerebral artery occlusion/reperfusion, fibrosis and macrophage infiltration were apparent in the ischemic core in the early stage of injury (within 14 days of injury). The number of infiltrated macrophages was positively correlated with fibronectin expression. Depletion of circulating monocyte-derived macrophages attenuated fibrotic scar formation. Interleukin 4 (IL4) expression was strongly enhanced in the ischemic cerebral tissues, and IL4-induced M2 macrophage polarization promoted fibrotic scar formation in the ischemic core. In addition, macrophage-conditioned medium directly promoted fibroblast proliferation and the production of extracellular matrix proteins in vitro. Further pharmacological and genetic analyses showed that sonic hedgehog secreted by M2 macrophages promoted fibrogenesis in vitro and in vivo, and that this process was mediated by secretion of the key fibrosis-associated regulatory proteins transforming growth factor beta 1 and matrix metalloproteinase 9. Furthermore, IL4-afforded functional restoration on angiogenesis, cell apoptosis, and infarct volume in the ischemic core of cerebral ischemia rats were markedly impaired by treatment with an sonic hedgehog signaling inhibitor, paralleling the extent of fibrosis. Taken together, our findings show that IL4/sonic hedgehog/transforming growth factor beta 1 signaling targeting macrophages regulates the formation of fibrotic scar and is a potential therapeutic target for ischemic stroke. 

Key words: central nervous system, extracellular matrix, fibronectin, fibrotic scar, macrophage, interleukin 4, ischemic cerebral injury, neurological function, Sonic hedgehog, transforming growth factor β1