中国神经再生研究(英文版) ›› 2021, Vol. 16 ›› Issue (10): 1928-1934.doi: 10.4103/1673-5374.308067

• 综述:神经损伤修复保护与再生 • 上一篇    下一篇

低剂量脂多糖通过转化为神经保护性小胶质细胞作为中枢神经系统稳态维持的免疫调节剂

  

  • 出版日期:2021-10-15 发布日期:2021-03-18

Low-dose lipopolysaccharide as an immune regulator for homeostasis maintenance in the central nervous system through transformation to neuroprotective microglia

Haruka Mizobuchi1, *, Gen-Ichiro Soma1, 2, 3   

  1. 1Control of Innate Immunity, Technology Research Association, Kagawa, Japan; 2Macrophi Inc., Kagawa, Japan; 3Research Institute for Healthy Living, Niigata University of Pharmacy and Applied Life Sciences, Niigata, Japan
  • Online:2021-10-15 Published:2021-03-18
  • Contact: Haruka Mizobuchi, PhD, mizobuchi@shizenmeneki.org.
  • Supported by:
    This work was funded by Control of Innate Immunity Technology Research Association; a grant of Cross-ministerial Strategic Innovation Promotion Program, SIP-No. 14533073 (to GIS) from the Council for Science from Technology and Innovation (CSTI) in Cabinet Office of Japanese Government and the National Agriculture and Food Research Organization (NARO). 

摘要:

Neural Regen Res: 口服脂多糖可能是治疗或预防各种神经系统疾病的创新方法

小胶质细胞是脑组织内的巨噬细胞,在脑内天然免疫中起重要作用,有助于维持脑内稳态。脂多糖是革兰氏阴性菌外膜的组成部分,通过Toll样受体4信号转导激活包括小胶质细胞在内的免疫细胞。脂多糖通常被称为内毒素,因为大剂量的脂多糖会引起全身炎症。人们早就认识到脂多糖会加剧神经炎症。最近的研究已经积累了证据证明低剂量脂多糖的控制性免疫训练通过将小胶质细胞转化为神经保护表型来防止神经元损伤。因此,脂多糖可能不仅仅是一种炎症诱导剂,而是一种免疫调节剂,可以在大脑中产生神经保护作用。

来自日本控制先天免疫技术研究会的Haruka Mizobuchi团队认为,脂多糖预处理转化的小胶质细胞不能简单地以其对促炎介质的普遍抑制和对抗炎介质的普遍促进为特征,而是必须通过其包含与炎症调节相关的各种分子的复杂结构来描述,吞噬、神经保护、抗凋亡和抗氧化。此外,小胶质细胞的转化似乎取决于在免疫训练中使用的脂多糖的剂量。分子靶向药物是目前神经系统疾病的主要治疗手段,但其疗效有限。使用低剂量脂多糖对神经保护性小胶质细胞进行免疫训练,尤其是口服脂多糖,可能是神经系统疾病的一种创新性预防或治疗方法;然而,还需要更有力的研究来适当调整这些治疗方法。

文章《中国神经再生研究(英文版)》杂志202110 10 期发表。

https://orcid.org/0000-0002-6667-4820 (Haruka Mizobuchi) 

Abstract: Microglia, which are tissue-resident macrophages in the brain, play a central role in the brain innate immunity and contribute to the maintenance of brain homeostasis. Lipopolysaccharide is a component of the outer membrane of gram-negative bacteria, and activates immune cells including microglia via Toll-like receptor 4 signaling. Lipopolysaccharide is generally known as an endotoxin, as administration of high-dose lipopolysaccharide induces potent systemic inflammation. Also, it has long been recognized that lipopolysaccharide exacerbates neuroinflammation. In contrast, our study revealed that oral administration of lipopolysaccharide ameliorates Alzheimer’s disease pathology and suggested that neuroprotective microglia are involved in this phenomenon. Additionally, other recent studies have accumulated evidence demonstrating that controlled immune training with low-dose lipopolysaccharide prevents neuronal damage by transforming the microglia into a neuroprotective phenotype. Therefore, lipopolysaccharide may not a mere inflammatory inducer, but an immunomodulator that can lead to neuroprotective effects in the brain. In this review, we summarized current studies regarding neuroprotective microglia transformed by immune training with lipopolysaccharide. We state that microglia transformed by lipopolysaccharide preconditioning cannot simply be characterized by their general suppression of proinflammatory mediators and general promotion of anti-inflammatory mediators, but instead must be described by their complex profile comprising various molecules related to inflammatory regulation, phagocytosis, neuroprotection, anti-apoptosis, and antioxidation. In addition, microglial transformation seems to depend on the dose of lipopolysaccharide used during immune training. Immune training of neuroprotective microglia using low-dose lipopolysaccharide, especially through oral lipopolysaccharide administration, may represent an innovative prevention or treatment for neurological diseases; however more vigorous studies are still required to properly modulate these treatments.

Key words: cognitive impairment, endotoxin, lipopolysaccharide, low-dose, microglia, neuroprotection, oral administration, preconditioning, tolerance, trained innate immunity