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Phospholipase A 2 and Its Role in Brain Tissue
Author(s) -
Farooqui Akhlaq A.,
Yang HsiuChiung,
Rosenberger Thad A.,
Horrocks Lloyd A.
Publication year - 1997
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1046/j.1471-4159.1997.69030889.x
Subject(s) - brain tissue , neuroscience , phospholipase d , chemistry , biology , microbiology and biotechnology , signal transduction
Phospholipase A 2 (PLA 2 ) is the name for the class of lipolytic enzymes that hydrolyze the acyl group from the sn ‐2 position of glycerophospholipids, generating free fatty acids and lysophospholipids. The products of the PLA 2 ‐catalyzed reaction can potentially act as second messengers themselves, or be further metabolized to eicosanoids, platelet‐activating factor, and lysophosphatidic acid. All of these are recognized as bioactive lipids that can potentially alter many ongoing cellular processes. The presence of PLA 2 in the central nervous system, accompanied by the relatively large quantity of potential substrate, poses an interesting dilemma as to the role PLA 2 has during both physiologic and pathologic states. Several different PLA 2 enzymes exist in brain, some of which have been partially characterized. They are classified into two subtypes, CA 2+ ‐dependent and Ca 2+ ‐independent, based on their catalytic dependence on Ca 2+ . Under physiologic conditions, PLA 2 may be involved in phospholipid turnover, membrane remodeling, exocytosis, detoxification of phospholipid peroxides, and neurotransmitter release. However, under pathological situations, increased PLA 2 activity may result in the loss of essential membrane glycerophospholipids, resulting in altered membrane permeability, ion homeostasis, increased free fatty acid release, and the accumulation of lipid peroxides. These processes, along with loss of ATP, may be responsible for the loss of membrane phospholipid and subsequent neuronal injury found in ischemia, spinal cord injury, and other neurodegenerative diseases. This review outlines the current knowledge of the PLA 2 found in the central nervous system and attempts to define the role of PLA 2 during both physiologic and pathologic conditions.