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Ghaffari LT, Trotti D, Haeusler AR. Differential response of C9orf72 transcripts following neuronal depolarization. iScience 2023; 26:106959. [PMID: 37332610 PMCID: PMC10272498 DOI: 10.1016/j.isci.2023.106959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 04/19/2023] [Accepted: 05/22/2023] [Indexed: 06/20/2023] Open
Abstract
The (G4C2)n nucleotide repeat expansion (NRE) mutation in C9orf72 is the most common genetic cause of ALS and FTD. The biological functions of C9orf72 are becoming understood, but it is unclear if this gene is regulated in a neural-specific manner. Neuronal activity is a crucial modifier of biological processes in health and neurodegenerative disease contexts. Here, we show that prolonged membrane depolarization in healthy human iPSC-cortical neurons leads to a significant downregulation of a transcript variant 3 (V3) of C9orf72, with a concomitant increase in variant 2 (V2), which leads to total C9orf72 RNA transcript levels remaining unchanged. However, the same response is not observed in cortical neurons derived from patients with the C9-NRE mutation. These findings reveal the impact of depolarization on C9orf72 transcripts, and how this response diverges in C9-NRE-carriers, which may have important implications in the underlying unique clinical associations of C9-NRE transcripts and disease pathogenesis.
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Affiliation(s)
- Layla T. Ghaffari
- Jefferson Weinberg ALS Center, Vickie and Jack Farber Institute for Neuroscience, Department of Neuroscience, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Davide Trotti
- Jefferson Weinberg ALS Center, Vickie and Jack Farber Institute for Neuroscience, Department of Neuroscience, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Aaron R. Haeusler
- Jefferson Weinberg ALS Center, Vickie and Jack Farber Institute for Neuroscience, Department of Neuroscience, Thomas Jefferson University, Philadelphia, PA 19107, USA
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2
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Rienecker KDA, Poston RG, Saha RN. Merits and Limitations of Studying Neuronal Depolarization-Dependent Processes Using Elevated External Potassium. ASN Neuro 2020; 12:1759091420974807. [PMID: 33256465 PMCID: PMC7711227 DOI: 10.1177/1759091420974807] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 10/07/2020] [Accepted: 10/22/2020] [Indexed: 01/24/2023] Open
Abstract
Elevated extracellular potassium chloride is widely used to achieve membrane depolarization of cultured neurons. This technique has illuminated mechanisms of calcium influx through L-type voltage sensitive calcium channels, activity-regulated signaling, downstream transcriptional events, and many other intracellular responses to depolarization. However, there is enormous variability in these treatments, including durations from seconds to days and concentrations from 3mM to 150 mM KCl. Differential effects of these variable protocols on neuronal activity and transcriptional programs are underexplored. Furthermore, potassium chloride treatments in vitro are criticized for being poor representatives of in vivo phenomena and are questioned for their effects on cell viability. In this review, we discuss the intracellular consequences of elevated extracellular potassium chloride treatment in vitro, the variability of such treatments in the literature, the strengths and limitations of this tool, and relevance of these studies to brain functions and dysfunctions.
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Affiliation(s)
- Kira D. A. Rienecker
- Department of Molecular and Cell Biology,
School of Natural Sciences, University of California, Merced, United
States
| | - Robert G. Poston
- Department of Molecular and Cell Biology,
School of Natural Sciences, University of California, Merced, United
States
| | - Ramendra N. Saha
- Department of Molecular and Cell Biology,
School of Natural Sciences, University of California, Merced, United
States
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3
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Impact of immunosuppressive therapy on brain derived cytokines after liver transplantation. Transpl Immunol 2019; 58:101248. [PMID: 31669260 DOI: 10.1016/j.trim.2019.101248] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 09/27/2019] [Indexed: 01/02/2023]
Abstract
BACKGROUND While acute neurotoxic side effects of calcineurin inhibitors (CNI) are well-known, data upon long-term effects on brain structure and function are sparse. We hypothesize that long-term CNI therapy affects the neuroimmune system, thereby, increasing the risk of neurodegeneration. Here, we measured the impact of CNI therapy on plasma levels of brain- and T cell-derived cytokines in a cohort of patients after liver transplantation (LT). METHODS Levels of T cell-mediated cytokines (e.g. Interferon-γ (IFN-γ)) and brain-derived cytokines (e.g. brain derived neurotrophic factor (BDNF), platelet derived growth factor (PDGF)) were measured by multiplex assays in plasma of 82 patients about 10 years after LT (17 with CNI free, 35 with CNI low dose, 30 with standard dose CNI immunosuppression) and 33 healthy controls. Data were related to psychometric test results and parameters of cerebral magnetic resonance imaging. RESULTS IFN-γ levels were significantly higher in the CNI free LT patient group (p=0.027) compared to healthy controls. BDNF levels were significantly lower in LT patients treated with CNI (CNI low: p<0.001; CNI standard: p=0.016) compared to controls. PDGF levels were significantly lower in the CNI low dose group (p=0.004) and for PDGF-AB/BB also in the CNI standard dose group (p=0.029) compared to controls. BDNF and PDGF negatively correlated with cognitive function and brain volume (p<0.05) in the CNI low dose group. CONCLUSION Our results imply that long-term treatment with CNI suppresses BDNF and PDGF expression, both crucial for neuronal signaling, cell survival and synaptic plasticity and thereby may lead to cognitive dysfunction and neurodegeneration.
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4
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Calcineurin controls gene transcription following stimulation of a Gαq-coupled designer receptor. Exp Cell Res 2019; 383:111553. [DOI: 10.1016/j.yexcr.2019.111553] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2019] [Revised: 08/07/2019] [Accepted: 08/10/2019] [Indexed: 01/07/2023]
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5
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High-Amplitude Circadian Rhythms in Drosophila Driven by Calcineurin-Mediated Post-translational Control of sarah. Genetics 2018; 209:815-828. [PMID: 29724861 DOI: 10.1534/genetics.118.300808] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Accepted: 04/18/2018] [Indexed: 12/26/2022] Open
Abstract
Post-translational control is a crucial mechanism for circadian timekeeping. Evolutionarily conserved kinases and phosphatases have been implicated in circadian phosphorylation and the degradation of clock-relevant proteins, which sustain high-amplitude rhythms with 24-hr periodicity in animal behaviors and physiology. Here, we report a novel clock function of the heterodimeric Ca2+/calmodulin-dependent phosphatase calcineurin and its regulator sarah (sra) in Drosophila Genomic deletion of the sra locus dampened circadian locomotor activity rhythms in free-running constant dark after entrainment in light-dark cycles. Poor rhythms in sra mutant behaviors were accompanied by lower expression of two oscillating clock proteins, PERIOD (PER) and TIMELESS (TIM), at the post-transcriptional level. RNA interference-mediated sra depletion in circadian pacemaker neurons was sufficient to phenocopy loss-of-function mutation in sra On the other hand, a constitutively active form of the catalytic calcineurin subunit, Pp2B-14DACT, shortened circadian periodicity in locomotor behaviors and phase-advanced PER and TIM rhythms when overexpressed in clock neurons. Heterozygous sra deletion induced behavioral arrhythmicity in Pp2B-14DACT flies, whereas sra overexpression rescued short periods in these animals. Finally, pharmacological inhibition of calcineurin in either wild-type flies or clock-less S2 cells decreased the levels of PER and TIM, likely by facilitating their proteasomal degradation. Taken together, these data suggest that sra negatively regulates calcineurin by cell-autonomously titrating calcineurin-dependent stabilization of PER and TIM proteins, thereby sustaining high-amplitude behavioral rhythms in Drosophila.
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Tyssowski KM, DeStefino NR, Cho JH, Dunn CJ, Poston RG, Carty CE, Jones RD, Chang SM, Romeo P, Wurzelmann MK, Ward JM, Andermann ML, Saha RN, Dudek SM, Gray JM. Different Neuronal Activity Patterns Induce Different Gene Expression Programs. Neuron 2018; 98:530-546.e11. [PMID: 29681534 PMCID: PMC5934296 DOI: 10.1016/j.neuron.2018.04.001] [Citation(s) in RCA: 199] [Impact Index Per Article: 33.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 02/20/2018] [Accepted: 03/29/2018] [Indexed: 12/22/2022]
Abstract
A vast number of different neuronal activity patterns could each induce a different set of activity-regulated genes. Mapping this coupling between activity pattern and gene induction would allow inference of a neuron's activity-pattern history from its gene expression and improve our understanding of activity-pattern-dependent synaptic plasticity. In genome-scale experiments comparing brief and sustained activity patterns, we reveal that activity-duration history can be inferred from gene expression profiles. Brief activity selectively induces a small subset of the activity-regulated gene program that corresponds to the first of three temporal waves of genes induced by sustained activity. Induction of these first-wave genes is mechanistically distinct from that of the later waves because it requires MAPK/ERK signaling but does not require de novo translation. Thus, the same mechanisms that establish the multi-wave temporal structure of gene induction also enable different gene sets to be induced by different activity durations.
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Affiliation(s)
| | | | - Jin-Hyung Cho
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Carissa J Dunn
- Molecular Cell Biology Unit, University of California Merced, Merced, CA 95343, USA
| | - Robert G Poston
- Molecular Cell Biology Unit, University of California Merced, Merced, CA 95343, USA
| | - Crista E Carty
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA
| | - Richard D Jones
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Sarah M Chang
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Palmyra Romeo
- Neurobiology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Mary K Wurzelmann
- Neurobiology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - James M Ward
- Integrative Bioinformatics, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Mark L Andermann
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA
| | - Ramendra N Saha
- Molecular Cell Biology Unit, University of California Merced, Merced, CA 95343, USA; Neurobiology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA.
| | - Serena M Dudek
- Neurobiology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA.
| | - Jesse M Gray
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA.
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7
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Ronan PJ, Strait SA, Palmer GM, Beresford TP. Central Administration of Cyclosporine A Decreases Ethanol Drinking. Alcohol Alcohol 2018; 53:193-199. [PMID: 29281037 DOI: 10.1093/alcalc/agx102] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 11/13/2017] [Indexed: 01/08/2023] Open
Abstract
Aims Abstinence among alcohol dependent liver graft recipients is remarkably high. The routine use of anti-immune agents in these patients led to rodent studies showing that immunosuppressants acting through inhibition of calcineurin (CLN) are highly effective in decreasing alcohol consumption. It remained unclear, however, whether the decreased alcohol consumption in rodent models is mediated through peripheral suppression of immune response or centrally through direct inhibition of cyclophilin-CLN in the brain. We tested the hypothesis that direct brain inhibition of CLN with intracerebroventricular (ICV) injections of the immunosuppressant cyclosporine A (CsA) is sufficient to decrease ethanol consumption in a rodent model of binge-like drinking. Methods Male C57BL/6NHsd mice were put through a modified 'drinking in the dark' (DID) paradigm. Effects of both peripheral (IP) and central (ICV) injections of CsA on ethanol consumption were assessed. Results Here, as in earlier work, IP CsA administration significantly decreased alcohol consumption. Supporting our hypothesis, central administration of CsA was sufficient to decrease alcohol consumption in a dose-dependent manner. There was no significant effect of CsA on water or sucrose consumption. Conclusions These results clearly implicate a CLN-mediated mechanism in brain in the inhibitory effects of CsA on ethanol consumption and provide novel targets for investigation of treatment for Alcohol Use Disorders (AUD). These results also add to the growing body of literature implicating neuroimmune mechanisms in the etiology, pathophysiology and behaviors driving AUD. Short Summary The unusually high abstinence rate and routine use of immunosuppressants in AUD liver graft recipients led us to rodent studies showing that immunosuppressants acting through inhibition of calcineurin (CLN) are highly effective in decreasing drinking. Here we demonstrate that this effect is mediated by brain rather than peripheral immune mechanisms.
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Affiliation(s)
- Patrick J Ronan
- Laboratory for Clinical and Translational Research in Psychiatry, Research Service and Psychiatry, Denver VA Medical Center, 1050 Clermont Street, Denver, CO 80220-0116, USA.,Sioux Falls VA Research Service, 2501 W. 22nd St., Sioux Falls, SD 57105, USA.,Department of Psychiatry and Division of Basic Biomedical Sciences, Sanford USD School of Medicine, MC151, 2501 W. 22nd St., Sioux Falls, SD 57105, USA
| | - Sydney A Strait
- Sioux Falls VA Research Service, 2501 W. 22nd St., Sioux Falls, SD 57105, USA
| | - Geralyn M Palmer
- Sioux Falls VA Research Service, 2501 W. 22nd St., Sioux Falls, SD 57105, USA
| | - Thomas P Beresford
- Laboratory for Clinical and Translational Research in Psychiatry, Research Service and Psychiatry, Denver VA Medical Center, 1050 Clermont Street, Denver, CO 80220-0116, USA.,Department of Psychiatry, University of Colorado Denver School of Medicine, Anschutz Medical Campus, 13001 East 17th Place, Aurora, CO 80045, USA
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8
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Alvarez-Ricartes N, Oliveros-Matus P, Mendoza C, Perez-Urrutia N, Echeverria F, Iarkov A, Barreto GE, Echeverria V. Intranasal Cotinine Plus Krill Oil Facilitates Fear Extinction, Decreases Depressive-Like Behavior, and Increases Hippocampal Calcineurin A Levels in Mice. Mol Neurobiol 2018; 55:7949-7960. [PMID: 29488138 DOI: 10.1007/s12035-018-0916-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 01/18/2018] [Indexed: 02/07/2023]
Abstract
Failure in fear extinction is one of the more troublesome characteristics of posttraumatic stress disorder (PTSD). Cotinine facilitates fear memory extinction and reduces depressive-like behavior when administered 24 h after fear conditioning in mice. In this study, it was investigated the behavioral and molecular effects of cotinine, and other antidepressant preparations infused intranasally. Intranasal (IN) cotinine, IN krill oil, IN cotinine plus krill oil, and oral sertraline were evaluated on depressive-like behavior and fear retention and extinction after fear conditioning in C57BL/6 mice. Since calcineurin A has been involved in facilitating fear extinction in rodents, we also investigated changes of calcineurin in the hippocampus, a region key on contextual fear extinction. Short-term treatment with cotinine formulations was superior to krill oil and oral sertraline in reducing depressive-like behavior and fear consolidation and enhancing contextual fear memory extinction in mice. IN krill oil slowed the extinction of fear. IN cotinine preparations increased the levels of calcineurin A in the hippocampus of conditioned mice. In the light of the results, the future investigation of the use of IN cotinine preparations for the extinction of contextual fear memory and treatment of treatment-resistant depression (TRD) in PTSD is discussed.
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Affiliation(s)
- Nathalie Alvarez-Ricartes
- Facultad de Ciencias de la Salud, Universidad San Sebastián, Lientur 1457, 4030000, Concepción, Chile
| | - Patricia Oliveros-Matus
- Facultad de Ciencias de la Salud, Universidad San Sebastián, Lientur 1457, 4030000, Concepción, Chile
| | - Cristhian Mendoza
- Facultad de Ciencias de la Salud, Universidad San Sebastián, Lientur 1457, 4030000, Concepción, Chile
| | - Nelson Perez-Urrutia
- Facultad de Ciencias de la Salud, Universidad San Sebastián, Lientur 1457, 4030000, Concepción, Chile
| | - Florencia Echeverria
- Facultad de Ciencias de la Salud, Universidad San Sebastián, Lientur 1457, 4030000, Concepción, Chile
| | - Alexandre Iarkov
- Facultad de Ciencias de la Salud, Universidad San Sebastián, Lientur 1457, 4030000, Concepción, Chile.
| | - George E Barreto
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá D.C., Colombia.,Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, Santiago, Chile
| | - Valentina Echeverria
- Facultad de Ciencias de la Salud, Universidad San Sebastián, Lientur 1457, 4030000, Concepción, Chile. .,Bay Pines VA Healthcare System, Research and Development, Bay Pines VAHCS, 10,000 Bay Pines Blvd., Bldg. 23, Rm123, Bay Pines, FL, 33744, USA.
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9
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Qi R, Wang D, Xing L, Wu Z. Cyclosporin A inhibits mitochondrial biogenesis in Hep G2 cells. Biochem Biophys Res Commun 2018; 496:941-946. [PMID: 29391135 DOI: 10.1016/j.bbrc.2018.01.113] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 01/17/2018] [Indexed: 12/28/2022]
Abstract
Dysregulation of mitochondrial biogenesis is associated with pathogenesis in many diseases, including liver diseases. Cyclosporine A (CsA), one of the most commonly used drug to treat many autoimmune diseases and to prevent allograft rejection after organ transplantation, has been reported to cause mitochondrial dysfunction. However, the cellular mechanisms underlying CsA on mitochondrial dysfunction remain at present not completely elucidated. In this study, we found that CsA reduced the expression of PGC-1α at both the mRNA and protein levels in HepG2 cells. Correspondingly, the expressions of its target genes NRF 1 and TFAM were reduced in response to CsA treatment. In addition, mtDNA/nDNA, mitochondria mass, ATP production, and cytochrome C oxidase activity were significantly reduced by treatment with CsA. Over-expression of PGC-1α was found to rescue the negative effect of CsA administration on mitochondrial biogenesis. Mechanistically, CREB was involved in the inhibitory effects of CsA in mitochondrial biogenesis.
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Affiliation(s)
- Rui Qi
- Departrment of General Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, China; Departrment of Thoracic Surgery, Inner Mongolia People's Hospital, Hohhot City, Inner Mongolia, 010017, China
| | - Dongtao Wang
- Department of Oncological Surgery, Central Hospital, Baotou, Inner Mongolia, 014040, China
| | - Lifei Xing
- Neurology Department, Inner Mongolia North Heavy Industries Group Corp. Ltd Hospital, Third Affiliated Hospital of Baotou Medical College, Baotou, Inner Mongolia, 014030, China
| | - Zhongjun Wu
- Department of General Surgery, The First Affiliated Hospital of Chongqing Medical University, China.
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Inhibition of Calcineurin A by FK506 Suppresses Seizures and Reduces the Expression of GluN2B in Membrane Fraction. Neurochem Res 2017; 42:2154-2166. [PMID: 28299629 DOI: 10.1007/s11064-017-2221-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2016] [Revised: 02/28/2017] [Accepted: 03/02/2017] [Indexed: 02/08/2023]
Abstract
FK506, a calcineurin inhibitor, shows neuroprotective effects and has been associated with neurodegenerative diseases. Calcineurin A (CaNA), a catalytic subunit of calcineurin, mediates the dephosphorylation of various proteins. N-methyl-D-aspartate receptor (GluN) is closely related to epileptogenesis, and various phosphorylation sites of GluN2B, a regulatory subunit of the GluN complex, have different functions. Thus, we hypothesized that one of the potential anti-epileptic mechanisms of FK506 is mediated by its ability to promote the phosphorylation of GluN2B and reduce the expression of GluN2B in membrane fraction by down-regulating CaNA. CaNA expression was increased in the cortex of patients with temporal lobe epilepsy and pentylenetetrazol (PTZ)-induced epileptic models. CaNA was shown to be expressed in neurons using immunofluorescence staining. According to our behavioral observations, epileptic rats exhibited less severe seizures and were less sensitive to PTZ after a systemic injection of FK506. The levels of phosphorylated GluN2B were decreased in epileptic rats but increased after the FK506 treatment. Moreover, there was no difference in the total GluN2B levels before and after FK506 treatment. However, the expression of GluN2B in membrane fraction was suppressed after FK506 treatment. Based on these results, FK506 may reduce the severity and frequency of seizures by reducing the expression of GluN2B in membrane fraction.
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Shah SZA, Hussain T, Zhao D, Yang L. A central role for calcineurin in protein misfolding neurodegenerative diseases. Cell Mol Life Sci 2017; 74:1061-1074. [PMID: 27682820 PMCID: PMC11107525 DOI: 10.1007/s00018-016-2379-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Revised: 09/06/2016] [Accepted: 09/23/2016] [Indexed: 12/25/2022]
Abstract
Accumulation of misfolded/unfolded aggregated proteins in the brain is a hallmark of many neurodegenerative diseases affecting humans and animals. Dysregulation of calcium (Ca2+) and disruption of fast axonal transport (FAT) are early pathological events that lead to loss of synaptic integrity and axonal degeneration in early stages of neurodegenerative diseases. Dysregulated Ca2+ in the brain is triggered by accumulation of misfolded/unfolded aggregated proteins in the endoplasmic reticulum (ER), a major Ca2+ storing organelle, ultimately leading to neuronal dysfunction and apoptosis. Calcineurin (CaN), a Ca2+/calmodulin-dependent serine/threonine phosphatase, has been implicated in T cells activation through the induction of nuclear factor of activated T cells (NFAT). In addition to the involvement of several other signaling cascades, CaN has been shown to play a role in early synaptic dysfunction and neuronal death. Therefore, inhibiting hyperactivated CaN in early stages of disease might be a promising therapeutic strategy for treating patients with protein misfolding diseases. In this review, we briefly summarize the structure of CaN, inhibition mechanisms by which immunosuppressants inhibit CaN, role of CaN in maintaining neuronal and synaptic integrity and homeostasis and the role played by CaN in protein unfolding/misfolding neurodegenerative diseases.
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Affiliation(s)
- Syed Zahid Ali Shah
- National Animal Transmissible Spongiform Encephalopathy Laboratory and Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, 100193, China
| | - Tariq Hussain
- National Animal Transmissible Spongiform Encephalopathy Laboratory and Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, 100193, China
| | - Deming Zhao
- National Animal Transmissible Spongiform Encephalopathy Laboratory and Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, 100193, China
| | - Lifeng Yang
- National Animal Transmissible Spongiform Encephalopathy Laboratory and Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, 100193, China.
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Fukuchi M, Kanesaki K, Takasaki I, Tabuchi A, Tsuda M. Convergent effects of Ca(2+) and cAMP signals on the expression of immediate early genes in neurons. Biochem Biophys Res Commun 2015; 466:572-7. [PMID: 26386156 DOI: 10.1016/j.bbrc.2015.09.084] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 09/15/2015] [Indexed: 11/18/2022]
Abstract
How the expression of immediate early genes (IEGs) is controlled in response to neurotransmissions is unknown. Using cultured rat cortical cells, we investigated the expression of IEGs regulated by Ca(2+) and/or cAMP signals. The expression of c-fos was transiently induced by treatment of cells with high potassium (high K(+)), which evoked depolarization, or forskolin, an adenylate cyclase activator. c-fos expression was persistently and synergistically induced by simultaneous treatment with high K(+) and forskolin via cAMP-response element (CRE). Microarray analysis indicated the expression profiles of IEGs caused by depolarization in the presence or absence of forskolin. When a novel index was included to investigate the profile of IEGs, we found that high K(+)-induced expression of IEGs was stimulatory or negatively changed in the presence of forskolin, suggesting distinct convergent effects of Ca(2+) and cAMP signals on the expression of IEGs.
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Affiliation(s)
- Mamoru Fukuchi
- Department of Biological Chemistry, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan.
| | - Kazufumi Kanesaki
- Department of Biological Chemistry, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan
| | - Ichiro Takasaki
- Division of Molecular Genetics Research, Life Science Research Center, University of Toyama, Toyama, Japan
| | - Akiko Tabuchi
- Department of Biological Chemistry, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan
| | - Masaaki Tsuda
- Department of Biological Chemistry, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan.
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Evolutionary and functional perspectives on signaling from neuronal surface to nucleus. Biochem Biophys Res Commun 2015; 460:88-99. [PMID: 25998737 DOI: 10.1016/j.bbrc.2015.02.146] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Accepted: 02/25/2015] [Indexed: 01/08/2023]
Abstract
Reliance on Ca(2+) signaling has been well-preserved through the course of evolution. While the complexity of Ca(2+) signaling pathways has increased, activation of transcription factors including CREB by Ca(2+)/CaM-dependent kinases (CaMKs) has remained critical for long-term plasticity. In C. elegans, the CaMK family is made up of only three members, and CREB phosphorylation is mediated by CMK-1, the homologue of CaMKI. CMK-1 nuclear translocation directly regulates adaptation of thermotaxis behavior in response to changes in the environment. In mammals, the CaMK family has been expanded from three to ten members, enabling specialization of individual elements of a signal transduction pathway and increased reliance on the CaMKII subfamily. This increased complexity enables private line communication between Ca(2+) sources at the cell surface and specific cellular targets. Using both new and previously published data, we review the mechanism of a γCaMKII-CaM nuclear translocation. This intricate pathway depends on a specific role for multiple Ca(2+)/CaM-dependent kinases and phosphatases: α/βCaMKII phosphorylates γCaMKII to trap CaM; CaN dephosphorylates γCaMKII to dispatch it to the nucleus; and PP2A induces CaM release from γCaMKII so that CaMKK and CaMKIV can trigger CREB phosphorylation. Thus, while certain basic elements have been conserved from C. elegans, evolutionary modifications offer opportunities for targeted communication, regulation of key nodes and checkpoints, and greater specificity and flexibility in signaling.
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14
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Development of a Fluorescent Quenching Based High Throughput Assay to Screen for Calcineurin Inhibitors. PLoS One 2015; 10:e0131297. [PMID: 26176772 PMCID: PMC4503349 DOI: 10.1371/journal.pone.0131297] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Accepted: 05/11/2015] [Indexed: 01/11/2023] Open
Abstract
Currently there is no effective treatment available for major neurodegenerative disorders associated to protein misfolding, including Alzheimer's and Parkinson's disease. One of most promising therapeutic approaches under development focuses on inhibiting the misfolding and aggregation pathway. However, it is likely that by the time clinical symptoms appear, there is a large accumulation of misfolded aggregates and a very substantial damage to the brain. Thus, it seems that at the clinical stage of the disease it is necessary also to develop strategies aiming to prevent the neuronal damage produced by already formed misfolded aggregates. Chronic activation of calcineurin (CaN), a type IIB phosphatase, has been implicated as a pivotal molecule connecting synaptic loss and neuronal damage to protein misfolding. The fact that the crystal structure of CaN is also well established makes it an ideal target for drug discovery. CaN activity assays for High Throughput Screening (HTS) reported so far are based on absorbance. In this article we report the development of a fluorescent quenching based CaN activity assay suitable for robotic screening of large chemical libraries to find novel inhibitors. The assay yielded a Z score of 0.84 with coefficient of variance ≤ 15%. Our results also show that this assay can be used to identify CaN inhibitors with a wide range of potencies.
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Soto C, Satani N. The intricate mechanisms of neurodegeneration in prion diseases. Trends Mol Med 2015; 17:14-24. [PMID: 20889378 DOI: 10.1016/j.molmed.2010.09.001] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2010] [Revised: 08/27/2010] [Accepted: 09/01/2010] [Indexed: 12/20/2022]
Abstract
Prion diseases are a group of infectious neurodegenerative diseases with an entirely novel mechanism of transmission, involving a protein-only infectious agent that propagates the disease by transmitting protein conformational changes. The disease results from extensive and progressive brain degeneration. The molecular mechanisms involved in neurodegeneration are not entirely known but involve multiple processes operating simultaneously and synergistically in the brain, including spongiform degeneration, synaptic alterations, brain inflammation, neuronal death and the accumulation of protein aggregates. Here, we review the pathways implicated in prion-induced brain damage and put the pieces together into a possible model of neurodegeneration in prion disorders. A more comprehensive understanding of the molecular basis of brain degeneration is essential to develop a much needed therapy for these devastating diseases.
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Affiliation(s)
- Claudio Soto
- Mitchell Center for Alzheimer's disease and related Brain disorders, Department of Neurology, University of Texas Houston Medical School, 6431 Fannin St, Houston, TX 77030, USA
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Ma H, Groth RD, Cohen SM, Emery JF, Li B, Hoedt E, Zhang G, Neubert TA, Tsien RW. γCaMKII shuttles Ca²⁺/CaM to the nucleus to trigger CREB phosphorylation and gene expression. Cell 2015; 159:281-94. [PMID: 25303525 DOI: 10.1016/j.cell.2014.09.019] [Citation(s) in RCA: 189] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Revised: 07/02/2014] [Accepted: 09/09/2014] [Indexed: 12/23/2022]
Abstract
Activity-dependent CREB phosphorylation and gene expression are critical for long-term neuronal plasticity. Local signaling at CaV1 channels triggers these events, but how information is relayed onward to the nucleus remains unclear. Here, we report a mechanism that mediates long-distance communication within cells: a shuttle that transports Ca(2+)/calmodulin from the surface membrane to the nucleus. We show that the shuttle protein is γCaMKII, its phosphorylation at Thr287 by βCaMKII protects the Ca(2+)/CaM signal, and CaN triggers its nuclear translocation. Both βCaMKII and CaN act in close proximity to CaV1 channels, supporting their dominance, whereas γCaMKII operates as a carrier, not as a kinase. Upon arrival within the nucleus, Ca(2+)/CaM activates CaMKK and its substrate CaMKIV, the CREB kinase. This mechanism resolves long-standing puzzles about CaM/CaMK-dependent signaling to the nucleus. The significance of the mechanism is emphasized by dysregulation of CaV1, γCaMKII, βCaMKII, and CaN in multiple neuropsychiatric disorders.
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Affiliation(s)
- Huan Ma
- Department of Neuroscience and Physiology, Neuroscience Institute, NYU Langone Medical Center, New York, NY 10016, USA.
| | - Rachel D Groth
- Centers for Therapeutic Innovation, Pfizer, 1700 Owens Street, San Francisco, CA 94158, USA
| | - Samuel M Cohen
- Department of Neuroscience and Physiology, Neuroscience Institute, NYU Langone Medical Center, New York, NY 10016, USA
| | - John F Emery
- Department of Neuroscience and Physiology, Neuroscience Institute, NYU Langone Medical Center, New York, NY 10016, USA
| | - Boxing Li
- Department of Neuroscience and Physiology, Neuroscience Institute, NYU Langone Medical Center, New York, NY 10016, USA
| | - Esthelle Hoedt
- Department of Biochemistry and Molecular Pharmacology and Skirball Institute, NYU Langone Medical Center, New York, NY 10016, USA
| | - Guoan Zhang
- Department of Biochemistry and Molecular Pharmacology and Skirball Institute, NYU Langone Medical Center, New York, NY 10016, USA
| | - Thomas A Neubert
- Department of Biochemistry and Molecular Pharmacology and Skirball Institute, NYU Langone Medical Center, New York, NY 10016, USA
| | - Richard W Tsien
- Department of Neuroscience and Physiology, Neuroscience Institute, NYU Langone Medical Center, New York, NY 10016, USA.
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17
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Fukuchi M, Kirikoshi Y, Mori A, Eda R, Ihara D, Takasaki I, Tabuchi A, Tsuda M. Excitatory GABA induces BDNF transcription via CRTC1 and phosphorylated CREB-related pathways in immature cortical cells. J Neurochem 2014; 131:134-46. [PMID: 24965890 DOI: 10.1111/jnc.12801] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Revised: 06/11/2014] [Accepted: 06/22/2014] [Indexed: 11/29/2022]
Abstract
Although the excitatory action of GABA has been shown to activate the expression of brain-derived neurotrophic factor (BDNF), its molecular mechanisms remain unclear. Using cultured rat cortical cells, we here demonstrated that GABA induced Bdnf mRNA expression mainly via L-type voltage-dependent Ca(2+) channels (L-VDCC) at the early stage and inhibited it at the late stage of the culture, which corresponded to the excitatory and inhibitory states of cortical cells. The excitatory GABA-induced Bdnf mRNA expression was controlled by multiple Ca(2+) signaling pathways including Ca(2+) /calmodulin-dependent protein kinase (CaMK), mitogen-activated protein kinase (MAPK) and calcineurin (CN). The Bdnf-promoter IV (Bdnf-pIV) was activated by GABA, mainly via cAMP-response element (CRE)/CREB, and this was prevented by the over-expression of a dominant negative CREB. The nuclear translocation of CREB-regulated transcriptional coactivator 1 (CRTC1) was selectively induced by the GABA-induced CN pathway to activate Bdnf-pIV. On the other hand, GABA-induced Gal4-CREB-dependent transcription, which was controlled by multiple Ca(2+) signaling pathways, was prevented when the serine at position 133 of Gal4-CREB was mutated to alanine. Taken together, the excitatory action of GABA transcriptionally activated Bdnf expression through the combination of nuclear-localized CRTC1 and phosphorylated CREB in immature cortical cells, and may be the molecular mechanisms underlying Bdnf expression to control neuronal development. We demonstrated that GABA induced Bdnf expression at the early stage of the culture, in which GABA exerted its excitatory action. The excitatory GABA-induced Bdnf expression was controlled by multiple Ca(2+) signaling pathways evoked via L-VDCC. Both the CREB coactivator, CRTC1 and CREB phosphorylation participated in excitatory GABA-induced Bdnf transcription. Our present study indicates the mechanism underlying the excitatory GABA-induced Bdnf expression in immature neurons and provide new insights into molecular mechanisms underlying Bdnf expression to control neuronal development.
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Affiliation(s)
- Mamoru Fukuchi
- Department of Biological Chemistry, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan
| | - Yuya Kirikoshi
- Department of Biological Chemistry, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan
| | - Atsumi Mori
- Department of Biological Chemistry, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan
| | - Reika Eda
- Department of Biological Chemistry, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan
| | - Daisuke Ihara
- Department of Biological Chemistry, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan
| | - Ichiro Takasaki
- Division of Molecular Genetics Research, Life Science Research Center, University of Toyama, Toyama, Japan.,Department of Pharmacology, Graduate School of Science and Engineering, University of Toyama, Toyama, Japan
| | - Akiko Tabuchi
- Department of Biological Chemistry, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan
| | - Masaaki Tsuda
- Department of Biological Chemistry, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan
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Regulator of calcineurin 1 modulates expression of innate anxiety and anxiogenic responses to selective serotonin reuptake inhibitor treatment. J Neurosci 2013; 33:16930-44. [PMID: 24155299 DOI: 10.1523/jneurosci.3513-12.2013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Regulator of calcineurin 1 (RCAN1) controls the activity of calcium/calmodulin-dependent phosphatase calcineurin (CaN), which has been implicated in human anxiety disorders. Previously, we reported that RCAN1 functioned as an inhibitor of CaN activity in the brain. However, we now find enhanced phosphorylation of a CaN substrate, cAMP response element-binding protein (CREB), in the brains of Rcan1 knock-out (KO) mice. Consistent with enhanced CREB activation, we also observe enhanced expression of a CREB transcriptional target, brain-derived neurotrophic factor (BDNF) in Rcan1 KO mice. We also discovered that RCAN1 deletion or blockade of RCAN1-CaN interaction reduced CaN and protein phosphatase-1 localization to nuclear-enriched protein fractions and promoted CREB activation. Because of the potential links between CREB, BDNF, and anxiety, we examined the role of RCAN1 in the expression of innate anxiety. Rcan1 KO mice displayed reduced anxiety in several tests of unconditioned anxiety. Acute pharmacological inhibition of CaN rescued these deficits while transgenic overexpression of human RCAN1 increased anxiety. Finally, we found that Rcan1 KO mice lacked the early anxiogenic response to the selective serotonin reuptake inhibitor (SSRI) fluoxetine and had improved latency for its therapeutic anxiolytic effects. Together, our study suggests that RCAN1 plays an important role in the expression of anxiety-related and SSRI-related behaviors through CaN-dependent signaling pathways. These results identify RCAN1 as a mediator of innate emotional states and possible therapeutic target for anxiety.
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Zuloaga R, Fuentes EN, Molina A, Valdés JA. The cAMP response element binding protein (CREB) is activated by insulin-like growth factor-1 (IGF-1) and regulates myostatin gene expression in skeletal myoblast. Biochem Biophys Res Commun 2013; 440:258-64. [PMID: 24064350 DOI: 10.1016/j.bbrc.2013.09.067] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Accepted: 09/12/2013] [Indexed: 11/28/2022]
Abstract
Myostatin, a member of the Transforming Growth Factor beta (TGF-β) superfamily, plays an important role as a negative regulator of skeletal muscle growth and differentiation. We have previously reported that IGF-1 induces a transient myostatin mRNA expression, through the activation of the Nuclear Factor of Activated T cells (NFAT) in an IP3/calcium-dependent manner. Here we examined the activation of CREB transcription factor as downstream targets of IGF-1 during myoblast differentiation and its role as a regulator of myostatin gene expression. In cultured skeletal myoblast, IGF-1 induced the phosphorylation and transcriptional activation of CREB via IGF-1 Receptor/Phosphatidylinositol 3-Kinase (PI3K)/Phospholipase C gamma (PLC γ), signaling pathways. Also, IGF-1 induced calcium-dependent molecules such as Calmodulin Kinase II (CaMK II), Extracellular signal-regulated Kinases (ERK), Protein Kinase C (PKC). Additionally, we examined myostatin mRNA levels and myostatin promoter activity in differentiated myoblasts stimulated with IGF-1. We found a significant increase in mRNA contents of myostatin and its reporter activity after treatment with IGF-1. The expression of myostatin in differentiated myoblast was downregulated by the transfection of siRNA-CREB and by pharmacological inhibitors of the signaling pathways involved in CREB activation. By using pharmacological and genetic approaches together these data demonstrate that IGF-1 regulates the myostatin gene expression via CREB transcription factor during muscle cell differentiation.
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Affiliation(s)
- R Zuloaga
- Facultad de Ciencias Biológicas, Universidad Andres Bello, Santiago, Chile
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20
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Song Z, Zhao D, Yang L. Molecular mechanisms of neurodegeneration mediated by dysfunctional subcellular organelles in transmissible spongiform encephalopathies. Acta Biochim Biophys Sin (Shanghai) 2013; 45:452-64. [PMID: 23439666 DOI: 10.1093/abbs/gmt014] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Transmissible spongiform encephalopathies refer to a group of infectious neurodegenerative diseases with an entirely novel mechanism of transmission and pathophysiology including synaptic damage, dendritic atrophy, vacuolization, and microglial activation. Extensive neuronal loss is the main cause of chronic brain deterioration and fatal outcome of prion diseases. As the final outcome of pathological alterations, neuronal death is a prominent feature of all prion diseases. The mechanisms responsible for prion diseases are not well understood. A more comprehensive understanding of the molecular basis of neuronal damage is essential for the development of an effective therapy for transmissible spongiform encephalopathies and other neurodegenerative diseases sharing similar features. Here, we review the molecular mechanisms of mitochondrial dysfunction and endoplasmic reticulum stress-mediated neuronal death, which play crucial roles in the pathogenisis of prion diseases.
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Affiliation(s)
- Zhiqi Song
- State Key Laboratories for Agrobiotechnology, China Agricultural University, Beijing 100193, China
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21
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Kim SS, Seo SR. The regulator of calcineurin 1 (RCAN1/DSCR1) activates the cAMP response element-binding protein (CREB) pathway. J Biol Chem 2011; 286:37841-8. [PMID: 21890628 DOI: 10.1074/jbc.m111.232165] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
cAMP response element-binding protein (CREB) is one of the best known transcription factors in the development and function of the nervous system. In this report, we found that the regulator of calcineurin 1 (RCAN1), which is overexpressed in the brain of patients with Down syndrome, increased the phosphorylation of CREB and cAMP response element-mediated gene transcription in response to the activation of the intracellular cAMP pathway. Furthermore, we found that the increased activation of CREB signaling by RCAN1 depended on the ability of RCAN1 to inhibit calcineurin activity. Our data provide the first evidence that RCAN1 acts as an important regulatory component in the control of CREB signaling.
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Affiliation(s)
- Seon Sook Kim
- Department of Molecular Bioscience, College of Biomedical Science, Kangwon National University, Chuncheon 200-701, Republic of Korea
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22
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Lacroix J, Halaszovich CR, Schreiber DN, Leitner MG, Bezanilla F, Oliver D, Villalba-Galea CA. Controlling the activity of a phosphatase and tensin homolog (PTEN) by membrane potential. J Biol Chem 2011; 286:17945-53. [PMID: 21454672 DOI: 10.1074/jbc.m110.201749] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The recently discovered voltage-sensitive phosphatases (VSPs) hydrolyze phosphoinositides upon depolarization of the membrane potential, thus representing a novel principle for the transduction of electrical activity into biochemical signals. Here, we demonstrate the possibility to confer voltage sensitivity to cytosolic enzymes. By fusing the tumor suppressor PTEN to the voltage sensor of the prototypic VSP from Ciona intestinalis, Ci-VSP, we generated chimeric proteins that are voltage-sensitive and display PTEN-like enzymatic activity in a strictly depolarization-dependent manner in vivo. Functional coupling of the exogenous enzymatic activity to the voltage sensor is mediated by a phospholipid-binding motif at the interface between voltage sensor and catalytic domains. Our findings reveal that the main domains of VSPs and related phosphoinositide phosphatases are intrinsically modular and define structural requirements for coupling of enzymatic activity to a voltage sensor domain. A key feature of this prototype of novel engineered voltage-sensitive enzymes, termed Ci-VSPTEN, is the novel ability to switch enzymatic activity of PTEN rapidly and reversibly. We demonstrate that experimental control of Ci-VSPTEN can be obtained either by electrophysiological techniques or more general techniques, using potassium-induced depolarization of intact cells. Thus, Ci-VSPTEN provides a novel approach for studying the complex mechanism of activation, cellular control, and pharmacology of this important tumor suppressor. Moreover, by inducing temporally precise perturbation of phosphoinositide concentrations, Ci-VSPTEN will be useful for probing the role and specificity of these messengers in many cellular processes and to analyze the timing of phosphoinositide signaling.
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Affiliation(s)
- Jérôme Lacroix
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, Illinois 60637, USA
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23
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Mukherjee A, Soto C. Role of calcineurin in neurodegeneration produced by misfolded proteins and endoplasmic reticulum stress. Curr Opin Cell Biol 2011; 23:223-30. [PMID: 21295458 DOI: 10.1016/j.ceb.2010.12.006] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2010] [Revised: 12/06/2010] [Accepted: 12/31/2010] [Indexed: 11/29/2022]
Abstract
A hallmark event in neurodegenerative diseases is the accumulation of misfolded aggregated proteins in the brain leading to neuronal dysfunction and disease. Compelling evidence suggests that misfolded proteins damage cells by inducing endoplasmic reticulum (ER) stress and alterations in calcium homeostasis. Changes in cytoplasmic calcium concentration lead to unbalances on several signaling pathways. Recent data suggest that calcium-mediated hyperactivation of calcineurin (CaN), a key phosphatase in the brain, triggers synaptic dysfunction and neuronal death, the two central events responsible for brain degeneration in neurodegenerative diseases. Therefore, blocking CaN hyper-activation might be a promising therapeutic strategy to prevent brain damage in neurodegenerative diseases.
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Affiliation(s)
- Abhisek Mukherjee
- Mitchell Center for Alzheimer's Disease and Related Brain Disorders, Department of Neurology, The University of Texas Medical School at Houston, 6431 Fannin St., Houston, TX, United States
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24
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Saura CA, Valero J. The role of CREB signaling in Alzheimer’s disease and other cognitive disorders. Rev Neurosci 2011; 22:153-69. [DOI: 10.1515/rns.2011.018] [Citation(s) in RCA: 201] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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25
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beta-Amyloid disrupts activity-dependent gene transcription required for memory through the CREB coactivator CRTC1. J Neurosci 2010; 30:9402-10. [PMID: 20631169 DOI: 10.1523/jneurosci.2154-10.2010] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Activity-dependent gene expression mediating changes of synaptic efficacy is important for memory storage, but the mechanisms underlying gene transcriptional changes in age-related memory disorders are poorly understood. In this study, we report that gene transcription mediated by the cAMP-response element binding protein (CREB)-regulated transcription coactivator CRTC1 is impaired in neurons and brain from an Alzheimer's disease (AD) transgenic mouse expressing the human beta-amyloid precursor protein (APP(Sw,Ind)). Suppression of CRTC1-dependent gene transcription by beta-amyloid (Abeta) in response to cAMP and Ca(2+) signals is mediated by reduced calcium influx and disruption of PP2B/calcineurin-dependent CRTC1 dephosphorylation at Ser151. Consistently, expression of CRTC1 or active CRTC1 S151A and calcineurin mutants reverse the deficits on CRTC1 transcriptional activity in APP(Sw,Ind) neurons. Inhibition of calcium influx by pharmacological blockade of L-type voltage-gated calcium channels (VGCCs), but not by blocking NMDA or AMPA receptors, mimics the decrease on CRTC1 transcriptional activity observed in APP(Sw,Ind) neurons, whereas agonists of L-type VGCCs reverse efficiently these deficits. Consistent with a role of CRTC1 on Abeta-induced synaptic and memory dysfunction, we demonstrate a selective reduction of CRTC1-dependent genes related to memory (Bdnf, c-fos, and Nr4a2) coinciding with hippocampal-dependent spatial memory deficits in APP(Sw,Ind) mice. These findings suggest that CRTC1 plays a key role in coupling synaptic activity to gene transcription required for hippocampal-dependent memory, and that Abeta could disrupt cognition by affecting CRTC1 function.
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Chen CC, Hsu LW, Huang LT, Huang TL. Chronic administration of cyclosporine A changes expression of BDNF and TrkB in rat hippocampus and midbrain. Neurochem Res 2010; 35:1098-104. [PMID: 20361354 DOI: 10.1007/s11064-010-0160-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/22/2010] [Indexed: 12/11/2022]
Abstract
Neurotrophins, including the brain-derived neurotrophic factor (BDNF), are essential for regulating neuronal differentiation in developing brains. BDNF and its receptor tyrosine kinase receptor B (TrkB) are involved in neuronal signaling, survival and plasticity. Cyclosporine A (CsA) is a potent immunosuppressive agent which prevents allograft rejection in organ transplantation and various immunological diseases. We investigated whether chronic administration of CsA decreases BDNF gene expression in rats, and the influence of CsA on mRNA levels of TrkB receptors was also examined. For 30 days of CsA (10 mg/kg/day) administration, the expression of BDNF and TrkB mRNA was significantly decreased in the hippocampus and midbrain, but there was no significant difference in the cortex. CsA (0, 1, 5 10, 15 ug/ml) down-regulated BDNF and TrkB gene expression through cultured SH-SY5Y cells, as did all-trans retinoic acid (ATRA), and there was no effect on cell viability. These experimental results indicate that suppression of the BDNF and TrkB mRNA, protein level of BDNF expression in the hippocampus and midbrain may be related to altered behavior observed following chronic administration of CsA. A common mechanism of adverse effects of CsA induced depressive symptoms may involve neurotoxicity mediated by down-regulation of brain BDNF and TrkB.
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Affiliation(s)
- Chien-Chih Chen
- Department of Psychiatry, Chang Gung Memorial Hospital-Kaohsiung Medical Center, Chang Gung University College of Medicine, 123 Ta-Pei Rd, Niao-Sung, Kaohsiung, 83305, Taiwan, ROC
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27
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Allen DL, Uyenishi JJ, Cleary AS, Mehan RS, Lindsay SF, Reed JM. Calcineurin activates interleukin-6 transcription in mouse skeletal muscle in vivo and in C2C12 myotubes in vitro. Am J Physiol Regul Integr Comp Physiol 2010; 298:R198-210. [PMID: 19907005 PMCID: PMC2806210 DOI: 10.1152/ajpregu.00325.2009] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2009] [Accepted: 11/09/2009] [Indexed: 01/21/2023]
Abstract
Expression of the cytokine interleukin-6 (IL-6) by skeletal muscle is hugely increased in response to a single bout of endurance exercise, and this appears to be mediated by increases in intracellular calcium. We examined the effects of endurance exercise on IL-6 mRNA levels and promoter activity in skeletal muscle in vivo, and the role of the calcium-activated calcineurin signaling pathway on muscle IL-6 expression in vivo and in vitro. IL-6 mRNA levels in the mouse tibialis anterior (TA) were increased 2-10-fold by a single bout of treadmill exercise or by 3 days of voluntary wheel running. Moreover, an IL-6 promoter-driven luciferase transgene was activated in TA by both treadmill and wheel-running exercise and by injection with a calcineurin plasmid. Exercise also increased muscle mRNA expression of the calcineurin regulatory gene MCIP1, as did treatment of C(2)C(12) myotubes with the calcium ionophore A23187. Cotransfection of C(2)C(12) myotubes with a constitutively active calcineurin construct significantly increased while cotransfection with the calcineurin inhibitor CAIN inhibited activity of a mouse IL-6 promoter-reporter construct. Cotransfection with a myocyte enhancer-factor-2 (MEF-2) expression construct increased basal IL-6 promoter activity and augmented the effects of calcineurin cotransfection, while cotransfection with the MEF-2 antagonist MITR repressed calcineurin-activated IL-6 promoter activity in vitro. Surprisingly, cotransfection with a dominant-negative form of another calcineurin-activated transcription factor, nuclear factor activator of T cells (NFAT), greatly potentiated both basal and calcineurin-stimulated IL-6 promoter activity in C(2)C(12) myotubes. Mutation of the MEF-2 DNA binding sites attenuated, while mutation of the NFAT DNA binding sites potentiated basal and calcineurin-activated IL-6 promoter activity. Finally, CREB and C/EBP were necessary for basal IL-6 promoter activity and sufficient to increase IL-6 promoter activity but had minimal roles in calcineurin-activated IL-6 promoter activity. Together, these results suggest that IL-6 transcription in skeletal muscle cells can be activated by a calcineurin-MEF-2 axis which is antagonized by NFAT.
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Affiliation(s)
- David L Allen
- Dept. of Integrative Physiology, Univ. of Colorado, Boulder, Campus Box 354, Boulder, CO 80309, USA.
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Qiu Z, Ghosh A. A calcium-dependent switch in a CREST-BRG1 complex regulates activity-dependent gene expression. Neuron 2009; 60:775-87. [PMID: 19081374 DOI: 10.1016/j.neuron.2008.09.040] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2008] [Revised: 07/14/2008] [Accepted: 09/29/2008] [Indexed: 01/27/2023]
Abstract
CREST plays a critical role in activity-dependent development, but its mechanism of action is not well understood. Here, we show that a CREST-BRG1 complex regulates promoter activation by orchestrating a calcium-dependent release of a repressor complex and a recruitment of an activator complex. In resting neurons, transcription of the c-fos promoter is inhibited by BRG1-dependent recruitment of a phospho-Rb-HDAC repressor complex. Upon calcium influx, Rb becomes dephosphorylated at serine 795 by calcineurin, which leads to release of the repressor complex. At the same time, there is increased recruitment of CBP to the promoter by a CREST-dependent mechanism, which leads to transcriptional activation. The CREST-BRG1 also binds to the NR2B promoter, and activity-dependent induction of NR2B expression involves a release of HDAC1 and recruitment of CBP, suggesting that this mechanism may be generally involved in regulating calcium-dependent transcription of neuronal genes.
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Affiliation(s)
- Zilong Qiu
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093-0366, USA
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29
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TORC1 regulates activity-dependent CREB-target gene transcription and dendritic growth of developing cortical neurons. J Neurosci 2009; 29:2334-43. [PMID: 19244510 DOI: 10.1523/jneurosci.2296-08.2009] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
CREB-target gene transcription during neuronal excitation is important for many aspects of neuronal development and function, including dendrite morphogenesis. However, the signaling events that regulate cAMP response element-binding protein (CREB)-mediated gene transcription during dendritic development are not well understood. Herein we report that the CREB coactivator TORC1 (transducer of regulated CREB 1) is required for activity-dependent CREB-target gene expression and dendrite growth in developing cortical neurons. Ca(2+) influx via voltage-gated calcium channels induced TORC1 dephosphorylation and translocation into the nucleus in a calcineurin-dependent manner. Nuclear accumulation of TORC1 initiated the expression of CREB-target genes, including salt-inducible kinase 1 (SIK1). In response of persistent depolarization, de novo SIK1 protein in turn promoted TORC1 phosphorylation and consequent depletion of nucleus-localized TORC1. SIK1 induction thus appears to act as a negative feedback signal that prevents persistent CREB/TORC1-dependent transcription in the face of long-lasting neuronal activity. Overexpressing wild type TORC1 promoted basal as well as activity-induced dendritic growth, whereas expressing a dominant-negative form of TORC1 or downregulating TORC1 inhibited activity-dependent dendritic growth in vitro and in vivo. Together, these results suggest that neuronal activity-dependent dendritic growth in developing cortical neurons relies on transient TORC1-mediated CREB-target gene transcription.
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Lam BYH, Zhang W, Enticknap N, Haggis E, Cader MZ, Chawla S. Inverse regulation of plasticity-related immediate early genes by calcineurin in hippocampal neurons. J Biol Chem 2009; 284:12562-71. [PMID: 19270309 DOI: 10.1074/jbc.m901121200] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In the mammalian hippocampus, changes in the expression of immediate early genes (IEGs) is thought to contribute to long term plastic changes in neurons brought about by learning tasks and high frequency stimulation of synapses. The phosphatase calcineurin has emerged as an important negative regulator of hippocampus-dependent learning and long term potentiation. Here we investigated the possibility that the constraining action of calcineurin on hippocampal plasticity is mediated in part by regulation of gene expression through negative control of transcription factors, such as cAMP-response element (CRE)-binding protein (CREB). We assessed the effect of calcineurin inhibitors on CREB activation by neuronal activity and show that calcineurin activity is in fact required for CREB-mediated gene expression. However, inhibition of calcineurin had disparate effects on the transcriptional induction of CREB-dependent IEGs. We find that the IEG c-fos is unaffected by suppression of calcineurin activity, the plasticity-related genes Egr1/Zif268 and Egr2/Krox-20 are up-regulated, and genes encoding the orphan nuclear hormone receptors Nor1 and Nur77 are down-regulated. We further show that the up-regulation of particular IEGs is probably due to the presence of serum response elements (SREs) in their promoters, because SRE-mediated gene expression is enhanced by calcineurin blockers. Moreover, expression of the c-fos gene, which is unaffected by calcineurin inhibitors, could be down-regulated by mutating the SRE. Conversely, SRE-mediated c-fos induction in the absence of a functional CRE was enhanced by calcineurin inhibitors. Our experiments thus implicate calcineurin as a negative regulator of SRE-dependent neuronal genes.
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Affiliation(s)
- Brian Yee Hong Lam
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, United Kingdom
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Kunjilwar KK, Fishman HM, Englot DJ, O'Neil RG, Walters ET. Long-lasting hyperexcitability induced by depolarization in the absence of detectable Ca2+ signals. J Neurophysiol 2009; 101:1351-60. [PMID: 19144743 DOI: 10.1152/jn.91012.2008] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Learning and memory depend on neuronal alterations induced by electrical activity. Most examples of activity-dependent plasticity, as well as adaptive responses to neuronal injury, have been linked explicitly or implicitly to induction by Ca(2+) signals produced by depolarization. Indeed, transient Ca(2+) signals are commonly assumed to be the only effective transducers of depolarization into adaptive neuronal responses. Nevertheless, Ca(2+)-independent depolarization-induced signals might also trigger plastic changes. Establishing the existence of such signals is a challenge because procedures that eliminate Ca(2+) transients also impair neuronal viability and tolerance to cellular stress. We have taken advantage of nociceptive sensory neurons in the marine snail Aplysia, which exhibit unusual tolerance to extreme reduction of extracellular and intracellular free Ca(2+) levels. The axons of these neurons exhibit a depolarization-induced memory-like hyperexcitability that lasts a day or longer and depends on local protein synthesis for induction. Here we show that transient localized depolarization of these axons in an excised nerve-ganglion preparation or in dissociated cell culture can induce short- and intermediate-term axonal hyperexcitability as well as long-term protein synthesis-dependent hyperexcitability under conditions in which Ca(2+) entry is prevented (by bathing in nominally Ca(2+) -free solutions containing EGTA) and detectable Ca(2+) transients are eliminated (by adding BAPTA-AM). Disruption of Ca(2+) release from intracellular stores by pretreatment with thapsigargin also failed to affect induction of axonal hyperexcitability. These findings suggest that unrecognized Ca(2+)-independent signals exist that can transduce intense depolarization into adaptive cellular responses during neuronal injury, prolonged high-frequency activity, or other sustained depolarizing events.
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Affiliation(s)
- Kumud K Kunjilwar
- Department of Integrative Biology and Pharmacology, University of Texas Medical School at Houston, Houston, TX, USA
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Control of the establishment of aversive memory by calcineurin and Zif268. Nat Neurosci 2008; 11:572-8. [PMID: 18425121 DOI: 10.1038/nn.2113] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2007] [Accepted: 03/24/2008] [Indexed: 11/08/2022]
Abstract
Emotional memory is a rapidly acquired and persistent form of memory, and its robustness is in part determined by the initial strength of the memory. Here, we provide new evidence that the protein phosphatase calcineurin (CaN), a potent negative regulator of neuronal signaling that is known to constrain learning and memory, critically regulates the establishment of emotional memory through mechanisms involving the immediate early gene Zif268 (also known as Egr1). We found that CaN is inhibited in the amygdala during the establishment of aversive memory, but Zif268 is activated. Using inducible transgenesis in mice, we further saw that CaN inhibition and Zif268 overexpression during memory establishment strengthen the memory trace and enhance its resistance to extinction. We found that CaN inhibition correlates with increased Zif268 expression and that a common pool of proteins is regulated in the amygdala after CaN inhibition and Zif268 overexpression. Together, these findings reveal a previously unknown mechanism for the control of emotional memory that depends on CaN and Zif268.
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