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Dalhäusser AK, Rössler OG, Thiel G. Regulation of c-Fos gene transcription by stimulus-responsive protein kinases. Gene 2022; 821:146284. [PMID: 35143939 DOI: 10.1016/j.gene.2022.146284] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 01/20/2022] [Accepted: 02/03/2022] [Indexed: 12/12/2022]
Abstract
The basic region leucin zipper (bZIP) protein c-Fos constitutes together with other bZIP proteins the AP-1 transcription factor complex. Expression of the c-Fos gene is regulated by numerous extracellular signaling molecules including mitogens, metabolites, and ligands for receptor tyrosine kinases, G protein-coupled receptors, and cytokine receptors. Here, we analyzed the effects of the stimulus-responsive MAP kinases ERK1/2 (extracellular signal-regulated protein kinase), JNK (c-Jun N-terminal protein kinase) and p38 protein kinase on transcription of the c-Fos gene. We used chromatin-integrated c-Fos promoter-luciferase reporter genes containing inactivating point mutations of DNA binding sites for distinct transcription factors. ERK1/2, JNK, and p38 protein kinases were specifically activated following expression of either a mutant of B-Raf, a truncated version of mitogen-activated/extracellular signal responsive kinase kinase kinase-1 (MEKK1), or a mutant of MAP kinase kinase-6 (MKK6), respectively. The results show that the DNA binding sites for serum response factor (SRF) and for the ternary complex factor (TCF) are of major importance for stimulating c-Fos promoter activity by MAP kinases. ERK1/2 and p38-induced stimulation of the c-Fos promoter additionally required the DNA binding site for the transcription factor AP-1. Mutation of the DNA binding site for STAT had no or only a small effect on c-Fos promoter activity. We conclude that MAP kinases do not activate distinct transcription factors involving distinct genetic elements. Rather, these kinases mainly target SRF and TCF proteins, leading to an activation of transcription of the c-Fos gene via the serum response element.
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Affiliation(s)
- Alisia K Dalhäusser
- Department of Medical Biochemistry and Molecular Biology, Saarland University Medical Faculty, D-66421 Homburg, Germany
| | - Oliver G Rössler
- Department of Medical Biochemistry and Molecular Biology, Saarland University Medical Faculty, D-66421 Homburg, Germany
| | - Gerald Thiel
- Department of Medical Biochemistry and Molecular Biology, Saarland University Medical Faculty, D-66421 Homburg, Germany.
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Little HJ. L-Type Calcium Channel Blockers: A Potential Novel Therapeutic Approach to Drug Dependence. Pharmacol Rev 2021; 73:127-154. [PMID: 34663686 DOI: 10.1124/pharmrev.120.000245] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This review describes interactions between compounds, primarily dihydropyridines, that block L-type calcium channels and drugs that cause dependence, and the potential importance of these interactions. The main dependence-inducing drugs covered are alcohol, psychostimulants, opioids, and nicotine. In preclinical studies, L-type calcium channel blockers prevent or reduce important components of dependence on these drugs, particularly their reinforcing actions and the withdrawal syndromes. The channel blockers also reduce the development of tolerance and/or sensitization, and they have no intrinsic dependence liability. In some instances, their effects include reversal of brain changes established during drug dependence. Prolonged treatment with alcohol, opioids, psychostimulant drugs, or nicotine causes upregulation of dihydropyridine binding sites. Few clinical studies have been carried out so far, and reports are conflicting, although there is some evidence of effectiveness of L-channel blockers in opioid withdrawal. However, the doses of L-type channel blockers used clinically so far have necessarily been limited by potential cardiovascular problems and may not have provided sufficient central levels of the drugs to affect neuronal dihydropyridine binding sites. New L-type calcium channel blocking compounds are being developed with more selective actions on subtypes of L-channel. The preclinical evidence suggests that L-type calcium channels may play a crucial role in the development of dependence to different types of drugs. Mechanisms for this are proposed, including changes in the activity of mesolimbic dopamine neurons, genomic effects, and alterations in synaptic plasticity. Newly developed, more selective L-type calcium channel blockers could be of considerable value in the treatment of drug dependence. SIGNIFICANCE STATEMENT: Dependence on drugs is a very serious health problem with little effective treatment. Preclinical evidence shows drugs that block particular calcium channels, the L-type, reduce dependence-related effects of alcohol, opioids, psychostimulants, and nicotine. Clinical studies have been restricted by potential cardiovascular side effects, but new, more selective L-channel blockers are becoming available. L-channel blockers have no intrinsic dependence liability, and laboratory evidence suggests they reverse previously developed effects of dependence-inducing drugs. They could provide a novel approach to addiction treatment.
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Affiliation(s)
- Hilary J Little
- Section of Alcohol Research, National Addiction Centre, Institute of Psychiatry, King's College, London, United Kingdom
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3
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Servili E, Trus M, Atlas D. Ion occupancy of the channel pore is critical for triggering excitation-transcription (ET) coupling. Cell Calcium 2019; 84:102102. [DOI: 10.1016/j.ceca.2019.102102] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 10/07/2019] [Accepted: 10/07/2019] [Indexed: 11/28/2022]
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Thiel G, Rössler OG. Resveratrol stimulates c-Fos gene transcription via activation of ERK1/2 involving multiple genetic elements. Gene 2018. [PMID: 29514046 DOI: 10.1016/j.gene.2018.03.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The polyphenol resveratrol is found in many plant and fruits and is a constituent of our diet. Resveratrol has been proposed to have chemopreventive and anti-inflammatory activities. On the cellular level, resveratrol activates stimulus-regulated transcription factors. To identify resveratrol-responsive elements within a natural gene promoter, the molecular pathway leading to c-Fos gene expression by resveratrol was dissected. The c-Fos gene encodes a basic region leucine zipper transcription factor and is a prototype of an immediate-early gene that is regulated by a wide range of signaling molecules. We analyzed chromatin-integrated c-Fos promoter-luciferase reporter genes where transcription factor binding sites were destroyed by point mutations or deletion mutagenesis. The results show that mutation of the binding sites for serum response factor (SRF), activator protein-1 (AP-1) and cAMP response element binding protein (CREB) significantly reduced reporter gene transcription following stimulation of the cells with resveratrol. Inactivation of the binding sites for signal transducer and activator of transcription (STAT) or ternary complex factors did not influence resveratrol-regulated c-Fos promoter activity. Thus, the c-Fos promoter contains three resveratrol-responsive elements, the cAMP response element (CRE), and the binding sites for SRF and AP-1. Moreover, we show that the transcriptional activation potential of the c-Fos protein is increased in resveratrol-stimulated cells, indicating that the biological activity of c-Fos is elevated by resveratrol stimulation. Pharmacological and genetic experiments revealed that the protein kinase ERK1/2 is the signal transducer that connects resveratrol treatment with the c-Fos gene.
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Affiliation(s)
- Gerald Thiel
- Department of Medical Biochemistry and Molecular Biology, Saarland University Medical Faculty, D-66421 Homburg, Germany.
| | - Oliver G Rössler
- Department of Medical Biochemistry and Molecular Biology, Saarland University Medical Faculty, D-66421 Homburg, Germany
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5
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Physiological and Pathological Roles of CaMKII-PP1 Signaling in the Brain. Int J Mol Sci 2017; 19:ijms19010020. [PMID: 29271887 PMCID: PMC5795971 DOI: 10.3390/ijms19010020] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Revised: 12/19/2017] [Accepted: 12/20/2017] [Indexed: 01/25/2023] Open
Abstract
Ca2+/calmodulin (CaM)-dependent protein kinase II (CaMKII), a multifunctional serine (Ser)/threonine (Thr) protein kinase, regulates diverse activities related to Ca2+-mediated neuronal plasticity in the brain, including synaptic activity and gene expression. Among its regulators, protein phosphatase-1 (PP1), a Ser/Thr phosphatase, appears to be critical in controlling CaMKII-dependent neuronal signaling. In postsynaptic densities (PSDs), CaMKII is required for hippocampal long-term potentiation (LTP), a cellular process correlated with learning and memory. In response to Ca2+ elevation during hippocampal LTP induction, CaMKIIα, an isoform that translocates from the cytosol to PSDs, is activated through autophosphorylation at Thr286, generating autonomous kinase activity and a prolonged Ca2+/CaM-bound state. Moreover, PP1 inhibition enhances Thr286 autophosphorylation of CaMKIIα during LTP induction. By contrast, CaMKII nuclear import is regulated by Ser332 phosphorylation state. CaMKIIδ3, a nuclear isoform, is dephosphorylated at Ser332 by PP1, promoting its nuclear translocation, where it regulates transcription. In this review, we summarize physio-pathological roles of CaMKII/PP1 signaling in neurons. CaMKII and PP1 crosstalk and regulation of gene expression is important for neuronal plasticity as well as survival and/or differentiation.
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Madabhushi R, Kim TK. Emerging themes in neuronal activity-dependent gene expression. Mol Cell Neurosci 2017; 87:27-34. [PMID: 29254824 DOI: 10.1016/j.mcn.2017.11.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Revised: 10/23/2017] [Accepted: 11/08/2017] [Indexed: 12/29/2022] Open
Abstract
In this review, we attempt to discuss emerging themes in the regulation of neuronal activity-regulated genes, focusing primarily on an important subset of immediate-early genes. We first discuss earlier studies that have illuminated the role of cis-acting elements within the promoters of immediate-early genes, the corresponding transcription factors that bind these elements, and the roles of major activity-regulated signaling pathways. However, our emphasis is on new studies that have revealed an important role for epigenetic and topological mechanisms, including enhancer-promoter interactions, enhancer RNAs (eRNAs), and activity-induced DNA breaks, that have emerged as important factors that govern the temporal dynamics of activity-induced gene transcription.
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Affiliation(s)
- Ram Madabhushi
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX, USA.
| | - Tae-Kyung Kim
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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Human native Ca v1 channels in chromaffin cells: contribution to exocytosis and firing of spontaneous action potentials. Eur J Pharmacol 2017; 796:115-121. [PMID: 27988286 DOI: 10.1016/j.ejphar.2016.12.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Revised: 12/02/2016] [Accepted: 12/05/2016] [Indexed: 01/31/2023]
Abstract
The present study was performed to evaluate the Cav1 channel subtypes expressed in human chromaffin cells and the role that these channels play in exocytosis and cell excitability. Here we show that human chromaffin cells obtained from organ donors express Cav1.2 and Cav1.3 subtypes using molecular and pharmacological techniques. Immunocytochemical data demonstrated the presence of Cav1.2 and Cav1.3 subtypes, but not Cav1.1 or Cav1.4. Electrophysiological experiments were conducted to investigate the contribution of Cav1 channels to the exocytotic process and cell excitability. Cav1 channels contribute to the exocytosis of secretory vesicles, evidenced by the block of 3μM nifedipine (36.5±2%) of membrane capacitance increment elicited by 200ms depolarizing pulses. These channels show a minor contribution to the initiation of spontaneous action potential firing, as shown by the 2.5 pA of current at the threshold potential (-34mV), which elicits 10.4mV of potential increment. In addition, we found that only 8% of human chromaffin cells exhibit spontaneous action potentials. These data offer novel information regarding human chromaffin cells and the role of human native Cav1 channels in exocytosis and cell excitability.
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Kuzniewska B, Nader K, Dabrowski M, Kaczmarek L, Kalita K. Adult Deletion of SRF Increases Epileptogenesis and Decreases Activity-Induced Gene Expression. Mol Neurobiol 2016; 53:1478-1493. [PMID: 25636686 PMCID: PMC4789231 DOI: 10.1007/s12035-014-9089-7] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Accepted: 12/29/2014] [Indexed: 11/27/2022]
Abstract
Although the transcription factor serum response factor (SRF) has been suggested to play a role in activity-dependent gene expression and mediate plasticity-associated structural changes in the hippocampus, no unequivocal evidence has been provided for its role in brain pathology, such as epilepsy. A genome-wide program of activity-induced genes that are regulated by SRF also remains unknown. In the present study, we show that the inducible and conditional deletion of SRF in the adult mouse hippocampus increases the epileptic phenotype in the kainic acid model of epilepsy, reflected by more severe and frequent seizures. Moreover, we observe a robust decrease in activity-induced gene transcription in SRF knockout mice. We characterize the genetic program controlled by SRF in neurons and using functional annotation, we find that SRF target genes are associated with synaptic plasticity and epilepsy. Several of these SRF targets function as regulators of inhibitory or excitatory balance and the structural plasticity of neurons. Interestingly, mutations in those SRF targets have found to be associated with such human neuropsychiatric disorders, as autism and intellectual disability. We also identify novel direct SRF targets in hippocampus: Npas4, Gadd45g, and Zfp36. Altogether, our data indicate that proteins that are highly upregulated by neuronal stimulation, identified in the present study as SRF targets, may function as endogenous protectors against overactivation. Thus, the lack of these effector proteins in SRF knockout animals may lead to uncontrolled excitation and eventually epilepsy.
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Affiliation(s)
- Bozena Kuzniewska
- Laboratory of Neurobiology, Nencki Institute, 3 Pasteur Street, Warsaw, Poland
| | - Karolina Nader
- Laboratory of Neurobiology, Nencki Institute, 3 Pasteur Street, Warsaw, Poland
| | - Michal Dabrowski
- Laboratory of Bioinformatics, Neurobiology Center, Nencki Institute, 3 Pasteur Street, Warsaw, Poland
| | - Leszek Kaczmarek
- Laboratory of Neurobiology, Nencki Institute, 3 Pasteur Street, Warsaw, Poland
| | - Katarzyna Kalita
- Laboratory of Neurobiology, Nencki Institute, 3 Pasteur Street, Warsaw, Poland.
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9
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Rubil S, Rössler OG, Thiel G. CREB, AP-1, ternary complex factors and MAP kinases connect transient receptor potential melastatin-3 (TRPM3) channel stimulation with increased c-Fos expression. Br J Pharmacol 2015; 173:305-18. [PMID: 26493679 DOI: 10.1111/bph.13372] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Revised: 10/08/2015] [Accepted: 10/14/2015] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND AND PURPOSE The rise in intracellular Ca(2+) stimulates the expression of the transcription factor c-Fos. Depending on the mode of entry of Ca(2+) into the cytosol, distinct signal transducers and transcription factors are required. Here, we have analysed the signalling pathway connecting a Ca(2+) influx via activation of transient receptor potential melastatin-3 (TRPM3) channels with enhanced c-Fos expression. EXPERIMENTAL APPROACH Transcription of c-Fos promoter/reporter genes that were integrated into the chromatin via lentiviral gene transfer was analysed in HEK293 cells overexpressing TRPM3. The transcriptional activation potential of c-Fos was measured using a GAL4-c-Fos fusion protein. KEY RESULTS The signalling pathway connecting TRPM3 stimulation with enhanced c-Fos expression requires the activation of MAP kinases. On the transcriptional level, three Ca(2+) -responsive elements, the cAMP-response element and the binding sites for the serum response factor (SRF) and AP-1, are essential for the TRPM3-mediated stimulation of the c-Fos promoter. Ternary complex factors are additionally involved in connecting TRPM3 stimulation with the up-regulation of c-Fos expression. Stimulation of TRPM3 channels also increases the transcriptional activation potential of c-Fos. CONCLUSIONS AND IMPLICATIONS Signalling molecules involved in connecting TRPM3 with the c-Fos gene are MAP kinases and the transcription factors CREB, SRF, AP-1 and ternary complex factors. As c-Fos constitutes, together with other basic region leucine zipper transcription factors, the AP-1 transcription factor complex, the results of this study explain TRPM3-induced activation of AP-1 and connects TRPM3 with the biological functions regulated by AP-1.
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Affiliation(s)
- Sandra Rubil
- Department of Medical Biochemistry and Molecular Biology, Medical Faculty, Saarland University, Homburg, Germany
| | - Oliver G Rössler
- Department of Medical Biochemistry and Molecular Biology, Medical Faculty, Saarland University, Homburg, Germany
| | - Gerald Thiel
- Department of Medical Biochemistry and Molecular Biology, Medical Faculty, Saarland University, Homburg, Germany
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10
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Joo JY, Schaukowitch K, Farbiak L, Kilaru G, Kim TK. Stimulus-specific combinatorial functionality of neuronal c-fos enhancers. Nat Neurosci 2015; 19:75-83. [PMID: 26595656 PMCID: PMC4696896 DOI: 10.1038/nn.4170] [Citation(s) in RCA: 164] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 10/09/2015] [Indexed: 12/16/2022]
Abstract
The c-fos gene is induced by a broad range of stimuli, and has been commonly used as a reliable marker for neural activity. Its induction mechanism and available reporter mouse lines are exclusively based on the c-fos promoter activity. Here, we demonstrate that multiple enhancers surrounding the c-fos gene are critical for ensuring robust c-fos response to various stimuli. Membrane depolarization, brain-derived neurotrophic factor (BDNF), and Forskolin activate distinct subsets of the enhancers to induce c-fos transcription in neurons, suggesting that stimulus-specific combinatorial activation of multiple enhancers underlies the broad inducibility of the c-fos gene. Accordingly, the functional requirement of key transcription factors varies depending on the type of stimulation. Combinatorial enhancer activation also occurs in the brain. Providing a comprehensive picture of the c-fos induction mechanism beyond the minimal promoter, our study should help in understanding the physiological nature of c-fos induction in relation to neural activity and plasticity.
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Affiliation(s)
- Jae-Yeol Joo
- Department of Neuroscience, The University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Katie Schaukowitch
- Department of Neuroscience, The University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Lukas Farbiak
- Department of Neuroscience, The University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Gokhul Kilaru
- Department of Neuroscience, The University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Tae-Kyung Kim
- Department of Neuroscience, The University of Texas Southwestern Medical Center, Dallas, Texas, USA
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11
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Shioda N, Sawai M, Ishizuka Y, Shirao T, Fukunaga K. Nuclear Translocation of Calcium/Calmodulin-dependent Protein Kinase IIδ3 Promoted by Protein Phosphatase-1 Enhances Brain-derived Neurotrophic Factor Expression in Dopaminergic Neurons. J Biol Chem 2015; 290:21663-75. [PMID: 26163515 DOI: 10.1074/jbc.m115.664920] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Indexed: 02/05/2023] Open
Abstract
We have reported previously that dopamine D2 receptor stimulation activates calcium/calmodulin-dependent protein kinase II (CaMKII) δ3, a CaMKII nuclear isoform, increasing BDNF gene expression. However, the mechanisms underlying that activity remained unclear. Here we report that CaMKIIδ3 is dephosphorylated at Ser(332) by protein phosphatase 1 (PP1), promoting CaMKIIδ3 nuclear translocation. Neuro-2a cells transfected with CaMKIIδ3 showed cytoplasmic and nuclear staining, but the staining was predominantly nuclear when CaMKIIδ3 was coexpressed with PP1. Indeed, PP1 and CaMKIIδ3 coexpression significantly increased nuclear CaMKII activity and enhanced BDNF expression. In support of this idea, chronic administration of the dopamine D2 receptor partial agonist aripiprazole increased PP1 activity and promoted nuclear CaMKIIδ3 translocation and BDNF expression in the rat brain substantia nigra. Moreover, aripiprazole treatment enhanced neurite extension and inhibited cell death in cultured dopaminergic neurons, effects blocked by PP1γ knockdown. Taken together, nuclear translocation of CaMKIIδ3 following dephosphorylation at Ser(332) by PP1 likely accounts for BDNF expression and subsequent neurite extension and survival of dopaminergic neurons.
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Affiliation(s)
- Norifumi Shioda
- From the Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, 980-8578, Japan and
| | - Masahiro Sawai
- From the Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, 980-8578, Japan and
| | - Yuta Ishizuka
- the Department of Neurobiology and Behavior, Gunma University Graduate School of Medicine, Maebashi 371-8511, Japan
| | - Tomoaki Shirao
- the Department of Neurobiology and Behavior, Gunma University Graduate School of Medicine, Maebashi 371-8511, Japan
| | - Kohji Fukunaga
- From the Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, 980-8578, Japan and
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12
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Shin S, Kwon O, Kang JI, Kwon S, Oh S, Choi J, Kim CH, Kim DG. mGluR5 in the nucleus accumbens is critical for promoting resilience to chronic stress. Nat Neurosci 2015; 18:1017-24. [PMID: 26005851 DOI: 10.1038/nn.4028] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2015] [Accepted: 04/29/2015] [Indexed: 12/12/2022]
Abstract
Resilience to aversive events has a central role in determining whether stress leads to the development of depression. mGluR5 has been implicated in the pathophysiology of depression, but the effect of mGluR5 activity on stress resilience remains unexplored. We found that mGluR5(-/-) (also known as Grm5(-/-)) mice displayed more depression-like behaviors (for example, learned helplessness, social withdrawal and anhedonia) than control mice following exposure to various stressful stimuli. Lentiviral 'rescue' of mGluR5 in the nucleus accumbens (NAc) decreased these depression-like behaviors in mGluR5(-/-) mice. In the NAc, ΔFosB, whose induction promotes stress resilience, failed to be upregulated by stress in mGluR5(-/-) mice. Notably, targeted pharmacological activation of mGluR5 in the NAc increased ΔFosB expression. Our findings point to an essential role for mGluR5 in promoting stress resilience and suggest that a defect in mGluR5-mediated signaling in the NAc may represent an endophenotype for stress-induced depression.
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Affiliation(s)
- Sora Shin
- Department of Pharmacology, BK21 PLUS Project for Medical Science, Brain Research Institute, Yonsei University College of Medicine, Seoul, Korea
| | - Obin Kwon
- Department of Pharmacology, BK21 PLUS Project for Medical Science, Brain Research Institute, Yonsei University College of Medicine, Seoul, Korea
| | - Jee In Kang
- Department of Psychiatry and Institute of Behavioral Science in Medicine, Yonsei University College of Medicine, Seoul, Korea
| | - Somin Kwon
- Department of Pharmacology, BK21 PLUS Project for Medical Science, Brain Research Institute, Yonsei University College of Medicine, Seoul, Korea
| | - Sora Oh
- 1] Department of Pharmacology, BK21 PLUS Project for Medical Science, Brain Research Institute, Yonsei University College of Medicine, Seoul, Korea. [2] Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul, Korea
| | - Jiwon Choi
- Department of Bioindustrial Technologies, College of Animal Bioscience and Technology, Konkuk University, Seoul, Korea
| | - Chul Hoon Kim
- 1] Department of Pharmacology, BK21 PLUS Project for Medical Science, Brain Research Institute, Yonsei University College of Medicine, Seoul, Korea. [2] Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul, Korea
| | - Dong Goo Kim
- Department of Pharmacology, BK21 PLUS Project for Medical Science, Brain Research Institute, Yonsei University College of Medicine, Seoul, Korea
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Endoh T, Nobushima H, Tazaki M. Neuropeptide Y modulates calcium channels in hamster submandibular ganglion neurons. Neurosci Res 2012; 73:275-81. [PMID: 22613697 DOI: 10.1016/j.neures.2012.05.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Revised: 05/02/2012] [Accepted: 05/02/2012] [Indexed: 11/28/2022]
Abstract
It is established that neuropeptide Y (NPY) is a transmitter of parasympathetic secretory impulses in submandibular gland. The neuropeptides substance P, vasoactive intestinal peptide (VIP) and calcitonin gene-related peptide (CGRP) are likely mediators of secretory parasympathetic responses of the gland. Previously, we have shown that substance P, VIP and CGRP modulate voltage-dependent Ca(2+) channels (VDCCs) in hamster submandibular ganglion (SMG) neurons. In this study, we attempt to characterize the effect of NPY on VDCCs current using Ba(2+) (I(Ba)) in SMG neurons. Application of NPY caused both facilitation and inhibition of L-type and N/P/Q-type I(Ba), respectively. Intracellular dialysis of the Gα(s)-protein antibody attenuated the NPY-induced facilitation of I(Ba). The adenylate cyclase (AC) inhibitor, as well as protein kinase A (PKA) inhibitor attenuated the NPY-induced facilitation of I(Ba). Intracellular dialysis of the Gα(i)-protein antibody attenuated the NPY-induced inhibition of I(Ba). Application of a strong depolarizing voltage prepulse attenuated the NPY-induced inhibition of I(Ba). These results indicate that NPY facilitates L-type VDCCs via Gα(s)-protein involving AC and PKA. On the other hand, NPY also inhibits N/P/Q-type VDCCs via Gα(i)-protein βγ subunits in the SMG neurons.
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Affiliation(s)
- Takayuki Endoh
- Department of Physiology, Tokyo Dental College, 1-2-2 Masago, Mihama-ku, Chiba 261-8502, Japan.
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14
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Templeton DM, Liu Y. Multiple roles of cadmium in cell death and survival. Chem Biol Interact 2010; 188:267-75. [DOI: 10.1016/j.cbi.2010.03.040] [Citation(s) in RCA: 208] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2010] [Revised: 03/22/2010] [Accepted: 03/22/2010] [Indexed: 12/01/2022]
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15
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Knöll B, Nordheim A. Functional versatility of transcription factors in the nervous system: the SRF paradigm. Trends Neurosci 2009; 32:432-42. [PMID: 19643506 DOI: 10.1016/j.tins.2009.05.004] [Citation(s) in RCA: 116] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2009] [Revised: 05/18/2009] [Accepted: 05/18/2009] [Indexed: 12/23/2022]
Abstract
Individual transcription factors in the brain frequently display broad functional versatility, thereby controlling multiple cellular outputs. In accordance, neuron-restricted mutagenesis of the murine Srf gene, encoding the transcription factor serum response factor (SRF), revealed numerous SRF functions in the nervous system. First, SRF controls immediate early gene (IEG) activation associated with perception of synaptic activity, learning and memory. Second, processes linked to actin cytoskeletal dynamics are mediated by SRF, such as developmental neuronal migration, outgrowth and pathfinding of neurites, as well as synaptic targeting. Therefore, SRF seems to be instrumental in converting synaptic activity into plasticity-associated structural changes in neuronal connectivities. This highlights the decisive role of SRF in integrating cytoskeletal actin dynamics and nuclear gene expression. Finally, we relate SRF to the multi-functional transcription factor CREB and point out overlapping, distinct and concerted functions of these two transcriptional regulators in the brain.
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Affiliation(s)
- Bernd Knöll
- Neuronal Gene Expression Laboratory, Eberhard-Karls-University Tübingen, Interfaculty Institute for Cell Biology, Department of Molecular Biology, Auf der Morgenstelle 15, 72076 Tübingen, Germany.
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Abstract
The activator protein 1 (AP-1) transcription factor c-Jun is crucial for neuronal apoptosis. However, c-Jun dimerization partners and the regulation of these proteins in neuronal apoptosis remain unknown. Here we report that c-Jun-mediated neuronal apoptosis requires the concomitant activation of activating transcription factor-2 (ATF2) and downregulation of c-Fos. Furthermore, we have observed that c-Jun predominantly heterodimerizes with ATF2 and that the c-Jun/ATF2 complex promotes apoptosis by triggering ATF activity. Inhibition of c-Jun/ATF2 heterodimerization using dominant negative mutants, small hairpin RNAs, or decoy oligonucleotides was able to rescue neurons from apoptosis, whereas constitutively active ATF2 and c-Jun mutants were found to synergistically stimulate apoptosis. Bimolecular fluorescence complementation analysis confirmed that, in living neurons, c-Fos downregulation facilitates c-Jun/ATF2 heterodimerization. A chromatin immunoprecipitation assay also revealed that c-Fos expression prevents the binding of c-Jun/ATF2 heterodimers to conserved ATF sites. Moreover, the presence of c-Fos is able to suppress the expression of c-Jun/ATF2-mediated target genes and, therefore, apoptosis. Taken together, our findings provide evidence that potassium deprivation-induced neuronal apoptosis is mediated by concurrent upregulation of c-Jun/ATF2 heterodimerization and downregulation of c-Fos expression. This paradigm demonstrates opposing roles for ATF2 and c-Fos in c-Jun-mediated neuronal apoptosis.
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Barbado M, Fablet K, Ronjat M, De Waard M. Gene regulation by voltage-dependent calcium channels. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2009; 1793:1096-104. [PMID: 19250948 DOI: 10.1016/j.bbamcr.2009.02.004] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2008] [Revised: 02/13/2009] [Accepted: 02/16/2009] [Indexed: 12/11/2022]
Abstract
Ca2+ is the most widely used second messenger in cell biology and fulfills a plethora of essential cell functions. One of the most exciting findings of the last decades was the involvement of Ca2+ in the regulation of long-term cell adaptation through its ability to control gene expression. This finding provided a link between cell excitation and gene expression. In this review, we chose to focus on the role of voltage-dependent calcium channels in mediating gene expression in response to membrane depolarization. We illustrate the different pathways by which these channels are involved in excitation-transcription coupling, including the most recent Ca2+ ion-independent strategies that highlight the transcription factor role of calcium channels.
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Affiliation(s)
- Maud Barbado
- Grenoble Institute of Neuroscience, Inserm U 836-Team 3 Calcium Channels, Functions and Pathologies, Bâtiment Edmond Safra, Université Joseph Fourier, Site santé de la Tronche, BP 170, 38042 Grenoble cedex 9, France
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18
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Downregulation of SRF-FOS-JUNB pathway in fumarate hydratase deficiency and in uterine leiomyomas. Oncogene 2009; 28:1261-73. [PMID: 19151755 DOI: 10.1038/onc.2008.472] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Defects of metabolic enzymes result in a variety of manifestations not logically explained by the primary metabolic function. Dominant defects of fumarate hydratase (FH) result in predisposition to cutaneous and uterine leiomyomas, and renal cell cancer. FH is a metabolic enzyme of the tricarboxylic acid cycle, and its tumor-suppressor mechanism is not fully understood. We compared the consequences of FH deficiency and respiratory chain (RC) deficiency using global expression pattern of diploid primary fibroblasts. This approach utilized the information that RC defects do not seem to predispose to tumorigenesis, and the aim was to identify FH-specific signaling effects that might have relevance to tumor formation. These results were then compared to global expression patterns of FH-deficient and sporadic uterine leiomyoma data sets. We show here that FH-deficient fibroblasts share a common transcriptional fingerprint with FH-deficient and sporadic leiomyomas, highlighting the downregulation of serum response factor (SRF)-regulated transcripts, particularly the FOS-JUNB pathway. We confirmed the downregulation of this pathway at transcriptional and protein level. SRF has a fundamental function in the differentiation of smooth muscle progenitor cells, and its downregulation both in diploid FH-deficient primary fibroblasts and in leiomyomas suggests an early function in the mechanism of uterine leiomyoma formation in FH deficiency. Concordantly, the phosphorylated form of SRF, known to activate transcription, is undetectable in leiomyomas whereas clearly detected in several nuclei in the differentiated myometrium. A similar transcriptional SRF-pathway fingerprint in FH-deficient and sporadic leiomyomas emphasizes the potential importance of this pathway in primary events leading to leiomyomatosis.
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Brooks S, Croft A, Norman G, Shaw S, Little H. Nimodipine prior to alcohol withdrawal prevents memory deficits during the abstinence phase. Neuroscience 2008; 157:376-84. [DOI: 10.1016/j.neuroscience.2008.09.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2008] [Revised: 08/20/2008] [Accepted: 09/04/2008] [Indexed: 10/21/2022]
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20
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Flavell SW, Greenberg ME. Signaling mechanisms linking neuronal activity to gene expression and plasticity of the nervous system. Annu Rev Neurosci 2008; 31:563-90. [PMID: 18558867 DOI: 10.1146/annurev.neuro.31.060407.125631] [Citation(s) in RCA: 625] [Impact Index Per Article: 39.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Sensory experience and the resulting synaptic activity within the brain are critical for the proper development of neural circuits. Experience-driven synaptic activity causes membrane depolarization and calcium influx into select neurons within a neural circuit, which in turn trigger a wide variety of cellular changes that alter the synaptic connectivity within the neural circuit. One way in which calcium influx leads to the remodeling of synapses made by neurons is through the activation of new gene transcription. Recent studies have identified many of the signaling pathways that link neuronal activity to transcription, revealing both the transcription factors that mediate this process and the neuronal activity-regulated genes. These studies indicate that neuronal activity regulates a complex program of gene expression involved in many aspects of neuronal development, including dendritic branching, synapse maturation, and synapse elimination. Genetic mutations in several key regulators of activity-dependent transcription give rise to neurological disorders in humans, suggesting that future studies of this gene expression program will likely provide insight into the mechanisms by which the disruption of proper synapse development can give rise to a variety of neurological disorders.
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Affiliation(s)
- Steven W Flavell
- F.M. Kirby Neurobiology Center, Children's Hospital Boston, and Departments of Neurology and Neurobiology, Harvard Medical School, Boston, Massachusetts 02115, USA.
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21
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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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22
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Lee J, Rushlow WJ, Rajakumar N. L-type calcium channel blockade on haloperidol-induced c-Fos expression in the striatum. Neuroscience 2007; 149:602-16. [PMID: 17913375 DOI: 10.1016/j.neuroscience.2007.08.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2006] [Revised: 08/01/2007] [Accepted: 09/05/2007] [Indexed: 11/19/2022]
Abstract
Haloperidol-induced c-Fos expression in the lateral part of the neostriatum has been correlated with motor side effects while c-Fos induction in the medial part of the neostriatum and the nucleus accumbens is thought to be associated with the therapeutic effects of the drug. Induction of c-Fos in the striatum by haloperidol involves dopamine D(2) (DA D(2)) receptor antagonism and is dependent on activation of N-methyl-d-aspartate (NMDA) receptors and L-type Ca(2+) channels. In the current study, pretreatment with L-type Ca(2+) channel blockers suppressed haloperidol-induced c-Fos throughout the neostriatum and the nucleus accumbens at 2 h postinjection. However, elevated c-Fos protein expression was observed only in the lateral part of the neostriatum at 5 h postinjection of haloperidol following pretreatment of L-type Ca(2+) channel blocker compared with rats pretreated with vehicle alone. In addition, pretreatment prolonged the duration of haloperidol-induced catalepsy in rats. Infusions of L-type Ca(2+) channel blockers directly into the neostriatum mimicked similar patterns of changes in haloperidol-induced c-Fos expression. Prolonged expression of c-Fos was not observed following coadministration of nifedipine and a dopamine D(1) (DA D(1)) receptor agonist, SKF 81297, but could be mimicked by the DA D(2/3) receptor antagonist raclopride, suggesting that the phenomenon is likely related to DA D(2) receptor antagonism. Moreover, the expression levels of haloperidol-induced zif 268 and haloperidol-induced phosphorylated CREB and phosphorylated Elk-1 were also substantially elevated for a prolonged period of time in the lateral, but not the medial part of the neostriatum, following blockade of L-type Ca(2+) channels. Collectively, the results suggest that coadministration of L-type Ca(2+) channel blockers affects haloperidol signaling in the lateral part of the neostriatum and may exacerbate the development of acute motor side effects.
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Affiliation(s)
- J Lee
- Department of Anatomy & Cell Biology, University of Western Ontario, London, Ontario N6A 5C1, Canada
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23
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Bal R, Oertel D. Voltage-activated calcium currents in octopus cells of the mouse cochlear nucleus. J Assoc Res Otolaryngol 2007; 8:509-21. [PMID: 17710492 PMCID: PMC2538346 DOI: 10.1007/s10162-007-0091-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2007] [Accepted: 06/28/2007] [Indexed: 12/22/2022] Open
Abstract
Octopus cells, neurons in the most posterior and dorsal part of the mammalian ventral cochlear nucleus, convey the timing of synchronous firing of auditory nerve fibers to targets in the contralateral superior paraolivary nucleus and ventral nucleus of the lateral lemniscus. The low input resistances and short time constants at rest that arise from the partial activation of a large, low-voltage-activated K(+) conductance (g(KL)) and a large mixed-cation, hyperpolarization-activated conductance (g(h)) enable octopus cells to detect coincident firing of auditory nerve fibers with exceptional temporal precision. Octopus cells fire conventional, Na(+) action potentials but a voltage-sensitive Ca(2+) conductance was also detected. In this study, we explore the nature of that calcium conductance under voltage-clamp. Currents, carried by Ca(2+) or Ba(2+) and blocked by 0.4 mM Cd(2+), were activated by depolarizations positive to -50 mV and peaked at -23 mV. At -23 mV they reached 1.1 +/- 0.1 nA in the presence of 5 mM Ca(2+) and 1.6 +/- 0.1 nA in 5 mM Ba(2+). Ten micromolar BAY K 8644, an agonist of high-voltage-activated L-type channels, enhanced I(Ba) by 63 +/- 11% (n = 8) and 150 microM nifedipine, an antagonist of L-type channels, reduced the I(Ba) by 65 +/- 5% (n = 5). Meanwhile, 0.5 microM omega-Agatoxin IVA, an antagonist of P/Q-type channels, or 1 microM omega-conotoxin GVIA, an antagonist of N-type channels, suppressed I(Ba) by 15 +/- 4% (n = 5) and 9 +/- 4% (n = 5), respectively. On average 16% of the current remained in the presence of the cocktail of blockers, indicative of the presence of R-type channels. Together these experiments show that octopus cells have a depolarization-sensitive g(Ca) that is largely formed from L-type Ca(2+) channels and that P/Q-, N-, and R-type channels are expressed at lower levels in octopus cells.
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Affiliation(s)
- Ramazan Bal
- Department of Biophysics, Faculty of Medicine, Firat University, 23119 Elazig, Turkey
| | - Donata Oertel
- Department of Physiology, University of Wisconsin Medical School, 1300 University Avenue, Madison, WI 53706 USA
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24
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Liu Y, Templeton DM. Cadmium activates CaMK-II and initiates CaMK-II-dependent apoptosis in mesangial cells. FEBS Lett 2007; 581:1481-6. [PMID: 17367784 DOI: 10.1016/j.febslet.2007.03.003] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2007] [Accepted: 03/01/2007] [Indexed: 10/23/2022]
Abstract
Cadmium is a toxic metal that initiates both mitogenic responses and cell death. We show that Cd(2+) increases phosphorylation and activity of Ca(2+)/calmodulin-dependent protein kinase II (CaMK-II) in mesangial cells, in a concentration-dependent manner. Activation is biphasic with peaks at 1-5 min and 4-6 h. Cadmium also activates Erk, but this appears to be independent of CaMK-II. At 10-20 microM, Cd(2+) initiates apoptosis in 25-55% of mesangial cells by 6h. Inhibition of CaMK-II, but not of Erk, suppresses Cd(2+)-induced apoptosis. We conclude that activation of CaMK-II by Cd(2+) contributes to apoptotic cell death, independent of Erk activation.
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Affiliation(s)
- Ying Liu
- University of Toronto, Laboratory Medicine and Pathobiology, 1 King's College Circle, Toronto, Ont., Canada M5S 1A8
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25
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Major ML, Cheung HS, Misra RP. Basic calcium phosphate crystals activate c-fos expression through a Ras/ERK dependent signaling mechanism. Biochem Biophys Res Commun 2007; 355:654-60. [PMID: 17307136 PMCID: PMC1855205 DOI: 10.1016/j.bbrc.2007.01.177] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2007] [Accepted: 01/31/2007] [Indexed: 10/23/2022]
Abstract
Diseases caused by calcium pyrophosphate dihydrate (CPPD) and basic calcium phosphate (BCP) crystals occur frequently in osteoarthritic joints. Both crystals induce mitogenesis, metalloproteinase synthesis and secretion by fibroblasts and chondrocytes, promoting degradation of articular tissue. We investigated the mechanism by which BCP activates the c-fos proto-oncogene, which has been shown to activate various matrix metalloproteinases (MMPs). We demonstrate that BCP crystals induce c-fos expression primarily through a Ras/ERK-dependent signaling mechanism targeting two highly conserved regulatory binding sites, the serum response element (SRE) and the cAMP response element (CRE). These results establish a calcium crystal induced, calcium/calmodulin independent, signaling pathway in which BCP crystals activate Ras/MAPK, which can directly target an SRF-containing transcription factor complex, to induce fibroblasts to secrete metalloproteinases.
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Affiliation(s)
| | - Herman S. Cheung
- Geriatric Research Education and Clinical Center, VA Medical Center and Department of Medicine, University of Miami School of Medicine, Miami, FL 33101
| | - Ravi P. Misra
- *To whom correspondence should be addressed: Tel. # 414-456-8433, Fax # 414-456-6510, Internet:
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26
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27
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Ang ESM, Zhang P, Steer JH, Tan JWY, Yip K, Zheng MH, Joyce DA, Xu J. Calcium/calmodulin-dependent kinase activity is required for efficient induction of osteoclast differentiation and bone resorption by receptor activator of nuclear factor kappa B ligand (RANKL). J Cell Physiol 2007; 212:787-95. [PMID: 17477372 DOI: 10.1002/jcp.21076] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Calcium/calmodulin-dependent protein kinase (CaMK) is a major down stream mediator of Ca(2+) signaling in a wide range of cellular functions, including ion channel and cell cycle regulation and neurotransmitter synthesis and release. Here we have investigated the role of the CaMK signaling pathway in osteoclast differentiation and bone resorption. We observed that the CaMKI, CaMKII gamma isoforms were present in both bone-marrow derived macrophages and RAW264.7 murine macrophage cell line, and that expression persisted during osteoclast differentiation in the presence of receptor activator of nuclear factor kappa B (NF-kappaB) ligand (RANKL). RANKL-induced differentiation was accompanied by increased cyclic AMP response element transcriptional activity, and ERK phosphorylation, which are both downstream targets of CaMK. Two selective inhibitors of CaMKs, KN-93 and KN-62, inhibited osteoclastogenesis in a time and concentration-dependent manner. This was accompanied by suppression of cathepsin K expression and osteoclastic bone resorption, which are markers for differentiated osteoclast function. KN-93 and KN-62 both inhibited RANKL-induced ERK phosphorylation and CREB transcriptional activity. These findings imply a role for CaMK in osteoclast differentiation and bone resorption.
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Affiliation(s)
- Estabelle S M Ang
- Molecular Orthopedic Laboratory, School of Surgery and Pathology, University of Western Australia, Nedlands, WA, Australia
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28
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Li B, Dedman JR, Kaetzel MA. Nuclear Ca2+/calmodulin-dependent protein kinase II in the murine heart. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2006; 1763:1275-81. [PMID: 17069901 DOI: 10.1016/j.bbamcr.2006.09.029] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2006] [Revised: 09/20/2006] [Accepted: 09/21/2006] [Indexed: 11/19/2022]
Abstract
Ca(2+) signaling through CaMKII is critical in regulating myocyte function with regard to excitation-contraction-relaxation cycles and excitation-transcription coupling. To investigate the role of nuclear CaMKII in cardiac function, transgenic mice were designed and generated to target the expression of a CaMKII inhibitory peptide, AIP (KKALRRQEAVDAL), to the nucleus. The transgenic construct consists of the murine alpha-myosin heavy chain promoter followed by the expression unit containing nucleotides encoding a four repeat concatemer of AIP (AIP(4)) and a nuclear localization signal (NLS). Western blot and immunohistochemical analyses demonstrate that AIP(4) is expressed only in the nucleus of cardiac myocytes of the transgenic mice (NLS-AIP(4)). The function of cytoplasmic CaMKII is not affected by the expression of AIP(4) in the nucleus. Inhibition of nuclear CaMKII activity resulted in reduced translocation of HDAC5 from nucleus to cytoplasm in NLS-AIP(4) mouse hearts. Loss of nuclear CaMKII activity causes NLS-AIP(4) mice to have smaller hearts than their nontransgenic littermates. Transcription factors including CREB and NFkappaB are not regulated by cardiac nuclear CaMKII. With physiological stresses such as pregnancy or aging (8 months), NLS-AIP(4) mice develop hypertrophy symptoms including enlarged atria, systemic edema, sedentariness, and morbidity. RT-PCR analyses revealed that the hypertrophic marker genes, such as ANF and beta-myosin heavy chain, were upregulated in pregnancy stressed mice. Our results suggest that absence of adequate Ca2+signaling through nuclear CaMKII regulated pathways leads to development of cardiac disease.
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Affiliation(s)
- Bailing Li
- Department of Genome Science, University of Cincinnati, Genome Research Institute, 2180 E. Galbraith Rd., Cincinnati, OH 45237-0505, USA
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29
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Wang ZJ, Wang LX. Phosphorylation: A molecular switch in opioid tolerance. Life Sci 2006; 79:1681-91. [PMID: 16831450 DOI: 10.1016/j.lfs.2006.05.023] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2005] [Revised: 04/26/2006] [Accepted: 05/24/2006] [Indexed: 02/07/2023]
Abstract
Protein phosphorylation is a key posttranslational modification mechanism controlling the conformation and activity of many proteins. Increasing evidence has implicated an essential role of phosphorylation by several major protein kinases in promoting and maintaining opioid tolerance. We review some of the most recent studies on protein kinase C (PKC), cyclic AMP dependent protein kinase A (PKA), calcium/calmodulin-dependent protein kinase II (CaMKII), protein kinase G (PKG), and G protein receptor kinase (GRK). These kinases act as the molecular switches to modulate opioid tolerance. Pharmacological interventions at one or more of the protein kinases and phosphatases may provide valuable strategies to improve opioid analgesia by attenuating tolerance to these drugs.
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Affiliation(s)
- Zaijie Jim Wang
- Department of Biopharmaceutical Sciences and Cancer Center, University of Illinois, Chicago, IL 60612, USA.
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Gao L, Blair LAC, Marshall J. CaMKII-independent effects of KN93 and its inactive analog KN92: Reversible inhibition of L-type calcium channels. Biochem Biophys Res Commun 2006; 345:1606-10. [PMID: 16730662 DOI: 10.1016/j.bbrc.2006.05.066] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2006] [Accepted: 05/11/2006] [Indexed: 10/24/2022]
Abstract
Widely regarded as a specific and potent inhibitor of CaM kinases, especially CaMKII, KN93 has long been used to investigate the possible roles of CaMKII in a wide range of biological functions and systems, such as cultured cells, primary neurons, and brain slices. However, here we present evidence showing that KN93 and its structural analog KN92, which does not inhibit CaMKII, exert an unexpected, reversible, and specific reduction of currents of L-type calcium channels (CaV1.3 and CaV1.2), as compared to N-type calcium channels (CaV2.2). This effect is dependent not only on incubation time, but also on the dose of KN93 or KN92. Moreover, the effect appears to be independent of endocytosis, exocytosis, and proteasome activity. Washout and return to normal media rescues the L channel currents. Conversely, the structurally unrelated CaMKII inhibitor, AIP, fails to mimic the KN93/KN92 effect on L channel currents. Together, our data suggest that, in addition to inhibiting CaMKII, KN93 also affects CaV1.3 and CaV1.2 calcium channels in a CaMKII-independent manner.
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Affiliation(s)
- Lei Gao
- Department of Molecular Pharmacology, Physiology and Biotechnology, Brown University, Providence, RI 02912, USA
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31
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O'Leary H, Sui X, Lin PJ, Volpe P, Bayer KU. Nuclear targeting of the CaMKII anchoring protein αKAP is regulated by alternative splicing and protein kinases. Brain Res 2006; 1086:17-26. [PMID: 16616897 DOI: 10.1016/j.brainres.2006.02.120] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2005] [Revised: 02/14/2006] [Accepted: 02/26/2006] [Indexed: 11/22/2022]
Abstract
alphaKAP is an anchoring protein for the Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) and is encoded within the same gene as the CaMKIIalpha isoform. alphaKAP co-assembles with CaMKII and targets such heteromers to the membrane of the sarcoplasmic reticulum, where CaMKII can regulate Ca(2+) homeostasis. CaMKII has also nuclear functions in skeletal muscle, however, the nuclear targeting mechanism has been elusive. We show here that developmentally regulated splicing of exon Ealpha(B) generates a functional nuclear localization signal (NLS) in alphaKAP(B), the dominant alphaKAP variant in mature muscle. The alphaKAP(A) variant lacks the NLS and dominates in developing muscle before and around birth. Both alphaKAP variants localize to membranes, but a small fraction of alphaKAP(B) is additionally found in the nucleus. Indeed, alpha-karyopherins that mediate nuclear import bound to alphaKAP(B) but not alphaKAP(A) in vitro. When the N-terminal membrane anchor of alphaKAP was deleted, localization of alphaKAP(B) but not alphaKAP(A) became predominantly nuclear. Co-expression of constitutively active CaMKI and IV, which do not bind to alphaKAP, interfered with nuclear localization of alphaKAP(B). CaMKIIalpha was found essentially exclusively in the cytoplasm when expressed in cell lines but was targeted to the nucleus when co-expressed with the nuclear form of alphaKAP(B). Thus, nuclear targeting of cytoplasmic CaMKII isoforms by alphaKAP may be regulated by developmentally controlled alternative splicing and by protein kinases.
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Affiliation(s)
- Heather O'Leary
- Department of Pharmacology, Program in Neuroscience, University of Colorado Health Science Center, P.O. Box 6511, Aurora, 80045-0508, USA
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Tang L, Shukla PK, Wang LX, Wang ZJ. Reversal of Morphine Antinociceptive Tolerance and Dependence by the Acute Supraspinal Inhibition of Ca2+/Calmodulin-Dependent Protein Kinase II. J Pharmacol Exp Ther 2006; 317:901-9. [PMID: 16505162 DOI: 10.1124/jpet.105.097733] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Previous studies have suggested that Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) can modulate opioid tolerance and dependence via its action on learning and memory. In this study, we examined whether CaMKII could directly regulate opioid tolerance and dependence. CaMKII activity was increased after the treatment with morphine (100 mg/kg s.c. or 75 mg s.c. of morphine/pellet/mouse); the effect exhibited a temporal correction with the development of opioid tolerance and dependence. In mice treated with morphine (100 mg/kg s.c.), morphine tolerance and dependence developed in 2 to 6 h. An acute supraspinal administration of KN93 [2-[N-(2-hydroxyethyl)]-N-(4-methoxybenzenesulfonyl)]amino-N-(4-chlorocinnamyl)-N-methylbenzylamine)], a CaMKII inhibitor, was able to dose-dependently reverse the already-established antinociceptive tolerance to morphine (p < 0.001 for 15-30 nmol; not significant for 5 nmol). KN92 [2-[N-(4-methoxybenzenesulfonyl)]amino-N-(4-chlorocinnamyl)-N-methylbenzylamine] (30 nmol i.c.v.), a kinase-inactive analog of KN93, did not affect opioid tolerance. Neither KN92 nor KN93 affected basal nociception or acute morphine antinociception (1-10 nmol i.c.v.). Likewise, dependence on morphine was abolished by the acute administration of KN93, but not KN92, in a dose-dependent manner. Pretreatment of mice with KN93 also prevented the development of morphine tolerance and dependence. The effect of acute CaMKII inhibition was not limited to the particular experimental model, because KN93 also acutely reversed the established opioid tolerance and dependence in mice treated with morphine (75 mg/pellet/mouse s.c.) for 6 days. Taken together, these data strongly support the hypothesis that CaMKII can act as a key and direct factor in promoting opioid tolerance and dependence. Identifying such a direct mechanism may be useful for designing pharmacological treatments for these conditions.
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Affiliation(s)
- Lei Tang
- Department of Biopharmaceutical Sciences, University of Illinois, 833 South Woods Street, Chicago, IL 60612, USA
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33
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Webb SE, Moreau M, Leclerc C, Miller AL. Calcium transients and neural induction in vertebrates. Cell Calcium 2005; 37:375-85. [PMID: 15820384 DOI: 10.1016/j.ceca.2005.01.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2004] [Accepted: 01/06/2005] [Indexed: 11/18/2022]
Abstract
Evidence indicates that a variety of different types of Ca2+ transients (i.e., standing gradients, pulses and propagating waves) may be occurring both simultaneously and sequentially during neural induction in vertebrate embryos. Transients have been observed in the dorsal marginal zone and in the presumptive neural ectoderm, suggesting that they may be generated within two distinct germ layers at separate embryological locations. It has been proposed that the Ca2+ transients might have multiple roles during the period of neural induction, ranging from: activating the expression of early neural genes; contributing to the inhibition of BMP-4 signalling; generating secretion gradients of morphogens; regulating and co-ordinating convergent extension; and establishing and reinforcing dorsoventral axis specification. Both intra- and extracellular stores (either acting separately or in combination) have been shown to generate the neuralizing Ca2+ transients via well-established release mechanisms, and transients have been shown to propagate between connected cells, suggesting an intercellular signalling dimension. Thus, good evidence is accumulating to suggest that Ca2+ might be a key central regulator in the process of neural induction.
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Affiliation(s)
- Sarah E Webb
- Department of Biology, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong SAR, PR China
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Miyashita T, Tabuchi A, Fukuchi M, Hara D, Kisukeda T, Shimohata T, Tsuji S, Tsuda M. Interference with activity-dependent transcriptional activation of BDNF gene depending upon the expanded polyglutamines in neurons. Biochem Biophys Res Commun 2005; 333:1241-8. [PMID: 15979572 DOI: 10.1016/j.bbrc.2005.06.032] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2005] [Accepted: 06/09/2005] [Indexed: 11/22/2022]
Abstract
Expanded polyglutamines (polyQ) have been demonstrated to impair the CREB-dependent transcription in established cell lines. Since activity-dependent transcription in neurons, which plays an important role in forming neuronal plasticity, is largely controlled by CREB, it is important to study whether polyQ interferes with the activity-dependent transcriptional activation of genes in neurons. In cultured rat cortical neurons, over-expression of truncated dentatorubral-pallidoluysian atrophy proteins containing expanded polyQ, which form aggregation bodies in nucleus, reduced the calcium (Ca(2+)) signal-mediated transcriptional activation of brain-derived neurotrophic factor, c-fos, and pituitary adenylate cyclase-activating polypeptide gene promoters in a dose-dependent manner. The interference with the transcriptional activation was dependent upon the presence of polyQ, the strength of which was increased as the length of polyQ stretches was expanded. Thus, polyQ interferes with the activity-dependent transcription in a polyQ-length-dependent manner, which may correspond to the severity of polyglutamine diseases.
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Affiliation(s)
- Toshihide Miyashita
- Department of Biological Chemistry, Faculty of Pharmaceutical Sciences, Toyama Medical and Pharmaceutical University, Sugitani 2630, Toyama 930-0194, Japan
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35
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Abstract
New mRNA must be transcribed in order to consolidate changes in synaptic strength. But how are events at the synapse communicated to the nucleus? Some research has shown that proteins can move from activated synapses to the nucleus. However, other work has shown that action potentials can directly inform the nucleus about cellular activation. Here we contend that action potential-induced signalling to the nucleus best meets the requirements of the consolidation of synapse-specific plasticity, which include both timing and stoichiometric constraints.
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Affiliation(s)
- J Paige Adams
- Laboratory of Neurobiology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina 27709, USA
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36
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Endoh T. Involvement of Src tyrosine kinase and mitogen-activated protein kinase in the facilitation of calcium channels in rat nucleus of the tractus solitarius by angiotensin II. J Physiol 2005; 568:851-65. [PMID: 16123104 PMCID: PMC1464193 DOI: 10.1113/jphysiol.2005.095307] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
It is recognized that brain contains all the components of the renin-angiotensin systems (RAS). The nucleus of the tractus solitarius (NTS) is known to play a major role in the regulation of cardiovascular, respiratory, gustatory, hepatic and swallowing functions. Voltage-dependent Ca2+ channels (VDCCs) serve as crucial mediators of membrane excitability and Ca2+-dependent functions such as neurotransmitter release, enzyme activity and gene expression. The purpose of this study was to investigate the effects of angiotensin II (Ang II) on VDCC currents (I(Ca)) in the NTS using patch-clamp recording methods. An application of Ang II caused facilitation of L-type I(Ca) in a concentration-dependent manner with an EC50 of 167 nm and a Hill coefficient of 1.73. AT1 receptor antagonist losartan antagonized the Ang II-induced facilitation of I(Ca). Intracellular dialysis of the Galpha(i)-protein antibody attenuated the Ang II-induced facilitation of I(Ca). Both Src tyrosine kinase inhibitor and mitogen-activated protein kinase (MAPK) inhibitor attenuated the Ang II-induced facilitation of I(Ca). p38 MAPK inhibitor also attenuated the Ang II-induced facilitation of I(Ca). These results indicate that Ang II facilitates L-type VDCCs via Galpha(i)-proteins involving Src tyrosine kinase and p38 MAPK kinase mediated by AT1 receptors in NTS.
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Affiliation(s)
- Takayuki Endoh
- Department of Physiology, Tokyo Dental College, 1-2-2 Masago, Mihama-ku, Chiba 261-8502, Japan.
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37
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Alberti S, Krause SM, Kretz O, Philippar U, Lemberger T, Casanova E, Wiebel FF, Schwarz H, Frotscher M, Schütz G, Nordheim A. Neuronal migration in the murine rostral migratory stream requires serum response factor. Proc Natl Acad Sci U S A 2005; 102:6148-53. [PMID: 15837932 PMCID: PMC1087932 DOI: 10.1073/pnas.0501191102] [Citation(s) in RCA: 116] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The central nervous system is fundamentally dependent on guided cell migration, both during development and in adulthood. We report an absolute requirement of the transcription factor serum response factor (SRF) for neuronal migration in the mouse forebrain. Conditional, late-prenatal deletion of Srf causes neurons to accumulate ectopically at the subventricular zone (SVZ), a prime neurogenic region in the brain. SRF-deficient cells of the SVZ exhibit impaired tangential chain migration along the rostral migratory stream into the olfactory bulb. SVZ explants display retarded chain migration in vitro. Regarding target genes, SRF deficiency impairs expression of the beta-actin and gelsolin genes, accompanied by reduced cytoskeletal actin fiber density. At the posttranslational level, cofilin, a key regulator of actin dynamics, displays dramatically elevated inhibitory phosphorylation at Ser-3. Our studies indicate that SRF-controlled gene expression directs both the structure and dynamics of the actin microfilament, thereby determining cell-autonomous neuronal migration.
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Affiliation(s)
- Siegfried Alberti
- Department of Molecular Biology, Institute for Cell Biology, Tübingen University, 72076 Tübingen, Germany
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38
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MESH Headings
- Animals
- Calcium Channels, L-Type/physiology
- Cells, Cultured/metabolism
- Chromatin/metabolism
- Gene Expression Regulation/physiology
- Genes, fos
- Macromolecular Substances
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/metabolism
- Myocytes, Smooth Muscle/metabolism
- Nuclear Proteins/physiology
- Promoter Regions, Genetic
- RNA Polymerase II/metabolism
- RNA, Small Interfering/pharmacology
- Rats
- Serum Response Factor/physiology
- Signal Transduction
- Trans-Activators/physiology
- Transcription, Genetic
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39
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Zayzafoon M, Fulzele K, McDonald JM. Calmodulin and Calmodulin-dependent Kinase IIα Regulate Osteoblast Differentiation by Controlling c-fos Expression. J Biol Chem 2005; 280:7049-59. [PMID: 15590632 DOI: 10.1074/jbc.m412680200] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Ca(2+)/calmodulin-dependent protein kinase IIalpha (alpha-CaMKII) was once thought to be exclusively expressed in neuronal tissue, but it is becoming increasingly evident that CaMKII is also expressed in various extraneural cells. CaMKII plays a critical role in regulating various signaling pathways leading to modulation of several aspects of cellular functions, including proliferation, differentiation, cytoskeletal structure, and gene expression. The purpose of this study was to examine the expression of CaMKII in osteoblast-like cells (MC4) and to elucidate its role in osteoblast differentiation. We demonstrated that CaMKII, specifically the alpha isoform, is expressed in osteoblasts both in vitro and in vivo. Inhibition of CaMKII by the calmodulin antagonist trifluoperazine or the CaMKII antagonist KN93 reduces alkaline phosphatase activity and mineralization, as well as causes 85 and 56% decreases in alkaline phosphatase and osteocalcin gene expression, respectively. CaM and CaMKII antagonists, using the newborn mouse calvaria in vivo model, cause a 50% decrease in osteoblast number (N.Ob-BS) and a 32% decrease in mineralization (BV/TV). Pharmacologic and genetic inhibition of alpha-CaMKII by using trifluoperazine, KN93, and alpha-CaMKII small interfering RNA decreases the phosphorylation of ERK and of cAMP-response element-binding protein, leading to a significant decrease in the transactivation of serum response element and cAMP-response element. Inhibition of alpha-CaMKII decreases the expression of c-fos, AP-1 transactivation, and AP-1 DNA binding activity. Our findings demonstrated that alpha-CaMKII is expressed in osteoblasts and is involved in c-fos expression via regulation of serum response element and cAMP-response element. Inhibition of alpha-CaMKII results in a decrease in c-fos expression and AP-1 activation, leading to inhibition of osteoblast differentiation.
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Affiliation(s)
- Majd Zayzafoon
- Department of Pathology, University of Alabama at Birmingham, USA
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40
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Kang TC, Kim DS, Yoo KY, Hwang IK, Kwak SE, Kim JE, Jung JY, Won MH, Suh JG, Oh YS. Elevated voltage-gated Ca2+ channel immunoreactivities in the hippocampus of seizure-prone gerbil. Brain Res 2005; 1029:168-78. [PMID: 15542071 DOI: 10.1016/j.brainres.2004.09.040] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/27/2004] [Indexed: 11/20/2022]
Abstract
In present study, we investigated voltage-gated Ca2+ channel (VGCC) expressions in the hippocampus of the Mongolian gerbil and its association with different sequelae of spontaneous seizures, in an effort to identify the epileptogenesis in this animal. In the hippocampus of pre-seizure seizure sensitive (SS) gerbils, VGCC subunit expressions were significantly elevated, as compared with seizure-resistant (SR) gerbils. In 3 h postictal group, the alteration of VGCC expressions showed regional- and neuronal-specific manners; VGCC immunoreactivities in principal neurons were markedly decreased; however, their immunoreactivities in interneurons were significantly elevated. These results are the first comprehensive description of the distribution of VGCC immunoreactivities in the normal and epileptic hippocampus of gerbils, and suggest that these alterations in the hippocampus of the SS gerbil may be related with tissue excitability and have a role in modulating recurrent excitation following seizures.
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Affiliation(s)
- Tae-Cheon Kang
- Department of Anatomy, College of Medicine, Hallym University, Chunchon, Kangwon-Do 200-702, South Korea.
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41
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Xiao W, Liu Y, Templeton DM. Ca(2+)/calmodulin-dependent protein kinase II inhibition by heparin in mesangial cells. Am J Physiol Renal Physiol 2004; 288:F142-9. [PMID: 15383398 DOI: 10.1152/ajprenal.00145.2004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Heparin exerts an antiproliferative effect in smooth muscle cells, and the Ca(2+)/calmodulin-dependent protein kinase (CaMK) signaling pathway is heparin sensitive. Here, we report that transfection with a truncated 326-amino acid fragment of CaMK-IIalpha increases basal activity of CaMK-II in mesangial cells. Ionomycin increased CaMK-II activity in both transfected and untransfected cells, with a concomitant increase in activated Ca(2+)/calmodulin. Heparin (1 microg/ml), but not chondroitin or dermatan sulfate, significantly attenuated both serum- or ionomycin-induced CaMK-II activity, and attendant c-fos mRNA expression, but did not affect upstream Ca(2+)/calmodulin. Autophosphorylation of Thr286 generates an autonomously active CaMK-II. Both serum and ionomycin increased phosphorylation at this site and increased CaMK-II activity in antiphosphothreonine immunoprecipitates. Heparin (1 microg/ml) did not inhibit phosphorylation of Thr286 (although much higher concentrations did). Replacement of Thr286 with Asp produces a constitutively active mutant that was insensitive to ionomycin but was inhibited by heparin maximally at 1 microg/ml. These results suggest that heparin at physiological concentrations acts at or downstream of CaMK-II to suppress its activity independent of an effect on autophosphorylation.
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Affiliation(s)
- Weiqun Xiao
- Department of Laboratory Medicine and Pathobiology, Medical Sciences Bldg. Rm. 6302, University of Toronto, 1 King's College Circle, Toronto, Ontario, Canada M5S 1A8
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42
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Wamhoff BR, Bowles DK, McDonald OG, Sinha S, Somlyo AP, Somlyo AV, Owens GK. L-type Voltage-Gated Ca
2+
Channels Modulate Expression of Smooth Muscle Differentiation Marker Genes via a Rho Kinase/Myocardin/SRF–Dependent Mechanism. Circ Res 2004; 95:406-14. [PMID: 15256479 DOI: 10.1161/01.res.0000138582.36921.9e] [Citation(s) in RCA: 151] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Vascular smooth muscle cell (SMC) contraction is mediated in part by calcium influx through L-type voltage-gated Ca
2+
channels (VGCC) and activation of the RhoA/Rho kinase (ROK) signaling cascade. We tested the hypothesis that Ca
2+
influx through VGCCs regulates SMC differentiation marker expression and that these effects are dependent on RhoA/ROK signaling. Depolarization-induced activation of VGCCs resulted in a nifedipine-sensitive increase in endogenous smooth muscle myosin heavy chain (SMMHC) and SM α-actin expression and CArG-dependent promoter activity, as well as c-fos promoter activity. The ROK inhibitor, Y-27632, prevented depolarization-induced increase in SMMHC/SM α-actin but had no effect on c-fos expression. Conversely, the Ca
2+
/calmodulin-dependent kinase inhibitor, KN93, prevented depolarization-induced increases in c-fos expression with no effect on SMMHC/SM α-actin. Depolarization increased expression of myocardin, a coactivator of SRF that mediates CArG-dependent transcription of SMC marker gene promoters containing paired CArG
cis
regulatory elements (SMMHC/SM α-actin). Both nifedipine and Y-27632 prevented the depolarization-induced increase in myocardin expression. Moreover, short interfering RNA (siRNA) specific for myocardin attenuated depolarization-induced SMMHC/SM α-actin transcription. Chromatin immunoprecipitation (ChIP) assays revealed that depolarization increased SRF enrichment of the CArG regions in the SMMHC, SM α-actin, and c-fos promoters in intact chromatin. Whereas Y-27632 decreased basal and depolarization-induced SRF enrichment in the SMMHC/SM α-actin promoter regions, it had no effect of SRF enrichment of c-fos. Taken together, these results provide evidence for a novel mechanism whereby Ca
2+
influx via VGCCs stimulates expression of SMC differentiation marker genes through mechanisms that are dependent on ROK, myocardin, and increased binding of SRF to CArG
cis
regulatory elements.
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MESH Headings
- 3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester/pharmacology
- Actins/physiology
- Animals
- Aorta
- Calcium Channel Blockers/pharmacology
- Calcium Channels, L-Type/drug effects
- Calcium Channels, L-Type/physiology
- Cell Differentiation/physiology
- Cells, Cultured/cytology
- Cells, Cultured/metabolism
- Gene Expression Profiling
- Gene Expression Regulation, Developmental/drug effects
- Genes, fos
- Intracellular Signaling Peptides and Proteins
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/metabolism
- Myocytes, Smooth Muscle/cytology
- Myocytes, Smooth Muscle/metabolism
- Myosin Heavy Chains/physiology
- Nifedipine/pharmacology
- Nuclear Proteins/physiology
- Organoids/cytology
- Patch-Clamp Techniques
- Potassium Chloride/pharmacology
- Protein Serine-Threonine Kinases/physiology
- Protein Transport
- RNA, Small Interfering/pharmacology
- Rats
- Reverse Transcriptase Polymerase Chain Reaction
- Serum Response Element/genetics
- Serum Response Factor/physiology
- Trans-Activators/physiology
- Transfection
- rho-Associated Kinases
- rhoA GTP-Binding Protein/physiology
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Affiliation(s)
- B R Wamhoff
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA 22908-0736, USA
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43
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Fantozzi I, Zhang S, Platoshyn O, Remillard CV, Cowling RT, Yuan JXJ. Hypoxia increases AP-1 binding activity by enhancing capacitative Ca2+ entry in human pulmonary artery endothelial cells. Am J Physiol Lung Cell Mol Physiol 2003; 285:L1233-45. [PMID: 12909593 DOI: 10.1152/ajplung.00445.2002] [Citation(s) in RCA: 150] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Activating protein (AP)-1 transcription factors modulate expression of genes involved in cell proliferation and migration. Chronic hypoxia increases pulmonary artery smooth muscle cell proliferation by upregulating AP-1-responsive genes encoding for endothelium-derived vasoactive and mitogenic factors implicated in pulmonary hypertension development. The expression of AP-1 transcription factors is sensitive to changes in cytosolic free [Ca2+] ([Ca2+]cyt). Capacitative Ca2+ entry (CCE) via store-operated Ca2+ channels (SOC) is an important mechanism for raising [Ca2+]cyt in pulmonary artery endothelial cells (PAEC). Using combined molecular biological, fluorescence microscopy, and biophysical approaches, we examined the effect of chronic hypoxia (3% O2, 72 h) on AP-1 DNA binding activity, CCE, and transient receptor potential (TRP) gene expression in human (h) PAEC. EMSA showed that AP-1 binding to hPAEC nuclear protein extracts was significantly enhanced by hypoxia, the increase being dependent on store-operated Ca2+ influx and sensitive to La3+, an SOC inhibitor. Hypoxia also increased basal [Ca2+]cyt, the amount of CCE produced by store depletion with cyclopiazonic acid, and the amplitude of SOC-mediated currents (ISOC). The increases of CCE amplitude and ISOC current density by hypoxia were paralleled by enhanced TRPC4 mRNA and protein expression. Hypoxia-enhanced CCE and TRPC4 expression were also attenuated by La3+. These data suggest that hypoxia increases AP-1 binding activity by enhancing Ca2+ influx via La3+-sensitive TRP-encoded SOC channels in hPAEC. The Ca2+-mediated increase in AP-1 binding may play an important role in upregulating AP-1-responsive gene expression, in stimulating pulmonary vascular cell proliferation and, ultimately, in pulmonary vascular remodeling in patients with hypoxia-mediated pulmonary hypertension.
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Affiliation(s)
- Ivana Fantozzi
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, School of Medicine, University of California, San Diego, CA 92103-8382, USA
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44
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Marshall J, Dolan BM, Garcia EP, Sathe S, Tang X, Mao Z, Blair LAC. Calcium channel and NMDA receptor activities differentially regulate nuclear C/EBPbeta levels to control neuronal survival. Neuron 2003; 39:625-39. [PMID: 12925277 DOI: 10.1016/s0896-6273(03)00496-3] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Insulin-like growth factor-1 (IGF-1) promotes the survival of cerebellar granule neurons by enhancing calcium influx through L-type calcium channels, whereas NMDA receptor-mediated calcium influx can lead to excitotoxic death. Here we demonstrate that L and NMDA receptor channel activities differentially regulate the transcription factor C/EBPbeta to control neuronal survival. Specifically, we show that L channel-dependent calcium influx results in increased CaMKIV activity, which acts to decrease nuclear C/EBPbeta levels. Conversely, NMDA receptor-mediated influx rapidly elevates nuclear C/EBPbeta and induces excitotoxic death via activation of the calcium-dependent phosphatase, calcineurin. Moderate levels of AMPA receptor activity stimulate L channels to improve survival, whereas higher levels stimulate NMDA receptors and reduce neuronal survival, suggesting differential synaptic effects. Finally, N-type calcium channel activity reduces survival, potentially by increasing glutamate release. Together, these results show that the L-type calcium channel-dependent survival and NMDA receptor death pathways converge to regulate nuclear C/EBPbeta levels, which appears to be pivotal in these mechanisms.
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Affiliation(s)
- John Marshall
- Department of Molecular Pharmacology, Physiology, and Biotechnology, Brown University, Providence, RI 02912, USA.
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45
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Davis FJ, Gupta M, Camoretti-Mercado B, Schwartz RJ, Gupta MP. Calcium/calmodulin-dependent protein kinase activates serum response factor transcription activity by its dissociation from histone deacetylase, HDAC4. Implications in cardiac muscle gene regulation during hypertrophy. J Biol Chem 2003; 278:20047-58. [PMID: 12663674 DOI: 10.1074/jbc.m209998200] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Serum response factor (SRF) plays a pivotal role in cardiac myocyte development, muscle gene transcription, and hypertrophy. Previously, elevation of intracellular levels of Ca2+ was shown to activate SRF function without involving the Ets family of tertiary complex factors through an unknown regulatory mechanism. Here, we tested the hypothesis that the chromatin remodeling enzymes of class II histone deacetylases (HDAC4) regulate SRF activity in a Ca2+-sensitive manner. Expression of HDAC4 profoundly repressed SRF-mediated transcription in both muscle and nonmuscle cells. Protein interaction studies demonstrated physical association of HDAC4 with SRF in living cells. The SRF/HDAC4 co-association was disrupted by treatment of cells with hypertrophic agonists such as angiotensin-II and a Ca2+ ionophore, ionomycin. Furthermore, activation of Ca2+/calmodulin-dependent protein kinase (CaMK)-IV prevented SRF/HDAC4 interaction and derepressed SRF-dependent transcription activity. The SRF.HDAC4 complex was localized to the cell nucleus, and the activated CaMK-IV disrupted HDAC4/SRF association, leading to export of HDAC4 from the nucleus and stimulation of SRF transcription activity. Thus, these results identify SRF as a functional interacting target of HDAC4 and define a novel tertiary complex factor-independent mechanism for SRF activation by Ca2+/CaMK-mediated signaling.
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46
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Bébien M, Salinas S, Becamel C, Richard V, Linares L, Hipskind RA. Immediate-early gene induction by the stresses anisomycin and arsenite in human osteosarcoma cells involves MAPK cascade signaling to Elk-1, CREB and SRF. Oncogene 2003; 22:1836-47. [PMID: 12660819 DOI: 10.1038/sj.onc.1206334] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Cellular stress activates multiple mitogen-activated protein kinase (MAPK) cascades and immediate-early gene (IEG) transcription. To address how these events are linked, we investigated the endogenous signaling/transcription factor network driving IEG activation by arsenite and anisomycin in the human osteosarcoma cell line HOS/TE-85. Induction of IEG transcription by both stresses corresponded temporally with the phosphorylation of the regulatory factors Elk-1 and cAMP response element-binding protein (CREB), along with activation of the extracellular signal-regulated kinase (ERK), stress-activated protein kinase (SAPK) and p38 MAPK cascades. To assess the role of the different cascades, they were selectively inhibited with PD98059, SP600125 and SB203580, respectively. This implicated all three cascades in Elk-1 phosphorylation after arsenite treatment, whereas ERK and SAPK inhibition diminished this, and IEG mRNA levels, downstream of anisomycin. SB blocked phosphorylation of both serum response factor (SRF) and CREB, and strongly reduced IEG activation by both stresses. Combining PD with SB further reduced arsenite induction of IEG transcription. Thus, all three MAPK cascades mediate anisomycin- and arsenite-induced signaling to IEG promoters in HOS cells through the differential targeting of Elk-1, SRF and CREB.
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Affiliation(s)
- Magali Bébien
- Institut de Génétique Moléculaire de Montpellier, CNRS, UMR 5535, IFR 24, France
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47
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Zeng H, Liu Y, Templeton DM. Ca(2+)/calmodulin-dependent and cAMP-dependent kinases in induction of c-fos in human mesangial cells. Am J Physiol Renal Physiol 2002; 283:F888-94. [PMID: 12372763 DOI: 10.1152/ajprenal.00074.2002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Mesangial cell proliferation is an early event in several progressive renal diseases. When mesangial cells in culture are rendered quiescent by serum starvation and subsequently stimulated to proliferate, induction of c-fos is an early indicator of entry into the cell cycle. Several heparin-sensitive signals transduce these events. We have examined the potential roles of CaMK and PKA. Selective stimulation of CaMK with Ca(2+) ionophores and of PKA with forskolin or dibutyryl cAMP both result in induction of c-fos mRNA. CaMK but not PKA signaling is suppressed by low concentrations of heparin. Cross talk between the pathways has been demonstrated in some cells, with evidence of CaMK phosphorylating cAMP response element binding protein (CREB) at an inhibitory site and PKA suppressing CaMK-dependent signaling. However, in the present study, both pathways phosphorylated CREB on Ser(133) and induced c-fos in an additive manner. Serum, ionomycin, and forskolin all caused a rapid decline in cyclin D1 levels, but only serum effected a subsequent increase, indicative of cell cycle progression. We conclude that, in human mesangial cells, CaMK and PKA can both contribute to cell cycle entry, and, although induction of c-fos by CaMK requires active PKA, neither pathway antagonizes or synergizes c-fos induction by the other.
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Affiliation(s)
- Hong Zeng
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada M5S 1A8
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48
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Maturana A, Van Haasteren G, Piuz I, Castelbou C, Demaurex N, Schlegel W. Spontaneous calcium oscillations control c-fos transcription via the serum response element in neuroendocrine cells. J Biol Chem 2002; 277:39713-21. [PMID: 12121970 DOI: 10.1074/jbc.m200464200] [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: 11/06/2022] Open
Abstract
In excitable cells the localization of Ca2+ signals plays a central role in the cellular response, especially in the control of gene transcription. To study the effect of localized Ca2+ signals on the transcriptional activation of the c-fos oncogene, we stably expressed various c-fos beta-lactamase reporter constructs in pituitary AtT20 cells. A significant, but heterogenous expression of c-fos beta-lactamase was observed in unstimulated cells, and a further increase was observed using KCl depolarization, epidermal growth factor (EGF), pituitary adenylate cyclase-activating polypeptide (PACAP), and serum. The KCl response was almost abolished by a nuclear Ca2+ clamp, indicating that a rise in nuclear Ca2+ is required. In contrast, the basal expression was not affected by the nuclear Ca2+ clamp, but it was strongly reduced by nifedipine, a specific antagonist of l-type Ca2+ channels. Spontaneous Ca2+ oscillations, blocked by nifedipine, were observed in the cytosol but did not propagate to the nucleus, suggesting that a rise in cytosolic Ca2+ is sufficient for basal c-fos expression. Inactivation of the c-fos promoter cAMP/Ca2+ response element (CRE) had no effect on basal or stimulated expression, whereas inactivation of the serum response element (SRE) had the same marked inhibitory effect as nifedipine. These experiments suggest that in AtT20 cells spontaneous Ca2+ oscillations maintain a basal c-fos transcription through the serum response element. Further induction of c-fos expression by depolarization requires a nuclear Ca2+ increase.
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Affiliation(s)
- Andres Maturana
- Fondation pour Recherches Médicales, University of Geneva, 1211 Geneva 4, Switzerland
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Abstract
Calcium ions are ubiquitous second messengers that control diverse cellular functions. The versatility of Ca(2+) arises both from the ability of cells to employ a range of mechanisms to generate stimulus-induced Ca(2+) signals with defined characteristics and the existence of a large repertoire of Ca(2+) receptive proteins that mediate the effects of Ca(2+). In neurons, the regulation of gene expression by electrical activity-induced increases in Ca(2+) is critical for the long-term maintenance of neuronal adaptive responses. Different patterns of synaptic activity are able to generate Ca(2+) signals varying in their amplitude, temporal profile, spatial properties and source or site of entry. The information embedded in Ca(2+) signals is decoded by Ca(2+)-responsive transcriptional regulators, including protein kinases, phosphatases and transcription factors, with differing Ca(2+) sensitivities, kinetics of activation and deactivation, and subcellular localisation. The coordinated control of many transcriptional regulators by Ca(2+) signals determines the qualitative and quantitative nature of the genomic response.
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Affiliation(s)
- Sangeeta Chawla
- Department of Physiology, Downing Street, Cambridge CB2 3EG, UK.
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Hassan WN, Cantuti-Castelevetri I, Denisova NA, Yee AS, Joseph JA, Paulson KE. The nitrone spin trap PBN alters the cellular response to H(2)O(2): activation of the EGF receptor/ERK pathway. Free Radic Biol Med 2002; 32:551-61. [PMID: 11958956 DOI: 10.1016/s0891-5849(02)00744-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The nitrone spin trap PBN has been shown to protect neuronal cells from reactive oxygen species both in culture and in vivo. As an approach to understanding the molecular mechanisms by which PBN may function to protect cells, we examined whether PBN alters the cellular response to reactive oxygen species. H(2)O(2) stimulation of PC-12 cells results in weak activation of both the ERK and JNK signal transduction pathways. PBN pretreatment of PC-12 cells, followed by H(2)O(2) stimulation, results in strong and selective activation of the pro-survival ERK pathway. H(2)O(2) induction of ERK activity in PBN-pretreated cells was shown to be dependent on extracellular Ca(+2) influx. Further analysis of the ERK pathway showed that in PBN-pretreated cells, EGF receptor and the adapter protein SHC were phosphorylated in a Ca(+2)-dependent, ligand-independent manner following H(2)O(2) stimulation. Interestingly, H(2)O(2) stimulation of PBN-pretreated cells results in only 30% of the increase in intracellular Ca(+2) as compared to untreated cells following H(2)O(2) stimulation. These data suggest a model in which PBN attenuates H(2)O(2)-induced Ca(+2) entry, yet magnifies or alters Ca(+2) action, resulting in the activation of the EGF receptor/ERK pathway.
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Affiliation(s)
- Waleed N Hassan
- Department of Biochemistry, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
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