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Protein expression of targets of the FMRP regulon is altered in brains of subjects with schizophrenia and mood disorders. Schizophr Res 2015; 165:201-11. [PMID: 25956630 PMCID: PMC5037955 DOI: 10.1016/j.schres.2015.04.012] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Revised: 03/25/2015] [Accepted: 04/09/2015] [Indexed: 12/31/2022]
Abstract
Fragile X mental retardation protein (FMRP) is an RNA binding protein with 842 target mRNAs in mammalian brain. Silencing of the fragile X mental retardation 1 (FMR1) gene leads to loss of expression of FMRP and upregulated metabotropic glutamate receptor 5 (mGluR5) signaling resulting in the multiple physical and cognitive deficits associated with fragile X syndrome (FXS). Reduced FMRP expression has been identified in subjects with autism, schizophrenia, bipolar disorder, and major depression who do not carry the mutation for FMR1. Our laboratory has recently demonstrated altered expression of four downstream targets of FMRP-mGluR5 signaling in brains of subjects with autism: homer 1, amyloid beta A4 precursor protein (APP), ras-related C3 botulinum toxin substrate 1 (RAC1), and striatal-enriched protein tyrosine phosphatase (STEP). In the current study we investigated the expression of the same four proteins in lateral cerebella of subjects with schizophrenia, bipolar disorder, and major depression and in frontal cortex of subjects with schizophrenia and bipolar disorder. In frontal cortex we observed: 1) reduced expression of 120 kDa form of APP in subjects with schizophrenia and bipolar disorder; 2) reduced expression of 61 kDa and 33k Da forms of STEP in subjects with schizophrenia; 3) reduced expression of 88 kDa form of APP in subjects with bipolar disorder; and 3) trends for reduced expression of 88 kDa form of APP and homer 1 in subjects with schizophrenia and bipolar disorder, respectively. In lateral cerebella there was no group difference, however we observed increased expression of RAC1 in subjects with bipolar disorder, and trends for increased RAC1 in subjects with schizophrenia and major depression. Our results provide further evidence that proteins involved in the FMRP-mGluR5 signaling pathway are altered in schizophrenia and mood disorders.
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Arnott ER, Peek L, Early JB, Pan AYH, Haase B, Chew T, McGreevy PD, Wade CM. Strong selection for behavioural resilience in Australian stock working dogs identified by selective sweep analysis. Canine Genet Epidemiol 2015; 2:6. [PMID: 26401334 PMCID: PMC4579362 DOI: 10.1186/s40575-015-0017-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 03/26/2015] [Indexed: 01/08/2023] Open
Abstract
Background Working dog handlers and breeders have strong opinions on characteristics that are desirable in the breeds that they use to handle stock. Most of these characteristics are related to conformation or behaviour. This study explored whether the genetics underlying desirable working behaviour traits might be identified by selective sweep analysis; a method that identifies long regions of strong homozygosity combined with allelic divergence from a comparison group. For this analysis, we compared genomic haplotype architecture in two breeds derived from common founder stock but subjected to divergent selective pressures. The breeds studied were the Australian Kelpie, which is registered with the Australian National Kennel Council, and the Australian Working Kelpie, which is registered with the Working Kelpie Council. Results A selective sweep spanning 3 megabases on chromosome 3 was identified in the Australian Working Kelpie. This region is the location of genes related to fear-memory formation and pain perception. Selective sweep loci of similar magnitude were observed in the Australian Kelpie. On chromosome 8 is a locus which may be related to behavioural excitability and on chromosome 30 is a smaller locus which most likely is related to morphology. Conclusions Active working stock dogs of the Australian Working Kelpie breed have been bred primarily for gene loci influencing pain perception and fear memory formation. By contrast Australian Kelpies are commonly maintained in urban environments where these characteristics are not required and have been affected by selection for conformation and coat colour. The identified loci may aid in the identification of superior working dogs. Electronic supplementary material The online version of this article (doi:10.1186/s40575-015-0017-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Elizabeth R Arnott
- Faculty of Veterinary Science, University of Sydney, Camperdown, NSW 2006 Australia
| | - Lincoln Peek
- Faculty of Veterinary Science, University of Sydney, Camperdown, NSW 2006 Australia
| | - Jonathan B Early
- Faculty of Veterinary Science, University of Sydney, Camperdown, NSW 2006 Australia
| | - Annie Y H Pan
- Faculty of Veterinary Science, University of Sydney, Camperdown, NSW 2006 Australia
| | - Bianca Haase
- Faculty of Veterinary Science, University of Sydney, Camperdown, NSW 2006 Australia
| | - Tracy Chew
- Faculty of Veterinary Science, University of Sydney, Camperdown, NSW 2006 Australia
| | - Paul D McGreevy
- Faculty of Veterinary Science, University of Sydney, Camperdown, NSW 2006 Australia
| | - Claire M Wade
- Faculty of Veterinary Science, University of Sydney, Camperdown, NSW 2006 Australia
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Wagner KV, Hartmann J, Labermaier C, Häusl AS, Zhao G, Harbich D, Schmid B, Wang XD, Santarelli S, Kohl C, Gassen NC, Matosin N, Schieven M, Webhofer C, Turck CW, Lindemann L, Jaschke G, Wettstein JG, Rein T, Müller MB, Schmidt MV. Homer1/mGluR5 activity moderates vulnerability to chronic social stress. Neuropsychopharmacology 2015; 40:1222-33. [PMID: 25409593 PMCID: PMC4367467 DOI: 10.1038/npp.2014.308] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Revised: 11/03/2014] [Accepted: 11/04/2014] [Indexed: 12/28/2022]
Abstract
Stress-induced psychiatric disorders, such as depression, have recently been linked to changes in glutamate transmission in the central nervous system. Glutamate signaling is mediated by a range of receptors, including metabotropic glutamate receptors (mGluRs). In particular, mGluR subtype 5 (mGluR5) is highly implicated in stress-induced psychopathology. The major scaffold protein Homer1 critically interacts with mGluR5 and has also been linked to several psychopathologies. Yet, the specific role of Homer1 in this context remains poorly understood. We used chronic social defeat stress as an established animal model of depression and investigated changes in transcription of Homer1a and Homer1b/c isoforms and functional coupling of Homer1 to mGluR5. Next, we investigated the consequences of Homer1 deletion, overexpression of Homer1a, and chronic administration of the mGluR5 inverse agonist CTEP (2-chloro-4-((2,5-dimethyl-1-(4-(trifluoromethoxy)phenyl)-1H-imidazol-4-yl)ethynyl)pyridine) on the effects of chronic stress. In mice exposed to chronic stress, Homer1b/c, but not Homer1a, mRNA was upregulated and, accordingly, Homer1/mGluR5 coupling was disrupted. We found a marked hyperactivity behavior as well as a dysregulated hypothalamic-pituitary-adrenal axis activity in chronically stressed Homer1 knockout (KO) mice. Chronic administration of the selective and orally bioavailable mGluR5 inverse agonist, CTEP, was able to recover behavioral alterations induced by chronic stress, whereas overexpression of Homer1a in the hippocampus led to an increased vulnerability to chronic stress, reflected in an increased physiological response to stress as well as enhanced depression-like behavior. Overall, our results implicate the glutamatergic system in the emergence of stress-induced psychiatric disorders, and support the Homer1/mGluR5 complex as a target for the development of novel antidepressant agents.
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Affiliation(s)
- Klaus V Wagner
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Munich, Germany
| | - Jakob Hartmann
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Munich, Germany
| | - Christiana Labermaier
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Munich, Germany
| | - Alexander S Häusl
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Munich, Germany
| | - Gengjing Zhao
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Munich, Germany
| | - Daniela Harbich
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Munich, Germany
| | - Bianca Schmid
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Munich, Germany
| | - Xiao-Dong Wang
- Department of Neurobiology, Key Laboratory of Medical Neurobiology of Ministry of Health of China, Zhejiang Province Key Laboratory of Neurobiology, Zhejiang University School of Medicine, Hangzhou, China
| | - Sara Santarelli
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Munich, Germany
| | - Christine Kohl
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Munich, Germany
| | - Nils C Gassen
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Munich, Germany
| | - Natalie Matosin
- Faculty of Science, Medicine and Health and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia,Schizophrenia Research Institute, Sydney NSW, Australia
| | - Marcel Schieven
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Munich, Germany
| | - Christian Webhofer
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Munich, Germany
| | - Christoph W Turck
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Munich, Germany
| | - Lothar Lindemann
- Roche Pharmaceutical Research and Early Development, Neuroscience, Ophthalmology, and Rare Diseases Translational Area (NORD), Basel, Switzerland
| | - Georg Jaschke
- Roche Pharmaceutical Research and Early Development, Discovery Chemistry, Basel, Switzerland
| | - Joseph G Wettstein
- Roche Pharmaceutical Research and Early Development, Neuroscience, Ophthalmology, and Rare Diseases Translational Area (NORD), Basel, Switzerland
| | - Theo Rein
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Munich, Germany
| | - Marianne B Müller
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Munich, Germany
| | - Mathias V Schmidt
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Munich, Germany,Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Kraepelinstrasse 2-10, 80804 Munich, Germany, Tel: +49 89 30622 519, Fax: +49 89 30622 610, E-mail:
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de Bartolomeis A, Iasevoli F, Marmo F, Buonaguro EF, Eramo A, Rossi R, Avvisati L, Latte G, Tomasetti C. Progressive recruitment of cortical and striatal regions by inducible postsynaptic density transcripts after increasing doses of antipsychotics with different receptor profiles: insights for psychosis treatment. Eur Neuropsychopharmacol 2015; 25:566-82. [PMID: 25649681 DOI: 10.1016/j.euroneuro.2015.01.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Revised: 01/05/2015] [Accepted: 01/09/2015] [Indexed: 02/07/2023]
Abstract
Antipsychotics may modulate the transcription of multiple gene programs, including those belonging to postsynaptic density (PSD) network, within cortical and subcortical brain regions. Understanding which brain region is activated progressively by increasing doses of antipsychotics and how their different receptor profiles may impact such an activation could be relevant to better correlate the mechanism of action of antipsychotics both with their efficacy and side effects. We analyzed the differential topography of PSD transcripts by incremental doses of two antipsychotics: haloperidol, the prototypical first generation antipsychotic with prevalent dopamine D2 receptors antagonism, and asenapine, a second generation antipsychotic characterized by multiple receptors occupancy. We investigated the expression of PSD genes involved in synaptic plasticity and previously demonstrated to be modulated by antipsychotics: Homer1a, and its related interacting constitutive genes Homer1b/c and PSD95, as well as Arc, C-fos and Zif-268, also known to be induced by antipsychotics administration. We found that increasing acute doses of haloperidol induced immediate-early genes (IEGs) expression in different striatal areas, which were progressively recruited by incremental doses with a dorsal-to-ventral gradient of expression. Conversely, increasing acute asenapine doses progressively de-recruited IEGs expression in cortical areas and increased striatal genes signal intensity. These effects were mirrored by a progressive reduction in locomotor animal activity by haloperidol, and an opposite increase by asenapine. Thus, we demonstrated for the first time that antipsychotics may progressively recruit PSD-related IEGs expression in cortical and subcortical areas when administered at incremental doses and these effects may reflect a fine-tuned dose-dependent modulation of the PSD.
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Affiliation(s)
- Andrea de Bartolomeis
- Laboratory of Molecular and Translational Psychiatry, Department of Neuroscience, University Medical School of Naples Federico II, Italy.
| | - Felice Iasevoli
- Laboratory of Molecular and Translational Psychiatry, Department of Neuroscience, University Medical School of Naples Federico II, Italy
| | - Federica Marmo
- Laboratory of Molecular and Translational Psychiatry, Department of Neuroscience, University Medical School of Naples Federico II, Italy
| | - Elisabetta F Buonaguro
- Laboratory of Molecular and Translational Psychiatry, Department of Neuroscience, University Medical School of Naples Federico II, Italy
| | - Anna Eramo
- Medical Affairs & Phase IV Clinical Affair. Lundbeck Pharmaceutical Services LLC, Deerfield, IL, United States
| | - Rodolfo Rossi
- Laboratory of Molecular and Translational Psychiatry, Department of Neuroscience, University Medical School of Naples Federico II, Italy
| | - Livia Avvisati
- Laboratory of Molecular and Translational Psychiatry, Department of Neuroscience, University Medical School of Naples Federico II, Italy
| | - Gianmarco Latte
- Laboratory of Molecular and Translational Psychiatry, Department of Neuroscience, University Medical School of Naples Federico II, Italy
| | - Carmine Tomasetti
- Laboratory of Molecular and Translational Psychiatry, Department of Neuroscience, University Medical School of Naples Federico II, Italy
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55
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Gould AT, Sacramento AD, Wroten MG, Miller BW, von Jonquieres G, Klugmann M, Ben-Shahar O, Szumlinski KK. Cocaine-elicited imbalances in ventromedial prefrontal cortex Homer1 versus Homer2 expression: implications for relapse. Addict Biol 2015; 20:148-57. [PMID: 24118426 DOI: 10.1111/adb.12088] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Withdrawal from a history of extended access to self-administered cocaine produces a time-dependent intensification of drug seeking, which might relate to a cocaine-induced imbalance in the relative expression of constitutively expressed Homer1 versus Homer2 isoforms within the ventromedial aspect of the prefrontal cortex (vmPFC). Thus, we employed immunoblotting to examine the relation between cue-reinforced lever pressing at 3- versus 30-day withdrawal from a 10-day history of extended access (6 hours/day) to intravenous cocaine (0.25 mg/infusion) or saline (Sal6h), and the expression of Homer1b/c and Homer2a/b within the vmPFC versus the more dorsomedial aspect of this structure (dmPFC). Behavioral studies employed adeno-associated virus (AAV) vectors to reverse cocaine-elicited changes in the relative expression of Homer1 versus Homer2 isoforms and tested animals for cocaine prime-, and cue-induced responding following extinction training. Cocaine self-administration elevated both Homer1b/c and Homer2a/b levels within the vmPFC at 3-day withdrawal, and the rise in Homer2a/b persisted for at least 30 days. dmPFC Homer levels did not change as a function of self-administration history. Reversing the relative increase in Homer2 versus Homer1 expression via Homer1c overexpression or Homer2b knockdown failed to influence cue-reinforced lever pressing when animals were tested in a drug-free state, but both AAV treatments prevented cocaine-primed reinstatement of lever-pressing behavior. These data suggest that a cocaine-elicited imbalance in the relative expression of constitutively expressed Homer2 versus Homer1 within the vmPFC is necessary for the capacity of cocaine to reinstate drug-seeking behavior, posing drug-induced changes in vmPFC Homer expression as a molecular trigger contributing to drug-elicited relapse.
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Affiliation(s)
- Adam T. Gould
- Department of Psychological and Brain Sciences and the Neuroscience Research Institute; University of California at Santa Barbara; Santa Barbara CA USA
| | - Arianne D. Sacramento
- Department of Psychological and Brain Sciences and the Neuroscience Research Institute; University of California at Santa Barbara; Santa Barbara CA USA
| | - Melissa G. Wroten
- Department of Psychological and Brain Sciences and the Neuroscience Research Institute; University of California at Santa Barbara; Santa Barbara CA USA
| | - Bailey W. Miller
- Department of Psychological and Brain Sciences and the Neuroscience Research Institute; University of California at Santa Barbara; Santa Barbara CA USA
| | - Georg von Jonquieres
- Translational Neuroscience Facility; School of Medical Sciences; University of New South Wales; Australia
| | - Matthias Klugmann
- Translational Neuroscience Facility; School of Medical Sciences; University of New South Wales; Australia
| | - Osnat Ben-Shahar
- Department of Psychological and Brain Sciences and the Neuroscience Research Institute; University of California at Santa Barbara; Santa Barbara CA USA
| | - Karen K. Szumlinski
- Department of Psychological and Brain Sciences and the Neuroscience Research Institute; University of California at Santa Barbara; Santa Barbara CA USA
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Brand SJ, Moller M, Harvey BH. A Review of Biomarkers in Mood and Psychotic Disorders: A Dissection of Clinical vs. Preclinical Correlates. Curr Neuropharmacol 2015; 13:324-68. [PMID: 26411964 PMCID: PMC4812797 DOI: 10.2174/1570159x13666150307004545] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 02/04/2015] [Accepted: 03/06/2015] [Indexed: 11/23/2022] Open
Abstract
Despite significant research efforts aimed at understanding the neurobiological underpinnings of mood (depression, bipolar disorder) and psychotic disorders, the diagnosis and evaluation of treatment of these disorders are still based solely on relatively subjective assessment of symptoms as well as psychometric evaluations. Therefore, biological markers aimed at improving the current classification of psychotic and mood-related disorders, and that will enable patients to be stratified on a biological basis into more homogeneous clinically distinct subgroups, are urgently needed. The attainment of this goal can be facilitated by identifying biomarkers that accurately reflect pathophysiologic processes in these disorders. This review postulates that the field of psychotic and mood disorder research has advanced sufficiently to develop biochemical hypotheses of the etiopathology of the particular illness and to target the same for more effective disease modifying therapy. This implies that a "one-size fits all" paradigm in the treatment of psychotic and mood disorders is not a viable approach, but that a customized regime based on individual biological abnormalities would pave the way forward to more effective treatment. In reviewing the clinical and preclinical literature, this paper discusses the most highly regarded pathophysiologic processes in mood and psychotic disorders, thereby providing a scaffold for the selection of suitable biomarkers for future studies in this field, to develope biomarker panels, as well as to improve diagnosis and to customize treatment regimens for better therapeutic outcomes.
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Affiliation(s)
| | | | - Brian H Harvey
- Division of Pharmacology and Center of Excellence for Pharmaceutical Sciences, School of Pharmacy, North-West University, Potchefstroom, South Africa.
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57
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Prenatal stress and adult drug-seeking behavior: interactions with genes and relation to nondrug-related behavior. ADVANCES IN NEUROBIOLOGY 2015; 10:75-100. [PMID: 25287537 DOI: 10.1007/978-1-4939-1372-5_5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Addiction inflicts large personal, social, and economic burdens, yet its etiology is poorly defined and effective treatments are lacking. As with other neuropsychiatric disorders, addiction is characterized by a core set of symptoms and behaviors that are believed to be influenced by complex gene-environment interactions. Our group focuses on the interaction between early stress and genetic background in determining addiction vulnerability. Prior work by our group and others has indicated that a history of prenatal stress (PNS) in rodents elevates adult drug seeking in a number of behavioral paradigms. The focus of the present chapter is to summarize work in the area of PNS and addiction models as well as our recent studies of PNS on drug seeking in different strains of mice as a strategy to dissect gene-environment interactions underlying cocaine addiction vulnerability. These studies indicate that ability of PNS to elevate adult cocaine seeking is strain dependent. Further, PNS also alters other nondrug behaviors in a fashion that is dependent on different strains and independent from the strain dependence of drug seeking. Thus, it appears that the ability of PNS to alter behavior related to different psychiatric conditions is orthogonal, with similar nonspecific susceptibility to prenatal stress across genetic backgrounds but with the genetic background determining the specific nature of the PNS effects. Finally, the advent of recombinant inbred mouse strains is allowing us to determine the genetic bases of these gene-environment interactions. Understanding these effects will have broad implications to determining the nature of vulnerability to addiction and perhaps other disorders.
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Iasevoli F, Tomasetti C, Buonaguro EF, de Bartolomeis A. The glutamatergic aspects of schizophrenia molecular pathophysiology: role of the postsynaptic density, and implications for treatment. Curr Neuropharmacol 2014; 12:219-38. [PMID: 24851087 PMCID: PMC4023453 DOI: 10.2174/1570159x12666140324183406] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Revised: 02/14/2014] [Accepted: 03/14/2014] [Indexed: 01/23/2023] Open
Abstract
Schizophrenia is one of the most debilitating psychiatric diseases with a lifetime prevalence of approximately
1%. Although the specific molecular underpinnings of schizophrenia are still unknown, evidence has long linked its
pathophysiology to postsynaptic abnormalities.
The postsynaptic density (PSD) is among the molecular structures suggested to be potentially involved in schizophrenia.
More specifically, the PSD is an electron-dense thickening of glutamatergic synapses, including ionotropic and
metabotropic glutamate receptors, cytoskeletal and scaffolding proteins, and adhesion and signaling molecules. Being
implicated in the postsynaptic signaling of multiple neurotransmitter systems, mostly dopamine and glutamate, the PSD
constitutes an ideal candidate for studying dopamine-glutamate disturbances in schizophrenia. Recent evidence suggests
that some PSD proteins, such as PSD-95, Shank, and Homer are implicated in severe behavioral disorders, including
schizophrenia. These findings, further corroborated by genetic and animal studies of schizophrenia, offer new insights for
the development of pharmacological strategies able to overcome the limitations in terms of efficacy and side effects of
current schizophrenia treatment. Indeed, PSD proteins are now being considered as potential molecular targets against this
devastating illness.
The current paper reviews the most recent hypotheses on the molecular mechanisms underlying schizophrenia
pathophysiology. First, we review glutamatergic dysfunctions in schizophrenia and we provide an update on postsynaptic
molecules involvement in schizophrenia pathophysiology by addressing both human and animal studies. Finally, the
possibility that PSD proteins may represent potential targets for new molecular interventions in psychosis will be
discussed.
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Affiliation(s)
- Felice Iasevoli
- Department of Neuroscience, Reproductive and Odontostomatological Sciences - University "Federico II", Naples, Italy
| | - Carmine Tomasetti
- Department of Neuroscience, Reproductive and Odontostomatological Sciences - University "Federico II", Naples, Italy
| | - Elisabetta F Buonaguro
- Department of Neuroscience, Reproductive and Odontostomatological Sciences - University "Federico II", Naples, Italy
| | - Andrea de Bartolomeis
- Department of Neuroscience, Reproductive and Odontostomatological Sciences - University "Federico II", Naples, Italy
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Newell KA, Matosin N. Rethinking metabotropic glutamate receptor 5 pathological findings in psychiatric disorders: implications for the future of novel therapeutics. BMC Psychiatry 2014; 14:23. [PMID: 24472577 PMCID: PMC3907147 DOI: 10.1186/1471-244x-14-23] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Accepted: 01/21/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Pharmacological modulation of metabotropic glutamate receptor 5 (mGluR5) is of marked interest as a novel therapeutic mechanism to treat schizophrenia and major depression. However, the status of mGluR5 in the pathophysiology of these disorders remains unknown. DISCUSSION The majority of studies in the schizophrenia post-mortem brain indicate that total mGluR5 expression is unaltered. However, close examination of the literature suggests that these findings are superficial, and in actuality, a number of critical factors have not yet been considered; alterations may be highly dependent on brain region, neuronal population or molecular organisation in specific cellular compartments. A number of genetic knockout studies (mGluR5, Norbin, Homer1 etc.) continue to lend support to a role of mGluR5 in the pathology of schizophrenia, providing impetus to explore the regulation of mGluR5 beyond total mGluR5 protein and mRNA levels. With regards to major depression, preliminary evidence to date shows a reduction in total mGluR5 protein and mRNA levels; however, as in schizophrenia, there are no studies examining mGluR5 function or regulation in the pathological state. A comprehensive understanding of mGluR5 regulation in major depression, particularly in comparison to schizophrenia, is crucial as this has extensive implications for mGluR5 targeting novel therapeutics, especially considering that opposing modulation of mGluR5 is of therapeutic interest for these two disorders. SUMMARY Despite the complexities, examinations of post-mortem human brain provide valuable insights into the pathologies of these inherently human disorders. It is important, especially with regards to the identification of novel therapeutic drug targets, to have an in depth understanding of the pathophysiologies of these disorders. We posit that brain region- and cell type-specific alterations exist in mGluR5 in schizophrenia and depression, with evidence pointing towards altered regulation of this receptor in psychiatric pathology. We consider the implications of these alterations, as well as the distinction between schizophrenia and depression, in the context of novel mGluR5 based therapeutics.
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Affiliation(s)
- Kelly A Newell
- Centre for Translational Neuroscience, Faculty of Science, Medicine and Health and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW 2522, Australia.
| | - Natalie Matosin
- Centre for Translational Neuroscience, Faculty of Science, Medicine and Health and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW 2522, Australia,Schizophrenia Research Institute, Darlinghurst, NSW 2010, Australia
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Wagner KV, Häusl AS, Pöhlmann ML, Hartmann J, Labermaier C, Müller MB, Schmidt MV. Hippocampal Homer1 levels influence motivational behavior in an operant conditioning task. PLoS One 2014; 9:e85975. [PMID: 24465821 PMCID: PMC3897610 DOI: 10.1371/journal.pone.0085975] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Accepted: 12/03/2013] [Indexed: 11/23/2022] Open
Abstract
Loss of motivation and learning impairments are commonly accepted core symptoms of psychiatric disorders such as depression and schizophrenia. Reward-motivated learning is dependent on the hippocampal formation but the molecular mechanisms that lead to functional incentive motivation in this brain region are still largely unknown. Recent evidence implicates neurotransmission via metabotropic glutamate receptors and Homer1, their interaction partner in the postsynaptic density, in drug addiction and motivational learning. As previous reports mainly focused on the prefrontal cortex and the nucleus accumbens, we now investigated the role of hippocampal Homer1 in operant reward learning in the present study. We therefore tested either Homer1 knockout mice or mice that overexpress Homer1 in the hippocampus in an operant conditioning paradigm. Our results show that deletion of Homer1 leads to a diverging phenotype that either displays an inability to perform the task or outstanding hyperactivity in both learning and motivational sessions. Due to the apparent bimodal distribution of this phenotype, the overall effect of Homer1 deletion in this paradigm is not significantly altered. Overexpression of hippocampal Homer1 did not lead to a significantly altered learning performance in any stage of the testing paradigm, yet may subtly contribute to emerging motivational deficits. Our results indicate an involvement of Homer1-mediated signaling in the hippocampus in motivation-based learning tasks and encourage further investigations regarding the specific molecular underpinnings of the phenotypes observed in this study. We also suggest to cautiously interpret the results of this and other studies regarding the phenotype following Homer1 manipulations in animals, since their behavioral phenotype appears to be highly diverse. Future studies would benefit from larger group sizes that would allow splitting the experimental groups in responders and non-responders.
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Affiliation(s)
- Klaus V. Wagner
- Research Group Neurobiology of Stress, Max Planck Institute of Psychiatry, Munich, Bavaria, Germany
- * E-mail:
| | - Alexander S. Häusl
- Research Group Neurobiology of Stress, Max Planck Institute of Psychiatry, Munich, Bavaria, Germany
| | - Max L. Pöhlmann
- Research Group Neurobiology of Stress, Max Planck Institute of Psychiatry, Munich, Bavaria, Germany
| | - Jakob Hartmann
- Research Group Neurobiology of Stress, Max Planck Institute of Psychiatry, Munich, Bavaria, Germany
| | - Christiana Labermaier
- Research Group Neurobiology of Stress, Max Planck Institute of Psychiatry, Munich, Bavaria, Germany
| | - Marianne B. Müller
- Research Group Neurobiology of Stress, Max Planck Institute of Psychiatry, Munich, Bavaria, Germany
| | - Mathias V. Schmidt
- Research Group Neurobiology of Stress, Max Planck Institute of Psychiatry, Munich, Bavaria, Germany
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McCullumsmith RE, Hammond JH, Shan D, Meador-Woodruff JH. Postmortem brain: an underutilized substrate for studying severe mental illness. Neuropsychopharmacology 2014; 39:65-87. [PMID: 24091486 PMCID: PMC3857666 DOI: 10.1038/npp.2013.239] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Revised: 07/30/2013] [Accepted: 08/02/2013] [Indexed: 02/08/2023]
Abstract
We propose that postmortem tissue is an underutilized substrate that may be used to translate genetic and/or preclinical studies, particularly for neuropsychiatric illnesses with complex etiologies. Postmortem brain tissues from subjects with schizophrenia have been extensively studied, and thus serve as a useful vehicle for illustrating the challenges associated with this biological substrate. Schizophrenia is likely caused by a combination of genetic risk and environmental factors that combine to create a disease phenotype that is typically not apparent until late adolescence. The complexity of this illness creates challenges for hypothesis testing aimed at understanding the pathophysiology of the illness, as postmortem brain tissues collected from individuals with schizophrenia reflect neuroplastic changes from a lifetime of severe mental illness, as well as treatment with antipsychotic medications. While there are significant challenges with studying postmortem brain, such as the postmortem interval, it confers a translational element that is difficult to recapitulate in animal models. On the other hand, data derived from animal models typically provide specific mechanistic and behavioral measures that cannot be generated using human subjects. Convergence of these two approaches has led to important insights for understanding molecular deficits and their causes in this illness. In this review, we discuss the problem of schizophrenia, review the common challenges related to postmortem studies, discuss the application of biochemical approaches to this substrate, and present examples of postmortem schizophrenia studies that illustrate the role of the postmortem approach for generating important new leads for understanding the pathophysiology of severe mental illness.
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Affiliation(s)
| | - John H Hammond
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama-Birmingham, Birmingham, AL, USA
| | - Dan Shan
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama-Birmingham, Birmingham, AL, USA
| | - James H Meador-Woodruff
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama-Birmingham, Birmingham, AL, USA
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Moore ED, Kooshki M, Wheeler KT, Metheny-Barlow LJ, Robbins ME. Differential expression of Homer1a in the hippocampus and cortex likely plays a role in radiation-induced brain injury. Radiat Res 2013; 181:21-32. [PMID: 24377717 DOI: 10.1667/rr13475.1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Fractionated partial or whole-brain irradiation is the primary treatment for metastatic brain tumors. Despite reducing tumor burden and increasing lifespan, progressive, irreversible cognitive impairment occurs in >50% of the patients who survive >6 months after fractionated whole-brain irradiation. The exact mechanism(s) responsible for this radiation-induced brain injury are unknown; however, preclinical studies suggest that radiation modulates the extracellular receptor kinase signaling pathway, which is associated with cognitive impairment in many neurological diseases. In the study reported here, we demonstrated that the extracellular receptor kinase transcriptionally-regulated early response gene, Homer1a, was up-regulated transiently in the hippocampus and down-regulated in the cortex of young adult male Fischer 344 X Brown Norway rats at 48 h after 40 Gy of fractionated whole-brain irradiation. Two months after fractionated whole-brain irradiation, these changes in Homer1a expression correlated with a down-regulation of the hippocampal glutamate receptor 1 and protein kinase Cγ, and an up-regulation of cortical glutamate receptor 1 and protein kinase Cγ. Two drugs that prevent radiation-induced cognitive impairment in rats, the angiotensin type-1 receptor blocker, L-158,809, and the angiotensin converting enzyme inhibitor, ramipril, reversed the fractionated whole-brain irradiation-induced Homer1a expression at 48 h in the hippocampus and cortex and restored glutamate receptor 1 and protein kinase Cγ to the levels in sham-irradiated controls at 2 months after fractionated whole-brain irradiation. These data indicate that Homer1a is, (1) a brain region specific regulator of radiation-induced brain injury, including cognitive impairment and (2) potentially a druggable target for preventing it.
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63
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de Bartolomeis A, Sarappa C, Buonaguro EF, Marmo F, Eramo A, Tomasetti C, Iasevoli F. Different effects of the NMDA receptor antagonists ketamine, MK-801, and memantine on postsynaptic density transcripts and their topography: role of Homer signaling, and implications for novel antipsychotic and pro-cognitive targets in psychosis. Prog Neuropsychopharmacol Biol Psychiatry 2013; 46:1-12. [PMID: 23800465 DOI: 10.1016/j.pnpbp.2013.06.010] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Revised: 06/10/2013] [Accepted: 06/14/2013] [Indexed: 12/15/2022]
Abstract
Administration of NMDA receptor antagonists, such as ketamine and MK-801, may induce psychotic-like behaviors in preclinical models of schizophrenia. Ketamine has also been observed to exacerbate psychotic symptoms in schizophrenia patients. However, memantine, a non-competitive NMDA receptor antagonist approved for Alzheimer's disease and proposed for antipsychotic augmentation, may challenge this view. To date, the molecular mechanisms by which these NMDA receptor antagonists cause different neurochemical, behavioral, and clinical effects are still a matter of debate. Here, we investigated by molecular imaging whether these agents could differently modulate gene expression and topographical distribution of glutamatergic postsynaptic density (PSD) proteins. We focused on Homer1a/Homer1b/PSD-95 signaling network, which may be implicated in glutamate-dependent synaptic plasticity, as well as in psychosis pathophysiology and treatment. Ketamine (25 and 50mg/kg) and MK-801 (0.8mg/kg) significantly induced the transcripts of immediate-early genes (Arc, c-fos, and Homer1a) in cortical regions compared to vehicle, whereas they reduced Homer1b and PSD-95 expression in cortical and striatal regions. Differently, memantine (5mg/kg) did not increase Homer1a signal compared to vehicle, whereas it induced c-fos in the somatosensory and in the medial agranular cortices. Moreover, memantine did not affect Homer1b and PSD-95 expression. When compared to ketamine and MK-801, memantine significantly increased the expression of c-fos, Homer1b and PSD-95. Overall, ketamine and MK-801 prominently increased Homer1a/Homer1b expression ratio, whereas memantine elicited the opposite effect. These data may support the view that ketamine, MK-801 and memantine exert divergent effects on PSD transcripts, which may contribute to their partially different behavioral and clinical effects.
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Affiliation(s)
- Andrea de Bartolomeis
- Laboratory of Molecular and Translational Psychiatry, Department of Neuroscience, University School of Medicine "Federico II", Naples, Italy.
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de Bartolomeis A, Latte G, Tomasetti C, Iasevoli F. Glutamatergic postsynaptic density protein dysfunctions in synaptic plasticity and dendritic spines morphology: relevance to schizophrenia and other behavioral disorders pathophysiology, and implications for novel therapeutic approaches. Mol Neurobiol 2013; 49:484-511. [PMID: 23999870 DOI: 10.1007/s12035-013-8534-3] [Citation(s) in RCA: 101] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2013] [Accepted: 08/13/2013] [Indexed: 02/06/2023]
Abstract
Emerging researches point to a relevant role of postsynaptic density (PSD) proteins, such as PSD-95, Homer, Shank, and DISC-1, in the pathophysiology of schizophrenia and autism spectrum disorders. The PSD is a thickness, detectable at electronic microscopy, localized at the postsynaptic membrane of glutamatergic synapses, and made by scaffolding proteins, receptors, and effector proteins; it is considered a structural and functional crossroad where multiple neurotransmitter systems converge, including the dopaminergic, serotonergic, and glutamatergic ones, which are all implicated in the pathophysiology of psychosis. Decreased PSD-95 protein levels have been reported in postmortem brains of schizophrenia patients. Variants of Homer1, a key PSD protein for glutamate signaling, have been associated with schizophrenia symptoms severity and therapeutic response. Mutations in Shank gene have been recognized in autism spectrum disorder patients, as well as reported to be associated to behaviors reminiscent of schizophrenia symptoms when expressed in genetically engineered mice. Here, we provide a critical appraisal of PSD proteins role in the pathophysiology of schizophrenia and autism spectrum disorders. Then, we discuss how antipsychotics may affect PSD proteins in brain regions relevant to psychosis pathophysiology, possibly by controlling synaptic plasticity and dendritic spine rearrangements through the modulation of glutamate-related targets. We finally provide a framework that may explain how PSD proteins might be useful candidates to develop new therapeutic approaches for schizophrenia and related disorders in which there is a need for new biological treatments, especially against some symptom domains, such as negative symptoms, that are poorly affected by current antipsychotics.
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Affiliation(s)
- Andrea de Bartolomeis
- Laboratory of Molecular and Translational Psychiatry, Unit of Treatment Resistant Psychosis, Department of Neuroscience, Reproductive and Odontostomatologic Sciences, Section of Psychiatry, University School of Medicine "Federico II", Via Pansini 5, 80131, Naples, Italy,
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Imbalances in prefrontal cortex CC-Homer1 versus CC-Homer2 expression promote cocaine preference. J Neurosci 2013; 33:8101-13. [PMID: 23658151 DOI: 10.1523/jneurosci.1727-12.2013] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Homer postsynaptic scaffolding proteins regulate forebrain glutamate transmission and thus, are likely molecular candidates mediating hypofrontality in addiction. Protracted withdrawal from cocaine experience increases the relative expression of Homer2 versus Homer1 isoforms within medial prefrontal cortex (mPFC). Thus, this study used virus-mediated gene transfer strategies to investigate the functional relevance of an imbalance in mPFC Homer1/2 expression as it relates to various measures of sensorimotor, cognitive, emotional and motivational processing, as well as accompanying alterations in extracellular glutamate in C57BL/6J mice. mPFC Homer2b overexpression elevated basal glutamate content and blunted cocaine-induced glutamate release within the mPFC, whereas Homer2b knockdown produced the opposite effects. Despite altering mPFC glutamate, Homer2b knockdown failed to influence cocaine-elicited conditioned place preferences, nor did it produce consistent effects on any other behavioral measures. In contrast, elevating the relative expression of Homer2b versus Homer1 within mPFC, by overexpressing Homer2b or knocking down Homer1c, shifted the dose-response function for cocaine-conditioned reward to the left, without affecting cocaine locomotion or sensitization. Intriguingly, both these transgenic manipulations produced glutamate anomalies within the nucleus accumbens (NAC) of cocaine-naive animals that are reminiscent of those observed in cocaine experienced animals, including reduced basal extracellular glutamate content, reduced Homer1/2 and glutamate receptor expression, and augmented cocaine-elicited glutamate release. Together, these data provide novel evidence in support of opposing roles for constitutively expressed Homer1 and Homer2 isoforms in regulating mPFC glutamate transmission in vivo and support the hypothesis that cocaine-elicited increases in the relative amount of mPFC Homer2 versus Homer1 signaling produces abnormalities in NAC glutamate transmission that enhance vulnerability to cocaine reward.
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66
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Postnatal development ofHomer1ain the rat hippocampus. Hippocampus 2013; 23:890-902. [DOI: 10.1002/hipo.22146] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/21/2013] [Indexed: 01/11/2023]
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67
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The role of Homer 1a in increasing locomotor activity and non-selective attention, and impairing learning and memory abilities. Brain Res 2013; 1515:39-47. [DOI: 10.1016/j.brainres.2013.03.030] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2012] [Revised: 02/12/2013] [Accepted: 03/13/2013] [Indexed: 10/26/2022]
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Gao C, Tronson NC, Radulovic J. Modulation of behavior by scaffolding proteins of the post-synaptic density. Neurobiol Learn Mem 2013; 105:3-12. [PMID: 23701866 DOI: 10.1016/j.nlm.2013.04.014] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Revised: 04/05/2013] [Accepted: 04/09/2013] [Indexed: 12/23/2022]
Abstract
Scaffolding proteins of the neuronal post-synaptic density (PSD) are principal organizers of glutamatergic neurotransmission that bring together glutamate receptors and signaling molecules at discrete synaptic locations. Genetic alterations of individual PSD scaffolds therefore disrupt the function of entire multiprotein modules rather than a single glutamatergic mechanism, and thus induce a range of molecular and structural abnormalities in affected neurons. Despite such broad molecular consequences, knockout, knockdown, or knockin of glutamate receptor scaffolds typically affect a subset of specific behaviors and thereby mold and specialize the actions of the ubiquitous glutamatergic neurotransmitter system. Approaches designed to control the function of neuronal scaffolds may therefore have high potential to restore behavioral morbidities and comorbidities in patients with psychiatric disorders. Here we summarize a series of experiments with genetically modified mice revealing the roles of main N-methyl-d-aspartate (NMDA) and group I metabotropic glutamate (mGluR1/5) receptor scaffolds in behavior, discuss the clinical implications of the findings, and propose future research directions.
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Affiliation(s)
- Can Gao
- Jiangsu Key Laboratory of Anesthesiology, Xuzhou Medical College, 209 Tongshan Road, Xuzhou, Jiangsu 221004, China.
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69
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Abstract
In recent years, the glutamatergic system has been implicated in the development and treatment of psychiatric disorders. Glutamate signaling is processed by different receptors, including metabotropic glutamate receptors (mGluRs), which in turn interact with the scaffolding protein Homer1 to modulate downstream Ca(2+) signaling. Stress is a major risk factor for the incidence of psychiatric diseases, yet acute stress episodes may have diverging effects on individuals. Cognitive impairments have often been shown to occur after episodes of stress, however the specific role of mGluR5/Homer1 signaling in the interaction of stress and cognition has not yet been elucidated. In this study we show that a single episode of social defeat stress is sufficient to specifically induce cognitive impairments in mice 8 h after the stressor without affecting the animals' locomotion or anxiety levels. We also demonstrate that Homer1b/c levels as well as mGluR5/Homer1b/c interactions in the dorsal hippocampus are reduced up to 8 h after stress. Blockade of mGluR5 during the occurrence of social stress was able to rescue the cognitive impairments. In addition, a specific overexpression of Homer1b/c in the dorsal hippocampus also reversed the behavioral phenotype, indicating that both mGluR5 and Homer1b/c play a crucial role in the mediation of the stress effects. In summary, we could demonstrate that stress induces a cognitive deficit that is likely mediated by mGluR5/Homer1 signaling in the hippocampus. These findings help to reveal the underlying effects of cognitive impairments in patients suffering from stress-related psychiatric disorders.
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70
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Gerstein H, Lindstrom MJ, Burger C. Gene delivery of Homer1c rescues spatial learning in a rodent model of cognitive aging. Neurobiol Aging 2013; 34:1963-70. [PMID: 23523268 DOI: 10.1016/j.neurobiolaging.2013.02.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Revised: 02/04/2013] [Accepted: 02/09/2013] [Indexed: 01/13/2023]
Abstract
Homer1c has been shown to play a role in learning and memory. Overexpression of Homer1c in the hippocampus can improve memory in normal rats and can also rescue spatial learning deficits in Homer1 knockout mice. In a previous study, we found that Homer1c mRNA is upregulated after a spatial learning paradigm in aged rats that successfully learn the task, when compared to aged rats that are learning-impaired (AI). This study was designed to validate the role of Homer1c in successful cognitive aging. In this article, we report that gene delivery of Homer1c into the hippocampus of aged learning-impaired rats significantly improves individual performance on an object location memory task. The learning ability of these rats on the Morris Water Maze was also superior to that of AI control rats. In summary, using 2 independent spatial memory tasks, we demonstrate that Homer1c is sufficient to improve the spatial learning deficits in a rodent model of cognitive aging. These results point to Homer1c as a potential therapeutic target for improving age-related cognitive impairment.
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Affiliation(s)
- Hilary Gerstein
- Department of Neurology, University of Wisconsin-Madison, Medical Sciences Center, Madison, WI 53706, USA
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71
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Hong Q, Yang L, Zhang M, Pan XQ, Guo M, Fei L, Tong ML, Chen RH, Guo XR, Chi X. Increased locomotor activity and non-selective attention and impaired learning ability in SD rats after lentiviral vector-mediated RNA interference of Homer 1a in the brain. Int J Med Sci 2013; 10:90-102. [PMID: 23289010 PMCID: PMC3534882 DOI: 10.7150/ijms.4892] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2012] [Accepted: 12/24/2012] [Indexed: 12/27/2022] Open
Abstract
Our previous studies found that Homer 1a, a scaffolding protein localized at the post-synaptic density (PSD) of glutamatergic excitatory synapses, is significantly down-regulated in the brain of spontaneous hypertensive rats (SHR), an animal model of attention deficit hyperactivity disorder (ADHD). Furthermore, a first-line treatment drug for ADHD, methylphenidate, can up-regulate the expression of Homer 1a. To investigate the possible role of Homer 1a in the etiology and pathogenesis of ADHD, a lentiviral vector containing miRNA specific for Homer 1a was constructed in this study. Intracerebroventricular injection of this vector into the brain of Sprague Dawley (SD) rats significantly decreased Homer 1a mRNA and protein expression levels. Compared to their negative controls, these rats displayed a range of abnormal behaviors, including increased locomotor activity and non-selective attention and impaired learning ability. Our results indicated that Homer 1a down-regulation results in deficits in control over behavioral output and learning similar to ADHD.
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Affiliation(s)
- Qin Hong
- State Key Laboratory of Reproductive Medicine, Department of Pediatrics, Nanjing Maternity and Child Health Hospital of Nanjing Medical University, Nanjing, China
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72
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Marsman A, van den Heuvel MP, Klomp DWJ, Kahn RS, Luijten PR, Hulshoff Pol HE. Glutamate in schizophrenia: a focused review and meta-analysis of ¹H-MRS studies. Schizophr Bull 2013; 39:120-9. [PMID: 21746807 PMCID: PMC3523901 DOI: 10.1093/schbul/sbr069] [Citation(s) in RCA: 331] [Impact Index Per Article: 30.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Schizophrenia is a severe chronic psychiatric illness, characterized by hallucinations and delusions. Decreased brain volumes have been observed in the disease, although the origin of these changes is unknown. Changes in the n-methyl-d-aspartate (NMDA)-receptor mediated glutamatergic neurotransmission are implicated, since it is hypothesized that NMDA-receptor dysfunction in schizophrenia leads to increased glutamate release, which can have excitotoxic effects. However, the magnitude and extent of changes in glutamatergic metabolites in schizophrenia are not clear. With (1)H magnetic resonance spectroscopy ((1)H-MRS), in vivo information about glutamate and glutamine concentrations can be obtained in the brain. A systematic search through the MEDLINE database was conducted to identify relevant (1)H-MRS studies that examined differences in glutamate and glutamine concentrations between patients with schizophrenia and healthy control subjects. Twenty-eight studies were identified and included a total of 647 patients with schizophrenia and 608 healthy-control subjects. For each study, Cohen's d was calculated and main effects for group analyses were performed using the random-effects model. Medial frontal region glutamate was decreased and glutamine was increased in patients with schizophrenia as compared with healthy individuals. Group-by-age associations revealed that in patients with schizophrenia, glutamate and glutamine concentrations decreased at a faster rate with age as compared with healthy controls. This could reflect aberrant processes in schizophrenia, such as altered synaptic activity, changed glutamate receptor functioning, abnormal glutamine-glutamate cycling, or dysfunctional glutamate transport.
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Affiliation(s)
- Anouk Marsman
- Department of Psychiatry, Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, Internal address A.01.126, PO Box 85500, 3508 GA Utrecht, The Netherlands.
| | - Martijn P. van den Heuvel
- Department of Psychiatry, Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Dennis W. J. Klomp
- Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - René S. Kahn
- Department of Psychiatry, Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Peter R. Luijten
- Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Hilleke E. Hulshoff Pol
- Department of Psychiatry, Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, Utrecht, The Netherlands
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Scaffolding proteins of the post-synaptic density contribute to synaptic plasticity by regulating receptor localization and distribution: relevance for neuropsychiatric diseases. Neurochem Res 2012; 38:1-22. [PMID: 22991141 DOI: 10.1007/s11064-012-0886-y] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2012] [Revised: 08/16/2012] [Accepted: 09/10/2012] [Indexed: 10/27/2022]
Abstract
Synaptic plasticity represents the long lasting activity-related strengthening or weakening of synaptic transmission, whose well-characterized types are the long term potentiation and depression. Despite this classical definition, however, the molecular mechanisms by which synaptic plasticity may occur appear to be extremely complex and various. The post-synaptic density (PSD) of glutamatergic synapses is a major site for synaptic plasticity processes and alterations of PSD members have been recently implicated in neuropsychiatric diseases where an impairment of synaptic plasticity has also been reported. Among PSD members, scaffolding proteins have been demonstrated to bridge surface receptors with their intracellular effectors and to regulate receptors distribution and localization both at surface membranes and within the PSD. This review will focus on the molecular physiology and pathophysiology of synaptic plasticity processes, which are tuned by scaffolding PSD proteins and their close related partners, through the modulation of receptor localization and distribution at post-synaptic sites. We suggest that, by regulating both the compartmentalization of receptors along surface membrane and their degradation as well as by modulating receptor trafficking into the PSD, postsynaptic scaffolding proteins may contribute to form distinct signaling micro-domains, whose efficacy in transmitting synaptic signals depends on the dynamic stability of the scaffold, which in turn is provided by relative amounts and post-translational modifications of scaffolding members. The putative relevance for neuropsychiatric diseases and possible pathophysiological mechanisms are discussed in the last part of this work.
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Moutin E, Raynaud F, Roger J, Pellegrino E, Homburger V, Bertaso F, Ollendorff V, Bockaert J, Fagni L, Perroy J. Dynamic remodeling of scaffold interactions in dendritic spines controls synaptic excitability. ACTA ACUST UNITED AC 2012; 198:251-63. [PMID: 22801779 PMCID: PMC3410417 DOI: 10.1083/jcb.201110101] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
Synaptic activity–dependent remodeling of the glutamate receptor scaffold complex generates a negative feedback loop that limits further NMDA receptor activation. Scaffolding proteins interact with membrane receptors to control signaling pathways and cellular functions. However, the dynamics and specific roles of interactions between different components of scaffold complexes are poorly understood because of the dearth of methods available to monitor binding interactions. Using a unique combination of single-cell bioluminescence resonance energy transfer imaging in living neurons and electrophysiological recordings, in this paper, we depict the role of glutamate receptor scaffold complex remodeling in space and time to control synaptic transmission. Despite a broad colocalization of the proteins in neurons, we show that spine-confined assembly/disassembly of this scaffold complex, physiologically triggered by sustained activation of synaptic NMDA (N-methyl-d-aspartate) receptors, induces physical association between ionotropic (NMDA) and metabotropic (mGlu5a) synaptic glutamate receptors. This physical interaction results in an mGlu5a receptor–mediated inhibition of NMDA currents, providing an activity-dependent negative feedback loop on NMDA receptor activity. Such protein scaffold remodeling represents a form of homeostatic control of synaptic excitability.
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Affiliation(s)
- Enora Moutin
- Centre national de la recherche scientifique, UMR-5203, Institut de Génomique Fonctionnelle, F-34000 Montpellier, Cedex 16, France
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de Bartolomeis A, Tomasetti C. Calcium-Dependent Networks in Dopamine–Glutamate Interaction: The Role of Postsynaptic Scaffolding Proteins. Mol Neurobiol 2012; 46:275-96. [DOI: 10.1007/s12035-012-8293-6] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Accepted: 06/21/2012] [Indexed: 01/11/2023]
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76
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Luo P, Li X, Fei Z, Poon W. Scaffold protein Homer 1: implications for neurological diseases. Neurochem Int 2012; 61:731-8. [PMID: 22749857 DOI: 10.1016/j.neuint.2012.06.014] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2011] [Revised: 06/16/2012] [Accepted: 06/20/2012] [Indexed: 11/17/2022]
Abstract
Homer proteins are commonly known as scaffold proteins at postsynaptic density. Homer 1 is a widely studied member of the Homer protein family, comprising both synaptic structure and mediating postsynaptic signaling transduction. Both an immediate-early gene encoding a Homer 1 variant and a constitutively expressed Homer 1 variant regulate receptor clustering and trafficking, intracellular calcium homeostasis, and intracellular molecule complex formation. Substantial preclinical investigations have implicated that each of these Homer 1 variants are associated with the etiology of many neurological diseases, such as pain, mental retardation syndromes, Alzheimer's disease, schizophrenia, drug-induced addiction, and traumatic brain injury.
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Affiliation(s)
- Peng Luo
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, PR China
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Strauss J, McGregor S, Freeman N, Tiwari A, George CJ, Kovacs M, Kennedy JL. Association study of early-immediate genes in childhood-onset mood disorders and suicide attempt. Psychiatry Res 2012; 197:49-54. [PMID: 22460132 PMCID: PMC3376203 DOI: 10.1016/j.psychres.2011.11.022] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2011] [Revised: 11/06/2011] [Accepted: 11/26/2011] [Indexed: 01/17/2023]
Abstract
Childhood-onset mood disorders (COMD) are serious affective disorders with deleterious developmental sequelae including interpersonal dysfunction, psychotic symptoms and suicidal behavior. The current study examines 10 markers from two early-immediate genes for association with COMD and suicide attempt (SA) - HOMER1 and human neuronal pentraxin II (NPTX2). We examined individuals diagnosed with COMD versus matched controls, as well as individuals with COMD and a history of at least one lifetime SA versus COMD participants with no history of SA. No significant genotypic association was noted between any of the single nucleotide polymorphisms (SNPs) and COMD. Our sample yielded a nominally significant allelic association between the HOMER1 rs7713917 SNP and COMD. We report significant genotype associations between HOMER1 rs2290639 and SA , and between NPTX2 markers rs705315 and rs1681248 and SA, findings that remained statistically significant after multiple test correction. A three-way interaction was observed among HOMER1 rs4704560, rs2290639 and NPTX2 rs705318. The associations we describe for HOMER1 and NPTX2 with SA should be considered preliminary until replicated.
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Affiliation(s)
- John Strauss
- Centre for Addiction and Mental Health, University of Toronto, Toronto, ON, Canada.
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Wilkinson FL, Holley RJ, Langford-Smith KJ, Badrinath S, Liao A, Langford-Smith A, Cooper JD, Jones SA, Wraith JE, Wynn RF, Merry CLR, Bigger BW. Neuropathology in mouse models of mucopolysaccharidosis type I, IIIA and IIIB. PLoS One 2012; 7:e35787. [PMID: 22558223 PMCID: PMC3338781 DOI: 10.1371/journal.pone.0035787] [Citation(s) in RCA: 135] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2011] [Accepted: 03/22/2012] [Indexed: 12/30/2022] Open
Abstract
Mucopolysaccharide diseases (MPS) are caused by deficiency of glycosaminoglycan (GAG) degrading enzymes, leading to GAG accumulation. Neurodegenerative MPS diseases exhibit cognitive decline, behavioural problems and shortened lifespan. We have characterised neuropathological changes in mouse models of MPSI, IIIA and IIIB to provide a better understanding of these events. Wild-type (WT), MPSI, IIIA and IIIB mouse brains were analysed at 4 and 9 months of age. Quantitative immunohistochemistry showed significantly increased lysosomal compartment, GM2 ganglioside storage, neuroinflammation, decreased and mislocalised synaptic vesicle associated membrane protein, (VAMP2), and decreased post-synaptic protein, Homer-1, in layers II/III-VI of the primary motor, somatosensory and parietal cortex. Total heparan sulphate (HS), was significantly elevated, and abnormally N-, 6-O and 2-O sulphated compared to WT, potentially altering HS-dependent cellular functions. Neuroinflammation was confirmed by significantly increased MCP-1, MIP-1α, IL-1α, using cytometric bead arrays. An overall genotype effect was seen in all parameters tested except for synaptophysin staining, neuronal cell number and cortical thickness which were not significantly different from WT. MPSIIIA and IIIB showed significantly more pronounced pathology than MPSI in lysosomal storage, astrocytosis, microgliosis and the percentage of 2-O sulphation of HS. We also observed significant time progression of all genotypes from 4–9 months in lysosomal storage, astrocytosis, microgliosis and synaptic disorganisation but not GM2 gangliosidosis. Individual genotype*time differences were disparate, with significant progression from 4 to 9 months only seen for MPSIIIB with lysosomal storage, MPSI with astrocytocis and MPSIIIA with microgliosis as well as neuronal loss. Transmission electron microscopy of MPS brains revealed dystrophic axons, axonal storage, and extensive lipid and lysosomal storage. These data lend novel insight to MPS neuropathology, suggesting that MPSIIIA and IIIB have more pronounced neuropathology than MPSI, yet all are still progressive, at least in some aspects of neuropathology, from 4–9 months.
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Affiliation(s)
- Fiona L. Wilkinson
- Stem Cell & Neurotherapies, Faculty of Medical and Human Sciences, University of Manchester, Manchester, United Kingdom
| | - Rebecca J. Holley
- Stem Cell Glycobiology, School of Materials, University of Manchester, Manchester, United Kingdom
| | - Kia J. Langford-Smith
- Stem Cell & Neurotherapies, Faculty of Medical and Human Sciences, University of Manchester, Manchester, United Kingdom
| | - Soumya Badrinath
- Stem Cell & Neurotherapies, Faculty of Medical and Human Sciences, University of Manchester, Manchester, United Kingdom
| | - Aiyin Liao
- Stem Cell & Neurotherapies, Faculty of Medical and Human Sciences, University of Manchester, Manchester, United Kingdom
| | - Alex Langford-Smith
- Stem Cell & Neurotherapies, Faculty of Medical and Human Sciences, University of Manchester, Manchester, United Kingdom
| | - Jonathan D. Cooper
- Pediatric Storage Disorders Laboratory, Department of Neuroscience, and Centre for the Cellular Basis of Behaviour, MRC Centre for Neurodegeneration Research, Institute of Psychiatry, King's College London, United Kingdom
| | - Simon A. Jones
- Genetic Medicine, St Mary's Hospital, Manchester, United Kingdom
| | - J. Ed Wraith
- Genetic Medicine, St Mary's Hospital, Manchester, United Kingdom
| | - Rob F. Wynn
- Blood and Marrow Transplant Unit, Royal Manchester Children's Hospital, Manchester, United Kingdom
| | - Catherine L. R. Merry
- Stem Cell Glycobiology, School of Materials, University of Manchester, Manchester, United Kingdom
| | - Brian W. Bigger
- Stem Cell & Neurotherapies, Faculty of Medical and Human Sciences, University of Manchester, Manchester, United Kingdom
- * E-mail:
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79
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Ting JT, Peça J, Feng G. Functional consequences of mutations in postsynaptic scaffolding proteins and relevance to psychiatric disorders. Annu Rev Neurosci 2012; 35:49-71. [PMID: 22540979 DOI: 10.1146/annurev-neuro-062111-150442] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Functional studies on postsynaptic scaffolding proteins at excitatory synapses have revealed a plethora of important roles for synaptic structure and function. In addition, a convergence of recent in vivo functional evidence together with human genetics data strongly suggest that mutations in a variety of these postsynaptic scaffolding proteins may contribute to the etiology of diverse human psychiatric disorders such as schizophrenia, autism spectrum disorders, and obsessive-compulsive spectrum disorders. Here we review the most recent evidence for several key postsynaptic scaffolding protein families and explore how mouse genetics and human genetics have intersected to advance our knowledge concerning the contributions of these important players to complex brain function and dysfunction.
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Affiliation(s)
- Jonathan T Ting
- McGovern Institute for Brain Research and Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
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80
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Murotomi K, Takagi N, Muroyama A, Kaji N, Takeo S, Tanonaka K. Transient focal cerebral ischemia differentially decreases Homer1a and 1b/c contents in the postsynaptic density. Neurosci Lett 2012; 515:92-6. [PMID: 22465321 DOI: 10.1016/j.neulet.2012.03.036] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2012] [Revised: 02/25/2012] [Accepted: 03/13/2012] [Indexed: 11/25/2022]
Abstract
Homer is a scaffold protein in the postsynaptic density (PSD) and binds to the intracellular tail of group I metabotropic glutamate receptors (mGluRs). Although Homer contributes to the regulation of physiological function in synapses, the role of Homer proteins under pathophysiological conditions, such as cerebral ischemia, is still not fully clear. In the present study, we sought to determine whether transient focal cerebral ischemia would affect the level of Homer1 in the isolated-PSD fraction from rats. We showed that Homer1a (short form) and Homer1b/c (long form) as well as group I mGluR were localized in the cortical PSD. Cerebral ischemia decreased the content of Homer1a, which is a dominant-negative inhibitor of the long form of Homer proteins, in the PSD at 4 h of reperfusion without changing the level of Homer1a in cortical homogenates. On the other hand, the levels of Homer1b/c in the both PSD and homogenates were decreased at 24 h of reperfusion. These results suggest that these decreases in the level of Homer1 proteins after cerebral ischemia may contribute to the disturbance of synaptic function and subsequent development of cerebral ischemia.
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Affiliation(s)
- Kazutoshi Murotomi
- Department of Molecular and Cellular Pharmacology, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan
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81
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Diversity of metabotropic glutamate receptor-interacting proteins and pathophysiological functions. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 970:63-79. [PMID: 22351051 DOI: 10.1007/978-3-7091-0932-8_3] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
In the mammalian brain, the large majority of excitatory synapses express pre- and postsynaptic glutamate receptors. These are ion channels and G protein-coupled membrane proteins that are organized into functional signaling complexes. Here, we will review the nature and pathophysiological functions of the scaffolding proteins associated to these receptors, focusing on the G protein-coupled subtypes.
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82
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Knockdown of Synaptic Scaffolding Protein Homer 1b/c Attenuates Secondary Hyperalgesia Induced by Complete Freund's Adjuvant in Rats. Anesth Analg 2011; 113:1501-8. [DOI: 10.1213/ane.0b013e31822c0b98] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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83
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Moussawi K, Riegel A, Nair S, Kalivas PW. Extracellular glutamate: functional compartments operate in different concentration ranges. Front Syst Neurosci 2011; 5:94. [PMID: 22275885 PMCID: PMC3254064 DOI: 10.3389/fnsys.2011.00094] [Citation(s) in RCA: 130] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2011] [Accepted: 10/31/2011] [Indexed: 12/24/2022] Open
Abstract
Extracellular glutamate of glial origin modulates glial and neuronal glutamate release and synaptic plasticity. Estimates of the tonic basal concentration of extracellular glutamate range over three orders of magnitude (0.02-20 μM) depending on the technology employed to make the measurement. Based upon binding constants for glutamate receptors and transporters, this range of concentrations translates into distinct physiological and pathophysiological roles for extracellular glutamate. Here we speculate that the difference in glutamate measurements can be explained if there is patterned membrane surface expression of glutamate release and transporter sites creating extracellular subcompartments that vary in glutamate concentration and are preferentially sampled by different technologies.
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Affiliation(s)
- Khaled Moussawi
- Department of Neurosciences, Medical University of South Carolina Charleston, SC, USA
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84
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Gerstein H, O'Riordan K, Osting S, Schwarz M, Burger C. Rescue of synaptic plasticity and spatial learning deficits in the hippocampus of Homer1 knockout mice by recombinant Adeno-associated viral gene delivery of Homer1c. Neurobiol Learn Mem 2011; 97:17-29. [PMID: 21945599 DOI: 10.1016/j.nlm.2011.08.009] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2011] [Revised: 08/18/2011] [Accepted: 08/23/2011] [Indexed: 10/17/2022]
Abstract
Homer1 belongs to a family of scaffolding proteins that interact with various post-synaptic density proteins including group I metabotropic glutamate receptors (mGluR1/5). Previous research in our laboratory implicates the Homer1c isoform in spatial learning. Homer1 knockout mice (H1-KO) display cognitive impairments, but their synaptic plasticity properties have not been described. Here, we investigated the role of Homer1 in long-term potentiation (LTP) in the hippocampal CA1 region of H1-KO mice in vitro. We found that late-phase LTP elicited by high frequency stimulation (HFS) was impaired, and that the induction and maintenance of theta burst stimulation (TBS) LTP were reduced in H1-KO. To test the hypothesis that Homer1c was sufficient to rescue these LTP deficits, we delivered Homer1c to the hippocampus of H1-KO using recombinant adeno-associated virus (rAAV). We found that rAAV-Homer1c rescued HFS and TBS-LTP in H1-KO animals. Next, we tested whether the LTP rescue by Homer1c was occurring via mGluR1/5. A selective mGluR5 antagonist, but not an mGluR1 antagonist, blocked the Homer1c-induced recovery of late-LTP, suggesting that Homer1c mediates functional effects on plasticity via mGluR5. To investigate the role of Homer1c in spatial learning, we injected rAAV-Homer1c to the hippocampus of H1-KO. We found that rAAV-Homer1c significantly improved H1-KO performance in the Radial Arm Water Maze. These results point to a significant role for Homer1c in synaptic plasticity and learning.
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Affiliation(s)
- Hilary Gerstein
- Department of Neurology, University of Wisconsin-Madison, Medical Sciences Center, 1300 University Ave., Room 73 Bardeen, Madison, WI 53706, USA
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85
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Iasevoli F, Ambesi-Impiombato A, Fiore G, Panariello F, Muscettola G, de Bartolomeis A. Pattern of acute induction of Homer1a gene is preserved after chronic treatment with first- and second-generation antipsychotics: effect of short-term drug discontinuation and comparison with Homer1a-interacting genes. J Psychopharmacol 2011; 25:875-87. [PMID: 20147574 DOI: 10.1177/0269881109358199] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Homer1a is a glutamate-related gene whose expression is induced by antipsychotics acutely (i.e. 90 min after treatment). Acute Homer1a expression is preserved after prolonged antipsychotic treatments, while the effects of short-term discontinuation after chronic antipsychotic treatment have not yet been assessed. Here, we studied early and long-term effects on gene expression by antipsychotics for Homer1a and other components of glutamatergic synapses. In the first paradigm, we evaluated Homer1a acute expression by single administration of antipsychotics (haloperidol 0.8 mg/kg, ziprasidone 10 and 4 mg/kg, clozapine 15 mg/kg). Haloperidol and ziprasidone induced Homer1a in the striatum. Induction by ziprasidone was dose-dependent. These results suggest that acute Homer1a expression correlates with dopaminergic affinity and motor side effects of antipsychotics. In the second paradigm, we studied antipsychotic-mediated long-term changes in Homer1a and glutamate-related genes. Rats were treated (21 days) with haloperidol 0.8 mg/kg, ziprasidone 4 mg/kg, or vehicle, and then sacrificed at 90 min (early time-point) or 24 h (delayed time-point) after last injection. Gene expression at these two time-points was compared. Homer1a preserved its pattern of expression at the early but not at the delayed time-point. Significant changes were also observed for PSD-95. The results suggest that Homer1a preserves its expression profile after chronic antipsychotics.
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Affiliation(s)
- Felice Iasevoli
- Laboratory of Molecular Psychiatry and Psychopharmacotherapy, Section of Psychiatry, Department of Neuroscience, University School of Medicine 'Federico II', Naples, Italy
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86
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Nam HW, Lee MR, Zhu Y, Wu J, Hinton DJ, Choi S, Kim T, Hammack N, Yin JC, Choi DS. Type 1 equilibrative nucleoside transporter regulates ethanol drinking through accumbal N-methyl-D-aspartate receptor signaling. Biol Psychiatry 2011; 69:1043-51. [PMID: 21489406 PMCID: PMC3090461 DOI: 10.1016/j.biopsych.2011.02.013] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2010] [Revised: 12/24/2010] [Accepted: 02/04/2011] [Indexed: 12/18/2022]
Abstract
BACKGROUND Mice lacking type 1 equilibrative nucleoside transporter (ENT1(-/-)) exhibit increased ethanol-preferring behavior compared with wild-type littermates. This phenotype of ENT1(-/-) mice appears to be correlated with increased glutamate levels in the nucleus accumbens (NAc). However, little is known about the downstream consequences of increased glutamate signaling in the NAc. METHODS To investigate the significance of the deletion of ENT1 and its effect on glutamate signaling in the NAc, we employed microdialysis and iTRAQ proteomics. We validated altered proteins using Western blot analysis. We then examined the pharmacological effects of the inhibition of the N-methyl-D-aspartate (NMDA) glutamate receptor and protein kinase Cγ (PKCγ) on alcohol drinking in wild-type mice. In addition, we investigated in vivo cyclic adenosine monophosphate response element binding activity using cyclic adenosine monophosphate response element-β-galactosidase mice in an ENT1(-/-) background. RESULTS We identified that NMDA glutamate receptor-mediated downregulation of intracellular PKCγ-neurogranin-calcium-calmodulin dependent protein kinase type II signaling is correlated with reduced cyclic adenosine monophosphate response element binding activity in ENT1(-/-) mice. Inhibition of PKCγ promotes ethanol drinking in wild-type mice to levels similar to those of ENT1(-/-) mice. In contrast, an NMDA glutamate receptor antagonist reduces ethanol drinking of ENT1(-/-) mice. CONCLUSIONS These findings demonstrate that the genetic deletion or pharmacological inhibition of ENT1 regulates NMDA glutamate receptor-mediated signaling in the NAc, which provides a molecular basis that underlies the ethanol-preferring behavior of ENT1(-/-) mice.
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Affiliation(s)
- Hyung Wook Nam
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine, Rochester, Minnesota 55905
| | - Moonnoh R. Lee
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine, Rochester, Minnesota 55905
| | - Yu Zhu
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine, Rochester, Minnesota 55905
| | - Jinhua Wu
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine, Rochester, Minnesota 55905
| | - David J. Hinton
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine, Rochester, Minnesota 55905
| | - Sun Choi
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine, Rochester, Minnesota 55905
| | - Taehyun Kim
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine, Rochester, Minnesota 55905
| | - Nora Hammack
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine, Rochester, Minnesota 55905
| | - Jerry C.P. Yin
- Department of Genetics and Neurology, University of Wisconsin, Madison, Wisconsin 53706
| | - Doo-Sup Choi
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine, Rochester, Minnesota 55905,Department of Psychiatry and Psychology, Mayo Clinic College of Medicine, Rochester, Minnesota 55905,Molecular Neuroscience Program, Mayo Clinic College of Medicine, Rochester, Minnesota 55905
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87
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Abstract
The possible role of the CB(2) receptor (CB(2)r) in psychiatric disorders has been considered. Several animal models use knockout (KO) mice that display schizophrenia-like behaviors and this study evaluated the role of CB(2)r in the regulation of such behaviors. Mice lacking the CB(2)r (CB(2)KO) were challenged in open field, light-dark box, elevated plus-maze, tail suspension, step down inhibitory avoidance, and pre-pulse inhibition tests (PPI). Furthermore, the effects of treatment with cocaine and risperidone were evaluated using the OF and the PPI test. Gene expression of dopamine D(2) (D(2)r), adrenergic-α(2C) (α(2C)r), serotonergic 5-HT(2A) and 5-HT(2C) receptors (5-HT(2A)r and 5-HT(2C)r) were studied by RT-PCR in brain regions related to schizophrenia. Deletion of CB(2)r decreased motor activity in the OF test, but enhanced response to acute cocaine and produced mood-related alterations, PPI deficit, and cognitive impairment. Chronic treatment with risperidone tended to impair PPI in WT mice, whereas it 'normalized' the PPI deficit in CB(2)KO mice. CB(2)KO mice presented increased D(2)r and α(2C)r gene expressions in the prefrontal cortex (PFC) and locus coeruleus (LC), decreased 5-HT(2C)r gene expression in the dorsal raphe (DR), and 5-HT(2A)r gene expression in the PFC. Chronic risperidone treatment in WT mice left α(2C)r gene expression unchanged, decreased D(2)r gene expression (15 μg/kg), and decreased 5-HT(2C)r and 5-HT(2A)r in PFC and DR. In CB(2)KO, the gene expression of D(2)r in the PFC, of α(2C)r in the LC, and of 5-HT(2C)r and 5-HT(2A)r in PFC was reduced; 5-HT(2C)r and 5-HT(2A)r gene expressions in DR were increased after treatment with risperidone. These results suggest that deletion of CB(2)r has a relation with schizophrenia-like behaviors. Pharmacological manipulation of CB(2)r may merit further study as a potential therapeutic target for the treatment of schizophrenia-related disorders.
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88
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Enhanced polyubiquitination of Shank3 and NMDA receptor in a mouse model of autism. Cell 2011; 145:758-72. [PMID: 21565394 DOI: 10.1016/j.cell.2011.03.052] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2010] [Revised: 02/03/2011] [Accepted: 03/28/2011] [Indexed: 12/28/2022]
Abstract
We have created a mouse genetic model that mimics a human mutation of Shank3 that deletes the C terminus and is associated with autism. Expressed as a single copy [Shank3(+/ΔC) mice], Shank3ΔC protein interacts with the wild-type (WT) gene product and results in >90% reduction of Shank3 at synapses. This "gain-of-function" phenotype is linked to increased polyubiquitination of WT Shank3 and its redistribution into proteasomes. Similarly, the NR1 subunit of the NMDA receptor is reduced at synapses with increased polyubiquitination. Assays of postsynaptic density proteins, spine morphology, and synapse number are unchanged in Shank3(+/ΔC) mice, but the amplitude of NMDAR responses is reduced together with reduced NMDAR-dependent LTP and LTD. Reciprocally, mGluR-dependent LTD is markedly enhanced. Shank3(+/ΔC) mice show behavioral deficits suggestive of autism and reduced NMDA receptor function. These studies reveal a mechanism distinct from haploinsufficiency by which mutations of Shank3 can evoke an autism-like disorder.
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89
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Qi C, Roseboom PH, Nanda SA, Lane JC, Speers JM, Kalin NH. Anxiety-related behavioral inhibition in rats: a model to examine mechanisms underlying the risk to develop stress-related psychopathology. GENES BRAIN AND BEHAVIOR 2011; 9:974-84. [PMID: 20738409 DOI: 10.1111/j.1601-183x.2010.00636.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Behavioral inhibition (BI) is an adaptive defensive response to threat; however, children who display extreme BI as a stable trait are at risk for development of anxiety disorders and depression. The present study validates a rodent model of BI based on an ethologically relevant predator exposure paradigm. We show that individual differences in rat BI are stable and trait-like from adolescence into adulthood. Using in situ hybridization to quantify expression of the immediate early genes homer1a and fos as measures of neuronal activation, we show that individual differences in BI are correlated with the activation of various stress-responsive brain regions that include the paraventricular nucleus of the hypothalamus and CA3 region of the hippocampus. Further supporting the concept that threat-induced BI in rodents reflects levels of anxiety, we also show that BI is decreased by administration of the anxiolytic, diazepam. Finally, we developed criteria for identifying extreme BI animals that are stable in their expression of high levels of BI and also show that high BI (HBI) individuals exhibit maladaptive appetitive responses following stress exposure. These findings support the use of predator threat as a stimulus and HBI rats as a model to study mechanisms underlying extreme and stable BI in humans.
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Affiliation(s)
- C Qi
- Molecular and Cellular Pharmacology Training Program, University of Wisconsin-Madison, Madison, WI 53719-1176, USA
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90
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Kondo S, Okabe S. Turnover of synapse and dynamic nature of synaptic molecules in vitro and in vivo. Acta Histochem Cytochem 2011; 44:9-15. [PMID: 21448313 PMCID: PMC3061450 DOI: 10.1267/ahc.10035] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2010] [Accepted: 01/14/2011] [Indexed: 11/22/2022] Open
Abstract
Recent advances of imaging techniques have enabled us to investigate the dynamics of synapses in living neurons. The synapse is constructed of presynaptic and postsynaptic elements which contain various kinds of structural and functional molecules. The postsynaptic density (PSD) is the most prominent structure among the excitatory postsynaptic elements. One of the main components of PSD is the scaffolding proteins which interact with multiple proteins in the synapse. Scaffolding proteins are suggested to play key roles in the emergence, maintenance, and remodeling of the excitatory synapses. Several kinds of scaffolding proteins are known to be present in the mammalian and also other vertebrate brains. These proteins were labeled with green fluorescent protein (GFP) and expressed in cultured neurons to analyze the dynamics and turnover of molecules in the synapses. In this review we describe how these molecules behave when the synapse is newly added or eliminated in the steady state and also when neuronal activity is changed.
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Affiliation(s)
- Satoru Kondo
- Department of Cellular Neurobiology, Graduate School of Medicine, University of Tokyo
| | - Shigeo Okabe
- Department of Cellular Neurobiology, Graduate School of Medicine, University of Tokyo
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91
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Spellmann I, Rujescu D, Musil R, Mayr A, Giegling I, Genius J, Zill P, Dehning S, Opgen-Rhein M, Cerovecki A, Hartmann AM, Schäfer M, Bondy B, Müller N, Möller HJ, Riedel M. Homer-1 polymorphisms are associated with psychopathology and response to treatment in schizophrenic patients. J Psychiatr Res 2011; 45:234-41. [PMID: 20598711 DOI: 10.1016/j.jpsychires.2010.06.004] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2010] [Revised: 05/17/2010] [Accepted: 06/07/2010] [Indexed: 11/30/2022]
Abstract
The HOMER 1 protein plays a crucial role in mediating glutamatergic neurotransmission. It has previously shown to be a candidate gene for etiology and pathophysiology of different psychiatric diseases such as schizophrenia. To identify genes involved in response to antipsychotics, subgroups of animals were treated with haloperidol (1 mg/kg, n = 11) or saline (n = 12) for one week. By analyzing microarray data, we replicated the observed increase of Homer 1 gene expression. Furthermore, we genotyped 267 schizophrenic patients, who were treated monotherapeutically with different antipsychotics within randomized-controlled trials. Psychopathology was measured weekly using the PANSS for a minimum of four and a maximum of twelve weeks. Correlations between PANSS subscale scores at baseline and PANSS improvement scores after four weeks of treatment and genotypes were calculated by using a linear model for all investigated SNP's. We found an association between two HOMER 1 polymorphisms (rs2290639 and rs4704560) and different PANSS subscales at baseline. Furthermore all seven investigated polymorphisms were found to be associated with therapy response in terms of a significant correlation with different PANSS improvement subscores after four weeks of antipsychotic treatment. Most significant associations have been shown between the rs2290639 HOMER 1 polymorphism and PANSS subscales both at baseline conditions and after four weeks of antipsychotic treatment. This is the first study which shows an association between HOMER 1 polymorphisms and psychopathology data at baseline and therapy response in a clinical sample of schizophrenic patients. Thus, these data might further help in detecting differential therapy response in individuals with schizophrenia.
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Affiliation(s)
- Ilja Spellmann
- Department of Psychiatry and Psychotherapy, Ludwig-Maximilians-University of Munich, Nußbaumstrasse 7, 80336 Munich, Germany.
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92
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The acute and chronic effects of combined antipsychotic-mood stabilizing treatment on the expression of cortical and striatal postsynaptic density genes. Prog Neuropsychopharmacol Biol Psychiatry 2011; 35:184-97. [PMID: 21055435 DOI: 10.1016/j.pnpbp.2010.10.025] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2010] [Revised: 10/10/2010] [Accepted: 10/27/2010] [Indexed: 02/08/2023]
Abstract
The detection of changes in postsynaptic gene expression after the administration of mood stabilizers, alone or in combination with antipsychotics, and antidepressants in animal models of drug treatment, may represent a valuable strategy to explore the molecular targets of the mainstay treatments for bipolar disorder. In this study we investigated, in both acute and chronic paradigms, the expression of specific postsynaptic density genes (Homer1a, Homer1b/c, and PSD95) and genes putatively implicated in mood stabilizers mechanism of action (GSK3b, ERK) after administration of first (haloperidol) or second generation antipsychotics (quetiapine 30 mg/kg), alone or in combination with valproate. Moreover, we compared the effects of an antidepressant agent widely used in bipolar depression (citalopram) with a low dose of quetiapine (15 mg/kg), which has been demonstrated to display antidepressant action in bipolar depression. In striatal regions, Homer1a expression was strongly induced by haloperidol compared to all the other treatments. Haloperidol plus valproate also markedly induced Homer1a, but to a significant lesser extent than haloperidol alone. Also in the chronic paradigm haloperidol, but not haloperidol plus valproate, induced Homer1a expression in all the subregions of the caudate-putamen and in the nucleus accumbens core. The high dose of quetiapine significantly induced Homer1a in anterior cingulated, premotor and motor subregions of the cortex, and the extent of induction was significantly higher as compared to the lower dose. Oppositely, Homer1a expression was decreased in the cortex by citalopram acute administration. ERK gene was upregulated in cortex and striatum by the acute treatment with valproate and with the combination of haloperidol or quetiapine plus valproate, whereas no significant differences were noticed in GSK3b expression among treatments. PSD95 showed a significant upregulation by acute citalopram and by haloperidol plus valproate in both cortical and subcortical regions. Haloperidol and quetiapine 30 mg/kg, oppositely, significantly reduced the expression of the gene in the cortex. In conclusion, these results suggest that the combined treatment with a typical or an atypical antipsychotic plus valproate may induce differential modulation of postsynaptic genes expression when compared to the effects of these drugs individually administered.
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93
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Iasevoli F, Tomasetti C, Marmo F, Bravi D, Arnt J, de Bartolomeis A. Divergent acute and chronic modulation of glutamatergic postsynaptic density genes expression by the antipsychotics haloperidol and sertindole. Psychopharmacology (Berl) 2010; 212:329-44. [PMID: 20652539 DOI: 10.1007/s00213-010-1954-0] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2010] [Accepted: 07/09/2010] [Indexed: 10/19/2022]
Abstract
RATIONALE A pivotal role for glutamate in the pathophysiology and treatment of schizophrenia has been suggested. Few reports have investigated the impact of antipsychotics on postsynaptic density (PSD) molecules involved in glutamatergic transmission and synaptic remodeling. Homer is a key PSD molecule putatively implicated in schizophrenia. OBJECTIVES We studied the effect, in acute and chronic paradigms, of a first and a second generation antipsychotic (haloperidol and sertindole, respectively) on the expression of Homer1a and Homer-interacting PSD molecules. RESULTS In the acute paradigm, Homer1a expression was induced by haloperidol but not sertindole in the striatum, consistent with the less propensity of sertindole to affect nigrostriatal neurotransmission. The profile of expression of two other inducible genes, Ania3 and Arc, was highly similar to Homer1a. In the cortex, haloperidol reduced Homer1a and induced Ania3. In the chronic paradigm, striatal expression of Homer1a and Ania3 resembled that observed in the acute paradigm. In the cortex, haloperidol induced Homer1a, while sertindole did not. Homer1b expression was increased by haloperidol in the striatum and cortex whereas sertindole selectively induced Homer1b in the cortex. The expression of mGluR5 was increased by both antipsychotics. A modulation by haloperidol was also seen for PSD-95 and αCaMKII. CONCLUSIONS These results suggest that haloperidol and sertindole may significantly modulate glutamatergic transcripts of the postsynaptic density. Sertindole induces constitutive genes in the cortex predominantly, which may correlate with its propensity to improve cognitive functions. Haloperidol preferentially modulates gene expression in the striatum, consistent with its action at nigrostriatal projections and its propensity to give motor side effects.
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Affiliation(s)
- Felice Iasevoli
- Laboratory of Molecular Psychiatry and Psychopharmacotherapeutics, Section of Psychiatry, Department of Neuroscience, University School of Medicine Federico II, Edificio 18, Via Pansini 5, 80131, Naples, Italy
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94
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Strain differences in stress responsivity are associated with divergent amygdala gene expression and glutamate-mediated neuronal excitability. J Neurosci 2010; 30:5357-67. [PMID: 20392957 DOI: 10.1523/jneurosci.5017-09.2010] [Citation(s) in RCA: 182] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Stress is a major risk factor for numerous neuropsychiatric diseases. However, susceptibility to stress and the qualitative nature of stress effects on behavior differ markedly among individuals. This is partly because of the moderating influence of genetic factors. Inbred mouse strains provide a relatively stable and restricted range of genetic and environmental variability that is valuable for disentangling gene-stress interactions. Here, we screened a panel of inbred strains for anxiety- and depression-related phenotypes at baseline (trait) and after exposure to repeated restraint. Two strains, DBA/2J and C57BL/6J, differed in trait and restraint-induced anxiety-related behavior (dark/light exploration, elevated plus maze). Gene expression analysis of amygdala, medial prefrontal cortex, and hippocampus revealed divergent expression in DBA/2J and C57BL/6J both at baseline and after repeated restraint. Restraint produced strain-dependent expression alterations in various genes including glutamate receptors (e.g., Grin1, Grik1). To elucidate neuronal correlates of these strain differences, we performed ex vivo analysis of glutamate excitatory neurotransmission in amygdala principal neurons. Repeated restraint augmented amygdala excitatory postsynaptic signaling and altered metaplasticity (temporal summation of NMDA receptor currents) in DBA/2J but not C57BL/6J. Furthermore, we found that the C57BL/6J-like changes in anxiety-related behavior after restraint were absent in null mutants lacking the modulatory NMDA receptor subunit Grin2a, but not the AMPA receptor subunit Gria1. Grin2a null mutants exhibited significant ( approximately 30%) loss of dendritic spines on amygdala principal neurons under nonrestraint conditions. Collectively, our data support a model in which genetic variation in glutamatergic neuroplasticity in corticolimbic circuitry underlies phenotypic variation in responsivity to stress.
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95
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Murphy KJ, ter Horst JPF, Cassidy AW, DeSouza IEJ, Morgunova M, Li C, Connole LM, O’Sullivan NC, Loscher JS, Brady AT, Rombach N, Connellan J, McGettigan PA, Scully D, Fedriani R, Lukasz B, Moran MP, McCabe OM, Wantuch CM, Hughes ZA, Mulvany SK, Higgins DG, Pangalos MN, Marquis KL, O’Connor WT, Ring RH, von Schack D, Regan CM. Temporal dysregulation of cortical gene expression in the isolation reared Wistar rat. J Neurochem 2010; 113:601-14. [DOI: 10.1111/j.1471-4159.2010.06617.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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96
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Bockaert J, Perroy J, Bécamel C, Marin P, Fagni L. GPCR interacting proteins (GIPs) in the nervous system: Roles in physiology and pathologies. Annu Rev Pharmacol Toxicol 2010; 50:89-109. [PMID: 20055699 DOI: 10.1146/annurev.pharmtox.010909.105705] [Citation(s) in RCA: 142] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
G protein-coupled receptors (GPCRs) are key transmembrane recognition molecules for regulatory signals such as light, odors, taste hormones, and neurotransmitters. In addition to activating guanine nucleotide binding proteins (G proteins), GPCRs associate with a variety of GPCR-interacting proteins (GIPs). GIPs contain structural interacting domains that allow the formation of large functional complexes involved in G protein-dependent and -independent signaling. At the cellular level, other functions of GIPs include targeting of GPCRs to subcellular compartments and their trafficking to and from the plasma membrane. Recently, roles of GPCR-GIP interactions in central nervous system physiology and pathologies have been revealed. Here, we highlight the role of GIPs in some important neurological and psychiatric disorders, as well as their potential for the future development of therapeutic drugs.
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Affiliation(s)
- Joël Bockaert
- Centre National de la Recherche Scientifique, UMR, Institut de Génomique Fonctionnelle, Montpellier, France.
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97
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van den Buuse M. Modeling the positive symptoms of schizophrenia in genetically modified mice: pharmacology and methodology aspects. Schizophr Bull 2010; 36:246-70. [PMID: 19900963 PMCID: PMC2833124 DOI: 10.1093/schbul/sbp132] [Citation(s) in RCA: 274] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
In recent years, there have been huge advances in the use of genetically modified mice to study pathophysiological mechanisms involved in schizophrenia. This has allowed rapid progress in our understanding of the role of several proposed gene mechanisms in schizophrenia, and yet this research has also revealed how much still remains unresolved. Behavioral studies in genetically modified mice are reviewed with special emphasis on modeling psychotic-like behavior. I will particularly focus on observations on locomotor hyperactivity and disruptions of prepulse inhibition (PPI). Recommendations are included to address pharmacological and methodological aspects in future studies. Mouse models of dopaminergic and glutamatergic dysfunction are then discussed, reflecting the most important and widely studied neurotransmitter systems in schizophrenia. Subsequently, psychosis-like behavior in mice with modifications in the most widely studied schizophrenia susceptibility genes is reviewed. Taken together, the available studies reveal a wealth of available data which have already provided crucial new insight and mechanistic clues which could lead to new treatments or even prevention strategies for schizophrenia.
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Affiliation(s)
- Maarten van den Buuse
- Mental Health Research Institute of Victoria, Parkville, Melbourne, Victoria 3052, Australia.
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98
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Milner LC, Buck KJ. Identifying quantitative trait loci (QTLs) and genes (QTGs) for alcohol-related phenotypes in mice. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2010; 91:173-204. [PMID: 20813243 DOI: 10.1016/s0074-7742(10)91006-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Alcoholism is a complex clinical disorder with genetic and environmental contributions. Although no animal model duplicates alcoholism, models for specific factors, such as the withdrawal syndrome, are useful to identify potential genetic determinants of liability in humans. Murine models have been invaluable to identify quantitative trait loci (QTLs) that influence a variety of alcohol responses. However, the QTL regions are typically large, at least initially, and contain numerous genes, making identification of the causal quantitative trait gene(s) (QTGs) challenging. Here, we present QTG identification strategies currently used in the field of alcohol genetics and discuss relevance to alcoholic human populations.
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Affiliation(s)
- Lauren C Milner
- Department of Behavioral Neuroscience, VA Medical Center and Oregon Health & Science University, Portland, OR 97239, USA
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99
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Engler-Chiurazzi E, Tsang C, Nonnenmacher S, Liang WS, Corneveaux JJ, Prokai L, Huentelman MJ, Bimonte-Nelson HA. Tonic Premarin dose-dependently enhances memory, affects neurotrophin protein levels and alters gene expression in middle-aged rats. Neurobiol Aging 2009; 32:680-97. [PMID: 19883953 DOI: 10.1016/j.neurobiolaging.2009.09.005] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2008] [Revised: 08/26/2009] [Accepted: 09/27/2009] [Indexed: 01/19/2023]
Abstract
Premarin™ is the most commonly prescribed estrogenic component of hormone therapy, given since 1942. The current study is the first examining cognitive effects of tonic Premarin treatment in an animal model. Middle-aged ovariectomized (Ovx) rats received vehicle or one of three doses of Premarin (12, 24 or 36μg daily). Rats were tested on a spatial working and reference memory maze battery. Both medium- and high-dose Premarin enhanced memory retention, while low-dose Premarin impaired learning and memory retention. Correlations with serum hormone levels showed that as the ratio of estrone:17β-estradiol increased, animals tended to show better working memory performance. Taken together with the dissociation of dose-specific estrogenic profiles, results suggest that higher levels of estrone, in the presence of 17β-estradiol concentrations higher than that of Ovx levels, may be beneficial for memory. Moreover, Premarin exerted dose and brain-region specific effects on BDNF and NGF protein levels, with most marked changes in cingulate and perirhinal cortices. Hippocampal gene expression profiling demonstrated significant Premarin-induced transcriptional changes in genes linked to plasticity and cognition. These findings indicate that Premarin can impact memory and the brain, and that dosing should be recognized as a clinically relevant factor possibly affecting the direction and efficacy of cognitive outcome.
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100
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Campbell JC, Szumlinski KK, Kippin TE. Contribution of early environmental stress to alcoholism vulnerability. Alcohol 2009; 43:547-54. [PMID: 19913199 DOI: 10.1016/j.alcohol.2009.09.029] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2008] [Revised: 05/06/2009] [Accepted: 08/11/2009] [Indexed: 11/29/2022]
Abstract
The most problematic aspects of alcohol abuse disorder are excessive alcohol consumption and the inability to refrain from alcohol consumption during attempted abstinence. The root causes that predispose certain individuals to these problems are poorly understood but are believed to be produced by a combination of genetic and environmental factors. Early environmental trauma alters neurodevelopmental trajectories that can predispose an individual to a number of neuropsychiatric disorders, including substance abuse. Prenatal stress (PNS) is a well-established protocol that produces perturbations in nervous system development, resulting in behavioral alterations that include hyperresponsiveness to stress, novelty, and psychomotor stimulant drugs (e.g., cocaine, amphetamine). Moreover, PNS animals exhibit enduring alterations in basal and cocaine-induced changes in dopamine and glutamate transmission within limbic structures, which exhibit pathology in drug addiction and alcoholism, suggesting that these alterations may contribute to an increased propensity to self-administer large amounts of drugs of abuse or to relapse after periods of drug withdrawal. Given that cocaine and alcohol have actions on common limbic neural substrates (albeit by different mechanisms), we hypothesized that PNS would elevate the motivation for, and consumption of, alcohol. Accordingly, we have found that male C57BL/6J mice subject to PNS exhibit higher operant responding and consume more alcohol during alcohol reinforcement as adults. Alterations in glutamate and dopamine neurotransmission within the forebrain structures appear to contribute to the PNS-induced predisposition to high alcohol intake and are induced by excessive alcohol intake. Accordingly, we are exploring the interactions between neurochemical changes produced by PNS and changes induced by consumption of alcohol in adulthood to model the biological bases of high vulnerability to alcohol abuse.
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Affiliation(s)
- Joannalee C Campbell
- Department of Psychology, University of California, Santa Barbara, CA 93106-9660, USA
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