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Suprunowicz M, Tomaszek N, Urbaniak A, Zackiewicz K, Modzelewski S, Waszkiewicz N. Between Dysbiosis, Maternal Immune Activation and Autism: Is There a Common Pathway? Nutrients 2024; 16:549. [PMID: 38398873 PMCID: PMC10891846 DOI: 10.3390/nu16040549] [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: 01/18/2024] [Revised: 02/05/2024] [Accepted: 02/15/2024] [Indexed: 02/25/2024] Open
Abstract
Autism spectrum disorder (ASD) is a neuropsychiatric condition characterized by impaired social interactions and repetitive stereotyped behaviors. Growing evidence highlights an important role of the gut-brain-microbiome axis in the pathogenesis of ASD. Research indicates an abnormal composition of the gut microbiome and the potential involvement of bacterial molecules in neuroinflammation and brain development disruptions. Concurrently, attention is directed towards the role of short-chain fatty acids (SCFAs) and impaired intestinal tightness. This comprehensive review emphasizes the potential impact of maternal gut microbiota changes on the development of autism in children, especially considering maternal immune activation (MIA). The following paper evaluates the impact of the birth route on the colonization of the child with bacteria in the first weeks of life. Furthermore, it explores the role of pro-inflammatory cytokines, such as IL-6 and IL-17a and mother's obesity as potentially environmental factors of ASD. The purpose of this review is to advance our understanding of ASD pathogenesis, while also searching for the positive implications of the latest therapies, such as probiotics, prebiotics or fecal microbiota transplantation, targeting the gut microbiota and reducing inflammation. This review aims to provide valuable insights that could instruct future studies and treatments for individuals affected by ASD.
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Affiliation(s)
| | | | | | | | - Stefan Modzelewski
- Department of Psychiatry, Medical University of Bialystok, pl. Wołodyjowskiego 2, 15-272 Białystok, Poland; (M.S.); (N.T.); (A.U.); (K.Z.); (N.W.)
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2
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Toya A, Fukada M, Aoki E, Matsuki T, Ueda M, Eda S, Hashizume Y, Iio A, Masaki S, Nakayama A. The distribution of neuroligin4, an autism-related postsynaptic molecule, in the human brain. Mol Brain 2023; 16:20. [PMID: 36747195 PMCID: PMC9903511 DOI: 10.1186/s13041-023-00999-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2022] [Accepted: 01/10/2023] [Indexed: 02/08/2023] Open
Abstract
NLGN4X was identified as a single causative gene of rare familial nonsyndromic autism for the first time. It encodes the postsynaptic membrane protein Neuroligin4 (NLGN4), the functions and roles of which, however, are not fully understood due to the lack of a closely homologous gene in rodents. It has been confirmed only recently that human NLGN4 is abundantly expressed in the cerebral cortex and is localized mainly to excitatory synapses. However, the detailed histological distribution of NLGN4, which may have important implications regarding the relationships between NLGN4 and autistic phenotypes, has not been clarified. In this study, we raised specific monoclonal and polyclonal antibodies against NLGN4 and examined the distribution of NLGN4 in developing and developed human brains by immunohistochemistry. We found that, in the brain, NLGN4 is expressed almost exclusively in neurons, in which it has a widespread cytoplasmic pattern of distribution. Among various types of neurons with NLGN4 expression, we identified consistently high expression of NLGN4 in hypothalamic oxytocin (OXT)/vasopressin (AVP)-producing cells. Quantitative analyses revealed that the majority of OXT/AVP-producing neurons expressed NLGN4. NLGN4 signals in other large neurons, such as pyramidal cells in the cerebral cortex and hippocampus as well as neurons in the locus coeruleus and the raphe nucleus, were also remarkable, clearly contrasting with no or scarce signals in Purkinje cells. These data suggest that NLGN4 functions in systems involved in intellectual abilities, social abilities, and sleep and wakefulness, impairments of which are commonly seen in autism.
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Affiliation(s)
- Akie Toya
- Department of Cellular Pathology, Institute for Developmental Research, Aichi Developmental Disability Center, Kasugai, 480-0392 Japan
- Department of Neurochemistry, Nagoya University Graduate School of Medicine, Nagoya, 466-8560 Japan
| | - Masahide Fukada
- Department of Cellular Pathology, Institute for Developmental Research, Aichi Developmental Disability Center, Kasugai, 480-0392 Japan
| | - Eiko Aoki
- Department of Cellular Pathology, Institute for Developmental Research, Aichi Developmental Disability Center, Kasugai, 480-0392 Japan
| | - Tohru Matsuki
- Department of Cellular Pathology, Institute for Developmental Research, Aichi Developmental Disability Center, Kasugai, 480-0392 Japan
| | - Masashi Ueda
- Department of Cellular Pathology, Institute for Developmental Research, Aichi Developmental Disability Center, Kasugai, 480-0392 Japan
| | - Shima Eda
- Department of Cellular Pathology, Institute for Developmental Research, Aichi Developmental Disability Center, Kasugai, 480-0392 Japan
| | - Yoshio Hashizume
- Institute for Medical Science of Aging, Aichi Medical University, Nagakute, 480-1195 Japan
| | - Akio Iio
- Department of Cellular Pathology, Institute for Developmental Research, Aichi Developmental Disability Center, Kasugai, 480-0392 Japan
| | - Shigeo Masaki
- Department of Cellular Pathology, Institute for Developmental Research, Aichi Developmental Disability Center, Kasugai, 480-0392 Japan
| | - Atsuo Nakayama
- Department of Cellular Pathology, Institute for Developmental Research, Aichi Developmental Disability Center, Kasugai, 480-0392 Japan
- Department of Neurochemistry, Nagoya University Graduate School of Medicine, Nagoya, 466-8560 Japan
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3
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Hegde R, Hegde S, Kulkarni SS, Pandurangi A, Gai PB, Das KK. Genetic analysis of the postsynaptic transmembrane X-linked neuroligin 3 gene in autism. Genomics Inform 2022; 19:e44. [PMID: 35012288 PMCID: PMC8752989 DOI: 10.5808/gi.21029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 12/09/2021] [Indexed: 11/20/2022] Open
Abstract
Autism is a complex neurodevelopmental disorder, the prevalence of which has increased drastically in India in recent years. Neuroligin is a type I transmembrane protein that plays a crucial role in synaptogenesis. Alterations in synaptic genes are most commonly implicated in autism and other cognitive disorders. The present study investigated the neuroligin 3 gene in the Indian autistic population by sequencing and in silico pathogenicity prediction of molecular changes. In total, 108 clinically described individuals with autism were included from the North Karnataka region of India, along with 150 age-, sex-, and ethnicity-matched healthy controls. Genomic DNA was extracted from peripheral blood, and exonic regions were sequenced. The functional and structural effects of variants of the neuroligin 3 protein were predicted. One coding sequence variant (a missense variant) and four non-coding variants (two 5'-untranslated region [UTR] variants and two 3'-UTR variants) were recorded. The novel missense variant was found in 25% of the autistic population. The C/C genotype of c.551T>C was significantly more common in autistic children than in controls (p = 0.001), and a significantly increased risk of autism (24.7-fold) was associated with this genotype (p = 0.001). The missense variant showed pathogenic effects and high evolutionary conservation over the functions of the neuroligin 3 protein. In the present study, we reported a novel missense variant, V184A, which causes abnormal neuroligin 3 and was found with high frequency in the Indian autistic population. Therefore, neuroligin is a candidate gene for future molecular investigations and functional analysis in the Indian autistic population.
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Affiliation(s)
- Rajat Hegde
- Laboratory of Vascular Physiology and Medicine, Department of Physiology, Shri B.M Patil Medical College, Hospital and Research Centre, BLDE (Deemed to be University), Vijayapura, Karnataka 586101, India.,Karnataka Institute for DNA Research (KIDNAR), Dharwad, Karnataka 580003, India
| | - Smita Hegde
- Karnataka Institute for DNA Research (KIDNAR), Dharwad, Karnataka 580003, India.,Human Genetics Laboratory, Department. of Anatomy, Shri B.M Patil Medical College, Hospital and Research Centre, BLDE (Deemed to be University), Vijayapura, Karnataka 586101, India
| | | | - Aditya Pandurangi
- Department of Psychiatry, Dharwad Institute of Mental Health and Neurosciences, Dharwad, Karnataka 580008, India
| | - Pramod B Gai
- Karnataka Institute for DNA Research (KIDNAR), Dharwad, Karnataka 580003, India
| | - Kusal K Das
- Laboratory of Vascular Physiology and Medicine, Department of Physiology, Shri B.M Patil Medical College, Hospital and Research Centre, BLDE (Deemed to be University), Vijayapura, Karnataka 586101, India
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4
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Postsynaptic autism spectrum disorder genes and synaptic dysfunction. Neurobiol Dis 2021; 162:105564. [PMID: 34838666 DOI: 10.1016/j.nbd.2021.105564] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 11/17/2021] [Accepted: 11/23/2021] [Indexed: 12/20/2022] Open
Abstract
This review provides an overview of the synaptic dysfunction of neuronal circuits and the ensuing behavioral alterations caused by mutations in autism spectrum disorder (ASD)-linked genes directly or indirectly affecting the postsynaptic neuronal compartment. There are plenty of ASD risk genes, that may be broadly grouped into those involved in gene expression regulation (epigenetic regulation and transcription) and genes regulating synaptic activity (neural communication and neurotransmission). Notably, the effects mediated by ASD-associated genes can vary extensively depending on the developmental time and/or subcellular site of expression. Therefore, in order to gain a better understanding of the mechanisms of disruptions in postsynaptic function, an effort to better model ASD in experimental animals is required to improve standardization and increase reproducibility within and among studies. Such an effort holds promise to provide deeper insight into the development of these disorders and to improve the translational value of preclinical studies.
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5
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Hegde R, Hegde S, Kulkarni SS, Pandurangi A, Gai PB, Das KK. Novel frameshift mutation in Indian autistic population causes neuroligin and neurexin binding defect. GENE REPORTS 2021. [DOI: 10.1016/j.genrep.2021.101245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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6
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Newbury DF, Simpson NH, Thompson PA, Bishop DVM. Stage 2 Registered Report: Variation in neurodevelopmental outcomes in children with sex chromosome trisomies: testing the double hit hypothesis. Wellcome Open Res 2021; 3:85. [PMID: 30271887 PMCID: PMC6134338 DOI: 10.12688/wellcomeopenres.14677.4] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/21/2021] [Indexed: 12/15/2022] Open
Abstract
Background: The presence of an extra sex chromosome is associated with an increased rate of neurodevelopmental difficulties involving language. The 'double hit' hypothesis proposes that the adverse impact of the extra sex chromosome is amplified when genes that are expressed from the sex chromosomes interact with autosomal variants that usually have only mild effects. We predicted that the impact of an additional sex chromosome on neurodevelopment would depend on common autosomal variants involved in synaptic functions. Methods: We analysed data from 130 children with sex chromosome trisomies (SCTs: 42 girls with trisomy X, 43 boys with Klinefelter syndrome, and 45 boys with XYY). Two comparison groups were formed from 370 children from a twin study. Three indicators of phenotype were: (i) Standard score on a test of nonword repetition; (ii). A language factor score derived from a test battery; (iii) A general scale of neurodevelopmental challenges based on all available information. Preselected regions of two genes, CNTNAP2 and NRXN1, were tested for association with neurodevelopmental outcomes using Generalised Structural Component Analysis. Results: There was wide phenotypic variation in the SCT group, as well as overall impairment on all three phenotypic measures. There was no association of phenotype with CNTNAP2 or NRXN1 variants in either the SCT group or the comparison groups. Supplementary analyses found no indication of any impact of trisomy type on the results, and exploratory analyses of individual SNPs confirmed the lack of association. Conclusions: We cannot rule out that a double hit may be implicated in the phenotypic variability in children with SCTs, but our analysis does not find any support for the idea that common variants in CNTNAP2 or NRXN1 are associated with the severity of language and neurodevelopmental impairments that often accompany an extra X or Y chromosome. Stage 1 report: http://dx.doi.org/10.12688/wellcomeopenres.13828.2.
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Affiliation(s)
- Dianne F. Newbury
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, OX3 0BP, UK
| | - Nuala H. Simpson
- Department of Experimental Psychology, University of Oxford, Oxford, OX2 6GG, UK
| | - Paul A. Thompson
- Department of Experimental Psychology, University of Oxford, Oxford, OX2 6GG, UK
| | - Dorothy V. M. Bishop
- Department of Experimental Psychology, University of Oxford, Oxford, OX2 6GG, UK
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7
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Kopp N, Amarillo I, Martinez-Agosto J, Quintero-Rivera F. Pathogenic paternally inherited NLGN4X deletion in a female with autism spectrum disorder: Clinical, cytogenetic, and molecular characterization. Am J Med Genet A 2020; 185:894-900. [PMID: 33369065 DOI: 10.1002/ajmg.a.62025] [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: 08/04/2020] [Revised: 11/03/2020] [Accepted: 11/27/2020] [Indexed: 11/07/2022]
Abstract
Neuroligin 4 X-linked (NLGN4X) is an X-linked postsynaptic scaffolding protein, with functional role in excitatory synapsis development and maintenance, that has been associated with neuropsychiatric disorders such as intellectual disability, autism spectrum disorders (ASD), anxiety, attention deficit hyperactivity disorder (ADHD), and Tourette's syndrome. Chromosomal microarray analysis identified a paternally inherited, 445 Kb deletion on Xp22.3 that includes the entire NLGN4X in a 2.5 year old female (46,XX) with congenital hypotonia, strabismus, ASD, and increased aggressive behavioral issues. Her family history is significant for a mother with learning disabilities, a father with anxiety, major depressive disorder, and substance abuse, as well as two maternal half-brothers with developmental delays. X-inactivation studies in the proband's blood showed random X-inactivation despite the presence of an abnormal X chromosome. Furthermore, trio exome sequencing did not reveal any other deleterious variant that could explain her phenotype. Our report describes the first example of a paternally inherited NLGN4X microdeletion as the genetic etiology of ASD in a female proband, and the psychiatric phenotypes in the father. It also provides further evidence that NLGN4X is sensitive to dosage changes in females, and can contribute to a variety of psychiatric features within the same family.
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Affiliation(s)
- Nathan Kopp
- Department of Pathology and Laboratory Medicine, UCLA Clinical Genomics Center, University of California, Los Angeles, David Geffen School of Medicine, Los Angeles, California, USA
| | - Ina Amarillo
- Department of Pathology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Julian Martinez-Agosto
- Department of Pediatrics and Human Genetics, UCLA Clinical Genomics Center, University of California, Los Angeles, Los Angeles, California, USA
| | - Fabiola Quintero-Rivera
- Department of Pathology and Laboratory Medicine, UCLA Clinical Genomics Center, University of California, Los Angeles, David Geffen School of Medicine, Los Angeles, California, USA.,Department of Pathology and Laboratory Medicine, University of California, Irvine, Irvine, California, USA
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8
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An Autism-Associated Mutation Impairs Neuroligin-4 Glycosylation and Enhances Excitatory Synaptic Transmission in Human Neurons. J Neurosci 2020; 41:392-407. [PMID: 33268543 DOI: 10.1523/jneurosci.0404-20.2020] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 11/18/2020] [Accepted: 11/20/2020] [Indexed: 02/06/2023] Open
Abstract
Neuroligins (NLGNs) are a class of postsynaptic cell adhesion molecules that interact with presynaptic neurexins (NRXNs) and regulate synapse function. NLGN4 is a member of the NLGN family and consists of a unique amino acid sequence in humans that is not evolutionarily well conserved in rodents. The human-specific NLGN4 gene has been reported to be mutated in many patients with autism and other neurodevelopmental disorders. However, it remained unclear how these mutations might alter the molecular properties of NLGN4 and affect synaptic transmission in human neurons. Here, we describe a severely autistic male patient carrying a single amino acid substitution (R101Q) in the NLGN4 gene. When expressed in HEK293 cells, the R101Q mutation in NLGN4 did not affect its binding affinity for NRXNs or its capacity to form homodimers. This mutation, however, impaired the maturation of NLGN4 protein by inhibiting N-linked glycosylation at an adjacent residue (N102), which is conserved in all NLGNs. As a result, the R101Q substitution significantly decreased the surface trafficking of NLGN4 and increased its retention in the endoplasmic reticulum and Golgi apparatus. In human neurons derived from male stem cell lines, the R101Q mutation also similarly reduced the synaptic localization of NLGN4, resulting in a loss-of-function phenotype. This mutation-induced trafficking defect substantially diminished the ability of NLGN4 to form excitatory synapses and modulate their functional properties. Viewed together, our findings suggest that the R101Q mutation is pathogenic for NLGN4 and can lead to synaptic dysfunction in autism.
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9
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Comoletti D, Trobiani L, Chatonnet A, Bourne Y, Marchot P. Comparative mapping of selected structural determinants on the extracellular domains of cholinesterase-like cell-adhesion molecules. Neuropharmacology 2020; 184:108381. [PMID: 33166544 DOI: 10.1016/j.neuropharm.2020.108381] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 09/10/2020] [Accepted: 10/29/2020] [Indexed: 11/18/2022]
Abstract
Cell adhesion generally involves formation of homophilic or heterophilic protein complexes between two cells to form transcellular junctions. Neural cell-adhesion members of the α/β-hydrolase fold superfamily of proteins use their extracellular or soluble cholinesterase-like domain to bind cognate partners across cell membranes, as illustrated by the neuroligins. These cell-adhesion molecules currently comprise the synaptic organizers neuroligins found in all animal phyla, along with three proteins found only in invertebrates: the guidance molecule neurotactin, the glia-specific gliotactin, and the basement membrane protein glutactin. Although these proteins share a cholinesterase-like fold, they lack one or more residues composing the catalytic triad responsible for the enzymatic activity of the cholinesterases. Conversely, they are found in various subcellular localisations and display specific disulfide bonding and N-glycosylation patterns, along with individual surface determinants possibly associated with recognition and binding of protein partners. Formation of non-covalent dimers typical of the cholinesterases is documented for mammalian neuroligins, yet whether invertebrate neuroligins and their neurotactin, gliotactin and glutactin relatives also form dimers in physiological conditions is unknown. Here we provide a brief overview of the localization, function, evolution, and conserved versus individual structural determinants of these cholinesterase-like cell-adhesion proteins. This article is part of the special issue entitled 'Acetylcholinesterase Inhibitors: From Bench to Bedside to Battlefield'.
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Affiliation(s)
- Davide Comoletti
- School of Biological Sciences, Victoria University of Wellington, Wellington, 6012, New Zealand; Child Health Institute of New Jersey, New Brunswick, NJ 08901, USA; Department of Neuroscience and Cell Biology Robert Wood Johnson Medical School, Rutgers University, New Brunswick, NJ 08901, USA.
| | - Laura Trobiani
- School of Biological Sciences, Victoria University of Wellington, Wellington, 6012, New Zealand
| | - Arnaud Chatonnet
- Lab 'Dynamique Musculaire et Métabolisme', Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement (INRAE) / Université Montpellier, Montpellier, France
| | - Yves Bourne
- Lab 'Architecture et Fonction des Macromolécules Biologiques (AFMB)', Centre National de la Recherche Scientifique (CNRS)/Aix-Marseille Univ, Faculté des Sciences - Campus Luminy, Marseille, France
| | - Pascale Marchot
- Lab 'Architecture et Fonction des Macromolécules Biologiques (AFMB)', Centre National de la Recherche Scientifique (CNRS)/Aix-Marseille Univ, Faculté des Sciences - Campus Luminy, Marseille, France.
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10
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Newbury DF, Simpson NH, Thompson PA, Bishop DVM. Stage 2 Registered Report: Variation in neurodevelopmental outcomes in children with sex chromosome trisomies: testing the double hit hypothesis. Wellcome Open Res 2020; 3:85. [PMID: 30271887 PMCID: PMC6134338 DOI: 10.12688/wellcomeopenres.14677.3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/18/2020] [Indexed: 04/03/2024] Open
Abstract
Background: The presence of an extra sex chromosome is associated with an increased rate of neurodevelopmental difficulties involving language. The 'double hit' hypothesis proposes that the adverse impact of the extra sex chromosome is amplified when genes that are expressed from the sex chromosomes interact with autosomal variants that usually have only mild effects. We predicted that the impact of an additional sex chromosome on neurodevelopment would depend on common autosomal variants involved in synaptic functions. Methods: We analysed data from 130 children with sex chromosome trisomies (SCTs: 42 girls with trisomy X, 43 boys with Klinefelter syndrome, and 45 boys with XYY). Two comparison groups were formed from 370 children from a twin study. Three indicators of phenotype were: (i) Standard score on a test of nonword repetition; (ii). A language factor score derived from a test battery; (iii) A general scale of neurodevelopmental challenges based on all available information. Preselected regions of two genes, CNTNAP2 and NRXN1, were tested for association with neurodevelopmental outcomes using Generalised Structural Component Analysis. Results: There was wide phenotypic variation in the SCT group, as well as overall impairment on all three phenotypic measures. There was no association of phenotype with CNTNAP2 or NRXN1 variants in either the SCT group or the comparison groups. Supplementary analyses found no indication of any impact of trisomy type on the results, and exploratory analyses of individual SNPs confirmed the lack of association. Conclusions: We cannot rule out that a double hit may be implicated in the phenotypic variability in children with SCTs, but our analysis does not find any support for the idea that common variants in CNTNAP2 or NRXN1 are associated with the severity of language and neurodevelopmental impairments that often accompany an extra X or Y chromosome. Stage 1 report: http://dx.doi.org/10.12688/wellcomeopenres.13828.2.
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Affiliation(s)
- Dianne F. Newbury
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, OX3 0BP, UK
| | - Nuala H. Simpson
- Department of Experimental Psychology, University of Oxford, Oxford, OX2 6GG, UK
| | - Paul A. Thompson
- Department of Experimental Psychology, University of Oxford, Oxford, OX2 6GG, UK
| | - Dorothy V. M. Bishop
- Department of Experimental Psychology, University of Oxford, Oxford, OX2 6GG, UK
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11
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Nguyen TA, Lehr AW, Roche KW. Neuroligins and Neurodevelopmental Disorders: X-Linked Genetics. Front Synaptic Neurosci 2020; 12:33. [PMID: 32848696 PMCID: PMC7431521 DOI: 10.3389/fnsyn.2020.00033] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 07/22/2020] [Indexed: 12/24/2022] Open
Abstract
Autism spectrum disorder (ASD) is a neurodevelopmental disorder that results in social-communication impairments, as well as restricted and repetitive behaviors. Moreover, ASD is more prevalent in males, with a male to female ratio of 4 to 1. Although the underlying etiology of ASD is generally unknown, recent advances in genome sequencing have facilitated the identification of a host of associated genes. Among these, synaptic proteins such as cell adhesion molecules have been strongly linked with ASD. Interestingly, many large genome sequencing studies exclude sex chromosomes, which leads to a shift in focus toward autosomal genes as targets for ASD research. However, there are many genes on the X chromosome that encode synaptic proteins, including strong candidate genes. Here, we review findings regarding two members of the neuroligin (NLGN) family of postsynaptic adhesion molecules, NLGN3 and NLGN4. Neuroligins have multiple isoforms (NLGN1-4), which are both autosomal and sex-linked. The sex-linked genes, NLGN3 and NLGN4, are both on the X chromosome and were among the first few genes to be linked with ASD and intellectual disability (ID). In addition, there is a less studied human neuroligin on the Y chromosome, NLGN4Y, which forms an X-Y pair with NLGN4X. We will discuss recent findings of these neuroligin isoforms regarding function at the synapse in both rodent models and human-derived differentiated neurons, and highlight the exciting challenges moving forward to a better understanding of ASD/ID.
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Affiliation(s)
- Thien A. Nguyen
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States
- Department of Pharmacology and Physiology, Georgetown University, Washington, DC, United States
| | - Alexander W. Lehr
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States
| | - Katherine W. Roche
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States
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12
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Nguyen TA, Wu K, Pandey S, Lehr AW, Li Y, Bemben MA, Badger JD, Lauzon JL, Wang T, Zaghloul KA, Thurm A, Jain M, Lu W, Roche KW. A Cluster of Autism-Associated Variants on X-Linked NLGN4X Functionally Resemble NLGN4Y. Neuron 2020; 106:759-768.e7. [PMID: 32243781 DOI: 10.1016/j.neuron.2020.03.008] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 02/12/2020] [Accepted: 03/11/2020] [Indexed: 12/20/2022]
Abstract
Autism spectrum disorder (ASD) is more prevalent in males; however, the etiology for this sex bias is not well understood. Many mutations on X-linked cell adhesion molecule NLGN4X result in ASD or intellectual disability. NLGN4X is part of an X-Y pair, with NLGN4Y sharing ∼97% sequence homology. Using biochemistry, electrophysiology, and imaging, we show that NLGN4Y displays severe deficits in maturation, surface expression, and synaptogenesis regulated by one amino acid difference with NLGN4X. Furthermore, we identify a cluster of ASD-associated mutations surrounding the critical amino acid in NLGN4X, and these mutations phenocopy NLGN4Y. We show that NLGN4Y cannot compensate for the functional deficits observed in ASD-associated NLGN4X mutations. Altogether, our data reveal a potential pathogenic mechanism for male bias in NLGN4X-associated ASD.
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Affiliation(s)
- Thien A Nguyen
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA; Department of Pharmacology and Physiology, Georgetown University, Washington DC 20057, USA
| | - Kunwei Wu
- Synapse and Neural Circuit Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Saurabh Pandey
- Synapse and Neural Circuit Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Alexander W Lehr
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Yan Li
- Protein/Peptide Sequencing Facility, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Michael A Bemben
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - John D Badger
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Julie L Lauzon
- Department of Medical Genetics and Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Tongguang Wang
- Translational Neuroscience Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Kareem A Zaghloul
- Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Audrey Thurm
- National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA
| | - Mahim Jain
- Department of Bone and OI, Kennedy Krieger Institute, Baltimore, MD 21205, USA
| | - Wei Lu
- Synapse and Neural Circuit Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Katherine W Roche
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA.
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13
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Quartier A, Courraud J, Thi Ha T, McGillivray G, Isidor B, Rose K, Drouot N, Savidan MA, Feger C, Jagline H, Chelly J, Shaw M, Laumonnier F, Gecz J, Mandel JL, Piton A. Novel mutations in NLGN3 causing autism spectrum disorder and cognitive impairment. Hum Mutat 2019; 40:2021-2032. [PMID: 31184401 DOI: 10.1002/humu.23836] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 05/10/2019] [Accepted: 06/05/2019] [Indexed: 12/22/2022]
Abstract
The X-linked NLGN3 gene, encoding a postsynaptic cell adhesion molecule, was involved in a nonsyndromic monogenic form of autism spectrum disorder (ASD) by the description of one unique missense variant, p.Arg451Cys (Jamain et al. 2003). We investigated here the pathogenicity of additional missense variants identified in two multiplex families with intellectual disability (ID) and ASD: c.1789C>T, p.Arg597Trp, previously reported by our group (Redin et al. 2014) and present in three affected cousins and c.1540C>T, p.Pro514Ser, identified in two affected brothers. Overexpression experiments in HEK293 and HeLa cell lines revealed that both variants affect the level of the mature NLGN3 protein, its localization at the plasma membrane and its presence as a cleaved form in the extracellular environment, even more drastically than what was reported for the initial p.Arg451Cys mutation. The variants also induced an unfolded protein response, probably due to the retention of immature NLGN3 proteins in the endoplasmic reticulum. In comparison, the c.1894A>G, p.Ala632Thr and c.1022T>C, p.Val341Ala variants, present in males from the general population, have no effect. Our report of two missense variants affecting the normal localization of NLGN3 in a total of five affected individuals reinforces the involvement of the NLGN3 gene in a neurodevelopmental disorder characterized by ID and ASD.
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Affiliation(s)
- Angélique Quartier
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France.,Centre National de la Recherche Scientifique, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, Illkirch, France.,Université de Strasbourg, Illkirch, France
| | - Jérémie Courraud
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France.,Centre National de la Recherche Scientifique, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, Illkirch, France.,Université de Strasbourg, Illkirch, France
| | - Thuong Thi Ha
- School of Biological Sciences, University of Adelaide, Adelaide, South Australia, Australia.,Adelaide Medical School and Robinson Research Institute, University of Adelaide, Adelaide, South Australia, Australia
| | - George McGillivray
- Victorian Clinical Genetics Services, Murdoch Children's Research Institute, Royal Children's Hospital, Melbourne, Victoria, Australia
| | - Bertrand Isidor
- Service de Génétique Médicale, CHU de Nantes, Nantes, France
| | - Katherine Rose
- Monash Genetics, Monash Health, Clayton, Victoria, Australia
| | - Nathalie Drouot
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France.,Centre National de la Recherche Scientifique, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, Illkirch, France.,Université de Strasbourg, Illkirch, France
| | - Marie-Armel Savidan
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France.,Centre National de la Recherche Scientifique, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, Illkirch, France.,Université de Strasbourg, Illkirch, France
| | - Claire Feger
- Molecular Genetic Unit, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Hélène Jagline
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France.,Centre National de la Recherche Scientifique, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, Illkirch, France.,Université de Strasbourg, Illkirch, France
| | - Jamel Chelly
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France.,Centre National de la Recherche Scientifique, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, Illkirch, France.,Université de Strasbourg, Illkirch, France.,Molecular Genetic Unit, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Marie Shaw
- School of Biological Sciences, University of Adelaide, Adelaide, South Australia, Australia.,Adelaide Medical School and Robinson Research Institute, University of Adelaide, Adelaide, South Australia, Australia
| | - Frédéric Laumonnier
- UMR 1253, iBrain, Université de Tours, Inserm, Tours, France.,Service de Génétique, Centre Hospitalier Universitaire de Tours, Tours, France
| | - Jozef Gecz
- School of Biological Sciences, University of Adelaide, Adelaide, South Australia, Australia.,Adelaide Medical School and Robinson Research Institute, University of Adelaide, Adelaide, South Australia, Australia
| | - Jean-Louis Mandel
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France.,Centre National de la Recherche Scientifique, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, Illkirch, France.,Université de Strasbourg, Illkirch, France.,University of Strasbourg Institute of Advanced Studies, Strasbourg, France
| | - Amélie Piton
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France.,Centre National de la Recherche Scientifique, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, Illkirch, France.,Université de Strasbourg, Illkirch, France.,Molecular Genetic Unit, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
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14
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Marro SG, Chanda S, Yang N, Janas JA, Valperga G, Trotter J, Zhou B, Merrill S, Yousif I, Shelby H, Vogel H, Kalani MYS, Südhof TC, Wernig M. Neuroligin-4 Regulates Excitatory Synaptic Transmission in Human Neurons. Neuron 2019; 103:617-626.e6. [PMID: 31257103 DOI: 10.1016/j.neuron.2019.05.043] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 04/17/2019] [Accepted: 05/28/2019] [Indexed: 12/26/2022]
Abstract
The autism-associated synaptic-adhesion gene Neuroligin-4 (NLGN4) is poorly conserved evolutionarily, limiting conclusions from Nlgn4 mouse models for human cells. Here, we show that the cellular and subcellular expression of human and murine Neuroligin-4 differ, with human Neuroligin-4 primarily expressed in cerebral cortex and localized to excitatory synapses. Overexpression of NLGN4 in human embryonic stem cell-derived neurons resulted in an increase in excitatory synapse numbers but a remarkable decrease in synaptic strength. Human neurons carrying the syndromic autism mutation NLGN4-R704C also formed more excitatory synapses but with increased functional synaptic transmission due to a postsynaptic mechanism, while genetic loss of NLGN4 did not significantly affect synapses in the human neurons analyzed. Thus, the NLGN4-R704C mutation represents a change-of-function mutation. Our work reveals contrasting roles of NLGN4 in human and mouse neurons, suggesting that human evolution has impacted even fundamental cell biological processes generally assumed to be highly conserved.
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Affiliation(s)
- Samuele G Marro
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA; Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Soham Chanda
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA; Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Nan Yang
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA; Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Justyna A Janas
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA; Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Giulio Valperga
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA; Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Justin Trotter
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA; Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Bo Zhou
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA; Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Sean Merrill
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA; Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Issa Yousif
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA; Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Hannah Shelby
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA; Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Hannes Vogel
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - M Yashar S Kalani
- Departments of Neurosurgery and Neuroscience, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Thomas C Südhof
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA; Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA 94305, USA.
| | - Marius Wernig
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA; Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA.
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15
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Newbury DF, Simpson NH, Thompson PA, Bishop DVM. Stage 2 Registered Report: Variation in neurodevelopmental outcomes in children with sex chromosome trisomies: testing the double hit hypothesis. Wellcome Open Res 2018; 3:85. [PMID: 30271887 PMCID: PMC6134338 DOI: 10.12688/wellcomeopenres.14677.2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/02/2018] [Indexed: 01/26/2024] Open
Abstract
Background: The presence of an extra sex chromosome is associated with an increased rate of neurodevelopmental difficulties involving language. The 'double hit' hypothesis proposes that the adverse impact of the extra sex chromosome is amplified when genes that are expressed from the sex chromosomes interact with autosomal variants that usually have only mild effects. We predicted that the impact of an additional sex chromosome on neurodevelopment would depend on common autosomal variants involved in synaptic functions. Methods: We analysed data from 130 children with sex chromosome trisomies (SCTs: 42 girls with trisomy X, 43 boys with Klinefelter syndrome, and 45 boys with XYY). Two comparison groups were formed from 370 children from a twin study. Three indicators of phenotype were: (i) Standard score on a test of nonword repetition; (ii). A language factor score derived from a test battery; (iii) A general scale of neurodevelopmental challenges based on all available information. Preselected regions of two genes, CNTNAP2 and NRXN1, were tested for association with neurodevelopmental outcomes using Generalised Structural Component Analysis. Results: There was wide phenotypic variation in the SCT group, as well as overall impairment on all three phenotypic measures. There was no association of phenotype with CNTNAP2 or NRXN1 variants in either the SCT group or the comparison groups. Supplementary analyses found no indication of any impact of trisomy type on the results, and exploratory analyses of individual SNPs confirmed the lack of association. Conclusions: We cannot rule out that a double hit may be implicated in the phenotypic variability in children with SCTs, but our analysis does not find any support for the idea that common variants in CNTNAP2 or NRXN1 are associated with the severity of language and neurodevelopmental impairments that often accompany an extra X or Y chromosome. Stage 1 report: http://dx.doi.org/10.12688/wellcomeopenres.13828.2.
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Affiliation(s)
- Dianne F. Newbury
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, OX3 0BP, UK
| | - Nuala H. Simpson
- Department of Experimental Psychology, University of Oxford, Oxford, OX2 6GG, UK
| | - Paul A. Thompson
- Department of Experimental Psychology, University of Oxford, Oxford, OX2 6GG, UK
| | - Dorothy V. M. Bishop
- Department of Experimental Psychology, University of Oxford, Oxford, OX2 6GG, UK
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16
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Newbury DF, Simpson NH, Thompson PA, Bishop DVM. Stage 2 Registered Report: Variation in neurodevelopmental outcomes in children with sex chromosome trisomies: testing the double hit hypothesis. Wellcome Open Res 2018; 3:85. [PMID: 30271887 PMCID: PMC6134338 DOI: 10.12688/wellcomeopenres.14677.1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/12/2018] [Indexed: 12/26/2022] Open
Abstract
Background: The presence of an extra sex chromosome is associated with an increased rate of neurodevelopmental difficulties involving language. The 'double hit' hypothesis proposes that the adverse impact of the extra sex chromosome is amplified when genes that are expressed from the sex chromosomes interact with autosomal variants that usually have only mild effects. We predicted that the impact of an additional sex chromosome on neurodevelopment would depend on common autosomal variants involved in synaptic functions. Methods: We analysed data from 130 children with sex chromosome trisomies (SCTs: 42 girls with trisomy X, 43 boys with Klinefelter syndrome, and 45 boys with XYY). Two comparison groups were formed from 370 children from a twin study. Three indicators of phenotype were: (i) Standard score on a test of nonword repetition; (ii). A language factor score derived from a test battery; (iii) A general scale of neurodevelopmental challenges based on all available information. Preselected regions of two genes, CNTNAP2 and NRXN1, were tested for association with neurodevelopmental outcomes using Generalised Structural Component Analysis. Results: There was wide phenotypic variation in the SCT group, as well as overall impairment on all three phenotypic measures. There was no association of phenotype with CNTNAP2 or NRXN1 variants in either the SCT group or the comparison groups. Supplementary analyses found no indication of any impact of trisomy type on the results, and exploratory analyses of individual SNPs confirmed the lack of association. Conclusions: We cannot rule out that a double hit may be implicated in the phenotypic variability in children with SCTs, but our analysis does not find any support for the idea that common variants in CNTNAP2 or NRXN1 are associated with the severity of language and neurodevelopmental impairments that often accompany an extra X or Y chromosome. Stage 1 report: http://dx.doi.org/10.12688/wellcomeopenres.13828.2.
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Affiliation(s)
- Dianne F. Newbury
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, OX3 0BP, UK
| | - Nuala H. Simpson
- Department of Experimental Psychology, University of Oxford, Oxford, OX2 6GG, UK
| | - Paul A. Thompson
- Department of Experimental Psychology, University of Oxford, Oxford, OX2 6GG, UK
| | - Dorothy V. M. Bishop
- Department of Experimental Psychology, University of Oxford, Oxford, OX2 6GG, UK
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17
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Zhang B, Gokce O, Hale WD, Brose N, Südhof TC. Autism-associated neuroligin-4 mutation selectively impairs glycinergic synaptic transmission in mouse brainstem synapses. J Exp Med 2018; 215:1543-1553. [PMID: 29724786 PMCID: PMC5987923 DOI: 10.1084/jem.20172162] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 03/25/2018] [Accepted: 04/24/2018] [Indexed: 01/01/2023] Open
Abstract
Loss-of-function mutations of the human postsynaptic cell-adhesion protein neuroligin-4 have been repeatedly associated with autism, but the precise synaptic function of neuroligin-4 that may account for its role in autism remains unclear. Here, we show in murine brainstem synapses that neuroligin-4 is selectively required for glycinergic synaptic transmission in mice. In human patients, loss-of-function mutations of the postsynaptic cell-adhesion molecule neuroligin-4 were repeatedly identified as monogenetic causes of autism. In mice, neuroligin-4 deletions caused autism-related behavioral impairments and subtle changes in synaptic transmission, and neuroligin-4 was found, at least in part, at glycinergic synapses. However, low expression levels precluded a comprehensive analysis of neuroligin-4 localization, and overexpression of neuroligin-4 puzzlingly impaired excitatory but not inhibitory synaptic function. As a result, the function of neuroligin-4 remains unclear, as does its relation to other neuroligins. To clarify these issues, we systematically examined the function of neuroligin-4, focusing on excitatory and inhibitory inputs to defined projection neurons of the mouse brainstem as central model synapses. We show that loss of neuroligin-4 causes a profound impairment of glycinergic but not glutamatergic synaptic transmission and a decrease in glycinergic synapse numbers. Thus, neuroligin-4 is essential for the organization and/or maintenance of glycinergic synapses.
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Affiliation(s)
- Bo Zhang
- Department of Molecular and Cellular Physiology and Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA
| | - Ozgun Gokce
- Department of Molecular and Cellular Physiology and Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA
| | - W Dylan Hale
- Department of Molecular and Cellular Physiology and Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA
| | - Nils Brose
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Thomas C Südhof
- Department of Molecular and Cellular Physiology and Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA
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18
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Newbury DF, Simpson NH, Thompson PA, Bishop DVM. Stage 1 Registered Report: Variation in neurodevelopmental outcomes in children with sex chromosome trisomies: protocol for a test of the double hit hypothesis. Wellcome Open Res 2018; 3:10. [PMID: 29744390 PMCID: PMC5904730 DOI: 10.12688/wellcomeopenres.13828.2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/02/2018] [Indexed: 12/20/2022] Open
Abstract
Background: The presence of an extra sex chromosome is associated with an increased rate of neurodevelopmental difficulties involving language. Group averages, however, obscure a wide range of outcomes. Hypothesis: The 'double hit' hypothesis proposes that the adverse impact of the extra sex chromosome is amplified when genes that are expressed from the sex chromosomes interact with autosomal variants that usually have only mild effects.
Neuroligin-4 genes are expressed from X and Y chromosomes; they play an important role in synaptic development and have been implicated in neurodevelopment. We predict that the impact of an additional sex chromosome on neurodevelopment will be correlated with common autosomal variants involved in related synaptic functions. We describe here an analysis plan for testing this hypothesis using existing data. The analysis of genotype-phenotype associations will be conducted after this plan is published and peer-reviewed Methods: Neurodevelopmental data and DNA are available for 130 children with sex chromosome trisomies (SCTs: 42 girls with trisomy X, 43 boys with Klinefelter syndrome, and 45 boys with XYY). Children from a twin study using the same phenotype measures will form two comparison groups (Ns = 184 and 186). Three indicators of a neurodevelopment disorder phenotype will be used: (i) Standard score on a test of nonword repetition; (ii). A language factor score derived from a test battery; (iii) A general scale of neurodevelopmental challenges based on all available information. Autosomal genes were identified by literature search on the basis of prior association with (a) speech/language/reading phenotypes and (b) synaptic function. Preselected regions of two genes scoring high on both criteria,
CNTNAP2 and
NRXN1, will be tested for association with neurodevelopmental outcomes using Generalised Structural Component Analysis. We predict the association with one or both genes will be detectable in children with SCTs and stronger than in the comparison samples.
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Affiliation(s)
- Dianne F Newbury
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, Oxfordshire, OX3 0BP, UK
| | - Nuala H Simpson
- Department of Experimental Psychology, University of Oxford, Oxford, Oxfordshire, OX1 3UD, UK
| | - Paul A Thompson
- Department of Experimental Psychology, University of Oxford, Oxford, Oxfordshire, OX1 3UD, UK
| | - Dorothy V M Bishop
- Department of Experimental Psychology, University of Oxford, Oxford, Oxfordshire, OX1 3UD, UK
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19
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Newbury DF, Simpson NH, Thompson PA, Bishop DVM. Stage 1 Registered Report: Variation in neurodevelopmental outcomes in children with sex chromosome trisomies: protocol for a test of the double hit hypothesis. Wellcome Open Res 2018. [DOI: 10.12688/wellcomeopenres.13828.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Background: The presence of an extra sex chromosome is associated with an increased rate of neurodevelopmental difficulties involving language. Group averages, however, obscure a wide range of outcomes. Hypothesis: The 'double hit' hypothesis proposes that the adverse impact of the extra sex chromosome is amplified when genes that are expressed from the sex chromosomes interact with autosomal variants that usually have only mild effects. Neuroligin-4 genes are expressed from X and Y chromosomes; they play an important role in synaptic development and have been implicated in neurodevelopment. We predict that the impact of an additional sex chromosome on neurodevelopment will be correlated with common autosomal variants involved in related synaptic functions. We describe here an analysis plan for testing this hypothesis using existing data. The analysis of genotype-phenotype associations will be conducted after this plan is published and peer-reviewed Methods: Neurodevelopmental data and DNA are available for 130 children with sex chromosome trisomies (SCTs: 42 girls with trisomy X, 43 boys with Klinefelter syndrome, and 45 boys with XYY). Children from a twin study using the same phenotype measures will form two comparison groups (Ns = 184 and 186). Three indicators of a neurodevelopment disorder phenotype will be used: (i) Standard score on a test of nonword repetition; (ii). A language factor score derived from a test battery; (iii) A general scale of neurodevelopmental challenges based on all available information. Autosomal genes were identified by literature search on the basis of prior association with (a) speech/language/reading phenotypes and (b) synaptic function. Preselected regions of two genes scoring high on both criteria, CNTNAP2 and NRXN1, will be tested for association with neurodevelopmental outcomes using Generalised Structural Component Analysis. We predict the association with one or both genes will be detectable in children with SCTs and stronger than in the comparison samples.
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20
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Kasem E, Kurihara T, Tabuchi K. Neurexins and neuropsychiatric disorders. Neurosci Res 2017; 127:53-60. [PMID: 29221905 DOI: 10.1016/j.neures.2017.10.012] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Revised: 09/24/2017] [Accepted: 10/03/2017] [Indexed: 12/29/2022]
Abstract
Neurexins are a family of presynaptic single-pass transmembrane proteins that act as synaptic organizers in mammals. The neurexins consist of three genes (NRXN1, NRXN2, and NRXN3), each of which produces a longer α- and shorter β-form. Genomic alterations in NRXN genes have been identified in a wide variety of neuropsychiatric disorders, including autism spectrum disorders (ASD), schizophrenia, intellectual disability (ID), and addiction. Remarkably, a bi-allelic deficiency of NRXN1 was recently linked to Pitt-Hopkins syndrome. The fact that some mono-allelic functional variants of NRXNs are also found in healthy controls indicates that other genetic or environmental factors affect the penetrance of NRXN deficiency. In this review, we summarize the common research methods and representative results of human genetic studies that have implicated NRXN variants in various neuropsychiatric disorders. We also summarize studies of rodent models with NRXN deficiencies that complement our knowledge of human genetics.
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Affiliation(s)
- Enas Kasem
- Department of Molecular & Cellular Physiology, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, 390-8621 Japan
| | - Taiga Kurihara
- Department of Molecular & Cellular Physiology, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, 390-8621 Japan
| | - Katsuhiko Tabuchi
- Department of Molecular & Cellular Physiology, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, 390-8621 Japan; Institute for Biomedical Sciences, Interdisciplinary Cluster for Cutting Edge Research, Shinshu University, Matsumoto 390-8621, Japan.
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21
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Yin J, Schaaf CP. Autism genetics - an overview. Prenat Diagn 2016; 37:14-30. [DOI: 10.1002/pd.4942] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Revised: 10/04/2016] [Accepted: 10/11/2016] [Indexed: 12/13/2022]
Affiliation(s)
- Jiani Yin
- Department of Molecular and Human Genetics; Baylor College of Medicine; Houston TX USA
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital; Houston TX USA
| | - Christian P. Schaaf
- Department of Molecular and Human Genetics; Baylor College of Medicine; Houston TX USA
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital; Houston TX USA
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22
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Abstract
Autism spectrum disorders (ASD) are highly heterogeneous pediatric developmental disorders with estimated heritability more than 70%. Although the genetic factors in ASD are mainly unknown, a large number of gene mutations have been found, especially in genes involved in neurogenesis. The Neurexin-Neuroligin-Shank (NRXN-NLGN-SHANK) pathway plays a key role in the formation, maturation and maintenance of synapses, consistent with the hypothesis of neurodevelopmental abnormality in ASD. Presynaptic NRXNs interact with postsynaptic NLGNs in excitatory glutamatergic synapses. SHANK proteins function as core components of the postsynaptic density (PSD) by interacting with multiple proteins. Recently, deletions and point mutations of the SHANK1 gene have been detected in ASD individuals, indicating the involvement of SHANK1 in ASD. This review focuses on the function of SHANK1 protein, Shank1 mouse models, and the molecular genetics of the SHANK1 gene in human ASD.
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Affiliation(s)
- XiaoHong Gong
- MOE Key Laboratory of Contemporary Anthropology and State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, 200433, China.
| | - HongYan Wang
- MOE Key Laboratory of Contemporary Anthropology and State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, 200433, China.
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23
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Hua R, Wei M, Zhang C. The complex genetics in autism spectrum disorders. SCIENCE CHINA-LIFE SCIENCES 2015; 58:933-45. [PMID: 26335739 DOI: 10.1007/s11427-015-4893-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Autism spectrum disorders (ASD) are a pervasive neurodevelopmental disease characterized by deficits in social interaction and nonverbal communication, as well as restricted interests and stereotypical behavior. Genetic changes/heritability is one of the major contributing factors, and hundreds to thousands of causative and susceptible genes, copy number variants (CNVs), linkage regions, and microRNAs have been associated with ASD which clearly indicates that ASD is a complex genetic disorder. Here, we will briefly summarize some of the high-confidence genetic changes in ASD and their possible roles in their pathogenesis.
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Affiliation(s)
- Rui Hua
- State Key Laboratory of Membrane Biology, School of Life Sciences; PKU-IDG/McGovern Institute for Brain Research, Peking University, Beijing, 100871, China
| | - MengPing Wei
- State Key Laboratory of Membrane Biology, School of Life Sciences; PKU-IDG/McGovern Institute for Brain Research, Peking University, Beijing, 100871, China
| | - Chen Zhang
- State Key Laboratory of Membrane Biology, School of Life Sciences; PKU-IDG/McGovern Institute for Brain Research, Peking University, Beijing, 100871, China.
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24
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Davies W. Sex differences in attention Deficit Hyperactivity Disorder: candidate genetic and endocrine mechanisms. Front Neuroendocrinol 2014; 35:331-46. [PMID: 24680800 DOI: 10.1016/j.yfrne.2014.03.003] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Revised: 02/13/2014] [Accepted: 03/17/2014] [Indexed: 02/07/2023]
Abstract
Attention Deficit Hyperactivity Disorder (ADHD) is a developmental condition characterised by severe inattention, pathological impulsivity and hyperactivity; it is relatively common affecting up to 6% of children, and is associated with a risk of long-term adverse educational and social consequences. Males are considerably more likely to be diagnosed with ADHD than females; the course of the disorder and its associated co-morbidities also appear to be sensitive to sex. Here, I discuss fundamental biological (genetic and endocrine) mechanisms that have been shown to, or could theoretically, contribute towards these sexually dimorphic phenomena. Greater understanding of how and why the sexes differ with respect to ADHD vulnerability should allow us to identify and characterise novel protective and risk factors for the disorder, and should ultimately facilitate improved diagnosis, prognosis and treatment.
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Affiliation(s)
- William Davies
- Behavioural Genetics Group, Neuroscience and Mental Health Research Institute, Schools of Psychology and Medicine, Cardiff University, Tower Building, Park Place, Cardiff CF10 3AT, UK; Medical Research Council Centre for Neuropsychiatric Genetics and Genomics, Cardiff University, Hadyn Ellis Building, Cardiff CF24 4HQ, UK.
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25
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Schaafsma SM, Pfaff DW. Etiologies underlying sex differences in Autism Spectrum Disorders. Front Neuroendocrinol 2014; 35:255-71. [PMID: 24705124 DOI: 10.1016/j.yfrne.2014.03.006] [Citation(s) in RCA: 93] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Revised: 02/06/2014] [Accepted: 03/17/2014] [Indexed: 01/09/2023]
Abstract
The male predominance of Autism Spectrum Disorders (ASD) is one of the best-known, and at the same time, one of the least understood characteristics of these disorders. In this paper we review genetic, epigenetic, hormonal, and environmental mechanisms underlying this male preponderance. Sex-specific effects of Y-linked genes (including SRY expression leading to testicular development), balanced and skewed X-inactivation, genes that escape X-inactivation, parent-of-origin allelic imprinting, and the hypothetical heterochromatin sink are reviewed. These mechanisms likely contribute to etiology, instead of being simply causative to ASD. Environments, both internal and external, also play important roles in ASD's etiology. Early exposure to androgenic hormones and early maternal immune activation comprise environmental factors affecting sex-specific susceptibility to ASD. The gene-environment interactions underlying ASD, suggested here, implicate early prenatal stress as being especially detrimental to boys with a vulnerable genotype.
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Affiliation(s)
- Sara M Schaafsma
- Laboratory of Neurobiology and Behavior, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA.
| | - Donald W Pfaff
- Laboratory of Neurobiology and Behavior, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
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Stewart AM, Nguyen M, Wong K, Poudel MK, Kalueff AV. Developing zebrafish models of autism spectrum disorder (ASD). Prog Neuropsychopharmacol Biol Psychiatry 2014; 50:27-36. [PMID: 24315837 DOI: 10.1016/j.pnpbp.2013.11.014] [Citation(s) in RCA: 107] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Revised: 11/22/2013] [Accepted: 11/28/2013] [Indexed: 01/07/2023]
Abstract
Autism spectrum disorder (ASD) is a serious neurodevelopmental disorder with complex symptoms and unclear, multi-factorial pathogenesis. Animal (rodent) models of ASD-like behavior are extensively used to study genetics, circuitry and molecular mechanisms of ASD. The evolutionarily conserved nature of social behavior and its molecular pathways suggests that alternative experimental models can be developed to complement and enhance the existing rodent ASD paradigms. The zebrafish (Danio rerio) is rapidly becoming a popular model organism in neuroscience and biological psychiatry to study brain function, model human brain disorders and explore their genetic or pharmacological modulation. Representing highly social animals, zebrafish emerge as a strong potential model organism to study normal and pathological social phenotypes, as well as several other ASD-like symptoms. Here, we discuss the developing utility of zebrafish in modeling ASD as a new emerging field in translational neuroscience and drug discovery.
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Affiliation(s)
- Adam Michael Stewart
- ZENEREI Institute and Zebrafish Neuroscience Research Consortium (ZNRC), 309 Palmer Court, Slidell, LA 70458, USA; Department of Neuroscience, University of Pittsburgh, A210 Langley Hall, Pittsburgh, PA 15260, USA
| | - Michael Nguyen
- Department of Biomedical Engineering, University of Virginia, 415 Lane Road, Charlottesville, VA 22908, USA
| | - Keith Wong
- University of California San Diego (UCSD) School of Medicine, 9500 Gilman Dr, La Jolla, CA 92093, USA
| | - Manoj K Poudel
- ZENEREI Institute and Zebrafish Neuroscience Research Consortium (ZNRC), 309 Palmer Court, Slidell, LA 70458, USA
| | - Allan V Kalueff
- ZENEREI Institute and Zebrafish Neuroscience Research Consortium (ZNRC), 309 Palmer Court, Slidell, LA 70458, USA.
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Uzunova G, Hollander E, Shepherd J. The role of ionotropic glutamate receptors in childhood neurodevelopmental disorders: autism spectrum disorders and fragile x syndrome. Curr Neuropharmacol 2014; 12:71-98. [PMID: 24533017 PMCID: PMC3915351 DOI: 10.2174/1570159x113116660046] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Revised: 08/20/2013] [Accepted: 09/25/2013] [Indexed: 12/20/2022] Open
Abstract
Autism spectrum disorder (ASD) and Fragile X syndrome (FXS) are relatively common childhood neurodevelopmental disorders with increasing incidence in recent years. They are currently accepted as disorders of the synapse with alterations in different forms of synaptic communication and neuronal network connectivity. The major excitatory neurotransmitter system in brain, the glutamatergic system, is implicated in learning and memory, synaptic plasticity, neuronal development. While much attention is attributed to the role of metabotropic glutamate receptors in ASD and FXS, studies indicate that the ionotropic glutamate receptors (iGluRs) and their regulatory proteins are also altered in several brain regions. Role of iGluRs in the neurobiology of ASD and FXS is supported by a weight of evidence that ranges from human genetics to in vitro cultured neurons. In this review we will discuss clinical, molecular, cellular and functional changes in NMDA, AMPA and kainate receptors and the synaptic proteins that regulate them in the context of ASD and FXS. We will also discuss the significance for the development of translational biomarkers and treatments for the core symptoms of ASD and FXS.
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Affiliation(s)
- Genoveva Uzunova
- Autism and Obsessive Compulsive Spectrum Program, Department of Psychiatry, Montefiore Medical Center, Albert Einstein College of Medicine, 111 East 210th St, Bronx, New York 10467-2490
| | - Eric Hollander
- Autism and Obsessive Compulsive Spectrum Program, Department of Psychiatry, Montefiore Medical Center, Albert Einstein College of Medicine, 111 East 210th St, Bronx, New York 10467-2490
| | - Jason Shepherd
- Department of Neurobiology and Anatomy, University of Utah School of Medicine, 531A Wintrobe, 20N 1900 E, Salt Lake City, Utah 84132
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Liao HM, Gau SSF, Tsai WC, Fang JS, Su YC, Chou MC, Liu SK, Chou WJ, Wu YY, Chen CH. Chromosomal abnormalities in patients with autism spectrum disorders from Taiwan. Am J Med Genet B Neuropsychiatr Genet 2013; 162B:734-41. [PMID: 24132905 DOI: 10.1002/ajmg.b.32153] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2012] [Accepted: 03/05/2013] [Indexed: 12/12/2022]
Abstract
Autism spectrum disorders (ASD) are childhood-onset neurodevelopmental disorders characterized by verbal communication impairments, social reciprocity deficits, and the presence of restricted interests and stereotyped behaviors. Genetic factors contribute to the incidence of ASD evidently. However, the genetic spectrum of ASD is highly heterogeneous. Chromosomal abnormalities contribute significantly to the genetic deficits of syndromic and non-syndromic ASD. In this study, we conducted karyotyping analysis in a sample of 500 patients (447 males, 53 females) with ASD from Taiwan, the largest cohort in Asia, to the best of our knowledge. We found three patients having sex chromosome aneuploidy, including two cases of 47, XXY and one case of 47, XYY. In addition, we detected a novel reciprocal chromosomal translocation between long arms of chromosomes 4 and 14, designated t(4;14)(q31.3;q24.1), in a patient with Asperger's disorder. This translocation was inherited from his unaffected father, suggesting it might not be pathogenic or it needs further hits to become pathogenic. In line with other studies, our study revealed that subjects with sex chromosomal aneuploidy are liable to neurodevelopmental disorders, including ASD, and conventional karyotyping analysis is still a useful tool in detecting chromosomal translocation in patients with ASD, given that array-based comparative genomic hybridization technology can provide better resolution in detecting copy number variations of genomic DNA.
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Affiliation(s)
- Hsiao-Mei Liao
- Department of Psychiatry, National Taiwan University College of Medicine, Taipei, Taiwan
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29
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Persico AM, Napolioni V. Autism genetics. Behav Brain Res 2013; 251:95-112. [PMID: 23769996 DOI: 10.1016/j.bbr.2013.06.012] [Citation(s) in RCA: 173] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Revised: 06/03/2013] [Accepted: 06/04/2013] [Indexed: 12/22/2022]
Abstract
Autism spectrum disorder (ASD) is a severe neuropsychiatric disease with strong genetic underpinnings. However, genetic contributions to autism are extremely heterogeneous, with many different loci underlying the disease to a different extent in different individuals. Moreover, the phenotypic expression (i.e., "penetrance") of these genetic components is also highly variable, ranging from fully penetrant point mutations to polygenic forms with multiple gene-gene and gene-environment interactions. Furthermore, many genes involved in ASD are also involved in intellectual disability, further underscoring their lack of specificity in phenotypic expression. We shall hereby review current knowledge on the genetic basis of ASD, spanning genetic/genomic syndromes associated with autism, monogenic forms due to copy number variants (CNVs) or rare point mutations, mitochondrial forms, and polygenic autisms. Finally, the recent contributions of genome-wide association and whole exome sequencing studies will be highlighted.
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Affiliation(s)
- Antonio M Persico
- Child and Adolescent Neuropsychiatry Unit, University Campus Bio-Medico, Rome, Italy.
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Shi L, Chang X, Zhang P, Coba MP, Lu W, Wang K. The functional genetic link of NLGN4X knockdown and neurodevelopment in neural stem cells. Hum Mol Genet 2013; 22:3749-60. [PMID: 23710042 DOI: 10.1093/hmg/ddt226] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Genetic mutations in NLGN4X (neuroligin 4), including point mutations and copy number variants (CNVs), have been associated with susceptibility to autism spectrum disorders (ASDs). However, it is unclear how mutations in NLGN4X result in neurodevelopmental defects. Here, we used neural stem cells (NSCs) as in vitro models to explore the impacts of NLGN4X knockdown on neurodevelopment. Using two shRNAmir-based vectors targeting NLGN4X and one control shRNAmir vector, we modulated NLGN4X expression and differentiated these NSCs into mature neurons. We monitored the neurodevelopmental process at Weeks 0, 0.5, 1, 2, 4 and 6, based on morphological analysis and whole-genome gene expression profiling. At the cellular level, in NSCs with NLGN4X knockdown, we observed increasingly delayed neuronal development and compromised neurite formation, starting from Week 2 through Week 6 post differentiation. At the molecular level, we identified multiple pathways, such as neurogenesis, neuron differentiation and muscle development, which are increasingly disturbed in cells with NLGN4X knockdown. Notably, several postsynaptic genes, including DLG4, NLGN1 and NLGN3, also have decreased expression. Based on in vitro models, NLGN4X knockdown directly impacts neurodevelopmental process during the formation of neurons and their connections. Our functional genomics study highlights the utility of NSCs models in understanding the functional roles of CNVs in affecting neurodevelopment and conferring susceptibility to neurodevelopmental diseases.
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Affiliation(s)
- Lingling Shi
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
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31
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Bang ML, Owczarek S. A Matter of Balance: Role of Neurexin and Neuroligin at the Synapse. Neurochem Res 2013; 38:1174-89. [DOI: 10.1007/s11064-013-1029-9] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Revised: 02/01/2013] [Accepted: 03/26/2013] [Indexed: 11/29/2022]
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Bushman DM, Chun J. The genomically mosaic brain: aneuploidy and more in neural diversity and disease. Semin Cell Dev Biol 2013; 24:357-69. [PMID: 23466288 PMCID: PMC3637860 DOI: 10.1016/j.semcdb.2013.02.003] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2012] [Revised: 01/25/2013] [Accepted: 02/06/2013] [Indexed: 10/27/2022]
Abstract
Genomically identical cells have long been assumed to comprise the human brain, with post-genomic mechanisms giving rise to its enormous diversity, complexity, and disease susceptibility. However, the identification of neural cells containing somatically generated mosaic aneuploidy - loss and/or gain of chromosomes from a euploid complement - and other genomic variations including LINE1 retrotransposons and regional patterns of DNA content variation (DCV), demonstrate that the brain is genomically heterogeneous. The precise phenotypes and functions produced by genomic mosaicism are not well understood, although the effects of constitutive aberrations, as observed in Down syndrome, implicate roles for defined mosaic genomes relevant to cellular survival, differentiation potential, stem cell biology, and brain organization. Here we discuss genomic mosaicism as a feature of the normal brain as well as a possible factor in the weak or complex genetic linkages observed for many of the most common forms of neurological and psychiatric diseases.
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Affiliation(s)
- Diane M. Bushman
- Molecular and Cellular Neuroscience Department, Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, California, USA
- Biomedical Sciences Graduate Program, School of Medicine, University of California San Diego, La Jolla, California, USA
| | - Jerold Chun
- Molecular and Cellular Neuroscience Department, Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, California, USA
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Liu Y, Du Y, Liu W, Yang C, Liu Y, Wang H, Gong X. Lack of association between NLGN3, NLGN4, SHANK2 and SHANK3 gene variants and autism spectrum disorder in a Chinese population. PLoS One 2013; 8:e56639. [PMID: 23468870 PMCID: PMC3582503 DOI: 10.1371/journal.pone.0056639] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Accepted: 01/11/2013] [Indexed: 12/13/2022] Open
Abstract
Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by deficits in social communication, absence or delay in language development, and stereotyped or repetitive behaviors. Genetic studies show that neurexin-neuroligin (NRXN-NLGN) pathway genes contribute susceptibility to ASD, which include cell adhesion molecules NLGN3, NLGN4 and scaffolding proteins SHANK2 and SHANK3. Neuroligin proteins play an important role in synaptic function and trans-synaptic signaling by interacting with presynaptic neurexins. Shank proteins are scaffolding molecules of excitatory synapses, which function as central organizers of the postsynaptic density. Sequence level mutations and structural variations in these genes have been identified in ASD cases, while few studies were performed in Chinese population. In this study, we examined the copy numbers of four genes NLGN4, NLGN3, SHANK2, and SHANK3 in 285 ASD cases using multiplex fluorescence competitive polymerase chain reaction (PCR). We also screened the regulatory region including the promoter region and 5'/3' untranslated regions (UTR) and the entire coding region of NLGN4 in a cohort of 285 ASD patients and 384 controls by direct sequencing of genomic DNA using the Sanger method. DNA copy number calculation in four genes showed no deletion or duplication in our cases. No missense mutations in NLGN4 were identified in our cohort. Association analysis of 6 common SNPs in NLGN4 did not find significant difference between ASD cases and controls. These findings showed that these genes may not be major disease genes in Chinese ASD cases.
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Affiliation(s)
- Yanyan Liu
- The MOE Key Laboratory of Contemporary Anthropology and State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China
| | - Yasong Du
- Department of Child and Adolescent Psychiatry, Shanghai Mental Health Center, Shanghai, China
- School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Wenwen Liu
- Department of Child and Adolescent Psychiatry, Shanghai Mental Health Center, Shanghai, China
- School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Caohua Yang
- Department of Child and Adolescent Psychiatry, Shanghai Mental Health Center, Shanghai, China
- School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Yan Liu
- Genesky Biotechnologies Inc., Shanghai, China
| | - Hongyan Wang
- The MOE Key Laboratory of Contemporary Anthropology and State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China
| | - Xiaohong Gong
- The MOE Key Laboratory of Contemporary Anthropology and State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China
- * E-mail:
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Steinberg KM, Ramachandran D, Patel VC, Shetty AC, Cutler DJ, Zwick ME. Identification of rare X-linked neuroligin variants by massively parallel sequencing in males with autism spectrum disorder. Mol Autism 2012; 3:8. [PMID: 23020841 PMCID: PMC3492087 DOI: 10.1186/2040-2392-3-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2012] [Accepted: 09/14/2012] [Indexed: 01/03/2023] Open
Abstract
UNLABELLED BACKGROUND Autism spectrum disorder (ASD) is highly heritable, but the genetic risk factors for it remain largely unknown. Although structural variants with large effect sizes may explain up to 15% ASD, genome-wide association studies have failed to uncover common single nucleotide variants with large effects on phenotype. The focus within ASD genetics is now shifting to the examination of rare sequence variants of modest effect, which is most often achieved via exome selection and sequencing. This strategy has indeed identified some rare candidate variants; however, the approach does not capture the full spectrum of genetic variation that might contribute to the phenotype. METHODS We surveyed two loci with known rare variants that contribute to ASD, the X-linked neuroligin genes by performing massively parallel Illumina sequencing of the coding and noncoding regions from these genes in males from families with multiplex autism. We annotated all variant sites and functionally tested a subset to identify other rare mutations contributing to ASD susceptibility. RESULTS We found seven rare variants at evolutionary conserved sites in our study population. Functional analyses of the three 3' UTR variants did not show statistically significant effects on the expression of NLGN3 and NLGN4X. In addition, we identified two NLGN3 intronic variants located within conserved transcription factor binding sites that could potentially affect gene regulation. CONCLUSIONS These data demonstrate the power of massively parallel, targeted sequencing studies of affected individuals for identifying rare, potentially disease-contributing variation. However, they also point out the challenges and limitations of current methods of direct functional testing of rare variants and the difficulties of identifying alleles with modest effects.
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Affiliation(s)
- Karyn Meltz Steinberg
- Department of Human Genetics, Emory University School of Medicine, Whitehead Biomedical Research Building, Suite 301, Atlanta, 30322, GA, USA
- Graduate Program in Population Biology, Ecology and Evolution, Emory University, 1510 Clifton Road, Atlanta, 30322, GA, USA
- Department of Genome Sciences, University of Washington, 3720 15th Avenue NE, Seattle, 98195, WA, USA
| | - Dhanya Ramachandran
- Department of Human Genetics, Emory University School of Medicine, Whitehead Biomedical Research Building, Suite 301, Atlanta, 30322, GA, USA
| | - Viren C Patel
- Department of Human Genetics, Emory University School of Medicine, Whitehead Biomedical Research Building, Suite 301, Atlanta, 30322, GA, USA
| | - Amol C Shetty
- Department of Human Genetics, Emory University School of Medicine, Whitehead Biomedical Research Building, Suite 301, Atlanta, 30322, GA, USA
| | - David J Cutler
- Department of Human Genetics, Emory University School of Medicine, Whitehead Biomedical Research Building, Suite 301, Atlanta, 30322, GA, USA
| | - Michael E Zwick
- Department of Human Genetics, Emory University School of Medicine, Whitehead Biomedical Research Building, Suite 301, Atlanta, 30322, GA, USA
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Identification of Four Novel Synonymous Substitutions in the X-Linked Genes Neuroligin 3 and Neuroligin 4X in Japanese Patients with Autistic Spectrum Disorder. AUTISM RESEARCH AND TREATMENT 2012; 2012:724072. [PMID: 22934180 PMCID: PMC3420546 DOI: 10.1155/2012/724072] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 01/22/2012] [Revised: 04/06/2012] [Accepted: 05/23/2012] [Indexed: 01/05/2023]
Abstract
Mutations in the X-linked genes neuroligin 3 (NLGN3) and neuroligin 4X (NLGN4X) were first implicated in the pathogenesis of X-linked autism in Swedish families. However, reports of mutations in these genes in autism spectrum disorder (ASD) patients from various ethnic backgrounds present conflicting results regarding the etiology of ASD, possibly because of genetic heterogeneity and/or differences in their ethnic background. Additional mutation screening study on another ethnic background could help to clarify the relevance of the genes to ASD. We scanned the entire coding regions of NLGN3 and NLGN4X in 62 Japanese patients with ASD by polymerase chain reaction-high-resolution melting curve and direct sequencing analyses. Four synonymous substitutions, one in NLGN3 and three in NLGN4X, were identified in four of the 62 patients. These substitutions were not present in 278 control X-chromosomes from unrelated Japanese individuals and were not registered in the database of Single Nucleotide Polymorphisms build 132 or in the Japanese Single Nucleotide Polymorphisms database, indicating that they were novel and specific to ASD. Though further analysis is necessary to determine the physiological and clinical importance of such substitutions, the possibility of the relevance of both synonymous and nonsynonymous substitutions with the etiology of ASD should be considered.
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Li X, Zou H, Brown WT. Genes associated with autism spectrum disorder. Brain Res Bull 2012; 88:543-52. [PMID: 22688012 DOI: 10.1016/j.brainresbull.2012.05.017] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2012] [Accepted: 05/31/2012] [Indexed: 01/06/2023]
Abstract
Autism spectrum disorder (ASD) is a heterogeneous grouping of neurodevelopmental disorders characterized by impairment in social interaction, verbal communication and repetitive/stereotypic behaviors. Much evidence suggests that ASD is multifactorial with a strong genetic basis, but the underlying mechanisms are far from clear. Recent advances in genetic technologies are beginning to shed light on possible etiologies of ASD. This review discusses current evidence for several widely studied candidate ASD genes, as well as various rare genes that supports their relationship to the etiology of ASD. The majority of the data are based on molecular, cytogenetic, linkage and association studies of autistic subjects, but newer methods, including whole-exome sequencing, are also beginning to make significant contributions to our understanding of autism.
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Affiliation(s)
- Xiaohong Li
- Department of Neurochemistry, New York State Institute for Basic Research in Developmental Disabilities, New York, NY 10314, United States.
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Bishop DVM, Jacobs PA, Lachlan K, Wellesley D, Barnicoat A, Boyd PA, Fryer A, Middlemiss P, Smithson S, Metcalfe K, Shears D, Leggett V, Nation K, Scerif G. Autism, language and communication in children with sex chromosome trisomies. Arch Dis Child 2011; 96:954-9. [PMID: 20656736 PMCID: PMC3182523 DOI: 10.1136/adc.2009.179747] [Citation(s) in RCA: 121] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
PURPOSE Sex chromosome trisomies (SCTs) are found on amniocentesis in 2.3-3.7 per 1000 same-sex births, yet there is a limited database on which to base a prognosis. Autism has been described in postnatally diagnosed cases of Klinefelter syndrome (XXY karyotype), but the prevalence in non-referred samples, and in other trisomies, is unclear. The authors recruited the largest sample including all three SCTs to be reported to date, including children identified on prenatal screening, to clarify this issue. DESIGN Parents of children with a SCT were recruited either via prenatal screening or via a parental support group, to give a sample of 58 XXX, 19 XXY and 58 XYY cases. Parents were interviewed using the Vineland Adaptive Behavior Scales and completed questionnaires about the communicative development of children with SCTs and their siblings (42 brothers and 26 sisters). RESULTS Rates of language and communication problems were high in all three trisomies. Diagnoses of autism spectrum disorder (ASD) were found in 2/19 cases of XXY (11%) and 11/58 XYY (19%). After excluding those with an ASD diagnosis, communicative profiles indicative of mild autistic features were common, although there was wide individual variation. CONCLUSIONS Autistic features have not previously been remarked upon in studies of non-referred samples with SCTs, yet the rate is substantially above population levels in this sample, even when attention is restricted to early-identified cases. The authors hypothesise that X-linked and Y-linked neuroligins may play a significant role in the aetiology of communication impairments and ASD.
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Affiliation(s)
- Dorothy V M Bishop
- Department of Experimental Psychology, University of Oxford, Tinbergen Building, 2, South Parks Road, Oxford OX1 3UD, UK.
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Abstract
Recent studies have identified the leucine rich repeat protein LRRTM2 as a post-synaptic ligand of Neurexins. Neurexins also bind the post-synaptic adhesion molecules, Neuroligins. All three families of genes have been implicated in the etiologies of neurodevelopmental disorders, specifically autism spectrum disorders and schizophrenia. Does the binding promiscuity of Neurexins now suggest complex cooperativity or redundancy at the synapse? While recent studies in primary neuronal cultures and also systematic extracellular protein interaction screens suggest summative effects of these systems, we propose that studying these interactions in the developing zebrafish embryo or larvae may shed more light on their functions during synaptogenesis in vivo. These gene families have recently been extensively characterized in zebrafish, demonstrating high sequence conservation with the human genes. The simpler circuitry of the zebrafish, together with the characterization of the expression patterns down to single, identifiable neurons and the ability to knock-down or over-express multiple genes in a rapid way lend themselves to dissecting complex interaction pathways. Furthermore, the capability of performing high-throughput drug screens suggests that these small vertebrates may prove extremely useful in identifying pharmacological approaches to treating autism spectrum disorders.
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Affiliation(s)
| | - Philip Washbourne
- Institute of Neuroscience, University of Oregon, Eugene OR 97403, USA
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39
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Smith RM, Sadee W. Synaptic signaling and aberrant RNA splicing in autism spectrum disorders. Front Synaptic Neurosci 2011; 3:1. [PMID: 21423409 PMCID: PMC3059609 DOI: 10.3389/fnsyn.2011.00001] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2010] [Accepted: 01/12/2011] [Indexed: 11/13/2022] Open
Abstract
Interactions between presynaptic and postsynaptic cellular adhesion molecules (CAMs) drive synapse maturation during development. These trans-synaptic interactions are regulated by alternative splicing of CAM RNAs, which ultimately determines neurotransmitter phenotype. The diverse assortment of RNAs produced by alternative splicing generates countless protein isoforms necessary for guiding specialized cell-to-cell connectivity. Failure to generate the appropriate synaptic adhesion proteins is associated with disrupted glutamatergic and gamma-aminobutyric acid signaling, resulting in loss of activity-dependent neuronal plasticity, and risk for developmental disorders, including autism. While the majority of genetic mutations currently linked to autism are rare variants that change the protein-coding sequence of synaptic candidate genes, regulatory polymorphisms affecting constitutive and alternative splicing have emerged as risk factors in numerous other diseases, accounting for an estimated 40–60% of general disease risk. Here, we review the relationship between aberrant RNA splicing of synapse-related genes and autism spectrum disorders.
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Affiliation(s)
- Ryan M Smith
- Program in Pharmacogenomics, Department of Pharmacology, The Ohio State University Columbus, OH, USA
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Bavaro SL, Calabrò M, Kanduc D. Pentapeptide sharing between Corynebacterium diphtheria toxin and the human neural protein network. Immunopharmacol Immunotoxicol 2010; 33:360-72. [PMID: 20874613 DOI: 10.3109/08923973.2010.518618] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
We describe the pentapeptides shared between the Corynebacterium diphtheria toxin and the human proteins associated with fundamental neural functions. We report that diphtheria toxin pentapeptides are spread among human antigens such as tuberous sclerosis proteins 1 and 2, reelin, contactin-4, neuroligins, semaphorin-5A, sodium channel protein type 1 subunit α, Williams-Beuren syndrome chromosomal region 1 protein, Williams-Beuren syndrome chromosomal region 20A protein. Williams-Beuren syndrome chromosomal region 8 protein, Bardet-Biedl syndrome 9 protein, Bardet-Biedl syndrome 10 protein, oligodendrocyte-myelin glycoprotein, neurofibromin-2, and periaxin. The data are discussed in relation to the bacterial immune escape phenomenon, and in the context of potential cross-reactions in diagnostic tests and immune therapies.
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Abstract
PURPOSE OF REVIEW There are several common medical conditions occurring in people with autism spectrum disorders (ASD) that can benefit from treatment and can in turn improve the health and quality of life of people with ASD. This review will primarily focus on these medical comorbidities, with a brief review of potential future treatments. RECENT FINDINGS There continues to be disagreement regarding the exact prevalence and etiological significance of gastrointestinal conditions, epilepsy and other abnormal electroencephalographic findings, and sleep problems. It is not clear whether gastrointestinal conditions occur more frequently than in typically developing children, and whether there are distinct conditions that occur more often in ASD than in non-ASD populations. Abnormal electroencephalographic findings have been reported in up to 60% of children with ASD, and some believe that these abnormalities may be responsible for parts of the ASD phenotype. Sleep problems are reported more frequently than in the general population, and effective treatments are available. Future medical treatments for ASD may be directed at underlying core symptoms and have greater impact than today's symptomatic approach. SUMMARY Further research in these areas is needed to better guide diagnosis and treatment of a variety of medical conditions experienced by people with ASD.
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SCAMP5, NBEA and AMISYN: three candidate genes for autism involved in secretion of large dense-core vesicles. Hum Mol Genet 2010; 19:1368-78. [DOI: 10.1093/hmg/ddq013] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
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