Phospholipase A(2) in astrocytes - Responses to oxidative stress, inflammation, and G protein-coupled receptor agonists

Astrocytes comprise the major cell type in the central nervous system (CNS) and they are essential for support of neuronal functions by providing nutrients and regulating cell-to-cell communication. Astrocytes also are immune-like cells that become reactive in response to neuronal injury. Phospholipases A(2) (PLA(2)) are a family of ubiquitous enzymes that degrade membrane phospholipids and produce lipid mediators for regulating cellular functions. Three major classes of PLA(2) are expressed in astrocytes: group IV calcium-dependent cytosolic PLA(2) (cPLA2), group VI calcium-independent PLA(2) (iPLA(2)), and group 11 secretory PLA(2) (sPLA(2)). Upregulation of PLA(2) in reactive astrocytes has been shown to occur in a number of neurodegenerative diseases, including stroke and Alzheimer's disease. This review focuses on describing the effects of oxidative stress, inflammation, and activation of G protein-coupled receptors on PLA(2) activation, arachidonic acid (AA) release, and production of prostanoids in astrocytes.