Fig. 1
From: Lysosomal acidification impairment in astrocyte-mediated neuroinflammation
The multifaceted roles of astrocytes in the brain. (A) Astrocytes control ion homeostasis and water exchange in the brain microenvironment by regulating channel proteins including aquaporin-4 (AQP4) water channel as well as potassium, sodium, and calcium channels. (B) Astrocytes support the formation of tight junctions (e.g., claudin, occludin, junctional adhesion molecules (JAM), and cadherin) and the maintenance of epithelial cells at the blood-brain barrier (BBB). (C) Contraction and blood flow movement of the BBB is mediated by smooth muscle tissue that respond to Ca2+ ions released and regulated by astrocytes. (D) Astrocytes mediate nutrient transport to neurons to regulate neuronal metabolism. (E) Astrocytes operate as phagocytes to carry out synaptic pruning as well as remove cell debris, damaged organelles, and myelin. (F) Astrocytes participate in autophagic degradation of intracellular toxic protein aggregates, myelin/lipids and cellular debris phagocytosed from damaged neurons. (G) Astrocytes release inflammatory cytokines that can recruit microglia to sites of brain injury and/or induce neuronal impairment and death. The figure was created with BioRender.com