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Abstract
Schizophrenia is a psychiatric disorder characterized by hallucinations, anhedonia, disordered thinking, and cognitive impairments. Both genetic and environmental factors contribute to schizophrenia. Dysbindin-1 (DTNBP1) and brain-derived neurotrophic factor (BDNF) are both genetic factors associated with schizophrenia. Mice lacking Dtnbp1 showed behavioral deficits similar to human patients suffering from schizophrenia. DTNBP1 plays important functions in synapse formation and maintenance, receptor trafficking, and neurotransmitter release. DTNBP1 is co-assembled with 7 other proteins into a large protein complex, known as the biogenesis of lysosome-related organelles complex-1 (BLOC-1). Large dense-core vesicles (LDCVs) are involved in the secretion of hormones and neuropeptides, including BDNF. BDNF plays important roles in neuronal development, survival, and synaptic plasticity. BDNF is also critical in maintaining GABAergic inhibitory transmission in the brain. Two studies independently showed that DTNBP1 mediated activity-dependent BDNF secretion to maintain inhibitory transmission. Imbalance of excitatory and inhibitory neural activities is thought to contribute to schizophrenia. In this mini-review, we will discuss a potential pathogenetic mechanism for schizophrenia involving DTNBP1, BDNF, and inhibitory transmission. We will also discuss how these processes are interrelated and associated with a higher risk of schizophrenia development.
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Affiliation(s)
- Rachel Jun
- Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, United States
| | - Wen Zhang
- National Institute on Drug Dependence and Beijing Key Laboratory of Drug Dependence, Peking University, Beijing, China
| | - Nicholas J Beacher
- Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, United States
| | - Yan Zhang
- Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, United States
| | - Yun Li
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY, United States
| | - Da-Ting Lin
- Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, United States
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Li M, Yue W. VRK2, a Candidate Gene for Psychiatric and Neurological Disorders. Mol Neuropsychiatry 2018; 4:119-133. [PMID: 30643786 PMCID: PMC6323383 DOI: 10.1159/000493941] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Accepted: 09/20/2018] [Indexed: 12/20/2022]
Abstract
Recent large-scale genetic approaches, such as genome-wide association studies, have identified multiple genetic variations that contribute to the risk of mental illnesses, among which single nucleotide polymorphisms (SNPs) within or near the vaccinia related kinase 2 (VRK2) gene have gained consistent support for their correlations with multiple psychiatric and neurological disorders including schizophrenia (SCZ), major depressive disorder (MDD), and genetic generalized epilepsy. For instance, the genetic variant rs1518395 in VRK2 showed genome-wide significant associations with SCZ (35,476 cases and 46,839 controls, p = 3.43 × 10-8) and MDD (130,620 cases and 347,620 controls, p = 4.32 × 10-12) in European populations. This SNP was also genome-wide significantly associated with SCZ in Han Chinese population (12,083 cases and 24,097 controls, p = 3.78 × 10-13), and all associations were in the same direction of allelic effects. These studies highlight the potential roles of VRK2 in the central nervous system, and this gene therefore might be a good candidate to investigate the shared genetic and molecular basis between SCZ and MDD, as it is one of the few genes known to show genome-wide significant associations with both illnesses. Furthermore, the VRK2 gene was found to be involved in multiple other congenital deficits related to the malfunction of neurodevelopment, adding further support for the involvement of this gene in the pathogenesis of these neurological and psychiatric illnesses. While the precise function of VRK2 in these conditions remains unclear, preliminary evidence suggests that it may affect neuronal proliferation and migration via interacting with multiple essential signaling pathways involving other susceptibility genes/proteins for psychiatric disorders. Here, we have reviewed the recent progress of genetic and molecular studies of VRK2, with an emphasis on its role in psychiatric illnesses and neurological functions. We believe that attention to this important gene is necessary, and further investigations of VRK2 may provide hints into the underlying mechanisms of SCZ and MDD.
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Affiliation(s)
- Ming Li
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences and Yunnan Province, Kunming Institute of Zoology, Kunming, China
- CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
| | - Weihua Yue
- Peking University Sixth Hospital/Institute of Mental Health, Beijing, China
- Key Laboratory of Mental Health, Ministry of Health (Peking University) and National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital), Beijing, China
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Jeong YH, Choi JH, Lee D, Kim S, Kim KT. Vaccinia-related kinase 2 modulates role of dysbindin by regulating protein stability. J Neurochem 2018; 147:609-625. [PMID: 30062698 DOI: 10.1111/jnc.14562] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 07/13/2018] [Accepted: 07/24/2018] [Indexed: 12/23/2022]
Abstract
Vaccinia-related kinase 2 (VRK2) is a serine/threonine kinase that belongs to the casein kinase 1 family. VRK2 has long been known for its relationship with neurodegenerative disorders such as schizophrenia. However, the role of VRK2 and the substrates associated with it are unknown. Dysbindin is known as one of the strong risk factors for schizophrenia. The expression of dysbindin is indeed significantly reduced in schizophrenia patients. Moreover, dysbindin is involved in neurite outgrowth and regulation of NMDA receptor signaling. Here, we first identified dysbindin as a novel interacting protein of VRK2 through immunoprecipitation. We hypothesized that dysbindin is phosphorylated by VRK2 and further that this phosphorylation plays an important role in the function of dysbindin. We show that VRK2 phosphorylates Ser 297 and Ser 299 of dysbindin using in vitro kinase assay. In addition, we found that VRK2-mediated phosphorylation of dysbindin enhanced ubiquitination of dysbindin and consequently resulted in the decrease in its protein stability through western blotting. Over-expression of VRK2 in human neuroblastoma (SH-SY5Y) cells reduced neurite outgrowth induced by retinoic acid. Furthermore, a phosphomimetic mutant of dysbindin alleviated neurite outgrowth and affected surface expression of N-methyl-d-aspartate 2A, a subunit of NMDA receptor in mouse hippocampal neurons. Together, our work reveals the regulation of dysbindin by VRK2, providing the association of these two proteins, which are commonly implicated in schizophrenia. OPEN SCIENCE BADGES: This article has received a badge for *Open Materials* because it provided all relevant information to reproduce the study in the manuscript. The complete Open Science Disclosure form for this article can be found at the end of the article. More information about the Open Practices badges can be found at https://cos.io/our-services/open-science-badges/.
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Affiliation(s)
- Young-Hun Jeong
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Korea
| | - Jung-Hyun Choi
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Korea
| | - Dohyun Lee
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Korea.,R&D Center, NovMetaPharma Co., Ltd., Pohang, 37668, Korea
| | - Sangjune Kim
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Korea.,Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Kyong-Tai Kim
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Korea.,Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang, Korea
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Xu Y, Sun Y, Ye H, Zhu L, Liu J, Wu X, Wang L, He T, Shen Y, Wu JY, Xu Q. Increased dysbindin-1B isoform expression in schizophrenia and its propensity in aggresome formation. Cell Discov 2015; 1:15032. [PMID: 27462430 DOI: 10.1038/celldisc.2015.32] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 09/13/2015] [Indexed: 02/06/2023] Open
Abstract
Genetic variations in the human dysbindin-1 gene (DTNBP1) have been associated with schizophrenia. As a result of alternative splicing, the human DTNBP1 gene generates at least three distinct protein isoforms, dysbindin-1A, -1B and -1C. Significant effort has focused on dysbindin-1A, an important player in multiple steps of neurodevelopment. However, the other isoforms, dysbindin-1B and dysbindin-1C have not been well characterized. Nor have been associated with human diseases. Here we report an increase in expression of DTNBP1b mRNA in patients with paranoid schizophrenia as compared with healthy controls. A single-nucleotide polymorphism located in intron 9, rs117610176, has been identified and associated with paranoid schizophrenia, and its C allele leads to an increase of DTNBP1b mRNA splicing. Our data show that different dysbindin splicing isoforms exhibit distinct subcellular distribution, suggesting their distinct functional activities. Dysbindin-1B forms aggresomes at the perinuclear region, whereas dysbindin-1A and -1C proteins exhibit diffused patterns in the cytoplasm. Dysbindin-1A interacts with dysbindin-1B, getting recruited to the aggresome structure when co-expressed with dysbindin-1B. Moreover, cortical neurons over-expressing dysbindin-1B show reduction in neurite outgrowth, suggesting that dysbindin-1B may interfere with dysbindin-1A function in a dominant-negative manner. Taken together, our study uncovers a previously unknown association of DTNBP1b expression with schizophrenia in addition to its distinct biochemical and functional properties.
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Spiegel S, Chiu A, James AS, Jentsch JD, Karlsgodt KH. Recognition deficits in mice carrying mutations of genes encoding BLOC-1 subunits pallidin or dysbindin. Genes Brain Behav 2015; 14:618-24. [PMID: 26294018 DOI: 10.1111/gbb.12240] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Revised: 08/04/2015] [Accepted: 08/14/2015] [Indexed: 01/31/2023]
Abstract
Numerous studies have implicated DTNBP1, the gene encoding dystrobrevin-binding protein or dysbindin, as a candidate risk gene for schizophrenia, though this relationship remains somewhat controversial. Variation in dysbindin, and its location on chromosome 6p, has been associated with cognitive processes, including those relying on a complex system of glutamatergic and dopaminergic interactions. Dysbindin is one of the seven protein subunits that comprise the biogenesis of lysosome-related organelles complex 1 (BLOC-1). Dysbindin protein levels are lower in mice with null mutations in pallidin, another gene in the BLOC-1, and pallidin levels are lower in mice with null mutations in the dysbindin gene, suggesting that multiple subunit proteins must be present to form a functional oligomeric complex. Furthermore, pallidin and dysbindin have similar distribution patterns in a mouse and human brain. Here, we investigated whether the apparent correspondence of pallid and dysbindin at the level of gene expression is also found at the level of behavior. Hypothesizing a mutation leading to underexpression of either of these proteins should show similar phenotypic effects, we studied recognition memory in both strains using the novel object recognition task (NORT) and social novelty recognition task (SNRT). We found that mice with a null mutation in either gene are impaired on SNRT and NORT when compared with wild-type controls. These results support the conclusion that deficits consistent with recognition memory impairment, a cognitive function that is impaired in schizophrenia, result from either pallidin or dysbindin mutations, possibly through degradation of BLOC-1 expression and/or function.
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Affiliation(s)
- S Spiegel
- Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA
| | - A Chiu
- Department of Pharmacology, University of California Irvine, Irvine
| | - A S James
- Department of Psychology, UCLA, Los Angeles, CA
| | - J D Jentsch
- Department of Psychology, UCLA, Los Angeles, CA.,Department of Psychiatry, UCLA, Los Angeles, CA
| | - K H Karlsgodt
- Psychiatry Research Division, Zucker Hillside Hospital, Glen Oaks.,Psychiatry Research Division, Feinstein Institute for Medical Research, Manhasset.,Department of Psychiatry, Hofstra North Shore-LIJ School of Medicine, Hempstead, NY, USA
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Sim MS, Hatim A, Diong SH, Mohamed Z. Genetic polymorphism in DTNBP1 gene is associated with methamphetamine-induced panic disorder. J Addict Med 2014; 8:431-7. [PMID: 25303981 DOI: 10.1097/ADM.0000000000000075] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
OBJECTIVE The dysbindin-1 (dystrobrevin-binding protein-1 [DTNBP-1]) gene has repeatedly been shown to be associated with psychotic disorder across diverse populations. In this study, we attempted to investigate the association of the rs3213207 (P1635) genetic polymorphism of the DTNBP1 gene with methamphetamine dependence and with methamphetamine-induced psychosis, manic episodes, and panic disorder in a male Malaysian population. METHODS This polymorphism was genotyped in 233 male methamphetamine-dependent subjects and in 301 male controls of the following 4 different ethnicities: Malay, Chinese, Kadazan-Dusun, and Bajau. Intergroup statistical analyses were performed by using the χ(2) test and the Fisher exact test where necessary. In cases of multiple comparisons, the Bonferroni correction was performed. RESULTS Our results indicated that the DTNBP1 rs3213207 polymorphism did not show any significant association with risk of methamphetamine dependence, either in the pooled subjects or after stratification into the 4 different ethnic groups (P > 0.05). Furthermore, we did not find any association of this polymorphism with methamphetamine-induced psychosis and episodes of methamphetamine-induced mania. However, there was a strong association between this polymorphism and the occurrence of methamphetamine-induced panic disorder in the pooled subjects (odds ratio [OR] = 6.739, P < 0.001) and in the Malay (OR = 11.93, P = 0.022) and Kadazan-Dusun (OR = 115.0, P < 0.001) groups. CONCLUSIONS Our findings suggest that the DTNBP1 rs3213207 polymorphism may contribute to methamphetamine-induced panic disorder in the pooled Malaysian male population, especially in the Malay and Kadazan-Dusun ethnic groups. However, no association was found with methamphetamine dependence, methamphetamine-induced psychosis, or methamphetamine-induced mania.
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Tan GKN, Tee SF, Tang PY. Genetic association of single nucleotide polymorphisms in dystrobrevin binding protein 1 gene with schizophrenia in a Malaysian population. Genet Mol Biol 2015; 38:138-46. [PMID: 26273215 PMCID: PMC4530642 DOI: 10.1590/s1415-4757382220140142] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Accepted: 12/15/2014] [Indexed: 12/19/2022] Open
Abstract
Dystrobrevin binding protein 1 (DTNBP1) gene is pivotal in regulating the glutamatergic system. Genetic variants of the DTNBP1 affect cognition and thus may be particularly relevant to schizophrenia. We therefore evaluated the association of six single nucleotide polymorphisms (SNPs) with schizophrenia in a Malaysian population (171 cases; 171 controls). Associations between these six SNPs and schizophrenia were tested in two stages. Association signals with p < 0.05 and minor allele frequency > 0.05 in stage 1 were followed by genotyping the SNPs in a replication phase (stage 2). Genotyping was performed with sequenced specific primer (PCR-SSP) and restriction fragment length polymorphism (PCR-RFLP). In our sample, we found significant associations between rs2619522 (allele p = 0.002, OR = 1.902, 95%CI = 1.266 – 2.859; genotype p = 0.002) and rs2619528 (allele p = 0.008, OR = 1.606, 95%CI = 1.130 – 2.281; genotype p = 6.18 × 10−5) and schizophrenia. Given that these two SNPs may be associated with the pathophysiology of schizophrenia, further studies on the other DTNBP1 variants are warranted.
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Affiliation(s)
- Grace Kang Ning Tan
- Department of Mechatronics and Biomedical Engineering, Universiti Tunku Abdul Rahman, Kuala Lumpur, Malaysia
| | - Shiau Foon Tee
- Department of Chemical Engineering, Universiti Tunku Abdul Rahman, Kuala Lumpur, Malaysia
| | - Pek Yee Tang
- Department of Mechatronics and Biomedical Engineering, Universiti Tunku Abdul Rahman, Kuala Lumpur, Malaysia
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Lee SA, Kim SM, Suh BK, Sun HY, Park YU, Hong JH, Park C, Nguyen MD, Nagata KI, Yoo JY, Park SK. Disrupted-in-schizophrenia 1 (DISC1) regulates dysbindin function by enhancing its stability. J Biol Chem 2015; 290:7087-96. [PMID: 25635053 DOI: 10.1074/jbc.m114.614750] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Dysbindin and DISC1 are schizophrenia susceptibility factors playing roles in neuronal development. Here we show that the physical interaction between dysbindin and DISC1 is critical for the stability of dysbindin and for the process of neurite outgrowth. We found that DISC1 forms a complex with dysbindin and increases its stability in association with a reduction in ubiquitylation. Furthermore, knockdown of DISC1 or expression of a deletion mutant, DISC1 lacking amino acid residues 403-504 of DISC1 (DISC1(Δ403-504)), effectively decreased levels of endogenous dysbindin. Finally, the neurite outgrowth defect induced by knockdown of DISC1 was partially reversed by coexpression of dysbindin. Taken together, these results indicate that dysbindin and DISC1 form a physiologically functional complex that is essential for normal neurite outgrowth.
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Affiliation(s)
- Seol-Ae Lee
- From the Department of Life Sciences, Pohang University of Science and Technology, Pohang 790-784, Republic of Korea
| | - Seong-Mo Kim
- From the Department of Life Sciences, Pohang University of Science and Technology, Pohang 790-784, Republic of Korea
| | - Bo Kyoung Suh
- From the Department of Life Sciences, Pohang University of Science and Technology, Pohang 790-784, Republic of Korea
| | - Hwa-Young Sun
- From the Department of Life Sciences, Pohang University of Science and Technology, Pohang 790-784, Republic of Korea
| | - Young-Un Park
- From the Department of Life Sciences, Pohang University of Science and Technology, Pohang 790-784, Republic of Korea
| | - Ji-Ho Hong
- From the Department of Life Sciences, Pohang University of Science and Technology, Pohang 790-784, Republic of Korea
| | - Cana Park
- From the Department of Life Sciences, Pohang University of Science and Technology, Pohang 790-784, Republic of Korea
| | - Minh Dang Nguyen
- the Hotchkiss Brain Institute, Departments of Clinical Neurosciences, Cell Biology and Anatomy, and Biochemistry and Molecular Biology, University of Calgary, Calgary T2N 4N1, Canada, and
| | - Koh-Ichi Nagata
- the Department of Molecular Neurobiology, Institute for Developmental Research, Aichi Human Service Center, 713-8 Kamiya, Kasugai 480-0392, Japan
| | - Joo-Yeon Yoo
- From the Department of Life Sciences, Pohang University of Science and Technology, Pohang 790-784, Republic of Korea
| | - Sang Ki Park
- From the Department of Life Sciences, Pohang University of Science and Technology, Pohang 790-784, Republic of Korea,
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Abstract
Recent data have begun to elucidate the genetic architecture of schizophrenia, as well as provide new insights into the relationships of specific genetic factors across diagnostic boundaries, with specific symptom domains, and in the prediction of antipsychotic treatment response. Not surprisingly, work conducted at the Maryland Psychiatric Research Center (MPRC), led by Dr William Carpenter, has helped to guide the thinking behind much of this work, as well as contributed valuable data toward these efforts. In this article, I will briefly summarize some of the major findings emerging from these lines of research and highlight the role of the Dr Carpenter and his colleagues at the MPRC in this area.
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Affiliation(s)
- Anil K. Malhotra
- *To whom correspondence should be addressed; Division of Psychiatry Research, The Zucker Hillside Hospital, 75-59 263rd Street, Glen Oaks, NY 11004, US; tel: 718-470-8012, fax: 718-343-1659, e-mail:
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Trost S, Platz B, Usher J, Scherk H, Wobrock T, Ekawardhani S, Meyer J, Reith W, Falkai P, Gruber O. The DTNBP1 (dysbindin-1) gene variant rs2619522 is associated with variation of hippocampal and prefrontal grey matter volumes in humans. Eur Arch Psychiatry Clin Neurosci 2013; 263:53-63. [PMID: 22580710 PMCID: PMC3560950 DOI: 10.1007/s00406-012-0320-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2011] [Accepted: 04/22/2012] [Indexed: 12/19/2022]
Abstract
DTNBP1 is one of the most established susceptibility genes for schizophrenia, and hippocampal volume reduction is one of the major neuropathological findings in this severe disorder. Consistent with these findings, the encoded protein dysbindin-1 has been shown to be diminished in glutamatergic hippocampal neurons in schizophrenic patients. The aim of this study was to investigate the effects of two single nucleotide polymorphisms of DTNBP1 on grey matter volumes in human subjects using voxel-based morphometry. Seventy-two subjects were included and genotyped with respect to two single nucleotide polymorphisms of DTNBP1 (rs2619522 and rs1018381). All participants underwent structural magnetic resonance imaging (MRI). MRI data were preprocessed and statistically analysed using standard procedures as implemented in SPM5 (Statistical Parametric Mapping), in particular the voxel-based morphometry (VBM) toolbox. We found significant effects of the DTNBP1 SNP rs2619522 bilaterally in the hippocampus as well as in the anterior middle frontal gyrus and the intraparietal cortex. Carriers of the G allele showed significantly higher grey matter volumes in these brain regions than T/T homozygotes. Compatible with previous findings on a role of dysbindin in hippocampal functions as well as in major psychoses, the present study provides first direct in vivo evidence that the DTNBP1 SNP rs2619522 is associated with variation of grey matter volumes bilaterally in the hippocampus.
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Affiliation(s)
- S. Trost
- Department of Psychiatry and Psychotherapy, Centre for Translational Research in Systems Neuroscience and Clinical Psychiatry, Georg August University, Goettingen, Germany
| | - B. Platz
- Department of Psychiatry and Psychotherapy, Centre for Translational Research in Systems Neuroscience and Clinical Psychiatry, Georg August University, Goettingen, Germany
| | - J. Usher
- Department of Psychiatry and Psychotherapy, Centre for Translational Research in Systems Neuroscience and Clinical Psychiatry, Georg August University, Goettingen, Germany
| | - H. Scherk
- Department of Psychiatry and Psychotherapy, Ameos Clinic Osnabrueck, Osnabrueck, Germany
| | - T. Wobrock
- Centre for Mental Health, County Hospitals Darmstadt-Dieburg, Groß-Umstadt, Germany
| | - S. Ekawardhani
- Department of Neurobehavioral Genetics, University of Trier, Trier, Germany
| | - J. Meyer
- Department of Neurobehavioral Genetics, University of Trier, Trier, Germany
| | - W. Reith
- Department of Neuroradiology, Saarland University, Homburg, Germany
| | - P. Falkai
- Department of Psychiatry and Psychotherapy, Centre for Translational Research in Systems Neuroscience and Clinical Psychiatry, Georg August University, Goettingen, Germany
| | - O. Gruber
- Department of Psychiatry and Psychotherapy, Centre for Translational Research in Systems Neuroscience and Clinical Psychiatry, Georg August University, Goettingen, Germany
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Baek JH, Kim JS, Ryu S, Oh S, Noh J, Lee WK, Park T, Lee YS, Lee D, Kwon JS, Hong KS. Association of genetic variations in DTNBP1 with cognitive function in schizophrenia patients and healthy subjects. Am J Med Genet B Neuropsychiatr Genet 2012; 159B:841-9. [PMID: 22911901 DOI: 10.1002/ajmg.b.32091] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2012] [Accepted: 07/12/2012] [Indexed: 12/13/2022]
Abstract
The dystrobrevin-binding protein 1 gene (DTNBP1) has been regarded as a susceptibility gene for schizophrenia. Recent studies have investigated its role on cognitive function that is frequently impaired in schizophrenia patients, and generated inconsistent results. The present study was performed to elucidate effects of genetic variations in DTNBP1 on various cognitive domains in both schizophrenia patients and healthy subjects. Comprehensive neuropsychological tests were administered to 122 clinically stable schizophrenia patients and 119 healthy subjects. Based on positive findings reported in previous association studies, six SNPs were selected and genotyped. Compared to healthy subjects, schizophrenia patients showed expected lower performance for all of the cognitive domains. After adjusting for age, gender, and educational level, four SNPs showed a nominally significant association with cognitive domains. The association of rs760761 and rs1018381 with the attention and vigilance domain remained significant after applying the correction for multiple testing (P < 0.001). Similar association patterns were observed both, in patients and healthy subjects. The observed results suggest the involvement of DTNBP1 not only in the development of attention deficit of schizophrenia, but also in the inter-individual variability of this cognitive domain within the normal functional range.
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Affiliation(s)
- Ji Hyun Baek
- Department of Psychiatry, Sungkyunkwan University School of Medicine, Samsung Medical Center, Seoul, Republic of Korea
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Alizadeh F, Tabatabaiefar MA, Ghadiri M, Yekaninejad MS, Jalilian N, Noori-Daloii MR. Association of P1635 and P1655 polymorphisms in dysbindin (DTNBP1) gene with schizophrenia. Acta Neuropsychiatr 2012; 24:155-9. [PMID: 26953008 DOI: 10.1111/j.1601-5215.2011.00598.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVES Schizophrenia (SCZ) is a severe psychiatric disorder with a lifetime prevalence of approximately 1% in most of the populations studied. SCZ is multifactorial with the contribution of multiple susceptibility genes that could act in conjunction with epigenetic processes and environmental factors. There is some evidence supporting the association between genetic variants in dysbindin (DTNBP1) gene and SCZ in populations. In this study, we investigated the association between polymorphisms P1635 and P1655 in dysbindin gene with SCZ. METHODS Totally, 115 unrelated patients with SCZ and 117 unrelated healthy volunteers were studied. Genomic DNA was extracted from blood. Genotyping was done with the PCR-RFLP method. The allele and genotype associations were analysed with X 2 test. The Benjamini-Hochberg procedure was used to correct p values for multiple comparisons. RESULTS The results showed no significant difference between patients and controls in allelic frequencies or genotypic distributions of SNP P1635 (p = 0.809), but a significant difference between the case and control groups for SNP P1655 (p = 0.009) was found. We could also find a significant positive association between A-C haplotype and SCZ (OR = 1.7, 95% CI 1.18-2.42; p = 0.004, p c = 0.02) and a protective effect for A-G haplotype (p = 0.003, OR = 0.57, 95% CI 1.18-2.42; p = 0.003, p c = 0.02). CONCLUSION This study may provide further support for the association between SNP polymorphisms in DTNBP1 and SCZ in the Iranian population. Studies with more markers and subjects for various populations will be necessary to understand the genetic contribution of the gene to the development of SCZ.
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Affiliation(s)
- Fatemeh Alizadeh
- Department of Medical Genetics, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | | | - Mohammad Ghadiri
- Department of Psychiatrics, Tehran Psychiatric Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Mir Saeed Yekaninejad
- Department of Biostatics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Nazanin Jalilian
- Department of Medical Genetics, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
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Abstract
There is no doubt that schizophrenia has a significant genetic component and a number of candidate genes have been identified for this debilitating disorder. Of note, several of these are implicated in cognition. Cognitive deficits constitute core symptoms of schizophrenia, and while current antipsychotic treatment strategies aim to help psychosis-related symptomatology, the cognitive symptom domain is largely inadequately treated. A number of other pharmacological approaches (e.g. using drugs that target specific neurotransmitter systems) have also been attempted for the amelioration of cognitive deficits in this population; however, these too have had limited success so far. Psychological interventions appear promising, though there has been speculation regarding whether or not these produce long-term functional improvements. Pharmacogenetic studies of the cognitive effects of currently available antipsychotics, although in relatively early stages, suggest that the treatment of cognitive deficits in schizophrenia may be advanced by focusing on genetic variants associated with specific cognitive dysfunctions in the general population and using this to match the most relevant pharmacological and/or psychological interventions with the genetic and cognitive profiles of the target population. Such a strategy would encourage bottom-up advances in drug development and provide a platform for individualised treatment of cognitive deficits in schizophrenia.
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Affiliation(s)
- Nora S Vyas
- King's College London, Institute of Psychiatry, MRC SGDP Centre, London, UK.
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14
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Holliday EG, Handoko HY, James MR, McGrath JJ, Nertney DA, Tirupati S, Thara R, Levinson DF, Hayward NK, Mowry BJ, Nyholt DR. Association Study of the Dystrobrevin-Binding Gene With Schizophrenia in Australian and Indian Samples. Twin Res Hum Genet 2012. [DOI: 10.1375/twin.9.4.531] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
AbstractNumerous studies have reported association between variants in the dystrobrevin binding protein 1 (dysbindin) gene (DTNBP1) and schizophrenia. However, the pattern of results is complex and to date, no specific risk marker or haplotype has been consistently identified. The number of single nucleotide polymorphisms (SNPs) tested in these studies has ranged from 5 to 20. We attempted to replicate previous findings by testing 16 SNPs in samples of 41 Australian pedigrees, 194 Australian cases and 180 controls, and 197 Indian pedigrees. No globally significant evidence for association was observed in any sample, despite power calculations indicating sufficient power to replicate several previous findings. Possible explanations for our results include sample differences in background linkage dis-equilibrium and/or risk allele effect size, the presence of multiple risk alleles upon different haplotypes, or the presence of a single risk allele upon multiple haplotypes. Some previous associations may also represent false positives. Examination of Caucasian HapMap phase II genotype data spanning theDTNBP1region indicates upwards of 40 SNPs are required to satisfactorily assess all nonredundant variation withinDTNBP1and its potential regulatory regions for association with schizophrenia. More comprehensive studies in multiple samples will be required to determine whether specificDTNBP1variants function as risk factors for schizophrenia.
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15
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Abstract
Schizophrenia alters basic brain processes of perception, emotion, and judgment to cause hallucinations, delusions, thought disorder, and cognitive deficits. Unlike neurodegeneration diseases that have irreversible neuronal degeneration and death, schizophrenia lacks agreeable pathological hallmarks, which makes it one of the least understood psychiatric disorders. With identification of schizophrenia susceptibility genes, recent studies have begun to shed light on underlying pathological mechanisms. Schizophrenia is believed to result from problems during neural development that lead to improper function of synaptic transmission and plasticity, and in agreement, many of the susceptibility genes encode proteins critical for neural development. Some, however, are also expressed at high levels in adult brain. Here, we will review evidence for altered neurotransmission at glutamatergic, GABAergic, dopaminergic, and cholinergic synapses in schizophrenia and discuss roles of susceptibility genes in neural development as well as in synaptic plasticity and how their malfunction may contribute to pathogenic mechanisms of schizophrenia. We propose that mouse models with precise temporal and spatial control of mutation or overexpression would be useful to delineate schizophrenia pathogenic mechanisms.
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Affiliation(s)
- Dong-Min Yin
- Department of Neurology, Institute of Molecular Medicine and Genetics, Georgia Health Sciences University, Augusta, GA 30912, USA
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16
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Ma X, Fei E, Fu C, Ren H, Wang G. Dysbindin-1, a schizophrenia-related protein, facilitates neurite outgrowth by promoting the transcriptional activity of p53. Mol Psychiatry 2011; 16:1105-16. [PMID: 21502952 DOI: 10.1038/mp.2011.43] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Genetic variations in the DTNBP1 gene (encoding the protein dysbindin-1) have been implicated as risk factors in the pathogenesis of schizophrenia. Previous studies have indicated that dysbindin-1 functions in the regulation of synaptic activity. Recently, dysbindin-1 has also been documented to be involved in neuronal development. In this study, we identified necdin as a binding partner of dysbindin-1 using a yeast two-hybrid screen. Dysbindin-1 recruits necdin to the cytoplasm, thereby attenuating the repressive effects of necdin on p53 transcriptional activity. Knockdown of dysbindin-1, like knockdown of p53, greatly decreases the expressions of the p53 target genes coronin 1b and rab13, which are required for neurite outgrowth. Moreover, overexpression of p53 restores the neurite outgrowth blocked by dysbindin-1 knockdown. In brains of dysbindin-1 null mice (the sandy strain), p21, Coronin 1b and Rab13 levels are reduced. Furthermore, primary cultured cortical neurons from sandy mice display neurite outgrowth defects when compared with those from wild-type mice. Thus, our data provide evidence that dysbindin-1 has an important role in neurite outgrowth through its regulation of p53's transcriptional activity.
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Nickl-Jockschat T, Stöcker T, Markov V, Krug A, Huang R, Schneider F, Habel U, Zerres K, Nöthen MM, Treutlein J, Rietschel M, Shah NJ, Kircher T. The impact of a Dysbindin schizophrenia susceptibility variant on fiber tract integrity in healthy individuals: a TBSS-based diffusion tensor imaging study. Neuroimage 2011; 60:847-53. [PMID: 22019876 DOI: 10.1016/j.neuroimage.2011.10.012] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2011] [Revised: 10/02/2011] [Accepted: 10/03/2011] [Indexed: 11/30/2022] Open
Abstract
Schizophrenia is a severe neuropsychiatric disorder with high heritability, though its exact etiopathogenesis is yet unknown. An increasing number of studies point to the importance of white matter anomalies in the pathophysiology of schizophrenia. While several studies have identified the impact of schizophrenia susceptibility gene variants on gray matter anatomy in both schizophrenia patients and healthy risk variant carriers, studies dealing with the impact of these gene variants on white matter integrity are still scarce. We here present a study on the effects of a Dysbindin schizophrenia susceptibility gene variant on fiber tract integrity in healthy young subjects. 101 subjects genotyped for Dysbindin-gene variant rs1018381, though without personal or first degree relative history of psychiatric disorders underwent diffusion tensor imaging (DTI), 83 of them were included in the final analysis. We used Tract-Based Spatial Statistics (TBSS) analysis to delineate the major fiber tracts. Carriers of the minor allele T of the rs1018381 in the Dysbindin gene showed two clusters of reduced fractional anisotropy (FA) values in the perihippocampal region of the right temporal lobe compared to homozygote carriers of the major allele C. Clusters of increased FA values in T-allele carriers were found in the left prefrontal white matter, the right fornix, the right midbrain area, the left callosal body, the left cerebellum and in proximity of the right superior medial gyrus. Dysbindin has been implicated in neurite outgrowth and morphology. Impairments in anatomic connectivity as found associated with the minor Dysbindin allele in our study may result in increased risk for schizophrenia due to altered fiber tracts.
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Karlsgodt KH, Bachman P, Winkler AM, Bearden CE, Glahn DC. Genetic influence on the working memory circuitry: behavior, structure, function and extensions to illness. Behav Brain Res 2011; 225:610-22. [PMID: 21878355 DOI: 10.1016/j.bbr.2011.08.016] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2011] [Accepted: 08/07/2011] [Indexed: 10/17/2022]
Abstract
Working memory is a highly heritable complex cognitive trait that is critical for a number of higher-level functions. However, the neural substrates of this behavioral phenotype are intricate and it is unknown through what precise biological mechanism variation in working memory is transmitted. In this review we explore different functional and structural components of the working memory circuitry, and the degree to which each of them is contributed to by genetic factors. Specifically, we consider dopaminergic function, glutamatergic function, white matter integrity and gray matter structure all of which provide potential mechanisms for the inheritance of working memory deficits. In addition to discussing the overall heritability of these measures we also address specific genes that may play a role. Each of these heritable components has the potential to uniquely contribute to the working memory deficits observed in genetic disorders, including 22q deletion syndrome, fragile X syndrome, phenylketonuria (PKU), and schizophrenia. By observing the individual contributions of disruptions in different components of the working memory circuitry to behavioral performance, we highlight the concept that there may be many routes to a working memory deficit; even though the same cognitive measure may be a valid endophenotype across different disorders, the underlying cause of, and treatment for, the deficit may differ. This has implications for our understanding of the transmission of working memory deficits in both healthy and disordered populations.
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Affiliation(s)
- Katherine H Karlsgodt
- Department of Psychiatry and Biobehavioral Sciences, Semel Institute for Neuroscience and Human Behavior, University of California Los Angeles, Los Angeles, CA, USA.
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Tosato S, Lasalvia A. The contribution of epidemiology to defining the most appropriate approach to genetic research on schizophrenia. ACTA ACUST UNITED AC 2009; 18:81-90. [DOI: 10.1017/s1121189x00000932] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
AbstractPsychosis is thought to have a strong genetic component, but many efforts to discover the underlying putative schizophrenia genes have yielded disappointing results. In fact, no strong associations emerged in the first genome-wide association studies in psychiatry and weakly observed associations were not related to the candidate genes identified in previous studies. These partially successful findings may be explained by the fact that genetic research in psychiatry suffers from confounding issues related to phenotype definition, the considerable degree of phenotypic variability and diagnostic uncertainty, absence of specific neuropathological features and environmental influences. To make progress it is first necessary to deconstruct psychosis based on symptomatology, and then to correlate particular phenotypes with genetic variants. Moreover, it is time to conduct studies that define persistent aspects of the schizophrenic profile that are more likely to represent an underlying biological pathogenesis, as opposed to fluctuating symptoms that are possibly environmentally mediated. In fact, progress in understanding the etiology of schizophrenia will depend upon the availability of good measures of genetic liability as well as relevant environmental exposures during critical periods of an individual's life. If environmental and/or genetic factors are not precisely measured, it is impossible to study their independent effects or interactions.
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Karlsgodt KH, Robleto K, Trantham-Davidson H, Jairl C, Cannon TD, Lavin A, Jentsch JD. Reduced dysbindin expression mediates N-methyl-D-aspartate receptor hypofunction and impaired working memory performance. Biol Psychiatry 2011; 69:28-34. [PMID: 21035792 PMCID: PMC4204919 DOI: 10.1016/j.biopsych.2010.09.012] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2010] [Revised: 08/13/2010] [Accepted: 09/07/2010] [Indexed: 11/19/2022]
Abstract
BACKGROUND Schizophrenia is a heritable disorder associated with disrupted neural transmission and dysfunction of brain systems involved in higher cognition. The gene encoding dystrobrevin-binding-protein-1 (dysbindin) is a putative candidate gene associated with cognitive impairments, including memory deficits, in both schizophrenia patients and unaffected individuals. The underlying mechanism is thought to be based in changes in glutamatergic and dopaminergic function within the corticostriatal networks known to be critical for schizophrenia. This hypothesis derives support from studies of mice with a null mutation in the dysbindin gene that exhibit memory dysfunction and excitatory neurotransmission abnormalities in prefrontal and hippocampal networks. At a cellular level, dysbindin is thought to mediate presynaptic glutamatergic transmission. METHODS We investigated the relationship between glutamate receptor dynamics and memory performance in dysbindin mutant mice. We assessed N-methyl-D-aspartate (NMDA) and α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptor function in prefrontal cortex pyramidal neurons in vitro with whole-cell recordings, molecular quantitative analyses (reverse transcription-polymerase chain reaction) of the mandatory NMDA receptor subunit NR1, and cognitive function with a spatial working memory task. RESULTS Decreases in dysbindin are associated with specific decreases in NMDA-evoked currents in prefrontal pyramidal neurons, as well as decreases in NR1 expression. Furthermore, the degree of NR1 expression correlates with spatial working memory performance, providing a mechanistic explanation for cognitive changes previously associated with dysbindin expression. CONCLUSIONS These data show a significant downregulation of NMDA receptors due to dysbindin deficiency and illuminate molecular mechanisms mediating the association between dysbindin insufficiency and cognitive impairments associated with schizophrenia, encouraging study of the dysbindin/NR1 expression association in humans with schizophrenia.
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Affiliation(s)
- Katherine H Karlsgodt
- Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, California, USA
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21
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Fei E, Ma X, Zhu C, Xue T, Yan J, Xu Y, Zhou J, Wang G. Nucleocytoplasmic shuttling of dysbindin-1, a schizophrenia-related protein, regulates synapsin I expression. J Biol Chem 2010; 285:38630-40. [PMID: 20921223 PMCID: PMC2992295 DOI: 10.1074/jbc.m110.107912] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2010] [Revised: 09/23/2010] [Indexed: 01/29/2023] Open
Abstract
Dysbindin-1 is a 50-kDa coiled-coil-containing protein encoded by the gene DTNBP1 (dystrobrevin-binding protein 1), a candidate genetic factor for schizophrenia. Genetic variations in this gene confer a susceptibility to schizophrenia through a decreased expression of dysbindin-1. It was reported that dysbindin-1 regulates the expression of presynaptic proteins and the release of neurotransmitters. However, the precise functions of dysbindin-1 are largely unknown. Here, we show that dysbindin-1 is a novel nucleocytoplasmic shuttling protein and translocated to the nucleus upon treatment with leptomycin B, an inhibitor of exportin-1/CRM1-mediated nuclear export. Dysbindin-1 harbors a functional nuclear export signal necessary for its nuclear export, and the nucleocytoplasmic shuttling of dysbindin-1 affects its regulation of synapsin I expression. In brains of sandy mice, a dysbindin-1-null strain that displays abnormal behaviors related to schizophrenia, the protein and mRNA levels of synapsin I are decreased. These findings demonstrate that the nucleocytoplasmic shuttling of dysbindin-1 regulates synapsin I expression and thus may be involved in the pathogenesis of schizophrenia.
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MESH Headings
- Active Transport, Cell Nucleus/drug effects
- Active Transport, Cell Nucleus/genetics
- Animals
- Antibiotics, Antineoplastic/pharmacology
- Brain/metabolism
- Carrier Proteins/genetics
- Carrier Proteins/metabolism
- Cell Nucleus/genetics
- Cell Nucleus/metabolism
- Cytoplasm/genetics
- Cytoplasm/metabolism
- Dysbindin
- Dystrophin-Associated Proteins
- Fatty Acids, Unsaturated/pharmacology
- Gene Expression Regulation
- HEK293 Cells
- Humans
- Karyopherins/antagonists & inhibitors
- Karyopherins/genetics
- Karyopherins/metabolism
- Mice
- Mice, Mutant Strains
- Presynaptic Terminals/metabolism
- RNA, Messenger/biosynthesis
- RNA, Messenger/genetics
- Receptors, Cytoplasmic and Nuclear/antagonists & inhibitors
- Receptors, Cytoplasmic and Nuclear/genetics
- Receptors, Cytoplasmic and Nuclear/metabolism
- Schizophrenia/genetics
- Schizophrenia/metabolism
- Synapsins/biosynthesis
- Synapsins/genetics
- Exportin 1 Protein
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Affiliation(s)
- Erkang Fei
- From the Laboratory of Molecular Neuropathology, Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China and
| | - Xiaochuan Ma
- From the Laboratory of Molecular Neuropathology, Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China and
| | - Cuiqing Zhu
- the State Key Laboratory of Medical Neurobiology, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Ting Xue
- From the Laboratory of Molecular Neuropathology, Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China and
| | - Jie Yan
- the State Key Laboratory of Medical Neurobiology, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Yuxia Xu
- the State Key Laboratory of Medical Neurobiology, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Jiangning Zhou
- From the Laboratory of Molecular Neuropathology, Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China and
| | - Guanghui Wang
- From the Laboratory of Molecular Neuropathology, Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China and
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Ito H, Morishita R, Shinoda T, Iwamoto I, Sudo K, Okamoto K, Nagata K. Dysbindin-1, WAVE2 and Abi-1 form a complex that regulates dendritic spine formation. Mol Psychiatry 2010; 15:976-86. [PMID: 20531346 DOI: 10.1038/mp.2010.69] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Genetic variations in dysbindin-1 (dystrobrevin-binding protein-1) are one of the most commonly reported variations associated with schizophrenia. As schizophrenia could be regarded as a neurodevelopmental disorder resulting from abnormalities of synaptic connectivity, we attempted to clarify the function of dysbindin-1 in neuronal development. We examined the developmental change of dysbindin-1 in rat brain by western blotting and found that a 50 kDa isoform is highly expressed during the embryonic stage, whereas a 40 kDa one is detected at postnatal day 11 and increased thereafter. Immunofluorescent analyses revealed that dysbindin-1 is enriched at the spine-like structure of primary cultured rat hippocampal neurons. We identified WAVE2, but not N-WASP, as a binding partner for dysbindin-1. We also found that Abi-1, a binding molecule for WAVE2 involved in spine morphogenesis, interacts with dysbindin-1. Although dysbindin-1, WAVE2 and Abi-1 form a ternary complex, dysbindin-1 promoted the binding of WAVE2 to Abi-1. RNA interference-mediated knockdown of dysbindin-1 led to the generation of abnormally elongated immature dendritic protrusions. The present results indicate possible functions of dysbindin-1 at the postsynapse in the regulation of dendritic spine morphogenesis through the interaction with WAVE2 and Abi-1.
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23
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Abstract
Schizophrenia is a devastating mental illness that is associated with a lifetime of disability. For patients to successfully function in society, the amelioration of disease symptoms is imperative. The recently published results of two large antipsychotic clinical trials (e.g., CATIE, CUtLASS) clearly exemplified the limitations of currently available treatment options for schizophrenia, and further highlighted the critical need for novel drug discovery and development in this field. One of the biggest challenges in schizophrenia-related drug discovery is to find an appropriate animal model of the illness so that novel hypotheses can be tested at the basic science level. A number of pharmacological, genetic, and neurodevelopmental models have been introduced; however, none of these models has been rigorously evaluated for translational relevance or to satisfy requirements of "face," "construct" and "predictive" validity. Given the apparent polygenic nature of schizophrenia and the limited translational significance of pharmacological models, neurodevelopmental models may offer the best chance of success. The purpose of this review is to provide a general overview of the various neurodevelopmental models of schizophrenia that have been introduced to date, and to summarize their behavioral and neurochemical phenotypes that may be useful from a drug discovery and development standpoint. While it may be that, in the final analysis, no single animal model will satisfy all the requirements necessary for drug discovery purposes, several of the models may be useful for modeling various phenomenological and pathophysiological components of schizophrenia that could be targeted independently with separate molecules or multi-target drugs.
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Affiliation(s)
- Christina Wilson
- Department of Pharmacology and Toxicology, School of Graduate Studies, Medical College of Georgia, Augusta, GA 30912-2300, USA
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Voisey J, Swagell CD, Hughes IP, Lawford BR, Young RM, Morris CP. Analysis of HapMap tag-SNPs in dysbindin (DTNBP1) reveals evidence of consistent association with schizophrenia. Eur Psychiatry 2010; 25:314-9. [PMID: 20615671 DOI: 10.1016/j.eurpsy.2009.11.011] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2009] [Revised: 11/02/2009] [Accepted: 11/08/2009] [Indexed: 12/20/2022] Open
Abstract
Dystrobrevin binding protein 1 (DTNBP1), or dysbindin, is thought to be critical in regulating the glutamatergic system. While the dopamine pathway is known to be important in the aetiology of schizophrenia, it seems likely that glutamatergic dysfunction can lead to the development of schizophrenia. DTNBP1 is widely expressed in brain, levels are reduced in brains of schizophrenia patients and a DTNBP1 polymorphism has been associated with reduced brain expression. Despite numerous genetic studies no DTNBP1 polymorphism has been strongly implicated in schizophrenia aetiology. Using a haplotype block-based gene-tagging approach we genotyped 13 SNPs in DTNBP1 to investigate possible associations with DTNBP1 and schizophrenia. Four polymorphisms were found to be significantly associated with schizophrenia. The strongest association was found with an A/C SNP in intron 7 (rs9370822). Homozygotes for the C allele of rs9370822 were more than two and a half times as likely to have schizophrenia compared to controls. The other polymorphisms showed much weaker association and are less likely to be biologically significant. These results suggest that DTNBP1 is a good candidate for schizophrenia risk and rs9370822 is either functionally important or in disequilibrium with a functional SNP, although our observations should be viewed with caution until they are independently replicated.
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Affiliation(s)
- J Voisey
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
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25
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Abstract
Both genetic and nongenetic risk factors, as well as interactions and correlations between them, are thought to contribute to the etiology of psychiatric and behavioral phenotypes. Genetic epidemiology consistently supports the involvement of genes in liability. Molecular genetic studies have been less successful in identifying liability genes, but recent progress suggests that a number of specific genes contributing to risk have been identified. Collectively, the results are complex and inconsistent, with a single common DNA variant in any gene influencing risk across human populations. Few specific genetic variants influencing risk have been unambiguously identified. Contemporary approaches, however, hold great promise to further elucidate liability genes and variants, as well as their potential inter-relationships with each other and with the environment. We will review the fields of genetic epidemiology and molecular genetics, providing examples from the literature to illustrate the key concepts emerging from this work.
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Affiliation(s)
- Danielle M Dick
- Department of Psychiatry, Virginia Institute of Psychiatric and Behavioral Genetics, Richmond 23298, USA
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Markov V, Krug A, Krach S, Jansen A, Eggermann T, Zerres K, Stöcker T, Shah NJ, Nöthen MM, Treutlein J, Rietschel M, Kircher T. Impact of schizophrenia-risk gene dysbindin 1 on brain activation in bilateral middle frontal gyrus during a working memory task in healthy individuals. Hum Brain Mapp 2010; 31:266-75. [PMID: 19650139 DOI: 10.1002/hbm.20862] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Working memory (WM) dysfunction is a hallmark feature of schizophrenia. Functional imaging studies using WM tasks have documented both prefrontal hypo- and hyperactivation in schizophrenia. Schizophrenia is highly heritable, and it is unclear which susceptibility genes modulate WM and its neural correlates. A strong linkage between genetic variants in the dysbindin 1 gene and schizophrenia has been demonstrated. The aim of this study was to investigate the influence of the DTNBP1 schizophrenia susceptibility gene on WM and its neural correlates in healthy individuals. Fifty-seven right-handed, healthy male volunteers genotyped for DTNBP1 SNP rs1018381 status were divided in heterozygous risk-allele carriers (T/C) and homozygous noncarriers (C/C). WM was assessed by a 2-back vs. 0-back version of the Continuous Performance Test (CPT), while brain activation was measured with fMRI. DTNBP1 SNP rs1018381 carrier status was determined and correlated with WM performance and brain activation. Despite any differences in behavioral performance, risk-allele carriers exhibited significantly increased activation of the bilateral middle frontal gyrus (BA 9), a part of the dorsolateral prefrontal cortex (DLPFC), compared to noncarriers. This difference did not correlate with WM performance. The fMRI data provide evidence for an influence of genetic variation in DTNBP1 gene region tagged by SNP rs1018381 on bilateral middle frontal gyrus activation during a WM task. The increased activation in these brain areas may be a consequence of "inefficient" or compensatory DLPFC cognitive control functions.
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Affiliation(s)
- Valentin Markov
- Department of Psychiatry and Psychotherapy, Medical Faculty, RWTH Aachen University, Aachen, Germany.
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27
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Mead CLR, Kuzyk MA, Moradian A, Wilson GM, Holt RA, Morin GB. Cytosolic protein interactions of the schizophrenia susceptibility gene dysbindin. J Neurochem 2010; 113:1491-503. [PMID: 20236384 DOI: 10.1111/j.1471-4159.2010.06690.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Using immunoprecipitation, mass spectrometry, and western blot analysis we investigated cytosolic protein interactions of the schizophrenia susceptibility gene dysbindin in mammalian cells. We identified novel interactions with members of the exocyst, dynactin and chaperonin containing T-complex protein complexes, and we confirmed interactions reported previously with all members of the biogenesis of lysosome-related organelles complex-1 and the adaptor-related protein complex 3. We report interactions between dysbindin and the exocyst and dynactin complex that confirm a link between two important schizophrenia susceptibility genes: dysbindin and disrupted-in-schizophrenia-1. To expand upon this network of interacting proteins we also investigated protein interactions for members of the exocyst and dynactin complexes in mammalian cells. Our results are consistent with the notion that impairment of aspects of the synaptic vesicle life cycle may be a pathogenic mechanism in schizophrenia.
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Affiliation(s)
- Carri-Lyn R Mead
- Michael Smith Genome Sciences Centre, British Columbia Cancer Research Centre, Vancouver, British Columbia, Canada
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28
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Hashimoto R, Noguchi H, Hori H, Nakabayashi T, Suzuki T, Iwata N, Ozaki N, Kosuga A, Tatsumi M, Kamijima K, Harada S, Takeda M, Saitoh O, Kunugi H. A genetic variation in the dysbindin gene (DTNBP1) is associated with memory performance in healthy controls. World J Biol Psychiatry 2010; 11:431-8. [DOI: 10.3109/15622970902736503] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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29
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Okuda H, Kuwahara R, Matsuzaki S, Miyata S, Kumamoto N, Hattori T, Shimizu S, Yamada K, Kawamoto K, Hashimoto R, Takeda M, Katayama T, Tohyama M. Dysbindin regulates the transcriptional level of myristoylated alanine-rich protein kinase C substrate via the interaction with NF-YB in mice brain. PLoS One 2010; 5:e8773. [PMID: 20098743 DOI: 10.1371/journal.pone.0008773] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2009] [Accepted: 12/09/2009] [Indexed: 01/21/2023] Open
Abstract
Background An accumulating body of evidence suggests that Dtnbp1 (Dysbindin) is a key susceptibility gene for schizophrenia. Using the yeast-two-hybrid screening system, we examined the candidate proteins interacting with Dysbindin and revealed one of these candidates to be the transcription factor NF-YB. Methods We employed an immunoprecipitation (IP) assay to demonstrate the Dysbindin-NF-YB interaction. DNA chips were used to screen for altered expression of genes in cells in which Dysbindin or NF-YB was down regulated, while Chromatin IP and Reporter assays were used to confirm the involvement of these genes in transcription of Myristoylated alanine-rich protein kinase C substrate (MARCKS). The sdy mutant mice with a deletion in Dysbindin, which exhibit behavioral abnormalities, and wild-type DBA2J mice were used to investigate MARCKS expression. Results We revealed an interaction between Dysbindin and NF-YB. DNA chips showed that MARCKS expression was increased in both Dysbindin knockdown cells and NF-YB knockdown cells, and Chromatin IP revealed interaction of these proteins at the MARCKS promoter region. Reporter assay results suggested functional involvement of the interaction between Dysbindin and NF-YB in MARCKS transcription levels, via the CCAAT motif which is a NF-YB binding sequence. MARCKS expression was increased in sdy mutant mice when compared to wild-type mice. Conclusions These findings suggest that abnormal expression of MARCKS via dysfunction of Dysbindin might cause impairment of neural transmission and abnormal synaptogenesis. Our results should provide new insights into the mechanisms of neuronal development and the pathogenesis of schizophrenia.
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Zuo L, Luo X, Kranzler HR, Lu L, Rosenheck RA, Cramer J, van Kammen DP, Erdos J, Charney DS, Krystal J, Gelernter J. Association study of DTNBP1 with schizophrenia in a US sample. Psychiatr Genet 2009; 19:292-304. [PMID: 19862852 DOI: 10.1097/ypg.0b013e32832a50bc] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
BACKGROUND Straub et al. (2002b) located a susceptibility region for schizophrenia at the DTNBP1 locus. At least 40 studies (including one study in US populations) attempted to replicate this original finding, but the reported findings are highly diverse and at least five pathways by which dysbindin protein might be involved in schizophrenia have been proposed. This study aimed to test the association in two common US populations by using powerful analytic methods. METHODS Six markers at DTNBP1 were genotyped by mass spectroscopy ('MassARRAY' technique) in a sample of 663 individuals, including 346 healthy individuals European-Americans (EAs) and 48 African-Americans (AAs), and 317 individuals with schizophrenia (235 EAs and 82 AAs). Thirty-eight ancestry-informative markers were genotyped in this sample to infer the ancestry proportions. Diplotype, haplotype, genotype, and allele frequency distributions were compared between the cases and controls, controlling for possible population stratification, admixture, and sex-specific effects, and taking interaction effects into account, using a logistic regression analysis (an extended structured association method). RESULTS Conventional case-control comparisons showed that genotypes of the markers P1578 (rs1018381) and P1583 (rs909706) were nominally associated with schizophrenia in EAs and in AAs, respectively. These associations became less or nonsignificant after controlling for population stratification and admixture effects (using structured association or regression analysis), and became nonsignificant after correction for multiple testing. However, regression analysis showed that the common diplotypes (ACCCTT/GCCGCC or GCCGCC/GCCGCC) and the interaction effects of haplotypes GCCGCC/GCCGCC significantly affected risk for schizophrenia in EAs, effects that were modified by sex. Fine-mapping using d or J statistics located the specific markers (d: P1328; J: P1333) closest to the putative risk sites in EAs. CONCLUSION This study shows that DTNBP1 is a risk gene for schizophrenia in EAs. Variation at DTNBP1 may modify risk for schizophrenia in this population.
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Narr KL, Szeszko PR, Lencz T, Woods RP, Hamilton LS, Phillips O, Robinson D, Burdick KE, DeRosse P, Kucherlapati R, Thompson PM, Toga AW, Malhotra AK, Bilder RM. DTNBP1 is associated with imaging phenotypes in schizophrenia. Hum Brain Mapp 2010; 30:3783-94. [PMID: 19449336 DOI: 10.1002/hbm.20806] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Dystrobrevin binding protein 1 (DTNBP1) has been identified as putative schizophrenia susceptibility gene, but it remains unknown whether polymorphisms relate to altered cerebral structure. We examined relationships between a previously implicated DTNBP1 risk variant [P1578] and global and segmented brain tissue volumes and regional cortical thickness in schizophrenia (n = 62; 24 risk carriers) and healthy subjects (n = 42; 11 risk carriers), across ethnic groups and within Caucasians. Schizophrenia patients showed similar brain volumes, but significantly reduced brain-size adjusted gray matter and CSF volumes and cortical thinning in a widespread neocortical distribution compared to controls. DTNBP1 risk was found associated with reduced brain volume, but not with tissue sub-compartments. Cortical thickness, which was weakly associated with brain size, showed regional variations in association with genetic risk, although effects were dominated by highly significant genotype by diagnosis interactions over broad areas of cortex. Risk status was found associated with regional cortical thinning in patients, particularly in temporal networks, but with thickness increases in controls. DTNBP1 effects for brain volume and cortical thickness appear driven by different neurobiological processes. Smaller brain volumes observed in risk carriers may relate to previously reported DTNBP1/cognitive function relationships irrespective of diagnosis. Regional cortical thinning in patient, but not in control risk carriers, may suggest that DTNBP1 interacts with other schizophrenia-related risk factors to affect laminar thickness. Alternatively, DTNBP1 may influence neural processes for which individuals with thicker cortex are less vulnerable. Although DTNBP1 relates to cortical thinning in schizophrenia, morphological changes in the disorder are influenced by additional genetic and/or environmental factors.
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Affiliation(s)
- Katherine L Narr
- Laboratory of Neuro Imaging and Ahmanson-Lovelace Brain Mapping Center, Department of Neurology, Geffen School of Medicine at UCLA, Los Angeles, California 90095, USA.
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Riley B, Kuo PH, Maher BS, Fanous AH, Sun J, Wormley B, O’Neill FA, Walsh D, Zhao Z, Kendler KS. The dystrobrevin binding protein 1 (DTNBP1) gene is associated with schizophrenia in the Irish Case Control Study of Schizophrenia (ICCSS) sample. Schizophr Res 2009; 115:245-53. [PMID: 19800201 PMCID: PMC2783814 DOI: 10.1016/j.schres.2009.09.008] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2009] [Revised: 09/01/2009] [Accepted: 09/07/2009] [Indexed: 10/20/2022]
Abstract
BACKGROUND DTNBP1 is associated with schizophrenia in many studies, but the associated alleles and haplotypes vary between samples. METHOD We assessed nine single nucleotide polymorphisms (SNPs) in this gene for association with schizophrenia in a new sample of 1021 cases and 626 controls from Ireland. RESULTS Four SNPs give evidence of association (0.000018<p<0.045), most strongly with the common allele at rs760761. A haplotype of the common alleles of five markers (including rs760761) and the minor allele of rs2619538 overlapping the 5' end of the DTNBP1 gene also gives evidence for association (p=0.0002). Secondary analyses showed no difference in the association signal based on sex or family history. These results are in agreement with the most consistently observed association with common alleles and common-allele haplotypes, reported in a previous study of Irish cases and controls but not in an Irish high-density family sample. Our results do not support the prior report from a Swedish sample of increased association in cases with a family history of psychotic illness. Comparison of human, chimpanzee and rhesus sequence suggest that rs760761 is a particularly variable position in the primate lineage. CONCLUSION This study provides further evidence from a large case/control sample for association of common DTNBP1 alleles and haplotypes with schizophrenia.
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Affiliation(s)
- Brien Riley
- Department of Psychiatry, Virginia Commonwealth University, Richmond, VA, USA.
| | - Po-Hsiu Kuo
- Department of Psychiatry, Virginia Commonwealth University, Richmond, VA, USA, Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University, Richmond, VA, USA
| | - Brion S. Maher
- Department of Psychiatry, Virginia Commonwealth University, Richmond, VA, USA, Department of Human & Molecular Genetics, Virginia Commonwealth University, Richmond, VA, USA, Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University, Richmond, VA, USA
| | - Ayman H. Fanous
- Department of Psychiatry, Virginia Commonwealth University, Richmond, VA, USA, Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University, Richmond, VA, USA, Department of Psychiatry, Georgetown University School of Medicine, Washington DC, USA, Mental Health Service Line, Washington VA Medical Center, Washington DC, USA
| | - Jingchun Sun
- Department of Psychiatry, Virginia Commonwealth University, Richmond, VA, USA, Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University, Richmond, VA, USA
| | - Brandon Wormley
- Department of Psychiatry, Virginia Commonwealth University, Richmond, VA, USA, Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University, Richmond, VA, USA
| | | | | | - Zhongming Zhao
- Department of Psychiatry, Virginia Commonwealth University, Richmond, VA, USA, Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University, Richmond, VA, USA
| | - Kenneth S. Kendler
- Department of Psychiatry, Virginia Commonwealth University, Richmond, VA, USA, Department of Human & Molecular Genetics, Virginia Commonwealth University, Richmond, VA, USA, Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University, Richmond, VA, USA
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Liu Y, Chen G, Norton N, Liu W, Zhu H, Zhou P, Luan M, Yang S, Chen X, Carroll L, Williams NM, O'Donovan MC, Kirov G, Owen MJ. Whole genome association study in a homogenous population in Shandong peninsula of China reveals JARID2 as a susceptibility gene for schizophrenia. J Biomed Biotechnol 2009; 2009:536918. [PMID: 19884986 DOI: 10.1155/2009/536918] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2009] [Revised: 07/21/2009] [Accepted: 07/29/2009] [Indexed: 02/04/2023] Open
Abstract
DNA pooling can provide an economic and efficient way to detect susceptibility loci to complex diseases. We carried out a genome screen with 400 microsatellite markers spaced at approximately 10 cm in two DNA pools consisting of 119 schizophrenia (SZ) patients and 119 controls recruited from a homogenous population in the Chang Le area of the Shandong peninsula of China. Association of D6S289, a dinucleotide repeat polymorphism in the JARID2 gene with SZ, was found and confirmed by individual genotyping (X2 = 17.89; P = .047). In order to refine the signal, we genotyped 14 single nucleotide polymorphisms (SNPs) covering JARID2 and the neighboring gene, DNTBP1, in an extended sample of 309 cases and 309 controls from Shandong peninsula (including the samples from the pools). However, rs2235258 and rs9654600 in JARID2 showed association in allelic, genotypic and haplotypic tests with SZ patients from Chang Le area. This was not replicates in the extended sample, we conclude that JARID2 could be a susceptibility gene for SZ.
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Markov V, Krug A, Krach S, Whitney C, Eggermann T, Zerres K, Stöcker T, Shah N, Nöthen M, Treutlein J, Rietschel M, Kircher T. Genetic variation in schizophrenia-risk-gene dysbindin 1 modulates brain activation in anterior cingulate cortex and right temporal gyrus during language production in healthy individuals. Neuroimage 2009; 47:2016-22. [DOI: 10.1016/j.neuroimage.2009.05.067] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2008] [Revised: 05/06/2009] [Accepted: 05/21/2009] [Indexed: 10/20/2022] Open
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Kircher T, Markov V, Krug A, Eggermann T, Zerres K, Nöthen MM, Skowronek MH, Rietschel M. Association of the DTNBP1 genotype with cognition and personality traits in healthy subjects. Psychol Med 2009; 39:1657-1665. [PMID: 19335929 DOI: 10.1017/s0033291709005388] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND Schizophrenia is a complex disorder with a high heritability. Family members have an increased risk not only for schizophrenia per se but also for schizophrenia spectrum disorders. Impairment of neuropsychological functions found in schizophrenia patients are also frequently observed in their relatives. The dystrobrevin-binding protein 1 (DTNBP1) gene located at chromosome 6p22.3 is one of the most often replicated vulnerability genes for schizophrenia. In addition, this gene has been shown to modulate general cognitive abilities both in healthy subjects and in patients with schizophrenia. METHOD In a sample of 521 healthy subjects we investigated an association between the DTNBP1 genotype [single nucleotide polymorphism (SNP) rs1018381], personality traits [using the NEO Five-Factor Inventory (NEO-FFI) and the Schizotypal Personality Questionnaire - Brief Version (SPQ-B)] and cognitive function (estimated IQ, verbal fluency, attention, working memory and executive function). RESULTS Significantly lower scores on the SPQ-B (p=0.0005) and the Interpersonal Deficit subscale (p=0.0005) in carriers of the A-risk allele were detected. There were no differences in any of the cognitive variables between groups. CONCLUSIONS The results indicate that genetic variation of the DTNBP1 genotype might exert gene-specific modulating effects on schizophrenia endophenotypes at the population level.
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Affiliation(s)
- T Kircher
- Department of Psychiatry and Psychotherapy, Philipps-University Marburg, Germany.
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Zuo L, Luo X, Krystal JH, Cramer J, Charney DS, Gelernter J. The efficacies of clozapine and haloperidol in refractory schizophrenia are related to DTNBP1 variation. Pharmacogenet Genomics 2009; 19:437-46. [PMID: 19369910 DOI: 10.1097/FPC.0b013e32832b9cfc] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE The prototypical atypical antipsychotic agent, clozapine, is more efficacious for refractory schizophrenia than the 'typical' antipsychotics, but the mechanism underlying this enhanced efficacy is still under investigation. Since 2002, at least 22 association studies have shown that the DTNBP1 can be associated with the risk for schizophrenia. We hypothesized that DTNBP1 might also influence the response to antipsychotic treatments. This study aimed to investigate the relationship between the DTNBP1 and the effects of clozapine and haloperidol on refractory schizophrenia. METHODS Patients with refractory schizophrenia were assigned to clozapine (n=85) or haloperidol (n=96) and followed for 3 months. Symptom improvement was evaluated by Positive and Negative Syndrome Scale score. Six markers at DTNBP1 and 38 ancestry-informative markers were genotyped in all participants. The relationships between the effects of antipsychotics and the diplotypes, haplotypes, genotypes, and alleles of DTNBP1 were tested by analysis of covariance, analysis of variance, and t-test. RESULTS Patients with diplotype ACCCTC/GTTGCC, genotypes T/T+T/C, or allele T of marker rs742105 (P1333) have better response to clozapine (0.005< or =P< or =0.049), and patients with diplotype ACCCTC/GCCGCC, genotype A/G, or allele A of marker rs909706 (P1583) have better response to haloperidol (0.007< or =P< or =0.080) in European-Americans, African-Americans, and/or the combined sample; European-American patients with diplotype ACCCTC/GCCGCC have worse response to clozapine on positive symptoms (P=0.011). CONCLUSION This study shows that the DTNBP1 gene modulates the effects of both the atypical antipsychotic clozapine and the typical antipsychotic haloperidol. Participants with different DTNBP1 diplotypes, haplotypes, genotypes, or alleles might have different responses to these antipsychotics.
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Hashimoto R, Noguchi H, Hori H, Ohi K, Yasuda Y, Takeda M, Kunugi H. Association between the dysbindin gene (DTNBP1) and cognitive functions in Japanese subjects. Psychiatry Clin Neurosci 2009; 63:550-6. [PMID: 19496996 DOI: 10.1111/j.1440-1819.2009.01985.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
AIM The dysbindin gene (dystrobrevin binding protein 1: DTNBP1) is a susceptibility gene for schizophrenia. Susceptibility genes for schizophrenia have been hypothesized to mediate liability for the disorder at least partly by influencing cognitive performance. This report investigated the relationship between cognitive function and the dysbindin gene. METHODS The possible association between a single nucleotide polymorphism (SNP) of DTNBP1 (rs2619539: P1655), which is a risk-independent SNP for schizophrenia in Japanese populations, and memory and IQ was investigated in 70 schizophrenia patients and 165 healthy volunteers in a Japanese population. RESULTS This SNP was associated with two memory scales, verbal memory and general memory, on the Wechsler Memory Scale-Revised (WMS-R), and three subcategories of the Wechsler Adult Intelligence Scale-Revised (WAIS-R), vocabulary, similarities and picture completion in healthy subjects. The SNP, however, did not influence either the indices of WMS-R, IQ or subcategories of WAIS-R in schizophrenia patients. CONCLUSION A risk-independent SNP in DTNBP1 may have an impact on cognitive functions such as memory and IQ in healthy subjects.
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Affiliation(s)
- Ryota Hashimoto
- Osaka-Hamamatsu Joint Research Center for Child Mental Development, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
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Mechelli A, Viding E, Kumar A, Pettersson-Yeo W, Fusar-Poli P, Tognin S, O'Donovan MC, McGuire P. Dysbindin modulates brain function during visual processing in children. Neuroimage 2009; 49:817-22. [PMID: 19631276 DOI: 10.1016/j.neuroimage.2009.07.030] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2009] [Revised: 07/10/2009] [Accepted: 07/14/2009] [Indexed: 11/29/2022] Open
Abstract
Schizophrenia is a neurodevelopmental disorder, and risk genes are thought to act through disruption of brain development. Several genetic studies have identified dystrobrevin binding protein 1 (DTNBP1, also known as dysbindin) as a potential susceptibility gene for schizophrenia, but its impact on brain function is poorly understood. It has been proposed that DTNBP1 may be associated with differences in visual processing. To test this, we examined the impact on visual processing in 61 healthy children aged 10-12 years of a genetic variant in DTNBP1 (rs2619538) that was common to all schizophrenia associated haplotypes in an earlier UK-Irish study. We tested the hypothesis that carriers of the risk allele would show altered occipital cortical function relative to noncarriers. Functional Magnetic Resonance Imaging (fMRI) was used to measure brain responses during a visual matching task. The data were analysed using statistical parametric mapping and statistical inferences were made at p<0.05 (corrected for multiple comparisons). Relative to noncarriers, carriers of the risk allele had greater activation in the lingual, fusiform gyrus and inferior occipital gyri. In these regions DTNBP1 genotype accounted for 19%, 20% and 14% of the inter-individual variance, respectively. Our results suggest that that genetic variation in DTNBP1 is associated with differences in the function of brain areas that mediate visual processing, and that these effects are evident in young children. These findings are consistent with the notion that the DTNBP1 gene influences brain development and can thereby modulate vulnerability to schizophrenia.
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Affiliation(s)
- A Mechelli
- Department of Psychology, Institute of Psychiatry, King's College London, 103 Denmark Hill, London, UK.
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Webb BT, McClay JL, Vargas-Irwin C, York TP, van den Oord EJ. In silico whole genome association scan for murine prepulse inhibition. PLoS One 2009; 4:e5246. [PMID: 19370154 DOI: 10.1371/journal.pone.0005246] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2008] [Accepted: 03/05/2009] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND The complex trait of prepulse inhibition (PPI) is a sensory gating measure related to schizophrenia and can be measured in mice. Large-scale public repositories of inbred mouse strain genotypes and phenotypes such as PPI can be used to detect Quantitative Trait Loci (QTLs) in silico. However, the method has been criticized for issues including insufficient number of strains, not controlling for false discoveries, the complex haplotype structure of inbred mice, and failing to account for genotypic and phenotypic subgroups. METHODOLOGY/PRINCIPAL FINDINGS We have implemented a method that addresses these issues by incorporating phylogenetic analyses, multilevel regression with mixed effects, and false discovery rate (FDR) control. A genome-wide scan for PPI was conducted using over 17,000 single nucleotide polymorphisms (SNPs) in 37 strains phenotyped. Eighty-nine SNPs were significant at a false discovery rate (FDR) of 5%. After accounting for long-range linkage disequilibrium, we found 3 independent QTLs located on murine chromosomes 1 and 13. One of the PPI positives corresponds to a region of human chromosome 6p which includes DTNBP1, a gene implicated in schizophrenia. Another region includes the gene Tsn which alters PPI when knocked out. These genes also appear to have correlated expression with PPI. CONCLUSIONS/SIGNIFICANCE These results support the usefulness of using an improved in silico mapping method to identify QTLs for complex traits such as PPI which can be then be used for to help identify loci influencing schizophrenia in humans.
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Pae CU, Mandelli L, De Ronchi D, Kim JJ, Jun TY, Patkar AA, Serretti A. Dysbindin gene (DTNBP1) and schizophrenia in Korean population. Eur Arch Psychiatry Clin Neurosci 2009; 259:137-42. [PMID: 19252939 DOI: 10.1007/s00406-008-0830-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2007] [Accepted: 04/30/2008] [Indexed: 12/18/2022]
Abstract
Dysbindin gene (DTNBP1) has been consistently reported to be associated with schizophrenia. However data from East Asian population has been sparse and inconsistent till today. This study tried to replicate the genetic association of DTNBP1 with schizophrenia in a large Korean sample, as well as analyzing the association of DTNBP1 with clinical variables. Nine hundred and eight (908) patients with schizophrenia and 601 controls were investigated. The high-throughput genotyping method using pyrosequencer (Biotage AB, Sweden) was used for genotyping 4 SNPs (rs3213207, rs1011313, rs760761, and rs2619522). Haplotype analyses revealed a significant association with schizophrenia (P < 0.0001) with the haplotypes A-C-C-C and A-C-T-A having an eminent protective effect toward schizophrenia. The major contribution to the difference in the haplotype distribution between patients and the controls was the rs760761 (C/T) and rs2619522 (A/C) haplotypes (P < 0.0001). No association of DTNBP1 with other clinical variables was found. In conclusion, the present study suggests a possible protective effect of rare DTNBP1 variants in schizophrenia, although subsequent studies in different ethnic groups are warranted.
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Affiliation(s)
- Chi-Un Pae
- Department of Psychiatry, The Catholic University of Korea College of Medicine, 505 Banpo-Dong, Seocho-Gu, Seoul 137-701, South Korea
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Taneichi-Kuroda S, Taya S, Hikita T, Fujino Y, Kaibuchi K. Direct interaction of Dysbindin with the AP-3 complex via its mu subunit. Neurochem Int 2009; 54:431-8. [PMID: 19428785 DOI: 10.1016/j.neuint.2009.01.014] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2008] [Revised: 01/20/2009] [Accepted: 01/21/2009] [Indexed: 11/26/2022]
Abstract
Genetic factors are important in the etiology of schizophrenia. Recent studies have revealed the association between genetic variation of Dysbindin (DTNBP1) and schizophrenia. Dysbindin is one of the essential components of the biogenesis of lysosome-related organelles complex 1 (BLOC-1). BLOC-1 physically interacts with the adaptor protein (AP)-3 complex, which is essential for vesicle or protein sorting. However, it remains largely unknown how BLOC-1 interacts with the AP-3 complex. To investigate the binding mode of BLOC-1 and the AP-3 complex, we examined the relation between Dysbindin and the AP-3 complex and found that Dysbindin formed a complex with the AP-3 complex through the direct binding to its mu subunit. Dysbindin partially co-localized with the AP-3 complex in CA1 and CA3 of mouse hippocampus, and at presynaptic terminals and axonal growth cones of cultured hippocampal neurons. Suppression of Dysbindin results in the reduction of presynaptic protein expression and glutamate release. Thus, Dysbindin appears to participate in the exocytosis or sorting of the synaptic vesicle via direct interaction with the AP-3 complex.
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Affiliation(s)
- Setsuko Taneichi-Kuroda
- Department of Cell Pharmacology, Graduate School of Medicine, Nagoya University, 65 Tsurumai, Showa, Nagoya 466-8550, Japan
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Oyama S, Yamakawa H, Sasagawa N, Hosoi Y, Futai E, Ishiura S. Dysbindin-1, a schizophrenia-related protein, functionally interacts with the DNA- dependent protein kinase complex in an isoform-dependent manner. PLoS One 2009; 4:e4199. [PMID: 19142223 PMCID: PMC2614472 DOI: 10.1371/journal.pone.0004199] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2008] [Accepted: 12/03/2008] [Indexed: 11/18/2022] Open
Abstract
DTNBP1 has been recognized as a schizophrenia susceptible gene, and its protein product, dysbindin-1, is down-regulated in the brains of schizophrenic patients. However, little is known about the physiological role of dysbindin-1 in the central nervous system. We hypothesized that disruption of dysbindin-1 with unidentified proteins could contribute to pathogenesis and the symptoms of schizophrenia. GST pull-down from human neuroblastoma lysates showed an association of dysbindin-1 with the DNA-dependent protein kinase (DNA-PK) complex. The DNA-PK complex interacts only with splice isoforms A and B, but not with C. We found that isoforms A and B localized in nucleus, where the kinase complex exist, whereas the isoform C was found exclusively in cytosol. Furthermore, results of phosphorylation assay suggest that the DNA-PK complex phosphorylated dysbindin-1 isoforms A and B in cells. These observations suggest that DNA-PK regulates the dysbindin-1 isoforms A and B by phosphorylation in nucleus. Isoform C does not contain exons from 1 to 6. Since schizophrenia-related single nucleotide polymorphisms (SNPs) occur in these introns between exon 1 and exon 6, we suggest that these SNPs might affect splicing of DTNBP1, which leads to impairment of the functional interaction between dysbindin-1 and DNA-PK in schizophrenic patients.
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Affiliation(s)
- Satoko Oyama
- Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Meguro-ku, Tokyo, Japan
| | - Hidekuni Yamakawa
- Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Meguro-ku, Tokyo, Japan
| | - Noboru Sasagawa
- Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Meguro-ku, Tokyo, Japan
| | - Yoshio Hosoi
- Department of Radiological Technology, School of Health Sciences, Niigata University, Niigata-shi, Niigata, Japan
| | - Eugene Futai
- Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Meguro-ku, Tokyo, Japan
| | - Shoichi Ishiura
- Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Meguro-ku, Tokyo, Japan
- * E-mail:
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Abstract
Schizophrenia is a debilitating lifelong disorder affecting up to 1% of the population worldwide, producing significant financial and emotional hardship for patients and their families. As yet, the causes of schizophrenia and the mechanism of action of antipsychotic drugs are unknown, and many patients do not respond well to currently available medications. Attempts to find risk factors for the disorder using epidemiological methods have shown that schizophrenia is highly heritable, and path analyses predict that the disorder is caused by several genes in combination with nongenetic factors. Therefore, intensive research efforts have been made to identify genes creating vulnerability to schizophrenia and also genes predicting response to treatment. Interactions of the glutamatergic system with dopaminergic and serotonergic circuitry are crucial for normal brain function, and their disruption may be a mechanism by which the pathophysiology of schizophrenia is manifest. Genes within the glutamatergic system are therefore strong candidates for investigation, and these include the glutamate receptor genes in addition to genes encoding neuregulin, dysbindin, D-amino acid oxidase and G72/G30. These genetic studies could eventually reveal new targets for antipsychotic drug treatment, which currently focuses on inhibition of the dopaminergic system. However, a recent breakthrough indicates clinical efficacy of a drug stimulating the metabotropic glutamate receptor II, LY2140023, which has improved efficacy for negative and cognitive symptoms of schizophrenia. Studies of larger patient samples are required to consolidate these data. Further investigation of glutamatergic targets is likely to reinvigorate antipsychotic drug development.
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Affiliation(s)
- Monsheel Sodhi
- Department of Psychiatry & Behavioral Neurobiology, University of Alabama at Birmingham, 1720 7th Avenue Sth, Rm 590C CIRC, Birmingham, AL 35294, USA.
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Luciano M, Miyajima F, Lind PA, Bates TC, Horan M, Harris SE, Wright MJ, Ollier WE, Hayward C, Pendleton N, Gow AJ, Visscher PM, Starr JM, Deary IJ, Martin NG, Payton A. Variation in the dysbindin gene and normal cognitive function in three independent population samples. Genes Brain Behav 2008; 8:218-27. [PMID: 19077176 DOI: 10.1111/j.1601-183x.2008.00462.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The association between DTNBP1 genotype and cognitive abilities was investigated in three population samples (1054 Scottish, 1806 Australian and 745 English) of varying age. There was evidence in each of the cohorts for association (P < 0.05) to single nucleotide polymorphisms (SNPs) and haplotypes previously shown to relate to cognition. By comparison with previous findings, these associations included measures of memory, and there was at best equivocal evidence of association with general cognitive ability. Of the SNPs typed in all three cohorts, rs2619528 and rs1011313 showed significant association with measures of executive function in two cohorts, rs1018381 showed significant association with verbal ability in one cohort and rs2619522 showed significance/marginal significance with tests of memory, speed and executive function in two cohorts. For all these SNPs, the direction and magnitude of the allelic effects were consistent between cohorts and with previous findings. In the English cohort, a previously untested SNP (rs742105) located in a distinct haplotype block upstream of the other SNPs showed the strongest significance (P < 0.01) for measures of memory but weaker significance for general cognitive ability. Our results therefore support involvement of the dysbindin gene in cognitive function, but further work is needed to clarify the specific functional variants involved and the cognitive abilities with which they are associated.
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Affiliation(s)
- M Luciano
- Centre for Cognitive Ageing and Cognitive Epidemiology, Department of Psychology, University of Edinburgh, Edinburgh, UK.
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Karlsgodt KH, Sun D, Jimenez AM, Lutkenhoff ES, Willhite R, van Erp TGM, Cannon TD. Developmental disruptions in neural connectivity in the pathophysiology of schizophrenia. Dev Psychopathol 2008; 20:1297-327. [DOI: 10.1017/s095457940800062x] [Citation(s) in RCA: 115] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
AbstractSchizophrenia has been thought of as a disorder of reduced functional and structural connectivity. Recent advances in neuroimaging techniques such as functional magnetic resonance imaging, structural magnetic resonance imaging, diffusion tensor imaging, and small animal imaging have advanced our ability to investigate this hypothesis. Moreover, the power of longitudinal designs possible with these noninvasive techniques enable the study of not just how connectivity is disrupted in schizophrenia, but when this disruption emerges during development. This article reviews genetic and neurodevelopmental influences on structural and functional connectivity in human populations with or at risk for schizophrenia and in animal models of the disorder. We conclude that the weight of evidence across these diverse lines of inquiry points to a developmental disruption of neural connectivity in schizophrenia and that this disrupted connectivity likely involves susceptibility genes that affect processes involved in establishing intra- and interregional connectivity.
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Webb BT, Sullivan PF, Skelly T, van den Oord EJ. Model-based gene selection shows engrailed 1 is associated with antipsychotic response. Pharmacogenet Genomics 2008; 18:751-9. [DOI: 10.1097/fpc.0b013e32830162bc] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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47
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Abstract
Two major theories of schizophrenia are respectively, the neurodevelopmental hypothesis and the dopamine hypothesis. Each of these has recently been revised. Firstly, the classical neurodevelopmental hypothesis has been modified to include the pathogenic effects of psychostimulants and cannabis abuse, and also of chronic social adversity; it is perhaps now more appropriately termed, the developmental hypothesis. Secondly, recent amendments to the dopamine hypothesis suggest that excess striatal dopamine is responsible for increased salience being given to insignificant events and thoughts, and that this underpins the development of psychotic symptoms. Traditionally, it has been thought that this striatal dopamine dysregulation might be secondary to frontal dysfunction. However, recent animal research shows that over-expression of striatal D(2) receptors results in frontal dysfunction manifesting as cognitive difficulties and animal equivalents of so-called negative symptoms. This raises the question whether early intervention may prevent the development of these latter problems. Finally, the two theories are beginning to be integrated through the growing evidence that all the developmental risk factors which increase risk of schizophrenia appear to act by facilitating dopamine dysregulation.
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Affiliation(s)
- Robin M Murray
- Institute of Psychiatry, De Crespigny Park, London, United Kingdom.
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48
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Abstract
The evolutionary origins of one of the most dramatic and seemingly deleterious behavioral phenotypes, the syndrome known as schizophrenia, are mysterious. Schizophrenia occurs in all cultures and is inherited. Although most phenotypes are said to be "selected for" based on adaptive qualities, it is difficult to understand how the genetic basis of schizophrenia could have operated under a similar framework. This has lead several theorists analyzing the proposed evolutionary origins of other disease states to that of schizophrenia. To date, several models have been applied. We have tried to conceptualize schizophrenia in a compensatory advantage framework whereby incomplete penetrance of the full disorder, or alternatively, the inheritance of risk alleles insufficient in number to manifest as the classic clinical syndrome, may manifest as a behavioral phenotype with adaptive advantages (eg, creative behavior or novel illuminating ideas). The idea that even full penetrance can also be advantageous has been offered as applied to religious experience and ancient social standing, but is unlikely. Can complex behavioral phenotypes such as schizophrenia, and particularly those that seem purely deleterious, be explained by mechanisms of Darwinian psychiatry? Can models from other disease classes be applied successfully to schizophrenia? Such ideas have generated intense speculation, but often in the absence of testable models. In this article, we will examine some of these proposed ideas and offer suggestions for future research.
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Affiliation(s)
- Godfrey D. Pearlson
- The Olin Neuropsychiatry Research Center, 200 Retreat Avenue, Whitehall Building, Hartford, CT 06106,Department of Psychiatry, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510,Department of Psychiatry, Johns Hopkins University, 600 North Wolfe Street, Baltimore, MD 21287,To whom correspondence should be addressed; tel: 860-545-7757, fax: 860-545-7797, e-mail:
| | - Bradley S. Folley
- The Olin Neuropsychiatry Research Center, 200 Retreat Avenue, Whitehall Building, Hartford, CT 06106
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Abstract
It has recently been demonstrated that a large amount of structural variation exists in the human genome. Since 2004, when two landmark studies reported polymorphic levels of copy number variation in phenotypically normal individuals, our understanding of genome-wide levels of copy number variation has grown. This has inspired hypotheses about this class of variation's contribution to complex genetic phenotypes, including the specific hypothesis that structural variation is associated with psychiatric illness. The technology to accurately and efficiently detect polymorphic structural variants is still largely under development, but some examples of genomic imbalance contributing to schizophrenia and bipolar disorder already have been identified. Although much optimism surrounds this burgeoning field, the technical challenges in reliably identifying structural variation mean recent literature should be approached with caution.
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Affiliation(s)
- Jennifer Gladys Mulle
- Department of Human Genetics, Emory University School of Medicine, 615 Michael Street, Atlanta, GA 30317, USA.
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Vilella E, Costas J, Sanjuan J, Guitart M, De Diego Y, Carracedo A, Martorell L, Valero J, Labad A, De Frutos R, Nájera C, Moltó MD, Toirac I, Guillamat R, Brunet A, Vallès V, Pérez L, Leon M, de Fonseca FR, Phillips C, Torres M. Association of schizophrenia with DTNBP1 but not with DAO, DAOA, NRG1 and RGS4 nor their genetic interaction. J Psychiatr Res 2008; 42:278-88. [PMID: 17408693 DOI: 10.1016/j.jpsychires.2007.02.005] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2006] [Revised: 01/30/2007] [Accepted: 02/16/2007] [Indexed: 01/16/2023]
Abstract
Recent reports indicate that DAO, DAOA, DTNBP1, NRG1 and RGS4 are some of the most-replicated genes implicated in susceptibility to schizophrenia. Also, the functions of these genes could converge in a common pathway of glutamate metabolism. The aim of this study was to evaluate if each of these genes, or their interaction, was associated with schizophrenia. A case-control study was conducted in 589 Spanish patients having a diagnosis of schizophrenia, and compared with 617 equivalent control subjects. Several single nucleotide polymorphisms (SNPs) in each gene were determined in all individuals. SNP and haplotype frequencies were compared between cases and controls. The interaction between different SNPs at the same, or at different gene, loci was analyzed by the multifactor dimensionality reduction (MDR) method. We found a new schizophrenia risk and protective haplotypes in intron VII of DTNBP1; one of the most important candidate genes for this disorder, to-date. However, no association was found between DAO, DAOA, NRG1 and RGS4 and schizophrenia. The hypothesis that gene-gene interaction in these five genes could increase the risk for the disorder was not confirmed in the present study. In summary, these results may provide further support for an association between the dysbindin gene (DTNBP1) and schizophrenia, but not between the disease and DAO, DAOA, NRG1 and RGS4 or with the interaction of these genes. In the light of recent data, these results need to be interpreted with caution and future analyses with dense genetic maps are awaited.
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