1
|
Feng Y, Xie N, Inoue F, Fan S, Saskin J, Zhang C, Zhang F, Hansen MEB, Nyambo T, Mpoloka SW, Mokone GG, Fokunang C, Belay G, Njamnshi AK, Marks MS, Oancea E, Ahituv N, Tishkoff SA. Integrative functional genomic analyses identify genetic variants influencing skin pigmentation in Africans. Nat Genet 2024; 56:258-272. [PMID: 38200130 PMCID: PMC11005318 DOI: 10.1038/s41588-023-01626-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 11/28/2023] [Indexed: 01/12/2024]
Abstract
Skin color is highly variable in Africans, yet little is known about the underlying molecular mechanism. Here we applied massively parallel reporter assays to screen 1,157 candidate variants influencing skin pigmentation in Africans and identified 165 single-nucleotide polymorphisms showing differential regulatory activities between alleles. We combine Hi-C, genome editing and melanin assays to identify regulatory elements for MFSD12, HMG20B, OCA2, MITF, LEF1, TRPS1, BLOC1S6 and CYB561A3 that impact melanin levels in vitro and modulate human skin color. We found that independent mutations in an OCA2 enhancer contribute to the evolution of human skin color diversity and detect signals of local adaptation at enhancers of MITF, LEF1 and TRPS1, which may contribute to the light skin color of Khoesan-speaking populations from Southern Africa. Additionally, we identified CYB561A3 as a novel pigmentation regulator that impacts genes involved in oxidative phosphorylation and melanogenesis. These results provide insights into the mechanisms underlying human skin color diversity and adaptive evolution.
Collapse
Affiliation(s)
- Yuanqing Feng
- Department of Genetics, University of Pennsylvania, Philadelphia, PA, USA
| | - Ning Xie
- Department of Genetics, University of Pennsylvania, Philadelphia, PA, USA
| | - Fumitaka Inoue
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, CA, USA
- Institute for Human Genetics, University of California San Francisco, San Francisco, CA, USA
- Institute for the Advanced Study of Human Biology (WPI-ASHBi), Kyoto University, Kyoto, Japan
| | - Shaohua Fan
- Department of Genetics, University of Pennsylvania, Philadelphia, PA, USA
- Human Phenome Institute, School of Life Science, Fudan University, Shanghai, China
| | - Joshua Saskin
- Department of Neuroscience, Brown University, Providence, RI, USA
| | - Chao Zhang
- Department of Genetics, University of Pennsylvania, Philadelphia, PA, USA
| | - Fang Zhang
- Department of Genetics, University of Pennsylvania, Philadelphia, PA, USA
| | - Matthew E B Hansen
- Department of Genetics, University of Pennsylvania, Philadelphia, PA, USA
| | - Thomas Nyambo
- Department of Biochemistry and Molecular Biology, Hubert Kairuki Memorial University, Dar es Salaam, Tanzania
| | - Sununguko Wata Mpoloka
- Department of Biological Sciences, Faculty of Sciences, University of Botswana, Gaborone, Botswana
| | | | - Charles Fokunang
- Department of Pharmacotoxicology and Pharmacokinetics, Faculty of Medicine and Biomedical Sciences, The University of Yaoundé I, Yaoundé, Cameroon
| | - Gurja Belay
- Department of Biology, Addis Ababa University, Addis Ababa, Ethiopia
| | - Alfred K Njamnshi
- Brain Research Africa Initiative (BRAIN); Neuroscience Lab, Faculty of Medicine and Biomedical Sciences, The University of Yaoundé I, Department of Neurology, Central Hospital Yaoundé, Yaoundé, Cameroon
| | - Michael S Marks
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia Research Institute, Philadelphia, PA, USA
| | - Elena Oancea
- Department of Neuroscience, Brown University, Providence, RI, USA
| | - Nadav Ahituv
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, CA, USA
- Institute for Human Genetics, University of California San Francisco, San Francisco, CA, USA
| | - Sarah A Tishkoff
- Department of Genetics, University of Pennsylvania, Philadelphia, PA, USA.
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA.
- Center for Global Genomics and Health Equity, University of Pennsylvania, Philadelphia, PA, USA.
| |
Collapse
|
2
|
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.
Collapse
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.
| |
Collapse
|
3
|
Mastrogiacomo R, Trigilio G, Devroye C, Dautan D, Ferretti V, Losi G, Caffino L, Orso G, Marotta R, Maltese F, Vitali E, Piras G, Forgiarini A, Pacinelli G, Lia A, Rothmond DA, Waddington JL, Drago F, Fumagalli F, Luca MAD, Leggio GM, Carmignoto G, Weickert CS, Managò F, Papaleo F. Dysbindin-1A modulation of astrocytic dopamine and basal ganglia dependent behaviors relevant to schizophrenia. Mol Psychiatry 2022; 27:4201-4217. [PMID: 35821415 DOI: 10.1038/s41380-022-01683-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 06/21/2022] [Accepted: 06/27/2022] [Indexed: 02/07/2023]
Abstract
The mechanisms underlying the dichotomic cortical/basal ganglia dopaminergic abnormalities in schizophrenia are unclear. Astrocytes are important non-neuronal modulators of brain circuits, but their role in dopaminergic system remains poorly explored. Microarray analyses, immunohistochemistry, and two-photon laser scanning microscopy revealed that Dys1 hypofunction increases the reactivity of astrocytes, which express only the Dys1A isoform. Notably, behavioral and electrochemical assessments in mice selectively lacking the Dys1A isoform unraveled a more prominent impact of Dys1A in behavioral and dopaminergic/D2 alterations related to basal ganglia, but not cortical functioning. Ex vivo electron microscopy and protein expression analyses indicated that selective Dys1A disruption might alter intracellular trafficking in astrocytes, but not in neurons. In agreement, Dys1A disruption only in astrocytes resulted in decreased motivation and sensorimotor gating deficits, increased astrocytic dopamine D2 receptors and decreased dopaminergic tone within basal ganglia. These processes might have clinical relevance because the caudate, but not the cortex, of patients with schizophrenia shows a reduction of the Dys1A isoform. Therefore, we started to show a hitherto unknown role for the Dys1A isoform in astrocytic-related modulation of basal ganglia behavioral and dopaminergic phenotypes, with relevance to schizophrenia.
Collapse
Affiliation(s)
- Rosa Mastrogiacomo
- Genetics of Cognition laboratory, Neuroscience area, Istituto Italiano di Tecnologia, via Morego, 30, 16163, Genova, Italy
| | - Gabriella Trigilio
- Genetics of Cognition laboratory, Neuroscience area, Istituto Italiano di Tecnologia, via Morego, 30, 16163, Genova, Italy.,Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Céline Devroye
- Genetics of Cognition laboratory, Neuroscience area, Istituto Italiano di Tecnologia, via Morego, 30, 16163, Genova, Italy
| | - Daniel Dautan
- Genetics of Cognition laboratory, Neuroscience area, Istituto Italiano di Tecnologia, via Morego, 30, 16163, Genova, Italy.,Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milano, Italy
| | - Valentina Ferretti
- Genetics of Cognition laboratory, Neuroscience area, Istituto Italiano di Tecnologia, via Morego, 30, 16163, Genova, Italy
| | - Gabriele Losi
- Neuroscience Institute, CNR, Padova, Italy.,Department of Biomedical Science, University of Padova, Padova, Italy
| | - Lucia Caffino
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan, Italy
| | - Genny Orso
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Padova, Italy
| | - Roberto Marotta
- Genetics of Cognition laboratory, Neuroscience area, Istituto Italiano di Tecnologia, via Morego, 30, 16163, Genova, Italy
| | - Federica Maltese
- Genetics of Cognition laboratory, Neuroscience area, Istituto Italiano di Tecnologia, via Morego, 30, 16163, Genova, Italy
| | - Enrica Vitali
- Genetics of Cognition laboratory, Neuroscience area, Istituto Italiano di Tecnologia, via Morego, 30, 16163, Genova, Italy
| | - Gessica Piras
- Department of Biomedical Sciences, University of Cagliari, Cagliari, Italy
| | - Alessia Forgiarini
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Padova, Italy
| | - Giada Pacinelli
- Genetics of Cognition laboratory, Neuroscience area, Istituto Italiano di Tecnologia, via Morego, 30, 16163, Genova, Italy
| | - Annamaria Lia
- Neuroscience Institute, CNR, Padova, Italy.,Department of Biomedical Science, University of Padova, Padova, Italy
| | - Debora A Rothmond
- Schizophrenia Research Laboratory, Neuroscience Research Australia, Sydney, NSW, Australia
| | - John L Waddington
- School of Pharmacy and Biomolecular Sciences, Royal College of Surgeons in Ireland, Dublin 2, Ireland
| | - Filippo Drago
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Fabio Fumagalli
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan, Italy
| | | | - Gian Marco Leggio
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Giorgio Carmignoto
- Neuroscience Institute, CNR, Padova, Italy.,Department of Biomedical Science, University of Padova, Padova, Italy
| | - Cynthia S Weickert
- Schizophrenia Research Laboratory, Neuroscience Research Australia, Sydney, NSW, Australia
| | - Francesca Managò
- Genetics of Cognition laboratory, Neuroscience area, Istituto Italiano di Tecnologia, via Morego, 30, 16163, Genova, Italy.
| | - Francesco Papaleo
- Genetics of Cognition laboratory, Neuroscience area, Istituto Italiano di Tecnologia, via Morego, 30, 16163, Genova, Italy. .,Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milano, Italy.
| |
Collapse
|
4
|
Expanding the phenotype associated with interstitial 6p25.1p24.3 microdeletion: a new case and review of the literature. J Genet 2021. [DOI: 10.1007/s12041-021-01261-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
5
|
Borlepawar A, Schmiedel N, Eden M, Christen L, Rosskopf A, Frank D, Lüllmann-Rauch R, Frey N, Rangrez AY. Dysbindin deficiency Alters Cardiac BLOC-1 Complex and Myozap Levels in Mice. Cells 2020; 9:cells9112390. [PMID: 33142804 PMCID: PMC7692170 DOI: 10.3390/cells9112390] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 10/30/2020] [Accepted: 10/30/2020] [Indexed: 11/16/2022] Open
Abstract
Dysbindin, a schizophrenia susceptibility marker and an essential constituent of BLOC-1 (biogenesis of lysosome-related organelles complex-1), has recently been associated with cardiomyocyte hypertrophy through the activation of Myozap-RhoA-mediated SRF signaling. We employed sandy mice (Dtnbp1_KO), which completely lack Dysbindin protein because of a spontaneous deletion of introns 5-7 of the Dtnbp1 gene, for pathophysiological characterization of the heart. Unlike in vitro, the loss-of-function of Dysbindin did not attenuate cardiac hypertrophy, either in response to transverse aortic constriction stress or upon phenylephrine treatment. Interestingly, however, the levels of hypertrophy-inducing interaction partner Myozap as well as the BLOC-1 partners of Dysbindin like Muted and Pallidin were dramatically reduced in Dtnbp1_KO mouse hearts. Taken together, our data suggest that Dysbindin's role in cardiomyocyte hypertrophy is redundant in vivo, yet essential to maintain the stability of its direct interaction partners like Myozap, Pallidin and Muted.
Collapse
Affiliation(s)
- Ankush Borlepawar
- Department of Internal Medicine III (Cardiology, Angiology, Intensive Care), University Medical Center Kiel, 24105 Kiel, Germany; (A.B.); (N.S.); (M.E.); (L.C.); (A.R.); (D.F.); (N.F.)
- DZHK (German Centre for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, 24105 Kiel, Germany
| | - Nesrin Schmiedel
- Department of Internal Medicine III (Cardiology, Angiology, Intensive Care), University Medical Center Kiel, 24105 Kiel, Germany; (A.B.); (N.S.); (M.E.); (L.C.); (A.R.); (D.F.); (N.F.)
- DZHK (German Centre for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, 24105 Kiel, Germany
| | - Matthias Eden
- Department of Internal Medicine III (Cardiology, Angiology, Intensive Care), University Medical Center Kiel, 24105 Kiel, Germany; (A.B.); (N.S.); (M.E.); (L.C.); (A.R.); (D.F.); (N.F.)
- DZHK (German Centre for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, 24105 Kiel, Germany
| | - Lynn Christen
- Department of Internal Medicine III (Cardiology, Angiology, Intensive Care), University Medical Center Kiel, 24105 Kiel, Germany; (A.B.); (N.S.); (M.E.); (L.C.); (A.R.); (D.F.); (N.F.)
| | - Alexandra Rosskopf
- Department of Internal Medicine III (Cardiology, Angiology, Intensive Care), University Medical Center Kiel, 24105 Kiel, Germany; (A.B.); (N.S.); (M.E.); (L.C.); (A.R.); (D.F.); (N.F.)
- DZHK (German Centre for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, 24105 Kiel, Germany
| | - Derk Frank
- Department of Internal Medicine III (Cardiology, Angiology, Intensive Care), University Medical Center Kiel, 24105 Kiel, Germany; (A.B.); (N.S.); (M.E.); (L.C.); (A.R.); (D.F.); (N.F.)
- DZHK (German Centre for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, 24105 Kiel, Germany
| | | | - Norbert Frey
- Department of Internal Medicine III (Cardiology, Angiology, Intensive Care), University Medical Center Kiel, 24105 Kiel, Germany; (A.B.); (N.S.); (M.E.); (L.C.); (A.R.); (D.F.); (N.F.)
- DZHK (German Centre for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, 24105 Kiel, Germany
| | - Ashraf Yusuf Rangrez
- Department of Internal Medicine III (Cardiology, Angiology, Intensive Care), University Medical Center Kiel, 24105 Kiel, Germany; (A.B.); (N.S.); (M.E.); (L.C.); (A.R.); (D.F.); (N.F.)
- DZHK (German Centre for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, 24105 Kiel, Germany
- Correspondence: ; Tel.: +49-431-500-22966; Fax: +49-431-500-22938
| |
Collapse
|
6
|
Interactions between knockout of schizophrenia risk factor Dysbindin-1 and copper metabolism in mice. Brain Res Bull 2020; 164:339-349. [PMID: 32795490 DOI: 10.1016/j.brainresbull.2020.07.024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 07/28/2020] [Accepted: 07/31/2020] [Indexed: 11/22/2022]
Abstract
BACKGROUND AND PURPOSE DTNBP1 gene variation and lower dysbindin-1 protein are associated with schizophrenia. Previous evidence suggests that downregulated dysbindin-1 expression results in lower expression of copper transporters ATP7A (intracellular copper transporter) and SLC31A1 (CTR1; extracellular copper transporter), which are required for copper transport across the blood brain barrier. However, whether antipsychotic medications used for schizophrenia treatment may modulate these systems is unclear. EXPERIMENTAL APPROACH The current study measured behavioral indices of neurological function in dysbindin-1 functional knockout (KO) mice and their wild-type (WT) littermates with or without quetiapine treatment. We assessed serum and brain copper levels, ATP7A and CTR1 mRNA, and copper transporter-expressing cellular population transcripts: TTR (transthyretin; choroid plexus epithelial cells), MBP (myelin basic protein; oligodendrocytes), and GJA1 (gap-junction protein alpha-1; astrocytes) in cortex and hippocampus. KEY RESULTS Regardless of genotype, quetiapine significantly reduced TTR, MBP, CTR1 mRNA, and serum copper levels. Neurological function of untreated KO mice was abnormal, and ledge instability was rescued with quetiapine. KO mice were hyperactive after 10 min in the open-field assay, which was not affected by treatment. CONCLUSIONS AND IMPLICATIONS Dysbindin-1 KO results in hyperactivity, altered serum copper, and neurological impairment, the last of which is selectively rescued with quetiapine. Antipsychotic treatment modulates specific cellular populations, affecting myelin, the choroid plexus, and copper transport across the blood brain barrier. Together these results indicate the widespread impact of antipsychotic treatment, and that alteration of dysbindin-1 may be sufficient, but not necessary, for specific schizophrenia pathology.
Collapse
|
7
|
Lee FY, Larimore J, Faundez V, Dell'Angelica EC, Ghiani CA. Sex-dimorphic effects of biogenesis of lysosome-related organelles complex-1 deficiency on mouse perinatal brain development. J Neurosci Res 2020; 99:67-89. [PMID: 32436302 DOI: 10.1002/jnr.24620] [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: 11/12/2019] [Revised: 02/04/2020] [Accepted: 03/05/2020] [Indexed: 11/09/2022]
Abstract
The function(s) of the Biogenesis of Lysosome-related Organelles Complex-1 (BLOC-1) during brain development is to date largely unknown. Here, we investigated how its absence alters the trajectory of postnatal brain development using as model the pallid mouse. Most of the defects observed early postnatally in the mutant mice were more prominent in males than in females and in the hippocampus. Male mutant mice, but not females, had smaller brains as compared to sex-matching wild types at postnatal day 1 (P1), this deficit was largely recovered by P14 and P45. An abnormal cytoarchitecture of the pyramidal cell layer of the hippocampus was observed in P1 pallid male, but not female, or juvenile mice (P45), along with severely decreased expression levels of the radial glial marker Glutamate-Aspartate Transporter. Transcriptomic analyses showed that the overall response to the lack of functional BLOC-1 was more pronounced in hippocampi at P1 than at P45 or in the cerebral cortex. These observations suggest that absence of BLOC-1 renders males more susceptible to perinatal brain maldevelopment and although most abnormalities appear to have been resolved in juvenile animals, still permanent defects may be present, resulting in faulty neuronal circuits, and contribute to previously reported cognitive and behavioral phenotypes in adult BLOC-1-deficient mice.
Collapse
Affiliation(s)
- Frank Y Lee
- Department of Human Genetics, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | | | - Victor Faundez
- Department of Cell Biology, Emory University, Atlanta, GA, USA
| | - Esteban C Dell'Angelica
- Department of Human Genetics, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Cristina A Ghiani
- Department of Pathology & Laboratory Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA.,Department of Psychiatry & Biobehavioral Sciences, Intellectual and Developmental Disabilities Research Center, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| |
Collapse
|
8
|
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
|
9
|
Nakazawa K, Sapkota K. The origin of NMDA receptor hypofunction in schizophrenia. Pharmacol Ther 2019; 205:107426. [PMID: 31629007 DOI: 10.1016/j.pharmthera.2019.107426] [Citation(s) in RCA: 124] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 10/10/2019] [Indexed: 12/12/2022]
Abstract
N-methyl-d-aspartate (NMDA) receptor (NMDAR) hypofunction plays a key role in pathophysiology of schizophrenia. Since NMDAR hypofunction has also been reported in autism, Alzheimer's disease and cognitive dementia, it is crucial to identify the location, timing, and mechanism of NMDAR hypofunction for schizophrenia for better understanding of disease etiology and for novel therapeutic intervention. In this review, we first discuss the shared underlying mechanisms of NMDAR hypofunction in NMDAR antagonist models and the anti-NMDAR autoantibody model of schizophrenia and suggest that NMDAR hypofunction could occur in GABAergic neurons in both models. Preclinical models using transgenic mice have shown that NMDAR hypofunction in cortical GABAergic neurons, in particular parvalbumin-positive fast-spiking interneurons, in the early postnatal period confers schizophrenia-related phenotypes. Recent studies suggest that NMDAR hypofunction can also occur in PV-positive GABAergic neurons with alterations of NMDAR-associated proteins, such as neuregulin/ErbB4, α7nAChR, and serine racemase. Furthermore, several environmental factors, such as oxidative stress, kynurenic acid and hypoxia, may also potentially elicit NMDAR hypofunction in GABAergic neurons in early postnatal period. Altogether, the studies discussed here support a central role for GABAergic abnormalities in the context of NMDAR hypofunction. We conclude by suggesting potential therapeutic strategies to improve the function of fast-spiking neurons.
Collapse
|
10
|
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.
Collapse
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
| |
Collapse
|
11
|
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
|
12
|
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.
Collapse
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
| |
Collapse
|
13
|
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
|
14
|
Monis WJ, Faundez V, Pazour GJ. BLOC-1 is required for selective membrane protein trafficking from endosomes to primary cilia. J Cell Biol 2017; 216:2131-2150. [PMID: 28576874 PMCID: PMC5496619 DOI: 10.1083/jcb.201611138] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 03/24/2017] [Accepted: 05/03/2017] [Indexed: 11/30/2022] Open
Abstract
Monis et al. demonstrate that the BLOC-1 protein complex is required for trafficking polycystin-2, but not fibrocystin or smoothened, from endosomes to primary cilia. This is the first demonstration of a role for BLOC-1 in ciliary assembly and emphasizes the complexity of distinct ciliary membrane protein trafficking routes. Primary cilia perceive the extracellular environment through receptors localized in the ciliary membrane, but mechanisms directing specific proteins to this domain are poorly understood. To address this question, we knocked down proteins potentially important for ciliary membrane targeting and determined how this affects the ciliary trafficking of fibrocystin, polycystin-2, and smoothened. Our analysis showed that fibrocystin and polycystin-2 are dependent on IFT20, GMAP210, and the exocyst complex, while smoothened delivery is largely independent of these components. In addition, we found that polycystin-2, but not smoothened or fibrocystin, requires the biogenesis of lysosome-related organelles complex-1 (BLOC-1) for ciliary delivery. Consistent with the role of BLOC-1 in sorting from the endosome, we find that disrupting the recycling endosome reduces ciliary polycystin-2 and causes its accumulation in the recycling endosome. This is the first demonstration of a role for BLOC-1 in ciliary assembly and highlights the complexity of pathways taken to the cilium.
Collapse
Affiliation(s)
- William J Monis
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA
| | - Victor Faundez
- Department of Cell Biology, Emory University, Atlanta, GA
| | - Gregory J Pazour
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA
| |
Collapse
|
15
|
Petit EI, Michalak Z, Cox R, O'Tuathaigh CMP, Clarke N, Tighe O, Talbot K, Blake D, Joel J, Shaw A, Sheardown SA, Morrison AD, Wilson S, Shapland EM, Henshall DC, Kew JN, Kirby BP, Waddington JL. Dysregulation of Specialized Delay/Interference-Dependent Working Memory Following Loss of Dysbindin-1A in Schizophrenia-Related Phenotypes. Neuropsychopharmacology 2017; 42:1349-1360. [PMID: 27986973 PMCID: PMC5437891 DOI: 10.1038/npp.2016.282] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2016] [Revised: 11/28/2016] [Accepted: 12/11/2016] [Indexed: 01/12/2023]
Abstract
Dysbindin-1, a protein that regulates aspects of early and late brain development, has been implicated in the pathobiology of schizophrenia. As the functional roles of the three major isoforms of dysbindin-1, (A, B, and C) remain unknown, we generated a novel mutant mouse, dys-1A-/-, with selective loss of dysbindin-1A and investigated schizophrenia-related phenotypes in both males and females. Loss of dysbindin-1A resulted in heightened initial exploration and disruption in subsequent habituation to a novel environment, together with heightened anxiety-related behavior in a stressful environment. Loss of dysbindin-1A was not associated with disruption of either long-term (olfactory) memory or spontaneous alternation behavior. However, dys-1A-/- showed enhancement in delay-dependent working memory under high levels of interference relative to controls, ie, impairment in sensitivity to the disruptive effect of such interference. These findings in dys-1A-/- provide the first evidence for differential functional roles for dysbindin-1A vs dysbindin-1C isoforms among phenotypes relevant to the pathobiology of schizophrenia. Future studies should investigate putative sex differences in these phenotypic effects.
Collapse
Affiliation(s)
- Emilie I Petit
- Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin, Ireland
- Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Zuzanna Michalak
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland
- Clinical and Experimental Epilepsy, University College London Institute of Neurology, London, UK
| | - Rachel Cox
- Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Colm M P O'Tuathaigh
- Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin, Ireland
- School of Medicine, University College Cork, Cork, Ireland
| | - Niamh Clarke
- Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin, Ireland
- Office of Research and Innovation, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Orna Tighe
- Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Konrad Talbot
- Department of Neurology, University of California at Los Angeles, Los Angeles, CA, USA
| | - Derek Blake
- Institute of Psychological Medicine and Clinical Neurosciences, MRC Centre for Neuropsychiatric Genetics and Genomics, Cardiff University, Cardiff, UK
| | - Josephine Joel
- Neurology Centre of Excellence for Drug Discovery, GlaxoSmithKline, Harlow, UK
- Horizon Discovery, Cambridge, UK
| | - Alexander Shaw
- Neurology Centre of Excellence for Drug Discovery, GlaxoSmithKline, Harlow, UK
| | - Steven A Sheardown
- Neurology Centre of Excellence for Drug Discovery, GlaxoSmithKline, Harlow, UK
- Takeda Cambridge, Cambridge, UK
| | - Alastair D Morrison
- Neurology Centre of Excellence for Drug Discovery, GlaxoSmithKline, Harlow, UK
- Worldwide Business Development, GlaxoSmithKline, Stevenage, UK
| | - Stephen Wilson
- Neurology Centre of Excellence for Drug Discovery, GlaxoSmithKline, Harlow, UK
- Laboratory Animal Sciences, GlaxoSmithKline, Stevenage, UK
| | - Ellen M Shapland
- Neurology Centre of Excellence for Drug Discovery, GlaxoSmithKline, Harlow, UK
| | - David C Henshall
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - James N Kew
- Neurology Centre of Excellence for Drug Discovery, GlaxoSmithKline, Harlow, UK
| | - Brian P Kirby
- School of Pharmacy, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - John L Waddington
- Molecular and Cellular Therapeutics, 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
| |
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
|
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.
Collapse
|
18
|
Shi Q, Li C, Li K, Liu Q. Pallidin protein in neurodevelopment and its relation to the pathogenesis of schizophrenia. Mol Med Rep 2016; 15:665-672. [PMID: 28035416 PMCID: PMC5364864 DOI: 10.3892/mmr.2016.6064] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Accepted: 11/18/2016] [Indexed: 11/05/2022] Open
Abstract
Pallidin is a protein found throughout the nervous system and it has been linked to the development of schizophrenia. At the same time, it has been suggested that schizophrenia is a neurodevelopmental disease. The p38 protein participates in neuronal differentiation and apoptosis. We hypothesized pallidin and p38 play a role in neural system development and the pathogenesis of schizophrenia, and designed several experiments to test this possibility. During pull-down experiments GST-pallidin was able to bind His-Ndn (an HDAC3 binding protein) in vitro. In cells co-transfected with HDAC3 and p38, the transcriptional activity of p38 was significantly inhibited by HDAC3. When pallidin was overexpressed, the transcriptional activity of the endogenous HDAC3 improved significantly. Overexpression of pallidin-EGFP in HCT116 p38 wild-type cells increased the endogenous p21 protein and the mRNA levels. The decrease in the expression of endogenous p38 affected the differentiation of N2a cells. The lengths of the neurites generated in the experimental group were significantly shorter than those in the control group. We conclude that pallidin indirectly regulates the transcriptional activity of p38 during neurodevelopment by binding HDAC3 and changing its cellular localization, which leaves p38 uninhibited. Moreover, since pallidin can also affect neuronal differentiation and its variants seem to be related to an increased risk of schizophrenia, it is possible that both pallidin and p38 play a role in the pathogenesis of the disease.
Collapse
Affiliation(s)
- Qing Shi
- Mental Health Center, Binzhou People's Hospital, Binzhou, Shandong 256610, P.R. China
| | - Congmei Li
- Mental Health Center, Binzhou People's Hospital, Binzhou, Shandong 256610, P.R. China
| | - Kuichen Li
- Department of Pharmacy, Binzhou People's Hospital, Binzhou, Shandong 256610, P.R. China
| | - Qin Liu
- Mental Health Center, Binzhou People's Hospital, Binzhou, Shandong 256610, P.R. China
| |
Collapse
|
19
|
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.
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
| | - 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
| | | |
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
|
Ju P, Cui D. The involvement of N-methyl-D-aspartate receptor (NMDAR) subunit NR1 in the pathophysiology of schizophrenia. Acta Biochim Biophys Sin (Shanghai) 2016; 48:209-19. [PMID: 26837414 DOI: 10.1093/abbs/gmv135] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2015] [Accepted: 10/26/2015] [Indexed: 01/22/2023] Open
Abstract
Schizophrenia is a severe mental illness that afflicts nearly 1% of the world population. Although the exact pathophysiology of schizophrenia is unknown, the N-methyl-d-aspartate receptor (NMDAR), a major glutamate receptor subtype, has received great attention. The NR1 subunit is often considered indispensable for functional NMDAR assemblies, abnormal modulation of which is found in patients with schizophrenia. In this review, we discuss how disrupted function of NR1 subunits in NMDAR leads to the progression and development of symptoms of schizophrenia-like behaviors in a variety of genetically modified mouse models. We also discuss some of the susceptible genes and shared signaling pathways among the schizophrenia, and how their mutations lead to NR1 subunits hypofunction. Finally, we suggest that the subunit-selective modulators of NR1 subunits in NMDA receptors may be promising tools for the therapy of schizophrenia.
Collapse
Affiliation(s)
- Peijun Ju
- Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 201108, China
| | - Donghong Cui
- Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 201108, China
| |
Collapse
|
22
|
Schmieg N, Rocchi C, Romeo S, Maggio R, Millan MJ, Mannoury la Cour C. Dysbindin-1 modifies signaling and cellular localization of recombinant, human D₃ and D₂ receptors. J Neurochem 2016; 136:1037-51. [PMID: 26685100 DOI: 10.1111/jnc.13501] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Accepted: 12/09/2015] [Indexed: 01/20/2023]
Abstract
Dystrobrevin binding protein-1 (dysbindin-1), a candidate gene for schizophrenia, modulates cognition, synaptic plasticity and frontocortical circuitry and interacts with glutamatergic and dopaminergic transmission. Loss of dysbindin-1 modifies cellular trafficking of dopamine (DA) D2 receptors to increase cell surface expression, but its influence upon signaling has never been characterized. Further, the effects of dysbindin-1 upon closely related D3 receptors remain unexplored. Hence, we examined the impact of dysbindin-1 (isoform A) co-expression on the localization and coupling of human D2L and D3 receptors stably expressed in Chinese hamster ovary or SH-SY5Y cells lacking endogenous dysbindin-1. Dysbindin-1 co-transfection decreased cell surface expression of both D3 and D2L receptors. Further, while their affinity for DA was unchanged, dysbindin-1 reduced the magnitude and potency of DA-induced adenylate cylase recruitment/cAMP production. Dysbindin-1 also blunted the amplitude of DA-induced phosphorylation of ERK1/2 and Akt at both D2L and D3 receptors without, in contrast to cAMP, affecting the potency of DA. Interference with calveolin/clathrin-mediated processes of internalization prevented the modification by dysbindin-1 of ERK1/2 and adenylyl cyclase stimulation at D2L and D3 receptors. Finally, underpinning the specificity of the influence of dysbindin-1 on D2L and D3 receptors, dysbindin-1 did not modify recruitment of adenylyl cyclase by D1 receptors. These observations demonstrate that dysbindin-1 influences cell surface expression of D3 in addition to D2L receptors, and that it modulates activation of their signaling pathways. Accordingly, both a deficiency and an excess of dysbindin-1 may be disruptive for dopaminergic transmission, supporting its link to schizophrenia and other CNS disorders. Dysbindin-1, a candidate gene for schizophrenia, alters D2 receptors cell surface expression. We demonstrate that dysbindin-1 expression also influences cell surface levels of D3 receptors. Further, Dysbindin-1 reduces DA-induced adenylate cylase recruitment/cAMP production and modifies major signaling pathways (Akt and extracellular signal-regulated kinases1/2 (ERK1/2)) of both D2 and D3 receptors. Dysbindin-1 modulates thus D2 and D3 receptor signaling, supporting a link to schizophrenia.
Collapse
Affiliation(s)
- Nathalie Schmieg
- PIT-Neuropsychiatry, Institut de Recherches Servier, Centre de Recherches de Croissy, Croissy-sur-Seine, France
| | - Cristina Rocchi
- Biotechnological and Applied Clinical Sciences Department, University of L'Aquila, L'Aquila, Italy
| | - Stefania Romeo
- Biotechnological and Applied Clinical Sciences Department, University of L'Aquila, L'Aquila, Italy
| | - Roberto Maggio
- Biotechnological and Applied Clinical Sciences Department, University of L'Aquila, L'Aquila, Italy
| | - Mark J Millan
- PIT-Neuropsychiatry, Institut de Recherches Servier, Centre de Recherches de Croissy, Croissy-sur-Seine, France
| | - Clotilde Mannoury la Cour
- PIT-Neuropsychiatry, Institut de Recherches Servier, Centre de Recherches de Croissy, Croissy-sur-Seine, France
| |
Collapse
|
23
|
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
|
24
|
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
|
25
|
Gokhale A, Vrailas-Mortimer A, Larimore J, Comstra HS, Zlatic SA, Werner E, Manvich DF, Iuvone PM, Weinshenker D, Faundez V. Neuronal copper homeostasis susceptibility by genetic defects in dysbindin, a schizophrenia susceptibility factor. Hum Mol Genet 2015. [PMID: 26199316 DOI: 10.1093/hmg/ddv282] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Environmental factors and susceptible genomes interact to determine the risk of neurodevelopmental disorders. Although few genes and environmental factors have been linked, the intervening cellular and molecular mechanisms connecting a disorder susceptibility gene with environmental factors remain mostly unexplored. Here we focus on the schizophrenia susceptibility gene DTNBP1 and its product dysbindin, a subunit of the BLOC-1 complex, and describe a neuronal pathway modulating copper metabolism via ATP7A. Mutations in ATP7A result in Menkes disease, a disorder of copper metabolism. Dysbindin/BLOC-1 and ATP7A genetically and biochemically interact. Furthermore, disruption of this pathway causes alteration in the transcriptional profile of copper-regulatory and dependent factors in the hippocampus of dysbindin/BLOC-1-null mice. Dysbindin/BLOC-1 loss-of-function alleles do not affect cell and tissue copper content, yet they alter the susceptibility to toxic copper challenges in both mammalian cells and Drosophila. Our results demonstrate that perturbations downstream of the schizophrenia susceptibility gene DTNBP1 confer susceptibility to copper, a metal that in excess is a neurotoxin and whose depletion constitutes a micronutrient deficiency.
Collapse
Affiliation(s)
- Avanti Gokhale
- Department of Cell Biology, Emory University, Atlanta, GA 30322, USA
| | | | | | - Heather S Comstra
- Department of Cell Biology, Emory University, Atlanta, GA 30322, USA
| | | | - Erica Werner
- Department of Biochemistry, Emory University, Atlanta, GA 30322, USA
| | - Daniel F Manvich
- Department of Human Genetics, Emory University, Atlanta, GA 30322, USA
| | - P Michael Iuvone
- Department of Ophthalmology, Emory University, Atlanta, GA 30322, USA
| | - David Weinshenker
- Department of Human Genetics, Emory University, Atlanta, GA 30322, USA
| | - Victor Faundez
- Department of Cell Biology, Emory University, Atlanta, GA 30322, USA, Center for Social Translational Neuroscience, Emory University, Atlanta, GA 30322, USA,
| |
Collapse
|
26
|
Gene dosage in the dysbindin schizophrenia susceptibility network differentially affect synaptic function and plasticity. J Neurosci 2015; 35:325-38. [PMID: 25568125 DOI: 10.1523/jneurosci.3542-14.2015] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Neurodevelopmental disorders arise from single or multiple gene defects. However, the way multiple loci interact to modify phenotypic outcomes remains poorly understood. Here, we studied phenotypes associated with mutations in the schizophrenia susceptibility gene dysbindin (dysb), in isolation or in combination with null alleles in the dysb network component Blos1. In humans, the Blos1 ortholog Bloc1s1 encodes a polypeptide that assembles, with dysbindin, into the octameric BLOC-1 complex. We biochemically confirmed BLOC-1 presence in Drosophila neurons, and measured synaptic output and complex adaptive behavior in response to BLOC-1 perturbation. Homozygous loss-of-function alleles of dysb, Blos1, or compound heterozygotes of these alleles impaired neurotransmitter release, synapse morphology, and homeostatic plasticity at the larval neuromuscular junction, and impaired olfactory habituation. This multiparameter assessment indicated that phenotypes were differentially sensitive to genetic dosages of loss-of-function BLOC-1 alleles. Our findings suggest that modification of a second genetic locus in a defined neurodevelopmental regulatory network does not follow a strict additive genetic inheritance, but rather, precise stoichiometry within the network determines phenotypic outcomes.
Collapse
|
27
|
Waugh MG. PIPs in neurological diseases. Biochim Biophys Acta Mol Cell Biol Lipids 2015; 1851:1066-82. [PMID: 25680866 DOI: 10.1016/j.bbalip.2015.02.002] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Revised: 01/29/2015] [Accepted: 02/01/2015] [Indexed: 12/19/2022]
Abstract
Phosphoinositide (PIP) lipids regulate many aspects of cell function in the nervous system including receptor signalling, secretion, endocytosis, migration and survival. Levels of PIPs such as PI4P, PI(4,5)P2 and PI(3,4,5)P3 are normally tightly regulated by phosphoinositide kinases and phosphatases. Deregulation of these biochemical pathways leads to lipid imbalances, usually on intracellular endosomal membranes, and these changes have been linked to a number of major neurological diseases including Alzheimer's, Parkinson's, epilepsy, stroke, cancer and a range of rarer inherited disorders including brain overgrowth syndromes, Charcot-Marie-Tooth neuropathies and neurodevelopmental conditions such as Lowe's syndrome. This article analyses recent progress in this area and explains how PIP lipids are involved, to varying degrees, in almost every class of neurological disease. This article is part of a Special Issue entitled Brain Lipids.
Collapse
Affiliation(s)
- Mark G Waugh
- Lipid and Membrane Biology Group, Institute for Liver and Digestive Health, UCL, Royal Free Campus, Rowland Hill Street, London NW3 2PF, United Kingdom.
| |
Collapse
|
28
|
Yuan Y, Wang H, Wei Z, Li W. Impaired autophagy in hilar mossy cells of the dentate gyrus and its implication in schizophrenia. J Genet Genomics 2014; 42:1-8. [PMID: 25619597 DOI: 10.1016/j.jgg.2014.12.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Revised: 12/08/2014] [Accepted: 12/12/2014] [Indexed: 01/08/2023]
Abstract
Schizophrenia (SCZ) is a complex disease that has been regarded as a neurodevelopmental, synaptic or epigenetic disorder. Here we provide evidence that neurodegeneration is implicated in SCZ. The DTNBP1 (dystrobrevin-binding protein 1) gene encodes dysbindin-1 and is a leading susceptibility gene of SCZ. We previously reported that the dysbindin-1C isoform regulates the survival of the hilar glutamatergic mossy cells in the dentate gyrus, which controls the adult hippocampal neurogenesis. However, the underlying mechanism of hilar mossy cell loss in the dysbindin-1-deficient sandy (sdy) mice (a mouse model of SCZ) is unknown. In this study, we did not observe the apoptotic signals in the hilar mossy cells of the sdy mice by using the TUNEL assay and immunostaining of cleaved caspase-3 or necdin, a dysbindin-1- and p53-interacting protein required for neuronal survival. However, we found that the steady-state level of LC3-II, a marker of autophagosomes, was decreased in the hippocampal formation in the mice lacking dysbindin-1C. Furthermore, we observed a significant reduction of the cytosolic LC3-II puncta in the mossy cells of sdy mice. In addition, overexpression of dysbindin-1C, but not 1A, in cultured cells increased LC3-II level and the LC3 puncta in the transfected cells. These results suggest that dysbindin-1C deficiency causes impaired autophagy, which is likely implicated in the pathogenesis of SCZ.
Collapse
Affiliation(s)
- Yefeng Yuan
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100039, China
| | - Hao Wang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Zongbo Wei
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100039, China
| | - Wei Li
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; Center of Alzheimer's Disease, Beijing Institute for Brain Disorders, Beijing 100053, China.
| |
Collapse
|
29
|
Zhang A, He X, Zhang L, Yang L, Woodman P, Li W. Biogenesis of lysosome-related organelles complex-1 subunit 1 (BLOS1) interacts with sorting nexin 2 and the endosomal sorting complex required for transport-I (ESCRT-I) component TSG101 to mediate the sorting of epidermal growth factor receptor into endosomal compartments. J Biol Chem 2014; 289:29180-94. [PMID: 25183008 DOI: 10.1074/jbc.m114.576561] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Biogenesis of lysosome-related organelles complex-1 (BLOC-1) is a component of the molecular machinery required for the biogenesis of specialized organelles and lysosomal targeting of cargoes via the endosomal to lysosomal trafficking pathway. BLOS1, one subunit of BLOC-1, is implicated in lysosomal trafficking of membrane proteins. We found that the degradation and trafficking of epidermal growth factor receptor (EGFR) were delayed in BLOS1 knockdown cells, which were rescued through BLOS1 overexpression. A key feature to the delayed EGFR degradation is the accumulation of endolysosomes in BLOS1 knockdown cells or BLOS1 knock-out mouse embryonic fibroblasts. BLOS1 interacted with SNX2 (a retromer subunit) and TSG101 (an endosomal sorting complex required for transport subunit-I) to mediate EGFR lysosomal trafficking. These results suggest that coordination of the endolysosomal trafficking proteins is important for proper targeting of EGFR to lysosomes.
Collapse
Affiliation(s)
- Aili Zhang
- From the State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China, the University of Chinese Academy of Sciences, Beijing 100039, China, and
| | - Xin He
- From the State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Ling Zhang
- the Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, United Kingdom
| | - Lin Yang
- From the State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Philip Woodman
- the Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, United Kingdom
| | - Wei Li
- From the State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China,
| |
Collapse
|
30
|
Wang H, Yuan Y, Zhang Z, Yan H, Feng Y, Li W. Dysbindin-1C is required for the survival of hilar mossy cells and the maturation of adult newborn neurons in dentate gyrus. J Biol Chem 2014; 289:29060-72. [PMID: 25157109 DOI: 10.1074/jbc.m114.590927] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
DTNBP1 (dystrobrevin-binding protein 1), which encodes dysbindin-1, is one of the leading susceptibility genes for schizophrenia. Both dysbindin-1B and -1C isoforms are decreased, but the dysbindin-1A isoform is unchanged in schizophrenic hippocampal formation, suggesting dysbindin-1 isoforms may have distinct roles in schizophrenia. We found that mouse dysbindin-1C, but not dysbindin-1A, is localized in the hilar glutamatergic mossy cells of the dentate gyrus. The maturation rate of newborn neurons in sandy (sdy) mice, in which both dysbindin-1A and -1C are deleted, is significantly delayed when compared with that in wild-type mice or with that in muted (mu) mice in which dysbindin-1A is destabilized but dysbindin-1C is unaltered. Dysbindin-1C deficiency leads to a decrease in mossy cells, which causes the delayed maturation of newborn neurons. This suggests that dysbindin-1C, rather than dysbindin-1A, regulates adult hippocampal neurogenesis in a non-cell autonomous manner.
Collapse
Affiliation(s)
- Hao Wang
- From the State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, the University of Chinese Academy of Sciences, Beijing 100039
| | - Yefeng Yuan
- From the State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, the University of Chinese Academy of Sciences, Beijing 100039
| | - Zhao Zhang
- From the State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, the University of Chinese Academy of Sciences, Beijing 100039
| | - Hui Yan
- From the State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, the Department of Histology and Embryology, Shanxi Medical University, Taiyuan 030001, and
| | - Yaqin Feng
- From the State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, the Department of Histology and Embryology, Shanxi Medical University, Taiyuan 030001, and
| | - Wei Li
- From the State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, the Center of Alzheimer's Disease, Beijing Institute for Brain Disorders, Beijing 100053, China
| |
Collapse
|