Zorec Robert, Verkhratsky Alexei
Institute of Pathophysiology, Laboratory of Neuroendocrinology and Molecular Cell Physiology, University of Ljubljana, Zaloska cesta 4, SI-1000, Ljubljana, Slovenia.
Celica, BIOMEDICAL, Technology Park 24, 1000 Ljubljana, Slovenia.
Essays Biochem. 2023 Mar 3;67(1):131-145. doi: 10.1042/EBC20220082.
Key homeostasis providing cells in the central nervous system (CNS) are astrocytes, which belong to the class of cells known as atroglia, a highly heterogeneous type of neuroglia and a prominent element of the brain defence. Diseases evolve due to altered homeostatic state, associated with pathology-induced astroglia remodelling represented by reactive astrocytes, astroglial atrophy and astrodegeneration. These features are hallmarks of most infectious insults, mediated by bacteria, protozoa and viruses; they are also prominent in the systemic infection. The COVID-19 pandemic revived the focus into neurotropic viruses such as SARS-CoV2 (Coronaviridae) but also the Flaviviridae viruses including tick-borne encephalitis (TBEV) and Zika virus (ZIKV) causing the epidemic in South America prior to COVID-19. Astrocytes provide a key response to neurotropic infections in the CNS. Astrocytes form a parenchymal part of the blood-brain barrier, the site of virus entry into the CNS. Astrocytes exhibit aerobic glycolysis, a form of metabolism characteristic of highly morphologically plastic cells, like cancer cells, hence a suitable milieu for multiplication of infectious agent, including viral particles. However, why the protection afforded by astrocytes fails in some circumstances is an open question to be studied in the future.
中枢神经系统（CNS）中维持关键内稳态的细胞是星形胶质细胞，它们属于被称为星形胶质的细胞类别，是一种高度异质性的神经胶质细胞类型，也是脑防御的重要组成部分。疾病的发生是由于内稳态状态改变，这与病理诱导的星形胶质细胞重塑有关，表现为反应性星形胶质细胞、星形胶质细胞萎缩和星形胶质细胞退变。这些特征是大多数由细菌、原生动物和病毒介导的感染性损伤的标志；它们在全身感染中也很突出。COVID-19大流行使人们重新关注嗜神经病毒，如SARS-CoV2（冠状病毒科），以及黄病毒科病毒，包括蜱传脑炎病毒（TBEV）和在COVID-19之前在南美洲引发疫情的寨卡病毒（ZIKV）。星形胶质细胞对中枢神经系统中的嗜神经感染提供关键反应。星形胶质细胞构成血脑屏障的实质部分，是病毒进入中枢神经系统的部位。星形胶质细胞表现出有氧糖酵解，这是一种高度形态可塑性细胞（如癌细胞）特有的代谢形式，因此是包括病毒颗粒在内的感染因子增殖的适宜环境。然而，星形胶质细胞提供的保护为何在某些情况下会失效，这是一个有待未来研究的开放性问题。
