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Salmerón AM, Pérez-Fernández C, Abreu AC, Fernández S, Tristán AI, Ruiz-Sobremazas D, Cabré M, Guardia-Escote L, Fernández I, Sánchez-Santed F. Exploring microbiota-gut-brain axis biomarkers linked to autism spectrum disorder in prenatally chlorpyrifos-exposed Fmr1 knock-out and wild-type male rats. Toxicology 2024; 506:153871. [PMID: 38925359 DOI: 10.1016/j.tox.2024.153871] [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: 03/14/2024] [Revised: 06/19/2024] [Accepted: 06/21/2024] [Indexed: 06/28/2024]
Abstract
Fmr1 (fragile X messenger ribonucleoprotein 1)-knockout (KO) rats, modeling the human Fragile X Syndrome (FXS), are of particular interest for exploring the ASD-like phenotype in preclinical studies. Gestational exposure to chlorpyrifos (CPF) has been associated with ASD diagnosis in humans and ASD-like behaviors in rodents and linked to the microbiota-gut-brain axis. In this study, we have used both Fmr1-KO and wild-type male rats (F2 generation) at postnatal days (PND) 7 and 40 obtained after F1 pregnant females were randomly exposed to 1 mg/kg/mL/day of CPF or vehicle. A nuclear magnetic resonance (NMR) metabolomics approach together with gene expression profiles of these F2 generation rats were employed to analyze different brain regions (such as prefrontal cortex, hippocampus, and cerebellum), whole large intestine (at PND7) and gut content (PND40). The statistical comparison of each matrix spectral profile unveiled tissue-specific metabolic fingerprints. Significant variations in some biomarker levels were detected among brain tissues of different genotypes, including taurine, myo-inositol, and 3-hydroxybutyric acid, and exposure to CPF induced distinct metabolic alterations, particularly in serine and myo-inositol. Additionally, this study provides a set of metabolites associated with gastrointestinal dysfunction in ASD, encompassing several amino acids, choline-derived compounds, bile acids, and sterol molecules. In terms of gene expression, genotype and gestational exposure to CPF had only minimal effects on decarboxylase 2 (gad2) and cholinergic receptor muscarinic 2 (chrm2) genes.
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Affiliation(s)
- Ana M Salmerón
- Department of Chemistry and Physics, Research Centre CIAIMBITAL, University of Almería, Almería, Spain
| | - Cristian Pérez-Fernández
- Department of Psychology and Health Research Centre, Research Centre for Social Welfare and Inclusion (CIBIS), University of Almería, Ctra. Sacramento s/n, Almería 04120, Spain
| | - Ana C Abreu
- Department of Chemistry and Physics, Research Centre CIAIMBITAL, University of Almería, Almería, Spain.
| | - Silvia Fernández
- Department of Chemistry and Physics, Research Centre CIAIMBITAL, University of Almería, Almería, Spain
| | - Ana I Tristán
- Department of Chemistry and Physics, Research Centre CIAIMBITAL, University of Almería, Almería, Spain
| | - Diego Ruiz-Sobremazas
- Department of Psychology and Health Research Centre, Research Centre for Social Welfare and Inclusion (CIBIS), University of Almería, Ctra. Sacramento s/n, Almería 04120, Spain
| | - María Cabré
- Research Group in Neurobehavior and Health (NEUROLAB) and Department of Biochemistry and Biotechnology, Universitat Rovira i Virgili, Tarragona, Spain
| | - Laia Guardia-Escote
- Research Group in Neurobehavior and Health (NEUROLAB) and Department of Psychology and Research Center for Behavior Assessment (CRAMC), Universitat Rovira i Virgili, Tarragona, Spain
| | - Ignacio Fernández
- Department of Chemistry and Physics, Research Centre CIAIMBITAL, University of Almería, Almería, Spain.
| | - Fernando Sánchez-Santed
- Department of Psychology and Health Research Centre, Research Centre for Social Welfare and Inclusion (CIBIS), University of Almería, Ctra. Sacramento s/n, Almería 04120, Spain.
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2
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Westmark PR, Gholston AK, Swietlik TJ, Maganti RK, Westmark CJ. Ketogenic Diet Affects Sleep Architecture in C57BL/6J Wild Type and Fragile X Mice. Int J Mol Sci 2023; 24:14460. [PMID: 37833907 PMCID: PMC10572443 DOI: 10.3390/ijms241914460] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 09/15/2023] [Accepted: 09/18/2023] [Indexed: 10/15/2023] Open
Abstract
Nearly half of children with fragile X syndrome experience sleep problems including trouble falling asleep and frequent nighttime awakenings. The goals here were to assess sleep-wake cycles in mice in response to Fmr1 genotype and a dietary intervention that reduces hyperactivity. Electroencephalography (EEG) results were compared with published rest-activity patterns to determine if actigraphy is a viable surrogate for sleep EEG. Specifically, sleep-wake patterns in adult wild type and Fmr1KO littermate mice were recorded after EEG electrode implantation and the recordings manually scored for vigilance states. The data indicated that Fmr1KO mice exhibited sleep-wake patterns similar to wild type littermates when maintained on a control purified ingredient diet. Treatment with a high-fat, low-carbohydrate ketogenic diet increased the percentage of non-rapid eye movement (NREM) sleep in both wild type and Fmr1KO mice during the dark cycle, which corresponded to decreased activity levels. Treatment with a ketogenic diet flattened diurnal sleep periodicity in both wild type and Fmr1KO mice. Differences in several sleep microstructure outcomes (number and length of sleep and wake bouts) supported the altered sleep states in response to a ketogenic diet and were correlated with altered rest-activity cycles. While actigraphy may be a less expensive, reduced labor surrogate for sleep EEG during the dark cycle, daytime resting in mice did not correlate with EEG sleep states.
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Affiliation(s)
- Pamela R. Westmark
- Department of Neurology, University of Wisconsin, Madison, WI 53706, USA; (P.R.W.); (A.K.G.); (T.J.S.); (R.K.M.)
| | - Aaron K. Gholston
- Department of Neurology, University of Wisconsin, Madison, WI 53706, USA; (P.R.W.); (A.K.G.); (T.J.S.); (R.K.M.)
- Molecular Environmental Toxicology Center, University of Wisconsin, Madison, WI 53706, USA
| | - Timothy J. Swietlik
- Department of Neurology, University of Wisconsin, Madison, WI 53706, USA; (P.R.W.); (A.K.G.); (T.J.S.); (R.K.M.)
| | - Rama K. Maganti
- Department of Neurology, University of Wisconsin, Madison, WI 53706, USA; (P.R.W.); (A.K.G.); (T.J.S.); (R.K.M.)
| | - Cara J. Westmark
- Department of Neurology, University of Wisconsin, Madison, WI 53706, USA; (P.R.W.); (A.K.G.); (T.J.S.); (R.K.M.)
- Molecular Environmental Toxicology Center, University of Wisconsin, Madison, WI 53706, USA
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3
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Premoli M, Fyke W, Bellocchio L, Lemaire V, Wolley-Roberts M, Bontempi B, Pietropaolo S. Early Administration of the Phytocannabinoid Cannabidivarin Prevents the Neurobehavioral Abnormalities Associated with the Fmr1-KO Mouse Model of Fragile X Syndrome. Cells 2023; 12:1927. [PMID: 37566006 PMCID: PMC10416983 DOI: 10.3390/cells12151927] [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: 06/17/2023] [Revised: 07/14/2023] [Accepted: 07/18/2023] [Indexed: 08/12/2023] Open
Abstract
Phytocannabinoids, including the non-addictive cannabis component cannabidivarin (CBDV), have been reported to hold therapeutic potential in several neurodevelopmental disorders (NDDs). Nonetheless, the therapeutic value of phytocannabinoids for treating Fragile X syndrome (FXS), a major NDD, remains unexplored. Here, we characterized the neurobehavioral effects of CBDV at doses of 20 or 100 mg/kg in the Fmr1-knockout (Fmr1-KO) mouse model of FXS using two temporally different intraperitoneal regimens: subchronic 10-day delivery during adulthood (Study 1: rescue treatment) or chronic 5-week delivery at adolescence (Study 2: preventive treatment). Behavioral tests assessing FXS-like abnormalities included anxiety, locomotor, cognitive, social and sensory alterations. Expression of inflammatory and plasticity markers was investigated in the hippocampus and prefrontal cortex. When administered during adulthood (Study 1), the effects of CBDV were marginal, rescuing at the lower dose only the acoustic hyper-responsiveness of Fmr1-KO mice and at both doses their altered hippocampal expression of neurotrophins. When administered during adolescence (Study 2), CBDV at both doses prevented the cognitive, social and acoustic alterations of adult Fmr1-KO mice and modified the expression of several inflammatory brain markers in both wild-type littermates and mutants. These findings warrant the therapeutic potential of CBDV for preventing neurobehavioral alterations associated with FXS, highlighting the relevance of its early administration.
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Affiliation(s)
- Marika Premoli
- CNRS, EPHE, INCIA, UMR 5287, Univ. Bordeaux, 33000 Bordeaux, France
- Department of Molecular and Translational Medicine, University of Brescia, 25123 Brescia, Italy
| | - William Fyke
- CNRS, EPHE, INCIA, UMR 5287, Univ. Bordeaux, 33000 Bordeaux, France
- Graduate Program in Neural and Behavioral Science, SUNY Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203, USA
| | - Luigi Bellocchio
- INSERM, U1215 NeuroCentre Magendie, Group Endocannabinoids and Neuroadaptation, University of Bordeaux, 33077 Bordeaux, France
| | - Valerie Lemaire
- CNRS, EPHE, INCIA, UMR 5287, Univ. Bordeaux, 33000 Bordeaux, France
| | | | - Bruno Bontempi
- CNRS, EPHE, INCIA, UMR 5287, Univ. Bordeaux, 33000 Bordeaux, France
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4
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Abstract
The fragile X-related disorders are an important group of hereditary disorders that are caused by expanded CGG repeats in the 5' untranslated region of the FMR1 gene or by mutations in the coding sequence of this gene. Two categories of pathological CGG repeats are associated with these disorders, full mutation alleles and shorter premutation alleles. Individuals with full mutation alleles develop fragile X syndrome, which causes autism and intellectual disability, whereas those with premutation alleles, which have shorter CGG expansions, can develop fragile X-associated tremor/ataxia syndrome, a progressive neurodegenerative disease. Thus, fragile X-related disorders can manifest as neurodegenerative or neurodevelopmental disorders, depending on the size of the repeat expansion. Here, we review mouse models of fragile X-related disorders and discuss how they have informed our understanding of neurodegenerative and neurodevelopmental disorders. We also assess the translational value of these models for developing rational targeted therapies for intellectual disability and autism disorders.
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Affiliation(s)
- Rob Willemsen
- Department of Clinical Genetics, Erasmus University Medical Center, 3015 CN Rotterdam, the Netherlands. Department of Medical Genetics, University of Antwerp, 2000 Antwerp, Belgium
| | - R. Frank Kooy
- Department of Clinical Genetics, Erasmus University Medical Center, 3015 CN Rotterdam, the Netherlands. Department of Medical Genetics, University of Antwerp, 2000 Antwerp, Belgium
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5
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Robust and replicable measurement for prepulse inhibition of the acoustic startle response. Mol Psychiatry 2021; 26:1909-1927. [PMID: 32144356 PMCID: PMC7483293 DOI: 10.1038/s41380-020-0703-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 02/18/2020] [Accepted: 02/21/2020] [Indexed: 12/13/2022]
Abstract
Measuring animal behavior in the context of experimental manipulation is critical for modeling, and understanding neuropsychiatric disease. Prepulse inhibition of the acoustic startle response (PPI) is a behavioral phenomenon studied extensively for this purpose, but the results of PPI studies are often inconsistent. As a result, the utility of this phenomenon remains uncertain. Here, we deconstruct the phenomenon of PPI and confirm several limitations of the methodology traditionally utilized to describe PPI, including that the underlying startle response has a non-Gaussian distribution, and that the traditional PPI metric changes with different stimuli. We then develop a novel model that reveals PPI to be a combination of the previously appreciated scaling of the startle response, as well as a scaling of sound processing. Using our model, we find no evidence for differences in PPI in a rat model of Fragile-X Syndrome (FXS) compared with wild-type controls. These results in the rat provide a reliable methodology that could be used to clarify inconsistent PPI results in mice and humans. In contrast, we find robust differences between wild-type male and female rats. Our model allows us to understand the nature of these differences, and we find that both the startle-scaling and sound-scaling components of PPI are a function of the baseline startle response. Males and females differ specifically in the startle-scaling, but not the sound-scaling, component of PPI. These findings establish a robust experimental and analytical approach that has the potential to provide a consistent biomarker of brain function.
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Abstract
Altered prepulse inhibition (PPI) is an endophenotype associated with multiple brain disorders, including schizophrenia. Circuit mechanisms that regulate PPI have been suggested, but none has been demonstrated through direct manipulations. IRSp53 is an abundant excitatory postsynaptic scaffold implicated in schizophrenia, autism spectrum disorders, and attention-deficit/hyperactivity disorder. We found that mice lacking IRSp53 in cortical excitatory neurons display decreased PPI. IRSp53-mutant layer 6 cortical neurons in the anterior cingulate cortex (ACC) displayed decreased excitatory synaptic input but markedly increased neuronal excitability, which was associated with excessive excitatory synaptic input in downstream mediodorsal thalamic (MDT) neurons. Importantly, chemogenetic inhibition of mutant neurons projecting to MDT normalized the decreased PPI and increased excitatory synaptic input onto MDT neurons. In addition, chemogenetic activation of MDT-projecting layer 6 neurons in the ACC decreased PPI in wild-type mice. These results suggest that the hyperactive ACC-MDT pathway suppresses PPI in wild-type and IRSp53-mutant mice.
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Affiliation(s)
- Yangsik Kim
- Mental Health Research Institute, National Center for Mental Health, Seoul, South Korea,Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon, South Korea,Center for Synaptic Brain Dysfunction, Institute for Basic Science, Daejeon, South Korea,To whom correspondence should be addressed; Mental Health Research Institute, National Center for Mental Health, Yongmasan-ro 127, Gwangjin-gu, Seoul, South Korea 04933; tel: +82-2-2204-0502, fax: +82-2-2204-0393, e-mail:
| | - Young Woo Noh
- Department of Biological Science, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
| | - Kyungdeok Kim
- Department of Biological Science, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
| | - Eunjoon Kim
- Center for Synaptic Brain Dysfunction, Institute for Basic Science, Daejeon, South Korea,Department of Biological Science, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
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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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8
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Characterization of Auditory and Binaural Spatial Hearing in a Fragile X Syndrome Mouse Model. eNeuro 2020; 7:ENEURO.0300-19.2019. [PMID: 31953317 PMCID: PMC7031856 DOI: 10.1523/eneuro.0300-19.2019] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 12/01/2019] [Accepted: 12/20/2019] [Indexed: 12/31/2022] Open
Abstract
The auditory brainstem compares sound-evoked excitation and inhibition from both ears to compute sound source location and determine spatial acuity. Although alterations to the anatomy and physiology of the auditory brainstem have been demonstrated in fragile X syndrome (FXS), it is not known whether these changes cause spatial acuity deficits in FXS. To test the hypothesis that FXS-related alterations to brainstem circuits impair spatial hearing abilities, a reflexive prepulse inhibition (PPI) task, with variations in sound (gap, location, masking) as the prepulse stimulus, was used on Fmr1 knock-out mice and B6 controls. Specifically, Fmr1 mice show decreased PPI compared with wild-type mice during gap detection, changes in sound source location, and spatial release from masking with no alteration to their overall startle thresholds compared with wild-type mice. Last, Fmr1 mice have increased latency to respond in these tasks, suggesting additional impairments in the pathway responsible for reacting to a startling sound. This study further supports data in humans with FXS that show similar deficits in PPI.
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9
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Gonzalez D, Tomasek M, Hays S, Sridhar V, Ammanuel S, Chang CW, Pawlowski K, Huber KM, Gibson JR. Audiogenic Seizures in the Fmr1 Knock-Out Mouse Are Induced by Fmr1 Deletion in Subcortical, VGlut2-Expressing Excitatory Neurons and Require Deletion in the Inferior Colliculus. J Neurosci 2019; 39:9852-9863. [PMID: 31666356 PMCID: PMC6891051 DOI: 10.1523/jneurosci.0886-19.2019] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 09/06/2019] [Accepted: 10/16/2019] [Indexed: 02/07/2023] Open
Abstract
Fragile X syndrome (FXS) is the most common form of inherited intellectual disability and the leading monogenetic cause of autism. One symptom of FXS and autism is sensory hypersensitivity (also called sensory over-responsivity). Perhaps related to this, the audiogenic seizure (AGS) is arguably the most robust behavioral phenotype in the FXS mouse model-the Fmr1 knock-out (KO) mouse. Therefore, the AGS may be considered a mouse model of sensory hypersensitivity. Hyperactive circuits are hypothesized to underlie dysfunction in a number of brain regions in patients with FXS and Fmr1 KO mice, and the AGS may be a result of this. But the specific cell types and brain regions underlying AGSs in the Fmr1 KO are unknown. We used conditional deletion or expression of Fmr1 in different cell populations to determine whether Fmr1 deletion in those cells was sufficient or necessary, respectively, for the AGS phenotype in males. Our data indicate that Fmr1 deletion in glutamatergic neurons that express vesicular glutamate transporter 2 (VGlut2) and are located in subcortical brain regions is sufficient and necessary to cause AGSs. Furthermore, the deletion of Fmr1 in glutamatergic neurons of the inferior colliculus is necessary for AGSs. When we demonstrate necessity, we show that Fmr1 expression in either the larger population of VGlut2-expressing glutamatergic neurons or the smaller population of inferior collicular glutamatergic neurons-in an otherwise Fmr1 KO mouse-eliminates AGSs. Therefore, targeting these neuronal populations in FXS and autism may be part of a therapeutic strategy to alleviate sensory hypersensitivity.SIGNIFICANCE STATEMENT Sensory hypersensitivity in fragile X syndrome (FXS) and autism patients significantly interferes with quality of life. Audiogenic seizures (AGSs) are arguably the most robust behavioral phenotype in the FXS mouse model-the Fmr1 knockout-and may be considered a model of sensory hypersensitivity in FXS. We provide the clearest and most precise genetic evidence to date for the cell types and brain regions involved in causing AGSs in the Fmr1 knockout and, more broadly, for any mouse mutant. The expression of Fmr1 in these same cell types in an otherwise Fmr1 knockout eliminates AGSs indicating possible cellular targets for alleviating sensory hypersensitivity in FXS and other forms of autism.
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Affiliation(s)
| | | | - Seth Hays
- Department of Neuroscience, Dallas, and
| | | | | | | | - Karen Pawlowski
- Department of Otolaryngology and Biomedical Engineering Program, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9035
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10
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Hodges SL, Reynolds CD, Nolan SO, Huebschman JL, Okoh JT, Binder MS, Lugo JN. A single early-life seizure results in long-term behavioral changes in the adult Fmr1 knockout mouse. Epilepsy Res 2019; 157:106193. [PMID: 31520894 PMCID: PMC6823160 DOI: 10.1016/j.eplepsyres.2019.106193] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 08/06/2019] [Accepted: 08/28/2019] [Indexed: 12/20/2022]
Abstract
Fragile X syndrome (FXS) is the leading cause of inherited intellectual disability and a significant genetic contributor to Autism spectrum disorder. In addition to autistic-like phenotypes, individuals with FXS are subject to developing numerous comorbidities, one of the most prevalent being seizures. In the present study, we investigated how a single early-life seizure superimposed on a genetic condition impacts the autistic-like behavioral phenotype of the mouse. We induced status epilepticus (SE) on postnatal day (PD) 10 in Fmr1 wild type (WT) and knockout (KO) mice. We then tested the mice in a battery of behavioral tests during adulthood (PD90) to examine the long-term impact of an early-life seizure. Our findings replicated prior work that reported a single instance of SE results in behavioral deficits, including increases in repetitive behavior, enhanced hippocampal-dependent learning, and reduced sociability and prepulse inhibition (p < 0.05). We also observed genotypic differences characteristic of the FXS phenotype in Fmr1 KO mice, such as enhanced prepulse inhibition and repetitive behavior, hyperactivity, and reduced startle responses (p < 0.05). Superimposing a seizure on deletion of Fmr1 significantly impacted repetitive behavior in a nosepoke task. Specifically, a single early-life seizure increased consecutive nose poking behavior in the task in WT mice (p < 0.05), yet seizures did not exacerbate the elevated stereotypy observed in Fmr1 KO mice (p > 0.05). Overall, these findings help to elucidate how seizures in a critical period of development can impact long-term behavioral manifestations caused by underlying gene mutations in Fmr1. Utilizing double-hit models, such as superimposing seizures on the Fmr1 mutation, can help to enhance our understanding of comorbidities in disease models.
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Affiliation(s)
- Samantha L Hodges
- Institute of Biomedical Studies, Baylor University, Waco, TX 76798, USA
| | - Conner D Reynolds
- Texas College of Osteopathic Medicine, University of North Texas Health Science Center, Fort Worth TX, 76107, USA
| | - Suzanne O Nolan
- Department of Psychology and Neuroscience, Baylor University, Waco, TX 76798, USA
| | | | - James T Okoh
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
| | - Matthew S Binder
- Department of Psychology and Neuroscience, Baylor University, Waco, TX 76798, USA
| | - Joaquin N Lugo
- Institute of Biomedical Studies, Baylor University, Waco, TX 76798, USA; Department of Psychology and Neuroscience, Baylor University, Waco, TX 76798, USA; Department of Biology, Baylor University, Waco, TX 76798, USA.
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11
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Bruno JL, Hosseini SH, Lightbody AA, Manchanda MK, Reiss AL. Brain circuitry, behavior, and cognition: A randomized placebo-controlled trial of donepezil in fragile X syndrome. J Psychopharmacol 2019; 33:975-985. [PMID: 31264943 PMCID: PMC6894490 DOI: 10.1177/0269881119858304] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
BACKGROUND Fragile X syndrome, the most common inherited cause for intellectual disability, is associated with alterations in cholinergic among other neurotransmitter systems. This study investigated the effects of donepezil hydrochloride, a cholinesterase inhibitor that has potential to correct aberrant cholinergic signaling. METHOD Forty-two individuals with fragile X syndrome (mean age=19.61 years) were randomized to receive 2.5-10.0 mg of donepezil (n=20, seven females) or placebo (n=22, eight females) per day. One individual in the active group withdrew at week 7. Outcomes included the contingency naming test, the aberrant behavior checklist, and behavior and brain activation patterns during a functional magnetic resonance imaging gaze discrimination task. RESULTS There were no significant differences between active and placebo groups on cognitive (contingency naming task) or behavioral (total score or subscales of the aberrant behavior checklist) outcomes. At baseline, the active and placebo groups did not differ in functional magnetic resonance imaging activation patterns during the gaze task. After 12 weeks of treatment the active group displayed reduced activation in response to the averted vs direct gaze contrast, relative to the placebo group, in the left superior frontal gyrus. CONCLUSIONS Reduced functional brain activation for the active group may represent less arousal in response to direct eye gaze, relative to the placebo group. Change in functional magnetic resonance imaging activation patterns may serve as a more sensitive metric and predictor of response to treatment when compared to cognitive and behavioral assessments. Our results suggest that donepezil may have an impact on brain functioning, but longer term follow-up and concomitant behavioral intervention may be required to demonstrate improvement in cognition and behavior.
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Affiliation(s)
- Jennifer L. Bruno
- Center for Interdisciplinary Brain Sciences Research, Stanford University.,To whom correspondence should be addressed: 401 Quarry Road, Palo Alto, CA 94304, Phone: 818-415-9119, Fax: (650) 724-4761,
| | - S.M. Hadi Hosseini
- Center for Interdisciplinary Brain Sciences Research, Stanford University
| | - Amy A. Lightbody
- Center for Interdisciplinary Brain Sciences Research, Stanford University
| | - Mai K. Manchanda
- Center for Interdisciplinary Brain Sciences Research, Stanford University
| | - Allan L. Reiss
- Center for Interdisciplinary Brain Sciences Research, Stanford University.,Department of Radiology, Stanford University.,Department of Pediatrics, Stanford University
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12
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Zhao X, Bhattacharyya A. Human Models Are Needed for Studying Human Neurodevelopmental Disorders. Am J Hum Genet 2018; 103:829-857. [PMID: 30526865 DOI: 10.1016/j.ajhg.2018.10.009] [Citation(s) in RCA: 94] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 10/09/2018] [Indexed: 12/19/2022] Open
Abstract
The analysis of animal models of neurological disease has been instrumental in furthering our understanding of neurodevelopment and brain diseases. However, animal models are limited in revealing some of the most fundamental aspects of development, genetics, pathology, and disease mechanisms that are unique to humans. These shortcomings are exaggerated in disorders that affect the brain, where the most significant differences between humans and animal models exist, and could underscore failures in targeted therapeutic interventions in affected individuals. Human pluripotent stem cells have emerged as a much-needed model system for investigating human-specific biology and disease mechanisms. However, questions remain regarding whether these cell-culture-based models are sufficient or even necessary. In this review, we summarize human-specific features of neurodevelopment and the most common neurodevelopmental disorders, present discrepancies between animal models and human diseases, demonstrate how human stem cell models can provide meaningful information, and discuss the challenges that exist in our pursuit to understand distinctively human aspects of neurodevelopment and brain disease. This information argues for a more thoughtful approach to disease modeling through consideration of the valuable features and limitations of each model system, be they human or animal, to mimic disease characteristics.
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Affiliation(s)
- Xinyu Zhao
- Waisman Center, School of Medicine and Public Health, University of Wisconsin-Madison, Madison WI 53705, USA; Department of Neuroscience, School of Medicine and Public Health, University of Wisconsin-Madison, Madison WI 53705, USA.
| | - Anita Bhattacharyya
- Waisman Center, School of Medicine and Public Health, University of Wisconsin-Madison, Madison WI 53705, USA; Department of Cell and Regenerative Biology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison WI 53705, USA.
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13
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Costa L, Sardone LM, Bonaccorso CM, D'Antoni S, Spatuzza M, Gulisano W, Tropea MR, Puzzo D, Leopoldo M, Lacivita E, Catania MV, Ciranna L. Activation of Serotonin 5-HT 7 Receptors Modulates Hippocampal Synaptic Plasticity by Stimulation of Adenylate Cyclases and Rescues Learning and Behavior in a Mouse Model of Fragile X Syndrome. Front Mol Neurosci 2018; 11:353. [PMID: 30333723 PMCID: PMC6176069 DOI: 10.3389/fnmol.2018.00353] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Accepted: 09/10/2018] [Indexed: 01/06/2023] Open
Abstract
We have previously demonstrated that activation of serotonin 5-HT7 receptors (5-HT7R) reverses metabotropic glutamate receptor-mediated long term depression (mGluR-LTD) in the hippocampus of wild-type (WT) and Fmr1 Knockout (KO) mice, a model of Fragile X Syndrome (FXS) in which mGluR-LTD is abnormally enhanced. Here, we have investigated intracellular mechanisms underlying the effect of 5-HT7R activation using patch clamp on hippocampal slices. Furthermore, we have tested whether in vivo administration of LP-211, a selective 5-HT7R agonist, can rescue learning and behavior in Fmr1 KO mice. In the presence of an adenylate cyclase blocker, mGluR-LTD was slightly enhanced in WT and therefore the difference between mGluR-LTD in WT and Fmr1 KO slices was no longer present. Conversely, activation of adenylate cyclase by either forskolin or Pituitary Adenylate Cyclase Activating Polypeptide (PACAP) completely reversed mGluR-LTD in WT and Fmr1 KO. 5-HT7R activation reversed mGluR-LTD in WT and corrected exaggerated mGluR-LTD in Fmr1 KO; this effect was abolished by blockade of either adenylate cyclase or protein kinase A (PKA). Exposure of hippocampal slices to LP-211 caused an increased phosphorylation of extracellular signal regulated kinase (ERK), an intracellular effector involved in mGluR-LTD, in WT mice. Conversely, this effect was barely detectable in Fmr1 KO mice, suggesting that 5-HT7R-mediated reversal of mGluR-LTD does not require ERK stimulation. Finally, an acute in vivo administration of LP-211 improved novel object recognition (NOR) performance in WT and Fmr1 KO mice and reduced stereotyped behavior in Fmr1 KO mice. Our results indicate that mGluR-LTD in WT and Fmr1 KO slices is bidirectionally modulated in conditions of either reduced or enhanced cAMP formation. Activation of 5-HT7 receptors reverses mGluR-LTD by activation of the cAMP/PKA intracellular pathway. Importantly, a systemic administration of a 5-HT7R agonist to Fmr1 KO mice corrected learning deficits and repetitive behavior. We suggest that selective 5-HT7R agonists might become novel pharmacological tools for FXS therapy.
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Affiliation(s)
- Lara Costa
- Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - Lara Maria Sardone
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | | | - Simona D'Antoni
- Institute of Neurological Sciences (ISN), National Research Council (CNR), Catania, Italy
| | | | - Walter Gulisano
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Maria Rosaria Tropea
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Daniela Puzzo
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Marcello Leopoldo
- Department of Pharmacy - Drug Sciences, University of Bari, Bari, Italy
| | - Enza Lacivita
- Department of Pharmacy - Drug Sciences, University of Bari, Bari, Italy
| | - Maria Vincenza Catania
- Oasi Research Institute, IRCCS, Troina, Italy.,Institute of Neurological Sciences (ISN), National Research Council (CNR), Catania, Italy
| | - Lucia Ciranna
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
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14
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Neuhofer D, Lassalle O, Manzoni OJ. Muscarinic M1 Receptor Modulation of Synaptic Plasticity in Nucleus Accumbens of Wild-Type and Fragile X Mice. ACS Chem Neurosci 2018; 9:2233-2240. [PMID: 29486555 DOI: 10.1021/acschemneuro.7b00398] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
We investigated how metabotropic acetylcholine receptors control excitatory synaptic plasticity in the mouse nucleus accumbens core. Pharmacological and genetic approaches revealed that M1 mAChRs (muscarinic acetylcholine receptors) trigger multiple and interacting forms of synaptic plasticity. As previously described in the dorsal striatum, moderate pharmacological activation of M1 mAChR potentiated postsynaptic NMDARs. The M1-potentiation of NMDAR masked a previously unknown coincident TRPV1-mediated long-term depression (LTD). In addition, strong pharmacological activation of M1 mAChR induced canonical retrograde LTD, mediated by presynaptic CB1R. In the fmr1-/y mouse model of Fragile X, we found that CB1R but not TRPV1 M1-LTD was impaired. Finally, pharmacological blockade of the degradation of anandamide and 2-arachidonylglycerol, the two principal endocannabinoids restored fmr1-/y LTD to wild-type levels. These findings shed new light on the complex influence of acetylcholine on excitatory synapses in the nucleus accumbens core and identify new substrates of the synaptic deficits of Fragile X.
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Affiliation(s)
- Daniela Neuhofer
- INMED, INSERM
U901, 13273 Marseille, France
- Aix-Marseille University, 13007 Marseille, France
- Université
de Aix-Marseille, UMR S901, 13273 Marseille, France
- Department of Neuroscience, Medical University of South Carolina, Charleston, South Carolina 29425, United States
| | - Olivier Lassalle
- INMED, INSERM
U901, 13273 Marseille, France
- Aix-Marseille University, 13007 Marseille, France
- Université
de Aix-Marseille, UMR S901, 13273 Marseille, France
| | - Olivier J. Manzoni
- INMED, INSERM
U901, 13273 Marseille, France
- Aix-Marseille University, 13007 Marseille, France
- Université
de Aix-Marseille, UMR S901, 13273 Marseille, France
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15
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Melancia F, Trezza V. Modelling fragile X syndrome in the laboratory setting: A behavioral perspective. Behav Brain Res 2018; 350:149-163. [DOI: 10.1016/j.bbr.2018.04.042] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Revised: 04/24/2018] [Accepted: 04/24/2018] [Indexed: 12/13/2022]
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16
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Gogliotti RG, Fisher NM, Stansley BJ, Jones CK, Lindsley CW, Conn PJ, Niswender CM. Total RNA Sequencing of Rett Syndrome Autopsy Samples Identifies the M 4 Muscarinic Receptor as a Novel Therapeutic Target. J Pharmacol Exp Ther 2018; 365:291-300. [PMID: 29523700 PMCID: PMC5878667 DOI: 10.1124/jpet.117.246991] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 03/08/2018] [Indexed: 02/04/2023] Open
Abstract
Mutations in the MeCP2 gene are responsible for the neurodevelopmental disorder Rett syndrome (RTT). MeCP2 is a DNA-binding protein whose abundance and ability to complex with histone deacetylase 3 is linked to the regulation of chromatin structure. Consequently, loss-of-function mutations in MeCP2 are predicted to have broad effects on gene expression. However, to date, studies in mouse models of RTT have identified a limited number of gene or pathway-level disruptions, and even fewer genes have been identified that could be considered amenable to classic drug discovery approaches. Here, we performed RNA sequencing (RNA-seq) on nine motor cortex and six cerebellar autopsy samples from RTT patients and controls. This approach identified 1887 significantly affected genes in the motor cortex and 2110 genes in the cerebellum, with a global trend toward increased expression. Pathway-level analysis identified enrichment in genes associated with mitogen-activated protein kinase signaling, long-term potentiation, and axon guidance. A survey of our RNA-seq results also identified a significant decrease in expression of the CHRM4 gene, which encodes a receptor [muscarinic acetylcholine receptor 4 (M4)] that is the subject of multiple large drug discovery efforts for schizophrenia and Alzheimer's disease. We confirmed that CHRM4 expression was decreased in RTT patients, and, excitingly, we demonstrated that M4 potentiation normalizes social and cognitive phenotypes in Mecp2+/- mice. This work provides an experimental paradigm in which translationally relevant targets can be identified using transcriptomics in RTT autopsy samples, back-modeled in Mecp2+/- mice, and assessed for preclinical efficacy using existing pharmacological tool compounds.
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Affiliation(s)
- Rocco G Gogliotti
- Departments of Pharmacology (R.G.G., N.M.F., B.J.S., C.K.J., C.W.L., P.J.C., C.M.N.) and Chemistry (C.W.L.), and Vanderbilt Center for Neuroscience Drug Discovery (R.G.G., N.M.F., B.J.S., C.K.J., C.W.L., P.J.C., C.M.N.), Vanderbilt University, Nashville, Tennessee; and Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee (P.J.C., C.M.N.)
| | - Nicole M Fisher
- Departments of Pharmacology (R.G.G., N.M.F., B.J.S., C.K.J., C.W.L., P.J.C., C.M.N.) and Chemistry (C.W.L.), and Vanderbilt Center for Neuroscience Drug Discovery (R.G.G., N.M.F., B.J.S., C.K.J., C.W.L., P.J.C., C.M.N.), Vanderbilt University, Nashville, Tennessee; and Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee (P.J.C., C.M.N.)
| | - Branden J Stansley
- Departments of Pharmacology (R.G.G., N.M.F., B.J.S., C.K.J., C.W.L., P.J.C., C.M.N.) and Chemistry (C.W.L.), and Vanderbilt Center for Neuroscience Drug Discovery (R.G.G., N.M.F., B.J.S., C.K.J., C.W.L., P.J.C., C.M.N.), Vanderbilt University, Nashville, Tennessee; and Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee (P.J.C., C.M.N.)
| | - Carrie K Jones
- Departments of Pharmacology (R.G.G., N.M.F., B.J.S., C.K.J., C.W.L., P.J.C., C.M.N.) and Chemistry (C.W.L.), and Vanderbilt Center for Neuroscience Drug Discovery (R.G.G., N.M.F., B.J.S., C.K.J., C.W.L., P.J.C., C.M.N.), Vanderbilt University, Nashville, Tennessee; and Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee (P.J.C., C.M.N.)
| | - Craig W Lindsley
- Departments of Pharmacology (R.G.G., N.M.F., B.J.S., C.K.J., C.W.L., P.J.C., C.M.N.) and Chemistry (C.W.L.), and Vanderbilt Center for Neuroscience Drug Discovery (R.G.G., N.M.F., B.J.S., C.K.J., C.W.L., P.J.C., C.M.N.), Vanderbilt University, Nashville, Tennessee; and Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee (P.J.C., C.M.N.)
| | - P Jeffrey Conn
- Departments of Pharmacology (R.G.G., N.M.F., B.J.S., C.K.J., C.W.L., P.J.C., C.M.N.) and Chemistry (C.W.L.), and Vanderbilt Center for Neuroscience Drug Discovery (R.G.G., N.M.F., B.J.S., C.K.J., C.W.L., P.J.C., C.M.N.), Vanderbilt University, Nashville, Tennessee; and Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee (P.J.C., C.M.N.)
| | - Colleen M Niswender
- Departments of Pharmacology (R.G.G., N.M.F., B.J.S., C.K.J., C.W.L., P.J.C., C.M.N.) and Chemistry (C.W.L.), and Vanderbilt Center for Neuroscience Drug Discovery (R.G.G., N.M.F., B.J.S., C.K.J., C.W.L., P.J.C., C.M.N.), Vanderbilt University, Nashville, Tennessee; and Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee (P.J.C., C.M.N.)
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17
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Martinez LA, Tejada-Simon MV. Pharmacological Rescue of Hippocampal Fear Learning Deficits in Fragile X Syndrome. Mol Neurobiol 2017; 55:5951-5961. [DOI: 10.1007/s12035-017-0819-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Accepted: 11/02/2017] [Indexed: 11/28/2022]
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18
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Thomson SR, Seo SS, Barnes SA, Louros SR, Muscas M, Dando O, Kirby C, Wyllie DJA, Hardingham GE, Kind PC, Osterweil EK. Cell-Type-Specific Translation Profiling Reveals a Novel Strategy for Treating Fragile X Syndrome. Neuron 2017; 95:550-563.e5. [PMID: 28772121 PMCID: PMC5548955 DOI: 10.1016/j.neuron.2017.07.013] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 04/22/2017] [Accepted: 07/12/2017] [Indexed: 11/08/2022]
Abstract
Excessive mRNA translation downstream of group I metabotropic glutamate receptors (mGlu1/5) is a core pathophysiology of fragile X syndrome (FX); however, the differentially translating mRNAs that contribute to altered neural function are not known. We used translating ribosome affinity purification (TRAP) and RNA-seq to identify mistranslating mRNAs in CA1 pyramidal neurons of the FX mouse model (Fmr1−/y) hippocampus, which exhibit exaggerated mGlu1/5-induced long-term synaptic depression (LTD). In these neurons, we find that the Chrm4 transcript encoding muscarinic acetylcholine receptor 4 (M4) is excessively translated, and synthesis of M4 downstream of mGlu5 activation is mimicked and occluded. Surprisingly, enhancement rather than inhibition of M4 activity normalizes core phenotypes in the Fmr1−/y, including excessive protein synthesis, exaggerated mGluR-LTD, and audiogenic seizures. These results suggest that not all excessively translated mRNAs in the Fmr1−/y brain are detrimental, and some may be candidates for enhancement to correct pathological changes in the FX brain. TRAP-seq reveals altered translation of >120 mRNAs in Fmr1−/y CA1 pyramidal neurons Muscarinic receptor M4 is excessively translated in Fmr1−/y hippocampus Enhancement, not inhibition, of M4 corrects core phenotypes in the Fmr1−/y mouse Not all excessively translating mRNAs are detrimental to Fmr1−/y brain function
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Affiliation(s)
- Sophie R Thomson
- Centre for Integrative Physiology/Patrick Wild Centre, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh, EH8 9XD, UK; Simons Initiative for the Developing Brain, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh, EH8 9XD, UK
| | - Sang S Seo
- Centre for Integrative Physiology/Patrick Wild Centre, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh, EH8 9XD, UK; Simons Initiative for the Developing Brain, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh, EH8 9XD, UK
| | - Stephanie A Barnes
- Centre for Integrative Physiology/Patrick Wild Centre, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh, EH8 9XD, UK; Simons Initiative for the Developing Brain, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh, EH8 9XD, UK
| | - Susana R Louros
- Centre for Integrative Physiology/Patrick Wild Centre, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh, EH8 9XD, UK; Simons Initiative for the Developing Brain, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh, EH8 9XD, UK
| | - Melania Muscas
- Centre for Integrative Physiology/Patrick Wild Centre, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh, EH8 9XD, UK; Simons Initiative for the Developing Brain, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh, EH8 9XD, UK
| | - Owen Dando
- Centre for Integrative Physiology/Patrick Wild Centre, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh, EH8 9XD, UK; Simons Initiative for the Developing Brain, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh, EH8 9XD, UK
| | - Caoimhe Kirby
- Centre for Integrative Physiology/Patrick Wild Centre, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh, EH8 9XD, UK; Simons Initiative for the Developing Brain, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh, EH8 9XD, UK
| | - David J A Wyllie
- Centre for Integrative Physiology/Patrick Wild Centre, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh, EH8 9XD, UK; Simons Initiative for the Developing Brain, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh, EH8 9XD, UK
| | - Giles E Hardingham
- Centre for Integrative Physiology/Patrick Wild Centre, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh, EH8 9XD, UK; Simons Initiative for the Developing Brain, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh, EH8 9XD, UK; UK Dementia Research Institute, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh, EH8 9XD, UK
| | - Peter C Kind
- Centre for Integrative Physiology/Patrick Wild Centre, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh, EH8 9XD, UK; Simons Initiative for the Developing Brain, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh, EH8 9XD, UK
| | - Emily K Osterweil
- Centre for Integrative Physiology/Patrick Wild Centre, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh, EH8 9XD, UK; Simons Initiative for the Developing Brain, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh, EH8 9XD, UK.
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19
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Kashima R, Redmond PL, Ghatpande P, Roy S, Kornberg TB, Hanke T, Knapp S, Lagna G, Hata A. Hyperactive locomotion in a Drosophila model is a functional readout for the synaptic abnormalities underlying fragile X syndrome. Sci Signal 2017; 10:10/477/eaai8133. [PMID: 28465421 DOI: 10.1126/scisignal.aai8133] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Fragile X syndrome (FXS) is the most common cause of heritable intellectual disability and autism and affects ~1 in 4000 males and 1 in 8000 females. The discovery of effective treatments for FXS has been hampered by the lack of effective animal models and phenotypic readouts for drug screening. FXS ensues from the epigenetic silencing or loss-of-function mutation of the fragile X mental retardation 1 (FMR1) gene, which encodes an RNA binding protein that associates with and represses the translation of target mRNAs. We previously found that the activation of LIM kinase 1 (LIMK1) downstream of augmented synthesis of bone morphogenetic protein (BMP) type 2 receptor (BMPR2) promotes aberrant synaptic development in mouse and Drosophila models of FXS and that these molecular and cellular markers were correlated in patients with FXS. We report that larval locomotion is augmented in a Drosophila FXS model. Genetic or pharmacological intervention on the BMPR2-LIMK pathway ameliorated the synaptic abnormality and locomotion phenotypes of FXS larvae, as well as hyperactivity in an FXS mouse model. Our study demonstrates that (i) the BMPR2-LIMK pathway is a promising therapeutic target for FXS and (ii) the locomotion phenotype of FXS larvae is a quantitative functional readout for the neuromorphological phenotype associated with FXS and is amenable to the screening novel FXS therapeutics.
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Affiliation(s)
- Risa Kashima
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Patrick L Redmond
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Prajakta Ghatpande
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Sougata Roy
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA
| | - Thomas B Kornberg
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Thomas Hanke
- Institute of Pharmaceutical Chemistry and Buchmann Institute for Life Sciences, Goethe University, Frankfurt, Germany
| | - Stefan Knapp
- Institute of Pharmaceutical Chemistry and Buchmann Institute for Life Sciences, Goethe University, Frankfurt, Germany.,Department of Clinical Medicine, Structural Genomics Consortium, University of Oxford, Oxford OX3 7DQ, U.K
| | - Giorgio Lagna
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Akiko Hata
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158, USA.
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20
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Wang L, Almeida LEF, Nettleton M, Khaibullina A, Albani S, Kamimura S, Nouraie M, Quezado ZMN. Altered nocifensive behavior in animal models of autism spectrum disorder: The role of the nicotinic cholinergic system. Neuropharmacology 2016; 111:323-334. [PMID: 27638450 PMCID: PMC5075237 DOI: 10.1016/j.neuropharm.2016.09.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Revised: 08/21/2016] [Accepted: 09/12/2016] [Indexed: 02/05/2023]
Abstract
Caretakers and clinicians alike have long recognized that individuals with autism spectrum disorder (ASD) can have altered sensory processing, which can contribute to its core symptoms. However, the pathobiology of sensory alterations in ASD is poorly understood. Here we examined nocifensive behavior in ASD mouse models, the BTBR T+Itpr3tf/J (BTBR) and the fragile-X mental retardation-1 knockout (Fmr1-KO) mice. We also examined the effects of nicotine on nocifensive behavior given that nicotine, a nicotinic cholinergic receptor (nAChR) agonist that has antinociceptive effects, was shown to improve social deficits and decrease repetitive behaviors in BTBR mice. Compared to respective controls, both BTBR and Fmr1-KO had hyporesponsiveness to noxious thermal stimuli and electrical stimulation of C-sensory fibers, normal responsiveness to electrical stimulation of Aβ- and Aδ-fiber, and hyperresponsiveness to visceral pain after acetic acid intraperitoneal injection. In BTBR, nicotine at lower doses increased, whereas at higher doses, it decreased hotplate latency compared to vehicle. In a significantly different effect pattern, in control mice, nicotine had antinociceptive effects to noxious heat only at the high dose. Interestingly, these nocifensive behavior alterations and differential responses to nicotine antinociceptive effects in BTBR mice were associated with significant downregulation of α3, α4, α5, α7, β2, β3, and β4 nAChR subunits in several cerebral regions both, during embryonic development and adulthood. Taken together, these findings further implicate nAChRs in behaviors alterations in the BTBR model and lend support to the hypothesis that nAChRs may be a target for treatment of behavior deficits and sensory dysfunction in ASD.
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Affiliation(s)
- Li Wang
- The Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's Research Institute, Division of Anesthesiology, Pain and Perioperative Medicine, Children's National Health System, School of Medicine and Health Sciences, George Washington University, Washington, DC, 20010, USA
| | - Luis E F Almeida
- The Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's Research Institute, Division of Anesthesiology, Pain and Perioperative Medicine, Children's National Health System, School of Medicine and Health Sciences, George Washington University, Washington, DC, 20010, USA
| | - Margaret Nettleton
- The Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's Research Institute, Division of Anesthesiology, Pain and Perioperative Medicine, Children's National Health System, School of Medicine and Health Sciences, George Washington University, Washington, DC, 20010, USA
| | - Alfia Khaibullina
- The Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's Research Institute, Division of Anesthesiology, Pain and Perioperative Medicine, Children's National Health System, School of Medicine and Health Sciences, George Washington University, Washington, DC, 20010, USA
| | - Sarah Albani
- The Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's Research Institute, Division of Anesthesiology, Pain and Perioperative Medicine, Children's National Health System, School of Medicine and Health Sciences, George Washington University, Washington, DC, 20010, USA
| | - Sayuri Kamimura
- The Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's Research Institute, Division of Anesthesiology, Pain and Perioperative Medicine, Children's National Health System, School of Medicine and Health Sciences, George Washington University, Washington, DC, 20010, USA
| | - Mehdi Nouraie
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Zenaide M N Quezado
- The Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's Research Institute, Division of Anesthesiology, Pain and Perioperative Medicine, Children's National Health System, School of Medicine and Health Sciences, George Washington University, Washington, DC, 20010, USA; Center for Neuroscience Research, Children's Research Institute, Children's National Health System, School of Medicine and Health Sciences, George Washington University, Washington, DC, 20010, USA.
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21
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Arsenault J, Gholizadeh S, Niibori Y, Pacey LK, Halder SK, Koxhioni E, Konno A, Hirai H, Hampson DR. FMRP Expression Levels in Mouse Central Nervous System Neurons Determine Behavioral Phenotype. Hum Gene Ther 2016; 27:982-996. [PMID: 27604541 PMCID: PMC5178026 DOI: 10.1089/hum.2016.090] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Fragile X mental retardation protein (FMRP) is absent or highly reduced in Fragile X Syndrome, a genetic disorder causing cognitive impairment and autistic behaviors. Previous proof-of-principle studies have demonstrated that restoring FMRP in the brain using viral vectors can improve pathological abnormalities in mouse models of fragile X. However, unlike small molecule drugs where the dose can readily be adjusted during treatment, viral vector–based biological therapeutic drugs present challenges in terms of achieving optimal dosing and expression levels. The objective of this study was to investigate the consequences of expressing varying levels of FMRP selectively in neurons of Fmr1 knockout and wild-type (WT) mice. A wide range of neuronal FMRP transgene levels was achieved in individual mice after intra-cerebroventricular administration of adeno-associated viral vectors coding for FMRP. In all treated knockout mice, prominent FMRP transgene expression was observed in forebrain structures, whereas lower levels were present in more caudal regions of the brain. Reduced levels of the synaptic protein PSD-95, elevated levels of the transcriptional modulator MeCP2, and abnormal motor activity, anxiety, and acoustic startle responses in Fmr1 knockout mice were fully or partially rescued after expression of FMRP at about 35–115% of WT expression, depending on the brain region examined. In the WT mouse, moderate FMRP over-expression of up to about twofold had little or no effect on PSD-95 and MeCP2 levels or on behavioral endophenotypes. In contrast, excessive over-expression in the Fmr1 knockout mouse forebrain (approximately 2.5–6-fold over WT) induced pathological motor hyperactivity and suppressed the startle response relative to WT mice. These results delineate a range of FMRP expression levels in the central nervous system that confer phenotypic improvement in fragile X mice. Collectively, these findings are pertinent to the development of long-term curative gene therapy strategies for treating Fragile X Syndrome and other neurodevelopmental disorders.
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Affiliation(s)
- Jason Arsenault
- 1 Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
| | - Shervin Gholizadeh
- 1 Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
| | - Yosuke Niibori
- 1 Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
| | - Laura K Pacey
- 1 Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
| | - Sebok K Halder
- 1 Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
| | - Enea Koxhioni
- 1 Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
| | - Ayumu Konno
- 2 Department of Neurophysiology and Neural Repair, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Hirokazu Hirai
- 2 Department of Neurophysiology and Neural Repair, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - David R Hampson
- 1 Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada.,3 Department of Pharmacology, Faculty of Medicine, University of Toronto , Toronto, Ontario, Canada
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Abstract
The aims of this study were to investigate behaviour relevant to human autism spectrum disorder (ASD) and the fragile X syndrome in adolescent Fmr1 knockout (KO) mice and to evaluate the tissue levels of striatal monoamines. Fmr1 KO mice were evaluated in the open field, marble burying and three-chamber test for the presence of hyperactivity, anxiety, repetitive behaviour, sociability and observation of social novelty compared with wild-type (WT) mice. The Fmr1 KO mice expressed anxiety and hyperactivity in the open field compared with WT mice. This increased level of hyperactivity was confirmed in the three-chamber test. Fmr1 KO mice spent more time with stranger mice compared with the WT. However, after a correction for hyperactivity, their apparent increase in sociability became identical to that of the WT. Furthermore, the Fmr1 KO mice could not differentiate between a familiar or a novel mouse. Monoamines were measured by HPLC: Fmr1 KO mice showed an increase in the striatal dopamine level. We conclude that the fragile X syndrome model seems to be useful for understanding certain aspects of ASD and may have translational interest for studies of social behaviour when hyperactivity coexists in ASD patients.
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Normal Performance of Fmr1 Mice on a Touchscreen Delayed Nonmatching to Position Working Memory Task. eNeuro 2016; 3:eN-CFN-0143-15. [PMID: 27022628 PMCID: PMC4800045 DOI: 10.1523/eneuro.0143-15.2016] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 02/10/2016] [Accepted: 02/10/2016] [Indexed: 11/21/2022] Open
Abstract
Fragile X syndrome is a neurodevelopmental disorder characterized by mild-to-severe cognitive deficits. The complete absence of Fmr1 and its protein product in the mouse model of fragile X (Fmr1 KO) provides construct validity. A major conundrum in the field is the remarkably normal performance of Fmr1 mice on cognitive tests in most reports. One explanation may be insufficiently challenging cognitive testing procedures. Here we developed a delayed nonmatching to position touchscreen task to test the hypothesis that paradigms placing demands on working memory would reveal robust and replicable cognitive deficits in the Fmr1 KO mouse. We first tested Fmr1 KO mice (Fmr1) and their wild-type (WT) littermates in a simple visual discrimination task, followed by assessment of reversal learning. We then tested Fmr1 and WT mice in a new touchscreen nonmatch to position task and subsequently challenged their working memory abilities by adding delays, representing a higher cognitive load. The performance by Fmr1 KO mice was equal to WTs on both touchscreen tasks. Last, we replicated previous reports of normal performance by Fmr1 mice on Morris water maze spatial navigation and reversal. These results indicate that, while the Fmr1 mouse model effectively recapitulates many molecular and cellular aspects of fragile X syndrome, the cognitive profile of Fmr1 mice generally does not recapitulate the primary cognitive deficits in the human syndrome, even when diverse and challenging tasks are imposed.
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Kazdoba TM, Leach PT, Crawley JN. Behavioral phenotypes of genetic mouse models of autism. GENES, BRAIN, AND BEHAVIOR 2016; 15:7-26. [PMID: 26403076 PMCID: PMC4775274 DOI: 10.1111/gbb.12256] [Citation(s) in RCA: 119] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Revised: 08/27/2015] [Accepted: 09/18/2015] [Indexed: 12/11/2022]
Abstract
More than a hundred de novo single gene mutations and copy-number variants have been implicated in autism, each occurring in a small subset of cases. Mutant mouse models with syntenic mutations offer research tools to gain an understanding of the role of each gene in modulating biological and behavioral phenotypes relevant to autism. Knockout, knockin and transgenic mice incorporating risk gene mutations detected in autism spectrum disorder and comorbid neurodevelopmental disorders are now widely available. At present, autism spectrum disorder is diagnosed solely by behavioral criteria. We developed a constellation of mouse behavioral assays designed to maximize face validity to the types of social deficits and repetitive behaviors that are central to an autism diagnosis. Mouse behavioral assays for associated symptoms of autism, which include cognitive inflexibility, anxiety, hyperactivity, and unusual reactivity to sensory stimuli, are frequently included in the phenotypic analyses. Over the past 10 years, we and many other laboratories around the world have employed these and additional behavioral tests to phenotype a large number of mutant mouse models of autism. In this review, we highlight mouse models with mutations in genes that have been identified as risk genes for autism, which work through synaptic mechanisms and through the mTOR signaling pathway. Robust, replicated autism-relevant behavioral outcomes in a genetic mouse model lend credence to a causal role for specific gene contributions and downstream biological mechanisms in the etiology of autism.
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Affiliation(s)
- T. M. Kazdoba
- MIND Institute, Department of Psychiatry and Behavioral Sciences, University of California Davis School of Medicine, Sacramento, CA, USA
| | - P. T. Leach
- MIND Institute, Department of Psychiatry and Behavioral Sciences, University of California Davis School of Medicine, Sacramento, CA, USA
| | - J. N. Crawley
- MIND Institute, Department of Psychiatry and Behavioral Sciences, University of California Davis School of Medicine, Sacramento, CA, USA
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Sastre A, Campillo NE, Gil C, Martinez A. Therapeutic approaches for the future treatment of Fragile X. Curr Opin Behav Sci 2015. [DOI: 10.1016/j.cobeha.2015.01.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Gross C, Hoffmann A, Bassell GJ, Berry-Kravis EM. Therapeutic Strategies in Fragile X Syndrome: From Bench to Bedside and Back. Neurotherapeutics 2015; 12:584-608. [PMID: 25986746 PMCID: PMC4489963 DOI: 10.1007/s13311-015-0355-9] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Fragile X syndrome (FXS), an inherited intellectual disability often associated with autism, is caused by the loss of expression of the fragile X mental retardation protein. Tremendous progress in basic, preclinical, and translational clinical research has elucidated a variety of molecular-, cellular-, and system-level defects in FXS. This has led to the development of several promising therapeutic strategies, some of which have been tested in larger-scale controlled clinical trials. Here, we will summarize recent advances in understanding molecular functions of fragile X mental retardation protein beyond the well-known role as an mRNA-binding protein, and will describe current developments and emerging limitations in the use of the FXS mouse model as a preclinical tool to identify therapeutic targets. We will review the results of recent clinical trials conducted in FXS that were based on some of the preclinical findings, and discuss how the observed outcomes and obstacles will inform future therapy development in FXS and other autism spectrum disorders.
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Affiliation(s)
- Christina Gross
- />Division of Neurology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229 USA
| | - Anne Hoffmann
- />Department of Pediatrics, Rush University Medical Center, Chicago, IL 60612 USA
| | - Gary J. Bassell
- />Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322 USA
| | - Elizabeth M. Berry-Kravis
- />Departments of Pediatrics, Neurological Sciences, Biochemistry, Rush University Medical Center, Chicago, IL 60612 USA
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Schaefer TL, Davenport MH, Erickson CA. Emerging pharmacologic treatment options for fragile X syndrome. APPLICATION OF CLINICAL GENETICS 2015; 8:75-93. [PMID: 25897255 PMCID: PMC4396424 DOI: 10.2147/tacg.s35673] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Fragile X syndrome (FXS) is the most common single gene cause of intellectual disability and autism spectrum disorder. Caused by a silenced fragile X mental retardation 1 gene and the subsequent deficiency in fragile X mental retardation protein, patients with FXS experience a range of physical, behavioral, and intellectual debilitations. The FXS field, as a whole, has recently met with some challenges, as several targeted clinical trials with high expectations of success have failed to elucidate significant improvements in a variety of symptom domains. As new clinical trials in FXS are planned, there has been much discussion about the use of the commonly used clinical outcome measures, as well as study design considerations, patient stratification, and optimal age range for treatment. The evidence that modification of these drug targets and use of these failed compounds would prove to be efficacious in human clinical study were rooted in years of basic and translational research. There are questions arising as to the use of the mouse models for studying FXS treatment development. This issue is twofold: many of the symptom domains and molecular and biochemical changes assessed and indicative of efficacy in mouse model study are not easily amenable to clinical trials in people with FXS because of the intolerability of the testing paradigm or a lack of noninvasive techniques (prepulse inhibition, sensory hypersensitivity, startle reactivity, or electrophysiologic, biochemical, or structural changes in the brain); and capturing subtle yet meaningful changes in symptom domains such as sociability, anxiety, and hyperactivity in human FXS clinical trials is challenging with the currently used measures (typically parent/caregiver rating scales). Clinicians, researchers, and the pharmaceutical industry have all had to take a step back and critically evaluate the way we think about how to best optimize future investigations into pharmacologic FXS treatments. As new clinical trials are coming down the drug discovery pipeline, it is clear that the field is moving in a direction that values the development of molecular biomarkers, less subjective quantitative measures of symptom improvement, and rating scales developed specifically for use in FXS in conjunction with drug safety. While summarizing preclinical evidence, where applicable, and discussing challenges in FXS treatment development, this review details both completed clinical trials for the targeted and symptomatic treatment of FXS and introduces novel projects on the cusp of clinical trial investigation.
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Affiliation(s)
- Tori L Schaefer
- Division of Child and Adolescent Psychiatry, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Matthew H Davenport
- Division of Child and Adolescent Psychiatry, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Craig A Erickson
- Division of Child and Adolescent Psychiatry, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
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Wang H, Pati S, Pozzo-Miller L, Doering LC. Targeted pharmacological treatment of autism spectrum disorders: fragile X and Rett syndromes. Front Cell Neurosci 2015; 9:55. [PMID: 25767435 PMCID: PMC4341567 DOI: 10.3389/fncel.2015.00055] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2015] [Accepted: 02/05/2015] [Indexed: 12/27/2022] Open
Abstract
Autism spectrum disorders (ASDs) are genetically and clinically heterogeneous and lack effective medications to treat their core symptoms. Studies of syndromic ASDs caused by single gene mutations have provided insights into the pathophysiology of autism. Fragile X and Rett syndromes belong to the syndromic ASDs in which preclinical studies have identified rational targets for drug therapies focused on correcting underlying neural dysfunction. These preclinical discoveries are increasingly translating into exciting human clinical trials. Since there are significant molecular and neurobiological overlaps among ASDs, targeted treatments developed for fragile X and Rett syndromes may be helpful for autism of different etiologies. Here, we review the targeted pharmacological treatment of fragile X and Rett syndromes and discuss related issues in both preclinical studies and clinical trials of potential therapies for the diseases.
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Affiliation(s)
- Hansen Wang
- Faculty of Medicine, University of Toronto, 1 King's College Circle Toronto, ON, Canada
| | - Sandipan Pati
- Department of Neurology, Epilepsy Division, The University of Alabama at Birmingham Birmingham, AL, USA
| | - Lucas Pozzo-Miller
- Department of Neurobiology, Civitan International Research Center, The University of Alabama at Birmingham Birmingham, AL, USA
| | - Laurie C Doering
- Faculty of Health Sciences, Department of Pathology and Molecular Medicine, McMaster University Hamilton, ON, Canada
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Roubertoux PL, Carlier M, Tordjman S. Deficit in Social Relationships and Reduced Field of Interest in Mice. ORGANISM MODELS OF AUTISM SPECTRUM DISORDERS 2015. [DOI: 10.1007/978-1-4939-2250-5_14] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Braat S, D'Hulst C, Heulens I, De Rubeis S, Mientjes E, Nelson DL, Willemsen R, Bagni C, Van Dam D, De Deyn PP, Kooy RF. The GABAA receptor is an FMRP target with therapeutic potential in fragile X syndrome. Cell Cycle 2015; 14:2985-95. [PMID: 25790165 PMCID: PMC4827888 DOI: 10.4161/15384101.2014.989114] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Accepted: 04/11/2015] [Indexed: 01/08/2023] Open
Abstract
Previous research indicates that the GABAAergic system is involved in the pathophysiology of the fragile X syndrome, a frequent form of inherited intellectual disability and associated with autism spectrum disorder. However, the molecular mechanism underlying GABAAergic deficits has remained largely unknown. Here, we demonstrate reduced mRNA expression of GABAA receptor subunits in the cortex and cerebellum of young Fmr1 knockout mice. In addition, we show that the previously reported underexpression of specific subunits of the GABAA receptor can be corrected in YAC transgenic rescue mice, containing the full-length human FMR1 gene in an Fmr1 knockout background. Moreover, we demonstrate that FMRP directly binds several GABAA receptor mRNAs. Finally, positive allosteric modulation of GABAA receptors with the neurosteroid ganaxolone can modulate specific behaviors in Fmr1 knockout mice, emphasizing the therapeutic potential of the receptor.
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Affiliation(s)
- Sien Braat
- Department of Medical Genetics; University of Antwerp; Antwerp, Belgium
| | - Charlotte D'Hulst
- Department of Medical Genetics; University of Antwerp; Antwerp, Belgium
- Present address: Department of Biological Sciences; Hunter College; City University of New York; New York, NY USA
| | - Inge Heulens
- Department of Medical Genetics; University of Antwerp; Antwerp, Belgium
| | - Silvia De Rubeis
- VIB Department of Molecular and Developmental Genetics; Molecular Neurobiology; Catholic University Leuven; Leuven, Belgium
- Present address: Seaver Autism Centre for Research and Treatment; Icahn School of Medicine at Mount Sinai; New York, NY USA
| | - Edwin Mientjes
- Department of Clinical Genetics; Erasmus MC Rotterdam; Rotterdam, The Netherlands
| | - David L Nelson
- Department of Molecular and Human Genetics; Baylor College of Medicine; One Baylor Plaza; Houston, TX USA
| | - Rob Willemsen
- Department of Clinical Genetics; Erasmus MC Rotterdam; Rotterdam, The Netherlands
| | - Claudia Bagni
- VIB Department of Molecular and Developmental Genetics; Molecular Neurobiology; Catholic University Leuven; Leuven, Belgium
- Department of Biomedicine and Prevention; University of Rome Tor Vergata; Rome, Italy
| | - Debby Van Dam
- Laboratory of Neurochemistry and Behaviour; Institute Born-Bunge; Department of Biomedical Sciences; University of Antwerp; Antwerp, Belgium
| | - Peter P De Deyn
- Laboratory of Neurochemistry and Behaviour; Institute Born-Bunge; Department of Biomedical Sciences; University of Antwerp; Antwerp, Belgium
- Memory clinic; Department of Neurology; Middelheim General Hospital; ZNA; Antwerp, Belgium
- Department of Neurology and Alzheimer Research Centre; University Medical Centre; Groningen, The Netherlands
| | - R Frank Kooy
- Department of Medical Genetics; University of Antwerp; Antwerp, Belgium
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31
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Kazdoba TM, Leach PT, Silverman JL, Crawley JN. Modeling fragile X syndrome in the Fmr1 knockout mouse. Intractable Rare Dis Res 2014; 3:118-33. [PMID: 25606362 PMCID: PMC4298642 DOI: 10.5582/irdr.2014.01024] [Citation(s) in RCA: 168] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Accepted: 11/28/2014] [Indexed: 11/05/2022] Open
Abstract
Fragile X Syndrome (FXS) is a commonly inherited form of intellectual disability and one of the leading genetic causes for autism spectrum disorder. Clinical symptoms of FXS can include impaired cognition, anxiety, hyperactivity, social phobia, and repetitive behaviors. FXS is caused by a CGG repeat mutation which expands a region on the X chromosome containing the FMR1 gene. In FXS, a full mutation (> 200 repeats) leads to hypermethylation of FMR1, an epigenetic mechanism that effectively silences FMR1 gene expression and reduces levels of the FMR1 gene product, fragile X mental retardation protein (FMRP). FMRP is an RNA-binding protein that is important for the regulation of protein expression. In an effort to further understand how loss of FMR1 and FMRP contribute to FXS symptomology, several FXS animal models have been created. The most well characterized rodent model is the Fmr1 knockout (KO) mouse, which lacks FMRP protein due to a disruption in its Fmr1 gene. Here, we review the behavioral phenotyping of the Fmr1 KO mouse to date, and discuss the clinical relevance of this mouse model to the human FXS condition. While much remains to be learned about FXS, the Fmr1 KO mouse is a valuable tool for understanding the repercussions of functional loss of FMRP and assessing the efficacy of pharmacological compounds in ameliorating the molecular and behavioral phenotypes relevant to FXS.
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Affiliation(s)
- Tatiana M. Kazdoba
- MIND Institute, Department of Psychiatry and Behavioral Sciences, University of California, Davis, School of Medicine, Sacramento, CA, USA
- Address correspondence to: Dr. Tatiana M. Kazdoba, MIND Institute, Department of Psychiatry and Behavioral Sciences, University of California, Davis, School of Medicine, Sacramento, Research II Building 96, 4625 2nd Avenue, Sacramento, CA 95817, USA. E-mail:
| | - Prescott T. Leach
- MIND Institute, Department of Psychiatry and Behavioral Sciences, University of California, Davis, School of Medicine, Sacramento, CA, USA
| | - Jill L. Silverman
- MIND Institute, Department of Psychiatry and Behavioral Sciences, University of California, Davis, School of Medicine, Sacramento, CA, USA
| | - Jacqueline N. Crawley
- MIND Institute, Department of Psychiatry and Behavioral Sciences, University of California, Davis, School of Medicine, Sacramento, CA, USA
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Santos AR, Kanellopoulos AK, Bagni C. Learning and behavioral deficits associated with the absence of the fragile X mental retardation protein: what a fly and mouse model can teach us. ACTA ACUST UNITED AC 2014; 21:543-55. [PMID: 25227249 PMCID: PMC4175497 DOI: 10.1101/lm.035956.114] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The Fragile X syndrome (FXS) is the most frequent form of inherited mental disability and is considered a monogenic cause of autism spectrum disorder. FXS is caused by a triplet expansion that inhibits the expression of the FMR1 gene. The gene product, the Fragile X Mental Retardation Protein (FMRP), regulates mRNA metabolism in brain and nonneuronal cells. During brain development, FMRP controls the expression of key molecules involved in receptor signaling, cytoskeleton remodeling, protein synthesis and, ultimately, spine morphology. Symptoms associated with FXS include neurodevelopmental delay, cognitive impairment, anxiety, hyperactivity, and autistic-like behavior. Twenty years ago the first Fmr1 KO mouse to study FXS was generated, and several years later other key models including the mutant Drosophila melanogaster, dFmr1, have further helped the understanding of the cellular and molecular causes behind this complex syndrome. Here, we review to which extent these biological models are affected by the absence of FMRP, pointing out the similarities with the observed human dysfunction. Additionally, we discuss several potential treatments under study in animal models that are able to partially revert some of the FXS abnormalities.
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Affiliation(s)
- Ana Rita Santos
- VIB Center for the Biology of Disease, 3000 Leuven, Belgium Center for Human Genetics, KU Leuven, 3000 Leuven, Belgium Leuven Institute for Neurodegenerative Diseases (LIND), KU Leuven, 3000 Leuven, Belgium
| | - Alexandros K Kanellopoulos
- VIB Center for the Biology of Disease, 3000 Leuven, Belgium Center for Human Genetics, KU Leuven, 3000 Leuven, Belgium Leuven Institute for Neurodegenerative Diseases (LIND), KU Leuven, 3000 Leuven, Belgium
| | - Claudia Bagni
- VIB Center for the Biology of Disease, 3000 Leuven, Belgium Center for Human Genetics, KU Leuven, 3000 Leuven, Belgium Leuven Institute for Neurodegenerative Diseases (LIND), KU Leuven, 3000 Leuven, Belgium Department of Biomedicine and Prevention, University of Rome "Tor Vergata" 00133, Rome, Italy
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Ding Q, Sethna F, Wang H. Behavioral analysis of male and female Fmr1 knockout mice on C57BL/6 background. Behav Brain Res 2014; 271:72-8. [PMID: 24886775 DOI: 10.1016/j.bbr.2014.05.046] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2013] [Revised: 05/20/2014] [Accepted: 05/22/2014] [Indexed: 11/17/2022]
Abstract
Fragile X syndrome (FXS) is a monogenic disease caused by mutations in the FMR1 gene. The Fmr1 knockout (KO) mice show many aspects of FXS-related phenotypes, and have been used as a major pre-clinical model for FXS. Although FXS occurs in both male and female patients, most studies on the mouse model use male animals. Few studies test whether gender affects the face validity of the mouse model. Here, we examined multiple behavioral phenotypes with male hemizygous and female homozygous Fmr1 KO mice on C57BL/6 background. For each behavioral paradigm, we examined multiple cohorts from different litters. We found that both male and female Fmr1 KO mice displayed significant audiogenic seizures, hyperactivity in the open field test, deficits in passive avoidance and contextual fear memory, and significant enhancement of PPI at low stimulus intensity. Male and female Fmr1 KO mice also showed more transitional movement between the lit and dark chambers in the light-dark tests. The lack of gender effects suggests that the Fmr1 KO mouse is a reasonable tool to test the efficacy of potential FXS therapies.
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Affiliation(s)
- Qi Ding
- Department of Physiology, Michigan State University, East Lansing, MI 48824, USA
| | - Ferzin Sethna
- Genetics Program, Michigan State University, East Lansing, MI 48824, USA
| | - Hongbing Wang
- Department of Physiology, Michigan State University, East Lansing, MI 48824, USA; Neuroscience Program, Michigan State University, East Lansing, MI 48824, USA.
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Sawin EA, Murali SG, Ney DM. Differential effects of low-phenylalanine protein sources on brain neurotransmitters and behavior in C57Bl/6-Pah(enu2) mice. Mol Genet Metab 2014; 111:452-61. [PMID: 24560888 PMCID: PMC3995025 DOI: 10.1016/j.ymgme.2014.01.015] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Accepted: 01/30/2014] [Indexed: 11/24/2022]
Abstract
Phenylketonuria (PKU) is an inborn error of metabolism caused by a deficiency of the enzyme phenylalanine hydroxylase, which metabolizes phenylalanine (phe) to tyrosine. A low-phe diet plus amino acid (AA) formula is necessary to prevent cognitive impairment; glycomacropeptide (GMP) contains minimal phe and provides a palatable alternative to the AA formula. Our objective was to assess neurotransmitter concentrations in the brain and the behavioral phenotype of PKU mice (Pah(enu2) on the C57Bl/6 background) and how this is affected by low-phe protein sources. Wild type (WT) and PKU mice, both male and female, were fed high-phe casein, low-phe AA, or low-phe GMP diets between 3 and 18 weeks of age. Behavioral phenotype was assessed using the open field and marble burying tests, and brain neurotransmitter concentrations were measured using HPLC with electrochemical detection system. Data were analyzed by 3-way ANOVA with genotype, sex, and diet as the main treatment effects. Brain mass and the concentrations of catecholamines and serotonin were reduced in PKU mice compared to WT mice; the low-phe AA and GMP diets improved these parameters in PKU mice. Relative brain mass was increased in female PKU mice fed the GMP diet compared to the AA diet. PKU mice exhibited hyperactivity and impaired vertical exploration compared to their WT littermates during the open field test. Regardless of genotype or diet, female mice demonstrated increased vertical activity time and increased total ambulatory and horizontal activity counts compared with male mice. PKU mice fed the high-phe casein diet buried significantly fewer marbles than WT control mice fed casein; this was normalized in PKU mice fed the low-phe AA and GMP diets. In summary, C57Bl/6-Pah(enu2) mice showed an impaired behavioral phenotype and reduced brain neurotransmitter concentrations that were improved by the low-phe AA or GMP diets. These data support lifelong adherence to a low-phe diet for PKU.
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Affiliation(s)
- Emily A Sawin
- Department of Nutritional Sciences, University of Wisconsin-Madison, WI 53706, USA.
| | - Sangita G Murali
- Department of Nutritional Sciences, University of Wisconsin-Madison, WI 53706, USA.
| | - Denise M Ney
- Department of Nutritional Sciences, University of Wisconsin-Madison, WI 53706, USA.
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35
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Impaired sensorimotor gating in Fmr1 knock out and Fragile X premutation model mice. Behav Brain Res 2014; 267:42-5. [PMID: 24657592 DOI: 10.1016/j.bbr.2014.03.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Revised: 03/04/2014] [Accepted: 03/11/2014] [Indexed: 01/20/2023]
Abstract
Fragile X syndrome (FXS) is a common inherited cause of intellectual disability that results from a CGG repeat expansion in the FMR1 gene. Large repeat expansions trigger both transcriptional and translational suppression of Fragile X protein (FMRP) production. Fragile X-associated Tremor/Ataxia Syndrome (FXTAS) is an allelic neurodegenerative disease caused by smaller "pre-mutation" CGG repeat expansions that enhance FMR1 transcription but lead to translational inefficiency and reduced FMRP expression in animal models. Sensorimotor gating as measured by pre-pulse inhibition (PPI) is altered in both FXS patients and Fmr1 knock out (KO) mice. Similarly, FXTAS patients have demonstrated PPI deficits. Recent work suggests there may be overlapping synaptic defects between Fmr1 KO and CGG knock-in premutation mouse models (CGG KI). We therefore sought to interrogate PPI in CGG KI mice. Using a quiet PPI protocol more akin to human testing conditions, we find that Fmr1 KO animals have significantly impaired PPI. Using this same protocol, we find CGG KI mice demonstrate an age-dependent impairment in PPI compared to wild type (WT) controls. This study describes a novel phenotype in CGG KI mice that can be used in future therapeutic development targeting premutation associated symptoms.
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Braat S, Kooy RF. Fragile X syndrome neurobiology translates into rational therapy. Drug Discov Today 2014; 19:510-9. [PMID: 24508819 DOI: 10.1016/j.drudis.2014.01.013] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Revised: 01/19/2014] [Accepted: 01/27/2014] [Indexed: 12/29/2022]
Abstract
Causal genetic defects have been identified for various neurodevelopmental disorders. A key example in this respect is fragile X syndrome, one of the most frequent genetic causes of intellectual disability and autism. Since the discovery of the causal gene, insights into the underlying pathophysiological mechanisms have increased exponentially. Over the past years, defects were discovered in pathways that are potentially amendable by pharmacological treatment. These findings have inspired the initiation of clinical trials in patients. The targeted pathways converge in part with those of related neurodevelopmental disorders raising hopes that the treatments developed for this specific disorder might be more broadly applicable.
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Affiliation(s)
- Sien Braat
- Department of Medical Genetics, University of Antwerp, Prins Boudewijnlaan 43, Antwerp, Belgium
| | - R Frank Kooy
- Department of Medical Genetics, University of Antwerp, Prins Boudewijnlaan 43, Antwerp, Belgium.
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Sethna F, Moon C, Wang H. From FMRP function to potential therapies for fragile X syndrome. Neurochem Res 2013; 39:1016-31. [PMID: 24346713 DOI: 10.1007/s11064-013-1229-3] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Revised: 12/03/2013] [Accepted: 12/12/2013] [Indexed: 12/12/2022]
Abstract
Fragile X syndrome (FXS) is caused by mutations in the fragile X mental retardation 1 (FMR1) gene. Most FXS cases occur due to the expansion of the CGG trinucleotide repeats in the 5' un-translated region of FMR1, which leads to hypermethylation and in turn silences the expression of FMRP (fragile X mental retardation protein). Numerous studies have demonstrated that FMRP interacts with both coding and non-coding RNAs and represses protein synthesis at dendritic and synaptic locations. In the absence of FMRP, the basal protein translation is enhanced and not responsive to neuronal stimulation. The altered protein translation may contribute to functional abnormalities in certain aspects of synaptic plasticity and intracellular signaling triggered by Gq-coupled receptors. This review focuses on the current understanding of FMRP function and potential therapeutic strategies that are mainly based on the manipulation of FMRP targets and knowledge gained from FXS pathophysiology.
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Affiliation(s)
- Ferzin Sethna
- Genetics Program, Michigan State University, East Lansing, MI, 48824, USA
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Henderson C, Wijetunge L, Kinoshita MN, Shumway M, Hammond RS, Postma FR, Brynczka C, Rush R, Thomas A, Paylor R, Warren ST, Vanderklish PW, Kind PC, Carpenter RL, Bear MF, Healy AM. Reversal of disease-related pathologies in the fragile X mouse model by selective activation of GABAB receptors with arbaclofen. Sci Transl Med 2013; 4:152ra128. [PMID: 22993295 DOI: 10.1126/scitranslmed.3004218] [Citation(s) in RCA: 189] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Fragile X syndrome (FXS), the most common inherited cause of intellectual disability and autism, results from the transcriptional silencing of FMR1 and loss of the mRNA translational repressor protein fragile X mental retardation protein (FMRP). Patients with FXS exhibit changes in neuronal dendritic spine morphology, a pathology associated with altered synaptic function. Studies in the mouse model of fragile X have shown that loss of FMRP causes excessive synaptic protein synthesis, which results in synaptic dysfunction and altered spine morphology. We tested whether the pharmacologic activation of the γ-aminobutyric acid type B (GABA(B)) receptor could correct or reverse these phenotypes in Fmr1-knockout mice. Basal protein synthesis, which is elevated in the hippocampus of Fmr1-knockout mice, was corrected by the in vitro application of the selective GABA(B) receptor agonist STX209 (arbaclofen, R-baclofen). STX209 also reduced to wild-type values the elevated AMPA receptor internalization in Fmr1-knockout cultured neurons, a known functional consequence of increased protein synthesis. Acute administration of STX209 in vivo, at doses that modify behavior, decreased mRNA translation in the cortex of Fmr1-knockout mice. Finally, the chronic administration of STX209 in juvenile mice corrected the increased spine density in Fmr1-knockout mice without affecting spine density in wild-type mice. Thus, activation of the GABA(B) receptor with STX209 corrected synaptic abnormalities considered central to fragile X pathophysiology, a finding that suggests that STX209 may be a potentially effective therapy to treat the core symptoms of FXS.
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Progress toward treatments for synaptic defects in autism. Nat Med 2013; 19:685-94. [PMID: 23744158 DOI: 10.1038/nm.3193] [Citation(s) in RCA: 134] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Accepted: 04/11/2013] [Indexed: 12/11/2022]
Abstract
Autism spectrum disorder (ASD) encompasses a range of disorders that are characterized by social and communication deficits and repetitive behaviors. For the majority of affected individuals, the cause of ASD remains unknown, but in at least 20% of the cases, a genetic cause can be identified. There is currently no cure for ASD; however, results from mouse models indicate that some forms of the disorder could be alleviated even at the adult stage. Genes involved in ASD seem to converge on common pathways altering synaptic homeostasis. We propose, given the clinical heterogeneity of ASD, that specific 'synaptic clinical trials' should be designed and launched with the aim of establishing whether phenotype 'reversals' could also occur in humans.
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