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Joshi S, Kapur J. N-methyl-D-aspartic acid receptor activation downregulates expression of δ subunit-containing GABAA receptors in cultured hippocampal neurons. Mol Pharmacol 2013; 84:1-11. [PMID: 23585058 PMCID: PMC3684822 DOI: 10.1124/mol.112.084715] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2012] [Accepted: 04/09/2013] [Indexed: 01/26/2023] Open
Abstract
Neurosteroids are endogenous allosteric modulators of GABAA receptors (GABARs), and they enhance GABAR-mediated inhibition. However, GABARs expressed on hippocampal dentate granule neurons of epileptic animals are modified such that their neurosteroid sensitivity is reduced and δ subunit expression is diminished. We explored the molecular mechanisms triggering this GABAR plasticity. In the cultured hippocampal neurons, treatment with N-methyl-D-aspartic acid (NMDA) (10 μM) for 48 hours reduced the surface expression of δ and α4 subunits but did not increase the expression of γ2 subunits. The tonic current recorded from neurons in NMDA-treated cultures was reduced, and its neurosteroid modulation was also diminished. In contrast, synaptic inhibition and its modulation by neurosteroids were preserved in these neurons. The time course of NMDA's effects on surface and total δ subunit expression was distinct; shorter (6 hours) treatment decreased surface expression, whereas longer treatment reduced both surface and total expression. Dl-2-amino-5-phosphonopentanoic acid (APV) blocked NMDA's effects on δ subunit expression. Chelation of calcium ions by 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetra-acetic acid tetrakis (acetoxymethyl ester) (BAPTA-AM) or blockade of extracellular signal-regulated kinase (ERK) 1/2 activation by UO126 (1,4-diamino-2,3-dicyano-1,4-bis[2-aminophenylthio] butadiene) also prevented the effects of NMDA. Thus, prolonged activation of NMDA receptors in hippocampal neurons reduced GABAR δ subunit expression through Ca(2+) entry and at least in part by ERK1/2 activation.
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Affiliation(s)
- Suchitra Joshi
- Department of Neurology, Box 800394, University of Virginia-HSC, Charlottesville, VA 22908, USA.
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Cooper NGF, Laabich A, Fan W, Wang X. The relationship between neurotrophic factors and CaMKII in the death and survival of retinal ganglion cells. PROGRESS IN BRAIN RESEARCH 2008; 173:521-40. [PMID: 18929132 DOI: 10.1016/s0079-6123(08)01136-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
The scientific discourse relating to the causes and treatments for glaucoma are becoming reflective of the need to protect and preserve retinal neurons from degenerative changes, which result from the injurious environment associated with this disease. Knowledge, in particular, of the signal transduction pathways which affect death and survival of the retinal ganglion cells is critical to this discourse and to the development of a suitable neurotherapeutic strategy for this disease. The goal of this chapter is to review what is known of the chief suspects involved in initiating the cell death/survival pathways in these cells, and what still remains to be uncovered. The least controversial aspect of the subject relates to the potential role of neurotrophic factors in the protection of the retinal ganglion cells. On the other hand, the postulated triggers for signaling cell death in glaucoma remain controversial. Certainly, the restricted flow of neurotrophic factors has been cited as one possible trigger. However, the connections between glaucoma and other factors present in the retina, such as glutamate, long held to be a prospective culprit in retinal ganglion cell death are still being questioned. Whatever the outcome of this particular debate, it is clear that the downstream intersections between the cell death and survival pathways should provide important foci for future studies whose goal is to protect retinal neurons, situated as they are, in the stressful environment of a cell destroying disease. The evidence for CaMKII being one of these intersecting points is discussed.
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Affiliation(s)
- N G F Cooper
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, KY 40292, USA.
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Harvey BP, Banga SS, Ozer HL. Regulation of the Multifunctional Ca2+/Calmodulin-dependent Protein Kinase II by the PP2C Phosphatase PPM1F in Fibroblasts. J Biol Chem 2004; 279:24889-98. [PMID: 15140879 DOI: 10.1074/jbc.m400656200] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The regulation of the multifunctional calcium/calmodulin dependent protein kinase II (CaMKII) by serine/threonine protein phosphatases has been extensively studied in neuronal cells; however, this regulation has not been investigated previously in fibroblasts. We cloned a cDNA from SV40-transformed human fibroblasts that shares 80% homology to a rat calcium/calmodulin-dependent protein kinase phosphatase that encodes a PPM1F protein. By using extracts from transfected cells, PPM1F, but not a mutant (R326A) in the conserved catalytic domain, was found to dephosphorylate in vitro a peptide corresponding to the auto-inhibitory region of CaMKII. Further analyses demonstrated that PPM1F specifically dephosphorylates the phospho-Thr-286 in autophosphorylated CaMKII substrate and thus deactivates the CaMKII in vitro. Coimmunoprecipitation of CaMKII with PPM1F indicates that the two proteins can interact intracellularly. Binding of PPM1F to CaMKII involves multiple regions and is not dependent on intact phosphatase activity. Furthermore, overexpression of PPM1F in fibroblasts caused a reduction in the CaMKII-specific phosphorylation of the known substrate vimentin(Ser-82) following induction of the endogenous CaM kinase. These results identify PPM1F as a CaM kinase phosphatase within fibroblasts, although it may have additional functions intracellularly since it has been presented elsewhere as POPX2 and hFEM-2. We conclude that PPM1F, possibly together with the other previously described protein phosphatases PP1 and PP2A, can regulate the activity of CaMKII. Moreover, because PPM1F dephosphorylates the critical autophosphorylation site of CaMKII, we propose that this phosphatase plays a key role in the regulation of the kinase intracellularly.
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Affiliation(s)
- Bohdan P Harvey
- Department of Microbiology and Molecular Genetics, University of Medicine and Dentistry of New Jersey (UMDNJ)-New Jersey Medical School and UMDNJ-Graduate School of Biomedical Sciences, Newark, New Jersey 07101, USA
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Laabich A, Li G, Cooper NGF. Enhanced expression of TNF-R1 protein in NMDA-mediated cell death in the retina. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 2002; 109:239-46. [PMID: 12531535 DOI: 10.1016/s0169-328x(02)00553-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Multiple apoptosis-related genes are expressed in the retina after exposure to N-methyl-D-aspartic acid (NMDA). For example, the mRNAs for TNF-R1, FasL, and Nur77 are up-regulated between 2.8 and 7-fold [Mol. Brain Res. 91 (2001) 34-42]. The purpose of the present study is to examine prospective changes in protein expression for these genes and to determine their cellular localizations subsequent to NMDA stimulation. Following anesthesia, a single intravitreal injection of 4 mM NMDA was administered into the right eye of anesthetized rats. The left eye was injected with phosphate-buffered saline. Retinae were harvested at 2 and 24 h postinjection. Western-blot and immunocytochemical techniques were used to detect changes in protein expression levels, and to localize their distributions within the retina. Analyses of Western blots demonstrated a significant increase in TNF-R1 (100 and 80%) compared to the sham-controls at 2 and 24 h postinjection with NMDA. Immunolabeling of TNF-R1 was observed in the inner nuclear layer (INL) at 2 h postinjection with NMDA. TNF-R1 was also clearly evident in cells within the INL and ganglion cell layers (GCL) at 24 h post-injection with NMDA. In contrast to these changes in TNF-R1 there were no significant changes in the levels or distributions of FasL or Nur77 in NMDA-stimulated animals at either 2 or 24 h when compared to the sham-controls. These results implicate the TNF-R1 signal transduction pathway in NMDA-induced cell death in the INL and GCL of the retina.
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MESH Headings
- Animals
- Antigens, CD/genetics
- Antigens, CD/metabolism
- Apoptosis/physiology
- DNA-Binding Proteins/genetics
- DNA-Binding Proteins/metabolism
- Excitatory Amino Acid Agonists/pharmacology
- Fas Ligand Protein
- Female
- Gene Expression Regulation
- Immunohistochemistry
- Membrane Glycoproteins/genetics
- Membrane Glycoproteins/metabolism
- N-Methylaspartate/pharmacology
- Nuclear Receptor Subfamily 4, Group A, Member 1
- Rats
- Receptors, Cytoplasmic and Nuclear
- Receptors, Steroid
- Receptors, Tumor Necrosis Factor/genetics
- Receptors, Tumor Necrosis Factor/metabolism
- Receptors, Tumor Necrosis Factor, Type I
- Retina/cytology
- Retina/drug effects
- Retina/metabolism
- Transcription Factors/genetics
- Transcription Factors/metabolism
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Affiliation(s)
- Aicha Laabich
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, 500 S. Preston St, Louisville, KY 40292, USA
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5
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Laabich A, Li G, Cooper NG. Characterization of apoptosis-genes associated with NMDA mediated cell death in the adult rat retina. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 2001; 91:34-42. [PMID: 11457490 DOI: 10.1016/s0169-328x(01)00116-4] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Calcium/calmodulin-dependent protein kinase II containing a nuclear localizing signal (CaMKII-alphaB) is altered in retinal neurons exposed to N-methyl-D-aspartate (NMDA). AIP (myristoylated autocamtide-2-related inhibitory peptide), a specific inhibitor of CaMKII provides neuroprotection against NMDA-mediated neurotoxicity. In this study, gene-arrays were used to investigate which apoptosis-associated genes are altered after exposure to NMDA. The data indicate an increased expression (2-7-fold) of five such genes encoding proteins that could be involved in NMDA induced cell death. The up-regulated genes are: FasL; GADD45; GADD153; Nur77 and TNF-R1. Treatment with AIP blocked their altered expression. The results suggest that multiples genes are involved in NMDA-induced excitotoxicity and that AIP, a specific inhibitor for CaMKII, regulates the expression of these apoptosis-associated genes in the retina.
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MESH Headings
- Animals
- Antigens, CD/genetics
- Apoptosis/drug effects
- Apoptosis/genetics
- CCAAT-Enhancer-Binding Proteins/genetics
- DNA-Binding Proteins/genetics
- Excitatory Amino Acid Agonists/toxicity
- Fas Ligand Protein
- Female
- Gene Expression/drug effects
- Gene Expression/physiology
- Intracellular Signaling Peptides and Proteins
- Membrane Glycoproteins/genetics
- N-Methylaspartate/toxicity
- Neurons
- Nuclear Receptor Subfamily 4, Group A, Member 1
- Oligonucleotide Array Sequence Analysis
- Peptides/pharmacology
- Proteins/genetics
- Rats
- Rats, Sprague-Dawley
- Receptors, Cytoplasmic and Nuclear
- Receptors, Steroid
- Receptors, Tumor Necrosis Factor/genetics
- Receptors, Tumor Necrosis Factor, Type I
- Retina/pathology
- Retina/physiology
- Reverse Transcriptase Polymerase Chain Reaction
- Transcription Factor CHOP
- Transcription Factors/genetics
- Transcription, Genetic/drug effects
- Transcription, Genetic/physiology
- GADD45 Proteins
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Affiliation(s)
- A Laabich
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, 500 South Preston St., Louisville, KY 40202, USA
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6
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Laabich A, Cooper NG. Neuroprotective effect of AIP on N-methyl-D-aspartate-induced cell death in retinal neurons. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 2000; 85:32-40. [PMID: 11146104 DOI: 10.1016/s0169-328x(00)00226-6] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Excessive activation of glutamate receptors mediates neuronal death, but the intracellular signaling pathways that mediate this type of neuronal death are only partly understood. Previously, we have demonstrated that calcium/calmodulin-dependent protein kinase II-alpha(B) (CaMKII-alpha(B)) containing a nuclear localizing signal but not CaMKII-alpha is altered in retinal neurons exposed to N-methyl-D-aspartate (NMDA). The present study describes a prospective function of CaMKII-alpha(B) in signal transduction leading to apoptosis. The terminal deoxyribonucleotidyl transferase (TdT)-mediated biotin-16-dUTP nick-end labelling (TUNEL) method was used to detect fragmented DNA in fixed tissue sections of rat retina. The TUNEL assay confirmed that cell death occurs in the inner nuclear and ganglion cell layers following injection of 4 mM NMDA. A specific AIP (myristoylated autocamtide-2-related inhibitory peptide) with proven cell permeability inhibits CaMKII activity in vivo. Neuroprotection achieved by 500 microM AIP was complete when administered 2 h before and coincident with the NMDA application. Additionally, 100 microM of AIP protects only partially against the NMDA-induced excitotoxicity. The conformationally active fragment of caspase-3 (17 kDa), known to be involved in neuronal apoptosis was apparent within 30 min and at 2 h postinjection with NMDA. This activation was inhibited by 500 microM AIP when administered 2 h before and coincident with the NMDA application. The results suggest that CaMKII-alpha(B) isoform plays a role in excitotoxicity-induced neuronal apoptosis.
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Affiliation(s)
- A Laabich
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, 500 S. Preston St., Louisville, KY 40202, USA
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7
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Carlier E, Dargent B, De Waard M, Couraud F. Na(+) channel regulation by calmodulin kinase II in rat cerebellar granule cells. Biochem Biophys Res Commun 2000; 274:394-9. [PMID: 10913349 DOI: 10.1006/bbrc.2000.3145] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The effects of specific CaM kinase II inhibitors were investigated on Na(+) channels from rat cerebellar granule cells. A maximal effect of KN-62 was observed at 20 microM and consisted of an 80% reduction of the peak Na(+) current after only a 10-min application. A hyperpolarizing shift of 8 mV in the steady-state inactivation was also observed. KN-04 (20 microM), an inactive analog, had no detectable effect. KN-62 was however inactive on Na(+) currents recorded from Chinese hamster ovary cells expressing the type II A alpha subunit. We have also analyzed the inhibitory effects of CaM kinase II 296-311 and CaM kinase II 281-309 peptides. Both peptides (75 microM) induced a maximum peak Na(+) current reduction within 30 min. Under similar conditions, a truncated peptide CaM kinase II 284-302 was ineffective. These results demonstrate that CaM kinase II acts as a modulator of Na(+) channel activity in cerebellar granule cells.
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Affiliation(s)
- E Carlier
- Institut National de la Santé et de la Recherche Médicale U464, Laboratoire de Neurobiologie des Canaux Ioniques, Faculté de Médecine Secteur Nord, Institut Jean Roche, Marseille Cedex 20, 13916, France.
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8
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Murray KD, Isackson PJ, Eskin TA, King MA, Montesinos SP, Abraham LA, Roper SN. Altered mRNA expression for brain-derived neurotrophic factor and type II calcium/calmodulin-dependent protein kinase in the hippocampus of patients with intractable temporal lobe epilepsy. J Comp Neurol 2000; 418:411-22. [PMID: 10713570 DOI: 10.1002/(sici)1096-9861(20000320)418:4<411::aid-cne4>3.0.co;2-f] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The expression of brain-derived neurotrophic factor and the alpha subunit of calcium/calmodulin-dependent protein kinase II mRNA in hippocampi obtained during surgical resections for intractable temporal lobe epilepsy were examined. Both calcium/calmodulin-dependent protein kinase II and brain-derived neurotrophic factor are localized heavily within the hippocampus and have been implicated in regulating hippocampal activity (Kang and Schuman [1995] Science 267:1658-1662; Suzuki [1994] Intl J Biochem 26:735-744). Also, the autocrine and paracrine actions of brain-derived neurotrophic factor within the central nervous system make it a likely candidate for mediating morphologic changes typically seen in the epileptic hippocampus. Quantitative assessments of mRNA levels in epileptic hippocampi relative to autopsy controls were made by using normalized densitometric analysis of in situ hybridization. In addition, correlations between clinical data and mRNA levels were studied. Relative to autopsy control tissue, decreased hybridization to mRNA of the alpha subunit of calcium/calmodulin-dependent protein kinase II and increased hybridization to brain-derived neurotrophic factor mRNA were found throughout the granule cells of the epileptic hippocampus. There also was a significant negative correlation between the duration of epilepsy and the expression of mRNA for brain-derived neurotrophic factor. These results are similar qualitatively to those found in animal models of epilepsy and suggest that chronic seizure activity in humans leads to persistent alterations in gene expression. Furthermore, these alterations in gene expression may play a role in the etiology of the epileptic condition.
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Affiliation(s)
- K D Murray
- Mayo Clinic Jacksonville, Jacksonville, Florida 32224, USA
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9
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Takeuchi Y, Yamamoto H, Matsumoto K, Kimura T, Katsuragi S, Miyakawa T, Miyamoto E. Nuclear localization of the delta subunit of Ca2+/calmodulin-dependent protein kinase II in rat cerebellar granule cells. J Neurochem 1999; 72:815-25. [PMID: 9930758 DOI: 10.1046/j.1471-4159.1999.0720815.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
To examine the physiological roles of the delta subunit of Ca2+/calmodulin-dependent protein kinase II (CaM kinase IIdelta) in brain, we examined the localization of CaM kinase IIdelta in the rat brain. A specific antibody to CaM kinase IIdelta1-delta4 isoforms was prepared by immunizing rabbits with a synthesized peptide corresponding to the unique carboxyl-terminal end of these isoforms. The prepared antibody did not recognize the alpha, beta, and gamma subunits, which were each overexpressed in NG108-15 cells. Immunoblot analysis on various regions and the nuclear fractions from rat brains suggested that some isoforms of CaM kinase IIdelta1-delta4 were abundant in the nucleus in the cerebellum. Total RNA from the cerebellum was analyzed by RT-PCR with a primer pair from variable domain 1 to variable domain 2. We detected the three PCR products delta3.1, delta3.4, and delta3 that contained the nuclear localization signal. These CaM kinase IIdelta3 isoforms were localized in the nuclei in transfected NG108-15 cells. Immunohistochemical study suggested the existence of these isoforms in the nuclei in cerebellar granule cells. These results suggest that CaM kinase IIdelta3 isoforms are involved in nuclear Ca2+ signaling in cerebellar granule cells.
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Affiliation(s)
- Y Takeuchi
- Department of Pharmacology, Kumamoto University School of Medicine, Japan
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10
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Pazzaglia PJ, Post RM, Ketter TA, Callahan AM, Marangell LB, Frye MA, George MS, Kimbrell TA, Leverich GS, Cora-Locatelli G, Luckenbaugh D. Nimodipine monotherapy and carbamazepine augmentation in patients with refractory recurrent affective illness. J Clin Psychopharmacol 1998; 18:404-13. [PMID: 9790159 DOI: 10.1097/00004714-199810000-00009] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Of 30 patients with treatment-refractory affective illness, 10 showed a moderate to marked response to blind nimodipine monotherapy compared with placebo on the Clinical Global Impressions Scale. Fourteen inadequately responsive patients (3 unipolar [UP], 11 bipolar [BP]) were treated with the blind addition of carbamazepine. Carbamazepine augmentation of nimodipine converted four (29%) of the partial responders to more robust responders. Patients who showed an excellent response to the nimodipine-carbamazepine combination included individual patients with patterns of rapid cycling, ultradian cycling, UP recurrent brief depression, and one with BP type II depression. When verapamil was blindly substituted for nimodipine, two BP patients failed to maintain improvement but responded again to nimodipine and remained well with a blind transition to another dihydropyridine L-type calcium channel blocker (CCB), isradipine. Mechanistic implications of the response to the dihydropyridine L-type CCB nimodipine alone and in combination with carbamazepine are discussed.
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Affiliation(s)
- P J Pazzaglia
- Biological Psychiatry Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland 20892-1272, USA
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11
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Kim-Park WK, Moore MA, Hakki ZW, Kowolik MJ. Activation of the neutrophil respiratory burst requires both intracellular and extracellular calcium. Ann N Y Acad Sci 1997; 832:394-404. [PMID: 9704067 DOI: 10.1111/j.1749-6632.1997.tb46267.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Activation of neutrophil oxidases, including NADPH oxidase, is Ca2+ dependent. The aim of this study was to determine the roles of intra- and extracellular Ca2+, leading to generation of the respiratory burst, as monitored by luminol-dependent chemiluminescence (CL). All results were recorded as integrals (millivolt.min) and compared by a two-tail Student's t test. Preincubation of cells with chelators of intra- or extracellular Ca2+ inhibited N-Formyl-Met-Leu-Phe (FMLP)-stimulated burst activity (p < 0.01). In contrast, stimulation by phorbol myristate acetate (PMA), while inhibited by extracellular Ca2+ chelation with EGTA (p < 0.001), was potentiated by intracellular Ca2+ chelation with BAPTA (p < 0.01). This suggests that the protein kinase C (PKC)-mediated burst may be diminished by intracellular Ca(2+)-dependent phosphatase. A selective inhibitor of tyrosine phosphatase, sodium vanadate, potentiated CL generation by both FMLP and PMA, indicating a dominant phosphatase activation with transiently increased Ca2+, masking the kinase-mediated respiratory burst. The selective inhibitors of PKC or tyrosine kinase prevented PMA and vanadate/PMA stimulation (p < 0.005). Furthermore, the putative Ca2+ channel agonists glutamate (10(-5)M) and N-methyl-D-aspartate (NMDA) (10(-5)M) alone failed to influence CL output, but produced marked potentiation following pre-treatment with vanadate. Again this indicates a dominant activation of phosphatase triggered by the glutamate-mediated Ca2+ influx, so masking the kinase-dependent NADPH oxidase activity. A competitive antagonist of NMDA, AP7, significantly decreased vanadate-mediated CL in an EGTA-sensitive manner (p < 0.001). The data confirm a requirement for intra- and extracellular Ca2+ in neutrophil respiratory burst activation via the kinase/phosphatase cycle, and an agonist effect by NMDA within the Ca2+ cascade mechanism.
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Affiliation(s)
- W K Kim-Park
- Indiana University, Department of Oral Biology, Indianapolis 46202-5186, USA
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12
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Kano M, Kano M, Fukunaga K, Konnerth A. Ca(2+)-induced rebound potentiation of gamma-aminobutyric acid-mediated currents requires activation of Ca2+/calmodulin-dependent kinase II. Proc Natl Acad Sci U S A 1996; 93:13351-6. [PMID: 8917594 PMCID: PMC24096 DOI: 10.1073/pnas.93.23.13351] [Citation(s) in RCA: 109] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
In cerebellar Purkinje neurons, gamma-aminobutyric acid (GABA)-mediated inhibitory synaptic transmission undergoes a long-lasting "rebound potentiation" after the activation of excitatory climbing fiber inputs. Rebound potentiation is triggered by the climbing-fiber-induced transient elevation of intracellular Ca2+ concentration and is expressed as a long-lasting increase of postsynaptic GABAA receptor sensitivity. Herein we show that inhibitors of the Ca2+/calmodulin-dependent protein kinase II (CaM-KII) signal transduction pathway effectively block the induction of rebound potentiation. These inhibitors have no effect on the once established rebound potentiation, on voltage-gated Ca2+ channel currents, or on the basal inhibitory transmission itself. Furthermore, a protein phosphatase inhibitor and the intracellularly applied CaM-KII markedly enhanced GABA-mediated currents in Purkinje neurons. Our results demonstrate that CaM-KII activation and the following phosphorylation are key steps for rebound potentiation.
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Affiliation(s)
- M Kano
- Department of Physiology, Jichi Medical School, Tochigi, Japan.
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13
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Soderling TR. Structure and regulation of calcium/calmodulin-dependent protein kinases II and IV. BIOCHIMICA ET BIOPHYSICA ACTA 1996; 1297:131-8. [PMID: 8917614 DOI: 10.1016/s0167-4838(96)00105-7] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- T R Soderling
- Vollum Institute, Oregon Health Sciences University, Portland 97225, USA
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14
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Yano S, Fukunaga K, Takiguchi M, Ushio Y, Mori M, Miyamoto E. Regulation of CCAAT/enhancer-binding protein family members by stimulation of glutamate receptors in cultured rat cortical astrocytes. J Biol Chem 1996; 271:23520-7. [PMID: 8798561 DOI: 10.1074/jbc.271.38.23520] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Regulation of mRNA levels, DNA binding activities, and phosphorylation of CCAAT/enhancer-binding protein (C/EBP) family members by stimulation of glutamate receptors were studied in cultured rat cortical astrocytes. Indirect immunofluorescence and immunoblot analyses with specific antibodies to C/EBP family members revealed that both C/EBPbeta and C/EBPdelta but not C/EBPalpha are expressed in the nuclei of astrocytes. After exposure to glutamate, C/EBPbeta mRNA levels increased within 10 min, reached the maximal level at about 1 h, and returned to the basal level within 6 h. In contrast, C/EBPdelta mRNA levels decreased by 6 h and were recovered within 12 h. These changes in mRNA levels were accompanied by an increase and a decrease in proteins for C/EBPbeta and C/EBPdelta, respectively. Elevation of C/EBPbeta mRNA levels by glutamate treatment required an increase in intracellular Ca2+ concentration and depended on activations of protein kinase C and calmodulin-dependent protein kinases. Gel mobility shift analysis using nuclear extracts from the glutamate-treated cells showed increases in C/EBP site binding activities 2 h after the exposure to glutamate. Moreover, glutamate stimulated phosphorylation of C/EBPbeta in 32P-labeled astrocytes in a Ca2+-dependent manner. These results suggest that glutamate regulates functions of C/EBP family members in brain astrocytes through changes in mRNA levels of C/EBPbeta and C/EBPdelta as well as through phosphorylation of C/EBPbeta.
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Affiliation(s)
- S Yano
- Department of Pharmacology, Kumamoto University School of Medicine, Kumamoto 860, Japan
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15
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Abstract
The observation that autophosphorylation converts CaM kinase II from the Ca(2+)-dependent form to the Ca(2+)-independent form has led to speculation that the formation of the Ca(2+)-independent form of the enzyme could encode frequency of synaptic usage and serve as a molecular explanation of "memory". In cultured rat hippocampal neurons, glutamate elevated the Ca(2+)-independent activity of CaM kinase II through autophosphorylation, and this response was blocked by an NMDA receptor antagonist, D-2-amino-5-phosphonopentanoate (AP5). In addition, we confirmed that high, but not low frequency stimulation, applied to two groups of CA1 afferents in the rat hippocampus, resulted in LTP induction with concomitant long-lasting increases in Ca(2+)-independent and total activities of CaM kinase II. In experiments with 32P-labeled hippocampal slices, the LTP induction in the CA1 region was associated with increases in autophosphorylation of both alpha and beta subunits of CaM kinase II 1 h after LTP induction. Significant increases in phosphorylation of endogenous CaM kinase II substrates, synapsin I and microtubule-associated protein 2 (MAP2), which are originally located in presynaptic and postsynaptic regions, respectively, were also observed in the same slice. All these changes were prevented when high frequency stimulation was applied in the presence of AP5 or a calmodulin antagonist, calmidazolium. Furthermore, in vitro phosphorylation of the AMPA receptor by CaM kinase II was reported in the postsynaptic density and infusion of the constitutively active CaM kinase II into the hippocampal neurons enhanced kainate-induced response. These results support the idea that CaM kinase II contributes to the induction of hippocampal LTP in both postsynaptic and presynaptic regions through phosphorylation of target proteins such as the AMPA receptor, MAP2 and synapsin I.
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Affiliation(s)
- K Fukunaga
- Department of Pharmacology, Kumamoto University School of Medicine, Japan
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16
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Murray KD, Gall CM, Benson DL, Jones EG, Isackson PJ. Decreased expression of the alpha subunit of Ca2+/ calmodulin-dependent protein kinase type II mRNA in the adult rat CNS following recurrent limbic seizures. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 1995; 32:221-32. [PMID: 7500833 DOI: 10.1016/0169-328x(95)00080-c] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Calcium/calmodulin-dependent protein kinase type II (CamKII) is a ubiquitous brain enzyme implicated in a wide variety of neuronal processes. Understanding CamKII has become increasingly complicated with the recent identification of multiple gene transcripts coding for separate subunits. Previous studies have shown that mRNA for the alpha subunit of CamKII can be increased by reduction of afferent input. In this study we have examined the regulation of alpha CamKII mRNA following increased activity due to seizures. Using in situ hybridization with a cRNA probe against the rat alpha CamKII sequence we found reduced levels of hybridization following limbic seizures induced by lesions of the hilus of the dentate gyrus. Hybridization was most dramatically reduced in the granule cells of the dentate gyrus and the pyramidal cells of hippocampal region CA1. There were also significant reductions in hybridization in the superficial layers of neocortex and piriform cortex. In each of these region hybridization was decreased in the molecular layers which is consistent with the reported dendritic localization of alpha CamKII mRNA. All changes in mRNA content were transient, with maximal reductions at 24 h following lesion placement and a return to control levels by 96 h. These findings demonstrate the negative regulation of alpha CamKII mRNA by seizure activity and raise the possibility that synthesis of this kinase may be regulated by normal physiological activity.
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Affiliation(s)
- K D Murray
- Department of Biochemistry and Molecular Biology, Mayo Clinic Jacksonville, FL, USA
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17
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Zhuo M, Hawkins RD. Long-term depression: a learning-related type of synaptic plasticity in the mammalian central nervous system. Rev Neurosci 1995; 6:259-77. [PMID: 8717637 DOI: 10.1515/revneuro.1995.6.3.259] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Studies of various forms of synaptic plasticity in the central nervous system have provided insights into the cellular and molecular mechanisms for certain types of learning and memory. Activity-induced decreases and increases in synaptic efficacy can be elicited in mammalian neurons. Long-term depression (LTD) and long-term potentiation (LTP) are two major forms of activity-dependent synaptic plasticity in the brain. LTD of excitatory synaptic transmission in the cerebellum in the most well studied form of synaptic depression. The induction of cerebellar LTD requires conjunctive activation of alpha-amino-3-hydroxy-5-methyl-4-isoxalepropionate (AMPA) receptors, metabotropic glutamate receptors (mGluRs) and L-type voltage-dependent Ca2+ channels. Several intracellular second messengers and protein kinases are critical for cerebellar LTD, including cGMP, cGMP-dependent protein kinase and protein kinase C (PKC). A novel intercellular messenger, nitric oxide (NO), is found in the cerebellum, is released durinng synaptic stimulation, and may contribute to cerebellar LTD. The expression of cerebellar LTD is mediated by postsynaptic desensitization of AMPA receptors. Recently, a form of homosynaptic LTD has been described in the CA1 region of the hippocampus. The induction of hippocampal LTD is postsynaptic. N-Methyl-D-aspartate receptors and mGluRs are important for induction of hippocampal LTD. Other intracellular and intercellular messengers, such as NO, cGMP and cAMP, might act downstream from glutamate receptors during hippocampal LTD. The expression of hippocampal LTD is likely to be in part presynaptic. While cerebellar LTD may be important for motor learning, the behavioral role of hippocampal LTD remains to be explored.
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Affiliation(s)
- M Zhuo
- Center for Neurobiology and Behavior, Columbia University, New York, New York, USA
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18
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Fukunaga K, Muller D, Miyamoto E. Increased phosphorylation of Ca2+/calmodulin-dependent protein kinase II and its endogenous substrates in the induction of long-term potentiation. J Biol Chem 1995; 270:6119-24. [PMID: 7890745 DOI: 10.1074/jbc.270.11.6119] [Citation(s) in RCA: 174] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Induction of long-term potentiation in the CA1 region of hippocampal slices is associated with increased activity of Ca2+/calmodulin-dependent protein kinase II (CaM kinase II) (Fukunaga, K., Stoppini, L., Miyamoto, E., and Muller, D. (1993) J. Biol. Chem. 268, 7863-7867). Here we report that application of high but not low frequency stimulation to two groups of afferents in the CA1 region of 32P-labeled slices resulted in the phosphorylation of two major substrates of this enzyme, synapsin I and microtubule-associated protein 2, as well as in the autophosphorylation of CaM kinase II. Furthermore, immunoblotting analysis revealed that long term potentiation induction was associated with an increase in the amount of CaM kinase II in the same region. All these changes were prevented when high frequency stimulation was applied in the presence of the N-methyl-D-aspartate receptor antagonist, D-2-amino-5-phosphonopentanoate. These results indicate that activation of CaM kinase II is involved in the induction of synaptic potentiation in both the postsynaptic and presynaptic regions.
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Affiliation(s)
- K Fukunaga
- Department of Pharmacology, Kumamoto University School of Medicine, Japan
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19
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Churn SB. Multifunctional calcium and calmodulin-dependent kinase II in neuronal function and disease. ADVANCES IN NEUROIMMUNOLOGY 1995; 5:241-59. [PMID: 8748069 DOI: 10.1016/0960-5428(95)00016-u] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- S B Churn
- Department of Neurology, Medical College of Virginia, Richmond 23298-0599, USA
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20
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Soderling TR. Calcium-dependent protein kinases in learning and memory. ADVANCES IN SECOND MESSENGER AND PHOSPHOPROTEIN RESEARCH 1995; 30:175-89. [PMID: 7695989 DOI: 10.1016/s1040-7952(05)80007-2] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- T R Soderling
- Vollum Institute, Oregon Health Sciences University, Portland 97201
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21
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Soderling TR, Tan SE, McGlade-McCulloh E, Yamamoto H, Fukunaga K. Excitatory interactions between glutamate receptors and protein kinases. JOURNAL OF NEUROBIOLOGY 1994; 25:304-11. [PMID: 7910847 DOI: 10.1002/neu.480250310] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
One of the most active areas of neurobiology research concerns mechanisms involved in paradigms of synaptic plasticity. A popular model for cellular learning and memory is long term potentiation (LTP) in hippocampus. LTP requires postsynaptic influx of Ca2+ which triggers multiple biochemical pathways resulting in pre- and postsynaptic mechanisms enhancing long term synaptic efficiency. This article focuses on an acute postsynaptic mechanism that can enhance responsiveness of glutamate receptors. Evidence is presented that calcium/calmodulin-dependent protein kinase II, the major postsynaptic density protein at excitatory glutaminergic synapses, can phosphorylate glutamate receptors and enhance ion current flowing through them.
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Affiliation(s)
- T R Soderling
- Vollum Institute, Oregon Health Sciences University, Portland 97201
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22
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Yano S, Fukunaga K, Ushio Y, Miyamoto E. Activation of Ca2+/calmodulin-dependent protein kinase II and phosphorylation of intermediate filament proteins by stimulation of glutamate receptors in cultured rat cortical astrocytes. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)37704-9] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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23
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Soderling TR. Calcium/calmodulin-dependent protein kinase II: role in learning and memory. Mol Cell Biochem 1993; 127-128:93-101. [PMID: 7935366 DOI: 10.1007/bf01076760] [Citation(s) in RCA: 60] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Numerous studies over the past decade have established a role(s) for protein phosphorylation in modulation of synaptic efficiency. This article reviews this data and focuses on putative functions of Ca2+/calmodulin-dependent protein kinase II (CaM-kinase II) which is highly concentrated at these synapses which utilize glutamate as the neurotransmitter. Evidence is presented that CaM-kinase II can phosphorylate these glutamate receptor/ion channels and enhance the ion current flowing through them. This may contribute to mechanisms of synaptic plasticity that are important in cellular paradigms of learning and memory such as long-term potentiation in the hippocampus.
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Affiliation(s)
- T R Soderling
- Vollum Institute, Oregon Health Sciences University, Portland 97201
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24
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McGlade-McCulloh E, Yamamoto H, Tan SE, Brickey DA, Soderling TR. Phosphorylation and regulation of glutamate receptors by calcium/calmodulin-dependent protein kinase II. Nature 1993; 362:640-2. [PMID: 8385275 DOI: 10.1038/362640a0] [Citation(s) in RCA: 365] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The major postsynaptic density (PSD) protein at glutaminergic synapses is calcium/calmodulin-dependent protein kinase II (CaM-K II), but its function in the PSD is not known. We have examined glutamate receptors (GluRs) as substrates for CaM-K II because (1) they are colocalized in the PSD, (2) cloned GluRs contain consensus phosphorylation sites for protein kinases including CaM-K II, and (3) several GluRs are regulated by other protein kinases. Regulation of GluRs, which are involved in excitatory synaptic transmission and in mechanisms of learning and memory, by CaM-K II is of interest because of the postulated role of CaM-K II in synaptic plasticity and its known involvement in induction of long-term potentiation. Furthermore, mice lacking the major neural isoform of CaM-K II exhibit deficits in models of learning and memory that require hippocampal input. We report here that CaM-K II phosphorylates GluR in several in vitro systems, including the PSD, and that activated CaM-K II enhances kainate-induced ion current three- to fourfold in cultured hippocampal neurons. These results are consistent with a role for PSD CaM-K II in strengthening postsynaptic GluR responses in synaptic plasticity.
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25
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Fukunaga K, Stoppini L, Miyamoto E, Muller D. Long-term potentiation is associated with an increased activity of Ca2+/calmodulin-dependent protein kinase II. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(18)53037-4] [Citation(s) in RCA: 294] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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26
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Colbran R. Inactivation of Ca2+/calmodulin-dependent protein kinase II by basal autophosphorylation. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(18)53160-4] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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27
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Goto S, Nagahiro S, Korematsu K, Ushio Y, Fukunaga K, Miyamoto E, Hofer W. Cellular colocalization of calcium/calmodulin-dependent protein kinase II and calcineurin in the rat cerebral cortex and hippocampus. Neurosci Lett 1993; 149:189-92. [PMID: 8386348 DOI: 10.1016/0304-3940(93)90768-g] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
An immunoperoxidase technique was used to locate multifunctional Ca2+/calmodulin-regulated protein phosphatase (calcineurin) and kinase (CaM-kinase II) in the rat cerebral cortex and hippocampus. Immunoreactivities for both enzymes were highly concentrated in the brain regions, where pyramidal-shaped neurons revealed strong immunoreactivities in their perikarya and dendrites. Serial thin section analysis using the polyethylene glycol embedding procedure disclosed that the cellular distribution of calcineurin immunolabelling in the cerebral cortex and hippocampus was similar to that of CaM-kinase II. The present findings suggest that the phosphatase and kinase may interact with each other in such neuronal subsets.
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Affiliation(s)
- S Goto
- Department of Neurosurgery, Kumamoto University Medical School, Japan
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28
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Dephosphorylation of autophosphorylated Ca2+/calmodulin-dependent protein kinase II by protein phosphatase 2C. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(18)54124-7] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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29
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Abstract
Ca2+/calmodulin-dependent protein kinase II (CaMKII) exhibits a broad substrate specificity and regulates diverse responses to physiological changes of intracellular Ca2+ concentrations. Five isozymic subunits of the highly abundant brain kinase are encoded by four distinct genes. Expression of each gene is tightly regulated in a cell-specific and developmental manner. CaMKII immunoreactivity is broadly distributed within neurons but is discretely associated with a number of subcellular structures. The unique regulatory properties of CaMKII have attracted a lot of attention. Ca2+/calmodulin-dependent autophosphorylation of a specific threonine residue (alpha-Thr286) within the autoinhibitory domain generates partially Ca(2+)-independent CaMKII activity. Phosphorylation of this threonine in CaMKII is modulated by changes in intracellular Ca2+ concentrations in a variety of cells, and may prolong physiological responses to transient increases in Ca2+. Additional residues within the calmodulin-binding domain are autophosphorylated in the presence of Ca2+ chelators and block activation by Ca2+/calmodulin. This Ca(2+)-independent autophosphorylation is very rapid following prior Ca2+/calmodulin-dependent autophosphorylation at alpha-Thr286 and generates constitutively active, Ca2+/calmodulin-insensitive CaMKII activity. Ca(2+)-independent autophosphorylation of CaMKII also occurs at a slower rate when alpha-Thr286 is not autophosphorylated and results in inactivation of CaMKII. Thus, Ca(2+)-independent autophosphorylation of CaMKII generates a form of the kinase that is refractory to activation by Ca2+/calmodulin. CaMKII phosphorylates a wide range of neuronal proteins in vitro, presumably reflecting its involvement in the regulation of diverse functions such as postsynaptic responses (e.g. long-term potentiation), neurotransmitter synthesis and exocytosis, cytoskeletal interactions and gene transcription. Recent evidence indicates that the levels of CaMKII are altered in pathological states such as Alzheimer's disease and also following ischemia.
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Affiliation(s)
- R J Colbran
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232-0615
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30
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Fukunaga K, Soderling T, Miyamoto E. Activation of Ca2+/calmodulin-dependent protein kinase II and protein kinase C by glutamate in cultured rat hippocampal neurons. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(18)41704-8] [Citation(s) in RCA: 121] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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31
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Abstract
Signal transduction in the nervous system is heavily dependent on the three multifunctional serine/threonine protein kinases, PKA, PKC, and CaM-KII. Recent studies have furthered our understanding of how the multiple isoforms of these kinases and their subcellular localizations, regulatory properties, and substrate determinants are important for the specificity of kinase functions.
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Affiliation(s)
- J D Scott
- Vollum Institute for Advanced Biomedical Research, Oregon Health Sciences University, Portland 97201
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32
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Morioka M, Fukunaga K, Yasugawa S, Nagahiro S, Ushio Y, Miyamoto E. Regional and temporal alterations in Ca2+/calmodulin-dependent protein kinase II and calcineurin in the hippocampus of rat brain after transient forebrain ischemia. J Neurochem 1992; 58:1798-809. [PMID: 1313854 DOI: 10.1111/j.1471-4159.1992.tb10056.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
We have investigated regional and temporal alterations in Ca2+/calmodulin-dependent protein kinase II (CaM kinase II) and calcineurin (Ca2+/calmodulin-dependent protein phosphatase) after transient forebrain ischemia. Immunoreactivity and enzyme activity of CaM kinase II decreased in regions CA1 and CA3, and in the dentate gyrus, of the hippocampus early (6-12 h) after ischemia, but the decrease in immunoreactivity gradually recovered over time, except in the CA1 region. Furthermore, the increase in Ca2+/calmodulin-independent activity was detected up to 3 days after ischemia in all regions tested, suggesting that the concentration of intracellular Ca2+ increased. In contrast to CaM kinase II, as immunohistochemistry and regional immunoblot analysis revealed, calcineurin was preserved in the CA1 region until 1.5 days and then lost with the increase in morphological degeneration of neurons. Immunoblot analysis confirmed the findings of the immunohistochemistry. These results suggest that there is a difference between CaM kinase II and calcineurin in regional and temporal loss after ischemia and that imbalance of Ca2+/calmodulin-dependent protein phosphorylation-dephosphorylation may occur.
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Affiliation(s)
- M Morioka
- Department of Neurosurgery, Kumamoto University Medical School, Japan
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33
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Yamamoto H, Fukunaga K, Lee K, Soderling TR. Ischemia-induced loss of brain calcium/calmodulin-dependent protein kinase II. J Neurochem 1992; 58:1110-7. [PMID: 1310719 DOI: 10.1111/j.1471-4159.1992.tb09369.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Forebrain ischemia in gerbils, produced by brief bilateral carotid occlusion, induced the dramatic loss of Ca2+/calmodulin-dependent protein kinase II (CaM-kinase II) as determined by both kinase activity assays and western blot analysis. In cortex and hippocampus, cytosolic CaM-kinase II was completely lost within 2-5 min of ischemia. Particulate CaM-kinase II was more stable and decreased in level approximately 40% after 10 min of ischemia followed by 2 h of reperfusion. CaM-kinase II in cerebellum, which does not become ischemic, was not affected. The rapid loss of CaM-kinase II within 2-5 min was quite specific because cytosolic cyclic AMP kinase and protein kinase C in hippocampus were not affected. These data indicate that cytosolic CaM-kinase II is one of the most rapidly degraded proteins after brief ischemia. Because the multifunctional CaM-kinase II has been implicated in the regulation of numerous neuronal functions, its loss may destine the neuronal cell for death.
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Affiliation(s)
- H Yamamoto
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee
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34
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Soderling TR, Fukunaga K, Brickey DA, Fong YL, Rich DP, Smith K, Colbran RJ. Molecular and cellular studies on brain calcium/calmodulin-dependent protein kinase II. PROGRESS IN BRAIN RESEARCH 1991; 89:169-83. [PMID: 1796140 DOI: 10.1016/s0079-6123(08)61722-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- T R Soderling
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232-0615
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