ABSTRACT
Astrocytes constitute the most abundant cell type in the central nervous system.Under physi-ological conditions,astrocytes have a variety of functions,and play an important role in maintaining the homeostasis of the central nervous system.However,in response to insults such as injury,inflammation and hypoxia,astro-cytes undergo rapid changes in gene expression,morphology and function,and these responses collectively called as astrocyte reactivity.Activated astrocytes have been divided into neurotoxic phenotype(type A1)and neuropro-tective phenotype(type A2).Recent studies have shown that A1 astrocytes are widely involved in the occurrence and development of various central nervous system diseases.Therefore,targeted regulation of activated astrocytes by combining multiple techniques is expected to be a potential treatment for central nervous system diseases.Here,we review recent advances of A1 astrocytes,including the molecular mechanism of phenotypic transformation and its role in neurodegenerative and neuroinflammatory diseases.