Neuroinflammation: An astrocyte perspective

Abstract

Astrocytes are abundant glial cells in the central nervous system (CNS) that play active roles in health and disease. Recent technologies have uncovered the functional heterogeneity of astrocytes and their extensive interactions with other cell types in the CNS. In this Review, we highlight the intricate interactions between astrocytes, other CNS-resident cells, and CNS-infiltrating cells as well as their potential therapeutic value in the context of inflammation and neurodegeneration.

AhR Agonistic Components in Urban Particulate Matter Regulate Astrocytic Activation and Function

“…A variety of neurodegenerative diseases can be facilitated by astrocyte activation, and this type of reactive cells have two polarization states, including A1 (i.e., neurotoxic or pro-inflammatory) and A2 (neuroprotective or anti-inflammatory) phenotypes . The mixed cell population with two distinct states are important for the initiation and progression of various neurological disorders .…”

“…8 Astrocytes, as the most abundant population of neuroglial cells, have also been extensively explored in modulation of the neuroinflammatory response. 9 Of two polarization states identified in reactive astrocytes, the neurotoxic or pro-inflammatory phenotype (A1) cells lose their abilities to promote neuronal survival, growth, synaptogenesis, or phagocytosis and cause neuronal and oligodendrocyte death. In contrast, the neuroprotective or anti-inflammatory phenotype (A2) astrocytes can upregulate neurotrophic factors and expert a beneficial effect on repairing CNS injury.…”

“…The neuroinflammation is responsible for the association between PM stimulus and neurodegenerative disorders, and the activated microglia is involved in airborne PM 2.5 -mediated neuroinflammation and neurotoxicity . Astrocytes, as the most abundant population of neuroglial cells, have also been extensively explored in modulation of the neuroinflammatory response . Of two polarization states identified in reactive astrocytes, the neurotoxic or pro-inflammatory phenotype (A1) cells lose their abilities to promote neuronal survival, growth, synaptogenesis, or phagocytosis and cause neuronal and oligodendrocyte death.…”

Disease-associated astrocyte epigenetic memory promotes CNS pathology

“…Astrocytes play important roles in the central nervous system (CNS) physiology and pathology. Indeed, astrocyte subsets defined by specific transcriptional activation states contribute to the pathology of neurologic diseases, including multiple sclerosis (MS) and its pre-clinical model experimental autoimmune encephalomyelitis (EAE) [1][2][3][4][5][6][7][8] . However, little is known about the stability of these disease-associated astrocyte subsets, their regulation, and whether they integrate past stimulation events to respond to subsequent challenges.…”

“…Astrocytes participate in key processes relevant to CNS development and homeostasis 1 . In addition, cytokines, interactions with CNS-resident and CNS-recruited immune cells, and other factors trigger astrocyte responses with important roles in CNS pathology 2,4,5 . Indeed, several astrocyte subsets have been described in neurologic diseases [6][7][8] .…”