中国神经再生研究(英文版) ›› 2021, Vol. 16 ›› Issue (12): 2395-2396.doi: 10.4103/1673-5374.313036

• 观点:神经损伤修复保护与再生 • 上一篇    下一篇

点亮星星:在自身反应性CD4 + T细胞存在的情况下钙信号点亮星形胶质细胞

  

  • 出版日期:2021-12-15 发布日期:2021-05-14

Light of the stars: calcium signals light up astrocytes in the presence of autoreactive CD4+ T cells

Jelena Bogdanović Pristov, Ljiljana Nikolić*   

  1. Department of Life Sciences, University of Belgrade, Institute for Multidisciplinary Research, Belgrade, Serbia (Bogdanović Pristov J) Department of Neurophysiology, University of Belgrade, Institute for Biological Research Siniša Stanković, National Institute of Republic of Serbia, Belgrade, Serbia (Nikolić L)
  • Online:2021-12-15 Published:2021-05-14
  • Contact: Ljiljana Nikolić, PhD, ljnikolic@ibiss.bg.ac.rs or nikolic13@gmail.com.
  • Supported by:
    The present work was supported by the Ministry of Education, Science and Technological Development of Republic of Serbia (Contract No. 451-03-68/2020-14/200007 (to LN), 451-03-68/2020-14/200053) (to JBP), and a Fellowship Start up for Science from the Centre for Leadership Development (to LN).

摘要:

Neural Regen Res:星形胶质细胞对中枢神经系统浸润的免疫细胞显示Ca2+反应选择性

   在实验性自身免疫性脑脊髓炎的整个过程中,不同类型的免疫细胞渗入中枢神经系统,主要包括T细胞,而巨噬细胞、单核细胞、粒细胞和自然杀伤细胞的百分比较低。在T细胞中,从外周招募的CD4+T淋巴细胞是浸润到中枢神经系统的最大免疫细胞群,它们被认为是实验性自身免疫性脑脊髓炎的早期阶段和长期存在的关键因素。星形胶质细胞对CD4+T细胞的影响可特异性的升高Ca2+,而剩下的含有CD4-群体的孤立CNS浸润免疫细胞池不会引起星形胶质细胞Ca2+的变化。然而,中枢神经系统浸润的CD4+T免疫细胞对星形胶质细胞Ca2+信号的影响还需要进一步的实验来分析。研究这种免疫细胞类型依赖性星形胶质细胞钙离子信号可能有助于进一步了解多发性硬化的发病机制。对实验性自身免疫性脑脊髓炎大鼠脊髓中免疫标记的星形胶质细胞和CD4+T细胞分析发现60%以上浸润的CD4+T细胞与中枢神经系统疾病中的星形胶质细胞相互作用。CD4+T细胞在脊髓实质内分布较深,并与星形胶质细胞的网状结构紧密相连,说明这两种细胞之间的物理接触和相互作用在中枢神经系统自身免疫中是不可避免和频繁的。最新研究结果可能会显著改变多发性硬化病理学的观点,即神经系统和免疫系统之间的相互作用。在中枢神经系统自身免疫的炎症环境的形成中,快速和频繁的星形胶质细胞和自身反应性CD4+T细胞相互作用可能是至关重要的。

来自塞尔维亚贝尔格莱德大学的Ljiljana Nikolic发现星形胶质细胞利用Ca2+信号与中枢神经系统浸润的免疫细胞进行通讯。这些Ca2+信号代表一个独立的星形胶质细胞-免疫细胞通讯系统。星形胶质细胞Ca2+的增加是由于与自身反应性CD4+T细胞的物理接触所致。这一引人注目的星形胶质细胞免疫细胞通讯的新层次为进一步了解中枢神经系统自身免疫性疾病的病理学提供了新的概念框架。通过使用多发性硬化的动物模型研究星形胶质细胞Ca2+在体内的动态变化,并考虑其他中枢神经系统驻留细胞(如小胶质细胞和神经元)的输入,这些细胞可以形成星形胶质细胞Ca2+信号,从而加强体外研究的框架。研究星形细胞钙离子信号是否参与了中枢神经系统自身免疫的免疫细胞功能的调节,对今后的研究也很重要。值得注意的是,星形胶质细胞源性ATP不仅可以调节星形胶质细胞内的Ca2+信号,而且可能是调节免疫细胞活性的反馈信号。了解免疫细胞诱导的星形胶质细胞Ca2+信号和ATP释放对神经元活动的影响也很重要。激活星形胶质细胞中的Ca2+信号可促进谷氨酸的释放,谷氨酸可增加神经元活性,但星形胶质细胞释放的ATP可导致腺苷的形成,腺苷可抑制神经元活性。星形胶质细胞-免疫细胞相互作用对中枢神经系统自身免疫中神经网络兴奋和抑制的影响是一个有待解决的重要问题。即将进行的研究将越来越多地将Ca2+信号介导的星形胶质细胞-免疫细胞相互作用视为多发性硬化病理过程的重要组成部分,并可能成为下一代治疗该病的重要途径。尽管星形胶质细胞-免疫细胞相互作用在中枢神经系统自身免疫中的作用仍有待进一步研究,但是Ca2+信号可以照亮中枢神经系统特定免疫细胞附近的星形胶质细胞。

 文章在《中国神经再生研究(英文版)》杂志2021年 12 12  期发表。

https://orcid.org/0000-0002-8575-7824(Ljiljana Nikolić)

Abstract: Astrocytes play important roles in the central nervous system (CNS) to support and regulate CNS function. They are abundant type of glia that form a meshwork of interconnected cells almost completely tiling the CNS. Each astrocyte extends densely ramified processes that establish close contacts and interaction with other astrocytes, neurons and blood vessels, placing these cells in an ideal position to control extracellular milieu and to exert global effects on CNS physiology. Astrocytes are dynamic cells that continuously sense and respond to the physiological and pathological cues within their local environment. This responsiveness of astrocytes and their intercellular communication with neighboring cells in the CNS principally relies on increase in intracellular Ca2+ and release of neuroactive compounds such as adenosine 5′-triphosphate (ATP), that are critical for maintaining proper CNS function (Butt, 2011; Bazargani and Attwell, 2016). Intracellular Ca2+ level in astrocytes is under the control of diverse ionotropic and metabotropic receptors that upon activation promote Ca2+ entry into the cell or its liberation from cellular Ca2+ stores. This promotes rise of Ca2+ signals in astrocytes that spread information between astrocytes themselves and toward neurons to regulate CNS function. When CNS environment becomes disturbed following injury or in disease, astrocytes generally respond with an augmentation of Ca2+ signaling within their network that has deleterious effects and drive pathological processes (Shigetomi et al., 2019). Thus, Ca2+ signaling acts as a powerful and highly adaptable system for astrocyte communication with neighboring cells in the CNS and enables astrocytes to detect and respond to changes in their local environment in both, physiological and pathological conditions. In our recent paper (Bijelić et al., 2020) we show that astrocyte Ca2+ signals controlled by purinergic P2X7 ionotropic receptors are also important for astrocytic communication with specific immune cells that infiltrate into the CNS in experimental autoimmune encephalomyelitis, a commonly used animal model of multiple sclerosis. We show that astrocytes respond to the nearby autoreactive CD4+ T cells with an increase in their intracellular Ca2+ (Figure 1), hinting at the previously unrecognized involvement of astrocytic Ca2+ signaling in the nervous system-immune system communication in an autoimmune disease of CNS.