Spreading depression induces expression of calcium-independent protein kinase C subspecies in ischaemia-sensitive cortical layers: regulation by N-methyl-D-aspartate receptors and glucocorticoids.
Spreading depression is a wave of sustained depolarization challenging the energy metabolism of the cells without causing irreversible damage. In the ischaemic brain, sreading depression-like depolarization contributes to the evolution of ischaemia to infarction. The depolarization is propagated by activation of N-methyl-D-aspartate receptors, but changes in signal transduction downstream of the receptors are not known. Because protein phosphorylation is a general mechanism whereby most cellular processes are regulated, and inhibition of N-methyl-D-aspartate receptors or protein kinase C is neuroprotective, the expression of protein kinase C subspecies in spreading depression was examined. Cortical treatment with KCl induced an upregulation of protein kinase Cdelta and zeta messenger RNA at 4 and 8 h, whereas protein kinase Calpha, beta, gamma and epsilon did not show significant changes. The gene induction was the strongest in layers 2 and 3, and was followed by an increased number of protein kinase Cdelta-immunoreactive neurons. Protein kinase Cdelta and zeta inductions were inhibited by pretreatment with an N-methyl-D-aspartate receptor antagonist, dizocilpine maleate, which also blocked spreading depression propagation, and with dexamethasone, which acted without blocking the propagation. Quinacrine, a phospholipase A2 inhibitor, reduced only protein kinase C5 induction. In addition, N(G)(-nitro-L-arginine methyl ester, a nitric oxide synthase inhibitor, did not influence protein kinase Cdelta or zeta induction, whereas 6-nitro-7-sulphamoylbenzo[f]quinoxaline-2,3-dione, an alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate/kainate receptor antagonist, and the cyclo-oxygenase inhibitors indomethacin and diclophenac tended to increase gene expression. The data show that cortical spreading depression induces Ca2(+)-independent protein kinase C subspecies delta and zeta, but not Ca(2+)-dependent subspecies, through activation of N-methyl-D-aspartate receptors and phospholipase A2. Even though the signal pathway is similar to the induction described previously in ischaemia for genes implicated in delayed neuronal death, the gene inductions observed here are not necessarily pathogenetic, but may represent a general reaction to metabolic stress.
Koponen
S
S
A.I. Virtanen Institute, University of Kuopio, Finland.
Keinänen
R
R
Roivainen
R
R
Hirvonen
T
T
Närhi
M
M
Chan
P H
PH
Koistinaho
J
J
D000818:Animals; D002545:Brain Ischemia / Q000201:enzymology*; D013181:Cortical Spreading Depression / Q000502:physiology*; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D003907:Dexamethasone / Q000494:pharmacology*; D004008:Diclofenac / Q000494:pharmacology; D004198:Disease Susceptibility; D016291:Dizocilpine Maleate / Q000494:pharmacology; D004790:Enzyme Induction / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology*; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D007213:Indomethacin / Q000494:pharmacology; D007527:Isoenzymes / Q000096:biosynthesis* / Q000235:genetics; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009419:Nerve Tissue Proteins / Q000096:biosynthesis* / Q000235:genetics; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D010296:Parietal Lobe / Q000201:enzymology / Q000502:physiology*; D010741:Phospholipases A / Q000037:antagonists & inhibitors; D054467:Phospholipases A2; D011401:Promoter Regions, Genetic; D011493:Protein Kinase C / Q000096:biosynthesis* / Q000235:genetics; D051745:Protein Kinase C-delta; D011796:Quinacrine / Q000494:pharmacology; D011810:Quinoxalines / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D018092:Kainic Acid Receptors / Q000187:drug effects; D016194:Receptors, N-Methyl-D-Aspartate / Q000187:drug effects / Q000502:physiology*; D015398:Signal Transduction / Q000187:drug effects*; D015533:Transcriptional Activation; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid / Q000494:pharmacology; D000099221:Protein Kinase C zeta
D016861:Cyclooxygenase Inhibitors; D003907:Dexamethasone; D004008:Diclofenac; D016291:Dizocilpine Maleate; D004791:Enzyme Inhibitors; D018691:Excitatory Amino Acid Antagonists; D007213:Indomethacin; D007527:Isoenzymes; D019331:NG-Nitroarginine Methyl Ester; D009419:Nerve Tissue Proteins; D019001:Nitric Oxide Synthase; D010741:Phospholipases A; D054467:Phospholipases A2; D011493:Protein Kinase C; D051745:Protein Kinase C-delta; D011796:Quinacrine; D011810:Quinoxalines; D018092:Kainic Acid Receptors; D016194:Receptors, N-Methyl-D-Aspartate; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid; D000099221:Protein Kinase C zeta; C062865:2,3-dioxo-6-nitro-7-sulfamoylbenzo(f)quinoxaline; C497260:Prkcd protein, rat