1
|
Zhong Y, Zhang N, Zhao F, Chang S, Chen W, Cao Q, Sun L, Wang Y, Gong Z, Lu L, Liu D, Yang L. RBFOX1 and Working Memory: From Genome to Transcriptome Revealed Posttranscriptional Mechanism Separate From Attention-Deficit/Hyperactivity Disorder. BIOLOGICAL PSYCHIATRY GLOBAL OPEN SCIENCE 2023; 3:1042-1052. [PMID: 37881587 PMCID: PMC10593897 DOI: 10.1016/j.bpsgos.2022.08.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 08/09/2022] [Accepted: 08/12/2022] [Indexed: 11/22/2022] Open
Abstract
Background Many psychiatric disorders share a working memory (WM) impairment phenotype, yet the genetic causes remain unclear. Here, we generated genetic profiles of WM deficits using attention-deficit/hyperactivity disorder samples and validated the results in zebrafish models. Methods We used 2 relatively large attention-deficit/hyperactivity disorder cohorts, 799 and 776 cases, respectively. WM impairment was assessed using the Rey Complex Figure Test. First, association analyses were conducted at single-variant, gene-based, and gene-set levels. Deeper insights into the biological mechanism were gained from further functional exploration by bioinformatic analyses and zebrafish models. Results Genomic analyses identified and replicated a locus with rs75885813 as the index single nucleotide polymorphism showing significant association with WM defects but not with attention-deficit/hyperactivity disorder. Functional feature exploration found that these single nucleotide polymorphisms may regulate the expression level of RBFOX1 through chromatin interaction. Further pathway enrichment analysis of potential associated single nucleotide polymorphisms revealed the involvement of posttranscription regulation that affects messenger RNA stability and/or alternative splicing. Zebrafish with functionally knocked down or genome-edited rbfox1 exhibited WM impairment but no hyperactivity. Transcriptome profiling of rbfox1-defective zebrafish indicated that alternative exon usages of snap25a might partially lead to reduced WM learning of larval zebrafish. Conclusions The locus with rs75885813 in RBFOX1 was identified as associated with WM. Rbfox1 regulates synaptic and long-term potentiation-related gene snap25a to adjust WM at the posttranscriptional level.
Collapse
Affiliation(s)
- Yuanxin Zhong
- Peking University Sixth Hospital, Peking University Institute of Mental Health, NHC Key Laboratory of Mental Health, National Clinical Research Center for Mental Disorders, Beijing, China
| | - Na Zhang
- School of Life Science, Southern University of Science and Technology, Shenzhen, China
- Department of Biological Science, National University of Singapore, Singapore
| | - Feng Zhao
- School of Life Science, Southern University of Science and Technology, Shenzhen, China
| | - Suhua Chang
- Peking University Sixth Hospital, Peking University Institute of Mental Health, NHC Key Laboratory of Mental Health, National Clinical Research Center for Mental Disorders, Beijing, China
| | - Wei Chen
- Peking University Sixth Hospital, Peking University Institute of Mental Health, NHC Key Laboratory of Mental Health, National Clinical Research Center for Mental Disorders, Beijing, China
| | - Qingjiu Cao
- Peking University Sixth Hospital, Peking University Institute of Mental Health, NHC Key Laboratory of Mental Health, National Clinical Research Center for Mental Disorders, Beijing, China
| | - Li Sun
- Peking University Sixth Hospital, Peking University Institute of Mental Health, NHC Key Laboratory of Mental Health, National Clinical Research Center for Mental Disorders, Beijing, China
| | - Yufeng Wang
- Peking University Sixth Hospital, Peking University Institute of Mental Health, NHC Key Laboratory of Mental Health, National Clinical Research Center for Mental Disorders, Beijing, China
| | - Zhiyuan Gong
- Department of Biological Science, National University of Singapore, Singapore
| | - Lin Lu
- Peking University Sixth Hospital, Peking University Institute of Mental Health, NHC Key Laboratory of Mental Health, National Clinical Research Center for Mental Disorders, Beijing, China
- Peking-Tsinghua Center for Life Sciences, International Data Group, McGovern Institute for Brain Research at Peking University, Peking University, Beijing, China
| | - Dong Liu
- School of Life Science, Southern University of Science and Technology, Shenzhen, China
| | - Li Yang
- Peking University Sixth Hospital, Peking University Institute of Mental Health, NHC Key Laboratory of Mental Health, National Clinical Research Center for Mental Disorders, Beijing, China
| |
Collapse
|
2
|
Dong B, Yue Y, Dong H, Wang Y. N-methyl-D-aspartate receptor hypofunction as a potential contributor to the progression and manifestation of many neurological disorders. Front Mol Neurosci 2023; 16:1174738. [PMID: 37396784 PMCID: PMC10308130 DOI: 10.3389/fnmol.2023.1174738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 05/26/2023] [Indexed: 07/04/2023] Open
Abstract
N-methyl-D-aspartate receptors (NMDA) are glutamate-gated ion channels critical for synaptic transmission and plasticity. A slight variation of NMDAR expression and function can result in devastating consequences, and both hyperactivation and hypoactivation of NMDARs are detrimental to neural function. Compared to NMDAR hyperfunction, NMDAR hypofunction is widely implicated in many neurological disorders, such as intellectual disability, autism, schizophrenia, and age-related cognitive decline. Additionally, NMDAR hypofunction is associated with the progression and manifestation of these diseases. Here, we review the underlying mechanisms of NMDAR hypofunction in the progression of these neurological disorders and highlight that targeting NMDAR hypofunction is a promising therapeutic intervention in some neurological disorders.
Collapse
Affiliation(s)
- Bin Dong
- Department of Geriatrics, Jilin Geriatrics Clinical Research Center, The First Hospital of Jilin University, Changchun, China
| | - Yang Yue
- School of Psychology, Northeast Normal University, Changchun, China
| | - Han Dong
- Department of Geriatrics, Jilin Geriatrics Clinical Research Center, The First Hospital of Jilin University, Changchun, China
| | - Yuehui Wang
- Department of Geriatrics, Jilin Geriatrics Clinical Research Center, The First Hospital of Jilin University, Changchun, China
| |
Collapse
|
3
|
Keeping Excitation-Inhibition Ratio in Balance. Int J Mol Sci 2022; 23:ijms23105746. [PMID: 35628556 PMCID: PMC9145842 DOI: 10.3390/ijms23105746] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 05/17/2022] [Accepted: 05/20/2022] [Indexed: 11/17/2022] Open
Abstract
Unrelated genetic mutations can lead to convergent manifestations of neurological disorders with similar behavioral phenotypes. Experimental data frequently show a lack of dramatic changes in neuroanatomy, indicating that the key cause of symptoms might arise from impairment in the communication between neurons. A transient imbalance between excitatory (glutamatergic) and inhibitory (GABAergic) synaptic transmission (the E/I balance) during early development is generally considered to underlie the development of several neurological disorders in adults. However, the E/I ratio is a multidimensional variable. Synaptic contacts are highly dynamic and the actual strength of synaptic projections is determined from the balance between synaptogenesis and synaptic elimination. During development, relatively slow postsynaptic receptors are replaced by fast ones that allow for fast stimulus-locked excitation/inhibition. Using the binomial model of synaptic transmission allows for the reassessing of experimental data from different mouse models, showing that a transient E/I shift is frequently counterbalanced by additional pre- and/or postsynaptic changes. Such changes—for instance, the slowing down of postsynaptic currents by means of immature postsynaptic receptors—stabilize the average synaptic strength, but impair the timing of information flow. Compensatory processes and/or astrocytic signaling may represent possible targets for medical treatments of different disorders directed to rescue the proper information processing.
Collapse
|
4
|
Suh BK, Lee SA, Park C, Suh Y, Kim SJ, Woo Y, Nhung TTM, Lee SB, Mun DJ, Goo BS, Choi HS, Kim SJ, Park SK. Schizophrenia-associated dysbindin modulates axonal mitochondrial movement in cooperation with p150 glued. Mol Brain 2021; 14:14. [PMID: 33461576 PMCID: PMC7814725 DOI: 10.1186/s13041-020-00720-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 12/23/2020] [Indexed: 11/10/2022] Open
Abstract
Mitochondrial movement in neurons is finely regulated to meet the local demand for energy and calcium buffering. Elaborate transport machinery including motor complexes is required to deliver and localize mitochondria to appropriate positions. Defects in mitochondrial transport are associated with various neurological disorders without a detailed mechanistic information. In this study, we present evidence that dystrobrevin-binding protein 1 (dysbindin), a schizophrenia-associated factor, plays a critical role in axonal mitochondrial movement. We observed that mitochondrial movement was impaired in dysbindin knockout mouse neurons. Reduced mitochondrial motility caused by dysbindin deficiency decreased the density of mitochondria in the distal part of axons. Moreover, the transport and distribution of mitochondria were regulated by the association between dysbindin and p150glued. Furthermore, altered mitochondrial distribution in axons led to disrupted calcium dynamics, showing abnormal calcium influx in presynaptic terminals. These data collectively suggest that dysbindin forms a functional complex with p150glued that regulates axonal mitochondrial transport, thereby affecting presynaptic calcium homeostasis.
Collapse
Affiliation(s)
- Bo Kyoung Suh
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Seol-Ae Lee
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Cana Park
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Republic of Korea
- Weill Institute of Neurosciences, Department of Neurology, University of California, San Francisco, San Francisco, USA
| | - Yeongjun Suh
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Soo Jeong Kim
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Youngsik Woo
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Truong Thi My Nhung
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Su Been Lee
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Dong Jin Mun
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Bon Seong Goo
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Hyun Sun Choi
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Republic of Korea
- Department of Chemical Engineering, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - So Jung Kim
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Sang Ki Park
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Republic of Korea.
| |
Collapse
|
5
|
Mice with dopaminergic neuron-specific deletion of DTNBP-1 gene show blunted nucleus accumbens dopamine release and associated behaviors. Neuropharmacology 2020; 184:108440. [PMID: 33340529 DOI: 10.1016/j.neuropharm.2020.108440] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 12/05/2020] [Accepted: 12/12/2020] [Indexed: 11/21/2022]
Abstract
Reduced expression of a schizophrenia-associated gene Dystrobrevin Binding Protein 1 (DTNBP1) and its protein product dysbindin-1, has been reported in the brains of schizophrenia patients. DTNBP1-null mutant Sdy (Sandy) mice exhibit several behavioral features relevant to schizophrenia. Changes in dopaminergic as well as glutamatergic and GABAergic neurotransmission in cortico-limbic regions have been reported in Sdy mice. Since dysbindin-1 is expressed in multiple brain regions, it is not known whether dopamine (DA) changes observed in Sdy null mutants are due to dysbindin-1 deficiency in DAergic neurons specifically. Here, using a mouse line with conditional knockout (cKO) of DTNBP1 in DA neurons, we studied the effects of dysbindin-1 deficiency on DA release and DA-dependent behaviors. Spontaneous locomotor activity of cKO mice in novel environment was significantly reduced initially but was comparable at later time points with littermate controls. However, the locomotion-enhancing effect of a low dose of d-amphetamine (d-AMPH; 2.5 mg/kg, ip) was significantly attenuated in the cKO mice suggesting a dampened mesolimbic DA transmission. Similarly, the prepulse inhibition disrupting effect of d-AMPH was found to be significantly reduced in the mutant mice. No significant differences between the cKO and control mice were observed in tests of anxiety, spatial learning and memory and social interaction. In- vivo microdialysis in the nucleus accumbens (NAc) showed a decrease in d-AMPH-induced extracellular DA release in the cKO mice. No significant alterations in protein levels of DA transporter, phosphorylated CaM kinase-II or Akt308 in the NAc were observed in the cKO mice. Taken together, our data suggest an important role of dysbindin-1 in maintaining mesolimbic DA tone and call for further investigations identifying mechanisms linking dysbindin-1, DA and schizophrenia.
Collapse
|
6
|
Waddington JL, Zhen X, O'Tuathaigh CMP. Developmental Genes and Regulatory Proteins, Domains of Cognitive Impairment in Schizophrenia Spectrum Psychosis and Implications for Antipsychotic Drug Discovery: The Example of Dysbindin-1 Isoforms and Beyond. Front Pharmacol 2020; 10:1638. [PMID: 32063853 PMCID: PMC7000454 DOI: 10.3389/fphar.2019.01638] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2019] [Accepted: 12/16/2019] [Indexed: 12/19/2022] Open
Abstract
Alongside positive and negative symptomatology, deficits in working memory, attention, selective learning processes, and executive function have been widely documented in schizophrenia spectrum psychosis. These cognitive abnormalities are strongly associated with impairment across multiple function domains and are generally treatment-resistant. The DTNBP1 (dystrobrevin-binding protein-1) gene, encoding dysbindin, is considered a risk factor for schizophrenia and is associated with variation in cognitive function in both clinical and nonclinical samples. Downregulation of DTNBP1 expression in dorsolateral prefrontal cortex and hippocampal formation of patients with schizophrenia has been suggested to serve as a primary pathophysiological process. Described as a "hub," dysbindin is an important regulatory protein that is linked with multiple complexes in the brain and is involved in a wide variety of functions implicated in neurodevelopment and neuroplasticity. The expression pattern of the various dysbindin isoforms (-1A, -1B, -1C) changes depending upon stage of brain development, tissue areas and subcellular localizations, and can involve interaction with different protein partners. We review evidence describing how sequence variation in DTNBP1 isoforms has been differentially associated with schizophrenia-associated symptoms. We discuss results linking these isoform proteins, and their interacting molecular partners, with cognitive dysfunction in schizophrenia, including evidence from drosophila through to genetic mouse models of dysbindin function. Finally, we discuss preclinical evidence investigating the antipsychotic potential of molecules that influence dysbindin expression and functionality. These studies, and other recent work that has extended this approach to other developmental regulators, may facilitate identification of novel molecular pathways leading to improved antipsychotic treatments.
Collapse
Affiliation(s)
- John L Waddington
- School of Pharmacy and Biomolecular Sciences, Royal College of Surgeons in Ireland, Dublin, Ireland.,Jiangsu Key Laboratory of Translational Research & Therapy for Neuro-Psychiatric Disorders and Department of Pharmacology, College of Pharmaceutical Sciences, Soochow University, Suzhou, China
| | - Xuechu Zhen
- Jiangsu Key Laboratory of Translational Research & Therapy for Neuro-Psychiatric Disorders and Department of Pharmacology, College of Pharmaceutical Sciences, Soochow University, Suzhou, China
| | - Colm M P O'Tuathaigh
- School of Pharmacy and Biomolecular Sciences, Royal College of Surgeons in Ireland, Dublin, Ireland.,Medical Education Unit, School of Medicine, Brookfield Health Sciences Complex, University College Cork, Cork, Ireland
| |
Collapse
|
7
|
Trantham-Davidson H, Lavin A. Loss of dysbindin-1 affects GABAergic transmission in the PFC. Psychopharmacology (Berl) 2019; 236:3291-3300. [PMID: 31201475 PMCID: PMC6832803 DOI: 10.1007/s00213-019-05285-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Accepted: 05/24/2019] [Indexed: 10/26/2022]
Abstract
It has been shown that dystrobrevin-binding protein 1 gene that encodes the protein dysbindin-1 is associated with risk for cognitive deficits, and studies have shown decreases in glutamate and correlated decreases in dysbindin-1 protein in the prefrontal cortex (PFC) and hippocampus of post-mortem tissue from schizophrenia patients. The PFC and the hippocampus have been shown to play a fundamental role in cognition, and studies in dysbindin-1 null mice have shown alterations in NMDAR located in pyramidal neurons as well as perturbation in LTP and cognitive deficits. The balance between excitatory and inhibitory transmission is crucial for normal cognitive functions; however, there is a dearth of information regarding the effects of loss of dysbindin-1 in GABAergic transmission. Using in vitro whole-cell clamp recordings, Western blots, and immunohistochemistry, we report here that dysbindin-1-deficient mice exhibit a significant decrease in the frequency of sIPSCs and in the amplitude of mIPSCs and significant decreases in PV staining and protein level. These results suggest that loss of dysbindin-1 affects GABAergic transmission at pre- and postsynaptic level and decreases parvalbumin markers.
Collapse
Affiliation(s)
| | - A Lavin
- Department of Neuroscience, MUSC, Charleston, SC, 29425, USA.
| |
Collapse
|
8
|
Dysbindin-1 contributes to prefrontal cortical dendritic arbor pathology in schizophrenia. Schizophr Res 2018; 201:270-277. [PMID: 29759351 PMCID: PMC6230503 DOI: 10.1016/j.schres.2018.04.042] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 04/20/2018] [Accepted: 04/29/2018] [Indexed: 01/22/2023]
Abstract
Deep layer III pyramidal cells in the dorsolateral prefrontal cortex (DLPFC) from subjects with schizophrenia and bipolar disorder previously were shown to exhibit dendritic arbor pathology. This study sought to determine whether MARCKS, its regulatory protein dysbindin-1, and two proteins, identified using microarray data, CDC42BPA and ARHGEF6, were associated with dendritic arbor pathology in the DLPFC from schizophrenia and bipolar disorder subjects. Using western blotting, relative protein expression was assessed in the DLPFC (BA 46) grey matter from subjects with schizophrenia (n = 19), bipolar disorder (n = 17) and unaffected control subjects (n = 19). Protein expression data were then correlated with dendritic parameter data obtained previously. MARCKS and dysbindin-1a expression levels did not differ among the three groups. Dysbindin-1b expression was 26% higher in schizophrenia subjects (p = 0.01) and correlated inversely with basilar dendrite length (r = -0.31, p = 0.048) and the number of spines per basilar dendrite (r = -0.31, p = 0.048), but not with dendritic spine density (r = -0.16, p = 0.32). The protein expression of CDC42BPA was 33% higher in schizophrenia subjects (p = 0.03) but, did not correlate with any dendritic parameter (p > 0.05). ARHGEF6 87 kDa isoform expression did not differ among the groups. CDC42BPA expression was not altered in frontal cortex from rats chronically administered haloperidol or clozapine. Dysbindin-1b appears to play a role in dendritic arbor pathology observed previously in the DLPFC in schizophrenia.
Collapse
|
9
|
Ito A, Fukaya M, Saegusa S, Kobayashi E, Sugawara T, Hara Y, Yamauchi J, Okamoto H, Sakagami H. Pallidin is a novel interacting protein for cytohesin-2 and regulates the early endosomal pathway and dendritic formation in neurons. J Neurochem 2018; 147:153-177. [PMID: 30151872 DOI: 10.1111/jnc.14579] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 07/25/2018] [Accepted: 08/21/2018] [Indexed: 12/29/2022]
Abstract
Cytohesin-2 is a member of the guanine nucleotide exchange factors for ADP ribosylation factor 1 (Arf1) and Arf6, which are small GTPases that regulate membrane traffic and actin dynamics. In this study, we first demonstrated that cytohesin-2 localized to the plasma membrane and vesicles in various subcellular compartment in hippocampal neurons by immunoelectron microscopy. Next, to understand the molecular network of cytohesin-2 in neurons, we conducted yeast two-hybrid screening of brain cDNA libraries using cytohesin-2 as bait and isolated pallidin, a component of the biogenesis of lysosome-related organelles complex 1 (BLOC-1) involved in endosomal trafficking. Pallidin interacted specifically with cytohesin-2 among cytohesin family members. Glutathione S-transferase pull-down and immunoprecipitation assays further confirmed the formation of a protein complex between cytohesin-2 and pallidin. Immunofluorescence demonstrated that cytohesin-2 and pallidin partially colocalized in various subsets of endosomes immunopositive for EEA1, syntaxin 12, and LAMP2 in hippocampal neurons. Knockdown of pallidin or cytohesin-2 reduced cytoplasmic EEA1-positive early endosomes. Furthermore, knockdown of pallidin increased the total dendritic length of cultured hippocampal neurons, which was rescued by co-expression of wild-type pallidin but not a mutant lacking the ability to interact with cytohesin-2. In contrast, knockdown of cytohesin-2 had the opposite effect on total dendritic length. The present results suggested that the interaction between pallidin and cytohesin-2 may participate in various neuronal functions such as endosomal trafficking and dendritic formation in hippocampal neurons. Cover Image for this issue: doi: 10.1111/jnc.14197.
Collapse
Affiliation(s)
- Akiko Ito
- Department of Anatomy, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan.,Department of Anesthesiology, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| | - Masahiro Fukaya
- Department of Anatomy, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| | - Shintaro Saegusa
- Department of Anatomy, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| | - Emi Kobayashi
- Department of Anatomy, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| | - Takeyuki Sugawara
- Department of Anatomy, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| | - Yoshinobu Hara
- Department of Anatomy, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| | - Junji Yamauchi
- Laboratory of Molecular Neuroscience and Neurology, School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, Japan
| | - Hirotsugu Okamoto
- Department of Anesthesiology, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| | - Hiroyuki Sakagami
- Department of Anatomy, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| |
Collapse
|
10
|
Nikiforuk A. Assessment of cognitive functions in animal models of schizophrenia. Pharmacol Rep 2018; 70:639-649. [DOI: 10.1016/j.pharep.2018.01.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 01/19/2018] [Accepted: 01/31/2018] [Indexed: 12/16/2022]
|
11
|
Shi L, Hines T, Bergson C, Smith D. Coupling of microtubule motors with AP-3 generated organelles in axons by NEEP21 family member calcyon. Mol Biol Cell 2018; 29:2055-2068. [PMID: 29949458 PMCID: PMC6232961 DOI: 10.1091/mbc.e18-01-0007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Transport of late endosomes and lysosome-related organelles (LE/LROs) in axons is essential for supplying synaptic cargoes and for removing damaged macromolecules. Defects in this system are implicated in a range of human neurodegenerative and neurodevelopmental disorders. The findings reported here identify a novel mechanism regulating LE/LRO transport based on the coordinated coupling of microtubule motors and vesicle coat proteins to the neuron-enriched, transmembrane protein calcyon (Caly). We found that the cytoplasmic C-terminus of Caly pulled down proteins involved in microtubule-dependent transport (DIC, KIF5A, p150Glued, Lis1) and organelle biogenesis (AP-1 and AP-3) from the brain. In addition, RNA interference-mediated knockdown of Caly increased the percentage of static LE/LROs labeled by LysoTracker in cultured dorsal root ganglion axons. In contrast, overexpression of Caly stimulated movement of organelles positive for LysoTracker or the AP-3 cargo GFP-PI4KIIα. However, a Caly mutant (ATEA) that does not bind AP-3 was unable to pull down motor proteins from brain, and expression of the ATEA mutant failed to increase either LE/LRO flux or levels of associated dynein. Taken together, these data support the hypothesis that Caly is a multifunctional scaffolding protein that regulates axonal transport of LE/LROs by coordinately interacting with motor and vesicle coat proteins.
Collapse
Affiliation(s)
- Liang Shi
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA 30912
| | - Timothy Hines
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208
| | - Clare Bergson
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA 30912
| | - Deanna Smith
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208
| |
Collapse
|
12
|
Chang EH, Fernando K, Yeung LWE, Barbari K, Chandon TSS, Malhotra AK. Single point mutation on the gene encoding dysbindin results in recognition deficits. GENES BRAIN AND BEHAVIOR 2018; 17:e12449. [PMID: 29227583 DOI: 10.1111/gbb.12449] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 11/14/2017] [Accepted: 12/07/2017] [Indexed: 11/30/2022]
Abstract
The dystrobrevin-binding protein 1 (DTNBP1) gene is a candidate risk factor for schizophrenia and has been associated with cognitive ability in both patient populations and healthy controls. DTNBP1 encodes dysbindin protein, which is localized to synaptic sites and is reduced in the prefrontal cortex and hippocampus of patients with schizophrenia, indicating a potential role in schizophrenia etiology. Most studies of dysbindin function have focused on the sandy (sdy) mice that lack dysbindin protein and have a wide range of abnormalities. In this study, we examined dysbindin salt and pepper (spp) mice that possess a single point mutation on the Dtnbp1 gene predicted to reduce, but not eliminate, dysbindin expression. By western blot analysis, we found that spp homozygous (spp -/-) mutants had reduced dysbindin and synaptosomal-associated protein 25 (SNAP-25) in the prefrontal cortex, but unaltered levels in hippocampus. Behaviorally, spp mutants performed comparably to controls on a wide range of tasks assessing locomotion, anxiety, spatial recognition and working memory. However, spp -/- mice had selective deficits in tasks measuring novel object recognition and social novelty recognition. Our results indicate that reduced dysbindin and SNAP-25 protein in the prefrontal cortex of spp -/- is associated with selective impairments in recognition processing. These spp mice may prove useful as a novel mouse model to study cognitive deficits linked to dysbindin alterations. Our findings also suggest that aspects of recognition memory may be specifically influenced by DTNBP1 single nucleotide polymorphisms or risk haplotypes in humans and this connection should be further investigated.
Collapse
Affiliation(s)
- E H Chang
- Center for Psychiatric Neuroscience, The Feinstein Institute for Medical Research, Northwell Health, Manhasset, New York.,Division of Psychiatry Research, Zucker Hillside Hospital, Northwell Health, Glen Oaks, New York.,Department of Psychiatry, Hofstra Northwell School of Medicine, Hofstra University, Hempstead, New York.,Department of Molecular Medicine, Hofstra Northwell School of Medicine, Hofstra University, Hempstead, New York
| | - K Fernando
- Center for Psychiatric Neuroscience, The Feinstein Institute for Medical Research, Northwell Health, Manhasset, New York.,Division of Psychiatry Research, Zucker Hillside Hospital, Northwell Health, Glen Oaks, New York
| | - L W E Yeung
- Center for Psychiatric Neuroscience, The Feinstein Institute for Medical Research, Northwell Health, Manhasset, New York.,Division of Psychiatry Research, Zucker Hillside Hospital, Northwell Health, Glen Oaks, New York
| | - K Barbari
- Center for Psychiatric Neuroscience, The Feinstein Institute for Medical Research, Northwell Health, Manhasset, New York.,Division of Psychiatry Research, Zucker Hillside Hospital, Northwell Health, Glen Oaks, New York
| | - T-S S Chandon
- Center for Psychiatric Neuroscience, The Feinstein Institute for Medical Research, Northwell Health, Manhasset, New York.,Division of Psychiatry Research, Zucker Hillside Hospital, Northwell Health, Glen Oaks, New York
| | - A K Malhotra
- Center for Psychiatric Neuroscience, The Feinstein Institute for Medical Research, Northwell Health, Manhasset, New York.,Division of Psychiatry Research, Zucker Hillside Hospital, Northwell Health, Glen Oaks, New York.,Department of Psychiatry, Hofstra Northwell School of Medicine, Hofstra University, Hempstead, New York.,Department of Molecular Medicine, Hofstra Northwell School of Medicine, Hofstra University, Hempstead, New York
| |
Collapse
|
13
|
Dysbindin-1 Involvement in the Etiology of Schizophrenia. Int J Mol Sci 2017; 18:ijms18102044. [PMID: 28937620 PMCID: PMC5666726 DOI: 10.3390/ijms18102044] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Revised: 09/16/2017] [Accepted: 09/19/2017] [Indexed: 12/13/2022] Open
Abstract
Schizophrenia is a major psychiatric disorder that afflicts about 1% of the world’s population, falling into the top 10 medical disorders causing disability. Existing therapeutic strategies have had limited success on cognitive impairment and long-term disability and are burdened by side effects. Although new antipsychotic medications have been launched in the past decades, there has been a general lack of significant innovation. This lack of significant progress in the pharmacotherapy of schizophrenia is a reflection of the complexity and heterogeneity of the disease. To date, many susceptibility genes have been identified to be associated with schizophrenia. DTNBP1 gene, which encodes dysbindin-1, has been linked to schizophrenia in multiple populations. Studies on genetic variations show that DTNBP1 modulate prefrontal brain functions and psychiatric phenotypes. Dysbindin-1 is enriched in the dorsolateral prefrontal cortex and hippocampus, while postmortem brain studies of individuals with schizophrenia show decreased levels of dysbindin-1 mRNA and protein in these brain regions. These studies proposed a strong connection between dysbindin-1 function and the pathogenesis of disease. Dysbindin-1 protein was localized at both pre- and post-synaptic sites, where it regulates neurotransmitter release and receptors signaling. Moreover, dysbindin-1 has also been found to be involved in neuronal development. Reduced expression levels of dysbindin-1 mRNA and protein appear to be common in dysfunctional brain areas of schizophrenic patients. The present review addresses our current knowledge of dysbindin-1 with emphasis on its potential role in the schizophrenia pathology. We propose that dysbindin-1 and its signaling pathways may constitute potential therapeutic targets in the therapy of schizophrenia.
Collapse
|
14
|
O'Tuathaigh CMP, Moran PM, Zhen XC, Waddington JL. Translating advances in the molecular basis of schizophrenia into novel cognitive treatment strategies. Br J Pharmacol 2017; 174:3173-3190. [PMID: 28667666 DOI: 10.1111/bph.13938] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 06/07/2017] [Accepted: 06/12/2017] [Indexed: 02/06/2023] Open
Abstract
The presence and severity of cognitive symptoms, including working memory, executive dysfunction and attentional impairment, contributes materially to functional impairment in schizophrenia. Cognitive symptoms have proved to be resistant to both first- and second-generation antipsychotic drugs. Efforts to develop a consensus set of cognitive domains that are both disrupted in schizophrenia and are amenable to cross-species validation (e.g. the National Institute of Mental Health Cognitive Neuroscience Treatment Research to Improve Cognition in Schizophrenia and Research Domain Criteria initiatives) are an important step towards standardization of outcome measures that can be used in preclinical testing of new drugs. While causative genetic mutations have not been identified, new technologies have identified novel genes as well as hitherto candidate genes previously implicated in the pathophysiology of schizophrenia and/or mechanisms of antipsychotic efficacy. This review comprises a selective summary of these developments, particularly phenotypic data arising from preclinical genetic models for cognitive dysfunction in schizophrenia, with the aim of indicating potential new directions for pro-cognitive therapeutics. Linked Articles This article is part of a themed section on Pharmacology of Cognition: a Panacea for Neuropsychiatric Disease? To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.19/issuetoc.
Collapse
Affiliation(s)
- Colm M P O'Tuathaigh
- School of Medicine, University College Cork, Brookfield Health Sciences Complex, Cork, Ireland
| | - Paula M Moran
- School of Psychology, University of Nottingham, Nottingham, UK
| | - Xuechu C Zhen
- Jiangsu Key Laboratory of Translational Research & Therapy for Neuropsychiatric Disorders and Department of Pharmacology, College of Pharmaceutical Sciences, Soochow University, Suzhou, China
| | - John L Waddington
- Jiangsu Key Laboratory of Translational Research & Therapy for Neuropsychiatric Disorders and Department of Pharmacology, College of Pharmaceutical Sciences, Soochow University, Suzhou, China.,Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin 2, Ireland
| |
Collapse
|
15
|
The Proteome of BLOC-1 Genetic Defects Identifies the Arp2/3 Actin Polymerization Complex to Function Downstream of the Schizophrenia Susceptibility Factor Dysbindin at the Synapse. J Neurosci 2017; 36:12393-12411. [PMID: 27927957 DOI: 10.1523/jneurosci.1321-16.2016] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Revised: 10/01/2016] [Accepted: 10/20/2016] [Indexed: 12/16/2022] Open
Abstract
Proteome modifications downstream of monogenic or polygenic disorders have the potential to uncover novel molecular mechanisms participating in pathogenesis and/or extragenic modification of phenotypic expression. We tested this idea by determining the proteome sensitive to genetic defects in a locus encoding dysbindin, a protein required for synapse biology and implicated in schizophrenia risk. We applied quantitative mass spectrometry to identify proteins expressed in neuronal cells the abundance of which was altered after downregulation of the schizophrenia susceptibility factor dysbindin (Bloc1s8) or two other dysbindin-interacting polypeptides, which assemble into the octameric biogenesis of lysosome-related organelles complex 1 (BLOC-1). We found 491 proteins sensitive to dysbindin and BLOC-1 loss of function. Gene ontology of these 491 proteins singled out the actin cytoskeleton and the actin polymerization factor, the Arp2/3 complex, as top statistical molecular pathways contained within the BLOC-1-sensitive proteome. Subunits of the Arp2/3 complex were downregulated by BLOC-1 loss of function, thus affecting actin dynamics in early endosomes of BLOC-1-deficient cells. Furthermore, we demonstrated that Arp2/3, dysbindin, and subunits of the BLOC-1 complex biochemically and genetically interact, modulating Drosophila melanogaster synapse morphology and homeostatic synaptic plasticity. Our results indicate that ontologically prioritized proteomics identifies novel pathways that modify synaptic phenotypes associated with neurodevelopmental disorder gene defects. SIGNIFICANCE STATEMENT The mechanisms associated with schizophrenia are mostly unknown despite the increasing number of genetic loci identified that increase disease risk. We present an experimental strategy that impartially and comprehensively interrogates the proteome of neurons to identify effects of genetic mutations in a schizophrenia risk factor, dysbindin. We find that the expression of the actin polymerization complex Arp2/3 is reduced in dysbindin-deficient cells, thus affecting actin-dependent phenotypes in two cellular compartments where dysbindin resides, endosomes and presynapses. Our studies indicate that a central cellular structure affected by schizophrenia susceptibility loci is the actin cytoskeleton, an organelle necessary for synaptic function in the presynaptic and postsynaptic compartment.
Collapse
|
16
|
Larimore J, Zlatic SA, Arnold M, Singleton KS, Cross R, Rudolph H, Bruegge MV, Sweetman A, Garza C, Whisnant E, Faundez V. Dysbindin Deficiency Modifies the Expression of GABA Neuron and Ion Permeation Transcripts in the Developing Hippocampus. Front Genet 2017; 8:28. [PMID: 28344592 PMCID: PMC5344932 DOI: 10.3389/fgene.2017.00028] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 02/20/2017] [Indexed: 12/25/2022] Open
Abstract
The neurodevelopmental factor dysbindin is required for synapse function and GABA interneuron development. Dysbindin protein levels are reduced in the hippocampus of schizophrenia patients. Mouse dysbindin genetic defects and other mouse models of neurodevelopmental disorders share defective GABAergic neurotransmission and, in several instances, a loss of parvalbumin-positive interneuron phenotypes. This suggests that mechanisms downstream of dysbindin deficiency, such as those affecting GABA interneurons, could inform pathways contributing to or ameliorating diverse neurodevelopmental disorders. Here we define the transcriptome of developing wild type and dysbindin null Bloc1s8sdy/sdy mouse hippocampus in order to identify mechanisms downstream dysbindin defects. The dysbindin mutant transcriptome revealed previously reported GABA parvalbumin interneuron defects. However, the Bloc1s8sdy/sdy transcriptome additionally uncovered changes in the expression of molecules controlling cellular excitability such as the cation-chloride cotransporters NKCC1, KCC2, and NCKX2 as well as the potassium channel subunits Kcne2 and Kcnj13. Our results suggest that dysbindin deficiency phenotypes, such as GABAergic defects, are modulated by the expression of molecules controlling the magnitude and cadence of neuronal excitability.
Collapse
Affiliation(s)
| | | | - Miranda Arnold
- Department of Biology, Agnes-Scott College, Decatur, GA, USA
| | | | - Rebecca Cross
- Department of Biology, Agnes-Scott College, Decatur, GA, USA
| | - Hannah Rudolph
- Department of Biology, Agnes-Scott College, Decatur, GA, USA
| | | | - Andrea Sweetman
- Department of Biology, Agnes-Scott College, Decatur, GA, USA
| | - Cecilia Garza
- Department of Biology, Agnes-Scott College, Decatur, GA, USA
| | - Eli Whisnant
- Department of Biology, Agnes-Scott College, Decatur, GA, USA
| | - Victor Faundez
- Department of Cell Biology, Emory University, Atlanta, GA, USA
| |
Collapse
|
17
|
Bueno-Junior LS, Ruggiero RN, Rossignoli MT, Del Bel EA, Leite JP, Uchitel OD. Acetazolamide potentiates the afferent drive to prefrontal cortex in vivo. Physiol Rep 2017; 5:5/1/e13066. [PMID: 28087816 PMCID: PMC5256155 DOI: 10.14814/phy2.13066] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Accepted: 11/14/2016] [Indexed: 11/24/2022] Open
Abstract
The knowledge on real-time neurophysiological effects of acetazolamide is still far behind the wide clinical use of this drug. Acetazolamide - a carbonic anhydrase inhibitor - has been shown to affect the neuromuscular transmission, implying a pH-mediated influence on the central synaptic transmission. To start filling such a gap, we chose a central substrate: hippocampal-prefrontal cortical projections; and a synaptic phenomenon: paired-pulse facilitation (a form of synaptic plasticity) to probe this drug's effects on interareal brain communication in chronically implanted rats. We observed that systemic acetazolamide potentiates the hippocampal-prefrontal paired-pulse facilitation. In addition to this field electrophysiology data, we found that acetazolamide exerts a net inhibitory effect on prefrontal cortical single-unit firing. We propose that systemic acetazolamide reduces the basal neuronal activity of the prefrontal cortex, whereas increasing the afferent drive it receives from the hippocampus. In addition to being relevant to the clinical and side effects of acetazolamide, these results suggest that exogenous pH regulation can have diverse impacts on afferent signaling across the neocortex.
Collapse
Affiliation(s)
- Lezio S Bueno-Junior
- Department of Neuroscience and Behavioral Sciences, Ribeirao Preto Medical School University of Sao Paulo, Ribeirao Preto, Brazil
| | - Rafael N Ruggiero
- Department of Neuroscience and Behavioral Sciences, Ribeirao Preto Medical School University of Sao Paulo, Ribeirao Preto, Brazil
| | - Matheus T Rossignoli
- Department of Neuroscience and Behavioral Sciences, Ribeirao Preto Medical School University of Sao Paulo, Ribeirao Preto, Brazil
| | - Elaine A Del Bel
- Department of Morphology, Physiology and Stomatology, Dentistry School of Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, Brazil
| | - Joao P Leite
- Department of Neuroscience and Behavioral Sciences, Ribeirao Preto Medical School University of Sao Paulo, Ribeirao Preto, Brazil
| | - Osvaldo D Uchitel
- Department of Physiology, Molecular and Cell Biology, Institute of Physiology Molecular Biology and Neuroscience University of Buenos Aires, Buenos Aires, Argentina
| |
Collapse
|
18
|
Cope ZA, Powell SB, Young JW. Modeling neurodevelopmental cognitive deficits in tasks with cross-species translational validity. GENES BRAIN AND BEHAVIOR 2016; 15:27-44. [PMID: 26667374 DOI: 10.1111/gbb.12268] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 10/14/2015] [Accepted: 10/27/2015] [Indexed: 12/24/2022]
Abstract
Numerous psychiatric disorders whose cognitive dysfunction links to functional outcome have neurodevelopmental origins including schizophrenia, autism and bipolar disorder. Treatments are needed for these cognitive deficits, which require development using animal models. Models of neurodevelopmental disorders are as varied and diverse as the disorders themselves, recreating some but not all aspects of the disorder. This variety may in part underlie why purported procognitive treatments translated from these models have failed to restore functioning in the targeted patient populations. Further complications arise from environmental factors used in these models that can contribute to numerous disorders, perhaps only impacting specific domains, while diagnostic boundaries define individual disorders, limiting translational efficacy. The Research Domain Criteria project seeks to 'develop new ways to classify mental disorders based on behavioral dimensions and neurobiological measures' in hopes of facilitating translational research by remaining agnostic toward diagnostic borders derived from clinical presentation in humans. Models could therefore recreate biosignatures of cognitive dysfunction irrespective of disease state. This review highlights work within the field of neurodevelopmental models of psychiatric disorders tested in cross-species translational cognitive paradigms that directly inform this newly developing research strategy. By expounding on this approach, the hopes are that a fuller understanding of each model may be attainable in terms of the cognitive profile elicited by each manipulation. Hence, conclusions may begin to be drawn on the nature of cognitive neuropathology on neurodevelopmental and other disorders, increasing the chances of procognitive treatment development for individuals affected in specific cognitive domains.
Collapse
Affiliation(s)
- Z A Cope
- Department of Psychiatry, University of California San Diego, La Jolla
| | - S B Powell
- Department of Psychiatry, University of California San Diego, La Jolla.,Research Service, VA San Diego Healthcare System, San Diego, CA, USA
| | - J W Young
- Department of Psychiatry, University of California San Diego, La Jolla.,Research Service, VA San Diego Healthcare System, San Diego, CA, USA
| |
Collapse
|
19
|
Gene × Environment Interactions in Schizophrenia: Evidence from Genetic Mouse Models. Neural Plast 2016; 2016:2173748. [PMID: 27725886 PMCID: PMC5048038 DOI: 10.1155/2016/2173748] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2016] [Revised: 07/20/2016] [Accepted: 08/21/2016] [Indexed: 02/06/2023] Open
Abstract
The study of gene × environment, as well as epistatic interactions in schizophrenia, has provided important insight into the complex etiopathologic basis of schizophrenia. It has also increased our understanding of the role of susceptibility genes in the disorder and is an important consideration as we seek to translate genetic advances into novel antipsychotic treatment targets. This review summarises data arising from research involving the modelling of gene × environment interactions in schizophrenia using preclinical genetic models. Evidence for synergistic effects on the expression of schizophrenia-relevant endophenotypes will be discussed. It is proposed that valid and multifactorial preclinical models are important tools for identifying critical areas, as well as underlying mechanisms, of convergence of genetic and environmental risk factors, and their interaction in schizophrenia.
Collapse
|
20
|
Yuan Q, Yang F, Xiao Y, Tan S, Husain N, Ren M, Hu Z, Martinowich K, Ng JS, Kim PJ, Han W, Nagata KI, Weinberger DR, Je HS. Regulation of Brain-Derived Neurotrophic Factor Exocytosis and Gamma-Aminobutyric Acidergic Interneuron Synapse by the Schizophrenia Susceptibility Gene Dysbindin-1. Biol Psychiatry 2016; 80:312-322. [PMID: 26386481 DOI: 10.1016/j.biopsych.2015.08.019] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Revised: 08/12/2015] [Accepted: 08/12/2015] [Indexed: 10/23/2022]
Abstract
BACKGROUND Genetic variations in dystrobrevin binding protein 1 (DTNBP1 or dysbindin-1) have been implicated as risk factors in the pathogenesis of schizophrenia. The encoded protein dysbindin-1 functions in the regulation of synaptic activity and synapse development. Intriguingly, a loss of function mutation in Dtnbp1 in mice disrupted both glutamatergic and gamma-aminobutyric acidergic transmission in the cerebral cortex; pyramidal neurons displayed enhanced excitability due to reductions in inhibitory synaptic inputs. However, the mechanism by which reduced dysbindin-1 activity causes inhibitory synaptic deficits remains unknown. METHODS We investigated the role of dysbindin-1 in the exocytosis of brain-derived neurotrophic factor (BDNF) from cortical excitatory neurons, organotypic brain slices, and acute slices from dysbindin-1 mutant mice and determined how this change in BDNF exocytosis transsynaptically affected the number of inhibitory synapses formed on excitatory neurons via whole-cell recordings, immunohistochemistry, and live-cell imaging using total internal reflection fluorescence microscopy. RESULTS A decrease in dysbindin-1 reduces the exocytosis of BDNF from cortical excitatory neurons, and this reduction in BDNF exocytosis transsynaptically resulted in reduced inhibitory synapse numbers formed on excitatory neurons. Furthermore, application of exogenous BDNF rescued the inhibitory synaptic deficits caused by the reduced dysbindin-1 level in both cultured cortical neurons and slice cultures. CONCLUSIONS Taken together, our results demonstrate that these two genes linked to risk for schizophrenia (BDNF and dysbindin-1) function together to regulate interneuron development and cortical network activity. This evidence supports the investigation of the association between dysbindin-1 and BDNF in humans with schizophrenia.
Collapse
Affiliation(s)
- Qiang Yuan
- Molecular Neurophysiology Laboratory, Signature Program in Neuroscience and Behavioral Disorders, Duke-National University of Singapore Graduate Medical School, Singapore, Singapore
| | - Feng Yang
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, Maryland
| | - Yixin Xiao
- Molecular Neurophysiology Laboratory, Signature Program in Neuroscience and Behavioral Disorders, Duke-National University of Singapore Graduate Medical School, Singapore, Singapore
| | - Shawn Tan
- Molecular Neurophysiology Laboratory, Signature Program in Neuroscience and Behavioral Disorders, Duke-National University of Singapore Graduate Medical School, Singapore, Singapore
| | - Nilofer Husain
- Molecular Neurophysiology Laboratory, Signature Program in Neuroscience and Behavioral Disorders, Duke-National University of Singapore Graduate Medical School, Singapore, Singapore
| | - Ming Ren
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, Maryland
| | - Zhonghua Hu
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, Maryland
| | - Keri Martinowich
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, Maryland
| | - Julia S Ng
- Molecular Neurophysiology Laboratory, Signature Program in Neuroscience and Behavioral Disorders, Duke-National University of Singapore Graduate Medical School, Singapore, Singapore
| | - Paul J Kim
- Molecular Neurophysiology Laboratory, Signature Program in Neuroscience and Behavioral Disorders, Duke-National University of Singapore Graduate Medical School, Singapore, Singapore
| | - Weiping Han
- Singapore Bioimaging Consortium, Singapore, Singapore
| | - Koh-Ichi Nagata
- Institute for Developmental Research, Aichi Human Service Center, Kasugai, Japan
| | - Daniel R Weinberger
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, Maryland
| | - H Shawn Je
- Molecular Neurophysiology Laboratory, Signature Program in Neuroscience and Behavioral Disorders, Duke-National University of Singapore Graduate Medical School, Singapore, Singapore; Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
| |
Collapse
|
21
|
Becker-Krail D, Farrand AQ, Boger HA, Lavin A. Effects of fingolimod administration in a genetic model of cognitive deficits. J Neurosci Res 2016; 95:1174-1181. [PMID: 27439747 DOI: 10.1002/jnr.23799] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 05/23/2016] [Accepted: 05/30/2016] [Indexed: 11/09/2022]
Abstract
Notwithstanding recent advances, cognitive impairments are among the most difficult-to-treat symptoms in neuropsychiatric disorders. Deficits in information processing contributing to memory and sociability impairments are found across neuropsychiatric-related disorders. Previously, we have shown that mutations in the DTNBP1 gene (encoding dystrobrevin-binding protein 1 [dysbindin-1]) lead to abnormalities in synaptic glutamate release in the prefrontal cortex (PFC) and hippocampus and to cognitive deficits; glutamatergic transmission is important for cortical recurrent excitation that allows information processing in the PFC. To investigate possible means of restoring glutamate release and improving cognitive impairments, we assess the effects of increasing endogenous levels of brain-derived neurotrophic factor (BDNF) in a dysbindin-1-deficient mouse model. Increasing endogenous levels of BDNF may aid in remediating cognitive deficits, given the roles of BDNF in synaptic transmission, plasticity, and neuroprotection. To increase BDNF, we use a novel strategy, repeated intraperitoneal injections of fingolimod (Gilenya). Sphingolipids have recently been shown to have therapeutic value in several neurology-related disorders. Both wild-type (WT) and mutant (MUT) genotypes were tested for sociability and recognition memory, followed by measuring endogenous BDNF levels and presynaptic [Ca2+ ]i within the PFC. Both genotypes were treated for 1 week with either saline or fingolimod. Relative to WT mice, MUT mice demonstrated impairments in sociability and recognition memory and lower presynaptic calcium. After fingolimod treatment, MUT mice exhibited significant improvements in sociability and recognition memory and increases in presynaptic calcium and endogenous concentrations of BDNF. These results show promise for counteracting the cognitive impairments seen in neuropsychiatric disorders and may shed light on the role of dysbindin-1. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
| | - A Q Farrand
- Deptartment of Neuroscience, Medical University of South Carolina, Charleston, South Carolina
| | - H A Boger
- Deptartment of Neuroscience, Medical University of South Carolina, Charleston, South Carolina
| | - A Lavin
- Deptartment of Neuroscience, Medical University of South Carolina, Charleston, South Carolina
| |
Collapse
|
22
|
Ito H, Morishita R, Nagata KI. Schizophrenia susceptibility gene product dysbindin-1 regulates the homeostasis of cyclin D1. Biochim Biophys Acta Mol Basis Dis 2016; 1862:1383-91. [PMID: 27130439 DOI: 10.1016/j.bbadis.2016.04.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Revised: 04/08/2016] [Accepted: 04/22/2016] [Indexed: 12/18/2022]
Abstract
Dysbindin-1 (dystrobrevin binding protein-1, DTNBP1) is now widely accepted as a potential schizophrenia susceptibility gene and accumulating evidence indicates its functions in the neural development. In this study, we tried to identify new binding partners for dysbindin-1 to clarify the novel function of this molecule. When consulted with BioGRID protein interaction database, cyclin D3 was found to be a possible binding partner for dysbindin-1. We then examined the interaction between various dysbindin-1 isoforms (dysbindin-1A, -1B and -1C) and all three D-type cyclins (cyclin D1, D2, and D3) by immunoprecipitation with the COS7 cell expression system, and found that dysbindin-1A preferentially interacts with cyclin D1. The mode of interaction between these molecules was considered as direct binding since recombinant dysbindin-1A and cyclin D1 formed a complex in vitro. Mapping analyses revealed that the C-terminal region of dysbindin-1A binds to the C-terminal of cyclin D1. Consistent with the results of the biochemical analyses, endogenous dysbindin-1was partially colocalized with cyclin D1 in NIH3T3 fibroblast cells and in neuronal stem and/or progenitor cells in embryonic mouse brain. While co-expression of dysbindin-1A with cyclin D1 changed the localization of the latter from the nucleus to cytosol, cyclin D1-binding partner CDK4 inhibited the dysbindin-cyclin D1 interaction. Meanwhile, depletion of endogenous dysbindin-1A increased cyclin D1 expression. These results indicate that dysbindin-1A may control the cyclin D1 function spatiotemporally and might contribute to better understanding of the pathophysiology of dysbindin-1-associated disorders.
Collapse
Affiliation(s)
- Hidenori Ito
- Department of Molecular Neurobiology, Institute for Developmental Research, Aichi Human Service Center, Kasugai, Japan
| | - Rika Morishita
- Department of Molecular Neurobiology, Institute for Developmental Research, Aichi Human Service Center, Kasugai, Japan
| | - Koh-Ichi Nagata
- Department of Molecular Neurobiology, Institute for Developmental Research, Aichi Human Service Center, Kasugai, Japan; Department of Neurochemistry, Nagoya University Graduate School of Medicine, Nagoya, Japan.
| |
Collapse
|
23
|
O'Tuathaigh CMP, Desbonnet L, Moran PM, Kirby BP, Waddington JL. Molecular genetic models related to schizophrenia and psychotic illness: heuristics and challenges. Curr Top Behav Neurosci 2016; 7:87-119. [PMID: 21298380 DOI: 10.1007/7854_2010_111] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Schizophrenia is a heritable disorder that may involve several common genes of small effect and/or rare copy number variation, with phenotypic heterogeneity across patients. Furthermore, any boundaries vis-à-vis other psychotic disorders are far from clear. Consequently, identification of informative animal models for this disorder, which typically relate to pharmacological and putative pathophysiological processes of uncertain validity, faces considerable challenges. In juxtaposition, the majority of mutant models for schizophrenia relate to the functional roles of a diverse set of genes associated with risk for the disorder or with such putative pathophysiological processes. This chapter seeks to outline the evidence from phenotypic studies in mutant models related to schizophrenia. These have commonly assessed the degree to which mutation of a schizophrenia-related gene is associated with the expression of several aspects of the schizophrenia phenotype or more circumscribed, schizophrenia-related endophenotypes; typically, they place specific emphasis on positive and negative symptoms and cognitive deficits, and extend to structural and other pathological features. We first consider the primary technological approaches to the generation of such mutants, to include their relative merits and demerits, and then highlight the diverse phenotypic approaches that have been developed for their assessment. The chapter then considers the application of mutant phenotypes to study pathobiological and pharmacological mechanisms thought to be relevant for schizophrenia, particularly in terms of dopaminergic and glutamatergic dysfunction, and to an increasing range of candidate susceptibility genes and copy number variants. Finally, we discuss several pertinent issues and challenges within the field which relate to both phenotypic evaluation and a growing appreciation of the functional genomics of schizophrenia and the involvement of gene × environment interactions.
Collapse
Affiliation(s)
- Colm M P O'Tuathaigh
- Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, 123 St. Stephen's Green, Dublin 2, Ireland,
| | | | | | | | | |
Collapse
|
24
|
Schwarz E, Tost H, Meyer-Lindenberg A. Working memory genetics in schizophrenia and related disorders: An RDoC perspective. Am J Med Genet B Neuropsychiatr Genet 2016; 171B:121-31. [PMID: 26365198 DOI: 10.1002/ajmg.b.32353] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Accepted: 07/08/2015] [Indexed: 12/29/2022]
Abstract
Improved classification of mental disorders through neurobiological measures will require a set of traits that map to transdiagnostic subgroups of patients and align with heritable, core psychopathological processes at the center of the disorders of interest. A promising candidate is working memory (WM) function, for which deficits have been reported across multiple diagnostic entities including schizophrenia, bipolar disorder, ADHD, autism, and major depressive disorder. Here we review genetic working memory associations and their brain functional correlates from the perspective of identifying patient subgroups across conventional diagnostic boundaries, explore the utility of multimodal investigations integrating functional information at the neural systems level and explore potential limitations as well as future directions for research.
Collapse
Affiliation(s)
- Emanuel Schwarz
- Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Heike Tost
- Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Andreas Meyer-Lindenberg
- Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| |
Collapse
|
25
|
Cottrell JR, Li B, Kyung JW, Ashford CJ, Mann JJ, Horvath TL, Ryan TA, Kim SH, Gerber DJ. Calcineurin Aγ is a Functional Phosphatase That Modulates Synaptic Vesicle Endocytosis. J Biol Chem 2015; 291:1948-1956. [PMID: 26627835 DOI: 10.1074/jbc.m115.705319] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Indexed: 12/11/2022] Open
Abstract
Variation in PPP3CC, the gene that encodes the γ isoform of the calcineurin catalytic subunit, has been reported to be associated with schizophrenia. Because of its low expression level in most tissues, there has been little research devoted to the specific function of the calcineurin Aγ (CNAγ) versus the calcineurin Aα (CNAα) and calcineurin Aβ (CNAβ) catalytic isoforms. Consequently, we have a limited understanding of the role of altered CNAγ function in psychiatric disease. In this study, we demonstrate that CNAγ is present in the rodent and human brain and dephosphorylates a presynaptic substrate of calcineurin. Through a combination of immunocytochemistry and immuno-EM, we further show that CNAγ is localized to presynaptic terminals in hippocampal neurons. Critically, we demonstrate that RNAi-mediated knockdown of CNAγ leads to a disruption of synaptic vesicle cycling in cultured rat hippocampal neurons. These data indicate that CNAγ regulates a critical aspect of synaptic vesicle cycling and suggest that variation in PPP3CC may contribute to psychiatric disease by altering presynaptic function.
Collapse
Affiliation(s)
| | - Bing Li
- From the Galenea Corporation, Wakefield, MA 01880
| | - Jae Won Kyung
- the Department of Physiology, Neurodegeneration Control Research Center, School of Medicine, Kyung Hee University, Seoul, 02447, South Korea
| | | | - James J Mann
- From the Galenea Corporation, Wakefield, MA 01880
| | - Tamas L Horvath
- the Program in Integrative Cell Signaling and Neurobiology of Metabolism, Section of Comparative Medicine, Yale University School of Medicine, New Haven, Connecticut 06511, and
| | - Timothy A Ryan
- the Department of Biochemistry, Weill Cornell Medical College, New York, New York 10021
| | - Sung Hyun Kim
- the Department of Physiology, Neurodegeneration Control Research Center, School of Medicine, Kyung Hee University, Seoul, 02447, South Korea.
| | | |
Collapse
|
26
|
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 AND BEHAVIOR 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] [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.
Collapse
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
| |
Collapse
|
27
|
Abstract
Dysbindin is a schizophrenia susceptibility factor and subunit of the biogenesis of lysosome-related organelles complex 1 (BLOC-1) required for lysosome-related organelle biogenesis, and in neurons, synaptic vesicle assembly, neurotransmission, and plasticity. Protein networks, or interactomes, downstream of dysbindin/BLOC-1 remain partially explored despite their potential to illuminate neurodevelopmental disorder mechanisms. Here, we conducted a proteome-wide search for polypeptides whose cellular content is sensitive to dysbindin/BLOC-1 loss of function. We identified components of the vesicle fusion machinery as factors downregulated in dysbindin/BLOC-1 deficiency in neuroectodermal cells and iPSC-derived human neurons, among them the N-ethylmaleimide-sensitive factor (NSF). Human dysbindin/BLOC-1 coprecipitates with NSF and vice versa, and both proteins colocalized in a Drosophila model synapse. To test the hypothesis that NSF and dysbindin/BLOC-1 participate in a pathway-regulating synaptic function, we examined the role for NSF in dysbindin/BLOC-1-dependent synaptic homeostatic plasticity in Drosophila. As previously described, we found that mutations in dysbindin precluded homeostatic synaptic plasticity elicited by acute blockage of postsynaptic receptors. This dysbindin mutant phenotype is fully rescued by presynaptic expression of either dysbindin or Drosophila NSF. However, neither reduction of NSF alone or in combination with dysbindin haploinsufficiency impaired homeostatic synaptic plasticity. Our results demonstrate that dysbindin/BLOC-1 expression defects result in altered cellular content of proteins of the vesicle fusion apparatus and therefore influence synaptic plasticity.
Collapse
|
28
|
Rosen AM, Spellman T, Gordon JA. Electrophysiological endophenotypes in rodent models of schizophrenia and psychosis. Biol Psychiatry 2015; 77:1041-9. [PMID: 25910423 PMCID: PMC4444383 DOI: 10.1016/j.biopsych.2015.03.021] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Revised: 03/03/2015] [Accepted: 03/23/2015] [Indexed: 02/06/2023]
Abstract
Schizophrenia is caused by a diverse array of risk factors and results in a similarly diverse set of symptoms. Electrophysiological endophenotypes lie between risks and symptoms and have the potential to link the two. Electrophysiological studies in rodent models, described here, demonstrate that widely differing risk factors result in a similar set of core electrophysiological endophenotypes, suggesting the possibility of a shared neurobiological substrate.
Collapse
Affiliation(s)
- Andrew M. Rosen
- Department of Psychiatry, College of Physicians and Surgeons Columbia University New York, NY 10032
| | - Timothy Spellman
- Department of Physiology, College of Physicians and Surgeons Columbia University New York, NY 10032
| | - Joshua A. Gordon
- Department of Psychiatry, College of Physicians and Surgeons Columbia University New York, NY 10032,Division of Integrative Neuroscience New York State Psychiatric Institute New York NY 10032,Correspondence to: Joshua A. Gordon 1051 Riverside Drive Unit 87 Kolb Annex Room 140 New York, NY 10032 Ph. 646 774-7116 Fax. 646 774-7101
| |
Collapse
|
29
|
Bhardwaj SK, Stojkovic K, Kiessling S, Srivastava LK, Cermakian N. Constant light uncovers behavioral effects of a mutation in the schizophrenia risk gene Dtnbp1 in mice. Behav Brain Res 2015; 284:58-68. [DOI: 10.1016/j.bbr.2015.01.048] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Revised: 01/23/2015] [Accepted: 01/26/2015] [Indexed: 10/24/2022]
|
30
|
Propagation of dysbindin-1B aggregates: Exosome-mediated transmission of neurotoxic deposits. Neuroscience 2015; 291:301-16. [DOI: 10.1016/j.neuroscience.2015.02.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Revised: 02/09/2015] [Accepted: 02/09/2015] [Indexed: 11/21/2022]
|
31
|
Bhardwaj SK, Ryan RT, Wong TP, Srivastava LK. Loss of dysbindin-1, a risk gene for schizophrenia, leads to impaired group 1 metabotropic glutamate receptor function in mice. Front Behav Neurosci 2015; 9:72. [PMID: 25859193 PMCID: PMC4374471 DOI: 10.3389/fnbeh.2015.00072] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Accepted: 03/06/2015] [Indexed: 11/13/2022] Open
Abstract
The expression of dysbindin-1, a protein coded by the risk gene dtnbp1, is reduced in the brains of schizophrenia patients. Evidence indicates a role of dysbindin-1 in dopaminergic and glutamatergic transmission. Glutamatergic transmission and plasticity at excitatory synapses is critically regulated by G-protein coupled metabotropic glutamate receptor (mGluR) family members, that have been implicated in schizophrenia. Here, we report a role of dysbindin-1 in hippocampal group 1 mGluR (mGluRI) function in mice. In hippocampal synaptoneurosomal preparations from sandy (sdy) mice, that have a loss of function mutation in dysbindin-1 gene, we observed a striking reduction in mGluRI agonist [(S)-3, 5-dihydroxyphenylglycine] (DHPG)-induced phosphorylation of extracellular signal regulated kinase 1/2 (ERK1/2). This mGluR-ERK1/2 deficit occurred in the absence of significant changes in protein levels of the two members of the mGluRI family (i.e., mGluR1 and mGluR5) or in another mGluRI signaling pathway, i.e., protein kinase C (PKC). Aberrant mGluRI-ERK1/2 signaling affected hippocampal synaptic plasticity in the sdy mutants as DHPG-induced long-term depression (LTD) at CA1 excitatory synapses was significantly reduced. Behavioral data suggest that the mGluRI hypofunction may underlie some of the cognitive abnormalities described in sdy mice as the administration of CDPPB (3-cyano-N-(1, 3-diphenyl-1H-pyrazol-5-yl benzamide), a positive allosteric modulator of mGluR5, rescued short-term object recognition and spatial learning and memory deficits in these mice. Taken together, our data suggest a novel role of dysbindin-1 in regulating mGluRI functions.
Collapse
Affiliation(s)
- Sanjeev K Bhardwaj
- Department of Psychiatry and Integrated Programme in Neuroscience, Douglas Mental Health University Institute, McGill University Montreal, QC, Canada
| | - Richard T Ryan
- Department of Psychiatry and Integrated Programme in Neuroscience, Douglas Mental Health University Institute, McGill University Montreal, QC, Canada
| | - Tak Pan Wong
- Department of Psychiatry and Integrated Programme in Neuroscience, Douglas Mental Health University Institute, McGill University Montreal, QC, Canada
| | - Lalit K Srivastava
- Department of Psychiatry and Integrated Programme in Neuroscience, Douglas Mental Health University Institute, McGill University Montreal, QC, Canada
| |
Collapse
|
32
|
Cheah SY, Lawford BR, Young RM, Morris CP, Voisey J. Dysbindin (DTNBP1) variants are associated with hallucinations in schizophrenia. Eur Psychiatry 2015; 30:486-91. [PMID: 25697573 DOI: 10.1016/j.eurpsy.2015.01.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Revised: 01/27/2015] [Accepted: 01/27/2015] [Indexed: 10/24/2022] Open
Abstract
BACKGROUND Dystrobrevin binding protein 1 (DTNBP1) is a schizophrenia susceptibility gene involved with neurotransmission regulation (especially dopamine and glutamate) and neurodevelopment. The gene is known to be associated with cognitive deficit phenotypes within schizophrenia. In our previous studies, DTNBP1 was found associated not only with schizophrenia but with other psychiatric disorders including psychotic depression, post-traumatic stress disorder, nicotine dependence and opiate dependence. These findings suggest that DNTBP1 may be involved in pathways that lead to multiple psychiatric phenotypes. In this study, we explored the association between DTNBP1 SNPs (single nucleotide polymorphisms) and multiple psychiatric phenotypes included in the Diagnostic Interview of Psychosis (DIP). METHODS Five DTNBP1 SNPs, rs17470454, rs1997679, rs4236167, rs9370822 and rs9370823, were genotyped in 235 schizophrenia subjects screened for various phenotypes in the domains of depression, mania, hallucinations, delusions, subjective thought disorder, behaviour and affect, and speech disorder. SNP-phenotype association was determined with ANOVA under general, dominant/recessive and over-dominance models. RESULTS Post hoc tests determined that SNP rs1997679 was associated with visual hallucination; SNP rs4236167 was associated with general auditory hallucination as well as specific features including non-verbal, abusive and third-person form auditory hallucinations; and SNP rs9370822 was associated with visual and olfactory hallucinations. SNPs that survived correction for multiple testing were rs4236167 for third-person and abusive form auditory hallucinations; and rs9370822 for olfactory hallucinations. CONCLUSION These data suggest that DTNBP1 is likely to play a role in development of auditory related, visual and olfactory hallucinations which is consistent with evidence of DTNBP1 activity in the auditory processing regions, in visual processing and in the regulation of glutamate and dopamine activity.
Collapse
Affiliation(s)
- S-Y Cheah
- Institute of Health and Biomedical Innovation, Queensland University of Technology, 60 Musk Ave., Kelvin Grove, Queensland 4059, Australia
| | - B R Lawford
- Institute of Health and Biomedical Innovation, Queensland University of Technology, 60 Musk Ave., Kelvin Grove, Queensland 4059, Australia; Discipline of Psychiatry, Royal Brisbane and Women's Hospital, Herston, Queensland 4006, Australia
| | - R M Young
- Institute of Health and Biomedical Innovation, Queensland University of Technology, 60 Musk Ave., Kelvin Grove, Queensland 4059, Australia
| | - C P Morris
- Institute of Health and Biomedical Innovation, Queensland University of Technology, 60 Musk Ave., Kelvin Grove, Queensland 4059, Australia
| | - J Voisey
- Institute of Health and Biomedical Innovation, Queensland University of Technology, 60 Musk Ave., Kelvin Grove, Queensland 4059, Australia.
| |
Collapse
|
33
|
O'Connor AM, Burton TJ, Leamey CA, Sawatari A. The use of the puzzle box as a means of assessing the efficacy of environmental enrichment. J Vis Exp 2014:52225. [PMID: 25590345 PMCID: PMC4354494 DOI: 10.3791/52225] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Environmental enrichment can dramatically influence the development and function of neural circuits. Further, enrichment has been shown to successfully delay the onset of symptoms in models of Huntington's disease (1-4), suggesting environmental factors can evoke a neuroprotective effect against the progressive, cellular level damage observed in neurodegenerative disorders. The ways in which an animal can be environmentally enriched, however, can vary considerably. Further, there is no straightforward manner in which the effects of environmental enrichment can be assessed: most methods require either fairly complicated behavioral paradigms and/or postmortem anatomical/physiological analyses. This protocol describes the use of a simple and inexpensive behavioral assay, the Puzzle Box (5-7) as a robust means of determining the efficacy of increased social, sensory and motor stimulation on mice compared to cohorts raised in standard laboratory conditions. This simple problem solving task takes advantage of a rodent's innate desire to avoid open enclosures by seeking shelter. Cognitive ability is assessed by adding increasingly complex impediments to the shelter's entrance. The time a given subject takes to successfully remove the obstructions and enter the shelter serves as the primary metric for task performance. This method could provide a reliable means of rapidly assessing the efficacy of different enrichment protocols on cognitive function, thus paving the way for systematically determining the role specific environmental factors play in delaying the onset of neurodevelopmental and neurodegenerative disease.
Collapse
Affiliation(s)
| | - Thomas J Burton
- Discipline of Physiology, University of Sydney; Bosch Animal Behavioural Facility, University of Sydney
| | | | | |
Collapse
|
34
|
Crabtree GW, Gogos JA. Synaptic plasticity, neural circuits, and the emerging role of altered short-term information processing in schizophrenia. Front Synaptic Neurosci 2014; 6:28. [PMID: 25505409 PMCID: PMC4243504 DOI: 10.3389/fnsyn.2014.00028] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Accepted: 10/22/2014] [Indexed: 01/01/2023] Open
Abstract
Synaptic plasticity alters the strength of information flow between presynaptic and postsynaptic neurons and thus modifies the likelihood that action potentials in a presynaptic neuron will lead to an action potential in a postsynaptic neuron. As such, synaptic plasticity and pathological changes in synaptic plasticity impact the synaptic computation which controls the information flow through the neural microcircuits responsible for the complex information processing necessary to drive adaptive behaviors. As current theories of neuropsychiatric disease suggest that distinct dysfunctions in neural circuit performance may critically underlie the unique symptoms of these diseases, pathological alterations in synaptic plasticity mechanisms may be fundamental to the disease process. Here we consider mechanisms of both short-term and long-term plasticity of synaptic transmission and their possible roles in information processing by neural microcircuits in both health and disease. As paradigms of neuropsychiatric diseases with strongly implicated risk genes, we discuss the findings in schizophrenia and autism and consider the alterations in synaptic plasticity and network function observed in both human studies and genetic mouse models of these diseases. Together these studies have begun to point toward a likely dominant role of short-term synaptic plasticity alterations in schizophrenia while dysfunction in autism spectrum disorders (ASDs) may be due to a combination of both short-term and long-term synaptic plasticity alterations.
Collapse
Affiliation(s)
- Gregg W. Crabtree
- Department of Physiology and Cellular Biophysics, College of Physicians and Surgeons, Columbia UniversityNew York, NY, USA
| | - Joseph A. Gogos
- Department of Physiology and Cellular Biophysics, College of Physicians and Surgeons, Columbia UniversityNew York, NY, USA
- Department of Neuroscience, College of Physicians and Surgeons, Columbia UniversityNew York, NY, USA
| |
Collapse
|
35
|
Shintani N, Onaka Y, Hashimoto R, Takamura H, Nagata T, Umeda-Yano S, Mouri A, Mamiya T, Haba R, Matsuzaki S, Katayama T, Yamamori H, Nakazawa T, Nagayasu K, Ago Y, Yagasaki Y, Nabeshima T, Takeda M, Hashimoto H. Behavioral characterization of mice overexpressing human dysbindin-1. Mol Brain 2014; 7:74. [PMID: 25298178 PMCID: PMC4201722 DOI: 10.1186/s13041-014-0074-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Accepted: 09/25/2014] [Indexed: 11/30/2022] Open
Abstract
Background The dysbindin-1 gene (DTNBP1: dystrobrevin binding protein 1) is a promising schizophrenia susceptibility gene, known to localize almost exclusively to neurons in the brain, and participates in the regulation of neurotransmitter release, membrane-surface receptor expression, and synaptic plasticity. Sandy mice, with spontaneous Dtnbp1 deletion, display behavioral abnormalities relevant to symptoms of schizophrenia. However, it remains unknown if dysbindin-1 gain-of-function is beneficial or detrimental. Results To answer this question and gain further insight into the pathophysiology and therapeutic potential of dysbindin-1, we developed transgenic mice expressing human DTNBP1 (Dys1A-Tg) and analyzed their behavioral phenotypes. Dys1A-Tg mice were born viable in the expected Mendelian ratios, apparently normal and fertile. Primary screening of behavior and function showed a marginal change in limb grasping in Dys1A-Tg mice. In addition, Dys1A-Tg mice exhibited increased hyperlocomotion after methamphetamine injection. Transcriptomic analysis identified several up- and down-regulated genes, including the immediate-early genes Arc and Egr2, in the prefrontal cortex of Dys1A-Tg mice. Conclusions The present findings in Dys1A-Tg mice support the role of dysbindin-1 in psychiatric disorders. The fact that either overexpression (Dys1A-Tg) or underexpression (Sandy) of dysbindin-1 leads to behavioral alterations in mice highlights the functional importance of dysbindin-1 in vivo.
Collapse
Affiliation(s)
- Norihito Shintani
- Laboratory of Molecular Neuropharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka, 565-0871, Japan.
| | - Yusuke Onaka
- Laboratory of Molecular Neuropharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka, 565-0871, Japan.
| | - Ryota Hashimoto
- Molecular Research Center for Children's Mental Development, United Graduate School of Child Development, Osaka University, Kanazawa University, Hamamatsu University School of Medicine, Chiba University and University of Fukui, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan. .,Department of Psychiatry, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan.
| | - Hironori Takamura
- Molecular Research Center for Children's Mental Development, United Graduate School of Child Development, Osaka University, Kanazawa University, Hamamatsu University School of Medicine, Chiba University and University of Fukui, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan.
| | - Tsuyoshi Nagata
- Laboratory of Molecular Neuropharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka, 565-0871, Japan.
| | - Satomi Umeda-Yano
- Department of Molecular Neuropsychiatry, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan.
| | - Akihiro Mouri
- Department of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, Meijo University, 150 Yagotoyama, Tempaku-ku, Nagoya, 468-8503, Japan.
| | - Takayoshi Mamiya
- Department of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, Meijo University, 150 Yagotoyama, Tempaku-ku, Nagoya, 468-8503, Japan.
| | - Ryota Haba
- Laboratory of Molecular Neuropharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka, 565-0871, Japan.
| | - Shinsuke Matsuzaki
- Molecular Research Center for Children's Mental Development, United Graduate School of Child Development, Osaka University, Kanazawa University, Hamamatsu University School of Medicine, Chiba University and University of Fukui, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan. .,Molecular Brain Science, United Graduate School of Child Development, Osaka University, Kanazawa University, Hamamatsu University School of Medicine, Chiba University and University of Fukui, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan. .,Anatomy and Neuroscience, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan.
| | - Taiichi Katayama
- Molecular Brain Science, United Graduate School of Child Development, Osaka University, Kanazawa University, Hamamatsu University School of Medicine, Chiba University and University of Fukui, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan.
| | - Hidenaga Yamamori
- Molecular Research Center for Children's Mental Development, United Graduate School of Child Development, Osaka University, Kanazawa University, Hamamatsu University School of Medicine, Chiba University and University of Fukui, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan. .,Department of Molecular Neuropsychiatry, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan.
| | - Takanobu Nakazawa
- iPS Cell-based Research Project on Brain Neuropharmacology and Toxicology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka, 565-0871, Japan.
| | - Kazuki Nagayasu
- iPS Cell-based Research Project on Brain Neuropharmacology and Toxicology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka, 565-0871, Japan.
| | - Yukio Ago
- Laboratory of Medicinal Pharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka, 565-0871, Japan.
| | - Yuki Yagasaki
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1 Ogawahigashicho, Kodaira, Tokyo, 187-8502, Japan.
| | - Toshitaka Nabeshima
- Department of Regional Pharmaceutical Care & Sciences, Graduate School of Pharmaceutical Sciences, Meijo University, 150 Yagotoyama, Tenpaku-ku, Nagoya, 468-8503, Japan.
| | - Masatoshi Takeda
- Molecular Research Center for Children's Mental Development, United Graduate School of Child Development, Osaka University, Kanazawa University, Hamamatsu University School of Medicine, Chiba University and University of Fukui, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan. .,Department of Psychiatry, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan.
| | - Hitoshi Hashimoto
- Laboratory of Molecular Neuropharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka, 565-0871, Japan. .,Molecular Research Center for Children's Mental Development, United Graduate School of Child Development, Osaka University, Kanazawa University, Hamamatsu University School of Medicine, Chiba University and University of Fukui, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan. .,iPS Cell-based Research Project on Brain Neuropharmacology and Toxicology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka, 565-0871, Japan.
| |
Collapse
|
36
|
Larimore J, Zlatic SA, Gokhale A, Tornieri K, Singleton KS, Mullin AP, Tang J, Talbot K, Faundez V. Mutations in the BLOC-1 subunits dysbindin and muted generate divergent and dosage-dependent phenotypes. J Biol Chem 2014; 289:14291-300. [PMID: 24713699 DOI: 10.1074/jbc.m114.553750] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Post-mortem analysis has revealed reduced levels of the protein dysbindin in the brains of those suffering from the neurodevelopmental disorder schizophrenia. Consequently, mechanisms controlling the cellular levels of dysbindin and its interacting partners may participate in neurodevelopmental processes impaired in that disorder. To address this question, we studied loss of function mutations in the genes encoding dysbindin and its interacting BLOC-1 subunits. We focused on BLOC-1 mutants affecting synapse composition and function in addition to their established systemic pigmentation, hematological, and lung phenotypes. We tested phenotypic homogeneity and gene dosage effects in the mouse null alleles muted (Bloc1s5(mu/mu)) and dysbindin (Bloc1s8(sdy/sdy)). Transcripts of NMDA receptor subunits and GABAergic interneuron markers, as well as expression of BLOC-1 subunit gene products, were affected differently in the brains of Bloc1s5(mu/mu) and Bloc1s8(sdy/sdy) mice. Unlike Bloc1s8(sdy/sdy), elimination of one or two copies of Bloc1s5 generated indistinguishable pallidin transcript phenotypes. We conclude that monogenic mutations abrogating the expression of a protein complex subunit differentially affect the expression of other complex transcripts and polypeptides as well as their downstream effectors. We propose that the genetic disruption of different subunits of protein complexes and combinations thereof diversifies phenotypic presentation of pathway deficiencies, contributing to the wide phenotypic spectrum and complexity of neurodevelopmental disorders.
Collapse
Affiliation(s)
- Jennifer Larimore
- From the Department of Biology, Agnes Scott College, Decatur, Georgia 30030
| | | | | | | | - Kaela S Singleton
- From the Department of Biology, Agnes Scott College, Decatur, Georgia 30030
| | | | - Junxia Tang
- the Center for Neurobiology and Behavior, Department of Psychiatry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, and
| | - Konrad Talbot
- the Department of Neurosurgery, Cedars-Sinai Medical Center, Los Angeles, California 90048
| | - Victor Faundez
- the Department of Cell Biology and the Center for Social Translational Neuroscience Emory University, Atlanta, Georgia 30322,
| |
Collapse
|
37
|
Pinner AL, Haroutunian V, Meador-Woodruff JH. Alterations of the myristoylated, alanine-rich C kinase substrate (MARCKS) in prefrontal cortex in schizophrenia. Schizophr Res 2014; 154:36-41. [PMID: 24568864 PMCID: PMC3999918 DOI: 10.1016/j.schres.2014.02.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Revised: 01/27/2014] [Accepted: 02/01/2014] [Indexed: 11/29/2022]
Abstract
Abnormal synaptic plasticity has been implicated in the cognitive deficits seen in schizophrenia, where alterations have been found in neurotransmission, signaling and dendritic dynamics. Rapid rearrangement of the actin cytoskeleton is critical for plasticity and abnormalities of molecular regulators of this process are candidates for understanding mechanisms underlying these changes in schizophrenia. The myristoylated, alanine-rich C-kinase substrate (MARCKS) is crucial for many roles associated with synaptic plasticity, including facilitation of neurotransmission, dendritic branching and in turn cognitive function. Accordingly, we hypothesized that this protein is abnormally expressed or regulated in schizophrenia. We measured protein expression of MARCKS by Western blot analysis in postmortem samples of dorsolateral prefrontal cortex (DLPFC) from elderly schizophrenia patients (N=16) and a comparison group (N=20). We also assayed phosphorylated-MARCKS (pMARCKS), given the role of phosphorylation in reversing membrane association by MARCKS. We found decreased expression of both MARCKS and pMARCKS in schizophrenia. Altered myristoylation may be a mechanism that explains this down-regulation of MARCKS, so we also assayed expression of the two isoforms of the key myristoylation enzyme, NMT, and an enzymatic inhibitor of this enzyme, NMT-inhibitor protein (NIP71) by Western blotting in these same subjects. Expression did not change between groups for these proteins, suggesting a mechanism other than myristoylation is responsible for decreased MARCKS expression in schizophrenia. These data suggest a potential mechanism underlying aspects of altered synaptic plasticity observed in schizophrenia.
Collapse
Affiliation(s)
- Anita L. Pinner
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, AL, USA
,Corresponding author: CIRC 593, 1719 6 Ave South, Birmingham, AL 35294-0021, USA, Tel: +1 205 996 6212, Fax: + 1 205 975 4879,
| | - Vahram Haroutunian
- Department of Psychiatry, Mt. Sinai School of Medicine, New York, NY, USA
| | - James H. Meador-Woodruff
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, AL, USA
| |
Collapse
|
38
|
Abstract
Psychosis is an abnormal mental state characterized by disorganization, delusions and hallucinations. Animal models have become an increasingly important research tool in the effort to understand both the underlying pathophysiology and treatment of psychosis. There are multiple animal models for psychosis, with each formed by the coupling of a manipulation and a measurement. In this manuscript we do not address the diseases of which psychosis is a prominent comorbidity. Instead, we summarize the current state of affairs and future directions for animal models of psychosis. To accomplish this, our manuscript will first discuss relevant behavioral and electrophysiological measurements. We then provide an overview of the different manipulations that are combined with these measurements to produce animal models. The strengths and limitations of each model will be addressed in order to evaluate its cross-species comparability.
Collapse
|
39
|
Papaleo F, Burdick MC, Callicott JH, Weinberger DR. Epistatic interaction between COMT and DTNBP1 modulates prefrontal function in mice and in humans. Mol Psychiatry 2014; 19:311-6. [PMID: 24145376 PMCID: PMC4845721 DOI: 10.1038/mp.2013.133] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Revised: 07/31/2013] [Accepted: 08/01/2013] [Indexed: 01/09/2023]
Abstract
Cognitive functions are highly heritable and the impact of complex genetic interactions, though undoubtedly important, has received little investigation. Here we show in an animal model and in a human neuroimaging experiment a consistent non-linear interaction between two genes--catechol-O-methyl transferase (COMT) and dysbindin (dys; dystrobrevin-binding protein 1 (DTNBP1))--implicated through different mechanisms in cortical dopamine signaling and prefrontal cognitive function. In mice, we found that a single genetic mutation reducing expression of either COMT or DTNBP1 alone produced working memory advantages, while, in dramatic contrast, genetic reduction of both in the same mouse produced working memory deficits. We found evidence of the same non-linear genetic interaction in prefrontal cortical function in humans. In healthy volunteers (N=176) studied with functional magnetic resonance imaging during a working memory paradigm, individuals homozygous for the COMT rs4680 Met allele that reduces COMT enzyme activity showed a relatively more efficient prefrontal engagement. In contrast, we found that the same genotype was less efficient on the background of a dys haplotype associated with decreased DTNBP1 expression. These results illustrate that epistasis can be functionally multi-directional and non-linear and that a putatively beneficial allele in one epistastic context is a relatively deleterious one in another. These data also have important implications for single-locus association analyses of complex traits.
Collapse
Affiliation(s)
- F Papaleo
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, Genova, Italy,Department of Scienze del Farmaco, Universita’ degli Studi di Padova, Padova, Italy,Clinical Brain Disorders Branch, Genes, Cognition and Psychosis Program, National Institute of Mental Health, Bethesda, MD, USA
| | - MC Burdick
- Clinical Brain Disorders Branch, Genes, Cognition and Psychosis Program, National Institute of Mental Health, Bethesda, MD, USA
| | - JH Callicott
- Clinical Brain Disorders Branch, Genes, Cognition and Psychosis Program, National Institute of Mental Health, Bethesda, MD, USA
| | - DR Weinberger
- Clinical Brain Disorders Branch, Genes, Cognition and Psychosis Program, National Institute of Mental Health, Bethesda, MD, USA,Lieber Institute for Brain Development, Johns Hopkins University Medical Campus, Baltimore, MD, USA,Departments of Psychiatry, Neurology, Neuroscience and the McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| |
Collapse
|
40
|
Glen WB, Horowitz B, Carlson GC, Cannon TD, Talbot K, Jentsch JD, Lavin A. Dysbindin-1 loss compromises NMDAR-dependent synaptic plasticity and contextual fear conditioning. Hippocampus 2013; 24:204-13. [PMID: 24446171 DOI: 10.1002/hipo.22215] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Revised: 09/23/2013] [Accepted: 09/25/2013] [Indexed: 01/19/2023]
Abstract
Genetic variants in DTNBP1 encoding the protein dysbindin-1 have often been associated with schizophrenia and with the cognitive deficits prominent in that disorder. Because impaired function of the hippocampus is thought to play a role in these memory deficits and because NMDAR-dependent synaptic plasticity in this region is a proposed biological substrate for some hippocampal-dependent memory functions in schizophrenia, we hypothesized that reduced dysbindin-1 expression would lead to impairments in NMDAR-dependent synaptic plasticity and in contextual fear conditioning. Acute slices from male mice carrying 0, 1, or 2 null mutant alleles of the Dtnbp1 gene were prepared, and field recordings from the CA1 striatum radiatum were obtained before and after tetanization of Schaffer collaterals of CA3 pyramidal cells. Mice homozygous for the null mutation in Dtnbp1 exhibited significantly reduced NMDAR-dependent synaptic potentiation compared to wild type mice, an effect that could be rescued by bath application of the NMDA receptor coagonist glycine (10 μM). Behavioral testing in adult mice revealed deficits in hippocampal memory processes. Homozygous null mice exhibited lower conditional freezing, without a change in the response to shock itself, indicative of a learning and memory deficit. Taken together, these results indicate that a loss of dysbindin-1 impairs hippocampal plasticity which may, in part, explain the role dysbindin-1 plays in the cognitive impairments of schizophrenia.
Collapse
Affiliation(s)
- W Bailey Glen
- Department of Neurosciences, Medical University of South Carolina, Charleston, South Carolina
| | | | | | | | | | | | | |
Collapse
|
41
|
Working memory impairment in calcineurin knock-out mice is associated with alterations in synaptic vesicle cycling and disruption of high-frequency synaptic and network activity in prefrontal cortex. J Neurosci 2013; 33:10938-49. [PMID: 23825400 DOI: 10.1523/jneurosci.5362-12.2013] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Working memory is an essential component of higher cognitive function, and its impairment is a core symptom of multiple CNS disorders, including schizophrenia. Neuronal mechanisms supporting working memory under normal conditions have been described and include persistent, high-frequency activity of prefrontal cortical neurons. However, little is known about the molecular and cellular basis of working memory dysfunction in the context of neuropsychiatric disorders. To elucidate synaptic and neuronal mechanisms of working memory dysfunction, we have performed a comprehensive analysis of a mouse model of schizophrenia, the forebrain-specific calcineurin knock-out mouse. Biochemical analyses of cortical tissue from these mice revealed a pronounced hyperphosphorylation of synaptic vesicle cycling proteins known to be necessary for high-frequency synaptic transmission. Examination of the synaptic vesicle cycle in calcineurin-deficient neurons demonstrated an impairment of vesicle release enhancement during periods of intense stimulation. Moreover, brain slice and in vivo electrophysiological analyses showed that loss of calcineurin leads to a gene dose-dependent disruption of high-frequency synaptic transmission and network activity in the PFC, correlating with selective working memory impairment. Finally, we showed that levels of dynamin I, a key presynaptic protein and calcineurin substrate, are significantly reduced in prefrontal cortical samples from schizophrenia patients, extending the disease relevance of our findings. Our data provide support for a model in which impaired synaptic vesicle cycling represents a critical node for disease pathologies underlying the cognitive deficits in schizophrenia.
Collapse
|
42
|
Abstract
This review provides a comprehensive overview of clinical and molecular genetic as well as pharmacogenetic studies regarding the clinical phenotype of "psychotic depression." Results are discussed with regard to the long-standing debate on categorical vs dimensional disease models of affective and psychotic disorders on a continuum from unipolar depression over bipolar disorder and schizoaffective disorder to schizophrenia. Clinical genetic studies suggest a familial aggregation and a considerable heritability (39%) of psychotic depression partly shared with schizoaffective disorder, schizophrenia, and affective disorders. Molecular genetic studies point to potential risk loci of psychotic depression shared with schizoaffective disorder (1q42, 22q11, 19p13), depression, bipolar disorder, and schizophrenia (6p, 8p22, 10p13-12, 10p14, 13q13-14, 13q32, 18p, 22q11-13) and several vulnerability genes possibly contributing to an increased risk of psychotic symptoms in depression (eg, BDNF, DBH, DTNBP1, DRD2, DRD4, GSK-3beta, MAO-A). Pharmacogenetic studies implicate 5-HTT, TPH1, and DTNBP1 gene variation in the mediation of antidepressant treatment response in psychotic depression. Genetic factors are suggested to contribute to the disease risk of psychotic depression in partial overlap with disorders along the affective-psychotic spectrum. Thus, genetic research focusing on psychotic depression might inspire a more dimensional, neurobiologically and symptom-oriented taxonomy of affective and psychotic disorders challenging the dichotomous Kraepelinian view. Additionally, pharmacogenetic studies might aid in the development of a more personalized treatment of psychotic depression with an individually tailored antidepressive/antipsychotic pharmacotherapy according to genotype.
Collapse
Affiliation(s)
- Katharina Domschke
- Department of Psychiatry, Psychosomatics and Psychotherapy, University of Wuerzburg, Wuerzburg, Germany.
| |
Collapse
|
43
|
Larimore J, Ryder PV, Kim KY, Ambrose LA, Chapleau C, Calfa G, Gross C, Bassell GJ, Pozzo-Miller L, Smith Y, Talbot K, Park IH, Faundez V. MeCP2 regulates the synaptic expression of a Dysbindin-BLOC-1 network component in mouse brain and human induced pluripotent stem cell-derived neurons. PLoS One 2013; 8:e65069. [PMID: 23750231 PMCID: PMC3672180 DOI: 10.1371/journal.pone.0065069] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Accepted: 04/22/2013] [Indexed: 02/06/2023] Open
Abstract
Clinical, epidemiological, and genetic evidence suggest overlapping pathogenic mechanisms between autism spectrum disorder (ASD) and schizophrenia. We tested this hypothesis by asking if mutations in the ASD gene MECP2 which cause Rett syndrome affect the expression of genes encoding the schizophrenia risk factor dysbindin, a subunit of the biogenesis of lysosome-related organelles complex-1 (BLOC-1), and associated interacting proteins. We measured mRNA and protein levels of key components of a dysbindin interaction network by, quantitative real time PCR and quantitative immunohistochemistry in hippocampal samples of wild-type and Mecp2 mutant mice. In addition, we confirmed results by performing immunohistochemistry of normal human hippocampus and quantitative qRT-PCR of human inducible pluripotent stem cells (iPSCs)-derived human neurons from Rett syndrome patients. We defined the distribution of the BLOC-1 subunit pallidin in human and mouse hippocampus and contrasted this distribution with that of symptomatic Mecp2 mutant mice. Neurons from mutant mice and Rett syndrome patients displayed selectively reduced levels of pallidin transcript. Pallidin immunoreactivity decreased in the hippocampus of symptomatic Mecp2 mutant mice, a feature most prominent at asymmetric synapses as determined by immunoelectron microcopy. Pallidin immunoreactivity decreased concomitantly with reduced BDNF content in the hippocampus of Mecp2 mice. Similarly, BDNF content was reduced in the hippocampus of BLOC-1 deficient mice suggesting that genetic defects in BLOC-1 are upstream of the BDNF phenotype in Mecp2 deficient mice. Our results demonstrate that the ASD-related gene Mecp2 regulates the expression of components belonging to the dysbindin interactome and these molecular differences may contribute to synaptic phenotypes that characterize Mecp2 deficiencies and ASD.
Collapse
Affiliation(s)
- Jennifer Larimore
- Department of Biology, Agnes Scott College, Decatur, Georgia, United States of America
| | - Pearl V. Ryder
- Cell Biology, Emory University, Atlanta, Georgia, United States of America
| | - Kun-Yong Kim
- Department of Genetics, Yale Stem Cell Center, Yale School of Medicine, New Haven, Connecticut, United States of America
| | - L. Alex Ambrose
- Department of Biology, Agnes Scott College, Decatur, Georgia, United States of America
| | - Christopher Chapleau
- Department of Neurobiology, The University of Alabama, Birmingham, Alabama, United States of America
| | - Gaston Calfa
- Department of Neurobiology, The University of Alabama, Birmingham, Alabama, United States of America
| | - Christina Gross
- Cell Biology, Emory University, Atlanta, Georgia, United States of America
| | - Gary J. Bassell
- Cell Biology, Emory University, Atlanta, Georgia, United States of America
| | - Lucas Pozzo-Miller
- Department of Neurobiology, The University of Alabama, Birmingham, Alabama, United States of America
| | - Yoland Smith
- Department of Neurology, Emory University, Atlanta, Georgia, United States of America
- Yerkes National Primate Center, Emory University, Atlanta, Georgia, United States of America
| | - Konrad Talbot
- Center for Neurobiology and Behavior, Department of Psychiatry, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - In-Hyun Park
- Department of Genetics, Yale Stem Cell Center, Yale School of Medicine, New Haven, Connecticut, United States of America
| | - Victor Faundez
- Cell Biology, Emory University, Atlanta, Georgia, United States of America
| |
Collapse
|
44
|
Holley SM, Wang EA, Cepeda C, Jentsch JD, Ross CA, Pletnikov MV, Levine MS. Frontal cortical synaptic communication is abnormal in Disc1 genetic mouse models of schizophrenia. Schizophr Res 2013; 146:264-72. [PMID: 23481583 PMCID: PMC3622830 DOI: 10.1016/j.schres.2013.02.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2012] [Revised: 02/04/2013] [Accepted: 02/06/2013] [Indexed: 12/25/2022]
Abstract
Mouse models carrying Disc1 mutations may provide insights into how Disc1 genetic variations contribute to schizophrenia (SZ) susceptibility. Disc1 mutant mice show behavioral and cognitive disturbances reminiscent of SZ. To dissect the synaptic mechanisms underlying these phenotypes, we examined electrophysiological properties of cortical neurons from two mouse models, the first expressing a truncated mouse Disc1 (mDisc1) protein throughout the entire brain, and the second expressing a truncated human Disc1 (hDisc1) protein in forebrain regions. We obtained whole-cell patch clamp recordings to examine how altered expression of Disc1 protein changes excitatory and inhibitory synaptic transmissions onto cortical pyramidal neurons in the medial prefrontal cortex in 4-7 month-old mDisc1 and hDisc1 mice. In both mDisc1 and hDisc1 mice, the frequency of spontaneous EPSCs was greater than in wild-type littermate controls. Male mice from both lines were more affected by the Disc1 mutation than were females, exhibiting increases in the ratio of excitatory to inhibitory events. Changes in spontaneous IPSCs were only observed in the mDisc1 model and were sex-specific, with diminished cortical GABAergic neurotransmission, a well-documented characteristic of SZ, occurring only in male mDisc1 mice. In contrast, female mDisc1 mice showed an increase in the frequency of small-amplitude sIPSCs. These findings indicate that truncations of Disc1 alter glutamatergic and GABAergic neurotransmission both commonly and differently in the models and some of the effects are sex-specific, revealing how altered Disc1 expression may contribute to behavioral disruptions and cognitive deficits of SZ.
Collapse
Affiliation(s)
- Sandra M. Holley
- Intellectual and Developmental Disabilities Research Center, Semel Institute for Neuroscience and Human Behavior, Brain Research Institute, David Geffen School of Medicine, University of California Los Angeles
| | - Elizabeth A. Wang
- Intellectual and Developmental Disabilities Research Center, Semel Institute for Neuroscience and Human Behavior, Brain Research Institute, David Geffen School of Medicine, University of California Los Angeles
| | - Carlos Cepeda
- Intellectual and Developmental Disabilities Research Center, Semel Institute for Neuroscience and Human Behavior, Brain Research Institute, David Geffen School of Medicine, University of California Los Angeles
| | - J. David Jentsch
- Department of Psychology, Brain Research Institute, University of California Los Angeles
| | - Christopher A. Ross
- Division of Neurobiology, Department of Psychiatry, Johns Hopkins University School of Medicine, Baltimore, MD,Departments of Neurology, Neuroscience and Pharmacology and Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Mikhail V. Pletnikov
- Division of Neurobiology, Department of Psychiatry, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Michael S. Levine
- Intellectual and Developmental Disabilities Research Center, Semel Institute for Neuroscience and Human Behavior, Brain Research Institute, David Geffen School of Medicine, University of California Los Angeles
| |
Collapse
|
45
|
Saggu S, Cannon TD, Jentsch JD, Lavin A. Potential molecular mechanisms for decreased synaptic glutamate release in dysbindin-1 mutant mice. Schizophr Res 2013; 146:254-63. [PMID: 23473812 PMCID: PMC3628687 DOI: 10.1016/j.schres.2013.01.037] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Revised: 01/28/2013] [Accepted: 01/30/2013] [Indexed: 01/14/2023]
Abstract
Behavioral genetic studies of humans have associated variation in the DTNBP1 gene with schizophrenia and its cognitive deficit phenotypes. The protein encoded by DTNBP1, dysbindin-1, is expressed in forebrain neurons where it interacts with proteins mediating vesicular trafficking and exocytosis. It has been shown that loss of dysbindin-1 results in a decrease in glutamate release in the prefrontal cortex; however the mechanisms underlying this decrease are not fully understood. In order to investigate this question, we evaluated dysbindin-1 null mutant mice, using electrophysiological recordings of prefrontal cortical neurons, imaging studies of vesicles, calcium dynamics and Western blot measures of synaptic proteins and Ca(2+) channels. Dysbindin-1 null mice showed a decrease in the ready releasable pool of synaptic vesicles, decreases in quantal size, decreases in the probability of release and deficits in the rate of endo- and exocytosis compared with wild-type controls. Moreover, the dysbindin-1 null mice show decreases in the [Ca(2+)]i,expression of L- and N-type Ca(2+)channels and several proteins involved in synaptic vesicle trafficking and priming. Our results provide new insights into the mechanisms of action of dysbindin-1.
Collapse
Affiliation(s)
- Shalini Saggu
- Dept of Neuroscience, Medical University of South Carolina, Charleston, SC
| | - Tyrone D. Cannon
- Depts of Psychology and Psychiatry & Biobehavioral Sciences, University of California, Los Angeles, CA
| | - J. David Jentsch
- Dept of Human Genetics, University of California, Los Angeles, CA
| | - Antonieta Lavin
- Dept of Neuroscience, Medical University of South Carolina, Charleston, SC
| |
Collapse
|
46
|
Carr GV, Jenkins KA, Weinberger DR, Papaleo F. Loss of dysbindin-1 in mice impairs reward-based operant learning by increasing impulsive and compulsive behavior. Behav Brain Res 2013; 241:173-84. [PMID: 23261874 PMCID: PMC3556458 DOI: 10.1016/j.bbr.2012.12.021] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Revised: 12/08/2012] [Accepted: 12/12/2012] [Indexed: 12/30/2022]
Abstract
The dystrobrevin-binding protein 1 (DTNBP1) gene, which encodes the dysbindin-1 protein, is a potential schizophrenia susceptibility gene. Polymorphisms in the DTNBP1 gene have been associated with altered cognitive abilities. In the present study, dysbindin-1 null mutant (dys-/-), heterozygous (dys+/-), and wild-type (dys+/+) mice, on a C57BL/6J genetic background, were tested in either a match to sample or nonmatch to sample visual discrimination task. This visual discrimination task was designed to measure rule learning and detect any changes in response timing over the course of testing. Dys-/- mice displayed significant learning deficits and required more trials to acquire this task. However, once criterion was reached, there were no differences between the genotypes on any behavioral measures. Dys-/- mice exhibited increased compulsive and impulsive behaviors compared to control littermates suggesting the inability to suppress incorrectly-timed responses underlies their increased time to acquisition. Indeed, group comparisons of behavior differences between the first and last day of testing showed that only dys-/- mice consistently decreased measures of perseverative, premature, timeout, and total responses. These findings illustrate how some aspects of altered cognitive performance in dys-/- mice might be related to increased impulsive and compulsive behaviors, analogous to cognitive deficits in some individuals with psychiatric disorders.
Collapse
Affiliation(s)
- Gregory V. Carr
- Clinical Brain Disorders Branch; Genes, Cognition and Psychosis Program, National Institute of Mental Health, Bethesda, MD, USA
| | - Kimberly A. Jenkins
- Clinical Brain Disorders Branch; Genes, Cognition and Psychosis Program, National Institute of Mental Health, Bethesda, MD, USA
| | - Daniel R. Weinberger
- Clinical Brain Disorders Branch; Genes, Cognition and Psychosis Program, National Institute of Mental Health, Bethesda, MD, USA
- Lieber Institute for Brain Development, Johns Hopkins University Medical Campus, Baltimore, MD, USA
- Department of Psychiatry, Neurology, and Neuroscience and the Institute of Genetic Medicine, Johns Hopkins School of Medicine, Baltimore, MD 21205
| | - Francesco Papaleo
- Clinical Brain Disorders Branch; Genes, Cognition and Psychosis Program, National Institute of Mental Health, Bethesda, MD, USA
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, via Morego, 30, 16163 Genova, Italy
- Dipartimento di Scienze del Farmaco, Universita’ degli Studi di Padova, Largo Meneghetti, 2, 35131 Padova, Italy
| |
Collapse
|
47
|
Neurodevelopmental role for VGLUT2 in pyramidal neuron plasticity, dendritic refinement, and in spatial learning. J Neurosci 2013; 32:15886-901. [PMID: 23136427 DOI: 10.1523/jneurosci.4505-11.2012] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The level and integrity of glutamate transmission during critical periods of postnatal development plays an important role in the refinement of pyramidal neuron dendritic arbor, synaptic plasticity, and cognition. Presently, it is not clear how excitatory transmission via the two predominant isoforms of the vesicular glutamate transporter (VGLUT1 and VGLUT2) participate in this process. To assess a neurodevelopmental role for VGLUT2 in pyramidal neuron maturation, we generated recombinant VGLUT2 knock-out mice and inactivated VGLUT2 throughout development using Emx1-Cre(+/+) knock-in mice. We show that VGLUT2 deficiency in corticolimbic circuits results in reduced evoked glutamate transmission, release probability, and LTD at hippocampal CA3-CA1 synapses during a formative developmental period (postnatal days 11-14). In adults, we find a marked reduction in the amount of dendritic arbor across the span of the dendritic tree of CA1 pyramidal neurons and reduced long-term potentiation and levels of synaptic markers spinophilin and VGLUT1. Loss of dendritic arbor is accompanied by corresponding reductions in the number of dendritic spines, suggesting widespread alterations in synaptic connectivity. Conditional VGLUT2 knock-out mice exhibit increased open-field exploratory activity yet impaired spatial learning and memory, endophenotypes similar to those of NMDA receptor knock-down mice. Remarkably, the impairment in learning can be partially restored by selectively increasing NMDA receptor-mediated glutamate transmission in adult mice by prolonged treatment with d-serine and a d-amino acid oxidase inhibitor. Our data indicate that VGLUT2 expression is pivotal to the proper development of mature pyramidal neuronal architecture and plasticity, and that such glutamatergic deficiency leads to cognitive malfunction as observed in several neurodevelopmental psychiatric disorders.
Collapse
|
48
|
Abstract
GABAergic interneurons of the cerebral cortex (cINs) play crucial roles in many aspects of cortical function. The diverse types of cINs are classified into subgroups according to their morphology, intrinsic physiology, neurochemical markers and synaptic targeting. Recent advances in mouse genetics, imaging and electrophysiology techniques have greatly advanced our efforts to understand the role of normal cIN function and its dysfunction in neuropsychiatric disorders. In schizophrenia (SCZ), a wealth of data suggests that cIN function is perturbed, and that interneuron dysfunction may underlie key symptoms of the disease. In this review, we discuss the link between cINs and SCZ, focusing on the evidence for GABAergic signaling deficits from both SCZ patients and mouse models.
Collapse
|
49
|
Zheng W, Wang H, Zeng Z, Lin J, Little PJ, Srivastava LK, Quirion R. The possible role of the Akt signaling pathway in schizophrenia. Brain Res 2012; 1470:145-58. [PMID: 22771711 DOI: 10.1016/j.brainres.2012.06.032] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2011] [Revised: 06/19/2012] [Accepted: 06/25/2012] [Indexed: 02/07/2023]
Abstract
Serine/threonine protein kinase v-akt murine thymoma viral oncogene homolog (Akt) is one of the survival kinases with multiple biological functions in the brain and throughout the body. Schizophrenia is one of the most devastating psychiatric disorders. Accumulating evidence has indicated the involvement of the Akt signaling pathway in the pathogenesis of this disorder. Genetic linkage and association studies have identified Akt-1 as a candidate susceptibility gene related for schizophrenia. The level of Akt-1 protein and its kinase activity decreased significantly both in white blood cells from schizophrenic patients and in postmortem brain tissue of schizophrenic patients. Consistent with these findings, alterations in the upstream and downstream pathways of Akt have also been found in many psychiatric disorders. Furthermore, both typical and atypical antipsychotic drugs modify the Akt signaling pathway in a variety of conditions relative to schizophrenia. In addition as a survival kinase, Akt participates in neurodevelopment, synaptic plasticity, protein synthesis and neurotransmission in the central nervous system. It is thought that reduced activity of phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway could at least partially explain the cognitive impairment, synaptic morphologic abnormality, neuronal atrophy and dysfunction of neurotransmitter signaling in schizophrenia. In addition, reduced levels of Akt may increase the effects of risk factors on neurodevelopment, attenuate the effects of growth factors on neurodevelopment and reduce the response of patients to antipsychotic agents. More recently, the role of Akt signaling in the functions of schizophrenia susceptibility genes such as disrupted-in-schizophrenia 1 (DISC-1), neuregulin-1 (NRG-1) and dysbindin-1 has been reported. Thus, Akt deficiency may create a context permissive for the expression of risk-gene effects in neuronal morphology and function. This paper reviews the role of Akt in the pathophysiology of schizophrenia and as a potential therapeutic strategy targeting Akt.
Collapse
Affiliation(s)
- Wenhua Zheng
- Neuropharmacology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China.
| | | | | | | | | | | | | |
Collapse
|
50
|
Schizophrenia. Transl Neurosci 2012. [DOI: 10.1017/cbo9780511980053.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
|