1
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Pengo M, Squitieri F. Beyond CAG Repeats: The Multifaceted Role of Genetics in Huntington Disease. Genes (Basel) 2024; 15:807. [PMID: 38927742 PMCID: PMC11203031 DOI: 10.3390/genes15060807] [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: 05/01/2024] [Revised: 06/11/2024] [Accepted: 06/18/2024] [Indexed: 06/28/2024] Open
Abstract
Huntington disease (HD) is a dominantly inherited neurodegenerative disorder caused by a CAG expansion on the huntingtin (HTT) gene and is characterized by progressive motor, cognitive, and neuropsychiatric decline. Recently, new genetic factors besides CAG repeats have been implicated in the disease pathogenesis. Most genetic modifiers are involved in DNA repair pathways and, as the cause of the loss of CAA interruption in the HTT gene, they exert their main influence through somatic expansion. However, this mechanism might not be the only driver of HD pathogenesis, and future studies are warranted in this field. The aim of the present review is to dissect the many faces of genetics in HD pathogenesis, from cis- and trans-acting genetic modifiers to RNA toxicity, mitochondrial DNA mutations, and epigenetics factors. Exploring genetic modifiers of HD onset and progression appears crucial to elucidate not only disease pathogenesis, but also to improve disease prediction and prevention, develop biomarkers of disease progression and response to therapies, and recognize new therapeutic opportunities. Since the same genetic mechanisms are also described in other repeat expansion diseases, their implications might encompass the whole spectrum of these disorders.
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Affiliation(s)
- Marta Pengo
- Department of Molecular and Translational Medicine, University of Brescia, 25121 Brescia, Italy;
| | - Ferdinando Squitieri
- Centre for Neurological Rare Diseases (CMNR), Fondazione Lega Italiana Ricerca Huntington (LIRH), 00161 Rome, Italy
- Huntington and Rare Diseases Unit, IRCCS Casa Sollievo della Sofferenza, 71013 San Giovanni Rotondo, Italy
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2
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Santhosh Kumar S, Naseri NN, Pather SR, Hallacli E, Ndayisaba A, Buenaventura C, Acosta K, Roof J, Fazelinia H, Spruce LA, Luk K, Khurana V, Rhoades E, Shalem O. Sequential CRISPR screening reveals partial NatB inhibition as a strategy to mitigate alpha-synuclein levels in human neurons. SCIENCE ADVANCES 2024; 10:eadj4767. [PMID: 38335281 PMCID: PMC10857481 DOI: 10.1126/sciadv.adj4767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/02/2023] [Accepted: 01/11/2024] [Indexed: 02/12/2024]
Abstract
Alpha-synuclein (αSyn) protein levels correlate with the risk and severity of Parkinson's disease and related neurodegenerative diseases. Lowering αSyn is being actively investigated as a therapeutic modality. Here, we systematically map the regulatory network that controls endogenous αSyn using sequential CRISPR-knockout and -interference screens in an αSyn gene (SNCA)-tagged cell line and induced pluripotent stem cell-derived neurons (iNeurons). We uncover αSyn modifiers at multiple regulatory layers, with amino-terminal acetyltransferase B (NatB) enzymes being the most potent endogenous αSyn modifiers in both cell lines. Amino-terminal acetylation protects the cytosolic αSyn from rapid degradation by the proteasome in a Ube2w-dependent manner. Moreover, we show that pharmacological inhibition of methionyl-aminopeptidase 2, a regulator of NatB complex formation, attenuates endogenous αSyn in iNeurons carrying SNCA triplication. Together, our study reveals several gene networks that control endogenous αSyn, identifies mechanisms mediating the degradation of nonacetylated αSyn, and illustrates potential therapeutic pathways for decreasing αSyn levels in synucleinopathies.
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Affiliation(s)
- Saranya Santhosh Kumar
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, PA, USA
- Center for Cellular and Molecular Therapeutics, Children’s Hospital of Philadelphia, Philadelphia, PA, USA
| | - Nima N. Naseri
- Center for Cellular and Molecular Therapeutics, Children’s Hospital of Philadelphia, Philadelphia, PA, USA
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA, USA
| | - Sarshan R. Pather
- Center for Cellular and Molecular Therapeutics, Children’s Hospital of Philadelphia, Philadelphia, PA, USA
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Erinc Hallacli
- Division of Movement Disorders and Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA, USA
| | - Alain Ndayisaba
- Division of Movement Disorders and Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA, USA
| | - Chris Buenaventura
- Center for Cellular and Molecular Therapeutics, Children’s Hospital of Philadelphia, Philadelphia, PA, USA
| | - Karen Acosta
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA, USA
| | - Jennifer Roof
- Proteomics Core Facility, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Hossein Fazelinia
- Proteomics Core Facility, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
- Department of Biomedical and Health Informatics, The Children’s Hospital of Philadelphia, Philadelphia, PA, USA
| | - Lynn A. Spruce
- Proteomics Core Facility, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Kelvin Luk
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Vikram Khurana
- Division of Movement Disorders and Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA, USA
- Broad Institute of Harvard and MIT, Cambridge, MA, USA
- Harvard Stem Cell Institute, Cambridge, MA, USA
| | - Elizabeth Rhoades
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA, USA
| | - Ophir Shalem
- Center for Cellular and Molecular Therapeutics, Children’s Hospital of Philadelphia, Philadelphia, PA, USA
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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3
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Smolka M, Paulin LF, Grochowski CM, Horner DW, Mahmoud M, Behera S, Kalef-Ezra E, Gandhi M, Hong K, Pehlivan D, Scholz SW, Carvalho CMB, Proukakis C, Sedlazeck FJ. Detection of mosaic and population-level structural variants with Sniffles2. Nat Biotechnol 2024:10.1038/s41587-023-02024-y. [PMID: 38168980 PMCID: PMC11217151 DOI: 10.1038/s41587-023-02024-y] [Citation(s) in RCA: 29] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Accepted: 10/11/2023] [Indexed: 01/05/2024]
Abstract
Calling structural variations (SVs) is technically challenging, but using long reads remains the most accurate way to identify complex genomic alterations. Here we present Sniffles2, which improves over current methods by implementing a repeat aware clustering coupled with a fast consensus sequence and coverage-adaptive filtering. Sniffles2 is 11.8 times faster and 29% more accurate than state-of-the-art SV callers across different coverages (5-50×), sequencing technologies (ONT and HiFi) and SV types. Furthermore, Sniffles2 solves the problem of family-level to population-level SV calling to produce fully genotyped VCF files. Across 11 probands, we accurately identified causative SVs around MECP2, including highly complex alleles with three overlapping SVs. Sniffles2 also enables the detection of mosaic SVs in bulk long-read data. As a result, we identified multiple mosaic SVs in brain tissue from a patient with multiple system atrophy. The identified SV showed a remarkable diversity within the cingulate cortex, impacting both genes involved in neuron function and repetitive elements.
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Affiliation(s)
- Moritz Smolka
- Human Genome Sequencing Center Baylor College of Medicine, Houston, TX, USA
| | - Luis F Paulin
- Human Genome Sequencing Center Baylor College of Medicine, Houston, TX, USA
| | | | - Dominic W Horner
- Department of Clinical and Movement Neurosciences, Royal Free Campus, Queen Square Institute of Neurology, University College London, London, UK
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
| | - Medhat Mahmoud
- Human Genome Sequencing Center Baylor College of Medicine, Houston, TX, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Sairam Behera
- Human Genome Sequencing Center Baylor College of Medicine, Houston, TX, USA
| | - Ester Kalef-Ezra
- Department of Clinical and Movement Neurosciences, Royal Free Campus, Queen Square Institute of Neurology, University College London, London, UK
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
| | - Mira Gandhi
- Pacific Northwest Research Institute (PNRI), Seattle, WA, USA
| | - Karl Hong
- Bionano Genomics, San Diego, CA, USA
| | - Davut Pehlivan
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Division of Neurology and Developmental Neuroscience, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Sonja W Scholz
- Neurodegenerative Diseases Research Unit, National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
- Department of Neurology, Johns Hopkins University Medical Center, Baltimore, MD, USA
| | - Claudia M B Carvalho
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Pacific Northwest Research Institute (PNRI), Seattle, WA, USA
| | - Christos Proukakis
- Department of Clinical and Movement Neurosciences, Royal Free Campus, Queen Square Institute of Neurology, University College London, London, UK
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
| | - Fritz J Sedlazeck
- Human Genome Sequencing Center Baylor College of Medicine, Houston, TX, USA.
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA.
- Department of Computer Science, Rice University, Houston, TX, USA.
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4
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Zolzaya S, Narumoto A, Katsuyama Y. Genomic variation in neurons. Dev Growth Differ 2024; 66:35-42. [PMID: 37855730 DOI: 10.1111/dgd.12898] [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: 06/04/2023] [Revised: 10/15/2023] [Accepted: 10/16/2023] [Indexed: 10/20/2023]
Abstract
Neurons born during the fetal period have extreme longevity and survive until the death of the individual because the human brain has highly limited tissue regeneration. The brain is comprised of an enormous variety of neurons each exhibiting different morphological and physiological characteristics and recent studies have further reported variations in their genome including chromosomal abnormalities, copy number variations, and single nucleotide mutations. During the early stages of brain development, the increasing number of neurons generated at high speeds has been proposed to lead to chromosomal instability. Additionally, mutations in the neuronal genome can occur in the mature brain. This observed genomic mosaicism in the brain can be produced by multiple endogenous and environmental factors and careful analyses of these observed variations in the neuronal genome remain central for our understanding of the genetic basis of neurological disorders.
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Affiliation(s)
- Sunjidmaa Zolzaya
- Division of Neuroanatomy, Department of Anatomy, Shiga University of Medical Science, Otsu, Japan
| | - Ayano Narumoto
- Division of Neuroanatomy, Department of Anatomy, Shiga University of Medical Science, Otsu, Japan
| | - Yu Katsuyama
- Division of Neuroanatomy, Department of Anatomy, Shiga University of Medical Science, Otsu, Japan
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5
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Chang YL, Yang CC, Huang YY, Chen YA, Yang CW, Liao CY, Li H, Wu CS, Lin CH, Teng SC. The HSP40 family chaperone isoform DNAJB6b prevents neuronal cells from tau aggregation. BMC Biol 2023; 21:293. [PMID: 38110916 PMCID: PMC10729500 DOI: 10.1186/s12915-023-01798-6] [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: 02/23/2023] [Accepted: 12/05/2023] [Indexed: 12/20/2023] Open
Abstract
BACKGROUND Alzheimer's disease (AD) is the most common neurodegenerative disorder with clinical presentations of progressive cognitive and memory deterioration. The pathologic hallmarks of AD include tau neurofibrillary tangles and amyloid plaque depositions in the hippocampus and associated neocortex. The neuronal aggregated tau observed in AD cells suggests that the protein folding problem is a major cause of AD. J-domain-containing proteins (JDPs) are the largest family of cochaperones, which play a vital role in specifying and directing HSP70 chaperone functions. JDPs bind substrates and deliver them to HSP70. The association of JDP and HSP70 opens the substrate-binding domain of HSP70 to help the loading of the clients. However, in the initial HSP70 cycle, which JDP delivers tau to the HSP70 system in neuronal cells remains unclear. RESULTS We screened the requirement of a diverse panel of JDPs for preventing tau aggregation in the human neuroblastoma cell line SH-SY5Y by a filter retardation method. Interestingly, knockdown of DNAJB6, one of the JDPs, displayed tau aggregation and overexpression of DNAJB6b, one of the isoforms generated from the DNAJB6 gene by alternative splicing, reduced tau aggregation. Further, the tau bimolecular fluorescence complementation assay confirmed the DNAJB6b-dependent tau clearance. The co-immunoprecipitation and the proximity ligation assay demonstrated the protein-protein interaction between tau and the chaperone-cochaperone complex. The J-domain of DNAJB6b was critical for preventing tau aggregation. Moreover, reduced DNAJB6 expression and increased tau aggregation were detected in an age-dependent manner in immunohistochemical analysis of the hippocampus tissues of a mouse model of tau pathology. CONCLUSIONS In summary, downregulation of DNAJB6b increases the insoluble form of tau, while overexpression of DNAJB6b reduces tau aggregation. Moreover, DNAJB6b associates with tau. Therefore, this study reveals that DNAJB6b is a direct sensor for its client tau in the HSP70 folding system in neuronal cells, thus helping to prevent AD.
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Affiliation(s)
- Ya-Lan Chang
- Department of Microbiology, College of Medicine, National Taiwan University, No. 1, Section 1, Jen-Ai Road, Taipei, 10051, Taiwan
| | - Chan-Chih Yang
- Department of Microbiology, College of Medicine, National Taiwan University, No. 1, Section 1, Jen-Ai Road, Taipei, 10051, Taiwan
| | - Yun-Yu Huang
- Department of Microbiology, College of Medicine, National Taiwan University, No. 1, Section 1, Jen-Ai Road, Taipei, 10051, Taiwan
| | - Yi-An Chen
- Department of Microbiology, College of Medicine, National Taiwan University, No. 1, Section 1, Jen-Ai Road, Taipei, 10051, Taiwan
| | - Chia-Wei Yang
- Department of Microbiology, College of Medicine, National Taiwan University, No. 1, Section 1, Jen-Ai Road, Taipei, 10051, Taiwan
| | - Chia-Yu Liao
- Department of Microbiology, College of Medicine, National Taiwan University, No. 1, Section 1, Jen-Ai Road, Taipei, 10051, Taiwan
| | - Hsun Li
- Department of Neurology, National Taiwan University Hospital, No. 7, Chung-Shan South Road, Taipei, 10051, Taiwan
| | - Ching-Shyi Wu
- Department of Pharmacology, College of Medicine, National Taiwan University, Taipei, 10051, Taiwan
| | - Chin-Hsien Lin
- Department of Neurology, National Taiwan University Hospital, No. 7, Chung-Shan South Road, Taipei, 10051, Taiwan.
| | - Shu-Chun Teng
- Department of Microbiology, College of Medicine, National Taiwan University, No. 1, Section 1, Jen-Ai Road, Taipei, 10051, Taiwan.
- Center of Precision Medicine, National Taiwan University, Taipei, 10051, Taiwan.
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6
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Zhou Z, Kim J, Huang AY, Nolan M, Park J, Doan R, Shin T, Miller MB, Chhouk B, Morillo K, Yeh RC, Kenny C, Neil JE, Lee CZ, Ohkubo T, Ravits J, Ansorge O, Ostrow LW, Lagier-Tourenne C, Lee EA, Walsh CA. Somatic Mosaicism in Amyotrophic Lateral Sclerosis and Frontotemporal Dementia Reveals Widespread Degeneration from Focal Mutations. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.30.569436. [PMID: 38077003 PMCID: PMC10705414 DOI: 10.1101/2023.11.30.569436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/17/2023]
Abstract
Although mutations in dozens of genes have been implicated in familial forms of amyotrophic lateral sclerosis (fALS) and frontotemporal degeneration (fFTD), most cases of these conditions are sporadic (sALS and sFTD), with no family history, and their etiology remains obscure. We tested the hypothesis that somatic mosaic mutations, present in some but not all cells, might contribute in these cases, by performing ultra-deep, targeted sequencing of 88 genes associated with neurodegenerative diseases in postmortem brain and spinal cord samples from 404 individuals with sALS or sFTD and 144 controls. Known pathogenic germline mutations were found in 20.6% of ALS, and 26.5% of FTD cases. Predicted pathogenic somatic mutations in ALS/FTD genes were observed in 2.7% of sALS and sFTD cases that did not carry known pathogenic or novel germline mutations. Somatic mutations showed low variant allele fraction (typically <2%) and were often restricted to the region of initial discovery, preventing detection through genetic screening in peripheral tissues. Damaging somatic mutations were preferentially enriched in primary motor cortex of sALS and prefrontal cortex of sFTD, mirroring regions most severely affected in each disease. Somatic mutation analysis of bulk RNA-seq data from brain and spinal cord from an additional 143 sALS cases and 23 controls confirmed an overall enrichment of somatic mutations in sALS. Two adult sALS cases were identified bearing pathogenic somatic mutations in DYNC1H1 and LMNA, two genes associated with pediatric motor neuron degeneration. Our study suggests that somatic mutations in fALS/fFTD genes, and in genes associated with more severe diseases in the germline state, contribute to sALS and sFTD, and that mosaic mutations in a small fraction of cells in focal regions of the nervous system can ultimately result in widespread degeneration.
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Affiliation(s)
- Zinan Zhou
- Division of Genetics and Genomics, Boston Children’s Hospital, Boston, MA, USA
- Manton Center for Orphan Disease, Boston Children’s Hospital, Boston, MA, USA
- Department of Pediatrics, Harvard Medical School, Boston, MA, USA
| | - Junho Kim
- Division of Genetics and Genomics, Boston Children’s Hospital, Boston, MA, USA
- Manton Center for Orphan Disease, Boston Children’s Hospital, Boston, MA, USA
- Department of Pediatrics, Harvard Medical School, Boston, MA, USA
- Department of Biological Sciences, Sungkyunkwan University, Suwon, South Korea
| | - August Yue Huang
- Division of Genetics and Genomics, Boston Children’s Hospital, Boston, MA, USA
- Manton Center for Orphan Disease, Boston Children’s Hospital, Boston, MA, USA
- Department of Pediatrics, Harvard Medical School, Boston, MA, USA
| | - Matthew Nolan
- Department of Neurology, The Sean M. Healey and AMG Center for ALS at Mass General, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Junseok Park
- Division of Genetics and Genomics, Boston Children’s Hospital, Boston, MA, USA
- Manton Center for Orphan Disease, Boston Children’s Hospital, Boston, MA, USA
- Department of Pediatrics, Harvard Medical School, Boston, MA, USA
| | - Ryan Doan
- Division of Genetics and Genomics, Boston Children’s Hospital, Boston, MA, USA
- Department of Pediatrics, Harvard Medical School, Boston, MA, USA
| | - Taehwan Shin
- Division of Genetics and Genomics, Boston Children’s Hospital, Boston, MA, USA
- Manton Center for Orphan Disease, Boston Children’s Hospital, Boston, MA, USA
- Department of Pediatrics, Harvard Medical School, Boston, MA, USA
| | - Michael B. Miller
- Division of Genetics and Genomics, Boston Children’s Hospital, Boston, MA, USA
- Department of Pathology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Brian Chhouk
- Division of Genetics and Genomics, Boston Children’s Hospital, Boston, MA, USA
- Manton Center for Orphan Disease, Boston Children’s Hospital, Boston, MA, USA
- Department of Pediatrics, Harvard Medical School, Boston, MA, USA
| | - Katherine Morillo
- Division of Genetics and Genomics, Boston Children’s Hospital, Boston, MA, USA
- Manton Center for Orphan Disease, Boston Children’s Hospital, Boston, MA, USA
- Department of Pediatrics, Harvard Medical School, Boston, MA, USA
| | - Rebecca C. Yeh
- Division of Genetics and Genomics, Boston Children’s Hospital, Boston, MA, USA
- Manton Center for Orphan Disease, Boston Children’s Hospital, Boston, MA, USA
- Department of Pediatrics, Harvard Medical School, Boston, MA, USA
| | - Connor Kenny
- Division of Genetics and Genomics, Boston Children’s Hospital, Boston, MA, USA
- Manton Center for Orphan Disease, Boston Children’s Hospital, Boston, MA, USA
- Department of Pediatrics, Harvard Medical School, Boston, MA, USA
| | - Jennifer E. Neil
- Division of Genetics and Genomics, Boston Children’s Hospital, Boston, MA, USA
- Manton Center for Orphan Disease, Boston Children’s Hospital, Boston, MA, USA
- Department of Pediatrics, Harvard Medical School, Boston, MA, USA
- Howard Hughes Medical Institute, Boston Children’s Hospital, Boston, MA, USA
| | - Chao-Zong Lee
- Department of Neurology, The Sean M. Healey and AMG Center for ALS at Mass General, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Takuya Ohkubo
- Department of Neurology, Yokohama City Minato Red Cross Hospital, Yokohama, Kanagawa, Japan
- Department of Neurosciences, School of Medicine, University of California at San Diego, La Jolla, CA, USA
| | - John Ravits
- Department of Neurosciences, School of Medicine, University of California at San Diego, La Jolla, CA, USA
| | - Olaf Ansorge
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, Oxfordshire, UK
| | - Lyle W. Ostrow
- Department of Neurology, Lewis Katz School of Medicine at Temple University, Philadelphia, USA
| | - Clotilde Lagier-Tourenne
- Department of Neurology, The Sean M. Healey and AMG Center for ALS at Mass General, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Eunjung Alice Lee
- Division of Genetics and Genomics, Boston Children’s Hospital, Boston, MA, USA
- Manton Center for Orphan Disease, Boston Children’s Hospital, Boston, MA, USA
- Department of Pediatrics, Harvard Medical School, Boston, MA, USA
| | - Christopher A. Walsh
- Division of Genetics and Genomics, Boston Children’s Hospital, Boston, MA, USA
- Manton Center for Orphan Disease, Boston Children’s Hospital, Boston, MA, USA
- Department of Pediatrics, Harvard Medical School, Boston, MA, USA
- Howard Hughes Medical Institute, Boston Children’s Hospital, Boston, MA, USA
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7
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Kalef-Ezra E, Turan ZG, Perez-Rodriguez D, Bomann I, Behera S, Morley C, Scholz SW, Jaunmuktane Z, Demeulemeester J, Sedlazeck FJ, Proukakis C. Single-cell somatic copy number variants in brain using different amplification methods and reference genomes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.07.552289. [PMID: 37609320 PMCID: PMC10441336 DOI: 10.1101/2023.08.07.552289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
The presence of somatic mutations, including copy number variants (CNVs), in the brain is well recognized. Comprehensive study requires single-cell whole genome amplification, with several methods available, prior to sequencing. We compared PicoPLEX with two recent adaptations of multiple displacement amplification (MDA): primary template-directed amplification (PTA) and droplet MDA, across 93 human brain cortical nuclei. We demonstrated different properties for each, with PTA providing the broadest amplification, PicoPLEX the most even, and distinct chimeric profiles. Furthermore, we performed CNV calling on two brains with multiple system atrophy and one control brain using different reference genomes. We found that 38% of brain cells have at least one Mb-scale CNV, with some supported by bulk sequencing or single-cells from other brain regions. Our study highlights the importance of selecting whole genome amplification method and reference genome for CNV calling, while supporting the existence of somatic CNVs in healthy and diseased human brain.
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8
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Vandereyken K, Sifrim A, Thienpont B, Voet T. Methods and applications for single-cell and spatial multi-omics. Nat Rev Genet 2023; 24:494-515. [PMID: 36864178 PMCID: PMC9979144 DOI: 10.1038/s41576-023-00580-2] [Citation(s) in RCA: 228] [Impact Index Per Article: 228.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/20/2023] [Indexed: 03/04/2023]
Abstract
The joint analysis of the genome, epigenome, transcriptome, proteome and/or metabolome from single cells is transforming our understanding of cell biology in health and disease. In less than a decade, the field has seen tremendous technological revolutions that enable crucial new insights into the interplay between intracellular and intercellular molecular mechanisms that govern development, physiology and pathogenesis. In this Review, we highlight advances in the fast-developing field of single-cell and spatial multi-omics technologies (also known as multimodal omics approaches), and the computational strategies needed to integrate information across these molecular layers. We demonstrate their impact on fundamental cell biology and translational research, discuss current challenges and provide an outlook to the future.
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Affiliation(s)
- Katy Vandereyken
- KU Leuven Institute for Single Cell Omics (LISCO), University of Leuven, KU Leuven, Leuven, Belgium
- Department of Human Genetics, University of Leuven, KU Leuven, Leuven, Belgium
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
| | - Alejandro Sifrim
- KU Leuven Institute for Single Cell Omics (LISCO), University of Leuven, KU Leuven, Leuven, Belgium
- Department of Human Genetics, University of Leuven, KU Leuven, Leuven, Belgium
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
| | - Bernard Thienpont
- KU Leuven Institute for Single Cell Omics (LISCO), University of Leuven, KU Leuven, Leuven, Belgium
- Department of Human Genetics, University of Leuven, KU Leuven, Leuven, Belgium
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
| | - Thierry Voet
- KU Leuven Institute for Single Cell Omics (LISCO), University of Leuven, KU Leuven, Leuven, Belgium.
- Department of Human Genetics, University of Leuven, KU Leuven, Leuven, Belgium.
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA.
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9
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Pamphlett R, Bishop DP. The toxic metal hypothesis for neurological disorders. Front Neurol 2023; 14:1173779. [PMID: 37426441 PMCID: PMC10328356 DOI: 10.3389/fneur.2023.1173779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2023] [Accepted: 05/30/2023] [Indexed: 07/11/2023] Open
Abstract
Multiple sclerosis and the major sporadic neurogenerative disorders, amyotrophic lateral sclerosis, Parkinson disease, and Alzheimer disease are considered to have both genetic and environmental components. Advances have been made in finding genetic predispositions to these disorders, but it has been difficult to pin down environmental agents that trigger them. Environmental toxic metals have been implicated in neurological disorders, since human exposure to toxic metals is common from anthropogenic and natural sources, and toxic metals have damaging properties that are suspected to underlie many of these disorders. Questions remain, however, as to how toxic metals enter the nervous system, if one or combinations of metals are sufficient to precipitate disease, and how toxic metal exposure results in different patterns of neuronal and white matter loss. The hypothesis presented here is that damage to selective locus ceruleus neurons from toxic metals causes dysfunction of the blood-brain barrier. This allows circulating toxicants to enter astrocytes, from where they are transferred to, and damage, oligodendrocytes, and neurons. The type of neurological disorder that arises depends on (i) which locus ceruleus neurons are damaged, (ii) genetic variants that give rise to susceptibility to toxic metal uptake, cytotoxicity, or clearance, (iii) the age, frequency, and duration of toxicant exposure, and (iv) the uptake of various mixtures of toxic metals. Evidence supporting this hypothesis is presented, concentrating on studies that have examined the distribution of toxic metals in the human nervous system. Clinicopathological features shared between neurological disorders are listed that can be linked to toxic metals. Details are provided on how the hypothesis applies to multiple sclerosis and the major neurodegenerative disorders. Further avenues to explore the toxic metal hypothesis for neurological disorders are suggested. In conclusion, environmental toxic metals may play a part in several common neurological disorders. While further evidence to support this hypothesis is needed, to protect the nervous system it would be prudent to take steps to reduce environmental toxic metal pollution from industrial, mining, and manufacturing sources, and from the burning of fossil fuels.
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Affiliation(s)
- Roger Pamphlett
- Department of Pathology, Brain and Mind Centre, School of Medical Sciences, The University of Sydney, Sydney, NSW, Australia
- Department of Neuropathology, Royal Prince Alfred Hospital, Camperdown, NSW, Australia
- Hyphenated Mass Spectrometry Laboratory, School of Mathematical and Physical Sciences, University of Technology Sydney, Sydney, NSW, Australia
| | - David P. Bishop
- Hyphenated Mass Spectrometry Laboratory, School of Mathematical and Physical Sciences, University of Technology Sydney, Sydney, NSW, Australia
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10
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Jena NR, Das P, Shukla PK. Complementary base pair interactions between different rare tautomers of the second-generation artificial genetic alphabets. J Mol Model 2023; 29:125. [PMID: 37014428 DOI: 10.1007/s00894-023-05537-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 03/29/2023] [Indexed: 04/05/2023]
Abstract
The functionality of a semisynthetic DNA in the biological environment will depend on the base pair nature of its complementary base pairs. To understand this, base pair interactions between complementary bases of recently proposed eight second-generation artificial nucleobases are studied herein by considering their rare tautomeric conformations and a dispersion-corrected density functional theoretic method. It is found that the binding energies of two hydrogen-bonded complementary base pairs are more negative than those of the three hydrogen-bonded base pairs. However, as the former base pairs are endothermic, the semisynthetic duplex DNA would involve the latter base pairs.
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Affiliation(s)
- N R Jena
- Discipline of Natural Sciences, Indian Institute of Information Technology, Design, and Manufacturing, Jabalpur, 482005, India.
| | - P Das
- Discipline of Natural Sciences, Indian Institute of Information Technology, Design, and Manufacturing, Jabalpur, 482005, India
| | - P K Shukla
- Department of Physics, Assam University, Silchar, 788011, India
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11
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Murley AG, Nie Y, Golder Z, Keogh MJ, Smith C, Ironside JW, Chinnery PF. High-Depth PRNP Sequencing in Brains With Sporadic Creutzfeldt-Jakob Disease. Neurol Genet 2023; 9:e200054. [PMID: 36686280 PMCID: PMC9853313 DOI: 10.1212/nxg.0000000000200054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 11/23/2022] [Indexed: 01/20/2023]
Abstract
Background and Objectives Sporadic Creutzfeldt-Jakob disease (sCJD) has established genetic risk factors, but, in contrast to genetic and acquired CJD, the initial trigger for misfolded prion aggregation and spread is not known. In this study, we tested the hypotheses that pathologic somatic variants in the prion gene PRNP are increased in sCJD, potentially leading to the seeding of misfolded prion protein. Methods High-depth amplicon-based short read sequencing of the PRNP coding region was performed on postmortem brain tissue from patients with a clinical and neuropathologic diagnosis of sCJD (n = 142), Alzheimer disease (AD) (n = 51) and controls with no clinical or neuropathologic diagnosis of a neurodegenerative disease (n = 71). Each DNA sample was sequenced twice, including independent PCR amplification, library preparation, and sequencing. We used RePlow to call somatic variants with high sensitivity and specificity and optimal sequence kernel association test to compare variant burden between groups. Results Two sCJD cases had somatic (variant allele frequency 0.5-1%) PRNP variants not previously identified, but with high in silico predicated pathogenicity. However, the pathogenicity of these variants is uncertain, as both located in the octapeptide repeat region where no point variations have previously been associated with sCJD. There was no overall difference in burden somatic PRNP in sCJD compared with controls and a lower burden compared with Alzheimer disease. Discussion Somatic variants in PRNP are unlikely to play a major role in sCJD but may contribute to the disease mechanism in a minority of cases.
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Affiliation(s)
- Alexander G Murley
- Department of Clinical Neurosciences (A.G.M., Y.N., Z.G., M.J.K., C.), School of Clinical Medicine, University of Cambridge, Cambridge Biomedical Campus; Medical Research Council Mitochondrial Biology Unit (Y.N., Z.G.), University of Cambridge, Cambridge Biomedical Campus; Translational and Clinical Research Institute (M.J.K., P.F.C.), Newcastle University, Newcastle Upon Tyne; and Centre for Clinical Brain Sciences (C.S., J.W.I.), University of Edinburgh, Cambridge, UK
| | - Yu Nie
- Department of Clinical Neurosciences (A.G.M., Y.N., Z.G., M.J.K., C.), School of Clinical Medicine, University of Cambridge, Cambridge Biomedical Campus; Medical Research Council Mitochondrial Biology Unit (Y.N., Z.G.), University of Cambridge, Cambridge Biomedical Campus; Translational and Clinical Research Institute (M.J.K., P.F.C.), Newcastle University, Newcastle Upon Tyne; and Centre for Clinical Brain Sciences (C.S., J.W.I.), University of Edinburgh, Cambridge, UK
| | - Zoe Golder
- Department of Clinical Neurosciences (A.G.M., Y.N., Z.G., M.J.K., C.), School of Clinical Medicine, University of Cambridge, Cambridge Biomedical Campus; Medical Research Council Mitochondrial Biology Unit (Y.N., Z.G.), University of Cambridge, Cambridge Biomedical Campus; Translational and Clinical Research Institute (M.J.K., P.F.C.), Newcastle University, Newcastle Upon Tyne; and Centre for Clinical Brain Sciences (C.S., J.W.I.), University of Edinburgh, Cambridge, UK
| | - Michael John Keogh
- Department of Clinical Neurosciences (A.G.M., Y.N., Z.G., M.J.K., C.), School of Clinical Medicine, University of Cambridge, Cambridge Biomedical Campus; Medical Research Council Mitochondrial Biology Unit (Y.N., Z.G.), University of Cambridge, Cambridge Biomedical Campus; Translational and Clinical Research Institute (M.J.K., P.F.C.), Newcastle University, Newcastle Upon Tyne; and Centre for Clinical Brain Sciences (C.S., J.W.I.), University of Edinburgh, Cambridge, UK
| | - Colin Smith
- Department of Clinical Neurosciences (A.G.M., Y.N., Z.G., M.J.K., C.), School of Clinical Medicine, University of Cambridge, Cambridge Biomedical Campus; Medical Research Council Mitochondrial Biology Unit (Y.N., Z.G.), University of Cambridge, Cambridge Biomedical Campus; Translational and Clinical Research Institute (M.J.K., P.F.C.), Newcastle University, Newcastle Upon Tyne; and Centre for Clinical Brain Sciences (C.S., J.W.I.), University of Edinburgh, Cambridge, UK
| | - James W Ironside
- Department of Clinical Neurosciences (A.G.M., Y.N., Z.G., M.J.K., C.), School of Clinical Medicine, University of Cambridge, Cambridge Biomedical Campus; Medical Research Council Mitochondrial Biology Unit (Y.N., Z.G.), University of Cambridge, Cambridge Biomedical Campus; Translational and Clinical Research Institute (M.J.K., P.F.C.), Newcastle University, Newcastle Upon Tyne; and Centre for Clinical Brain Sciences (C.S., J.W.I.), University of Edinburgh, Cambridge, UK
| | - Patrick F Chinnery
- Department of Clinical Neurosciences (A.G.M., Y.N., Z.G., M.J.K., C.), School of Clinical Medicine, University of Cambridge, Cambridge Biomedical Campus; Medical Research Council Mitochondrial Biology Unit (Y.N., Z.G.), University of Cambridge, Cambridge Biomedical Campus; Translational and Clinical Research Institute (M.J.K., P.F.C.), Newcastle University, Newcastle Upon Tyne; and Centre for Clinical Brain Sciences (C.S., J.W.I.), University of Edinburgh, Cambridge, UK
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12
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Garcia-Segura ME, Perez-Rodriguez D, Chambers D, Jaunmuktane Z, Proukakis C. Somatic SNCA Copy Number Variants in Multiple System Atrophy are Related to Pathology and Inclusions. Mov Disord 2023; 38:338-342. [PMID: 36448620 DOI: 10.1002/mds.29291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 10/23/2022] [Accepted: 11/16/2022] [Indexed: 12/05/2022] Open
Abstract
BACKGROUND Somatic α-synuclein (SNCA) copy number variants (CNVs, specifically gains) occur in multiple system atrophy (MSA) and Parkinson's disease brains. OBJECTIVE The aim was to compare somatic SNCA CNVs in MSA subtypes (striatonigral degeneration [SND] and olivopontocerebellar atrophy [OPCA]) and correlate with inclusions. METHODS We combined fluorescent in situ hybridization with immunofluorescence for α-synuclein and in some cases oligodendrocyte marker tubulin polymerization promoting protein (TPPP). RESULTS We analyzed one to three brain regions from 24 MSA cases (13 SND, 11 OPCA). In a region preferentially affected in one subtype (putamen in SND, cerebellum in OPCA), mosaicism was higher in that subtype, and cells with CNVs were 4.2 times more likely to have inclusions. In the substantia nigra, nonpigmented cells with CNVs and TPPP were about six times more likely to have inclusions. CONCLUSIONS The correlation between SNCA CNVs and pathology (at a regional level) and inclusions (at a single-cell level) suggests a role for somatic SNCA CNVs in MSA pathogenesis. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Monica Emili Garcia-Segura
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Diego Perez-Rodriguez
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Darren Chambers
- The Dubowitz Neuromuscular Centre, Division of Neuropathology, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Zane Jaunmuktane
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, UK.,Queen Square Brain Bank for Neurological Disorders, UCL Queen Square Institute of Neurology, University College London, London, UK.,Division of Neuropathology, National Hospital for Neurology and Neurosurgery, University College London NHS Foundation Trust, London, UK
| | - Christos Proukakis
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, UK
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13
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Perez-Rodriguez D, Kalyva M, Santucci C, Proukakis C. Somatic CNV Detection by Single-Cell Whole-Genome Sequencing in Postmortem Human Brain. Methods Mol Biol 2023; 2561:205-230. [PMID: 36399272 DOI: 10.1007/978-1-0716-2655-9_11] [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] [Indexed: 06/16/2023]
Abstract
The evidence for a role of somatic mutations, including copy-number variants (CNVs), in neurodegeneration has increased in the last decade. However, the understanding of the types and origins of these mutations, and their exact contributions to disease onset and progression, is still in its infancy. The use of single-cell (or nuclear) whole-genome sequencing (scWGS) has emerged as a powerful tool to answer these questions. In the present chapter, we provide laboratory and bioinformatic protocols used successfully in our lab to detect megabase-scale CNVs in single cells from multiple system atrophy (MSA) human postmortem brains, using immunolabeling prior to selection of nuclei for whole-genome amplification (WGA). We also present an unpublished comparison of scWGS generated from the same control substantia nigra (SN) sample, using the latest versions of popular WGA chemistries, MDA and PicoPLEX. We have used this protocol to focus on brain cell types most relevant to synucleinopathies (dopaminergic [DA] neurons in Parkinson's disease [PD] and oligodendrocytes in MSA), but it can be applied to any tissue and/or cell type with appropriate markers.
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Affiliation(s)
- Diego Perez-Rodriguez
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London, UK
| | - Maria Kalyva
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London, UK
| | - Catherine Santucci
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London, UK
| | - Christos Proukakis
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London, UK.
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14
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Solís-Moruno M, Batlle-Masó L, Bonet N, Aróstegui JI, Casals F. Somatic genetic variation in healthy tissue and non-cancer diseases. Eur J Hum Genet 2023; 31:48-54. [PMID: 36289407 PMCID: PMC9823099 DOI: 10.1038/s41431-022-01213-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 09/19/2022] [Accepted: 10/03/2022] [Indexed: 02/08/2023] Open
Abstract
Somatic genetic variants have been studied for several years mostly concerning cancer, where they contribute to its origin and development. It is also clear that the somatic variants load is greater in aged individuals in comparison to younger ones, pointing to a cause/consequence of the senescence process. More recently, researchers have focused on the role of this type of variation in healthy tissue and its dynamics in cell lineages and different organs. In addition, somatic variants have been described to contribute to monogenic diseases, and the number of evidences of their role in complex disorders is also increasing. Thanks to recent advances in next-generation sequencing technologies, this type of genetic variation can be now more easily studied than in the past, although we still face some important limitations. Novel strategies for sampling, sequencing and filtering are being investigated to detect these variants, although validating them with an orthogonal approach will most likely still be needed. In this review, we aim to update our knowledge of somatic variation detection and its relation to healthy tissue and non-cancer diseases.
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Affiliation(s)
- Manuel Solís-Moruno
- grid.5612.00000 0001 2172 2676Institut de Biologia Evolutiva (CSIC-UPF), Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Doctor Aiguader 88, Barcelona, Spain ,grid.5612.00000 0001 2172 2676Genomics Core Facility, Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Parc de Recerca Biomèdica de Barcelona, 08003 Barcelona, Spain ,grid.410458.c0000 0000 9635 9413Department of Immunology, Hospital Clínic, Barcelona, Spain ,grid.10403.360000000091771775Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Laura Batlle-Masó
- grid.7080.f0000 0001 2296 0625Pediatric Infectious Diseases and Immunodeficiencies Unit, Hospital Universitari Vall d’Hebron (HUVH), Vall d’Hebron Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Núria Bonet
- grid.5612.00000 0001 2172 2676Genomics Core Facility, Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Parc de Recerca Biomèdica de Barcelona, 08003 Barcelona, Spain
| | - Juan I. Aróstegui
- grid.410458.c0000 0000 9635 9413Department of Immunology, Hospital Clínic, Barcelona, Spain ,grid.10403.360000000091771775Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain ,grid.5841.80000 0004 1937 0247Universitat de Barcelona, Barcelona, Spain
| | - Ferran Casals
- grid.5612.00000 0001 2172 2676Genomics Core Facility, Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Parc de Recerca Biomèdica de Barcelona, 08003 Barcelona, Spain ,grid.5841.80000 0004 1937 0247Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain ,grid.5841.80000 0004 1937 0247Institut de Biomedicina de la Universitat de Barcelona (IBUB), Universitat de Barcelona, Barcelona, Spain
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15
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Vojtechova I, Machacek T, Kristofikova Z, Stuchlik A, Petrasek T. Infectious origin of Alzheimer’s disease: Amyloid beta as a component of brain antimicrobial immunity. PLoS Pathog 2022; 18:e1010929. [PMCID: PMC9671327 DOI: 10.1371/journal.ppat.1010929] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The amyloid cascade hypothesis, focusing on pathological proteins aggregation, has so far failed to uncover the root cause of Alzheimer’s disease (AD), or to provide an effective therapy. This traditional paradigm essentially explains a mechanism involved in the development of sporadic AD rather than its cause. The failure of an overwhelming majority of clinical studies (99.6%) demonstrates that a breakthrough in therapy would be difficult if not impossible without understanding the etiology of AD. It becomes more and more apparent that the AD pathology might originate from brain infection. In this review, we discuss a potential role of bacteria, viruses, fungi, and eukaryotic parasites as triggers of AD pathology. We show evidence from the current literature that amyloid beta, traditionally viewed as pathological, actually acts as an antimicrobial peptide, protecting the brain against pathogens. However, in case of a prolonged or excessive activation of a senescent immune system, amyloid beta accumulation and aggregation becomes damaging and supports runaway neurodegenerative processes in AD. This is paralleled by the recent study by Alam and colleagues (2022) who showed that alpha-synuclein, the protein accumulating in synucleinopathies, also plays a critical physiological role in immune reactions and inflammation, showing an unforeseen link between the 2 unrelated classes of neurodegenerative disorders. The multiplication of the amyloid precursor protein gene, recently described by Lee and collegues (2018), and possible reactivation of human endogenous retroviruses by pathogens fits well into the same picture. We discuss these new findings from the viewpoint of the infection hypothesis of AD and offer suggestions for future research. More than a century after its discovery, Alzheimer’s disease (AD) remains incurable and mysterious. The dominant hypothesis of amyloid cascade has succeeded in explaining the key pathological mechanism, but not its trigger. Amyloid beta has been traditionally considered a pathological peptide, and its physiological functions remain poorly known. These knowledge gaps have contributed to repeated failures of clinical studies. The emerging infectious hypothesis of AD considers central nervous system (CNS) infection the primary trigger of sporadic AD. A closely connected hypothesis claims that amyloid beta is an antimicrobial peptide. In this review, we discuss the available evidence for the involvement of infections in AD, coming from epidemiological studies, post mortem analyses of brain tissue, and experiments in vitro and in vivo. We argue there is no unique “Alzheimer’s germ,” instead, AD is a general reaction of the CNS to chronic infections, in the milieu of an aged immune system. The pathology may become self-sustained even without continuous presence of microbes in the brain. Importantly, the infectious hypothesis leads to testable predictions. Targeting amyloid beta should be ineffective, unless the triggering pathogen and inflammatory response are addressed as well. Meticulous control of selected infections might be the best near-term strategy for AD prevention.
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Affiliation(s)
- Iveta Vojtechova
- National Institute of Mental Health, Klecany, Czech Republic
- Laboratory of Neurophysiology of Memory, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
- * E-mail: , (IV); , (TP)
| | - Tomas Machacek
- Department of Parasitology, Faculty of Science, Charles University, Prague, Czech Republic
| | | | - Ales Stuchlik
- National Institute of Mental Health, Klecany, Czech Republic
- Laboratory of Neurophysiology of Memory, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Tomas Petrasek
- National Institute of Mental Health, Klecany, Czech Republic
- Laboratory of Neurophysiology of Memory, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
- * E-mail: , (IV); , (TP)
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16
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Iourov IY, Vorsanova SG, Kurinnaia OS, Kutsev SI, Yurov YB. Somatic mosaicism in the diseased brain. Mol Cytogenet 2022; 15:45. [PMID: 36266706 PMCID: PMC9585840 DOI: 10.1186/s13039-022-00624-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 10/05/2022] [Accepted: 10/07/2022] [Indexed: 11/10/2022] Open
Abstract
It is hard to believe that all the cells of a human brain share identical genomes. Indeed, single cell genetic studies have demonstrated intercellular genomic variability in the normal and diseased brain. Moreover, there is a growing amount of evidence on the contribution of somatic mosaicism (the presence of genetically different cell populations in the same individual/tissue) to the etiology of brain diseases. However, brain-specific genomic variations are generally overlooked during the research of genetic defects associated with a brain disease. Accordingly, a review of brain-specific somatic mosaicism in disease context seems to be required. Here, we overview gene mutations, copy number variations and chromosome abnormalities (aneuploidy, deletions, duplications and supernumerary rearranged chromosomes) detected in the neural/neuronal cells of the diseased brain. Additionally, chromosome instability in non-cancerous brain diseases is addressed. Finally, theoretical analysis of possible mechanisms for neurodevelopmental and neurodegenerative disorders indicates that a genetic background for formation of somatic (chromosomal) mosaicism in the brain is likely to exist. In total, somatic mosaicism affecting the central nervous system seems to be a mechanism of brain diseases.
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Affiliation(s)
- Ivan Y Iourov
- Yurov's Laboratory of Molecular Genetics and Cytogenomics of the Brain, Mental Health Research Center, Moscow, Russia. .,Vorsanova's Laboratory of Molecular Cytogenetics of Neuropsychiatric Diseases, Veltischev Research and Clinical Institute for Pediatrics and Pediatric Surgery of the Pirogov Russian National Research Medical University of the Russian Ministry of Health, Moscow, Russia. .,Department of Medical Biological Disciplines, Belgorod State University, Belgorod, Russia.
| | - Svetlana G Vorsanova
- Yurov's Laboratory of Molecular Genetics and Cytogenomics of the Brain, Mental Health Research Center, Moscow, Russia.,Vorsanova's Laboratory of Molecular Cytogenetics of Neuropsychiatric Diseases, Veltischev Research and Clinical Institute for Pediatrics and Pediatric Surgery of the Pirogov Russian National Research Medical University of the Russian Ministry of Health, Moscow, Russia
| | - Oxana S Kurinnaia
- Yurov's Laboratory of Molecular Genetics and Cytogenomics of the Brain, Mental Health Research Center, Moscow, Russia.,Vorsanova's Laboratory of Molecular Cytogenetics of Neuropsychiatric Diseases, Veltischev Research and Clinical Institute for Pediatrics and Pediatric Surgery of the Pirogov Russian National Research Medical University of the Russian Ministry of Health, Moscow, Russia
| | | | - Yuri B Yurov
- Yurov's Laboratory of Molecular Genetics and Cytogenomics of the Brain, Mental Health Research Center, Moscow, Russia.,Vorsanova's Laboratory of Molecular Cytogenetics of Neuropsychiatric Diseases, Veltischev Research and Clinical Institute for Pediatrics and Pediatric Surgery of the Pirogov Russian National Research Medical University of the Russian Ministry of Health, Moscow, Russia
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17
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SINE Insertion May Act as a Repressor to Affect the Expression of Pig LEPROT and Growth Traits. Genes (Basel) 2022; 13:genes13081422. [PMID: 36011333 PMCID: PMC9407865 DOI: 10.3390/genes13081422] [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: 07/08/2022] [Revised: 08/04/2022] [Accepted: 08/05/2022] [Indexed: 12/03/2022] Open
Abstract
Retrotransposon is an important component of the mammalian genome. Previous studies have shown that the expression of protein-coding genes was affected by the insertion of retrotransposon into the proximal genes, and the phenotype variations would be related to the retrotransposon insertion polymorphisms (RIPs). In this study, leptin (LEP), leptin receptor (LEPR), and leptin receptor overlapping transcript (LEPROT), which play important roles in the regulation of fat synthesis and body weight, were screened to search for the RIPs and their effect on phenotype and gene expression, as well as to further study the function of the insertion. The results showed that three RIPs located in intron 1 of LEPROT and intron 2 and 21 of LEPR were identified, and they were all SINEA1, which was one type of retrotransposon. The SINE insertion at the LEPROT was the dominant allele in native pig breeds. The age of 100 kg body weight of SINE+/+ Large White individuals was significantly higher than those of SINE+/− and SINE−/− individuals (p < 0.05). The LEPROT gene expression in the liver and suet of 30-day-old SINE−/− Sujiang piglets were significantly higher than those of SINE+/+ and SINE+/− piglets (p < 0.01). The dual-luciferase reporter gene assay showed that SINE insertion in PK15 and 3T3-L1 cells significantly reduced the promoter activity of the LEPROT gene (p < 0.01). Therefore, SINE insertion can be a repressor to reduce the expression of LEPROT and could be a useful molecular marker for assisted selection of growth traits in pig breeding.
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18
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Zyuz’kov GN, Miroshnichenko LA, Kotlovskaya LY, Chaikovsky A. The Role of JAKs and STAT3 in Regulation of Regenerative-Competent Cells of the Nervous Tissue in β-Amyloid-Induced Neurodegeneration. Bull Exp Biol Med 2022; 173:419-423. [DOI: 10.1007/s10517-022-05560-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Indexed: 10/14/2022]
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19
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Proukakis C. Somatic mutations may contribute to asymmetry in neurodegenerative disorders. Brain Commun 2022; 4:fcac184. [PMID: 35865349 PMCID: PMC9297084 DOI: 10.1093/braincomms/fcac184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 05/16/2022] [Accepted: 07/15/2022] [Indexed: 11/28/2022] Open
Affiliation(s)
- Christos Proukakis
- Professor of Neurology and Neurogenetics, Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology , London , UK
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20
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Lee S, Lee JH. Brain somatic mutations as RNA therapeutic targets in neurological disorders. Ann N Y Acad Sci 2022; 1514:11-20. [PMID: 35527236 DOI: 10.1111/nyas.14786] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Research into the genetic etiology of a neurological disorder can provide directions for genetic diagnosis and targeted therapy. In the past, germline mutations, which are transmitted from parents or newly arise from parental germ cells, were considered as major genetic causes of neurological disorders. However, recent evidence has shown that somatic mutations in the brain, which can arise from neural stem cells during development or over aging, account for a significant number of brain disorders, ranging from neurodevelopmental, neurodegenerative, and neuropsychiatric to neoplastic disease. Moreover, the identification of disease-causing somatic mutations or mutated genes has provided new insights into molecular pathogenesis and unveiled potential therapeutic targets for treating neurological disorders that have few, or no, therapeutic options. RNA therapeutics, including antisense oligonucleotide (ASO) and small interfering RNA (siRNA), are emerging as promising therapeutic tools for treating genetic neurological disorders. As the number of approved and investigational ASO and siRNA drugs for neurological disorders associated with germline mutations increases, they may also prove to be attractive modalities for treating neurologic disorders resulting from somatic mutations. In this perspective, we highlight several neurological diseases caused by brain somatic mutations and discuss the potential role of RNA therapeutics in these conditions.
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Affiliation(s)
- Sungyul Lee
- SoVarGen Co., Ltd., Daejeon, Republic of Korea
| | - Jeong Ho Lee
- SoVarGen Co., Ltd., Daejeon, Republic of Korea.,Graduate School of Medical Science and Engineering, Korea Advanced Institute Science and Technology (KAIST), KAIST BioMedical Research Center, Daejeon, Republic of Korea
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21
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Jena NR. Rare Tautomers of Artificially Expanded Genetic Letters and their Effects on the Base pair Stabilities. Chemphyschem 2022; 23:e202100908. [PMID: 35029036 DOI: 10.1002/cphc.202100908] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Indexed: 11/11/2022]
Abstract
To expand the existing genetic letters, it is necessary to design robust nucleotides that can function naturally in living cells. Therefore, it is desirable to examine the roles of recently proposed second-generation artificially expanded genetic letters in producing stable duplex DNA. Here, a reliable dispersion-corrected density functional theory method is used to understand the electronic structures and properties of different rare tautomers of proposed expanded genetic letters and their effects on the base pair stabilities in the duplex DNA. It is found that the rare tautomers are not only stable in the aqueous medium but can also base pair with natural bases to produce stable mispairs. Except for J and V, all the artificial genetic letters are found to produce mispairs that are about 1-7 kcal/mol more stable than their complementary counterparts. They are also appreciably more stable than the naturally occurring G:C, A:T, and G:T pairs. The higher base pair stabilities are found to be mainly because of the polarity of monomers and attractive electrostatic interactions.
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Affiliation(s)
- N R Jena
- IIITDM Jabalpur, Discipline of Natural Sciences, Dumna Airport Road, Khamaria, India, 482005, Jabalpur, INDIA
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22
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Grima N, Henden L, Watson O, Blair IP, Williams KL. Simultaneous Isolation of High-Quality RNA and DNA From Postmortem Human Central Nervous System Tissues for Omics Studies. J Neuropathol Exp Neurol 2021; 81:135-145. [PMID: 34939123 DOI: 10.1093/jnen/nlab129] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Multi-omics approaches are increasingly being adopted to understand the complex networks underlying disease. The coisolation of high-quality nucleotides from affected tissues is paramount for the parallel analysis of transcriptomic, genomic, and epigenomic data sets. Although nucleotides extracted from postmortem central nervous system (CNS) tissue are widely used in the study of neurodegenerative disease, assessment of methods for the simultaneous isolation of DNA and RNA is limited. Herein, we describe a strategy for the isolation of high-quality DNA and RNA from postmortem human tissue from 7 CNS regions. Motor cortex, frontal cortex, hippocampus, occipital cortex, anterior cingulate cortex, cerebellum, and spinal cord tissues were obtained from 22 individuals diagnosed with motor neuron disease (MND) and 13 neurologically normal controls (n = 245 tissues). We demonstrated that the Qiagen AllPrep DNA/RNA kit consistently isolated DNA and RNA of high yield and quality from all 6 brain regions. Importantly, phenol-chloroform-based extraction was required to isolate high-yield RNA from spinal cord. RNA sequencing using RNA extracted from 6 CNS regions (n = 60) generated high-quality transcriptomes. Hierarchical clustering of data from motor cortex, using an MND susceptibility gene panel and marker genes of disease-associated microglia, demonstrated that MND-specific gene expression signatures could be detected in the transcriptome data.
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Affiliation(s)
- Natalie Grima
- From the Faculty of Medicine, Health and Human Sciences, Macquarie University Centre for Motor Neuron Disease Research, Macquarie Medical School, Macquarie University, Sydney, New South Wales, Australia
| | - Lyndal Henden
- From the Faculty of Medicine, Health and Human Sciences, Macquarie University Centre for Motor Neuron Disease Research, Macquarie Medical School, Macquarie University, Sydney, New South Wales, Australia
| | - Owen Watson
- From the Faculty of Medicine, Health and Human Sciences, Macquarie University Centre for Motor Neuron Disease Research, Macquarie Medical School, Macquarie University, Sydney, New South Wales, Australia
| | - Ian P Blair
- From the Faculty of Medicine, Health and Human Sciences, Macquarie University Centre for Motor Neuron Disease Research, Macquarie Medical School, Macquarie University, Sydney, New South Wales, Australia
| | - Kelly L Williams
- From the Faculty of Medicine, Health and Human Sciences, Macquarie University Centre for Motor Neuron Disease Research, Macquarie Medical School, Macquarie University, Sydney, New South Wales, Australia
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23
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Li Y, Laws SM, Miles LA, Wiley JS, Huang X, Masters CL, Gu BJ. Genomics of Alzheimer's disease implicates the innate and adaptive immune systems. Cell Mol Life Sci 2021; 78:7397-7426. [PMID: 34708251 PMCID: PMC11073066 DOI: 10.1007/s00018-021-03986-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 09/14/2021] [Accepted: 10/16/2021] [Indexed: 02/08/2023]
Abstract
Alzheimer's disease (AD) is a chronic neurodegenerative disease characterised by cognitive impairment, behavioural alteration, and functional decline. Over 130 AD-associated susceptibility loci have been identified by genome-wide association studies (GWAS), while whole genome sequencing (WGS) and whole exome sequencing (WES) studies have identified AD-associated rare variants. These variants are enriched in APOE, TREM2, CR1, CD33, CLU, BIN1, CD2AP, PILRA, SCIMP, PICALM, SORL1, SPI1, RIN3, and more genes. Given that aging is the single largest risk factor for late-onset AD (LOAD), the accumulation of somatic mutations in the brain and blood of AD patients have also been explored. Collectively, these genetic findings implicate the role of innate and adaptive immunity in LOAD pathogenesis and suggest that a systemic failure of cell-mediated amyloid-β (Aβ) clearance contributes to AD onset and progression. AD-associated variants are particularly enriched in myeloid-specific regulatory regions, implying that AD risk variants are likely to perturbate the expression of myeloid-specific AD-associated genes to interfere Aβ clearance. Defective phagocytosis, endocytosis, and autophagy may drive Aβ accumulation, which may be related to naturally-occurring antibodies to Aβ (Nabs-Aβ) produced by adaptive responses. Passive immunisation is providing efficiency in clearing Aβ and slowing cognitive decline, such as aducanumab, donanemab, and lecanemab (ban2401). Causation of AD by impairment of the innate immunity and treatment using the tools of adaptive immunity is emerging as a new paradigm for AD, but immunotherapy that boosts the innate immune functions of myeloid cells is highly expected to modulate disease progression at asymptomatic stage.
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Affiliation(s)
- Yihan Li
- The Florey Institute, The University of Melbourne, 30 Royal Parade, Parkville, VIC, 3052, Australia
| | - Simon M Laws
- Centre for Precision Health, Edith Cowan University, 270 Joondalup Dr, Joondalup, WA, 6027, Australia
- Collaborative Genomics and Translation Group, School of Medical and Health Sciences, Edith Cowan University, 270 Joondalup Dr, Joondalup, WA, 6027, Australia
| | - Luke A Miles
- The Florey Institute, The University of Melbourne, 30 Royal Parade, Parkville, VIC, 3052, Australia
| | - James S Wiley
- The Florey Institute, The University of Melbourne, 30 Royal Parade, Parkville, VIC, 3052, Australia
| | - Xin Huang
- The Florey Institute, The University of Melbourne, 30 Royal Parade, Parkville, VIC, 3052, Australia
| | - Colin L Masters
- The Florey Institute, The University of Melbourne, 30 Royal Parade, Parkville, VIC, 3052, Australia
| | - Ben J Gu
- The Florey Institute, The University of Melbourne, 30 Royal Parade, Parkville, VIC, 3052, Australia.
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24
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Abstract
Somatic mutations arise postzygotically, producing genetic differences between cells in an organism. Well established as a driver of cancer, somatic mutations also exist in nonneoplastic cells, including in the brain. Technological advances in nucleic acid sequencing have enabled recent break-throughs that illuminate the roles of somatic mutations in aging and degenerative diseases of the brain. Somatic mutations accumulate during aging in human neurons, a process termed genosenium. A number of recent studies have examined somatic mutations in Alzheimer’s disease (AD), primarily from the perspective of genes causing familial AD. We have also gained new information on genome-wide mutations, providing insights into the cellular events driving somatic mutation and cellular dysfunction. This review highlights recent concepts, methods, and findings in the progress to understand the role of brain somatic mutation in aging and AD.
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Affiliation(s)
- Michael B Miller
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, Massachusetts 02115, USA; .,Department of Pediatrics, Harvard Medical School, Boston, Massachusetts 02115, USA.,Division of Neuropathology, Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA; .,Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142, USA
| | - Hannah C Reed
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, Massachusetts 02115, USA; .,Department of Pediatrics, Harvard Medical School, Boston, Massachusetts 02115, USA.,Allegheny College, Meadville, Pennsylvania 16335, USA;
| | - Christopher A Walsh
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, Massachusetts 02115, USA; .,Department of Pediatrics, Harvard Medical School, Boston, Massachusetts 02115, USA.,Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142, USA.,Howard Hughes Medical Institute, Boston, Massachusetts 02115, USA.,Department of Neurology, Harvard Medical School, Boston, Massachusetts 02115, USA
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25
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Doan RN, Miller MB, Kim SN, Rodin RE, Ganz J, Bizzotto S, Morillo KS, Huang AY, Digumarthy R, Zemmel Z, Walsh CA. MIPP-Seq: ultra-sensitive rapid detection and validation of low-frequency mosaic mutations. BMC Med Genomics 2021; 14:47. [PMID: 33579278 PMCID: PMC7881461 DOI: 10.1186/s12920-021-00893-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 02/03/2021] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Mosaic mutations contribute to numerous human disorders. As such, the identification and precise quantification of mosaic mutations is essential for a wide range of research applications, clinical diagnoses, and early detection of cancers. Currently, the low-throughput nature of single allele assays (e.g., allele-specific ddPCR) commonly used for genotyping known mutations at very low alternate allelic fractions (AAFs) have limited the integration of low-level mosaic analyses into clinical and research applications. The growing importance of mosaic mutations requires a more rapid, low-cost solution for mutation detection and validation. METHODS To overcome these limitations, we developed Multiple Independent Primer PCR Sequencing (MIPP-Seq) which combines the power of ultra-deep sequencing and truly independent assays. The accuracy of MIPP-seq to quantifiable detect and measure extremely low allelic fractions was assessed using a combination of SNVs, insertions, and deletions at known allelic fractions in blood and brain derived DNA samples. RESULTS The Independent amplicon analyses of MIPP-Seq markedly reduce the impact of allelic dropout, amplification bias, PCR-induced, and sequencing artifacts. Using low DNA inputs of either 25 ng or 50 ng of DNA, MIPP-Seq provides sensitive and quantitative assessments of AAFs as low as 0.025% for SNVs, insertion, and deletions. CONCLUSIONS MIPP-Seq provides an ultra-sensitive, low-cost approach for detecting and validating known and novel mutations in a highly scalable system with broad utility spanning both research and clinical diagnostic testing applications. The scalability of MIPP-Seq allows for multiplexing mutations and samples, which dramatically reduce costs of variant validation when compared to methods like ddPCR. By leveraging the power of individual analyses of multiple unique and independent reactions, MIPP-Seq can validate and precisely quantitate extremely low AAFs across multiple tissues and mutational categories including both indels and SNVs. Furthermore, using Illumina sequencing technology, MIPP-seq provides a robust method for accurate detection of novel mutations at an extremely low AAF.
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Affiliation(s)
- Ryan N Doan
- Division of Genetics and Genomics, Department of Pediatrics, Boston Children's Hospital, Center for Life Sciences 15062, 300 Longwood Avenue, BCH3150, Boston, MA, 02115, USA.
- Allen Discovery Center for Human Brain Evolution, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.
- Departments of Pediatrics and Neurology, Harvard Medical School, Boston, MA, USA.
| | - Michael B Miller
- Division of Genetics and Genomics, Department of Pediatrics, Boston Children's Hospital, Center for Life Sciences 15062, 300 Longwood Avenue, BCH3150, Boston, MA, 02115, USA
- Department of Pathology, Brigham and Women's Hospital, Boston, MA, USA
| | - Sonia N Kim
- Division of Genetics and Genomics, Department of Pediatrics, Boston Children's Hospital, Center for Life Sciences 15062, 300 Longwood Avenue, BCH3150, Boston, MA, 02115, USA
- Program in Biological and Biomedical Sciences, Harvard University, Boston, MA, USA
| | - Rachel E Rodin
- Division of Genetics and Genomics, Department of Pediatrics, Boston Children's Hospital, Center for Life Sciences 15062, 300 Longwood Avenue, BCH3150, Boston, MA, 02115, USA
| | - Javier Ganz
- Division of Genetics and Genomics, Department of Pediatrics, Boston Children's Hospital, Center for Life Sciences 15062, 300 Longwood Avenue, BCH3150, Boston, MA, 02115, USA
| | - Sara Bizzotto
- Division of Genetics and Genomics, Department of Pediatrics, Boston Children's Hospital, Center for Life Sciences 15062, 300 Longwood Avenue, BCH3150, Boston, MA, 02115, USA
| | - Katherine S Morillo
- Division of Genetics and Genomics, Department of Pediatrics, Boston Children's Hospital, Center for Life Sciences 15062, 300 Longwood Avenue, BCH3150, Boston, MA, 02115, USA
| | - August Yue Huang
- Division of Genetics and Genomics, Department of Pediatrics, Boston Children's Hospital, Center for Life Sciences 15062, 300 Longwood Avenue, BCH3150, Boston, MA, 02115, USA
| | - Reethika Digumarthy
- Division of Genetics and Genomics, Department of Pediatrics, Boston Children's Hospital, Center for Life Sciences 15062, 300 Longwood Avenue, BCH3150, Boston, MA, 02115, USA
| | - Zachary Zemmel
- Division of Genetics and Genomics, Department of Pediatrics, Boston Children's Hospital, Center for Life Sciences 15062, 300 Longwood Avenue, BCH3150, Boston, MA, 02115, USA
| | - Christopher A Walsh
- Division of Genetics and Genomics, Department of Pediatrics, Boston Children's Hospital, Center for Life Sciences 15062, 300 Longwood Avenue, BCH3150, Boston, MA, 02115, USA.
- Allen Discovery Center for Human Brain Evolution, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.
- Howard Hughes Medical Institute, Chevy Chase, MD, 20815, USA.
- Departments of Pediatrics and Neurology, Harvard Medical School, Boston, MA, USA.
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26
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Abstract
DNA mismatch repair (MMR) is a highly conserved genome stabilizing pathway that corrects DNA replication errors, limits chromosomal rearrangements, and mediates the cellular response to many types of DNA damage. Counterintuitively, MMR is also involved in the generation of mutations, as evidenced by its role in causing somatic triplet repeat expansion in Huntington’s disease (HD) and other neurodegenerative disorders. In this review, we discuss the current state of mechanistic knowledge of MMR and review the roles of key enzymes in this pathway. We also present the evidence for mutagenic function of MMR in CAG repeat expansion and consider mechanistic hypotheses that have been proposed. Understanding the role of MMR in CAG expansion may shed light on potential avenues for therapeutic intervention in HD.
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Affiliation(s)
- Ravi R Iyer
- CHDI Management/CHDI Foundation, Princeton, NJ, USA
| | - Anna Pluciennik
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA, USA
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27
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Ryan ÉB, Deng HX. Does Somatic Mosaicism Account for Some Sporadic ALS? NEUROLOGY-GENETICS 2021; 7:e555. [PMID: 33977141 PMCID: PMC8105897 DOI: 10.1212/nxg.0000000000000555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Éanna B Ryan
- Ken and Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL
| | - Han-Xiang Deng
- Ken and Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL
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28
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Hisahara S, Nishiyama A, Tsuda E, Suzuki S, Matsumura A, Ishikawa A, Sakurai A, Motoike IN, Aoki M, Aoki Y, Shimohama S. Possible Somatic Mosaicism of Novel FUS Variant in Familial Amyotrophic Lateral Sclerosis. NEUROLOGY-GENETICS 2021; 7:e552. [PMID: 33987464 PMCID: PMC8112850 DOI: 10.1212/nxg.0000000000000552] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 11/09/2020] [Indexed: 12/11/2022]
Affiliation(s)
- Shin Hisahara
- Department of Neurology (S.H., S. Suzuki, A.M., S. Shimohama), School of Medicine, Sapporo Medical University, Japan; Department of Neurology (A.N., M.A.), Tohoku University School of Medicine, Sendai, Japan; Department of Neurology (E.T.), Sapporo Shirakabadai Hospital, Japan; Department of Medical Genetics and Genomics (A.I., A.S.), School of Medicine, Sapporo Medical University, Japan; Tohoku Medical Megabank Organization (I.N.M.), Tohoku University Graduate School of Information Sciences, Sendai, Japan; and Department of Medical Genetics (Y.A.), Tohoku University School of Medicine, Sendai, Japan
| | - Ayumi Nishiyama
- Department of Neurology (S.H., S. Suzuki, A.M., S. Shimohama), School of Medicine, Sapporo Medical University, Japan; Department of Neurology (A.N., M.A.), Tohoku University School of Medicine, Sendai, Japan; Department of Neurology (E.T.), Sapporo Shirakabadai Hospital, Japan; Department of Medical Genetics and Genomics (A.I., A.S.), School of Medicine, Sapporo Medical University, Japan; Tohoku Medical Megabank Organization (I.N.M.), Tohoku University Graduate School of Information Sciences, Sendai, Japan; and Department of Medical Genetics (Y.A.), Tohoku University School of Medicine, Sendai, Japan
| | - Emiko Tsuda
- Department of Neurology (S.H., S. Suzuki, A.M., S. Shimohama), School of Medicine, Sapporo Medical University, Japan; Department of Neurology (A.N., M.A.), Tohoku University School of Medicine, Sendai, Japan; Department of Neurology (E.T.), Sapporo Shirakabadai Hospital, Japan; Department of Medical Genetics and Genomics (A.I., A.S.), School of Medicine, Sapporo Medical University, Japan; Tohoku Medical Megabank Organization (I.N.M.), Tohoku University Graduate School of Information Sciences, Sendai, Japan; and Department of Medical Genetics (Y.A.), Tohoku University School of Medicine, Sendai, Japan
| | - Syuuichirou Suzuki
- Department of Neurology (S.H., S. Suzuki, A.M., S. Shimohama), School of Medicine, Sapporo Medical University, Japan; Department of Neurology (A.N., M.A.), Tohoku University School of Medicine, Sendai, Japan; Department of Neurology (E.T.), Sapporo Shirakabadai Hospital, Japan; Department of Medical Genetics and Genomics (A.I., A.S.), School of Medicine, Sapporo Medical University, Japan; Tohoku Medical Megabank Organization (I.N.M.), Tohoku University Graduate School of Information Sciences, Sendai, Japan; and Department of Medical Genetics (Y.A.), Tohoku University School of Medicine, Sendai, Japan
| | - Akihiro Matsumura
- Department of Neurology (S.H., S. Suzuki, A.M., S. Shimohama), School of Medicine, Sapporo Medical University, Japan; Department of Neurology (A.N., M.A.), Tohoku University School of Medicine, Sendai, Japan; Department of Neurology (E.T.), Sapporo Shirakabadai Hospital, Japan; Department of Medical Genetics and Genomics (A.I., A.S.), School of Medicine, Sapporo Medical University, Japan; Tohoku Medical Megabank Organization (I.N.M.), Tohoku University Graduate School of Information Sciences, Sendai, Japan; and Department of Medical Genetics (Y.A.), Tohoku University School of Medicine, Sendai, Japan
| | - Aki Ishikawa
- Department of Neurology (S.H., S. Suzuki, A.M., S. Shimohama), School of Medicine, Sapporo Medical University, Japan; Department of Neurology (A.N., M.A.), Tohoku University School of Medicine, Sendai, Japan; Department of Neurology (E.T.), Sapporo Shirakabadai Hospital, Japan; Department of Medical Genetics and Genomics (A.I., A.S.), School of Medicine, Sapporo Medical University, Japan; Tohoku Medical Megabank Organization (I.N.M.), Tohoku University Graduate School of Information Sciences, Sendai, Japan; and Department of Medical Genetics (Y.A.), Tohoku University School of Medicine, Sendai, Japan
| | - Akihiro Sakurai
- Department of Neurology (S.H., S. Suzuki, A.M., S. Shimohama), School of Medicine, Sapporo Medical University, Japan; Department of Neurology (A.N., M.A.), Tohoku University School of Medicine, Sendai, Japan; Department of Neurology (E.T.), Sapporo Shirakabadai Hospital, Japan; Department of Medical Genetics and Genomics (A.I., A.S.), School of Medicine, Sapporo Medical University, Japan; Tohoku Medical Megabank Organization (I.N.M.), Tohoku University Graduate School of Information Sciences, Sendai, Japan; and Department of Medical Genetics (Y.A.), Tohoku University School of Medicine, Sendai, Japan
| | - Ikuko N Motoike
- Department of Neurology (S.H., S. Suzuki, A.M., S. Shimohama), School of Medicine, Sapporo Medical University, Japan; Department of Neurology (A.N., M.A.), Tohoku University School of Medicine, Sendai, Japan; Department of Neurology (E.T.), Sapporo Shirakabadai Hospital, Japan; Department of Medical Genetics and Genomics (A.I., A.S.), School of Medicine, Sapporo Medical University, Japan; Tohoku Medical Megabank Organization (I.N.M.), Tohoku University Graduate School of Information Sciences, Sendai, Japan; and Department of Medical Genetics (Y.A.), Tohoku University School of Medicine, Sendai, Japan
| | - Masashi Aoki
- Department of Neurology (S.H., S. Suzuki, A.M., S. Shimohama), School of Medicine, Sapporo Medical University, Japan; Department of Neurology (A.N., M.A.), Tohoku University School of Medicine, Sendai, Japan; Department of Neurology (E.T.), Sapporo Shirakabadai Hospital, Japan; Department of Medical Genetics and Genomics (A.I., A.S.), School of Medicine, Sapporo Medical University, Japan; Tohoku Medical Megabank Organization (I.N.M.), Tohoku University Graduate School of Information Sciences, Sendai, Japan; and Department of Medical Genetics (Y.A.), Tohoku University School of Medicine, Sendai, Japan
| | - Yoko Aoki
- Department of Neurology (S.H., S. Suzuki, A.M., S. Shimohama), School of Medicine, Sapporo Medical University, Japan; Department of Neurology (A.N., M.A.), Tohoku University School of Medicine, Sendai, Japan; Department of Neurology (E.T.), Sapporo Shirakabadai Hospital, Japan; Department of Medical Genetics and Genomics (A.I., A.S.), School of Medicine, Sapporo Medical University, Japan; Tohoku Medical Megabank Organization (I.N.M.), Tohoku University Graduate School of Information Sciences, Sendai, Japan; and Department of Medical Genetics (Y.A.), Tohoku University School of Medicine, Sendai, Japan
| | - Shun Shimohama
- Department of Neurology (S.H., S. Suzuki, A.M., S. Shimohama), School of Medicine, Sapporo Medical University, Japan; Department of Neurology (A.N., M.A.), Tohoku University School of Medicine, Sendai, Japan; Department of Neurology (E.T.), Sapporo Shirakabadai Hospital, Japan; Department of Medical Genetics and Genomics (A.I., A.S.), School of Medicine, Sapporo Medical University, Japan; Tohoku Medical Megabank Organization (I.N.M.), Tohoku University Graduate School of Information Sciences, Sendai, Japan; and Department of Medical Genetics (Y.A.), Tohoku University School of Medicine, Sendai, Japan
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29
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Lattante S, Marangi G, Doronzio PN, Conte A, Bisogni G, Zollino M, Sabatelli M. High-Throughput Genetic Testing in ALS: The Challenging Path of Variant Classification Considering the ACMG Guidelines. Genes (Basel) 2020; 11:genes11101123. [PMID: 32987860 PMCID: PMC7600768 DOI: 10.3390/genes11101123] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 09/15/2020] [Accepted: 09/22/2020] [Indexed: 12/17/2022] Open
Abstract
The development of high-throughput sequencing technologies and screening of big patient cohorts with familial and sporadic amyotrophic lateral sclerosis (ALS) led to the identification of a significant number of genetic variants, which are sometimes difficult to interpret. The American College of Medical Genetics and Genomics (ACMG) provided guidelines to help molecular geneticists and pathologists to interpret variants found in laboratory testing. We assessed the application of the ACMG criteria to ALS-related variants, combining data from literature with our experience. We analyzed a cohort of 498 ALS patients using massive parallel sequencing of ALS-associated genes and identified 280 variants with a minor allele frequency < 1%. Examining all variants using the ACMG criteria, thus considering the type of variant, inheritance, familial segregation, and possible functional studies, we classified 20 variants as “pathogenic”. In conclusion, ALS’s genetic complexity, such as oligogenic inheritance, presence of genes acting as risk factors, and reduced penetrance, needs to be considered when interpreting variants. The goal of this work is to provide helpful suggestions to geneticists and clinicians dealing with ALS.
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Affiliation(s)
- Serena Lattante
- Section of Genomic Medicine, Department of Life Sciences and Public Health, Faculty of Medicine and Surgery, Catholic University of the Sacred Heart, 00168 Roma, Italy; (S.L.); (P.N.D.); (M.Z.)
- Complex Operational Unit of Medical Genetics, Department of Laboratory and Infectious Disease Sciences, A. Gemelli University Hospital Foundation IRCCS, 00168 Roma, Italy
| | - Giuseppe Marangi
- Section of Genomic Medicine, Department of Life Sciences and Public Health, Faculty of Medicine and Surgery, Catholic University of the Sacred Heart, 00168 Roma, Italy; (S.L.); (P.N.D.); (M.Z.)
- Complex Operational Unit of Medical Genetics, Department of Laboratory and Infectious Disease Sciences, A. Gemelli University Hospital Foundation IRCCS, 00168 Roma, Italy
- Correspondence: ; Tel.: +39-0630154606
| | - Paolo Niccolò Doronzio
- Section of Genomic Medicine, Department of Life Sciences and Public Health, Faculty of Medicine and Surgery, Catholic University of the Sacred Heart, 00168 Roma, Italy; (S.L.); (P.N.D.); (M.Z.)
- Complex Operational Unit of Medical Genetics, Department of Laboratory and Infectious Disease Sciences, A. Gemelli University Hospital Foundation IRCCS, 00168 Roma, Italy
| | - Amelia Conte
- Adult NEMO Clinical Center, Complex Operational Unit of Neurology, Department of Aging, Neurological, Orthopedic and Head-Neck Sciences, A. Gemelli University Hospital Foundation IRCCS, 00168 Roma, Italy; (A.C.); (G.B.); (M.S.)
| | - Giulia Bisogni
- Adult NEMO Clinical Center, Complex Operational Unit of Neurology, Department of Aging, Neurological, Orthopedic and Head-Neck Sciences, A. Gemelli University Hospital Foundation IRCCS, 00168 Roma, Italy; (A.C.); (G.B.); (M.S.)
| | - Marcella Zollino
- Section of Genomic Medicine, Department of Life Sciences and Public Health, Faculty of Medicine and Surgery, Catholic University of the Sacred Heart, 00168 Roma, Italy; (S.L.); (P.N.D.); (M.Z.)
- Complex Operational Unit of Medical Genetics, Department of Laboratory and Infectious Disease Sciences, A. Gemelli University Hospital Foundation IRCCS, 00168 Roma, Italy
| | - Mario Sabatelli
- Adult NEMO Clinical Center, Complex Operational Unit of Neurology, Department of Aging, Neurological, Orthopedic and Head-Neck Sciences, A. Gemelli University Hospital Foundation IRCCS, 00168 Roma, Italy; (A.C.); (G.B.); (M.S.)
- Section of Neurology, Department of Neuroscience, Faculty of Medicine and Surgery, Catholic University of the Sacred Heart, 00168 Roma, Italy
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