Inflammatory microglia signals drive A1-like polarization of astrocytes even in the presence of HIV-1 Tat.

ABSTRACT: In the context of neurodegeneration, activated microglia facilitate inflammation via secretion of TNF-α, IL-1α, and C1q. Astrocytes exposed to this signaling array polarize to a reactive inflammatory phenotype, termed A1 or A1-like. Astrocytes are essential for neuronal survival, synaptic support, and blood-brain barrier (BBB) function, but A1-like astrocytes upregulate inflammatory gene expression, downregulate neurotrophic factors, and secrete neurotoxic signals. The consequences of A1-like polarization on BBB function are unknown but may have etiological implications for some diseases. Frequently identified by upregulation of complement component 3 (C3), A1-like astrocytes have been characterized in neurodegenerative disorders like Alzheimer's disease, with polarization correlated with

SUBMITTER: Lawrence JM 

PROVIDER: S-EPMC12678590 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature