Studies on Plasmalogen-Selective Phospholipase A2 in Brain

Abstract

Plasmalogen-selective phospholipase A(2) (PlsEtn-PLA(2)) has been purified from pig brain using multiple column chromatographic procedure. The purified enzyme migrates as a single band on polyacrylamide. It is stimulated by Triton X-100 and inhibited by sodium deoxycholate. Purified PlsEtn-PLA(2) is inhibited by iodoacetate, and this inhibition can be prevented by beta-meracaptoethanol. Treatment of neuronal cell cultures with kainic acid stimulates PlsEtn-PLA(2) activity in a dose-dependent manner, and this stimulation can be blocked by Ly294486, a selective kainic acid receptor antagonist. Activities of PlsEtn-PLA(2) are markedly increased in plasma membrane and synaptosomal plasma membrane fraction prepared from nucleus basalis and hippocampal region of brains from Alzheimer disease patients compared to age-matched controls. It is proposed that accumulation of ceramide and increased expression of cytokines may be responsible for the stimulation of PlsEtn-PLA(2) in Alzheimer disease.

Mouse brain plasmalogens are targets for hypochlorous acid-mediated modification in vitro and in vivo

“…This is in agreement with published data [28,38,39] and most likely a reflection of pPE function: species with a low degree of unsaturation are present in white matter myelin, providing support for axonal membrane integrity [31]. The highly unsaturated species are mainly found in gray matter, where they promote membrane fusion [40] and provide a reservoir for plasmalogen-specific phospholipase that generates bioactive signaling lipids [41].…”

“…This is in agreement with published data [28,38,39] and most likely a reflection of pPE function: species with a low degree of unsaturation are present in white matter myelin, providing support for axonal membrane integrity [31]. The highly unsaturated species are mainly found in gray matter, where they promote membrane fusion [40] and provide a reservoir for plasmalogen-specific phospholipase that generates bioactive signaling lipids [41].The rate constants for HOCl-dependent plasmalogen modification are approx 10-fold higher compared to their non-vinyl ether-containing counterparts [42]. Accordingly, our in vitro data obtained during HOCl modification revealed higher sensitivity of brain plasmalogens toward HOCl compared to diacylglycerophospholipids.…”

“…5) under in vitro and in vivo conditions [64,65]. Activation of a plasmalogen-specific phospholipase could be another factor contributing to plasmalogen loss under inflammatory conditions [41].…”

Plasmalogens and fatty alcohols in rhizomelic chondrodysplasia punctata and Sjögren‐Larsson syndrome

“…Reservoirs for second messengers Polyunsaturated fatty acids (PUFAs) occupy the sn-2 position of the glycerol backbone of plasmalogens, which can be released upon enzymatic cleavage by phospholipases, such as phospholipase A 2 (Beckett et al 2007;Farooqui 2010). Docosahexaenoic acid (DHA), arachidonic acid (AA), and nervonic acid are preferentially esterified on plasmalogens when compared to other glycerophospholipids (Blank et al 1989;Ford and Gross 1989).…”

The Ether Lipid Precursor Hexadecylglycerol Stimulates the Release and Changes the Composition of Exosomes Derived from PC-3 Cells

“…Furthermore, ether lipids may serve as a storage depot of polyunsaturated fatty acids or lipid mediators and function as antioxidative agents (21)(22)(23)(24)(25). In fact, a plasmalogen-selective phospholipase A 2 that catalyzes the release of polyunsaturated fatty acid has been identified (26). Finally, ether lipids have been shown to be involved in signaling (27,28), membrane fusion, and trafficking (29 -33).…”