1
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Koike Y. Molecular mechanisms linking loss of TDP-43 function to amyotrophic lateral sclerosis/frontotemporal dementia-related genes. Neurosci Res 2024:S0168-0102(24)00063-4. [PMID: 38723906 DOI: 10.1016/j.neures.2024.05.001] [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: 03/08/2024] [Revised: 04/18/2024] [Accepted: 05/01/2024] [Indexed: 05/13/2024]
Abstract
Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are characterized by nuclear depletion and cytoplasmic aggregation of TAR DNA-binding protein-43 (TDP-43). TDP-43 plays a key role in regulating the splicing of numerous genes, including TARDBP. This review aims to delineate two aspects of ALS/FTD pathogenesis associated with TDP-43 function. First, we provide novel mechanistic insights into the splicing of UNC13A, a TDP-43 target gene. Single nucleotide polymorphisms (SNPs) in UNC13A are the most common risk factors for ALS/FTD. We found that TDP-43 represses "cryptic exon" inclusion during UNC13A RNA splicing. A risk-associated SNP in this exon results in increased RNA levels of UNC13A retaining the cryptic exon. Second, we described the perturbation of the TDP-43 autoregulatory mechanism caused by age-related DNA demethylation. Aging is a major risk factor for sporadic ALS/FTD. Typically, TDP-43 levels are regulated via alternative splicing of TARDBP mRNA. We hypothesized that TARDBP methylation is altered by aging, thereby disrupting TDP-43 autoregulation. We found that demethylation reduces the efficiency of alternative splicing and increases TARDBP mRNA levels. Moreover, we demonstrated that, with aging, this region is demethylated in the human motor cortex and is associated with the early onset of ALS.
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Affiliation(s)
- Yuka Koike
- Department of Molecular Neuroscience, Brain Research Institute, Niigata University, Japan.
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2
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Cheng F, Chapman T, Zhang S, Morsch M, Chung R, Lee A, Rayner SL. Understanding age-related pathologic changes in TDP-43 functions and the consequence on RNA splicing and signalling in health and disease. Ageing Res Rev 2024; 96:102246. [PMID: 38401571 DOI: 10.1016/j.arr.2024.102246] [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: 10/26/2023] [Revised: 02/07/2024] [Accepted: 02/21/2024] [Indexed: 02/26/2024]
Abstract
TAR DNA binding protein-43 (TDP-43) is a key component in RNA splicing which plays a crucial role in the aging process. In neurodegenerative diseases such as amyotrophic lateral sclerosis, frontotemporal dementia and limbic-predominant age-related TDP-43 encephalopathy, TDP-43 can be mutated, mislocalised out of the nucleus of neurons and glial cells and form cytoplasmic inclusions. These TDP-43 alterations can lead to its RNA splicing dysregulation and contribute to mis-splicing of various types of RNA, such as mRNA, microRNA, and circular RNA. These changes can result in the generation of an altered transcriptome and proteome within cells, ultimately changing the diversity and quantity of gene products. In this review, we summarise the findings of novel atypical RNAs resulting from TDP-43 dysfunction and their potential as biomarkers or targets for therapeutic development.
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Affiliation(s)
- Flora Cheng
- Motor Neuron Disease Research Centre, Macquarie Medical School, Macquarie University, Sydney, Australia.
| | - Tyler Chapman
- Motor Neuron Disease Research Centre, Macquarie Medical School, Macquarie University, Sydney, Australia
| | - Selina Zhang
- Motor Neuron Disease Research Centre, Macquarie Medical School, Macquarie University, Sydney, Australia
| | - Marco Morsch
- Motor Neuron Disease Research Centre, Macquarie Medical School, Macquarie University, Sydney, Australia
| | - Roger Chung
- Motor Neuron Disease Research Centre, Macquarie Medical School, Macquarie University, Sydney, Australia
| | - Albert Lee
- Motor Neuron Disease Research Centre, Macquarie Medical School, Macquarie University, Sydney, Australia
| | - Stephanie L Rayner
- Motor Neuron Disease Research Centre, Macquarie Medical School, Macquarie University, Sydney, Australia.
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3
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Chung M, Carter EK, Veire AM, Dammer EB, Chang J, Duong DM, Raj N, Bassell GJ, Glass JD, Gendron TF, Nelson PT, Levey AI, Seyfried NT, McEachin ZT. Cryptic exon inclusion is a molecular signature of LATE-NC in aging brains. Acta Neuropathol 2024; 147:29. [PMID: 38308693 PMCID: PMC10838224 DOI: 10.1007/s00401-023-02671-0] [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: 10/16/2023] [Revised: 11/30/2023] [Accepted: 12/17/2023] [Indexed: 02/05/2024]
Abstract
The aggregation, mislocalization, and phosphorylation of TDP-43 are pathologic hallmarks of several neurodegenerative diseases and provide a defining criterion for the neuropathologic diagnosis of Limbic-predominant Age-related TDP-43 Encephalopathy (LATE). LATE neuropathologic changes (LATE-NC) are often comorbid with other neurodegenerative pathologies including Alzheimer's disease neuropathologic changes (ADNC). We examined whether TDP-43 regulated cryptic exons accumulate in the hippocampus of neuropathologically confirmed LATE-NC cases. We found that several cryptic RNAs are robustly expressed in LATE-NC cases with or without comorbid ADNC and correlate with pTDP-43 abundance; however, the accumulation of cryptic RNAs is more robust in LATE-NC with comorbid ADNC. Additionally, cryptic RNAs can robustly distinguish LATE-NC from healthy controls and AD cases. These findings expand our current understanding and provide novel potential biomarkers for LATE pathogenesis.
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Affiliation(s)
- Mingee Chung
- Department of Cell Biology, Emory University, Atlanta, GA, 30322, USA
- Laboratory for Translational Cell Biology, Emory University, Atlanta, GA, 30322, USA
| | - E Kathleen Carter
- Department of Biochemistry, Emory University, Atlanta, GA, 30322, USA
| | - Austin M Veire
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, 32224, USA
| | - Eric B Dammer
- Department of Biochemistry, Emory University, Atlanta, GA, 30322, USA
| | - Jianjun Chang
- Department of Cell Biology, Emory University, Atlanta, GA, 30322, USA
| | - Duc M Duong
- Department of Biochemistry, Emory University, Atlanta, GA, 30322, USA
| | - Nisha Raj
- Department of Cell Biology, Emory University, Atlanta, GA, 30322, USA
- Laboratory for Translational Cell Biology, Emory University, Atlanta, GA, 30322, USA
- Department of Human Genetics, Emory University, Atlanta, GA, 30322, USA
| | - Gary J Bassell
- Department of Cell Biology, Emory University, Atlanta, GA, 30322, USA
- Laboratory for Translational Cell Biology, Emory University, Atlanta, GA, 30322, USA
- Center for Neurodegenerative Diseases, Emory University, Atlanta, GA, 30322, USA
| | - Jonathan D Glass
- Center for Neurodegenerative Diseases, Emory University, Atlanta, GA, 30322, USA
- Department of Neurology, Emory University, Atlanta, GA, 30322, USA
| | - Tania F Gendron
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, 32224, USA
- Mayo Clinic Graduate School of Biomedical Sciences, Mayo Clinic, Jacksonville, FL, 32224, USA
| | - Peter T Nelson
- Department of Pathology and Sanders-Brown Center On Aging, University of Kentucky, Lexington, KY, 40536, USA
| | - Allan I Levey
- Center for Neurodegenerative Diseases, Emory University, Atlanta, GA, 30322, USA.
- Department of Neurology, Emory University, Atlanta, GA, 30322, USA.
| | - Nicholas T Seyfried
- Department of Biochemistry, Emory University, Atlanta, GA, 30322, USA.
- Center for Neurodegenerative Diseases, Emory University, Atlanta, GA, 30322, USA.
| | - Zachary T McEachin
- Department of Cell Biology, Emory University, Atlanta, GA, 30322, USA.
- Laboratory for Translational Cell Biology, Emory University, Atlanta, GA, 30322, USA.
- Department of Human Genetics, Emory University, Atlanta, GA, 30322, USA.
- Center for Neurodegenerative Diseases, Emory University, Atlanta, GA, 30322, USA.
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4
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Irwin KE, Jasin P, Braunstein KE, Sinha IR, Garret MA, Bowden KD, Chang K, Troncoso JC, Moghekar A, Oh ES, Raitcheva D, Bartlett D, Miller T, Berry JD, Traynor BJ, Ling JP, Wong PC. A fluid biomarker reveals loss of TDP-43 splicing repression in presymptomatic ALS-FTD. Nat Med 2024; 30:382-393. [PMID: 38278991 PMCID: PMC10878965 DOI: 10.1038/s41591-023-02788-5] [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: 01/24/2023] [Accepted: 12/21/2023] [Indexed: 01/28/2024]
Abstract
Although loss of TAR DNA-binding protein 43 kDa (TDP-43) splicing repression is well documented in postmortem tissues of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), whether this abnormality occurs during early-stage disease remains unresolved. Cryptic exon inclusion reflects loss of function of TDP-43, and thus detection of proteins containing cryptic exon-encoded neoepitopes in cerebrospinal fluid (CSF) or blood could reveal the earliest stages of TDP-43 dysregulation in patients. Here we use a newly characterized monoclonal antibody specific to a TDP-43-dependent cryptic epitope (encoded by the cryptic exon found in HDGFL2) to show that loss of TDP-43 splicing repression occurs in ALS-FTD, including in presymptomatic C9orf72 mutation carriers. Cryptic hepatoma-derived growth factor-like protein 2 (HDGFL2) accumulates in CSF at significantly higher levels in familial ALS-FTD and sporadic ALS compared with controls and is elevated earlier than neurofilament light and phosphorylated neurofilament heavy chain protein levels in familial disease. Cryptic HDGFL2 can also be detected in blood of individuals with ALS-FTD, including in presymptomatic C9orf72 mutation carriers, and accumulates at levels highly correlated with those in CSF. Our findings indicate that loss of TDP-43 cryptic splicing repression occurs early in disease progression, even presymptomatically, and that detection of the HDGFL2 cryptic neoepitope serves as a potential diagnostic biomarker for ALS, which should facilitate patient recruitment and measurement of target engagement in clinical trials.
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Affiliation(s)
- Katherine E Irwin
- Department of Pathology, Johns Hopkins Medicine, Baltimore, MD, USA
- Department of Neuroscience, Johns Hopkins Medicine, Baltimore, MD, USA
| | - Pei Jasin
- Department of Pathology, Johns Hopkins Medicine, Baltimore, MD, USA
| | | | - Irika R Sinha
- Department of Pathology, Johns Hopkins Medicine, Baltimore, MD, USA
- Department of Neuroscience, Johns Hopkins Medicine, Baltimore, MD, USA
| | - Mark A Garret
- Sean M. Healey & AMG Center for ALS, Massachusetts General Hospital, Boston, MA, USA
| | - Kyra D Bowden
- Department of Pathology, Johns Hopkins Medicine, Baltimore, MD, USA
- Department of Neuroscience, Johns Hopkins Medicine, Baltimore, MD, USA
| | - Koping Chang
- Department of Pathology, Johns Hopkins Medicine, Baltimore, MD, USA
- Department and Graduate Institute of Pathology, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Juan C Troncoso
- Department of Pathology, Johns Hopkins Medicine, Baltimore, MD, USA
- Department of Neurology, Johns Hopkins Medicine, Baltimore, MD, USA
| | - Abhay Moghekar
- Department of Neurology, Johns Hopkins Medicine, Baltimore, MD, USA
| | - Esther S Oh
- Department of Pathology, Johns Hopkins Medicine, Baltimore, MD, USA
- Department of Medicine, Johns Hopkins Medicine, Baltimore, MD, USA
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medicine, Baltimore, MD, USA
| | | | | | - Timothy Miller
- Department of Neurology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | - James D Berry
- Sean M. Healey & AMG Center for ALS, Massachusetts General Hospital, Boston, MA, USA
| | - Bryan J Traynor
- Department of Neurology, Johns Hopkins Medicine, Baltimore, MD, USA
- Neuromuscular Diseases Research Section, National Institute on Aging, National Institutes of Health, Bethesda, MD, USA
- National Institute of Neurological Disorders, National Institutes of Health, Bethesda, MD, USA
- RNA Therapeutics Laboratory, Therapeutics Development Branch, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD, USA
| | - Jonathan P Ling
- Department of Pathology, Johns Hopkins Medicine, Baltimore, MD, USA
| | - Philip C Wong
- Department of Pathology, Johns Hopkins Medicine, Baltimore, MD, USA.
- Department of Neuroscience, Johns Hopkins Medicine, Baltimore, MD, USA.
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5
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Agra Almeida Quadros AR, Li Z, Wang X, Ndayambaje IS, Aryal S, Ramesh N, Nolan M, Jayakumar R, Han Y, Stillman H, Aguilar C, Wheeler HJ, Connors T, Lopez-Erauskin J, Baughn MW, Melamed Z, Beccari MS, Olmedo Martínez L, Canori M, Lee CZ, Moran L, Draper I, Kopin AS, Oakley DH, Dickson DW, Cleveland DW, Hyman BT, Das S, Ertekin-Taner N, Lagier-Tourenne C. Cryptic splicing of stathmin-2 and UNC13A mRNAs is a pathological hallmark of TDP-43-associated Alzheimer's disease. Acta Neuropathol 2024; 147:9. [PMID: 38175301 PMCID: PMC10766724 DOI: 10.1007/s00401-023-02655-0] [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: 05/29/2023] [Revised: 11/26/2023] [Accepted: 11/27/2023] [Indexed: 01/05/2024]
Abstract
Nuclear clearance and cytoplasmic accumulations of the RNA-binding protein TDP-43 are pathological hallmarks in almost all patients with amyotrophic lateral sclerosis (ALS) and up to 50% of patients with frontotemporal dementia (FTD) and Alzheimer's disease. In Alzheimer's disease, TDP-43 pathology is predominantly observed in the limbic system and correlates with cognitive decline and reduced hippocampal volume. Disruption of nuclear TDP-43 function leads to abnormal RNA splicing and incorporation of erroneous cryptic exons in numerous transcripts including Stathmin-2 (STMN2, also known as SCG10) and UNC13A, recently reported in tissues from patients with ALS and FTD. Here, we identify both STMN2 and UNC13A cryptic exons in Alzheimer's disease patients, that correlate with TDP-43 pathology burden, but not with amyloid-β or tau deposits. We also demonstrate that processing of the STMN2 pre-mRNA is more sensitive to TDP-43 loss of function than UNC13A. In addition, full-length RNAs encoding STMN2 and UNC13A are suppressed in large RNA-seq datasets generated from Alzheimer's disease post-mortem brain tissue. Collectively, these results open exciting new avenues to use STMN2 and UNC13A as potential therapeutic targets in a broad range of neurodegenerative conditions with TDP-43 proteinopathy including Alzheimer's disease.
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Affiliation(s)
- Ana Rita Agra Almeida Quadros
- Department of Neurology, The Sean M. Healey and AMG Center for ALS, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Department of Neurology, MassGeneral Institute for Neurodegenerative Diseases (MIND), Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Broad Institute of Harvard University and MIT, Cambridge, MA, USA
| | - Zhaozhi Li
- Department of Neurology, MassGeneral Institute for Neurodegenerative Diseases (MIND), Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Xue Wang
- Department of Quantitative Health Sciences, Mayo Clinic, Jacksonville, FL, USA
| | - I Sandra Ndayambaje
- Department of Neurology, The Sean M. Healey and AMG Center for ALS, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Department of Neurology, MassGeneral Institute for Neurodegenerative Diseases (MIND), Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Sandeep Aryal
- Department of Neurology, The Sean M. Healey and AMG Center for ALS, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Department of Neurology, MassGeneral Institute for Neurodegenerative Diseases (MIND), Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Broad Institute of Harvard University and MIT, Cambridge, MA, USA
| | - Nandini Ramesh
- Department of Neurology, The Sean M. Healey and AMG Center for ALS, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Department of Neurology, MassGeneral Institute for Neurodegenerative Diseases (MIND), Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Broad Institute of Harvard University and MIT, Cambridge, MA, USA
| | - Matthew Nolan
- Department of Neurology, The Sean M. Healey and AMG Center for ALS, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Department of Neurology, MassGeneral Institute for Neurodegenerative Diseases (MIND), Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Broad Institute of Harvard University and MIT, Cambridge, MA, USA
| | - Rojashree Jayakumar
- Department of Neurology, MassGeneral Institute for Neurodegenerative Diseases (MIND), Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Yi Han
- Department of Neurology, The Sean M. Healey and AMG Center for ALS, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Department of Neurology, MassGeneral Institute for Neurodegenerative Diseases (MIND), Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Hannah Stillman
- Department of Neurology, The Sean M. Healey and AMG Center for ALS, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Department of Neurology, MassGeneral Institute for Neurodegenerative Diseases (MIND), Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Corey Aguilar
- Department of Neurology, The Sean M. Healey and AMG Center for ALS, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Department of Neurology, MassGeneral Institute for Neurodegenerative Diseases (MIND), Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Hayden J Wheeler
- Department of Neurology, The Sean M. Healey and AMG Center for ALS, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Department of Neurology, MassGeneral Institute for Neurodegenerative Diseases (MIND), Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Theresa Connors
- Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Jone Lopez-Erauskin
- Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, CA, USA
| | - Michael W Baughn
- Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, CA, USA
| | - Ze'ev Melamed
- Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, CA, USA
| | - Melinda S Beccari
- Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, CA, USA
| | - Laura Olmedo Martínez
- Department of Neurology, The Sean M. Healey and AMG Center for ALS, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Department of Neurology, MassGeneral Institute for Neurodegenerative Diseases (MIND), Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Michael Canori
- Department of Neurology, The Sean M. Healey and AMG Center for ALS, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Department of Neurology, MassGeneral Institute for Neurodegenerative Diseases (MIND), Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Broad Institute of Harvard University and MIT, Cambridge, MA, USA
| | - Chao-Zong Lee
- Department of Neurology, The Sean M. Healey and AMG Center for ALS, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Department of Neurology, MassGeneral Institute for Neurodegenerative Diseases (MIND), Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Laura Moran
- Department of Neurology, The Sean M. Healey and AMG Center for ALS, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Department of Neurology, MassGeneral Institute for Neurodegenerative Diseases (MIND), Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | | | | | - Derek H Oakley
- Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | | | - Don W Cleveland
- Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, CA, USA
| | - Bradley T Hyman
- Department of Neurology, MassGeneral Institute for Neurodegenerative Diseases (MIND), Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Sudeshna Das
- Department of Neurology, MassGeneral Institute for Neurodegenerative Diseases (MIND), Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
| | - Nilüfer Ertekin-Taner
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA.
- Department of Neurology, Mayo Clinic, Jacksonville, FL, USA.
| | - Clotilde Lagier-Tourenne
- Department of Neurology, The Sean M. Healey and AMG Center for ALS, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
- Department of Neurology, MassGeneral Institute for Neurodegenerative Diseases (MIND), Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
- Broad Institute of Harvard University and MIT, Cambridge, MA, USA.
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6
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Chang K, Ling JP, Redding-Ochoa J, An Y, Li L, Dean SA, Blanchard TG, Pylyukh T, Barrett A, Irwin KE, Moghekar A, Resnick SM, Wong PC, Troncoso JC. Loss of TDP-43 splicing repression occurs early in the aging population and is associated with Alzheimer's disease neuropathologic changes and cognitive decline. Acta Neuropathol 2023; 147:4. [PMID: 38133681 DOI: 10.1007/s00401-023-02653-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 10/23/2023] [Accepted: 10/25/2023] [Indexed: 12/23/2023]
Abstract
LATE-NC, the neuropathologic changes of limbic-predominant age-related TAR DNA-binding protein 43 kDa (TDP-43) encephalopathy are frequently associated with Alzheimer's disease (AD) and cognitive impairment in older adults. The association of TDP-43 proteinopathy with AD neuropathologic changes (ADNC) and its impact on specific cognitive domains are not fully understood and whether loss of TDP-43 function occurs early in the aging brain remains unknown. Here, using a large set of autopsies from the Baltimore Longitudinal Study of Aging (BLSA) and another younger cohort, we were able to study brains from subjects 21-109 years of age. Examination of these brains show that loss of TDP-43 splicing repression, as judged by TDP-43 nuclear clearance and expression of a cryptic exon in HDGFL2, first occurs during the 6th decade, preceding by a decade the appearance of TDP-43+ neuronal cytoplasmic inclusions (NCIs). We corroborated this observation using a monoclonal antibody to demonstrate a cryptic exon-encoded neoepitope within HDGFL2 in neurons exhibiting nuclear clearance of TDP-43. TDP-43 nuclear clearance is associated with increased burden of tau pathology. Age at death, female sex, high CERAD neuritic plaque score, and high Braak neurofibrillary stage significantly increase the odds of LATE-NC. Faster rates of cognitive decline on verbal memory (California Verbal Learning Test immediate recall), visuospatial ability (Card Rotations Test), mental status (MMSE) and semantic fluency (Category Fluency Test) were associated with LATE-NC. Notably, the effects of LATE-NC on verbal memory and visuospatial ability are independent of ADNC. However, the effects of TDP-43 nuclear clearance in absence of NCI on the longitudinal trajectories and levels of cognitive measures are not significant. These results establish that loss of TDP-43 splicing repression is an early event occurring in the aging population during the development of TDP-43 proteinopathy and is associated with increased tau pathology. Furthermore, LATE-NC correlates with high levels of ADNC but also has an impact on specific memory and visuospatial functions in aging that is independent of AD.
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Affiliation(s)
- Koping Chang
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- Department and Graduate Institute of Pathology, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, 100225, Taiwan
| | - Jonathan P Ling
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Javier Redding-Ochoa
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Yang An
- Laboratory of Behavioral Neuroscience, National Institute on Aging, National Institutes of Health, Baltimore, MD, 21224, USA
| | - Ling Li
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- Office of the Chief Medical Examiner, State of Maryland, Baltimore, MD, 21223, USA
- Department of Pediatrics, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Stephanie A Dean
- Office of the Chief Medical Examiner, State of Maryland, Baltimore, MD, 21223, USA
| | - Thomas G Blanchard
- Department of Pediatrics, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Tatiana Pylyukh
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Alexander Barrett
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Katherine E Irwin
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Abhay Moghekar
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Susan M Resnick
- Laboratory of Behavioral Neuroscience, National Institute on Aging, National Institutes of Health, Baltimore, MD, 21224, USA
| | - Philip C Wong
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Juan C Troncoso
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
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7
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Baralle M, Romano M. Age-Related Alternative Splicing: Driver or Passenger in the Aging Process? Cells 2023; 12:2819. [PMID: 38132139 PMCID: PMC10742131 DOI: 10.3390/cells12242819] [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: 10/27/2023] [Revised: 12/01/2023] [Accepted: 12/08/2023] [Indexed: 12/23/2023] Open
Abstract
Alternative splicing changes are closely linked to aging, though it remains unclear if they are drivers or effects. As organisms age, splicing patterns change, varying gene isoform levels and functions. These changes may contribute to aging alterations rather than just reflect declining RNA quality control. Three main splicing types-intron retention, cassette exons, and cryptic exons-play key roles in age-related complexity. These events modify protein domains and increase nonsense-mediated decay, shifting protein isoform levels and functions. This may potentially drive aging or serve as a biomarker. Fluctuations in splicing factor expression also occur with aging. Somatic mutations in splicing genes can also promote aging and age-related disease. The interplay between splicing and aging has major implications for aging biology, though differentiating correlation and causation remains challenging. Declaring a splicing factor or event as a driver requires comprehensive evaluation of the associated molecular and physiological changes. A greater understanding of how RNA splicing machinery and downstream targets are impacted by aging is essential to conclusively establish the role of splicing in driving aging, representing a promising area with key implications for understanding aging, developing novel therapeutical options, and ultimately leading to an increase in the healthy human lifespan.
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Affiliation(s)
- Marco Baralle
- International Centre for Genetic Engineering and Biotechnology, Padriciano 99, 34149 Trieste, Italy;
| | - Maurizio Romano
- Department of Life Sciences, University of Trieste, Via A. Valerio 28, 34127 Trieste, Italy
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8
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Pasquini L, Pereira FL, Seddighi S, Zeng Y, Wei Y, Illán-Gala I, Vatsavayai SC, Friedberg A, Lee AJ, Brown JA, Spina S, Grinberg LT, Sirkis DW, Bonham LW, Yokoyama JS, Boxer AL, Kramer JH, Rosen HJ, Humphrey J, Gitler AD, Miller BL, Pollard KS, Ward ME, Seeley WW. FTLD targets brain regions expressing recently evolved genes. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.10.27.23297687. [PMID: 37961381 PMCID: PMC10635220 DOI: 10.1101/2023.10.27.23297687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
In frontotemporal lobar degeneration (FTLD), pathological protein aggregation is associated with a decline in human-specialized social-emotional and language functions. Most disease protein aggregates contain either TDP-43 (FTLD-TDP) or tau (FTLD-tau). Here, we explored whether FTLD targets brain regions that express genes containing human accelerated regions (HARs), conserved sequences that have undergone positive selection during recent human evolution. To this end, we used structural neuroimaging from patients with FTLD and normative human regional transcriptomic data to identify genes expressed in FTLD-targeted brain regions. We then integrated primate comparative genomic data to test our hypothesis that FTLD targets brain regions expressing recently evolved genes. In addition, we asked whether genes expressed in FTLD-targeted brain regions are enriched for genes that undergo cryptic splicing when TDP-43 function is impaired. We found that FTLD-TDP and FTLD-tau subtypes target brain regions that express overlapping and distinct genes, including many linked to neuromodulatory functions. Genes whose normative brain regional expression pattern correlated with FTLD cortical atrophy were strongly associated with HARs. Atrophy-correlated genes in FTLD-TDP showed greater overlap with TDP-43 cryptic splicing genes compared with atrophy-correlated genes in FTLD-tau. Cryptic splicing genes were enriched for HAR genes, and vice versa, but this effect was due to the confounding influence of gene length. Analyses performed at the individual-patient level revealed that the expression of HAR genes and cryptically spliced genes within putative regions of disease onset differed across FTLD-TDP subtypes. Overall, our findings suggest that FTLD targets brain regions that have undergone recent evolutionary specialization and provide intriguing potential leads regarding the transcriptomic basis for selective vulnerability in distinct FTLD molecular-anatomical subtypes.
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Affiliation(s)
- Lorenzo Pasquini
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, CA, USA
- Department of Neurology, Neuroscape, University of California, San Francisco, CA, USA
| | - Felipe L Pereira
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, CA, USA
| | - Sahba Seddighi
- National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
| | - Yi Zeng
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Yongbin Wei
- School of Artificial Intelligence, Beijing University of Posts and Telecommunications, Beijing, China
| | - Ignacio Illán-Gala
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, CA, USA
- Global Brain Health Institute, University of California, San Francisco, San Francisco, CA, USA and Trinity College Dublin, Dublin, Ireland
- Department of Neurology, Hospital de la Santa Creu i Sant Pau, Biomedical Research Institute, Universitat Autònoma de Barcelona, Barcelona, Catalunya, Spain
| | - Sarat C Vatsavayai
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, CA, USA
| | - Adit Friedberg
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, CA, USA
- Global Brain Health Institute, University of California, San Francisco, San Francisco, CA, USA and Trinity College Dublin, Dublin, Ireland
| | - Alex J Lee
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, CA, USA
| | - Jesse A Brown
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, CA, USA
| | - Salvatore Spina
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, CA, USA
| | - Lea T Grinberg
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, CA, USA
- Department of Pathology, University of California, San Francisco, CA, USA
| | - Daniel W Sirkis
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, CA, USA
| | - Luke W Bonham
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, CA, USA
- Department of Radiology, University of California, San Francisco, CA, USA
| | - Jennifer S Yokoyama
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, CA, USA
- Department of Radiology, University of California, San Francisco, CA, USA
| | - Adam L Boxer
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, CA, USA
| | - Joel H Kramer
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, CA, USA
| | - Howard J Rosen
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, CA, USA
| | - Jack Humphrey
- Nash Family Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Aaron D Gitler
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Bruce L Miller
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, CA, USA
| | - Katherine S Pollard
- Gladstone Institute of Data Science and Biotechnology, San Francisco, CA, USA
- Institute for Human Genetics, University of California San Francisco, San Francisco, CA, USA
- Department of Epidemiology & Biostatistics and Bakar Institute for Computational Health Sciences, University of California San Francisco, San Francisco, CA, USA
- Chan Zuckerberg Biohub, San Francisco, CA, USA
| | - Michael E Ward
- National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
| | - William W Seeley
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, CA, USA
- Department of Pathology, University of California, San Francisco, CA, USA
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9
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Cao MC, Ryan B, Wu J, Curtis MA, Faull RLM, Dragunow M, Scotter EL. A panel of TDP-43-regulated splicing events verifies loss of TDP-43 function in amyotrophic lateral sclerosis brain tissue. Neurobiol Dis 2023; 185:106245. [PMID: 37527763 DOI: 10.1016/j.nbd.2023.106245] [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: 05/11/2023] [Revised: 07/13/2023] [Accepted: 07/28/2023] [Indexed: 08/03/2023] Open
Abstract
TDP-43 dysfunction is a molecular hallmark of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). A major hypothesis of TDP-43 dysfunction in disease is the loss of normal nuclear function, resulting in impaired RNA regulation and the emergence of cryptic exons. Cryptic exons and differential exon usage are emerging as promising markers of lost TDP-43 function in addition to revealing biological pathways involved in neurodegeneration in ALS/FTD. In this brief report, we identified markers of TDP-43 loss of function by depleting TARDBP from post-mortem human brain pericytes, a manipulable in vitro primary human brain cell model, and identifying differential exon usage events with bulk RNA-sequencing analysis. We present these data in an interactive database (https://www.scotterlab.auckland.ac.nz/research-themes/tdp43-lof-db-v2/) together with seven other TDP-43-depletion datasets we meta-analysed previously, for user analysis of differential expression and splicing signatures. Differential exon usage events that were validated by qPCR were then compiled into a 'differential exon usage panel' with other well-established TDP-43 loss-of-function exon markers. This differential exon usage panel was investigated in ALS and control motor cortex tissue to verify whether, and to what extent, TDP-43 loss of function occurs in ALS. We find that profiles of TDP-43-regulated cryptic exons, changed exon usage and changed 3' UTR usage discriminate ALS brain tissue from controls, verifying that TDP-43 loss of function occurs in ALS. We propose that TDP-43-regulated splicing events that occur in brain tissue will have promise as predictors of disease.
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Affiliation(s)
- Maize C Cao
- Department of Pharmacology, University of Auckland, New Zealand; Centre for Brain Research, University of Auckland, New Zealand.
| | - Brigid Ryan
- Department of Anatomy and Medical Imaging, University of Auckland, New Zealand; Centre for Brain Research, University of Auckland, New Zealand.
| | - Jane Wu
- Department of Anatomy and Medical Imaging, University of Auckland, New Zealand; Centre for Brain Research, University of Auckland, New Zealand.
| | - Maurice A Curtis
- Department of Anatomy and Medical Imaging, University of Auckland, New Zealand; Centre for Brain Research, University of Auckland, New Zealand.
| | - Richard L M Faull
- Department of Anatomy and Medical Imaging, University of Auckland, New Zealand; Centre for Brain Research, University of Auckland, New Zealand.
| | - Mike Dragunow
- Department of Pharmacology, University of Auckland, New Zealand; Centre for Brain Research, University of Auckland, New Zealand.
| | - Emma L Scotter
- School of Biological Sciences, University of Auckland, New Zealand; Centre for Brain Research, University of Auckland, New Zealand.
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10
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Estades Ayuso V, Pickles S, Todd T, Yue M, Jansen-West K, Song Y, González Bejarano J, Rawlinson B, DeTure M, Graff-Radford NR, Boeve BF, Knopman DS, Petersen RC, Dickson DW, Josephs KA, Petrucelli L, Prudencio M. TDP-43-regulated cryptic RNAs accumulate in Alzheimer's disease brains. Mol Neurodegener 2023; 18:57. [PMID: 37605276 PMCID: PMC10441763 DOI: 10.1186/s13024-023-00646-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 08/04/2023] [Indexed: 08/23/2023] Open
Abstract
BACKGROUND Inclusions of TAR DNA-binding protein 43 kDa (TDP-43) has been designated limbic-predominant, age-related TDP-43 encephalopathy (LATE), with or without co-occurrence of Alzheimer's disease (AD). Approximately, 30-70% AD cases present TDP-43 proteinopathy (AD-TDP), and a greater disease severity compared to AD patients without TDP-43 pathology. However, it remains unclear to what extent TDP-43 dysfunction is involved in AD pathogenesis. METHODS To investigate whether TDP-43 dysfunction is a prominent feature in AD-TDP cases, we evaluated whether non-conserved cryptic exons, which serve as a marker of TDP-43 dysfunction in amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD-TDP), accumulate in AD-TDP brains. We assessed a cohort of 192 post-mortem brains from three different brain regions: amygdala, hippocampus, and frontal cortex. Following RNA and protein extraction, qRT-PCR and immunoassays were performed to quantify the accumulation of cryptic RNA targets and phosphorylated TDP-43 pathology, respectively. RESULTS We detected the accumulation of misspliced cryptic or skiptic RNAs of STMN2, KCNQ2, UNC13A, CAMK2B, and SYT7 in the amygdala and hippocampus of AD-TDP cases. The topographic distribution of cryptic RNA accumulation mimicked that of phosphorylated TDP-43, regardless of TDP-43 subtype classification. Further, cryptic RNAs efficiently discriminated AD-TDP cases from controls. CONCLUSIONS Overall, our results indicate that cryptic RNAs may represent an intriguing new therapeutic and diagnostic target in AD, and that methods aimed at detecting and measuring these species in patient biofluids could be used as a reliable tool to assess TDP-43 pathology in AD. Our work also raises the possibility that TDP-43 dysfunction and related changes in cryptic splicing could represent a common molecular mechanism shared between AD-TDP and FTLD-TDP.
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Affiliation(s)
- Virginia Estades Ayuso
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA
- Neuroscience Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, FL, USA
| | - Sarah Pickles
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA
- Neuroscience Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, FL, USA
| | - Tiffany Todd
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA
- Neuroscience Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, FL, USA
| | - Mei Yue
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA
| | | | - Yuping Song
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA
| | | | | | - Michael DeTure
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA
- Neuroscience Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, FL, USA
| | | | | | | | | | - Dennis W Dickson
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA
- Neuroscience Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, FL, USA
| | | | - Leonard Petrucelli
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA
- Neuroscience Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, FL, USA
| | - Mercedes Prudencio
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA.
- Neuroscience Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, FL, USA.
- Department of Research, Neuroscience, Mayo Clinic College of Medicine, 4500 San Pablo Rd, Jacksonville, FL, 32224, USA.
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11
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Carmen-Orozco RP, Tsao W, Ye Y, Sinha IR, Chang K, Trinh V, Chung W, Bowden K, Troncoso JC, Blackshaw S, Hayes LR, Sun S, Wong PC, Ling JP. Elevated nuclear TDP-43 induces constitutive exon skipping. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.11.540291. [PMID: 37215013 PMCID: PMC10197708 DOI: 10.1101/2023.05.11.540291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Cytoplasmic inclusions and loss of nuclear TDP-43 are key pathological features found in several neurodegenerative disorders, suggesting both gain- and loss-of-function mechanisms of disease. To study gain-of-function, TDP-43 overexpression has been used to generate in vitro and in vivo model systems. Our study shows that excessive levels of nuclear TDP-43 protein lead to constitutive exon skipping that is largely species-specific. Furthermore, while aberrant exon skipping is detected in some human brains, it is not correlated with disease, unlike the incorporation of cryptic exons that occurs after loss of TDP-43. Our findings emphasize the need for caution in interpreting TDP-43 overexpression data, and stress the importance of controlling for exon skipping when generating models of TDP-43 proteinopathy. Understanding the subtle aspects of TDP-43 toxicity within different subcellular locations is essential for the development of therapies targeting neurodegenerative disease.
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Affiliation(s)
- Rogger P Carmen-Orozco
- Department of Pathology Johns Hopkins School of Medicine, Baltimore, MD 21205
- Department of Neuroscience Johns Hopkins School of Medicine, Baltimore, MD 21205
| | - William Tsao
- Department of Pathology Johns Hopkins School of Medicine, Baltimore, MD 21205
- Department of Neuroscience Johns Hopkins School of Medicine, Baltimore, MD 21205
| | - Yingzhi Ye
- Department of Physiology Johns Hopkins School of Medicine, Baltimore, MD 21205
| | - Irika R Sinha
- Department of Pathology Johns Hopkins School of Medicine, Baltimore, MD 21205
- Department of Neuroscience Johns Hopkins School of Medicine, Baltimore, MD 21205
| | - Koping Chang
- Department of Pathology Johns Hopkins School of Medicine, Baltimore, MD 21205
| | - Vickie Trinh
- Department of Pathology Johns Hopkins School of Medicine, Baltimore, MD 21205
- Department of Neuroscience Johns Hopkins School of Medicine, Baltimore, MD 21205
| | - William Chung
- Department of Pathology Johns Hopkins School of Medicine, Baltimore, MD 21205
| | - Kyra Bowden
- Department of Pathology Johns Hopkins School of Medicine, Baltimore, MD 21205
| | - Juan C Troncoso
- Department of Pathology Johns Hopkins School of Medicine, Baltimore, MD 21205
| | - Seth Blackshaw
- Department of Neuroscience Johns Hopkins School of Medicine, Baltimore, MD 21205
- Department of Ophthalmology Johns Hopkins School of Medicine, Baltimore, MD 21205
- Department of Neurology Johns Hopkins School of Medicine, Baltimore, MD 21205
| | - Lindsey R Hayes
- Department of Neurology Johns Hopkins School of Medicine, Baltimore, MD 21205
| | - Shuying Sun
- Department of Physiology Johns Hopkins School of Medicine, Baltimore, MD 21205
| | - Philip C Wong
- Department of Pathology Johns Hopkins School of Medicine, Baltimore, MD 21205
- Department of Neuroscience Johns Hopkins School of Medicine, Baltimore, MD 21205
| | - Jonathan P Ling
- Department of Pathology Johns Hopkins School of Medicine, Baltimore, MD 21205
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12
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Milstead RA, Link CD, Xu Z, Hoeffer CA. TDP-43 knockdown in mouse model of ALS leads to dsRNA deposition, gliosis, and neurodegeneration in the spinal cord. Cereb Cortex 2023; 33:5808-5816. [PMID: 36443249 PMCID: PMC10183735 DOI: 10.1093/cercor/bhac461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 10/28/2022] [Accepted: 10/29/2022] [Indexed: 11/30/2022] Open
Abstract
Transactive response DNA binding protein 43 kilodaltons (TDP-43) is a DNA and RNA binding protein associated with severe neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS), primarily affecting motor neurons in the brain and spinal cord. Partial knockdown of TDP-43 expression in a mouse model (the amiR-TDP-43 mice) leads to progressive, age-related motor dysfunction, as observed in ALS patients. Work in Caenorhabditis elegans suggests that TDP-43 dysfunction can lead to deficits in chromatin processing and double-stranded RNA (dsRNA) accumulation, potentially activating the innate immune system and promoting neuroinflammation. To test this hypothesis, we used immunostaining to investigate dsRNA accumulation and other signs of CNS pathology in the spinal cords of amiR-TDP-43 mice. Compared with wild-type controls, TDP-43 knockdown animals show increases in dsRNA deposition in the dorsal and ventral horns of the spinal cord. Additionally, animals with heavy dsRNA expression show markedly increased levels of astrogliosis and microgliosis. Interestingly, areas of high dsRNA expression and microgliosis overlap with regions of heavy neurodegeneration, indicating that activated microglia could contribute to the degeneration of spinal cord neurons. This study suggests that loss of TDP-43 function could contribute to neuropathology by increasing dsRNA deposition and subsequent innate immune system activation.
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Affiliation(s)
- Ryan A Milstead
- Department of Integrative Physiology, University of Colorado, Boulder, Boulder CO 80303
- Institute for Behavioral Genetics, University of Colorado, Boulder, Boulder, CO 80303
| | - Christopher D Link
- Department of Integrative Physiology, University of Colorado, Boulder, Boulder CO 80303
| | - Zuoshang Xu
- Department of Biochemistry and Molecular Biotechnology, University of Massachusetts Chan Medical School, Worcester, MA, 01655
| | - Charles A Hoeffer
- Department of Integrative Physiology, University of Colorado, Boulder, Boulder CO 80303
- Institute for Behavioral Genetics, University of Colorado, Boulder, Boulder, CO 80303
- Linda Crnic Institute, Anschutz Medical Center, Aurora, CO 80217
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13
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Baughn MW, Melamed Z, López-Erauskin J, Beccari MS, Ling K, Zuberi A, Presa M, Gil EG, Maimon R, Vazquez-Sanchez S, Chaturvedi S, Bravo-Hernández M, Taupin V, Moore S, Artates JW, Acks E, Ndayambaje IS, de Almeida Quadros ARA, Jafar-nejad P, Rigo F, Bennett CF, Lutz C, Lagier-Tourenne C, Cleveland DW. Mechanism of STMN2 cryptic splice-polyadenylation and its correction for TDP-43 proteinopathies. Science 2023; 379:1140-1149. [PMID: 36927019 PMCID: PMC10148063 DOI: 10.1126/science.abq5622] [Citation(s) in RCA: 45] [Impact Index Per Article: 45.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2022] [Accepted: 02/02/2023] [Indexed: 03/18/2023]
Abstract
Loss of nuclear TDP-43 is a hallmark of neurodegeneration in TDP-43 proteinopathies, including amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). TDP-43 mislocalization results in cryptic splicing and polyadenylation of pre-messenger RNAs (pre-mRNAs) encoding stathmin-2 (also known as SCG10), a protein that is required for axonal regeneration. We found that TDP-43 binding to a GU-rich region sterically blocked recognition of the cryptic 3' splice site in STMN2 pre-mRNA. Targeting dCasRx or antisense oligonucleotides (ASOs) suppressed cryptic splicing, which restored axonal regeneration and stathmin-2-dependent lysosome trafficking in TDP-43-deficient human motor neurons. In mice that were gene-edited to contain human STMN2 cryptic splice-polyadenylation sequences, ASO injection into cerebral spinal fluid successfully corrected Stmn2 pre-mRNA misprocessing and restored stathmin-2 expression levels independently of TDP-43 binding.
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Affiliation(s)
- Michael W. Baughn
- Ludwig Institute for Cancer Research, University of California at San Diego; La Jolla, CA 92093, USA
- Department of Cellular and Molecular Medicine, University of California at San Diego; La Jolla, CA 92093, USA
| | - Ze’ev Melamed
- Ludwig Institute for Cancer Research, University of California at San Diego; La Jolla, CA 92093, USA
- Department of Cellular and Molecular Medicine, University of California at San Diego; La Jolla, CA 92093, USA
- Department of Medical Neurobiology, Faculty of Medicine, The Hebrew University of Jerusalem, Israel
| | - Jone López-Erauskin
- Ludwig Institute for Cancer Research, University of California at San Diego; La Jolla, CA 92093, USA
- Department of Cellular and Molecular Medicine, University of California at San Diego; La Jolla, CA 92093, USA
| | - Melinda S Beccari
- Ludwig Institute for Cancer Research, University of California at San Diego; La Jolla, CA 92093, USA
- Department of Cellular and Molecular Medicine, University of California at San Diego; La Jolla, CA 92093, USA
| | - Karen Ling
- Ionis Pharmaceuticals; Carlsbad, CA 92010, USA
| | - Aamir Zuberi
- Rare Disease Translation Center, The Jackson Laboratory; Bar Harbor, ME 04609
| | - Maximilliano Presa
- Rare Disease Translation Center, The Jackson Laboratory; Bar Harbor, ME 04609
| | - Elena Gonzalo Gil
- Rare Disease Translation Center, The Jackson Laboratory; Bar Harbor, ME 04609
| | - Roy Maimon
- Ludwig Institute for Cancer Research, University of California at San Diego; La Jolla, CA 92093, USA
- Department of Cellular and Molecular Medicine, University of California at San Diego; La Jolla, CA 92093, USA
| | - Sonia Vazquez-Sanchez
- Ludwig Institute for Cancer Research, University of California at San Diego; La Jolla, CA 92093, USA
- Department of Cellular and Molecular Medicine, University of California at San Diego; La Jolla, CA 92093, USA
| | - Som Chaturvedi
- Department of Cellular and Molecular Medicine, University of California at San Diego; La Jolla, CA 92093, USA
| | - Mariana Bravo-Hernández
- Department of Cellular and Molecular Medicine, University of California at San Diego; La Jolla, CA 92093, USA
| | - Vanessa Taupin
- Department of Cellular and Molecular Medicine, University of California at San Diego; La Jolla, CA 92093, USA
| | - Stephen Moore
- Department of Cellular and Molecular Medicine, University of California at San Diego; La Jolla, CA 92093, USA
| | - Jonathan W. Artates
- Ludwig Institute for Cancer Research, University of California at San Diego; La Jolla, CA 92093, USA
- Department of Cellular and Molecular Medicine, University of California at San Diego; La Jolla, CA 92093, USA
| | - Eitan Acks
- Ludwig Institute for Cancer Research, University of California at San Diego; La Jolla, CA 92093, USA
- Department of Cellular and Molecular Medicine, University of California at San Diego; La Jolla, CA 92093, USA
| | - I. Sandra Ndayambaje
- Department of Neurology, Sean M. Healey & AMG Center for ALS, Massachusetts General Hospital, Harvard Medical School; Boston, MA 02114, USA
| | - Ana R. Agra de Almeida Quadros
- Department of Neurology, Sean M. Healey & AMG Center for ALS, Massachusetts General Hospital, Harvard Medical School; Boston, MA 02114, USA
| | | | - Frank Rigo
- Ionis Pharmaceuticals; Carlsbad, CA 92010, USA
| | | | - Cathleen Lutz
- Rare Disease Translation Center, The Jackson Laboratory; Bar Harbor, ME 04609
| | - Clotilde Lagier-Tourenne
- Department of Neurology, Sean M. Healey & AMG Center for ALS, Massachusetts General Hospital, Harvard Medical School; Boston, MA 02114, USA
- Broad Institute of Harvard University and MIT; Cambridge, MA 02142, USA
| | - Don W. Cleveland
- Ludwig Institute for Cancer Research, University of California at San Diego; La Jolla, CA 92093, USA
- Department of Cellular and Molecular Medicine, University of California at San Diego; La Jolla, CA 92093, USA
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14
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Mehta PR, Brown AL, Ward ME, Fratta P. The era of cryptic exons: implications for ALS-FTD. Mol Neurodegener 2023; 18:16. [PMID: 36922834 PMCID: PMC10018954 DOI: 10.1186/s13024-023-00608-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 02/17/2023] [Indexed: 03/18/2023] Open
Abstract
TDP-43 is an RNA-binding protein with a crucial nuclear role in splicing, and mislocalises from the nucleus to the cytoplasm in a range of neurodegenerative disorders. TDP-43 proteinopathy spans a spectrum of incurable, heterogeneous, and increasingly prevalent neurodegenerative diseases, including the amyotrophic lateral sclerosis and frontotemporal dementia disease spectrum and a significant fraction of Alzheimer's disease. There are currently no directed disease-modifying therapies for TDP-43 proteinopathies, and no way to distinguish who is affected before death. It is now clear that TDP-43 proteinopathy leads to a number of molecular changes, including the de-repression and inclusion of cryptic exons. Importantly, some of these cryptic exons lead to the loss of crucial neuronal proteins and have been shown to be key pathogenic players in disease pathogenesis (e.g., STMN2), as well as being able to modify disease progression (e.g., UNC13A). Thus, these aberrant splicing events make promising novel therapeutic targets to restore functional gene expression. Moreover, presence of these cryptic exons is highly specific to patients and areas of the brain affected by TDP-43 proteinopathy, offering the potential to develop biomarkers for early detection and stratification of patients. In summary, the discovery of cryptic exons gives hope for novel diagnostics and therapeutics on the horizon for TDP-43 proteinopathies.
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Affiliation(s)
- Puja R Mehta
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, UCL Queen Square Motor Neuron Disease Centre, London, WC1N 3BG, UK
| | - Anna-Leigh Brown
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, UCL Queen Square Motor Neuron Disease Centre, London, WC1N 3BG, UK
| | - Michael E Ward
- National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA
| | - Pietro Fratta
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, UCL Queen Square Motor Neuron Disease Centre, London, WC1N 3BG, UK.
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15
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Koike Y, Pickles S, Estades Ayuso V, Jansen-West K, Qi YA, Li Z, Daughrity LM, Yue M, Zhang YJ, Cook CN, Dickson DW, Ward M, Petrucelli L, Prudencio M. TDP-43 and other hnRNPs regulate cryptic exon inclusion of a key ALS/FTD risk gene, UNC13A. PLoS Biol 2023; 21:e3002028. [PMID: 36930682 PMCID: PMC10057836 DOI: 10.1371/journal.pbio.3002028] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 03/29/2023] [Accepted: 02/08/2023] [Indexed: 03/18/2023] Open
Abstract
A major function of TAR DNA-binding protein-43 (TDP-43) is to repress the inclusion of cryptic exons during RNA splicing. One of these cryptic exons is in UNC13A, a genetic risk factor for amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). The accumulation of cryptic UNC13A in disease is heightened by the presence of a risk haplotype located within the cryptic exon itself. Here, we revealed that TDP-43 extreme N-terminus is important to repress UNC13A cryptic exon inclusion. Further, we found hnRNP L, hnRNP A1, and hnRNP A2B1 bind UNC13A RNA and repress cryptic exon inclusion, independently of TDP-43. Finally, higher levels of hnRNP L protein associate with lower burden of UNC13A cryptic RNA in ALS/FTD brains. Our findings suggest that while TDP-43 is the main repressor of UNC13A cryptic exon inclusion, other hnRNPs contribute to its regulation and may potentially function as disease modifiers.
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Affiliation(s)
- Yuka Koike
- Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, United States of America
- Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, Florida, United States of America
| | - Sarah Pickles
- Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, United States of America
- Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, Florida, United States of America
| | - Virginia Estades Ayuso
- Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, United States of America
| | - Karen Jansen-West
- Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, United States of America
| | - Yue A. Qi
- Center for Alzheimer’s and Related Dementias, National Institute on Aging, NIH, Bethesda, Maryland, United States of America
| | - Ziyi Li
- Center for Alzheimer’s and Related Dementias, National Institute on Aging, NIH, Bethesda, Maryland, United States of America
| | - Lillian M. Daughrity
- Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, United States of America
| | - Mei Yue
- Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, United States of America
| | - Yong-Jie Zhang
- Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, United States of America
- Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, Florida, United States of America
| | - Casey N. Cook
- Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, United States of America
- Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, Florida, United States of America
| | - Dennis W. Dickson
- Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, United States of America
- Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, Florida, United States of America
| | - Michael Ward
- Center for Alzheimer’s and Related Dementias, National Institute on Aging, NIH, Bethesda, Maryland, United States of America
- National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland, United States of America
| | - Leonard Petrucelli
- Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, United States of America
- Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, Florida, United States of America
| | - Mercedes Prudencio
- Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, United States of America
- Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, Florida, United States of America
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16
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Sekar D, Tusubira D, Ross K. TDP-43 and NEAT long non-coding RNA: Roles in neurodegenerative disease. Front Cell Neurosci 2022; 16:954912. [PMID: 36385948 PMCID: PMC9650703 DOI: 10.3389/fncel.2022.954912] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Accepted: 10/11/2022] [Indexed: 01/03/2023] Open
Abstract
Understanding and ameliorating neurodegenerative diseases represents a key challenge for supporting the health span of the aging population. Diverse protein aggregates have been implicated in such neurodegenerative disorders, including amyloid-β, α-synuclein, tau, fused in sarcoma (FUS), and transactivation response element (TAR) DNA-binding protein 43 (TDP-43). Recent years have seen significant growth in our mechanistic knowledge of relationships between these proteins and some of the membrane-less nuclear structures that fulfill key roles in the cell function. These include the nucleolus, nuclear speckles, and paraspeckles. The ability of macromolecular protein:RNA complexes to partition these nuclear condensates through biophysical processes that involve liquid-liquid phase separation (LLPS) has also gained attention recently. The paraspeckle, which is scaffolded by the architectural long-non-coding RNA nuclear enriched abundant transcript 1 (NEAT1) plays central roles in RNA processing and metabolism and has been linked dynamically to TDP-43. In this mini-review, we outline essential early and recent insights in relation to TDP-43 proteinopathies. We then appraise the relationships between TDP-43 and NEAT1 in the context of neuronal paraspeckles and neuronal stress. We highlight key areas for investigation based on recent advances in our understanding of how TDP-43 affects neuronal function, especially in relation to messenger ribosomal nucleic acid (mRNA) splicing. Finally, we offer perspectives that should be considered for translational pipelines in order to improve health outcomes for the management of neurodegenerative diseases.
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Affiliation(s)
- Durairaj Sekar
- Centre for Cellular and Molecular Research, Saveetha Dental College and Hospitals, Saveetha Institute of Medical and Technical Sciences (SIMATS), Saveetha University, Chennai, India
| | - Deusdedit Tusubira
- Department of Biochemistry, Mbarara University of Science and Technology, Mbarara, Uganda,*Correspondence: Deusdedit Tusubira, ; orcid.org/0000-0002-4698-424X
| | - Kehinde Ross
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Liverpool, United Kingdom,Institute for Health Research, Liverpool John Moores University, Liverpool, United Kingdom,Kehinde Ross, ; orcid.org/0000-0003-0252-1152
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17
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Pickles S, Gendron TF, Koike Y, Yue M, Song Y, Kachergus JM, Shi J, DeTure M, Thompson EA, Oskarsson B, Graff-Radford NR, Boeve BF, Petersen RC, Wszolek ZK, Josephs KA, Dickson DW, Petrucelli L, Cook CN, Prudencio M. Evidence of cerebellar TDP-43 loss of function in FTLD-TDP. Acta Neuropathol Commun 2022; 10:107. [PMID: 35879741 PMCID: PMC9310392 DOI: 10.1186/s40478-022-01408-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 07/11/2022] [Indexed: 02/08/2023] Open
Abstract
Frontotemporal lobar degeneration with TDP-43 pathology (FTLD-TDP) is a neurodegenerative disease primarily affecting the frontal and/or temporal cortices. However, a growing body of evidence suggests that the cerebellum contributes to biochemical, cognitive, and behavioral changes in FTLD-TDP. To evaluate cerebellar TDP-43 expression and function in FTLD-TDP, we analyzed TDP-43 protein levels and the splicing of a TDP-43 target, STMN2, in the cerebellum of 95 FTLD-TDP cases and 25 non-neurological disease controls. Soluble TDP-43 was decreased in the cerebellum of FTLD-TDP cases but a concomitant increase in insoluble TDP-43 was not seen. Truncated STMN2 transcripts, an indicator of TDP-43 dysfunction, were elevated in the cerebellum of FTLD-TDP cases and inversely associated with TDP-43 levels. Additionally, lower cerebellar TDP-43 associated with a younger age at disease onset. We provide evidence of TDP-43 loss of function in the cerebellum in FTLD-TDP, supporting further investigation into this understudied brain region.
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Affiliation(s)
- Sarah Pickles
- Department of Neuroscience, Mayo Clinic, Mangurian Research Building, 4500 San Pablo Road, Jacksonville, FL, 32224, USA
- Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, FL, USA
| | - Tania F Gendron
- Department of Neuroscience, Mayo Clinic, Mangurian Research Building, 4500 San Pablo Road, Jacksonville, FL, 32224, USA
- Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, FL, USA
| | - Yuka Koike
- Department of Neuroscience, Mayo Clinic, Mangurian Research Building, 4500 San Pablo Road, Jacksonville, FL, 32224, USA
- Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, FL, USA
| | - Mei Yue
- Department of Neuroscience, Mayo Clinic, Mangurian Research Building, 4500 San Pablo Road, Jacksonville, FL, 32224, USA
| | - Yuping Song
- Department of Neuroscience, Mayo Clinic, Mangurian Research Building, 4500 San Pablo Road, Jacksonville, FL, 32224, USA
| | | | - J Shi
- Department of Cancer Biology, Mayo Clinic, Jacksonville, FL, USA
| | - Michael DeTure
- Department of Neuroscience, Mayo Clinic, Mangurian Research Building, 4500 San Pablo Road, Jacksonville, FL, 32224, USA
- Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, FL, USA
| | | | | | | | | | | | | | | | - Dennis W Dickson
- Department of Neuroscience, Mayo Clinic, Mangurian Research Building, 4500 San Pablo Road, Jacksonville, FL, 32224, USA
- Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, FL, USA
| | - Leonard Petrucelli
- Department of Neuroscience, Mayo Clinic, Mangurian Research Building, 4500 San Pablo Road, Jacksonville, FL, 32224, USA
- Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, FL, USA
| | - Casey N Cook
- Department of Neuroscience, Mayo Clinic, Mangurian Research Building, 4500 San Pablo Road, Jacksonville, FL, 32224, USA.
- Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, FL, USA.
| | - Mercedes Prudencio
- Department of Neuroscience, Mayo Clinic, Mangurian Research Building, 4500 San Pablo Road, Jacksonville, FL, 32224, USA.
- Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, FL, USA.
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18
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Liang B, Thapa R, Zhang G, Moffitt C, Zhang Y, Zhang L, Johnston A, Ruby HP, Barbera G, Wong PC, Zhang Z, Chen R, Lin DT, Li Y. Aberrant Neural Activity in Prefrontal Pyramidal Neurons Lacking TDP-43 Precedes Neuron loss. Prog Neurobiol 2022; 215:102297. [PMID: 35667630 PMCID: PMC9258405 DOI: 10.1016/j.pneurobio.2022.102297] [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: 01/23/2022] [Revised: 04/25/2022] [Accepted: 05/31/2022] [Indexed: 11/16/2022]
Abstract
Mislocalization of TAR DNA binding protein 43 kDa (TARDBP, or TDP-43) is a principal pathological hallmark identified in cases of neurodegenerative disorders such as amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). As an RNA binding protein, TDP-43 serves in the nuclear compartment to repress non-conserved cryptic exons to ensure the normal transcriptome. Multiple lines of evidence from animal models and human studies support the view that loss of TDP-43 leads to neuron loss, independent of its cytosolic aggregation. However, the underlying pathogenic pathways driven by the loss-of-function mechanism are still poorly defined. We employed a genetic approach to determine the impact of TDP-43 loss in pyramidal neurons of the prefrontal cortex (PFC). Using a custom-built miniscope imaging system, we performed repetitive in vivo calcium imaging from freely behaving mice for up to 7 months. By comparing calcium activity in PFC pyramidal neurons between TDP-43 depleted and TDP-43 intact mice, we demonstrated remarkably increased numbers of pyramidal neurons exhibiting hyperactive calcium activity after short-term TDP-43 depletion, followed by rapid activity declines prior to neuron loss. Our results suggest aberrant neural activity driven by loss of TDP-43 as the pathogenic pathway at early stage in ALS and FTD.
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Affiliation(s)
- Bo Liang
- School of Electrical Engineering & Computer Science, College of Engineering & Mines, University of North Dakota, 243 Centennial Drive Stop 7165, Grand Forks, ND 58202, USA.
| | - Rashmi Thapa
- Department of Zoology and Physiology, University of Wyoming, 1000 E University Avenue, Laramie, WY 82071, USA.
| | - Gracie Zhang
- Laramie High School, 1710 Boulder Drive, Laramie, WY 82070, USA.
| | - Casey Moffitt
- Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, 333 Cassell Drive, Baltimore, MD 21224, USA.
| | - Yan Zhang
- Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, 333 Cassell Drive, Baltimore, MD 21224, USA.
| | - Lifeng Zhang
- School of Electrical Engineering & Computer Science, College of Engineering & Mines, University of North Dakota, 243 Centennial Drive Stop 7165, Grand Forks, ND 58202, USA; Department of Zoology and Physiology, University of Wyoming, 1000 E University Avenue, Laramie, WY 82071, USA; Laramie High School, 1710 Boulder Drive, Laramie, WY 82070, USA; Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, 333 Cassell Drive, Baltimore, MD 21224, USA; Department of Pathology, Johns Hopkins University School of Medicine, 725N. Wolfe Street, Baltimore, MD 21205, USA; Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, 100N. Greene St., Baltimore, MD 21201, USA; The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, 725N. Wolfe Street, Baltimore, MD 21205, USA.
| | - Amanda Johnston
- Department of Zoology and Physiology, University of Wyoming, 1000 E University Avenue, Laramie, WY 82071, USA.
| | - Hyrum P Ruby
- Department of Zoology and Physiology, University of Wyoming, 1000 E University Avenue, Laramie, WY 82071, USA.
| | - Giovanni Barbera
- Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, 333 Cassell Drive, Baltimore, MD 21224, USA.
| | - Philip C Wong
- Department of Pathology, Johns Hopkins University School of Medicine, 725N. Wolfe Street, Baltimore, MD 21205, USA; The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, 725N. Wolfe Street, Baltimore, MD 21205, USA.
| | - Zhaojie Zhang
- Department of Zoology and Physiology, University of Wyoming, 1000 E University Avenue, Laramie, WY 82071, USA.
| | - Rong Chen
- Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, 100N. Greene St., Baltimore, MD 21201, USA.
| | - Da-Ting Lin
- Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, 333 Cassell Drive, Baltimore, MD 21224, USA; The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, 725N. Wolfe Street, Baltimore, MD 21205, USA.
| | - Yun Li
- Department of Zoology and Physiology, University of Wyoming, 1000 E University Avenue, Laramie, WY 82071, USA.
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19
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Akiyama T, Koike Y, Petrucelli L, Gitler AD. Cracking the cryptic code in amyotrophic lateral sclerosis and frontotemporal dementia: Towards therapeutic targets and biomarkers. Clin Transl Med 2022; 12:e818. [PMID: 35567447 PMCID: PMC9098226 DOI: 10.1002/ctm2.818] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 03/29/2022] [Indexed: 12/19/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are two devastating human neurodegenerative diseases. A hallmark pathological feature of both diseases is the depletion of the RNA-binding protein TDP-43 from the nucleus in the brain and spinal cord of patients. A major function of TDP-43 is to repress the inclusion of cryptic exons during RNA splicing. When it becomes depleted from the nucleus in disease, this function is lost, and recently, several key cryptic splicing targets of TDP-43 have emerged, including STMN2, UNC13A, and others. UNC13A is a major ALS/FTD risk gene, and the genetic variations that increase the risk for disease seem to do so by making the gene more susceptible to cryptic exon inclusion when TDP-43 function is impaired. Here, we discuss the prospects and challenges of harnessing these cryptic splicing events as novel therapeutic targets and biomarkers. Deciphering this new cryptic code may be a touchstone for ALS and FTD diagnosis and treatment.
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Affiliation(s)
- Tetsuya Akiyama
- Department of Genetics, Stanford University School of Medicine, Stanford, California, USA
| | - Yuka Koike
- Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, USA
| | | | - Aaron D Gitler
- Department of Genetics, Stanford University School of Medicine, Stanford, California, USA.,Chan Zuckerberg Biohub, San Francisco, California, USA
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20
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Li Z, Guo W, Zeng T, Yin J, Feng K, Huang T, Cai YD. Detecting Brain Structure-Specific Methylation Signatures and Rules for Alzheimer's Disease. Front Neurosci 2022; 16:895181. [PMID: 35585924 PMCID: PMC9108872 DOI: 10.3389/fnins.2022.895181] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2022] [Accepted: 04/11/2022] [Indexed: 01/01/2023] Open
Abstract
Alzheimer's disease (AD) is a progressive disease that leads to irreversible behavioral changes, erratic emotions, and loss of motor skills. These conditions make people with AD hard or almost impossible to take care of. Multiple internal and external pathological factors may affect or even trigger the initiation and progression of AD. DNA methylation is one of the most effective regulatory roles during AD pathogenesis, and pathological methylation alterations may be potentially different in the various brain structures of people with AD. Although multiple loci associated with AD initiation and progression have been identified, the spatial distribution patterns of AD-associated DNA methylation in the brain have not been clarified. According to the systematic methylation profiles on different structural brain regions, we applied multiple machine learning algorithms to investigate such profiles. First, the profile on each brain region was analyzed by the Boruta feature filtering method. Some important methylation features were extracted and further analyzed by the max-relevance and min-redundancy method, resulting in a feature list. Then, the incremental feature selection method, incorporating some classification algorithms, adopted such list to identify candidate AD-associated loci at methylation with structural specificity, establish a group of quantitative rules for revealing the effects of DNA methylation in various brain regions (i.e., four brain structures) on AD pathogenesis. Furthermore, some efficient classifiers based on essential methylation sites were proposed to identify AD samples. Results revealed that methylation alterations in different brain structures have different contributions to AD pathogenesis. This study further illustrates the complex pathological mechanisms of AD.
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Affiliation(s)
- ZhanDong Li
- College of Food Engineering, Jilin Engineering Normal University, Changchun, China
| | - Wei Guo
- Key Laboratory of Stem Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Tao Zeng
- Bio-Med Big Data Center, CAS Key Laboratory of Computational Biology, Shanghai Institute of Nutrition and Health, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
| | - Jie Yin
- Cancer Institute, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
- Department of Human Genetics, Institute of Genetics, Zhejiang University School of Medicine, Zhejiang University, Hangzhou, China
| | - KaiYan Feng
- Department of Computer Science, Guangdong AIB Polytechnic College, Guangzhou, China
| | - Tao Huang
- Bio-Med Big Data Center, CAS Key Laboratory of Computational Biology, Shanghai Institute of Nutrition and Health, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
- CAS Key Laboratory of Tissue Microenvironment and Tumor, Shanghai Institute of Nutrition and Health, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
| | - Yu-Dong Cai
- School of Life Sciences, Shanghai University, Shanghai, China
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21
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Heo D, Ling JP, Molina-Castro GC, Langseth AJ, Waisman A, Nave KA, Möbius W, Wong PC, Bergles DE. Stage-specific control of oligodendrocyte survival and morphogenesis by TDP-43. eLife 2022; 11:75230. [PMID: 35311646 PMCID: PMC8970587 DOI: 10.7554/elife.75230] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 03/18/2022] [Indexed: 12/12/2022] Open
Abstract
Generation of oligodendrocytes in the adult brain enables both adaptive changes in neural circuits and regeneration of myelin sheaths destroyed by injury, disease, and normal aging. This transformation of oligodendrocyte precursor cells (OPCs) into myelinating oligodendrocytes requires processing of distinct mRNAs at different stages of cell maturation. Although mislocalization and aggregation of the RNA-binding protein, TDP-43, occur in both neurons and glia in neurodegenerative diseases, the consequences of TDP-43 loss within different stages of the oligodendrocyte lineage are not well understood. By performing stage-specific genetic inactivation of Tardbp in vivo, we show that oligodendrocyte lineage cells are differentially sensitive to loss of TDP-43. While OPCs depend on TDP-43 for survival, with conditional deletion resulting in cascading cell loss followed by rapid regeneration to restore their density, oligodendrocytes become less sensitive to TDP-43 depletion as they mature. Deletion of TDP-43 early in the maturation process led to eventual oligodendrocyte degeneration, seizures, and premature lethality, while oligodendrocytes that experienced late deletion survived and mice exhibited a normal lifespan. At both stages, TDP-43-deficient oligodendrocytes formed fewer and thinner myelin sheaths and extended new processes that inappropriately wrapped neuronal somata and blood vessels. Transcriptional analysis revealed that in the absence of TDP-43, key proteins involved in oligodendrocyte maturation and myelination were misspliced, leading to aberrant incorporation of cryptic exons. Inducible deletion of TDP-43 from oligodendrocytes in the adult central nervous system (CNS) induced the same progressive morphological changes and mice acquired profound hindlimb weakness, suggesting that loss of TDP-43 function in oligodendrocytes may contribute to neuronal dysfunction in neurodegenerative disease.
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Affiliation(s)
- Dongeun Heo
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, United States
| | - Jonathan P Ling
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, United States.,The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, United States
| | - Gian C Molina-Castro
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, United States
| | - Abraham J Langseth
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, United States
| | - Ari Waisman
- Institute for Molecular Medicine, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Klaus-Armin Nave
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Wiebke Möbius
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, Göttingen, Germany.,Electron Microscopy Core Unit, Max-Planck-Institute of Experimental Medicine, Göttingen, Germany
| | - Phil C Wong
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, United States
| | - Dwight E Bergles
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, United States.,Kavli Neuroscience Discovery Institute, Johns Hopkins University, Baltimore, United States
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22
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Ma XR, Prudencio M, Koike Y, Vatsavayai SC, Kim G, Harbinski F, Briner A, Rodriguez CM, Guo C, Akiyama T, Schmidt HB, Cummings BB, Wyatt DW, Kurylo K, Miller G, Mekhoubad S, Sallee N, Mekonnen G, Ganser L, Rubien JD, Jansen-West K, Cook CN, Pickles S, Oskarsson B, Graff-Radford NR, Boeve BF, Knopman DS, Petersen RC, Dickson DW, Shorter J, Myong S, Green EM, Seeley WW, Petrucelli L, Gitler AD. TDP-43 represses cryptic exon inclusion in the FTD-ALS gene UNC13A. Nature 2022; 603:124-130. [PMID: 35197626 PMCID: PMC8891019 DOI: 10.1038/s41586-022-04424-7] [Citation(s) in RCA: 173] [Impact Index Per Article: 86.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 01/13/2022] [Indexed: 02/08/2023]
Abstract
A hallmark pathological feature of the neurodegenerative diseases amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) is the depletion of RNA-binding protein TDP-43 from the nucleus of neurons in the brain and spinal cord1. A major function of TDP-43 is as a repressor of cryptic exon inclusion during RNA splicing2-4. Single nucleotide polymorphisms in UNC13A are among the strongest hits associated with FTD and ALS in human genome-wide association studies5,6, but how those variants increase risk for disease is unknown. Here we show that TDP-43 represses a cryptic exon-splicing event in UNC13A. Loss of TDP-43 from the nucleus in human brain, neuronal cell lines and motor neurons derived from induced pluripotent stem cells resulted in the inclusion of a cryptic exon in UNC13A mRNA and reduced UNC13A protein expression. The top variants associated with FTD or ALS risk in humans are located in the intron harbouring the cryptic exon, and we show that they increase UNC13A cryptic exon splicing in the face of TDP-43 dysfunction. Together, our data provide a direct functional link between one of the strongest genetic risk factors for FTD and ALS (UNC13A genetic variants), and loss of TDP-43 function.
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Affiliation(s)
- X Rosa Ma
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Mercedes Prudencio
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA
- Neuroscience Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, FL, USA
| | - Yuka Koike
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA
- Neuroscience Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, FL, USA
| | - Sarat C Vatsavayai
- Department of Neurology, University of California San Francisco, San Francisco, CA, USA
- Department of Pathology, University of California San Francisco, San Francisco, CA, USA
| | - Garam Kim
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
- Neurosciences Interdepartmental Program, Stanford University School of Medicine, Stanford, CA, USA
| | | | - Adam Briner
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
- Clem Jones Centre for Ageing Dementia Research (CJCADR), Queensland Brain Institute (QBI), The University of Queensland, Brisbane, Queensland, Australia
| | - Caitlin M Rodriguez
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Caiwei Guo
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Tetsuya Akiyama
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - H Broder Schmidt
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA, USA
| | | | | | | | | | | | | | - Gemechu Mekonnen
- Program in Cell, Molecular, Developmental Biology, and Biophysics, Johns Hopkins University, Baltimore, MD, USA
- Department of Biology, Johns Hopkins University, Baltimore, MD, USA
| | - Laura Ganser
- Department of Biophysics, Johns Hopkins University, Baltimore, MD, USA
| | - Jack D Rubien
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | | | - Casey N Cook
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA
- Neuroscience Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, FL, USA
| | - Sarah Pickles
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA
- Neuroscience Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, FL, USA
| | | | | | | | | | | | - Dennis W Dickson
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA
- Neuroscience Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, FL, USA
| | - James Shorter
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Sua Myong
- Program in Cell, Molecular, Developmental Biology, and Biophysics, Johns Hopkins University, Baltimore, MD, USA
- Department of Biology, Johns Hopkins University, Baltimore, MD, USA
- Department of Biophysics, Johns Hopkins University, Baltimore, MD, USA
| | | | - William W Seeley
- Department of Neurology, University of California San Francisco, San Francisco, CA, USA
- Department of Pathology, University of California San Francisco, San Francisco, CA, USA
| | - Leonard Petrucelli
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA.
- Neuroscience Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, FL, USA.
| | - Aaron D Gitler
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA.
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23
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Versluys L, Ervilha Pereira P, Schuermans N, De Paepe B, De Bleecker JL, Bogaert E, Dermaut B. Expanding the TDP-43 Proteinopathy Pathway From Neurons to Muscle: Physiological and Pathophysiological Functions. Front Neurosci 2022; 16:815765. [PMID: 35185458 PMCID: PMC8851062 DOI: 10.3389/fnins.2022.815765] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 01/03/2022] [Indexed: 01/02/2023] Open
Abstract
TAR DNA-binding protein 43, mostly referred to as TDP-43 (encoded by the TARDBP gene) is strongly linked to the pathogenesis of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). From the identification of TDP-43 positive aggregates in the brains and spinal cords of ALS/FTD patients, to a genetic link between TARBDP mutations and the development of TDP-43 pathology in ALS, there is strong evidence indicating that TDP-43 plays a pivotal role in the process of neuronal degeneration. What this role is, however, remains to be determined with evidence ranging from gain of toxic properties through the formation of cytotoxic aggregates, to an inability to perform its normal functions due to nuclear depletion. To add to an already complex subject, recent studies highlight a role for TDP-43 in muscle physiology and disease. We here review the biophysical, biochemical, cellular and tissue-specific properties of TDP-43 in the context of neurodegeneration and have a look at the nascent stream of evidence that positions TDP-43 in a myogenic context. By integrating the neurogenic and myogenic pathological roles of TDP-43 we provide a more comprehensive and encompassing view of the role and mechanisms associated with TDP-43 across the various cell types of the motor system, all the way from brain to limbs.
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Affiliation(s)
- Lauren Versluys
- Department Biomolecular Medicine, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | - Pedro Ervilha Pereira
- Department Biomolecular Medicine, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | - Nika Schuermans
- Department Biomolecular Medicine, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | - Boel De Paepe
- Department of Neurology and Neuromuscular Reference Center, Ghent University Hospital, Ghent, Belgium
- Department of Head and Skin, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
| | - Jan L. De Bleecker
- Department of Neurology and Neuromuscular Reference Center, Ghent University Hospital, Ghent, Belgium
- Department of Head and Skin, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
| | - Elke Bogaert
- Department Biomolecular Medicine, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | - Bart Dermaut
- Department Biomolecular Medicine, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
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24
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Britson KA, Ling JP, Braunstein KE, Montagne JM, Kastenschmidt JM, Wilson A, Ikenaga C, Tsao W, Pinal-Fernandez I, Russell KA, Reed N, Mozaffar T, Wagner KR, Ostrow LW, Corse AM, Mammen AL, Villalta SA, Larman HB, Wong PC, Lloyd TE. Loss of TDP-43 function and rimmed vacuoles persist after T cell depletion in a xenograft model of sporadic inclusion body myositis. Sci Transl Med 2022; 14:eabi9196. [PMID: 35044790 PMCID: PMC9118725 DOI: 10.1126/scitranslmed.abi9196] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Sporadic inclusion body myositis (IBM) is the most common acquired muscle disease in adults over age 50, yet it remains unclear whether the disease is primarily driven by T cell–mediated autoimmunity. IBM muscle biopsies display nuclear clearance and cytoplasmic aggregation of TDP-43 in muscle cells, a pathologic finding observed initially in neurodegenerative diseases, where nuclear loss of TDP-43 in neurons causes aberrant RNA splicing. Here, we show that loss of TDP-43–mediated splicing repression, as determined by inclusion of cryptic exons, occurs in skeletal muscle of subjects with IBM. Of 119 muscle biopsies tested, RT-PCR–mediated detection of cryptic exon inclusion was able to diagnose IBM with 84% sensitivity and 99% specificity. To determine the role of T cells in pathogenesis, we generated a xenograft model by transplanting human IBM muscle into the hindlimb of immunodeficient mice. Xenografts from subjects with IBM displayed robust regeneration of human myofibers and recapitulated both inflammatory and degenerative features of the disease. Myofibers in IBM xenografts showed invasion by human, oligoclonal CD8+ T cells and exhibited MHC-I up-regulation, rimmed vacuoles, mitochondrial pathology, p62-positive inclusions, and nuclear clearance and cytoplasmic aggregation of TDP-43, associated with cryptic exon inclusion. Reduction of human T cells within IBM xenografts by treating mice intraperitoneally with anti-CD3 (OKT3) suppressed MHC-I up-regulation. However, rimmed vacuoles and loss of TDP-43 function persisted. These data suggest that T cell depletion does not alter muscle degenerative pathology in IBM.
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Affiliation(s)
- Kyla A. Britson
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Jonathan P. Ling
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Kerstin E. Braunstein
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Janelle M. Montagne
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Jenna M. Kastenschmidt
- Department of Physiology and Biophysics, Institute for Immunology, University of California Irvine, Irvine, CA 92697, USA
| | - Andrew Wilson
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Chiseko Ikenaga
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - William Tsao
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Iago Pinal-Fernandez
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Muscle Disease Unit, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Katelyn A. Russell
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Nicole Reed
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Tahseen Mozaffar
- Institute for Immunology, Department of Neurology, University of California Irvine, Irvine, CA 92697, USA
| | - Kathryn R. Wagner
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Center for Genetic Muscle Disorders, Kennedy Krieger Institute, Baltimore, MD 21205, USA
| | - Lyle W. Ostrow
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Andrea M. Corse
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Andrew L. Mammen
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Muscle Disease Unit, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - S. Armando Villalta
- Department of Physiology and Biophysics, Institute for Immunology, University of California Irvine, Irvine, CA 92697, USA
| | - H. Benjamin Larman
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Philip C. Wong
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Solomon H. Synder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Thomas E. Lloyd
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Solomon H. Synder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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25
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Meneses A, Koga S, O’Leary J, Dickson DW, Bu G, Zhao N. TDP-43 Pathology in Alzheimer’s Disease. Mol Neurodegener 2021; 16:84. [PMID: 34930382 PMCID: PMC8691026 DOI: 10.1186/s13024-021-00503-x] [Citation(s) in RCA: 86] [Impact Index Per Article: 28.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 11/21/2021] [Indexed: 12/05/2022] Open
Abstract
Transactive response DNA binding protein of 43 kDa (TDP-43) is an intranuclear protein encoded by the TARDBP gene that is involved in RNA splicing, trafficking, stabilization, and thus, the regulation of gene expression. Cytoplasmic inclusion bodies containing phosphorylated and truncated forms of TDP-43 are hallmarks of amyotrophic lateral sclerosis (ALS) and a subset of frontotemporal lobar degeneration (FTLD). Additionally, TDP-43 inclusions have been found in up to 57% of Alzheimer’s disease (AD) cases, most often in a limbic distribution, with or without hippocampal sclerosis. In some cases, TDP-43 deposits are also found in neurons with neurofibrillary tangles. AD patients with TDP-43 pathology have increased severity of cognitive impairment compared to those without TDP-43 pathology. Furthermore, the most common genetic risk factor for AD, apolipoprotein E4 (APOE4), is associated with increased frequency of TDP-43 pathology. These findings provide strong evidence that TDP-43 pathology is an integral part of multiple neurodegenerative conditions, including AD. Here, we review the biology and pathobiology of TDP-43 with a focus on its role in AD. We emphasize the need for studies on the mechanisms that lead to TDP-43 pathology, especially in the setting of age-related disorders such as AD.
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26
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Aldalaqan S, Dalgliesh C, Luzzi S, Siachisumo C, Reynard LN, Ehrmann I, Elliott DJ. Cryptic splicing: common pathological mechanisms involved in male infertility and neuronal diseases. Cell Cycle 2021; 21:219-227. [PMID: 34927545 PMCID: PMC8855859 DOI: 10.1080/15384101.2021.2015672] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
High levels of transcription and alternative splicing are recognized hallmarks of gene expression in the testis and largely driven by cells in meiosis. Because of this, the male meiosis stage of the cell cycle is often viewed as having a relatively permissive environment for gene expression. In this review, we highlight recent findings that identify the RNA binding protein RBMXL2 as essential for male meiosis. RBMXL2 functions as a “guardian of the transcriptome” that protects against the use of aberrant (or “cryptic”) splice sites that would disrupt gene expression. This newly discovered protective role during meiosis links with a wider field investigating mechanisms of cryptic splicing control that protect neurons from amyotrophic lateral sclerosis and Alzheimer’s disease. We discuss how the mechanism repressing cryptic splicing patterns during meiosis evolved, and why it may be essential for sperm production and male fertility.
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Affiliation(s)
- Saad Aldalaqan
- Newcastle University Bioscience Institute, Newcastle University, Central Parkway Newcastle, UK
| | - Caroline Dalgliesh
- Newcastle University Bioscience Institute, Newcastle University, Central Parkway Newcastle, UK
| | - Sara Luzzi
- Newcastle University Bioscience Institute, Newcastle University, Central Parkway Newcastle, UK
| | - Chileleko Siachisumo
- Newcastle University Bioscience Institute, Newcastle University, Central Parkway Newcastle, UK
| | - Louise N Reynard
- Newcastle University Bioscience Institute, Newcastle University, Central Parkway Newcastle, UK
| | - Ingrid Ehrmann
- Newcastle University Bioscience Institute, Newcastle University, Central Parkway Newcastle, UK
| | - David J Elliott
- Newcastle University Bioscience Institute, Newcastle University, Central Parkway Newcastle, UK
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27
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S-nitrosylated TDP-43 triggers aggregation, cell-to-cell spread, and neurotoxicity in hiPSCs and in vivo models of ALS/FTD. Proc Natl Acad Sci U S A 2021; 118:2021368118. [PMID: 33692125 DOI: 10.1073/pnas.2021368118] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Rare genetic mutations result in aggregation and spreading of cognate proteins in neurodegenerative disorders; however, in the absence of mutation (i.e., in the vast majority of "sporadic" cases), mechanisms for protein misfolding/aggregation remain largely unknown. Here, we show environmentally induced nitrosative stress triggers protein aggregation and cell-to-cell spread. In patient brains with amyotrophic lateral sclerosis (ALS)/frontotemporal dementia (FTD), aggregation of the RNA-binding protein TDP-43 constitutes a major component of aberrant cytoplasmic inclusions. We identify a pathological signaling cascade whereby reactive nitrogen species cause S-nitrosylation of TDP-43 (forming SNO-TDP-43) to facilitate disulfide linkage and consequent TDP-43 aggregation. Similar pathological SNO-TDP-43 levels occur in postmortem human FTD/ALS brains and in cell-based models, including human-induced pluripotent stem cell (hiPSC)-derived neurons. Aggregated TDP-43 triggers additional nitrosative stress, representing positive feed forward leading to further SNO-TDP-43 formation and disulfide-linked oligomerization/aggregation. Critically, we show that these redox reactions facilitate cell spreading in vivo and interfere with the TDP-43 RNA-binding activity, affecting SNMT1 and phospho-(p)CREB levels, thus contributing to neuronal damage in ALS/FTD disorders.
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28
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White B, Lyketsos CG, Rosenberg PB, Oh ES, Chen L. Multiple Neurodegenerative Pathologies in an Alzheimer's Disease Patient Treated with Fornical Deep Brain Stimulation. J Alzheimers Dis 2021; 80:1383-1387. [PMID: 33682715 DOI: 10.3233/jad-201415] [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: 11/15/2022]
Abstract
As an established treatment for movement disorders, deep brain stimulation (DBS) has been adapted for the treatment of Alzheimer's disease (AD) by modulating fornix activity. Although it is generally regarded as a safe intervention in patients over 65 years of age, the complex neurophysiology and interconnection within circuits connected to the fornix warrants a careful ongoing evaluation of the true benefit and risk potential of DBS on slowing cognitive decline in AD patients. Here we report on a patient who died long after being implanted with a DBS device who donated her brain for neuropathologic study. The autopsy confirmed multiple proteinopathies including AD-related change, diffuse neocortical Lewy body disease, TDP-43 proteinopathy, and a nonspecific tauopathy. We discuss the possible mechanisms of these overlapping neurodegenerative disorders and caution that future studies of DBS for AD will need to take these findings into consideration.
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Affiliation(s)
- Bartholomew White
- Department of Pathology, Johns Hopkins School of Medicine, Baltimore, MD, USA.,Current affiliation: Department of Pathology, Emory School of Medicine, Atlanta, GA, USA
| | - Constantine G Lyketsos
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Paul B Rosenberg
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Esther S Oh
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins School of Medicine, Baltimore, MD, USA.,Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Liam Chen
- Department of Pathology, Johns Hopkins School of Medicine, Baltimore, MD, USA.,Current affiliation: Department of Laboratory Medicine and Pathology, University of Minnesota Medical School, Minneapolis, MN, USA
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29
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Hicks DA. TDP-43 and amyloid precursor protein processing: implications for Alzheimer's disease. Neural Regen Res 2021; 16:1402-1403. [PMID: 33318427 PMCID: PMC8284272 DOI: 10.4103/1673-5374.300983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Affiliation(s)
- David A Hicks
- Division of Neuroscience and Experimental Psychology, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester; Current address: RBMOnline, Bourn Hall, Bourn, Cambridge, UK
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30
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Chen L. The important functional role of TDP-43 plays in amyotrophic lateral sclerosis-frontotemporal dementia. Neural Regen Res 2021; 16:682-683. [PMID: 33063724 PMCID: PMC8067922 DOI: 10.4103/1673-5374.293142] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Affiliation(s)
- Liam Chen
- Neuropathology Division, Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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31
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Yang HS, White CC, Klein HU, Yu L, Gaiteri C, Ma Y, Felsky D, Mostafavi S, Petyuk VA, Sperling RA, Ertekin-Taner N, Schneider JA, Bennett DA, De Jager PL. Genetics of Gene Expression in the Aging Human Brain Reveal TDP-43 Proteinopathy Pathophysiology. Neuron 2020; 107:496-508.e6. [PMID: 32526197 PMCID: PMC7416464 DOI: 10.1016/j.neuron.2020.05.010] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 03/20/2020] [Accepted: 05/07/2020] [Indexed: 12/14/2022]
Abstract
Here, we perform a genome-wide screen for variants that regulate the expression of gene co-expression modules in the aging human brain; we discover and replicate such variants in the TMEM106B and RBFOX1 loci. The TMEM106B haplotype is known to influence the accumulation of TAR DNA-binding protein 43 kDa (TDP-43) proteinopathy, and the haplotype's large-scale transcriptomic effects include the dysregulation of lysosomal genes and alterations in synaptic gene splicing that are also seen in the pathophysiology of TDP-43 proteinopathy. Further, a variant near GRN, another TDP-43 proteinopathy susceptibility gene, shows concordant effects with the TMEM106B haplotype. Leveraging neuropathology data from the same participants, we also show that TMEM106B and APOE-amyloid-β effects converge to alter myelination and lysosomal gene expression, which then contributes to TDP-43 accumulation. These results advance our mechanistic understanding of the TMEM106B TDP-43 risk haplotype and uncover a transcriptional program that mediates the converging effects of APOE-amyloid-β and TMEM106B on TDP-43 aggregation in older adults.
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Affiliation(s)
- Hyun-Sik Yang
- Center for Alzheimer Research and Treatment, Department of Neurology, Brigham and Women's Hospital, Boston, MA 02115, USA; Department of Neurology, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Neurology, Harvard Medical School, Boston, MA 02115, USA; The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Charles C White
- The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Center for Translational and Computational Neuroimmunology, Department of Neurology, Columbia University Irving Medical Center, New York, NY 10032, USA; Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Hans-Ulrich Klein
- The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Center for Translational and Computational Neuroimmunology, Department of Neurology, Columbia University Irving Medical Center, New York, NY 10032, USA; Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Lei Yu
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL 60612, USA; Department of Neurological Sciences, Rush University Medical Center, Chicago, IL 60612, USA
| | - Christopher Gaiteri
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL 60612, USA; Department of Neurological Sciences, Rush University Medical Center, Chicago, IL 60612, USA
| | - Yiyi Ma
- The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Center for Translational and Computational Neuroimmunology, Department of Neurology, Columbia University Irving Medical Center, New York, NY 10032, USA; Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Daniel Felsky
- The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Center for Translational and Computational Neuroimmunology, Department of Neurology, Columbia University Irving Medical Center, New York, NY 10032, USA; Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Sara Mostafavi
- Department of Statistics, Department of Medical Genetics, University of British Columbia, Vancouver, BC V6H 3N1, Canada; Canadian Institute for Advanced Research, Toronto, ON M5G 1M1, Canada
| | | | - Reisa A Sperling
- Center for Alzheimer Research and Treatment, Department of Neurology, Brigham and Women's Hospital, Boston, MA 02115, USA; Department of Neurology, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Neurology, Harvard Medical School, Boston, MA 02115, USA
| | - Nilüfer Ertekin-Taner
- Department of Neurology, Mayo Clinic, Jacksonville, FL 32224, USA; Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224, USA
| | - Julie A Schneider
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL 60612, USA; Department of Neurological Sciences, Rush University Medical Center, Chicago, IL 60612, USA
| | - David A Bennett
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL 60612, USA; Department of Neurological Sciences, Rush University Medical Center, Chicago, IL 60612, USA
| | - Philip L De Jager
- The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Center for Translational and Computational Neuroimmunology, Department of Neurology, Columbia University Irving Medical Center, New York, NY 10032, USA; Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY 10032, USA.
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32
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Torres P, Andrés-Benito P, Fernàndez-Bernal A, Ricart M, Ayala V, Pamplona R, Ferrer I, Portero-Otin M. Selected cryptic exons accumulate in hippocampal cell nuclei in Alzheimer's disease with and without associated TDP-43 proteinopathy. Brain 2020; 143:e20. [PMID: 32016361 DOI: 10.1093/brain/awaa013] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Affiliation(s)
- Pascual Torres
- Department of Experimental Medicine, IRBLleida, University of Lleida, Lleida, Spain
| | - Pol Andrés-Benito
- Department of Pathology and Experimental Therapeutics, University of Barcelona, Barcelona, Spain.,CIBERNED (Network Centre of Biomedical Research of Neurodegenerative Diseases), Institute of Health Carlos III, Ministry of Economy and Competitiveness, Barcelona, Spain.,Bellvitge Biomedical Research Institute (IDIBELL), Hospitalet de Llobregat, Barcelona, Spain
| | | | - Marta Ricart
- Department of Experimental Medicine, IRBLleida, University of Lleida, Lleida, Spain
| | - Victòria Ayala
- Department of Experimental Medicine, IRBLleida, University of Lleida, Lleida, Spain
| | - Reinald Pamplona
- Department of Experimental Medicine, IRBLleida, University of Lleida, Lleida, Spain
| | - Isidro Ferrer
- Department of Pathology and Experimental Therapeutics, University of Barcelona, Barcelona, Spain.,CIBERNED (Network Centre of Biomedical Research of Neurodegenerative Diseases), Institute of Health Carlos III, Ministry of Economy and Competitiveness, Barcelona, Spain.,Bellvitge Biomedical Research Institute (IDIBELL), Hospitalet de Llobregat, Barcelona, Spain.,Senior Consultant, Bellvitge University Hospital, Barcelona, Spain.,Institute of Neurosciences, University of Barcelona, Barcelona, Spain
| | - Manuel Portero-Otin
- Department of Experimental Medicine, IRBLleida, University of Lleida, Lleida, Spain
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33
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Sackmann C, Sackmann V, Hallbeck M. TDP-43 Is Efficiently Transferred Between Neuron-Like Cells in a Manner Enhanced by Preservation of Its N-Terminus but Independent of Extracellular Vesicles. Front Neurosci 2020; 14:540. [PMID: 32595443 PMCID: PMC7301158 DOI: 10.3389/fnins.2020.00540] [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: 10/12/2019] [Accepted: 05/01/2020] [Indexed: 12/12/2022] Open
Abstract
The misfolding of transactive response DNA-binding protein (TDP-43) is a major contributor to the pathogenesis of TDP-43 proteinopathies, including amyotrophic lateral sclerosis and frontotemporal lobar degeneration with TDP-43 inclusions, but also plays a role in other neurodegenerative diseases including Alzheimer disease. It is thought that different truncations at the N- and C-termini of TDP-43 contribute to its misfolding and aggregation in the brain, and that these aberrant TDP-43 fragments contribute to disease. Despite this, little is known about whether different truncation events influence the protein’s transmissibility between cells and how this cell-to-cell transfer occurs. In this study, we use a well-established cellular model to study the efficiency by which full-length and truncated TDP-43 fragments are transferred between neuron-like cells. We demonstrate that preservation of the N-terminus of TDP-43 enhances its transmissibility between cells and that this protein transmission occurs in a manner exclusive of extracellular vesicles, instead requiring cellular proximity for efficient propagation. These data indicate that the N-terminus of TDP-43 might be a useful target in the generation of therapeutics to limit the spread of TDP-43 pathology.
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Affiliation(s)
- Christopher Sackmann
- Department of Clinical Pathology, Linköping University, Linköping, Sweden.,Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Valerie Sackmann
- Department of Clinical Pathology, Linköping University, Linköping, Sweden.,Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Martin Hallbeck
- Department of Clinical Pathology, Linköping University, Linköping, Sweden.,Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
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34
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Donde A, Sun M, Jeong YH, Wen X, Ling J, Lin S, Braunstein K, Nie S, Wang S, Chen L, Wong PC. Upregulation of ATG7 attenuates motor neuron dysfunction associated with depletion of TARDBP/TDP-43. Autophagy 2020; 16:672-682. [PMID: 31242080 PMCID: PMC7138241 DOI: 10.1080/15548627.2019.1635379] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 05/29/2019] [Accepted: 06/20/2019] [Indexed: 12/12/2022] Open
Abstract
A shared neuropathological hallmark in amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) is nuclear clearance and cytoplasmic aggregation of TARDBP/TDP-43 (TAR DNA binding protein). We previously showed that the ability of TARDBP to repress nonconserved cryptic exons was impaired in brains of patients with ALS and FTD, suggesting that its nuclear depletion contributes to neurodegeneration. However, the critical pathways impacted by the failure to repress cryptic exons that may contribute to neurodegeneration remain undefined. Here, we report that transcriptome analysis of TARDBP-deficient neurons revealed downregulation of ATG7, a critical gene required for macroautophagy/autophagy. Mouse and Drosophila models lacking TARDBP/TBPH in motor neurons exhibiting age-dependent neurodegeneration and motor deficits showed reduction of ATG7 and accumulation of SQSTM1/p62 inclusions. Importantly, genetic upregulation of the autophagy pathway improved motor function and survival in TBPH-deficient flies. Together with our observation that ATG7 is reduced in ALS-FTD brain tissues, these findings identify the autophagy pathway as one key effector of nuclear depletion of TARDBP that contributes to neurodegeneration. We thus suggest that the autophagy pathway is a therapeutic target for ALS-FTD and other disorders exhibiting TARDBP pathology.Abbreviations: ALS: amyotrophic lateral sclerosis; ANOVA: analysis of variance; ChAT: choline acetyltransferase; CTSD: cathepsin D; FTD: frontotemporal dementia; LAMP1: lysosomal associated membrane protein 1; NMJ: neuromuscular junction; RBFOX3/NeuN: RNA binding fox-1 homolog 3; SQSTM1: sequestosome 1; TARDBP/TDP-43: TAR DNA binding protein 43.
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Affiliation(s)
- Aneesh Donde
- Departments of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Mingkuan Sun
- Departments of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Yun Ha Jeong
- Departments of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Neural Development and Disease, Korea Brain Research Institute (KBRI), Daegu, Korea
| | - Xinrui Wen
- Departments of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jonathan Ling
- Departments of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Sophie Lin
- Departments of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Kerstin Braunstein
- Departments of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Shuke Nie
- Departments of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Sheng Wang
- Departments of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Liam Chen
- Departments of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Philip C. Wong
- Departments of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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35
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Splicing repression is a major function of TDP-43 in motor neurons. Acta Neuropathol 2019; 138:813-826. [PMID: 31332509 DOI: 10.1007/s00401-019-02042-8] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 07/07/2019] [Accepted: 07/07/2019] [Indexed: 02/08/2023]
Abstract
Nuclear depletion of TDP-43, an essential RNA binding protein, may underlie neurodegeneration in amyotrophic lateral sclerosis (ALS). As several functions have been ascribed to this protein, the critical role(s) of TDP-43 in motor neurons that may be compromised in ALS remains unknown. We show here that TDP-43 mediated splicing repression, which serves to protect the transcriptome by preventing aberrant splicing, is central to the physiology of motor neurons. Expression in Drosophila TDP-43 knockout models of a chimeric repressor, comprised of the RNA recognition domain of TDP-43 fused to an unrelated splicing repressor, RAVER1, attenuated motor deficits and extended lifespan. Likewise, AAV9-mediated delivery of this chimeric rescue repressor to mice lacking TDP-43 in motor neurons delayed the onset, slowed the progression of motor symptoms, and markedly extended their lifespan. In treated mice lacking TDP-43 in motor neurons, aberrant splicing was significantly decreased and accompanied by amelioration of axon degeneration and motor neuron loss. This AAV9 strategy allowed long-term expression of the chimeric repressor without any adverse effects. Our findings establish that splicing repression is a major function of TDP-43 in motor neurons and strongly support the idea that loss of TDP-43-mediated splicing fidelity represents a key pathogenic mechanism underlying motor neuron loss in ALS.
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36
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Koza P, Beroun A, Konopka A, Górkiewicz T, Bijoch L, Torres JC, Bulska E, Knapska E, Kaczmarek L, Konopka W. Neuronal TDP-43 depletion affects activity-dependent plasticity. Neurobiol Dis 2019; 130:104499. [PMID: 31176717 DOI: 10.1016/j.nbd.2019.104499] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 05/15/2019] [Accepted: 06/05/2019] [Indexed: 12/14/2022] Open
Abstract
TAR DNA-binding protein 43 (TDP-43) is a hallmark of some neurodegenerative disorders, such as frontotemporal lobar degeneration and amyotrophic lateral sclerosis. TDP-43-related pathology is characterized by its abnormally phosphorylated and ubiquitinated aggregates. It is involved in many aspects of RNA processing, including mRNA splicing, transport, and translation. However, its exact physiological function and role in mechanisms that lead to neuronal degeneration remain elusive. Transgenic rats that were characterized by TDP-43 depletion in neurons exhibited enhancement of the acquisition of fear memory. At the cellular level, TDP-43-depleted neurons exhibited a decrease in the short-term plasticity of intrinsic neuronal excitability. The induction of long-term potentiation in the CA3-CA1 areas of the hippocampus resulted in more stable synaptic enhancement. At the molecular level, the protein levels of an unedited (R) FLOP variant of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) GluR1 and GluR2/3 subunits decreased in the hippocampus. Alterations of FLOP/FLIP subunit composition affected AMPAR kinetics, reflected by cyclothiazide-dependent slowing of the decay time of AMPAR-mediated miniature excitatory postsynaptic currents. These findings suggest that TDP-43 may regulate activity-dependent neuronal plasticity, possibly by regulating the splicing of genes that are responsible for fast synaptic transmission and membrane potential.
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Affiliation(s)
- Paulina Koza
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
| | - Anna Beroun
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
| | - Anna Konopka
- Biological and Chemical Research Centre, Faculty of Chemistry, University of Warsaw, Warsaw, Poland
| | - Tomasz Górkiewicz
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
| | - Lukasz Bijoch
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
| | - Julio C Torres
- Biological and Chemical Research Centre, Faculty of Chemistry, University of Warsaw, Warsaw, Poland
| | - Ewa Bulska
- Biological and Chemical Research Centre, Faculty of Chemistry, University of Warsaw, Warsaw, Poland
| | - Ewelina Knapska
- BRAINCITY, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
| | - Leszek Kaczmarek
- BRAINCITY, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland.
| | - Witold Konopka
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland.
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37
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Ehrmann I, Crichton JH, Gazzara MR, James K, Liu Y, Grellscheid SN, Curk T, de Rooij D, Steyn JS, Cockell S, Adams IR, Barash Y, Elliott DJ. An ancient germ cell-specific RNA-binding protein protects the germline from cryptic splice site poisoning. eLife 2019; 8:39304. [PMID: 30674417 PMCID: PMC6345566 DOI: 10.7554/elife.39304] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 12/18/2018] [Indexed: 12/28/2022] Open
Abstract
Male germ cells of all placental mammals express an ancient nuclear RNA binding protein of unknown function called RBMXL2. Here we find that deletion of the retrogene encoding RBMXL2 blocks spermatogenesis. Transcriptome analyses of age-matched deletion mice show that RBMXL2 controls splicing patterns during meiosis. In particular, RBMXL2 represses the selection of aberrant splice sites and the insertion of cryptic and premature terminal exons. Our data suggest a Rbmxl2 retrogene has been conserved across mammals as part of a splicing control mechanism that is fundamentally important to germ cell biology. We propose that this mechanism is essential to meiosis because it buffers the high ambient concentrations of splicing activators, thereby preventing poisoning of key transcripts and disruption to gene expression by aberrant splice site selection. In humans and other mammals, a sperm from a male fuses with an egg cell from a female to produce an embryo that may ultimately grow into a new individual. Sperm and egg cells are made when certain cells in the body divide in a process called meiosis. Many proteins are required for meiosis to happen and these proteins are made using instructions provided by genes, which are made of a molecule called DNA. The DNA within a gene is transcribed to make molecules of ribonucleic acid (or RNA for short). The cell then modifies many of these RNAs in a process called splicing before using them as templates to make proteins. During splicing, segments of RNA known as introns are discarded and other segments termed exons are joined together. Some exons may also be removed from RNAs in different combinations to create different proteins from the same gene. A protein called RBMXL2 is able to bind to RNA molecules and is only made during and after meiosis in humans and most other mammals. RBMXL2 can also bind to other proteins that are known to be involved in controlling splicing of RNAs, but its role in splicing remains unclear. To address this question, Ehrmann et al. studied the gene that encodes the RBMXL2 protein in mice. Removing this gene prevented male mice from being able to make sperm. Further experiments using a technique called RNA sequencing showed that the RBMXL2 protein helps to ensure that splicing happens correctly by preventing bits of exons and introns in mouse genes from being rearranged. These findings suggest that the gene encoding RBMXL2 is part of a splicing control mechanism that is important for making sperm and egg cells. The work of Ehrmann et al. could eventually help some couples understand why they have problems conceiving children. Male infertility is poorly understood, and not knowing its causes can harm the mental health of affected men. Furthermore, these findings may help researchers to understand the role of a closely related protein called RBMY that has also been linked to infertility in men, but is much more difficult to study.
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Affiliation(s)
- Ingrid Ehrmann
- Institute of Genetic Medicine, Newcastle University, Newcastle, United Kingdom
| | - James H Crichton
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Matthew R Gazzara
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States.,Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States
| | - Katherine James
- Life Sciences, Natural History Museum, London, United Kingdom
| | - Yilei Liu
- Institute of Genetic Medicine, Newcastle University, Newcastle, United Kingdom.,Department of Plant and Microbial Biology, University of Zürich, Zürich, Switzerland
| | - Sushma Nagaraja Grellscheid
- Institute of Genetic Medicine, Newcastle University, Newcastle, United Kingdom.,School of Biological and Biomedical Sciences, University of Durham, Durham, United Kingdom
| | - Tomaž Curk
- Laboratory of Bioinformatics, Faculty of Computer and Information Sciences, University of Ljubljana, Ljubljana, Slovenia
| | - Dirk de Rooij
- Reproductive Biology Group, Division of Developmental Biology, Department of Biology, Faculty of Science, Utrecht University, Utrecht, The Netherlands.,Center for Reproductive Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Jannetta S Steyn
- Bioinformatics Support Unit, Faculty of Medical Sciences, Newcastle University, Newcastle, United Kingdom
| | - Simon Cockell
- Bioinformatics Support Unit, Faculty of Medical Sciences, Newcastle University, Newcastle, United Kingdom
| | - Ian R Adams
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Yoseph Barash
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States.,Department of Computer and Information Science, University of Pennsylvania, Philadelphia, United States
| | - David J Elliott
- Institute of Genetic Medicine, Newcastle University, Newcastle, United Kingdom
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38
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Premature polyadenylation-mediated loss of stathmin-2 is a hallmark of TDP-43-dependent neurodegeneration. Nat Neurosci 2019; 22:180-190. [PMID: 30643298 PMCID: PMC6348009 DOI: 10.1038/s41593-018-0293-z] [Citation(s) in RCA: 282] [Impact Index Per Article: 56.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 11/13/2018] [Indexed: 12/11/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are associated with loss of nuclear TDP-43. Here we identify that TDP-43 regulates expression of the neuronal growth-associated factor stathmin-2. Lowered TDP-43 levels, which reduce its binding to sites within the first intron of stathmin-2 pre-mRNA, uncover a cryptic polyadenylation site whose utilization produces a truncated, non-functional mRNA. Reduced stathmin-2 expression is found in neurons trans-differentiated from patient fibroblasts expressing an ALS-causing TDP-43 mutation, in motor cortex and spinal motor neurons from sporadic ALS patients and familial ALS patients with expansion in C9orf72, and in induced pluripotent stem cell (iPSC)-derived motor neurons depleted of TDP-43. Remarkably, while reduction in TDP-43 is shown to inhibit axonal regeneration of iPSC-derived motor neurons, rescue of stathmin-2 expression restores axonal regenerative capacity. Thus, premature polyadenylation-mediated reduction in stathmin-2 is a hallmark of ALS/FTD that functionally links reduced nuclear TDP-43 function to enhanced neuronal vulnerability.
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39
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Vatsavayai SC, Nana AL, Yokoyama JS, Seeley WW. C9orf72-FTD/ALS pathogenesis: evidence from human neuropathological studies. Acta Neuropathol 2019; 137:1-26. [PMID: 30368547 DOI: 10.1007/s00401-018-1921-0] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 10/16/2018] [Accepted: 10/16/2018] [Indexed: 12/11/2022]
Abstract
What are the most important and treatable pathogenic mechanisms in C9orf72-FTD/ALS? Model-based efforts to address this question are forging ahead at a blistering pace, often with conflicting results. But what does the human neuropathological literature reveal? Here, we provide a critical review of the human studies to date, seeking to highlight key gaps or uncertainties in our knowledge. First, we engage the C9orf72-specific mechanisms, including C9orf72 haploinsufficiency, repeat RNA foci, and dipeptide repeat protein inclusions. We then turn to some of the most prominent C9orf72-associated features, such as TDP-43 loss-of-function, TDP-43 aggregation, and nuclear transport defects. Finally, we review potential disease-modifying epigenetic and genetic factors and the natural history of the disease across the lifespan. Throughout, we emphasize the importance of anatomical precision when studying how candidate mechanisms relate to neuronal, regional, and behavioral findings. We further highlight methodological approaches that may help address lingering knowledge gaps and uncertainties, as well as other logical next steps for the field. We conclude that anatomically oriented human neuropathological studies have a critical role to play in guiding this fast-moving field toward effective new therapies.
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Affiliation(s)
- Sarat C Vatsavayai
- Memory and Aging Center, Department of Neurology, University of California, San Francisco, USA
| | - Alissa L Nana
- Memory and Aging Center, Department of Neurology, University of California, San Francisco, USA
| | - Jennifer S Yokoyama
- Memory and Aging Center, Department of Neurology, University of California, San Francisco, USA
| | - William W Seeley
- Memory and Aging Center, Department of Neurology, University of California, San Francisco, USA.
- Department of Pathology, University of California, San Francisco, Box 1207, San Francisco, CA, 94143-1207, USA.
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40
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Nana AL, Sidhu M, Gaus SE, Hwang JHL, Li L, Park Y, Kim EJ, Pasquini L, Allen IE, Rankin KP, Toller G, Kramer JH, Geschwind DH, Coppola G, Huang EJ, Grinberg LT, Miller BL, Seeley WW. Neurons selectively targeted in frontotemporal dementia reveal early stage TDP-43 pathobiology. Acta Neuropathol 2019; 137:27-46. [PMID: 30511086 DOI: 10.1007/s00401-018-1942-8] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 11/22/2018] [Accepted: 11/23/2018] [Indexed: 12/26/2022]
Abstract
TAR DNA-binding protein 43 (TDP-43) aggregation is the most common pathological hallmark in frontotemporal dementia (FTD) and characterizes nearly all patients with motor neuron disease (MND). The earliest stages of TDP-43 pathobiology are not well-characterized, and whether neurodegeneration results from TDP-43 loss-of-function or aggregation remains unclear. In the behavioral variant of FTD (bvFTD), patients undergo selective dropout of von Economo neurons (VENs) and fork cells within the frontoinsular (FI) and anterior cingulate cortices. Here, we examined TDP-43 pathobiology within these vulnerable neurons in the FI across a clinical spectrum including 17 patients with sporadic bvFTD, MND, or both. In an exploratory analysis based on our initial observations, we further assessed ten patients with C9orf72-associated bvFTD/MND. VENs and fork cells showed early, disproportionate TDP-43 aggregation that correlated with anatomical and clinical severity, including loss of emotional empathy. The presence of a TDP-43 inclusion was associated with striking nuclear and somatodendritic atrophy. An intriguing minority of neurons lacked detectable nuclear TDP-43 despite the apparent absence of a cytoplasmic TDP-43 inclusion. These cells showed neuronal atrophy comparable to inclusion-bearing neurons, suggesting that the loss of nuclear TDP-43 function promotes neurodegeneration, even when TDP-43 aggregation is inconspicuous or absent.
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Affiliation(s)
- Alissa L Nana
- Department of Neurology, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | - Manu Sidhu
- Department of Neurology, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | - Stephanie E Gaus
- Department of Neurology, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | - Ji-Hye L Hwang
- Department of Neurology, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | - Libo Li
- Department of Neurology, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
- Department of Psychopharmacology, Qiqihar Medical University, Qiqihar, China
| | - Youngsoon Park
- Department of Neurology, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | - Eun-Joo Kim
- Department of Neurology, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | - Lorenzo Pasquini
- Department of Neurology, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | - Isabel E Allen
- Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA, USA
| | - Katherine P Rankin
- Department of Neurology, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | - Gianina Toller
- Department of Neurology, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | - Joel H Kramer
- Department of Neurology, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | - Daniel H Geschwind
- Neurogenetics Program, Department of Neurology and Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Giovanni Coppola
- Neurogenetics Program, Department of Neurology and Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Eric J Huang
- Department of Pathology and Laboratory Medicine, University of California, San Francisco, San Francisco, CA, USA
| | - Lea T Grinberg
- Department of Neurology, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
- Department of Pathology and Laboratory Medicine, University of California, San Francisco, San Francisco, CA, USA
- Global Brain Health Institute, University of California, San Francisco, San Francisco, CA, USA
| | - Bruce L Miller
- Department of Neurology, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | - William W Seeley
- Department of Neurology, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA.
- Department of Pathology and Laboratory Medicine, University of California, San Francisco, San Francisco, CA, USA.
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41
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McClory SP, Lynch KW, Ling JP. HnRNP L represses cryptic exons. RNA (NEW YORK, N.Y.) 2018; 24:761-768. [PMID: 29581412 PMCID: PMC5959245 DOI: 10.1261/rna.065508.117] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Accepted: 03/21/2018] [Indexed: 05/14/2023]
Abstract
The fidelity of RNA splicing is regulated by a network of splicing enhancers and repressors, although the rules that govern this process are not yet fully understood. One mechanism that contributes to splicing fidelity is the repression of nonconserved cryptic exons by splicing factors that recognize dinucleotide repeats. We previously identified that TDP-43 and PTBP1/PTBP2 are capable of repressing cryptic exons utilizing UG and CU repeats, respectively. Here we demonstrate that hnRNP L (HNRNPL) also represses cryptic exons by utilizing exonic CA repeats, particularly near the 5'SS. We hypothesize that hnRNP L regulates CA repeat repression for both cryptic exon repression and developmental processes such as T cell differentiation.
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Affiliation(s)
- Sean P McClory
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6059, USA
| | - Kristen W Lynch
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6059, USA
| | - Jonathan P Ling
- Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205-2196, USA
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42
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Volkening K, Keller BA, Leystra-Lantz C, Strong MJ. RNA and Protein Interactors with TDP-43 in Human Spinal-Cord Lysates in Amyotrophic Lateral Sclerosis. J Proteome Res 2018. [DOI: 10.1021/acs.jproteome.8b00126] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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43
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Gao J, Wang L, Huntley ML, Perry G, Wang X. Pathomechanisms of TDP-43 in neurodegeneration. J Neurochem 2018; 146:10.1111/jnc.14327. [PMID: 29486049 PMCID: PMC6110993 DOI: 10.1111/jnc.14327] [Citation(s) in RCA: 123] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2017] [Revised: 02/08/2018] [Accepted: 02/20/2018] [Indexed: 12/11/2022]
Abstract
Neurodegeneration, a term that refers to the progressive loss of structure and function of neurons, is a feature of many neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS), frontotemporal lobar degeneration (FTLD), Alzheimer's disease (AD), Parkinson's disease (PD), and Huntington's disease (HD). There is no cure or treatment available that can prevent or reverse neurodegenerative conditions. The causes of neurodegeneration in these diseases remain largely unknown; yet, an extremely small proportion of these devastating diseases are associated with genetic mutations in proteins involved in a wide range of cellular pathways and processes. Over the past decade, it has become increasingly clear that the most notable neurodegenerative diseases, such as ALS, FTLD, and AD, share a common prominent pathological feature known as TAR DNA-binding protein 43 (TDP-43) proteinopathy, which is usually characterized by the presence of aberrant phosphorylation, ubiquitination, cleavage and/or nuclear depletion of TDP-43 in neurons and glial cells. The role of TDP-43 as a neurotoxicity trigger has been well documented in different in vitro and in vivo experimental models. As such, the investigation of TDP-43 pathomechanisms in various major neurodegenerative diseases is on the rise. Here, after a discussion of stages of TDP-43 proteinopathy during disease progression in various major neurodegenerative diseases, we review previous and most recent studies about the potential pathomechanisms with a particular emphasis on ALS, FTLD, and AD, and discuss the possibility of targeting TDP-43 as a common therapeutic approach to treat neurodegenerative diseases.
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Affiliation(s)
- Ju Gao
- Departments of Pathology, Case Western Reserve University, Cleveland, Ohio, USA
| | - Luwen Wang
- Departments of Pathology, Case Western Reserve University, Cleveland, Ohio, USA
| | - Mikayla L. Huntley
- Departments of Pathology, Case Western Reserve University, Cleveland, Ohio, USA
| | - George Perry
- College of Sciences, University of Texas at San Antonio, San Antonio, Texas, USA
| | - Xinglong Wang
- Departments of Pathology, Case Western Reserve University, Cleveland, Ohio, USA
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44
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Affiliation(s)
- Liam Chen
- Neuropathology Division, Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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45
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Gao FB, Almeida S, Lopez-Gonzalez R. Dysregulated molecular pathways in amyotrophic lateral sclerosis-frontotemporal dementia spectrum disorder. EMBO J 2017; 36:2931-2950. [PMID: 28916614 DOI: 10.15252/embj.201797568] [Citation(s) in RCA: 125] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 07/15/2017] [Accepted: 08/30/2017] [Indexed: 12/11/2022] Open
Abstract
Frontotemporal dementia (FTD), the second most common form of dementia in people under 65 years of age, is characterized by progressive atrophy of the frontal and/or temporal lobes. FTD overlaps extensively with the motor neuron disease amyotrophic lateral sclerosis (ALS), especially at the genetic level. Both FTD and ALS can be caused by many mutations in the same set of genes; the most prevalent of these mutations is a GGGGCC repeat expansion in the first intron of C9ORF72 As shown by recent intensive studies, some key cellular pathways are dysregulated in the ALS-FTD spectrum disorder, including autophagy, nucleocytoplasmic transport, DNA damage repair, pre-mRNA splicing, stress granule dynamics, and others. These exciting advances reveal the complexity of the pathogenic mechanisms of FTD and ALS and suggest promising molecular targets for future therapeutic interventions in these devastating disorders.
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Affiliation(s)
- Fen-Biao Gao
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Sandra Almeida
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA, USA
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46
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Barker HV, Niblock M, Lee YB, Shaw CE, Gallo JM. RNA Misprocessing in C9orf72-Linked Neurodegeneration. Front Cell Neurosci 2017; 11:195. [PMID: 28744202 PMCID: PMC5504096 DOI: 10.3389/fncel.2017.00195] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 06/21/2017] [Indexed: 12/12/2022] Open
Abstract
A large GGGGCC hexanucleotide repeat expansion in the first intron or promoter region of the C9orf72 gene is the most common genetic cause of familial and sporadic Amyotrophic lateral sclerosis (ALS), a devastating degenerative disease of motor neurons, and of Frontotemporal Dementia (FTD), the second most common form of presenile dementia after Alzheimer's disease. C9orf72-associated ALS/FTD is a multifaceted disease both in terms of its clinical presentation and the misregulated cellular pathways contributing to disease progression. Among the numerous pathways misregulated in C9orf72-associated ALS/FTD, altered RNA processing has consistently appeared at the forefront of C9orf72 research. This includes bidirectional transcription of the repeat sequence, accumulation of repeat RNA into nuclear foci sequestering specific RNA-binding proteins (RBPs) and translation of RNA repeats into dipeptide repeat proteins (DPRs) by repeat-associated non-AUG (RAN)-initiated translation. Over the past few years the true extent of RNA misprocessing in C9orf72-associated ALS/FTD has begun to emerge and disruptions have been identified in almost all aspects of the life of an RNA molecule, including release from RNA polymerase II, translation in the cytoplasm and degradation. Furthermore, several alterations have been identified in the processing of the C9orf72 RNA itself, in terms of its transcription, splicing and localization. This review article aims to consolidate our current knowledge on the consequence of the C9orf72 repeat expansion on RNA processing and draws attention to the mechanisms by which several aspects of C9orf72 molecular pathology converge to perturb every stage of RNA metabolism.
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Affiliation(s)
- Holly V. Barker
- Department of Basic and Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King’s College LondonLondon, United Kingdom
| | - Michael Niblock
- Department of Basic and Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King’s College LondonLondon, United Kingdom
| | - Youn-Bok Lee
- Department of Basic and Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King’s College LondonLondon, United Kingdom
| | - Christopher E. Shaw
- Department of Basic and Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King’s College LondonLondon, United Kingdom
| | - Jean-Marc Gallo
- Department of Basic and Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King’s College LondonLondon, United Kingdom
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