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Yang C, Huang YT, Yao YF, Fu JY, Long YS. Hippocampal proteome comparison of infant and adult Fmr1 deficiency mice reveals adult-related changes associated with postsynaptic density. J Proteomics 2024; 303:105202. [PMID: 38797434 DOI: 10.1016/j.jprot.2024.105202] [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: 03/27/2024] [Revised: 05/15/2024] [Accepted: 05/17/2024] [Indexed: 05/29/2024]
Abstract
Deficiency in fragile X mental retardation 1 (Fmr1) leads to loss of its encoded protein FMRP and causes fragile X syndrome (FXS) by dysregulating its target gene expression in an age-related fashion. Using comparative proteomic analysis, this study identified 105 differentially expressed proteins (DEPs) in the hippocampus of postnatal day 7 (P7) Fmr1-/y mice and 306 DEPs of P90 Fmr1-/y mice. We found that most DEPs in P90 hippocampus were not changed in P7 hippocampus upon FMRP absence, and some P90 DEPs exhibited diverse proteophenotypes with abnormal expression of protein isoform or allele variants. Bioinformatic analyses showed that the P7 DEPs were mainly enriched in fatty acid metabolism and oxidoreductase activity and nutrient responses; whereas the P90 PEPs (especially down-regulated DEPs) were primarily enriched in postsynaptic density (PSD), neuronal projection development and synaptic plasticity. Interestingly, 25 of 30 down-regulated PSD proteins present in the most enriched protein to protein interaction network, and 6 of them (ANK3, ATP2B2, DST, GRIN1, SHANK2 and SYNGAP1) are both FMRP targets and autism candidates. Therefore, this study suggests age-dependent alterations in hippocampal proteomes upon loss of FMRP that may be associated with the pathogenesis of FXS and its related disorders. SIGNIFICANCE: It is well known that loss of FMRP resulted from Fmr1 deficiency leads to fragile X syndrome (FXS), a common neurodevelopmental disorder accompanied by intellectual disability and autism spectrum disorder (ASD). FMRP exhibits distinctly spatiotemporal patterns in the hippocampus between early development and adulthood, which lead to distinct dysregulations of gene expression upon loss of FMRP at the two age stages potentially linked to age-related phenotypes. Therefore, comparison of hippocampal proteomes between infancy and adulthood is valuable to provide insights into the early causations and adult-dependent consequences for FXS and ASD. Using a comparative proteomic analysis, this study identified 105 and 306 differentially expressed proteins (DEPs) in the hippocampi of postnatal day 7 (P7) and P90 Fmr1-/y mice, respectively. Few overlapping DEPs were identified between P7 and P90 stages, and the P7 DEPs were mainly enriched in the regulation of fatty acid metabolism and oxidoreduction, whereas the P90 DEPs were preferentially enriched in the regulation of synaptic formation and plasticity. Particularly, the up-regulated P90 proteins are primarily involved in immune responses and neurodegeneration, and the down-regulated P90 proteins are associated with postsynaptic density, neuron projection and synaptic plasticity. Our findings suggest that distinctly changed proteins in FMRP-absence hippocampus between infancy and adulthood may contribute to age-dependent pathogenesis of FXS and ASD.
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Affiliation(s)
- Cui Yang
- Department of Neurology, Institute of Neuroscience, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou 510260, China
| | - Yu-Ting Huang
- Department of Neurology, Institute of Neuroscience, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou 510260, China
| | - Yi-Fei Yao
- Department of Neurology, Institute of Neuroscience, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou 510260, China
| | - Jun-Yi Fu
- Department of Neurology, Institute of Neuroscience, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou 510260, China.
| | - Yue-Sheng Long
- Department of Neurology, Institute of Neuroscience, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou 510260, China.
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2
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Chen Y, Guo L, Han M, Zhang S, Chen Y, Zou J, Bai S, Cheng G, Zeng Y. Cerebellum Neuropathology and Motor Skill Deficits in Fragile X Syndrome. Int J Dev Neurosci 2022; 82:557-568. [DOI: 10.1002/jdn.10217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 07/11/2022] [Accepted: 07/14/2022] [Indexed: 11/06/2022] Open
Affiliation(s)
- Yu‐shan Chen
- Brain Science and Advanced Technology Institute, School of Medicine Wuhan University of Science and Technology Wuhan China
| | - Liu Guo
- Brain Science and Advanced Technology Institute, School of Medicine Wuhan University of Science and Technology Wuhan China
| | - Man Han
- Brain Science and Advanced Technology Institute, School of Medicine Wuhan University of Science and Technology Wuhan China
| | - Si‐ming Zhang
- Brain Science and Advanced Technology Institute, School of Medicine Wuhan University of Science and Technology Wuhan China
| | - Yi‐qi Chen
- Brain Science and Advanced Technology Institute, School of Medicine Wuhan University of Science and Technology Wuhan China
| | - Jia Zou
- Brain Science and Advanced Technology Institute, School of Medicine Wuhan University of Science and Technology Wuhan China
| | - Shu‐yuan Bai
- Brain Science and Advanced Technology Institute, School of Medicine Wuhan University of Science and Technology Wuhan China
| | - Gui‐rong Cheng
- Brain Science and Advanced Technology Institute, School of Medicine Wuhan University of Science and Technology Wuhan China
| | - Yan Zeng
- Brain Science and Advanced Technology Institute, School of Medicine Wuhan University of Science and Technology Wuhan China
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3
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McCullagh EA, Rotschafer SE, Auerbach BD, Klug A, Kaczmarek LK, Cramer KS, Kulesza RJ, Razak KA, Lovelace JW, Lu Y, Koch U, Wang Y. Mechanisms underlying auditory processing deficits in Fragile X syndrome. FASEB J 2020; 34:3501-3518. [PMID: 32039504 DOI: 10.1096/fj.201902435r] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 12/31/2019] [Accepted: 01/18/2020] [Indexed: 01/14/2023]
Abstract
Autism spectrum disorders (ASD) are strongly associated with auditory hypersensitivity or hyperacusis (difficulty tolerating sounds). Fragile X syndrome (FXS), the most common monogenetic cause of ASD, has emerged as a powerful gateway for exploring underlying mechanisms of hyperacusis and auditory dysfunction in ASD. This review discusses examples of disruption of the auditory pathways in FXS at molecular, synaptic, and circuit levels in animal models as well as in FXS individuals. These examples highlight the involvement of multiple mechanisms, from aberrant synaptic development and ion channel deregulation of auditory brainstem circuits, to impaired neuronal plasticity and network hyperexcitability in the auditory cortex. Though a relatively new area of research, recent discoveries have increased interest in auditory dysfunction and mechanisms underlying hyperacusis in this disorder. This rapidly growing body of data has yielded novel research directions addressing critical questions regarding the timing and possible outcomes of human therapies for auditory dysfunction in ASD.
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Affiliation(s)
- Elizabeth A McCullagh
- Department of Physiology and Biophysics, University of Colorado Anschutz, Aurora, CO, USA.,Department of Integrative Biology, Oklahoma State University, Stillwater, OK, USA
| | - Sarah E Rotschafer
- Department of Neurobiology and Behavior, University of California, Irvine, CA, USA.,Department of Biomedical Sciences, Mercer University School of Medicine, Savannah, GA, USA
| | - Benjamin D Auerbach
- Center for Hearing and Deafness, Department of Communicative Disorders & Sciences, SUNY at Buffalo, Buffalo, NY, USA
| | - Achim Klug
- Department of Physiology and Biophysics, University of Colorado Anschutz, Aurora, CO, USA
| | - Leonard K Kaczmarek
- Departments of Pharmacology and Cellular and Molecular Physiology, Yale University, New Haven, CT, USA
| | - Karina S Cramer
- Department of Neurobiology and Behavior, University of California, Irvine, CA, USA
| | - Randy J Kulesza
- Department of Anatomy, Lake Erie College of Osteopathic Medicine, Erie, PA, USA
| | - Khaleel A Razak
- Department of Psychology, University of California, Riverside, CA, USA
| | | | - Yong Lu
- Department of Anatomy and Neurobiology, College of Medicine, Northeast Ohio Medical University, Rootstown, OH, USA
| | - Ursula Koch
- Institute of Biology, Neurophysiology, Freie Universität Berlin, Berlin, Germany
| | - Yuan Wang
- Department of Biomedical Sciences, Program in Neuroscience, Florida State University, Tallahassee, FL, USA
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4
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Ferro D, Yao S, Zarnescu DC. Dynamic duo - FMRP and TDP-43: Regulating common targets, causing different diseases. Brain Res 2018; 1693:37-42. [PMID: 29715444 PMCID: PMC5997554 DOI: 10.1016/j.brainres.2018.04.034] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2017] [Revised: 04/24/2018] [Accepted: 04/26/2018] [Indexed: 10/17/2022]
Abstract
RNA binding proteins play essential roles during development and aging, and are also involved in disease pathomechanisms. RNA sequencing and omics analyses have provided a window into systems level alterations in neurological disease, and have identified RNA processing defects among notable disease mechanisms. This review focuses on two seemingly distinct neurological disorders, the RNA binding proteins they are linked to, and their newly discovered functional relationship. When deficient, Fragile X Mental Retardation Protein (FMRP) causes developmental deficits and autistic behaviors while TAR-DNA Binding Protein (TDP-43) dysregulation causes age dependent neuronal degeneration. Recent findings that FMRP and TDP-43 associate in ribonuclear protein particles and share mRNA targets in neurons highlight the critical importance of translation regulation in synaptic plasticity and provide new perspectives on neuronal vulnerability during lifespan.
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Affiliation(s)
- Diana Ferro
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, AZ, United States
| | - Stephen Yao
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, AZ, United States
| | - Daniela C Zarnescu
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, AZ, United States; Department of Neuroscience, University of Arizona, Tucson, AZ, United States; Department of Neurology, University of Arizona, Tucson AZ, United States.
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5
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Zorio DAR, Jackson CM, Liu Y, Rubel EW, Wang Y. Cellular distribution of the fragile X mental retardation protein in the mouse brain. J Comp Neurol 2017; 525:818-849. [PMID: 27539535 PMCID: PMC5558202 DOI: 10.1002/cne.24100] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Revised: 08/10/2016] [Accepted: 08/11/2016] [Indexed: 11/07/2022]
Abstract
The fragile X mental retardation protein (FMRP) plays an important role in normal brain development. Absence of FMRP results in abnormal neuronal morphologies in a selected manner throughout the brain, leading to intellectual deficits and sensory dysfunction in the fragile X syndrome (FXS). Despite FMRP importance for proper brain function, its overall expression pattern in the mammalian brain at the resolution of individual neuronal cell groups is not known. In this study we used FMR1 knockout and isogenic wildtype mice to systematically map the distribution of FMRP expression in the entire mouse brain. Using immunocytochemistry and cellular quantification analyses, we identified a large number of prominent cell groups expressing high levels of FMRP at the subcortical levels, in particular sensory and motor neurons in the brainstem and thalamus. In contrast, many cell groups in the midbrain and hypothalamus exhibit low FMRP levels. More important, we describe differential patterns of FMRP distribution in both cortical and subcortical brain regions. Almost all major brain areas contain high and low levels of FMRP cell groups adjacent to each other or between layers of the same cortical areas. These differential patterns indicate that FMRP expression appears to be specific to individual neuronal cell groups instead of being associated with all neurons in distinct brain regions, as previously considered. Taken together, these findings support the notion of FMRP differential neuronal regulation and strongly implicate the contribution of fundamental sensory and motor processing at subcortical levels to FXS pathology. J. Comp. Neurol. 525:818-849, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Diego A. R. Zorio
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, FL 32306, USA
| | - Christine M. Jackson
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, FL 32306, USA
| | - Yong Liu
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, FL 32306, USA
| | - Edwin W Rubel
- Virginia Merrill Bloedel Hearing Research Center, Department of Otolaryngology-Head and Neck Surgery, University of Washington School of Medicine, Box 357923, Seattle, WA 98195, USA
| | - Yuan Wang
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, FL 32306, USA
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6
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Wong LM, Tassone F, Rivera SM, Simon TJ. Temporal dynamics of attentional selection in adult male carriers of the fragile X premutation allele and adult controls. Front Hum Neurosci 2015; 9:37. [PMID: 25698960 PMCID: PMC4318336 DOI: 10.3389/fnhum.2015.00037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Accepted: 01/14/2015] [Indexed: 11/13/2022] Open
Abstract
Carriers of the fragile X premutation allele (fXPCs) have an expanded CGG trinucleotide repeat size within the FMR1 gene and are at increased risk of developing fragile x-associated tremor/ataxia syndrome (FXTAS). Previous research has shown that male fXPCs with FXTAS exhibit cognitive decline, predominantly in executive functions such as inhibitory control and working memory. Recent evidence suggests fXPCs may also exhibit impairments in processing temporal information. The attentional blink (AB) task is often used to examine the dynamics of attentional selection, but disagreements exist as to whether the AB is due to excessive or insufficient attentional control. In this study, we used a variant of the AB task and neuropsychological testing to explore the dynamics of attentional selection, relate AB performance to attentional control, and determine whether fXPCs exhibited temporal and/or attentional control impairments. Participants were adult male fXPCs, aged 18–48 years and asymptomatic for FXTAS (n = 19) and age-matched male controls (n = 20). We found that fXPCs did not differ from controls in the AB task, indicating that the temporal dynamics of attentional selection were intact. However, they were impaired in the letter-number sequencing task, a test of executive working memory. In the combined fXPC and control group, letter-number sequencing performance correlated positively with AB magnitude. This finding supports models that posit the AB is due to excess attentional control. In our two-pronged analysis approach, in control participants we replicated a previously observed effect and demonstrated that it persists under more stringent theoretical constraints, and we enhance our understanding of fXPCs by demonstrating that at least some aspects of temporal processing may be spared.
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Affiliation(s)
- Ling M Wong
- MIND Institute, University of California Davis School of Medicine Sacramento, CA, USA ; Department of Psychiatry and Behavioral Sciences, University of California Davis School of Medicine Sacramento, CA, USA
| | - Flora Tassone
- MIND Institute, University of California Davis School of Medicine Sacramento, CA, USA ; Department of Biochemistry and Molecular Medicine, University of California Davis School of Medicine Sacramento, CA, USA
| | - Susan M Rivera
- MIND Institute, University of California Davis School of Medicine Sacramento, CA, USA ; Department of Psychology, University of California Davis Davis, CA, USA ; Center for Mind and Brain, University of California Davis Davis, CA, USA
| | - Tony J Simon
- MIND Institute, University of California Davis School of Medicine Sacramento, CA, USA ; Department of Psychiatry and Behavioral Sciences, University of California Davis School of Medicine Sacramento, CA, USA
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7
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Bonaccorso CM, Spatuzza M, Di Marco B, Gloria A, Barrancotto G, Cupo A, Musumeci SA, D'Antoni S, Bardoni B, Catania MV. Fragile X mental retardation protein (FMRP) interacting proteins exhibit different expression patterns during development. Int J Dev Neurosci 2015; 42:15-23. [PMID: 25681562 DOI: 10.1016/j.ijdevneu.2015.02.004] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Revised: 01/30/2015] [Accepted: 02/10/2015] [Indexed: 11/26/2022] Open
Abstract
Fragile X syndrome is caused by the lack of expression of fragile X mental retardation protein (FMRP), an RNA-binding protein involved in mRNA transport and translation. FMRP is a component of mRNA ribonucleoprotein complexes and it can interact with a range of proteins either directly or indirectly, as demonstrated by two-hybrid selection and co-immunoprecipitation, respectively. Most of FMRP-interacting proteins are RNA-binding proteins such as FXR1P, FXR2P and 82-FIP. Interestingly, FMRP can also interact directly with the cytoplasmic proteins CYFIP1 and CYFIP2, which do not bind RNA and link FMRP to the RhoGTPase pathway. The interaction with these different proteins may modulate the functions of FMRP by influencing its affinity to RNA and by affecting the FMRP ability of cytoskeleton remodeling through Rho/Rac GTPases. To better define the relationship of FMRP with its interacting proteins during brain development, we have analyzed the expression pattern of FMRP and its interacting proteins in the cortex, striatum, hippocampus and cerebellum at different ages in wild type (WT) mice. FMRP and FXR2P were strongly expressed during the first week and gradually decreased thereafter, more rapidly in the cerebellum than in the cortex. FXR1P was also expressed early and showed a reduction at later stages of development with a similar developmental pattern in these two regions. CYFIP1 was expressed at all ages and peaked in the third post-natal week. In contrast, CYFIP2 and 82-FIP (only in forebrain regions) were moderately expressed at P3 and gradually increased after P7. In general, the expression pattern of each protein was similar in the regions examined, except for 82-FIP, which exhibited a strong expression at P3 and low levels at later developmental stages in the cerebellum. Our data indicate that FMRP and its interacting proteins have distinct developmental patterns of expression and suggest that FMRP may be preferentially associated to certain proteins in early and late developmental periods. In particular, the RNA-binding and cytoskeleton remodeling functions of FMRP may be differently modulated during development.
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Affiliation(s)
| | - M Spatuzza
- Institute of Neurological Sciences, CNR, Catania, Italy
| | - B Di Marco
- Institute of Neurological Sciences, CNR, Catania, Italy; International PhD Program in Neuropharmacology, Department of Clinical and Molecular Biomedicine, University of Catania, Italy
| | - A Gloria
- IRCCS Oasi Maria SS, Troina, EN, Italy
| | | | - A Cupo
- CNRS UMR 7275, Institute of Molecular and Cellular Pharmacology, Valbonne Sophia-Antipolis, France; University of Nice Sophia-Antipolis, Nice, France
| | | | - S D'Antoni
- Institute of Neurological Sciences, CNR, Catania, Italy
| | - B Bardoni
- CNRS UMR 7275, Institute of Molecular and Cellular Pharmacology, Valbonne Sophia-Antipolis, France; University of Nice Sophia-Antipolis, Nice, France; CNRS LIA "NEOGENEX", Valbonne Sophia-Antipolis, France
| | - M V Catania
- IRCCS Oasi Maria SS, Troina, EN, Italy; Institute of Neurological Sciences, CNR, Catania, Italy.
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8
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Wang Y, Sakano H, Beebe K, Brown MR, de Laat R, Bothwell M, Kulesza RJ, Rubel EW. Intense and specialized dendritic localization of the fragile X mental retardation protein in binaural brainstem neurons: a comparative study in the alligator, chicken, gerbil, and human. J Comp Neurol 2015; 522:2107-28. [PMID: 24318628 DOI: 10.1002/cne.23520] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Revised: 12/04/2013] [Accepted: 12/05/2013] [Indexed: 11/09/2022]
Abstract
Neuronal dendrites are structurally and functionally dynamic in response to changes in afferent activity. The fragile X mental retardation protein (FMRP) is an mRNA binding protein that regulates activity-dependent protein synthesis and morphological dynamics of dendrites. Loss and abnormal expression of FMRP occur in fragile X syndrome (FXS) and some forms of autism spectrum disorders. To provide further understanding of how FMRP signaling regulates dendritic dynamics, we examined dendritic expression and localization of FMRP in the reptilian and avian nucleus laminaris (NL) and its mammalian analogue, the medial superior olive (MSO), in rodents and humans. NL/MSO neurons are specialized for temporal processing of low-frequency sounds for binaural hearing, which is impaired in FXS. Protein BLAST analyses first demonstrate that the FMRP amino acid sequences in the alligator and chicken are highly similar to human FMRP with identical mRNA-binding and phosphorylation sites, suggesting that FMRP functions similarly across vertebrates. Immunocytochemistry further reveals that NL/MSO neurons have very high levels of dendritic FMRP in low-frequency hearing vertebrates including alligator, chicken, gerbil, and human. Remarkably, dendritic FMRP in NL/MSO neurons often accumulates at branch points and enlarged distal tips, loci known to be critical for branch-specific dendritic arbor dynamics. These observations support an important role for FMRP in regulating dendritic properties of binaural neurons that are essential for low-frequency sound localization and auditory scene segregation, and support the relevance of studying this regulation in nonhuman vertebrates that use low frequencies in order to further understand human auditory processing disorders.
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Affiliation(s)
- Yuan Wang
- Virginia Merrill Bloedel Hearing Research Center, Department of Otolaryngology-Head and Neck Surgery, University of Washington School of Medicine, Seattle, WA, 98195-7923
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Grigsby J, Cornish K, Hocking D, Kraan C, Olichney JM, Rivera SM, Schneider A, Sherman S, Wang JY, Yang JC. The cognitive neuropsychological phenotype of carriers of the FMR1 premutation. J Neurodev Disord 2014; 6:28. [PMID: 25136377 PMCID: PMC4135346 DOI: 10.1186/1866-1955-6-28] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Accepted: 01/27/2014] [Indexed: 11/10/2022] Open
Abstract
The fragile X-associated tremor/ataxia syndrome (FXTAS) is a late-onset neurodegenerative disorder affecting a subset of carriers of the FMR1 (fragile X mental retardation 1) premutation. Penetrance and expression appear to be significantly higher in males than females. Although the most obvious aspect of the phenotype is the movement disorder that gives FXTAS its name, the disorder is also accompanied by progressive cognitive impairment. In this review, we address the cognitive neuropsychological and neurophysiological phenotype for males and females with FXTAS, and for male and female unaffected carriers. Despite differences in penetrance and expression, the cognitive features of the disorder appear similar for both genders, with impairment of executive functioning, working memory, and information processing the most prominent. Deficits in these functional systems may be largely responsible for impairment on other measures, including tests of general intelligence and declarative learning. FXTAS is to a large extent a white matter disease, and the cognitive phenotypes observed are consistent with what some have described as white matter dementia, in contrast to the impaired cortical functioning more characteristic of Alzheimer's disease and related disorders. Although some degree of impaired executive functioning appears to be ubiquitous among persons with FXTAS, the data suggest that only a subset of unaffected carriers of the premutation - both female and male - demonstrate such deficits, which typically are mild. The best-studied phenotype is that of males with FXTAS. The manifestations of cognitive impairment among asymptomatic male carriers, and among women with and without FXTAS, are less well understood, but have come under increased scrutiny.
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Affiliation(s)
- Jim Grigsby
- Department of Psychology, University of Colorado Denver, Denver, CO, USA ; Department of Medicine; Division of Health Care Policy and Research, University of Colorado School of Medicine, Aurora, CO, USA
| | - Kim Cornish
- School of Psychology & Psychiatry; Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne, Victoria, Australia
| | - Darren Hocking
- Olga Tennison Autism Research Centre, School of Psychological Science, La Trobe University, Melbourne, Victoria, Australia
| | - Claudine Kraan
- School of Psychology & Psychiatry; Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne, Victoria, Australia
| | - John M Olichney
- Center for Mind and Brain, University of California, Davis, CA, USA ; Department of Neurology, University of California, Davis, Sacramento, CA, USA
| | - Susan M Rivera
- Center for Mind and Brain, University of California, Davis, CA, USA ; Department of Psychology, University of California-Davis, Sacramento, CA, USA ; MIND Institute, University of California-Davis Medical Center, Sacramento, CA, USA
| | - Andrea Schneider
- Center for Mind and Brain, University of California, Davis, CA, USA ; MIND Institute, University of California-Davis Medical Center, Sacramento, CA, USA
| | | | - Jun Yi Wang
- Center for Mind and Brain, University of California, Davis, CA, USA ; Department of Pediatrics, University of California, Davis, Sacramento, CA, USA
| | - Jin-Chen Yang
- Center for Mind and Brain, University of California, Davis, CA, USA ; Department of Neurology, University of California, Davis, Sacramento, CA, USA
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10
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Wong LM, Goodrich-Hunsaker NJ, McLennan Y, Tassone F, Zhang M, Rivera SM, Simon TJ. Eye movements reveal impaired inhibitory control in adult male fragile X premutation carriers asymptomatic for FXTAS. Neuropsychology 2014; 28:571-584. [PMID: 24773414 DOI: 10.1037/neu0000066] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
OBJECTIVE Fragile X premutation carriers (fXPCs) have an expansion of 55-200 CGG repeats in the FMR1 gene. Male fXPCs are at risk for developing a neurodegenerative motor disorder (FXTAS) often accompanied by inhibitory control impairments, even in fXPCs without motor symptoms. Inhibitory control impairments might precede, and thus indicate elevated risk for motor impairment associated with FXTAS. We tested whether inhibitory impairments are observable in fXPCs by assessing oculomotor performance. METHOD Participants were males aged 18-48 years asymptomatic for FXTAS. FXPCs (n = 21) and healthy age-matched controls (n = 22) performed four oculomotor tasks. In a Fixation task, participants fixated on a central cross and maintained gaze position when a peripheral stimulus appeared. In a Pursuit task, participants maintained gaze on a square moving at constant velocity. In a Prosaccade task, participants fixated on a central cross, then looked at a peripheral stimulus. An Antisaccade task was identical to the Prosaccade task, except participants looked in the direction opposite the stimulus. Inhibitory cost was the difference in saccade latency between the Antisaccade and Prosaccade tasks. RESULTS Relative to controls, fXPCs had longer saccade latency in the Antisaccade task. In fXPCs, inhibitory cost was positively associated with vermis area in lobules VI-VII. CONCLUSION Antisaccades require inhibitory control to inhibit reflexive eye movements. We found that eye movements are sensitive to impaired inhibitory control in fXPCs asymptomatic for FXTAS. Thus, eye movements may be useful in assessing FXTAS risk or disease progression.
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Affiliation(s)
- Ling M Wong
- Department of Psychiatry and Behavioral Sciences, University of California, Davis Medical Center
| | | | - Yingratana McLennan
- Department of Psychiatry and Behavioral Sciences, University of California, Davis Medical Center
| | - Flora Tassone
- Department of Biochemistry and Molecular Medicine, University of California, Davis Medical Center
| | - Melody Zhang
- Department of Neurobiology, Physiology, and Behavior, University of California, Davis
| | - Susan M Rivera
- Department of Psychology, University of California, Davis
| | - Tony J Simon
- Department of Psychiatry and Behavioral Sciences, University of California, Davis Medical Center
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11
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Wong LM, Goodrich-Hunsaker NJ, McLennan YA, Tassone F, Rivera SM, Simon TJ. A cross-sectional analysis of orienting of visuospatial attention in child and adult carriers of the fragile X premutation. J Neurodev Disord 2014; 6:45. [PMID: 25937844 PMCID: PMC4416306 DOI: 10.1186/1866-1955-6-45] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Accepted: 11/15/2014] [Indexed: 11/13/2022] Open
Abstract
Background Fragile X premutation carriers (fXPCs) have an expansion of 55–200 CGG repeats in the FMR1 gene. Male fXPCs are at risk for developing a neurodegenerative motor disorder (fragile X-associated tremor/ataxia syndrome (FXTAS)) often accompanied by cognitive decline. Several broad domains are implicated as core systems of dysfunction in fXPCs, including perceptual processing of spatial information, orienting of attention to space, and inhibiting attention to irrelevant distractors. We tested whether orienting of spatial attention is impaired in fXPCs. Methods Participants were fXPCs or healthy controls (HCs) asymptomatic for FXTAS. In experiment 1, they were male and female children and adults (aged 7–45 years). They oriented attention in response to volitional (endogenous) and reflexive (exogenous) cues. In experiment 2, the participants were men (aged 18–48 years). They oriented attention in an endogenous cueing task that manipulated the amount of information in the cue. Results In women, fXPCs exhibited slower reaction times than HCs in both the endogenous and exogenous conditions. In men, fXPCs exhibited slower reaction times than HCs in the exogenous condition and in the challenging endogenous cueing task with probabilistic cues. In children, fXPCs did not differ from HCs. Conclusions Because adult fXPCs were slower even when controlling for psychomotor speed, results support the interpretation that a core dysfunction in fXPCs is the allocation of spatial attention, while perceptual processing and attention orienting are intact. These findings indicate the importance of considering age and sex when interpreting and generalizing studies of fXPCs.
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Affiliation(s)
- Ling M Wong
- Davis Medical Center, MIND Institute, University of California, Sacramento, CA 95817 USA ; War Related Illness and Injury Study Center, Veterans Affairs Medical Center, Washington, DC 20422 USA
| | | | - Yingratana A McLennan
- Davis Medical Center, MIND Institute, University of California, Sacramento, CA 95817 USA
| | - Flora Tassone
- Davis Medical Center, MIND Institute, University of California, Sacramento, CA 95817 USA ; Department of Biochemistry and Molecular Medicine, University of California, Davis Medical Center, Sacramento, CA 95817 USA
| | - Susan M Rivera
- Davis Medical Center, MIND Institute, University of California, Sacramento, CA 95817 USA ; Department of Psychology, University of California, Davis, CA 95616 USA ; Center for Mind and Brain, University of California, Davis, CA 95616 USA
| | - Tony J Simon
- Davis Medical Center, MIND Institute, University of California, Sacramento, CA 95817 USA ; Department of Psychiatry and Behavioral Sciences, University of California, Davis Medical Center, Sacramento, CA 95817 USA
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12
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Kelemen O, Kovács T, Kéri S. Contrast, motion, perceptual integration, and neurocognition in schizophrenia: the role of fragile-X related mechanisms. Prog Neuropsychopharmacol Biol Psychiatry 2013; 46:92-7. [PMID: 23838275 DOI: 10.1016/j.pnpbp.2013.06.017] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Revised: 06/23/2013] [Accepted: 06/27/2013] [Indexed: 10/26/2022]
Abstract
Recent studies demonstrated a reduced expression of Fragile X Mental Retardation Protein (FMRP), an RNA binding protein and translation regulator, in the brain and peripheral lymphocytes of patients with schizophrenia. Low FMRP levels may be related to impaired neurodevelopmental processes and synaptic plasticity. Here, we studied the relationship between peripheral FMRP level, visual perception (contrast sensitivity, perceptual integration, motion/form perception), and neuropsychological functions in schizophrenia as measured with the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Results revealed that patients with schizophrenia displayed lower FMRP levels in peripheral lymphocytes as compared to control individuals. We found significant correlations between FMRP levels and contrast sensitivity at low spatial and high temporal frequencies, perceptual integration, and motion perception. The relationship between FMRP level and neuropsychological functions was less pronounced than that seen in the case of visual perception, with the greatest effect for RBANS attention. FMRP level was not related to contrast sensitivity at high spatial and low temporal frequencies and form perception. This pattern of data is reminiscent to that observed in patients with Fragile X Syndrome (FXS). These results suggest that FMRP may be implicated in the pathogenesis of schizophrenia, possibly via the regulation of neurodevelopment, plasticity, GABA-ergic, and glutamatergic neurotransmission.
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Affiliation(s)
- Oguz Kelemen
- Bács-Kiskun County Hospital, Psychiatry Center, Kecskemét, Hungary
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13
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Cook D, Nuro E, Murai KK. Increasing our understanding of human cognition through the study of Fragile X Syndrome. Dev Neurobiol 2013; 74:147-77. [PMID: 23723176 PMCID: PMC4216185 DOI: 10.1002/dneu.22096] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2013] [Accepted: 05/17/2013] [Indexed: 12/16/2022]
Abstract
Fragile X Syndrome (FXS) is considered the most common form of inherited intellectual disability. It is caused by reductions in the expression level or function of a single protein, the Fragile X Mental Retardation Protein (FMRP), a translational regulator which binds to approximately 4% of brain messenger RNAs. Accumulating evidence suggests that FXS is a complex disorder of cognition, involving interactions between genetic and environmental influences, leading to difficulties in acquiring key life skills including motor skills, language, and proper social behaviors. Since many FXS patients also present with one or more features of autism spectrum disorders (ASDs), insights gained from studying the monogenic basis of FXS could pave the way to a greater understanding of underlying features of multigenic ASDs. Here we present an overview of the FXS and FMRP field with the goal of demonstrating how loss of a single protein involved in translational control affects multiple stages of brain development and leads to debilitating consequences on human cognition. We also focus on studies which have rescued or improved FXS symptoms in mice using genetic or therapeutic approaches to reduce protein expression. We end with a brief description of how deficits in translational control are implicated in FXS and certain cases of ASDs, with many recent studies demonstrating that ASDs are likely caused by increases or decreases in the levels of certain key synaptic proteins. The study of FXS and its underlying single genetic cause offers an invaluable opportunity to study how a single gene influences brain development and behavior.
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Affiliation(s)
- Denise Cook
- Department of Neurology and Neurosurgery, Centre for Research in Neuroscience, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, Quebec, Canada
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14
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Neurobehavioural evidence for the involvement of the FMR1 gene in female carriers of fragile X syndrome. Neurosci Biobehav Rev 2013; 37:522-47. [DOI: 10.1016/j.neubiorev.2013.01.010] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2012] [Revised: 12/11/2012] [Accepted: 01/06/2013] [Indexed: 12/19/2022]
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15
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Hocking DR, Kogan CS, Cornish KM. Selective spatial processing deficits in an at-risk subgroup of the fragile X premutation. Brain Cogn 2012; 79:39-44. [PMID: 22417865 DOI: 10.1016/j.bandc.2012.02.005] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Revised: 02/07/2012] [Accepted: 02/09/2012] [Indexed: 11/26/2022]
Abstract
Until a decade ago, it was assumed that males with the fragile X premutation were unaffected by any cognitive phenotype. Here we examined the extent to which CGG repeat toxicity extends to visuospatial functioning in male fragile X premutation carriers who are asymptomatic for a late-onset neurodegenerative disorder, fragile X-associated tremor/ataxia syndrome (FXTAS). Thirty-three premutation males aged 20-68 years [divided into two groups: 16 low-repeat carriers (CGG ≥ 55 ≤ 100) and 17 high-repeat carriers (CGG>100)] with a family history of fragile X syndrome and 62 non-affected adult males with normal FMR1 alleles were recruited. Subjects underwent neuropsychological tests of visuospatial and visual working memory functioning and visuoperceptual processing. On measures of visuospatial processing, the high-repeat carriers performed significantly worse than the normal allele group when age and IQ were covaried out. With increasing age and only in carriers of a larger (>100 repeats) premutation allele was there a greater decrement in visuospatial working memory functioning. Performance on spatial and perceptual judgement tasks failed to show similar specificity in males within the upper premutation range. We conclude that identification of selective visuospatial impairments in carriers of a larger premutation allele indicates greater CGG repeat toxicity in specific neural regions. Longitudinal follow-up studies will be needed to determine whether subtle decline in visuospatial functioning is associated with the later onset of motor symptoms of FXTAS.
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Affiliation(s)
- Darren R Hocking
- Monash Institute for Brain Development and Repair, Monash University, School of Psychology and Psychiatry, Faculty of Medicine, Melbourne, Australia
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16
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Why is vision impaired in fragile X premutation carriers? The role of fragile X mental retardation protein and potential FMR1 mRNA toxicity. Neuroscience 2012; 206:183-9. [PMID: 22266345 DOI: 10.1016/j.neuroscience.2012.01.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2011] [Revised: 01/02/2012] [Accepted: 01/04/2012] [Indexed: 11/20/2022]
Abstract
Dysfunctions of the geniculo-striatal magnocellular (M) visual pathway and its cortical recipients have been documented in fragile X syndrome and in FMR1 premutation carriers. However, the mechanism of this impairment is less clear. To elucidate this issue, we completed the measurement of visual functions at different stages of information processing: low-level mechanisms (contrast sensitivity biasing information processing toward the M and parvocellular [P] pathways), primary visual cortex (motion-defined and static Vernier threshold), and higher-level form and motion processing (coherence thresholds). Results revealed that FMR1 premutation carriers, relative to non-carrier controls, exhibited lower contrast sensitivity for M pathway-biased stimuli, higher Vernier threshold for motion-defined stimuli, and higher global motion coherence threshold. Although both elevated FMR1 mRNA and reduced fragile X mental retardation protein (FMRP) levels were associated with impaired visual functions, regression analysis indicated that FMRP was the primary factor. In premutation carriers, a toxic gain-of-function of elevated FMR1 mRNA has been suggested, whereas reduced FMRP is linked to neurodevelopmental aspects. Here, we showed that FMRP may the primary factor associated with visual dysfunctions.
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Bray S, Hirt M, Jo B, Hall SS, Lightbody AA, Walter E, Chen K, Patnaik S, Reiss AL. Aberrant frontal lobe maturation in adolescents with fragile X syndrome is related to delayed cognitive maturation. Biol Psychiatry 2011; 70:852-8. [PMID: 21802660 PMCID: PMC3191299 DOI: 10.1016/j.biopsych.2011.05.038] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2011] [Revised: 05/21/2011] [Accepted: 05/24/2011] [Indexed: 10/17/2022]
Abstract
BACKGROUND Fragile X syndrome (FXS) is the most common known heritable cause of intellectual disability. Prior studies in FXS have observed a plateau in cognitive and adaptive behavioral development in early adolescence, suggesting that brain development in FXS may diverge from typical development during this period. METHODS In this study, we examined adolescent brain development using structural magnetic resonance imaging data acquired from 59 individuals with FXS and 83 typically developing control subjects aged 9 to 22, a subset of whom were followed up longitudinally (1-5 years; typically developing: 17, FXS: 19). Regional volumes were modeled to obtain estimates of age-related change. RESULTS We found that while structures such as the caudate showed consistent volume differences from control subjects across adolescence, prefrontal cortex (PFC) gyri showed significantly aberrant maturation. Furthermore, we found that PFC-related measures of cognitive functioning followed a similarly aberrant developmental trajectory in FXS. CONCLUSIONS Our findings suggest that aberrant maturation of the PFC during adolescence may contribute to persistent or increasing intellectual deficits in FXS.
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Affiliation(s)
- Signe Bray
- Department of Psychiatry, Hotchkiss Brain Institute, University of Calgary, 1403 - 29 Street NW Calgary, Alberta, T2N 2T9, Canada,Center for Interdisciplinary Brain Sciences Research, Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, 401 Quarry Rd, Palo Alto, CA, 94305, USA
| | - Melissa Hirt
- Center for Interdisciplinary Brain Sciences Research, Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, 401 Quarry Rd, Palo Alto, CA, 94305, USA
| | - Booil Jo
- Center for Interdisciplinary Brain Sciences Research, Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, 401 Quarry Rd, Palo Alto, CA, 94305, USA
| | - Scott S. Hall
- Center for Interdisciplinary Brain Sciences Research, Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, 401 Quarry Rd, Palo Alto, CA, 94305, USA
| | - Amy A. Lightbody
- Center for Interdisciplinary Brain Sciences Research, Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, 401 Quarry Rd, Palo Alto, CA, 94305, USA
| | - Elizabeth Walter
- Center for Interdisciplinary Brain Sciences Research, Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, 401 Quarry Rd, Palo Alto, CA, 94305, USA
| | - Kelly Chen
- Center for Interdisciplinary Brain Sciences Research, Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, 401 Quarry Rd, Palo Alto, CA, 94305, USA
| | - Swetapadma Patnaik
- Center for Interdisciplinary Brain Sciences Research, Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, 401 Quarry Rd, Palo Alto, CA, 94305, USA
| | - Allan L. Reiss
- Center for Interdisciplinary Brain Sciences Research, Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, 401 Quarry Rd, Palo Alto, CA, 94305, USA,Corresponding Author: Allan L. Reiss, Center for Interdisciplinary Brain Sciences Research, Stanford University School of Medicine, 401 Quarry Rd., Palo Alto, CA, 94305, Phone: 650 498 4538, Fax: 650 724 4761,
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Kéri S, Benedek G. Fragile X protein expression is linked to visual functions in healthy male volunteers. Neuroscience 2011; 192:345-50. [PMID: 21749915 DOI: 10.1016/j.neuroscience.2011.06.074] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2011] [Revised: 06/27/2011] [Accepted: 06/28/2011] [Indexed: 11/25/2022]
Abstract
Fragile X syndrome (FXS) is characterized by the impairment of the magnocellular/dorsal visual system. In this study, we explored how fragile X protein (FMRP) expression may affect visual functions in healthy participants. The percentage of FMRP-positive lymphocytes was measured using a rapid antibody test in blood smears of 100 male volunteers. CGG triplet expansion was also determined. Results revealed that participants with fewer FMRP-positive lymphocytes exhibited lower performances on tests biasing information processing toward the magnocellular pathway and dorsal visual stream (contrast sensitivity at low spatial/high temporal frequency and motion coherence). It was not observed in the case of tests biasing information processing toward the parvocellular pathway and ventral stream (contrast sensitivity at high spatial/low temporal frequency and form coherence). These results suggest that healthy persons with lower peripheral FMRP expression display a visual phenotype similar to that described in patients with FXS.
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Affiliation(s)
- S Kéri
- Department of Physiology, University of Szeged, Szeged, Hungary; National Psychiatry Center, Budapest, Hungary.
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Genetic deletion of regulator of G-protein signaling 4 (RGS4) rescues a subset of fragile X related phenotypes in the FMR1 knockout mouse. Mol Cell Neurosci 2011; 46:563-72. [PMID: 21215802 DOI: 10.1016/j.mcn.2010.12.005] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2010] [Revised: 11/09/2010] [Accepted: 12/05/2010] [Indexed: 01/27/2023] Open
Abstract
Fragile X syndrome (FXS), the most common cause of inherited mental retardation, is caused by the loss of the mRNA binding protein, FMRP. Persons with FXS also display epileptic seizures, social anxiety, hyperactivity, and autistic behaviors. The metabotropic glutamate receptor theory of FXS postulates that in the absence of FMRP, enhanced signaling though G-protein coupled group I metabotropic glutamate receptors in the brain contributes to many of the abnormalities observed in the disorder. However, recent evidence suggests that alterations in cellular signaling through additional G-protein coupled receptors may also be involved in the pathogenesis of FXS, thus providing impetus for examining downstream molecules. One group of signaling molecules situated downstream of the receptors is the regulator of G-protein signaling (RGS) proteins. Notably, RGS4 is highly expressed in brain and has been shown to negatively regulate signaling through Group I mGluRs and GABA(B) receptors. To examine the potential role for RGS4 in the pathogenesis of FXS, we generated FXS/RGS4 double knockout mice. Characterization of these mice revealed that a subset of FXS related phenotypes, including increased body weight, altered synaptic protein expression, and abnormal social behaviors, were rescued in the double knockout mice. Other phenotypes, such as hyperactivity and macroorchidism, were not affected by the loss of RGS4. These findings suggest that tissue and cell-type specific differences in GPCR signaling and RGS function may contribute to the spectrum of phenotypic differences observed in FXS.
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