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Li H, Aboudhiaf S, Parrot S, Scote-Blachon C, Benetollo C, Lin JS, Seugnet L. Pallidin function in Drosophila surface glia regulates sleep and is dependent on amino acid availability. Cell Rep 2023; 42:113025. [PMID: 37682712 DOI: 10.1016/j.celrep.2023.113025] [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: 12/28/2022] [Revised: 06/16/2023] [Accepted: 08/09/2023] [Indexed: 09/10/2023] Open
Abstract
The Pallidin protein is a central subunit of a multimeric complex called biogenesis of lysosome-related organelles complex 1 (BLOC1) that regulates specific endosomal functions and has been linked to schizophrenia. We show here that downregulation of Pallidin and other members of BLOC1 in the surface glia, the Drosophila equivalent of the blood-brain barrier, reduces and delays nighttime sleep in a circadian-clock-dependent manner. In agreement with BLOC1 involvement in amino acid transport, downregulation of the large neutral amino acid transporter 1 (LAT1)-like transporters JhI-21 and mnd, as well as of TOR (target of rapamycin) amino acid signaling, phenocopy Pallidin knockdown. Furthermore, supplementing food with leucine normalizes the sleep/wake phenotypes of Pallidin downregulation, and we identify a role for Pallidin in the subcellular trafficking of JhI-21. Finally, we provide evidence that Pallidin in surface glia is required for GABAergic neuronal activity. These data identify a BLOC1 function linking essential amino acid availability and GABAergic sleep/wake regulation.
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Affiliation(s)
- Hui Li
- Centre de Recherche en Neurosciences de Lyon, Team WAKING, Université Claude Bernard Lyon 1, INSERM U1028, CNRS UMR 5292, 69675 Bron, France
| | - Sami Aboudhiaf
- Centre de Recherche en Neurosciences de Lyon, Team WAKING, Université Claude Bernard Lyon 1, INSERM U1028, CNRS UMR 5292, 69675 Bron, France
| | - Sandrine Parrot
- Centre de Recherche en Neurosciences de Lyon, NeuroDialyTics Facility, Université Claude Bernard Lyon 1, INSERM U1028, CNRS UMR 5292, 69675 Bron, France
| | - Céline Scote-Blachon
- Centre de Recherche en Neurosciences de Lyon, GenCyTi Facility, Université Claude Bernard Lyon 1, INSERM U1028, CNRS UMR 5292, 69675 Bron, France
| | - Claire Benetollo
- Centre de Recherche en Neurosciences de Lyon, GenCyTi Facility, Université Claude Bernard Lyon 1, INSERM U1028, CNRS UMR 5292, 69675 Bron, France
| | - Jian-Sheng Lin
- Centre de Recherche en Neurosciences de Lyon, Team WAKING, Université Claude Bernard Lyon 1, INSERM U1028, CNRS UMR 5292, 69675 Bron, France
| | - Laurent Seugnet
- Centre de Recherche en Neurosciences de Lyon, Team WAKING, Université Claude Bernard Lyon 1, INSERM U1028, CNRS UMR 5292, 69675 Bron, France.
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2
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Myospryn deficiency leads to impaired cardiac structure and function and schizophrenia-associated symptoms. Cell Tissue Res 2021; 385:675-696. [PMID: 34037836 DOI: 10.1007/s00441-021-03447-2] [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: 11/02/2020] [Accepted: 03/02/2021] [Indexed: 12/25/2022]
Abstract
The desmin-associated protein myospryn, encoded by the cardiomyopathy-associated gene 5 (CMYA5), is a TRIM-like protein associated to the BLOC-1 (Biogenesis of Lysosomes Related Organelles Complex 1) protein dysbindin. Human myospryn mutations are linked to both cardiomyopathy and schizophrenia; however, there is no evidence of a direct causative link of myospryn to these diseases. Therefore, we sought to unveil the role of myospryn in heart and brain. We have genetically inactivated the myospryn gene by homologous recombination and demonstrated that myospryn null hearts have dilated phenotype and compromised cardiac function. Ultrastructural analyses revealed that the sarcomere organization is not obviously affected; however, intercalated disk (ID) integrity is impaired, along with mislocalization of ID and sarcoplasmic reticulum (SR) protein components. Importantly, cardiac and skeletal muscles of myospryn null mice have severe mitochondrial defects with abnormal internal vacuoles and extensive cristolysis. In addition, swollen SR and T-tubules often accompany the mitochondrial defects, strongly implying a potential link of myospryn together with desmin to SR- mitochondrial physical and functional cross-talk. Furthermore, given the reported link of human myospryn mutations to schizophrenia, we performed behavioral studies, which demonstrated that myospryn-deficient male mice display disrupted startle reactivity and prepulse inhibition, asocial behavior, decreased exploratory behavior, and anhedonia. Brain neurochemical and ultrastructural analyses revealed prefrontal-striatal monoaminergic neurotransmitter defects and ultrastructural degenerative aberrations in cerebellar cytoarchitecture, respectively, in myospryn-deficient mice. In conclusion, myospryn is essential for both cardiac and brain structure and function and its deficiency leads to cardiomyopathy and schizophrenia-associated symptoms.
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3
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Delorme TC, Srivastava LK, Cermakian N. Are Circadian Disturbances a Core Pathophysiological Component of Schizophrenia? J Biol Rhythms 2020; 35:325-339. [DOI: 10.1177/0748730420929448] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Schizophrenia is a multifactorial disorder caused by a combination of genetic variations and exposure to environmental insults. Sleep and circadian rhythm disturbances are a prominent and ubiquitous feature of many psychiatric disorders, including schizophrenia. There is growing interest in uncovering the mechanistic link between schizophrenia and circadian rhythms, which may directly affect disorder outcomes. In this review, we explore the interaction between schizophrenia and circadian rhythms from 2 complementary angles. First, we review evidence that sleep and circadian rhythm disturbances constitute a fundamental component of schizophrenia, as supported by both human studies and animal models with genetic mutations related to schizophrenia. Second, we discuss the idea that circadian rhythm disruption interacts with existing risk factors for schizophrenia to promote schizophrenia-relevant behavioral and neurobiological abnormalities. Understanding the mechanistic link between schizophrenia and circadian rhythms will have implications for mitigating risk to the disorder and informing the development of circadian-based therapies.
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Affiliation(s)
- Tara C. Delorme
- Integrated Program in Neuroscience, McGill University, Montréal, Québec, Canada
- Douglas Mental Health University Institute, Montréal, Québec, Canada
| | - Lalit K. Srivastava
- Douglas Mental Health University Institute, Montréal, Québec, Canada
- Department of Psychiatry, McGill University, Montréal, Québec, Canada
| | - Nicolas Cermakian
- Douglas Mental Health University Institute, Montréal, Québec, Canada
- Department of Psychiatry, McGill University, Montréal, Québec, Canada
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4
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Pacault M, Nizon M, Pichon O, Vincent M, Le Caignec C, Isidor B. A de novo 2q37.2 deletion encompassing AGAP1 and SH3BP4 in a patient with autism and intellectual disability. Eur J Med Genet 2018; 62:103586. [PMID: 30472483 DOI: 10.1016/j.ejmg.2018.11.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 10/19/2018] [Accepted: 11/22/2018] [Indexed: 11/27/2022]
Abstract
Autism spectrum disorders are complex neurodevelopmental syndromes characterized by phenotypic and genetic heterogeneity. Further identification of causal genes may help in better understanding the underlying mechanisms of the disorder, thus improving the patients' management. To date, abnormal synaptogenesis is thought to be one of the major underlying causes of autism spectrum disorders. Here, using oligoarray-based comparative genomic hybridization, we identified a de novo deletion at 2q37.2 locus spanning 1 Mb and encompassing AGAP1 and SH3BP4, in a boy with autism and intellectual disability. Both genes have been described as being involved in endosomal trafficking, and AGAP1 in particular has been shown to be expressed in the developing brain and to play a role in dendritic spine formation and synapse function, making it a potential causative gene to our patient's phenotype.
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Affiliation(s)
| | - Mathilde Nizon
- CHU Nantes, Service de Génétique Médicale, Nantes, France
| | - Olivier Pichon
- CHU Nantes, Service de Génétique Médicale, Nantes, France
| | - Marie Vincent
- CHU Nantes, Service de Génétique Médicale, Nantes, France
| | - Cédric Le Caignec
- CHU Nantes, Service de Génétique Médicale, Nantes, France; INSERM, UMR 1238, Bone Sarcoma and Remodeling of Calcified Tissue, Nantes, France
| | - Bertrand Isidor
- CHU Nantes, Service de Génétique Médicale, Nantes, France; INSERM, UMR 1238, Bone Sarcoma and Remodeling of Calcified Tissue, Nantes, France
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5
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Lee FY, Wang HB, Hitchcock ON, Loh DH, Whittaker DS, Kim YS, Aiken A, Kokikian C, Dell'Angelica EC, Colwell CS, Ghiani CA. Sleep/Wake Disruption in a Mouse Model of BLOC-1 Deficiency. Front Neurosci 2018; 12:759. [PMID: 30498428 PMCID: PMC6249416 DOI: 10.3389/fnins.2018.00759] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 10/02/2018] [Indexed: 12/12/2022] Open
Abstract
Mice lacking a functional Biogenesis of Lysosome-related Organelles Complex 1 (BLOC-1), such as those of the pallid line, display cognitive and behavioural impairments reminiscent of those presented by individuals with intellectual and developmental disabilities. Although disturbances in the sleep/wake cycle are commonly lamented by these individuals, the underlying mechanisms, including the possible role of the circadian timing system, are still unknown. In this paper, we have explored sleep/circadian malfunctions and underlying mechanisms in BLOC-1-deficient pallid mice. These mutants exhibited less sleep behaviour in the beginning of the resting phase than wild-type mice with a more broken sleeping pattern in normal light-dark conditions. Furthermore, the strength of the activity rhythms in the mutants were reduced with significantly more fragmentation and lower precision than in age-matched controls. These symptoms were accompanied by an abnormal preference for the open arm in the elevated plus maze in the day and poor performance in the novel object recognition at night. At the level of the central circadian clock (the suprachiasmatic nucleus, SCN), loss of BLOC-1 caused subtle morphological changes including a larger SCN and increased expression of the relative levels of the clock gene Per2 product during the day but did not affect the neuronal activity rhythms. In the hippocampus, the pallid mice presented with anomalies in the cytoarchitecture of the Dentate Gyrus granule cells, but not in CA1 pyramidal neurones, along with altered PER2 protein levels as well as reduced pCREB/tCREB ratio during the day. Our findings suggest that lack of BLOC-1 in mice disrupts the sleep/wake cycle and performance in behavioural tests associated with specific alterations in cytoarchitecture and protein expression.
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Affiliation(s)
- Frank Y Lee
- Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Huei-Bin Wang
- Molecular, Cellular, & Integrative Physiology Program, University of California, Los Angeles, Los Angeles, CA, United States
| | - Olivia N Hitchcock
- Integrative Biology and Physiology Program, University of California, Los Angeles, Los Angeles, CA, United States
| | - Dawn Hsiao Loh
- Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Daniel S Whittaker
- Molecular, Cellular, & Integrative Physiology Program, University of California, Los Angeles, Los Angeles, CA, United States
| | - Yoon-Sik Kim
- Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Achilles Aiken
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Collette Kokikian
- Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Esteban C Dell'Angelica
- Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Christopher S Colwell
- Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Cristina A Ghiani
- Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States.,Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
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6
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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.
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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
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7
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Hartwig C, Monis WJ, Chen X, Dickman DK, Pazour GJ, Faundez V. Neurodevelopmental disease mechanisms, primary cilia, and endosomes converge on the BLOC-1 and BORC complexes. Dev Neurobiol 2017; 78:311-330. [PMID: 28986965 DOI: 10.1002/dneu.22542] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Revised: 09/08/2017] [Accepted: 09/15/2017] [Indexed: 12/12/2022]
Abstract
The biogenesis of lysosome-related organelles complex-1 (BLOC-1) and the bloc-one-related complex (BORC) are the cytosolic protein complexes required for specialized membrane protein traffic along the endocytic route and the spatial distribution of endosome-derived compartments, respectively. BLOC-1 and BORC complex subunits and components of their interactomes have been associated with the risk and/or pathomechanisms of neurodevelopmental disorders. Thus, cellular processes requiring BLOC-1 and BORC interactomes have the potential to offer novel insight into mechanisms underlying behavioral defects. We focus on interactions between BLOC-1 or BORC subunits with the actin and microtubule cytoskeleton, membrane tethers, and SNAREs. These interactions highlight requirements for BLOC-1 and BORC in membrane movement by motors, control of actin polymerization, and targeting of membrane proteins to specialized cellular domains such as the nerve terminal and the primary cilium. We propose that the endosome-primary cilia pathway is an underappreciated hub in the genesis and mechanisms of neurodevelopmental disorders. © 2017 Wiley Periodicals, Inc. Develop Neurobiol 78: 311-330, 2018.
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Affiliation(s)
- Cortnie Hartwig
- Department of Cell Biology, Emory University, Atlanta, Georgia, 30322
| | - William J Monis
- Program in Molecular Medicine, University of Massachusetts Medical School, Biotech II, Worcester, Massachusetts, 01605
| | - Xun Chen
- Department of Biology, Neurobiology Section, University of Southern California, Los Angeles, California, 90089
| | - Dion K Dickman
- Department of Biology, Neurobiology Section, University of Southern California, Los Angeles, California, 90089
| | - Gregory J Pazour
- Program in Molecular Medicine, University of Massachusetts Medical School, Biotech II, Worcester, Massachusetts, 01605
| | - Victor Faundez
- Department of Cell Biology, Emory University, Atlanta, Georgia, 30322
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8
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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: 28] [Impact Index Per Article: 4.0] [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.
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9
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Ghiani CA, Faundez V. Cellular and molecular mechanisms of neurodevelopmental disorders. J Neurosci Res 2017; 95:1093-1096. [PMID: 28225560 DOI: 10.1002/jnr.24041] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Revised: 01/30/2017] [Accepted: 01/31/2017] [Indexed: 01/19/2023]
Affiliation(s)
- Cristina A Ghiani
- Departments of Pathology & Laboratory Medicine and Psychiatry & Biobehavioral Sciences, Intellectual and Developmental Disabilities Research Center, University of California Los Angeles, Los Angeles, California, 90095, USA
| | - Victor Faundez
- Department of Cell Biology and the Center for Social Translational Neuroscience, Emory University, Atlanta, GA, 30322, USA
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10
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The BLOC-1 Subunit Pallidin Facilitates Activity-Dependent Synaptic Vesicle Recycling. eNeuro 2017; 4:eN-NWR-0335-16. [PMID: 28317021 PMCID: PMC5356223 DOI: 10.1523/eneuro.0335-16.2017] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Revised: 01/06/2017] [Accepted: 01/24/2017] [Indexed: 02/02/2023] Open
Abstract
Membrane trafficking pathways must be exquisitely coordinated at synaptic terminals to maintain functionality, particularly during conditions of high activity. We have generated null mutations in the Drosophila homolog of pallidin, a central subunit of the biogenesis of lysosome-related organelles complex-1 (BLOC-1), to determine its role in synaptic development and physiology. We find that Pallidin localizes to presynaptic microtubules and cytoskeletal structures, and that the stability of Pallidin protein is highly dependent on the BLOC-1 components Dysbindin and Blos1. We demonstrate that the rapidly recycling vesicle pool is not sustained during high synaptic activity in pallidin mutants, leading to accelerated rundown and slowed recovery. Following intense activity, we observe a loss of early endosomes and a concomitant increase in tubular endosomal structures in synapses without Pallidin. Together, our data reveal that Pallidin subserves a key role in promoting efficient synaptic vesicle recycling and re-formation through early endosomes during sustained activity.
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11
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Arnold M, Cross R, Singleton KS, Zlatic S, Chapleau C, Mullin AP, Rolle I, Moore CC, Theibert A, Pozzo-Miller L, Faundez V, Larimore J. The Endosome Localized Arf-GAP AGAP1 Modulates Dendritic Spine Morphology Downstream of the Neurodevelopmental Disorder Factor Dysbindin. Front Cell Neurosci 2016; 10:218. [PMID: 27713690 PMCID: PMC5031601 DOI: 10.3389/fncel.2016.00218] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2016] [Accepted: 09/06/2016] [Indexed: 11/13/2022] Open
Abstract
AGAP1 is an Arf1 GTPase activating protein that interacts with the vesicle-associated protein complexes adaptor protein 3 (AP-3) and Biogenesis of Lysosome Related Organelles Complex-1 (BLOC-1). Overexpression of AGAP1 in non-neuronal cells results in an accumulation of endosomal cargoes, which suggests a role in endosome-dependent traffic. In addition, AGAP1 is a candidate susceptibility gene for two neurodevelopmental disorders, autism spectrum disorder (ASD) and schizophrenia (SZ); yet its localization and function in neurons have not been described. Here, we describe that AGAP1 localizes to axons, dendrites, dendritic spines and synapses, colocalizing preferentially with markers of early and recycling endosomes. Functional studies reveal overexpression and down-regulation of AGAP1 affects both neuronal endosomal trafficking and dendritic spine morphology, supporting a role for AGAP1 in the recycling endosomal trafficking involved in their morphogenesis. Finally, we determined the sensitivity of AGAP1 expression to mutations in the DTNBP1 gene, which is associated with neurodevelopmental disorder, and found that AGAP1 mRNA and protein levels are selectively reduced in the null allele of the mouse ortholog of DTNBP1. We postulate that endosomal trafficking contributes to the pathogenesis of neurodevelopmental disorders affecting dendritic spine morphology, and thus excitatory synapse structure and function.
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Affiliation(s)
- Miranda Arnold
- Department of Biology, Agnes-Scott College Decatur, GA, USA
| | - Rebecca Cross
- Department of Biology, Agnes-Scott College Decatur, GA, USA
| | - Kaela S Singleton
- Interdisciplinary Program in Neuroscience, Georgetown University Washington, DC, USA
| | | | - Christopher Chapleau
- Department of Neurobiology, Civitan International Research Center, University of Alabama Birmingham, AL, USA
| | | | - Isaiah Rolle
- Heritage College of Osteopathic Medicine, The Medical School of Ohio University Athens, OH, USA
| | - Carlene C Moore
- Department of Neurobiology, Civitan International Research Center, University of Alabama Birmingham, AL, USA
| | - Anne Theibert
- Department of Neurobiology, Civitan International Research Center, University of Alabama Birmingham, AL, USA
| | - Lucas Pozzo-Miller
- Department of Neurobiology, Civitan International Research Center, University of Alabama Birmingham, AL, USA
| | - Victor Faundez
- Department of Cell Biology, Emory University Atlanta, GA, USA
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12
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Delevoye C, Heiligenstein X, Ripoll L, Gilles-Marsens F, Dennis MK, Linares RA, Derman L, Gokhale A, Morel E, Faundez V, Marks MS, Raposo G. BLOC-1 Brings Together the Actin and Microtubule Cytoskeletons to Generate Recycling Endosomes. Curr Biol 2015; 26:1-13. [PMID: 26725201 DOI: 10.1016/j.cub.2015.11.020] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Revised: 10/15/2015] [Accepted: 11/09/2015] [Indexed: 12/18/2022]
Abstract
Recycling endosomes consist of a tubular network that emerges from vacuolar sorting endosomes and diverts cargoes toward the cell surface, the Golgi, or lysosome-related organelles. How recycling tubules are formed remains unknown. We show that recycling endosome biogenesis requires the protein complex BLOC-1. Mutations in BLOC-1 subunits underlie an inherited disorder characterized by albinism, the Hermansky-Pudlak Syndrome, and are associated with schizophrenia risk. We show here that BLOC-1 coordinates the kinesin KIF13A-dependent pulling of endosomal tubules along microtubules to the Annexin A2/actin-dependent stabilization and detachment of recycling tubules. These components cooperate to extend, stabilize and form tubular endosomal carriers that function in cargo recycling and in the biogenesis of pigment granules in melanocytic cells. By shaping recycling endosomal tubules, our data reveal that dysfunction of the BLOC-1-KIF13A-Annexin A2 molecular network underlies the pathophysiology of neurological and pigmentary disorders.
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Affiliation(s)
- Cédric Delevoye
- Institut Curie, PSL Research University, CNRS, UMR144, Structure and Membrane Compartments, 75005 Paris, France; Institut Curie, PSL Research University, CNRS, UMR144, Cell and Tissue Imaging Facility (PICT-IBiSA), 75005 Paris, France.
| | - Xavier Heiligenstein
- Institut Curie, PSL Research University, CNRS, UMR144, Structure and Membrane Compartments, 75005 Paris, France
| | - Léa Ripoll
- Institut Curie, PSL Research University, CNRS, UMR144, Structure and Membrane Compartments, 75005 Paris, France
| | - Floriane Gilles-Marsens
- Institut Curie, PSL Research University, CNRS, UMR144, Structure and Membrane Compartments, 75005 Paris, France
| | - Megan K Dennis
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; Department of Pathology and Laboratory Medicine and Department of Physiology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Ricardo A Linares
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; Department of Pathology and Laboratory Medicine and Department of Physiology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Laura Derman
- Institut Curie, PSL Research University, CNRS, UMR144, Structure and Membrane Compartments, 75005 Paris, France
| | - Avanti Gokhale
- Department of Cell Biology and the Center for Social Translational Neuroscience, Emory University, Atlanta, GA 30322, USA
| | - Etienne Morel
- INSERM U1151-CNRS UMR 8253, Institut Necker Enfants-Malades (INEM) Université, Paris Descartes-Sorbonne Paris Cité Paris, 75993 Paris Cedex 14, France
| | - Victor Faundez
- Department of Cell Biology and the Center for Social Translational Neuroscience, Emory University, Atlanta, GA 30322, USA
| | - Michael S Marks
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; Department of Pathology and Laboratory Medicine and Department of Physiology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Graça Raposo
- Institut Curie, PSL Research University, CNRS, UMR144, Structure and Membrane Compartments, 75005 Paris, France; Institut Curie, PSL Research University, CNRS, UMR144, Cell and Tissue Imaging Facility (PICT-IBiSA), 75005 Paris, France
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13
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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.
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Zhao Z, Xu J, Chen J, Kim S, Reimers M, Bacanu SA, Yu H, Liu C, Sun J, Wang Q, Jia P, Xu F, Zhang Y, Kendler KS, Peng Z, Chen X. Transcriptome sequencing and genome-wide association analyses reveal lysosomal function and actin cytoskeleton remodeling in schizophrenia and bipolar disorder. Mol Psychiatry 2015; 20:563-572. [PMID: 25113377 PMCID: PMC4326626 DOI: 10.1038/mp.2014.82] [Citation(s) in RCA: 112] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Revised: 05/23/2014] [Accepted: 06/17/2014] [Indexed: 12/20/2022]
Abstract
Schizophrenia (SCZ) and bipolar disorder (BPD) are severe mental disorders with high heritability. Clinicians have long noticed the similarities of clinic symptoms between these disorders. In recent years, accumulating evidence indicates some shared genetic liabilities. However, what is shared remains elusive. In this study, we conducted whole transcriptome analysis of post-mortem brain tissues (cingulate cortex) from SCZ, BPD and control subjects, and identified differentially expressed genes in these disorders. We found 105 and 153 genes differentially expressed in SCZ and BPD, respectively. By comparing the t-test scores, we found that many of the genes differentially expressed in SCZ and BPD are concordant in their expression level (q⩽0.01, 53 genes; q⩽0.05, 213 genes; q⩽0.1, 885 genes). Using genome-wide association data from the Psychiatric Genomics Consortium, we found that these differentially and concordantly expressed genes were enriched in association signals for both SCZ (P<10(-7)) and BPD (P=0.029). To our knowledge, this is the first time that a substantially large number of genes show concordant expression and association for both SCZ and BPD. Pathway analyses of these genes indicated that they are involved in the lysosome, Fc gamma receptor-mediated phagocytosis, regulation of actin cytoskeleton pathways, along with several cancer pathways. Functional analyses of these genes revealed an interconnected pathway network centered on lysosomal function and the regulation of actin cytoskeleton. These pathways and their interacting network were principally confirmed by an independent transcriptome sequencing data set of the hippocampus. Dysregulation of lysosomal function and cytoskeleton remodeling has direct impacts on endocytosis, phagocytosis, exocytosis, vesicle trafficking, neuronal maturation and migration, neurite outgrowth and synaptic density and plasticity, and different aspects of these processes have been implicated in SCZ and BPD.
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Affiliation(s)
- Zhongming Zhao
- Departments of Biomedical Informatics and Psychiatry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Jiabao Xu
- Beijing Genomics Institute (BGI), Shenzhen, Guangdong, 518083, China
| | - Jingchun Chen
- Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Sanghyeon Kim
- Stanley Laboratory of Brain Research, 9800 Medical Center Drive, Rockville, MD 20850, USA
| | - Mark Reimers
- Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Silviu-Alin Bacanu
- Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Hui Yu
- Departments of Biomedical Informatics and Psychiatry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Chunyu Liu
- Department of Psychiatry, University of Illinois at Chicago, Chicago, IL 60637, USA
| | - Jingchun Sun
- Departments of Biomedical Informatics and Psychiatry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Quan Wang
- Departments of Biomedical Informatics and Psychiatry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Peilin Jia
- Departments of Biomedical Informatics and Psychiatry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Fengping Xu
- Beijing Genomics Institute (BGI), Shenzhen, Guangdong, 518083, China
| | - Yong Zhang
- Beijing Genomics Institute (BGI), Shenzhen, Guangdong, 518083, China
| | - Kenneth S. Kendler
- Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Zhiyu Peng
- Beijing Genomics Institute (BGI), Shenzhen, Guangdong, 518083, China
| | - Xiangning Chen
- Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University, Richmond, VA 23298, USA
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15
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Sun X, Pinacho R, Saia G, Punko D, Meana JJ, Ramos B, Gill G. Transcription factor Sp4 regulates expression of nervous wreck 2 to control NMDAR1 levels and dendrite patterning. Dev Neurobiol 2014; 75:93-108. [PMID: 25045015 DOI: 10.1002/dneu.22212] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Revised: 06/20/2014] [Accepted: 07/13/2014] [Indexed: 02/06/2023]
Abstract
Glutamatergic signaling through N-methyl-d-aspartate receptors (NMDARs) is important for neuronal development and plasticity and is often dysregulated in psychiatric disorders. Mice mutant for the transcription factor Sp4 have reduced levels of NMDAR subunit 1 (NR1) protein, but not mRNA, and exhibit behavioral and memory deficits (Zhou et al., [2010] Human Molecular Genetics 19: 3797-3805). In developing cerebellar granule neurons (CGNs), Sp4 controls dendrite patterning (Ramos et al., [2007] Proc Natl Acad Sci USA 104: 9882-9887). Sp4 target genes that regulate dendrite pruning or NR1 levels are not known. Here we report that Sp4 activates transcription of Nervous Wreck 2 (Nwk2; also known as Fchsd1) and, further, that Nwk2, an F-BAR domain-containing protein, mediates Sp4-dependent regulation of dendrite patterning and cell surface expression of NR1. Knockdown of Nwk2 in CGNs increased primary dendrite number, phenocopying Sp4 knockdown, and exogenous expression of Nwk2 in Sp4-depleted neurons rescued dendrite number. We observed that acute Sp4 depletion reduced levels of surface, but not total, NR1, and this was rescued by Nwk2 expression. Furthermore, expression of Nr1 suppressed the increase in dendrite number in Sp4- or Nwk2- depleted neurons. We previously reported that Sp4 protein levels were reduced in cerebellum of subjects with bipolar disorder (BD) (Pinacho et al., [2011] Bipolar Disorders 13: 474-485). Here we report that Nwk2 mRNA and NR1 protein levels were also reduced in postmortem cerebellum of BD subjects. Our data suggest a role for Sp4-regulated Nwk2 in NMDAR trafficking and identify a Sp4-Nwk2-NMDAR1 pathway that regulates neuronal morphogenesis during development and may be disrupted in bipolar disorder.
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Affiliation(s)
- Xinxin Sun
- Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine, Boston, Massachusetts, 02111; Genetics Program, Sackler School of Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts, 02111
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16
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An association study of the Hermansky-Pudlak syndrome type 4 gene in schizophrenic patients. Psychiatr Genet 2014; 23:163-73. [PMID: 23563589 DOI: 10.1097/ypg.0b013e32836130a9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
OBJECTIVE We encountered two Japanese siblings who had Hermansky-Pudlak syndrome (HPS) and major mental disorders (schizophrenia and major depression) as well. As it is known that HPS is caused by a local mutation in one of the human genes, named HPS1 to HPS8 and PLDN (HPS9), encoding subunit proteins involved in endosomal trafficking pathways, here, we report the mutation causing the siblings disease and a case-control association study of schizophrenia using polymorphisms of a gene to be screened in the mutation analysis. METHODS We analyzed three HPS-causing genes, HPS1, HPS4, and HPS7, to identify a genetic mutation involved in the siblings. A case-control association study of nine tagging single-nucleotide polymorphisms of the entire genetic region of the HPS4 gene resulting from the screening in the siblings was carried out for schizophrenic patients (n=422) and controls (n=578). RESULTS The two patients with HPS were homozygous for nonsense mutation (T/T) for the c.541C>T (rs119471022) in the HPS4 gene, which is mapped to human chromosome 22q12.1. The same nonsense mutation existed in the heterozygous state (C/T) in their mother and in two other siblings. The genotypic distribution of rs9608491 (C/T) in intron 4 showed a trend toward an association with schizophrenia as indicated by a corrected P-value of 0.053 controlling for multiple testing. Haplotype analyses showed that two of two-locus haplotypes, and all of three-locus, four-locus, and five-locus haplotypes, as they share rs9608491, yielded significant evidence for association with schizophrenia as shown by the following omnibus P-values. When rs4822724, rs61276843, rs9608491, rs713998, and rs2014410, five haplotype tagging single-nucleotide polymorphisms, are assigned serial numerals (1, 2, 3, 4, and 5), the omnibus P-values for the resulting haplotypes were P=0.0039 for 2-3, P=0.0142 for 3-4, P=0.0083 for 1-2-3, P=0.0187 for 2-3-4, P=0.0191 for 3-4-5, P=0.0270 for 1-2-3-4, P=0.0246 for 2-3-4-5, and 0.0261 for 1-2-3-4-5. CONCLUSION These results suggest that the HPS4 gene confers a susceptibility to schizophrenia.
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The effect of clozapine on mRNA expression for genes encoding G protein-coupled receptors and the protein components of clathrin-mediated endocytosis. Psychiatr Genet 2014; 23:153-62. [PMID: 23811784 PMCID: PMC4206381 DOI: 10.1097/ypg.0b013e32835fe51d] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVES Clathrin-mediated endocytosis (CME) is an intracellular trafficking mechanism for packaging cargo, including G protein-coupled receptors (GPCRs), into clathrin-coated vesicles (CCVs). The antipsychotic chlorpromazine inhibits CCV assembly of adaptor protein AP2 whereas clozapine increases serotonin2A receptor internalization. We hypothesized that clozapine alters the expression of CME genes modulating vesicle turnover and GPCR internalization. MATERIALS AND METHODS SH-SY5Y human neuroblastoma cells were incubated with clozapine (1-20 µmol/l) for 24-72 h. GPCR and CME-related gene mRNA expression was measured using RT-PCR. We quantified changes in the same genes using expression data from a microarray study of mice brains after 12 weeks of treatment with 12 mg/kg/day clozapine. RESULTS The expression of genes encoding adaptor and clathrin assembly proteins, AP2A2, AP2B1, AP180, CLINT1, HIP1, ITSN2, and PICALM, increased relative to the control in SH-SY5Y cells incubated with 5-10 µmol/l clozapine for 24-72 h. The microarray study showed significantly altered expression of the above CME-related genes, with a marked 641-fold and 17-fold increase in AP180 and the serotonin1A GPCR, respectively. The expression of three serotonergic receptor and lysophosphatidic acid receptor 2 (EDG4) GPCR genes was upregulated in SH-SY5Y cells incubated with 5 µmol/l clozapine for 24 h. EDG4 expression was also increased with 10-20 µmol/l clozapine treatment at 48-72 h. Clozapine significantly decreased the expression of β-arrestin, involved in GPCR desensitization, both in vitro and vivo. CONCLUSION The changes we report in CME and GPCR mRNAs implicate CCV-mediated internalization of GPCRs and the serotonergic system in clozapine's mechanism of action, which may be useful in the design of more effective and less toxic antipsychotic therapies.
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Mullin AP, Gokhale A, Moreno-De-Luca A, Sanyal S, Waddington JL, Faundez V. Neurodevelopmental disorders: mechanisms and boundary definitions from genomes, interactomes and proteomes. Transl Psychiatry 2013; 3:e329. [PMID: 24301647 PMCID: PMC4030327 DOI: 10.1038/tp.2013.108] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Accepted: 10/22/2013] [Indexed: 02/08/2023] Open
Abstract
Neurodevelopmental disorders such as intellectual disability, autism spectrum disorder and schizophrenia lack precise boundaries in their clinical definitions, epidemiology, genetics and protein-protein interactomes. This calls into question the appropriateness of current categorical disease concepts. Recently, there has been a rising tide to reformulate neurodevelopmental nosological entities from biology upward. To facilitate this developing trend, we propose that identification of unique proteomic signatures that can be strongly associated with patient's risk alleles and proteome-interactome-guided exploration of patient genomes could define biological mechanisms necessary to reformulate disorder definitions.
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Affiliation(s)
- A P Mullin
- Department of Cell Biology, Emory University School of Medicine, Center for Social Translational Neuroscience, Emory University, Atlanta, GA, USA
| | - A Gokhale
- Department of Cell Biology, Emory University School of Medicine, Center for Social Translational Neuroscience, Emory University, Atlanta, GA, USA
| | - A Moreno-De-Luca
- Autism and Developmental Medicine Institute, Genomic Medicine Institute, Geisinger Health System, Danville, PA, USA
| | - S Sanyal
- Department of Cell Biology, Emory University School of Medicine, Center for Social Translational Neuroscience, Emory University, Atlanta, GA, USA,Biogen-Idec, 14 Cambridge Center, Cambridge, MA, USA
| | - J L Waddington
- Molecular & Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - V Faundez
- Department of Cell Biology, Emory University School of Medicine, Center for Social Translational Neuroscience, Emory University, Atlanta, GA, USA,Center for Social Translational Neuroscience, Emory University, Atlanta, GA, USA,Department of Cell Biology, Emory University School of Medicine, Center for Social Translational Neuroscience, Emory University, Atlanta, GA 30322, USA. E-mail:
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19
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Wondolowski J, Dickman D. Emerging links between homeostatic synaptic plasticity and neurological disease. Front Cell Neurosci 2013; 7:223. [PMID: 24312013 PMCID: PMC3836049 DOI: 10.3389/fncel.2013.00223] [Citation(s) in RCA: 95] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2013] [Accepted: 11/03/2013] [Indexed: 01/22/2023] Open
Abstract
Homeostatic signaling systems are ubiquitous forms of biological regulation, having been studied for hundreds of years in the context of diverse physiological processes including body temperature and osmotic balance. However, only recently has this concept been brought to the study of excitatory and inhibitory electrical activity that the nervous system uses to establish and maintain stable communication. Synapses are a primary target of neuronal regulation with a variety of studies over the past 15 years demonstrating that these cellular junctions are under bidirectional homeostatic control. Recent work from an array of diverse systems and approaches has revealed exciting new links between homeostatic synaptic plasticity and a variety of seemingly disparate neurological and psychiatric diseases. These include autism spectrum disorders, intellectual disabilities, schizophrenia, and Fragile X Syndrome. Although the molecular mechanisms through which defective homeostatic signaling may lead to disease pathogenesis remain unclear, rapid progress is likely to be made in the coming years using a powerful combination of genetic, imaging, electrophysiological, and next generation sequencing approaches. Importantly, understanding homeostatic synaptic plasticity at a cellular and molecular level may lead to developments in new therapeutic innovations to treat these diseases. In this review we will examine recent studies that demonstrate homeostatic control of postsynaptic protein translation, retrograde signaling, and presynaptic function that may contribute to the etiology of complex neurological and psychiatric diseases.
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Affiliation(s)
- Joyce Wondolowski
- Department of Biology, University of Southern California Los Angeles, CA, USA
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20
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Tobe BTD, Brandel MG, Nye JS, Snyder EY. Implications and limitations of cellular reprogramming for psychiatric drug development. Exp Mol Med 2013; 45:e59. [PMID: 24232258 PMCID: PMC3849573 DOI: 10.1038/emm.2013.124] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Accepted: 08/28/2013] [Indexed: 12/28/2022] Open
Abstract
Human-induced pluripotent stem cells (hiPSCs) derived from somatic cells of patients have opened possibilities for in vitro modeling of the physiology of neural (and other) cells in psychiatric disease states. Issues in early stages of technology development include (1) establishing a library of cells from adequately phenotyped patients, (2) streamlining laborious, costly hiPSC derivation and characterization, (3) assessing whether mutations or other alterations introduced by reprogramming confound interpretation, (4) developing efficient differentiation strategies to relevant cell types, (5) identifying discernible cellular phenotypes meaningful for cyclic, stress induced or relapsing-remitting diseases, (6) converting phenotypes to screening assays suitable for genome-wide mechanistic studies or large collection compound testing and (7) controlling for variability in relation to disease specificity amidst low sample numbers. Coordination of material for reprogramming from patients well-characterized clinically, genetically and with neuroimaging are beginning, and initial studies have begun to identify cellular phenotypes. Finally, several psychiatric drugs have been found to alter reprogramming efficiency in vitro, suggesting further complexity in applying hiPSCs to psychiatric diseases or that some drugs influence neural differentiation moreso than generally recognized. Despite these challenges, studies utilizing hiPSCs may eventually serve to fill essential niches in the translational pipeline for the discovery of new therapeutics.
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Affiliation(s)
- Brian T D Tobe
- 1] Program in Stem Cell and Regenerative Biology, Sanford-Burnham Medical Research Institute, Burnham Institute for Medical Research, La Jolla, CA, USA [2] Department of Psychiatry, Veterans Administration Medical Center, La Jolla, CA, USA
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21
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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.
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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
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Cacabelos R, Cacabelos P, Aliev G. Genomics of schizophrenia and pharmacogenomics of antipsychotic drugs. ACTA ACUST UNITED AC 2013. [DOI: 10.4236/ojpsych.2013.31008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Schubert KO, Föcking M, Prehn JHM, Cotter DR. Hypothesis review: are clathrin-mediated endocytosis and clathrin-dependent membrane and protein trafficking core pathophysiological processes in schizophrenia and bipolar disorder? Mol Psychiatry 2012; 17:669-81. [PMID: 21986877 DOI: 10.1038/mp.2011.123] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Clathrin-mediated endocytosis (CME) is the best-characterized mechanism governing cellular membrane and protein trafficking. In this hypothesis review, we integrate recent evidence implicating CME and related cellular trafficking mechanisms in the pathophysiology of psychotic disorders such as schizophrenia and bipolar disorder. The evidence includes proteomic and genomic findings implicating proteins and genes of the clathrin interactome. Additionally, several important candidate genes for schizophrenia, such as dysbindin, are involved in processes closely linked to CME and membrane trafficking. We discuss that key aspects of psychosis neuropathology such as synaptic dysfunction, white matter changes and aberrant neurodevelopment are all influenced by clathrin-dependent processes, and that other cellular trafficking mechanisms previously linked to psychoses interact with the clathrin interactome in important ways. Furthermore, many antipsychotic drugs have been shown to affect clathrin-interacting proteins. We propose that the targeted pharmacological manipulation of the clathrin interactome may offer fruitful opportunities for novel treatments of schizophrenia.
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Affiliation(s)
- K O Schubert
- Department of Psychiatry, Royal College of Surgeons in Ireland, Beaumont Hospital, Dublin, Republic of Ireland
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Schmitt A, Leonardi-Essmann F, Durrenberger PF, Wichert SP, Spanagel R, Arzberger T, Kretzschmar H, Zink M, Herrera-Marschitz M, Reynolds R, Rossner MJ, Falkai P, Gebicke-Haerter PJ. Structural synaptic elements are differentially regulated in superior temporal cortex of schizophrenia patients. Eur Arch Psychiatry Clin Neurosci 2012; 262:565-77. [PMID: 22441714 PMCID: PMC3464383 DOI: 10.1007/s00406-012-0306-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2011] [Accepted: 03/01/2012] [Indexed: 11/26/2022]
Abstract
Inaccurate wiring and synaptic pathology appear to be major hallmarks of schizophrenia. A variety of gene products involved in synaptic neurotransmission and receptor signaling are differentially expressed in brains of schizophrenia patients. However, synaptic pathology may also develop by improper expression of intra- and extra-cellular structural elements weakening synaptic stability. Therefore, we have investigated transcription of these elements in the left superior temporal gyrus of 10 schizophrenia patients and 10 healthy controls by genome-wide microarrays (Illumina). Fourteen up-regulated and 22 downregulated genes encoding structural elements were chosen from the lists of differentially regulated genes for further qRT-PCR analysis. Almost all genes confirmed by this method were downregulated. Their gene products belonged to vesicle-associated proteins, that is, synaptotagmin 6 and syntaxin 12, to cytoskeletal proteins, like myosin 6, pleckstrin, or to proteins of the extracellular matrix, such as collagens, or laminin C3. Our results underline the pivotal roles of structural genes that control formation and stabilization of pre- and post-synaptic elements or influence axon guidance in schizophrenia. The glial origin of collagen or laminin highlights the close interrelationship between neurons and glial cells in establishment and maintenance of synaptic strength and plasticity. It is hypothesized that abnormal expression of these and related genes has a major impact on the pathophysiology of schizophrenia.
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Affiliation(s)
- Andrea Schmitt
- Department of Psychiatry and Psychotherapy, University of Göttingen, Germany.
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25
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Larimore J, Tornieri K, Ryder PV, Gokhale A, Zlatic SA, Craige B, Lee JD, Talbot K, Pare JF, Smith Y, Faundez V. The schizophrenia susceptibility factor dysbindin and its associated complex sort cargoes from cell bodies to the synapse. Mol Biol Cell 2011; 22:4854-67. [PMID: 21998198 PMCID: PMC3237628 DOI: 10.1091/mbc.e11-07-0592] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2011] [Revised: 09/08/2011] [Accepted: 10/07/2011] [Indexed: 11/11/2022] Open
Abstract
Dysbindin assembles into the biogenesis of lysosome-related organelles complex 1 (BLOC-1), which interacts with the adaptor protein complex 3 (AP-3), mediating a common endosome-trafficking route. Deficiencies in AP-3 and BLOC-1 affect synaptic vesicle composition. However, whether AP-3-BLOC-1-dependent sorting events that control synapse membrane protein content take place in cell bodies upstream of nerve terminals remains unknown. We tested this hypothesis by analyzing the targeting of phosphatidylinositol-4-kinase type II α (PI4KIIα), a membrane protein present in presynaptic and postsynaptic compartments. PI4KIIα copurified with BLOC-1 and AP-3 in neuronal cells. These interactions translated into a decreased PI4KIIα content in the dentate gyrus of dysbindin-null BLOC-1 deficiency and AP-3-null mice. Reduction of PI4KIIα in the dentate reflects a failure to traffic from the cell body. PI4KIIα was targeted to processes in wild-type primary cultured cortical neurons and PC12 cells but failed to reach neurites in cells lacking either AP-3 or BLOC-1. Similarly, disruption of an AP-3-sorting motif in PI4KIIα impaired its sorting into processes of PC12 and primary cultured cortical neuronal cells. Our findings indicate a novel vesicle transport mechanism requiring BLOC-1 and AP-3 complexes for cargo sorting from neuronal cell bodies to neurites and nerve terminals.
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Affiliation(s)
| | - Karine Tornieri
- Department of Cell Biology, Emory University, Atlanta, GA 30322
| | - Pearl V. Ryder
- Department of Cell Biology, Emory University, Atlanta, GA 30322
- Graduate Program in Biochemistry, Cell, and Developmental Biology, Emory University, Atlanta, GA 30322
| | - Avanti Gokhale
- Department of Cell Biology, Emory University, Atlanta, GA 30322
| | - Stephanie A. Zlatic
- Department of Cell Biology, Emory University, Atlanta, GA 30322
- Graduate Program in Biochemistry, Cell, and Developmental Biology, Emory University, Atlanta, GA 30322
| | - Branch Craige
- Department of Cell Biology, Emory University, Atlanta, GA 30322
- Graduate Program in Biochemistry, Cell, and Developmental Biology, Emory University, Atlanta, GA 30322
| | - Joshua D. Lee
- Center for Neurobiology and Behavior, Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104
| | - Konrad Talbot
- Center for Neurobiology and Behavior, Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104
| | | | - Yoland Smith
- Department of Neurology and Yerkes National Primate Research Center
| | - Victor Faundez
- Department of Cell Biology, Emory University, Atlanta, GA 30322
- Graduate Program in Biochemistry, Cell, and Developmental Biology, Emory University, Atlanta, GA 30322
- Center for Neurodegenerative Disease, Emory University, Atlanta, GA 30322
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Abstract
Schizophrenia (SCZ) is among the most disabling of mental disorders. Several neurobiological hypotheses have been postulated as responsible for SCZ pathogenesis: polygenic/multifactorial genomic defects, intrauterine and perinatal environment-genome interactions, neurodevelopmental defects, dopaminergic, cholinergic, serotonergic, gamma-aminobutiric acid (GABAergic), neuropeptidergic and glutamatergic/N-Methyl-D-Aspartate (NMDA) dysfunctions, seasonal infection, neuroimmune dysfunction, and epigenetic dysregulation. SCZ has a heritability estimated at 60-90%. Genetic studies in SCZ have revealed the presence of chromosome anomalies, copy number variants, multiple single-nucleotide polymorphisms of susceptibility distributed across the human genome, aberrant single nucleotide polymorphisms (SNPs) in microRNA genes, mitochondrial DNA mutations, and epigenetic phenomena. Pharmacogenetic studies of psychotropic drug response have focused on determining the relationship between variation in specific candidate genes and the positive and adverse effects of drug treatment. Approximately, 18% of neuroleptics are major substrates of CYP1A2 enzymes, 40% of CYP2D6, and 23% of CYP3A4; 24% of antidepressants are major substrates of CYP1A2 enzymes, 5% of CYP2B6, 38% of CYP2C19, 85% of CYP2D6, and 38% of CYP3A4; 7% of benzodiazepines are major substrates of CYP2C19 enzymes, 20% of CYP2D6, and 95% of CYP3A4. About 10-20% of Western populations are defective in genes of the CYP superfamily. Only 26% of Southern Europeans are pure extensive metabolizers for the trigenic cluster integrated by the CYP2D6+CYP2C19+CYP2C9 genes. The pharmacogenomic response of SCZ patients to conventional psychotropic drugs also depends on genetic variants associated with SCZ-related genes. Consequently, the incorporation of pharmacogenomic procedures both to drugs in development and drugs on the market would help to optimize therapeutics in SCZ and other central nervous system (CNS) disorders.
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Affiliation(s)
- Ramón Cacabelos
- EuroEspes Biomedical Research Center, 15165-Bergondo, Coruña, Spain.
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27
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Talbot K, Louneva N, Cohen JW, Kazi H, Blake DJ, Arnold SE. Synaptic dysbindin-1 reductions in schizophrenia occur in an isoform-specific manner indicating their subsynaptic location. PLoS One 2011; 6:e16886. [PMID: 21390302 PMCID: PMC3046962 DOI: 10.1371/journal.pone.0016886] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2010] [Accepted: 01/06/2011] [Indexed: 01/16/2023] Open
Abstract
BACKGROUND An increasing number of studies report associations between variation in DTNBP1, a top candidate gene in schizophrenia, and both the clinical symptoms of the disorder and its cognitive deficits. DTNBP1 encodes dysbindin-1, reduced levels of which have been found in synaptic fields of schizophrenia cases. This study determined whether such synaptic reductions are isoform-specific. METHODOLOGY/PRINCIPAL FINDINGS Using Western blotting of tissue fractions, we first determined the synaptic localization of the three major dysbindin-1 isoforms (A, B, and C). All three were concentrated in synaptosomes of multiple brain areas, including auditory association cortices in the posterior half of the superior temporal gyrus (pSTG) and the hippocampal formation (HF). Tests on the subsynaptic tissue fractions revealed that each isoform is predominantly, if not exclusively, associated with synaptic vesicles (dysbindin-1B) or with postsynaptic densities (dysbindin-1A and -1C). Using Western blotting on pSTG (n = 15) and HF (n = 15) synaptosomal fractions from schizophrenia cases and their matched controls, we discovered that synaptic dysbindin-1 is reduced in an isoform-specific manner in schizophrenia without changes in levels of synaptophysin or PSD-95. In pSTG, about 92% of the schizophrenia cases displayed synaptic dysbindin-1A reductions averaging 48% (p = 0.0007) without alterations in other dysbindin-1 isoforms. In the HF, by contrast, schizophrenia cases displayed normal levels of synaptic dysbindin-1A, but 67% showed synaptic reductions in dysbindin-1B averaging 33% (p = 0.0256), while 80% showed synaptic reductions in dysbindin-1C averaging 35% (p = 0.0171). CONCLUSIONS/SIGNIFICANCE Given the distinctive subsynaptic localization of dysbindin-1A, -1B, and -1C across brain regions, the observed pSTG reductions in dysbindin-1A are postsynaptic and may promote dendritic spine loss with consequent disruption of auditory information processing, while the noted HF reductions in dysbindin-1B and -1C are both presynaptic and postsynaptic and could promote deficits in spatial working memory.
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Affiliation(s)
- Konrad Talbot
- Department of Psychiatry, Center for Neurobiology and Behavior, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America.
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28
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O'Kane CJ. Drosophila as a model organism for the study of neuropsychiatric disorders. Curr Top Behav Neurosci 2011; 7:37-60. [PMID: 21225410 DOI: 10.1007/7854_2010_110] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The fruitfly Drosophila offers a model system in which powerful genetic tools can be applied to understanding the neurobiological bases of a range of complex behaviors. The Drosophila and human lineages diverged several hundred million years ago, and despite their obvious differences, flies and humans share many fundamental cellular and neurobiological processes. The similarities include fundamental mechanisms of neuronal signaling, a conserved underlying brain architecture and the main classes of neurotransmitter system. Drosophila also have a sophisticated behavioral repertoire that includes extensive abilities to adapt to experience and other circumstances, and is therefore susceptible to the same kinds of insults that can cause neuropsychiatric disorders in humans. Given the different physiologies, lifestyles, and cognitive abilities of flies and humans, many higher order behavioral features of the human disorders cannot be modeled readily in flies. However, an increasing understanding of the genetics of human neuropsychiatric disorders is suggesting parallels with underlying neurobiological mechanisms in flies, thus providing important insights into the possible mechanisms of these poorly understood disorders.
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Affiliation(s)
- Cahir J O'Kane
- Department of Genetics, University of Cambridge, Downing Street, Cambridge, CB2 3EH, UK,
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29
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Fei E, Ma X, Zhu C, Xue T, Yan J, Xu Y, Zhou J, Wang G. Nucleocytoplasmic shuttling of dysbindin-1, a schizophrenia-related protein, regulates synapsin I expression. J Biol Chem 2010; 285:38630-40. [PMID: 20921223 PMCID: PMC2992295 DOI: 10.1074/jbc.m110.107912] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2010] [Revised: 09/23/2010] [Indexed: 01/29/2023] Open
Abstract
Dysbindin-1 is a 50-kDa coiled-coil-containing protein encoded by the gene DTNBP1 (dystrobrevin-binding protein 1), a candidate genetic factor for schizophrenia. Genetic variations in this gene confer a susceptibility to schizophrenia through a decreased expression of dysbindin-1. It was reported that dysbindin-1 regulates the expression of presynaptic proteins and the release of neurotransmitters. However, the precise functions of dysbindin-1 are largely unknown. Here, we show that dysbindin-1 is a novel nucleocytoplasmic shuttling protein and translocated to the nucleus upon treatment with leptomycin B, an inhibitor of exportin-1/CRM1-mediated nuclear export. Dysbindin-1 harbors a functional nuclear export signal necessary for its nuclear export, and the nucleocytoplasmic shuttling of dysbindin-1 affects its regulation of synapsin I expression. In brains of sandy mice, a dysbindin-1-null strain that displays abnormal behaviors related to schizophrenia, the protein and mRNA levels of synapsin I are decreased. These findings demonstrate that the nucleocytoplasmic shuttling of dysbindin-1 regulates synapsin I expression and thus may be involved in the pathogenesis of schizophrenia.
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MESH Headings
- Active Transport, Cell Nucleus/drug effects
- Active Transport, Cell Nucleus/genetics
- Animals
- Antibiotics, Antineoplastic/pharmacology
- Brain/metabolism
- Carrier Proteins/genetics
- Carrier Proteins/metabolism
- Cell Nucleus/genetics
- Cell Nucleus/metabolism
- Cytoplasm/genetics
- Cytoplasm/metabolism
- Dysbindin
- Dystrophin-Associated Proteins
- Fatty Acids, Unsaturated/pharmacology
- Gene Expression Regulation
- HEK293 Cells
- Humans
- Karyopherins/antagonists & inhibitors
- Karyopherins/genetics
- Karyopherins/metabolism
- Mice
- Mice, Mutant Strains
- Presynaptic Terminals/metabolism
- RNA, Messenger/biosynthesis
- RNA, Messenger/genetics
- Receptors, Cytoplasmic and Nuclear/antagonists & inhibitors
- Receptors, Cytoplasmic and Nuclear/genetics
- Receptors, Cytoplasmic and Nuclear/metabolism
- Schizophrenia/genetics
- Schizophrenia/metabolism
- Synapsins/biosynthesis
- Synapsins/genetics
- Exportin 1 Protein
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Affiliation(s)
- Erkang Fei
- From the Laboratory of Molecular Neuropathology, Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China and
| | - Xiaochuan Ma
- From the Laboratory of Molecular Neuropathology, Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China and
| | - Cuiqing Zhu
- the State Key Laboratory of Medical Neurobiology, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Ting Xue
- From the Laboratory of Molecular Neuropathology, Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China and
| | - Jie Yan
- the State Key Laboratory of Medical Neurobiology, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Yuxia Xu
- the State Key Laboratory of Medical Neurobiology, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Jiangning Zhou
- From the Laboratory of Molecular Neuropathology, Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China and
| | - Guanghui Wang
- From the Laboratory of Molecular Neuropathology, Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China and
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30
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Monfregola J, Napolitano G, D'Urso M, Lappalainen P, Ursini MV. Functional characterization of Wiskott-Aldrich syndrome protein and scar homolog (WASH), a bi-modular nucleation-promoting factor able to interact with biogenesis of lysosome-related organelle subunit 2 (BLOS2) and gamma-tubulin. J Biol Chem 2010; 285:16951-7. [PMID: 20308062 PMCID: PMC2878011 DOI: 10.1074/jbc.m109.078501] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2009] [Revised: 03/17/2010] [Indexed: 11/06/2022] Open
Abstract
The Arp2/3 complex is essential for actin filament nucleation in a variety of cellular processes. The activation of the Arp2/3 complex is mediated by nucleation-promoting factors, such as the Wiskott-Aldrich syndrome family proteins, which share a WCA (WH2 domain, central region, acidic region) catalytic module at the C-terminal region, required for Arp2/3 activation, but diverge at the N-terminal region, required for binding to specific activators. Here, we report the characterization of WASH, a new member of the WAS family that has nucleation-promoting factor activity and recently has been demonstrated to play a role in endosomal sorting. We found that overexpression of the WASH-WCA domain induced disruption of the actin cytoskeleton, whereas overexpression of full-length WASH in mammalian cells did not affect stress fiber organization. Furthermore, our analysis has revealed that nerve growth factor treatment of PC12 cells overexpressing full-length WASH leads to disruption of the actin cytoskeleton. We have also found that WASH interacts through its N-terminal region with BLOS2, a centrosomal protein belonging to the BLOC-1 complex that functions as a scaffolding factor in the biogenesis of lysosome-related organelles. In addition to BLOS2, WASH also interacts with centrosomal gamma-tubulin and with pallidin, an additional component of the BLOC-1 complex. Collectively, our data propose that WASH is a bimodular protein in which the C terminus is involved in Arp2/3-mediated actin nucleation, whereas the N-terminal portion is required for its regulation and localization in the cells. Moreover, our data suggest that WASH is also a component of the BLOC-1 complex that is associated with the centrosomes.
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Affiliation(s)
- Jlenia Monfregola
- From the Institute of Genetics and Biophysics “Adriano Buzzati Traverso”, 80131 Naples, Italy and
| | - Gennaro Napolitano
- From the Institute of Genetics and Biophysics “Adriano Buzzati Traverso”, 80131 Naples, Italy and
| | - Michele D'Urso
- From the Institute of Genetics and Biophysics “Adriano Buzzati Traverso”, 80131 Naples, Italy and
| | - Pekka Lappalainen
- the Institute of Biotechnology, University of Helsinki, Helsinki FI-00014, Finland
| | - Matilde Valeria Ursini
- From the Institute of Genetics and Biophysics “Adriano Buzzati Traverso”, 80131 Naples, Italy and
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31
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Genome-wide gene expression analysis identifies K-ras as a regulator of alcohol intake. Brain Res 2010; 1339:1-10. [PMID: 20388501 DOI: 10.1016/j.brainres.2010.03.063] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2010] [Accepted: 03/17/2010] [Indexed: 12/30/2022]
Abstract
Adaptations in the anterior cingulate cortex (ACC) have been implicated in alcohol and drug addiction. To identify genes that may contribute to excessive drinking, here we performed microarray analyses in laser microdissected rat ACC after a single or repeated administration of an intoxicating dose of alcohol (3 g/kg). Expression of the small G protein K-ras was differentially regulated following both single and repeated alcohol administration. We also observed that voluntary alcohol intake in K-ras heterozygous null mice (K-ras(+/-)) did not increase after withdrawal from repeated cycles of intermittent ethanol vapor exposure, unlike in their wild-type littermates. To identify K-ras regulated pathways, we then profiled gene expression in the ACC of K-ras(+/-), heterozygous null mice for the K-ras negative regulator Nf1 (Nf1(+/-)) and wild-type mice following repeated administration of an intoxicating dose of alcohol. Pathway analysis showed that alcohol differentially affected various pathways in a K-ras dependent manner - some of which previously shown to be regulated by alcohol - including the insulin/PI3K pathway, the NF-kappaB, the phosphodiesterases (PDEs) pathway, the Jak/Stat and the adipokine signaling pathways. Altogether, the data implicate K-ras-regulated pathways in the regulation of excessive alcohol drinking after a history of dependence.
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32
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Mead CLR, Kuzyk MA, Moradian A, Wilson GM, Holt RA, Morin GB. Cytosolic protein interactions of the schizophrenia susceptibility gene dysbindin. J Neurochem 2010; 113:1491-503. [PMID: 20236384 DOI: 10.1111/j.1471-4159.2010.06690.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Using immunoprecipitation, mass spectrometry, and western blot analysis we investigated cytosolic protein interactions of the schizophrenia susceptibility gene dysbindin in mammalian cells. We identified novel interactions with members of the exocyst, dynactin and chaperonin containing T-complex protein complexes, and we confirmed interactions reported previously with all members of the biogenesis of lysosome-related organelles complex-1 and the adaptor-related protein complex 3. We report interactions between dysbindin and the exocyst and dynactin complex that confirm a link between two important schizophrenia susceptibility genes: dysbindin and disrupted-in-schizophrenia-1. To expand upon this network of interacting proteins we also investigated protein interactions for members of the exocyst and dynactin complexes in mammalian cells. Our results are consistent with the notion that impairment of aspects of the synaptic vesicle life cycle may be a pathogenic mechanism in schizophrenia.
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Affiliation(s)
- Carri-Lyn R Mead
- Michael Smith Genome Sciences Centre, British Columbia Cancer Research Centre, Vancouver, British Columbia, Canada
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33
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Marley A, von Zastrow M. Dysbindin promotes the post-endocytic sorting of G protein-coupled receptors to lysosomes. PLoS One 2010; 5:e9325. [PMID: 20174469 PMCID: PMC2824829 DOI: 10.1371/journal.pone.0009325] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2009] [Accepted: 02/01/2010] [Indexed: 01/27/2023] Open
Abstract
Background Dysbindin, a cytoplasmic protein long known to function in the biogenesis of specialized lysosome-related organelles (LROs), has been reported to reduce surface expression of D2 dopamine receptors in neurons. Dysbindin is broadly expressed, and dopamine receptors are members of the large family of G protein-coupled receptors (GPCRs) that function in diverse cell types. Thus we asked if dysbindin regulates receptor number in non-neural cells, and further investigated the cellular basis of this regulation. Methodology/Principal Findings We used RNA interference to deplete endogenous dysbindin in HEK293 and HeLa cells, then used immunochemical and biochemical methods to assess expression and endocytic trafficking of epitope-tagged GPCRs. Dysbindin knockdown up-regulated surface expression of D2 receptors compared to D1 receptors, as reported previously in neurons. This regulation was not mediated by a change in D2 receptor endocytosis. Instead, dysbindin knockdown specifically reduced the subsequent trafficking of internalized D2 receptors to lysosomes. This distinct post-endocytic sorting function explained the minimal effect of dysbindin depletion on D1 receptors, which recycle efficiently and traverse the lysosomal pathway to only a small degree. Moreover, dysbindin regulated the delta opioid receptor, a more distantly related GPCR that is also sorted to lysosomes after endocytosis. Dysbindin was not required for lysosomal trafficking of all signaling receptors, however, as its depletion did not detectably affect down-regulation of the EGF receptor tyrosine kinase. Dysbindin co-immunoprecipitated with GASP-1 (or GPRASP-1), a cytoplasmic protein shown previously to modulate lysosomal trafficking of D2 dopamine and delta opioid receptors by direct interaction, and with HRS that is a core component of the conserved ESCRT machinery mediating lysosome biogenesis and sorting. Conclusions/Significance These results identify a distinct, and potentially widespread function of dysbindin in promoting the sorting of specific GPCRs to lysosomes after endocytosis.
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Affiliation(s)
- Aaron Marley
- Departments of Psychiatry and Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, California, United States of America
| | - Mark von Zastrow
- Departments of Psychiatry and Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, California, United States of America
- * E-mail:
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34
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Cheli VT, Daniels RW, Godoy R, Hoyle DJ, Kandachar V, Starcevic M, Martinez-Agosto JA, Poole S, DiAntonio A, Lloyd VK, Chang HC, Krantz DE, Dell'Angelica EC. Genetic modifiers of abnormal organelle biogenesis in a Drosophila model of BLOC-1 deficiency. Hum Mol Genet 2009; 19:861-78. [PMID: 20015953 DOI: 10.1093/hmg/ddp555] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Biogenesis of lysosome-related organelles complex 1 (BLOC-1) is a protein complex formed by the products of eight distinct genes. Loss-of-function mutations in two of these genes, DTNBP1 and BLOC1S3, cause Hermansky-Pudlak syndrome, a human disorder characterized by defective biogenesis of lysosome-related organelles. In addition, haplotype variants within the same two genes have been postulated to increase the risk of developing schizophrenia. However, the molecular function of BLOC-1 remains unknown. Here, we have generated a fly model of BLOC-1 deficiency. Mutant flies lacking the conserved Blos1 subunit displayed eye pigmentation defects due to abnormal pigment granules, which are lysosome-related organelles, as well as abnormal glutamatergic transmission and behavior. Epistatic analyses revealed that BLOC-1 function in pigment granule biogenesis requires the activities of BLOC-2 and a putative Rab guanine-nucleotide-exchange factor named Claret. The eye pigmentation phenotype was modified by misexpression of proteins involved in intracellular protein trafficking; in particular, the phenotype was partially ameliorated by Rab11 and strongly enhanced by the clathrin-disassembly factor, Auxilin. These observations validate Drosophila melanogaster as a powerful model for the study of BLOC-1 function and its interactions with modifier genes.
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Affiliation(s)
- Verónica T Cheli
- Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
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