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Gaido OER, Pavlaki N, Granger JM, Mesubi OO, Liu B, Lin BL, Long A, Walker D, Mayourian J, Schole KL, Terrillion CE, Nkashama LJ, Hulsurkar MM, Dorn LE, Ferrero KM, Huganir RL, Müller FU, Wehrens XHT, Liu JO, Luczak ED, Bezzerides VJ, Anderson ME. An improved reporter identifies ruxolitinib as a potent and cardioprotective CaMKII inhibitor. Sci Transl Med 2023; 15:eabq7839. [PMID: 37343080 PMCID: PMC11022683 DOI: 10.1126/scitranslmed.abq7839] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 05/31/2023] [Indexed: 06/23/2023]
Abstract
Ca2+/calmodulin-dependent protein kinase II (CaMKII) hyperactivity causes cardiac arrhythmias, a major source of morbidity and mortality worldwide. Despite proven benefits of CaMKII inhibition in numerous preclinical models of heart disease, translation of CaMKII antagonists into humans has been stymied by low potency, toxicity, and an enduring concern for adverse effects on cognition due to an established role of CaMKII in learning and memory. To address these challenges, we asked whether any clinically approved drugs, developed for other purposes, were potent CaMKII inhibitors. For this, we engineered an improved fluorescent reporter, CaMKAR (CaMKII activity reporter), which features superior sensitivity, kinetics, and tractability for high-throughput screening. Using this tool, we carried out a drug repurposing screen (4475 compounds in clinical use) in human cells expressing constitutively active CaMKII. This yielded five previously unrecognized CaMKII inhibitors with clinically relevant potency: ruxolitinib, baricitinib, silmitasertib, crenolanib, and abemaciclib. We found that ruxolitinib, an orally bioavailable and U.S. Food and Drug Administration-approved medication, inhibited CaMKII in cultured cardiomyocytes and in mice. Ruxolitinib abolished arrhythmogenesis in mouse and patient-derived models of CaMKII-driven arrhythmias. A 10-min pretreatment in vivo was sufficient to prevent catecholaminergic polymorphic ventricular tachycardia, a congenital source of pediatric cardiac arrest, and rescue atrial fibrillation, the most common clinical arrhythmia. At cardioprotective doses, ruxolitinib-treated mice did not show any adverse effects in established cognitive assays. Our results support further clinical investigation of ruxolitinib as a potential treatment for cardiac indications.
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Affiliation(s)
- Oscar E. Reyes Gaido
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Nikoleta Pavlaki
- Department of Cardiology, Boston Children’s Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Jonathan M. Granger
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Olurotimi O. Mesubi
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Bian Liu
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Brian L. Lin
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Alan Long
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - David Walker
- Department of Cardiology, Boston Children’s Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Joshua Mayourian
- Department of Cardiology, Boston Children’s Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Kate L. Schole
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Chantelle E. Terrillion
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Lubika J. Nkashama
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Mohit M. Hulsurkar
- Cardiovascular Research Institute and Department of Integrative Physiology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Lauren E. Dorn
- Cardiovascular Research Institute and Department of Integrative Physiology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Kimberly M. Ferrero
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Richard L. Huganir
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Frank U. Müller
- Institute of Pharmacology and Toxicology, University of Münster, Münster 48149, Germany
| | - Xander H. T. Wehrens
- Cardiovascular Research Institute and Department of Integrative Physiology, Baylor College of Medicine, Houston, TX 77030, USA
- Departments of Medicine, Neuroscience, and Pediatrics, Center for Space Medicine, Baylor College of Medicine, Houston, TX 77030, USA
| | - Jun O. Liu
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Elizabeth D. Luczak
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Vassilios J. Bezzerides
- Department of Cardiology, Boston Children’s Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Mark E. Anderson
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Division of Biological Sciences and the Pritzker School of Medicine, University of Chicago, Chicago, IL 60637, USA
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2
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Shiosaka S. Kallikrein 8: A key sheddase to strengthen and stabilize neural plasticity. Neurosci Biobehav Rev 2022; 140:104774. [PMID: 35820483 DOI: 10.1016/j.neubiorev.2022.104774] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 07/01/2022] [Accepted: 07/06/2022] [Indexed: 11/19/2022]
Abstract
Neural networks are modified and reorganized throughout life, even in the matured brain. Synapses in the networks form, change, or disappear dynamically in the plasticity state. The pre- and postsynaptic signaling, transmission, and structural dynamics have been studied considerably well. However, not many studies have shed light on the events in the synaptic cleft and intercellular space. Neural activity-dependent protein shedding is a phenomenon in which (1) presynaptic excitation evokes secretion or activation of sheddases, (2) sheddases are involved not only in cleavage of membrane- or matrix-bound proteins but also in mechanical modulation of cell-to-cell connectivity, and (3) freed activity domains of protein factors play a role in receptor-mediated or non-mediated biological actions. Kallikrein 8/neuropsin (KLK8) is a kallikrein family serine protease rich in the mammalian limbic brain. Accumulated evidence has suggested that KLK8 is an important modulator of neural plasticity and consequently, cognition. Insufficiency, as well as excess of KLK8 may have detrimental effects on limbic functions.
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Affiliation(s)
- Sadao Shiosaka
- Osaka Psychiatric Research Center, Osaka Psychiatric Medical Center, Osaka Prefectural Hospital Organization, Miyanosaka 3-16-21, Hirakata-shi, Osaka 573-0022, Japan.
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Mohanan AG, Gunasekaran S, Jacob RS, Omkumar RV. Role of Ca2+/Calmodulin-Dependent Protein Kinase Type II in Mediating Function and Dysfunction at Glutamatergic Synapses. Front Mol Neurosci 2022; 15:855752. [PMID: 35795689 PMCID: PMC9252440 DOI: 10.3389/fnmol.2022.855752] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Accepted: 03/21/2022] [Indexed: 01/25/2023] Open
Abstract
Glutamatergic synapses harbor abundant amounts of the multifunctional Ca2+/calmodulin-dependent protein kinase type II (CaMKII). Both in the postsynaptic density as well as in the cytosolic compartment of postsynaptic terminals, CaMKII plays major roles. In addition to its Ca2+-stimulated kinase activity, it can also bind to a variety of membrane proteins at the synapse and thus exert spatially restricted activity. The abundance of CaMKII in glutamatergic synapse is akin to scaffolding proteins although its prominent function still appears to be that of a kinase. The multimeric structure of CaMKII also confers several functional capabilities on the enzyme. The versatility of the enzyme has prompted hypotheses proposing several roles for the enzyme such as Ca2+ signal transduction, memory molecule function and scaffolding. The article will review the multiple roles played by CaMKII in glutamatergic synapses and how they are affected in disease conditions.
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Affiliation(s)
- Archana G. Mohanan
- Neurobiology Division, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, India
| | - Sowmya Gunasekaran
- Neurobiology Division, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, India
- Research Scholar, Manipal Academy of Higher Education, Manipal, India
| | - Reena Sarah Jacob
- Neurobiology Division, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, India
- Research Scholar, Manipal Academy of Higher Education, Manipal, India
| | - R. V. Omkumar
- Neurobiology Division, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, India
- *Correspondence: R. V. Omkumar,
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Trans-cinnamaldehyde improves neuroinflammation-mediated NMDA receptor dysfunction and memory deficits through blocking NF-κB pathway in presenilin1/2 conditional double knockout mice. Brain Behav Immun 2019; 82:45-62. [PMID: 31376499 DOI: 10.1016/j.bbi.2019.07.032] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2019] [Revised: 07/11/2019] [Accepted: 07/30/2019] [Indexed: 12/24/2022] Open
Abstract
A chronic neuroinflammatory response has been considered as a critical pathogenesis promoting neurodegenerative progression in Alzheimer's disease (AD). During neuroinflammatory process, microglia are excessively activated and simultaneously release numerous pro-inflammatory mediators that cause synaptic dysfunction in the forebrain prior to neuronal degeneration and memory deficits in AD. Thus, prevention of neuroinflammation-mediated synaptic dysfunction may be a potential therapeutic approach against neurodegenerative disorders. Trans-cinnamaldehyde (TCA) is a primary bioactive component derived from the stem bark of Cinnamomum cassia, and it possesses potent anti-inflammatory and neuroprotective activities in in vivo and in vitro experiments. However, the in-depth molecular mechanisms of TCA underlying anti-neuroinflammatory and neuroprotective effects on memory deficits in AD are still unclear. The presenilin 1 and 2 conditional double knockout (PS cDKO) mice exhibit AD-like phenotypes including obvious neuroinflammatory responses and synaptic dysfunction and memory deficits. Here, PS cDKO were used to evaluate the potential neuroprotective effects of TCA against neuroinflammation-mediated dementia by performing behavioral tests, electrophysiological recordings and molecular biology analyses. We observed that TCA treatment reversed abnormal expression of synaptic proteins and tau hyperphosphorylation in the hippocampus and prefrontal cortex of PS cDKO mice. TCA treatment also ameliorated NMDA receptor (NMDAR) dysfunction including impaired NMDAR-mediated responses and long-term potentiation (LTP) induction in the hippocampus of PS cDKO mice. Moreover, TCA possesses an ability to suppress neuroinflammatory responses by diminishing microglial activation and levels of pro-inflammatory mediators in the hippocampus and prefrontal cortex of PS cDKO mice. Importantly, improving NMDAR dysfunction and memory deficits of PS cDKO mice was due to the inhibition of neuroinflammatory responses through TCA's interruptive effect on the nuclear factor kappa B (NF-κB) signaling pathway. Therefore, TCA may be a potential anti-neuroinflammatory agent for deterring neurodegenerative progression of AD.
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Neuromodulators and Long-Term Synaptic Plasticity in Learning and Memory: A Steered-Glutamatergic Perspective. Brain Sci 2019; 9:brainsci9110300. [PMID: 31683595 PMCID: PMC6896105 DOI: 10.3390/brainsci9110300] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 10/24/2019] [Accepted: 10/29/2019] [Indexed: 12/19/2022] Open
Abstract
The molecular pathways underlying the induction and maintenance of long-term synaptic plasticity have been extensively investigated revealing various mechanisms by which neurons control their synaptic strength. The dynamic nature of neuronal connections combined with plasticity-mediated long-lasting structural and functional alterations provide valuable insights into neuronal encoding processes as molecular substrates of not only learning and memory but potentially other sensory, motor and behavioural functions that reflect previous experience. However, one key element receiving little attention in the study of synaptic plasticity is the role of neuromodulators, which are known to orchestrate neuronal activity on brain-wide, network and synaptic scales. We aim to review current evidence on the mechanisms by which certain modulators, namely dopamine, acetylcholine, noradrenaline and serotonin, control synaptic plasticity induction through corresponding metabotropic receptors in a pathway-specific manner. Lastly, we propose that neuromodulators control plasticity outcomes through steering glutamatergic transmission, thereby gating its induction and maintenance.
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6
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Rhee J, Park K, Kim KC, Shin CY, Chung C. Impaired Hippocampal Synaptic Plasticity and Enhanced Excitatory Transmission in a Novel Animal Model of Autism Spectrum Disorders with Telomerase Reverse Transcriptase Overexpression. Mol Cells 2018; 41:486-494. [PMID: 29696935 PMCID: PMC5974625 DOI: 10.14348/molcells.2018.0145] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Accepted: 04/02/2018] [Indexed: 01/23/2023] Open
Abstract
Recently, we have reported that animals with telomerase reverse transcriptase (TERT) overexpression exhibit reduced social interaction, decreased preference for novel social interaction and poor nest-building behaviors symptoms that mirror those observed in human autism spectrum disorders (ASD). Overexpression of TERT also alters the excitatory/inhibitory (E/I) ratio in the medial prefrontal cortex. However, the effects of TERT overexpression on hippocampal-dependent learning and synaptic efficacy have not been investigated. In the present study, we employed electrophysiological approaches in combination with behavioral analysis to examine hippocampal function of TERT transgenic (TERT-tg) mice and FVB controls. We found that TERT overexpression results in enhanced hippocampal excitation with no changes in inhibition and significantly impairs long-term synaptic plasticity. Interestingly, the expression levels of phosphorylated CREB and phosphory-lated CaMKIIα were significantly decreased while the expression level of CaMKIIα was slightly increased in the hippocampus of TERT-overexpressing mice. Our observations highlight the importance of TERT in normal synaptic function and behavior and provide additional information on a novel animal model of ASD associated with TERT overexpression.
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Affiliation(s)
- Jeehae Rhee
- Department of Biological Sciences, College of Bioscience and Biotechnology, Konkuk University, Seoul 05029,
Korea
| | - Kwanghoon Park
- Department of Biological Sciences, College of Bioscience and Biotechnology, Konkuk University, Seoul 05029,
Korea
| | - Ki Chan Kim
- Department of Neuroscience and Department of Advanced Translational Medicine, School of Medicine, Konkuk University, Seoul 05029,
Korea
| | - Chan Young Shin
- Department of Neuroscience and Department of Advanced Translational Medicine, School of Medicine, Konkuk University, Seoul 05029,
Korea
| | - ChiHye Chung
- Department of Biological Sciences, College of Bioscience and Biotechnology, Konkuk University, Seoul 05029,
Korea
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7
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Pérez Ortiz JM, Mollema N, Toker N, Adamski CJ, O'Callaghan B, Duvick L, Friedrich J, Walters MA, Strasser J, Hawkinson JE, Zoghbi HY, Henzler C, Orr HT, Lagalwar S. Reduction of protein kinase A-mediated phosphorylation of ATXN1-S776 in Purkinje cells delays onset of Ataxia in a SCA1 mouse model. Neurobiol Dis 2018; 116:93-105. [PMID: 29758256 DOI: 10.1016/j.nbd.2018.05.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 04/17/2018] [Accepted: 05/09/2018] [Indexed: 12/27/2022] Open
Abstract
Spinocerebellar ataxia type 1 (SCA1) is a polyglutamine (polyQ) repeat neurodegenerative disease in which a primary site of pathogenesis are cerebellar Purkinje cells. In addition to polyQ expansion of ataxin-1 protein (ATXN1), phosphorylation of ATXN1 at the serine 776 residue (ATXN1-pS776) plays a significant role in protein toxicity. Utilizing a biochemical approach, pharmacological agents and cell-based assays, including SCA1 patient iPSC-derived neurons, we examine the role of Protein Kinase A (PKA) as an effector of ATXN1-S776 phosphorylation. We further examine the implications of PKA-mediated phosphorylation at ATXN1-S776 on SCA1 through genetic manipulation of the PKA catalytic subunit Cα in Pcp2-ATXN1[82Q] mice. Here we show that pharmacologic inhibition of S776 phosphorylation in transfected cells and SCA1 patient iPSC-derived neuronal cells lead to a decrease in ATXN1. In vivo, reduction of PKA-mediated ATXN1-pS776 results in enhanced degradation of ATXN1 and improved cerebellar-dependent motor performance. These results provide evidence that PKA is a biologically important kinase for ATXN1-pS776 in cerebellar Purkinje cells.
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Affiliation(s)
- Judit M Pérez Ortiz
- Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN, United States; Graduate Program in Neuroscience, University of Minnesota, Minneapolis, MN, United States
| | - Nissa Mollema
- Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN, United States; Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN, United States
| | - Nicholas Toker
- Skidmore College Neuroscience Program, Saratoga Springs, NY, United States
| | - Carolyn J Adamski
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, and Department of Molecular and Human Genetics, Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX, United States
| | - Brennon O'Callaghan
- Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN, United States; Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN, United States
| | - Lisa Duvick
- Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN, United States; Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN, United States
| | - Jillian Friedrich
- Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN, United States; Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN, United States
| | - Michael A Walters
- Department of Medicinal Chemistry, Institute for Therapeutics Discovery and Development, University of Minnesota, United States
| | - Jessica Strasser
- Department of Medicinal Chemistry, Institute for Therapeutics Discovery and Development, University of Minnesota, United States
| | - Jon E Hawkinson
- Department of Medicinal Chemistry, Institute for Therapeutics Discovery and Development, University of Minnesota, United States
| | - Huda Y Zoghbi
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, and Department of Molecular and Human Genetics, Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX, United States
| | - Christine Henzler
- RISS Bioinformatics, Minnesota Supercomputing Institute, University of Minnesota, Minneapolis, MN, United States
| | - Harry T Orr
- Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN, United States; Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN, United States.
| | - Sarita Lagalwar
- Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN, United States; Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN, United States; Skidmore College Neuroscience Program, Saratoga Springs, NY, United States.
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8
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Nicotinic modulation of hippocampal cell signaling and associated effects on learning and memory. Physiol Behav 2015; 155:162-71. [PMID: 26687895 DOI: 10.1016/j.physbeh.2015.12.008] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Revised: 11/30/2015] [Accepted: 12/10/2015] [Indexed: 11/21/2022]
Abstract
The hippocampus is a key brain structure involved in synaptic plasticity associated with long-term declarative memory formation. Importantly, nicotine and activation of nicotinic acetylcholine receptors (nAChRs) can alter hippocampal plasticity and these changes may occur through modulation of hippocampal kinases and transcription factors. Hippocampal kinases such as cAMP-dependent protein kinase (PKA), calcium/calmodulin-dependent protein kinases (CAMKs), extracellular signal-regulated kinases 1 and 2 (ERK1/2), and c-jun N-terminal kinase 1 (JNK1), and the transcription factor cAMP-response element-binding protein (CREB) that are activated either directly or indirectly by nicotine may modulate hippocampal plasticity and in parallel hippocampus-dependent learning and memory. Evidence suggests that nicotine may alter hippocampus-dependent learning by changing the time and magnitude of activation of kinases and transcription factors normally involved in learning and by recruiting additional cell signaling molecules. Understanding how nicotine alters learning and memory will advance basic understanding of the neural substrates of learning and aid in understanding mental disorders that involve cognitive and learning deficits.
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9
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Ma J, Duan Y, Qin Z, Wang J, Liu W, Xu M, Zhou S, Cao X. Overexpression of αCaMKII impairs behavioral flexibility and NMDAR-dependent long-term depression in the medial prefrontal cortex. Neuroscience 2015; 310:528-40. [PMID: 26415772 DOI: 10.1016/j.neuroscience.2015.09.051] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Revised: 09/02/2015] [Accepted: 09/20/2015] [Indexed: 01/24/2023]
Abstract
The medial prefrontal cortex (mPFC) participates in the behavioral flexibility. As a major downstream molecule in the NMDA receptor signaling, alpha-Ca(2+)/calmodulin-dependent protein kinase II (αCaMKII) is crucial for hippocampal long-term potentiation (LTP) and hippocampus-related memory. However, the role of αCaMKII in mPFC-related behavioral flexibility and mPFC synaptic plasticity remains elusive. In the present study, using chemical-genetic approaches to temporally up-regulate αCaMKII activity, we found that αCaMKII-F89G transgenic mice exhibited impaired behavioral flexibility in Y-water maze arm reversal task. Notably, in vitro electrophysiological analysis showed normal basal synaptic transmission, LTP and depotentiation, but selectively impaired NMDAR-dependent long-term depression (LTD) in the mPFC of αCaMKII-F89G transgenic mice. In accordance with the deficit in NMDAR-dependent LTD, αCaMKII-F89G transgenic mice exhibited impaired AMPAR internalization during NMDAR-dependent chemical LTD expression in the mPFC. Furthermore, the above deficits in behavioral flexibility, NMDAR-dependent LTD and AMPAR internalization could all be reversed by 1-naphthylmethyl (NM)-PP1, a specific inhibitor of exogenous αCaMKII-F89G activity. Taken together, our results for the first time indicate that αCaMKII overexpression in the forebrain impairs behavioral flexibility and NMDAR-dependent LTD in the mPFC, and supports the notion that there is a close relationship between NMDAR-dependent LTD and behavioral flexibility.
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Affiliation(s)
- J Ma
- Key Laboratory of Brain Functional Genomics (East China Normal University), Ministry of Education, Shanghai Key Laboratory of Brain Functional Genomics (East China Normal University), School of Life Sciences, East China Normal University, 3663 North Zhongshan Road, Shanghai 200062, China
| | - Y Duan
- Key Laboratory of Brain Functional Genomics (East China Normal University), Ministry of Education, Shanghai Key Laboratory of Brain Functional Genomics (East China Normal University), School of Life Sciences, East China Normal University, 3663 North Zhongshan Road, Shanghai 200062, China
| | - Z Qin
- Key Laboratory of Brain Functional Genomics (East China Normal University), Ministry of Education, Shanghai Key Laboratory of Brain Functional Genomics (East China Normal University), School of Life Sciences, East China Normal University, 3663 North Zhongshan Road, Shanghai 200062, China
| | - J Wang
- Key Laboratory of Brain Functional Genomics (East China Normal University), Ministry of Education, Shanghai Key Laboratory of Brain Functional Genomics (East China Normal University), School of Life Sciences, East China Normal University, 3663 North Zhongshan Road, Shanghai 200062, China
| | - W Liu
- Key Laboratory of Brain Functional Genomics (East China Normal University), Ministry of Education, Shanghai Key Laboratory of Brain Functional Genomics (East China Normal University), School of Life Sciences, East China Normal University, 3663 North Zhongshan Road, Shanghai 200062, China
| | - M Xu
- Key Laboratory of Brain Functional Genomics (East China Normal University), Ministry of Education, Shanghai Key Laboratory of Brain Functional Genomics (East China Normal University), School of Life Sciences, East China Normal University, 3663 North Zhongshan Road, Shanghai 200062, China
| | - S Zhou
- Key Laboratory of Brain Functional Genomics (East China Normal University), Ministry of Education, Shanghai Key Laboratory of Brain Functional Genomics (East China Normal University), School of Life Sciences, East China Normal University, 3663 North Zhongshan Road, Shanghai 200062, China
| | - X Cao
- Key Laboratory of Brain Functional Genomics (East China Normal University), Ministry of Education, Shanghai Key Laboratory of Brain Functional Genomics (East China Normal University), School of Life Sciences, East China Normal University, 3663 North Zhongshan Road, Shanghai 200062, China.
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10
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Shifting towards a model of mGluR5 dysregulation in schizophrenia: Consequences for future schizophrenia treatment. Neuropharmacology 2015; 115:73-91. [PMID: 26349010 DOI: 10.1016/j.neuropharm.2015.08.003] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Revised: 08/02/2015] [Accepted: 08/03/2015] [Indexed: 12/22/2022]
Abstract
Metabotropic glutamate receptor subtype 5 (mGluR5), encoded by the GRM5 gene, represents a compelling novel drug target for the treatment of schizophrenia. mGluR5 is a postsynaptic G-protein coupled glutamate receptor strongly linked with several critical cellular processes that are reported to be disrupted in schizophrenia. Accordingly, mGluR5 positive allosteric modulators show encouraging therapeutic potential in preclinical schizophrenia models, particularly for the treatment of cognitive dysfunctions against which currently available therapeutics are largely ineffective. More work is required to support the progression of mGluR5-targeting drugs into the clinic for schizophrenia treatment, although some obstacles may be overcome by comprehensively understanding how mGluR5 itself is involved in the neurobiology of the disorder. Several processes that are necessary for the regulation of mGluR5 activity have been identified, but not examined, in the context of schizophrenia. These processes include protein-protein interactions, dimerisation, subcellular trafficking, the impact of genetic variability or mutations on protein function, as well as epigenetic, post-transcriptional and post-translational processes. It is essential to understand these aspects of mGluR5 to determine whether they are affected in schizophrenia pathology, and to assess the consequences of mGluR5 dysfunction for the future use of mGluR5-based drugs. Here, we summarise the known processes that regulate mGluR5 and those that have already been studied in schizophrenia, and discuss the consequences of this dysregulation for current mGluR5 pharmacological strategies. This article is part of the Special Issue entitled 'Metabotropic Glutamate Receptors, 5 years on'.
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11
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Olivito L, Saccone P, Perri V, Bachman JL, Fragapane P, Mele A, Huganir RL, De Leonibus E. Phosphorylation of the AMPA receptor GluA1 subunit regulates memory load capacity. Brain Struct Funct 2014; 221:591-603. [PMID: 25381005 PMCID: PMC4425615 DOI: 10.1007/s00429-014-0927-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Accepted: 10/17/2014] [Indexed: 01/13/2023]
Abstract
Memory capacity (MC) refers to the number of elements one can maintain for a short retention interval. The molecular mechanisms underlying MC are unexplored. We have recently reported that mice as well as humans have a limited MC, which is reduced by hippocampal lesions. Here, we addressed the molecular mechanisms supporting MC. GluA1 AMPA-receptors (AMPA-R) mediate the majority of fast excitatory synaptic transmission in the brain and are critically involved in memory. Phosphorylation of GluA1 at serine residues S831 and S845 is promoted by CaMKII and PKA, respectively, and regulates AMPA-R function in memory duration. We hypothesized that AMPA-R phosphorylation may also be a key plastic process for supporting MC because it occurs in a few minutes, and potentiates AMPA-R ion channel function. Here, we show that knock-in mutant mice that specifically lack both of S845 and S831 phosphorylation sites on the GluA1 subunit had reduced MC in two different behavioral tasks specifically designed to assess MC in mice. This demonstrated a causal link between AMPA-R phosphorylation and MC. We then showed that information load regulates AMPA-R phosphorylation within the hippocampus, and that an overload condition associated with impaired memory is paralleled by a lack of AMPA-R phosphorylation. Accordingly, we showed that in conditions of high load, but not of low load, the pharmacological inhibition of the NMDA–CaMKII–PKA pathways within the hippocampus prevents memory as well as associated AMPA-R phosphorylation. These data provide the first identified molecular mechanism that regulates MC.
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Affiliation(s)
- Laura Olivito
- Institute of Genetics and Biophysics, CNR, Via P. Castellino 111, 80131, Naples, Italy
| | - Paola Saccone
- Telethon Institute of Genetics and Medicine (TIGEM), Naples, Italy
| | - Valentina Perri
- Dipartimento di Biologia e Biotecnologie, Università degli Studi di Roma "La Sapienza", Rome, Italy
- Centro di Ricerca in Neurobiologia-D. Bovet, Università degli Studi di Roma "La Sapienza", Rome, Italy
| | - Julia L Bachman
- Department of Neuroscience and Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Hunterian 1001, 725 North Wolfe Street, Baltimore, MD, 21205, USA
| | - Paola Fragapane
- Istituto di Biologia e Patologia Molecolare, CNR, Rome, Italy
| | - Andrea Mele
- Dipartimento di Biologia e Biotecnologie, Università degli Studi di Roma "La Sapienza", Rome, Italy
- Centro di Ricerca in Neurobiologia-D. Bovet, Università degli Studi di Roma "La Sapienza", Rome, Italy
| | - Richard L Huganir
- Department of Neuroscience and Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Hunterian 1001, 725 North Wolfe Street, Baltimore, MD, 21205, USA
| | - Elvira De Leonibus
- Institute of Genetics and Biophysics, CNR, Via P. Castellino 111, 80131, Naples, Italy.
- Telethon Institute of Genetics and Medicine (TIGEM), Naples, Italy.
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12
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Jacobs S, Cui Z, Feng R, Wang H, Wang D, Tsien JZ. Molecular and genetic determinants of the NMDA receptor for superior learning and memory functions. PLoS One 2014; 9:e111865. [PMID: 25360708 PMCID: PMC4216132 DOI: 10.1371/journal.pone.0111865] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 10/06/2014] [Indexed: 12/17/2022] Open
Abstract
The opening-duration of the NMDA receptors implements Hebb's synaptic coincidence-detection and is long thought to be the rate-limiting factor underlying superior memory. Here, we investigate the molecular and genetic determinants of the NMDA receptors by testing the “synaptic coincidence-detection time-duration” hypothesis vs. “GluN2B intracellular signaling domain” hypothesis. Accordingly, we generated a series of GluN2A, GluN2B, and GluN2D chimeric subunit transgenic mice in which C-terminal intracellular domains were systematically swapped and overexpressed in the forebrain excitatory neurons. The data presented in the present study supports the second hypothesis, the “GluN2B intracellular signaling domain” hypothesis. Surprisingly, we found that the voltage-gated channel opening-durations through either GluN2A or GluN2B are sufficient and their temporal differences are marginal. In contrast, the C-terminal intracellular domain of the GluN2B subunit is necessary and sufficient for superior performances in long-term novel object recognition and cued fear memories and superior flexibility in fear extinction. Intriguingly, memory enhancement correlates with enhanced long-term potentiation in the 10–100 Hz range while requiring intact long-term depression capacity at the 1–5 Hz range.
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Affiliation(s)
- Stephanie Jacobs
- Brain and Behavior Discovery Institute and Department of Neurology, Medical College of Georgia at Georgia Regents University, Augusta, Georgia, United States of America
| | - Zhenzhong Cui
- Brain and Behavior Discovery Institute and Department of Neurology, Medical College of Georgia at Georgia Regents University, Augusta, Georgia, United States of America
| | - Ruiben Feng
- Brain and Behavior Discovery Institute and Department of Neurology, Medical College of Georgia at Georgia Regents University, Augusta, Georgia, United States of America
| | - Huimin Wang
- Shanghai Institute of Functional Genomics, East China Normal University, Shanghai, China
| | - Deheng Wang
- Banna Biomedical Research Institute, Xi-Shuang-Ban-Na Prefecture, Yunnan Province, China
| | - Joe Z. Tsien
- Brain and Behavior Discovery Institute and Department of Neurology, Medical College of Georgia at Georgia Regents University, Augusta, Georgia, United States of America
- * E-mail:
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13
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Cui Z, Feng R, Jacobs S, Duan Y, Wang H, Cao X, Tsien JZ. Increased NR2A:NR2B ratio compresses long-term depression range and constrains long-term memory. Sci Rep 2013; 3:1036. [PMID: 23301157 PMCID: PMC3539144 DOI: 10.1038/srep01036] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2012] [Accepted: 11/02/2012] [Indexed: 12/28/2022] Open
Abstract
The NR2A:NR2B subunit ratio of the NMDA receptors is widely known to increase in the brain from postnatal development to sexual maturity and to aging, yet its impact on memory function remains speculative. We have generated forebrain-specific NR2A overexpression transgenic mice and show that these mice had normal basic behaviors and short-term memory, but exhibited broad long-term memory deficits as revealed by several behavioral paradigms. Surprisingly, increased NR2A expression did not affect 1-Hz-induced long-term depression (LTD) or 100 Hz-induced long-term potentiation (LTP) in the CA1 region of the hippocampus, but selectively abolished LTD responses in the 3–5 Hz frequency range. Our results demonstrate that the increased NR2A:NR2B ratio is a critical genetic factor in constraining long-term memory in the adult brain. We postulate that LTD-like process underlies post-learning information sculpting, a novel and essential consolidation step in transforming new information into long-term memory.
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Affiliation(s)
- Zhenzhong Cui
- Brain and Behavior Discovery Institute and Department of Neurology, Medical College of Georgia, Georgia Health Sciences University, Augusta, GA 30907, USA
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14
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Wade JJ, McDaid LJ, Harkin J, Crunelli V, Kelso JAS. Bidirectional coupling between astrocytes and neurons mediates learning and dynamic coordination in the brain: a multiple modeling approach. PLoS One 2011; 6:e29445. [PMID: 22242121 PMCID: PMC3248449 DOI: 10.1371/journal.pone.0029445] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2011] [Accepted: 11/28/2011] [Indexed: 11/30/2022] Open
Abstract
In recent years research suggests that astrocyte networks, in addition to nutrient and waste processing functions, regulate both structural and synaptic plasticity. To understand the biological mechanisms that underpin such plasticity requires the development of cell level models that capture the mutual interaction between astrocytes and neurons. This paper presents a detailed model of bidirectional signaling between astrocytes and neurons (the astrocyte-neuron model or AN model) which yields new insights into the computational role of astrocyte-neuronal coupling. From a set of modeling studies we demonstrate two significant findings. Firstly, that spatial signaling via astrocytes can relay a "learning signal" to remote synaptic sites. Results show that slow inward currents cause synchronized postsynaptic activity in remote neurons and subsequently allow Spike-Timing-Dependent Plasticity based learning to occur at the associated synapses. Secondly, that bidirectional communication between neurons and astrocytes underpins dynamic coordination between neuron clusters. Although our composite AN model is presently applied to simplified neural structures and limited to coordination between localized neurons, the principle (which embodies structural, functional and dynamic complexity), and the modeling strategy may be extended to coordination among remote neuron clusters.
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Affiliation(s)
- John J Wade
- Intelligent Systems Research Centre, School of Computing and Intelligent Systems, University of Ulster, Derry, Northern Ireland.
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15
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Wolf C, Linden DEJ. Biological pathways to adaptability - interactions between genome, epigenome, nervous system and environment for adaptive behavior. GENES BRAIN AND BEHAVIOR 2011; 11:3-28. [DOI: 10.1111/j.1601-183x.2011.00752.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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16
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Gejman PV, Sanders AR, Kendler KS. Genetics of Schizophrenia: New Findings and Challenges. Annu Rev Genomics Hum Genet 2011; 12:121-44. [DOI: 10.1146/annurev-genom-082410-101459] [Citation(s) in RCA: 142] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Pablo V. Gejman
- Center for Psychiatric Genetics, NorthShore University HealthSystem Research Institute, and University of Chicago, Evanston, Illinois 60201;
| | - Alan R. Sanders
- Center for Psychiatric Genetics, NorthShore University HealthSystem Research Institute, and University of Chicago, Evanston, Illinois 60201;
| | - Kenneth S. Kendler
- Virginia Institute for Psychiatric and Behavioral Genetics and Departments of Psychiatry and Human and Molecular Genetics, Virginia Commonwealth University School of Medicine, Richmond, Virginia 23298;
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17
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βCaMKII plays a nonenzymatic role in hippocampal synaptic plasticity and learning by targeting αCaMKII to synapses. J Neurosci 2011; 31:10141-8. [PMID: 21752990 DOI: 10.1523/jneurosci.5105-10.2011] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The calcium/calmodulin-dependent kinase type II (CaMKII) holoenzyme of the forebrain predominantly consists of heteromeric complexes of the αCaMKII and βCaMKII isoforms. Yet, in contrast to αCaMKII, the role of βCaMKII in hippocampal synaptic plasticity and learning has not been investigated. Here, we compare two targeted Camk2b mouse mutants to study the role of βCaMKII in hippocampal function. Using a Camk2b(-/-) mutant, in which βCaMKII is absent, we show that both hippocampal-dependent learning and Schaffer collateral-CA1 long-term potentiation (LTP) are highly dependent upon the presence of βCaMKII. We further show that βCaMKII is required for proper targeting of αCaMKII to the synapse, indicating that βCaMKII regulates the distribution of αCaMKII between the synaptic pool and the adjacent dendritic shaft. In contrast, localization of αCaMKII, hippocampal synaptic plasticity and learning were unaffected in the Camk2b(A303R) mutant, in which the calcium/calmodulin-dependent activation of βCaMKII is prevented, while the F-actin binding and bundling property is preserved. This indicates that the calcium/calmodulin-dependent kinase activity of βCaMKII is fully dispensable for hippocampal learning, LTP, and targeting of αCaMKII, but implies a critical role for the F-actin binding and bundling properties of βCaMKII in synaptic function. Together, our data provide compelling support for a model of CaMKII function in which αCaMKII and βCaMKII act in concert, but with distinct functions, to regulate hippocampal synaptic plasticity and learning.
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18
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Abstract
During long-term potentiation (LTP), synapses undergo stable changes in synaptic strength. The molecular memory processes that maintain strength have not been identified. One hypothesis is that the complex formed by the Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) and the NMDA-type glutamate receptor (NMDAR) is a molecular memory at the synapse. To establish a molecule as a molecular memory, it must be shown that interfering with the molecule produces a persistent reversal of LTP. We used the CN class of peptides that inhibit CaMKII binding to the NR2B subunit in vitro to test this prediction in rat hippocampal slices. We found that CN peptides can reverse saturated LTP, allowing additional LTP to be induced. The peptide also produced a persistent reduction in basal transmission. We then tested whether CN compounds actually affect CaMKII binding in living cells. Application of CN peptide to slice cultures reduced the amount of CaMKII concentrated in spines, consistent with delocalization of the kinase from a binding partner in the spine. To more specifically assay the binding of CaMKII to the NMDAR, we used coimmunoprecipitation methods. We found that CN peptide decreased synaptic strength only at concentrations necessary to disrupt the CaMKII/NMDAR complex, but not at lower concentrations sufficient to inhibit CaMKII activity. Importantly, both the reduction of the complex and the reduction of synaptic strength persisted after removal of the inhibitor. These results support the hypothesis that the CaMKII/NMDAR complex has switch-like properties that are important in the maintenance of synaptic strength.
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19
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Gottesmann C. To what extent do neurobiological sleep-waking processes support psychoanalysis? INTERNATIONAL REVIEW OF NEUROBIOLOGY 2011; 92:233-90. [PMID: 20870071 DOI: 10.1016/s0074-7742(10)92012-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
Sigmund Freud's thesis was that there is a censorship during waking that prevents memory of events, drives, wishes, and feelings from entering the consciousness because they would induce anxiety due to their emotional or ethical unacceptability. During dreaming, because the efficiency of censorship is decreased, latent thought contents can, after dream-work involving condensation and displacement, enter the dreamer's consciousness under the figurative form of manifest content. The quasi-closed dogma of psychoanalytic theory as related to unconscious processes is beginning to find neurobiological confirmation during waking. Indeed, there are active processes that suppress (repress) unwanted memories from entering consciousness. In contrast, it is more difficult to find neurobiological evidence supporting an organized dream-work that would induce meaningful symbolic content, since dream mentation most often only shows psychotic-like activities.
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Affiliation(s)
- Claude Gottesmann
- Département de Biologie, Faculté des Sciences, Université de Nice-Sophia Antipolis, Nice, France
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20
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A neuropsychological investigation of the genome wide associated schizophrenia risk variant NRGN rs12807809. Schizophr Res 2011; 125:304-6. [PMID: 21112188 DOI: 10.1016/j.schres.2010.10.019] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2010] [Revised: 10/15/2010] [Accepted: 10/15/2010] [Indexed: 12/13/2022]
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21
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Redondo RL, Morris RGM. Making memories last: the synaptic tagging and capture hypothesis. Nat Rev Neurosci 2011; 12:17-30. [PMID: 21170072 DOI: 10.1038/nrn2963] [Citation(s) in RCA: 522] [Impact Index Per Article: 37.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The synaptic tagging and capture hypothesis of protein synthesis-dependent long-term potentiation asserts that the induction of synaptic potentiation creates only the potential for a lasting change in synaptic efficacy, but not the commitment to such a change. Other neural activity, before or after induction, can also determine whether persistent change occurs. Recent findings, leading us to revise the original hypothesis, indicate that the induction of a local, synapse-specific 'tagged' state and the expression of long-term potentiation are dissociable. Additional observations suggest that there are major differences in the mechanisms of functional and structural plasticity. These advances call for a revised theory that incorporates the specific molecular and structural processes involved. Addressing the physiological relevance of previous in vitro findings, new behavioural studies have experimentally translated the hypothesis to learning and the consolidation of newly formed memories.
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Affiliation(s)
- Roger L Redondo
- Laboratory for Cognitive Neuroscience, Centre for Cognitive and Neural Systems, The University of Edinburgh, 1 George Square, Edinburgh EH8 9JZ, UK
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22
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Pereira A, Furlan FA. Astrocytes and human cognition: modeling information integration and modulation of neuronal activity. Prog Neurobiol 2010; 92:405-20. [PMID: 20633599 DOI: 10.1016/j.pneurobio.2010.07.001] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2010] [Revised: 06/18/2010] [Accepted: 07/06/2010] [Indexed: 10/19/2022]
Abstract
Recent research focusing on the participation of astrocytes in glutamatergic tripartite synapses has revealed mechanisms that support cognitive functions common to human and other mammalian species, such as learning, perception, conscious integration, memory formation/retrieval and the control of voluntary behavior. Astrocytes can modulate neuronal activity by means of release of glutamate, d-serine, adenosine triphosphate and other signaling molecules, contributing to sustain, reinforce or depress pre- and post-synaptic membranes. We review molecular mechanisms present in tripartite synapses and model the cognitive role of astrocytes. Single protoplasmic astrocytes operate as a "Local Hub", integrating information patterns from neuronal and glial populations. Two mechanisms, here modeled as the "domino" and "carousel" effects, contribute to the formation of intercellular calcium waves. As waves propagate through gap junctions and reach other types of astrocytes (interlaminar, polarized, fibrous and varicose projection), the active astroglial network functions as a "Master Hub" that integrates results of distributed processing from several brain areas and supports conscious states. Response of this network would define the effect exerted on neuronal plasticity (membrane potentiation or depression), behavior and psychosomatic processes. Theoretical results of our modeling can contribute to the development of new experimental research programs to test cognitive functions of astrocytes.
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Affiliation(s)
- Alfredo Pereira
- Institute of Biosciences, State University of São Paulo (UNESP), Campus Rubião Jr., 18618-000 Botucatu-SP, Brazil.
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23
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Abstract
Schizophrenia is a complex genetic disorder manifesting combined environmental and genetic causation. Recently, genome-wide association experiments yielded remarkable new experimental evidence that is leading to a better understanding of the genetic models and the biological risk factors involved in schizophrenia. These studies have discovered uncommon copy number variations (mainly deletions) and common single nucleotide polymorphisms with alleles associated with schizophrenia. The aggregate data provide support for polygenic inheritance and for genetic overlap of schizophrenia with autism and with bipolar disorder. It is anticipated that the application of a myriad of tools from systems biology, in combination with biological functional experiments, will lead to a delineation of biological pathways involved in the pathophysiology of schizophrenia, and eventually to new therapies.
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Affiliation(s)
- Pablo V Gejman
- Department of Psychiatry and Behavioral Sciences; and Research Institute, Center for Psychiatric Genetics, NorthShore University HealthSystem Research Institute, Evanston, IL 60201, USA.
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24
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Stefansson H, Ophoff RA, Steinberg S, Andreassen OA, Cichon S, Rujescu D, Werge T, Pietiläinen OPH, Mors O, Mortensen PB, Sigurdsson E, Gustafsson O, Nyegaard M, Tuulio-Henriksson A, Ingason A, Hansen T, Suvisaari J, Lonnqvist J, Paunio T, Børglum AD, Hartmann A, Fink-Jensen A, Nordentoft M, Hougaard D, Norgaard-Pedersen B, Böttcher Y, Olesen J, Breuer R, Möller HJ, Giegling I, Rasmussen HB, Timm S, Mattheisen M, Bitter I, Réthelyi JM, Magnusdottir BB, Sigmundsson T, Olason P, Masson G, Gulcher JR, Haraldsson M, Fossdal R, Thorgeirsson TE, Thorsteinsdottir U, Ruggeri M, Tosato S, Franke B, Strengman E, Kiemeney LA, Melle I, Djurovic S, Abramova L, Kaleda V, Sanjuan J, de Frutos R, Bramon E, Vassos E, Fraser G, Ettinger U, Picchioni M, Walker N, Toulopoulou T, Need AC, Ge D, Yoon JL, Shianna KV, Freimer NB, Cantor RM, Murray R, Kong A, Golimbet V, Carracedo A, Arango C, Costas J, Jönsson EG, Terenius L, Agartz I, Petursson H, Nöthen MM, Rietschel M, Matthews PM, Muglia P, Peltonen L, St Clair D, Goldstein DB, Stefansson K, Collier DA. Common variants conferring risk of schizophrenia. Nature 2009; 460:744-7. [PMID: 19571808 PMCID: PMC3077530 DOI: 10.1038/nature08186] [Citation(s) in RCA: 1277] [Impact Index Per Article: 79.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2009] [Accepted: 06/05/2009] [Indexed: 12/12/2022]
Abstract
Schizophrenia is a complex disorder, caused by both genetic and environmental factors and their interactions. Research on pathogenesis has traditionally focused on neurotransmitter systems in the brain, particularly those involving dopamine. Schizophrenia has been considered a separate disease for over a century, but in the absence of clear biological markers, diagnosis has historically been based on signs and symptoms. A fundamental message emerging from genome-wide association studies of copy number variations (CNVs) associated with the disease is that its genetic basis does not necessarily conform to classical nosological disease boundaries. Certain CNVs confer not only high relative risk of schizophrenia but also of other psychiatric disorders. The structural variations associated with schizophrenia can involve several genes and the phenotypic syndromes, or the 'genomic disorders', have not yet been characterized. Single nucleotide polymorphism (SNP)-based genome-wide association studies with the potential to implicate individual genes in complex diseases may reveal underlying biological pathways. Here we combined SNP data from several large genome-wide scans and followed up the most significant association signals. We found significant association with several markers spanning the major histocompatibility complex (MHC) region on chromosome 6p21.3-22.1, a marker located upstream of the neurogranin gene (NRGN) on 11q24.2 and a marker in intron four of transcription factor 4 (TCF4) on 18q21.2. Our findings implicating the MHC region are consistent with an immune component to schizophrenia risk, whereas the association with NRGN and TCF4 points to perturbation of pathways involved in brain development, memory and cognition.
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25
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Jama AM, Fenton J, Robertson SD, Török K. Time-dependent autoinactivation of phospho-Thr286-alphaCa2+/calmodulin-dependent protein kinase II. J Biol Chem 2009; 284:28146-28155. [PMID: 19654320 PMCID: PMC2788865 DOI: 10.1074/jbc.m109.005900] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Ca2+/calmodulin-dependent protein kinase II (αCaMKII) is thought to exert its role in memory formation by autonomous Ca2+-independent persistent activity conferred by Thr286 autophosphorylation, allowing the enzyme to remain active even when intracellular [Ca2+] has returned to resting levels. Ca2+ sequestration-induced inhibition, caused by a burst of Thr305/306 autophosphorylation via calmodulin (CaM) dissociation from the Thr305/306 sites, is in conflict with this view. The processes of CaM binding, autophosphorylation, and inactivation are dissected to resolve this conflict. Upon Ca2+ withdrawal, CaM sequential domain dissociation is observed, starting with the rapid release of the first (presumed N-terminal) CaM lobe, thought to be bound at the Thr305/306 sites. The time courses of Thr305/306 autophosphorylation and inactivation, however, correlate with the slow dissociation of the second (presumed C-terminal) CaM lobe. Exposure of the Thr305/306 sites is thus not sufficient for their autophosphorylation. Moreover, Thr305/306 autophosphorylation and autoinactivation are shown to occur in the continuous presence of Ca2+ and bound Ca2+/CaM by time courses similar to those seen following Ca2+ sequestration. Our investigation of the activity and mechanisms of phospho-Thr286-αCaMKII thus shows time-dependent autoinactivation, irrespective of the continued presence of Ca2+ and CaM, allowing a very short, if any, time window for Ca2+/CaM-free phospho-Thr286-αCaMKII activity. Physiologically, the time-dependent autoinactivation mechanisms of phospho-Thr286-αCaMKII (t½ of ∼50 s at 37 °C) suggest a transient kinase activity of ∼1 min duration in the induction of long term potentiation and thus memory formation.
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Affiliation(s)
- Abdirahman M Jama
- Division of Basic Medical Sciences, St George's, University of London, Cranmer Terrace, London SW17 0RE, United Kingdom
| | - Jon Fenton
- Division of Basic Medical Sciences, St George's, University of London, Cranmer Terrace, London SW17 0RE, United Kingdom
| | - Saralili D Robertson
- Division of Basic Medical Sciences, St George's, University of London, Cranmer Terrace, London SW17 0RE, United Kingdom
| | - Katalin Török
- Division of Basic Medical Sciences, St George's, University of London, Cranmer Terrace, London SW17 0RE, United Kingdom.
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26
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KUANG H, WANG PL, TSIEN JZ. Towards transgenic primates: What can we learn from mouse genetics? ACTA ACUST UNITED AC 2009; 52:506-14. [PMID: 19557327 DOI: 10.1007/s11427-009-0082-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2009] [Accepted: 05/28/2009] [Indexed: 01/29/2023]
Abstract
Considering the great physiological and behavioral similarities with humans, monkeys represent the ideal models not only for the study of complex cognitive behavior but also for the preclinical research and development of novel therapeutics for treating human diseases. Various powerful genetic technologies initially developed for making mouse models are being explored for generating transgenic primate models. We review the latest genetic engineering technologies and discuss the potentials and limitations for systematic production of transgenic primates.
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Affiliation(s)
- Hui KUANG
- Brain and Behavior Discovery Institute, School of Medicine, Medical College of Georgia, Augusta, GA 30912, USA
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27
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Liraz O, Rosenblum K, Barkai E. CAMKII activation is not required for maintenance of learning-induced enhancement of neuronal excitability. PLoS One 2009; 4:e4289. [PMID: 19172997 PMCID: PMC2627926 DOI: 10.1371/journal.pone.0004289] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2008] [Accepted: 12/17/2008] [Indexed: 11/18/2022] Open
Abstract
Pyramidal neurons in the piriform cortex from olfactory-discrimination trained rats show enhanced intrinsic neuronal excitability that lasts for several days after learning. Such enhanced intrinsic excitability is mediated by long-term reduction in the post-burst after-hyperpolarization (AHP) which is generated by repetitive spike firing. AHP reduction is due to decreased conductance of a calcium-dependent potassium current, the sIAHP. We have previously shown that learning-induced AHP reduction is maintained by persistent protein kinase C (PKC) and extracellular regulated kinase (ERK) activation. However, the molecular machinery underlying this long-lasting modulation of intrinsic excitability is yet to be fully described. Here we examine whether the CaMKII, which is known to be crucial in learning, memory and synaptic plasticity processes, is instrumental for the maintenance of learning-induced AHP reduction. KN93, that selectively blocks CaMKII autophosphorylation at Thr286, reduced the AHP in neurons from trained and control rat to the same extent. Consequently, the differences in AHP amplitude and neuronal adaptation between neurons from trained rats and controls remained. Accordingly, the level of activated CaMKII was similar in pirifrom cortex samples taken form trained and control rats. Our data show that although CaMKII modulates the amplitude of AHP of pyramidal neurons in the piriform cortex, its activation is not required for maintaining learning-induced enhancement of neuronal excitability.
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Affiliation(s)
- Ori Liraz
- Department of Neurobiology, Faculty of Sciences, Haifa University, Haifa, Israel
- Department of Biology, Faculty of Sciences, Haifa University, Haifa, Israel
| | - Kobi Rosenblum
- Department of Neurobiology, Faculty of Sciences, Haifa University, Haifa, Israel
- Department of Biology, Faculty of Sciences, Haifa University, Haifa, Israel
| | - Edi Barkai
- Department of Neurobiology, Faculty of Sciences, Haifa University, Haifa, Israel
- Department of Biology, Faculty of Sciences, Haifa University, Haifa, Israel
- * E-mail:
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28
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Havekes R, Abel T. Genetic dissection of neural circuits and behavior in Mus musculus. ADVANCES IN GENETICS 2009; 65:1-38. [PMID: 19615530 DOI: 10.1016/s0065-2660(09)65001-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
One of the major challenges in the field of neurobiology is to elucidate the molecular machinery that underlies the formation and storage of memories. For many decades, genetic studies in the fruit fly (Drosophila melanogaster) have provided insight into the role of specific genes underlying memory storage. Although these pioneering studies were groundbreaking, a transition to a mammalian system more closely resembling the human brain is critical for the translation of basic research findings into therapeutic strategies in humans. Because the mouse (Mus musculus) shares the complex genomic and neuroanatomical organization of mammals and there is a wealth of molecular tools that are available to manipulate gene function in mice, the mouse has become the primary model for research into the genetic basis of mammalian memory. Another major advantage of mouse research is the ability to examine in vivo electrophysiological processes, such as synaptic plasticity and neuronal firing patterns during behavior (e.g., the analysis of place cell activity). The focus on mouse models for memory research has led to the development of sophisticated behavioral protocols capable of exploring the role of particular genes in distinct phases of learning and memory formation, which is one of the major accomplishments of the past decade. In this chapter, we will give an overview of several state of the art genetic approaches to study gene function in the mouse brain in a spatially and temporally restricted fashion.
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Affiliation(s)
- Robbert Havekes
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - Ted Abel
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA
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29
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Lee SJR, Yasuda R. Spatiotemporal Regulation of Signaling in and out of Dendritic Spines: CaMKII and Ras. THE OPEN NEUROSCIENCE JOURNAL 2009; 3:117-127. [PMID: 20463853 PMCID: PMC2867484 DOI: 10.2174/1874082000903020117] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Recent advances in 2-photon fluorescence lifetime imaging microscopy (2pFLIM) in combination with 2-photon photochemistry have enabled the visualization of neuronal signaling during synaptic plasticity at the level of single dendritic spines in light scattering tissue. Using these techniques, the activity of Ca(2+)/Calmodulin-dependent kinase II (CaMKII) and Ras have been imaged in single spines during synaptic plasticity and associated spine enlargement. These provide two contrasting examples of spatiotemporal regulation of spine signaling: Ras signaling is diffusive and spread over ~10 μm along the dendrites, while CaMKII activation is restricted to the spine undergoing plasticity. In this review, we will discuss the mechanisms and roles of the different spatiotemporal regulation of signaling in neurons, and the impact of the spine structure upon these biochemical signaling processes.
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Affiliation(s)
- Seok-Jin R. Lee
- Department of Neurobiology, Duke University Medical Center, Durham, NC 27710
| | - Ryohei Yasuda
- Department of Neurobiology, Duke University Medical Center, Durham, NC 27710
- Howard Hughes Medical Institute, Duke University Medical Center, Durham, NC 27710
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