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Zhang Y, Liu X, Li Z, Li H, Miao Z, Wan B, Xu X. Advances on the Mechanisms and Therapeutic Strategies in Non-coding CGG Repeat Expansion Diseases. Mol Neurobiol 2024:10.1007/s12035-024-04239-9. [PMID: 38780719 DOI: 10.1007/s12035-024-04239-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Accepted: 05/02/2024] [Indexed: 05/25/2024]
Abstract
Non-coding CGG repeat expansions within the 5' untranslated region are implicated in a range of neurological disorders, including fragile X-associated tremor/ataxia syndrome, oculopharyngeal myopathy with leukodystrophy, and oculopharyngodistal myopathy. This review outlined the general characteristics of diseases associated with non-coding CGG repeat expansions, detailing their clinical manifestations and neuroimaging patterns, which often overlap and indicate shared pathophysiological traits. We summarized the underlying molecular mechanisms of these disorders, providing new insights into the roles that DNA, RNA, and toxic proteins play. Understanding these mechanisms is crucial for the development of targeted therapeutic strategies. These strategies include a range of approaches, such as antisense oligonucleotides, RNA interference, genomic DNA editing, small molecule interventions, and other treatments aimed at correcting the dysregulated processes inherent in these disorders. A deeper understanding of the shared mechanisms among non-coding CGG repeat expansion disorders may hold the potential to catalyze the development of innovative therapies, ultimately offering relief to individuals grappling with these debilitating neurological conditions.
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Affiliation(s)
- Yutong Zhang
- Departments of Neurology, The First Affiliated Hospital of Soochow University, Suzhou City, China
| | - Xuan Liu
- Departments of Neurology, The First Affiliated Hospital of Soochow University, Suzhou City, China
| | - Zeheng Li
- Departments of Neurology, The First Affiliated Hospital of Soochow University, Suzhou City, China
| | - Hao Li
- Departments of Neurology, The First Affiliated Hospital of Soochow University, Suzhou City, China
- Department of Neurology, The Fourth Affiliated Hospital of Soochow University, Suzhou, 215124, China
| | - Zhigang Miao
- The Institute of Neuroscience, Soochow University, Suzhou City, China
| | - Bo Wan
- The Institute of Neuroscience, Soochow University, Suzhou City, China
| | - Xingshun Xu
- Departments of Neurology, The First Affiliated Hospital of Soochow University, Suzhou City, China.
- The Institute of Neuroscience, Soochow University, Suzhou City, China.
- Department of Neurology, The First Affiliated Hospital of Soochow University, Suzhou, 215000, China.
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2
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Kudo K, Hori K, Asamitsu S, Maeda K, Aida Y, Hokimoto M, Matsuo K, Yabuki Y, Shioda N. Structural polymorphism of the nucleic acids in pentanucleotide repeats associated with the neurological disorder CANVAS. J Biol Chem 2024; 300:107138. [PMID: 38447794 PMCID: PMC10999818 DOI: 10.1016/j.jbc.2024.107138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 02/15/2024] [Accepted: 02/27/2024] [Indexed: 03/08/2024] Open
Abstract
Short tandem repeats are inherently unstable during DNA replication depending on repeat length, and the expansion of the repeat length in the human genome is responsible for repeat expansion disorders. Pentanucleotide AAGGG and ACAGG repeat expansions in intron 2 of the gene encoding replication factor C subunit 1 (RFC1) cause cerebellar ataxia, neuropathy, vestibular areflexia syndrome (CANVAS) and other phenotypes of late-onset cerebellar ataxia. Herein, we reveal the structural polymorphism of the RFC1 repeats associated with CANVAS in vitro. Single-stranded AAGGG repeat DNA formed a hybrid-type G-quadruplex, whereas its RNA formed a parallel-type G-quadruplex with three layers. The RNA of the ACAGG repeat formed hairpin structure comprising C-G and G-C base pairs with A:A and GA:AG mismatched repeats. Furthermore, both pathogenic repeat RNAs formed more rigid structures than those of the nonpathogenic repeat RNAs. These findings provide novel insights into the structural polymorphism of the RFC1 repeats, which may be closely related to the disease mechanism of CANVAS.
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Affiliation(s)
- Kenta Kudo
- Department of Genomic Neurology, Institute of Molecular Embryology and Genetics (IMEG), Kumamoto University, Kumamoto, Japan; Graduate School of Pharmaceutical Sciences, Kumamoto University, Kumamoto, Japan
| | - Karin Hori
- Department of Genomic Neurology, Institute of Molecular Embryology and Genetics (IMEG), Kumamoto University, Kumamoto, Japan
| | - Sefan Asamitsu
- Laboratory for Functional Non-coding Genomics, RIKEN Center for Integrative Medical Sciences (IMS), Yokohama, Japan
| | - Kohei Maeda
- Department of Genomic Neurology, Institute of Molecular Embryology and Genetics (IMEG), Kumamoto University, Kumamoto, Japan; Graduate School of Pharmaceutical Sciences, Kumamoto University, Kumamoto, Japan
| | - Yukari Aida
- Department of Genomic Neurology, Institute of Molecular Embryology and Genetics (IMEG), Kumamoto University, Kumamoto, Japan; Graduate School of Pharmaceutical Sciences, Kumamoto University, Kumamoto, Japan
| | - Mei Hokimoto
- Department of Genomic Neurology, Institute of Molecular Embryology and Genetics (IMEG), Kumamoto University, Kumamoto, Japan; Graduate School of Pharmaceutical Sciences, Kumamoto University, Kumamoto, Japan
| | - Kazuya Matsuo
- Department of Genomic Neurology, Institute of Molecular Embryology and Genetics (IMEG), Kumamoto University, Kumamoto, Japan
| | - Yasushi Yabuki
- Department of Genomic Neurology, Institute of Molecular Embryology and Genetics (IMEG), Kumamoto University, Kumamoto, Japan; Graduate School of Pharmaceutical Sciences, Kumamoto University, Kumamoto, Japan
| | - Norifumi Shioda
- Department of Genomic Neurology, Institute of Molecular Embryology and Genetics (IMEG), Kumamoto University, Kumamoto, Japan; Graduate School of Pharmaceutical Sciences, Kumamoto University, Kumamoto, Japan.
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3
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Dufour BD, Bartley T, McBride E, Allen E, McLennan YA, Hagerman RJ, Martínez-Cerdeño V. FXTAS Neuropathology Includes Widespread Reactive Astrogliosis and White Matter Specific Astrocyte Degeneration. Ann Neurol 2024; 95:558-575. [PMID: 38069470 PMCID: PMC10922917 DOI: 10.1002/ana.26851] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 12/05/2023] [Accepted: 12/06/2023] [Indexed: 01/17/2024]
Abstract
OBJECTIVE Fragile X-associated tremor/ataxia syndrome (FXTAS) is a late-onset progressive genetic neurodegenerative disorder that occurs in FMR1 premutation carriers. The temporal, spatial, and cell-type specific patterns of neurodegeneration in the FXTAS brain remain incompletely characterized. Intranuclear inclusion bodies are the neuropathological hallmark of FXTAS, which are largest and occur most frequently in astrocytes, glial cells that maintain brain homeostasis. Here, we characterized neuropathological alterations in astrocytes in multiple regions of the FXTAS brain. METHODS Striatal and cerebellar sections from FXTAS cases (n = 12) and controls (n = 12) were stained for the astrocyte markers glial fibrillary acidic protein (GFAP) and aldehyde dehydrogenase 1L1 (ALDH1L1) using immunohistochemistry. Reactive astrogliosis severity, the prevalence of GFAP+ fragments, and astrocyte density were scored. Double label immunofluorescence was utilized to detect co-localization of GFAP and cleaved caspase-3. RESULTS FXTAS cases showed widespread reactive gliosis in both grey and white matter. GFAP staining also revealed remarkably severe astrocyte pathology in FXTAS white matter - characterized by a significant and visible reduction in astrocyte density (-38.7% in striatum and - 32.2% in cerebellum) and the widespread presence of GFAP+ fragments reminiscent of apoptotic bodies. White matter specific reductions in astrocyte density were confirmed with ALDH1L1 staining. GFAP+ astrocytes and fragments in white matter were positive for cleaved caspase-3, suggesting that apoptosis-mediated degeneration is responsible for reduced astrocyte counts. INTERPRETATION We have established that FXTAS neuropathology includes robust degeneration of astrocytes, which is specific to white matter. Because astrocytes are essential for maintaining homeostasis within the central nervous system, a loss of astrocytes likely further exacerbates neuropathological progression of other cell types in the FXTAS brain. ANN NEUROL 2024;95:558-575.
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Affiliation(s)
- Brett D. Dufour
- Department of Psychiatry & Behavioral Sciences, UC Davis School of Medicine, Sacramento, CA, USA
- Institute for Pediatric Regenerative Medicine (IPRM), Shriner’s Hospital for Children and UC Davis School of Medicine, Sacramento, CA, USA
- Department of Pathology & Laboratory Medicine, UC Davis School of Medicine, Sacramento, CA, USA
- MIND Institute, UC Davis School of Medicine, Sacramento, CA, USA
| | - Trevor Bartley
- Institute for Pediatric Regenerative Medicine (IPRM), Shriner’s Hospital for Children and UC Davis School of Medicine, Sacramento, CA, USA
- Department of Pathology & Laboratory Medicine, UC Davis School of Medicine, Sacramento, CA, USA
| | - Erin McBride
- Institute for Pediatric Regenerative Medicine (IPRM), Shriner’s Hospital for Children and UC Davis School of Medicine, Sacramento, CA, USA
- Department of Pathology & Laboratory Medicine, UC Davis School of Medicine, Sacramento, CA, USA
| | - Erik Allen
- Institute for Pediatric Regenerative Medicine (IPRM), Shriner’s Hospital for Children and UC Davis School of Medicine, Sacramento, CA, USA
- Department of Pathology & Laboratory Medicine, UC Davis School of Medicine, Sacramento, CA, USA
| | - Yingratana A. McLennan
- Institute for Pediatric Regenerative Medicine (IPRM), Shriner’s Hospital for Children and UC Davis School of Medicine, Sacramento, CA, USA
- Department of Pathology & Laboratory Medicine, UC Davis School of Medicine, Sacramento, CA, USA
| | - Randi J. Hagerman
- MIND Institute, UC Davis School of Medicine, Sacramento, CA, USA
- Department of Pediatrics, UC Davis School of Medicine, Sacramento, CA, USA
| | - Verónica Martínez-Cerdeño
- Institute for Pediatric Regenerative Medicine (IPRM), Shriner’s Hospital for Children and UC Davis School of Medicine, Sacramento, CA, USA
- Department of Pathology & Laboratory Medicine, UC Davis School of Medicine, Sacramento, CA, USA
- MIND Institute, UC Davis School of Medicine, Sacramento, CA, USA
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4
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Keuenhof KS, Kohler V, Broeskamp F, Panagaki D, Speese SD, Büttner S, Höög JL. Nuclear envelope budding and its cellular functions. Nucleus 2023; 14:2178184. [PMID: 36814098 PMCID: PMC9980700 DOI: 10.1080/19491034.2023.2178184] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Accepted: 02/03/2023] [Indexed: 02/24/2023] Open
Abstract
The nuclear pore complex (NPC) has long been assumed to be the sole route across the nuclear envelope, and under normal homeostatic conditions it is indeed the main mechanism of nucleo-cytoplasmic transport. However, it has also been known that e.g. herpesviruses cross the nuclear envelope utilizing a pathway entitled nuclear egress or envelopment/de-envelopment. Despite this, a thread of observations suggests that mechanisms similar to viral egress may be transiently used also in healthy cells. It has since been proposed that mechanisms like nuclear envelope budding (NEB) can facilitate the transport of RNA granules, aggregated proteins, inner nuclear membrane proteins, and mis-assembled NPCs. Herein, we will summarize the known roles of NEB as a physiological and intrinsic cellular feature and highlight the many unanswered questions surrounding these intriguing nuclear events.
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Affiliation(s)
| | - Verena Kohler
- Institute of Molecular Biosciences, University of Graz, Austria
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Sweden
| | - Filomena Broeskamp
- Department for Chemistry and Molecular biology, University of Gothenburg, Sweden
| | - Dimitra Panagaki
- Department for Chemistry and Molecular biology, University of Gothenburg, Sweden
| | - Sean D. Speese
- Knight Cancer Early Detection Advanced Research Center, Oregon Health and Science University, 2720 S Moody Ave, Portland, OR, 97201, USA
| | - Sabrina Büttner
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Sweden
| | - Johanna L. Höög
- Department for Chemistry and Molecular biology, University of Gothenburg, Sweden
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5
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Wu Y, Song T, Xu Q. R-LOOPs on Short Tandem Repeat Expansion Disorders in Neurodegenerative Diseases. Mol Neurobiol 2023; 60:7185-7195. [PMID: 37540313 DOI: 10.1007/s12035-023-03531-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Accepted: 07/24/2023] [Indexed: 08/05/2023]
Abstract
Expansions of short tandem repeats (STRs) have been found to be present in more than 50 diseases and have a close connection with neurodegenerative diseases. Transcriptional silencing and R-LOOP formation, RNA-mediated sequestration of RNA-binding proteins (RBPs), gain-of-function (GOF) proteins containing expanded repeats, and repeat-associated non-AUG (RAN) translation of toxic repeat peptides are some potential molecular mechanisms underlying STR expansion disorders. R-LOOP, a byproduct of transcription, is a three-stranded nucleic acid structure with abnormal accumulation that participates in the pathogenesis of STR expansion disorders by inducing DNA damage and genome instability. R-LOOPs can engender a series of DNA damage, such as DNA double-strand breaks (DSBs), single-strand breaks (SSBs), DNA recombination, or mutations in the DNA replication, transcription, or repair processes. In this review, we provide an in-depth discussion of recent advancements in R-LOOP and systematically elaborate on its genetic destabilizing effects in several neurodegenerative diseases. These molecular mechanisms will provide novel targets for drug design and therapeutic upgrading of these devastating diseases.
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Affiliation(s)
- Yiting Wu
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Tingwei Song
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Qian Xu
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China.
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Changsha, China.
- Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, China.
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6
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Alvarez-Mora MI, Garrabou G, Molina-Porcel L, Grillo-Risco R, Garcia-Garcia F, Barcos T, Cantó-Santos J, Rodriguez-Revenga L. Exploration of SUMO2/3 Expression Levels and Autophagy Process in Fragile X-Associated Tremor/Ataxia Syndrome: Addressing Study Limitations and Insights for Future Research. Cells 2023; 12:2364. [PMID: 37830578 PMCID: PMC10571773 DOI: 10.3390/cells12192364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 08/21/2023] [Accepted: 09/20/2023] [Indexed: 10/14/2023] Open
Abstract
Fragile X-associated tremor/ataxia syndrome (FXTAS) is a late-onset neurodegenerative disorder that appears in adult FMR1 premutation carriers. The neuropathological hallmark of FXTAS is an intranuclear inclusion in neurons and astrocytes. Nearly 200 different proteins have been identified in FXTAS inclusions, being the small ubiquitin-related modifier 2 (SUMO2), ubiquitin and p62 the most highly abundant. These proteins are components of the protein degradation machinery. This study aimed to characterize SUMO2/3 expression levels and autophagy process in human postmortem brain samples and skin fibroblast cultures from FXTAS patients. Results revealed that FXTAS postmortem brain samples are positive for SUMO2/3 conjugates and supported the idea that SUMO2/3 accumulation is involved in inclusion formation. Insights from RNA-sequencing data indicated that SUMOylation processes are significantly upregulated in FXTAS samples. In addition, the analysis of the autophagy flux showed the accumulation of p62 protein levels and autophagosomes in skin fibroblasts from FXTAS patients. Similarly, gene set analysis evidenced a significant downregulation in gene ontology terms related to autophagy in FXTAS samples. Overall, this study provides new evidence supporting the role of SUMOylation and autophagic processes in the pathogenic mechanisms underlying FXTAS.
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Affiliation(s)
- Maria Isabel Alvarez-Mora
- Biochemistry and Molecular Genetics Department, Hospital Clinic of Barcelona, 08036 Barcelona, Spain; (M.I.A.-M.); (T.B.)
- CIBER of Rare Diseases (CIBERER), Instituto de Salud Carlos III, 08036 Barcelona, Spain; (G.G.)
- Fundacio de Recerca Clínic Barcelona-Institut d’Investigacions Biomediques August Pi i Sunyer (FRCB-IDIBAPS), 08036 Barcelona, Spain;
| | - Glòria Garrabou
- CIBER of Rare Diseases (CIBERER), Instituto de Salud Carlos III, 08036 Barcelona, Spain; (G.G.)
- Inherited Metabolic Diseases and Muscle Disorders’ Research Laboratory (U722), Cellex-IDIBAPS, Faculty of Medicine and Health Sciences, University of Barcelona, Internal Medicine Department––Hospital Clínic Clinic of Barcelona, 08036 Barcelona, Spain
| | - Laura Molina-Porcel
- Fundacio de Recerca Clínic Barcelona-Institut d’Investigacions Biomediques August Pi i Sunyer (FRCB-IDIBAPS), 08036 Barcelona, Spain;
- Alzheimer’s Disease and Other Cognitive Disorders Unit, Neurology Service, Hospital Clinic, 08036 Barcelona, Spain
- Neurological Tissue Bank of the Biobanc-Hospital Clinic-FCRB-IDIBAPS, 08036 Barcelona, Spain
| | - Ruben Grillo-Risco
- Bioinformatics and Biostatistics Unit, Principe Felipe Research Center (CIPF), 46012 Valencia, Spain; (R.G.-R.); (F.G.-G.)
| | - Francisco Garcia-Garcia
- Bioinformatics and Biostatistics Unit, Principe Felipe Research Center (CIPF), 46012 Valencia, Spain; (R.G.-R.); (F.G.-G.)
| | - Tamara Barcos
- Biochemistry and Molecular Genetics Department, Hospital Clinic of Barcelona, 08036 Barcelona, Spain; (M.I.A.-M.); (T.B.)
| | - Judith Cantó-Santos
- CIBER of Rare Diseases (CIBERER), Instituto de Salud Carlos III, 08036 Barcelona, Spain; (G.G.)
- Inherited Metabolic Diseases and Muscle Disorders’ Research Laboratory (U722), Cellex-IDIBAPS, Faculty of Medicine and Health Sciences, University of Barcelona, Internal Medicine Department––Hospital Clínic Clinic of Barcelona, 08036 Barcelona, Spain
| | - Laia Rodriguez-Revenga
- Biochemistry and Molecular Genetics Department, Hospital Clinic of Barcelona, 08036 Barcelona, Spain; (M.I.A.-M.); (T.B.)
- CIBER of Rare Diseases (CIBERER), Instituto de Salud Carlos III, 08036 Barcelona, Spain; (G.G.)
- Fundacio de Recerca Clínic Barcelona-Institut d’Investigacions Biomediques August Pi i Sunyer (FRCB-IDIBAPS), 08036 Barcelona, Spain;
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7
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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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8
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LaForce GR, Philippidou P, Schaffer AE. mRNA isoform balance in neuronal development and disease. WILEY INTERDISCIPLINARY REVIEWS. RNA 2023; 14:e1762. [PMID: 36123820 PMCID: PMC10024649 DOI: 10.1002/wrna.1762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 07/11/2022] [Accepted: 08/15/2022] [Indexed: 11/07/2022]
Abstract
Balanced mRNA isoform diversity and abundance are spatially and temporally regulated throughout cellular differentiation. The proportion of expressed isoforms contributes to cell type specification and determines key properties of the differentiated cells. Neurons are unique cell types with intricate developmental programs, characteristic cellular morphologies, and electrophysiological potential. Neuron-specific gene expression programs establish these distinctive cellular characteristics and drive diversity among neuronal subtypes. Genes with neuron-specific alternative processing are enriched in key neuronal functions, including synaptic proteins, adhesion molecules, and scaffold proteins. Despite the similarity of neuronal gene expression programs, each neuronal subclass can be distinguished by unique alternative mRNA processing events. Alternative processing of developmentally important transcripts alters coding and regulatory information, including interaction domains, transcript stability, subcellular localization, and targeting by RNA binding proteins. Fine-tuning of mRNA processing is essential for neuronal activity and maintenance. Thus, the focus of neuronal RNA biology research is to dissect the transcriptomic mechanisms that underlie neuronal homeostasis, and consequently, predispose neuronal subtypes to disease. This article is categorized under: RNA in Disease and Development > RNA in Disease RNA in Disease and Development > RNA in Development.
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Affiliation(s)
- Geneva R LaForce
- Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, Ohio, USA
| | - Polyxeni Philippidou
- Department of Neurosciences, Case Western Reserve University, Cleveland, Ohio, USA
| | - Ashleigh E Schaffer
- Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, Ohio, USA
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9
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Wright SE, Todd PK. Native functions of short tandem repeats. eLife 2023; 12:e84043. [PMID: 36940239 PMCID: PMC10027321 DOI: 10.7554/elife.84043] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Accepted: 03/08/2023] [Indexed: 03/21/2023] Open
Abstract
Over a third of the human genome is comprised of repetitive sequences, including more than a million short tandem repeats (STRs). While studies of the pathologic consequences of repeat expansions that cause syndromic human diseases are extensive, the potential native functions of STRs are often ignored. Here, we summarize a growing body of research into the normal biological functions for repetitive elements across the genome, with a particular focus on the roles of STRs in regulating gene expression. We propose reconceptualizing the pathogenic consequences of repeat expansions as aberrancies in normal gene regulation. From this altered viewpoint, we predict that future work will reveal broader roles for STRs in neuronal function and as risk alleles for more common human neurological diseases.
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Affiliation(s)
- Shannon E Wright
- Department of Neurology, University of Michigan–Ann ArborAnn ArborUnited States
- Neuroscience Graduate Program, University of Michigan–Ann ArborAnn ArborUnited States
- Department of Neuroscience, Picower InstituteCambridgeUnited States
| | - Peter K Todd
- Department of Neurology, University of Michigan–Ann ArborAnn ArborUnited States
- VA Ann Arbor Healthcare SystemAnn ArborUnited States
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10
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Reyes CJF, Asano K. Between Order and Chaos: Understanding the Mechanism and Pathology of RAN Translation. Biol Pharm Bull 2023; 46:139-146. [PMID: 36724941 DOI: 10.1248/bpb.b22-00448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Repeat-associated non-AUG (RAN) translation is a pathogenic mechanism in which repetitive sequences are translated into aggregation-prone proteins from multiple reading frames, even without a canonical AUG start codon. Since its discovery in spinocerebellar ataxia type 8 (SCA8) and myotonic dystrophy type 1 (DM1), RAN translation is now known to occur in the context of 12 disease-linked repeat expansions. This review discusses recent advances in understanding the regulatory mechanisms controlling RAN translation and its contribution to the pathophysiology of repeat expansion diseases. We discuss the key findings in the context of Fragile X Tremor Ataxia Syndrome (FXTAS), a neurodegenerative disorder caused by a CGG repeat expansion in the 5' untranslated region of FMR1.
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Affiliation(s)
| | - Katsura Asano
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University.,Laboratory of Translational Control Study, Graduate School of Integrated Sciences for Life, Hiroshima University.,Hiroshima Research Center for Healthy Aging, Hiroshima University
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11
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Kurihara M, Mano T, Eto F, Yao I, Sato K, Ohtomo G, Bannai T, Shibata S, Ishiura H, Ikemura M, Matsubara T, Morishima M, Saito Y, Murayama S, Toda T, Setou M, Iwata A. Proteomic profile of nuclei containing p62-positive inclusions in a patient with neuronal intranuclear inclusion disease. Neurobiol Dis 2023; 177:105989. [PMID: 36621630 DOI: 10.1016/j.nbd.2023.105989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 12/19/2022] [Accepted: 01/04/2023] [Indexed: 01/07/2023] Open
Abstract
Neuronal intranuclear inclusion disease (NIID) is a neurodegenerative disease characterized by eosinophilic hyaline intranuclear inclusions in the neurons, glial cells, and other somatic cells. Although CGG repeat expansions in NOTCH2NLC have been identified in most East Asian patients with NIID, the pathophysiology of NIID remains unclear. Ubiquitin- and p62-positive intranuclear inclusions are the pathological hallmark of NIID. Targeted immunostaining studies have identified several other proteins present in these inclusions. However, the global molecular changes within nuclei with these inclusions remained unclear. Herein, we analyzed the proteomic profile of nuclei with p62-positive inclusions in a NIID patient with CGG repeat expansion in NOTCH2NLC to discover candidate proteins involved in the NIID pathophysiology. We used fluorescence-activated cell sorting and liquid chromatography-tandem mass spectrometry (LC-MS/MS) to quantify each protein identified in the nuclei with p62-positive inclusions. The distribution of increased proteins was confirmed via immunofluorescence in autopsy brain samples from three patients with genetically confirmed NIID. Overall, 526 proteins were identified, of which 243 were consistently quantified using MS. A 1.4-fold increase was consistently observed for 20 proteins in nuclei with p62-positive inclusions compared to those without. Fifteen proteins identified with medium or high confidence in the LC-MS/MS analysis were further evaluated. Gene ontology enrichment analysis showed enrichment of several terms, including poly(A) RNA binding, nucleosomal DNA binding, and protein binding. Immunofluorescence studies confirmed that the fluorescent intensities of increased RNA-binding proteins identified by proteomic analysis, namely hnRNP A2/B1, hnRNP A3, and hnRNP C1/C2, were higher in the nuclei with p62-positive inclusions than in those without, which were not confined to the intranuclear inclusions. We identified several increased proteins in nuclei with p62-positive inclusions. Although larger studies are needed to validate our results, these proteomic data may form the basis for understanding the pathophysiology of NIID.
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Affiliation(s)
- Masanori Kurihara
- Department of Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan; Department of Neurology, Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology, Tokyo, Japan
| | - Tatsuo Mano
- Department of Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Fumihiro Eto
- Department of Cellular and Molecular Anatomy and International Mass Imaging Center, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, Japan
| | - Ikuko Yao
- Department of Cellular and Molecular Anatomy and International Mass Imaging Center, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, Japan; Department of Biomedical Chemistry, School of Science and Technology, Kwansei Gakuin University, Sanda, Hyogo, Japan
| | - Kenichiro Sato
- Department of Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan; Department of Neuropathology, Graduate School of Medicine, The University of Tokyo. Tokyo, Japan
| | - Gaku Ohtomo
- Department of Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Taro Bannai
- Department of Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Shota Shibata
- Department of Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Hiroyuki Ishiura
- Department of Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Masako Ikemura
- Department of Pathology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Tomoyasu Matsubara
- Department of Neuropathology (the Brain Bank for Aging Research), Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology, Tokyo, Japan
| | - Maho Morishima
- Department of Neuropathology (the Brain Bank for Aging Research), Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology, Tokyo, Japan
| | - Yuko Saito
- Department of Neuropathology (the Brain Bank for Aging Research), Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology, Tokyo, Japan
| | - Shigeo Murayama
- Department of Neuropathology (the Brain Bank for Aging Research), Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology, Tokyo, Japan; Brain Bank for Neurodevelopmental, Neurological and Psychiatric Disorders, United Graduate School of Child Development, Osaka University, Osaka, Japan
| | - Tatsushi Toda
- Department of Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Mitsutoshi Setou
- Department of Cellular and Molecular Anatomy and International Mass Imaging Center, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, Japan
| | - Atsushi Iwata
- Department of Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan; Department of Neurology, Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology, Tokyo, Japan.
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12
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Rosario R, Stewart HL, Choudhury NR, Michlewski G, Charlet‐Berguerand N, Anderson RA. Evidence for a fragile X messenger ribonucleoprotein 1 (FMR1) mRNA gain-of-function toxicity mechanism contributing to the pathogenesis of fragile X-associated premature ovarian insufficiency. FASEB J 2022; 36:e22612. [PMID: 36250920 PMCID: PMC9828574 DOI: 10.1096/fj.202200468rr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 09/22/2022] [Accepted: 10/03/2022] [Indexed: 01/12/2023]
Abstract
Fragile X-associated premature ovarian insufficiency (FXPOI) is among a family of disorders caused by expansion of a CGG trinucleotide repeat sequence located in the 5' untranslated region (UTR) of the fragile X messenger ribonucleoprotein 1 (FMR1) gene on the X chromosome. Women with FXPOI have a depleted ovarian follicle population, resulting in amenorrhea, hypoestrogenism, and loss of fertility before the age of 40. FXPOI is caused by expansions of the CGG sequence to lengths between 55 and 200 repeats, known as a FMRI premutation, however the mechanism by which the premutation drives disease pathogenesis remains unclear. Two main hypotheses exist, which describe an mRNA toxic gain-of-function mechanism or a protein-based mechanism, where repeat-associated non-AUG (RAN) translation results in the production of an abnormal protein, called FMRpolyG. Here, we have developed an in vitro granulosa cell model of the FMR1 premutation by ectopically expressing CGG-repeat RNA and FMRpolyG protein. We show that expanded CGG-repeat RNA accumulated in intranuclear RNA structures, and these aggregates were able to cause significant granulosa cell death independent of FMRpolyG expression. Using an innovative RNA pulldown, mass spectrometry-based approach we have identified proteins that are specifically sequestered by CGG RNA aggregates in granulosa cells in vitro, and thus may be deregulated as consequence of this interaction. Furthermore, we have demonstrated reduced expression of three proteins identified via our RNA pulldown (FUS, PA2G4 and TRA2β) in ovarian follicles in a FMR1 premutation mouse model. Collectively, these data provide evidence for the contribution of an mRNA gain-of-function mechanism to FXPOI disease biology.
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Affiliation(s)
- Roseanne Rosario
- MRC Centre for Reproductive Health, Queen's Medical Research InstituteUniversity of EdinburghEdinburghUK,Biomedical SciencesUniversity of EdinburghEdinburghUK
| | - Hazel L. Stewart
- MRC Centre for Reproductive Health, Queen's Medical Research InstituteUniversity of EdinburghEdinburghUK
| | | | - Gracjan Michlewski
- Infection MedicineUniversity of EdinburghEdinburghUK,Zhejiang University‐University of Edinburgh InstituteZhejiang UniversityZhejiangP.R. China,Dioscuri Centre for RNA‐Protein Interactions in Human Health and DiseaseInternational Institute of Molecular and Cell Biology in WarsawWarsawPoland
| | - Nicholas Charlet‐Berguerand
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC)INSERM U 1258, CNRS UMR 7104, Université of StrasbourgIllkirchFrance
| | - Richard A. Anderson
- MRC Centre for Reproductive Health, Queen's Medical Research InstituteUniversity of EdinburghEdinburghUK
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13
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Yousuf A, Ahmed N, Qurashi A. Non-canonical DNA/RNA structures associated with the pathogenesis of Fragile X-associated tremor/ataxia syndrome and Fragile X syndrome. Front Genet 2022; 13:866021. [PMID: 36110216 PMCID: PMC9468596 DOI: 10.3389/fgene.2022.866021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Accepted: 07/22/2022] [Indexed: 11/13/2022] Open
Abstract
Fragile X-associated tremor/ataxia syndrome (FXTAS) and fragile X syndrome (FXS) are primary examples of fragile X-related disorders (FXDs) caused by abnormal expansion of CGG repeats above a certain threshold in the 5′-untranslated region of the fragile X mental retardation (FMR1) gene. Both diseases have distinct clinical manifestations and molecular pathogenesis. FXTAS is a late-adult-onset neurodegenerative disorder caused by a premutation (PM) allele (CGG expansion of 55–200 repeats), resulting in FMR1 gene hyperexpression. On the other hand, FXS is a neurodevelopmental disorder that results from a full mutation (FM) allele (CGG expansions of ≥200 repeats) leading to heterochromatization and transcriptional silencing of the FMR1 gene. The main challenge is to determine how CGG repeat expansion affects the fundamentally distinct nature of FMR1 expression in FM and PM ranges. Abnormal CGG repeat expansions form a variety of non-canonical DNA and RNA structures that can disrupt various cellular processes and cause distinct effects in PM and FM alleles. Here, we review these structures and how they are related to underlying mutations and disease pathology in FXS and FXTAS. Finally, as new CGG expansions within the genome have been identified, it will be interesting to determine their implications in disease pathology and treatment.
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14
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Baud A, Derbis M, Tutak K, Sobczak K. Partners in crime: Proteins implicated in
RNA
repeat expansion diseases. WIRES RNA 2022; 13:e1709. [PMID: 35229468 PMCID: PMC9539487 DOI: 10.1002/wrna.1709] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 12/07/2021] [Accepted: 12/08/2021] [Indexed: 11/06/2022]
Affiliation(s)
- Anna Baud
- Department of Gene Expression Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University Poznan Poland
| | - Magdalena Derbis
- Department of Gene Expression Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University Poznan Poland
| | - Katarzyna Tutak
- Department of Gene Expression Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University Poznan Poland
| | - Krzysztof Sobczak
- Department of Gene Expression Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University Poznan Poland
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15
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Corrêa-Velloso JC, Linardi AM, Glaser T, Velloso FJ, Rivas MP, Leite REP, Grinberg LT, Ulrich H, Akins MR, Chiavegatto S, Haddad LA. Fmr1 exon 14 skipping in late embryonic development of the rat forebrain. BMC Neurosci 2022; 23:32. [PMID: 35641906 PMCID: PMC9158170 DOI: 10.1186/s12868-022-00711-1] [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: 12/06/2021] [Accepted: 04/24/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Fragile X syndrome, the major cause of inherited intellectual disability among men, is due to deficiency of the synaptic functional regulator FMR1 protein (FMRP), encoded by the FMRP translational regulator 1 (FMR1) gene. FMR1 alternative splicing produces distinct transcripts that may consequently impact FMRP functional roles. In transcripts without exon 14 the translational reading frame is shifted. For deepening current knowledge of the differential expression of Fmr1 exon 14 along the rat nervous system development, we conducted a descriptive study employing quantitative RT-PCR and BLAST of RNA-Seq datasets. RESULTS We observed in the rat forebrain progressive decline of total Fmr1 mRNA from E11 to P112 albeit an elevation on P3; and exon-14 skipping in E17-E20 with downregulation of the resulting mRNA. We tested if the reduced detection of messages without exon 14 could be explained by nonsense-mediated mRNA decay (NMD) vulnerability, but knocking down UPF1, a major component of this pathway, did not increase their quantities. Conversely, it significantly decreased FMR1 mRNA having exon 13 joined with either exon 14 or exon 15 site A. CONCLUSIONS The forebrain in the third embryonic week of the rat development is a period with significant skipping of Fmr1 exon 14. This alternative splicing event chronologically precedes a reduction of total Fmr1 mRNA, suggesting that it may be part of combinatorial mechanisms downregulating the gene's expression in the late embryonic period. The decay of FMR1 mRNA without exon 14 should be mediated by a pathway different from NMD. Finally, we provide evidence of FMR1 mRNA stabilization by UPF1, likely depending on FMRP.
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Affiliation(s)
- Juliana C Corrêa-Velloso
- Department of Genetics and Evolutionary Biology, Instituto de Biociências, Universidade de São Paulo, Rua do Matão, 277 # 327, São Paulo, SP, 05508-090, Brazil
| | - Alessandra M Linardi
- Department of Genetics and Evolutionary Biology, Instituto de Biociências, Universidade de São Paulo, Rua do Matão, 277 # 327, São Paulo, SP, 05508-090, Brazil
| | - Talita Glaser
- Department of Biochemistry, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Fernando J Velloso
- Department of Genetics and Evolutionary Biology, Instituto de Biociências, Universidade de São Paulo, Rua do Matão, 277 # 327, São Paulo, SP, 05508-090, Brazil
| | - Maria P Rivas
- Department of Genetics and Evolutionary Biology, Instituto de Biociências, Universidade de São Paulo, Rua do Matão, 277 # 327, São Paulo, SP, 05508-090, Brazil
| | - Renata E P Leite
- Department of Pathology, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Lea T Grinberg
- Department of Pathology, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Henning Ulrich
- Department of Biochemistry, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Michael R Akins
- Department of Biology, Drexel University, Philadelphia, PA, USA
| | - Silvana Chiavegatto
- Department of Pharmacology, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, SP, Brazil.,Department of Psychiatry, Instituto de Psiquiatria, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Luciana A Haddad
- Department of Genetics and Evolutionary Biology, Instituto de Biociências, Universidade de São Paulo, Rua do Matão, 277 # 327, São Paulo, SP, 05508-090, Brazil.
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16
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Boivin M, Charlet-Berguerand N. Trinucleotide CGG Repeat Diseases: An Expanding Field of Polyglycine Proteins? Front Genet 2022; 13:843014. [PMID: 35295941 PMCID: PMC8918734 DOI: 10.3389/fgene.2022.843014] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Accepted: 01/31/2022] [Indexed: 12/30/2022] Open
Abstract
Microsatellites are repeated DNA sequences of 3–6 nucleotides highly variable in length and sequence and that have important roles in genomes regulation and evolution. However, expansion of a subset of these microsatellites over a threshold size is responsible of more than 50 human genetic diseases. Interestingly, some of these disorders are caused by expansions of similar sequences, sizes and localizations and present striking similarities in clinical manifestations and histopathological features, which suggest a common mechanism of disease. Notably, five identical CGG repeat expansions, but located in different genes, are the causes of fragile X-associated tremor/ataxia syndrome (FXTAS), neuronal intranuclear inclusion disease (NIID), oculopharyngodistal myopathy type 1 to 3 (OPDM1-3) and oculopharyngeal myopathy with leukoencephalopathy (OPML), which are neuromuscular and neurodegenerative syndromes with overlapping symptoms and similar histopathological features, notably the presence of characteristic eosinophilic ubiquitin-positive intranuclear inclusions. In this review we summarize recent finding in neuronal intranuclear inclusion disease and FXTAS, where the causing CGG expansions were found to be embedded within small upstream ORFs (uORFs), resulting in their translation into novel proteins containing a stretch of polyglycine (polyG). Importantly, expression of these polyG proteins is toxic in animal models and is sufficient to reproduce the formation of ubiquitin-positive intranuclear inclusions. These data suggest the existence of a novel class of human genetic pathology, the polyG diseases, and question whether a similar mechanism may exist in other diseases, notably in OPDM and OPML.
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17
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Zhang Y, Glineburg MR, Basrur V, Conlon K, Wright SE, Krans A, Hall DA, Todd PK. Mechanistic convergence across initiation sites for RAN translation in fragile X associated tremor ataxia syndrome. Hum Mol Genet 2022; 31:2317-2332. [PMID: 35137065 PMCID: PMC9307318 DOI: 10.1093/hmg/ddab353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 11/30/2021] [Accepted: 12/06/2021] [Indexed: 11/13/2022] Open
Abstract
Repeat associated non-AUG (RAN) translation of CGG repeats in the 5'UTR of FMR1 produces toxic proteins that contribute to fragile X-associated tremor/ataxia syndrome (FXTAS) pathogenesis. The most abundant RAN product, FMRpolyG, initiates predominantly at an ACG upstream of the repeat. Accurate FMRpolyG measurements in FXTAS patients are lacking. We used data-dependent acquisition and parallel reaction monitoring (PRM) mass spectrometry coupled with stable isotope labeled standard peptides to identify signature FMRpolyG fragments in patient samples. Following immunoprecipitation, PRM detected FMRpolyG signature peptides in transfected cells, and FXTAS tissues and cells, but not in controls. We identified two amino-terminal peptides: an ACG-initiated Ac-MEAPLPGGVR and a GUG-initiated Ac-TEAPLPGGVR, as well as evidence for RAN translation initiation within the CGG repeat itself in two reading frames. Initiation at all sites increased following cellular stress, decreased following eIF1 overexpression and was eIF4A and M7G cap-dependent. These data demonstrate that FMRpolyG is quantifiable in human samples and FMR1 RAN translation initiates via similar mechanisms for near-cognate codons and within the repeat through processes dependent on available initiation factors and cellular environment.
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Affiliation(s)
- Yuan Zhang
- Department of Neurology, University of Michigan, Ann Arbor, MI, USA,Department of Respiratory Medicine, Xiangya Hospital, Central South University, Changsha 410008, China
| | - M Rebecca Glineburg
- To whom correspondence should be addressed at: Todd Lab (ATTN: Drs Glineburg and Todd), 4005 BSRB, 109 Zina Pitcher Place, Ann Arbor, MI 48109-2200, USA. Tel: +1 7346155632; Fax: +1 7346479777; ;
| | | | - Kevin Conlon
- Department of Pathology, University of Michigan, Ann Arbor, MI, USA
| | - Shannon E Wright
- Department of Neurology, University of Michigan, Ann Arbor, MI, USA
| | - Amy Krans
- Department of Neurology, University of Michigan, Ann Arbor, MI, USA
| | - Deborah A Hall
- Department of Neurological Sciences, Rush University, Chicago, IL, USA
| | - Peter K Todd
- To whom correspondence should be addressed at: Todd Lab (ATTN: Drs Glineburg and Todd), 4005 BSRB, 109 Zina Pitcher Place, Ann Arbor, MI 48109-2200, USA. Tel: +1 7346155632; Fax: +1 7346479777; ;
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18
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Prevalence of Fragile X-Associated Tremor/Ataxia Syndrome in Patients with Cerebellar Ataxia in Japan. THE CEREBELLUM 2021; 21:851-860. [PMID: 34498198 PMCID: PMC9411241 DOI: 10.1007/s12311-021-01323-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Accepted: 08/22/2021] [Indexed: 12/17/2022]
Abstract
The presence of fragile X mental retardation 1 (FMR1) premutation has been linked to patients with a certain type of cerebellar ataxia, the fragile X-associated tremor/ataxia syndrome (FXTAS). However, its prevalence in Japan has yet to be clarified. The aim of the present study is to determine the prevalence of FXTAS in Japanese patients with cerebellar ataxia and to describe their clinical characteristics. DNA samples were collected from 1328 Japanese patients with cerebellar ataxia, referred for genetic diagnosis. Among them, 995 patients with negative results for the most common spinocerebellar ataxia subtypes were screened for FMR1 premutation. Comprehensive clinical and radiological analyses were performed for the patients harbouring FMR1 premutation. We herein identified FMR1 premutation from one female and two male patients, who satisfied both clinical and radiological criteria of FXTAS (0.3%; 3/995) as well. Both male patients presented with high signal intensity of corticomedullary junction on diffusion-weighted magnetic resonance imaging, a finding comparable to that of neuronal intranuclear inclusion disease. The female patient mimicked multiple system atrophy in the early stages of her disease and developed aseptic meningitis with a suspected immune-mediated mechanism after the onset of FXTAS, which made her unique. Despite the lower prevalence rate in Japan than the previous reports in other countries, the present study emphasises the necessity to consider FXTAS with undiagnosed ataxia, regardless of men or women, particularly for those cases presenting with similar clinical and radiological findings with multiple system atrophy or neuronal intranuclear inclusion disease.
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19
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Napoli E, Flores A, Mansuri Y, Hagerman RJ, Giulivi C. Sulforaphane improves mitochondrial metabolism in fibroblasts from patients with fragile X-associated tremor and ataxia syndrome. Neurobiol Dis 2021; 157:105427. [PMID: 34153466 PMCID: PMC8475276 DOI: 10.1016/j.nbd.2021.105427] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 06/10/2021] [Accepted: 06/16/2021] [Indexed: 02/09/2023] Open
Abstract
CGG expansions between 55 and 200 in the 5'-untranslated region of the fragile-X mental retardation gene (FMR1) increase the risk of developing the late-onset debilitating neuromuscular disease Fragile X-Associated Tremor/Ataxia Syndrome (FXTAS). While the science behind this mutation, as a paradigm for RNA-mediated nucleotide triplet repeat expansion diseases, has progressed rapidly, no treatment has proven effective at delaying the onset or decreasing morbidity, especially at later stages of the disease. Here, we demonstrated the beneficial effect of the phytochemical sulforaphane (SFN), exerted through NRF2-dependent and independent manner, on pathways relevant to brain function, bioenergetics, unfolded protein response, proteosome, antioxidant defenses, and iron metabolism in fibroblasts from FXTAS-affected subjects at all disease stages. This study paves the way for future clinical studies with SFN in the treatment of FXTAS, substantiated by the established use of this agent in clinical trials of diseases with NRF2 dysregulation and in which age is the leading risk factor.
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Affiliation(s)
- Eleonora Napoli
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, CA 95616
| | - Amanda Flores
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, CA 95616;,Department of Biochemistry, Medical Sciences Campus, University of Puerto Rico, San Juan, Puerto Rico
| | - Yasmeen Mansuri
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, CA 95616
| | - Randi J. Hagerman
- Department of Pediatrics, University of California Davis Medical Center, Sacramento, CA;,Medical Investigations of Neurodevelopmental Disorders (M.I.N.D.) Institute, University of California Davis, CA 95817
| | - Cecilia Giulivi
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, CA 95616, United States of America; Medical Investigations of Neurodevelopmental Disorders (M.I.N.D.) Institute, University of California Davis, CA 95817, USA.
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20
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Zhao X, Usdin K. (Dys)function Follows Form: Nucleic Acid Structure, Repeat Expansion, and Disease Pathology in FMR1 Disorders. Int J Mol Sci 2021; 22:ijms22179167. [PMID: 34502075 PMCID: PMC8431139 DOI: 10.3390/ijms22179167] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 08/17/2021] [Accepted: 08/18/2021] [Indexed: 12/26/2022] Open
Abstract
Fragile X-related disorders (FXDs), also known as FMR1 disorders, are examples of repeat expansion diseases (REDs), clinical conditions that arise from an increase in the number of repeats in a disease-specific microsatellite. In the case of FXDs, the repeat unit is CGG/CCG and the repeat tract is located in the 5' UTR of the X-linked FMR1 gene. Expansion can result in neurodegeneration, ovarian dysfunction, or intellectual disability depending on the number of repeats in the expanded allele. A growing body of evidence suggests that the mutational mechanisms responsible for many REDs share several common features. It is also increasingly apparent that in some of these diseases the pathologic consequences of expansion may arise in similar ways. It has long been known that many of the disease-associated repeats form unusual DNA and RNA structures. This review will focus on what is known about these structures, the proteins with which they interact, and how they may be related to the causative mutation and disease pathology in the FMR1 disorders.
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Affiliation(s)
- Xiaonan Zhao
- Correspondence: (X.Z.); (K.U.); Tel.: +1-301-451-6322 (X.Z.); +1-301-496-2189 (K.U.)
| | - Karen Usdin
- Correspondence: (X.Z.); (K.U.); Tel.: +1-301-451-6322 (X.Z.); +1-301-496-2189 (K.U.)
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21
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Molecular Pathogenesis and Peripheral Monitoring of Adult Fragile X-Associated Syndromes. Int J Mol Sci 2021; 22:ijms22168368. [PMID: 34445074 PMCID: PMC8395059 DOI: 10.3390/ijms22168368] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 07/29/2021] [Accepted: 07/30/2021] [Indexed: 12/16/2022] Open
Abstract
Abnormal trinucleotide expansions cause rare disorders that compromise quality of life and, in some cases, lifespan. In particular, the expansions of the CGG-repeats stretch at the 5’-UTR of the Fragile X Mental Retardation 1 (FMR1) gene have pleiotropic effects that lead to a variety of Fragile X-associated syndromes: the neurodevelopmental Fragile X syndrome (FXS) in children, the late-onset neurodegenerative disorder Fragile X-associated tremor-ataxia syndrome (FXTAS) that mainly affects adult men, the Fragile X-associated primary ovarian insufficiency (FXPOI) in adult women, and a variety of psychiatric and affective disorders that are under the term of Fragile X-associated neuropsychiatric disorders (FXAND). In this review, we will describe the pathological mechanisms of the adult “gain-of-function” syndromes that are mainly caused by the toxic actions of CGG RNA and FMRpolyG peptide. There have been intensive attempts to identify reliable peripheral biomarkers to assess disease progression and onset of specific pathological traits. Mitochondrial dysfunction, altered miRNA expression, endocrine system failure, and impairment of the GABAergic transmission are some of the affectations that are susceptible to be tracked using peripheral blood for monitoring of the motor, cognitive, psychiatric and reproductive impairment of the CGG-expansion carriers. We provided some illustrative examples from our own cohort. Understanding the association between molecular pathogenesis and biomarkers dynamics will improve effective prognosis and clinical management of CGG-expansion carriers.
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22
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Haify SN, Buijsen RAM, Verwegen L, Severijnen LAWFM, de Boer H, Boumeester V, Monshouwer R, Yang WY, Cameron MD, Willemsen R, Disney MD, Hukema RK. Small molecule 1a reduces FMRpolyG-mediated toxicity in in vitro and in vivo models for FMR1 premutation. Hum Mol Genet 2021; 30:1632-1648. [PMID: 34077515 PMCID: PMC8369842 DOI: 10.1093/hmg/ddab143] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 05/13/2021] [Accepted: 05/15/2021] [Indexed: 12/15/2022] Open
Abstract
Fragile X-associated tremor and ataxia syndrome (FXTAS) is a late-onset, progressive neurodegenerative disorder characterized by tremors, ataxia and neuropsychological problems. This disease is quite common in the general population with approximately 20 million carriers worldwide. The risk of developing FXTAS increases dramatically with age, with about 45% of male carriers over the age of 50 being affected. FXTAS is caused by a CGG-repeat expansion (CGGexp) in the fragile X mental retardation 1 (FMR1) gene. CGGexp RNA is translated into the FMRpolyG protein by a mechanism called RAN translation. Although both gene and pathogenic trigger are known, no therapeutic interventions are available at this moment. Here, we present, for the first time, primary hippocampal neurons derived from the ubiquitous inducible mouse model which is used as a screening tool for targeted interventions. A promising candidate is the repeat binding, RAN translation blocking, small molecule 1a. Small molecule 1a shields the disease-causing CGGexp from being translated into the toxic FMRpolyG protein. Primary hippocampal neurons formed FMRpolyG-positive inclusions, and upon treatment with 1a, the numbers of FMRpolyG-positive inclusions are reduced. We also describe for the first time the formation of FMRpolyG-positive inclusions in the liver of this mouse model. Treatment with 1a reduced the insoluble FMRpolyG protein fraction in the liver but not the number of inclusions. Moreover, 1a treatment had a reducing effect on the number of Rad23b-positive inclusions and insoluble Rad23b protein levels. These data suggest that targeted small molecule therapy is effective in an FXTAS mouse model and has the potential to treat CGGexp-mediated diseases, including FXTAS.
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Affiliation(s)
- Saif N Haify
- Department of Clinical Genetics, Erasmus MC, Rotterdam, the Netherlands
| | - Ronald A M Buijsen
- Department of Clinical Genetics, Erasmus MC, Rotterdam, the Netherlands.,Department of Human Genetics, LUMC, Leiden, the Netherlands
| | - Lucas Verwegen
- Department of Clinical Genetics, Erasmus MC, Rotterdam, the Netherlands.,Department of Cell Biology, Erasmus MC, Rotterdam, the Netherlands
| | | | - Helen de Boer
- Department of Clinical Genetics, Erasmus MC, Rotterdam, the Netherlands
| | | | - Roos Monshouwer
- Department of Clinical Genetics, Erasmus MC, Rotterdam, the Netherlands
| | - Wong Y Yang
- Department of Chemistry, Scripps Research Institute, Florida, the United States
| | - Michael D Cameron
- Department of Chemistry, Scripps Research Institute, Florida, the United States
| | - Rob Willemsen
- Department of Clinical Genetics, Erasmus MC, Rotterdam, the Netherlands
| | - Matthew D Disney
- Department of Chemistry, Scripps Research Institute, Florida, the United States
| | - Renate K Hukema
- Department of Clinical Genetics, Erasmus MC, Rotterdam, the Netherlands.,Department of Health Care Studies, Rotterdam University of Applied Sciences, Rotterdam, the Netherlands
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23
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Nolin SL, Napoli E, Flores A, Hagerman RJ, Giulivi C. Deficits in Prenatal Serine Biosynthesis Underlie the Mitochondrial Dysfunction Associated with the Autism-Linked FMR1 Gene. Int J Mol Sci 2021; 22:ijms22115886. [PMID: 34070950 PMCID: PMC8198117 DOI: 10.3390/ijms22115886] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 05/25/2021] [Accepted: 05/27/2021] [Indexed: 12/22/2022] Open
Abstract
Fifty-five to two hundred CGG repeats (called a premutation, or PM) in the 5′-UTR of the FMR1 gene are generally unstable, often expanding to a full mutation (>200) in one generation through maternal inheritance, leading to fragile X syndrome, a condition associated with autism and other intellectual disabilities. To uncover the early mechanisms of pathogenesis, we performed metabolomics and proteomics on amniotic fluids from PM carriers, pregnant with male fetuses, who had undergone amniocentesis for fragile X prenatal diagnosis. The prenatal metabolic footprint identified mitochondrial deficits, which were further validated by using internal and external cohorts. Deficits in the anaplerosis of the Krebs cycle were noted at the level of serine biosynthesis, which was confirmed by rescuing the mitochondrial dysfunction in the carriers’ umbilical cord fibroblasts using alpha-ketoglutarate precursors. Maternal administration of serine and its precursors has the potential to decrease the risk of developing energy shortages associated with mitochondrial dysfunction and linked comorbidities.
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Affiliation(s)
- Sarah L. Nolin
- Department of Human Genetics, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY 10314, USA;
| | - Eleonora Napoli
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, CA 95616, USA; (E.N.); (A.F.)
| | - Amanda Flores
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, CA 95616, USA; (E.N.); (A.F.)
- Medical Sciences Campus, Department of Biochemistry, University of Puerto Rico, San Juan PR00936, Puerto Rico
| | - Randi J. Hagerman
- Department of Pediatrics, University of California Davis Medical Center, Sacramento, CA 95817, USA;
- The MIND Institute, University of California Davis Medical Center, Sacramento, CA 95817, USA
| | - Cecilia Giulivi
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, CA 95616, USA; (E.N.); (A.F.)
- The MIND Institute, University of California Davis Medical Center, Sacramento, CA 95817, USA
- Correspondence: ; Tel.: +1-530-754-8603
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24
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Xu K, Li Y, Allen EG, Jin P. Therapeutic Development for CGG Repeat Expansion-Associated Neurodegeneration. Front Cell Neurosci 2021; 15:655568. [PMID: 34054431 PMCID: PMC8149615 DOI: 10.3389/fncel.2021.655568] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 04/12/2021] [Indexed: 12/16/2022] Open
Abstract
Non-coding repeat expansions, such as CGG, GGC, CUG, CCUG, and GGGGCC, have been shown to be involved in many human diseases, particularly neurological disorders. Of the diverse pathogenic mechanisms proposed in these neurodegenerative diseases, dysregulated RNA metabolism has emerged as an important contributor. Expanded repeat RNAs that form particular structures aggregate to form RNA foci, sequestering various RNA binding proteins and consequently altering RNA splicing, transport, and other downstream biological processes. One of these repeat expansion-associated diseases, fragile X-associated tremor/ataxia syndrome (FXTAS), is caused by a CGG repeat expansion in the 5'UTR region of the fragile X mental retardation 1 (FMR1) gene. Moreover, recent studies have revealed abnormal GGC repeat expansion within the 5'UTR region of the NOTCH2NLC gene in both essential tremor (ET) and neuronal intranuclear inclusion disease (NIID). These CGG repeat expansion-associated diseases share genetic, pathological, and clinical features. Identification of the similarities at the molecular level could lead to a better understanding of the disease mechanisms as well as developing novel therapeutic strategies. Here, we highlight our current understanding of the molecular pathogenesis of CGG repeat expansion-associated diseases and discuss potential therapeutic interventions for these neurological disorders.
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Affiliation(s)
- Keqin Xu
- Department of Human Genetics, School of Medicine, Emory University, Atlanta, GA, United States.,Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Yujing Li
- Department of Human Genetics, School of Medicine, Emory University, Atlanta, GA, United States
| | - Emily G Allen
- Department of Human Genetics, School of Medicine, Emory University, Atlanta, GA, United States
| | - Peng Jin
- Department of Human Genetics, School of Medicine, Emory University, Atlanta, GA, United States
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25
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Glineburg MR, Zhang Y, Krans A, Tank EM, Barmada SJ, Todd PK. Enhanced detection of expanded repeat mRNA foci with hybridization chain reaction. Acta Neuropathol Commun 2021; 9:73. [PMID: 33892814 PMCID: PMC8063431 DOI: 10.1186/s40478-021-01169-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 03/27/2021] [Indexed: 12/17/2022] Open
Abstract
Transcribed nucleotide repeat expansions form detectable RNA foci in patient cells that contribute to disease pathogenesis. The most widely used method for detecting RNA foci, fluorescence in situ hybridization (FISH), is powerful but can suffer from issues related to signal above background. Here we developed a repeat-specific form of hybridization chain reaction (R-HCR) as an alternative method for detection of repeat RNA foci in two neurodegenerative disorders: C9orf72 associated ALS and frontotemporal dementia (C9 ALS/FTD) and Fragile X-associated tremor/ataxia syndrome. R-HCR to both G4C2 and CGG repeats exhibited comparable specificity but > 40 × sensitivity compared to FISH, with better detection of both nuclear and cytoplasmic foci in human C9 ALS/FTD fibroblasts, patient iPSC derived neurons, and patient brain samples. Using R-HCR, we observed that integrated stress response (ISR) activation significantly increased the number of endogenous G4C2 repeat RNA foci and triggered their selective nuclear accumulation without evidence of stress granule co-localization in patient fibroblasts and patient derived neurons. These data suggest that R-HCR can be a useful tool for tracking the behavior of repeat expansion mRNA in C9 ALS/FTD and other repeat expansion disorders.
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26
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Ajjugal Y, Kolimi N, Rathinavelan T. Secondary structural choice of DNA and RNA associated with CGG/CCG trinucleotide repeat expansion rationalizes the RNA misprocessing in FXTAS. Sci Rep 2021; 11:8163. [PMID: 33854084 PMCID: PMC8046799 DOI: 10.1038/s41598-021-87097-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Accepted: 03/22/2021] [Indexed: 11/09/2022] Open
Abstract
CGG tandem repeat expansion in the 5'-untranslated region of the fragile X mental retardation-1 (FMR1) gene leads to unusual nucleic acid conformations, hence causing genetic instabilities. We show that the number of G…G (in CGG repeat) or C…C (in CCG repeat) mismatches (other than A…T, T…A, C…G and G…C canonical base pairs) dictates the secondary structural choice of the sense and antisense strands of the FMR1 gene and their corresponding transcripts in fragile X-associated tremor/ataxia syndrome (FXTAS). The circular dichroism (CD) spectra and electrophoretic mobility shift assay (EMSA) reveal that CGG DNA (sense strand of the FMR1 gene) and its transcript favor a quadruplex structure. CD, EMSA and molecular dynamics (MD) simulations also show that more than four C…C mismatches cannot be accommodated in the RNA duplex consisting of the CCG repeat (antisense transcript); instead, it favors an i-motif conformational intermediate. Such a preference for unusual secondary structures provides a convincing justification for the RNA foci formation due to the sequestration of RNA-binding proteins to the bidirectional transcripts and the repeat-associated non-AUG translation that are observed in FXTAS. The results presented here also suggest that small molecule modulators that can destabilize FMR1 CGG DNA and RNA quadruplex structures could be promising candidates for treating FXTAS.
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Affiliation(s)
- Yogeeshwar Ajjugal
- Department of Biotechnology, Indian Institute of Technology Hyderabad, Kandi, Telangana State, 502285, India
| | - Narendar Kolimi
- Department of Biotechnology, Indian Institute of Technology Hyderabad, Kandi, Telangana State, 502285, India
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27
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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: 1] [Impact Index Per Article: 0.3] [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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28
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Molitor L, Bacher S, Burczyk S, Niessing D. The Molecular Function of PURA and Its Implications in Neurological Diseases. Front Genet 2021; 12:638217. [PMID: 33777106 PMCID: PMC7990775 DOI: 10.3389/fgene.2021.638217] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 02/09/2021] [Indexed: 12/19/2022] Open
Abstract
In recent years, genome-wide analyses of patients have resulted in the identification of a number of neurodevelopmental disorders. Several of them are caused by mutations in genes that encode for RNA-binding proteins. One of these genes is PURA, for which in 2014 mutations have been shown to cause the neurodevelopmental disorder PURA syndrome. Besides intellectual disability (ID), patients develop a variety of symptoms, including hypotonia, metabolic abnormalities as well as epileptic seizures. This review aims to provide a comprehensive assessment of research of the last 30 years on PURA and its recently discovered involvement in neuropathological abnormalities. Being a DNA- and RNA-binding protein, PURA has been implicated in transcriptional control as well as in cytoplasmic RNA localization. Molecular interactions are described and rated according to their validation state as physiological targets. This information will be put into perspective with available structural and biophysical insights on PURA’s molecular functions. Two different knock-out mouse models have been reported with partially contradicting observations. They are compared and put into context with cell biological observations and patient-derived information. In addition to PURA syndrome, the PURA protein has been found in pathological, RNA-containing foci of patients with the RNA-repeat expansion diseases such as fragile X-associated tremor ataxia syndrome (FXTAS) and amyotrophic lateral sclerosis (ALS)/fronto-temporal dementia (FTD) spectrum disorder. We discuss the potential role of PURA in these neurodegenerative disorders and existing evidence that PURA might act as a neuroprotective factor. In summary, this review aims at informing researchers as well as clinicians on our current knowledge of PURA’s molecular and cellular functions as well as its implications in very different neuronal disorders.
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Affiliation(s)
- Lena Molitor
- Institute of Structural Biology, Helmholtz Zentrum München - German Research Center for Environmental Health, Neuherberg, Germany
| | - Sabrina Bacher
- Institute of Structural Biology, Helmholtz Zentrum München - German Research Center for Environmental Health, Neuherberg, Germany
| | - Sandra Burczyk
- Institute of Pharmaceutical Biotechnology, Ulm University, Ulm, Germany
| | - Dierk Niessing
- Institute of Structural Biology, Helmholtz Zentrum München - German Research Center for Environmental Health, Neuherberg, Germany.,Institute of Pharmaceutical Biotechnology, Ulm University, Ulm, Germany
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29
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Derbis M, Kul E, Niewiadomska D, Sekrecki M, Piasecka A, Taylor K, Hukema RK, Stork O, Sobczak K. Short antisense oligonucleotides alleviate the pleiotropic toxicity of RNA harboring expanded CGG repeats. Nat Commun 2021; 12:1265. [PMID: 33627639 PMCID: PMC7904788 DOI: 10.1038/s41467-021-21021-w] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Accepted: 12/24/2020] [Indexed: 01/31/2023] Open
Abstract
Fragile X-associated tremor/ataxia syndrome (FXTAS) is an incurable neurodegenerative disorder caused by expansion of CGG repeats in the FMR1 5'UTR. The RNA containing expanded CGG repeats (rCGGexp) causes cell damage by interaction with complementary DNA, forming R-loop structures, sequestration of nuclear proteins involved in RNA metabolism and initiation of translation of polyglycine-containing protein (FMRpolyG), which forms nuclear insoluble inclusions. Here we show the therapeutic potential of short antisense oligonucleotide steric blockers (ASOs) targeting directly the rCGGexp. In nuclei of FXTAS cells ASOs affect R-loop formation and correct miRNA biogenesis and alternative splicing, indicating that nuclear proteins are released from toxic sequestration. In cytoplasm, ASOs significantly decrease the biosynthesis and accumulation of FMRpolyG. Delivery of ASO into a brain of FXTAS mouse model reduces formation of inclusions, improves motor behavior and corrects gene expression profile with marginal signs of toxicity after a few weeks from a treatment.
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Affiliation(s)
- Magdalena Derbis
- grid.5633.30000 0001 2097 3545Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, Uniwersytetu Poznanskiego 6, Poznan, Poland
| | - Emre Kul
- grid.5807.a0000 0001 1018 4307Department of Genetics and Molecular Neurobiology, Institute of Biology, Otto von Guericke University, Magdeburg, Germany
| | - Daria Niewiadomska
- grid.5633.30000 0001 2097 3545Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, Uniwersytetu Poznanskiego 6, Poznan, Poland
| | - Michał Sekrecki
- grid.5633.30000 0001 2097 3545Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, Uniwersytetu Poznanskiego 6, Poznan, Poland
| | - Agnieszka Piasecka
- grid.5633.30000 0001 2097 3545Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, Uniwersytetu Poznanskiego 6, Poznan, Poland
| | - Katarzyna Taylor
- grid.5633.30000 0001 2097 3545Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, Uniwersytetu Poznanskiego 6, Poznan, Poland
| | - Renate K. Hukema
- grid.5645.2000000040459992XDepartment of Clinical Genetics, Erasmus MC, CA Rotterdam, The Netherlands ,grid.450253.50000 0001 0688 0318Present Address: Department of Health Care Studies, Rotterdam University of Applied Sciences, HR Rotterdam, The Netherlands
| | - Oliver Stork
- grid.5807.a0000 0001 1018 4307Department of Genetics and Molecular Neurobiology, Institute of Biology, Otto von Guericke University, Magdeburg, Germany
| | - Krzysztof Sobczak
- grid.5633.30000 0001 2097 3545Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, Uniwersytetu Poznanskiego 6, Poznan, Poland
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30
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Asamitsu S, Yabuki Y, Ikenoshita S, Kawakubo K, Kawasaki M, Usuki S, Nakayama Y, Adachi K, Kugoh H, Ishii K, Matsuura T, Nanba E, Sugiyama H, Fukunaga K, Shioda N. CGG repeat RNA G-quadruplexes interact with FMRpolyG to cause neuronal dysfunction in fragile X-related tremor/ataxia syndrome. SCIENCE ADVANCES 2021; 7:7/3/eabd9440. [PMID: 33523882 PMCID: PMC7806243 DOI: 10.1126/sciadv.abd9440] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 11/18/2020] [Indexed: 05/25/2023]
Abstract
Fragile X-related tremor/ataxia syndrome (FXTAS) is a neurodegenerative disease caused by CGG triplet repeat expansions in FMR1, which elicit repeat-associated non-AUG (RAN) translation and produce the toxic protein FMRpolyG. We show that FMRpolyG interacts with pathogenic CGG repeat-derived RNA G-quadruplexes (CGG-G4RNA), propagates cell to cell, and induces neuronal dysfunction. The FMRpolyG polyglycine domain has a prion-like property, preferentially binding to CGG-G4RNA. Treatment with 5-aminolevulinic acid, which is metabolized to protoporphyrin IX, inhibited RAN translation of FMRpolyG and CGG-G4RNA-induced FMRpolyG aggregation, ameliorating aberrant synaptic plasticity and behavior in FXTAS model mice. Thus, we present a novel therapeutic strategy to target G4RNA prionoids.
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Affiliation(s)
- Sefan Asamitsu
- Department of Genomic Neurology, Institute of Molecular Embryology and Genetics (IMEG), Kumamoto University, Kumamoto, Japan
| | - Yasushi Yabuki
- Department of Genomic Neurology, Institute of Molecular Embryology and Genetics (IMEG), Kumamoto University, Kumamoto, Japan
- Graduate School of Pharmaceutical Sciences, Kumamoto University, Kumamoto, Japan
| | - Susumu Ikenoshita
- Department of Genomic Neurology, Institute of Molecular Embryology and Genetics (IMEG), Kumamoto University, Kumamoto, Japan
- Department of Neurology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan
| | - Kosuke Kawakubo
- Department of Genomic Neurology, Institute of Molecular Embryology and Genetics (IMEG), Kumamoto University, Kumamoto, Japan
- Graduate School of Pharmaceutical Sciences, Kumamoto University, Kumamoto, Japan
| | - Moe Kawasaki
- Department of Genomic Neurology, Institute of Molecular Embryology and Genetics (IMEG), Kumamoto University, Kumamoto, Japan
- Graduate School of Pharmaceutical Sciences, Kumamoto University, Kumamoto, Japan
| | - Shingo Usuki
- Liaison Laboratory Research Promotion Center, Institute of Molecular Embryology and Genetics (IMEG), Kumamoto University, Kumamoto, Japan
| | - Yuji Nakayama
- Division of Radioisotope Science, Research Initiative Center, Organization for Research Initiative and Promotion, Tottori University, Tottori, Japan
| | - Kaori Adachi
- Division of Genomic Science, Research Initiative Center, Organization for Research Initiative and Promotion, Tottori University, Tottori, Japan
| | - Hiroyuki Kugoh
- Department of Biomedical Science, Institute of Regenerative Medicine and Biofunction, Graduate School of Medical Science, Tottori University, Tottori, Japan
- Chromosome Engineering Research Center, Tottori University, Tottori, Japan
| | - Kazuhiro Ishii
- Department of the Neurology, Division of Clinical Medicine, Faculty of Medicine, University of Tsukuba, Ibaraki, Japan
| | - Tohru Matsuura
- Division of Neurology, Department of Medicine, Jichi Medical University, Shimono, Japan
| | - Eiji Nanba
- Office for Research Strategy, Organization for Research Initiative and Promotion, Tottori University, Tottori, Japan
| | - Hiroshi Sugiyama
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto, Japan
| | - Kohji Fukunaga
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - Norifumi Shioda
- Department of Genomic Neurology, Institute of Molecular Embryology and Genetics (IMEG), Kumamoto University, Kumamoto, Japan.
- Graduate School of Pharmaceutical Sciences, Kumamoto University, Kumamoto, Japan
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31
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Haify SN, Mankoe RSD, Boumeester V, van der Toorn EC, Verhagen RFM, Willemsen R, Hukema RK, Bosman LWJ. Lack of a Clear Behavioral Phenotype in an Inducible FXTAS Mouse Model Despite the Presence of Neuronal FMRpolyG-Positive Aggregates. Front Mol Biosci 2020; 7:599101. [PMID: 33381520 PMCID: PMC7768028 DOI: 10.3389/fmolb.2020.599101] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 11/23/2020] [Indexed: 11/25/2022] Open
Abstract
Fragile X-associated tremor/ataxia syndrome (FXTAS) is a rare neurodegenerative disorder caused by a 55–200 CGG repeat expansion in the 5′ untranslated region of the Fragile X Mental Retardation 1 (FMR1) gene. FXTAS is characterized by progressive cerebellar ataxia, Parkinsonism, intention tremors and cognitive decline. The main neuropathological hallmark of FXTAS is the presence of ubiquitin-positive intranuclear inclusions in neurons and astrocytes throughout the brain. The molecular pathology of FXTAS involves the presence of 2 to 8-fold elevated levels of FMR1 mRNA, and of a repeat-associated non-AUG (RAN) translated polyglycine peptide (FMRpolyG). Increased levels of FMR1 mRNA containing an expanded CGG repeat can result in cellular toxicity by an RNA gain-of-function mechanism. The increased levels of CGG repeat-expanded FMR1 transcripts may create RNA foci that sequester important cellular proteins, including RNA-binding proteins and FMRpolyG, in intranuclear inclusions. To date, it is unclear whether the FMRpolyG-positive intranuclear inclusions are a cause or a consequence of FXTAS disease pathology. In this report we studied the relation between the presence of neuronal intranuclear inclusions and behavioral deficits using an inducible mouse model for FXTAS. Neuronal intranuclear inclusions were observed 4 weeks after dox-induction. After 12 weeks, high numbers of FMRpolyG-positive intranuclear inclusions could be detected in the hippocampus and striatum, but no clear signs of behavioral deficits related to these specific brain regions were found. In conclusion, the observations in our inducible mouse model for FXTAS suggest a lack of correlation between the presence of intranuclear FMRpolyG-positive aggregates in brain regions and specific behavioral phenotypes.
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Affiliation(s)
- Saif N Haify
- Department of Clinical Genetics, Erasmus MC, Rotterdam, Netherlands
| | - Ruchira S D Mankoe
- Department of Clinical Genetics, Erasmus MC, Rotterdam, Netherlands.,Department of Neuroscience, Erasmus MC, Rotterdam, Netherlands
| | | | | | - Rob F M Verhagen
- Department of Clinical Genetics, Erasmus MC, Rotterdam, Netherlands
| | - Rob Willemsen
- Department of Clinical Genetics, Erasmus MC, Rotterdam, Netherlands
| | - Renate K Hukema
- Department of Clinical Genetics, Erasmus MC, Rotterdam, Netherlands.,Department of Health Care Studies, Rotterdam University of Applied Sciences, Rotterdam, Netherlands
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Antisense Transcription across Nucleotide Repeat Expansions in Neurodegenerative and Neuromuscular Diseases: Progress and Mysteries. Genes (Basel) 2020; 11:genes11121418. [PMID: 33261024 PMCID: PMC7760973 DOI: 10.3390/genes11121418] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 11/24/2020] [Accepted: 11/24/2020] [Indexed: 12/14/2022] Open
Abstract
Unstable repeat expansions and insertions cause more than 30 neurodegenerative and neuromuscular diseases. Remarkably, bidirectional transcription of repeat expansions has been identified in at least 14 of these diseases. More remarkably, a growing number of studies has been showing that both sense and antisense repeat RNAs are able to dysregulate important cellular pathways, contributing together to the observed clinical phenotype. Notably, antisense repeat RNAs from spinocerebellar ataxia type 7, myotonic dystrophy type 1, Huntington's disease and frontotemporal dementia/amyotrophic lateral sclerosis associated genes have been implicated in transcriptional regulation of sense gene expression, acting either at a transcriptional or posttranscriptional level. The recent evidence that antisense repeat RNAs could modulate gene expression broadens our understanding of the pathogenic pathways and adds more complexity to the development of therapeutic strategies for these disorders. In this review, we cover the amazing progress made in the understanding of the pathogenic mechanisms associated with repeat expansion neurodegenerative and neuromuscular diseases with a focus on the impact of antisense repeat transcription in the development of efficient therapies.
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Schwartz JL, Jones KL, Yeo GW. Repeat RNA expansion disorders of the nervous system: post-transcriptional mechanisms and therapeutic strategies. Crit Rev Biochem Mol Biol 2020; 56:31-53. [PMID: 33172304 PMCID: PMC8192115 DOI: 10.1080/10409238.2020.1841726] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Dozens of incurable neurological disorders result from expansion of short repeat sequences in both coding and non-coding regions of the transcriptome. Short repeat expansions underlie microsatellite repeat expansion (MRE) disorders including myotonic dystrophy (DM1, CUG50–3,500 in DMPK; DM2, CCTG75–11,000 in ZNF9), fragile X tremor ataxia syndrome (FXTAS, CGG50–200 in FMR1), spinal bulbar muscular atrophy (SBMA, CAG40–55 in AR), Huntington’s disease (HD, CAG36–121 in HTT), C9ORF72-amyotrophic lateral sclerosis (ALS)/frontotemporal dementia (FTD and C9-ALS/FTD, GGGGCC in C9ORF72), and many others, like ataxias. Recent research has highlighted several mechanisms that may contribute to pathology in this heterogeneous class of neurological MRE disorders – bidirectional transcription, intranuclear RNA foci, and repeat associated non-AUG (RAN) translation – which are the subject of this review. Additionally, many MRE disorders share similar underlying molecular pathologies that have been recently targeted in experimental and preclinical contexts. We discuss the therapeutic potential of versatile therapeutic strategies that may selectively target disrupted RNA-based processes and may be readily adaptable for the treatment of multiple MRE disorders. Collectively, the strategies under consideration for treatment of multiple MRE disorders include reducing levels of toxic RNA, preventing RNA foci formation, and eliminating the downstream cellular toxicity associated with peptide repeats produced by RAN translation. While treatments are still lacking for the majority of MRE disorders, several promising therapeutic strategies have emerged and will be evaluated within this review.
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Affiliation(s)
- Joshua L Schwartz
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA, USA
| | - Krysten Leigh Jones
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA, USA
| | - Gene W Yeo
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA, USA
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Tassanakijpanich N, Cohen J, Cohen R, Srivatsa UN, Hagerman RJ. Cardiovascular Problems in the Fragile X Premutation. Front Genet 2020; 11:586910. [PMID: 33133171 PMCID: PMC7578382 DOI: 10.3389/fgene.2020.586910] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 09/21/2020] [Indexed: 12/12/2022] Open
Abstract
There is a dearth of information about cardiovascular problems in fragile X premutation carriers who have 55–200 CGG repeats in fragile X mental retardation 1 (FMR1) gene. The FMR1 expansion in the premutation range leads to toxic RNA gain-of-function resulting in cellular dysregulation. The mechanism of RNA toxicity underlies all of the premutation disorders including fragile X-associated tremor/ataxia syndrome, fragile X-associated primary ovarian insufficiency, and fragile X-associated neuropsychiatric disorder. Cardiovascular problems particularly autonomic dysfunction, hypertension, and cardiac arrhythmias are not uncommon in premutation carriers. Some arterial problems and valvular heart diseases have also been reported. This article reviews cardiovascular problems in premutation carriers and discusses possible contributing mechanisms including RNA toxicity and mild fragile X mental retardation protein deficiency. Further research studies are needed in order to prove a direct association of the cardiovascular problems in fragile X premutation carriers because such knowledge will lead to better preventative treatment.
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Affiliation(s)
- Nattaporn Tassanakijpanich
- UC Davis MIND Institute, UC Davis Health, Sacramento, CA, United States.,Department of Pediatrics, Faculty of Medicine, Prince of Songkla University, Songkhla, Thailand
| | - Jonathan Cohen
- Fragile X Alliance Clinic, Genetic Clinics Australia, Melbourne, VIC, Australia
| | - Rashelle Cohen
- Fragile X Alliance Clinic, Genetic Clinics Australia, Melbourne, VIC, Australia
| | - Uma N Srivatsa
- Division of Cardiovascular Medicine, Department of Internal Medicine, UC Davis Medical Center, Sacramento, CA, United States
| | - Randi J Hagerman
- UC Davis MIND Institute, UC Davis Health, Sacramento, CA, United States.,Department of Pediatrics, University of California, Davis, Davis, School of Medicine, Sacramento, CA, United States
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35
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Asamitsu S, Yabuki Y, Ikenoshita S, Wada T, Shioda N. Pharmacological prospects of G-quadruplexes for neurological diseases using porphyrins. Biochem Biophys Res Commun 2020; 531:51-55. [DOI: 10.1016/j.bbrc.2020.01.054] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 12/26/2019] [Accepted: 01/09/2020] [Indexed: 12/14/2022]
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36
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Low YH, Asi Y, Foti SC, Lashley T. Heterogeneous Nuclear Ribonucleoproteins: Implications in Neurological Diseases. Mol Neurobiol 2020; 58:631-646. [PMID: 33000450 PMCID: PMC7843550 DOI: 10.1007/s12035-020-02137-4] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 09/17/2020] [Indexed: 12/13/2022]
Abstract
Heterogenous nuclear ribonucleoproteins (hnRNPs) are a complex and functionally diverse family of RNA binding proteins with multifarious roles. They are involved, directly or indirectly, in alternative splicing, transcriptional and translational regulation, stress granule formation, cell cycle regulation, and axonal transport. It is unsurprising, given their heavy involvement in maintaining functional integrity of the cell, that their dysfunction has neurological implications. However, compared to their more established roles in cancer, the evidence of hnRNP implication in neurological diseases is still in its infancy. This review aims to consolidate the evidences for hnRNP involvement in neurological diseases, with a focus on spinal muscular atrophy (SMA), Alzheimer’s disease (AD), amyotrophic lateral sclerosis (ALS), frontotemporal dementia (FTD), multiple sclerosis (MS), congenital myasthenic syndrome (CMS), and fragile X-associated tremor/ataxia syndrome (FXTAS). Understanding more about hnRNP involvement in neurological diseases can further elucidate the pathomechanisms involved in these diseases and perhaps guide future therapeutic advances.
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Affiliation(s)
- Yi-Hua Low
- The Queen Square Brain Bank for Neurological Disorders, Department of Clinical and Movement Disorders, UCL Queen Square Institute of Neurology, University College London, London, WC1N 3BG, UK.,Duke-NUS Medical School, Singapore, Singapore
| | - Yasmine Asi
- The Queen Square Brain Bank for Neurological Disorders, Department of Clinical and Movement Disorders, UCL Queen Square Institute of Neurology, University College London, London, WC1N 3BG, UK
| | - Sandrine C Foti
- The Queen Square Brain Bank for Neurological Disorders, Department of Clinical and Movement Disorders, UCL Queen Square Institute of Neurology, University College London, London, WC1N 3BG, UK.,Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Tammaryn Lashley
- The Queen Square Brain Bank for Neurological Disorders, Department of Clinical and Movement Disorders, UCL Queen Square Institute of Neurology, University College London, London, WC1N 3BG, UK. .,Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, University College London, London, UK.
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Robinson AC, Bajaj N, Hadjivassiliou M, Minshull J, Mahmood A, Roncaroli F. Neuropathology of a case of fragile X-associated tremor ataxia syndrome without tremor. Neuropathology 2020; 40:611-619. [PMID: 32830366 DOI: 10.1111/neup.12674] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Revised: 05/08/2020] [Accepted: 05/08/2020] [Indexed: 12/01/2022]
Abstract
Fragile X-associated tremor ataxia syndrome (FXTAS) is a neurodegenerative disorder caused by a CGG trinucleotide expansion from 55 to 200 repeats in the non-coding region of the fragile X mental retardation 1 (FMR1) gene (FMR1). Clinical features include cognitive decline, progressive tremor, and gait ataxia. Neuropathologically, FXTAS shows white matter changes, hippocampal and cerebellar involvement, and p62-positive eosinophilic intranuclear inclusions in astrocytes and neurons. Here, we document the neuropathological findings from a subject who developed cognitive impairment but not tremor and was proved to have genetically confirmed FMR1 premutation. Microscopically, typical p62-postive intranuclear inclusions were present in all the regions examined. Neocortical regions demonstrated gliosis of layer I and mild degree of neuronal loss and atrophy across the other layers. The molecular, Purkinje's cell, and granule cell layers of the cerebellar folia demonstrated mild gliosis, and cerebellar white matter was mildly affected. Aside from p62-positive inclusions, the hippocampus was spared. Arteries in the deep white matter often showed changes consistent with moderate small vessel disease (SVD). Reactive gliosis and severe SVD were features of basal ganglia. Florid reactive astrocytosis was found in the white matter of all regions. Axonal loss and features of axonal damage were found in the white matter of the centrum semiovale. Microglial activation was widespread and evenly seen in both the white matter and grey matter, although the grey matter appeared more severely affected. Pathology associated with Alzheimer's disease was limited. Similarly, no abnormal accumulations of α-synuclein were present. We postulate that age at death and disease duration may play a role in the extent of the pathological features associated with FXTAS. The present results suggest that immunohistochemical staining for p62 can help with the diagnosis of cases with atypical phenotype. In addition, it is likely that the cognitive impairment observed was a result of white matter changes.
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Affiliation(s)
- Andrew C Robinson
- Faculty of Biology, Medicine and Health, School of Biological Sciences, Division of Neuroscience & Experimental Psychology, The University of Manchester, Salford Royal Hospital, Salford, UK
| | - Nin Bajaj
- Department of Neurology, University of Nottingham, Nottingham, UK
| | - Marios Hadjivassiliou
- Department of Neurology, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, UK
| | - James Minshull
- Faculty of Biology, Medicine and Health, School of Biological Sciences, Division of Neuroscience & Experimental Psychology, The University of Manchester, Salford Royal Hospital, Salford, UK
| | - Aiza Mahmood
- Neuropathology Unit, Salford Royal Hospital, Manchester, UK
| | - Federico Roncaroli
- Faculty of Biology, Medicine and Health, School of Biological Sciences, Division of Neuroscience & Experimental Psychology, The University of Manchester, Salford Royal Hospital, Salford, UK.,Neuropathology Unit, Salford Royal Hospital, Manchester, UK
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38
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Potokar M, Morita M, Wiche G, Jorgačevski J. The Diversity of Intermediate Filaments in Astrocytes. Cells 2020; 9:E1604. [PMID: 32630739 PMCID: PMC7408014 DOI: 10.3390/cells9071604] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 06/26/2020] [Accepted: 07/01/2020] [Indexed: 01/02/2023] Open
Abstract
Despite the remarkable complexity of the individual neuron and of neuronal circuits, it has been clear for quite a while that, in order to understand the functioning of the brain, the contribution of other cell types in the brain have to be accounted for. Among glial cells, astrocytes have multiple roles in orchestrating neuronal functions. Their communication with neurons by exchanging signaling molecules and removing molecules from extracellular space takes place at several levels and is governed by different cellular processes, supported by multiple cellular structures, including the cytoskeleton. Intermediate filaments in astrocytes are emerging as important integrators of cellular processes. Astrocytes express five types of intermediate filaments: glial fibrillary acidic protein (GFAP); vimentin; nestin; synemin; lamins. Variability, interactions with different cellular structures and the particular roles of individual intermediate filaments in astrocytes have been studied extensively in the case of GFAP and vimentin, but far less attention has been given to nestin, synemin and lamins. Similarly, the interplay between different types of cytoskeleton and the interaction between the cytoskeleton and membranous structures, which is mediated by cytolinker proteins, are understudied in astrocytes. The present review summarizes the basic properties of astrocytic intermediate filaments and of other cytoskeletal macromolecules, such as cytolinker proteins, and describes the current knowledge of their roles in normal physiological and pathological conditions.
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Affiliation(s)
- Maja Potokar
- Laboratory of Neuroendocrinology – Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia;
- Celica BIOMEDICAL, 1000 Ljubljana, Slovenia;
| | - Mitsuhiro Morita
- Department of Biology, Kobe University Graduate School of Science, Kobe 657-8501, Japan;
| | - Gerhard Wiche
- Celica BIOMEDICAL, 1000 Ljubljana, Slovenia;
- Department of Biochemistry and Cell Biology, Max F. Perutz Laboratories, University of Vienna, 1030 Vienna, Austria
| | - Jernej Jorgačevski
- Laboratory of Neuroendocrinology – Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia;
- Celica BIOMEDICAL, 1000 Ljubljana, Slovenia;
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Fragile X-Associated Tremor/Ataxia Syndrome (FXTAS): Pathophysiology and Clinical Implications. Int J Mol Sci 2020; 21:ijms21124391. [PMID: 32575683 PMCID: PMC7352421 DOI: 10.3390/ijms21124391] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 05/23/2020] [Accepted: 05/28/2020] [Indexed: 02/06/2023] Open
Abstract
The fragile X-associated tremor/ataxia syndrome (FXTAS) is a neurodegenerative disorder seen in older premutation (55-200 CGG repeats) carriers of FMR1. The premutation has excessive levels of FMR1 mRNA that lead to toxicity and mitochondrial dysfunction. The clinical features usually begin in the 60 s with an action or intention tremor followed by cerebellar ataxia, although 20% have only ataxia. MRI features include brain atrophy and white matter disease, especially in the middle cerebellar peduncles, periventricular areas, and splenium of the corpus callosum. Neurocognitive problems include memory and executive function deficits, although 50% of males can develop dementia. Females can be less affected by FXTAS because of a second X chromosome that does not carry the premutation. Approximately 40% of males and 16% of female carriers develop FXTAS. Since the premutation can occur in less than 1 in 200 women and 1 in 400 men, the FXTAS diagnosis should be considered in patients that present with tremor, ataxia, parkinsonian symptoms, neuropathy, and psychiatric problems. If a family history of a fragile X mutation is known, then FMR1 DNA testing is essential in patients with these symptoms.
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40
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Ma L, Hagerman PJ. Autofluorescence-based analyses of intranuclear inclusions of Fragile X-associated tremor/ataxia syndrome. Biotechniques 2020; 69:414-420. [PMID: 32486839 DOI: 10.2144/btn-2019-0144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Intranuclear inclusions present in the brains of patients with Fragile X-associated tremor/ataxia syndrome (FXTAS) have historically been difficult to study due to their location and scarcity. The recent finding that these particles autofluoresce has complicated the use of immunofluorescence techniques, but also offers new opportunities for purification. We have ascertained the features of the autofluorescence, including its excitation/emission spectrum, similarities and differences compared with lipofuscin autofluorescence, and its presence/absence under various fixation, mounting and UV light exposure conditions. Immunofluorescence at various wavelengths was conducted to determine which conditions are ideal for minimizing autofluorescence confounds. We also present a technique for autofluorescence-based sorting of FXTAS inclusions using flow cytometry, which will allow researchers in the field to purify inclusions more successfully for unbiased analyses.
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Affiliation(s)
- Lisa Ma
- Department of Biochemistry & Molecular Medicine, University of California Davis School of Medicine, Davis, CA 95616, USA
| | - Paul J Hagerman
- Department of Biochemistry & Molecular Medicine, University of California Davis School of Medicine, Davis, CA 95616, USA.,MIND Institute, University of California Davis Health, Sacramento, CA 95817, USA
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Shani V, Safory H, Szargel R, Wang N, Cohen T, Elghani FA, Hamza H, Savyon M, Radzishevsky I, Shaulov L, Rott R, Lim KL, Ross CA, Bandopadhyay R, Zhang H, Engelender S. Physiological and pathological roles of LRRK2 in the nuclear envelope integrity. Hum Mol Genet 2020; 28:3982-3996. [PMID: 31626293 DOI: 10.1093/hmg/ddz245] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Revised: 09/12/2019] [Accepted: 10/03/2019] [Indexed: 01/28/2023] Open
Abstract
Mutations in LRRK2 cause autosomal dominant and sporadic Parkinson's disease, but the mechanisms involved in LRRK2 toxicity in PD are yet to be fully understood. We found that LRRK2 translocates to the nucleus by binding to seven in absentia homolog (SIAH-1), and in the nucleus it directly interacts with lamin A/C, independent of its kinase activity. LRRK2 knockdown caused nuclear lamina abnormalities and nuclear disruption. LRRK2 disease mutations mostly abolish the interaction with lamin A/C and, similar to LRRK2 knockdown, cause disorganization of lamin A/C and leakage of nuclear proteins. Dopaminergic neurons of LRRK2 G2019S transgenic and LRRK2 -/- mice display decreased circularity of the nuclear lamina and leakage of the nuclear protein 53BP1 to the cytosol. Dopaminergic nigral and cortical neurons of both LRRK2 G2019S and idiopathic PD patients exhibit abnormalities of the nuclear lamina. Our data indicate that LRRK2 plays an essential role in maintaining nuclear envelope integrity. Disruption of this function by disease mutations suggests a novel phosphorylation-independent loss-of-function mechanism that may synergize with other neurotoxic effects caused by LRRK2 mutations.
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Affiliation(s)
- Vered Shani
- Dept. of Biochemistry, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Hazem Safory
- Dept. of Biochemistry, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Raymonde Szargel
- Dept. of Biochemistry, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Ninghan Wang
- Department of Neuroscience, Thomas Jefferson University, Philadelphia, PA, USA
| | - Tsipora Cohen
- Dept. of Biochemistry, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Fatimah Abd Elghani
- Dept. of Biochemistry, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Haya Hamza
- Dept. of Biochemistry, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Mor Savyon
- Dept. of Biochemistry, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Inna Radzishevsky
- Dept. of Biochemistry, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Lihi Shaulov
- Dept. of Biochemistry, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Ruth Rott
- Dept. of Biochemistry, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Kah-Leong Lim
- Department of Physiology, National University of Singapore, Singapore, Singapore
| | - Christopher A Ross
- Department of Psychiatry, The Johns Hopkins Medical School, Baltimore, MD, USA
| | | | - Hui Zhang
- Department of Neuroscience, Thomas Jefferson University, Philadelphia, PA, USA
| | - Simone Engelender
- Dept. of Biochemistry, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
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42
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Chernoff YO, Grizel AV, Rubel AA, Zelinsky AA, Chandramowlishwaran P, Chernova TA. Application of yeast to studying amyloid and prion diseases. ADVANCES IN GENETICS 2020; 105:293-380. [PMID: 32560789 PMCID: PMC7527210 DOI: 10.1016/bs.adgen.2020.01.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Amyloids are fibrous cross-β protein aggregates that are capable of proliferation via nucleated polymerization. Amyloid conformation likely represents an ancient protein fold and is linked to various biological or pathological manifestations. Self-perpetuating amyloid-based protein conformers provide a molecular basis for transmissible (infectious or heritable) protein isoforms, termed prions. Amyloids and prions, as well as other types of misfolded aggregated proteins are associated with a variety of devastating mammalian and human diseases, such as Alzheimer's, Parkinson's and Huntington's diseases, transmissible spongiform encephalopathies (TSEs), amyotrophic lateral sclerosis (ALS) and transthyretinopathies. In yeast and fungi, amyloid-based prions control phenotypically detectable heritable traits. Simplicity of cultivation requirements and availability of powerful genetic approaches makes yeast Saccharomyces cerevisiae an excellent model system for studying molecular and cellular mechanisms governing amyloid formation and propagation. Genetic techniques allowing for the expression of mammalian or human amyloidogenic and prionogenic proteins in yeast enable researchers to capitalize on yeast advantages for characterization of the properties of disease-related proteins. Chimeric constructs employing mammalian and human aggregation-prone proteins or domains, fused to fluorophores or to endogenous yeast proteins allow for cytological or phenotypic detection of disease-related protein aggregation in yeast cells. Yeast systems are amenable to high-throughput screening for antagonists of amyloid formation, propagation and/or toxicity. This review summarizes up to date achievements of yeast assays in application to studying mammalian and human disease-related aggregating proteins, and discusses both limitations and further perspectives of yeast-based strategies.
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Affiliation(s)
- Yury O Chernoff
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, United States; Laboratory of Amyloid Biology, St. Petersburg State University, St. Petersburg, Russia.
| | - Anastasia V Grizel
- Laboratory of Amyloid Biology, St. Petersburg State University, St. Petersburg, Russia
| | - Aleksandr A Rubel
- Laboratory of Amyloid Biology, St. Petersburg State University, St. Petersburg, Russia; Department of Genetics and Biotechnology, St. Petersburg State University, St. Petersburg, Russia; Sirius University of Science and Technology, Sochi, Russia
| | - Andrew A Zelinsky
- Laboratory of Amyloid Biology, St. Petersburg State University, St. Petersburg, Russia
| | | | - Tatiana A Chernova
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, United States
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La Rosa P, Petrillo S, Bertini ES, Piemonte F. Oxidative Stress in DNA Repeat Expansion Disorders: A Focus on NRF2 Signaling Involvement. Biomolecules 2020; 10:biom10050702. [PMID: 32369911 PMCID: PMC7277112 DOI: 10.3390/biom10050702] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 04/24/2020] [Accepted: 04/27/2020] [Indexed: 12/13/2022] Open
Abstract
DNA repeat expansion disorders are a group of neuromuscular and neurodegenerative diseases that arise from the inheritance of long tracts of nucleotide repetitions, located in the regulatory region, introns, or inside the coding sequence of a gene. Although loss of protein expression and/or the gain of function of its transcribed mRNA or translated product represent the major pathogenic effect of these pathologies, mitochondrial dysfunction and imbalance in redox homeostasis are reported as common features in these disorders, deeply affecting their severity and progression. In this review, we examine the role that the redox imbalance plays in the pathological mechanisms of DNA expansion disorders and the recent advances on antioxidant treatments, particularly focusing on the expression and the activity of the transcription factor NRF2, the main cellular regulator of the antioxidant response.
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Verma AK, Khan E, Mishra SK, Mishra A, Charlet-Berguerand N, Kumar A. Curcumin Regulates the r(CGG) exp RNA Hairpin Structure and Ameliorate Defects in Fragile X-Associated Tremor Ataxia Syndrome. Front Neurosci 2020; 14:295. [PMID: 32317919 PMCID: PMC7155420 DOI: 10.3389/fnins.2020.00295] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 03/16/2020] [Indexed: 12/21/2022] Open
Abstract
Fragile X-associated tremor ataxia syndrome is an untreatable neurological and neuromuscular disorder caused by unstable expansion of 55–200 CGG nucleotide repeats in 5′ UTR of Fragile X intellectual disability 1 (FMR1) gene. The expansion of CGG repeats in the FMR1 mRNA elicits neuronal cell toxicity through two main pathogenic mechanisms. First, mRNA with CGG expanded repeats sequester specific RNA regulatory proteins resulting in splicing alterations and formation of ribonuclear inclusions. Second, repeat-associated non-canonical translation (RANT) of the CGG expansion produces a toxic homopolymeric protein, FMRpolyG. Very few small molecules are known to modulate these pathogenic events, limiting the therapeutic possibilities for FXTAS. Here, we found that a naturally available biologically active small molecule, Curcumin, selectively binds to CGG RNA repeats. Interestingly, Curcumin improves FXTAS associated alternative splicing defects and decreases the production and accumulation of FMRpolyG protein inclusion. Furthermore, Curcumin decreases cell cytotoxicity promptly by expression of CGG RNA in FXTAS cell models. In conclusion, our data suggest that small molecules like Curcumin and its derivatives may be explored as a potential therapeutic strategy against the debilitating repeats associated neurodegenerative disorders.
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Affiliation(s)
- Arun Kumar Verma
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, India
| | - Eshan Khan
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, India
| | - Subodh Kumar Mishra
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, India
| | - Amit Mishra
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology Jodhpur, Rajasthan, India
| | - Nicolas Charlet-Berguerand
- Translational Medicine and Neurogenetics, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U964, CNRS UMR7104, University of Strasbourg, Strasbourg, France
| | - Amit Kumar
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, India
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Haify SN, Botta-Orfila T, Hukema RK, Tartaglia GG. In silico, in vitro, and in vivo Approaches to Identify Molecular Players in Fragile X Tremor and Ataxia Syndrome. Front Mol Biosci 2020; 7:31. [PMID: 32219099 PMCID: PMC7078329 DOI: 10.3389/fmolb.2020.00031] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 02/11/2020] [Indexed: 12/22/2022] Open
Abstract
Fragile X-associated tremor/ataxia syndrome (FXTAS) is a late-onset neurodegenerative monogenetic disorder affecting carriers of premutation (PM) forms of the FMR1 gene, resulting in a progressive development of tremors, ataxia, and neuropsychological problems. This highly disabling disease is quite common in the general population with an estimation of about 20 million PM carriers worldwide. The chances of developing FXTAS increase dramatically with age, with about 45% of male carriers over the age of 50 being affected. Both the gene and pathogenic trigger, a mutant expansion of CGG RNA, causing FXTAS are known. This makes it an interesting disease to develop targeted therapeutic interventions for. Yet, no such interventions are available at this moment. Here we discuss in silico, in vitro, and in vivo approaches and how they have been used to identify the molecular determinants of FXTAS pathology. These approaches have yielded substantial information about FXTAS pathology and, consequently, many markers have emerged to play a key role in understanding the disease mechanism. Integration of the different approaches is expected to provide crucial information about the value of these markers as either therapeutic target or biomarker, essential to monitor therapeutic interventions in the future.
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Affiliation(s)
- Saif N Haify
- Department of Clinical Genetics, Erasmus MC, Rotterdam, Netherlands
| | - Teresa Botta-Orfila
- Biological Fluids Bank of the Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Renate K Hukema
- Department of Clinical Genetics, Erasmus MC, Rotterdam, Netherlands
| | - Gian Gaetano Tartaglia
- Centre for Genomic Regulation (CRG), The Barcelona Institute for Science and Technology, Barcelona, Spain.,Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain.,Department of Biology 'Charles Darwin', Sapienza University of Rome, Rome, Italy.,Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, Genoa, Italy.,Universitat Pompeu Fabra (UPF), Barcelona, Spain
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Salcedo-Arellano MJ, Dufour B, McLennan Y, Martinez-Cerdeno V, Hagerman R. Fragile X syndrome and associated disorders: Clinical aspects and pathology. Neurobiol Dis 2020; 136:104740. [PMID: 31927143 PMCID: PMC7027994 DOI: 10.1016/j.nbd.2020.104740] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 12/17/2019] [Accepted: 01/08/2020] [Indexed: 12/23/2022] Open
Abstract
This review aims to assemble many years of research and clinical experience in the fields of neurodevelopment and neuroscience to present an up-to-date understanding of the clinical presentation, molecular and brain pathology associated with Fragile X syndrome, a neurodevelopmental condition that develops with the full mutation of the FMR1 gene, located in the q27.3 loci of the X chromosome, and Fragile X-associated tremor/ataxia syndrome a neurodegenerative disease experienced by aging premutation carriers of the FMR1 gene. It is important to understand that these two syndromes have a very distinct clinical and pathological presentation while sharing the same origin: the mutation of the FMR1 gene; revealing the complexity of expansion genetics.
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Affiliation(s)
- Maria Jimena Salcedo-Arellano
- Department of Pediatrics, University of California Davis School of Medicine, Sacramento, CA, USA; Medical Investigation of Neurodevelopmental Disorders (MIND) Institute, University of California Davis, Sacramento, CA, USA; Institute for Pediatric Regenerative Medicine and Shriners Hospitals for Children Northern California, Sacramento, CA, USA; Department of Pathology and Laboratory Medicine, UC Davis School of Medicine, Sacramento, CA, USA.
| | - Brett Dufour
- Institute for Pediatric Regenerative Medicine and Shriners Hospitals for Children Northern California, Sacramento, CA, USA; Department of Pathology and Laboratory Medicine, UC Davis School of Medicine, Sacramento, CA, USA
| | - Yingratana McLennan
- Department of Pediatrics, University of California Davis School of Medicine, Sacramento, CA, USA; Medical Investigation of Neurodevelopmental Disorders (MIND) Institute, University of California Davis, Sacramento, CA, USA; Institute for Pediatric Regenerative Medicine and Shriners Hospitals for Children Northern California, Sacramento, CA, USA
| | - Veronica Martinez-Cerdeno
- Medical Investigation of Neurodevelopmental Disorders (MIND) Institute, University of California Davis, Sacramento, CA, USA; Institute for Pediatric Regenerative Medicine and Shriners Hospitals for Children Northern California, Sacramento, CA, USA; Department of Pathology and Laboratory Medicine, UC Davis School of Medicine, Sacramento, CA, USA
| | - Randi Hagerman
- Department of Pediatrics, University of California Davis School of Medicine, Sacramento, CA, USA; Medical Investigation of Neurodevelopmental Disorders (MIND) Institute, University of California Davis, Sacramento, CA, USA.
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47
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Suardi GAM, Haddad LA. FMRP ribonucleoprotein complexes and RNA homeostasis. ADVANCES IN GENETICS 2020; 105:95-136. [PMID: 32560791 DOI: 10.1016/bs.adgen.2020.01.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The Fragile Mental Retardation 1 gene (FMR1), at Xq27.3, encodes the fragile mental retardation protein (FMRP), and displays in its 5'-untranslated region a series of polymorphic CGG triplet repeats that may undergo dynamic mutation. Fragile X syndrome (FXS) is the leading cause of inherited intellectual disability among men, and is most frequently due to FMR1 full mutation and consequent transcription repression. FMR1 premutations may associate with at least two other clinical conditions, named fragile X-associated primary ovarian insufficiency (FXPOI) and tremor and ataxia syndrome (FXTAS). While FXPOI and FXTAS appear to be mediated by FMR1 mRNA accumulation, relative reduction of FMRP, and triplet repeat translation, FXS is due to the lack of the RNA-binding protein FMRP. Besides its function as mRNA translation repressor in neuronal and stem/progenitor cells, RNA editing roles have been assigned to FMRP. In this review, we provide a brief description of FMR1 transcribed microsatellite and associated clinical disorders, and discuss FMRP molecular roles in ribonucleoprotein complex assembly and trafficking, as well as aspects of RNA homeostasis affected in FXS cells.
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Affiliation(s)
- Gabriela Aparecida Marcondes Suardi
- Human Genome and Stem Cell Research Center, Department of Genetics and Evolutionary Biology, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil
| | - Luciana Amaral Haddad
- Human Genome and Stem Cell Research Center, Department of Genetics and Evolutionary Biology, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil.
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Kim K, Hessl D, Randol JL, Espinal GM, Schneider A, Protic D, Aydin EY, Hagerman RJ, Hagerman PJ. Association between IQ and FMR1 protein (FMRP) across the spectrum of CGG repeat expansions. PLoS One 2019; 14:e0226811. [PMID: 31891607 PMCID: PMC6938341 DOI: 10.1371/journal.pone.0226811] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Accepted: 12/05/2019] [Indexed: 12/20/2022] Open
Abstract
Fragile X syndrome, the leading heritable form of intellectual disability, is caused by hypermethylation and transcriptional silencing of large (CGG) repeat expansions (> 200 repeats) in the 5′ untranslated region of the fragile X mental retardation 1 (FMR1) gene. As a consequence of FMR1 gene silencing, there is little or no production of FMR1 protein (FMRP), an important element in normal synaptic function. Although the absence of FMRP has long been known to be responsible for the cognitive impairment in fragile X syndrome, the relationship between FMRP level and cognitive ability (IQ) is only imprecisely understood. To address this issue, a high-throughput, fluorescence resonance energy transfer (FRET) assay has been used to quantify FMRP levels in dermal fibroblasts, and the relationship between FMRP and IQ measures was assessed by statistical analysis in a cohort of 184 individuals with CGG-repeat lengths spanning normal (< 45 CGGs) to full mutation (> 200 CGGs) repeat ranges in fibroblasts. The principal findings of the current study are twofold: i) For those with normal CGG repeats, IQ is no longer sensitive to further increases in FMRP above an FMRP threshold of ~70% of the mean FMRP level; below this threshold, IQ decreases steeply with further decreases in FMRP; and ii) For the current cohort, a mean IQ of 85 (lower bound for the normal IQ range) is attained for FMRP levels that are only ~35% of the mean FMRP level among normal CGG-repeat controls. The current results should help guide expectations for efforts to induce FMR1 gene activity and for the levels of cognitive function expected for a given range of FMRP levels.
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Affiliation(s)
- Kyoungmi Kim
- UC Davis MIND Institute, UC Davis Health, Sacramento, California, United States of America
- Department of Public Health Sciences, University of California, Davis, School of Medicine, Davis, California, United States of America
| | - David Hessl
- UC Davis MIND Institute, UC Davis Health, Sacramento, California, United States of America
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, School of Medicine, Sacramento, California, United States of America
| | - Jamie L. Randol
- Department of Biochemistry and Molecular Medicine, University of California, Davis, School of Medicine, Davis, California, United States of America
| | - Glenda M. Espinal
- Department of Biochemistry and Molecular Medicine, University of California, Davis, School of Medicine, Davis, California, United States of America
| | - Andrea Schneider
- UC Davis MIND Institute, UC Davis Health, Sacramento, California, United States of America
- Department of Pediatrics, University of California, Davis, School of Medicine, Sacramento, California, United States of America
| | - Dragana Protic
- UC Davis MIND Institute, UC Davis Health, Sacramento, California, United States of America
| | - Elber Yuksel Aydin
- UC Davis MIND Institute, UC Davis Health, Sacramento, California, United States of America
| | - Randi J. Hagerman
- UC Davis MIND Institute, UC Davis Health, Sacramento, California, United States of America
- Department of Pediatrics, University of California, Davis, School of Medicine, Sacramento, California, United States of America
| | - Paul J. Hagerman
- UC Davis MIND Institute, UC Davis Health, Sacramento, California, United States of America
- Department of Biochemistry and Molecular Medicine, University of California, Davis, School of Medicine, Davis, California, United States of America
- * E-mail:
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Cid-Samper F, Gelabert-Baldrich M, Lang B, Lorenzo-Gotor N, Ponti RD, Severijnen LAWFM, Bolognesi B, Gelpi E, Hukema RK, Botta-Orfila T, Tartaglia GG. An Integrative Study of Protein-RNA Condensates Identifies Scaffolding RNAs and Reveals Players in Fragile X-Associated Tremor/Ataxia Syndrome. Cell Rep 2019; 25:3422-3434.e7. [PMID: 30566867 PMCID: PMC6315285 DOI: 10.1016/j.celrep.2018.11.076] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 09/26/2018] [Accepted: 11/19/2018] [Indexed: 12/21/2022] Open
Abstract
Recent evidence indicates that specific RNAs promote the formation of ribonucleoprotein condensates by acting as scaffolds for RNA-binding proteins (RBPs). We systematically investigated RNA-RBP interaction networks to understand ribonucleoprotein assembly. We found that highly contacted RNAs are structured, have long UTRs, and contain nucleotide repeat expansions. Among the RNAs with such properties, we identified the FMR1 3' UTR that harbors CGG expansions implicated in fragile X-associated tremor/ataxia syndrome (FXTAS). We studied FMR1 binding partners in silico and in vitro and prioritized the splicing regulator TRA2A for further characterization. In a FXTAS cellular model, we validated the TRA2A-FMR1 interaction and investigated implications of its sequestration at both transcriptomic and post-transcriptomic levels. We found that TRA2A co-aggregates with FMR1 in a FXTAS mouse model and in post-mortem human samples. Our integrative study identifies key components of ribonucleoprotein aggregates, providing links to neurodegenerative disease and allowing the discovery of therapeutic targets.
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Affiliation(s)
- Fernando Cid-Samper
- Centre for Genomic Regulation (CRG), The Barcelona Institute for Science and Technology, Dr. Aiguader 88, 08003 Barcelona, Spain
| | - Mariona Gelabert-Baldrich
- Centre for Genomic Regulation (CRG), The Barcelona Institute for Science and Technology, Dr. Aiguader 88, 08003 Barcelona, Spain
| | - Benjamin Lang
- Centre for Genomic Regulation (CRG), The Barcelona Institute for Science and Technology, Dr. Aiguader 88, 08003 Barcelona, Spain
| | - Nieves Lorenzo-Gotor
- Centre for Genomic Regulation (CRG), The Barcelona Institute for Science and Technology, Dr. Aiguader 88, 08003 Barcelona, Spain
| | - Riccardo Delli Ponti
- Centre for Genomic Regulation (CRG), The Barcelona Institute for Science and Technology, Dr. Aiguader 88, 08003 Barcelona, Spain
| | | | - Benedetta Bolognesi
- Centre for Genomic Regulation (CRG), The Barcelona Institute for Science and Technology, Dr. Aiguader 88, 08003 Barcelona, Spain
| | - Ellen Gelpi
- Neurological Tissue Biobank of the Hospital Clinic and Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Carrer del Rosselló, 149, 08036, Barcelona, Spain; Institute of Neurology, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Renate K Hukema
- Department of Clinical Genetics, Erasmus MC, 3000 CA Rotterdam, the Netherlands
| | - Teresa Botta-Orfila
- Centre for Genomic Regulation (CRG), The Barcelona Institute for Science and Technology, Dr. Aiguader 88, 08003 Barcelona, Spain.
| | - Gian Gaetano Tartaglia
- Centre for Genomic Regulation (CRG), The Barcelona Institute for Science and Technology, Dr. Aiguader 88, 08003 Barcelona, Spain; Universitat Pompeu Fabra (UPF), 08003 Barcelona, Spain; Department of Biology 'Charles Darwin', Sapienza University of Rome, P.le A. Moro 5, Rome 00185, Italy; Institució Catalana de Recerca i Estudis Avançats (ICREA), 23 Passeig Lluís Companys, 08010 Barcelona, Spain.
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50
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Krans A, Skariah G, Zhang Y, Bayly B, Todd PK. Neuropathology of RAN translation proteins in fragile X-associated tremor/ataxia syndrome. Acta Neuropathol Commun 2019; 7:152. [PMID: 31665086 PMCID: PMC6821001 DOI: 10.1186/s40478-019-0782-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 07/30/2019] [Indexed: 11/10/2022] Open
Abstract
CGG repeat expansions in FMR1 cause the neurodegenerative disorder Fragile X-associated Tremor/Ataxia Syndrome (FXTAS). Ubiquitinated neuronal intranuclear inclusions (NIIs) are the neuropathological hallmark of FXTAS. Both sense strand derived CGG repeats and antisense strand derived CCG repeats support non-AUG initiated (RAN) translation of homopolymeric proteins in potentially 6 different reading frames. However, the relative abundance of these proteins in FXTAS brains and their co-localization with each other and NIIs is lacking. Here we describe rater-blinded assessment of immunohistochemical and immunofluorescence staining with newly generated antibodies to different CGG RAN translation products in FXTAS and control brains as well as co-staining with ubiquitin, p62/SQSTM1, and ubiquilin 2. We find that both FMRpolyG and a second CGG repeat derived RAN translation product, FMRpolyA, accumulate in aggregates in FXTAS brains. FMRpolyG is a near-obligate component of both ubiquitin-positive and p62-positive NIIs in FXTAS, with occurrence of aggregates in 20% of all hippocampal neurons and > 90% of all inclusions. A subset of these inclusions also stain positive for the ALS/FTD associated protein ubiquilin 2. Ubiquitinated inclusions and FMRpolyG+ aggregates are rarer in cortex and cerebellum. Intriguingly, FMRpolyG staining is also visible in control neuronal nuclei. In contrast to FMRpolyG, staining for FMRpolyA and CCG antisense derived RAN translation products were less abundant and less frequent components of ubiquitinated inclusions. In conclusion, RAN translated FMRpolyG is a common component of ubiquitin and p62 positive inclusions in FXTAS patient brains.
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Affiliation(s)
- Amy Krans
- University of Michigan Medical School, Ann Arbor, USA
- Ann Arbor VA Medical Center, Ann Arbor, MI, USA
| | - Geena Skariah
- University of Michigan Medical School, Ann Arbor, USA
| | - Yuan Zhang
- University of Michigan Medical School, Ann Arbor, USA
| | - Bryana Bayly
- University of Michigan Medical School, Ann Arbor, USA
| | - Peter K Todd
- University of Michigan Medical School, Ann Arbor, USA.
- Ann Arbor VA Medical Center, Ann Arbor, MI, USA.
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