1
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Gardner Z, Holbrook O, Tian Y, Odamah K, Man HY. The role of glia in the dysregulation of neuronal spinogenesis in Ube3a-dependent ASD. Exp Neurol 2024; 376:114756. [PMID: 38508482 PMCID: PMC11058030 DOI: 10.1016/j.expneurol.2024.114756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 02/14/2024] [Accepted: 03/14/2024] [Indexed: 03/22/2024]
Abstract
Overexpression of the Ube3a gene and the resulting increase in Ube3a protein are linked to autism spectrum disorder (ASD). However, the cellular and molecular processes underlying Ube3a-dependent ASD remain unclear. Using both male and female mice, we find that neurons in the somatosensory cortex of the Ube3a 2× Tg ASD mouse model display reduced dendritic spine density and increased immature filopodia density. Importantly, the increased gene dosage of Ube3a in astrocytes alone is sufficient to confer alterations in neurons as immature dendritic protrusions, as observed in primary hippocampal neuron cultures. We show that Ube3a overexpression in astrocytes leads to a loss of astrocyte-derived spinogenic protein, thrombospondin-2 (TSP2), due to a suppression of TSP2 gene transcription. By neonatal intraventricular injection of astrocyte-specific virus, we demonstrate that Ube3a overexpression in astrocytes in vivo results in a reduction in dendritic spine maturation in prelimbic cortical neurons, accompanied with autistic-like behaviors in mice. These findings reveal an astrocytic dominance in initiating ASD pathobiology at the neuronal and behavior levels. SIGNIFICANCE STATEMENT: Increased gene dosage of Ube3a is tied to autism spectrum disorders (ASDs), yet cellular and molecular alterations underlying autistic phenotypes remain unclear. We show that Ube3a overexpression leads to impaired dendritic spine maturation, resulting in reduced spine density and increased filopodia density. We find that dysregulation of spine development is not neuron autonomous, rather, it is mediated by an astrocytic mechanism. Increased gene dosage of Ube3a in astrocytes leads to reduced production of the spinogenic glycoprotein thrombospondin-2 (TSP2), leading to abnormalities in spines. Astrocyte-specific Ube3a overexpression in the brain in vivo confers dysregulated spine maturation concomitant with autistic-like behaviors in mice. These findings indicate the importance of astrocytes in aberrant neurodevelopment and brain function in Ube3a-depdendent ASD.
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Affiliation(s)
- Zachary Gardner
- Department of Biology, Boston University, 5 Cummington Mall, Boston, MA 02215, United States of America
| | - Otto Holbrook
- Department of Biology, Boston University, 5 Cummington Mall, Boston, MA 02215, United States of America
| | - Yuan Tian
- Department of Biology, Boston University, 5 Cummington Mall, Boston, MA 02215, United States of America
| | - KathrynAnn Odamah
- Department of Biology, Boston University, 5 Cummington Mall, Boston, MA 02215, United States of America
| | - Heng-Ye Man
- Department of Biology, Boston University, 5 Cummington Mall, Boston, MA 02215, United States of America; Department of Pharmacology, Physiology & Biophysics, Boston University School of Medicine, 72 East Concord St., L-603, Boston, MA 02118, United States of America; Center for Systems Neuroscience, Boston University, 610 Commonwealth Ave, Boston, MA 02215, United States of America.
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2
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Sleep M, Landaverde S, Lacoste A, Tan S, Schuback R, Reiter LT, Iyengar A. Glial expression of Drosophila UBE3A causes spontaneous seizures modulated by 5-HT signaling. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.08.579543. [PMID: 38370819 PMCID: PMC10871353 DOI: 10.1101/2024.02.08.579543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
Misexpression of the E3 ubiquitin ligase UBE3A is thought to contribute to a range of neurological disorders. In the context of Dup15q syndrome, excess genomic copies of UBE3A is thought to contribute to the autism, muscle tone and spontaneous seizures characteristic of the disorder. In a Drosophila model of Dup 15q syndrome, it was recently shown glial-driven expression of the UBE3A ortholog dube3a led to a "bang-sensitive" phenotype, where mechanical shock triggers convulsions, suggesting glial dube3a expression contributes to hyperexcitability in flies. Here we directly compare the consequences of glial- and neuronal-driven dube3a expression on motor coordination and neuronal excitability in Drosophila. We utilized IowaFLI tracker and developed a hidden Markov Model to classify seizure-related immobilization. Both glial and neuronal driven dube3a expression led to clear motor phenotypes. However, only glial-driven dube3a expression displayed spontaneous immobilization events, that were exacerbated at high-temperature (38 °C). Using a tethered fly preparation we monitored flight muscle activity, we found glial-driven dube3a flies display spontaneous spike discharges which were bilaterally synchronized indicative of seizure activity. Neither control flies, nor neuronal- dube3a overexpressing flies display such firing patterns. Prior drug screen indicated bang-sensitivity in glial-driven dube3a expressing flies could be suppressed by certain 5-HT modulators. Consistent with this report, we found glial-driven dube3a flies fed the serotonin reuptake inhibitor vortioxetine and the 5HT 2A antagonist ketanserin displayed reduced immobilization and spike bursting. Together these findings highlight the potential for glial pathophysiology to drive Dup15q syndrome-related seizure activity.
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3
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Fitzgerald PJ. Neural hyperexcitability in Angelman syndrome: Genetic factors and pharmacologic treatment approaches. Epilepsy Res 2024; 200:107286. [PMID: 38217951 DOI: 10.1016/j.eplepsyres.2024.107286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2023] [Revised: 12/18/2023] [Accepted: 01/02/2024] [Indexed: 01/15/2024]
Abstract
Angelman syndrome (AS) is a rare neurodevelopmental disorder that is typically caused by deletion or a loss-of-function mutation of the maternal copy of the ubiquitin ligase E3A (UBE3A) gene. The disorder is characterized by severe intellectual disability, deficits in speech, motor abnormalities, altered electroencephalography (EEG) activity, spontaneous epileptic seizures, sleep disturbances, and a happy demeanor with frequent laughter. Regarding electrophysiologic abnormalities in particular, enhanced delta oscillatory power and an elevated excitatory/inhibitory (E/I) ratio have been documented in AS, with E/I ratio especially studied in rodent models. These electrophysiologic characteristics appear to relate with the greatly elevated rates of epilepsy in individuals with AS, and associated hypersynchronous neural activity. Here we briefly review findings on EEG, E/I ratio, and epileptic seizures in AS, including data from rodent models of the disorder. We summarize pharmacologic approaches that have been used to treat behavioral aspects of AS, including neuropsychiatric phenomena and sleep disturbances, as well as seizures in the context of the disorder. Antidepressants such as SSRIs and atypical antipsychotics are among the medications that have been used behaviorally, whereas anticonvulsant drugs such as valproic acid and lamotrigine have frequently been used to control seizures in AS. We end by suggesting novel uses for some existing pharmacologic agents in AS, including noradrenergic transmission reducing drugs (alpha2 agonists, beta blockers, alpha1 antagonists) and cholinesterase inhibitors, where these various classes of drugs may have the ability to ameliorate both behavioral disturbances and seizures.
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Affiliation(s)
- Paul J Fitzgerald
- Department of Psychological Sciences, Purdue University, West Lafayette, IN, USA.
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4
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DiCarlo GE, Wallace MT. Modeling dopamine dysfunction in autism spectrum disorder: From invertebrates to vertebrates. Neurosci Biobehav Rev 2022; 133:104494. [PMID: 34906613 PMCID: PMC8792250 DOI: 10.1016/j.neubiorev.2021.12.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 11/29/2021] [Accepted: 12/09/2021] [Indexed: 02/03/2023]
Abstract
Autism Spectrum Disorder (ASD) is a highly heterogeneous neurodevelopmental disorder characterized by deficits in social communication and by patterns of restricted interests and/or repetitive behaviors. The Simons Foundation Autism Research Initiative's Human Gene and CNV Modules now list over 1000 genes implicated in ASD and over 2000 copy number variant loci reported in individuals with ASD. Given this ever-growing list of genetic changes associated with ASD, it has become evident that there is likely not a single genetic cause of this disorder nor a single neurobiological basis of this disorder. Instead, it is likely that many different neurobiological perturbations (which may represent subtypes of ASD) can result in the set of behavioral symptoms that we called ASD. One such of possible subtype of ASD may be associated with dopamine dysfunction. Precise regulation of synaptic dopamine (DA) is required for reward processing and behavioral learning, behaviors which are disrupted in ASD. Here we review evidence for DA dysfunction in ASD and in animal models of ASD. Further, we propose that these studies provide a scaffold for scientists and clinicians to consider subcategorizing the ASD diagnosis based on the genetic changes, neurobiological difference, and behavioral features identified in individuals with ASD.
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Affiliation(s)
- Gabriella E DiCarlo
- Massachusetts General Hospital, Department of Medicine, Boston, MA, United States
| | - Mark T Wallace
- Vanderbilt University Brain Institute, Nashville, TN, United States; Department of Psychology, Vanderbilt University, Nashville, TN, United States; Department of Hearing & Speech Sciences, Vanderbilt University Medical Center, Nashville, TN, United States; Department of Pharmacology, Vanderbilt University, Nashville, TN, United States; Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, TN, United States.
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5
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Judson MC, Shyng C, Simon JM, Davis CR, Punt AM, Salmon MT, Miller NW, Ritola KD, Elgersma Y, Amaral DG, Gray SJ, Philpot BD. Dual-isoform hUBE3A gene transfer improves behavioral and seizure outcomes in Angelman syndrome model mice. JCI Insight 2021; 6:144712. [PMID: 34676830 PMCID: PMC8564914 DOI: 10.1172/jci.insight.144712] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 09/02/2021] [Indexed: 12/23/2022] Open
Abstract
Loss of the maternal UBE3A allele causes Angelman syndrome (AS), a debilitating neurodevelopmental disorder. Here, we devised an AS treatment strategy based on reinstating dual-isoform expression of human UBE3A (hUBE3A) in the developing brain. Kozak sequence engineering of our codon-optimized vector (hUBE3Aopt) enabled translation of both short and long hUBE3A protein isoforms at a near-endogenous 3:1 (short/long) ratio, a feature that could help to support optimal therapeutic outcomes. To model widespread brain delivery and early postnatal onset of hUBE3A expression, we packaged the hUBE3Aopt vector into PHP.B capsids and performed intracerebroventricular injections in neonates. This treatment significantly improved motor learning and innate behaviors in AS mice, and it rendered them resilient to epileptogenesis and associated hippocampal neuropathologies induced by seizure kindling. hUBE3A overexpression occurred frequently in the hippocampus but was uncommon in the neocortex and other major brain structures; furthermore, it did not correlate with behavioral performance. Our results demonstrate the feasibility, tolerability, and therapeutic potential for dual-isoform hUBE3A gene transfer in the treatment of AS.
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Affiliation(s)
- Matthew C Judson
- Neuroscience Center.,Department of Cell Biology and Physiology.,Carolina Institute for Developmental Disabilities
| | - Charles Shyng
- Carolina Institute for Developmental Disabilities.,Gene Therapy Center, and
| | - Jeremy M Simon
- Neuroscience Center.,Carolina Institute for Developmental Disabilities.,Department of Genetics, University of North Carolina (UNC), Chapel Hill, North Carolina, USA
| | | | - A Mattijs Punt
- Department of Clinical Genetics and.,Department of Neuroscience, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | | | - Noah W Miller
- Neuroscience Center.,Department of Cell Biology and Physiology
| | - Kimberly D Ritola
- Neuroscience Center.,Department of Pharmacology, UNC, Chapel Hill, North Carolina, USA.,Scientific Operations Manager-Viral Tools, Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, USA
| | - Ype Elgersma
- Department of Clinical Genetics and.,Department of Neuroscience, Erasmus MC University Medical Center, Rotterdam, The Netherlands.,ENCORE Expertise Center for Neurodevelopmental Disorders, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - David G Amaral
- Department of Psychiatry and Behavioral Sciences, MIND Institute, and.,California National Primate Research Center, University of California, Davis, California, USA
| | - Steven J Gray
- Gene Therapy Center, and.,Department of Pediatrics and.,Eugene McDermott Center for Human Growth and Development, University of Texas (UT) Southwestern Medical Center, Dallas, Texas, USA
| | - Benjamin D Philpot
- Neuroscience Center.,Department of Cell Biology and Physiology.,Carolina Institute for Developmental Disabilities
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6
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Keary CJ, Mullett JE, Nowinski L, Wagner K, Walsh B, Saro HK, Erhabor G, Thibert RL, McDougle CJ, Ravichandran CT. Parent Description of Anxiety in Angelman Syndrome. J Autism Dev Disord 2021; 52:3612-3625. [PMID: 34417655 DOI: 10.1007/s10803-021-05238-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/10/2021] [Indexed: 01/17/2023]
Abstract
Anxiety is being increasingly identified in Angelman syndrome (AS). Qualitative questions and quantitative assessments were used to evaluate for anxiety in 50 subjects with AS. In-person evaluations assessed behaviors concerning for anxiety and circumstances wherein they occurred. Caregivers completed anxiety and other behavioral rating scales. Caregiver responses were categorized and compared to items from anxiety rating scales. The most common behavioral manifestation of anxiety was "aggression." The most common circumstance was "separation from caregiver/parent." Subjects had elevated scores on anxiety, irritability and hyperactivity scales with lower mean scores among subjects with a maternal deletion. The Pediatric Anxiety Rating Scale best captured behaviors described by caregivers. Existing anxiety scales should be adapted for use in AS.
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Affiliation(s)
- Christopher J Keary
- Angelman Syndrome Program, Massachusetts General Hospital for Children, Boston, MA, USA. .,Lurie Center for Autism, Massachusetts General Hospital, One Maguire Road, Lexington, MA, 02421, USA. .,Department of Psychiatry, Harvard Medical School, Boston, MA, USA.
| | - Jennifer E Mullett
- Lurie Center for Autism, Massachusetts General Hospital, One Maguire Road, Lexington, MA, 02421, USA
| | - Lisa Nowinski
- Lurie Center for Autism, Massachusetts General Hospital, One Maguire Road, Lexington, MA, 02421, USA.,Department of Psychiatry, Harvard Medical School, Boston, MA, USA
| | - Karyn Wagner
- Lurie Center for Autism, Massachusetts General Hospital, One Maguire Road, Lexington, MA, 02421, USA
| | - Briana Walsh
- Lurie Center for Autism, Massachusetts General Hospital, One Maguire Road, Lexington, MA, 02421, USA
| | - Hannah K Saro
- Lurie Center for Autism, Massachusetts General Hospital, One Maguire Road, Lexington, MA, 02421, USA
| | - Gillian Erhabor
- Lurie Center for Autism, Massachusetts General Hospital, One Maguire Road, Lexington, MA, 02421, USA.,Department of Psychiatry, Harvard Medical School, Boston, MA, USA
| | - Ronald L Thibert
- Angelman Syndrome Program, Massachusetts General Hospital for Children, Boston, MA, USA.,Lurie Center for Autism, Massachusetts General Hospital, One Maguire Road, Lexington, MA, 02421, USA.,Department of Neurology, Harvard Medical School, Boston, MA, USA
| | - Christopher J McDougle
- Angelman Syndrome Program, Massachusetts General Hospital for Children, Boston, MA, USA.,Lurie Center for Autism, Massachusetts General Hospital, One Maguire Road, Lexington, MA, 02421, USA.,Department of Psychiatry, Harvard Medical School, Boston, MA, USA
| | - Caitlin T Ravichandran
- Lurie Center for Autism, Massachusetts General Hospital, One Maguire Road, Lexington, MA, 02421, USA.,McLean Hospital, Belmont, MA, USA.,Department of Psychiatry, Harvard Medical School, Boston, MA, USA
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7
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Ueoka I, Pham HTN, Matsumoto K, Yamaguchi M. Autism Spectrum Disorder-Related Syndromes: Modeling with Drosophila and Rodents. Int J Mol Sci 2019; 20:E4071. [PMID: 31438473 PMCID: PMC6747505 DOI: 10.3390/ijms20174071] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Revised: 08/17/2019] [Accepted: 08/18/2019] [Indexed: 12/11/2022] Open
Abstract
Whole exome analyses have identified a number of genes associated with autism spectrum disorder (ASD) and ASD-related syndromes. These genes encode key regulators of synaptogenesis, synaptic plasticity, cytoskeleton dynamics, protein synthesis and degradation, chromatin remodeling, transcription, and lipid homeostasis. Furthermore, in silico studies suggest complex regulatory networks among these genes. Drosophila is a useful genetic model system for studies of ASD and ASD-related syndromes to clarify the in vivo roles of ASD-associated genes and the complex gene regulatory networks operating in the pathogenesis of ASD and ASD-related syndromes. In this review, we discuss what we have learned from studies with vertebrate models, mostly mouse models. We then highlight studies with Drosophila models. We also discuss future developments in the related field.
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Affiliation(s)
- Ibuki Ueoka
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 603-8585, Japan
| | - Hang Thi Nguyet Pham
- Department of Pharmacology and Biochemistry, National Institute of Medicinal Materials, Hanoi 110100, Vietnam
| | - Kinzo Matsumoto
- Division of Medicinal Pharmacology, Institute of Natural Medicine, University of Toyama, Toyama 930-0194, Japan
| | - Masamitsu Yamaguchi
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 603-8585, Japan.
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8
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9
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A genome-wide enhancer/suppressor screen for Dube3a interacting genes in Drosophila melanogaster. Sci Rep 2019; 9:2382. [PMID: 30787400 PMCID: PMC6382765 DOI: 10.1038/s41598-019-38663-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 12/27/2018] [Indexed: 12/26/2022] Open
Abstract
The genetics underlying autism spectrum disorder (ASD) are complex. Approximately 3–5% of ASD cases arise from maternally inherited duplications of 15q11.2-q13.1, termed Duplication 15q syndrome (Dup15q). 15q11.2-q13.1 includes the gene UBE3A which is believed to underlie ASD observed in Dup15q syndrome. UBE3A is an E3 ubiquitin ligase that targets proteins for degradation and trafficking, so finding UBE3A substrates and interacting partners is critical to understanding Dup15q ASD. In this study, we take an unbiased genetics approach to identify genes that genetically interact with Dube3a, the Drosophila melanogaster homolog of UBE3A. We conducted an enhancer/suppressor screen using a rough eye phenotype produced by Dube3a overexpression with GMR-GAL4. Using the DrosDel deficiency kit, we identified 3 out of 346 deficiency lines that enhanced rough eyes when crossed to two separate Dube3a overexpression lines, and subsequently identified IA2, GABA-B-R3, and lola as single genes responsible for rough eye enhancement. Using the FlyLight GAL4 lines to express uas-Dube3a + uas-GFP in the endogenous lola pattern, we observed an increase in the GFP signal compared to uas-GFP alone, suggesting a transcriptional co-activation effect of Dube3a on the lola promoter region. These findings extend the role of Dube3a/UBE3A as a transcriptional co-activator, and reveal new Dube3a interacting genes.
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10
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Neuronal Proteomic Analysis of the Ubiquitinated Substrates of the Disease-Linked E3 Ligases Parkin and Ube3a. BIOMED RESEARCH INTERNATIONAL 2018; 2018:3180413. [PMID: 29693004 PMCID: PMC5859835 DOI: 10.1155/2018/3180413] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Accepted: 01/15/2018] [Indexed: 01/09/2023]
Abstract
Both Parkin and UBE3A are E3 ubiquitin ligases whose mutations result in severe brain dysfunction. Several of their substrates have been identified using cell culture models in combination with proteasome inhibitors, but not in more physiological settings. We recently developed the bioUb strategy to isolate ubiquitinated proteins in flies and have now identified by mass spectrometry analysis the neuronal proteins differentially ubiquitinated by those ligases. This is an example of how flies can be used to provide biological material in order to reveal steady state substrates of disease causing genes. Collectively our results provide new leads to the possible physiological functions of the activity of those two disease causing E3 ligases. Particularly, in the case of Parkin the novelty of our data originates from the experimental setup, which is not overtly biased by acute mitochondrial depolarisation. In the case of UBE3A, it is the first time that a nonbiased screen for its neuronal substrates has been reported.
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11
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Urraca N, Hope K, Victor AK, Belgard TG, Memon R, Goorha S, Valdez C, Tran QT, Sanchez S, Ramirez J, Donaldson M, Bridges D, Reiter LT. Significant transcriptional changes in 15q duplication but not Angelman syndrome deletion stem cell-derived neurons. Mol Autism 2018; 9:6. [PMID: 29423132 PMCID: PMC5787244 DOI: 10.1186/s13229-018-0191-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 01/15/2018] [Indexed: 01/09/2023] Open
Abstract
Background The inability to analyze gene expression in living neurons from Angelman (AS) and Duplication 15q (Dup15q) syndrome subjects has limited our understanding of these disorders at the molecular level. Method Here, we use dental pulp stem cells (DPSC) from AS deletion, 15q Duplication, and neurotypical control subjects for whole transcriptome analysis. We identified 20 genes unique to AS neurons, 120 genes unique to 15q duplication, and 3 shared transcripts that were differentially expressed in DPSC neurons vs controls. Results Copy number correlated with gene expression for most genes across the 15q11.2-q13.1 critical region. Two thirds of the genes differentially expressed in 15q duplication neurons were downregulated compared to controls including several transcription factors, while in AS differential expression was restricted primarily to the 15q region. Here, we show significant downregulation of the transcription factors FOXO1 and HAND2 in neurons from 15q duplication, but not AS deletion subjects suggesting that disruptions in transcriptional regulation may be a driving factor in the autism phenotype in Dup15q syndrome. Downstream analysis revealed downregulation of the ASD associated genes EHPB2 and RORA, both genes with FOXO1 binding sites. Genes upregulated in either Dup15q cortex or idiopathic ASD cortex both overlapped significantly with the most upregulated genes in Dup15q DPSC-derived neurons. Conclusions Finding a significant increase in both HERC2 and UBE3A in Dup15q neurons and significant decrease in these two genes in AS deletion neurons may explain differences between AS deletion class and UBE3A specific classes of AS mutation where HERC2 is expressed at normal levels. Also, we identified an enrichment for FOXO1-regulated transcripts in Dup15q neurons including ASD-associated genes EHPB2 and RORA indicating a possible connection between this syndromic form of ASD and idiopathic cases.
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Affiliation(s)
- Nora Urraca
- Department of Neurology, The University of Tennessee Health Science Center, 855 Monroe Ave., Link 415, Memphis, TN 38163 USA
| | - Kevin Hope
- Department of Neurology, The University of Tennessee Health Science Center, 855 Monroe Ave., Link 415, Memphis, TN 38163 USA
- IPBS Program, The University of Tennessee Health Science Center, Memphis, TN 38163 USA
| | - A. Kaitlyn Victor
- Department of Neurology, The University of Tennessee Health Science Center, 855 Monroe Ave., Link 415, Memphis, TN 38163 USA
- IPBS Program, The University of Tennessee Health Science Center, Memphis, TN 38163 USA
| | - T. Grant Belgard
- MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3QX UK
| | - Rawaha Memon
- Department of Pediatric Dentistry, The University of Tennessee Health Science Center, Memphis, TN 38163 USA
| | - Sarita Goorha
- Department of Neurology, The University of Tennessee Health Science Center, 855 Monroe Ave., Link 415, Memphis, TN 38163 USA
| | - Colleen Valdez
- Department of Neurology, The University of Tennessee Health Science Center, 855 Monroe Ave., Link 415, Memphis, TN 38163 USA
| | - Quynh T. Tran
- Department of Preventive Medicine, The University of Tennessee Health Science Center, Memphis, TN 38163 USA
| | - Silvia Sanchez
- Instituto Nacional de Pediatria, 04530 Mexico City, Mexico
| | - Juanma Ramirez
- Department of Biochemistry and Molecular Biology, University of Basque Country, Bilbao, Spain
| | - Martin Donaldson
- Department of Pediatric Dentistry, The University of Tennessee Health Science Center, Memphis, TN 38163 USA
| | - Dave Bridges
- Department of Nutritional Sciences, University of Michigan School of Public Health, 1415 Washington Heights, Ann Arbor, MI 48109 USA
| | - Lawrence T. Reiter
- Department of Neurology, The University of Tennessee Health Science Center, 855 Monroe Ave., Link 415, Memphis, TN 38163 USA
- Department of Pediatrics, The University of Tennessee Health Science Center, Memphis, TN 38163 USA
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12
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Copping NA, Christian SGB, Ritter DJ, Islam MS, Buscher N, Zolkowska D, Pride MC, Berg EL, LaSalle JM, Ellegood J, Lerch JP, Reiter LT, Silverman JL, Dindot SV. Neuronal overexpression of Ube3a isoform 2 causes behavioral impairments and neuroanatomical pathology relevant to 15q11.2-q13.3 duplication syndrome. Hum Mol Genet 2017; 26:3995-4010. [PMID: 29016856 PMCID: PMC5886211 DOI: 10.1093/hmg/ddx289] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Revised: 06/21/2017] [Accepted: 07/10/2017] [Indexed: 01/07/2023] Open
Abstract
Maternally derived copy number gains of human chromosome 15q11.2-q13.3 (Dup15q syndrome or Dup15q) cause intellectual disability, epilepsy, developmental delay, hypotonia, speech impairments, and minor dysmorphic features. Dup15q syndrome is one of the most common and penetrant chromosomal abnormalities observed in individuals with autism spectrum disorder (ASD). Although ∼40 genes are located in the 15q11.2-q13.3 region, overexpression of the ubiquitin-protein E3A ligase (UBE3A) gene is thought to be the predominant molecular cause of the phenotypes observed in Dup15q syndrome. The UBE3A gene demonstrates maternal-specific expression in neurons and loss of maternal UBE3A causes Angelman syndrome, a neurodevelopmental disorder with some overlapping neurological features to Dup15q. To directly test the hypothesis that overexpression of UBE3A is an important underlying molecular cause of neurodevelopmental dysfunction, we developed and characterized a mouse overexpressing Ube3a isoform 2 in excitatory neurons. Ube3a isoform 2 is conserved between mouse and human and known to play key roles in neuronal function. Transgenic mice overexpressing Ube3a isoform 2 in excitatory forebrain neurons exhibited increased anxiety-like behaviors, learning impairments, and reduced seizure thresholds. However, these transgenic mice displayed normal social approach, social interactions, and repetitive motor stereotypies that are relevant to ASD. Reduced forebrain, hippocampus, striatum, amygdala, and cortical volume were also observed. Altogether, these findings show neuronal overexpression of Ube3a isoform 2 causes phenotypes translatable to neurodevelopmental disorders.
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Affiliation(s)
- Nycole A Copping
- MIND Institute, School of Medicine, University of California, Davis, Sacramento, CA, USA
| | | | - Dylan J Ritter
- MIND Institute, School of Medicine, University of California, Davis, Sacramento, CA, USA
- Texas A&M, College Station, TX, USA
| | - M Saharul Islam
- MIND Institute, School of Medicine, University of California, Davis, Sacramento, CA, USA
| | - Nathalie Buscher
- MIND Institute, School of Medicine, University of California, Davis, Sacramento, CA, USA
| | - Dorota Zolkowska
- MIND Institute, School of Medicine, University of California, Davis, Sacramento, CA, USA
| | - Michael C Pride
- MIND Institute, School of Medicine, University of California, Davis, Sacramento, CA, USA
| | - Elizabeth L Berg
- MIND Institute, School of Medicine, University of California, Davis, Sacramento, CA, USA
| | - Janine M LaSalle
- MIND Institute, School of Medicine, University of California, Davis, Sacramento, CA, USA
| | - Jacob Ellegood
- The Hospital for Sick Children, Mouse Imaging Centre, Toronto, ON, Canada
| | - Jason P Lerch
- The Hospital for Sick Children, Mouse Imaging Centre, Toronto, ON, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
| | - Lawrence T Reiter
- Departments of Neurology, Pediatrics and Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Jill L Silverman
- MIND Institute, School of Medicine, University of California, Davis, Sacramento, CA, USA
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13
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Tian Y, Zhang ZC, Han J. Drosophila Studies on Autism Spectrum Disorders. Neurosci Bull 2017; 33:737-746. [PMID: 28795356 DOI: 10.1007/s12264-017-0166-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 04/23/2017] [Indexed: 02/07/2023] Open
Abstract
In the past decade, numerous genes associated with autism spectrum disorders (ASDs) have been identified. These genes encode key regulators of synaptogenesis, synaptic function, and synaptic plasticity. Drosophila is a prominent model system for ASD studies to define novel genes linked to ASDs and decipher their molecular roles in synaptogenesis, synaptic function, synaptic plasticity, and neural circuit assembly and consolidation. Here, we review Drosophila studies on ASD genes that regulate synaptogenesis, synaptic function, and synaptic plasticity through modulating chromatin remodeling, transcription, protein synthesis and degradation, cytoskeleton dynamics, and synaptic scaffolding.
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Affiliation(s)
- Yao Tian
- Institute of Life Sciences, The Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, 210096, China
| | - Zi Chao Zhang
- Institute of Life Sciences, The Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, 210096, China
| | - Junhai Han
- Institute of Life Sciences, The Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, 210096, China.
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Crespi BJ, Procyshyn TL. Williams syndrome deletions and duplications: Genetic windows to understanding anxiety, sociality, autism, and schizophrenia. Neurosci Biobehav Rev 2017; 79:14-26. [DOI: 10.1016/j.neubiorev.2017.05.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 04/06/2017] [Accepted: 05/06/2017] [Indexed: 12/30/2022]
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15
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Elhamamsy AR. Role of DNA methylation in imprinting disorders: an updated review. J Assist Reprod Genet 2017; 34:549-562. [PMID: 28281142 PMCID: PMC5427654 DOI: 10.1007/s10815-017-0895-5] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 02/23/2017] [Indexed: 12/20/2022] Open
Abstract
Genomic imprinting is a complex epigenetic process that contributes substantially to embryogenesis, reproduction, and gametogenesis. Only small fraction of genes within the whole genome undergoes imprinting. Imprinted genes are expressed in a monoallelic parent-of-origin-specific manner, which means that only one of the two inherited alleles is expressed either from the paternal or maternal side. Imprinted genes are typically arranged in clusters controlled by differentially methylated regions or imprinting control regions. Any defect or relaxation in imprinting process can cause loss of imprinting in the key imprinted loci. Loss of imprinting in most cases has a harmful effect on fetal development and can result in neurological, developmental, and metabolic disorders. Since DNA methylation and histone modifications play a key role in the process of imprinting. This review focuses on the role of DNA methylation in imprinting process and describes DNA methylation aberrations in different imprinting disorders.
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Affiliation(s)
- Amr Rafat Elhamamsy
- Department of Clinical Pharmacy, School of Pharmacy, Tanta University, Tanta, 31512, Gharbia, Egypt.
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16
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Abstract
Sleep disorders in humans are increasingly appreciated to be not only widespread but also detrimental to multiple facets of physical and mental health. Recent work has begun to shed light on the mechanistic basis of sleep disorders like insomnia, restless legs syndrome, narcolepsy, and a host of others, but a more detailed genetic and molecular understanding of how sleep goes awry is lacking. Over the past 15 years, studies in Drosophila have yielded new insights into basic questions regarding sleep function and regulation. More recently, powerful genetic approaches in the fly have been applied toward studying primary human sleep disorders and other disease states associated with dysregulated sleep. In this review, we discuss the contribution of Drosophila to the landscape of sleep biology, examining not only fundamental advances in sleep neurobiology but also how flies have begun to inform pathological sleep states in humans.
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Li W, Yao A, Zhi H, Kaur K, Zhu YC, Jia M, Zhao H, Wang Q, Jin S, Zhao G, Xiong ZQ, Zhang YQ. Angelman Syndrome Protein Ube3a Regulates Synaptic Growth and Endocytosis by Inhibiting BMP Signaling in Drosophila. PLoS Genet 2016; 12:e1006062. [PMID: 27232889 PMCID: PMC4883773 DOI: 10.1371/journal.pgen.1006062] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Accepted: 04/27/2016] [Indexed: 11/19/2022] Open
Abstract
Altered expression of the E3 ubiquitin ligase UBE3A, which is involved in protein degradation through the proteasome-mediated pathway, is associated with neurodevelopmental and behavioral defects observed in Angelman syndrome (AS) and autism. However, little is known about the neuronal function of UBE3A and the pathogenesis of UBE3A-associated disorders. To understand the in vivo function of UBE3A in the nervous system, we generated multiple mutations of ube3a, the Drosophila ortholog of UBE3A. We found a significantly increased number of total boutons and satellite boutons in conjunction with compromised endocytosis in the neuromuscular junctions (NMJs) of ube3a mutants compared to the wild type. Genetic and biochemical analysis showed upregulation of bone morphogenetic protein (BMP) signaling in the nervous system of ube3a mutants. An immunochemical study revealed a specific increase in the protein level of Thickveins (Tkv), a type I BMP receptor, but not other BMP receptors Wishful thinking (Wit) and Saxophone (Sax), in ube3a mutants. Ube3a was associated with and specifically ubiquitinated lysine 227 within the cytoplasmic tail of Tkv, and promoted its proteasomal degradation in Schneider 2 cells. Negative regulation of Tkv by Ube3a was conserved in mammalian cells. These results reveal a critical role for Ube3a in regulating NMJ synapse development by repressing BMP signaling. This study sheds new light onto the neuronal functions of UBE3A and provides novel perspectives for understanding the pathogenesis of UBE3A-associated disorders.
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Affiliation(s)
- Wenhua Li
- Key Laboratory of Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Aiyu Yao
- Key Laboratory of Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
- * E-mail: (AY); (YQZ)
| | - Hui Zhi
- Key Laboratory of Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Kuldeep Kaur
- Key Laboratory of Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Yong-chuan Zhu
- Institute of Neuroscience and State Key Laboratory of Neuroscience, Shanghai Institute of Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Mingyue Jia
- Key Laboratory of Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Hui Zhao
- Key Laboratory of Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Qifu Wang
- Key Laboratory of Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Shan Jin
- College of Life Science, Hubei University, Wuhan, Hubei, China
| | - Guoli Zhao
- Key Laboratory of Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Zhi-Qi Xiong
- Institute of Neuroscience and State Key Laboratory of Neuroscience, Shanghai Institute of Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Yong Q. Zhang
- Key Laboratory of Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
- * E-mail: (AY); (YQZ)
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18
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LaSalle JM, Reiter LT, Chamberlain SJ. Epigenetic regulation of UBE3A and roles in human neurodevelopmental disorders. Epigenomics 2015; 7:1213-28. [PMID: 26585570 DOI: 10.2217/epi.15.70] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The E3 ubiquitin ligase UBE3A, also known as E6-AP, has a multitude of ascribed functions and targets relevant to human health and disease. Epigenetic regulation of the UBE3A gene by parentally imprinted noncoding transcription within human chromosome 15q11.2-q13.3 is responsible for the maternal-specific effects of 15q11.2-q13.3 deletion or duplication disorders. Here, we review the evidence for diverse and emerging roles for UBE3A in the proteasome, synapse and nucleus in regulating protein stability and transcription as well as the current mechanistic understanding of UBE3A imprinting in neurons. Angelman and Dup15q syndromes as well as experimental models of these neurodevelopmental disorders are highlighted as improving understanding of UBE3A and its complex regulation for improving therapeutic strategies.
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Affiliation(s)
- Janine M LaSalle
- Medical Microbiology & Immunology, Genome Center & MIND Institute, University of California, Davis, CA 95616, USA
| | - Lawrence T Reiter
- Department of Pediatrics, University of Tennessee Health Science Center, Memphis, TN 38163, USA.,Department of Neurology, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Stormy J Chamberlain
- Department of Genetics & Developmental Biology & Stem Cell Institute, University of Connecticut, Farmington, CT 06030, USA
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19
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The E3 ligase ube3a is required for learning in Drosophila melanogaster. Biochem Biophys Res Commun 2015; 462:71-7. [DOI: 10.1016/j.bbrc.2015.04.110] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Accepted: 04/12/2015] [Indexed: 11/18/2022]
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20
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Valdez C, Scroggs R, Chassen R, Reiter LT. Variation in Dube3a expression affects neurotransmission at the Drosophila neuromuscular junction. Biol Open 2015; 4:776-82. [PMID: 25948754 PMCID: PMC4571101 DOI: 10.1242/bio.20148045] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Changes in UBE3A expression levels in neurons can cause neurogenetic disorders ranging from Angelman syndrome (AS) (decreased levels) to autism (increased levels). Here we investigated the effects on neuronal function of varying UBE3A levels using the Drosophila neuromuscular junction as a model for both of these neurogenetic disorders. Stimulations that evoked excitatory junction potentials (EJPs) at 1 Hz intermittently failed to evoke EJPs at 15 Hz in a significantly higher proportion of Dube3a over-expressors using the pan neuronal GAL4 driver C155-GAL4 (C155-GAL4>UAS-Dube3a) relative to controls (C155>+ alone). However, in the Dube3a over-expressing larval neurons with no failures, there was no difference in EJP amplitude at the beginning of the train, or the rate of decrease in EJP amplitude over the course of the train compared to controls. In the absence of tetrodotoxin (TTX), spontaneous EJPs were observed in significantly more C155-GAL4>UAS-Dube3a larva compared to controls. In the presence of TTX, spontaneous and evoked EJPs were completely blocked and mEJP amplitude and frequency did not differ among genotypes. These data suggest that over-expression of wild type Dube3a, but not a ubiquitination defective Dube3a-C/A protein, compromises the ability of motor neuron axons to support closely spaced trains of action potentials, while at the same time increasing excitability. EJPs evoked at 15 Hz in the absence of Dube3a (Dube3a15b homozygous mutant larvae) decayed more rapidly over the course of 30 stimulations compared to w1118 controls, and Dube3a15b larval muscles had significantly more negative resting membrane potentials (RMP). However, these results could not be recapitulated using RNAi knockdown of Dube3a in muscle or neurons alone, suggesting more global developmental defects contribute to this phenotype. These data suggest that reduced UBE3A expression levels may cause global changes that affect RMP and neurotransmitter release from motorneurons at the neuromuscular junction. Similar affects of under- and over-expression of UBE3A on membrane potential and synaptic transmission may underlie the synaptic plasticity defects observed in both AS and autism.
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Affiliation(s)
- Colleen Valdez
- Department of Neurology, The University of Tennessee Health Science Center, 855 Monroe Ave., Link 415, Memphis, TN 38163, USA
| | - Reese Scroggs
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, 855 Monroe Ave., Link 515, Memphis, TN 38163, USA
| | - Rachel Chassen
- Department of Neurology, The University of Tennessee Health Science Center, 855 Monroe Ave., Link 415, Memphis, TN 38163, USA
| | - Lawrence T Reiter
- Department of Neurology, The University of Tennessee Health Science Center, 855 Monroe Ave., Link 415, Memphis, TN 38163, USA Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, 855 Monroe Ave., Link 515, Memphis, TN 38163, USA
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21
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Fukumura S, Watanabe T, Takayama R, Tsutsumi H. Paroxysmal tonic upward gaze complicating Angelman syndrome. Pediatr Neurol 2015; 52:125-7. [PMID: 25439489 DOI: 10.1016/j.pediatrneurol.2014.08.022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Revised: 08/21/2014] [Accepted: 08/26/2014] [Indexed: 10/24/2022]
Abstract
BACKGROUND Paroxysmal tonic upward gaze is a childhood oculomotor syndrome characterized by episodes of conjugate upward deviation of the eyes. Its pathogenesis is unknown, and the etiology is heterogeneous. PATIENT DESCRIPTION We describe a 2-year-old girl with Angelman syndrome who developed paroxysmal tonic upward gaze at 9 months of age. She presented with developmental delay, blond hair, jerky movements, ataxia, and epilepsy. Genetic testing revealed a maternal deletion of 15q11-13, confirming Angelman syndrome. CONCLUSIONS This is the first report of Angelman syndrome complicated by paroxysmal tonic upward gaze. Both transient paroxysmal tonic upward gaze and Angelman syndrome have been associated with dopaminergic neurons. We speculate that the dopaminergic abnormalities present in Angelman syndrome may cause paroxysmal tonic upward gaze.
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Affiliation(s)
- Shinobu Fukumura
- Department of Child Neurology, Hokkaido Medical Center for Child Health and Rehabilitation, Sapporo, Japan; Department of Pediatrics, School of Medicine, Sapporo Medical University, Sapporo, Japan.
| | - Toshihide Watanabe
- Department of Child Neurology, Hokkaido Medical Center for Child Health and Rehabilitation, Sapporo, Japan; Department of Pediatrics, School of Medicine, Sapporo Medical University, Sapporo, Japan
| | - Rumiko Takayama
- Department of Child Neurology, Hokkaido Medical Center for Child Health and Rehabilitation, Sapporo, Japan; Department of Pediatrics, School of Medicine, Sapporo Medical University, Sapporo, Japan
| | - Hiroyuki Tsutsumi
- Department of Pediatrics, School of Medicine, Sapporo Medical University, Sapporo, Japan
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22
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Godavarthi SK, Sharma A, Jana NR. Reversal of reduced parvalbumin neurons in hippocampus and amygdala of Angelman syndrome model mice by chronic treatment of fluoxetine. J Neurochem 2014; 130:444-54. [DOI: 10.1111/jnc.12726] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Revised: 03/20/2014] [Accepted: 03/25/2014] [Indexed: 01/23/2023]
Affiliation(s)
- Swetha K. Godavarthi
- Cellular and Molecular Neuroscience Laboratory; National Brain Research Centre; Manesar Gurgaon India
| | - Ankit Sharma
- Cellular and Molecular Neuroscience Laboratory; National Brain Research Centre; Manesar Gurgaon India
| | - Nihar Ranjan Jana
- Cellular and Molecular Neuroscience Laboratory; National Brain Research Centre; Manesar Gurgaon India
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23
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E6AP in the brain: one protein, dual function, multiple diseases. Mol Neurobiol 2013; 49:827-39. [PMID: 24091829 DOI: 10.1007/s12035-013-8563-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Accepted: 09/22/2013] [Indexed: 02/06/2023]
Abstract
E6-Associated Protein (E6AP), the founding member of the HECT (Homologus to E6AP C terminus) family of ubiquitin ligases, has been gaining increased attention from the scientific community. In addition to its ubiquitin ligase function, our laboratory has also identified steroid hormone receptor transcriptional coactivation as yet another essential function of this protein. Furthermore, it has been established that E6AP has a role in numerous diseases including cancers and neurological syndromes. In this review, we delineate genetic and biochemical knowledge of E6AP and we focus on its role in the pathobiology of neuro-developmental and neuro-aging diseases; bringing to light important gaps of knowledge related to the involvement of its well-studied ligase function versus the much less studied nuclear receptor transcriptional coactivation function in the pathogenesis of these diseases. Tackling these gaps of knowledge could reveal novel possible neuro-pathobiological mechanisms and present crucial information for the design of effective treatment modalities for devastating CNS diseases.
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24
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Jensen L, Farook MF, Reiter LT. Proteomic profiling in Drosophila reveals potential Dube3a regulation of the actin cytoskeleton and neuronal homeostasis. PLoS One 2013; 8:e61952. [PMID: 23626758 PMCID: PMC3633955 DOI: 10.1371/journal.pone.0061952] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2013] [Accepted: 03/15/2013] [Indexed: 12/19/2022] Open
Abstract
The molecular defects associated with Angelman syndrome (AS) and 15q duplication autism are directly correlated to expression levels of the E3 ubiquitin ligase protein UBE3A. Here we used Drosophila melanogaster to screen for the targets of this ubiquitin ligase under conditions of both decreased (as in AS) or increased (as in dup(15)) levels of the fly Dube3a or human UBE3A proteins. Using liquid phase isoelectric focusing of proteins from whole fly head extracts we identified a total of 50 proteins that show changes in protein, and in some cases transcriptional levels, when Dube3a fluctuates. We analyzed head extracts from cytoplasmic, nuclear and membrane fractions for Dube3a regulated proteins. Our results indicate that Dube3a is involved in the regulation of cellular functions related to ATP synthesis/metabolism, actin cytoskeletal integrity, both catabolism and carbohydrate metabolism as well as nervous system development and function. Sixty-two percent of the proteins were >50% identical to homologous human proteins and 8 have previously be shown to be ubiquitinated in the fly nervous system. Eight proteins may be regulated by Dube3a at the transcript level through the transcriptional co-activation function of Dube3a. We investigated one autism-associated protein, ATPα, and found that it can be ubiquitinated in a Dube3a dependent manner. We also found that Dube3a mutants have significantly less filamentous actin than wild type larvae consistent with the identification of actin targets regulated by Dube3a. The identification of UBE3A targets is the first step in unraveling the molecular etiology of AS and duplication 15q autism.
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Affiliation(s)
- Laura Jensen
- Department of Neurology, University of Tennessee Health Science Center, Memphis, Tennessee, United States of America
| | - M. Febin Farook
- Department of Neurology, University of Tennessee Health Science Center, Memphis, Tennessee, United States of America
| | - Lawrence T. Reiter
- Department of Neurology, University of Tennessee Health Science Center, Memphis, Tennessee, United States of America
- Department of Pediatrics, University of Tennessee Health Science Center, Memphis, Tennessee, United States of America
- Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, Tennessee, United States of America
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25
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Riday TT, Dankoski EC, Krouse MC, Fish EW, Walsh PL, Han JE, Hodge CW, Wightman RM, Philpot BD, Malanga CJ. Pathway-specific dopaminergic deficits in a mouse model of Angelman syndrome. J Clin Invest 2012; 122:4544-54. [PMID: 23143301 DOI: 10.1172/jci61888] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Accepted: 09/10/2012] [Indexed: 11/17/2022] Open
Abstract
Angelman syndrome (AS) is a neurodevelopmental disorder caused by maternal deletions or mutations of the ubiquitin ligase E3A (UBE3A) allele and characterized by minimal verbal communication, seizures, and disorders of voluntary movement. Previous studies have suggested that abnormal dopamine neurotransmission may underlie some of these deficits, but no effective treatment currently exists for the core features of AS. A clinical trial of levodopa (L-DOPA) in AS is ongoing, although the underlying rationale for this treatment strategy has not yet been thoroughly examined in preclinical models. We found that AS model mice lacking maternal Ube3a (Ube3a(m-/p+) mice) exhibit behavioral deficits that correlated with abnormal dopamine signaling. These deficits were not due to loss of dopaminergic neurons or impaired dopamine synthesis. Unexpectedly, Ube3a(m-/p+) mice exhibited increased dopamine release in the mesolimbic pathway while also exhibiting a decrease in dopamine release in the nigrostriatal pathway, as measured with fast-scan cyclic voltammetry. These findings demonstrate the complex effects of UBE3A loss on dopamine signaling in subcortical motor pathways that may inform ongoing clinical trials of L-DOPA therapy in patients with AS.
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Affiliation(s)
- Thorfinn T Riday
- Curriculum in Neurobiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina North Carolina 27599, USA
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26
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Okray Z, Hassan BA. Genetic approaches in Drosophila for the study neurodevelopmental disorders. Neuropharmacology 2012; 68:150-6. [PMID: 23067575 DOI: 10.1016/j.neuropharm.2012.09.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2012] [Revised: 08/31/2012] [Accepted: 09/07/2012] [Indexed: 12/16/2022]
Abstract
The fruit fly Drosophila melanogaster is one of the premier genetic model organisms used in biomedical research today owing to the extraordinary power of its genetic tool-kit. Made famous by numerous seminal discoveries of basic developmental mechanisms and behavioral genetics, the power of fruit fly genetics is becoming increasingly applied to questions directly relevant to human health. In this review we discuss how Drosophila research is applied to address major questions in neurodevelopmental disorders. This article is part of the Special Issue entitled 'Neurodevelopmental Disorders'.
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Affiliation(s)
- Zeynep Okray
- Laboratory of Neurogenetics, VIB Center for the Biology of Disease, VIB, Herestraat 49, Leuven, Belgium
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27
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Farook MF, DeCuypere M, Hyland K, Takumi T, LeDoux MS, Reiter LT. Altered serotonin, dopamine and norepinepherine levels in 15q duplication and Angelman syndrome mouse models. PLoS One 2012; 7:e43030. [PMID: 22916201 PMCID: PMC3420863 DOI: 10.1371/journal.pone.0043030] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2012] [Accepted: 07/16/2012] [Indexed: 01/18/2023] Open
Abstract
Childhood neurodevelopmental disorders like Angelman syndrome and autism may be the result of underlying defects in neuronal plasticity and ongoing problems with synaptic signaling. Some of these defects may be due to abnormal monoamine levels in different regions of the brain. Ube3a, a gene that causes Angelman syndrome (AS) when maternally deleted and is associated with autism when maternally duplicated has recently been shown to regulate monoamine synthesis in the Drosophila brain. Therefore, we examined monoamine levels in striatum, ventral midbrain, frontal cerebral cortex, cerebellar cortex and hippocampus in Ube3a deficient and Ube3a duplication animals. We found that serotonin (5HT), a monoamine affected in autism, was elevated in the striatum and cortex of AS mice. Dopamine levels were almost uniformly elevated compared to control littermates in the striatum, midbrain and frontal cortex regardless of genotype in Ube3a deficient and Ube3a duplication animals. In the duplication 15q autism mouse model, paternal but not maternal duplication animals showed a decrease in 5HT levels when compared to their wild type littermates, in accordance with previously published data. However, maternal duplication animals show no significant changes in 5HT levels throughout the brain. These abnormal monoamine levels could be responsible for many of the behavioral abnormalities observed in both AS and autism, but further investigation is required to determine if any of these changes are purely dependent on Ube3a levels in the brain.
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Affiliation(s)
- M. Febin Farook
- Department of Neurology, UTHSC, Memphis, Tennessee, United States of America
| | - Michael DeCuypere
- Department of Neurosurgery, UTHSC, Memphis, Tennessee, United States of America
| | - Keith Hyland
- Medical Neurogenetics, LCC, Atlanta, Georgia, United States of America
| | - Toru Takumi
- Hiroshima University, School of Medicine, Hiroshima, Japan
| | - Mark S. LeDoux
- Department of Neurology, UTHSC, Memphis, Tennessee, United States of America
- Department of Anatomy and Neurobiology, UTHSC, Memphis, Tennessee, United States of America
| | - Lawrence T. Reiter
- Department of Neurology, UTHSC, Memphis, Tennessee, United States of America
- Department of Anatomy and Neurobiology, UTHSC, Memphis, Tennessee, United States of America
- Department of Pediatrics, UTHSC, Memphis, Tennessee, United States of America
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28
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Dichter GS, Damiano CA, Allen JA. Reward circuitry dysfunction in psychiatric and neurodevelopmental disorders and genetic syndromes: animal models and clinical findings. J Neurodev Disord 2012; 4:19. [PMID: 22958744 PMCID: PMC3464940 DOI: 10.1186/1866-1955-4-19] [Citation(s) in RCA: 202] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Accepted: 05/02/2012] [Indexed: 02/07/2023] Open
Abstract
This review summarizes evidence of dysregulated reward circuitry function in a range of neurodevelopmental and psychiatric disorders and genetic syndromes. First, the contribution of identifying a core mechanistic process across disparate disorders to disease classification is discussed, followed by a review of the neurobiology of reward circuitry. We next consider preclinical animal models and clinical evidence of reward-pathway dysfunction in a range of disorders, including psychiatric disorders (i.e., substance-use disorders, affective disorders, eating disorders, and obsessive compulsive disorders), neurodevelopmental disorders (i.e., schizophrenia, attention-deficit/hyperactivity disorder, autism spectrum disorders, Tourette's syndrome, conduct disorder/oppositional defiant disorder), and genetic syndromes (i.e., Fragile X syndrome, Prader-Willi syndrome, Williams syndrome, Angelman syndrome, and Rett syndrome). We also provide brief overviews of effective psychopharmacologic agents that have an effect on the dopamine system in these disorders. This review concludes with methodological considerations for future research designed to more clearly probe reward-circuitry dysfunction, with the ultimate goal of improved intervention strategies.
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Affiliation(s)
- Gabriel S Dichter
- Carolina Institute for Developmental Disabilities, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
- Department of Psychiatry, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
- Department of Psychology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Department of Psychiatry, University of North Carolina School of Medicine, CB# 7255, 101 Manning Drive, Chapel Hill, NC, 275997255, USA
| | - Cara A Damiano
- Department of Psychology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - John A Allen
- Neuroscience Research Unit Pfizer Global Research and Development, Groton, CT 06340, USA
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29
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Scoles HA, Urraca N, Chadwick SW, Reiter LT, Lasalle JM. Increased copy number for methylated maternal 15q duplications leads to changes in gene and protein expression in human cortical samples. Mol Autism 2011; 2:19. [PMID: 22152151 PMCID: PMC3287113 DOI: 10.1186/2040-2392-2-19] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2011] [Accepted: 12/12/2011] [Indexed: 11/23/2022] Open
Abstract
Background Duplication of chromosome 15q11-q13 (dup15q) accounts for approximately 3% of autism cases. Chromosome 15q11-q13 contains imprinted genes necessary for normal mammalian neurodevelopment controlled by a differentially methylated imprinting center (imprinting center of the Prader-Willi locus, PWS-IC). Maternal dup15q occurs as both interstitial duplications and isodicentric chromosome 15. Overexpression of the maternally expressed gene UBE3A is predicted to be the primary cause of the autistic features associated with dup15q. Previous analysis of two postmortem dup15q frontal cortical samples showed heterogeneity between the two cases, with one showing levels of the GABAA receptor genes, UBE3A and SNRPN in a manner not predicted by copy number or parental imprint. Methods Postmortem human brain tissue (Brodmann area 19, extrastriate visual cortex) was obtained from 8 dup15q, 10 idiopathic autism and 21 typical control tissue samples. Quantitative PCR was used to confirm duplication status. Quantitative RT-PCR and Western blot analyses were performed to measure 15q11-q13 transcript and protein levels, respectively. Methylation-sensitive high-resolution melting-curve analysis was performed on brain genomic DNA to identify the maternal:paternal ratio of methylation at PWS-IC. Results Dup15q brain samples showed a higher level of PWS-IC methylation than control or autism samples, indicating that dup15q was maternal in origin. UBE3A transcript and protein levels were significantly higher than control and autism in dup15q, as expected, although levels were variable and lower than expected based on copy number in some samples. In contrast, this increase in copy number did not result in consistently increased GABRB3 transcript or protein levels for dup15q samples. Furthermore, SNRPN was expected to be unchanged in expression in dup15q because it is expressed from the single unmethylated paternal allele, yet SNRPN levels were significantly reduced in dup15q samples compared to controls. PWS-IC methylation positively correlated with UBE3A and GABRB3 levels but negatively correlated with SNRPN levels. Idiopathic autism samples exhibited significantly lower GABRB3 and significantly more variable SNRPN levels compared to controls. Conclusions Although these results show that increased UBE3A/UBE3A is a consistent feature of dup15q syndrome, they also suggest that gene expression within 15q11-q13 is not based entirely on copy number but can be influenced by epigenetic mechanisms in brain.
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Affiliation(s)
- Haley A Scoles
- Medical Microbiology and Immunology, Genome Center, and Medical Institute of Neurodevelopmental Disorders, One Shields Avenue, University of California, Davis, Davis, CA 95616, USA.
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Smith SEP, Zhou YD, Zhang G, Jin Z, Stoppel DC, Anderson MP. Increased gene dosage of Ube3a results in autism traits and decreased glutamate synaptic transmission in mice. Sci Transl Med 2011; 3:103ra97. [PMID: 21974935 PMCID: PMC3356696 DOI: 10.1126/scitranslmed.3002627] [Citation(s) in RCA: 204] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
People with autism spectrum disorder are characterized by impaired social interaction, reduced communication, and increased repetitive behaviors. The disorder has a substantial genetic component, and recent studies have revealed frequent genome copy number variations (CNVs) in some individuals. A common CNV that occurs in 1 to 3% of those with autism--maternal 15q11-13 duplication (dup15) and triplication (isodicentric extranumerary chromosome, idic15)--affects several genes that have been suggested to underlie autism behavioral traits. To test this, we tripled the dosage of one of these genes, the ubiquitin protein ligase Ube3a, which is expressed solely from the maternal allele in mature neurons, and reconstituted the three core autism traits in mice: defective social interaction, impaired communication, and increased repetitive stereotypic behavior. The penetrance of these autism traits depended on Ube3a gene copy number. In animals with increased Ube3a gene dosage, glutamatergic, but not GABAergic, synaptic transmission was suppressed as a result of reduced presynaptic release probability, synaptic glutamate concentration, and postsynaptic action potential coupling. These results suggest that Ube3a gene dosage may contribute to the autism traits of individuals with maternal 15q11-13 duplication and support the idea that increased E3A ubiquitin ligase gene dosage results in reduced excitatory synaptic transmission.
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Affiliation(s)
- Stephen E. P. Smith
- Beth Israel Deaconess Medical Center, Departments of Pathology and Neurology, Harvard Medical School, Boston, MA 02215, USA
| | - Yu-Dong Zhou
- Beth Israel Deaconess Medical Center, Departments of Pathology and Neurology, Harvard Medical School, Boston, MA 02215, USA
| | - Guangping Zhang
- Beth Israel Deaconess Medical Center, Departments of Pathology and Neurology, Harvard Medical School, Boston, MA 02215, USA
| | - Zhe Jin
- Beth Israel Deaconess Medical Center, Departments of Pathology and Neurology, Harvard Medical School, Boston, MA 02215, USA
| | - David C. Stoppel
- Beth Israel Deaconess Medical Center, Departments of Pathology and Neurology, Harvard Medical School, Boston, MA 02215, USA
- Program in Neuroscience, Harvard Medical School, Boston, MA 02215, USA
| | - Matthew P. Anderson
- Beth Israel Deaconess Medical Center, Departments of Pathology and Neurology, Harvard Medical School, Boston, MA 02215, USA
- Program in Neuroscience, Harvard Medical School, Boston, MA 02215, USA
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Gatto CL, Broadie K. Drosophila modeling of heritable neurodevelopmental disorders. Curr Opin Neurobiol 2011; 21:834-41. [PMID: 21596554 DOI: 10.1016/j.conb.2011.04.009] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2011] [Revised: 04/08/2011] [Accepted: 04/25/2011] [Indexed: 11/16/2022]
Abstract
Heritable neurodevelopmental disorders are multifaceted disease conditions encompassing a wide range of symptoms including intellectual disability, cognitive dysfunction, autism and myriad other behavioral impairments. In cases where single, causative genetic defects have been identified, such as Angelman syndrome, Rett syndrome, Neurofibromatosis Type 1 and Fragile X syndrome, the classical Drosophila genetic system has provided fruitful disease models. Recent Drosophila studies have advanced our understanding of UBE3A, MECP2, NF1 and FMR1 function, respectively, in genetic, biochemical, anatomical, physiological and behavioral contexts. Investigations in Drosophila continue to provide the essential mechanistic understanding required to facilitate the conception of rational therapeutic treatments.
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Affiliation(s)
- Cheryl L Gatto
- Departments of Biological Sciences and Cell and Developmental Biology, Kennedy Center for Research on Human Development, Vanderbilt University, Nashville, TN 37232, USA
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