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Neul JL. Challenges in developing therapies in fragile X syndrome: how the FXLEARN trial can guide research. J Clin Invest 2024; 134:e175036. [PMID: 38426491 PMCID: PMC10904042 DOI: 10.1172/jci175036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2024] Open
Abstract
Fragile X syndrome (FXS), the most common inherited cause of intellectual disability and the single-gene cause of autism, is caused by decreased expression of the fragile X messenger ribonucleoprotein protein (FMRP), a ribosomal-associated RNA-binding protein involved in translational repression. Extensive preclinical work in several FXS animal models supported the therapeutic potential of decreasing metabotropic glutamate receptor (mGluR) signaling to correct translation of proteins related to synaptic plasticity; however, multiple clinical trials failed to show conclusive evidence of efficacy. In this issue of the JCI, Berry-Kravis and colleagues conducted the FXLEARN clinical trial to address experimental design concerns from previous trials. Unfortunately, despite treatment of young children with combined pharmacological and learning interventions for a prolonged period, no efficacy of blocking mGluR activity was observed. Future systematic evaluation of potential therapeutic approaches should evaluate consistency between human and animal pathophysiological mechanisms, utilize innovative clinical trial design from FXLEARN, and incorporate translatable biomarkers.
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Berry-Kravis E, Abbeduto L, Hagerman R, Coffey CS, Cudkowicz M, Erickson CA, McDuffie A, Hessl D, Ethridge L, Tassone F, Kaufmann WE, Friedmann K, Bullard L, Hoffmann A, Veenstra-VanderWeele J, Staley K, Klements D, Moshinsky M, Harkey B, Long J, Fedler J, Klingner E, Ecklund D, Costigan M, Huff T, Pearson B. Effects of AFQ056 on language learning in fragile X syndrome. J Clin Invest 2023; 134:e171723. [PMID: 37651202 PMCID: PMC10904045 DOI: 10.1172/jci171723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Accepted: 08/22/2023] [Indexed: 09/02/2023] Open
Abstract
BACKGROUNDFXLEARN, the first-ever large multisite trial of effects of disease-targeted pharmacotherapy on learning, was designed to explore a paradigm for measuring effects of mechanism-targeted treatment in fragile X syndrome (FXS). In FXLEARN, the effects of metabotropic glutamate receptor type 5 (mGluR5) negative allosteric modulator (NAM) AFQ056 on language learning were evaluated in 3- to 6-year-old children with FXS, expected to have more learning plasticity than adults, for whom prior trials of mGluR5 NAMs have failed.METHODSAfter a 4-month single-blind placebo lead-in, participants were randomized 1:1 to AFQ056 or placebo, with 2 months of dose optimization to the maximum tolerated dose, then 6 months of treatment during which a language-learning intervention was implemented for both groups. The primary outcome was a centrally scored videotaped communication measure, the Weighted Communication Scale (WCS). Secondary outcomes were objective performance-based and parent-reported cognitive and language measures.RESULTSFXLEARN enrolled 110 participants, randomized 99, and had 91 who completed the placebo-controlled period. Although both groups made language progress and there were no safety issues, the change in WCS score during the placebo-controlled period was not significantly different between the AFQ056 and placebo-treated groups, nor were there any significant between-group differences in change in any secondary measures.CONCLUSIONDespite the large body of evidence supporting use of mGluR5 NAMs in animal models of FXS, this study suggests that this mechanism of action does not translate into benefit for the human FXS population and that better strategies are needed to determine which mechanisms will translate from preclinical models to humans in genetic neurodevelopmental disorders.TRIAL REGISTRATIONClincalTrials.gov NCT02920892.FUNDING SOURCESNeuroNEXT network NIH grants U01NS096767, U24NS107200, U24NS107209, U01NS077323, U24NS107183, U24NS107168, U24NS107128, U24NS107199, U24NS107198, U24NS107166, U10NS077368, U01NS077366, U24NS107205, U01NS077179, and U01NS077352; NIH grant P50HD103526; and Novartis IIT grant AFQ056X2201T for provision of AFQ056.
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Affiliation(s)
- Elizabeth Berry-Kravis
- Departments of Pediatrics, Neurological Sciences, and Anatomy & Cell Biology, Rush University Medical Center, Chicago, Illinois, USA
| | - Leonard Abbeduto
- MIND Institute and Department of Psychiatry and Behavioral Sciences and
| | - Randi Hagerman
- MIND Institute and Department of Pediatrics, UCD, Sacramento, California, USA
| | | | - Merit Cudkowicz
- Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Craig A. Erickson
- Division of Child and Adolescent Psychiatry, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA
| | - Andrea McDuffie
- MIND Institute and Department of Psychiatry and Behavioral Sciences and
| | - David Hessl
- MIND Institute and Department of Psychiatry and Behavioral Sciences and
| | - Lauren Ethridge
- Department of Psychology, University of Oklahoma, Norman, Oklahoma, and Department of Pediatrics, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - Flora Tassone
- MIND Institute and Department of Biochemistry and Molecular Medicine, UCD, Sacramento, California, USA
| | - Walter E. Kaufmann
- Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia, USA
| | | | - Lauren Bullard
- MIND Institute and Department of Psychiatry and Behavioral Sciences and
| | - Anne Hoffmann
- Departments of Pediatrics and Communication Disorders and Sciences, Rush University Medical Center, Chicago, Illinois, USA
| | - Jeremy Veenstra-VanderWeele
- Department of Psychiatry, Columbia University, and New York State Psychiatric Institute, New York, New York, USA
| | - Kevin Staley
- Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - David Klements
- Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Michael Moshinsky
- Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Brittney Harkey
- Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Jeff Long
- Department of Biostatistics, University of Iowa, Iowa City, Iowa, USA
| | - Janel Fedler
- Department of Biostatistics, University of Iowa, Iowa City, Iowa, USA
| | | | - Dixie Ecklund
- Department of Biostatistics, University of Iowa, Iowa City, Iowa, USA
| | - Michele Costigan
- Department of Biostatistics, University of Iowa, Iowa City, Iowa, USA
| | - Trevis Huff
- Department of Biostatistics, University of Iowa, Iowa City, Iowa, USA
| | - Brenda Pearson
- Department of Biostatistics, University of Iowa, Iowa City, Iowa, USA
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Dupont AC, Arlicot N, Vercouillie J, Serrière S, Maia S, Bonnet-Brilhault F, Santiago-Ribeiro MJ. Metabotropic Glutamate Receptor Subtype 5 Positron-Emission-Tomography Radioligands as a Tool for Central Nervous System Drug Development: Between Progress and Setbacks. Pharmaceuticals (Basel) 2023; 16:1127. [PMID: 37631042 PMCID: PMC10458693 DOI: 10.3390/ph16081127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 08/03/2023] [Accepted: 08/09/2023] [Indexed: 08/27/2023] Open
Abstract
The metabotropic glutamate receptor subtype 5 (mGluR5) is a class C G-protein-coupled receptor (GPCR) that has been implicated in various neuronal processes and, consequently, in several neuropsychiatric or neurodevelopmental disorders. Over the past few decades, mGluR5 has become a major focus for pharmaceutical companies, as an attractive target for drug development, particularly through the therapeutic potential of its modulators. In particular, allosteric binding sites have been targeted for better specificity and efficacy. In this context, Positron Emission Tomography (PET) appears as a useful tool for making decisions along a drug candidate's development process, saving time and money. Thus, PET provides quantitative information about a potential drug candidate and its target at the molecular level. However, in this area, particular attention has to be given to the interpretation of the PET signal and its conclusions. Indeed, the complex pharmacology of both mGluR5 and radioligands, allosterism, the influence of endogenous glutamate and the choice of pharmacokinetic model are all factors that may influence the PET signal. This review focuses on mGluR5 PET radioligands used at several stages of central nervous system drug development, highlighting advances and setbacks related to the complex pharmacology of these radiotracers.
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Affiliation(s)
- Anne-Claire Dupont
- Radiopharmacie, CHRU de Tours, 37000 Tours, France
- UMR 1253, iBrain, Tours University, INSERM, 37000 Tours, France
| | - Nicolas Arlicot
- Radiopharmacie, CHRU de Tours, 37000 Tours, France
- UMR 1253, iBrain, Tours University, INSERM, 37000 Tours, France
- CIC 1415, Tours University, INSERM, 37000 Tours, France
| | | | - Sophie Serrière
- UMR 1253, iBrain, Tours University, INSERM, 37000 Tours, France
| | - Serge Maia
- Radiopharmacie, CHRU de Tours, 37000 Tours, France
- UMR 1253, iBrain, Tours University, INSERM, 37000 Tours, France
| | - Frédérique Bonnet-Brilhault
- UMR 1253, iBrain, Tours University, INSERM, 37000 Tours, France
- Excellence Center for Autism and Neurodevelopmental Disorders, CHRU de Tours, 37000 Tours, France
| | - Maria-Joao Santiago-Ribeiro
- UMR 1253, iBrain, Tours University, INSERM, 37000 Tours, France
- Nuclear Medicine Department, CHRU de Tours, 37000 Tours, France
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Di Menna L, Orlando R, D'Errico G, Ginerete RP, Machaczka A, Bonaccorso CM, Arena A, Spatuzza M, Celli R, Alborghetti M, Ciocca E, Zuena AR, Scioli MR, Bruno V, Battaglia G, Nicoletti F, Catania MV. Blunted type-5 metabotropic glutamate receptor-mediated polyphosphoinositide hydrolysis in two mouse models of monogenic autism. Neuropharmacology 2023:109642. [PMID: 37392820 DOI: 10.1016/j.neuropharm.2023.109642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 06/06/2023] [Accepted: 06/20/2023] [Indexed: 07/03/2023]
Abstract
The involvement of the mGlu5 receptors in the pathophysiology of several forms of monogenic autism has been supported by numerous studies following the seminal observation that mGlu5 receptor-dependent long-term depression was enhanced in the hippocampus of mice modeling the fragile-X syndrome (FXS). Surprisingly, there are no studies examining the canonical signal transduction pathway activated by mGlu5 receptors (i.e. polyphosphoinositide - PI - hydrolysis) in mouse models of autism. We have developed a method for in vivo assessment of PI hydrolysis based on systemic injection of lithium chloride followed by treatment with the selective mGlu5 receptor PAM, VU0360172, and measurement of endogenous inositolmonophosphate (InsP) in brain tissue. Here, we report that mGlu5 receptor-mediated PI hydrolysis was blunted in the cerebral cortex, hippocampus, and corpus striatum of Ube3am-/p+ mice modeling Angelman syndrome (AS), and in the cerebral cortex and hippocampus of fmr1 knockout mice modeling FXS. In vivo mGlu5 receptor-mediated stimulation of Akt on threonine 308 was also blunted in the hippocampus of FXS mice. These changes were associated with a significant increase in cortical and striatal Homer1 levels and striatal mGlu5 receptor and Gαq levels in AS mice, and with a reduction in cortical mGlu5 receptor and hippocampal Gαq levels, and an increase in cortical phospholipase-Cβ and hippocampal Homer1 levels in FXS mice. This is the first evidence that the canonical transduction pathway activated by mGlu5 receptors is down-regulated in brain regions of mice modeling monogenic autism.
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Affiliation(s)
| | - Rosamaria Orlando
- IRCCS Neuromed, Pozzilli, Italy; Department of Physiology and Pharmacology, Sapienza University, Roma, Italy
| | | | | | - Agata Machaczka
- Department of Neurobiology, Maj Institute of Pharmacology, Polish Academy of Science, Krakow, Poland
| | | | | | | | | | - Marika Alborghetti
- Department of Neuroscience, Mental Health, and Sensory Organs, Sapienza University, Italy
| | - Eleonora Ciocca
- Department of Physiology and Pharmacology, Sapienza University, Roma, Italy
| | - Anna Rita Zuena
- Department of Physiology and Pharmacology, Sapienza University, Roma, Italy
| | | | - Valeria Bruno
- IRCCS Neuromed, Pozzilli, Italy; Department of Physiology and Pharmacology, Sapienza University, Roma, Italy
| | - Giuseppe Battaglia
- IRCCS Neuromed, Pozzilli, Italy; Department of Physiology and Pharmacology, Sapienza University, Roma, Italy
| | - Ferdinando Nicoletti
- IRCCS Neuromed, Pozzilli, Italy; Department of Physiology and Pharmacology, Sapienza University, Roma, Italy
| | - Maria Vincenza Catania
- Institute for Biomedical Research and Innovation, The National Research Council (IRIB-CNR), Catania, Italy.
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Carey C, Singh N, Dunn JT, Sementa T, Mendez MA, Velthuis H, Pereira AC, Pretzsch CM, Horder J, Hader S, Lythgoe DJ, Rotaru DG, Gee A, Cash D, Veronese M, Murphy D, McAlonan G. From bench to bedside: The mGluR5 system in people with and without Autism Spectrum Disorder and animal model systems. Transl Psychiatry 2022; 12:395. [PMID: 36127322 DOI: 10.1038/s41398-022-02143-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 08/19/2022] [Accepted: 09/01/2022] [Indexed: 11/08/2022] Open
Abstract
The metabotropic glutamate receptor 5 (mGluR5) is a key regulator of excitatory (E) glutamate and inhibitory (I) γ-amino butyric acid (GABA) signalling in the brain. Despite the close functional ties between mGluR5 and E/I signalling, no-one has directly examined the relationship between mGluR5 and glutamate or GABA in vivo in the human brain of autistic individuals. We measured [18F] FPEB (18F-3-fluoro-5-[(pyridin-3-yl)ethynyl]benzonitrile) binding in 15 adults (6 with Autism Spectrum Disorder) using two regions of interest, the left dorsomedial prefrontal cortex and a region primarily composed of left striatum and thalamus. These two regions were mapped out using MEGA-PRESS voxels and then superimposed on reconstructed PET images. This allowed for direct comparison between mGluR5, GABA + and Glx. To better understand the molecular underpinnings of our results we used an autoradiography study of mGluR5 in three mouse models associated with ASD: Cntnap2 knockout, Shank3 knockout, and 16p11.2 deletion. Autistic individuals had significantly higher [18F] FPEB binding (t (13) = -2.86, p = 0.047) in the left striatum/thalamus region of interest as compared to controls. Within this region, there was a strong negative correlation between GABA + and mGluR5 density across the entire cohort (Pearson's correlation: r (14) = -0.763, p = 0.002). Cntnap2 KO mice had significantly higher mGlu5 receptor binding in the striatum (caudate-putamen) as compared to wild-type (WT) mice (n = 15, p = 0.03). There were no differences in mGluR5 binding for mice with the Shank3 knockout or 16p11.2 deletion. Given that Cntnap2 is associated with a specific striatal deficit of parvalbumin positive GABA interneurons and 'autistic' features, our findings suggest that an increase in mGluR5 in ASD may relate to GABAergic interneuron abnormalities.
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Ardourel M, Pâris A, Felgerolle C, Lesne F, Ranchon-Cole I, Briault S, Perche O. FMRP-related retinal phenotypes: Evidence of glutamate-glutamine metabolic cycle impairment. Exp Eye Res 2022; 224:109238. [PMID: 36067823 DOI: 10.1016/j.exer.2022.109238] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 08/16/2022] [Accepted: 08/29/2022] [Indexed: 11/18/2022]
Abstract
FMRP, the fragile X mental retardation protein coded by the FMR1 gene, is an RNA-binding protein that assists transport, stabilization and translational regulation of specific synaptic mRNAs. Its expression has been found in multiple cell types of central nervous system (CNS) including glial cells where its involvement in glutamate neurotransmitter homeostasis have been shown. Indeed, glutamate homeostasis deficit has been observed in absence of FMRP in-vivo in cortex and hippocampus structures as well as in vitro on astroglial cell culture. Interestingly, the retina which is an extension of the CNS is presenting electrophysiological alterations in absence of FMRP in both human and murine models suggesting neurotransmitter impairments. Therefore, we investigate the consequences of Fmrp absence on Glutamate-Glutamine cycle in whole retinas and primary retinal Müller cells culture which are the main glial cells of the retina. Using the Fmr1-/y mice, we have shown in vivo and in vitro that the absence of Fmrp in Müller cells is characterized by loss of Glutamate-Glutamine cycle homeostasis due to a lower Glutamine Synthetase protein expression and activity. The lack of Fmrp in the retina induces a reduced flow of glutamine synthesis. Our data established for the first time in literature a direct link between the lack of Fmrp and neurotransmitter homeostasis in the retina.
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Affiliation(s)
- Maryvonne Ardourel
- UMR7355, CNRS, Orléans, France; Experimental and Molecular Immunology and Neurogenetics, University of Orléans, 3b rue de la Ferollerie, F-45071, Orléans Cedex 2, France
| | - Arnaud Pâris
- UMR7355, CNRS, Orléans, France; Experimental and Molecular Immunology and Neurogenetics, University of Orléans, 3b rue de la Ferollerie, F-45071, Orléans Cedex 2, France
| | - Chloé Felgerolle
- UMR7355, CNRS, Orléans, France; Experimental and Molecular Immunology and Neurogenetics, University of Orléans, 3b rue de la Ferollerie, F-45071, Orléans Cedex 2, France
| | - Fabien Lesne
- Genetic Department, Regional Hospital, 14 Avenue de l'hôpital, 45100, Orléans, France
| | - Isabelle Ranchon-Cole
- Université Clermont Auvergne, CHU Clermont-Ferrand, Inserm, Neuro-Dol, F-63000, Clermont-Ferrand, France
| | - Sylvain Briault
- Genetic Department, Regional Hospital, 14 Avenue de l'hôpital, 45100, Orléans, France; UMR7355, CNRS, Orléans, France; Experimental and Molecular Immunology and Neurogenetics, University of Orléans, 3b rue de la Ferollerie, F-45071, Orléans Cedex 2, France
| | - Olivier Perche
- Genetic Department, Regional Hospital, 14 Avenue de l'hôpital, 45100, Orléans, France; UMR7355, CNRS, Orléans, France; Experimental and Molecular Immunology and Neurogenetics, University of Orléans, 3b rue de la Ferollerie, F-45071, Orléans Cedex 2, France.
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Afshar S, Lule S, Yuan G, Qu X, Pan C, Whalen M, Brownell AL, Mody M. Longitudinal PET studies of mGluR5 in FXS using an FMR1 knockout mouse model. Transl Neurosci 2022; 13:80-92. [PMID: 35582646 PMCID: PMC9055256 DOI: 10.1515/tnsci-2022-0217] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 03/28/2022] [Accepted: 04/04/2022] [Indexed: 11/15/2022] Open
Abstract
Abstract
Fragile X syndrome (FXS) is a monogenic disorder characterized by intellectual disability and behavioral challenges. It is caused by aberrant methylation of the fragile X mental retardation 1 (FMR1) gene. Given the failure of clinical trials in FXS and growing evidence of a role of metabotropic glutamate subtype 5 receptors (mGluR5) in the pathophysiology of the disorder, we investigated mGluR5 function in FMR1 Knockout (FMR1-KO) mice and age- and sex-matched control mice using longitudinal positron emission tomography (PET) imaging to better understand the disorder. The studies were repeated at four time points to examine age- and disease-induced changes in mGluR5 availability using 3-fluoro-[18F]5-(2-pyridinylethynyl)benzonitrile ([18F]FPEB). We found that the binding potential (BP) of [18F]FPEB was significantly lower in the KO mice in mGluR5-implicated brain areas including striatum, cortex, hippocampus, thalamus, and olfactory bulb. The BP also changed with age, regardless of disorder status, increasing in early adulthood in male but not in female mice before decreasing later in both sexes. The difference in mGluR5 availability between the FMR1-KO and control mice and the change in BP in the KO mice as a function of age and sex illustrate the nature of the disorder and its progression, providing mechanistic insights for treatment design.
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Affiliation(s)
- Sepideh Afshar
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School , Charlestown , 02129 MA , United States of America
| | - Sevda Lule
- Department of Pediatrics, Massachusetts General Hospital, Harvard Medical School , Charlestown , 02129 MA , United States of America
| | - Gengyang Yuan
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School , Charlestown , 02129 MA , United States of America
| | - Xiying Qu
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School , Charlestown , 02129 MA , United States of America
| | - Chuzhi Pan
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School , Charlestown , 02129 MA , United States of America
| | - Michael Whalen
- Department of Pediatrics, Massachusetts General Hospital, Harvard Medical School , Charlestown , 02129 MA , United States of America
| | - Anna-Liisa Brownell
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School , Charlestown , 02129 MA , United States of America
| | - Maria Mody
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School , Charlestown , 02129 MA , USA
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Brašić JR, Goodman JA, Nandi A, Russell DS, Jennings D, Barret O, Martin SD, Slifer K, Sedlak T, Mathur AK, Seibyl JP, Berry-Kravis EM, Wong DF, Budimirovic DB. Fragile X Mental Retardation Protein and Cerebral Expression of Metabotropic Glutamate Receptor Subtype 5 in Men with Fragile X Syndrome: A Pilot Study. Brain Sci 2022; 12:314. [PMID: 35326270 PMCID: PMC8946825 DOI: 10.3390/brainsci12030314] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 01/26/2022] [Accepted: 02/09/2022] [Indexed: 02/04/2023] Open
Abstract
Multiple lines of evidence suggest that a deficiency of Fragile X Mental Retardation Protein (FMRP) mediates dysfunction of the metabotropic glutamate receptor subtype 5 (mGluR5) in the pathogenesis of fragile X syndrome (FXS), the most commonly known single-gene cause of inherited intellectual disability (ID) and autism spectrum disorder (ASD). Nevertheless, animal and human studies regarding the link between FMRP and mGluR5 expression provide inconsistent or conflicting findings about the nature of those relationships. Since multiple clinical trials of glutamatergic agents in humans with FXS did not demonstrate the amelioration of the behavioral phenotype observed in animal models of FXS, we sought measure if mGluR5 expression is increased in men with FXS to form the basis for improved clinical trials. Unexpectedly marked reductions in mGluR5 expression were observed in cortical and subcortical regions in men with FXS. Reduced mGluR5 expression throughout the living brains of men with FXS provides a clue to examine FMRP and mGluR5 expression in FXS. In order to develop the findings of our previous study and to strengthen the objective tools for future clinical trials of glutamatergic agents in FXS, we sought to assess the possible value of measuring both FMRP levels and mGluR5 expression in men with FXS. We aimed to show the value of measurement of FMRP levels and mGluR5 expression for the diagnosis and treatment of individuals with FXS and related conditions. We administered 3-[18F]fluoro-5-(2-pyridinylethynyl)benzonitrile ([18F]FPEB), a specific mGluR5 radioligand for quantitative measurements of the density and the distribution of mGluR5s, to six men with the full mutation (FM) of FXS and to one man with allele size mosaicism for FXS (FXS-M). Utilizing the seven cortical and subcortical regions affected in neurodegenerative disorders as indicator variables, adjusted linear regression of mGluR5 expression and FMRP showed that mGluR5 expression was significantly reduced in the occipital cortex and the thalamus relative to baseline (anterior cingulate cortex) if FMRP levels are held constant (F(7,47) = 6.84, p < 0.001).These findings indicate the usefulness of cerebral mGluR5 expression measured by PET with [18F]FPEB and FMRP values in men with FXS and related conditions for assessments in community facilities within a hundred-mile radius of a production center with a cyclotron. These initial results of this pilot study advance our previous study regarding the measurement of mGluR5 expression by combining both FMRP levels and mGluR5 expression as tools for meaningful clinical trials of glutamatergic agents for men with FXS. We confirm the feasibility of this protocol as a valuable tool to measure FMRP levels and mGluR5 expression in clinical trials of individuals with FXS and related conditions and to provide the foundations to apply precision medicine to tailor treatment plans to the specific needs of individuals with FXS and related conditions.
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Affiliation(s)
- James Robert Brašić
- Section of High Resolution Brain Positron Emission Tomography Imaging, Division of Nuclear Medicine and Molecular Imaging, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; (A.N.); (S.D.M.); (T.S.); (A.K.M.); (D.F.W.)
| | - Jack Alexander Goodman
- Frank H. Netter MD School of Medicine, Quinnipiac University, North Haven, CT 06473, USA;
| | - Ayon Nandi
- Section of High Resolution Brain Positron Emission Tomography Imaging, Division of Nuclear Medicine and Molecular Imaging, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; (A.N.); (S.D.M.); (T.S.); (A.K.M.); (D.F.W.)
| | - David S. Russell
- Institute for Neurodegenerative Disorders, New Haven, CT 06510, USA; (D.S.R.); (D.J.); (O.B.); (J.P.S.)
- Invicro, New Haven, CT 06510, USA
| | - Danna Jennings
- Institute for Neurodegenerative Disorders, New Haven, CT 06510, USA; (D.S.R.); (D.J.); (O.B.); (J.P.S.)
- Invicro, New Haven, CT 06510, USA
- Denali Therapeutics, Inc., South San Francisco, CA 94080, USA
| | - Olivier Barret
- Institute for Neurodegenerative Disorders, New Haven, CT 06510, USA; (D.S.R.); (D.J.); (O.B.); (J.P.S.)
- Invicro, New Haven, CT 06510, USA
- Laboratoire des Maladies Neurodégénératives, Molecular Imaging Research Center (MIRCen), Institut de Biologie François Jacob, Centre National de la Recherche Scientifique (CNRS), Commissariat à l’Énergie Atomique et aux Énergies Alternatives (CEA), Université Paris-Saclay, CEDEX, 92265 Fontenay-aux-Roses, France
| | - Samuel D. Martin
- Section of High Resolution Brain Positron Emission Tomography Imaging, Division of Nuclear Medicine and Molecular Imaging, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; (A.N.); (S.D.M.); (T.S.); (A.K.M.); (D.F.W.)
- Department of Neuroscience, Zanvyl Krieger School of Arts and Sciences, The Johns Hopkins University, Baltimore, MD 21218, USA
| | - Keith Slifer
- Department of Psychiatry and Behavioral Sciences-Child Psychiatry, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA;
- Department of Behavioral Psychology, Kennedy Krieger Institute, Baltimore, MD 21205, USA
| | - Thomas Sedlak
- Section of High Resolution Brain Positron Emission Tomography Imaging, Division of Nuclear Medicine and Molecular Imaging, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; (A.N.); (S.D.M.); (T.S.); (A.K.M.); (D.F.W.)
- Department of Psychiatry and Behavioral Sciences-General Psychiatry, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Anil Kumar Mathur
- Section of High Resolution Brain Positron Emission Tomography Imaging, Division of Nuclear Medicine and Molecular Imaging, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; (A.N.); (S.D.M.); (T.S.); (A.K.M.); (D.F.W.)
| | - John P. Seibyl
- Institute for Neurodegenerative Disorders, New Haven, CT 06510, USA; (D.S.R.); (D.J.); (O.B.); (J.P.S.)
- Invicro, New Haven, CT 06510, USA
| | - Elizabeth M. Berry-Kravis
- Departments of Pediatrics, Neurological Sciences, and Biochemistry, Rush University Medical Center, Chicago, IL 60612, USA;
| | - Dean F. Wong
- Section of High Resolution Brain Positron Emission Tomography Imaging, Division of Nuclear Medicine and Molecular Imaging, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; (A.N.); (S.D.M.); (T.S.); (A.K.M.); (D.F.W.)
- Laboratory of Central Nervous System (CNS) Neuropsychopharmacology and Multimodal, Imaging (CNAMI), Mallinckrodt Institute of Radiology, Washington University, Saint Louis, MO 63110, USA
| | - Dejan B. Budimirovic
- Department of Psychiatry and Behavioral Sciences-Child Psychiatry, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA;
- Department of Psychiatry, Kennedy Krieger Institute, Baltimore, MD 21205, USA
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Protic DD, Aishworiya R, Salcedo-Arellano MJ, Tang SJ, Milisavljevic J, Mitrovic F, Hagerman RJ, Budimirovic DB. Fragile X Syndrome: From Molecular Aspect to Clinical Treatment. Int J Mol Sci 2022; 23:ijms23041935. [PMID: 35216055 PMCID: PMC8875233 DOI: 10.3390/ijms23041935] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 02/01/2022] [Accepted: 02/02/2022] [Indexed: 02/01/2023] Open
Abstract
Fragile X syndrome (FXS) is a neurodevelopmental disorder caused by the full mutation as well as highly localized methylation of the fragile X mental retardation 1 (FMR1) gene on the long arm of the X chromosome. Children with FXS are commonly co-diagnosed with Autism Spectrum Disorder, attention and learning problems, anxiety, aggressive behavior and sleep disorder, and early interventions have improved many behavior symptoms associated with FXS. In this review, we performed a literature search of original and review articles data of clinical trials and book chapters using MEDLINE (1990-2021) and ClinicalTrials.gov. While we have reviewed the biological importance of the fragile X mental retardation protein (FMRP), the FXS phenotype, and current diagnosis techniques, the emphasis of this review is on clinical interventions. Early non-pharmacological interventions in combination with pharmacotherapy and targeted treatments aiming to reverse dysregulated brain pathways are the mainstream of treatment in FXS. Overall, early diagnosis and interventions are fundamental to achieve optimal clinical outcomes in FXS.
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Affiliation(s)
- Dragana D. Protic
- Department of Pharmacology, Clinical Pharmacology and Toxicology, Faculty of Medicine, University of Belgrade, 11129 Belgrade, Serbia
- Correspondence: (D.D.P.); (D.B.B.); Tel.: +381-11-36-43-389 (D.D.P.); +1-443-923-2634 (D.B.B.)
| | - Ramkumar Aishworiya
- Medical Investigation of Neurodevelopmental Disorders (MIND) Institute UCDH, University of California Davis, 2825 50th Street, Sacramento, CA 95817, USA; (R.A.); (M.J.S.-A.); (S.J.T.); (R.J.H.)
- Khoo Teck Puat-National University Children’s Medical Institute, National University Health System, 5 Lower Kent Ridge Road, Singapore 119074, Singapore
| | - Maria Jimena Salcedo-Arellano
- Medical Investigation of Neurodevelopmental Disorders (MIND) Institute UCDH, University of California Davis, 2825 50th Street, Sacramento, CA 95817, USA; (R.A.); (M.J.S.-A.); (S.J.T.); (R.J.H.)
- Department of Pediatrics, University of California Davis School of Medicine, Sacramento, CA 95817, USA
- Department of Pathology and Laboratory Medicine, University of California Davis School of Medicine, Sacramento, CA 95817, USA
| | - Si Jie Tang
- Medical Investigation of Neurodevelopmental Disorders (MIND) Institute UCDH, University of California Davis, 2825 50th Street, Sacramento, CA 95817, USA; (R.A.); (M.J.S.-A.); (S.J.T.); (R.J.H.)
| | - Jelena Milisavljevic
- Faculty of Medicine, University of Belgrade, 11129 Belgrade, Serbia; (J.M.); (F.M.)
| | - Filip Mitrovic
- Faculty of Medicine, University of Belgrade, 11129 Belgrade, Serbia; (J.M.); (F.M.)
| | - Randi J. Hagerman
- Medical Investigation of Neurodevelopmental Disorders (MIND) Institute UCDH, University of California Davis, 2825 50th Street, Sacramento, CA 95817, USA; (R.A.); (M.J.S.-A.); (S.J.T.); (R.J.H.)
- Department of Pediatrics, University of California Davis School of Medicine, Sacramento, CA 95817, USA
| | - Dejan B. Budimirovic
- Department of Psychiatry, Fragile X Clinic, Kennedy Krieger Institute, Baltimore, MD 21205, USA
- Department of Psychiatry & Behavioral Sciences-Child Psychiatry, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
- Correspondence: (D.D.P.); (D.B.B.); Tel.: +381-11-36-43-389 (D.D.P.); +1-443-923-2634 (D.B.B.)
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11
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Budimirovic DB, Dominick KC, Gabis LV, Adams M, Adera M, Huang L, Ventola P, Tartaglia NR, Berry-Kravis E. Gaboxadol in Fragile X Syndrome: A 12-Week Randomized, Double-Blind, Parallel-Group, Phase 2a Study. Front Pharmacol 2021; 12:757825. [PMID: 34690787 PMCID: PMC8531725 DOI: 10.3389/fphar.2021.757825] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 09/23/2021] [Indexed: 11/13/2022] Open
Abstract
Background: Fragile X syndrome (FXS), the most common single-gene cause of intellectual disability and autism spectrum disorder (ASD), is caused by a >200-trinucleotide repeat expansion in the 5' untranslated region of the fragile X mental retardation 1 (FMR1) gene. Individuals with FXS can present with a range of neurobehavioral impairments including, but not limited to: cognitive, language, and adaptive deficits; ASD; anxiety; social withdrawal and avoidance; and aggression. Decreased expression of the γ-aminobutyric acid type A (GABAA) receptor δ subunit and deficient GABAergic tonic inhibition could be associated with symptoms of FXS. Gaboxadol (OV101) is a δ-subunit-selective, extrasynaptic GABAA receptor agonist that enhances GABAergic tonic inhibition, providing the rationale for assessment of OV101 as a potential targeted treatment of FXS. No drug is approved in the United States for the treatment of FXS. Methods: This 12-weeks, randomized (1:1:1), double-blind, parallel-group, phase 2a study was designed to assess the safety, tolerability, efficacy, and optimal daily dose of OV101 5 mg [once (QD), twice (BID), or three-times daily (TID)] when administered for 12 weeks to adolescent and adult men with FXS. Safety was the primary study objective, with key assessments including treatment-emergent adverse events (TEAEs), treatment-related adverse events leading to study discontinuation, and serious adverse events (SAEs). The secondary study objective was to evaluate the effect of OV101 on a variety of problem behaviors. Results: A total of 23 participants with FXS (13 adolescents, 10 adults) with moderate-to-severe neurobehavioral phenotypes (Full Scale Intelligence Quotient, 41.5 ± 3.29; ASD, 82.6%) were randomized to OV101 5 mg QD (n = 8), 5 mg BID (n = 8), or 5 mg TID (n = 7) for 12 weeks. OV101 was well tolerated across all 3 treatment regimens. The most common TEAEs were upper respiratory tract infection (n = 4), headache (n = 3), diarrhea (n = 2), and irritability (n = 2). No SAEs were reported. Improvements from baseline to end-of-treatment were observed on several efficacy endpoints, and 60% of participants were identified as treatment responders based on Clinical Global Impressions-Improvement. Conclusions: Overall, OV101 was safe and well tolerated. Efficacy results demonstrate an initial signal for OV101 in individuals with FXS. These results need to be confirmed in a larger, randomized, placebo-controlled study with optimal outcomes and in the most appropriate age group. Clinical Trial Registration: www.ClinicalTrials.gov, identifier: NCT03697161.
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Affiliation(s)
- Dejan B Budimirovic
- Department of Psychiatry, Kennedy Krieger Institute, Johns Hopkins University, Baltimore, MD, United States.,Department of Psychiatry and Behavioral Sciences-Child Psychiatry, Johns Hopkins School of Medicine, Baltimore, MD, United States
| | - Kelli C Dominick
- Department of Psychiatry, University of Cincinnati College of Medicine, Cincinnati, OH, United States.,Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States
| | - Lidia V Gabis
- Maccabi HMO, Tel Aviv-Yafo, Israel.,Sackler School of Medicine, Tel Aviv University, Tel Aviv-Yafo, Israel
| | | | | | - Linda Huang
- Ovid Therapeutics Inc., New York, NY, United States
| | - Pamela Ventola
- Child Study Center, Yale University, New Haven, CT, United States
| | - Nicole R Tartaglia
- University of Colorado School of Medicine, Children's Hospital Colorado, Aurora, CO, United States
| | - Elizabeth Berry-Kravis
- Department of Pediatrics, Neurological Sciences, Biochemistry, Rush University Medical Center, Chicago, IL, United States
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Mody M, Petibon Y, Han P, Kuruppu D, Ma C, Yokell D, Neelamegam R, Normandin MD, Fakhri GE, Brownell AL. In vivo imaging of mGlu5 receptor expression in humans with Fragile X Syndrome towards development of a potential biomarker. Sci Rep 2021; 11:15897. [PMID: 34354107 PMCID: PMC8342610 DOI: 10.1038/s41598-021-94967-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 07/16/2021] [Indexed: 11/21/2022] Open
Abstract
Fragile X Syndrome (FXS) is a neurodevelopmental disorder caused by silencing of the Fragile X Mental Retardation (FMR1) gene. The resulting loss of Fragile X Mental Retardation Protein (FMRP) leads to excessive glutamate signaling via metabotropic glutamate subtype 5 receptors (mGluR5) which has been implicated in the pathogenesis of the disorder. In the present study we used the radioligand 3-[18F]fluoro-5-(2-pyridinylethynyl)benzonitrile ([18F]FPEB) in simultaneous PET-MR imaging of males with FXS and age- and gender-matched controls to assess the availability of mGlu5 receptors in relevant brain areas. Patients with FXS showed lower [18F]FPEB binding potential (p < 0.01), reflecting reduced mGluR5 availability, than the healthy controls throughout the brain, with significant group differences in insula, anterior cingulate, parahippocampal, inferior temporal and olfactory cortices, regions associated with deficits in inhibition, memory, and visuospatial processes characteristic of the disorder. The results are among the first to provide in vivo evidence of decreased availability of mGluR5 in the brain in individuals with FXS than in healthy controls. The consistent results across the subjects, despite the tremendous challenges with neuroimaging this population, highlight the robustness of the protocol and support for its use in drug occupancy studies; extending our radiotracer development and application efforts from mice to humans.
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Affiliation(s)
- Maria Mody
- Athinoula A Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, MA, 02129, USA.
| | - Yoann Petibon
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, MA, 02129, USA
| | - Paul Han
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, MA, 02129, USA
| | - Darshini Kuruppu
- Department of Surgery, Massachusetts General Hospital and Harvard Medical School, Boston, MA, 02129, USA
| | - Chao Ma
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, MA, 02129, USA
| | - Daniel Yokell
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, MA, 02129, USA
| | - Ramesh Neelamegam
- Department of Radiology, University of Texas Health Science at San Antonio, San Antonio, TX, 78229, USA
| | - Marc D Normandin
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, MA, 02129, USA
| | - Georges El Fakhri
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, MA, 02129, USA
| | - Anna-Liisa Brownell
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, MA, 02129, USA
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Brašić JR, Nandi A, Russell DS, Jennings D, Barret O, Martin SD, Slifer K, Sedlak T, Seibyl JP, Wong DF, Budimirovic DB. Cerebral Expression of Metabotropic Glutamate Receptor Subtype 5 in Idiopathic Autism Spectrum Disorder and Fragile X Syndrome: A Pilot Study. Int J Mol Sci 2021; 22:2863. [PMID: 33799851 PMCID: PMC7999711 DOI: 10.3390/ijms22062863] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 02/26/2021] [Accepted: 03/04/2021] [Indexed: 12/13/2022] Open
Abstract
Multiple lines of evidence suggest that dysfunction of the metabotropic glutamate receptor subtype 5 (mGluR5) plays a role in the pathogenesis of autism spectrum disorder (ASD). Yet animal and human investigations of mGluR5 expression provide conflicting findings about the nature of dysregulation of cerebral mGluR5 pathways in subtypes of ASD. The demonstration of reduced mGluR5 expression throughout the living brains of men with fragile X syndrome (FXS), the most common known single-gene cause of ASD, provides a clue to examine mGluR5 expression in ASD. We aimed to (A) compare and contrast mGluR5 expression in idiopathic autism spectrum disorder (IASD), FXS, and typical development (TD) and (B) show the value of positron emission tomography (PET) for the application of precision medicine for the diagnosis and treatment of individuals with IASD, FXS, and related conditions. Two teams of investigators independently administered 3-[18F]fluoro-5-(2-pyridinylethynyl)benzonitrile ([18F]FPEB), a novel, specific mGluR5 PET ligand to quantitatively measure the density and the distribution of mGluR5s in the brain regions, to participants of both sexes with IASD and TD and men with FXS. In contrast to participants with TD, mGluR5 expression was significantly increased in the cortical regions of participants with IASD and significantly reduced in all regions of men with FXS. These results suggest the feasibility of this protocol as a valuable tool to measure mGluR5 expression in clinical trials of individuals with IASD and FXS and related conditions.
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Affiliation(s)
- James Robert Brašić
- Section of High Resolution Brain Positron Emission Tomography Imaging, Division of Nuclear Medicine and Molecular Imaging, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; (A.N.); (S.D.M.); (T.S.); (D.F.W.)
| | - Ayon Nandi
- Section of High Resolution Brain Positron Emission Tomography Imaging, Division of Nuclear Medicine and Molecular Imaging, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; (A.N.); (S.D.M.); (T.S.); (D.F.W.)
| | - David S. Russell
- Institute for Neurodegenerative Disorders, New Haven, CT 06510, USA; (D.S.R.); (D.J.); (O.B.); (J.P.S.)
- Research Clinic, Invicro, New Haven, CT 06510, USA
| | - Danna Jennings
- Institute for Neurodegenerative Disorders, New Haven, CT 06510, USA; (D.S.R.); (D.J.); (O.B.); (J.P.S.)
- Research Clinic, Invicro, New Haven, CT 06510, USA
- Denali Therapeutics, Inc., South San Francisco, CA 94080, USA
| | - Olivier Barret
- Institute for Neurodegenerative Disorders, New Haven, CT 06510, USA; (D.S.R.); (D.J.); (O.B.); (J.P.S.)
- Research Clinic, Invicro, New Haven, CT 06510, USA
- Laboratoire des Maladies Neurodégénératives, Molecular Imaging Research Center (MIRCen), Institut de Biologie François Jacob, Centre National de la Recherche Scientifique (CNRS), Commissariat à l’Énergie Atomique et aux Énergies Alternatives (CEA), Université Paris-Saclay, 92265 Fontenay-aux-Roses CEDEX, France
| | - Samuel D. Martin
- Section of High Resolution Brain Positron Emission Tomography Imaging, Division of Nuclear Medicine and Molecular Imaging, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; (A.N.); (S.D.M.); (T.S.); (D.F.W.)
- Department of Neuroscience, Zanvyl Krieger School of Arts and Sciences, The Johns Hopkins University, Baltimore, MD 21218, USA
| | - Keith Slifer
- Department of Psychiatry and Behavioral Sciences-Child Psychiatry, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA;
- Department of Behavioral Psychology, Kennedy Krieger Institute, Baltimore, MD 21205, USA
| | - Thomas Sedlak
- Section of High Resolution Brain Positron Emission Tomography Imaging, Division of Nuclear Medicine and Molecular Imaging, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; (A.N.); (S.D.M.); (T.S.); (D.F.W.)
- Department of Psychiatry and Behavioral Sciences-General Psychiatry, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - John P. Seibyl
- Institute for Neurodegenerative Disorders, New Haven, CT 06510, USA; (D.S.R.); (D.J.); (O.B.); (J.P.S.)
- Research Clinic, Invicro, New Haven, CT 06510, USA
| | - Dean F. Wong
- Section of High Resolution Brain Positron Emission Tomography Imaging, Division of Nuclear Medicine and Molecular Imaging, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; (A.N.); (S.D.M.); (T.S.); (D.F.W.)
- Laboratory of Central Nervous System (CNS) Neuropsychopharmacology and Multimodal Imaging (CNAMI), Mallinckrodt Institute of Radiology, Washington University, Saint Louis, MO 63110, USA
| | - Dejan B. Budimirovic
- Department of Psychiatry and Behavioral Sciences-Child Psychiatry, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA;
- Department of Psychiatry, Kennedy Krieger Institute, Baltimore, MD 21205, USA
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14
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Brašić JR, Nandi A, Russell DS, Jennings D, Barret O, Mathur A, Slifer K, Sedlak T, Martin SD, Brinson Z, Vyas P, Seibyl JP, Berry-Kravis EM, Wong DF, Budimirovic DB. Reduced Expression of Cerebral Metabotropic Glutamate Receptor Subtype 5 in Men with Fragile X Syndrome. Brain Sci 2020; 10:E899. [PMID: 33255214 PMCID: PMC7760509 DOI: 10.3390/brainsci10120899] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Revised: 11/07/2020] [Accepted: 11/14/2020] [Indexed: 12/28/2022] Open
Abstract
Glutamatergic receptor expression is mostly unknown in adults with fragile X syndrome (FXS). Favorable behavioral effects of negative allosteric modulators (NAMs) of the metabotropic glutamate receptor subtype 5 (mGluR5) in fmr1 knockout (KO) mouse models have not been confirmed in humans with FXS. Measurement of cerebral mGluR5 expression in humans with FXS exposed to NAMs might help in that effort. We used positron emission tomography (PET) to measure the mGluR5 density as a proxy of mGluR5 expression in cortical and subcortical brain regions to confirm target engagement of NAMs for mGluR5s. The density and the distribution of mGluR5 were measured in two independent samples of men with FXS (N = 9) and typical development (TD) (N = 8). We showed the feasibility of this complex study including MRI and PET, meaning that this challenging protocol can be accomplished in men with FXS with an adequate preparation. Analysis of variance of estimated mGluR5 expression showed that mGluR5 expression was significantly reduced in cortical and subcortical regions of men with FXS in contrast to age-matched men with TD.
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Affiliation(s)
- James R. Brašić
- Section of High Resolution Brain Positron Emission Tomography Imaging, Division of Nuclear Medicine and Molecular Imaging, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; (A.N.); (A.M.); (T.S.); (S.D.M.); (Z.B.); (P.V.); (D.F.W.)
| | - Ayon Nandi
- Section of High Resolution Brain Positron Emission Tomography Imaging, Division of Nuclear Medicine and Molecular Imaging, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; (A.N.); (A.M.); (T.S.); (S.D.M.); (Z.B.); (P.V.); (D.F.W.)
| | - David S. Russell
- Clinical Research, Institute for Neurodegenerative Disorders, New Haven, CT 06510, USA; (D.S.R.); (D.J.); (O.B.); (J.P.S.)
- Research Clinic, Invicro LLC, New Haven, CT 06510, USA
| | - Danna Jennings
- Clinical Research, Institute for Neurodegenerative Disorders, New Haven, CT 06510, USA; (D.S.R.); (D.J.); (O.B.); (J.P.S.)
- Research Clinic, Invicro LLC, New Haven, CT 06510, USA
- Denali Therapeutics, Inc., South San Francisco, CA 94080, USA
| | - Olivier Barret
- Clinical Research, Institute for Neurodegenerative Disorders, New Haven, CT 06510, USA; (D.S.R.); (D.J.); (O.B.); (J.P.S.)
| | - Anil Mathur
- Section of High Resolution Brain Positron Emission Tomography Imaging, Division of Nuclear Medicine and Molecular Imaging, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; (A.N.); (A.M.); (T.S.); (S.D.M.); (Z.B.); (P.V.); (D.F.W.)
| | - Keith Slifer
- Department of Psychiatry and Behavioral Sciences-Child Psychiatry, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA;
- Department of Behavioral Psychology, Kennedy Krieger Institute, Baltimore, MD 21205, USA
| | - Thomas Sedlak
- Section of High Resolution Brain Positron Emission Tomography Imaging, Division of Nuclear Medicine and Molecular Imaging, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; (A.N.); (A.M.); (T.S.); (S.D.M.); (Z.B.); (P.V.); (D.F.W.)
- Department of Psychiatry and Behavioral Sciences-General Psychiatry, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Samuel D. Martin
- Section of High Resolution Brain Positron Emission Tomography Imaging, Division of Nuclear Medicine and Molecular Imaging, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; (A.N.); (A.M.); (T.S.); (S.D.M.); (Z.B.); (P.V.); (D.F.W.)
- Department of Neuroscience, Zanvyl Krieger School of Arts and Sciences, The Johns Hopkins University, Baltimore, MD 21218, USA
| | - Zabecca Brinson
- Section of High Resolution Brain Positron Emission Tomography Imaging, Division of Nuclear Medicine and Molecular Imaging, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; (A.N.); (A.M.); (T.S.); (S.D.M.); (Z.B.); (P.V.); (D.F.W.)
| | - Pankhuri Vyas
- Section of High Resolution Brain Positron Emission Tomography Imaging, Division of Nuclear Medicine and Molecular Imaging, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; (A.N.); (A.M.); (T.S.); (S.D.M.); (Z.B.); (P.V.); (D.F.W.)
| | - John P. Seibyl
- Clinical Research, Institute for Neurodegenerative Disorders, New Haven, CT 06510, USA; (D.S.R.); (D.J.); (O.B.); (J.P.S.)
- Research Clinic, Invicro LLC, New Haven, CT 06510, USA
| | - Elizabeth M. Berry-Kravis
- Departments of Pediatrics, Neurological Sciences, and Biochemistry, Rush University Medical Center, Chicago, IL 60612, USA;
| | - Dean F. Wong
- Section of High Resolution Brain Positron Emission Tomography Imaging, Division of Nuclear Medicine and Molecular Imaging, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; (A.N.); (A.M.); (T.S.); (S.D.M.); (Z.B.); (P.V.); (D.F.W.)
- Precision Radio-Theranostics Translational Laboratories, Mallinckrodt Institute of Radiology, School of Medicine, Washington University, Saint Louis, MO 63110, USA
| | - Dejan B. Budimirovic
- Department of Psychiatry and Behavioral Sciences-Child Psychiatry, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA;
- Departments of Psychiatry and Neurogenetics, Kennedy Krieger Institute, Baltimore, MD 21205, USA
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