Abstract
Rationale
Phospholipase A2 (PLA2) is a family of enzymes that cleave membrane phospholipids generating important lipid mediators in signal transduction. In rat hippocampal slices, both intracellular cytosolic Ca2+-dependent PLA2 (cPLA2) and Ca2+-independent PLA2 (iPLA2) have been implicated in mechanisms of synaptic plasticity underlying memory processes. In mice, intraperitoneal injections of a selective iPLA2 inhibitor impaired spatial learning. Accordingly, reduced cPLA2 and iPLA2 activities were found in postmortem hippocampus of patients with Alzheimer’s disease.
Objective
This study investigates the effects of injections of PLA2 inhibitors directly into rat hippocampus on the acquisition of short-term (STM) and long-term memory (LTM) of a one-trial step-down inhibitory avoidance (IA) task.
Methods
Wistar rats were bilaterally implanted with cannulae in the CA1 region of the dorsal hippocampus. After surgery, the rats received bilateral injections of a vehicle, or of dual cPLA2 and iPLA2 inhibitors (MAFP or PACOCF3), or a selective iPLA2 inhibitor (bromoenol lactone) before training in IA. The animals were tested 1.5 h (for STM) and 24 h (for LTM) after training.
Results
Significant inhibition of iPLA2 activity in rat hippocampus impaired acquisition of STM and LTM. Memory impairment did not result from neuronal death after iPLA2 inhibition. Moreover, IA training per se increased significantly hippocampal PLA2 activity.
Conclusion
The present results suggest a functional effect of hippocampal PLA2 on the neurochemistry of memory acquisition and support the hypothesis that reduced PLA2 activity may contribute to memory impairment in Alzheimer’s disease.
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References
Ackermann EJ, Conde-Frieboes K, Dennis EA (1995) Inhibition of macrophage Ca(2+)-independent phospholipase A2 by bromoenol lactone and trifluoromethyl ketones. J Biol Chem 270:445–450
Akiba S, Mizunaga S, Kume K, Hayama M, Sato T (1999) Involvement of group VI Ca2+-independent phospholipase A2 in protein kinase C-dependent arachidonic acid liberation in zymosan-stimulated macrophage-like P388D1 cells. J Biol Chem 274:19906–19912
Alonso M, Viola H, Izquierdo I, Medina JH (2002) Aversive experiences are associated with a rapid and transient activation of ERKs in the rat hippocampus. Neurobiol Learn Mem 77:119–124
Alzheimer A, Stelzmann RA, Schnitzlein HN, Murtagh FR (1995) An English translation of Alzheimer’s 1907 paper, “Uber eine eigenartige Erkankung der Hirnrinde”. Clin Anat 8:429–431
Balsinde J, Dennis EA (1996) Distinct roles in signal transduction for each of the phospholipase A2 enzymes present in P388D1 macrophages. J Biol Chem 271:6758–6765
Balsinde J, Dennis EA (1997) Function and inhibition of intracellular calcium-independent phospholipase A2. J Biol Chem 272:16069–16072
Balsinde J, Balboa MA, Insel PA, Dennis EA (1999) Regulation and inhibition of phospholipase A2. Annu Rev Pharmacol Toxicol 39:175–189
Bernabeu R, Izquierdo I, Cammarota M, Jerusalinsky D, Medina JH (1995) Learning-specific, time-dependent increase in [3H]phorbol dibutyrate binding to protein kinase C in selected regions of the rat brain. Brain Res 685:163–168
Bernard J, Lahsaini A, Massicotte G (1994) Potassium-induced long-term potentiation in area CA1 of the hippocampus involves phospholipase activation. Hippocampus 4:447–453
Bianchin M, Da Silva RC, Schmitz PK, Medina JH, Izquierdo I (1994) Memory of inhibitory avoidance in the rat is regulated by glutamate metabotropic receptors in the hippocampus. Behav Pharmacol 5:356–359
Bliss TV, Collingridge GL (1993) A synaptic model of memory: long-term potentiation in the hippocampus. Nature 361:31–39
Brown GG, Levine SR, Gorell JM, Pettegrew JW, Gdowski JW, Bueri JA, Helpern JA, Welch KM (1989) In vivo 31P NMR profiles of Alzheimer’s disease and multiple subcortical infarct dementia. Neurology 39:1423–1427
Cammarota M, Izquierdo I, Wolfman C, Levi de Stein M, Bernabeu R, Jerusalinsky D, Medina JH (1995) Inhibitory avoidance training induces rapid and selective changes in 3[H]AMPA receptor binding in the rat hippocampal formation. Neurobiol Learn Mem 64:257–264
Cammarota M, de Stein ML, Paratcha G, Bevilaqua LR, Izquierdo I, Medina JH (2000) Rapid and transient learning-associated increase in NMDA NR1 subunit in the rat hippocampus. Neurochem Res 25:567–572
Clements MP, Bliss TV, Lynch MA (1991) Increase in arachidonic acid concentration in a postsynaptic membrane fraction following the induction of long-term potentiation in the dentate gyrus. Neuroscience 45:379–389
Collins DR, Smith RC, Davies SN (1995) Interactions between arachidonic acid and metabotropic glutamate receptors in the induction of synaptic potentiation in the rat hippocampal slice. Eur J Pharmacol 294:147–154
Dennis EA (1994) Diversity of group types, regulation, and function of phospholipase A2. J Biol Chem 269:13057–13060
Eckert GP, Cairns NJ, Maras A, Gattaz WF, Muller WE (2000) Cholesterol modulates the membrane-disordering effects of beta-amyloid peptides in the hippocampus: specific changes in Alzheimer’s disease. Dement Geriatr Cogn Disord 11:181–186
Emmerling MR, Moore CJ, Doyle PD, Carroll RT, Davis RE (1993) Phospholipase A2 activation influences the processing and secretion of the amyloid precursor protein. Biochem Biophys Res Commun 197:292–297
Emmerling MR, Dudley DT, Dyer RD, Carroll RT, Doyle PD, Davis RE (1996) The role of arachidonic acid in the secretion of the amyloid precursor protein (APP). Ann N Y Acad Sci 777:310–315
Farooqui AA, Yang HC, Rosenberger TA, Horrocks LA (1997) Phospholipase A2 and its role in brain tissue. J Neurochem 69:889–901
Farooqui AA, Litsky ML, Farooqui T, Horrocks LA (1999) Inhibitors of intracellular phospholipase A2 activity: their neurochemical effects and therapeutical importance for neurological disorders. Brain Res Bull 49:139–153
Forlenza OV, Schaeffer EL, Gattaz WF (2002) Phospholipase A2 activity in rat embryonic brain and in primary cultures of cortical neurons. J Neural Transm 109:623–631
Fujita S, Ikegaya Y, Nishiyama N, Matsuki N (2000) Ca2+-independent phospholipase A2 inhibitor impairs spatial memory of mice. Jpn J Pharmacol 83:277–278
Fujita S, Ikegaya Y, Nishikawa M, Nishiyama N, Matsuki N (2001) Docosahexaenoic acid improves long-term potentiation attenuated by phospholipase A(2) inhibitor in rat hippocampal slices. Br J Pharmacol 132:1417–1422
Gattaz WF, Maras A, Cairns NJ, Levy R, Forstl H (1995) Decreased phospholipase A2 activity in Alzheimer brains. Biol Psychiatry 37:13–17
Holscher C, Rose SP (1994) Inhibitors of phospholipase A2 produce amnesia for a passive avoidance task in the chick. Behav Neural Biol 61:225–232
Holscher C, Canevari L, Richter-Levin G (1995) Inhibitors of PLA2 and NO synthase cooperate in producing amnesia of a spatial task. NeuroReport 6:730–732
Izquierdo I (1989) Mechanism of action of scopolamine as an amnestic. Trends Pharmacol Sci 10:175–177
Izquierdo I, Medina JH (1997) Memory formation: the sequence of biochemical events in the hippocampus and its connection to activity in other brain structures. Neurobiol Learn Mem 68:285–316
Izquierdo I, Quillfeldt JA, Zanatta MS, Quevedo J, Schaeffer E, Schmitz PK, Medina JH (1997) Sequential role of hippocampus and amygdala, entorhinal cortex and parietal cortex in formation and retrieval of memory for IA in rats. Eur J Neurosci 9:786–793
Izquierdo I, Barros DM, Mello e Souza T, de Souza MM, Izquierdo LA, Medina JH (1998) Mechanisms for memory types differ. Nature 393:635–636
Izquierdo I, Medina JH, Vianna MR, Izquierdo LA, Barros DM (1999) Separate mechanisms for short- and long-term memory. Behav Brain Res 103:1–11
Kishimoto K, Matsumura K, Kataoka Y, Morii H, Watanabe Y (1999) Localization of cytosolic phospholipase A2 messenger RNA mainly in neurons in the rat brain. Neuroscience 92:1061–1077
Kudo I, Murakami M (2002) Phospholipase A2 enzymes. Prostaglandins Other Lipid Mediat 68–69:3–58
Larsson PK, Claesson HE, Kennedy BP (1998) Multiple splice variants of the human calcium-independent phospholipase A2 and their effect on enzyme activity. J Biol Chem 273:207–214
Lin LL, Wartmann M, Lin AY, Knopf JL, Seth A, Davis RJ (1993) cPLA2 is phosphorylated and activated by MAP kinase. Cell 72:269–278
Lio YC, Reynolds LJ, Balsinde J, Dennis EA (1996) Irreversible inhibition of Ca(2+)-independent phospholipase A2 by methyl arachidonyl fluorophosphonate. Biochim Biophys Acta 1302:55–60
Lowry OH, Rowebrough NJ, Farr LA, Randall RJ (1951) Protein measurement with the Folin phenol reagent. J Biol Chem 193:265–275
Mancuso DJ, Jenkins CM, Gross RW (2000) The genomic organization, complete mRNA sequence, cloning, and expression of a novel human intracellular membrane-associated calcium-independent phospholipase A(2). J Biol Chem 275:9937–9945
Molloy GY, Rattray M, Williams RJ (1998) Genes encoding multiple forms of phospholipase A2 are expressed in rat brain. Neurosci Lett 258:139–142
Nemenoff RA, Winitz S, Qian NX, Van Putten V, Johnson GL, Heasley LE (1993) Phosphorylation and activation of a high molecular weight form of phospholipase A2 by p42 microtubule-associated protein 2 kinase and protein kinase C. J Biol Chem 268:1960–1964
Nitsch RM, Deng A, Wurtman RJ, Growdon JH (1997) Metabotropic glutamate receptor subtype mGluR1alpha stimulates the secretion of the amyloid beta-protein precursor ectodomain. J Neurochem 69:704–712
Owada Y, Tominaga T, Yoshimoto T, Kondo H (1994) Molecular cloning of rat cDNA for cytosolic phospholipase A2 and the increased gene expression in the dentate gyrus following transient forebrain ischemia. Brain Res Mol Brain Res 25:364–368
Paxinos G, Watson C (1998) The rat brain in stereotaxic coordinates. Academic, San Diego
Pettegrew JW, Klunk WE, Panchalingam K, Kanfer JN, McClure RJ (1995) Clinical and neurochemical effects of acetyl-l-carnitine in Alzheimer’s disease. Neurobiol Aging 16:1–4
Pickard RT, Strifler BA, Kramer RM, Sharp JD (1999) Molecular cloning of two new human paralogs of 85-kDa cytosolic phospholipase A2. J Biol Chem 274:8823–8831
Quevedo J, Vianna MR, Martins MR, Barichello T, Medina JH, Roesler R, Izquierdo I (2004) Protein synthesis, PKA, and MAP kinase are differentially involved in short- and long-term memory in rats. Behav Brain Res 154:339–343
Quillfeldt JA, Zanatta MS, Schmitz PK, Quevedo J, Schaeffer E, Lima JB, Medina JH, Izquierdo I (1996) Different brain areas are involved in memory expression at different times from training. Neurobiol Learn Mem 66:97–101
Ross BM, Moszczynska A, Erlich J, Kish SJ (1998) Phospholipid-metabolizing enzymes in Alzheimer’s disease: increased lysophospholipid acyltransferase activity and decreased phospholipase A2 activity. J Neurochem 70:786–793
Talbot K, Young RA, Jolly-Tornetta C, Lee VM, Trojanowski JQ, Wolf BA (2000) A frontal variant of Alzheimer’s disease exhibits decreased calcium-independent phospholipase A2 activity in the prefrontal cortex. Neurochem Int 37:17–31
Tanaka H, Takeya R, Sumimoto H (2000) A novel intracellular membrane-bound calcium-independent phospholipase A(2). Biochem Biophys Res Commun 272:320–326
Underwood KW, Song C, Kriz RW, Chang XJ, Knopf JL, Lin LL (1998) A novel calcium-independent phospholipase A2, cPLA2-gamma, that is renylated and contains homology to cPLA2. J Biol Chem 273:21926–21932
Vianna MR, Barros DM, Silva T, Choi H, Madche C, Rodrigues C, Medina JH, Izquierdo I (2000) Pharmacological demonstration of the differential involvement of protein kinase C isoforms in short- and long-term memory formation and retrieval of one-trial avoidance in rats. Psychopharmacology (Berl) 150:77–84
Weichel O, Hilgert M, Chatterjee SS, Lehr M, Klein J (1999) Bilobalide, a constituent of Ginkgo biloba, inhibits NMDA-induced phospholipase A2 activation and phospholipid breakdown in rat hippocampus. Naunyn-Schmiedeberg’s Arch Pharmacol 360:609–615
Wolf MJ, Izumi Y, Zorumski CF, Gross RW (1995) Long-term potentiation requires activation of calcium-independent phospholipase A2. FEBS Lett 377:358–362
Yang HC, Mosior M, Ni B, Dennis EA (1999) Regional distribution, ontogeny, purification, and characterization of the Ca2+-independent phospholipase A2 from rat brain. J Neurochem 73:1278–1287
Yoshihara Y, Watanabe Y (1990) Translocation of phospholipase A2 from cytosol to membranes in rat brain induced by calcium ions. Biochem Biophys Res Commun 170:484–490
Acknowledgements
The present study was financially supported by Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP; Projects 97/11083-0, 00/05288-2, 00/14528-7) and by Pfizer Laboratories Brazil. The Laboratory of Neuroscience receives financial support from the Associação Beneficente Alzira Denise Hertzog da Silva (ABADHS). We acknowledge the technical help of F. Bassi Jr., L.A. Jardim, and I.A. Zainaghi in some of the experiments.
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Schaeffer, E.L., Gattaz, W.F. Inhibition of calcium-independent phospholipase A2 activity in rat hippocampus impairs acquisition of short- and long-term memory. Psychopharmacology 181, 392–400 (2005). https://doi.org/10.1007/s00213-005-2256-9
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DOI: https://doi.org/10.1007/s00213-005-2256-9