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Tassone F, Protic D, Allen EG, Archibald AD, Baud A, Brown TW, Budimirovic DB, Cohen J, Dufour B, Eiges R, Elvassore N, Gabis LV, Grudzien SJ, Hall DA, Hessl D, Hogan A, Hunter JE, Jin P, Jiraanont P, Klusek J, Kooy RF, Kraan CM, Laterza C, Lee A, Lipworth K, Losh M, Loesch D, Lozano R, Mailick MR, Manolopoulos A, Martinez-Cerdeno V, McLennan Y, Miller RM, Montanaro FAM, Mosconi MW, Potter SN, Raspa M, Rivera SM, Shelly K, Todd PK, Tutak K, Wang JY, Wheeler A, Winarni TI, Zafarullah M, Hagerman RJ. Insight and Recommendations for Fragile X-Premutation-Associated Conditions from the Fifth International Conference on FMR1 Premutation. Cells 2023; 12:2330. [PMID: 37759552 PMCID: PMC10529056 DOI: 10.3390/cells12182330] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 09/09/2023] [Accepted: 09/12/2023] [Indexed: 09/29/2023] Open
Abstract
The premutation of the fragile X messenger ribonucleoprotein 1 (FMR1) gene is characterized by an expansion of the CGG trinucleotide repeats (55 to 200 CGGs) in the 5' untranslated region and increased levels of FMR1 mRNA. Molecular mechanisms leading to fragile X-premutation-associated conditions (FXPAC) include cotranscriptional R-loop formations, FMR1 mRNA toxicity through both RNA gelation into nuclear foci and sequestration of various CGG-repeat-binding proteins, and the repeat-associated non-AUG (RAN)-initiated translation of potentially toxic proteins. Such molecular mechanisms contribute to subsequent consequences, including mitochondrial dysfunction and neuronal death. Clinically, premutation carriers may exhibit a wide range of symptoms and phenotypes. Any of the problems associated with the premutation can appropriately be called FXPAC. Fragile X-associated tremor/ataxia syndrome (FXTAS), fragile X-associated primary ovarian insufficiency (FXPOI), and fragile X-associated neuropsychiatric disorders (FXAND) can fall under FXPAC. Understanding the molecular and clinical aspects of the premutation of the FMR1 gene is crucial for the accurate diagnosis, genetic counseling, and appropriate management of affected individuals and families. This paper summarizes all the known problems associated with the premutation and documents the presentations and discussions that occurred at the International Premutation Conference, which took place in New Zealand in 2023.
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Affiliation(s)
- Flora Tassone
- Department of Biochemistry and Molecular Medicine, School of Medicine, University of California Davis, Sacramento, CA 95817, USA;
- MIND Institute, University of California Davis, Davis, CA 95817, USA; (B.D.); (D.H.); (V.M.-C.)
| | - Dragana Protic
- Department of Pharmacology, Clinical Pharmacology and Toxicology, Faculty of Medicine, University of Belgrade, 11129 Belgrade, Serbia;
- Fragile X Clinic, Special Hospital for Cerebral Palsy and Developmental Neurology, 11040 Belgrade, Serbia
| | - Emily Graves Allen
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322, USA; (E.G.A.); (P.J.); (K.S.)
| | - Alison D. Archibald
- Victorian Clinical Genetics Services, Royal Children’s Hospital, Melbourne, VIC 3052, Australia;
- Department of Paediatrics, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Melbourne, VIC 3052, Australia;
- Genomics in Society Group, Murdoch Children’s Research Institute, Royal Children’s Hospital, Melbourne, VIC 3052, Australia
| | - Anna Baud
- Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, Uniwersytetu Poznańskiego 6, 61-614 Poznan, Poland; (A.B.); (K.T.)
| | - Ted W. Brown
- Central Clinical School, University of Sydney, Sydney, NSW 2006, Australia;
- Fragile X Association of Australia, Brookvale, NSW 2100, Australia;
- NYS Institute for Basic Research in Developmental Disabilities, New York, NY 10314, USA
| | - Dejan B. Budimirovic
- Department of Psychiatry, Fragile X Clinic, Kennedy Krieger Institute, Baltimore, MD 21205, USA;
- Department of Psychiatry & Behavioral Sciences-Child Psychiatry, School of Medicine, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Jonathan Cohen
- Fragile X Alliance Clinic, Melbourne, VIC 3161, Australia;
| | - Brett Dufour
- MIND Institute, University of California Davis, Davis, CA 95817, USA; (B.D.); (D.H.); (V.M.-C.)
- Department of Pathology and Laboratory Medicine, Institute for Pediatric Regenerative Medicine, Shriners Hospitals for Children of Northern California, School of Medicine, University of California Davis, Sacramento, CA 95817, USA;
| | - Rachel Eiges
- Stem Cell Research Laboratory, Medical Genetics Institute, Shaare Zedek Medical Center Affiliated with the Hebrew University School of Medicine, Jerusalem 91031, Israel;
| | - Nicola Elvassore
- Veneto Institute of Molecular Medicine (VIMM), 35129 Padova, Italy; (N.E.); (C.L.)
- Department of Industrial Engineering, University of Padova, 35131 Padova, Italy
| | - Lidia V. Gabis
- Keshet Autism Center Maccabi Wolfson, Holon 5822012, Israel;
- Faculty of Medicine, Tel-Aviv University, Tel Aviv 6997801, Israel
| | - Samantha J. Grudzien
- Department of Neurology, University of Michigan, 4148 BSRB, 109 Zina Pitcher Place, Ann Arbor, MI 48109, USA; (S.J.G.); (P.K.T.)
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI 48109, USA
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Deborah A. Hall
- Department of Neurological Sciences, Rush University, Chicago, IL 60612, USA;
| | - David Hessl
- MIND Institute, University of California Davis, Davis, CA 95817, USA; (B.D.); (D.H.); (V.M.-C.)
- Department of Psychiatry and Behavioral Sciences, School of Medicine, University of California Davis, Sacramento, CA 95817, USA
| | - Abigail Hogan
- Department of Communication Sciences and Disorders, Arnold School of Public Health, University of South Carolina, Columbia, SC 29208, USA; (A.H.); (J.K.)
| | - Jessica Ezzell Hunter
- RTI International, Research Triangle Park, NC 27709, USA; (J.E.H.); (S.N.P.); (M.R.); (A.W.)
| | - Peng Jin
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322, USA; (E.G.A.); (P.J.); (K.S.)
| | - Poonnada Jiraanont
- Faculty of Medicine, King Mongkut’s Institute of Technology Ladkrabang, Bangkok 10520, Thailand;
| | - Jessica Klusek
- Department of Communication Sciences and Disorders, Arnold School of Public Health, University of South Carolina, Columbia, SC 29208, USA; (A.H.); (J.K.)
| | - R. Frank Kooy
- Department of Medical Genetics, University of Antwerp, 2000 Antwerp, Belgium;
| | - Claudine M. Kraan
- Department of Paediatrics, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Melbourne, VIC 3052, Australia;
- Diagnosis and Development, Murdoch Children’s Research Institute, Melbourne, VIC 3052, Australia
| | - Cecilia Laterza
- Veneto Institute of Molecular Medicine (VIMM), 35129 Padova, Italy; (N.E.); (C.L.)
- Department of Industrial Engineering, University of Padova, 35131 Padova, Italy
| | - Andrea Lee
- Fragile X New Zealand, Nelson 7040, New Zealand;
| | - Karen Lipworth
- Fragile X Association of Australia, Brookvale, NSW 2100, Australia;
| | - Molly Losh
- Roxelyn and Richard Pepper Department of Communication Sciences and Disorders, Northwestern University, Evanston, IL 60201, USA;
| | - Danuta Loesch
- School of Psychology and Public Health, La Trobe University, Melbourne, VIC 3086, Australia;
| | - Reymundo Lozano
- Departments of Genetics and Genomic Sciences and Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA;
| | - Marsha R. Mailick
- Waisman Center, University of Wisconsin-Madison, Madison, WI 53705, USA;
| | - Apostolos Manolopoulos
- Intramural Research Program, Laboratory of Clinical Investigation, National Institute on Aging, Baltimore, MD 21224, USA;
| | - Veronica Martinez-Cerdeno
- MIND Institute, University of California Davis, Davis, CA 95817, USA; (B.D.); (D.H.); (V.M.-C.)
- Department of Pathology and Laboratory Medicine, Institute for Pediatric Regenerative Medicine, Shriners Hospitals for Children of Northern California, School of Medicine, University of California Davis, Sacramento, CA 95817, USA;
| | - Yingratana McLennan
- Department of Pathology and Laboratory Medicine, Institute for Pediatric Regenerative Medicine, Shriners Hospitals for Children of Northern California, School of Medicine, University of California Davis, Sacramento, CA 95817, USA;
| | | | - Federica Alice Maria Montanaro
- Child and Adolescent Neuropsychiatry Unit, Department of Neuroscience, Bambino Gesù Children’s Hospital, IRCCS, 00165 Rome, Italy;
- Department of Education, Psychology, Communication, University of Bari Aldo Moro, 70121 Bari, Italy
| | - Matthew W. Mosconi
- Schiefelbusch Institute for Life Span Studies, University of Kansas, Lawrence, KS 66045, USA;
- Clinical Child Psychology Program, University of Kansas, Lawrence, KS 66045, USA
- Kansas Center for Autism Research and Training (K-CART), University of Kansas, Lawrence, KS 66045, USA
| | - Sarah Nelson Potter
- RTI International, Research Triangle Park, NC 27709, USA; (J.E.H.); (S.N.P.); (M.R.); (A.W.)
| | - Melissa Raspa
- RTI International, Research Triangle Park, NC 27709, USA; (J.E.H.); (S.N.P.); (M.R.); (A.W.)
| | - Susan M. Rivera
- Department of Psychology, University of Maryland, College Park, MD 20742, USA;
| | - Katharine Shelly
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322, USA; (E.G.A.); (P.J.); (K.S.)
| | - Peter K. Todd
- Department of Neurology, University of Michigan, 4148 BSRB, 109 Zina Pitcher Place, Ann Arbor, MI 48109, USA; (S.J.G.); (P.K.T.)
- Ann Arbor Veterans Administration Healthcare, Ann Arbor, MI 48105, USA
| | - Katarzyna Tutak
- Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, Uniwersytetu Poznańskiego 6, 61-614 Poznan, Poland; (A.B.); (K.T.)
| | - Jun Yi Wang
- Center for Mind and Brain, University of California Davis, Davis, CA 95618, USA;
| | - Anne Wheeler
- RTI International, Research Triangle Park, NC 27709, USA; (J.E.H.); (S.N.P.); (M.R.); (A.W.)
| | - Tri Indah Winarni
- Center for Biomedical Research (CEBIOR), Faculty of Medicine, Universitas Diponegoro, Semarang 502754, Central Java, Indonesia;
| | - Marwa Zafarullah
- Department of Biochemistry and Molecular Medicine, School of Medicine, University of California Davis, Sacramento, CA 95817, USA;
| | - Randi J. Hagerman
- MIND Institute, University of California Davis, Davis, CA 95817, USA; (B.D.); (D.H.); (V.M.-C.)
- Department of Pediatrics, School of Medicine, University of California Davis, Sacramento, CA 95817, USA
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Shelly KE, Candelaria NR, Li Z, Allen EG, Jin P, Nelson DL. Ectopic expression of CGG-repeats alters ovarian response to gonadotropins and leads to infertility in a murine FMR1 premutation model. Hum Mol Genet 2021; 30:923-938. [PMID: 33856019 PMCID: PMC8165648 DOI: 10.1093/hmg/ddab083] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 02/18/2021] [Accepted: 03/30/2021] [Indexed: 01/03/2023] Open
Abstract
Women heterozygous for an expansion of CGG repeats in the 5'UTR of FMR1 risk developing fragile X-associated primary ovarian insufficiency (FXPOI) and/or tremor and ataxia syndrome (FXTAS). We show that expanded CGGs, independent of FMR1, are sufficient to drive ovarian insufficiency and that expression of CGG-containing mRNAs alone or in conjunction with a polyglycine-containing peptide translated from these RNAs contribute to dysfunction. Heterozygous females from two mouse lines expressing either CGG RNA-only (RNA-only) or CGG RNA and the polyglycine product FMRpolyG (FMRpolyG+RNA) were used to assess ovarian function in aging animals. The expression of FMRpolyG+RNA led to early cessation of breeding, ovulation and transcriptomic changes affecting cholesterol and steroid hormone biosynthesis. Females expressing CGG RNA-only did not exhibit decreased progeny during natural breeding, but their ovarian transcriptomes were enriched for alterations in cholesterol and lipid biosynthesis. The enrichment of CGG RNA-only ovaries for differentially expressed genes related to cholesterol processing provided a link to the ovarian cysts observed in both CGG-expressing lines. Early changes in transcriptome profiles led us to measure ovarian function in prepubertal females that revealed deficiencies in ovulatory responses to gonadotropins. These include impairments in cumulus expansion and resumption of oocyte meiosis, as well as reduced ovulated oocyte number. Cumulatively, we demonstrated the sufficiency of ectopically expressed CGG repeats to lead to ovarian insufficiency and that co-expression of CGG-RNA and FMRpolyG lead to premature cessation of breeding. However, the expression of CGG RNA-alone was sufficient to lead to ovarian dysfunction by impairing responses to hormonal stimulation.
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Affiliation(s)
- Katharine E Shelly
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Nicholes R Candelaria
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Ziyi Li
- Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Emily G Allen
- Department of Human Genetics, Emory University, Atlanta, GA 30322, USA
| | - Peng Jin
- Department of Human Genetics, Emory University, Atlanta, GA 30322, USA
| | - David L Nelson
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
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Bhat SA, Yousuf A, Mushtaq Z, Kumar V, Qurashi A. Fragile X Premutation rCGG Repeats Impair Synaptic Growth and Synaptic Transmission at Drosophila larval Neuromuscular Junction. Hum Mol Genet 2021; 30:1677-1692. [PMID: 33772546 DOI: 10.1093/hmg/ddab087] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 03/21/2021] [Accepted: 03/22/2021] [Indexed: 11/14/2022] Open
Abstract
Fragile X-associated tremor/ataxia syndrome (FXTAS) is a late-onset neurodegenerative disease that develops in some premutation (PM) carriers of the FMR1 gene with alleles bearing 55-200 CGG repeats. The discovery of a broad spectrum of clinical and cell developmental abnormalities among PM carriers with or without FXTAS and in model systems suggests that neurodegeneration seen in FXTAS could be the inevitable end-result of pathophysiological processes set during early development. Hence, it is imperative to trace early PM-induced pathological abnormalities. Previous studies have shown that transgenic Drosophila carrying PM-length CGG repeats are sufficient to cause neurodegeneration. Here, we used the same transgenic model to understand the effect of CGG repeats on the structure and function of the developing nervous system. We show that presynaptic expression of CGG repeats restricts synaptic growth, reduces the number of synaptic boutons, leads to aberrant presynaptic varicosities, and impairs synaptic transmission at the larval neuromuscular junctions. The postsynaptic analysis shows that both glutamate receptors and subsynaptic reticulum proteins were normal. However, a high percentage of boutons show a reduced density of Bruchpilot protein, a key component of presynaptic active zones required for vesicle release. The electrophysiological analysis shows a significant reduction in quantal content, a measure of total synaptic vesicles released per excitation potential. Together, these findings suggest that synapse perturbation caused by rCGG repeats mediates presynaptically during larval NMJ development. We also suggest that the stress-activated c-Jun N-terminal kinase protein Basket and CIDE-N protein Drep-2 positively mediate Bruchpilot active zone defects caused by rCGG repeats.
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Affiliation(s)
- Sajad A Bhat
- Department of Biotechnology, University of Kashmir, Srinagar, JK, 190006, India
| | - Aadil Yousuf
- Department of Biotechnology, University of Kashmir, Srinagar, JK, 190006, India
| | - Zeeshan Mushtaq
- Laboratory of Neurogenetics, IISER-Bhopal, Bhopal, MP, 462066, India
| | - Vimlesh Kumar
- Laboratory of Neurogenetics, IISER-Bhopal, Bhopal, MP, 462066, India
| | - Abrar Qurashi
- Department of Biotechnology, University of Kashmir, Srinagar, JK, 190006, India
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Glineburg MR, Todd PK, Charlet-Berguerand N, Sellier C. Repeat-associated non-AUG (RAN) translation and other molecular mechanisms in Fragile X Tremor Ataxia Syndrome. Brain Res 2018; 1693:43-54. [PMID: 29453961 PMCID: PMC6010627 DOI: 10.1016/j.brainres.2018.02.006] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 01/31/2018] [Accepted: 02/02/2018] [Indexed: 11/11/2022]
Abstract
Fragile X-associated tremor/ataxia syndrome (FXTAS) is a late-onset inherited neurodegenerative disorder characterized by progressive intention tremor, gait ataxia and dementia associated with mild brain atrophy. The cause of FXTAS is a premutation expansion, of 55 to 200 CGG repeats localized within the 5'UTR of FMR1. These repeats are transcribed in the sense and antisense directions into mutants RNAs, which have increased expression in FXTAS. Furthermore, CGG sense and CCG antisense expanded repeats are translated into novel proteins despite their localization in putatively non-coding regions of the transcript. Here we focus on two proposed disease mechanisms for FXTAS: 1) RNA gain-of-function, whereby the mutant RNAs bind specific proteins and preclude their normal functions, and 2) repeat-associated non-AUG (RAN) translation, whereby translation through the CGG or CCG repeats leads to the production of toxic homopolypeptides, which in turn interfere with a variety of cellular functions. Here, we analyze the data generated to date on both of these potential molecular mechanisms and lay out a path forward for determining which factors drive FXTAS pathogenicity.
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Affiliation(s)
| | - Peter K Todd
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109, USA; Veteran's Affairs Medical Center, Ann Arbor, MI 48105, USA
| | - Nicolas Charlet-Berguerand
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U964, CNRS UMR7104, University of Strasbourg, 67400 Illkirch, France
| | - Chantal Sellier
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U964, CNRS UMR7104, University of Strasbourg, 67400 Illkirch, France.
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5
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Mostafavi S, Gaiteri C, Sullivan SE, White CC, Tasaki S, Xu J, Taga M, Klein HU, Patrick E, Komashko V, McCabe C, Smith R, Bradshaw EM, Root DE, Regev A, Yu L, Chibnik LB, Schneider JA, Young-Pearse TL, Bennett DA, De Jager PL. A molecular network of the aging human brain provides insights into the pathology and cognitive decline of Alzheimer's disease. Nat Neurosci 2018; 21:811-819. [PMID: 29802388 PMCID: PMC6599633 DOI: 10.1038/s41593-018-0154-9] [Citation(s) in RCA: 315] [Impact Index Per Article: 52.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2016] [Accepted: 04/20/2018] [Indexed: 02/07/2023]
Abstract
There is a need for new therapeutic targets with which to prevent Alzheimer’s disease (AD), a major contributor to aging-related cognitive decline. Here, we report the construction and validation of a molecular network of the aging human frontal cortex. Using RNA sequence data from 478 individuals, we first build a molecular network using modules of coexpressed genes and then relate these modules to AD and its neuropathologic and cognitive endophenotypes. We confirm these associations in two independent AD datasets as well as in epigenomic data. We also illustrate the use of the network in prioritizing amyloid-associated genes for in vitro validation in human neurons and astrocytes. These analyses based on unique cohorts enable us to resolve the role of distinct cortical modules that have a direct effect on the accumulation of AD pathology from those that have a direct effect on cognitive decline, exemplifying a network approach to complex diseases. Systems biology analysis of RNA sequencing data from the aging human cortex identifies a molecular network which prioritizes groups of genes that influence cognitive decline or neuropathology in Alzheimer’s disease.
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Affiliation(s)
- Sara Mostafavi
- Department of Statistics, Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada.,Canadian Institute for Advanced Research, Toronto, ON, Canada
| | - Chris Gaiteri
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA
| | - Sarah E Sullivan
- Department of Neurology, Brigham and Women's Hospital, Boston, MA, USA
| | | | - Shinya Tasaki
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA
| | - Jishu Xu
- Broad Institute, Cambridge, MA, USA
| | - Mariko Taga
- Broad Institute, Cambridge, MA, USA.,Center for Translational & Computational Neuroimmunology, Department of Neurology, Columbia University Medical Center, New York, NY, USA
| | - Hans-Ulrich Klein
- Broad Institute, Cambridge, MA, USA.,Center for Translational & Computational Neuroimmunology, Department of Neurology, Columbia University Medical Center, New York, NY, USA
| | | | - Vitalina Komashko
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA
| | | | - Robert Smith
- Department of Neurology, Brigham and Women's Hospital, Boston, MA, USA
| | - Elizabeth M Bradshaw
- Broad Institute, Cambridge, MA, USA.,Center for Translational & Computational Neuroimmunology, Department of Neurology, Columbia University Medical Center, New York, NY, USA
| | | | | | - Lei Yu
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA
| | - Lori B Chibnik
- Broad Institute, Cambridge, MA, USA.,Harvard Medical School, Boston, MA, USA.,Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Julie A Schneider
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA
| | - Tracy L Young-Pearse
- Department of Neurology, Brigham and Women's Hospital, Boston, MA, USA.,Harvard Medical School, Boston, MA, USA
| | - David A Bennett
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA.
| | - Philip L De Jager
- Broad Institute, Cambridge, MA, USA. .,Center for Translational & Computational Neuroimmunology, Department of Neurology, Columbia University Medical Center, New York, NY, USA.
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6
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The Expanding Toolkit of Translating Ribosome Affinity Purification. J Neurosci 2018; 37:12079-12087. [PMID: 29237735 DOI: 10.1523/jneurosci.1929-17.2017] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Revised: 10/16/2017] [Accepted: 11/03/2017] [Indexed: 01/23/2023] Open
Abstract
Translating ribosome affinity purification is a method initially developed for profiling mRNA from genetically defined cell types in complex tissues. It has been applied both to identify target molecules in cell types that are important for controlling a variety of behaviors in the brain, and to understand the molecular consequences on those cells due to experimental manipulations, ranging from drugs of abuse to disease-causing mutations. Since its inception, a variety of methodological advances are opening new avenues of investigation. These advances include a variety of new methods for targeting cells for translating ribosome affinity purification by features such as their projections or activity, additional tags and mouse reagents increasing the flexibility of the system, and new modifications of the method specifically focused on studying the regulation of translation. The latter includes methods to assess cell type-specific regulation of translation in specific subcellular compartments. Here, I provide a summary of these recent advances and resources, highlighting both new experimental opportunities and areas for future technical development.
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Boivin M, Willemsen R, Hukema RK, Sellier C. Potential pathogenic mechanisms underlying Fragile X Tremor Ataxia Syndrome: RAN translation and/or RNA gain-of-function? Eur J Med Genet 2017; 61:674-679. [PMID: 29223504 DOI: 10.1016/j.ejmg.2017.11.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Revised: 09/19/2017] [Accepted: 11/08/2017] [Indexed: 10/18/2022]
Abstract
Fragile X-associated tremor/ataxia syndrome (FXTAS) is an inherited neurodegenerative disease caused by an expansion of 55-200 CGG repeats located in the FMR1 gene. The main clinical and neuropathological features of FXTAS are progressive intention tremor and gait ataxia associated with brain atrophy, neuronal cell loss and presence of ubiquitin-positive intranuclear inclusions in both neurons and astrocytes. At the molecular level, FXTAS is characterized by increased expression of FMR1 sense and antisense RNA containing expanded CGG or GGC repeats, respectively. Here, we discuss the putative molecular mechanisms underlying FXTAS and notably recent reports that expanded CGG and GGC repeats may be pathogenic through RAN translation into toxic proteins.
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Affiliation(s)
- Manon Boivin
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U964, CNRS UMR7104, University of Strasbourg, 67400 Illkirch, France
| | - Rob Willemsen
- Department of Clinical Genetics, Erasmus MC, 3015 CN Rotterdam, The Netherlands
| | - Renate K Hukema
- Department of Clinical Genetics, Erasmus MC, 3015 CN Rotterdam, The Netherlands
| | - Chantal Sellier
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U964, CNRS UMR7104, University of Strasbourg, 67400 Illkirch, France.
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8
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Mancarci BO, Toker L, Tripathy SJ, Li B, Rocco B, Sibille E, Pavlidis P. Cross-Laboratory Analysis of Brain Cell Type Transcriptomes with Applications to Interpretation of Bulk Tissue Data. eNeuro 2017; 4:ENEURO.0212-17.2017. [PMID: 29204516 PMCID: PMC5707795 DOI: 10.1523/eneuro.0212-17.2017] [Citation(s) in RCA: 108] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 10/25/2017] [Accepted: 10/31/2017] [Indexed: 12/13/2022] Open
Abstract
Establishing the molecular diversity of cell types is crucial for the study of the nervous system. We compiled a cross-laboratory database of mouse brain cell type-specific transcriptomes from 36 major cell types from across the mammalian brain using rigorously curated published data from pooled cell type microarray and single-cell RNA-sequencing (RNA-seq) studies. We used these data to identify cell type-specific marker genes, discovering a substantial number of novel markers, many of which we validated using computational and experimental approaches. We further demonstrate that summarized expression of marker gene sets (MGSs) in bulk tissue data can be used to estimate the relative cell type abundance across samples. To facilitate use of this expanding resource, we provide a user-friendly web interface at www.neuroexpresso.org.
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Affiliation(s)
- B. Ogan Mancarci
- Graduate Program in Bioinformatics, University of British Columbia, Vancouver V6T 1Z4, Canada
- Department of Psychiatry, University of British Columbia, Vancouver V6T 2A1, Canada
- Michael Smith Laboratories, University of British Columbia, Vancouver V6T 1Z4, Canada
| | - Lilah Toker
- Department of Psychiatry, University of British Columbia, Vancouver V6T 2A1, Canada
- Michael Smith Laboratories, University of British Columbia, Vancouver V6T 1Z4, Canada
| | - Shreejoy J. Tripathy
- Department of Psychiatry, University of British Columbia, Vancouver V6T 2A1, Canada
- Michael Smith Laboratories, University of British Columbia, Vancouver V6T 1Z4, Canada
| | - Brenna Li
- Department of Psychiatry, University of British Columbia, Vancouver V6T 2A1, Canada
- Michael Smith Laboratories, University of British Columbia, Vancouver V6T 1Z4, Canada
| | - Brad Rocco
- Campbell Family Mental Health Research Institute of CAMH
- Department of Psychiatry and the Department of Pharmacology and Toxicology, University of Toronto, Vancouver M5S 1A8, Canada
| | - Etienne Sibille
- Campbell Family Mental Health Research Institute of CAMH
- Department of Psychiatry and the Department of Pharmacology and Toxicology, University of Toronto, Vancouver M5S 1A8, Canada
| | - Paul Pavlidis
- Department of Psychiatry, University of British Columbia, Vancouver V6T 2A1, Canada
- Michael Smith Laboratories, University of British Columbia, Vancouver V6T 1Z4, Canada
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9
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Chao HT, Liu L, Bellen HJ. Building dialogues between clinical and biomedical research through cross-species collaborations. Semin Cell Dev Biol 2017; 70:49-57. [PMID: 28579453 PMCID: PMC5623622 DOI: 10.1016/j.semcdb.2017.05.022] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 05/16/2017] [Accepted: 05/23/2017] [Indexed: 10/19/2022]
Abstract
Today, biomedical science is equipped with an impressive array of technologies and genetic resources that bolster our basic understanding of fundamental biology and enhance the practice of modern medicine by providing clinicians with a diverse toolkit to diagnose, prognosticate, and treat a plethora of conditions. Many significant advances in our understanding of disease mechanisms and therapeutic interventions have arisen from fruitful dialogues between clinicians and biomedical research scientists. However, the increasingly specialized scientific and medical disciplines, globalization of science and technology, and complex datasets often hinder the development of effective interdisciplinary collaborations between clinical medicine and biomedical research. The goal of this review is to provide examples of diverse strategies to enhance communication and collaboration across diverse disciplines. First, we discuss examples of efforts to foster interdisciplinary collaborations at institutional and multi-institutional levels. Second, we explore resources and tools for clinicians and research scientists to facilitate effective bi-directional dialogues. Third, we use our experiences in neurobiology and human genetics to highlight how communication between clinical medicine and biomedical research lead to effective implementation of cross-species model organism approaches to uncover the biological underpinnings of health and disease.
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Affiliation(s)
- Hsiao-Tuan Chao
- Department of Pediatrics, Section of Child Neurology, Baylor College of Medicine, Houston, TX 77030, United States; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, United States.
| | - Lucy Liu
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, United States; Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, United States
| | - Hugo J Bellen
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, United States; Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, United States; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, United States; Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, United States; Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX 77030, United States.
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10
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Kong HE, Zhao J, Xu S, Jin P, Jin Y. Fragile X-Associated Tremor/Ataxia Syndrome: From Molecular Pathogenesis to Development of Therapeutics. Front Cell Neurosci 2017; 11:128. [PMID: 28529475 PMCID: PMC5418347 DOI: 10.3389/fncel.2017.00128] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Accepted: 04/18/2017] [Indexed: 12/31/2022] Open
Abstract
Fragile X-associated tremor/ataxia syndrome (FXTAS) is a neurodegenerative disorder caused by a premutation CGG repeat expansion (55-200 repeats) within the 5' UTR of the fragile X gene (FMR1). FXTAS is characterized by intension tremor, cerebellar ataxia, progressive neurodegeneration, parkinsonism and cognitive decline. The development of transgenic mouse and Drosophila melanogaster models carrying an expanded CGG repeat has yielded valuable insight into the pathophysiology of FXTAS. To date, we know of two main molecular mechanisms of this disorder: (1) a toxic gain of function of the expanded CGG-repeat FMR1 mRNA, which results in the binding/sequestration of the CGG-binding proteins; and (2) CGG repeat-associated non-AUG-initiated (RAN) translation, which generates a polyglycine peptide toxic to cells. Besides these CGG-mediated mechanisms, recent studies have shed light on additional mechanisms of pathogenesis, such as the antisense transcript ASFMR1, mitochondrial dysfunction, DNA damage from R-loop formation and 5-hydroxymethylcytosine (5hmC)-mediated epigenetic modulation. Here we summarize the recent progress towards understanding the etiology of FXTAS and provide an overview of potential treatment strategies.
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Affiliation(s)
- Ha Eun Kong
- Department of Human Genetics, School of Medicine, Emory UniversityAtlanta, GA, USA
| | - Juan Zhao
- The State Key Laboratory of Medical Genetics, School of Life Sciences, Central South UniversityChangsha, China
| | - Shunliang Xu
- Department of Neurology, 2nd Hospital of Shandong UniversityJinan, China
| | - Peng Jin
- Department of Human Genetics, School of Medicine, Emory UniversityAtlanta, GA, USA
| | - Yan Jin
- Department of Ophthalmology, Second Hospital, Jilin UniversityChangchun, China
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11
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Koon AC, Chan HYE. Drosophila melanogaster As a Model Organism to Study RNA Toxicity of Repeat Expansion-Associated Neurodegenerative and Neuromuscular Diseases. Front Cell Neurosci 2017; 11:70. [PMID: 28377694 PMCID: PMC5359753 DOI: 10.3389/fncel.2017.00070] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Accepted: 02/27/2017] [Indexed: 12/14/2022] Open
Abstract
For nearly a century, the fruit fly, Drosophila melanogaster, has proven to be a valuable tool in our understanding of fundamental biological processes, and has empowered our discoveries, particularly in the field of neuroscience. In recent years, Drosophila has emerged as a model organism for human neurodegenerative and neuromuscular disorders. In this review, we highlight a number of recent studies that utilized the Drosophila model to study repeat-expansion associated diseases (READs), such as polyglutamine diseases, fragile X-associated tremor/ataxia syndrome (FXTAS), myotonic dystrophy type 1 (DM1) and type 2 (DM2), and C9ORF72-associated amyotrophic lateral sclerosis/frontotemporal dementia (C9-ALS/FTD). Discoveries regarding the possible mechanisms of RNA toxicity will be focused here. These studies demonstrate Drosophila as an excellent in vivo model system that can reveal novel mechanistic insights into human disorders, providing the foundation for translational research and therapeutic development.
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Affiliation(s)
- Alex C Koon
- Laboratory of Drosophila ResearchHong Kong, Hong Kong; Biochemistry ProgramHong Kong, Hong Kong
| | - Ho Yin Edwin Chan
- Laboratory of Drosophila ResearchHong Kong, Hong Kong; Biochemistry ProgramHong Kong, Hong Kong; Cell and Molecular Biology ProgramHong Kong, Hong Kong; Molecular Biotechnology Program, Faculty of Science, School of Life SciencesHong Kong, Hong Kong; School of Life Sciences, Gerald Choa Neuroscience Centre, The Chinese University of Hong KongHong Kong, Hong Kong
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12
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Rovozzo R, Korza G, Baker MW, Li M, Bhattacharyya A, Barbarese E, Carson JH. CGG Repeats in the 5'UTR of FMR1 RNA Regulate Translation of Other RNAs Localized in the Same RNA Granules. PLoS One 2016; 11:e0168204. [PMID: 28005950 PMCID: PMC5179066 DOI: 10.1371/journal.pone.0168204] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Accepted: 11/28/2016] [Indexed: 01/24/2023] Open
Abstract
CGG repeats in the 5’UTR of Fragile X Mental Retardation 1 (FMR1) RNA mediate RNA localization and translation in granules. Large expansions of CGG repeats (> 200 repeats) in FMR1, referred to as full mutations, are associated with fragile X syndrome (FXS). Smaller expansions (55–200 repeats), referred to as premutations, are associated with fragile X tremor ataxia syndrome (FXTAS) and fragile X premature ovarian insufficiency (FXPOI). TMPyP4 is a porphyrin ring compound that destabilizes CGG repeat RNA secondary structure. Here we show that exogenous CGG repeat RNA by itself, lacking the FMRP ORF, microinjected into hippocampal neurons is localized in RNA granules and inhibits translation of ARC RNA, which is localized in the same granules. TMPyP4 rescues translation of ARC RNA in granules. We also show that in human premutation fibroblasts with endogenous CGG repeat expansions in the FMR1 gene, translation of ARC RNA is inhibited and calcium homeostasis is disrupted and both phenotypes are rescued by TMPyP4. Inhibition of granule translation by expanded CGG repeats and rescue of granule translation by TMPy4, represent potential pathogenic mechanism and therapeutic strategy, respectively, for FXTAS and FXPOI.
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Affiliation(s)
- René Rovozzo
- Center for Cell Analysis and Modeling, UConn Health, Farmington, Connecticut, United States of America
| | - George Korza
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, Connecticut, United States of America
| | - Mei W. Baker
- Departments of Pediatrics, School of Medicine and Public Health, University of Wisconsin-Madison, Wisconsin State Laboratory of Hygiene, Newborn Screening Laboratory, Madison, Wisconsin, United States of America
| | - Meng Li
- Waisman Center, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Anita Bhattacharyya
- Waisman Center, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Elisa Barbarese
- Department of Neuroscience, UConn Health, Farmington, Connecticut, United States of America
| | - John H. Carson
- Center for Cell Analysis and Modeling, UConn Health, Farmington, Connecticut, United States of America
- * E-mail:
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13
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Ishiguro A, Kimura N, Watanabe Y, Watanabe S, Ishihama A. TDP-43 binds and transports G-quadruplex-containing mRNAs into neurites for local translation. Genes Cells 2016; 21:466-81. [PMID: 26915990 DOI: 10.1111/gtc.12352] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2015] [Accepted: 02/01/2016] [Indexed: 12/14/2022]
Abstract
Growth and differentiation of the neurites depends on long-distance transport of a specific set of mRNAs to restricted area and their local translation. Here, we found that a TAR DNA-binding protein of 43 kDa in size (TDP-43) plays an essential role in intracellular transport of mRNA. For identification of target RNAs recognized by TDP-43, we purified TDP-43 in soluble dimer form and subjected to in vitro systematic evolution of ligands by exponential enrichment (SELEX) screening. All the TDP-43-bound RNAs were found to contain G-quadruplex (G4). Using a double-fluorescent probe system, G4-containing RNAs were found to be transported, together with TDP-43, into the distal neurites. Two lines of evidence indicated that loss of function of TDP-43 results in the neurodegenerative disorder: (i) amyotrophic lateral sclerosis (ALS)-linked mutant TDP-43M337V lacks the activity of binding and transport of G4-containing mRNAs; and (ii) RNA containing G4-forming GGGGCC repeat expansion from the ALS-linked C9orf72 gene absorbs TDP-43, thereby reducing the intracellular pool of functional TDP-43. Taken together, we propose that TDP-43 within neurons plays an essential role of mRNA transport into distal neurites for local translation, and thus, dysfunctions of TDP-43 cause neural diseases such as ALS and frontotemporal lobar degeneration.
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Affiliation(s)
- Akira Ishiguro
- Research Center for Micro-Nano Technology, University of Hosei, Midori-cho 3-11-15, Koganei, Tokyo, 184-0003, Japan
| | - Nobuyuki Kimura
- Section of Cell Biology and Pathology, Department of Alzheimer's Disease Research, Center for Development of Advanced Medicine for Dementia, National Center for Geriatrics and Gerontology, Morioka 7-430, Obu, Aichi, 474-8511, Japan
| | - Yuto Watanabe
- Department of Biophysics and Biochemistry, Graduate School of Science, The University of Tokyo, Yayoi 2-11-16, Bunkyo-ku, Tokyo, 113-0032, Japan
| | - Sumiko Watanabe
- Department of Molecular and Developmental Biology, Institute of Medical Science, The University of Tokyo, Shirokane-dai 4-6-1, Minatoku-ku, Tokyo, 108-8639, Japan
| | - Akira Ishihama
- Research Center for Micro-Nano Technology, University of Hosei, Midori-cho 3-11-15, Koganei, Tokyo, 184-0003, Japan
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14
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Coyne AN, Yamada SB, Siddegowda BB, Estes PS, Zaepfel BL, Johannesmeyer JS, Lockwood DB, Pham LT, Hart MP, Cassel JA, Freibaum B, Boehringer AV, Taylor JP, Reitz AB, Gitler AD, Zarnescu DC. Fragile X protein mitigates TDP-43 toxicity by remodeling RNA granules and restoring translation. Hum Mol Genet 2015; 24:6886-98. [PMID: 26385636 DOI: 10.1093/hmg/ddv389] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 09/14/2015] [Indexed: 12/12/2022] Open
Abstract
RNA dysregulation is a newly recognized disease mechanism in amyotrophic lateral sclerosis (ALS). Here we identify Drosophila fragile X mental retardation protein (dFMRP) as a robust genetic modifier of TDP-43-dependent toxicity in a Drosophila model of ALS. We find that dFMRP overexpression (dFMRP OE) mitigates TDP-43 dependent locomotor defects and reduced lifespan in Drosophila. TDP-43 and FMRP form a complex in flies and human cells. In motor neurons, TDP-43 expression increases the association of dFMRP with stress granules and colocalizes with polyA binding protein in a variant-dependent manner. Furthermore, dFMRP dosage modulates TDP-43 solubility and molecular mobility with overexpression of dFMRP resulting in a significant reduction of TDP-43 in the aggregate fraction. Polysome fractionation experiments indicate that dFMRP OE also relieves the translation inhibition of futsch mRNA, a TDP-43 target mRNA, which regulates neuromuscular synapse architecture. Restoration of futsch translation by dFMRP OE mitigates Futsch-dependent morphological phenotypes at the neuromuscular junction including synaptic size and presence of satellite boutons. Our data suggest a model whereby dFMRP is neuroprotective by remodeling TDP-43 containing RNA granules, reducing aggregation and restoring the translation of specific mRNAs in motor neurons.
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Affiliation(s)
- Alyssa N Coyne
- Department of Molecular and Cellular Biology, Department of Neuroscience
| | | | | | | | | | | | - Donovan B Lockwood
- Department of Molecular and Cellular Biology, Department of Neuroscience
| | - Linh T Pham
- Department of Molecular and Cellular Biology
| | - Michael P Hart
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | | | - Brian Freibaum
- Department of Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Ashley V Boehringer
- Department of Molecular and Cellular Biology, Department of Neuroscience, Department of Neurology, University of Arizona, Tucson, AZ, USA
| | - J Paul Taylor
- Department of Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | | | - Aaron D Gitler
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Daniela C Zarnescu
- Department of Molecular and Cellular Biology, Department of Neuroscience, Department of Neurology, University of Arizona, Tucson, AZ, USA,
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15
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Zhang T, Baldie G, Periz G, Wang J. RNA-processing protein TDP-43 regulates FOXO-dependent protein quality control in stress response. PLoS Genet 2014; 10:e1004693. [PMID: 25329970 PMCID: PMC4199500 DOI: 10.1371/journal.pgen.1004693] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Accepted: 08/20/2014] [Indexed: 12/12/2022] Open
Abstract
Protein homeostasis is critical for cell survival and functions during stress and is regulated at both RNA and protein levels. However, how the cell integrates RNA-processing programs with post-translational protein quality control systems is unknown. Transactive response DNA-binding protein (TARDBP/TDP-43) is an RNA-processing protein that is involved in the pathogenesis of major neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Here, we report a conserved role for TDP-43, from C. elegans to mammals, in the regulation of protein clearance via activation of FOXO transcription factors. In response to proteotoxic insults, TDP-43 redistributes from the nucleus to the cytoplasm, promoting nuclear translocation of FOXOs and relieving an inhibition of FOXO activity in the nucleus. The interaction between TDP-43 and the FOXO pathway in mammalian cells is mediated by their competitive binding to 14-3-3 proteins. Consistent with FOXO-dependent protein quality control, TDP-43 regulates the levels of misfolded proteins. Therefore, TDP-43 mediates stress responses and couples the regulation of RNA metabolism and protein quality control in a FOXO-dependent manner. The results suggest that compromising the function of TDP-43 in regulating protein homeostasis may contribute to the pathogenesis of related neurodegenerative diseases. TDP-43 is linked to pathogenesis of major neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). How TDP-43 contributes to the development of these degenerative diseases remains unsolved, and the full range of TDP-43 functions has yet to be established. In the present study, we explored a conversed function of TDP-43 in regulating protein homeostasis from C. elegans to mammals. Under conditions of stress, TDP-43 translocates from the nucleus to the cytoplasm, competes with FOXO transcription factors for binding to 14-3-3 proteins, and releases FOXO for nuclear translocation and activation. These data are consistent with the ability of TDP-43 to regulate protein aggregation. Together the results provide important insight into the role of TDP-43 in stress responses and disease mechanisms. Since chronic stress is associated with neurodegenerative diseases, the TDP-43 switch could be kept in overdrive mode in these disorders, with its capacity to buffer further stress and maintain protein homeostasis being compromised. This mechanism also suggests that other RNA-processing proteins that exhibit similar stress-induced behavior may be coupled to other cellular pathways to provide coordinated reprogramming in stress responses.
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Affiliation(s)
- Tao Zhang
- 1 Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, The Johns Hopkins University, Baltimore, Maryland, United States of America, 2 Department of Neuroscience, School of Medicine, The Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Gerard Baldie
- 1 Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, The Johns Hopkins University, Baltimore, Maryland, United States of America, 2 Department of Neuroscience, School of Medicine, The Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Goran Periz
- 1 Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, The Johns Hopkins University, Baltimore, Maryland, United States of America, 2 Department of Neuroscience, School of Medicine, The Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Jiou Wang
- 1 Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, The Johns Hopkins University, Baltimore, Maryland, United States of America, 2 Department of Neuroscience, School of Medicine, The Johns Hopkins University, Baltimore, Maryland, United States of America
- * E-mail:
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