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Tran H, Le L, Singh BN, Kramer J, Steward R. Tet controls axon guidance in early brain development through glutamatergic signaling. iScience 2024; 27:109634. [PMID: 38655199 PMCID: PMC11035372 DOI: 10.1016/j.isci.2024.109634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 12/18/2023] [Accepted: 03/26/2024] [Indexed: 04/26/2024] Open
Abstract
Mutations in ten-eleven translocation (TET) proteins are associated with human neurodevelopmental disorders. We find a function of Tet in regulating Drosophila early brain development. The Tet DNA-binding domain (TetAXXC) is required for axon guidance in the mushroom body (MB). Glutamine synthetase 2 (Gs2), a key enzyme in glutamatergic signaling, is significantly down-regulated in the TetAXXC brains. Loss of Gs2 recapitulates the TetAXXC phenotype. Surprisingly, Tet and Gs2 act in the insulin-producing cells (IPCs) to control MB axon guidance, and overexpression of Gs2 in IPCs rescues the defects of TetAXXC. Feeding TetAXXC with metabotropic glutamate receptor antagonist MPEP rescues the phenotype while glutamate enhances it. Mutants in Tet and Drosophila Fmr1, the homolog of human FMR1, have similar defects, and overexpression of Gs2 in IPCs also rescues the Fmr1 phenotype. We provide the first evidence that Tet controls the guidance of developing brain axons by modulating glutamatergic signaling.
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Affiliation(s)
- Hiep Tran
- Waksman Institute, Rutgers University, Piscataway, NJ 08854, USA
| | - Le Le
- Waksman Institute, Rutgers University, Piscataway, NJ 08854, USA
| | - Badri Nath Singh
- Waksman Institute, Rutgers University, Piscataway, NJ 08854, USA
| | - Joseph Kramer
- Department of Pathology and Laboratory Medicine, Rutgers Biomedical and Health Sciences, Rutgers University, New Brunswick, NJ 08901, USA
| | - Ruth Steward
- Waksman Institute, Rutgers University, Piscataway, NJ 08854, USA
- Department of Molecular Biology and Biochemistry, Cancer Institute of New Jersey, Rutgers University, New Brunswick, NJ 08901, USA
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Kumar V, Lee KY, Acharya A, Babik MS, Christian-Hinman CA, Rhodes JS, Tsai NP. mGluR7 allosteric modulator AMN082 corrects protein synthesis and pathological phenotypes in FXS. EMBO Mol Med 2024; 16:506-522. [PMID: 38374465 PMCID: PMC10940663 DOI: 10.1038/s44321-024-00038-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2023] [Revised: 01/31/2024] [Accepted: 02/06/2024] [Indexed: 02/21/2024] Open
Abstract
Fragile X syndrome (FXS) is the leading cause of inherited autism and intellectual disabilities. Aberrant protein synthesis due to the loss of fragile X messenger ribonucleoprotein (FMRP) is the major defect in FXS, leading to a plethora of cellular and behavioral abnormalities. However, no treatments are available to date. In this study, we found that activation of metabotropic glutamate receptor 7 (mGluR7) using a positive allosteric modulator named AMN082 represses protein synthesis through ERK1/2 and eIF4E signaling in an FMRP-independent manner. We further demonstrated that treatment of AMN082 leads to a reduction in neuronal excitability, which in turn ameliorates audiogenic seizure susceptibility in Fmr1 KO mice, the FXS mouse model. When evaluating the animals' behavior, we showed that treatment of AMN082 reduces repetitive behavior and improves learning and memory in Fmr1 KO mice. This study uncovers novel functions of mGluR7 and AMN082 and suggests the activation of mGluR7 as a potential therapeutic approach for treating FXS.
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Affiliation(s)
- Vipendra Kumar
- Department of Molecular and Integrative Physiology, School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Kwan Young Lee
- Department of Molecular and Integrative Physiology, School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Anirudh Acharya
- Department of Molecular and Integrative Physiology, School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Matthew S Babik
- Department of Molecular and Integrative Physiology, School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Catherine A Christian-Hinman
- Department of Molecular and Integrative Physiology, School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Justin S Rhodes
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
- Department of Psychology, University of Illinois at Urbana-Champaign, Champaign, IL, 61820, USA
| | - Nien-Pei Tsai
- Department of Molecular and Integrative Physiology, School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
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3
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Weisz ED, Fenton AR, Jongens TA. PGC-1α integrates insulin signaling with mitochondrial physiology and behavior in a Drosophila model of Fragile X Syndrome. NPJ METABOLIC HEALTH AND DISEASE 2024; 2:2. [PMID: 38741938 PMCID: PMC11090494 DOI: 10.1038/s44324-024-00004-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 01/02/2024] [Indexed: 05/16/2024]
Abstract
Fragile X Syndrome (FXS) is the most prevalent monogenetic form of intellectual disability and autism. Recently, dysregulation of insulin signaling (IS) and aberrations in mitochondrial function have emerged as robust, evolutionarily conserved components of FXS pathophysiology. However, the mechanisms by which altered IS and mitochondrial dysfunction impact behavior in the context of FXS remain elusive. Here, we show that normalization of IS improves mitochondrial volume and function in flies that lack expression of dfmr1, the Drosophila homolog of the causal gene of FXS in humans. Further, we demonstrate that dysregulation of IS underlies diminished expression of the mitochondrial master regulator PGC-1α/Spargel in dfmr1 mutant flies. These results are behaviorally relevant, as we show that pan-neuronal augmentation of PGC-1α/Spargel improves circadian behavior in dfmr1 mutants. Notably, we also show that modulation of PGC-1α/Spargel expression in wild-type flies phenocopies the dfmr1 mutant circadian defect. Taken together, the results presented herein provide a mechanistic link between mitochondrial function and circadian behavior both in FXS pathogenesis as well as more broadly at the interface between metabolism and behavioral output.
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Affiliation(s)
- Eliana D. Weisz
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- Autism Spectrum Program of Excellence, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Adam R. Fenton
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Thomas A. Jongens
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- Autism Spectrum Program of Excellence, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
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Lyu K, Li J, Chen M, Li W, Zhang W, Hu M, Zhang Y, Feng X. A bibliometric analysis of autism spectrum disorder signaling pathways research in the past decade. Front Psychiatry 2024; 15:1304916. [PMID: 38410675 PMCID: PMC10895046 DOI: 10.3389/fpsyt.2024.1304916] [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: 09/30/2023] [Accepted: 01/29/2024] [Indexed: 02/28/2024] Open
Abstract
Background This study employs bibliometric methods to comprehensively understand the fundamental structure of research about Autism Spectrum Disorder (ASD) Signaling Pathways by examining key indicators such as nations, institutions, journals, authors, and keywords. Methodology We utilized the WoScc database to retrieve literature relevant to ASD Signaling Pathways published between 2013 and 2023. Through visual analysis and tools like CiteSpace and VosViewer, we explored nations, institutions, journals, authors, and keywords, thereby constructing relevant networks. Results 26 The study encompasses 1,396 articles, revealing a consistent increase in publications. The United States, China, and Germany are leading nations in this literature. Regarding research institutions, the University of California system and Eric Klann have garnered significant attention due to their substantial contributions to the field of ASD Signaling Pathways. Most relevant research is published in the journal "Molecular Autism." Research interests are concentrated across various themes, including "elevating neuronal β-catenin levels," "Tunisian children," "Fmr1 knockout (KO) mice," "de novo mutations," "autistic children," "local translation," "propionic acid-induced mouse models," "neurosystems," "glucose metabolism," and "neuronal migration." Future research may emphasize exploring aspects such as gut microbiota, genes, stress, maternal immune activation, memory, and neurodevelopmental disorders of ASD. Conclusion This study, through bibliometric analysis of key indicators such as nations, institutions, journals, authors, and keywords, provides a comprehensive overview of the current state of research on ASD Signaling Pathways. These investigations predominantly focus on molecular mechanisms, animal model studies, population-based research, and the structure and function of neurosystems. Future research directions are also clearly proposed. First, in-depth research on the genes and neurodevelopmental disorders associated with ASD will continue to reveal the genetic basis and provide support for precise treatments. At the same time, attention to the gut microbiota will help explore its association with ASD, which may provide clues for new treatments. In addition, the relationship between stress and ASD will become the focus of research to understand better the emotional and behavioral characteristics of ASD patients in stressful situations. Maternal immune activation will also be further studied to explore how environmental factors influence the risk and development of ASD. Finally, a deeper understanding of the cognitive functions of patients with ASD, especially memory and learning, will help develop individualized treatment strategies to improve patients' quality of life. These directions will work together and are expected to provide a more comprehensive understanding of Signaling Pathways research in ASD and provide new ideas and opportunities for future intervention and treatment.
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Affiliation(s)
- Kaifeng Lyu
- Faculty of Chinese Medicine, Macau University of Science and Technology, Macau, China
| | - Jiangshan Li
- College of Acupuncture, Moxibustion, Massage, and Rehabilitation, Hunan University of Traditional Chinese Medicine, Changsha, China
| | - Min Chen
- Faculty of Chinese Medicine and State Key Laboratory of Quality Research in Chinese Medicines, Macau University of Science and Technology, Macau, China
| | - Wu Li
- College of Acupuncture, Moxibustion, Massage, and Rehabilitation, Hunan University of Traditional Chinese Medicine, Changsha, China
| | - Wei Zhang
- Pediatrics One, The First Affiliated Hospital of Heilongjiang University of Traditional Chinese Medicine, Harbin, China
| | - Meichao Hu
- Rehabilitation Department, Chifeng Obstetrics and Gynecology Hospitalal, Chifeng, China
| | - Yuxing Zhang
- College of Acupuncture, Moxibustion, Massage, and Rehabilitation, Hunan University of Traditional Chinese Medicine, Changsha, China
| | - Xiang Feng
- College of Acupuncture, Moxibustion, Massage, and Rehabilitation, Hunan University of Traditional Chinese Medicine, Changsha, China
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Yamazaki D, Maeyama Y, Tabata T. Combinatory Actions of Co-transmitters in Dopaminergic Systems Modulate Drosophila Olfactory Memories. J Neurosci 2023; 43:8294-8305. [PMID: 37429719 PMCID: PMC10711700 DOI: 10.1523/jneurosci.2152-22.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Revised: 04/30/2023] [Accepted: 05/27/2023] [Indexed: 07/12/2023] Open
Abstract
Dopamine neurons (DANs) are extensively studied in the context of associative learning, in both vertebrates and invertebrates. In the acquisition of male and female Drosophila olfactory memory, the PAM cluster of DANs provides the reward signal, and the PPL1 cluster of DANs sends the punishment signal to the Kenyon cells (KCs) of mushroom bodies, the center for memory formation. However, thermo-genetical activation of the PPL1 DANs after memory acquisition impaired aversive memory, and that of the PAM DANs impaired appetitive memory. We demonstrate that the knockdown of glutamate decarboxylase, which catalyzes glutamate conversion to GABA in PAM DANs, potentiated the appetitive memory. In addition, the knockdown of glutamate transporter in PPL1 DANs potentiated aversive memory, suggesting that GABA and glutamate co-transmitters act in an inhibitory manner in olfactory memory formation. We also found that, in γKCs, the Rdl receptor for GABA and the mGluR DmGluRA mediate the inhibition. Although multiple-spaced training is required to form long-term aversive memory, a single cycle of training was sufficient to develop long-term memory when the glutamate transporter was knocked down, in even a single subset of PPL1 DANs. Our results suggest that the mGluR signaling pathway may set a threshold for memory acquisition to allow the organisms' behaviors to adapt to changing physiological conditions and environments.SIGNIFICANCE STATEMENT In the acquisition of olfactory memory in Drosophila, the PAM cluster of dopamine neurons (DANs) mediates the reward signal, while the PPL1 cluster of DANs conveys the punishment signal to the Kenyon cells of the mushroom bodies, which serve as the center for memory formation. We found that GABA co-transmitters in the PAM DANs and glutamate co-transmitters in the PPL1 DANs inhibit olfactory memory formation. Our findings demonstrate that long-term memory acquisition, which typically necessitates multiple-spaced training sessions to establish aversive memory, can be triggered with a single training cycle in cases where the glutamate co-transmission is inhibited, even within a single subset of PPL1 DANs, suggesting that the glutamate co-transmission may modulate the threshold for memory acquisition.
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Affiliation(s)
- Daisuke Yamazaki
- Institute of Quantitative Biosciences, The University of Tokyo, Tokyo, 113-0032, Japan
| | - Yuko Maeyama
- Institute of Quantitative Biosciences, The University of Tokyo, Tokyo, 113-0032, Japan
| | - Tetsuya Tabata
- Institute of Quantitative Biosciences, The University of Tokyo, Tokyo, 113-0032, Japan
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6
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Tran H, Le L, Singh BN, Kramer J, Steward R. Tet Controls Axon Guidance in Early Brain Development through Glutamatergic Signaling. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.02.539069. [PMID: 37398066 PMCID: PMC10312521 DOI: 10.1101/2023.05.02.539069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Mutations in human TET proteins have been found in individuals with neurodevelopmental disorders. Here we report a new function of Tet in regulating Drosophila early brain development. We found that mutation in the Tet DNA-binding domain ( Tet AXXC ) resulted in axon guidance defects in the mushroom body (MB). Tet is required in early brain development during the outgrowth of MB β axons. Transcriptomic study shows that glutamine synthetase 2 (Gs2), a key enzyme in glutamatergic signaling, is significantly downregulated in the Tet AXXC mutant brains. CRISPR/Cas9 mutagenesis or RNAi knockdown of Gs2 recapitulates the Tet AXXC mutant phenotype. Surprisingly, Tet and Gs2 act in the insulin-producing cells (IPCs) to control MB axon guidance, and overexpression of Gs2 in these cells rescues the axon guidance defects of Tet AXXC . Treating Tet AXXC with the metabotropic glutamate receptor antagonist MPEP can rescue while treating with glutamate enhances the phenotype confirming Tet function in regulating glutamatergic signaling. Tet AXXC and the Drosophila homolog of Fragile X Messenger Ribonucleoprotein protein mutant ( Fmr1 3 ) have similar axon guidance defects and reduction in Gs2 mRNA levels. Interestingly, overexpression of Gs2 in the IPCs also rescues the Fmr1 3 phenotype, suggesting functional overlapping of the two genes. Our studies provide the first evidence that Tet can control the guidance of axons in the developing brain by modulating glutamatergic signaling and the function is mediated by its DNA-binding domain.
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7
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Ebstein F, Küry S, Most V, Rosenfelt C, Scott-Boyer MP, van Woerden GM, Besnard T, Papendorf JJ, Studencka-Turski M, Wang T, Hsieh TC, Golnik R, Baldridge D, Forster C, de Konink C, Teurlings SM, Vignard V, van Jaarsveld RH, Ades L, Cogné B, Mignot C, Deb W, Jongmans MC, Sessions Cole F, van den Boogaard MJH, Wambach JA, Wegner DJ, Yang S, Hannig V, Brault JA, Zadeh N, Bennetts B, Keren B, Gélineau AC, Powis Z, Towne M, Bachman K, Seeley A, Beck AE, Morrison J, Westman R, Averill K, Brunet T, Haasters J, Carter MT, Osmond M, Wheeler PG, Forzano F, Mohammed S, Trakadis Y, Accogli A, Harrison R, Guo Y, Hakonarson H, Rondeau S, Baujat G, Barcia G, Feichtinger RG, Mayr JA, Preisel M, Laumonnier F, Kallinich T, Knaus A, Isidor B, Krawitz P, Völker U, Hammer E, Droit A, Eichler EE, Elgersma Y, Hildebrand PW, Bolduc F, Krüger E, Bézieau S. PSMC3 proteasome subunit variants are associated with neurodevelopmental delay and type I interferon production. Sci Transl Med 2023; 15:eabo3189. [PMID: 37256937 PMCID: PMC10506367 DOI: 10.1126/scitranslmed.abo3189] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 05/10/2023] [Indexed: 06/02/2023]
Abstract
A critical step in preserving protein homeostasis is the recognition, binding, unfolding, and translocation of protein substrates by six AAA-ATPase proteasome subunits (ATPase-associated with various cellular activities) termed PSMC1-6, which are required for degradation of proteins by 26S proteasomes. Here, we identified 15 de novo missense variants in the PSMC3 gene encoding the AAA-ATPase proteasome subunit PSMC3/Rpt5 in 23 unrelated heterozygous patients with an autosomal dominant form of neurodevelopmental delay and intellectual disability. Expression of PSMC3 variants in mouse neuronal cultures led to altered dendrite development, and deletion of the PSMC3 fly ortholog Rpt5 impaired reversal learning capabilities in fruit flies. Structural modeling as well as proteomic and transcriptomic analyses of T cells derived from patients with PSMC3 variants implicated the PSMC3 variants in proteasome dysfunction through disruption of substrate translocation, induction of proteotoxic stress, and alterations in proteins controlling developmental and innate immune programs. The proteostatic perturbations in T cells from patients with PSMC3 variants correlated with a dysregulation in type I interferon (IFN) signaling in these T cells, which could be blocked by inhibition of the intracellular stress sensor protein kinase R (PKR). These results suggest that proteotoxic stress activated PKR in patient-derived T cells, resulting in a type I IFN response. The potential relationship among proteosome dysfunction, type I IFN production, and neurodevelopment suggests new directions in our understanding of pathogenesis in some neurodevelopmental disorders.
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Affiliation(s)
- Frédéric Ebstein
- Institut für Medizinische Biochemie und Molekularbiologie (IMBM), Universitätsmedizin Greifswald, Ferdinand-Sauerbruch-Straße, 17475 Greifswald, Germany
| | - Sébastien Küry
- Nantes Université, CHU Nantes, Service de Génétique Médicale, 44000 Nantes, France
- Nantes Université, CHU Nantes, CNRS, INSERM, l’institut du thorax, 44000 Nantes, France
| | - Victoria Most
- Institut für Medizinische Physik und Biophysik, Universität Leipzig, Medizinische Fakultät, Härtelstr. 16-18, 04107 Leipzig, Germany
| | - Cory Rosenfelt
- Department of Pediatrics, University of Alberta, Edmonton, AB CT6G 1C9, Canada
| | | | - Geeske M. van Woerden
- Department of Neuroscience, Erasmus University Medical Center, 3015 CN, Rotterdam, The Netherlands
- ENCORE Expertise Center for Neurodevelopmental Disorders, Erasmus University Medical Center, 3015 CN, Rotterdam, The Netherlands
- Department of Clinical Genetics, Erasmus University Medical Center, 3015 CN, Rotterdam, The Netherlands
| | - Thomas Besnard
- Nantes Université, CHU Nantes, Service de Génétique Médicale, 44000 Nantes, France
- Nantes Université, CHU Nantes, CNRS, INSERM, l’institut du thorax, 44000 Nantes, France
| | - Jonas Johannes Papendorf
- Institut für Medizinische Biochemie und Molekularbiologie (IMBM), Universitätsmedizin Greifswald, Ferdinand-Sauerbruch-Straße, 17475 Greifswald, Germany
| | - Maja Studencka-Turski
- Institut für Medizinische Biochemie und Molekularbiologie (IMBM), Universitätsmedizin Greifswald, Ferdinand-Sauerbruch-Straße, 17475 Greifswald, Germany
| | - Tianyun Wang
- Department of Genome Sciences, University of Washington School of Medicine, Seattle, WA 98195, USA
- Department of Medical Genetics, Center for Medical Genetics, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
- Neuroscience Research Institute, Peking University; Key Laboratory for Neuroscience, Ministry of Education of China & National Health Commission of China, Beijing 100191, China
| | - Tzung-Chien Hsieh
- Institute for Genomic Statistics and Bioinformatics, University Hospital Bonn, Rheinische Friedrich-Wilhelms-Universität Bonn, 53127 Bonn, Germany
| | - Richard Golnik
- Klinik für Pädiatrie I, Universitätsklinikum Halle (Saale), 06120 Halle (Saale)
| | - Dustin Baldridge
- The Edward Mallinckrodt Department of Pediatrics, Washington University School of Medicine, St. Louis, MO 63130-4899, USA
| | - Cara Forster
- GeneDx, 207 Perry Parkway, Gaithersburg, MD 20877, USA
| | - Charlotte de Konink
- Department of Neuroscience, Erasmus University Medical Center, 3015 CN, Rotterdam, The Netherlands
- ENCORE Expertise Center for Neurodevelopmental Disorders, Erasmus University Medical Center, 3015 CN, Rotterdam, The Netherlands
| | - Selina M.W. Teurlings
- Department of Neuroscience, Erasmus University Medical Center, 3015 CN, Rotterdam, The Netherlands
- ENCORE Expertise Center for Neurodevelopmental Disorders, Erasmus University Medical Center, 3015 CN, Rotterdam, The Netherlands
| | - Virginie Vignard
- Nantes Université, CHU Nantes, Service de Génétique Médicale, 44000 Nantes, France
- Nantes Université, CHU Nantes, CNRS, INSERM, l’institut du thorax, 44000 Nantes, France
| | | | - Lesley Ades
- Department of Clinical Genetics, The Children’s Hospital at Westmead, Locked Bag 4001, Westmead, NSW, 2145, Australia
- Disciplines of Genomic Medicine & Child and Adolescent Health, Faculty of Medicine and Health, University of Sydney, Sydney, NSW, 2145, Australia
| | - Benjamin Cogné
- Nantes Université, CHU Nantes, Service de Génétique Médicale, 44000 Nantes, France
- Nantes Université, CHU Nantes, CNRS, INSERM, l’institut du thorax, 44000 Nantes, France
| | - Cyril Mignot
- APHP, Hôpital Pitié-Salpêtrière, Département de Génétique, Centre de Reference Déficience Intellectuelle de Causes Rares, GRC UPMC «Déficience Intellectuelle et Autisme», 75013 Paris, France
- Sorbonne Universités, Institut du Cerveau et de la Moelle épinière, ICM, Inserm U1127, CNRS UMR 7225, 75013, Paris, France
| | - Wallid Deb
- Nantes Université, CHU Nantes, Service de Génétique Médicale, 44000 Nantes, France
- Nantes Université, CHU Nantes, CNRS, INSERM, l’institut du thorax, 44000 Nantes, France
| | - Marjolijn C.J. Jongmans
- Department of Genetics, University Medical Center Utrecht, 3508 AB, Utrecht, The Netherlands
- Princess Máxima Center for Pediatric Oncology, 3584 CS, Utrecht, The Netherlands
| | - F. Sessions Cole
- The Edward Mallinckrodt Department of Pediatrics, Washington University School of Medicine, St. Louis, MO 63130-4899, USA
| | | | - Jennifer A. Wambach
- The Edward Mallinckrodt Department of Pediatrics, Washington University School of Medicine, St. Louis, MO 63130-4899, USA
| | - Daniel J. Wegner
- The Edward Mallinckrodt Department of Pediatrics, Washington University School of Medicine, St. Louis, MO 63130-4899, USA
| | - Sandra Yang
- GeneDx, 207 Perry Parkway, Gaithersburg, MD 20877, USA
| | - Vickie Hannig
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Jennifer Ann Brault
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Neda Zadeh
- Genetics Center, Orange, CA 92868, USA; Division of Medical Genetics, Children’s Hospital of Orange County, Orange, CA 92868, USA
| | - Bruce Bennetts
- Disciplines of Genomic Medicine & Child and Adolescent Health, Faculty of Medicine and Health, University of Sydney, Sydney, NSW, 2145, Australia
- Sydney Genome Diagnostics, Western Sydney Genetics Program, The Children’s Hospital at Westmead, Sydney, NSW, 2145, Australia
| | - Boris Keren
- Département de Génétique, Centre de Référence des Déficiences Intellectuelles de Causes Rares, Groupe Hospitalier Pitié-Salpêtrière, Assistance Publique-Hôpitaux de Paris, 75013 Paris
| | - Anne-Claire Gélineau
- Département de Génétique, Centre de Référence des Déficiences Intellectuelles de Causes Rares, Groupe Hospitalier Pitié-Salpêtrière, Assistance Publique-Hôpitaux de Paris, 75013 Paris
| | - Zöe Powis
- Department of Clinical Research, Ambry Genetics, Aliso Viejo, CA 92656, USA
| | - Meghan Towne
- Department of Clinical Research, Ambry Genetics, Aliso Viejo, CA 92656, USA
| | | | - Andrea Seeley
- Genomic Medicine Institute, Geisinger, Danville, PA 17822, USA
| | - Anita E. Beck
- Department of Pediatrics, Division of Genetic Medicine, University of Washington & Seattle Children’s Hospital, Seattle, WA 98195-6320, USA
| | - Jennifer Morrison
- Division of Genetics, Arnold Palmer Hospital for Children, Orlando Health, Orlando, FL 32806, USA
| | - Rachel Westman
- Division of Genetics, St. Luke’s Clinic, Boise, ID 83712, USA
| | - Kelly Averill
- Department of Pediatrics, Division of Pediatric Neurology, UT Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Theresa Brunet
- Institute of Human Genetics, Technical University of Munich, School of Medicine, 81675 Munich, Germany
- Institute of Neurogenomics (ING), Helmholtz Zentrum München, German Research Center for Environmental Health, 85764 Neuherberg, Germany
| | - Judith Haasters
- Klinikum der Universität München, Integriertes Sozial- pädiatrisches Zentrum, 80337 Munich, Germany
| | - Melissa T. Carter
- Children’s Hospital of Eastern Ontario Research Institute, University of Ottawa, ON K1H 8L1, Canada
- Department of Genetics, Children’s Hospital of Eastern Ontario, Ottawa, ON K1H 8L1, Canada
| | - Matthew Osmond
- Children’s Hospital of Eastern Ontario Research Institute, University of Ottawa, ON K1H 8L1, Canada
| | - Patricia G. Wheeler
- Division of Genetics, Arnold Palmer Hospital for Children, Orlando Health, Orlando, FL 32806, USA
| | - Francesca Forzano
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK
- Clinical Genetics Department, Guy’s & St Thomas’ NHS Foundation Trust, London SE1 9RT, UK
| | - Shehla Mohammed
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK
- Clinical Genetics Department, Guy’s & St Thomas’ NHS Foundation Trust, London SE1 9RT, UK
| | - Yannis Trakadis
- Division of Medical Genetics, McGill University Health Centre, Montreal, QC H4A 3J1, Canada
| | - Andrea Accogli
- Division of Medical Genetics, McGill University Health Centre, Montreal, QC H4A 3J1, Canada
| | - Rachel Harrison
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK
- Department of Clinical Genetics, Nottingham University Hospitals NHS Trust, City Hospital Campus, The Gables, Gate 3, Hucknall Road, Nottingham NG5 1PB, UK
| | - Yiran Guo
- Center for Applied Genomics, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
- Center for Data Driven Discovery in Biomedicine, Children’s Hospital of Philadelphia, Philadelphia, PA 19146, USA
| | - Hakon Hakonarson
- Center for Applied Genomics, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Sophie Rondeau
- Service de Médecine Génomique des Maladies Rares, Hôpital Universitaire Necker-Enfants Malades, 75743 Paris, France
| | - Geneviève Baujat
- Service de Médecine Génomique des Maladies Rares, Hôpital Universitaire Necker-Enfants Malades, 75743 Paris, France
| | - Giulia Barcia
- Service de Médecine Génomique des Maladies Rares, Hôpital Universitaire Necker-Enfants Malades, 75743 Paris, France
| | - René Günther Feichtinger
- University Children’s Hospital, Salzburger Landeskliniken (SALK) and Paracelsus Medical University (PMU), 5020 Salzburg, Austria
| | - Johannes Adalbert Mayr
- University Children’s Hospital, Salzburger Landeskliniken (SALK) and Paracelsus Medical University (PMU), 5020 Salzburg, Austria
| | - Martin Preisel
- University Children’s Hospital, Salzburger Landeskliniken (SALK) and Paracelsus Medical University (PMU), 5020 Salzburg, Austria
| | - Frédéric Laumonnier
- UMR 1253, iBrain, Université de Tours, Inserm, 37032 Tours, France
- Service de Génétique, Centre Hospitalier Régional Universitaire, 37032 Tours, France
| | - Tilmann Kallinich
- Department of Pediatric Respiratory Medicine, Immunology and Critical Care Medicine, Charité Universitätsmedizin Berlin; 13353 Berlin, Germany
- Deutsches Rheumaforschungszentrum, An Institute of the Leibniz Association, Berlin and Berlin Institute of Health, 10117 Berlin, Germany
| | - Alexej Knaus
- Institute for Genomic Statistics and Bioinformatics, University Hospital Bonn, Rheinische Friedrich-Wilhelms-Universität Bonn, 53127 Bonn, Germany
| | - Bertrand Isidor
- Nantes Université, CHU Nantes, Service de Génétique Médicale, 44000 Nantes, France
- Nantes Université, CHU Nantes, CNRS, INSERM, l’institut du thorax, 44000 Nantes, France
| | - Peter Krawitz
- Institute for Genomic Statistics and Bioinformatics, University Hospital Bonn, Rheinische Friedrich-Wilhelms-Universität Bonn, 53127 Bonn, Germany
| | - Uwe Völker
- Universitätsmedizin Greifswald, Interfakultäres Institut für Genetik und Funktionelle Genomforschung, Abteilung für Funktionelle Genomforschung, 17487 Greifswald, Germany
| | - Elke Hammer
- Universitätsmedizin Greifswald, Interfakultäres Institut für Genetik und Funktionelle Genomforschung, Abteilung für Funktionelle Genomforschung, 17487 Greifswald, Germany
| | - Arnaud Droit
- Research Center of Quebec CHU-Université Laval, Québec, QC PQ G1E6W2, Canada
| | - Evan E. Eichler
- Department of Genome Sciences, University of Washington School of Medicine, Seattle, WA 98195, USA
- Howard Hughes Medical Institute, University of Washington, Seattle, WA, 98195, USA
| | - Ype Elgersma
- ENCORE Expertise Center for Neurodevelopmental Disorders, Erasmus University Medical Center, 3015 CN, Rotterdam, The Netherlands
- Department of Clinical Genetics, Erasmus University Medical Center, 3015 CN, Rotterdam, The Netherlands
| | - Peter W. Hildebrand
- Institut für Medizinische Physik und Biophysik, Universität Leipzig, Medizinische Fakultät, Härtelstr. 16-18, 04107 Leipzig, Germany
- Charité Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Medical Physics and Biophysics, Berlin, Germany
- Berlin Institute of Health, 10178 Berlin, Germany
| | - François Bolduc
- Department of Pediatrics, University of Alberta, Edmonton, AB CT6G 1C9, Canada
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB T6G 2E1, Canada
- Department of Medical Genetics, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - Elke Krüger
- Institut für Medizinische Biochemie und Molekularbiologie (IMBM), Universitätsmedizin Greifswald, Ferdinand-Sauerbruch-Straße, 17475 Greifswald, Germany
| | - Stéphane Bézieau
- Nantes Université, CHU Nantes, Service de Génétique Médicale, 44000 Nantes, France
- Nantes Université, CHU Nantes, CNRS, INSERM, l’institut du thorax, 44000 Nantes, France
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8
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De Donno MD, Puricella A, D'Attis S, Specchia V, Bozzetti MP. Expression of Transposable Elements in the Brain of the Drosophila melanogaster Model for Fragile X Syndrome. Genes (Basel) 2023; 14:genes14051060. [PMID: 37239420 DOI: 10.3390/genes14051060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 05/03/2023] [Accepted: 05/08/2023] [Indexed: 05/28/2023] Open
Abstract
Fragile X syndrome is a neuro-developmental disease affecting intellectual abilities and social interactions. Drosophila melanogaster represents a consolidated model to study neuronal pathways underlying this syndrome, especially because the model recapitulates complex behavioural phenotypes. Drosophila Fragile X protein, or FMRP, is required for a normal neuronal structure and for correct synaptic differentiation in both the peripheral and central nervous systems, as well as for synaptic connectivity during development of the neuronal circuits. At the molecular level, FMRP has a crucial role in RNA homeostasis, including a role in transposon RNA regulation in the gonads of D. m. Transposons are repetitive sequences regulated at both the transcriptional and post-transcriptional levels to avoid genomic instability. De-regulation of transposons in the brain in response to chromatin relaxation has previously been related to neurodegenerative events in Drosophila models. Here, we demonstrate for the first time that FMRP is required for transposon silencing in larval and adult brains of Drosophila "loss of function" dFmr1 mutants. This study highlights that flies kept in isolation, defined as asocial conditions, experience activation of transposable elements. In all, these results suggest a role for transposons in the pathogenesis of certain neurological alterations in Fragile X as well as in abnormal social behaviors.
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Affiliation(s)
- Maria Dolores De Donno
- Department of Biological and Environmental Sciences and Technologies, DiSTeBA, University of Salento, Via Monteroni 165, 73100 Lecce, Italy
| | - Antonietta Puricella
- Department of Biological and Environmental Sciences and Technologies, DiSTeBA, University of Salento, Via Monteroni 165, 73100 Lecce, Italy
| | - Simona D'Attis
- Department of Biological and Environmental Sciences and Technologies, DiSTeBA, University of Salento, Via Monteroni 165, 73100 Lecce, Italy
| | - Valeria Specchia
- Department of Biological and Environmental Sciences and Technologies, DiSTeBA, University of Salento, Via Monteroni 165, 73100 Lecce, Italy
| | - Maria Pia Bozzetti
- Department of Biological and Environmental Sciences and Technologies, DiSTeBA, University of Salento, Via Monteroni 165, 73100 Lecce, Italy
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9
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Louros SR, Seo SS, Maio B, Martinez-Gonzalez C, Gonzalez-Lozano MA, Muscas M, Verity NC, Wills JC, Li KW, Nolan MF, Osterweil EK. Excessive proteostasis contributes to pathology in fragile X syndrome. Neuron 2023; 111:508-525.e7. [PMID: 36495869 DOI: 10.1016/j.neuron.2022.11.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 09/06/2022] [Accepted: 11/16/2022] [Indexed: 12/13/2022]
Abstract
In fragile X syndrome (FX), the leading monogenic cause of autism, excessive neuronal protein synthesis is a core pathophysiology; however, an overall increase in protein expression is not observed. Here, we tested whether excessive protein synthesis drives a compensatory rise in protein degradation that is protective for FX mouse model (Fmr1-/y) neurons. Surprisingly, although we find a significant increase in protein degradation through ubiquitin proteasome system (UPS), this contributes to pathological changes. Normalizing proteasome activity with bortezomib corrects excessive hippocampal protein synthesis and hyperactivation of neurons in the inferior colliculus (IC) in response to auditory stimulation. Moreover, systemic administration of bortezomib significantly reduces the incidence and severity of audiogenic seizures (AGS) in the Fmr1-/y mouse, as does genetic reduction of proteasome, specifically in the IC. Together, these results identify excessive activation of the UPS pathway in Fmr1-/y neurons as a contributor to multiple phenotypes that can be targeted for therapeutic intervention.
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Affiliation(s)
- Susana R Louros
- Centre for Discovery Brain Sciences, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK; Simons Initiative for the Developing Brain, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK
| | - Sang S Seo
- Centre for Discovery Brain Sciences, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK; Simons Initiative for the Developing Brain, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK
| | - Beatriz Maio
- Centre for Discovery Brain Sciences, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK; Simons Initiative for the Developing Brain, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK
| | - Cristina Martinez-Gonzalez
- Centre for Discovery Brain Sciences, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK; Simons Initiative for the Developing Brain, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK
| | - Miguel A Gonzalez-Lozano
- Department of Molecular and Cellular Neurobiology, Centre for Neurogenomics and Cognitive Research, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Melania Muscas
- Centre for Discovery Brain Sciences, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK; Simons Initiative for the Developing Brain, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK
| | - Nick C Verity
- Centre for Discovery Brain Sciences, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK; Simons Initiative for the Developing Brain, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK
| | - Jimi C Wills
- CRUK Edinburgh Centre, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
| | - Ka Wan Li
- Department of Molecular and Cellular Neurobiology, Centre for Neurogenomics and Cognitive Research, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Matthew F Nolan
- Centre for Discovery Brain Sciences, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK; Simons Initiative for the Developing Brain, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK
| | - Emily K Osterweil
- Centre for Discovery Brain Sciences, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK; Simons Initiative for the Developing Brain, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK.
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10
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FMRP activity and control of Csw/SHP2 translation regulate MAPK-dependent synaptic transmission. PLoS Biol 2023; 21:e3001969. [PMID: 36701299 PMCID: PMC9879533 DOI: 10.1371/journal.pbio.3001969] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 12/16/2022] [Indexed: 01/27/2023] Open
Abstract
Noonan syndrome (NS) and NS with multiple lentigines (NSML) cognitive dysfunction are linked to SH2 domain-containing protein tyrosine phosphatase-2 (SHP2) gain-of-function (GoF) and loss-of-function (LoF), respectively. In Drosophila disease models, we find both SHP2 mutations from human patients and corkscrew (csw) homolog LoF/GoF elevate glutamatergic transmission. Cell-targeted RNAi and neurotransmitter release analyses reveal a presynaptic requirement. Consistently, all mutants exhibit reduced synaptic depression during high-frequency stimulation. Both LoF and GoF mutants also show impaired synaptic plasticity, including reduced facilitation, augmentation, and post-tetanic potentiation. NS/NSML diseases are characterized by elevated MAPK/ERK signaling, and drugs suppressing this signaling restore normal neurotransmission in mutants. Fragile X syndrome (FXS) is likewise characterized by elevated MAPK/ERK signaling. Fragile X Mental Retardation Protein (FMRP) binds csw mRNA and neuronal Csw protein is elevated in Drosophila fragile X mental retardation 1 (dfmr1) nulls. Moreover, phosphorylated ERK (pERK) is increased in dfmr1 and csw null presynaptic boutons. We find presynaptic pERK activation in response to stimulation is reduced in dfmr1 and csw nulls. Trans-heterozygous csw/+; dfmr1/+ recapitulate elevated presynaptic pERK activation and function, showing FMRP and Csw/SHP2 act within the same signaling pathway. Thus, a FMRP and SHP2 MAPK/ERK regulative mechanism controls basal and activity-dependent neurotransmission strength.
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11
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Trajković J, Makevic V, Pesic M, Pavković-Lučić S, Milojevic S, Cvjetkovic S, Hagerman R, Budimirovic DB, Protic D. Drosophila melanogaster as a Model to Study Fragile X-Associated Disorders. Genes (Basel) 2022; 14:genes14010087. [PMID: 36672829 PMCID: PMC9859539 DOI: 10.3390/genes14010087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 12/22/2022] [Accepted: 12/23/2022] [Indexed: 12/30/2022] Open
Abstract
Fragile X syndrome (FXS) is a global neurodevelopmental disorder caused by the expansion of CGG trinucleotide repeats (≥200) in the Fragile X Messenger Ribonucleoprotein 1 (FMR1) gene. FXS is the hallmark of Fragile X-associated disorders (FXD) and the most common monogenic cause of inherited intellectual disability and autism spectrum disorder. There are several animal models used to study FXS. In the FXS model of Drosophila, the only ortholog of FMR1, dfmr1, is mutated so that its protein is missing. This model has several relevant phenotypes, including defects in the circadian output pathway, sleep problems, memory deficits in the conditioned courtship and olfactory conditioning paradigms, deficits in social interaction, and deficits in neuronal development. In addition to FXS, a model of another FXD, Fragile X-associated tremor/ataxia syndrome (FXTAS), has also been established in Drosophila. This review summarizes many years of research on FXD in Drosophila models.
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Affiliation(s)
- Jelena Trajković
- Faculty of Biology, University of Belgrade, 11000 Belgrade, Serbia
| | - Vedrana Makevic
- Department of Pathophysiology, Faculty of Medicine, University of Belgrade, 11000 Belgrade, Serbia
| | - Milica Pesic
- Institute of Human Genetics, Faculty of Medicine, University of Belgrade, 11000 Belgrade, Serbia
| | | | - Sara Milojevic
- Department of Pharmacology, Clinical Pharmacology and Toxicology, Faculty of Medicine, University of Belgrade, 11000 Belgrade, Serbia
| | - Smiljana Cvjetkovic
- Department of Humanities, Faculty of Medicine, University of Belgrade, 11000 Belgrade, Serbia
| | - Randi Hagerman
- Medical Investigation of Neurodevelopmental Disorders (MIND) Institute, University of California Davis, 2825 50th Street, Sacramento, CA 95817, USA
- 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
| | - Dragana Protic
- Department of Pharmacology, Clinical Pharmacology and Toxicology, Faculty of Medicine, University of Belgrade, 11000 Belgrade, Serbia
- Correspondence:
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12
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Song C, Broadie K. Dysregulation of BMP, Wnt, and Insulin Signaling in Fragile X Syndrome. Front Cell Dev Biol 2022; 10:934662. [PMID: 35880195 PMCID: PMC9307498 DOI: 10.3389/fcell.2022.934662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Accepted: 06/06/2022] [Indexed: 01/21/2023] Open
Abstract
Drosophila models of neurological disease contribute tremendously to research progress due to the high conservation of human disease genes, the powerful and sophisticated genetic toolkit, and the rapid generation time. Fragile X syndrome (FXS) is the most prevalent heritable cause of intellectual disability and autism spectrum disorders, and the Drosophila FXS disease model has been critical for the genetic screening discovery of new intercellular secretion mechanisms. Here, we focus on the roles of three major signaling pathways: BMP, Wnt, and insulin-like peptides. We present Drosophila FXS model defects compared to mouse models in stem cells/embryos, the glutamatergic neuromuscular junction (NMJ) synapse model, and the developing adult brain. All three of these secreted signaling pathways are strikingly altered in FXS disease models, giving new mechanistic insights into impaired cellular outcomes and neurological phenotypes. Drosophila provides a powerful genetic screening platform to expand understanding of these secretory mechanisms and to test cellular roles in both peripheral and central nervous systems. The studies demonstrate the importance of exploring broad genetic interactions and unexpected regulatory mechanisms. We discuss a number of research avenues to pursue BMP, Wnt, and insulin signaling in future FXS investigations and the development of potential therapeutics.
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Affiliation(s)
- Chunzhu Song
- Department of Biological Sciences, College of Arts and Science, Vanderbilt University, Nashville, TN, United States
| | - Kendal Broadie
- Department of Biological Sciences, College of Arts and Science, Vanderbilt University, Nashville, TN, United States
- Department of Cell and Developmental Biology, School of Medicine, Vanderbilt University, Nashville, TN, United States
- Kennedy Center for Research on Human Development, Nashville, TN, United States
- Vanderbilt Brain Institute, School of Medicine, Vanderbilt University and Medical Center, Nashville, TN, United States
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13
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Seo SS, Louros SR, Anstey N, Gonzalez-Lozano MA, Harper CB, Verity NC, Dando O, Thomson SR, Darnell JC, Kind PC, Li KW, Osterweil EK. Excess ribosomal protein production unbalances translation in a model of Fragile X Syndrome. Nat Commun 2022; 13:3236. [PMID: 35688821 PMCID: PMC9187743 DOI: 10.1038/s41467-022-30979-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 05/23/2022] [Indexed: 12/21/2022] Open
Abstract
Dysregulated protein synthesis is a core pathogenic mechanism in Fragile X Syndrome (FX). The mGluR Theory of FX predicts that pathological synaptic changes arise from the excessive translation of mRNAs downstream of mGlu1/5 activation. Here, we use a combination of CA1 pyramidal neuron-specific TRAP-seq and proteomics to identify the overtranslating mRNAs supporting exaggerated mGlu1/5 -induced long-term synaptic depression (mGluR-LTD) in the FX mouse model (Fmr1−/y). Our results identify a significant increase in the translation of ribosomal proteins (RPs) upon mGlu1/5 stimulation that coincides with a reduced translation of long mRNAs encoding synaptic proteins. These changes are mimicked and occluded in Fmr1−/y neurons. Inhibiting RP translation significantly impairs mGluR-LTD and prevents the length-dependent shift in the translating population. Together, these results suggest that pathological changes in FX result from a length-dependent alteration in the translating population that is supported by excessive RP translation. Dysregulated protein synthesis is key contributor to Fragile X syndrome. Here the authors identify a relationship between ribosome expression and the translation of long mRNAs that contributes to synaptic weakening in a model of Fragile X syndrome.
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Affiliation(s)
- Sang S Seo
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK.,Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, UK
| | - Susana R Louros
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK.,Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, UK
| | - Natasha Anstey
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK.,Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, UK
| | - Miguel A Gonzalez-Lozano
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Callista B Harper
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK.,Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, UK
| | - Nicholas C Verity
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK.,Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, UK
| | - Owen Dando
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK.,Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, UK
| | - Sophie R Thomson
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK.,Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, UK
| | - Jennifer C Darnell
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK.,Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, UK
| | - Peter C Kind
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK.,Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, UK
| | - Ka Wan Li
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Emily K Osterweil
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK. .,Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, UK.
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14
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Song C, Leahy SN, Rushton EM, Broadie K. RNA-binding FMRP and Staufen sequentially regulate the Coracle scaffold to control synaptic glutamate receptor and bouton development. Development 2022; 149:274991. [PMID: 35394012 PMCID: PMC9148565 DOI: 10.1242/dev.200045] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 03/23/2022] [Indexed: 12/16/2022]
Abstract
Both mRNA-binding Fragile X mental retardation protein (FMRP; Fmr1) and mRNA-binding Staufen regulate synaptic bouton formation and glutamate receptor (GluR) levels at the Drosophila neuromuscular junction (NMJ) glutamatergic synapse. Here, we tested whether these RNA-binding proteins act jointly in a common mechanism. We found that both dfmr1 and staufen mutants, and trans-heterozygous double mutants, displayed increased synaptic bouton formation and GluRIIA accumulation. With cell-targeted RNA interference, we showed a downstream Staufen role within postsynaptic muscle. With immunoprecipitation, we showed that FMRP binds staufen mRNA to stabilize postsynaptic transcripts. Staufen is known to target actin-binding, GluRIIA anchor Coracle, and we confirmed that Staufen binds to coracle mRNA. We found that FMRP and Staufen act sequentially to co-regulate postsynaptic Coracle expression, and showed that Coracle, in turn, controls GluRIIA levels and synaptic bouton development. Consistently, we found that dfmr1, staufen and coracle mutants elevate neurotransmission strength. We also identified that FMRP, Staufen and Coracle all suppress pMad activation, providing a trans-synaptic signaling linkage between postsynaptic GluRIIA levels and presynaptic bouton development. This work supports an FMRP-Staufen-Coracle-GluRIIA-pMad pathway regulating structural and functional synapse development.
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Affiliation(s)
- Chunzhu Song
- Department of Biological Sciences, Vanderbilt University and Medical Center, Nashville, TN 37235, USA
| | - Shannon N. Leahy
- Department of Biological Sciences, Vanderbilt University and Medical Center, Nashville, TN 37235, USA
| | - Emma M. Rushton
- Department of Biological Sciences, Vanderbilt University and Medical Center, Nashville, TN 37235, USA
| | - Kendal Broadie
- Department of Biological Sciences, Vanderbilt University and Medical Center, Nashville, TN 37235, USA,Kennedy Center for Research on Human Development, Vanderbilt University and Medical Center, Nashville, TN 37235, USA,Vanderbilt Brain Institute, Vanderbilt University and Medical Center, Nashville, TN 37235, USA,Author for correspondence ()
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15
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Sears JC, Broadie K. Temporally and Spatially Localized PKA Activity within Learning and Memory Circuitry Regulated by Network Feedback. eNeuro 2022; 9:ENEURO.0450-21.2022. [PMID: 35301221 PMCID: PMC8982635 DOI: 10.1523/eneuro.0450-21.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2021] [Revised: 02/18/2022] [Accepted: 03/12/2022] [Indexed: 12/02/2022] Open
Abstract
Dynamic functional connectivity within brain circuits requires coordination of intercellular signaling and intracellular signal transduction. Critical roles for cAMP-dependent protein kinase A (PKA) signaling are well established in the Drosophila mushroom body (MB) learning and memory circuitry, but local PKA activity within this well-mapped neuronal network is uncharacterized. Here, we use an in vivo PKA activity sensor (PKA-SPARK) to test spatiotemporal regulatory requirements in the MB axon lobes. We find immature animals have little detectable PKA activity, whereas postcritical period adults show high field-selective activation primarily in just 3/16 defined output regions. In addition to the age-dependent PKA activity in distinct α'/β' lobe nodes, females show sex-dependent elevation compared with males in these same restricted regions. Loss of neural cell body Fragile X mental retardation protein (FMRP) and Rugose [human Neurobeachin (NBEA)] suppresses localized PKA activity, whereas overexpression (OE) of MB lobe PKA-synergist Meng-Po (human SBK1) promotes PKA activity. Elevated Meng-Po subverts the PKA age-dependence, with elevated activity in immature animals, and spatial-restriction, with striking γ lobe activity. Testing circuit signaling requirements with temperature-sensitive shibire (human Dynamin) blockade, we find broadly expanded PKA activity within the MB lobes. Using transgenic tetanus toxin to block MB synaptic output, we find greatly heightened PKA activity in virtually all MB lobe fields, although the age-dependence is maintained. We conclude spatiotemporally restricted PKA activity signaling within this well-mapped learning/memory circuit is age-dependent and sex-dependent, driven by FMRP-Rugose pathway activation, temporally promoted by Meng-Po kinase function, and restricted by output neurotransmission providing network feedback.
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Affiliation(s)
- James C Sears
- Department of Biological Sciences, Vanderbilt University and Medical Center, Nashville, TN 37235
- Vanderbilt Brain Institute, Vanderbilt University and Medical Center, Nashville, TN 37235
| | - Kendal Broadie
- Department of Biological Sciences, Vanderbilt University and Medical Center, Nashville, TN 37235
- Vanderbilt Brain Institute, Vanderbilt University and Medical Center, Nashville, TN 37235
- Department of Cell and Developmental Biology, Vanderbilt University and Medical Center, Nashville, TN 37235
- Department of Pharmacology, Vanderbilt University and Medical Center, Nashville, TN 37235
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16
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Querfurth H, Lee HK. Mammalian/mechanistic target of rapamycin (mTOR) complexes in neurodegeneration. Mol Neurodegener 2021; 16:44. [PMID: 34215308 PMCID: PMC8252260 DOI: 10.1186/s13024-021-00428-5] [Citation(s) in RCA: 106] [Impact Index Per Article: 35.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 02/01/2021] [Indexed: 12/12/2022] Open
Abstract
Novel targets to arrest neurodegeneration in several dementing conditions involving misfolded protein accumulations may be found in the diverse signaling pathways of the Mammalian/mechanistic target of rapamycin (mTOR). As a nutrient sensor, mTOR has important homeostatic functions to regulate energy metabolism and support neuronal growth and plasticity. However, in Alzheimer's disease (AD), mTOR alternately plays important pathogenic roles by inhibiting both insulin signaling and autophagic removal of β-amyloid (Aβ) and phospho-tau (ptau) aggregates. It also plays a role in the cerebrovascular dysfunction of AD. mTOR is a serine/threonine kinase residing at the core in either of two multiprotein complexes termed mTORC1 and mTORC2. Recent data suggest that their balanced actions also have implications for Parkinson's disease (PD) and Huntington's disease (HD), Frontotemporal dementia (FTD) and Amyotrophic Lateral Sclerosis (ALS). Beyond rapamycin; an mTOR inhibitor, there are rapalogs having greater tolerability and micro delivery modes, that hold promise in arresting these age dependent conditions.
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Affiliation(s)
- Henry Querfurth
- Department of Neurology, Tufts Medical Center, Boston, Massachusetts, USA.
| | - Han-Kyu Lee
- Department of Neurology, Tufts Medical Center, Boston, Massachusetts, USA
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17
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Dionne O, Corbin F. An "Omic" Overview of Fragile X Syndrome. BIOLOGY 2021; 10:433. [PMID: 34068266 PMCID: PMC8153138 DOI: 10.3390/biology10050433] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 05/01/2021] [Accepted: 05/08/2021] [Indexed: 01/16/2023]
Abstract
Fragile X syndrome (FXS) is a neurodevelopmental disorder associated with a wide range of cognitive, behavioral and medical problems. It arises from the silencing of the fragile X mental retardation 1 (FMR1) gene and, consequently, in the absence of its encoded protein, FMRP (fragile X mental retardation protein). FMRP is a ubiquitously expressed and multifunctional RNA-binding protein, primarily considered as a translational regulator. Pre-clinical studies of the past two decades have therefore focused on this function to relate FMRP's absence to the molecular mechanisms underlying FXS physiopathology. Based on these data, successful pharmacological strategies were developed to rescue fragile X phenotype in animal models. Unfortunately, these results did not translate into humans as clinical trials using same therapeutic approaches did not reach the expected outcomes. These failures highlight the need to put into perspective the different functions of FMRP in order to get a more comprehensive understanding of FXS pathophysiology. This work presents a review of FMRP's involvement on noteworthy molecular mechanisms that may ultimately contribute to various biochemical alterations composing the fragile X phenotype.
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Affiliation(s)
- Olivier Dionne
- Department of Biochemistry and Functional Genomics, Faculty of Medicine and Health Sciences, Université de Sherbrooke and Centre de Recherche du CHUS, CIUSSS de l’Estrie-CHUS, Sherbrooke, QC J1H 5H4, Canada;
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18
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Kim S, Kim J, Park S, Park JJ, Lee S. Drosophila Graf regulates mushroom body β-axon extension and olfactory long-term memory. Mol Brain 2021; 14:73. [PMID: 33892766 PMCID: PMC8067379 DOI: 10.1186/s13041-021-00782-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 04/15/2021] [Indexed: 11/10/2022] Open
Abstract
Loss-of-function mutations in the human oligophrenin-1 (OPHN1) gene cause intellectual disability, a prevailing neurodevelopmental condition. However, the role OPHN1 plays during neuronal development is not well understood. We investigated the role of the Drosophila OPHN1 ortholog Graf in the development of the mushroom body (MB), a key brain structure for learning and memory in insects. We show that loss of Graf causes abnormal crossing of the MB β lobe over the brain midline during metamorphosis. This defect in Graf mutants is rescued by MB-specific expression of Graf and OPHN1. Furthermore, MB α/β neuron-specific RNA interference experiments and mosaic analyses indicate that Graf acts via a cell-autonomous mechanism. Consistent with the negative regulation of epidermal growth factor receptor (EGFR)-mitogen-activated protein kinase (MAPK) signaling by Graf, activation of this pathway is required for the β-lobe midline-crossing phenotype of Graf mutants. Finally, Graf mutants have impaired olfactory long-term memory. Our findings reveal a role for Graf in MB axon development and suggest potential neurodevelopmental functions of human OPHN1.
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Affiliation(s)
- Sungdae Kim
- Department of Cell and Developmental Biology and Dental Research Institute, Seoul National University, Seoul, 08826, Republic of Korea
| | - Joohyung Kim
- Department of Brain and Cognitive Sciences, Seoul National University, Seoul, 08826, Republic of Korea
| | - Sunyoung Park
- Department of Cell and Developmental Biology and Dental Research Institute, Seoul National University, Seoul, 08826, Republic of Korea
| | - Joong-Jean Park
- Department of Physiology, College of Medicine, Korea University, Seoul, 02841, Republic of Korea
| | - Seungbok Lee
- Department of Cell and Developmental Biology and Dental Research Institute, Seoul National University, Seoul, 08826, Republic of Korea.
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19
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Roselli C, Ramaswami M, Boto T, Cervantes-Sandoval I. The Making of Long-Lasting Memories: A Fruit Fly Perspective. Front Behav Neurosci 2021; 15:662129. [PMID: 33859556 PMCID: PMC8042140 DOI: 10.3389/fnbeh.2021.662129] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 03/08/2021] [Indexed: 11/25/2022] Open
Abstract
Understanding the nature of the molecular mechanisms underlying memory formation, consolidation, and forgetting are some of the fascinating questions in modern neuroscience. The encoding, stabilization and elimination of memories, rely on the structural reorganization of synapses. These changes will enable the facilitation or depression of neural activity in response to the acquisition of new information. In other words, these changes affect the weight of specific nodes within a neural network. We know that these plastic reorganizations require de novo protein synthesis in the context of Long-term memory (LTM). This process depends on neural activity triggered by the learned experience. The use of model organisms like Drosophila melanogaster has been proven essential for advancing our knowledge in the field of neuroscience. Flies offer an optimal combination of a more straightforward nervous system, composed of a limited number of cells, and while still displaying complex behaviors. Studies in Drosophila neuroscience, which expanded over several decades, have been critical for understanding the cellular and molecular mechanisms leading to the synaptic and behavioral plasticity occurring in the context of learning and memory. This is possible thanks to sophisticated technical approaches that enable precise control of gene expression in the fruit fly as well as neural manipulation, like chemogenetics, thermogenetics, or optogenetics. The search for the identity of genes expressed as a result of memory acquisition has been an active interest since the origins of behavioral genetics. From screenings of more or less specific candidates to broader studies based on transcriptome analysis, our understanding of the genetic control behind LTM has expanded exponentially in the past years. Here we review recent literature regarding how the formation of memories induces a rapid, extensive and, in many cases, transient wave of transcriptional activity. After a consolidation period, transcriptome changes seem more stable and likely represent the synthesis of new proteins. The complexity of the circuitry involved in memory formation and consolidation is such that there are localized changes in neural activity, both regarding temporal dynamics and the nature of neurons and subcellular locations affected, hence inducing specific temporal and localized changes in protein expression. Different types of neurons are recruited at different times into memory traces. In LTM, the synthesis of new proteins is required in specific subsets of cells. This de novo translation can take place in the somatic cytoplasm and/or locally in distinct zones of compartmentalized synaptic activity, depending on the nature of the proteins and the plasticity-inducing processes that occur. We will also review recent advances in understanding how localized changes are confined to the relevant synapse. These recent studies have led to exciting discoveries regarding proteins that were not previously involved in learning and memory processes. This invaluable information will lead to future functional studies on the roles that hundreds of new molecular actors play in modulating neural activity.
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Affiliation(s)
- Camilla Roselli
- Trinity College Institute of Neuroscience, School of Genetics and Microbiology, Smurfit Institute of Genetics and School of Natural Sciences, Trinity College Dublin, Dublin, Ireland
| | - Mani Ramaswami
- Trinity College Institute of Neuroscience, School of Genetics and Microbiology, Smurfit Institute of Genetics and School of Natural Sciences, Trinity College Dublin, Dublin, Ireland.,National Centre for Biological Sciences, TIFR, Bengaluru, India
| | - Tamara Boto
- Trinity College Institute of Neuroscience, Department of Physiology, School of Medicine, Trinity College Dublin, Dublin, Ireland
| | - Isaac Cervantes-Sandoval
- Department of Biology, Georgetown University, Washington, DC, United States.,Interdisciplinary Program in Neuroscience, Georgetown University, Washington, DC, United States
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20
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Zhang Y, Zhou Y, Zhang X, Wang L, Zhong Y. Clock neurons gate memory extinction in Drosophila. Curr Biol 2021; 31:1337-1343.e4. [PMID: 33545046 DOI: 10.1016/j.cub.2021.01.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 08/15/2020] [Accepted: 01/06/2021] [Indexed: 11/25/2022]
Abstract
Memory forms when a previously neutral stimulus (CS+) becomes competent to predict a biologically potent stimulus (US). However, if the CS+ is repeatedly presented without the US after the memory formation, this memory will be suppressed by newly formed extinction memory.1,2 The striking feature of extinction learning is that it requires repeated trials to robustly form extinction. Extended repetition only yields memories that remain transient in nature,3 thus imposing challenges in understanding the underlying mechanisms of extinction learning. Here, we took advantage of the versatile genetic tools4 and the well-characterized circadian system of Drosophila5,6 to link these unique features to clock neurons. We report that inhibiting the activity of clock neurons blocks the formation of extinction memory. Further investigation attributes this role to a subset of cryptochrome-positive dorsal neurons 1 (DN1s) and their downstream SIFamide neurons. The requirement of clock neurons from a gating mechanism of extinction for a single extinction learning trial robustly causes typical extinction when coupled with acute activation of DN1s, as marked by the initially enhanced but eventually diminished memory suppression. Accordingly, we detected specific neural responses to extinction training in a few DN1s via calcium imaging fulfilled by the TRIC tool,7 but not in dorsal neurons 2 or dorsolateral neurons. Based on these findings, we propose that in extinction of appetitive long-term memory, multiple trials of extinction learning robustly activate DN1 clock neurons to open the gate of extinction, which may contribute to the transient nature of extinction memory.
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Affiliation(s)
- Yunchuan Zhang
- School of Life Science, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing 100084, China; Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
| | - Yinzhong Zhou
- School of Life Science, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing 100084, China; Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
| | - Xuchen Zhang
- School of Life Science, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing 100084, China; Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
| | - Lingling Wang
- School of Life Science, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing 100084, China; Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
| | - Yi Zhong
- School of Life Science, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing 100084, China; Tsinghua-Peking Center for Life Sciences, Beijing 100084, China.
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21
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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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22
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Neuron-Specific FMRP Roles in Experience-Dependent Remodeling of Olfactory Brain Innervation during an Early-Life Critical Period. J Neurosci 2021; 41:1218-1241. [PMID: 33402421 DOI: 10.1523/jneurosci.2167-20.2020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 12/04/2020] [Accepted: 12/08/2020] [Indexed: 01/12/2023] Open
Abstract
Critical periods are developmental windows during which neural circuits effectively adapt to the new sensory environment. Animal models of fragile X syndrome (FXS), a common monogenic autism spectrum disorder (ASD), exhibit profound impairments of sensory experience-driven critical periods. However, it is not known whether the causative fragile X mental retardation protein (FMRP) acts uniformly across neurons, or instead manifests neuron-specific functions. Here, we use the genetically-tractable Drosophila brain antennal lobe (AL) olfactory circuit of both sexes to investigate neuron-specific FMRP roles in the odorant experience-dependent remodeling of the olfactory sensory neuron (OSN) innervation during an early-life critical period. We find targeted OSN class-specific FMRP RNAi impairs innervation remodeling within AL synaptic glomeruli, whereas global dfmr1 null mutants display relatively normal odorant-driven refinement. We find both OSN cell autonomous and cell non-autonomous FMRP functions mediate odorant experience-dependent remodeling, with AL circuit FMRP imbalance causing defects in overall glomerulus innervation refinement. We find OSN class-specific FMRP levels bidirectionally regulate critical period remodeling, with odorant experience selectively controlling OSN synaptic terminals in AL glomeruli. We find OSN class-specific FMRP loss impairs critical period remodeling by disrupting responses to lateral modulation from other odorant-responsive OSNs mediating overall AL gain control. We find that silencing glutamatergic AL interneurons reduces OSN remodeling, while conversely, interfering with the OSN class-specific GABAA signaling enhances remodeling. These findings reveal control of OSN synaptic remodeling by FMRP with neuron-specific circuit functions, and indicate how neural circuitry can compensate for global FMRP loss to reinstate normal critical period brain circuit remodeling.SIGNIFICANCE STATEMENT Fragile X syndrome (FXS), the leading monogenic cause of intellectual disability and autism spectrum disorder (ASD), manifests severe neurodevelopmental delays. Likewise, FXS disease models display disrupted neurodevelopmental critical periods. In the well-mapped Drosophila olfactory circuit model, perturbing the causative fragile X mental retardation protein (FMRP) within a single olfactory sensory neuron (OSN) class impairs odorant-dependent remodeling during an early-life critical period. Importantly, this impairment requires activation of other OSNs, and the olfactory circuit can compensate when FMRP is removed from all OSNs. Understanding the neuron-specific FMRP requirements within a developing neural circuit, as well as the FMRP loss compensation mechanisms, should help us engineer FXS treatments. This work suggests FXS treatments could use homeostatic mechanisms to alleviate circuit-level deficits.
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23
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Proteau-Lemieux M, Knoth IS, Agbogba K, Côté V, Barlahan Biag HM, Thurman AJ, Martin CO, Bélanger AM, Rosenfelt C, Tassone F, Abbeduto LJ, Jacquemont S, Hagerman R, Bolduc F, Hessl D, Schneider A, Lippé S. EEG Signal Complexity Is Reduced During Resting-State in Fragile X Syndrome. Front Psychiatry 2021; 12:716707. [PMID: 34858220 PMCID: PMC8632368 DOI: 10.3389/fpsyt.2021.716707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Accepted: 10/06/2021] [Indexed: 11/13/2022] Open
Abstract
Introduction: Fragile X syndrome (FXS) is a genetic disorder caused by a mutation of the fragile X mental retardation 1 gene (FMR1). FXS is associated with neurophysiological abnormalities, including cortical hyperexcitability. Alterations in electroencephalogram (EEG) resting-state power spectral density (PSD) are well-defined in FXS and were found to be linked to neurodevelopmental delays. Whether non-linear dynamics of the brain signal are also altered remains to be studied. Methods: In this study, resting-state EEG power, including alpha peak frequency (APF) and theta/beta ratio (TBR), as well as signal complexity using multi-scale entropy (MSE) were compared between 26 FXS participants (ages 5-28 years), and 7 neurotypical (NT) controls with a similar age distribution. Subsequently a replication study was carried out, comparing our cohort to 19 FXS participants independently recorded at a different site. Results: PSD results confirmed the increased gamma, decreased alpha power and APF in FXS participants compared to NT controls. No alterations in TBR were found. Importantly, results revealed reduced signal complexity in FXS participants, specifically in higher scales, suggesting that altered signal complexity is sensitive to brain alterations in this population. The replication study mostly confirmed these results and suggested critical points of stagnation in the neurodevelopmental curve of FXS. Conclusion: Signal complexity is a powerful feature that can be added to the electrophysiological biomarkers of brain maturation in FXS.
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Affiliation(s)
- Mélodie Proteau-Lemieux
- Department of Psychology, University of Montreal, Montreal, QC, Canada.,Research Center of the Sainte-Justine University Hospital, Montreal, QC, Canada
| | - Inga Sophia Knoth
- Research Center of the Sainte-Justine University Hospital, Montreal, QC, Canada
| | - Kristian Agbogba
- Research Center of the Sainte-Justine University Hospital, Montreal, QC, Canada
| | - Valérie Côté
- Research Center of the Sainte-Justine University Hospital, Montreal, QC, Canada
| | - Hazel Maridith Barlahan Biag
- University of California Davis Medical Investigation of Neurodevelopmental Disorders (MIND) Institute, Sacramento, CA, United States
| | - Angela John Thurman
- University of California Davis Medical Investigation of Neurodevelopmental Disorders (MIND) Institute, Sacramento, CA, United States
| | | | - Anne-Marie Bélanger
- Research Center of the Sainte-Justine University Hospital, Montreal, QC, Canada
| | - Cory Rosenfelt
- Department of Pediatric Neurology, University of Alberta, Edmonton, AB, Canada
| | - Flora Tassone
- University of California Davis Medical Investigation of Neurodevelopmental Disorders (MIND) Institute, Sacramento, CA, United States.,Department of Biochemistry and Molecular Medicine, University of California Davis School of Medicine, Sacramento, CA, United States
| | - Leonard J Abbeduto
- University of California Davis Medical Investigation of Neurodevelopmental Disorders (MIND) Institute, Sacramento, CA, United States.,Department of Psychiatry and Behavioral Sciences, University of California Davis School of Medicine, Sacramento, CA, United States
| | - Sébastien Jacquemont
- Research Center of the Sainte-Justine University Hospital, Montreal, QC, Canada.,Department of Pediatrics, University of Montreal, Montreal, QC, Canada
| | - Randi Hagerman
- University of California Davis Medical Investigation of Neurodevelopmental Disorders (MIND) Institute, Sacramento, CA, United States
| | - François Bolduc
- Department of Pediatric Neurology, University of Alberta, Edmonton, AB, Canada
| | - David Hessl
- University of California Davis Medical Investigation of Neurodevelopmental Disorders (MIND) Institute, Sacramento, CA, United States.,Department of Psychiatry and Behavioral Sciences, University of California Davis School of Medicine, Sacramento, CA, United States
| | - Andrea Schneider
- University of California Davis Medical Investigation of Neurodevelopmental Disorders (MIND) Institute, Sacramento, CA, United States.,California North State University, College of Psychology, Rancho Cordova, CA, United States
| | - Sarah Lippé
- Department of Psychology, University of Montreal, Montreal, QC, Canada.,Research Center of the Sainte-Justine University Hospital, Montreal, QC, Canada
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24
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Andrew DR, Moe ME, Chen D, Tello JA, Doser RL, Conner WE, Ghuman JK, Restifo LL. Spontaneous motor-behavior abnormalities in two Drosophila models of neurodevelopmental disorders. J Neurogenet 2020; 35:1-22. [PMID: 33164597 DOI: 10.1080/01677063.2020.1833005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Mutations in hundreds of genes cause neurodevelopmental disorders with abnormal motor behavior alongside cognitive deficits. Boys with fragile X syndrome (FXS), a leading monogenic cause of intellectual disability, often display repetitive behaviors, a core feature of autism. By direct observation and manual analysis, we characterized spontaneous-motor-behavior phenotypes of Drosophila dfmr1 mutants, an established model for FXS. We recorded individual 1-day-old adult flies, with mature nervous systems and prior to the onset of aging, in small arenas. We scored behavior using open-source video-annotation software to generate continuous activity timelines, which were represented graphically and quantitatively. Young dfmr1 mutants spent excessive time grooming, with increased bout number and duration; both were rescued by transgenic wild-type dfmr1+. By two grooming-pattern measures, dfmr1-mutant flies showed elevated repetitions consistent with perseveration, which is common in FXS. In addition, the mutant flies display a preference for grooming posterior body structures, and an increased rate of grooming transitions from one site to another. We raise the possibility that courtship and circadian rhythm defects, previously reported for dfmr1 mutants, are complicated by excessive grooming. We also observed significantly increased grooming in CASK mutants, despite their dramatically decreased walking phenotype. The mutant flies, a model for human CASK-related neurodevelopmental disorders, displayed consistently elevated grooming indices throughout the assay, but transient locomotory activation immediately after placement in the arena. Based on published data identifying FMRP-target transcripts and functional analyses of mutations causing human genetic neurodevelopmental disorders, we propose the following proteins as candidate mediators of excessive repetitive behaviors in FXS: CaMKIIα, NMDA receptor subunits 2A and 2B, NLGN3, and SHANK3. Together, these fly-mutant phenotypes and mechanistic insights provide starting points for drug discovery to identify compounds that reduce dysfunctional repetitive behaviors.
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Affiliation(s)
- David R Andrew
- Department of Neurology, University of Arizona Health Sciences, Tucson, AZ, USA.,Center for Insect Science, University of Arizona, Tucson, AZ, USA.,Department of Biological Sciences, Lycoming College, Williamsport, PA, USA
| | - Mariah E Moe
- Department of Neurology, University of Arizona Health Sciences, Tucson, AZ, USA
| | - Dailu Chen
- Department of Neurology, University of Arizona Health Sciences, Tucson, AZ, USA
| | - Judith A Tello
- Department of Neurology, University of Arizona Health Sciences, Tucson, AZ, USA.,Graduate Interdisciplinary Program in Neuroscience, University of Arizona, Tucson, AZ, USA
| | - Rachel L Doser
- Department of Neurology, University of Arizona Health Sciences, Tucson, AZ, USA
| | - William E Conner
- Department of Biology, Wake Forest University, Winston-Salem, NC, USA
| | - Jaswinder K Ghuman
- Department of Psychiatry, University of Arizona Health Sciences, Tucson, AZ, USA
| | - Linda L Restifo
- Department of Neurology, University of Arizona Health Sciences, Tucson, AZ, USA.,Center for Insect Science, University of Arizona, Tucson, AZ, USA.,Graduate Interdisciplinary Program in Neuroscience, University of Arizona, Tucson, AZ, USA.,BIO5 Interdisciplinary Research Institute, University of Arizona, Tucson, AZ, USA
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25
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Schieweck R, Ninkovic J, Kiebler MA. RNA-binding proteins balance brain function in health and disease. Physiol Rev 2020; 101:1309-1370. [PMID: 33000986 DOI: 10.1152/physrev.00047.2019] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Posttranscriptional gene expression including splicing, RNA transport, translation, and RNA decay provides an important regulatory layer in many if not all molecular pathways. Research in the last decades has positioned RNA-binding proteins (RBPs) right in the center of posttranscriptional gene regulation. Here, we propose interdependent networks of RBPs to regulate complex pathways within the central nervous system (CNS). These are involved in multiple aspects of neuronal development and functioning, including higher cognition. Therefore, it is not sufficient to unravel the individual contribution of a single RBP and its consequences but rather to study and understand the tight interplay between different RBPs. In this review, we summarize recent findings in the field of RBP biology and discuss the complex interplay between different RBPs. Second, we emphasize the underlying dynamics within an RBP network and how this might regulate key processes such as neurogenesis, synaptic transmission, and synaptic plasticity. Importantly, we envision that dysfunction of specific RBPs could lead to perturbation within the RBP network. This would have direct and indirect (compensatory) effects in mRNA binding and translational control leading to global changes in cellular expression programs in general and in synaptic plasticity in particular. Therefore, we focus on RBP dysfunction and how this might cause neuropsychiatric and neurodegenerative disorders. Based on recent findings, we propose that alterations in the entire regulatory RBP network might account for phenotypic dysfunctions observed in complex diseases including neurodegeneration, epilepsy, and autism spectrum disorders.
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Affiliation(s)
- Rico Schieweck
- Biomedical Center (BMC), Department for Cell Biology and Anatomy, Medical Faculty, Ludwig-Maximilians-University, Planegg-Martinsried, Germany
| | - Jovica Ninkovic
- Biomedical Center (BMC), Department for Cell Biology and Anatomy, Medical Faculty, Ludwig-Maximilians-University, Planegg-Martinsried, Germany
| | - Michael A Kiebler
- Biomedical Center (BMC), Department for Cell Biology and Anatomy, Medical Faculty, Ludwig-Maximilians-University, Planegg-Martinsried, Germany
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26
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Sorrell MR, Killian KA. Innate immune system function following systemic RNA-interference of the Fragile X Mental Retardation 1 gene in the cricket Acheta domesticus. JOURNAL OF INSECT PHYSIOLOGY 2020; 126:104097. [PMID: 32791072 DOI: 10.1016/j.jinsphys.2020.104097] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 06/02/2020] [Accepted: 08/06/2020] [Indexed: 06/11/2023]
Abstract
Fragile X syndrome (FXS), caused by a mutation in the Fragile X Mental Retardation 1 (FMR1) gene, is a common form of inherited mental retardation. Mutation of the gene leads to a loss of the gene product Fragile X Mental Retardation Protein (FMRP). While a loss of FMRP has been primarily associated with neural and cognitive deficits, it has also been reported to lead to immune system dysfunction in both humans and flies. We used the Acheta domesticus transcriptome to identify a highly conserved cricket ortholog of FMR1 (adfmr1). We cloned a partial cDNA of adfmr1, used systemic RNA interference (RNAi) to knockdown adfmr1 expression, and examined the impact of this knockdown (KD) on the cellular and humoral responses of the insect innate immune system. Following RNAi, both male and female crickets exhibited an increase in the number of circulating hemocytes, a decrease in total hemolymph phenoloxidase (PO) activity, and an increase in fat body lysozyme expression. Despite similar changes in these immune parameters in both sexes, male and female crickets responded differently to an immune challenge. Most KD males failed to survive an intra-abdominal injection of bacterial lipopolysaccharide, while KD females were just as likely as control females to survive this challenge. Our results support that decreased fmr1 expression can alter the cellular and humoral defenses of the insect innate immune system, and may lead to a decrease in male, but not female, immunocompetence.
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Affiliation(s)
- Mollie R Sorrell
- Department of Biology, Miami University, 258 Pearson Hall, Oxford, OH 45056, USA; Department of Biology, Defiance College, Defiance, OH 43512, USA
| | - Kathleen A Killian
- Department of Biology, Miami University, 258 Pearson Hall, Oxford, OH 45056, USA.
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27
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Kulkarni A, Lopez DH, Extavour CG. Shared Cell Biological Functions May Underlie Pleiotropy of Molecular Interactions in the Germ Lines and Nervous Systems of Animals. Front Ecol Evol 2020. [DOI: 10.3389/fevo.2020.00215] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
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28
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Mariano V, Achsel T, Bagni C, Kanellopoulos AK. Modelling Learning and Memory in Drosophila to Understand Intellectual Disabilities. Neuroscience 2020; 445:12-30. [PMID: 32730949 DOI: 10.1016/j.neuroscience.2020.07.034] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Revised: 07/19/2020] [Accepted: 07/20/2020] [Indexed: 12/24/2022]
Abstract
Neurodevelopmental disorders (NDDs) include a large number of conditions such as Fragile X syndrome, autism spectrum disorders and Down syndrome, among others. They are characterized by limitations in adaptive and social behaviors, as well as intellectual disability (ID). Whole-exome and whole-genome sequencing studies have highlighted a large number of NDD/ID risk genes. To dissect the genetic causes and underlying biological pathways, in vivo experimental validation of the effects of these mutations is needed. The fruit fly, Drosophila melanogaster, is an ideal model to study NDDs, with highly tractable genetics, combined with simple behavioral and circuit assays, permitting rapid medium-throughput screening of NDD/ID risk genes. Here, we review studies where the use of well-established assays to study mechanisms of learning and memory in Drosophila has permitted insights into molecular mechanisms underlying IDs. We discuss how technologies in the fly model, combined with a high degree of molecular and physiological conservation between flies and mammals, highlight the Drosophila system as an ideal model to study neurodevelopmental disorders, from genetics to behavior.
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Affiliation(s)
- Vittoria Mariano
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne 1005, Switzerland; Department of Human Genetics, KU Leuven, Leuven 3000, Belgium
| | - Tilmann Achsel
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne 1005, Switzerland
| | - Claudia Bagni
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne 1005, Switzerland; Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome 00133, Italy.
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29
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From the Argonauts Mythological Sailors to the Argonautes RNA-Silencing Navigators: Their Emerging Roles in Human-Cell Pathologies. Int J Mol Sci 2020; 21:ijms21114007. [PMID: 32503341 PMCID: PMC7312461 DOI: 10.3390/ijms21114007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 06/01/2020] [Accepted: 06/01/2020] [Indexed: 12/27/2022] Open
Abstract
Regulation of gene expression has emerged as a fundamental element of transcript homeostasis. Key effectors in this process are the Argonautes (AGOs), highly specialized RNA-binding proteins (RBPs) that form complexes, such as the RNA-Induced Silencing Complex (RISC). AGOs dictate post-transcriptional gene-silencing by directly loading small RNAs and repressing their mRNA targets through small RNA-sequence complementarity. The four human highly-conserved family-members (AGO1, AGO2, AGO3, and AGO4) demonstrate multi-faceted and versatile roles in transcriptome’s stability, plasticity, and functionality. The post-translational modifications of AGOs in critical amino acid residues, the nucleotide polymorphisms and mutations, and the deregulation of expression and interactions are tightly associated with aberrant activities, which are observed in a wide spectrum of pathologies. Through constantly accumulating information, the AGOs’ fundamental engagement in multiple human diseases has recently emerged. The present review examines new insights into AGO-driven pathology and AGO-deregulation patterns in a variety of diseases such as in viral infections and propagations, autoimmune diseases, cancers, metabolic deficiencies, neuronal disorders, and human infertility. Altogether, AGO seems to be a crucial contributor to pathogenesis and its targeting may serve as a novel and powerful therapeutic tool for the successful management of diverse human diseases in the clinic.
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30
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Roy R, Shiina N, Wang DO. More dynamic, more quantitative, unexpectedly intricate: Advanced understanding on synaptic RNA localization in learning and memory. Neurobiol Learn Mem 2019; 168:107149. [PMID: 31881355 DOI: 10.1016/j.nlm.2019.107149] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 10/25/2019] [Accepted: 12/23/2019] [Indexed: 01/13/2023]
Abstract
Synaptic signaling exhibits great diversity, complexity, and plasticity which necessitates maintenance and rapid modification of a local proteome. One solution neurons actively exploit to meet such demands is the strategic deposition of mRNAs encoding proteins for both basal and experience-driven activities into ribonucleoprotein complexes at the synapse. Transcripts localized in this manner can be rapidly accessed for translation in response to a diverse range of stimuli in a temporal- and spatially-restricted manner. Here we review recent findings on localized RNAs and RNA binding proteins in the context of learning and memory, as revealed by cutting-edge in-vitro and in-vivo technologies capable of yielding quantitative and dynamic information. The new technologies include proteomic and transcriptomic analyses, high-resolution multiplexed RNA imaging, single-molecule RNA tracking in living neurons, animal models and human neuron cell models. Among many recent advances in the field, RNA chemical modification has emerged as one of the new regulatory layers of gene expression at synapse that is complex and yet largely unexplored. These exciting new discoveries have enhanced our understanding of the modulation mechanisms of synaptic gene expression and their roles in cognition.
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Affiliation(s)
- Rohini Roy
- Institute for Integrated Cell-Material Sciences (iCeMS), Kyoto University, Kyoto, Japan; Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Nobuyuki Shiina
- Laboratory of Neuronal Cell Biology, National Institute for Basic Biology, Okazaki, Japan; Department of Basic Biology, SOKENDAI, Okazaki, Japan; Exploratory Research Center on Life and Living Systems, Okazaki, Japan.
| | - Dan Ohtan Wang
- Wuya College of Innovation, Shenyang Pharmaceutical University, Liaoning, China; Institute for Integrated Cell-Material Sciences (iCeMS), Kyoto University, Kyoto, Japan; The Keihanshin Consortium for Fostering the Next Generation of Global Leaders in Research (K-CONNEX), Kyoto University, Kyoto, Japan.
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Abstract
Fragile X syndrome (FXS) is a neurodevelopmental disorder that causes intellectual disability. It is a leading known genetic cause of autism. In addition to cognitive, social, and communication deficits, humans with FXS demonstrate abnormal sensory processing including sensory hypersensitivity. Sensory hypersensitivity commonly manifests as auditory, tactile, or visual defensiveness or avoidance. Clinical, behavioral, and electrophysiological studies consistently show auditory hypersensitivity, impaired habituation to repeated sounds, and reduced auditory attention in humans with FXS. Children with FXS also exhibit significant visuospatial impairments. Studies in infants and toddlers with FXS have documented impairments in processing texture-defined motion stimuli, temporal flicker, perceiving ordinal numerical sequence, and the ability to maintain the identity of dynamic object information during occlusion. Consistent with the observations in humans with FXS, fragile X mental retardation 1 ( Fmr1) gene knockout (KO) rodent models of FXS also show seizures, abnormal visual-evoked responses, auditory hypersensitivity, and abnormal processing at multiple levels of the auditory system, including altered acoustic startle responses. Among other sensory symptoms, individuals with FXS exhibit tactile defensiveness. Fmr1 KO mice also show impaired encoding of tactile stimulation frequency and larger size of receptive fields in the somatosensory cortex. Since sensory deficits are relatively more tractable from circuit mechanisms and developmental perspectives than more complex social behaviors, the focus of this review is on clinical, functional, and structural studies that outline the auditory, visual, and somatosensory processing deficits in FXS. The similarities in sensory phenotypes between humans with FXS and animal models suggest a likely conservation of basic sensory processing circuits across species and may provide a translational platform to not just develop biomarkers but also to understand underlying mechanisms. We argue that preclinical studies in animal models of FXS can facilitate the ongoing search for new therapeutic approaches in FXS by understanding mechanisms of basic sensory processing circuits and behaviors that are conserved across species.
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Affiliation(s)
- Maham Rais
- 1 Division of Biomedical Sciences, University of California Riverside School of Medicine, CA, USA.,2 Biomedical Sciences Graduate Program, University of California Riverside, CA, USA
| | - Devin K Binder
- 1 Division of Biomedical Sciences, University of California Riverside School of Medicine, CA, USA.,2 Biomedical Sciences Graduate Program, University of California Riverside, CA, USA.,3 Neuroscience Graduate Program, University of California Riverside, CA, USA
| | - Khaleel A Razak
- 2 Biomedical Sciences Graduate Program, University of California Riverside, CA, USA.,3 Neuroscience Graduate Program, University of California Riverside, CA, USA.,4 Psychology Department, University of California Riverside, CA, USA
| | - Iryna M Ethell
- 1 Division of Biomedical Sciences, University of California Riverside School of Medicine, CA, USA.,2 Biomedical Sciences Graduate Program, University of California Riverside, CA, USA.,3 Neuroscience Graduate Program, University of California Riverside, CA, USA
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32
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Bodaleo F, Tapia-Monsalves C, Cea-Del Rio C, Gonzalez-Billault C, Nunez-Parra A. Structural and Functional Abnormalities in the Olfactory System of Fragile X Syndrome Models. Front Mol Neurosci 2019; 12:135. [PMID: 31191246 PMCID: PMC6548058 DOI: 10.3389/fnmol.2019.00135] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 05/09/2019] [Indexed: 12/18/2022] Open
Abstract
Fragile X Syndrome (FXS) is the most common inherited form of intellectual disability. It is produced by mutation of the Fmr1 gene that encodes for the Fragile Mental Retardation Protein (FMRP), an important RNA-binding protein that regulates the expression of multiple proteins located in neuronal synapses. Individuals with FXS exhibit abnormal sensory information processing frequently leading to hypersensitivity across sensory modalities and consequently a wide array of behavioral symptoms. Insects and mammals engage primarily their sense of smell to create proper representations of the external world and guide adequate decision-making processes. This feature in combination with the exquisitely organized neuronal circuits found throughout the olfactory system (OS) and the wide expression of FMRP in brain regions that process olfactory information makes it an ideal model to study sensory alterations in FXS models. In the last decade several groups have taken advantage of these features and have used the OS of fruit fly and rodents to understand neuronal alteration giving rise to sensory perception issues. In this review article, we will discuss molecular, morphological and physiological aspects of the olfactory information processing in FXS models. We will highlight the decreased inhibitory/excitatory synaptic balance and the diminished synaptic plasticity found in this system resulting in behavioral alteration of individuals in the presence of odorant stimuli.
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Affiliation(s)
- Felipe Bodaleo
- Laboratory of Cellular and Neuronal Dynamics, Department of Biology, Faculty of Science, Universidad de Chile, Santiago, Chile.,Geroscience Center for Brain Health and Metabolism (GERO), Santiago, Chile
| | | | - Christian Cea-Del Rio
- Laboratory of Neurophysiopathology, Centro de Investigacion Biomedica y Aplicada (CIBAP), School of Medicine, Universidad de Santiago de Chile, Santiago, Chile
| | - Christian Gonzalez-Billault
- Laboratory of Cellular and Neuronal Dynamics, Department of Biology, Faculty of Science, Universidad de Chile, Santiago, Chile.,Geroscience Center for Brain Health and Metabolism (GERO), Santiago, Chile.,The Buck Institute for Research on Aging, Novato, CA, United States
| | - Alexia Nunez-Parra
- Department of Biology, Faculty of Science, Universidad de Chile, Santiago, Chile.,Cell Physiology Center, Universidad de Chile, Santiago, Chile
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33
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Kang H, Zhao J, Jiang X, Li G, Huang W, Cheng H, Duan R. Drosophila Netrin-B controls mushroom body axon extension and regulates courtship-associated learning and memory of a Drosophila fragile X syndrome model. Mol Brain 2019; 12:52. [PMID: 31138234 PMCID: PMC6540430 DOI: 10.1186/s13041-019-0472-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Accepted: 05/06/2019] [Indexed: 01/29/2023] Open
Abstract
Mushroom body (MB) is a prominent structure essential for olfactory learning and memory in the Drosophila brain. The development of the MB involves the appropriate guidance of axon lobes and sister axon branches. Appropriate guidance that accurately shapes MB development requires the integration of various guidance cues provided by a series of cell types, which guide axons to reach their final positions within the MB neuropils. Netrins are axonal guidance molecules that are conserved regulators of embryonic nerve cord patterning. However, whether they contribute to MB morphogenesis has not yet been evaluated. Here, we find that Netrin-B (NetB) is highly expressed in the MB lobes, regulating lobe length through genetic interactions with the receptors Frazzled and Uncoordinated-5 from 24 h after pupal formation onwards. We observe that overexpression of NetB causes severe β lobe fusion in the MB, which is similar to the MB defects seen in the Drosophila model of fragile X syndrome (FXS). Our results further show that fragile-X mental retardation protein FMRP inhibits the translational activity of human ortholog Netrin-1 (NTN1). Knock-down of NetB significantly rescues the MB defects and ameliorates deficits in the learning and memory in FXS model Drosophila. These results indicate a critical role for NetB in MB lobe extension and identify NetB as a novel target of FMRP which contributes to learning and memory.
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Affiliation(s)
- Huaixing Kang
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, 410078, Hunan, China
| | - Juan Zhao
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, 410078, Hunan, China
| | - Xuan Jiang
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, 410078, Hunan, China
| | - Guangxu Li
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, 410078, Hunan, China
| | - Wen Huang
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, 410078, Hunan, China
| | - Huili Cheng
- Changchun Children' Hospital, Changchun, 130000, Jilin, China.
| | - Ranhui Duan
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, 410078, Hunan, China. .,Hunan Key Laboratory of Medical Genetics, Central South University, Changsha, 410078, Hunan, China. .,Hunan Key Laboratory of Animal Models for Human Diseases, Central South University, Changsha, 410078, Hunan, China.
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34
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Coll-Tané M, Krebbers A, Castells-Nobau A, Zweier C, Schenck A. Intellectual disability and autism spectrum disorders 'on the fly': insights from Drosophila. Dis Model Mech 2019; 12:dmm039180. [PMID: 31088981 PMCID: PMC6550041 DOI: 10.1242/dmm.039180] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Intellectual disability (ID) and autism spectrum disorders (ASD) are frequently co-occurring neurodevelopmental disorders and affect 2-3% of the population. Rapid advances in exome and genome sequencing have increased the number of known implicated genes by threefold, to more than a thousand. The main challenges in the field are now to understand the various pathomechanisms associated with this bewildering number of genetic disorders, to identify new genes and to establish causality of variants in still-undiagnosed cases, and to work towards causal treatment options that so far are available only for a few metabolic conditions. To meet these challenges, the research community needs highly efficient model systems. With an increasing number of relevant assays and rapidly developing novel methodologies, the fruit fly Drosophila melanogaster is ideally positioned to change gear in ID and ASD research. The aim of this Review is to summarize some of the exciting work that already has drawn attention to Drosophila as a model for these disorders. We highlight well-established ID- and ASD-relevant fly phenotypes at the (sub)cellular, brain and behavioral levels, and discuss strategies of how this extraordinarily efficient and versatile model can contribute to 'next generation' medical genomics and to a better understanding of these disorders.
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Affiliation(s)
- Mireia Coll-Tané
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Alina Krebbers
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Anna Castells-Nobau
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Christiane Zweier
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Annette Schenck
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
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35
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Altered steady state and activity-dependent de novo protein expression in fragile X syndrome. Nat Commun 2019; 10:1710. [PMID: 30979884 PMCID: PMC6461708 DOI: 10.1038/s41467-019-09553-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 03/15/2019] [Indexed: 12/22/2022] Open
Abstract
Whether fragile X mental retardation protein (FMRP) target mRNAs and neuronal activity contributing to elevated basal neuronal protein synthesis in fragile X syndrome (FXS) is unclear. Our proteomic experiments reveal that the de novo translational profile in FXS model mice is altered at steady state and in response to metabotropic glutamate receptor (mGluR) stimulation, but the proteins expressed differ under these conditions. Several altered proteins, including Hexokinase 1 and Ras, also are expressed in the blood of FXS model mice and pharmacological treatments previously reported to ameliorate phenotypes modify their abundance in blood. In addition, plasma levels of Hexokinase 1 and Ras differ between FXS patients and healthy volunteers. Our data suggest that brain-based de novo proteomics in FXS model mice can be used to find altered expression of proteins in blood that could serve as disease-state biomarkers in individuals with FXS. Elevated protein synthesis, and dysregulated mGluR signalling, are documented in fragile X syndrome (FXS) Here the authors use proteomic analysis in a mouse model of FXS, and following mGluR5 stimulation, to identify potential biomarkers for the disease.
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36
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Jacquemont S, Pacini L, Jønch AE, Cencelli G, Rozenberg I, He Y, D'Andrea L, Pedini G, Eldeeb M, Willemsen R, Gasparini F, Tassone F, Hagerman R, Gomez-Mancilla B, Bagni C. Protein synthesis levels are increased in a subset of individuals with fragile X syndrome. Hum Mol Genet 2019; 27:2039-2051. [PMID: 29590342 PMCID: PMC5985734 DOI: 10.1093/hmg/ddy099] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 03/15/2018] [Indexed: 12/15/2022] Open
Abstract
Fragile X syndrome (FXS) is a monogenic form of intellectual disability and autism spectrum disorder caused by the absence of the fragile X mental retardation protein (FMRP). In biological models for the disease, this leads to upregulated mRNA translation and as a consequence, deficits in synaptic architecture and plasticity. Preclinical studies revealed that pharmacological interventions restore those deficits, which are thought to mediate the FXS cognitive and behavioral symptoms. Here, we characterized the de novo rate of protein synthesis in patients with FXS and their relationship with clinical severity. We measured the rate of protein synthesis in fibroblasts derived from 32 individuals with FXS and from 17 controls as well as in fibroblasts and primary neurons of 27 Fmr1 KO mice and 20 controls. Here, we show that levels of protein synthesis are increased in fibroblasts of individuals with FXS and Fmr1 KO mice. However, this cellular phenotype displays a broad distribution and a proportion of fragile X individuals and Fmr1 KO mice do not show increased levels of protein synthesis, having measures in the normal range. Because the same Fmr1 KO animal measures in fibroblasts predict those in neurons we suggest the validity of this peripheral biomarker. Our study offers a potential explanation for the comprehensive drug development program undertaken thus far yielding negative results and suggests that a significant proportion, but not all individuals with FXS, may benefit from the reduction of excessive levels of protein synthesis.
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Affiliation(s)
- Sébastien Jacquemont
- Sainte-Justine University Hospital Research Centre, Montreal, QC H3T 1C5.,University of Montreal, Montreal, QC H3T 1J4, Canada
| | - Laura Pacini
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, 00133 Rome, Italy
| | - Aia E Jønch
- Department of Clinical Genetics, Odense University Hospital.,Human Genetics, Department of Clinical Research, University of Southern Denmark, 5000 Odense, Denmark
| | - Giulia Cencelli
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, 00133 Rome, Italy
| | - Izabela Rozenberg
- Neuroscience Translational Medicine, Novartis Institutes for Biomedical Research, Novartis Pharma AG, 4056 Basel, Switzerland
| | - Yunsheng He
- Biomarker Development, Novartis Institutes for Biomedical Research, Cambridge, MA 02139, USA
| | - Laura D'Andrea
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, 00133 Rome, Italy
| | - Giorgia Pedini
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, 00133 Rome, Italy
| | - Marwa Eldeeb
- Medical Investigation of Neurodevelopmental Disorders (MIND) Institute, University of California, Davis Medical Center, Sacramento, CA 95817, USA
| | - Rob Willemsen
- Department of Clinical Genetics, Erasmus Medical Center, 1738, 3000DR Rotterdam, The Netherlands
| | - Fabrizio Gasparini
- Neuroscience Discovery, Novartis Institutes for BioMedical Research, 4002 Basel, Switzerland
| | - Flora Tassone
- Department of Biochemistry and Molecular Medicine and Medical Investigation of Neurodevelopmental Disorders (MIND) Institute, Sacramento, CA 95817, USA
| | - Randi Hagerman
- Department of Pediatric and Medical Investigation of Neurodevelopmental Disorders (MIND) Institute, University of California Davis, School of Medicine, Sacramento, CA 95817, USA
| | - Baltazar Gomez-Mancilla
- Neuroscience Translational Medicine, Novartis Institutes for Biomedical Research, Novartis Pharma AG, 4056 Basel, Switzerland.,Department of Neurology and Neurosurgery, McGill University, Montreal, QC H3A 0G4, Canada
| | - Claudia Bagni
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, 00133 Rome, Italy.,Department of Fundamental Neuroscience, University of Lausanne, 1005 Lausanne, Switzerland
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37
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Specchia V, Puricella A, D'Attis S, Massari S, Giangrande A, Bozzetti MP. Drosophila melanogaster as a Model to Study the Multiple Phenotypes, Related to Genome Stability of the Fragile-X Syndrome. Front Genet 2019; 10:10. [PMID: 30815010 PMCID: PMC6381874 DOI: 10.3389/fgene.2019.00010] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 01/11/2019] [Indexed: 12/14/2022] Open
Abstract
Fragile-X syndrome is one of the most common forms of inherited mental retardation and autistic behaviors. The reduction/absence of the functional FMRP protein, coded by the X-linked Fmr1 gene in humans, is responsible for the syndrome. Patients exhibit a variety of symptoms predominantly linked to the function of FMRP protein in the nervous system like autistic behavior and mild-to-severe intellectual disability. Fragile-X (FraX) individuals also display cellular and morphological traits including branched dendritic spines, large ears, and macroorchidism. The dFmr1 gene is the Drosophila ortholog of the human Fmr1 gene. dFmr1 mutant flies exhibit synaptic abnormalities, behavioral defects as well as an altered germline development, resembling the phenotypes observed in FraX patients. Therefore, Drosophila melanogaster is considered a good model to study the physiopathological mechanisms underlying the Fragile-X syndrome. In this review, we explore how the multifaceted roles of the FMRP protein have been addressed in the Drosophila model and how the gained knowledge may open novel perspectives for understanding the molecular defects causing the disease and for identifying novel therapeutical targets.
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Affiliation(s)
- Valeria Specchia
- Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, DiSTeBA, Università del Salento, Lecce, Italy
| | - Antonietta Puricella
- Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, DiSTeBA, Università del Salento, Lecce, Italy
| | - Simona D'Attis
- Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, DiSTeBA, Università del Salento, Lecce, Italy
| | - Serafina Massari
- Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, DiSTeBA, Università del Salento, Lecce, Italy
| | - Angela Giangrande
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France.,Centre National de la Recherche Scientifique, UMR7104, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, U964, Illkirch, France.,Université de Strasbourg, Illkirch, France
| | - Maria Pia Bozzetti
- Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, DiSTeBA, Università del Salento, Lecce, Italy
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38
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Sears JC, Choi WJ, Broadie K. Fragile X Mental Retardation Protein positively regulates PKA anchor Rugose and PKA activity to control actin assembly in learning/memory circuitry. Neurobiol Dis 2019; 127:53-64. [PMID: 30771457 DOI: 10.1016/j.nbd.2019.02.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2018] [Accepted: 02/04/2019] [Indexed: 01/09/2023] Open
Abstract
Recent work shows Fragile X Mental Retardation Protein (FMRP) drives the translation of very large proteins (>2000 aa) mediating neurodevelopment. Loss of function results in Fragile X syndrome (FXS), the leading heritable cause of intellectual disability (ID) and autism spectrum disorder (ASD). Using the Drosophila FXS disease model, we discover FMRP positively regulates the translation of the very large A-Kinase Anchor Protein (AKAP) Rugose (>3000 aa), homolog of ASD-associated human Neurobeachin (NBEA). In the central brain Mushroom Body (MB) circuit, where Protein Kinase A (PKA) signaling is necessary for learning/memory, FMRP loss reduces Rugose levels and targeted FMRP overexpression elevates Rugose levels. Using a new in vivo transgenic PKA activity reporter (PKA-SPARK), we find FMRP loss reduces PKA activity in MB Kenyon cells whereas FMRP overexpression elevates PKA activity. Consistently, loss of Rugose reduces PKA activity, but Rugose overexpression has no independent effect. A well-established PKA output is regulation of F-actin cytoskeleton dynamics. In the FXS disease model, F-actin is aberrantly accumulated in MB lobes and single MB Kenyon cells. Consistently, Rugose loss results in similar F-actin accumulation. Moreover, targeted FMRP, Rugose and PKA overexpression all result in increased F-actin accumulation in the MB circuit. These findings uncover a FMRP-Rugose-PKA mechanism regulating actin cytoskeleton. This study reveals a novel FMRP mechanism controlling neuronal PKA activity, and demonstrates a shared mechanistic connection between FXS and NBEA associated ASD disease states, with a common link to PKA and F-actin misregulation in brain neural circuits. SIGNIFICANCE STATEMENT: Autism spectrum disorder (ASD) arises from a wide array of genetic lesions, and it is therefore critical to identify common underlying molecular mechanisms. Here, we link two ASD states; Neurobeachin (NBEA) associated ASD and Fragile X syndrome (FXS), the most common inherited ASD. Using established Drosophila disease models, we find Fragile X Mental Retardation Protein (FMRP) positively regulates translation of NBEA homolog Rugose, consistent with a recent advance showing FMRP promotes translation of very large proteins associated with ASD. FXS exhibits reduced cAMP induction, a potent activator of PKA, and Rugose/NBEA is a PKA anchor. Consistently, we find brain PKA activity strikingly reduced in both ASD models. We discover this pathway regulation controls actin cytoskeleton dynamics in brain neural circuits.
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Affiliation(s)
- James C Sears
- Vanderbilt Brain Institute, Departments of Biological Sciences, Vanderbilt University and Medical Center, Nashville, TN 37235, USA
| | - Woong Jae Choi
- Departments of Biological Sciences, Vanderbilt University and Medical Center, Nashville, TN 37235, USA
| | - Kendal Broadie
- Vanderbilt Brain Institute, Departments of Biological Sciences, Cell and Developmental Biology, and Pharmacology, Vanderbilt University and Medical Center, Nashville, TN 37235, USA.
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Fanoudi S, Hosseini M, Alavi MS, Boroushaki MT, Hosseini A, Sadeghnia HR. Everolimus, a mammalian target of rapamycin inhibitor, ameliorated streptozotocin-induced learning and memory deficits via neurochemical alterations in male rats. EXCLI JOURNAL 2018; 17:999-1017. [PMID: 30564080 PMCID: PMC6295637 DOI: 10.17179/excli2018-1626] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 10/05/2018] [Indexed: 12/15/2022]
Abstract
Everolimus (EVR), as a rapamycin analog, is a selective inhibitor of the mammalian target of rapamycin (mTOR) kinase and its associated signaling pathway. mTOR is a serine/threonine protein kinase and its hyperactivity is involved in the pathophysiology of Alzheimer's disease (AD) and associated cognitive deficits. The present study evaluated the impact of EVR, on cognitive functions, hippocampal cell loss, and neurochemical parameters in the intracerebroventricular streptozotocin (icv-STZ) model of AD rats. EVR (1 and 5 mg/kg) was administered for 21 days following the single administration of STZ (3 mg/kg, icv) or for 7 days on days 21-28 post-STZ injection after establishment of cognitive dysfunction. Cognitive deficits (passive avoidance and spatial memory), oxidative stress parameters, acetylcholinesterase (AChE) activity, and percentage of cell loss were evaluated in the hippocampus. Chronic administration (1 and 5 mg/kg for 21 days from the day of surgery and icv-STZ infusion) or acute injection (5 mg/kg for 7 days after establishment of cognitive impairment) of EVR significantly attenuated cognitive dysfunction, neuronal loss, oxidative stress and AChE activity in the hippocampus of STZ-AD rats. In conclusion, our study showed that EVR could prevent or improve deteriorations in behavioral, biochemical and histopathological features of the icv-STZ rat model of AD. Therefore, inhibition of the hyperactivated mTOR may be an important therapeutic target for AD.
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Affiliation(s)
- Sahar Fanoudi
- Department of Pharmacology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.,Pharmacological Research Center of Medicinal Plants, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Mahmoud Hosseini
- Division of Neurocognitive Sciences, Psychiatry and Behavioral Sciences Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Mohaddeseh Sadat Alavi
- Department of Pharmacology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.,Pharmacological Research Center of Medicinal Plants, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Mohammad Taher Boroushaki
- Department of Pharmacology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.,Pharmacological Research Center of Medicinal Plants, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Azar Hosseini
- Pharmacological Research Center of Medicinal Plants, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Hamid R Sadeghnia
- Department of Pharmacology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.,Pharmacological Research Center of Medicinal Plants, Mashhad University of Medical Sciences, Mashhad, Iran.,Division of Neurocognitive Sciences, Psychiatry and Behavioral Sciences Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
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40
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Androschuk A, He RX, Weber S, Rosenfelt C, Bolduc FV. Stress Odorant Sensory Response Dysfunction in Drosophila Fragile X Syndrome Mutants. Front Mol Neurosci 2018; 11:242. [PMID: 30135642 PMCID: PMC6092503 DOI: 10.3389/fnmol.2018.00242] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Accepted: 06/22/2018] [Indexed: 01/05/2023] Open
Abstract
Sensory processing dysfunction (SPD) is present in most patients with intellectual disability (ID) and autism spectrum disorder (ASD). Silencing expression of the Fragile X mental retardation 1 (FMR1) gene leads to Fragile X syndrome (FXS), the most common single gene cause of ID and ASD. Drosophila have a highly conserved FMR1 ortholog, dfmr1. dfmr1 mutants display cognitive and social defects reminiscent of symptoms seen in individuals with FXS. We utilized a robust behavioral assay for sensory processing of the Drosophila stress odorant (dSO) to gain a better understanding of the molecular basis of SPD in FXS. Here, we show that dfmr1 mutant flies present significant defects in dSO response. We found that dfmr1 expression in mushroom bodies is required for dSO processing. We also show that cyclic adenosine monophosphate (cAMP) signaling via PKA is activated after exposure to dSO and that several drugs regulating both cAMP and cyclic guanosine monophosphate (cGMP) levels significantly improved defects in dSO processing in dfmr1 mutant flies.
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Affiliation(s)
- Alaura Androschuk
- Department of Pediatrics, University of Alberta, Edmonton, AB, Canada
| | - Richard X He
- Department of Pediatrics, University of Alberta, Edmonton, AB, Canada
| | - Savannah Weber
- Department of Pediatrics, University of Alberta, Edmonton, AB, Canada
| | - Cory Rosenfelt
- Department of Pediatrics, University of Alberta, Edmonton, AB, Canada
| | - Francois V Bolduc
- Department of Pediatrics, University of Alberta, Edmonton, AB, Canada.,Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada.,Department of Medical Genetics, University of Alberta, Edmonton, AB, Canada
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41
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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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Hotspots of dendritic spine turnover facilitate clustered spine addition and learning and memory. Nat Commun 2018; 9:422. [PMID: 29379017 PMCID: PMC5789055 DOI: 10.1038/s41467-017-02751-2] [Citation(s) in RCA: 110] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Accepted: 12/22/2017] [Indexed: 01/08/2023] Open
Abstract
Modeling studies suggest that clustered structural plasticity of dendritic spines is an efficient mechanism of information storage in cortical circuits. However, why new clustered spines occur in specific locations and how their formation relates to learning and memory (L&M) remain unclear. Using in vivo two-photon microscopy, we track spine dynamics in retrosplenial cortex before, during, and after two forms of episodic-like learning and find that spine turnover before learning predicts future L&M performance, as well as the localization and rates of spine clustering. Consistent with the idea that these measures are causally related, a genetic manipulation that enhances spine turnover also enhances both L&M and spine clustering. Biophysically inspired modeling suggests turnover increases clustering, network sparsity, and memory capacity. These results support a hotspot model where spine turnover is the driver for localization of clustered spine formation, which serves to modulate network function, thus influencing storage capacity and L&M. Structural remodeling of dendritic spines is thought to be a mechanism of memory storage. Here, the authors look at how spine turnover and clustering predict future learning and memory performance, and see that a genetically modified mouse with enhanced spine turnover has enhanced learning.
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Sears JC, Broadie K. Fragile X Mental Retardation Protein Regulates Activity-Dependent Membrane Trafficking and Trans-Synaptic Signaling Mediating Synaptic Remodeling. Front Mol Neurosci 2018; 10:440. [PMID: 29375303 PMCID: PMC5770364 DOI: 10.3389/fnmol.2017.00440] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 12/18/2017] [Indexed: 12/31/2022] Open
Abstract
Fragile X syndrome (FXS) is the leading monogenic cause of autism and intellectual disability. The disease arises through loss of fragile X mental retardation protein (FMRP), which normally exhibits peak expression levels in early-use critical periods, and is required for activity-dependent synaptic remodeling during this transient developmental window. FMRP canonically binds mRNA to repress protein translation, with targets that regulate cytoskeleton dynamics, membrane trafficking, and trans-synaptic signaling. We focus here on recent advances emerging in these three areas from the Drosophila disease model. In the well-characterized central brain mushroom body (MB) olfactory learning/memory circuit, FMRP is required for activity-dependent synaptic remodeling of projection neurons innervating the MB calyx, with function tightly restricted to an early-use critical period. FMRP loss is phenocopied by conditional removal of FMRP only during this critical period, and rescued by FMRP conditional expression only during this critical period. Consistent with FXS hyperexcitation, FMRP loss defects are phenocopied by heightened sensory experience and targeted optogenetic hyperexcitation during this critical period. FMRP binds mRNA encoding Drosophila ESCRTIII core component Shrub (human CHMP4 homolog) to restrict Shrub translation in an activity-dependent mechanism only during this same critical period. Shrub mediates endosomal membrane trafficking, and perturbing Shrub expression is known to interfere with neuronal process pruning. Consistently, FMRP loss and Shrub overexpression targeted to projection neurons similarly causes endosomal membrane trafficking defects within synaptic boutons, and genetic reduction of Shrub strikingly rescues Drosophila FXS model defects. In parallel work on the well-characterized giant fiber (GF) circuit, FMRP limits iontophoretic dye loading into central interneurons, demonstrating an FMRP role controlling core neuronal properties through the activity-dependent repression of translation. In the well-characterized Drosophila neuromuscular junction (NMJ) model, developmental synaptogenesis and activity-dependent synaptic remodeling both require extracellular matrix metalloproteinase (MMP) enzymes interacting with the heparan sulfate proteoglycan (HSPG) glypican dally-like protein (Dlp) to restrict trans-synaptic Wnt signaling, with FXS synaptogenic defects alleviated by both MMP and HSPG reduction. This new mechanistic axis spanning from activity to FMRP to HSPG-dependent MMP regulation modulates activity-dependent synaptogenesis. We discuss future directions for these mechanisms, and intersecting research priorities for FMRP in glial and signaling interactions.
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Affiliation(s)
- James C. Sears
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, United States
| | - Kendal Broadie
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, United States
- Vanderbilt Kennedy Center for Research on Human Development, Nashville, TN, United States
- Vanderbilt Brain Institute, Vanderbilt University Medical Center, Nashville, TN, United States
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Tréfier A, Pellissier LP, Musnier A, Reiter E, Guillou F, Crépieux P. G Protein-Coupled Receptors As Regulators of Localized Translation: The Forgotten Pathway? Front Endocrinol (Lausanne) 2018; 9:17. [PMID: 29456523 PMCID: PMC5801404 DOI: 10.3389/fendo.2018.00017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 01/15/2018] [Indexed: 12/31/2022] Open
Abstract
G protein-coupled receptors (GPCRs) exert their physiological function by transducing a complex signaling network that coordinates gene expression and dictates the phenotype of highly differentiated cells. Much is known about the gene networks they transcriptionally regulate upon ligand exposure in a process that takes hours before a new protein is synthesized. However, far less is known about GPCR impact on the translational machinery and subsequent mRNA translation, although this gene regulation level alters the cell phenotype in a strikingly different timescale. In fact, mRNA translation is an early response kinetically connected to signaling events, hence it leads to the synthesis of a new protein within minutes following receptor activation. By these means, mRNA translation is responsive to subtle variations of the extracellular environment. In addition, when restricted to cell subcellular compartments, local mRNA translation contributes to cell micro-specialization, as observed in synaptic plasticity or in cell migration. The mechanisms that control where in the cell an mRNA is translated are starting to be deciphered. But how an extracellular signal triggers such local translation still deserves extensive investigations. With the advent of high-throughput data acquisition, it now becomes possible to review the current knowledge on the translatome that some GPCRs regulate, and how this information can be used to explore GPCR-controlled local translation of mRNAs.
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Affiliation(s)
- Aurélie Tréfier
- Biologie et Bioinformatique des Systèmes de Signalisation, INRA, UMR85, Physiologie de la Reproduction et des Comportements, Nouzilly, France
- CNRS, UMR7247, Nouzilly, France
- Université François Rabelais, Tours, France
- IFCE, Nouzilly, France
| | - Lucie P. Pellissier
- Déficit de Récompense, GPCR et sociabilité, INRA, UMR85, Physiologie de la Reproduction et des Comportements, Nouzilly, France
- CNRS, UMR7247, Nouzilly, France
- Université François Rabelais, Tours, France
- IFCE, Nouzilly, France
| | - Astrid Musnier
- Biologie et Bioinformatique des Systèmes de Signalisation, INRA, UMR85, Physiologie de la Reproduction et des Comportements, Nouzilly, France
- CNRS, UMR7247, Nouzilly, France
- Université François Rabelais, Tours, France
- IFCE, Nouzilly, France
| | - Eric Reiter
- Biologie et Bioinformatique des Systèmes de Signalisation, INRA, UMR85, Physiologie de la Reproduction et des Comportements, Nouzilly, France
- CNRS, UMR7247, Nouzilly, France
- Université François Rabelais, Tours, France
- IFCE, Nouzilly, France
| | - Florian Guillou
- Plasticité Génomique et Expression Phénotypique, INRA, UMR85, Physiologie de la Reproduction et des Comportements, Nouzilly, France
- CNRS, UMR7247, Nouzilly, France
- Université François Rabelais, Tours, France
- IFCE, Nouzilly, France
| | - Pascale Crépieux
- Biologie et Bioinformatique des Systèmes de Signalisation, INRA, UMR85, Physiologie de la Reproduction et des Comportements, Nouzilly, France
- CNRS, UMR7247, Nouzilly, France
- Université François Rabelais, Tours, France
- IFCE, Nouzilly, France
- *Correspondence: Pascale Crépieux,
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Roemmich AJ, Schutte SS, O'Dowd DK. Ex vivo Whole-cell Recordings in Adult Drosophila Brain. Bio Protoc 2018; 8:e2467. [PMID: 30148187 DOI: 10.21769/bioprotoc.2467] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Cost-effective and efficient, the fruit fly (Drosophila melanogaster) has been used to make many key discoveries in the field of neuroscience and to model a number of neurological disorders. Great strides in understanding have been made using sophisticated molecular genetic tools and behavioral assays. Functional analysis of neural activity was initially limited to the neuromuscular junction (NMJ) and in the central nervous system (CNS) of embryos and larvae. Elucidating the cellular mechanisms underlying neurological processes and disorders in the mature nervous system have been more challenging due to difficulty in recording from neurons in adult brains. To this aim we developed an ex vivo preparation in which a whole brain is isolated from the head capsule of an adult fly and placed in a recording chamber. With this preparation, whole cell recording of identified neurons in the adult brain can be combined with genetic, pharmacological and environmental manipulations to explore cellular mechanisms of neuronal function and dysfunction. It also serves as an important platform for evaluating the mechanism of action of new therapies identified through behavioral assays for treating neurological diseases. Here we present our protocol for ex vivo preparations and whole-cell recordings in the adult Drosophila brain.
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Affiliation(s)
- Alexa J Roemmich
- Department of Developmental and Cell Biology, University of California, Irvine, California, USA
| | - Soleil S Schutte
- Department of Anesthesiology, University of Florida, Gainesville, Florida, USA
| | - Diane K O'Dowd
- Department of Developmental and Cell Biology, University of California, Irvine, California, USA
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Nakayama K, Ohashi R, Shinoda Y, Yamazaki M, Abe M, Fujikawa A, Shigenobu S, Futatsugi A, Noda M, Mikoshiba K, Furuichi T, Sakimura K, Shiina N. RNG105/caprin1, an RNA granule protein for dendritic mRNA localization, is essential for long-term memory formation. eLife 2017; 6. [PMID: 29157358 PMCID: PMC5697933 DOI: 10.7554/elife.29677] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 10/22/2017] [Indexed: 12/18/2022] Open
Abstract
Local regulation of synaptic efficacy is thought to be important for proper networking of neurons and memory formation. Dysregulation of global translation influences long-term memory in mice, but the relevance of the regulation specific for local translation by RNA granules remains elusive. Here, we demonstrate roles of RNG105/caprin1 in long-term memory formation. RNG105 deletion in mice impaired synaptic strength and structural plasticity in hippocampal neurons. Furthermore, RNG105-deficient mice displayed unprecedentedly severe defects in long-term memory formation in spatial and contextual learning tasks. Genome-wide profiling of mRNA distribution in the hippocampus revealed an underlying mechanism: RNG105 deficiency impaired the asymmetric somato-dendritic localization of mRNAs. Particularly, RNG105 deficiency reduced the dendritic localization of mRNAs encoding regulators of AMPAR surface expression, which was consistent with attenuated homeostatic AMPAR scaling in dendrites and reduced synaptic strength. Thus, RNG105 has an essential role, as a key regulator of dendritic mRNA localization, in long-term memory formation. Messages pass from one nerve cell to the next across gaps called synapses. The first neuron releases chemical signals from the end of its long, thin nerve fiber. The second receives the message at receptors on branching structures known as dendrites. Each connection has a corresponding bump called a dendritic spine. As animals learn, these can grow larger, strengthening the connection. This is the basis of how memories form. To strengthen a synapse, the cell must transport the materials to the dendritic spine. The cell makes copies of the genetic instructions to strengthen the synapse in the form of messenger RNA (often shortened to mRNA). But, this happens in the body of the cell, a long way from the dendrites themselves. The mRNA travels from the cell body to the dendrites in collections of molecules referred to as ‘RNA granules’. One of the key components of the RNA granule system is a protein called RNG105/caprin1. Now, Nakayama, Ohashi et al. have engineered mice to delete the gene for RNG105/caprin1, revealing its effect on memory. Mice lacking RNG105/caprin1 struggled to make long-term memories. Unlike their normal counterparts, these mutant mice did not become accustomed to new environments or objects. They also found it more challenging to learn the position of a hidden platform in a water-based maze. Lastly, over time, the mutant mice forgot to be fearful of a dark chamber where they had received a small electric shock. Memories form in a part of the brain called the hippocampus and the dendritic spines in this region were smaller in mice lacking RNG105/caprin1. Furthermore, when the nerve cells from this part of the brain were grown in Petri dishes, they did not respond normally to stimulation. The dendritic spines of normal cells increased in size, but those on the cells lacking RNG105/caprin1 got smaller compared to normal cells. A closer look revealed that the distribution of mRNA in brain cells from mice lacking RNG105/caprin1 differed from that of normal mice. Some pieces of genetic information failed to make it from the cell body to the dendrites. This included mRNA involved in making regulators of a component of dendritic spines called the AMPA receptor. The AMPA receptor detects the chemical messenger, glutamate, and is crucial for memory formation. These findings further our understanding of long-term memory and open the way for future research into human disease. Mutations in RNA granule components, including RNG105/caprin1, have links to conditions such as amyotrophic lateral sclerosis (ALS) and autism spectrum disorder (ASD). Further investigation could reveal new targets for drug treatment.
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Affiliation(s)
- Kei Nakayama
- Laboratory of Neuronal Cell Biology, National Institute for Basic Biology, Okazaki, Japan.,Department of Basic Biology, SOKENDAI, Okazaki, Japan.,Okazaki Institute for Integrative Bioscience, Okazaki, Japan
| | - Rie Ohashi
- Laboratory of Neuronal Cell Biology, National Institute for Basic Biology, Okazaki, Japan.,Department of Basic Biology, SOKENDAI, Okazaki, Japan
| | - Yo Shinoda
- Department of Applied Biological Science, Tokyo University of Science, Noda, Japan.,School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Hachioji, Japan
| | - Maya Yamazaki
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata, Japan
| | - Manabu Abe
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata, Japan
| | - Akihiro Fujikawa
- Division of Molecular Neurobiology, National Institute for Basic Biology, Okazaki, Japan
| | - Shuji Shigenobu
- Department of Basic Biology, SOKENDAI, Okazaki, Japan.,Functional Genomics Facility, National Institute for Basic Biology, Okazaki, Japan
| | - Akira Futatsugi
- Department of Basic Medical Science, Kobe City College of Nursing, Hyogo, Japan
| | - Masaharu Noda
- Department of Basic Biology, SOKENDAI, Okazaki, Japan.,Division of Molecular Neurobiology, National Institute for Basic Biology, Okazaki, Japan
| | - Katsuhiko Mikoshiba
- Laboratory for Developmental Neurobiology, Brain Science Institute, Wako, Japan
| | - Teiichi Furuichi
- Department of Applied Biological Science, Tokyo University of Science, Noda, Japan
| | - Kenji Sakimura
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata, Japan
| | - Nobuyuki Shiina
- Laboratory of Neuronal Cell Biology, National Institute for Basic Biology, Okazaki, Japan.,Department of Basic Biology, SOKENDAI, Okazaki, Japan.,Okazaki Institute for Integrative Bioscience, Okazaki, Japan
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Gurney ME, Cogram P, Deacon RM, Rex C, Tranfaglia M. Multiple Behavior Phenotypes of the Fragile-X Syndrome Mouse Model Respond to Chronic Inhibition of Phosphodiesterase-4D (PDE4D). Sci Rep 2017; 7:14653. [PMID: 29116166 PMCID: PMC5677090 DOI: 10.1038/s41598-017-15028-x] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Accepted: 10/18/2017] [Indexed: 01/14/2023] Open
Abstract
Fragile-X syndrome (FXS) patients display intellectual disability and autism spectrum disorder due to silencing of the X-linked, fragile-X mental retardation-1 (FMR1) gene. Dysregulation of cAMP metabolism is a consistent finding in patients and in the mouse and fly FXS models. We therefore explored if BPN14770, a prototypic phosphodiesterase-4D negative allosteric modulator (PDE4D-NAM) in early human clinical trials, might provide therapeutic benefit in the mouse FXS model. Daily treatment of adult male fmr1 C57Bl6 knock-out mice with BPN14770 for 14 days reduced hyperarousal, improved social interaction, and improved natural behaviors such as nesting and marble burying as well as dendritic spine morphology. There was no decrement in behavioral scores in control C57Bl6 treated with BPN14770. The behavioral benefit of BPN14770 persisted two weeks after washout of the drug. Thus, BPN14770 may be useful for the treatment of fragile-X syndrome and other disorders with decreased cAMP signaling.
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Affiliation(s)
- Mark E Gurney
- Tetra Discovery Partners, Inc, Grand Rapids, MI, USA.
| | - Patricia Cogram
- FRAXA-DVI, FRAXA, Santiago, Chile.,Laboratory of Molecular Neuropsychiatry, Institute of Cognitive and Translational Neuroscience (INCyT), INECO Foundation, Favaloro University, National Scientific and Technical Research Council, Buenos Aires, Argentina.,IEB, Faculty of Science, University of Chile, Santiago, Chile
| | - Robert M Deacon
- FRAXA-DVI, FRAXA, Santiago, Chile.,Laboratory of Molecular Neuropsychiatry, Institute of Cognitive and Translational Neuroscience (INCyT), INECO Foundation, Favaloro University, National Scientific and Technical Research Council, Buenos Aires, Argentina.,IEB, Faculty of Science, University of Chile, Santiago, Chile
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Kennedy T, Broadie K. Fragile X Mental Retardation Protein Restricts Small Dye Iontophoresis Entry into Central Neurons. J Neurosci 2017; 37:9844-9858. [PMID: 28887386 PMCID: PMC5637114 DOI: 10.1523/jneurosci.0723-17.2017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 07/27/2017] [Accepted: 08/29/2017] [Indexed: 01/29/2023] Open
Abstract
Fragile X mental retardation protein (FMRP) loss causes Fragile X syndrome (FXS), a major disorder characterized by autism, intellectual disability, hyperactivity, and seizures. FMRP is both an RNA- and channel-binding regulator, with critical roles in neural circuit formation and function. However, it remains unclear how these FMRP activities relate to each other and how dysfunction in their absence underlies FXS neurological symptoms. In testing circuit level defects in the Drosophila FXS model, we discovered a completely unexpected and highly robust neuronal dye iontophoresis phenotype in the well mapped giant fiber (GF) circuit. Controlled dye injection into the GF interneuron results in a dramatic increase in dye uptake in neurons lacking FMRP. Transgenic wild-type FMRP reintroduction rescues the mutant defect, demonstrating a specific FMRP requirement. This phenotype affects only small dyes, but is independent of dye charge polarity. Surprisingly, the elevated dye iontophoresis persists in shaking B mutants that eliminate gap junctions and dye coupling among GF circuit neurons. We therefore used a wide range of manipulations to investigate the dye uptake defect, including timed injection series, pharmacology and ion replacement, and optogenetic activity studies. The results show that FMRP strongly limits the rate of dye entry via a cytosolic mechanism. This study reveals an unexpected new phenotype in a physical property of central neurons lacking FMRP that could underlie aspects of FXS disruption of neural function.SIGNIFICANCE STATEMENT FXS is a leading heritable cause of intellectual disability and autism spectrum disorders. Although researchers established the causal link with FMRP loss >;25 years ago, studies continue to reveal diverse FMRP functions. The Drosophila FXS model is key to discovering new FMRP roles, because of its genetic malleability and individually identified neuron maps. Taking advantage of a well characterized Drosophila neural circuit, we discovered that neurons lacking FMRP take up dramatically more current-injected small dye. After examining many neuronal properties, we determined that this dye defect is cytoplasmic and occurs due to a highly elevated dye iontophoresis rate. We also report several new factors affecting neuron dye uptake. Understanding how FMRP regulates iontophoresis should reveal new molecular factors underpinning FXS dysfunction.
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Affiliation(s)
| | - Kendal Broadie
- Department of Biological Sciences,
- Department of Cell and Developmental Biology, and
- Vanderbilt Brain Institute, Vanderbilt University and Medical Center, Nashville, Tennessee 37235
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Bozler J, Kacsoh BZ, Chen H, Theurkauf WE, Weng Z, Bosco G. A systems level approach to temporal expression dynamics in Drosophila reveals clusters of long term memory genes. PLoS Genet 2017; 13:e1007054. [PMID: 29084214 PMCID: PMC5679645 DOI: 10.1371/journal.pgen.1007054] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Revised: 11/09/2017] [Accepted: 10/04/2017] [Indexed: 01/05/2023] Open
Abstract
The ability to integrate experiential information and recall it in the form of memory is observed in a wide range of taxa, and is a hallmark of highly derived nervous systems. Storage of past experiences is critical for adaptive behaviors that anticipate both adverse and positive environmental factors. The process of memory formation and consolidation involve many synchronized biological events including gene transcription, protein modification, and intracellular trafficking: However, many of these molecular mechanisms remain illusive. With Drosophila as a model system we use a nonassociative memory paradigm and a systems level approach to uncover novel transcriptional patterns. RNA sequencing of Drosophila heads during and after memory formation identified a number of novel memory genes. Tracking the dynamic expression of these genes over time revealed complex gene networks involved in long term memory. In particular, this study focuses on two functional gene clusters of signal peptides and proteases. Bioinformatics network analysis and prediction in combination with high-throughput RNA sequencing identified previously unknown memory genes, which when genetically knocked down resulted in behaviorally validated memory defects.
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Affiliation(s)
- Julianna Bozler
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, NH, United States of America
| | - Balint Z. Kacsoh
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, NH, United States of America
| | - Hao Chen
- Bioinformatics Program, Boston University, Boston, MA, United States of America
- Program in Bioinformatics and Integrative Biology, University of Massachusetts Medical School, Worcester, MA, United States of America
| | - William E. Theurkauf
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, United States of America
| | - Zhiping Weng
- Program in Bioinformatics and Integrative Biology, University of Massachusetts Medical School, Worcester, MA, United States of America
| | - Giovanni Bosco
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, NH, United States of America
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ESCRT-III Membrane Trafficking Misregulation Contributes To Fragile X Syndrome Synaptic Defects. Sci Rep 2017; 7:8683. [PMID: 28819289 PMCID: PMC5561180 DOI: 10.1038/s41598-017-09103-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 07/19/2017] [Indexed: 12/12/2022] Open
Abstract
The leading cause of heritable intellectual disability (ID) and autism spectrum disorders (ASD), Fragile X syndrome (FXS), is caused by loss of the mRNA-binding translational suppressor Fragile X Mental Retardation Protein (FMRP). In the Drosophila FXS disease model, we found FMRP binds shrub mRNA (human Chmp4) to repress Shrub expression, causing overexpression during the disease state early-use critical period. The FXS hallmark is synaptic overelaboration causing circuit hyperconnectivity. Testing innervation of a central brain learning/memory center, we found FMRP loss and Shrub overexpression similarly increase connectivity. The ESCRT-III core protein Shrub has a central role in endosome-to-multivesicular body membrane trafficking, with synaptic requirements resembling FMRP. Consistently, we found FMRP loss and Shrub overexpression similarly elevate endosomes and result in the arrested accumulation of enlarged intraluminal vesicles within synaptic boutons. Importantly, genetic correction of Shrub levels in the FXS model prevents synaptic membrane trafficking defects and strongly restores innervation. These results reveal a new molecular mechanism underpinning the FXS disease state.
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