1
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Hooshmandi M, Sharma V, Thörn Perez C, Sood R, Krimbacher K, Wong C, Lister KC, Ureña Guzmán A, Bartley TD, Rocha C, Maussion G, Nadler E, Roque PM, Gantois I, Popic J, Lévesque M, Kaufman RJ, Avoli M, Sanz E, Nader K, Hagerman RJ, Durcan TM, Costa-Mattioli M, Prager-Khoutorsky M, Lacaille JC, Martinez-Cerdeno V, Gibson JR, Huber KM, Sonenberg N, Gkogkas CG, Khoutorsky A. Excitatory neuron-specific suppression of the integrated stress response contributes to autism-related phenotypes in fragile X syndrome. Neuron 2023; 111:3028-3040.e6. [PMID: 37473758 PMCID: PMC10592416 DOI: 10.1016/j.neuron.2023.06.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 05/11/2023] [Accepted: 06/22/2023] [Indexed: 07/22/2023]
Abstract
Dysregulation of protein synthesis is one of the key mechanisms underlying autism spectrum disorder (ASD). However, the role of a major pathway controlling protein synthesis, the integrated stress response (ISR), in ASD remains poorly understood. Here, we demonstrate that the main arm of the ISR, eIF2α phosphorylation (p-eIF2α), is suppressed in excitatory, but not inhibitory, neurons in a mouse model of fragile X syndrome (FXS; Fmr1-/y). We further show that the decrease in p-eIF2α is mediated via activation of mTORC1. Genetic reduction of p-eIF2α only in excitatory neurons is sufficient to increase general protein synthesis and cause autism-like behavior. In Fmr1-/y mice, restoration of p-eIF2α solely in excitatory neurons reverses elevated protein synthesis and rescues autism-related phenotypes. Thus, we reveal a previously unknown causal relationship between excitatory neuron-specific translational control via the ISR pathway, general protein synthesis, and core phenotypes reminiscent of autism in a mouse model of FXS.
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Affiliation(s)
- Mehdi Hooshmandi
- Department of Anesthesia and Faculty of Dental Medicine and Oral Health Sciences, McGill University, Montréal, QC, Canada
| | - Vijendra Sharma
- Department of Biochemistry, McGill University, Montréal, QC, Canada
| | - Carolina Thörn Perez
- Department of Anesthesia and Faculty of Dental Medicine and Oral Health Sciences, McGill University, Montréal, QC, Canada
| | - Rapita Sood
- Department of Biochemistry, McGill University, Montréal, QC, Canada
| | - Konstanze Krimbacher
- Department of Pharmacology, Medical University Innsbruck, 6020 Innsbruck, Austria
| | - Calvin Wong
- Department of Anesthesia and Faculty of Dental Medicine and Oral Health Sciences, McGill University, Montréal, QC, Canada
| | - Kevin C Lister
- Department of Anesthesia and Faculty of Dental Medicine and Oral Health Sciences, McGill University, Montréal, QC, Canada
| | - Alba Ureña Guzmán
- Department of Anesthesia and Faculty of Dental Medicine and Oral Health Sciences, McGill University, Montréal, QC, Canada
| | - Trevor D Bartley
- Department of Pathology and Laboratory Medicine, UC Davis School of Medicine, Institute for Pediatric Regenerative Medicine and Shriners Hospitals for Children of Northern California, MIND Institute, UC Davis Medical Center, Sacramento, CA, USA
| | - Cecilia Rocha
- The Neuro's Early Drug Discovery Unit (EDDU), Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, McGill University, Montréal, QC, Canada
| | - Gilles Maussion
- The Neuro's Early Drug Discovery Unit (EDDU), Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, McGill University, Montréal, QC, Canada
| | - Emma Nadler
- Department of Anesthesia and Faculty of Dental Medicine and Oral Health Sciences, McGill University, Montréal, QC, Canada
| | - Patricia Margarita Roque
- Department of Anesthesia and Faculty of Dental Medicine and Oral Health Sciences, McGill University, Montréal, QC, Canada
| | - Ilse Gantois
- Department of Biochemistry, McGill University, Montréal, QC, Canada
| | - Jelena Popic
- Department of Biochemistry, McGill University, Montréal, QC, Canada
| | - Maxime Lévesque
- Montreal Neurological Institute-Hospital, Departments of Neurology & Neurosurgery and of Physiology, McGill University, Montréal, QC, Canada
| | - Randal J Kaufman
- Degenerative Diseases Program, Center for Genetic Disorders and Aging Research, Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Massimo Avoli
- Montreal Neurological Institute-Hospital, Departments of Neurology & Neurosurgery and of Physiology, McGill University, Montréal, QC, Canada
| | - Elisenda Sanz
- Department of Cell Biology, Physiology and Immunology, and Neuroscience Institute, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Karim Nader
- Department of Psychology, Faculty of Science, McGill University, Montréal, QC, Canada
| | - Randi Jenssen Hagerman
- MIND Institute and Department of Pediatrics, University of California at Davis Medical Center, Sacramento, CA, USA
| | - Thomas M Durcan
- The Neuro's Early Drug Discovery Unit (EDDU), Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, McGill University, Montréal, QC, Canada
| | | | | | - Jean-Claude Lacaille
- Department of Neurosciences, Center for Interdisciplinary Research on Brain and Learning, and Research Group on Neural Signaling and Circuitry, Université de Montréal, Montréal, QC, Canada
| | - Veronica Martinez-Cerdeno
- Department of Pathology and Laboratory Medicine, UC Davis School of Medicine, Institute for Pediatric Regenerative Medicine and Shriners Hospitals for Children of Northern California, MIND Institute, UC Davis Medical Center, Sacramento, CA, USA
| | - Jay R Gibson
- University of Texas Southwestern Medical Center at Dallas, Department of Neuroscience, Dallas, TX 75390-9111, USA
| | - Kimberly M Huber
- University of Texas Southwestern Medical Center at Dallas, Department of Neuroscience, Dallas, TX 75390-9111, USA
| | - Nahum Sonenberg
- Department of Biochemistry, McGill University, Montréal, QC, Canada.
| | - Christos G Gkogkas
- Biomedical Research Institute, Foundation for Research and Technology-Hellas, University Campus, 45110 Ioannina, Greece.
| | - Arkady Khoutorsky
- Department of Anesthesia and Faculty of Dental Medicine and Oral Health Sciences, McGill University, Montréal, QC, Canada; Alan Edwards Centre for Research on Pain, McGill University, Montréal, QC, Canada.
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2
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Dias CM, Issac B, Sun L, Lukowicz A, Talukdar M, Akula SK, Miller MB, Walsh K, Rockowitz S, Walsh CA. Glial dysregulation in the human brain in fragile X-associated tremor/ataxia syndrome. Proc Natl Acad Sci U S A 2023; 120:e2300052120. [PMID: 37252957 PMCID: PMC10265985 DOI: 10.1073/pnas.2300052120] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 04/03/2023] [Indexed: 06/01/2023] Open
Abstract
Short trinucleotide expansions at the FMR1 locus are associated with the late-onset condition fragile X-associated tremor/ataxia syndrome (FXTAS), which shows very different clinical and pathological features from fragile X syndrome (associated with longer expansions), with no clear molecular explanation for these marked differences. One prevailing theory posits that the shorter, premutation expansion uniquely causes extreme neurotoxic increases in FMR1 mRNA (i.e., four to eightfold increases), but evidence to support this hypothesis is largely derived from analysis of peripheral blood. We applied single-nucleus RNA sequencing to postmortem frontal cortex and cerebellum from 7 individuals with premutation and matched controls (n = 6) to assess cell type-specific molecular neuropathology. We found only modest upregulation (~1.3-fold) of FMR1 in some glial populations associated with premutation expansions. In premutation cases, we also identified decreased astrocyte proportions in the cortex. Differential expression and gene ontology analysis demonstrated altered neuroregulatory roles of glia. Using network analyses, we identified cell type-specific and region-specific patterns of FMR1 protein target gene dysregulation unique to premutation cases, with notable network dysregulation in the cortical oligodendrocyte lineage. We used pseudotime trajectory analysis to determine how oligodendrocyte development was altered and identified differences in early gene expression in oligodendrocyte trajectories in premutation cases specifically, implicating early cortical glial developmental perturbations. These findings challenge dogma regarding extremely elevated FMR1 increases in FXTAS and implicate glial dysregulation as a critical facet of premutation pathophysiology, representing potential unique therapeutic targets directly derived from the human condition.
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Affiliation(s)
- Caroline M. Dias
- Division of Developmental Medicine, Boston Children’s Hospital, Boston, MA02115
- Division of Genetics and Genomics, Manton Center for Orphan Disease Research, Boston Children’s Hospital, Boston, MA02115
- Department of Pediatrics, Harvard Medical School, Boston, MA02115
- Department of Pediatrics, Section of Developmental Pediatrics, Section of Genetics and Metabolism, and Denver Fragile X Clinic and Research Center, Children’s Hospital Colorado, University of Colorado Anschutz Medical Campus, Aurora, CO80045
| | - Biju Issac
- Research Computing, Department of Information Technology, Boston Children’s Hospital, Boston, MA02115
| | - Liang Sun
- Research Computing, Department of Information Technology, Boston Children’s Hospital, Boston, MA02115
| | - Abigail Lukowicz
- Department of Pediatrics, Section of Developmental Pediatrics, Section of Genetics and Metabolism, and Denver Fragile X Clinic and Research Center, Children’s Hospital Colorado, University of Colorado Anschutz Medical Campus, Aurora, CO80045
| | - Maya Talukdar
- Division of Genetics and Genomics, Manton Center for Orphan Disease Research, Boston Children’s Hospital, Boston, MA02115
- Harvard-Massachusetts Institute of Technology MD/PhD Program, Program in Bioinformatics & Integrative Genomics, Harvard Medical School, Boston, MA02115
| | - Shyam K. Akula
- Division of Genetics and Genomics, Manton Center for Orphan Disease Research, Boston Children’s Hospital, Boston, MA02115
- Harvard-Massachusetts Institute of Technology MD/PhD Program, Program in Neuroscience, Harvard Medical School, Boston, MA02115
| | - Michael B. Miller
- Division of Genetics and Genomics, Manton Center for Orphan Disease Research, Boston Children’s Hospital, Boston, MA02115
- Department of Pathology, Brigham and Women’s Hospital, Boston, MA02115
| | - Katherine Walsh
- Division of Genetics and Genomics, Manton Center for Orphan Disease Research, Boston Children’s Hospital, Boston, MA02115
| | - Shira Rockowitz
- Division of Genetics and Genomics, Manton Center for Orphan Disease Research, Boston Children’s Hospital, Boston, MA02115
- Research Computing, Department of Information Technology, Boston Children’s Hospital, Boston, MA02115
| | - Christopher A. Walsh
- Division of Genetics and Genomics, Manton Center for Orphan Disease Research, Boston Children’s Hospital, Boston, MA02115
- Department of Pediatrics, Harvard Medical School, Boston, MA02115
- HHMI, Boston Children’s Hospital, Boston, MA02115
- Department of Neurology, Harvard Medical School, Boston, MA02115
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3
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Fiorentino F, Menna M, Rotili D, Valente S, Mai A. METTL3 from Target Validation to the First Small-Molecule Inhibitors: A Medicinal Chemistry Journey. J Med Chem 2023; 66:1654-1677. [PMID: 36692498 PMCID: PMC9923689 DOI: 10.1021/acs.jmedchem.2c01601] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
RNA methylation is a critical mechanism for regulating the transcription and translation of specific sequences or for eliminating unnecessary sequences during RNA maturation. METTL3, an RNA methyltransferase that catalyzes the transfer of a methyl group to the N6-adenosine of RNA, is one of the key mediators of this process. METTL3 dysregulation may result in the emergence of a variety of diseases ranging from cancer to cardiovascular and neurological disorders beyond contributing to viral infections. Hence, the discovery of METTL3 inhibitors may assist in furthering the understanding of the biological roles of this enzyme, in addition to contributing to the development of novel therapeutics. Through this work, we will examine the existing correlations between METTL3 and diseases. We will also analyze the development, mode of action, pharmacology, and structure-activity relationships of the currently known METTL3 inhibitors. They include both nucleoside and non-nucleoside compounds, with the latter comprising both competitive and allosteric inhibitors.
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Affiliation(s)
- Francesco Fiorentino
- Department
of Drug Chemistry and Technologies, Sapienza
University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Martina Menna
- Department
of Drug Chemistry and Technologies, Sapienza
University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Dante Rotili
- Department
of Drug Chemistry and Technologies, Sapienza
University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy,
| | - Sergio Valente
- Department
of Drug Chemistry and Technologies, Sapienza
University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy,
| | - Antonello Mai
- Department
of Drug Chemistry and Technologies, Sapienza
University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy,Pasteur
Institute, Cenci-Bolognetti Foundation, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy
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4
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Susco SG, Ghosh S, Mazzucato P, Angelini G, Beccard A, Barrera V, Berryer MH, Messana A, Lam D, Hazelbaker DZ, Barrett LE. Molecular convergence between Down syndrome and fragile X syndrome identified using human pluripotent stem cell models. Cell Rep 2022; 40:111312. [PMID: 36070702 PMCID: PMC9465809 DOI: 10.1016/j.celrep.2022.111312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Revised: 04/19/2022] [Accepted: 08/12/2022] [Indexed: 11/27/2022] Open
Abstract
Down syndrome (DS), driven by an extra copy of chromosome 21 (HSA21), and fragile X syndrome (FXS), driven by loss of the RNA-binding protein FMRP, are two common genetic causes of intellectual disability and autism. Based upon the number of DS-implicated transcripts bound by FMRP, we hypothesize that DS and FXS may share underlying mechanisms. Comparing DS and FXS human pluripotent stem cell (hPSC) and glutamatergic neuron models, we identify increased protein expression of select targets and overlapping transcriptional perturbations. Moreover, acute upregulation of endogenous FMRP in DS patient cells using CRISPRa is sufficient to significantly reduce expression levels of candidate proteins and reverse 40% of global transcriptional perturbations. These results pinpoint specific molecular perturbations shared between DS and FXS that can be leveraged as a strategy for target prioritization; they also provide evidence for the functional relevance of previous associations between FMRP targets and disease-implicated genes. Many neurodevelopmental disorders driven by distinct genetic alterations share phenotypes, but the extent to which they share underlying mechanisms remains an important unanswered question. Using transcript and protein-level analyses in human cellular models, Susco et al. uncover specific areas of molecular convergence between Down syndrome and fragile X syndrome.
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Affiliation(s)
- Sara G Susco
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA
| | - Sulagna Ghosh
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Patrizia Mazzucato
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Gabriella Angelini
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Amanda Beccard
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Victor Barrera
- Bioinformatics Core, Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA
| | - Martin H Berryer
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA
| | - Angelica Messana
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Daisy Lam
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Dane Z Hazelbaker
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Lindy E Barrett
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA.
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5
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Zhang A, Sokolova I, Domissy A, Davis J, Rao L, Hana Utami K, Wang Y, Hagerman RJ, Pouladi MA, Sanna P, Boland MJ, Loring JF. OUP accepted manuscript. Stem Cells Transl Med 2022; 11:613-629. [PMID: 35556144 PMCID: PMC9216490 DOI: 10.1093/stcltm/szac022] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2021] [Accepted: 02/25/2022] [Indexed: 12/03/2022] Open
Abstract
Fragile X Syndrome (FXS), the leading monogenic cause of intellectual disability and autism spectrum disorder, is caused by expansion of a CGG trinucleotide repeat in the 5ʹ-UTR of the Fragile X Mental Retardation-1 (FMR1) gene. Epigenetic silencing of FMR1 results in loss of the Fragile X Mental Retardation Protein (FMRP). Although most studies to date have focused on excitatory neurons, recent evidence suggests that GABAergic inhibitory networks are also affected. To investigate human GABAergic neurogenesis, we established a method to reproducibly derive inhibitory neurons from multiple FXS and control human pluripotent stem cell (hPSC) lines. Electrophysiological analyses suggested that the developing FXS neurons had a delay in the GABA functional switch, a transition in fetal development that converts the GABAA channel’s function from depolarization to hyperpolarization, with profound effects on the developing brain. To investigate the cause of this delay, we analyzed 14 400 single-cell transcriptomes from FXS and control cells at 2 stages of GABAergic neurogenesis. While control and FXS cells were similar at the earlier time point, the later-stage FXS cells retained expression of neuroblast proliferation-associated genes and had lower levels of genes associated with action potential regulation, synapses, and mitochondria compared with controls. Our analysis suggests that loss of FMRP prolongs the proliferative stage of progenitors, which may result in more neurons remaining immature during the later stages of neurogenesis. This could have profound implications for homeostatic excitatory-inhibitory circuit development in FXS, and suggests a novel direction for understanding disease mechanisms that may help to guide therapeutic interventions.
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Affiliation(s)
- Ai Zhang
- Department of Molecular Medicine, Scripps Research, La Jolla, CA, USA
- Skaggs Graduate School of Chemical and Biological Sciences, Scripps Research, La Jolla, CA, USA
- Aspen Neuroscience, Inc.San Diego, CA, USA
| | - Irina Sokolova
- Department of Immunology and Microbiology, Scripps Research, La Jolla, CA, USA
| | - Alain Domissy
- Center for Computational Biology, Scripps Research, La Jolla, CA, USA
| | - Joshua Davis
- Department of Molecular Medicine, Scripps Research, La Jolla, CA, USA
| | - Lee Rao
- Department of Molecular Medicine, Scripps Research, La Jolla, CA, USA
- Biological and Medical Informatics Graduate Program, University of California, San Francisco, CA, USA
| | - Kagistia Hana Utami
- Department of Physiology, National University of Singapore, Singapore
- Translational Laboratory in Genetic Medicine, Agency for Science, Technology and Research (A*STAR), Singapore
| | - Yanling Wang
- Department of Molecular Medicine, Scripps Research, La Jolla, CA, USA
- Rush Alzheimer’s Disease Center, Rush University Medical Center, Chicago, IL, USA
| | - Randi J Hagerman
- MIND Institute, University of California Davis, Sacramento, CA, USA
| | - Mahmoud A Pouladi
- Department of Physiology, National University of Singapore, Singapore
- Translational Laboratory in Genetic Medicine, Agency for Science, Technology and Research (A*STAR), Singapore
- British Columbia Children’s Hospital Research Institute, Department of Medical Genetics, University of British Columbia, Vancouver, Canada
| | - Pietro Sanna
- Department of Immunology and Microbiology, Scripps Research, La Jolla, CA, USA
| | - Michael J Boland
- Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, NY, USA
- Department of Neurology, Columbia University, New York, NY, USA
| | - Jeanne F Loring
- Corresponding author: Jeanne F. Loring, Department of Molecular Medicine, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, CA 92037, USA;
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6
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Bui TA, Shatto J, Cuppens T, Droit A, Bolduc FV. Phenotypic Trade-Offs: Deciphering the Impact of Neurodiversity on Drug Development in Fragile X Syndrome. Front Psychiatry 2021; 12:730987. [PMID: 34733188 PMCID: PMC8558248 DOI: 10.3389/fpsyt.2021.730987] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 09/20/2021] [Indexed: 11/24/2022] Open
Abstract
Fragile X syndrome (FXS) is the most common single-gene cause of intellectual disability and autism spectrum disorder. Individuals with FXS present with a wide range of severity in multiple phenotypes including cognitive delay, behavioral challenges, sleep issues, epilepsy, and anxiety. These symptoms are also shared by many individuals with other neurodevelopmental disorders (NDDs). Since the discovery of the FXS gene, FMR1, FXS has been the focus of intense preclinical investigation and is placed at the forefront of clinical trials in the field of NDDs. So far, most studies have aimed to translate the rescue of specific phenotypes in animal models, for example, learning, or improving general cognitive or behavioral functioning in individuals with FXS. Trial design, selection of outcome measures, and interpretation of results of recent trials have shown limitations in this type of approach. We propose a new paradigm in which all phenotypes involved in individuals with FXS would be considered and, more importantly, the possible interactions between these phenotypes. This approach would be implemented both at the baseline, meaning when entering a trial or when studying a patient population, and also after the intervention when the study subjects have been exposed to the investigational product. This approach would allow us to further understand potential trade-offs underlying the varying effects of the treatment on different individuals in clinical trials, and to connect the results to individual genetic differences. To better understand the interplay between different phenotypes, we emphasize the need for preclinical studies to investigate various interrelated biological and behavioral outcomes when assessing a specific treatment. In this paper, we present how such a conceptual shift in preclinical design could shed new light on clinical trial results. Future clinical studies should take into account the rich neurodiversity of individuals with FXS specifically and NDDs in general, and incorporate the idea of trade-offs in their designs.
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Affiliation(s)
- Truong An Bui
- Department of Pediatrics, University of Alberta, Edmonton, AB, Canada
| | - Julie Shatto
- Department of Pediatrics, University of Alberta, Edmonton, AB, Canada
| | - Tania Cuppens
- Centre de Recherche du CHU de Québec-Université Laval et Département de Médecine Moléculaire de l'Université Laval, Laval, QC, Canada
| | - Arnaud Droit
- Centre de Recherche du CHU de Québec-Université Laval et Département de Médecine Moléculaire de l'Université Laval, Laval, QC, Canada
| | - François V. Bolduc
- Department of Pediatrics, University of Alberta, Edmonton, AB, Canada
- Department of Medical Genetics, University of Alberta, Edmonton, AB, Canada
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
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7
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McCamphill PK, Stoppel LJ, Senter RK, Lewis MC, Heynen AJ, Stoppel DC, Sridhar V, Collins KA, Shi X, Pan JQ, Madison J, Cottrell JR, Huber KM, Scolnick EM, Holson EB, Wagner FF, Bear MF. Selective inhibition of glycogen synthase kinase 3α corrects pathophysiology in a mouse model of fragile X syndrome. Sci Transl Med 2021; 12:12/544/eaam8572. [PMID: 32434848 DOI: 10.1126/scitranslmed.aam8572] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 07/15/2019] [Accepted: 01/11/2020] [Indexed: 01/06/2023]
Abstract
Fragile X syndrome is caused by FMR1 gene silencing and loss of the encoded fragile X mental retardation protein (FMRP), which binds to mRNA and regulates translation. Studies in the Fmr1-/y mouse model of fragile X syndrome indicate that aberrant cerebral protein synthesis downstream of metabotropic glutamate receptor 5 (mGluR5) signaling contributes to disease pathogenesis, but clinical trials using mGluR5 inhibitors were not successful. Animal studies suggested that treatment with lithium might be an alternative approach. Targets of lithium include paralogs of glycogen synthase kinase 3 (GSK3), and nonselective small-molecule inhibitors of these enzymes improved disease phenotypes in a fragile X syndrome mouse model. However, the potential therapeutic use of GSK3 inhibitors has been hampered by toxicity arising from inhibition of both α and β paralogs. Recently, we developed GSK3 inhibitors with sufficient paralog selectivity to avoid a known toxic consequence of dual inhibition, that is, increased β-catenin stabilization. We show here that inhibition of GSK3α, but not GSK3β, corrected aberrant protein synthesis, audiogenic seizures, and sensory cortex hyperexcitability in Fmr1-/y mice. Although inhibiting either paralog prevented induction of NMDA receptor-dependent long-term depression (LTD) in the hippocampus, only inhibition of GSK3α impaired mGluR5-dependent and protein synthesis-dependent LTD. Inhibition of GSK3α additionally corrected deficits in learning and memory in Fmr1-/y mice; unlike mGluR5 inhibitors, there was no evidence of tachyphylaxis or enhanced psychotomimetic-induced hyperlocomotion. GSK3α selective inhibitors may have potential as a therapeutic approach for treating fragile X syndrome.
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Affiliation(s)
- Patrick K McCamphill
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Laura J Stoppel
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Rebecca K Senter
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Michael C Lewis
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Arnold J Heynen
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - David C Stoppel
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Vinay Sridhar
- University of Texas Southwestern Medical Center, Department of Neuroscience, Dallas, TX 75390, USA
| | - Katie A Collins
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Xi Shi
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Jen Q Pan
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Jon Madison
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Jeffrey R Cottrell
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Kimberly M Huber
- University of Texas Southwestern Medical Center, Department of Neuroscience, Dallas, TX 75390, USA
| | - Edward M Scolnick
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Edward B Holson
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Florence F Wagner
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
| | - Mark F Bear
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
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8
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Cell-type-specific profiling of human cellular models of fragile X syndrome reveal PI3K-dependent defects in translation and neurogenesis. Cell Rep 2021; 35:108991. [PMID: 33852833 PMCID: PMC8133829 DOI: 10.1016/j.celrep.2021.108991] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 03/08/2021] [Accepted: 03/23/2021] [Indexed: 02/06/2023] Open
Abstract
Transcriptional silencing of the FMR1 gene in fragile X syndrome (FXS) leads to the loss of the RNA-binding protein FMRP. In addition to regulating mRNA translation and protein synthesis, emerging evidence suggests that FMRP acts to coordinate proliferation and differentiation during early neural development. However, whether loss of FMRP-mediated translational control is related to impaired cell fate specification in the developing human brain remains unknown. Here, we use human patient induced pluripotent stem cell (iPSC)-derived neural progenitor cells and organoids to model neurogenesis in FXS. We developed a high-throughput, in vitro assay that allows for the simultaneous quantification of protein synthesis and proliferation within defined neural subpopulations. We demonstrate that abnormal protein synthesis in FXS is coupled to altered cellular decisions to favor proliferative over neurogenic cell fates during early development. Furthermore, pharmacologic inhibition of elevated phosphoinositide 3-kinase (PI3K) signaling corrects both excess protein synthesis and cell proliferation in a subset of patient neural cells. Raj et al. developed a multiparametric assay to measure cellular and molecular phenotypes during neurogenesis in fragile X syndrome iPSC-derived neural cells. Relative to controls, FXS patient cultures have more proliferative cells with increased protein synthesis. Defects in cell fate acquisition can be normalized by inhibiting overactive PI3K signaling.
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9
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Clifton NE, Thomas KL, Wilkinson LS, Hall J, Trent S. FMRP and CYFIP1 at the Synapse and Their Role in Psychiatric Vulnerability. Complex Psychiatry 2020; 6:5-19. [PMID: 34883502 PMCID: PMC7673588 DOI: 10.1159/000506858] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Accepted: 02/27/2020] [Indexed: 12/23/2022] Open
Abstract
There is increasing awareness of the role genetic risk variants have in mediating vulnerability to psychiatric disorders such as schizophrenia and autism. Many of these risk variants encode synaptic proteins, influencing biological pathways of the postsynaptic density and, ultimately, synaptic plasticity. Fragile-X mental retardation 1 (FMR1) and cytoplasmic fragile-X mental retardation protein (FMRP)-interacting protein 1 (CYFIP1) contain 2 such examples of highly penetrant risk variants and encode synaptic proteins with shared functional significance. In this review, we discuss the biological actions of FMRP and CYFIP1, including their regulation of (i) protein synthesis and specifically FMRP targets, (ii) dendritic and spine morphology, and (iii) forms of synaptic plasticity such as long-term depression. We draw upon a range of preclinical studies that have used genetic dosage models of FMR1 and CYFIP1 to determine their biological function. In parallel, we discuss how clinical studies of fragile X syndrome or 15q11.2 deletion patients have informed our understanding of FMRP and CYFIP1, and highlight the latest psychiatric genomic findings that continue to implicate FMRP and CYFIP1. Lastly, we assess the current limitations in our understanding of FMRP and CYFIP1 biology and how they must be addressed before mechanism-led therapeutic strategies can be developed for psychiatric disorders.
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Affiliation(s)
- Nicholas E. Clifton
- Neuroscience & Mental Health Research Institute, Cardiff University, Cardiff, United Kingdom
- MRC Centre for Neuropsychiatric Genetics and Genomics, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Kerrie L. Thomas
- Neuroscience & Mental Health Research Institute, Cardiff University, Cardiff, United Kingdom
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - Lawrence S. Wilkinson
- Neuroscience & Mental Health Research Institute, Cardiff University, Cardiff, United Kingdom
- School of Psychology, Cardiff University, Cardiff, United Kingdom
| | - Jeremy Hall
- Neuroscience & Mental Health Research Institute, Cardiff University, Cardiff, United Kingdom
- MRC Centre for Neuropsychiatric Genetics and Genomics, School of Medicine, Cardiff University, Cardiff, United Kingdom
- Division of Psychological Medicine and Clinical Neurosciences, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Simon Trent
- Neuroscience & Mental Health Research Institute, Cardiff University, Cardiff, United Kingdom
- School of Life Sciences, Faculty of Natural Sciences, Keele University, Keele, United Kingdom
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FMR1 loss in a human stem cell model reveals early changes to intrinsic membrane excitability. Dev Biol 2020; 468:93-100. [PMID: 32976839 DOI: 10.1016/j.ydbio.2020.09.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 09/18/2020] [Indexed: 11/21/2022]
Abstract
Fragile X mental retardation 1 (FMR1) encodes the RNA binding protein FMRP. Loss of FMRP drives Fragile X syndrome (FXS), the leading inherited cause of intellectual disability and a leading monogenic cause of autism. While cortical hyperexcitability is a hallmark of FXS, the reported phenotypes and underlying mechanisms, including alterations in synaptic transmission and ion channel properties, are heterogeneous and at times contradictory. Here, we report the generation of new isogenic FMR1y/+ and FMR1y/- human pluripotent stem cell (hPSC) lines using CRISPR-Cas9 to facilitate the study of how complete FMRP loss, independent of genetic background, drives molecular and cellular alterations relevant for FXS. After differentiating these stem cell tools into excitatory neurons, we systematically assessed the impact of FMRP loss on intrinsic membrane and synaptic properties over time. Using whole-cell patch clamp analyses, we found that FMR1y/- neurons overall showed an increased intrinsic membrane excitability compared to age-matched FMR1y/+ controls, with no discernable alternations in synaptic transmission. Surprisingly, longitudinal analyses of cell intrinsic defects revealed that a majority of significant changes emerged early following in vitro differentiation and some were not stable over time. Collectively, this study provides a new isogenic hPSC model which can be further leveraged by the scientific community to investigate basic mechanisms of FMR1 gene function relevant for FXS. Moreover, our results suggest that precocious changes in the intrinsic membrane properties during early developmental could be a critical cellular pathology ultimately contributing to cortical hyperexcitability in FXS.
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Wang JY. Using an Isogenic Human Pluripotent Stem Cell Model for Better Understanding Neurodevelopmental Defects in Fragile X Syndrome. Biol Psychiatry 2020; 88:e25-e27. [PMID: 32854833 DOI: 10.1016/j.biopsych.2020.07.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 07/14/2020] [Accepted: 07/14/2020] [Indexed: 12/31/2022]
Affiliation(s)
- Jun Yi Wang
- Center for Mind and Brain, University of California-Davis, Davis, California.
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12
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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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Nobile V, Palumbo F, Lanni S, Ghisio V, Vitali A, Castagnola M, Marzano V, Maulucci G, De Angelis C, De Spirito M, Pacini L, D'Andrea L, Ragno R, Stazi G, Valente S, Mai A, Chiurazzi P, Genuardi M, Neri G, Tabolacci E. Altered mitochondrial function in cells carrying a premutation or unmethylated full mutation of the FMR1 gene. Hum Genet 2020; 139:227-245. [PMID: 31919630 DOI: 10.1007/s00439-019-02104-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Accepted: 12/21/2019] [Indexed: 12/22/2022]
Abstract
Fragile X-related disorders are due to a dynamic mutation of the CGG repeat at the 5' UTR of the FMR1 gene, coding for the RNA-binding protein FMRP. As the CGG sequence expands from premutation (PM, 56-200 CGGs) to full mutation (> 200 CGGs), FMRP synthesis decreases until it is practically abolished in fragile X syndrome (FXS) patients, mainly due to FMR1 methylation. Cells from rare individuals with no intellectual disability and carriers of an unmethylated full mutation (UFM) produce slightly elevated levels of FMR1-mRNA and relatively low levels of FMRP, like in PM carriers. With the aim of clarifying how UFM cells differ from CTRL and FXS cells, a comparative proteomic approach was undertaken, from which emerged an overexpression of SOD2 in UFM cells, also confirmed in PM but not in FXS. The SOD2-mRNA bound to FMRP in UFM more than in the other cell types. The high SOD2 levels in UFM and PM cells correlated with lower levels of superoxide and reactive oxygen species (ROS), and with morphological anomalies and depolarization of the mitochondrial membrane detected through confocal microscopy. The same effect was observed in CTRL and FXS after treatment with MC2791, causing SOD2 overexpression. These mitochondrial phenotypes reverted after knock-down with siRNA against SOD2-mRNA and FMR1-mRNA in UFM and PM. Overall, these data suggest that in PM and UFM carriers, which have high levels of FMR1 transcription and may develop FXTAS, SOD2 overexpression helps to maintain low levels of both superoxide and ROS with signs of mitochondrial degradation.
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Affiliation(s)
- Veronica Nobile
- Istituto di Medicina Genomica, Università Cattolica del Sacro Cuore, Fondazione Policlinico Universitario A. Gemelli IRCCS, Largo F. Vito 1, 00168, Roma, Italy
| | - Federica Palumbo
- Istituto di Medicina Genomica, Università Cattolica del Sacro Cuore, Fondazione Policlinico Universitario A. Gemelli IRCCS, Largo F. Vito 1, 00168, Roma, Italy
| | - Stella Lanni
- Program of Genetics and Genome Biology, The Hospital for Sick Children, The Peter Gilgan Centre for Research and Learning, Toronto, ON, Canada
| | - Valentina Ghisio
- UOC Genetica Medica, Fondazione Policlinico Universitario A. Gemelli IRCCS, Roma, Italy
| | - Alberto Vitali
- Institute of Chemistry of Molecular Recognition, CNR, Roma, Italy
- Istituto di Biochimica e Chimica Clinica, Università Cattolica del Sacro Cuore, Fondazione Policlinico Universitario A. Gemelli IRCCS, Roma, Italy
| | - Massimo Castagnola
- Istituto di Biochimica e Chimica Clinica, Università Cattolica del Sacro Cuore, Fondazione Policlinico Universitario A. Gemelli IRCCS, Roma, Italy
| | - Valeria Marzano
- Istituto di Biochimica e Chimica Clinica, Università Cattolica del Sacro Cuore, Fondazione Policlinico Universitario A. Gemelli IRCCS, Roma, Italy
- Human Microbiome Unit, Bambino Gesù Children's Hospital IRCCS, Rome, Italy
| | - Giuseppe Maulucci
- Istituto di Fisica, Università Cattolica del Sacro Cuore, Fondazione Policlinico Universitario A. Gemelli IRCCS, Roma, Italy
| | - Claudio De Angelis
- Istituto di Fisica, Università Cattolica del Sacro Cuore, Fondazione Policlinico Universitario A. Gemelli IRCCS, Roma, Italy
| | - Marco De Spirito
- Istituto di Fisica, Università Cattolica del Sacro Cuore, Fondazione Policlinico Universitario A. Gemelli IRCCS, Roma, Italy
| | - Laura Pacini
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy
- UniCamillus, Saint Camillus International University of Health and Medical Sciences, Rome, Italy
| | - Laura D'Andrea
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy
| | - Rino Ragno
- Department of Chemistry and Technologies of Drugs, Sapienza University, Rome, Italy
| | - Giulia Stazi
- Department of Chemistry and Technologies of Drugs, Sapienza University, Rome, Italy
| | - Sergio Valente
- Department of Chemistry and Technologies of Drugs, Sapienza University, Rome, Italy
| | - Antonello Mai
- Department of Chemistry and Technologies of Drugs, Sapienza University, Rome, Italy
| | - Pietro Chiurazzi
- Istituto di Medicina Genomica, Università Cattolica del Sacro Cuore, Fondazione Policlinico Universitario A. Gemelli IRCCS, Largo F. Vito 1, 00168, Roma, Italy
- UOC Genetica Medica, Fondazione Policlinico Universitario A. Gemelli IRCCS, Roma, Italy
| | - Maurizio Genuardi
- Istituto di Medicina Genomica, Università Cattolica del Sacro Cuore, Fondazione Policlinico Universitario A. Gemelli IRCCS, Largo F. Vito 1, 00168, Roma, Italy
- UOC Genetica Medica, Fondazione Policlinico Universitario A. Gemelli IRCCS, Roma, Italy
| | - Giovanni Neri
- Istituto di Medicina Genomica, Università Cattolica del Sacro Cuore, Fondazione Policlinico Universitario A. Gemelli IRCCS, Largo F. Vito 1, 00168, Roma, Italy
- Self Research Institute, Greenwood Genetic Center, Greenwood, SC, USA
| | - Elisabetta Tabolacci
- Istituto di Medicina Genomica, Università Cattolica del Sacro Cuore, Fondazione Policlinico Universitario A. Gemelli IRCCS, Largo F. Vito 1, 00168, Roma, Italy.
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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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Pal R, Bhattacharya A. Modelling Protein Synthesis as A Biomarker in Fragile X Syndrome Patient-Derived Cells. Brain Sci 2019; 9:E59. [PMID: 30862080 PMCID: PMC6468675 DOI: 10.3390/brainsci9030059] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 02/27/2019] [Accepted: 03/06/2019] [Indexed: 12/26/2022] Open
Abstract
The most conserved molecular phenotype of Fragile X Syndrome (FXS) is aberrant protein synthesis. This has been validated in a variety of experimental model systems from zebrafish to rats, patient-derived lymphoblasts and fibroblasts. With the advent of personalized medicine paradigms, patient-derived cells and their derivatives are gaining more translational importance, not only to model disease in a dish, but also for biomarker discovery. Here we review past and current practices of measuring protein synthesis in FXS, studies in patient derived cells and the inherent challenges in measuring protein synthesis in them to offer usable avenues of modeling this important metabolic metric for further biomarker development.
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Affiliation(s)
- Rakhi Pal
- Centre for Brain Development and Repair, Institute for Stem Cell Biology and Regenerative Medicine, GKVK Post, Bellary Road, Bengaluru 560065, India.
| | - Aditi Bhattacharya
- Centre for Brain Development and Repair, Institute for Stem Cell Biology and Regenerative Medicine, GKVK Post, Bellary Road, Bengaluru 560065, India.
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