1
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Tempio A, Boulksibat A, Bardoni B, Delhaye S. Fragile X Syndrome as an interneuronopathy: a lesson for future studies and treatments. Front Neurosci 2023; 17:1171895. [PMID: 37188005 PMCID: PMC10176609 DOI: 10.3389/fnins.2023.1171895] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 04/05/2023] [Indexed: 05/17/2023] Open
Abstract
Fragile X Syndrome (FXS) is the most common form of inherited intellectual disability (ID) and a primary genetic cause of autism spectrum disorder (ASD). FXS arises from the silencing of the FMR1 gene causing the lack of translation of its encoded protein, the Fragile X Messenger RibonucleoProtein (FMRP), an RNA-binding protein involved in translational control and in RNA transport along dendrites. Although a large effort during the last 20 years has been made to investigate the cellular roles of FMRP, no effective and specific therapeutic intervention is available to treat FXS. Many studies revealed a role for FMRP in shaping sensory circuits during developmental critical periods to affect proper neurodevelopment. Dendritic spine stability, branching and density abnormalities are part of the developmental delay observed in various FXS brain areas. In particular, cortical neuronal networks in FXS are hyper-responsive and hyperexcitable, making these circuits highly synchronous. Overall, these data suggest that the excitatory/inhibitory (E/I) balance in FXS neuronal circuitry is altered. However, not much is known about how interneuron populations contribute to the unbalanced E/I ratio in FXS even if their abnormal functioning has an impact on the behavioral deficits of patients and animal models affected by neurodevelopmental disorders. We revise here the key literature concerning the role of interneurons in FXS not only with the purpose to better understand the pathophysiology of this disorder, but also to explore new possible therapeutic applications to treat FXS and other forms of ASD or ID. Indeed, for instance, the re-introduction of functional interneurons in the diseased brains has been proposed as a promising therapeutic approach for neurological and psychiatric disorders.
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Affiliation(s)
- Alessandra Tempio
- Université Côte d’Azur, CNRS, Institut de Pharmacologie Moléculaire et Cellulaire, Valbonne, France
- Alessandra Tempio,
| | - Asma Boulksibat
- Université Côte d’Azur, CNRS, Institut de Pharmacologie Moléculaire et Cellulaire, Valbonne, France
| | - Barbara Bardoni
- Université Côte d’Azur, CNRS, Institut de Pharmacologie Moléculaire et Cellulaire, Valbonne, France
- Inserm, Université Côte d’Azur, CNRS, Institut de Pharmacologie Moléculaire et Cellulaire, Valbonne, France
- *Correspondence: Barbara Bardoni,
| | - Sébastien Delhaye
- Université Côte d’Azur, CNRS, Institut de Pharmacologie Moléculaire et Cellulaire, Valbonne, France
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2
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Jalnapurkar I, Frazier JA, Roth M, Cochran DM, Foley A, Merk T, Venuti L, Ronco L, Raines S, Cadavid D. The feasibility and utility of hair follicle sampling to measure FMRP and FMR1 mRNA in children with or without fragile X syndrome: a pilot study. J Neurodev Disord 2022; 14:57. [PMID: 36494616 PMCID: PMC9733195 DOI: 10.1186/s11689-022-09465-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 10/26/2022] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Fragile X syndrome (FXS) is the most common inherited cause of intellectual disability in males and the most common single gene cause of autism. This X-linked disorder is caused by an expansion of a trinucleotide CGG repeat (> 200 base pairs) on the promotor region of the fragile X messenger ribonucleoprotein 1 gene (FMR1). This leads to the deficiency or absence of the encoded protein, fragile X messenger ribonucleoprotein 1 (FMRP). FMRP has a central role in the translation of mRNAs involved in synaptic connections and plasticity. Recent studies have demonstrated the benefit of therapeutics focused on reactivation of the FMR1 locus towards improving key clinical phenotypes via restoration of FMRP and ultimately disease modification. A key step in future studies directed towards this effort is the establishment of proof of concept (POC) for FMRP reactivation in individuals with FXS. For this, it is key to determine the feasibility of repeated collection of tissues or fluids to measure FMR1 mRNA and FMRP. METHODS Individuals, ages 3 to 22 years of age, with FXS and those who were typically developing participated in this single-site pilot clinical biomarker study. The repeated collection of hair follicles was compared with the collection of blood and buccal swabs for detection of FMR1 mRNA and FMRP and related molecules. RESULTS There were n = 15 participants, of whom 10 had a diagnosis of FXS (7.0 ± 3.56 years) and 5 were typically developing (8.2 ± 2.77 years). Absolute levels of FMRP and FMR1 mRNA were substantially higher in healthy participants compared to full mutation and mosaic FXS participants and lowest in the FXS boys. Measurement of FMR1 mRNA and FMRP levels by any method did not show any notable variation by collection location at home versus office across the various sample collection methodologies of hair follicle, blood sample, and buccal swab. CONCLUSION Findings demonstrated that repeated sampling of hair follicles in individuals with FXS, in both, home, and office settings, is feasible, repeatable, and can be used for measurement of FMR1 mRNA and FMRP in longitudinal studies.
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Affiliation(s)
- Isha Jalnapurkar
- grid.410516.70000 0001 0707 2056Department of Psychiatry, EK Shriver Center, University of Massachusetts Medical School, Worcester, MA USA
| | - Jean A. Frazier
- grid.410516.70000 0001 0707 2056Department of Psychiatry, EK Shriver Center, University of Massachusetts Medical School, Worcester, MA USA
| | - Mark Roth
- grid.509699.a0000 0004 5907 6392Fulcrum Therapeutics, Cambridge, MA USA
| | - David M. Cochran
- grid.410516.70000 0001 0707 2056Department of Psychiatry, EK Shriver Center, University of Massachusetts Medical School, Worcester, MA USA
| | - Ann Foley
- grid.410516.70000 0001 0707 2056Department of Psychiatry, EK Shriver Center, University of Massachusetts Medical School, Worcester, MA USA
| | - Taylor Merk
- grid.410516.70000 0001 0707 2056Department of Psychiatry, EK Shriver Center, University of Massachusetts Medical School, Worcester, MA USA
| | - Lauren Venuti
- grid.410516.70000 0001 0707 2056Department of Psychiatry, EK Shriver Center, University of Massachusetts Medical School, Worcester, MA USA
| | - Lucienne Ronco
- grid.509699.a0000 0004 5907 6392Fulcrum Therapeutics, Cambridge, MA USA
| | - Shane Raines
- grid.509699.a0000 0004 5907 6392Fulcrum Therapeutics, Cambridge, MA USA
| | - Diego Cadavid
- grid.509699.a0000 0004 5907 6392Fulcrum Therapeutics, Cambridge, MA USA
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3
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Romagnoli A, Di Marino D. The Use of Peptides in the Treatment of Fragile X Syndrome: Challenges and Opportunities. Front Psychiatry 2021; 12:754485. [PMID: 34803767 PMCID: PMC8599826 DOI: 10.3389/fpsyt.2021.754485] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 10/11/2021] [Indexed: 01/17/2023] Open
Abstract
Fragile X Syndrome (FXS) is the most frequent cause of inherited intellectual disabilities and autism spectrum disorders, characterized by cognitive deficits and autistic behaviors. The silencing of the Fmr1 gene and consequent lack of FMRP protein, is the major contribution to FXS pathophysiology. FMRP is an RNA binding protein involved in the maturation and plasticity of synapses and its absence culminates in a range of morphological, synaptic and behavioral phenotypes. Currently, there are no approved medications for the treatment of FXS, with the approaches under study being fairly specific and unsatisfying in human trials. Here we propose peptides/peptidomimetics as candidates in the pharmacotherapy of FXS; in the last years this class of molecules has catalyzed the attention of pharmaceutical research, being highly selective and well-tolerated. Thanks to their ability to target protein-protein interactions (PPIs), they are already being tested for a wide range of diseases, including cancer, diabetes, inflammation, Alzheimer's disease, but this approach has never been applied to FXS. As FXS is at the forefront of efforts to develop new drugs and approaches, we discuss opportunities, challenges and potential issues of peptides/peptidomimetics in FXS drug design and development.
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Affiliation(s)
| | - Daniele Di Marino
- Department of Life and Environmental Sciences, New York-Marche Structural Biology Center (NY-MaSBiC), Polytechnic University of Marche, Ancona, Italy
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4
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Worpenberg L, Paolantoni C, Longhi S, Mulorz MM, Lence T, Wessels HH, Dassi E, Aiello G, Sutandy FXR, Scheibe M, Edupuganti RR, Busch A, Möckel MM, Vermeulen M, Butter F, König J, Notarangelo M, Ohler U, Dieterich C, Quattrone A, Soldano A, Roignant JY. Ythdf is a N6-methyladenosine reader that modulates Fmr1 target mRNA selection and restricts axonal growth in Drosophila. EMBO J 2021; 40:e104975. [PMID: 33428246 PMCID: PMC7883056 DOI: 10.15252/embj.2020104975] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Revised: 11/18/2020] [Accepted: 11/30/2020] [Indexed: 12/19/2022] Open
Abstract
N6‐methyladenosine (m6A) regulates a variety of physiological processes through modulation of RNA metabolism. This modification is particularly enriched in the nervous system of several species, and its dysregulation has been associated with neurodevelopmental defects and neural dysfunctions. In Drosophila, loss of m6A alters fly behavior, albeit the underlying molecular mechanism and the role of m6A during nervous system development have remained elusive. Here we find that impairment of the m6A pathway leads to axonal overgrowth and misguidance at larval neuromuscular junctions as well as in the adult mushroom bodies. We identify Ythdf as the main m6A reader in the nervous system, being required to limit axonal growth. Mechanistically, we show that the m6A reader Ythdf directly interacts with Fmr1, the fly homolog of Fragile X mental retardation RNA binding protein (FMRP), to inhibit the translation of key transcripts involved in axonal growth regulation. Altogether, this study demonstrates that the m6A pathway controls development of the nervous system and modulates Fmr1 target transcript selection.
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Affiliation(s)
- Lina Worpenberg
- Center for Integrative Genomics, Génopode Building, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Chiara Paolantoni
- Center for Integrative Genomics, Génopode Building, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Sara Longhi
- Laboratory of Translational Genomics, Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy
| | | | - Tina Lence
- Institute of Molecular Biology (IMB), Mainz, Germany
| | - Hans-Hermann Wessels
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin Institute for Medical Systems Biology (BIMSB), Berlin, Germany.,Department of Biology, Humboldt University Berlin, Berlin, Germany
| | - Erik Dassi
- Laboratory of RNA Regulatory Networks, Department CIBIO, University of Trento, Trento, Italy
| | - Giuseppe Aiello
- Armenise-Harvard Laboratory of Brain Disorders and Cancer, Department CIBIO, University of Trento, Trento, Italy
| | | | | | - Raghu R Edupuganti
- Department of Molecular Biology, Faculty of Science, Radboud Institute for Molecular Life Sciences, Oncode Institute, Radboud University Nijmegen, Nijmegen, The Netherlands
| | - Anke Busch
- Bioinformatics Core Facility, IMB, Mainz, Germany
| | | | - Michiel Vermeulen
- Department of Molecular Biology, Faculty of Science, Radboud Institute for Molecular Life Sciences, Oncode Institute, Radboud University Nijmegen, Nijmegen, The Netherlands
| | - Falk Butter
- Institute of Molecular Biology (IMB), Mainz, Germany
| | - Julian König
- Institute of Molecular Biology (IMB), Mainz, Germany
| | - Michela Notarangelo
- Laboratory of Translational Genomics, Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy
| | - Uwe Ohler
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin Institute for Medical Systems Biology (BIMSB), Berlin, Germany.,Department of Biology, Humboldt University Berlin, Berlin, Germany
| | - Christoph Dieterich
- Klaus Tschira Institute for Integrative Computational Cardiology and Department of Internal Medicine III, University Hospital Heidelberg, Heidelberg, Germany.,German Center for Cardiovascular Research (DZHK), Partner site Heidelberg-Mannheim, Heidelberg, Germany
| | - Alessandro Quattrone
- Center for Integrative Genomics, Génopode Building, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland.,Laboratory of Translational Genomics, Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy
| | - Alessia Soldano
- Laboratory of Translational Genomics, Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy
| | - Jean-Yves Roignant
- Center for Integrative Genomics, Génopode Building, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland.,Institute of Pharmaceutical and Biomedical Sciences, Johannes Gutenberg-University Mainz, Mainz, Germany
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5
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Verdura E, Pérez-Cano L, Sabido-Vera R, Guney E, Hyvelin JM, Durham L, Gomez-Mancilla B. Heterogeneity in Fragile X Syndrome Highlights the Need for Precision Medicine-Based Treatments. Front Psychiatry 2021; 12:722378. [PMID: 34658958 PMCID: PMC8514715 DOI: 10.3389/fpsyt.2021.722378] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 09/01/2021] [Indexed: 11/21/2022] Open
Abstract
Fragile X syndrome (FXS) is the most frequent monogenic cause of autism or intellectual disability, and research on its pathogenetic mechanisms has provided important insights on this neurodevelopmental condition. Nevertheless, after 30 years of intense research, efforts to develop treatments have been mostly unsuccessful. The aim of this review is to compile evidence from existing research pointing to clinical, genetic, and therapeutic response heterogeneity in FXS and highlight the need of implementing precision medicine-based treatments. We comment on the high genetic and phenotypic heterogeneity present in FXS, as a contributing factor to the difficulties found during drug development. Given that several clinical trials have showed a non-negligeable fraction of positive responders to drugs targeting core FXS symptoms, we propose that success of clinical trials can be achieved by tackling the underlying heterogeneity in FXS by accurately stratifying patients into drug-responder subpopulations. These precision medicine-based approaches, which can be first applied to well-defined monogenic diseases such as FXS, can also serve to define drug responder profiles based on specific biomarkers or phenotypic features that can associate patients with different genetic backgrounds to a same candidate drug, thus repositioning a same drug for a larger number of patients with NDDs.
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Affiliation(s)
- Edgard Verdura
- Discovery and Data Science (DDS) Unit, Sociedad Limitada (STALICLA SL), Barcelona, Spain
| | - Laura Pérez-Cano
- Discovery and Data Science (DDS) Unit, Sociedad Limitada (STALICLA SL), Barcelona, Spain
| | - Rubén Sabido-Vera
- Discovery and Data Science (DDS) Unit, Sociedad Limitada (STALICLA SL), Barcelona, Spain
| | - Emre Guney
- Discovery and Data Science (DDS) Unit, Sociedad Limitada (STALICLA SL), Barcelona, Spain.,Research Programme on Biomedical Informatics, Hospital del Mar Medical Research Institute (IMIM), Departament de Ciències Experimentals i de la Salut (DCEXS), Pompeu Fabra University (UPF), Barcelona, Spain
| | - Jean-Marc Hyvelin
- Drug Development Unit (DDU), Société Anonyme (STALICLA SA), Geneva, Switzerland
| | - Lynn Durham
- Discovery and Data Science (DDS) Unit, Sociedad Limitada (STALICLA SL), Barcelona, Spain.,Drug Development Unit (DDU), Société Anonyme (STALICLA SA), Geneva, Switzerland
| | - Baltazar Gomez-Mancilla
- Drug Development Unit (DDU), Société Anonyme (STALICLA SA), Geneva, Switzerland.,Department Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
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6
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Drozd M, Bardoni B, Capovilla M. Modeling Fragile X Syndrome in Drosophila. Front Mol Neurosci 2018; 11:124. [PMID: 29713264 PMCID: PMC5911982 DOI: 10.3389/fnmol.2018.00124] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 03/29/2018] [Indexed: 01/18/2023] Open
Abstract
Intellectual disability (ID) and autism are hallmarks of Fragile X Syndrome (FXS), a hereditary neurodevelopmental disorder. The gene responsible for FXS is Fragile X Mental Retardation gene 1 (FMR1) encoding the Fragile X Mental Retardation Protein (FMRP), an RNA-binding protein involved in RNA metabolism and modulating the expression level of many targets. Most cases of FXS are caused by silencing of FMR1 due to CGG expansions in the 5'-UTR of the gene. Humans also carry the FXR1 and FXR2 paralogs of FMR1 while flies have only one FMR1 gene, here called dFMR1, sharing the same level of sequence homology with all three human genes, but functionally most similar to FMR1. This enables a much easier approach for FMR1 genetic studies. Drosophila has been widely used to investigate FMR1 functions at genetic, cellular, and molecular levels since dFMR1 mutants have many phenotypes in common with the wide spectrum of FMR1 functions that underlay the disease. In this review, we present very recent Drosophila studies investigating FMRP functions at genetic, cellular, molecular, and electrophysiological levels in addition to research on pharmacological treatments in the fly model. These studies have the potential to aid the discovery of pharmacological therapies for FXS.
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Affiliation(s)
- Małgorzata Drozd
- Université Côte d'Azur, CNRS, IPMC, Valbonne, France.,CNRS LIA (Neogenex), Valbonne, France
| | - Barbara Bardoni
- CNRS LIA (Neogenex), Valbonne, France.,Université Côte d'Azur, INSERM, CNRS, IPMC, Valbonne, France
| | - Maria Capovilla
- Université Côte d'Azur, CNRS, IPMC, Valbonne, France.,CNRS LIA (Neogenex), Valbonne, France
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7
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Goniotaki D, Lakkaraju AKK, Shrivastava AN, Bakirci P, Sorce S, Senatore A, Marpakwar R, Hornemann S, Gasparini F, Triller A, Aguzzi A. Inhibition of group-I metabotropic glutamate receptors protects against prion toxicity. PLoS Pathog 2017; 13:e1006733. [PMID: 29176838 PMCID: PMC5720820 DOI: 10.1371/journal.ppat.1006733] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Revised: 12/07/2017] [Accepted: 11/04/2017] [Indexed: 12/29/2022] Open
Abstract
Prion infections cause inexorable, progressive neurological dysfunction and neurodegeneration. Expression of the cellular prion protein PrPC is required for toxicity, suggesting the existence of deleterious PrPC-dependent signaling cascades. Because group-I metabotropic glutamate receptors (mGluR1 and mGluR5) can form complexes with the cellular prion protein (PrPC), we investigated the impact of mGluR1 and mGluR5 inhibition on prion toxicity ex vivo and in vivo. We found that pharmacological inhibition of mGluR1 and mGluR5 antagonized dose-dependently the neurotoxicity triggered by prion infection and by prion-mimetic anti-PrPC antibodies in organotypic brain slices. Prion-mimetic antibodies increased mGluR5 clustering around dendritic spines, mimicking the toxicity of Aβ oligomers. Oral treatment with the mGluR5 inhibitor, MPEP, delayed the onset of motor deficits and moderately prolonged survival of prion-infected mice. Although group-I mGluR inhibition was not curative, these results suggest that it may alleviate the neurological dysfunctions induced by prion diseases.
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Affiliation(s)
| | | | - Amulya N. Shrivastava
- École Normale Supérieure, Institut de Biologie de l'ENS (IBENS) INSERM CNRS PSL Research University, Paris, France
- Paris-Saclay Institute of Neuroscience, CNRS, Gif-sur-Yvette, France
| | - Pamela Bakirci
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
| | - Silvia Sorce
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
| | - Assunta Senatore
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
| | | | - Simone Hornemann
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
| | | | - Antoine Triller
- École Normale Supérieure, Institut de Biologie de l'ENS (IBENS) INSERM CNRS PSL Research University, Paris, France
| | - Adriano Aguzzi
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
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8
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Monyak RE, Emerson D, Schoenfeld BP, Zheng X, Chambers DB, Rosenfelt C, Langer S, Hinchey P, Choi CH, McDonald TV, Bolduc FV, Sehgal A, McBride SM, Jongens TA. Insulin signaling misregulation underlies circadian and cognitive deficits in a Drosophila fragile X model. Mol Psychiatry 2017; 22:1140-1148. [PMID: 27090306 PMCID: PMC5071102 DOI: 10.1038/mp.2016.51] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2016] [Accepted: 03/01/2016] [Indexed: 12/22/2022]
Abstract
Fragile X syndrome (FXS) is an undertreated neurodevelopmental disorder characterized by low intelligence quotent and a wide range of other symptoms including disordered sleep and autism. Although FXS is the most prevalent inherited cause of intellectual disability, its mechanistic underpinnings are not well understood. Using Drosophila as a model of FXS, we showed that select expression of dfmr1 in the insulin-producing cells (IPCs) of the brain was sufficient to restore normal circadian behavior and to rescue the memory deficits in the fragile X mutant fly. Examination of the insulin signaling (IS) pathway revealed elevated levels of Drosophila insulin-like peptide 2 (Dilp2) in the IPCs and elevated IS in the dfmr1 mutant brain. Consistent with a causal role for elevated IS in dfmr1 mutant phenotypes, the expression of dfmr1 specifically in the IPCs reduced IS, and genetic reduction of the insulin pathway also led to amelioration of circadian and memory defects. Furthermore, we showed that treatment with the FDA-approved drug metformin also rescued memory. Finally, we showed that reduction of IS is required at different time points to rescue circadian behavior and memory. Our results indicate that insulin misregulation underlies the circadian and cognitive phenotypes displayed by the Drosophila fragile X model, and thus reveal a metabolic pathway that can be targeted by new and already approved drugs to treat fragile X patients.
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Affiliation(s)
- Rachel E. Monyak
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104-5158
| | - Danielle Emerson
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104-5158
| | - Brian P. Schoenfeld
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104-5158,Section of Molecular Cardiology, Departments of Medicine and Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Xiangzhong Zheng
- Department of Neuroscience and Howard Hughes Medical Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104-5158
| | - Daniel B. Chambers
- Department of Pediatric Neurology, Center for Neuroscience, University of Alberta, Edmonton, Canada AB T6G 2H7
| | - Cory Rosenfelt
- Department of Pediatric Neurology, Center for Neuroscience, University of Alberta, Edmonton, Canada AB T6G 2H7
| | - Steven Langer
- Department of Pediatric Neurology, Center for Neuroscience, University of Alberta, Edmonton, Canada AB T6G 2H7
| | - Paul Hinchey
- Section of Molecular Cardiology, Departments of Medicine and Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Catherine H. Choi
- Section of Molecular Cardiology, Departments of Medicine and Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York 10461,Department of Dermatology, Drexel University College of Medicine, 219 N. Broad Street, Philadelphia, PA, 19107
| | - Thomas V. McDonald
- Section of Molecular Cardiology, Departments of Medicine and Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Francois V. Bolduc
- Department of Pediatric Neurology, Center for Neuroscience, University of Alberta, Edmonton, Canada AB T6G 2H7
| | - Amita Sehgal
- Department of Neuroscience and Howard Hughes Medical Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104-5158
| | - Sean M.J. McBride
- Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104-5158,To whom correspondence should be addressed: and , phone: 215-573-9332, fax: 215-573-9411
| | - Thomas A. Jongens
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104-5158,To whom correspondence should be addressed: and , phone: 215-573-9332, fax: 215-573-9411
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9
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Erickson CA, Davenport MH, Schaefer TL, Wink LK, Pedapati EV, Sweeney JA, Fitzpatrick SE, Brown WT, Budimirovic D, Hagerman RJ, Hessl D, Kaufmann WE, Berry-Kravis E. Fragile X targeted pharmacotherapy: lessons learned and future directions. J Neurodev Disord 2017; 9:7. [PMID: 28616096 PMCID: PMC5467059 DOI: 10.1186/s11689-017-9186-9] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 01/18/2017] [Indexed: 01/04/2023] Open
Abstract
Our understanding of fragile X syndrome (FXS) pathophysiology continues to improve and numerous potential drug targets have been identified. Yet, current prescribing practices are only symptom-based in order to manage difficult behaviors, as no drug to date is approved for the treatment of FXS. Drugs impacting a diversity of targets in the brain have been studied in recent FXS-specific clinical trials. While many drugs have focused on regulation of enhanced glutamatergic or deficient GABAergic neurotransmission, compounds studied have not been limited to these mechanisms. As a single-gene disorder, it was thought that FXS would have consistent drug targets that could be modulated with pharmacotherapy and lead to significant improvement. Unfortunately, despite promising results in FXS animal models, translational drug treatment development in FXS has largely failed. Future success in this field will depend on learning from past challenges to improve clinical trial design, choose appropriate outcome measures and age range choices, and find readily modulated drug targets. Even with many negative placebo-controlled study results, the field continues to move forward exploring both the new mechanistic drug approaches combined with ways to improve trial execution. This review summarizes the known phenotype and pathophysiology of FXS and past clinical trial rationale and results, and discusses current challenges facing the field and lessons from which to learn for future treatment development efforts.
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Affiliation(s)
- Craig A Erickson
- Division of Child and Adolescent Psychiatry (MLC 4002), Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH 45229-3039 USA.,Department of Psychiatry, College of Medicine, University of Cincinnati, Cincinnati, OH USA
| | - Matthew H Davenport
- Division of Child and Adolescent Psychiatry (MLC 4002), Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH 45229-3039 USA.,Department of Biomedical Engineering, College of Engineering and Applied Science, University of Cincinnati, Cincinnati, OH USA
| | - Tori L Schaefer
- Division of Child and Adolescent Psychiatry (MLC 4002), Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH 45229-3039 USA
| | - Logan K Wink
- Division of Child and Adolescent Psychiatry (MLC 4002), Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH 45229-3039 USA.,Department of Psychiatry, College of Medicine, University of Cincinnati, Cincinnati, OH USA
| | - Ernest V Pedapati
- Division of Child and Adolescent Psychiatry (MLC 4002), Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH 45229-3039 USA.,Department of Psychiatry, College of Medicine, University of Cincinnati, Cincinnati, OH USA
| | - John A Sweeney
- Department of Psychiatry, College of Medicine, University of Cincinnati, Cincinnati, OH USA
| | - Sarah E Fitzpatrick
- Division of Child and Adolescent Psychiatry (MLC 4002), Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH 45229-3039 USA
| | - W Ted Brown
- Institute for Basic Research in Developmental Disabilities, New York, NY USA
| | - Dejan Budimirovic
- Clinical Research Center, Clinical Trials Unit, Fragile X Clinic, Kennedy Krieger Institute, The Johns Hopkins Medical Institutions, Baltimore, MD USA.,Departments of Psychiatry & Behavioral Sciences, Child Psychiatry, The Johns Hopkins Medical Institutions, Baltimore, MD USA
| | - Randi J Hagerman
- Medical Investigation of Neurodevelopmental Disorders (MIND) Institute, Davis Medical Center, University of California, Sacramento, CA USA.,Department of Pediatrics, Davis Medical Center, University of California, Sacramento, California USA
| | - David Hessl
- Medical Investigation of Neurodevelopmental Disorders (MIND) Institute, Davis Medical Center, University of California, Sacramento, CA USA.,Department of Psychiatry and Behavioral Sciences, Davis Medical Center, University of California, Sacramento, California USA
| | - Walter E Kaufmann
- Greenwood Genetic Center, Greenwood, SC USA.,Boston Children's Hospital, Boston, Massachusetts USA
| | - Elizabeth Berry-Kravis
- Departments of Pediatrics, Neurological Sciences, Biochemistry, Rush University Medical Center, Chicago, Illinois USA
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10
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Budimirovic DB, Berry-Kravis E, Erickson CA, Hall SS, Hessl D, Reiss AL, King MK, Abbeduto L, Kaufmann WE. Updated report on tools to measure outcomes of clinical trials in fragile X syndrome. J Neurodev Disord 2017; 9:14. [PMID: 28616097 PMCID: PMC5467057 DOI: 10.1186/s11689-017-9193-x] [Citation(s) in RCA: 114] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 02/22/2017] [Indexed: 12/27/2022] Open
Abstract
OBJECTIVE Fragile X syndrome (FXS) has been the neurodevelopmental disorder with the most active translation of preclinical breakthroughs into clinical trials. This process has led to a critical assessment of outcome measures, which resulted in a comprehensive review published in 2013. Nevertheless, the disappointing outcome of several recent phase III drug trials in FXS, and parallel efforts at evaluating behavioral endpoints for trials in autism spectrum disorder (ASD), has emphasized the need for re-assessing outcome measures and revising recommendations for FXS. METHODS After performing an extensive database search (PubMed, Food and Drug Administration (FDA)/National Institutes of Health (NIH)'s www.ClinicalTrials.gov, etc.) to determine progress since 2013, members of the Working Groups who published the 2013 Report evaluated the available outcome measures for FXS and related neurodevelopmental disorders using the COSMIN grading system of levels of evidence. The latter has also been applied to a British survey of endpoints for ASD. In addition, we also generated an informal classification of outcome measures for use in FXS intervention studies as instruments appropriate to detect shorter- or longer-term changes. RESULTS To date, a total of 22 double-blind controlled clinical trials in FXS have been identified through www.ClinicalTrials.gov and an extensive literature search. The vast majority of these FDA/NIH-registered clinical trials has been completed between 2008 and 2015 and has targeted the core excitatory/inhibitory imbalance present in FXS and other neurodevelopmental disorders. Limited data exist on reliability and validity for most tools used to measure cognitive, behavioral, and other problems in FXS in these trials and other studies. Overall, evidence for most tools supports a moderate tool quality grading. Data on sensitivity to treatment, currently under evaluation, could improve ratings for some cognitive and behavioral tools. Some progress has also been made at identifying promising biomarkers, mainly on blood-based and neurophysiological measures. CONCLUSION Despite the tangible progress in implementing clinical trials in FXS, the increasing data on measurement properties of endpoints, and the ongoing process of new tool development, the vast majority of outcome measures are at the moderate quality level with limited information on reliability, validity, and sensitivity to treatment. This situation is not unique to FXS, since reviews of endpoints for ASD have arrived at similar conclusions. These findings, in conjunction with the predominance of parent-based measures particularly in the behavioral domain, indicate that endpoint development in FXS needs to continue with an emphasis on more objective measures (observational, direct testing, biomarkers) that reflect meaningful improvements in quality of life. A major continuous challenge is the development of measurement tools concurrently with testing drug safety and efficacy in clinical trials.
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Affiliation(s)
- Dejan B. Budimirovic
- Departments of Psychiatry and Behavioral Sciences, Kennedy Krieger Institute and Child Psychiatry, Johns Hopkins University School of Medicine, 716 N. Broadway, Baltimore, MD 21205 USA
| | - Elizabeth Berry-Kravis
- Departments of Pediatrics, Neurological Sciences, Biochemistry, Rush University Medical Center, 1725 West Harrison, Suite 718, Chicago, IL 60612 USA
| | - Craig A. Erickson
- Division of Child and Adolescent Psychiatry, Cincinnati Children’s Hospital Medical Center and the University of Cincinnati College of Medicine, 3333 Burnet Avenue MLC 4002, Cincinnati, OH 45229 USA
| | - Scott S. Hall
- Division of Interdisciplinary Brain Sciences, Department of Psychiatry and Behavioral Sciences, Stanford University, 401 Quarry Road, Stanford, CA 94305 USA
| | - David Hessl
- MIND Institute and Department of Psychiatry and Behavioral Sciences, University of California Davis Medical Center, 2825 50th Street, Sacramento, CA 95817 USA
| | - Allan L. Reiss
- Division of Interdisciplinary Brain Sciences, Departments of Psychiatry and Behavioral Sciences, Radiology and Pediatrics, Stanford University, 401 Quarry Road, Stanford, CA 94305 USA
| | - Margaret K. King
- Autism & Developmental Medicine Institute, Geisinger Health System, Present address: Novartis Pharmaceuticals Corporation, US Medical, One Health Plaza, East Hanover, NJ 07936 USA
| | - Leonard Abbeduto
- MIND Institute and Department of Psychiatry and Behavioral Sciences, University of California Davis Medical Center, 2825 50th Street, Sacramento, CA 95817 USA
| | - Walter E. Kaufmann
- Center for Translational Research, Greenwood Genetic Center, 113 Gregor Mendel Circle, Greenwood, SC 29646 USA
- Department of Neurology, Boston Children’s Hospital, Boston, MA 02115 USA
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11
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Schaefer TL, Davenport MH, Grainger LM, Robinson CK, Earnheart AT, Stegman MS, Lang AL, Ashworth AA, Molinaro G, Huber KM, Erickson CA. Acamprosate in a mouse model of fragile X syndrome: modulation of spontaneous cortical activity, ERK1/2 activation, locomotor behavior, and anxiety. J Neurodev Disord 2017; 9:6. [PMID: 28616095 PMCID: PMC5467053 DOI: 10.1186/s11689-017-9184-y] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 01/13/2017] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Fragile X Syndrome (FXS) occurs as a result of a silenced fragile X mental retardation 1 gene (FMR1) and subsequent loss of fragile X mental retardation protein (FMRP) expression. Loss of FMRP alters excitatory/inhibitory signaling balance, leading to increased neuronal hyperexcitability and altered behavior. Acamprosate (the calcium salt of N-acetylhomotaurinate), a drug FDA-approved for relapse prevention in the treatment of alcohol dependence in adults, is a novel agent with multiple mechanisms that may be beneficial for people with FXS. There are questions regarding the neuroactive effects of acamprosate and the significance of the molecule's calcium moiety. Therefore, the electrophysiological, cellular, molecular, and behavioral effects of acamprosate were assessed in the Fmr1-/y (knock out; KO) mouse model of FXS controlling for the calcium salt in several experiments. METHODS Fmr1 KO mice and their wild-type (WT) littermates were utilized to assess acamprosate treatment on cortical UP state parameters, dendritic spine density, and seizure susceptibility. Brain extracellular-signal regulated kinase 1/2 (ERK1/2) activation was used to investigate this signaling molecule as a potential biomarker for treatment response. Additional adult mice were used to assess chronic acamprosate treatment and any potential effects of the calcium moiety using CaCl2 treatment on behavior and nuclear ERK1/2 activation. RESULTS Acamprosate attenuated prolonged cortical UP state duration, decreased elevated ERK1/2 activation in brain tissue, and reduced nuclear ERK1/2 activation in the dentate gyrus in KO mice. Acamprosate treatment modified behavior in anxiety and locomotor tests in Fmr1 KO mice in which control-treated KO mice were shown to deviate from control-treated WT mice. Mice treated with CaCl2 were not different from saline-treated mice in the adult behavior battery or nuclear ERK1/2 activation. CONCLUSIONS These data indicate that acamprosate, and not calcium, improves function reminiscent of reduced anxiety-like behavior and hyperactivity in Fmr1 KO mice and that acamprosate attenuates select electrophysiological and molecular dysregulation that may play a role in the pathophysiology of FXS. Differences between control-treated KO and WT mice were not evident in a recognition memory test or in examination of acoustic startle response/prepulse inhibition which impeded conclusions from being made about the treatment effects of acamprosate in these instances.
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Affiliation(s)
- Tori L Schaefer
- Division of Psychiatry, MLC 7004, Cincinnati Children's Research Foundation, 3333 Burnet Ave., Cincinnati, OH 45229-3039 USA
| | - Matthew H Davenport
- Division of Psychiatry, MLC 7004, Cincinnati Children's Research Foundation, 3333 Burnet Ave., Cincinnati, OH 45229-3039 USA
| | - Lindsay M Grainger
- Division of Psychiatry, MLC 7004, Cincinnati Children's Research Foundation, 3333 Burnet Ave., Cincinnati, OH 45229-3039 USA
| | - Chandler K Robinson
- Division of Psychiatry, MLC 7004, Cincinnati Children's Research Foundation, 3333 Burnet Ave., Cincinnati, OH 45229-3039 USA
| | - Anthony T Earnheart
- Division of Psychiatry, MLC 7004, Cincinnati Children's Research Foundation, 3333 Burnet Ave., Cincinnati, OH 45229-3039 USA
| | - Melinda S Stegman
- Division of Psychiatry, MLC 7004, Cincinnati Children's Research Foundation, 3333 Burnet Ave., Cincinnati, OH 45229-3039 USA.,Present address: Division of Nephrology and Hypertension, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229 USA
| | - Anna L Lang
- Division of Psychiatry, MLC 7004, Cincinnati Children's Research Foundation, 3333 Burnet Ave., Cincinnati, OH 45229-3039 USA.,Present address: Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY 40202 USA
| | - Amy A Ashworth
- Division of Psychiatry, MLC 7004, Cincinnati Children's Research Foundation, 3333 Burnet Ave., Cincinnati, OH 45229-3039 USA.,Present address: BlackbookHR, Cincinnati, OH 45202 USA
| | - Gemma Molinaro
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX 75390 USA
| | - Kimberly M Huber
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX 75390 USA
| | - Craig A Erickson
- Division of Psychiatry, MLC 7004, Cincinnati Children's Research Foundation, 3333 Burnet Ave., Cincinnati, OH 45229-3039 USA
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12
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AlOlaby RR, Sweha SR, Silva M, Durbin-Johnson B, Yrigollen CM, Pretto D, Hagerman RJ, Tassone F. Molecular biomarkers predictive of sertraline treatment response in young children with fragile X syndrome. Brain Dev 2017; 39:483-492. [PMID: 28242040 PMCID: PMC5420478 DOI: 10.1016/j.braindev.2017.01.012] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Revised: 01/26/2017] [Accepted: 01/27/2017] [Indexed: 12/28/2022]
Abstract
OBJECTIVES Several neurotransmitters involved in brain development are altered in fragile X syndrome (FXS), the most common monogenic cause of autism spectrum disorder (ASD). Serotonin plays a vital role in synaptogenesis and postnatal brain development. Deficits in serotonin synthesis and abnormal neurogenesis were shown in young children with autism, suggesting that treating within the first years of life with a selective serotonin reuptake inhibitor might be the most effective time. In this study we aimed to identify molecular biomarkers involved in the serotonergic pathway that could predict the response to sertraline treatment in young children with FXS. METHODS Genotypes were determined for several genes involved in serotonergic pathway in 51 children with FXS, ages 24-72months. Correlations between genotypes and deviations from baseline in primary and secondary outcome measures were modeled using linear regression models. RESULTS A significant association was observed between a BDNF polymorphism and improvements for several clinical measures, including the Clinical Global Impression scale (P=0.008) and the cognitive T score (P=0.017) in those treated with sertraline compared to those in the placebo group. Additionally, polymorphisms in the MAOA, Cytochrome P450 2C19 and 2D6, and in the 5-HTTLPR gene showed a significant correlation with some of the secondary measures included in this study. CONCLUSION This study shows that polymorphisms of genes involved in the serotonergic pathway could play a potential role in predicting response to sertraline treatment in young children with FXS. Larger studies are warranted to confirm these initial findings.
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Affiliation(s)
- Reem Rafik AlOlaby
- Department of Biochemistry and Molecular Medicine, University of California, Davis, School of Medicine, Davis, CA, USA
| | - Stefan R Sweha
- Department of Biochemistry and Molecular Medicine, University of California, Davis, School of Medicine, Davis, CA, USA
| | - Marisol Silva
- Department of Biochemistry and Molecular Medicine, University of California, Davis, School of Medicine, Davis, CA, USA
| | - Blythe Durbin-Johnson
- Department of Biostatistics, University of California Davis, School of Medicine, Davis, CA, USA
| | - Carolyn M Yrigollen
- Department of Biochemistry and Molecular Medicine, University of California, Davis, School of Medicine, Davis, CA, USA
| | - Dalyir Pretto
- Department of Biochemistry and Molecular Medicine, University of California, Davis, School of Medicine, Davis, CA, USA
| | - Randi J Hagerman
- MIND Institute, University of California Davis Medical Center, Davis, CA, USA,Department of Pediatrics, University of California Davis, School of Medicine, Davis, CA, USA
| | - Flora Tassone
- Department of Biochemistry and Molecular Medicine, University of California, Davis, School of Medicine, Davis, CA, USA; MIND Institute, University of California Davis Medical Center, Davis, CA, USA.
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13
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Kang JY, Chadchankar J, Vien TN, Mighdoll MI, Hyde TM, Mather RJ, Deeb TZ, Pangalos MN, Brandon NJ, Dunlop J, Moss SJ. Deficits in the activity of presynaptic γ-aminobutyric acid type B receptors contribute to altered neuronal excitability in fragile X syndrome. J Biol Chem 2017; 292:6621-6632. [PMID: 28213518 PMCID: PMC5399111 DOI: 10.1074/jbc.m116.772541] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2016] [Revised: 02/07/2017] [Indexed: 11/06/2022] Open
Abstract
The behavioral and anatomical deficits seen in fragile X syndrome (FXS) are widely believed to result from imbalances in the relative strengths of excitatory and inhibitory neurotransmission. Although modified neuronal excitability is thought to be of significance, the contribution that alterations in GABAergic inhibition play in the pathophysiology of FXS are ill defined. Slow sustained neuronal inhibition is mediated by γ-aminobutyric acid type B (GABAB) receptors, which are heterodimeric G-protein-coupled receptors constructed from R1a and R2 or R1b and R2 subunits. Via the activation of Gi/o, they limit cAMP accumulation, diminish neurotransmitter release, and induce neuronal hyperpolarization. Here we reveal that selective deficits in R1a subunit expression are seen in Fmr1 knock-out mice (KO) mice, a widely used animal model of FXS, but the levels of the respective mRNAs were unaffected. Similar trends of R1a expression were seen in a subset of FXS patients. GABAB receptors (GABABRs) exert powerful pre- and postsynaptic inhibitory effects on neurotransmission. R1a-containing GABABRs are believed to mediate presynaptic inhibition in principal neurons. In accordance with this result, deficits in the ability of GABABRs to suppress glutamate release were seen in Fmr1-KO mice. In contrast, the ability of GABABRs to suppress GABA release and induce postsynaptic hyperpolarization was unaffected. Significantly, this deficit contributes to the pathophysiology of FXS as the GABABR agonist (R)-baclofen rescued the imbalances between excitatory and inhibitory neurotransmission evident in Fmr1-KO mice. Collectively, our results provided evidence that selective deficits in the activity of presynaptic GABABRs contribute to the pathophysiology of FXS.
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Affiliation(s)
- Ji-Yong Kang
- From the AstraZeneca Tufts Laboratory for Basic and Translational Neuroscience, Tufts University School of Medicine, Boston, Massachusetts 02111
| | - Jayashree Chadchankar
- From the AstraZeneca Tufts Laboratory for Basic and Translational Neuroscience, Tufts University School of Medicine, Boston, Massachusetts 02111
| | - Thuy N Vien
- From the AstraZeneca Tufts Laboratory for Basic and Translational Neuroscience, Tufts University School of Medicine, Boston, Massachusetts 02111
| | | | - Thomas M Hyde
- the Lieber Institute for Brain Development and
- Departments of Neurology and Psychiatry and Behavioral Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Robert J Mather
- From the AstraZeneca Tufts Laboratory for Basic and Translational Neuroscience, Tufts University School of Medicine, Boston, Massachusetts 02111
- Neuroscience, Innovative Medicines and Early Development, AstraZeneca, Waltham, Massachusetts 02451
| | - Tarek Z Deeb
- From the AstraZeneca Tufts Laboratory for Basic and Translational Neuroscience, Tufts University School of Medicine, Boston, Massachusetts 02111
| | - Menelas N Pangalos
- Innovative Medicines and Early Development, AstraZeneca, Melbourn Science Park, Cambridge Road, Royston Herts SG8 6EE, United Kingdom, and
| | - Nicholas J Brandon
- From the AstraZeneca Tufts Laboratory for Basic and Translational Neuroscience, Tufts University School of Medicine, Boston, Massachusetts 02111
- Neuroscience, Innovative Medicines and Early Development, AstraZeneca, Waltham, Massachusetts 02451
| | - John Dunlop
- From the AstraZeneca Tufts Laboratory for Basic and Translational Neuroscience, Tufts University School of Medicine, Boston, Massachusetts 02111
- Neuroscience, Innovative Medicines and Early Development, AstraZeneca, Waltham, Massachusetts 02451
| | - Stephen J Moss
- From the AstraZeneca Tufts Laboratory for Basic and Translational Neuroscience, Tufts University School of Medicine, Boston, Massachusetts 02111,
- Neuroscience, Innovative Medicines and Early Development, AstraZeneca, Waltham, Massachusetts 02451
- the Department of Neuroscience, Physiology and Pharmacology, University College, London WC1E 6BT, United Kingdom
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14
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Delineating the Common Biological Pathways Perturbed by ASD's Genetic Etiology: Lessons from Network-Based Studies. Int J Mol Sci 2017; 18:ijms18040828. [PMID: 28420080 PMCID: PMC5412412 DOI: 10.3390/ijms18040828] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 04/03/2017] [Accepted: 04/06/2017] [Indexed: 12/26/2022] Open
Abstract
In recent decades it has become clear that Autism Spectrum Disorder (ASD) possesses a diverse and heterogeneous genetic etiology. Aberrations in hundreds of genes have been associated with ASD so far, which include both rare and common variations. While one may expect that these genes converge on specific common molecular pathways, which drive the development of the core ASD characteristics, the task of elucidating these common molecular pathways has been proven to be challenging. Several studies have combined genetic analysis with bioinformatical techniques to uncover molecular mechanisms that are specifically targeted by autism-associated genetic aberrations. Recently, several analysis have suggested that particular signaling mechanisms, including the Wnt and Ca2+/Calmodulin-signaling pathways are often targeted by autism-associated mutations. In this review, we discuss several studies that determine specific molecular pathways affected by autism-associated mutations, and then discuss more in-depth into the biological roles of a few of these pathways, and how they may be involved in the development of ASD. Considering that these pathways may be targeted by specific pharmacological intervention, they may prove to be important therapeutic targets for the treatment of ASD.
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15
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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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16
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Tabolacci E, Palumbo F, Nobile V, Neri G. Transcriptional Reactivation of the FMR1 Gene. A Possible Approach to the Treatment of the Fragile X Syndrome. Genes (Basel) 2016; 7:genes7080049. [PMID: 27548224 PMCID: PMC4999837 DOI: 10.3390/genes7080049] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Revised: 07/29/2016] [Accepted: 08/09/2016] [Indexed: 12/15/2022] Open
Abstract
Fragile X syndrome (FXS) is the most common cause of inherited intellectual disability, caused by CGG expansion over 200 repeats (full mutation, FM) at the 5′ untranslated region (UTR) of the fragile X mental retardation 1 (FMR1) gene and subsequent DNA methylation of the promoter region, accompanied by additional epigenetic histone modifications that result in a block of transcription and absence of the fragile X mental retardation protein (FMRP). The lack of FMRP, involved in multiple aspects of mRNA metabolism in the brain, is thought to be the direct cause of the FXS phenotype. Restoration of FMR1 transcription and FMRP production can be obtained in vitro by treating FXS lymphoblastoid cell lines with the demethylating agent 5-azadeoxycytidine, demonstrating that DNA methylation is key to FMR1 inactivation. This concept is strengthened by the existence of rare male carriers of a FM, who are unable to methylate the FMR1 promoter. These individuals produce limited amounts of FMRP and are of normal intelligence. Their inability to methylate the FMR1 promoter, whose cause is not yet fully elucidated, rescues them from manifesting the FXS. These observations demonstrate that a therapeutic approach to FXS based on the pharmacological reactivation of the FMR1 gene is conceptually tenable and worthy of being further pursued.
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Affiliation(s)
- Elisabetta Tabolacci
- Institute of Genomic Medicine, School of Medicine, Catholic University, Largo Francesco Vito 1, Rome 00168, Italy.
| | - Federica Palumbo
- Institute of Genomic Medicine, School of Medicine, Catholic University, Largo Francesco Vito 1, Rome 00168, Italy.
| | - Veronica Nobile
- Institute of Genomic Medicine, School of Medicine, Catholic University, Largo Francesco Vito 1, Rome 00168, Italy.
| | - Giovanni Neri
- Institute of Genomic Medicine, School of Medicine, Catholic University, Largo Francesco Vito 1, Rome 00168, Italy.
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17
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Where Environment Meets Cognition: A Focus on Two Developmental Intellectual Disability Disorders. Neural Plast 2016; 2016:4235898. [PMID: 27547454 PMCID: PMC4980517 DOI: 10.1155/2016/4235898] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 04/03/2016] [Indexed: 11/22/2022] Open
Abstract
One of the most challenging questions in neuroscience is to dissect how learning and memory, the foundational pillars of cognition, are grounded in stable, yet plastic, gene expression states. All known epigenetic mechanisms such as DNA methylation and hydroxymethylation, histone modifications, chromatin remodelling, and noncoding RNAs regulate brain gene expression, both during neurodevelopment and in the adult brain in processes related to cognition. On the other hand, alterations in the various components of the epigenetic machinery have been linked to well-known causes of intellectual disability disorders (IDDs). Two examples are Down Syndrome (DS) and Fragile X Syndrome (FXS), where global and local epigenetic alterations lead to impairments in synaptic plasticity, memory, and learning. Since epigenetic modifications are reversible, it is theoretically possible to use epigenetic drugs as cognitive enhancers for the treatment of IDDs. Epigenetic treatments act in a context specific manner, targeting different regions based on cell and state specific chromatin accessibility, facilitating the establishment of the lost balance. Here, we discuss epigenetic studies of IDDs, focusing on DS and FXS, and the use of epidrugs in combinatorial therapies for IDDs.
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18
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Tabolacci E, Mancano G, Lanni S, Palumbo F, Goracci M, Ferrè F, Helmer-Citterich M, Neri G. Genome-wide methylation analysis demonstrates that 5-aza-2-deoxycytidine treatment does not cause random DNA demethylation in fragile X syndrome cells. Epigenetics Chromatin 2016; 9:12. [PMID: 27014370 PMCID: PMC4806452 DOI: 10.1186/s13072-016-0060-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 03/08/2016] [Indexed: 11/30/2022] Open
Abstract
Background Fragile X syndrome (FXS) is caused by CGG expansion over 200 repeats at the 5′ UTR of the FMR1 gene and subsequent DNA methylation of both the expanded sequence and the CpGs of the promoter region. This epigenetic change causes transcriptional silencing of the gene. We have previously demonstrated that 5-aza-2-deoxycytidine (5-azadC) treatment of FXS lymphoblastoid cell lines reactivates the FMR1 gene, concomitant with CpG sites demethylation, increased acetylation of histones H3 and H4 and methylation of lysine 4 on histone 3. Results In order to check the specificity of the 5-azadC-induced DNA demethylation, now we performed bisulphite sequencing of the entire methylation boundary upstream the FMR1 promoter region, which is preserved in control wild-type cells. We did not observe any modification of the methylation boundary after treatment. Furthermore, methylation analysis by MS-MLPA of PWS/AS and BWS/SRS loci demonstrated that 5-azadC treatment has no demethylating effect on these regions. Genome-wide methylation analysis through Infinium 450K (Illumina) showed no significant enrichment of specific GO terms in differentially methylated regions after 5-azadC treatment. We also observed that reactivation of FMR1 transcription lasts up to a month after a 7-day treatment and that maximum levels of transcription are reached at 10–15 days after last administration of 5-azadC. Conclusions Taken together, these data demonstrate that the demethylating effect of 5-azadC on genomic DNA is not random, but rather restricted to specific regions, if not exclusively to the FMR1 promoter. Moreover, we showed that 5-azadC has a long-lasting reactivating effect on the mutant FMR1 gene. Electronic supplementary material The online version of this article (doi:10.1186/s13072-016-0060-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Elisabetta Tabolacci
- Istituto di Medicina Genomica, Università Cattolica del Sacro Cuore, Largo F. Vito 1, 00168 Rome, Italy
| | - Giorgia Mancano
- Istituto di Medicina Genomica, Università Cattolica del Sacro Cuore, Largo F. Vito 1, 00168 Rome, Italy
| | - Stella Lanni
- Istituto di Medicina Genomica, Università Cattolica del Sacro Cuore, Largo F. Vito 1, 00168 Rome, Italy
| | - Federica Palumbo
- Istituto di Medicina Genomica, Università Cattolica del Sacro Cuore, Largo F. Vito 1, 00168 Rome, Italy
| | - Martina Goracci
- Istituto di Medicina Genomica, Università Cattolica del Sacro Cuore, Largo F. Vito 1, 00168 Rome, Italy
| | - Fabrizio Ferrè
- Department of Biology, Centre for Molecular Bioinformatics (CBM), University of Rome Tor Vergata, Rome, Italy
| | - Manuela Helmer-Citterich
- Department of Biology, Centre for Molecular Bioinformatics (CBM), University of Rome Tor Vergata, Rome, Italy
| | - Giovanni Neri
- Istituto di Medicina Genomica, Università Cattolica del Sacro Cuore, Largo F. Vito 1, 00168 Rome, Italy
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