Methylmercury stimulates arachidonic acid release and cytosolic phospholipase A2 expression in primary neuronal cultures.
Cytosolic phospholipase A2 (cPLA2) plays an important role in the stimulus-dependent hydrolysis of sn-2 ester bond from membrane phospholipids, releasing arachidonic acid (AA), which along with its metabolites is involved in a number of regulatory functions. The present study examined the effect of methylmercury (MeHg; 0, 2.5, 5.0 microM) on cPLA2 activation in primary hippocampal neurons by assessing the release of 3H-AA. A significant increase in AA release was observed in cultures treated with 5 microM MeHg (10, 30, 60 and 120 min). This effect was due to neuronal cPLA2 activation, since it was completely abolished by arachidonyl trifluoromethyl ketone (AACOCF3), a specific inhibitor of cPLA2. Additional studies confirmed, by means of western blot analysis, that MeHg (5.0 and 10 microM; 16h) potently increases neuronal cPLA2 protein expression. These results suggest that cPLA2-stimulated hydrolysis and release of AA are potential mediators of MeHg-induced neurotoxicity.
Shanker
Gouri
G
Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157-1083, USA.
Hampson
Robert E
RE
Aschner
Michael
M
D000818:Animals; D016718:Arachidonic Acid / Q000378:metabolism*; D002478:Cells, Cultured; D003600:Cytosol / Q000187:drug effects* / Q000378:metabolism; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism; D008767:Methylmercury Compounds / Q000494:pharmacology*; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism; D010741:Phospholipases A / Q000096:biosynthesis* / Q000235:genetics; D054467:Phospholipases A2; D051381:Rats
D008767:Methylmercury Compounds; D016718:Arachidonic Acid; D010741:Phospholipases A; D054467:Phospholipases A2