1
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Palombo F, Vaisfeld A, Tropeano VC, Ormanbekova D, Bacchi I, Fiorini C, Peruzzi A, Morandi L, Liguori R, Carelli V, Rizzo G. Two more families supporting the existence of monogenic spinocerebellar ataxia 48. Neurogenetics 2024:10.1007/s10048-024-00758-8. [PMID: 38625442 DOI: 10.1007/s10048-024-00758-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2023] [Accepted: 04/09/2024] [Indexed: 04/17/2024]
Abstract
The reduced penetrance of TBP intermediate alleles and the recently proposed possible digenic TBP/STUB1 inheritance raised questions on the possible mechanism involved opening a debate on the existence of SCA48 as a monogenic disorder. We here report clinical and genetic results of two apparently unrelated patients carrying the same STUB1 variant(c.244G > T;p.Asp82Tyr) with normal TBP alleles and a clinical picture fully resembling SCA48, including cerebellar ataxia, dysarthria and mild cognitive impairment. This report provides supportive evidence that this specific ataxia can also occur as a monogenic disease, considering classical TBP allelic ranges.
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Affiliation(s)
- Flavia Palombo
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Programma di Neurogenetica, Via Altura 3, Bologna, 40139, Italy.
| | - Alessandro Vaisfeld
- IRCCS Azienda Ospedaliero-Universitaria Policlinico Sant'Orsola-Malpighi, Medical Genetics Unit, Bologna, Italy
- Department of Medical and Surgical Sciences, University of Bologna, Bologna, Italy
| | - Valentina Concetta Tropeano
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Programma di Neurogenetica, Via Altura 3, Bologna, 40139, Italy
| | - Danara Ormanbekova
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Programma di Neurogenetica, Via Altura 3, Bologna, 40139, Italy
| | - Isabelle Bacchi
- IRCCS Azienda Ospedaliero-Universitaria Policlinico Sant'Orsola-Malpighi, Medical Genetics Unit, Bologna, Italy
- Department of Medical and Surgical Sciences, University of Bologna, Bologna, Italy
| | - Claudio Fiorini
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Programma di Neurogenetica, Via Altura 3, Bologna, 40139, Italy
| | - Adelaide Peruzzi
- IRCCS Azienda Ospedaliero-Universitaria Policlinico Sant'Orsola-Malpighi, Medical Genetics Unit, Bologna, Italy
- Department of Medical and Surgical Sciences, University of Bologna, Bologna, Italy
| | - Luca Morandi
- IRCCS Istituto delle Scienze Neurologiche di Bologna, UOC Clinica Neurologica, Bologna, Italy
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Rocco Liguori
- IRCCS Istituto delle Scienze Neurologiche di Bologna, UOC Clinica Neurologica, Bologna, Italy
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Valerio Carelli
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Programma di Neurogenetica, Via Altura 3, Bologna, 40139, Italy
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Giovanni Rizzo
- IRCCS Istituto delle Scienze Neurologiche di Bologna, UOC Clinica Neurologica, Bologna, Italy
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2
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Shafie A, Ashour AA, Anjum F, Shamsi A, Hassan MI. Elucidating the Impact of Deleterious Mutations on IGHG1 and Their Association with Huntington's Disease. J Pers Med 2024; 14:380. [PMID: 38673007 PMCID: PMC11050829 DOI: 10.3390/jpm14040380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Revised: 03/27/2024] [Accepted: 03/28/2024] [Indexed: 04/28/2024] Open
Abstract
Huntington's disease (HD) is a chronic, inherited neurodegenerative condition marked by chorea, dementia, and changes in personality. The primary cause of HD is a mutation characterized by the expansion of a triplet repeat (CAG) within the huntingtin gene located on chromosome 4. Despite substantial progress in elucidating the molecular and cellular mechanisms of HD, an effective treatment for this disorder is not available so far. In recent years, researchers have been interested in studying cerebrospinal fluid (CSF) as a source of biomarkers that could aid in the diagnosis and therapeutic development of this disorder. Immunoglobulin heavy constant gamma 1 (IGHG1) is one of the CSF proteins found to increase significantly in HD. Considering this, it is reasonable to study the potential involvement of deleterious mutations in IGHG1 in the pathogenesis of this disorder. In this study, we explored the potential impact of deleterious mutations on IGHG1 and their subsequent association with HD. We evaluated 126 single-point amino acid substitutions for their impact on the structure and functionality of the IGHG1 protein while exploiting multiple computational resources such as SIFT, PolyPhen-2, FATHMM, SNPs&Go mCSM, DynaMut2, MAESTROweb, PremPS, MutPred2, and PhD-SNP. The sequence- and structure-based tools highlighted 10 amino acid substitutions that were deleterious and destabilizing. Subsequently, out of these 10 mutations, eight variants (Y32C, Y32D, P34S, V39E, C83R, C83Y, V85M, and H87Q) were identified as pathogenic by disease phenotype predictors. Finally, two pathogenic variants (Y32C and P34S) were found to reduce the solubility of the protein, suggesting their propensity to form protein aggregates. These variants also exhibited higher residual frustration within the protein structure. Considering these findings, the study hypothesized that the identified variants of IGHG1 may compromise its function and potentially contribute to HD pathogenesis.
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Affiliation(s)
- Alaa Shafie
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia; (A.S.); (F.A.)
| | - Amal Adnan Ashour
- Department of Oral and Maxillofacial Surgery and Diagnostic Sciences, Faculty of Dentistry, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia;
| | - Farah Anjum
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia; (A.S.); (F.A.)
| | - Anas Shamsi
- Center of Medical and Bio-Allied Health Sciences Research (CMBHSR), Ajman University, Ajman P.O. Box 346, United Arab Emirates
| | - Md. Imtaiyaz Hassan
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India
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Pressl C, Mätlik K, Kus L, Darnell P, Luo JD, Paul MR, Weiss AR, Liguore W, Carroll TS, Davis DA, McBride J, Heintz N. Selective vulnerability of layer 5a corticostriatal neurons in Huntington's disease. Neuron 2024; 112:924-941.e10. [PMID: 38237588 DOI: 10.1016/j.neuron.2023.12.009] [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: 06/15/2023] [Revised: 08/18/2023] [Accepted: 12/13/2023] [Indexed: 01/30/2024]
Abstract
The properties of the cell types that are selectively vulnerable in Huntington's disease (HD) cortex, the nature of somatic CAG expansions of mHTT in these cells, and their importance in CNS circuitry have not been delineated. Here, we employed serial fluorescence-activated nuclear sorting (sFANS), deep molecular profiling, and single-nucleus RNA sequencing (snRNA-seq) of motor-cortex samples from thirteen predominantly early stage, clinically diagnosed HD donors and selected samples from cingulate, visual, insular, and prefrontal cortices to demonstrate loss of layer 5a pyramidal neurons in HD. Extensive mHTT CAG expansions occur in vulnerable layer 5a pyramidal cells, and in Betz cells, layers 6a and 6b neurons that are resilient in HD. Retrograde tracing experiments in macaque brains identify layer 5a neurons as corticostriatal pyramidal cells. We propose that enhanced somatic mHTT CAG expansion and altered synaptic function act together to cause corticostriatal disconnection and selective neuronal vulnerability in HD cerebral cortex.
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Affiliation(s)
- Christina Pressl
- Laboratory of Molecular Biology, The Rockefeller University, New York, NY, USA
| | - Kert Mätlik
- Laboratory of Molecular Biology, The Rockefeller University, New York, NY, USA
| | - Laura Kus
- Laboratory of Molecular Biology, The Rockefeller University, New York, NY, USA
| | - Paul Darnell
- Laboratory of Molecular Biology, The Rockefeller University, New York, NY, USA
| | - Ji-Dung Luo
- Bioinformatics Resource Center, The Rockefeller University, New York, NY, USA
| | - Matthew R Paul
- Bioinformatics Resource Center, The Rockefeller University, New York, NY, USA
| | - Alison R Weiss
- Division of Neuroscience, Oregon National Primate Research Center, Beaverton, OR, USA
| | - William Liguore
- Division of Neuroscience, Oregon National Primate Research Center, Beaverton, OR, USA
| | - Thomas S Carroll
- Bioinformatics Resource Center, The Rockefeller University, New York, NY, USA
| | - David A Davis
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Jodi McBride
- Division of Neuroscience, Oregon National Primate Research Center, Beaverton, OR, USA
| | - Nathaniel Heintz
- Laboratory of Molecular Biology, The Rockefeller University, New York, NY, USA.
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4
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Skeens A, Siriwardhana C, Massinople SE, Wunder MM, Ellis ZL, Keith KM, Girman T, Frey SL, Legleiter J. The polyglutamine domain is the primary driver of seeding in huntingtin aggregation. PLoS One 2024; 19:e0298323. [PMID: 38483973 PMCID: PMC10939245 DOI: 10.1371/journal.pone.0298323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 01/22/2024] [Indexed: 03/17/2024] Open
Abstract
Huntington's Disease (HD) is a fatal, neurodegenerative disease caused by aggregation of the huntingtin protein (htt) with an expanded polyglutamine (polyQ) domain into amyloid fibrils. Htt aggregation is modified by flanking sequences surrounding the polyQ domain as well as the binding of htt to lipid membranes. Upon fibrillization, htt fibrils are able to template the aggregation of monomers into fibrils in a phenomenon known as seeding, and this process appears to play a critical role in cell-to-cell spread of HD. Here, exposure of C. elegans expressing a nonpathogenic N-terminal htt fragment (15-repeat glutamine residues) to preformed htt-exon1 fibrils induced inclusion formation and resulted in decreased viability in a dose dependent manner, demonstrating that seeding can induce toxic aggregation of nonpathogenic forms of htt. To better understand this seeding process, the impact of flanking sequences adjacent to the polyQ stretch, polyQ length, and the presence of model lipid membranes on htt seeding was investigated. Htt seeding readily occurred across polyQ lengths and was independent of flanking sequence, suggesting that the structured polyQ domain within fibrils is the key contributor to the seeding phenomenon. However, the addition of lipid vesicles modified seeding efficiency in a manner suggesting that seeding primarily occurs in bulk solution and not at the membrane interface. In addition, fibrils formed in the presence of lipid membranes displayed similar seeding efficiencies. Collectively, this suggests that the polyQ domain that forms the amyloid fibril core is the main driver of seeding in htt aggregation.
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Affiliation(s)
- Adam Skeens
- The C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia, United States of America
| | - Chathuranga Siriwardhana
- The C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia, United States of America
| | - Sophia E. Massinople
- The C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia, United States of America
| | - Michelle M. Wunder
- The C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia, United States of America
| | - Zachary L. Ellis
- The C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia, United States of America
| | - Kaitlyn M. Keith
- The C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia, United States of America
| | - Tyler Girman
- The C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia, United States of America
| | - Shelli L. Frey
- The Department of Chemistry, Gettysburg College, Gettysburg, Pennsylvania, United States of America
| | - Justin Legleiter
- The C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia, United States of America
- Rockefeller Neurosciences Institutes, West Virginia University, Morgantown, West Virginia, United States of America
- Department of Neuroscience, West Virginia University, Morgantown, West Virginia, United States of America
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5
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Hoschek F, Natan J, Wagner M, Sathasivam K, Abdelmoez A, von Einem B, Bates GP, Landwehrmeyer GB, Neueder A. Huntingtin HTT1a is generated in a CAG repeat-length-dependent manner in human tissues. Mol Med 2024; 30:36. [PMID: 38459427 PMCID: PMC10924374 DOI: 10.1186/s10020-024-00801-2] [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: 11/10/2023] [Accepted: 02/19/2024] [Indexed: 03/10/2024] Open
Abstract
BACKGROUND The disease-causing mutation in Huntington disease (HD) is a CAG trinucleotide expansion in the huntingtin (HTT) gene. The mutated CAG tract results in the production of a small RNA, HTT1a, coding for only exon 1 of HTT. HTT1a is generated by a block in the splicing reaction of HTT exon 1 to exon 2 followed by cleavage in intron 1 and polyadenylation. Translation of HTT1a leads to the expression of the highly toxic HTT exon 1 protein fragment. We have previously shown that the levels of HTT1a expression in mouse models of HD is dependent on the CAG repeat length. However, these data are lacking for human tissues. METHODS To answer this question, we developed highly sensitive digital PCR assays to determine HTT1a levels in human samples. These assays allow the absolute quantification of transcript numbers and thus also facilitate the comparison of HTT1a levels between tissues, cell types and across different studies. Furthermore, we measured CAG repeat sizes for every sample used in the study. Finally, we analysed our data with ANOVA and linear modelling to determine the correlation of HTT1a expression levels with CAG repeat sizes. RESULTS In summary, we show that HTT1a is indeed expressed in a CAG repeat-length-dependent manner in human post mortem brain tissues as well as in several peripheral cell types. In particular, PBMCs show a statistically significant positive correlation of HTT1a expression with CAG repeat length, and elevated HTT1a expression levels even in the adult-onset CAG repeat range. CONCLUSIONS Our results show that HTT1a expression occurs throughout a wide range of tissues and likely with all CAG lengths. Our data from peripheral sample sources demonstrate that HTT1a is indeed generated throughout the body in a CAG repeat-length-dependent manner. Therefore, the levels of HTT1a might be a sensitive marker of disease state and/or progression and should be monitored over time, especially in clinical trials targeting HTT expression.
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Affiliation(s)
- Franziska Hoschek
- Department of Neurology, University Hospital Ulm, 89081, Ulm, Germany
| | - Julia Natan
- Department of Neurology, University Hospital Ulm, 89081, Ulm, Germany
| | - Maximilian Wagner
- Department of Neurology, University Hospital Ulm, 89081, Ulm, Germany
| | - Kirupa Sathasivam
- Huntington's Disease Centre, Department of Neurodegenerative Disease, Queen Square Institute of Neurology, University College London, WC1N 3BG, London, UK
| | - Alshaimaa Abdelmoez
- Department of Neurology, University Hospital Ulm, 89081, Ulm, Germany
- Department of Pharmaceutical Organic Chemistry, Faculty of Pharmacy, Assiut University, Assiut, Egypt
| | - Björn von Einem
- Department of Neurology, University Hospital Ulm, 89081, Ulm, Germany
| | - Gillian P Bates
- Huntington's Disease Centre, Department of Neurodegenerative Disease, Queen Square Institute of Neurology, University College London, WC1N 3BG, London, UK
| | | | - Andreas Neueder
- Department of Neurology, University Hospital Ulm, 89081, Ulm, Germany.
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6
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Dalene Skarping K, Arning L, Petersén Å, Nguyen HP, Gebre-Medhin S. Attenuated huntingtin gene CAG nucleotide repeat size in individuals with Lynch syndrome. Sci Rep 2024; 14:4300. [PMID: 38383663 PMCID: PMC10881568 DOI: 10.1038/s41598-024-54277-5] [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: 09/14/2023] [Accepted: 02/10/2024] [Indexed: 02/23/2024] Open
Abstract
DNA mismatch repair (MMR) is thought to contribute to the onset and progression of Huntington disease (HD) by promoting somatic expansion of the pathogenic CAG nucleotide repeat in the huntingtin gene (HTT). Here we have studied constitutional HTT CAG repeat size in two cohorts of individuals with Lynch syndrome (LS) carrying heterozygous loss-of-function variants in the MMR genes MLH1 (n = 12/60; Lund cohort/Bochum cohort, respectively), MSH2 (n = 15/88), MSH6 (n = 21/23), and controls (n = 19/559). The sum of CAG repeats for both HTT alleles in each individual was calculated due to unknown segregation with the LS allele. In the larger Bochum cohort, the sum of CAG repeats was lower in the MLH1 subgroup compared to controls (MLH1 35.40 CAG repeats ± 3.6 vs. controls 36.89 CAG repeats ± 4.5; p = 0.014). All LS genetic subgroups in the Bochum cohort displayed lower frequencies of unstable HTT intermediate alleles and lower HTT somatic CAG repeat expansion index values compared to controls. Collectively, our results indicate that MMR gene haploinsufficiency could have a restraining impact on constitutional HTT CAG repeat size and support the notion that the MMR pathway is a driver of nucleotide repeat expansion diseases.
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Affiliation(s)
- Karin Dalene Skarping
- Division of Clinical Genetics, Department of Laboratory Medicine, Lund University, Lund, Sweden
- Department of Clinical Genetics and Pathology, Office for Medical Service, 221 85, Lund, Sweden
- Translational Neuroendocrine Research Unit, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Larissa Arning
- Department of Human Genetics, Faculty of Medicine, Ruhr University Bochum, Universitätsstr. 150, 44801, Bochum, Germany
| | - Åsa Petersén
- Translational Neuroendocrine Research Unit, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Huu Phuc Nguyen
- Department of Human Genetics, Faculty of Medicine, Ruhr University Bochum, Universitätsstr. 150, 44801, Bochum, Germany.
| | - Samuel Gebre-Medhin
- Division of Clinical Genetics, Department of Laboratory Medicine, Lund University, Lund, Sweden.
- Department of Clinical Genetics and Pathology, Office for Medical Service, 221 85, Lund, Sweden.
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7
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Handley RR, Reid SJ, Burch Z, Jacobsen JC, Gillis T, Correia K, Rudiger SR, McLaughlin CJ, Bawden CS, MacDonald ME, Wheeler VC, Snell RG. Somatic CAG Repeat Stability in a Transgenic Sheep Model of Huntington's Disease. J Huntingtons Dis 2024; 13:33-40. [PMID: 38393920 DOI: 10.3233/jhd-231516] [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: 02/25/2024]
Abstract
Somatic instability of the huntingtin (HTT) CAG repeat mutation modifies age-at-onset of Huntington's disease (HD). Understanding the mechanism and pathogenic consequences of instability may reveal therapeutic targets. Using small-pool PCR we analyzed CAG instability in the OVT73 sheep model which expresses a full-length human cDNA HTT transgene. Analyses of five- and ten-year old sheep revealed the transgene (CAG)69 repeat was remarkably stable in liver, striatum, and other brain tissues. As OVT73 sheep at ten years old have minimal cell death and behavioral changes, our findings support instability of the HTT expanded-CAG repeat as being required for the progression of HD.
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Affiliation(s)
- Renee R Handley
- Centre for Brain Research, School of Biological Sciences, The University of Auckland, Auckland, New Zealand
| | - Suzanne J Reid
- Centre for Brain Research, School of Biological Sciences, The University of Auckland, Auckland, New Zealand
| | - Zoe Burch
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - Jessie C Jacobsen
- Centre for Brain Research, School of Biological Sciences, The University of Auckland, Auckland, New Zealand
| | - Tammy Gillis
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - Kevin Correia
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - Skye R Rudiger
- Molecular Biology and Reproductive Technology, Laboratories, South Australian Research and Development Institute, Adelaide, SA, Australia
| | - Clive J McLaughlin
- Molecular Biology and Reproductive Technology, Laboratories, South Australian Research and Development Institute, Adelaide, SA, Australia
| | - C Simon Bawden
- Molecular Biology and Reproductive Technology, Laboratories, South Australian Research and Development Institute, Adelaide, SA, Australia
| | - Marcy E MacDonald
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA
- Department of Neurology, Harvard Medical School, Boston, MA, USA
| | - Vanessa C Wheeler
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA
- Department of Neurology, Harvard Medical School, Boston, MA, USA
| | - Russell G Snell
- Centre for Brain Research, School of Biological Sciences, The University of Auckland, Auckland, New Zealand
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8
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Zhou C, Liu HB, Jahanbakhsh F, Deng L, Wu B, Ying M, Margolis RL, Li PP. Bidirectional Transcription at the PPP2R2B Gene Locus in Spinocerebellar Ataxia Type 12. Mov Disord 2023; 38:2230-2240. [PMID: 37735923 PMCID: PMC10840700 DOI: 10.1002/mds.29605] [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: 04/04/2023] [Revised: 08/12/2023] [Accepted: 08/29/2023] [Indexed: 09/23/2023] Open
Abstract
BACKGROUND Spinocerebellar ataxia type 12 (SCA12) is a neurodegenerative disease caused by expansion of a CAG repeat in the PPP2R2B gene. OBJECTIVE In this study, we tested the hypothesis that the PPP2R2B antisense (PPP2R2B-AS1) transcript containing a CUG repeat is expressed and contributes to SCA12 pathogenesis. METHODS Expression of PPP2R2B-AS1 transcript was detected in SCA12 human induced pluripotent stem cells (iPSCs), iPSC-derived NGN2 neurons, and SCA12 knock-in mouse brains using strand-specific reverse transcription polymerase chain reaction. The tendency of expanded PPP2R2B-AS1 (expPPP2R2B-AS1) RNA to form foci, a marker of toxic processes involving mutant RNAs, was examined in SCA12 cell models by fluorescence in situ hybridization. The apoptotic effect of expPPP2R2B-AS1 transcripts on SK-N-MC neuroblastoma cells was evaluated by caspase 3/7 activity. Western blot was used to examine the expression of repeat associated non-ATG-initiated translation of expPPP2R2B-AS1 transcript in SK-N-MC cells. RESULTS The repeat region in the PPP2R2B gene locus is bidirectionally transcribed in SCA12 iPSCs, iPSC-derived NGN2 neurons, and SCA12 mouse brains. Transfected expPPP2R2B-AS1 transcripts induce apoptosis in SK-N-MC cells, and the apoptotic effect may be mediated, at least in part, by the RNA secondary structure. The expPPP2R2B-AS1 transcripts form CUG RNA foci in SK-N-MC cells. expPPP2R2B-AS1 transcript is translated in the alanine open reading frame (ORF) via repeat-associated non-ATG translation, which is diminished by single-nucleotide interruptions within the CUG repeat and MBNL1 overexpression. CONCLUSIONS These findings suggest that PPP2R2B-AS1 contributes to SCA12 pathogenesis and may therefore provide a novel therapeutic target for the disease. © 2023 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Chengqian Zhou
- Department of Psychiatry and Behavioral Sciences, Division of Neurobiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Hans B. Liu
- Department of Psychiatry and Behavioral Sciences, Division of Neurobiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Fatemeh Jahanbakhsh
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University, Baltimore, Maryland, USA
| | - Leon Deng
- Department of Psychiatry and Behavioral Sciences, Division of Neurobiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Bin Wu
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University, Baltimore, Maryland, USA
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Mingyao Ying
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Hugo W. Moser Research Institute at Kennedy Krieger, Baltimore, Maryland, USA
| | - Russell L. Margolis
- Department of Psychiatry and Behavioral Sciences, Division of Neurobiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Pan P. Li
- Department of Psychiatry and Behavioral Sciences, Division of Neurobiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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9
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Nguyen TB, Miramontes R, Chillon-Marinas C, Maimon R, Vazquez-Sanchez S, Lau AL, McClure NR, England WE, Singha M, Stocksdale JT, Jang KH, Jung S, McKnight JI, Ho LN, Faull RLM, Steffan JS, Reidling JC, Jang C, Lee G, Cleveland DW, Lagier-Tourenne C, Spitale RC, Thompson LM. Aberrant splicing in Huntington's disease via disrupted TDP-43 activity accompanied by altered m6A RNA modification. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.31.565004. [PMID: 37961595 PMCID: PMC10635028 DOI: 10.1101/2023.10.31.565004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Huntington's disease (HD) is a neurodegenerative disorder caused by a CAG repeat expansion in the first exon of the HTT gene encoding huntingtin. Prior reports have established a correlation between CAG expanded HTT and altered gene expression. However, the mechanisms leading to disruption of RNA processing in HD remain unclear. Here, our analysis of the reported HTT protein interactome identifies interactions with known RNA-binding proteins (RBPs). Total, long-read sequencing and targeted RASL-seq of RNAs from cortex and striatum of the HD mouse model R6/2 reveals increased exon skipping which is confirmed in Q150 and Q175 knock-in mice and in HD human brain. We identify the RBP TDP-43 and the N6-methyladenosine (m6A) writer protein methyltransferase 3 (METTL3) to be upstream regulators of exon skipping in HD. Along with this novel mechanistic insight, we observe decreased nuclear localization of TDP-43 and cytoplasmic accumulation of phosphorylated TDP-43 in HD mice and human brain. In addition, TDP-43 co-localizes with HTT in human HD brain forming novel nuclear aggregate-like bodies distinct from mutant HTT inclusions or previously observed TDP-43 pathologies. Binding of TDP-43 onto RNAs encoding HD-associated differentially expressed and aberrantly spliced genes is decreased. Finally, m6A RNA modification is reduced on RNAs abnormally expressed in striatum from HD R6/2 mouse brain, including at clustered sites adjacent to TDP-43 binding sites. Our evidence supports TDP-43 loss of function coupled with altered m6A modification as a novel mechanism underlying alternative splicing/unannotated exon usage in HD and highlights the critical nature of TDP-43 function across multiple neurodegenerative diseases.
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10
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Pressl C, Mätlik K, Kus L, Darnell P, Luo JD, Paul MR, Weiss AR, Liguore W, Carroll TS, Davis DA, McBride J, Heintz N. Selective Vulnerability of Layer 5a Corticostriatal Neurons in Huntington's Disease. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.24.538096. [PMID: 37162977 PMCID: PMC10168234 DOI: 10.1101/2023.04.24.538096] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The properties of the cell types that are selectively vulnerable in Huntington's disease (HD) cortex, the nature of somatic CAG expansions of mHTT in these cells, and their importance in CNS circuitry have not been delineated. Here we employed serial fluorescence activated nuclear sorting (sFANS), deep molecular profiling, and single nucleus RNA sequencing (snRNAseq) to demonstrate that layer 5a pyramidal neurons are vulnerable in primary motor cortex and other cortical areas of HD donors. Extensive mHTT -CAG expansions occur in vulnerable layer 5a pyramidal cells, and in Betz cells, layer 6a, layer 6b neurons that are resilient in HD. Retrograde tracing experiments in macaque brains identify the vulnerable layer 5a neurons as corticostriatal pyramidal cells. We propose that enhanced somatic mHTT -CAG expansion and altered synaptic function act together to cause corticostriatal disconnection and selective neuronal vulnerability in the HD cerebral cortex.
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11
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Lutfi Ismaeel G, Makki AlHassani OJ, S Alazragi R, Hussein Ahmed A, H Mohamed A, Yasir Jasim N, Hassan Shari F, Almashhadani HA. Genetically engineered neural stem cells (NSCs) therapy for neurological diseases; state-of-the-art. Biotechnol Prog 2023; 39:e3363. [PMID: 37221947 DOI: 10.1002/btpr.3363] [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: 04/03/2023] [Revised: 04/28/2023] [Accepted: 05/01/2023] [Indexed: 05/25/2023]
Abstract
Neural stem cells (NSCs) are multipotent stem cells with remarkable self-renewal potential and also unique competencies to differentiate into neurons, astrocytes, and oligodendrocytes (ODCs) and improve the cellular microenvironment. In addition, NSCs secret diversity of mediators, including neurotrophic factors (e.g., BDNF, NGF, GDNF, CNTF, and NT-3), pro-angiogenic mediators (e.g., FGF-2 and VEGF), and anti-inflammatory biomolecules. Thereby, NSCs transplantation has become a reasonable and effective treatment for various neurodegenerative disorders by their capacity to induce neurogenesis and vasculogenesis and dampen neuroinflammation and oxidative stress. Nonetheless, various drawbacks such as lower migration and survival and less differential capacity to a particular cell lineage concerning the disease pathogenesis hinder their application. Thus, genetic engineering of NSCs before transplantation is recently regarded as an innovative strategy to bypass these hurdles. Indeed, genetically modified NSCs could bring about more favored therapeutic influences post-transplantation in vivo, making them an excellent option for neurological disease therapy. This review for the first time offers a comprehensive review of the therapeutic capability of genetically modified NSCs rather than naïve NSCs in neurological disease beyond brain tumors and sheds light on the recent progress and prospect in this context.
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Affiliation(s)
- Ghufran Lutfi Ismaeel
- Department of Pharmacology, College of Pharmacy, University of Al-Ameed, Karbala, Iraq
| | | | - Reem S Alazragi
- Department of Biochemistry, College of Science, University of Jeddah, Jeddah, Saudi Arabia
| | - Ammar Hussein Ahmed
- Department of Radiology and Sonar, College of Medical Techniques, Al-Farahidi University, Baghdad, Iraq
| | - Asma'a H Mohamed
- Intelligent Medical Systems Department, Al-Mustaqbal University College, Babylon, Iraq
| | - Nisreen Yasir Jasim
- Collage of Pharmacy, National University of Science and Technology, Dhi Qar, Iraq
| | - Falah Hassan Shari
- Department of Clinical Laboratory Sciences, College of Pharmacy, University of Basrah, Basrah, Iraq
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12
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Speidell A, Bin Abid N, Yano H. Brain-Derived Neurotrophic Factor Dysregulation as an Essential Pathological Feature in Huntington's Disease: Mechanisms and Potential Therapeutics. Biomedicines 2023; 11:2275. [PMID: 37626771 PMCID: PMC10452871 DOI: 10.3390/biomedicines11082275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 08/07/2023] [Accepted: 08/09/2023] [Indexed: 08/27/2023] Open
Abstract
Brain-derived neurotrophic factor (BDNF) is a major neurotrophin whose loss or interruption is well established to have numerous intersections with the pathogenesis of progressive neurological disorders. There is perhaps no greater example of disease pathogenesis resulting from the dysregulation of BDNF signaling than Huntington's disease (HD)-an inherited neurodegenerative disorder characterized by motor, psychiatric, and cognitive impairments associated with basal ganglia dysfunction and the ultimate death of striatal projection neurons. Investigation of the collection of mechanisms leading to BDNF loss in HD highlights this neurotrophin's importance to neuronal viability and calls attention to opportunities for therapeutic interventions. Using electronic database searches of existing and forthcoming research, we constructed a literature review with the overarching goal of exploring the diverse set of molecular events that trigger BDNF dysregulation within HD. We highlighted research that investigated these major mechanisms in preclinical models of HD and connected these studies to those evaluating similar endpoints in human HD subjects. We also included a special focus on the growing body of literature detailing key transcriptomic and epigenetic alterations that affect BDNF abundance in HD. Finally, we offer critical evaluation of proposed neurotrophin-directed therapies and assessed clinical trials seeking to correct BDNF expression in HD individuals.
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Affiliation(s)
- Andrew Speidell
- Department of Neurological Surgery, Washington University School of Medicine in St. Louis, St. Louis, MO 63110, USA; (A.S.); (N.B.A.)
| | - Noman Bin Abid
- Department of Neurological Surgery, Washington University School of Medicine in St. Louis, St. Louis, MO 63110, USA; (A.S.); (N.B.A.)
| | - Hiroko Yano
- Department of Neurological Surgery, Washington University School of Medicine in St. Louis, St. Louis, MO 63110, USA; (A.S.); (N.B.A.)
- Department of Neurology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110, USA
- Department of Genetics, Washington University School of Medicine in St. Louis, St. Louis, MO 63110, USA
- Hope Center for Neurological Disorders, Washington University School of Medicine in St. Louis, St. Louis, MO 63110, USA
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13
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O'Reilly D, Belgrad J, Ferguson C, Summers A, Sapp E, McHugh C, Mathews E, Boudi A, Buchwald J, Ly S, Moreno D, Furgal R, Luu E, Kennedy Z, Hariharan V, Monopoli K, Yang XW, Carroll J, DiFiglia M, Aronin N, Khvorova A. Di-valent siRNA-mediated silencing of MSH3 blocks somatic repeat expansion in mouse models of Huntington's disease. Mol Ther 2023; 31:1661-1674. [PMID: 37177784 PMCID: PMC10277892 DOI: 10.1016/j.ymthe.2023.05.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 03/10/2023] [Accepted: 05/08/2023] [Indexed: 05/15/2023] Open
Abstract
Huntington's disease (HD) is a severe neurodegenerative disorder caused by the expansion of the CAG trinucleotide repeat tract in the huntingtin gene. Inheritance of expanded CAG repeats is needed for HD manifestation, but further somatic expansion of the repeat tract in non-dividing cells, particularly striatal neurons, hastens disease onset. Called somatic repeat expansion, this process is mediated by the mismatch repair (MMR) pathway. Among MMR components identified as modifiers of HD onset, MutS homolog 3 (MSH3) has emerged as a potentially safe and effective target for therapeutic intervention. Here, we identify a fully chemically modified short interfering RNA (siRNA) that robustly silences Msh3 in vitro and in vivo. When synthesized in a di-valent scaffold, siRNA-mediated silencing of Msh3 effectively blocked CAG-repeat expansion in the striatum of two HD mouse models without affecting tumor-associated microsatellite instability or mRNA expression of other MMR genes. Our findings establish a promising treatment approach for patients with HD and other repeat expansion diseases.
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Affiliation(s)
- Daniel O'Reilly
- RNA Therapeutics Institute, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA
| | - Jillian Belgrad
- RNA Therapeutics Institute, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA
| | - Chantal Ferguson
- RNA Therapeutics Institute, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA
| | - Ashley Summers
- RNA Therapeutics Institute, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA
| | - Ellen Sapp
- Department of Neurology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Cassandra McHugh
- Behavioral Neuroscience Program, Psychology Department, Western Washington University, Bellingham, WA 98225, USA
| | - Ella Mathews
- Behavioral Neuroscience Program, Psychology Department, Western Washington University, Bellingham, WA 98225, USA
| | - Adel Boudi
- Department of Neurology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Julianna Buchwald
- RNA Therapeutics Institute, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA
| | - Socheata Ly
- RNA Therapeutics Institute, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA
| | - Dimas Moreno
- RNA Therapeutics Institute, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA
| | - Raymond Furgal
- RNA Therapeutics Institute, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA
| | - Eric Luu
- RNA Therapeutics Institute, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA
| | - Zachary Kennedy
- RNA Therapeutics Institute, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA
| | - Vignesh Hariharan
- RNA Therapeutics Institute, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA
| | - Kathryn Monopoli
- RNA Therapeutics Institute, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA
| | - X William Yang
- Center for Neurobehavioral Genetics, Jane and Terry Semel Institute of Neuroscience and Human Behavior, University of California Los Angeles, Los Angeles, CA 90095, USA; Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Jeffery Carroll
- Behavioral Neuroscience Program, Psychology Department, Western Washington University, Bellingham, WA 98225, USA; Department of Neurology, University of Washington, Seattle, WA 98104-2499, USA
| | - Marian DiFiglia
- Department of Neurology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Neil Aronin
- RNA Therapeutics Institute, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA; Department of Medicine, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA
| | - Anastasia Khvorova
- RNA Therapeutics Institute, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA.
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14
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Burgunder JM. Mechanisms underlying phenotypic variation in neurogenetic disorders. Nat Rev Neurol 2023:10.1038/s41582-023-00811-4. [PMID: 37202496 DOI: 10.1038/s41582-023-00811-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/12/2023] [Indexed: 05/20/2023]
Abstract
Neurological diseases associated with pathogenic variants in a specific gene, or even with a specific pathogenic variant, can show profound phenotypic variation with regard to symptom presentation, age at onset and disease course. Highlighting examples from a range of neurogenetic disorders, this Review explores emerging mechanisms that are involved in this variability, including environmental, genetic and epigenetic factors that influence the expressivity and penetrance of pathogenic variants. Environmental factors, some of which can potentially be modified to prevent disease, include trauma, stress and metabolic changes. Dynamic patterns of pathogenic variants might explain some of the phenotypic variations, for example, in the case of disorders caused by DNA repeat expansions such as Huntington disease (HD). An important role for modifier genes has also been identified in some neurogenetic disorders, including HD, spinocerebellar ataxia and X-linked dystonia-parkinsonism. In other disorders, such as spastic paraplegia, the basis for most of the phenotypic variability remains unclear. Epigenetic factors have been implicated in disorders such as SGCE-related myoclonus-dystonia and HD. Knowledge of the mechanisms underlying phenotypic variation is already starting to influence management strategies and clinical trials for neurogenetic disorders.
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15
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Zhang S, Cheng Y, Shang H. The updated development of blood-based biomarkers for Huntington's disease. J Neurol 2023; 270:2483-2503. [PMID: 36692635 PMCID: PMC9873222 DOI: 10.1007/s00415-023-11572-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 01/11/2023] [Accepted: 01/12/2023] [Indexed: 01/25/2023]
Abstract
Huntington's disease is a progressive neurodegenerative disease caused by mutation of the huntingtin (HTT) gene. The identification of mutation carriers before symptom onset provides an opportunity to intervene in the early stage of the disease course. Optimal biomarkers are of great value to reflect neuropathological and clinical progression and are sensitive to potential disease-modifying treatments. Blood-based biomarkers have the merits of minimal invasiveness, low cost, easy accessibility and safety. In this review, we summarized the updated development of blood-based biomarkers for HD from six aspects, including neuronal injuries, oxidative stress, endocrine functions, immune reactions, metabolism and differentially expressed miRNAs. The blood-based biomarkers presented and discussed in this review were close to clinical applicability and might facilitate clinical design as surrogate endpoints. Exploration and validation of robust blood-based biomarkers require further standard and systemic study design in the future.
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Affiliation(s)
- Sirui Zhang
- grid.412901.f0000 0004 1770 1022Laboratory of Neurodegenerative Disorders, Department of Neurology, Rare Disease Center, West China Hospital, Sichuan University, Chengdu, 610041 Sichuan China ,grid.412901.f0000 0004 1770 1022National Clinical Research Center for Geriatric, Laboratory of Neurodegenerative Disorders, West China Hospital, Sichuan University, Chengdu, 610041 China ,grid.412901.f0000 0004 1770 1022West China School of Medicine, West China Hospital, Sichuan University, Chengdu, 610041 China
| | - Yangfan Cheng
- grid.412901.f0000 0004 1770 1022Laboratory of Neurodegenerative Disorders, Department of Neurology, Rare Disease Center, West China Hospital, Sichuan University, Chengdu, 610041 Sichuan China ,grid.412901.f0000 0004 1770 1022National Clinical Research Center for Geriatric, Laboratory of Neurodegenerative Disorders, West China Hospital, Sichuan University, Chengdu, 610041 China
| | - Huifang Shang
- grid.412901.f0000 0004 1770 1022Laboratory of Neurodegenerative Disorders, Department of Neurology, Rare Disease Center, West China Hospital, Sichuan University, Chengdu, 610041 Sichuan China ,grid.412901.f0000 0004 1770 1022National Clinical Research Center for Geriatric, Laboratory of Neurodegenerative Disorders, West China Hospital, Sichuan University, Chengdu, 610041 China
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16
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Taylor A, Barros D, Gobet N, Schuepbach T, McAllister B, Aeschbach L, Randall E, Trofimenko E, Heuchan E, Barszcz P, Ciosi M, Morgan J, Hafford-Tear N, Davidson A, Massey T, Monckton D, Jones L, network REGISTRYH, Xenarios I, Dion V. Repeat Detector: versatile sizing of expanded tandem repeats and identification of interrupted alleles from targeted DNA sequencing. NAR Genom Bioinform 2022; 4:lqac089. [PMID: 36478959 PMCID: PMC9719798 DOI: 10.1093/nargab/lqac089] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 10/25/2022] [Accepted: 11/08/2022] [Indexed: 12/07/2022] Open
Abstract
Targeted DNA sequencing approaches will improve how the size of short tandem repeats is measured for diagnostic tests and preclinical studies. The expansion of these sequences causes dozens of disorders, with longer tracts generally leading to a more severe disease. Interrupted alleles are sometimes present within repeats and can alter disease manifestation. Determining repeat size mosaicism and identifying interruptions in targeted sequencing datasets remains a major challenge. This is in part because standard alignment tools are ill-suited for repetitive and unstable sequences. To address this, we have developed Repeat Detector (RD), a deterministic profile weighting algorithm for counting repeats in targeted sequencing data. We tested RD using blood-derived DNA samples from Huntington's disease and Fuchs endothelial corneal dystrophy patients sequenced using either Illumina MiSeq or Pacific Biosciences single-molecule, real-time sequencing platforms. RD was highly accurate in determining repeat sizes of 609 blood-derived samples from Huntington's disease individuals and did not require prior knowledge of the flanking sequences. Furthermore, RD can be used to identify alleles with interruptions and provide a measure of repeat instability within an individual. RD is therefore highly versatile and may find applications in the diagnosis of expanded repeat disorders and in the development of novel therapies.
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Affiliation(s)
- Alysha S Taylor
- UK Dementia Research Institute, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff, CF24 4HQ, UK
| | - Dinis Barros
- Centre for Integrative Genomics, University of Lausanne, Bâtiment Génopode, 1015 Lausanne, Switzerland
| | - Nastassia Gobet
- Centre for Integrative Genomics, University of Lausanne, Bâtiment Génopode, 1015 Lausanne, Switzerland
| | - Thierry Schuepbach
- Vital-IT Group, Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland
- Newbiologix, Ch. De la corniche 6-8, 1066 Epalinges, Switzerland
| | - Branduff McAllister
- MRC Centre for Neuropsychiatric Genetics and Genomics, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff CF24 4HQ, UK
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Lorene Aeschbach
- Centre for Integrative Genomics, University of Lausanne, Bâtiment Génopode, 1015 Lausanne, Switzerland
| | - Emma L Randall
- UK Dementia Research Institute, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff, CF24 4HQ, UK
| | - Evgeniya Trofimenko
- Centre for Integrative Genomics, University of Lausanne, Bâtiment Génopode, 1015 Lausanne, Switzerland
- Sorbonne Université, École normale supérieure, PSL University, CNRS, Laboratoire des biomolécules, LBM, 75005 Paris, France
| | - Eleanor R Heuchan
- UK Dementia Research Institute, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff, CF24 4HQ, UK
| | - Paula Barszcz
- Centre for Integrative Genomics, University of Lausanne, Bâtiment Génopode, 1015 Lausanne, Switzerland
| | - Marc Ciosi
- School of Molecular Biosciences, College of Medical, Veterinary and Life Sciences, Davidson Building, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Joanne Morgan
- MRC Centre for Neuropsychiatric Genetics and Genomics, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff CF24 4HQ, UK
| | | | - Alice E Davidson
- UCL Institute of Ophthalmology, 11-43 Bath Street, London, EC1V 9EL UK
| | - Thomas H Massey
- MRC Centre for Neuropsychiatric Genetics and Genomics, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff CF24 4HQ, UK
| | - Darren G Monckton
- School of Molecular Biosciences, College of Medical, Veterinary and Life Sciences, Davidson Building, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Lesley Jones
- MRC Centre for Neuropsychiatric Genetics and Genomics, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff CF24 4HQ, UK
| | | | - Ioannis Xenarios
- Centre for Integrative Genomics, University of Lausanne, Bâtiment Génopode, 1015 Lausanne, Switzerland
- Health2030 Genome Center, Ch des Mines 14, 1202 Genève, Switzerland
| | - Vincent Dion
- UK Dementia Research Institute, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff, CF24 4HQ, UK
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17
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Heterogeneous migration routes of DNA triplet repeat slip-outs. BIOPHYSICAL REPORTS 2022; 2:None. [PMID: 36299495 PMCID: PMC9586884 DOI: 10.1016/j.bpr.2022.100070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 08/08/2022] [Indexed: 12/02/2022]
Abstract
It is unclear how the length of a repetitive DNA tract determines the onset and progression of repeat expansion diseases, but the dynamics of secondary DNA structures formed by repeat sequences are believed to play an important role. It was recently shown that three-way DNA junctions containing slip-out hairpins of CAG or CTG repeats and contiguous triplet repeats in the adjacent duplex displayed single-molecule FRET (smFRET) dynamics that were ascribed to both local conformational motions and longer-range branch migration. Here we explore these so-called "mobile" slip-out structures through a detailed kinetic analysis of smFRET trajectories and coarse-grained modeling. Despite the apparent structural simplicity, with six FRET states resolvable, most smFRET states displayed biexponential dwell-time distributions, attributed to structural heterogeneity and overlapping FRET states. Coarse-grained modeling for a (GAC)10 repeat slip-out included trajectories that corresponded to a complete round of branch migration; the structured free energy landscape between slippage events supports the dynamical complexity observed by smFRET. A hairpin slip-out with 40 CAG repeats, which is above the repeat length required for disease in several triplet repeat disorders, displayed smFRET dwell times that were on average double those of 3WJs with 10 repeats. The rate of secondary-structure rearrangement via branch migration, relative to particular DNA processing pathways, may be an important factor in the expansion of triplet repeat expansion diseases.
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18
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Seefelder M, Klein FAC, Landwehrmeyer B, Fernández-Busnadiego R, Kochanek S. Huntingtin and Its Partner Huntingtin-Associated Protein 40: Structural and Functional Considerations in Health and Disease. J Huntingtons Dis 2022; 11:227-242. [PMID: 35871360 PMCID: PMC9484127 DOI: 10.3233/jhd-220543] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Since the discovery of the mutation causing Huntington’s disease (HD) in 1993, it has been debated whether an expanded polyglutamine (polyQ) stretch affects the properties of the huntingtin (HTT) protein and thus contributes to the pathological mechanisms responsible for HD. Here we review the current knowledge about the structure of HTT, alone (apo-HTT) or in a complex with Huntingtin-Associated Protein 40 (HAP40), the influence of polyQ-length variation on apo-HTT and the HTT-HAP40 complex, and the biology of HAP40. Phylogenetic analyses suggest that HAP40 performs essential functions. Highlighting the relevance of its interaction with HTT, HAP40 is one of the most abundant partners copurifying with HTT and is rapidly degraded, when HTT levels are reduced. As the levels of both proteins decrease during disease progression, HAP40 could also be a biomarker for HD. Whether declining HAP40 levels contribute to disease etiology is an open question. Structural studies have shown that the conformation of apo-HTT is less constrained but resembles that adopted in the HTT-HAP40 complex, which is exceptionally stable because of extensive interactions between HAP40 and the three domains of HTT. The complex— and to some extent apo-HTT— resists fragmentation after limited proteolysis. Unresolved regions of apo-HTT, constituting about 25% of the protein, are the main sites of post-translational modifications and likely have major regulatory functions. PolyQ elongation does not substantially alter the structure of HTT, alone or when associated with HAP40. Particularly, polyQ above the disease length threshold does not induce drastic conformational changes in full-length HTT. Therefore, models of HD pathogenesis stating that polyQ expansion drastically alters HTT properties should be reconsidered.
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Affiliation(s)
| | | | | | - Rubén Fernández-Busnadiego
- Institute of Neuropathology, University Medical Center Göttingen, Göttingen, Germany.,Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, Göttingen, Germany
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19
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Bocoum A, Coulibaly T, Ouologuem M, Cissé L, Diallo SH, Maiga BB, Dembélé K, Diallo S, Coulibaly SDP, Kané F, Coulibaly T, Coulibaly D, Taméga A, Yalcouyé A, Diarra S, Dembélé ME, Maiga AB, Cissé CAK, Traoré O, Fischbeck KH, Guinto CO, Maiga Y, Landouré G. Clinical and Genetic Aspects of Huntington's Disease in the Malian Population. J Huntingtons Dis 2022; 11:195-201. [PMID: 35311712 DOI: 10.3233/jhd-220529] [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: 12/14/2022]
Abstract
BACKGROUND Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder caused by mutation in the HTT gene and characterized by involuntary movements as well as cognitive and behavioral impairment. Since its first description 150 years ago, studies have been reported worldwide. However, genetically confirmed cases have been scarce in Africa. OBJECTIVE To describe the clinical and genetic aspects of HD in the Malian population. METHODS Patients with HD phenotype and their relatives were enrolled after obtaining consent. Symptoms were assessed using the Total Motor Scale (TMS) of the United Huntington's Disease Rating Scale (UHDRS) and the Mini-Mental State Examination (MMSE). Brain imaging and blood tests were performed to exclude other causes. DNA was extracted for HTT sequencing. RESULTS Eighteen patients (13 families) with a HD phenotype were evaluated. A familial history of the disease was found in 84.6% with 55.5% of maternal transmission. The average length of the HTT CAG repeat was 43.6±11.5 (39-56) CAGs. The mean age at onset was 43.1±9.7years. Choreic movements were the predominant symptoms (100% of the cases) with an average TMS of 49.4±30.8, followed by cognitive impairment (average MMSE score: 23.0±12.0) and psychiatric symptoms with 22.2% and 44.4%, respectively. CONCLUSION This is one of the largest HD cohorts reported in Africa. Increasing access to genetic testing could uncover many other HD cases and disease-modifying genetic variants. Future haplotype and psychosocial studies may inform the origin of the Malian mutation and the impact of the disease on patients and their relatives.
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Affiliation(s)
- Abdoulaye Bocoum
- Faculté de Médecine et d'Odontostomatologie, USTTB, Bamako, Mali
| | | | | | - Lassana Cissé
- Service de Neurologie, CHU du Point "G", Bamako, Mali
| | - Seybou H Diallo
- Faculté de Médecine et d'Odontostomatologie, USTTB, Bamako, Mali.,Service de Neurologie, CHU de Gabriel Touré, Bamako, Mali
| | | | | | | | - Souleymane Dit Papa Coulibaly
- Faculté de Médecine et d'Odontostomatologie, USTTB, Bamako, Mali.,Service de Psychiatrie, CHU du Point "G", Bamako, Mali
| | - Fousseyni Kané
- Faculté de Médecine et d'Odontostomatologie, USTTB, Bamako, Mali
| | - Thomas Coulibaly
- Faculté de Médecine et d'Odontostomatologie, USTTB, Bamako, Mali.,Service de Neurologie, CHU du Point "G", Bamako, Mali
| | | | - Abdoulaye Taméga
- Faculté de Médecine et d'Odontostomatologie, USTTB, Bamako, Mali
| | | | - Salimata Diarra
- Faculté de Médecine et d'Odontostomatologie, USTTB, Bamako, Mali.,Service de Psychiatrie, CHU du Point "G", Bamako, Mali
| | | | - Alassane B Maiga
- Faculté de Médecine et d'Odontostomatologie, USTTB, Bamako, Mali
| | - Cheick A K Cissé
- Faculté de Médecine et d'Odontostomatologie, USTTB, Bamako, Mali
| | - Oumou Traoré
- Faculté de Médecine et d'Odontostomatologie, USTTB, Bamako, Mali
| | | | - Cheick O Guinto
- Faculté de Médecine et d'Odontostomatologie, USTTB, Bamako, Mali.,Service de Neurologie, CHU du Point "G", Bamako, Mali
| | - Youssoufa Maiga
- Faculté de Médecine et d'Odontostomatologie, USTTB, Bamako, Mali.,Service de Neurologie, CHU de Gabriel Touré, Bamako, Mali
| | - Guida Landouré
- Faculté de Médecine et d'Odontostomatologie, USTTB, Bamako, Mali.,Service de Neurologie, CHU du Point "G", Bamako, Mali.,Neurogenetics Branch, NINDS, NIH, Bethesda, MD, USA
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20
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Kotowska-Zimmer A, Przybyl L, Pewinska M, Suszynska-Zajczyk J, Wronka D, Figiel M, Olejniczak M. A CAG repeat-targeting artificial miRNA lowers the mutant huntingtin level in the YAC128 model of Huntington's disease. MOLECULAR THERAPY - NUCLEIC ACIDS 2022; 28:702-715. [PMID: 35664700 PMCID: PMC9126840 DOI: 10.1016/j.omtn.2022.04.031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/11/2021] [Accepted: 04/29/2022] [Indexed: 12/12/2022]
Abstract
Among the many proposed therapeutic strategies for Huntington's disease (HD), allele-selective therapies are the most desirable but also the most challenging. RNA interference (RNAi) tools that target CAG repeats selectively reduce the mutant huntingtin level in cellular models of HD. The purpose of this study was to test the efficacy, selectivity, and safety of two vector-based RNAi triggers in an animal model of HD. CAG repeat-targeting short hairpin RNA (shRNA) and artificial miRNA (amiRNA) were delivered to the brains of YAC128 mice via intrastriatal injection of AAV5 vectors. Molecular tests demonstrated that both the shRNA and amiRNA reduced the mutant huntingtin level by 50% without influencing endogenous mouse huntingtin. In addition, a concentration-dependent reduction in HTT aggregates in the striatum was observed. In contrast to the shRNA, the amiRNA was well tolerated and did not show signs of toxicity during the course of the experiment up to 20 weeks post injection. Interestingly, amiRNA treatment reduced the spleen weight to values characteristic of healthy (WT) mice and improved motor performance on the static rod test. These preclinical data demonstrate that the CAG-targeting strategy and amiRNA could make an original and valuable contribution to currently used therapeutic approaches for HD.
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Affiliation(s)
- Anna Kotowska-Zimmer
- Department of Genome Engineering, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland
| | - Lukasz Przybyl
- Laboratory of Mammalian Model Organisms, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland
| | - Marianna Pewinska
- Department of Genome Engineering, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland
| | - Joanna Suszynska-Zajczyk
- Department of Biochemistry and Biotechnology, Poznan University of Life Sciences, 60-632 Poznan, Poland
| | - Dorota Wronka
- Laboratory of Mammalian Model Organisms, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland
| | - Maciej Figiel
- Department of Molecular Neurobiology, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland
| | - Marta Olejniczak
- Department of Genome Engineering, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland
- Corresponding author Marta Olejniczak, Department of Genome Engineering, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland.
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21
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Kroll F, Dimitriadis A, Campbell T, Darwent L, Collinge J, Mead S, Vire E. Prion protein gene mutation detection using long-read Nanopore sequencing. Sci Rep 2022; 12:8284. [PMID: 35585119 PMCID: PMC9117325 DOI: 10.1038/s41598-022-12130-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 05/05/2022] [Indexed: 01/04/2023] Open
Abstract
Prion diseases are fatal neurodegenerative conditions that affect humans and animals. Rapid and accurate sequencing of the prion gene PRNP is paramount to human prion disease diagnosis and for animal surveillance programmes. Current methods for PRNP genotyping involve sequencing of small fragments within the protein-coding region. The contribution of variants in the non-coding regions of PRNP including large structural changes is poorly understood. Here, we used long-range PCR and Nanopore sequencing to sequence the full length of PRNP, including its regulatory region, in 25 samples from blood and brain of individuals with inherited or sporadic prion diseases. Nanopore sequencing detected the same variants as identified by Sanger sequencing, including repeat expansions/deletions. Nanopore identified additional single-nucleotide variants in the non-coding regions of PRNP, but no novel structural variants were discovered. Finally, we explored somatic mosaicism of PRNP's octapeptide repeat region, which is a hypothetical cause of sporadic prion disease. While we found changes consistent with somatic mutations, we demonstrate that they may have been generated by the PCR. Our study illustrates the accuracy of Nanopore sequencing for rapid and field prion disease diagnosis and highlights the need for single-molecule sequencing methods for the detection of somatic mutations.
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Affiliation(s)
- François Kroll
- grid.83440.3b0000000121901201MRC Prion Unit at University College London (UCL), UCL Institute of Prion Diseases, UCL, London, W1W 7FF UK
| | - Athanasios Dimitriadis
- grid.83440.3b0000000121901201MRC Prion Unit at University College London (UCL), UCL Institute of Prion Diseases, UCL, London, W1W 7FF UK
| | - Tracy Campbell
- grid.83440.3b0000000121901201MRC Prion Unit at University College London (UCL), UCL Institute of Prion Diseases, UCL, London, W1W 7FF UK
| | - Lee Darwent
- grid.83440.3b0000000121901201MRC Prion Unit at University College London (UCL), UCL Institute of Prion Diseases, UCL, London, W1W 7FF UK
| | - John Collinge
- grid.83440.3b0000000121901201MRC Prion Unit at University College London (UCL), UCL Institute of Prion Diseases, UCL, London, W1W 7FF UK
| | - Simon Mead
- MRC Prion Unit at University College London (UCL), UCL Institute of Prion Diseases, UCL, London, W1W 7FF, UK.
| | - Emmanuelle Vire
- grid.83440.3b0000000121901201MRC Prion Unit at University College London (UCL), UCL Institute of Prion Diseases, UCL, London, W1W 7FF UK
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22
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Martí-Martínez S, Valor LM. A Glimpse of Molecular Biomarkers in Huntington's Disease. Int J Mol Sci 2022; 23:ijms23105411. [PMID: 35628221 PMCID: PMC9142992 DOI: 10.3390/ijms23105411] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 05/10/2022] [Accepted: 05/11/2022] [Indexed: 12/15/2022] Open
Abstract
Huntington's disease (HD) is a devastating neurodegenerative disorder that is caused by an abnormal expansion of CAG repeats in the Huntingtin (HTT) gene. Although the main symptomatology is explained by alterations at the level of the central nervous system, predominantly affecting the basal ganglia, a peripheral component of the disease is being increasingly acknowledged. Therefore, the manifestation of the disease is complex and variable among CAG expansion carriers, introducing uncertainty in the appearance of specific signs, age of onset and severity of disease. The monogenic nature of the disorder allows a precise diagnosis, but the use of biomarkers with prognostic value is still needed to achieve clinical management of the patients in an individual manner. In addition, we need tools to evaluate the patient's response to potential therapeutic approaches. In this review, we provide a succinct summary of the most interesting molecular biomarkers that have been assessed in patients, mostly obtained from body fluids such as cerebrospinal fluid, peripheral blood and saliva.
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Affiliation(s)
- Silvia Martí-Martínez
- Servicio de Neurología, Hospital General Universitario Dr. Balmis, Instituto de Investigación Sanitaria y Biomédica de Alicante (ISABIAL), 03010 Alicante, Spain;
| | - Luis M. Valor
- Laboratorio de Apoyo a la Investigación, Hospital General Universitario Dr. Balmis, Instituto de Investigación Sanitaria y Biomédica de Alicante (ISABIAL), 03010 Alicante, Spain
- Correspondence: ; Tel.: +34-965-913-988
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23
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Hickman RA, Faust PL, Marder K, Yamamoto A, Vonsattel JP. The distribution and density of Huntingtin inclusions across the Huntington disease neocortex: regional correlations with Huntingtin repeat expansion independent of pathologic grade. Acta Neuropathol Commun 2022; 10:55. [PMID: 35440014 PMCID: PMC9020040 DOI: 10.1186/s40478-022-01364-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 04/08/2022] [Indexed: 12/12/2022] Open
Abstract
Huntington disease is characterized by progressive neurodegeneration, especially of the striatum, and the presence of polyglutamine huntingtin (HTT) inclusions. Although HTT inclusions are most abundant in the neocortex, their neocortical distribution and density in relation to the extent of CAG repeat expansion in the HTT gene and striatal pathologic grade have yet to be formally established. We immunohistochemically studied 65 brains with a pathologic diagnosis of Huntington disease to investigate the cortical distributions and densities of HTT inclusions within the calcarine (BA17), precuneus (BA7), motor (BA4) and prefrontal (BA9) cortices; in 39 of these brains, a p62 immunostain was used for comparison. HTT inclusions predominate in the infragranular cortical layers (layers V-VI) and layer III, however, the densities of HTT inclusions across the human cerebral cortex are not uniform but are instead regionally contingent. The density of HTT and p62 inclusions (intranuclear and extranuclear) in layers V-VI increases caudally to rostrally (BA17 < BA7 < BA4 < BA9) with the median burden of HTT inclusions being 38-fold greater in the prefrontal cortex (BA9) than in the calcarine cortex (BA17). Conversely, intranuclear HTT inclusions prevail in the calcarine cortex irrespective of HTT CAG length. Neocortical HTT inclusion density correlates with CAG repeat expansion, but not with the neuropathologic grade of striatal degeneration (Vonsattel grade) or with the duration of clinical disease since motor onset. Extrapolation of these findings suggest that HTT inclusions are at a regionally-contingent, CAG-dependent, density during the advanced stages of HD. The distribution and density of HTT inclusions in HD therefore does not provide a measure of pathologic disease stage but rather infers the degree of pathogenic HTT expansion.
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Affiliation(s)
- Richard A. Hickman
- grid.51462.340000 0001 2171 9952Department of Pathology, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065 USA
| | - Phyllis L. Faust
- grid.413734.60000 0000 8499 1112Department of Pathology & Cell Biology, Columbia University Irving Medical Center, New York Presbyterian Hospital, 630 W 168th Street, New York, NY 10032 USA
| | - Karen Marder
- grid.21729.3f0000000419368729Department of Neurology, Columbia University Irving Medical Center, New York, USA
| | - Ai Yamamoto
- grid.413734.60000 0000 8499 1112Department of Pathology & Cell Biology, Columbia University Irving Medical Center, New York Presbyterian Hospital, 630 W 168th Street, New York, NY 10032 USA ,grid.21729.3f0000000419368729Department of Neurology, Columbia University Irving Medical Center, New York, USA
| | - Jean-Paul Vonsattel
- grid.413734.60000 0000 8499 1112Department of Pathology & Cell Biology, Columbia University Irving Medical Center, New York Presbyterian Hospital, 630 W 168th Street, New York, NY 10032 USA ,grid.239585.00000 0001 2285 2675Taub Institute for Research On Alzheimer’s Disease and the Aging Brain, Columbia University Medical Center, 710 West 168th Street, New York, NY 10032 USA
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24
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Campion LN, Mejia Maza A, Yadav R, Penney EB, Murcar MG, Correia K, Gillis T, Fernandez-Cerado C, Velasco-Andrada MS, Legarda GP, Ganza-Bautista NG, Lagarde JBB, Acuña PJ, Multhaupt-Buell T, Aldykiewicz G, Supnet ML, De Guzman JK, Go C, Sharma N, Munoz EL, Ang MC, Diesta CCE, Bragg DC, Ozelius LJ, Wheeler VC. Tissue-specific and repeat length-dependent somatic instability of the X-linked dystonia parkinsonism-associated CCCTCT repeat. Acta Neuropathol Commun 2022; 10:49. [PMID: 35395816 PMCID: PMC8994295 DOI: 10.1186/s40478-022-01349-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 03/14/2022] [Indexed: 12/17/2022] Open
Abstract
X-linked dystonia-parkinsonism (XDP) is a progressive adult-onset neurodegenerative disorder caused by insertion of a SINE-VNTR-Alu (SVA) retrotransposon in the TAF1 gene. The SVA retrotransposon contains a CCCTCT hexameric repeat tract of variable length, whose length is inversely correlated with age at onset. This places XDP in a broader class of repeat expansion diseases, characterized by the instability of their causative repeat mutations. Here, we observe similar inverse correlations between CCCTCT repeat length with age at onset and age at death and no obvious correlation with disease duration. To gain insight into repeat instability in XDP we performed comprehensive quantitative analyses of somatic instability of the XDP CCCTCT repeat in blood and in seventeen brain regions from affected males. Our findings reveal repeat length-dependent and expansion-based instability of the XDP CCCTCT repeat, with greater levels of expansion in brain than in blood. The brain exhibits regional-specific patterns of instability that are broadly similar across individuals, with cerebellum exhibiting low instability and cortical regions exhibiting relatively high instability. The spectrum of somatic instability in the brain includes a high proportion of moderate repeat length changes of up to 5 repeats, as well as expansions of ~ 20- > 100 repeats and contractions of ~ 20–40 repeats at lower frequencies. Comparison with HTT CAG repeat instability in postmortem Huntington’s disease brains reveals similar brain region-specific profiles, indicating common trans-acting factors that contribute to the instability of both repeats. Analyses in XDP brains of expansion of a different SVA-associated CCCTCT located in the LIPG gene, and not known to be disease-associated, reveals repeat length-dependent expansion at overall lower levels relative to the XDP CCCTCT repeat, suggesting that expansion propensity may be modified by local chromatin structure. Together, the data support a role for repeat length-dependent somatic expansion in the process(es) driving the onset of XDP and prompt further investigation into repeat dynamics and the relationship to disease.
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25
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Klonarakis M, De Vos M, Woo E, Ralph L, Thacker JS, Gil-Mohapel J. The three sisters of fate: Genetics, pathophysiology and outcomes of animal models of neurodegenerative diseases. Neurosci Biobehav Rev 2022; 135:104541. [DOI: 10.1016/j.neubiorev.2022.104541] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 11/28/2021] [Accepted: 01/13/2022] [Indexed: 02/07/2023]
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26
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Alpaugh M, Denis HL, Cicchetti F. Prion-like properties of the mutant huntingtin protein in living organisms: the evidence and the relevance. Mol Psychiatry 2022; 27:269-280. [PMID: 34711942 DOI: 10.1038/s41380-021-01350-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
If theories postulating that pathological proteins associated with neurodegenerative disorders behave similarly to prions were initially viewed with reluctance, it is now well-accepted that this occurs in several disease contexts. Notably, it has been reported that protein misfolding and subsequent prion-like properties can actively participate in neurodegenerative disorders. While this has been demonstrated in multiple cellular and animal model systems related to Alzheimer's and Parkinson's diseases, the prion-like properties of the mutant huntingtin protein (mHTT), associated with Huntington's disease (HD), have only recently been considered to play a role in this pathology, a concept our research group has contributed to extensively. In this review, we summarize the last few years of in vivo research in the field and speculate on the relationship between prion-like events and human HD. By interpreting observations primarily collected in in vivo models, our discussion will aim to discriminate which experimental factors contribute to the most efficient types of prion-like activities of mHTT and which routes of propagation may be more relevant to the human condition. A look back at nearly a decade of experimentation will inform future research and whether therapeutic strategies may emerge from this new knowledge.
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Affiliation(s)
- Melanie Alpaugh
- Centre de Recherche du CHU de Québec - Université Laval, Axe Neurosciences, Québec, QC, G1V 4G2, Canada.,Département de Psychiatrie & Neurosciences, Université Laval, Québec, QC, G1V 0A6, Canada
| | - Hélèna L Denis
- Centre de Recherche du CHU de Québec - Université Laval, Axe Neurosciences, Québec, QC, G1V 4G2, Canada.,Département de Psychiatrie & Neurosciences, Université Laval, Québec, QC, G1V 0A6, Canada
| | - Francesca Cicchetti
- Centre de Recherche du CHU de Québec - Université Laval, Axe Neurosciences, Québec, QC, G1V 4G2, Canada. .,Département de Psychiatrie & Neurosciences, Université Laval, Québec, QC, G1V 0A6, Canada.
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27
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Abstract
At fifteen different genomic locations, the expansion of a CAG/CTG repeat causes a neurodegenerative or neuromuscular disease, the most common being Huntington's disease and myotonic dystrophy type 1. These disorders are characterized by germline and somatic instability of the causative CAG/CTG repeat mutations. Repeat lengthening, or expansion, in the germline leads to an earlier age of onset or more severe symptoms in the next generation. In somatic cells, repeat expansion is thought to precipitate the rate of disease. The mechanisms underlying repeat instability are not well understood. Here we review the mammalian model systems that have been used to study CAG/CTG repeat instability, and the modifiers identified in these systems. Mouse models have demonstrated prominent roles for proteins in the mismatch repair pathway as critical drivers of CAG/CTG instability, which is also suggested by recent genome-wide association studies in humans. We draw attention to a network of connections between modifiers identified across several systems that might indicate pathway crosstalk in the context of repeat instability, and which could provide hypotheses for further validation or discovery. Overall, the data indicate that repeat dynamics might be modulated by altering the levels of DNA metabolic proteins, their regulation, their interaction with chromatin, or by direct perturbation of the repeat tract. Applying novel methodologies and technologies to this exciting area of research will be needed to gain deeper mechanistic insight that can be harnessed for therapies aimed at preventing repeat expansion or promoting repeat contraction.
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Affiliation(s)
- Vanessa C. Wheeler
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA,Department of Neurology, Harvard Medical School, Boston, MA, USA,Correspondence to: Vanessa C. Wheeler, Center for Genomic Medicine, Massachusetts Hospital, Boston MAA 02115, USA. E-mail: . and Vincent Dion, UK Dementia Research Institute at Cardiff University, Hadyn Ellis Building, Maindy Road, CF24 4HQ Cardiff, UK. E-mail:
| | - Vincent Dion
- UK Dementia Research Institute at Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff, UK,Correspondence to: Vanessa C. Wheeler, Center for Genomic Medicine, Massachusetts Hospital, Boston MAA 02115, USA. E-mail: . and Vincent Dion, UK Dementia Research Institute at Cardiff University, Hadyn Ellis Building, Maindy Road, CF24 4HQ Cardiff, UK. E-mail:
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28
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Gold MA, Whalen JM, Freon K, Hong Z, Iraqui I, Lambert SAE, Freudenreich CH. Restarted replication forks are error-prone and cause CAG repeat expansions and contractions. PLoS Genet 2021; 17:e1009863. [PMID: 34673780 PMCID: PMC8562783 DOI: 10.1371/journal.pgen.1009863] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 11/02/2021] [Accepted: 10/06/2021] [Indexed: 12/16/2022] Open
Abstract
Disease-associated trinucleotide repeats form secondary DNA structures that interfere with replication and repair. Replication has been implicated as a mechanism that can cause repeat expansions and contractions. However, because structure-forming repeats are also replication barriers, it has been unclear whether the instability occurs due to slippage during normal replication progression through the repeat, slippage or misalignment at a replication stall caused by the repeat, or during subsequent replication of the repeat by a restarted fork that has altered properties. In this study, we have specifically addressed the fidelity of a restarted fork as it replicates through a CAG/CTG repeat tract and its effect on repeat instability. To do this, we used a well-characterized site-specific replication fork barrier (RFB) system in fission yeast that creates an inducible and highly efficient stall that is known to restart by recombination-dependent replication (RDR), in combination with long CAG repeat tracts inserted at various distances and orientations with respect to the RFB. We find that replication by the restarted fork exhibits low fidelity through repeat sequences placed 2–7 kb from the RFB, exhibiting elevated levels of Rad52- and Rad8ScRad5/HsHLTF-dependent instability. CAG expansions and contractions are not elevated to the same degree when the tract is just in front or behind the barrier, suggesting that the long-traveling Polδ-Polδ restarted fork, rather than fork reversal or initial D-loop synthesis through the repeat during stalling and restart, is the greatest source of repeat instability. The switch in replication direction that occurs due to replication from a converging fork while the stalled fork is held at the barrier is also a significant contributor to the repeat instability profile. Our results shed light on a long-standing question of how fork stalling and RDR contribute to expansions and contractions of structure-forming trinucleotide repeats, and reveal that tolerance to replication stress by fork restart comes at the cost of increased instability of repetitive sequences. Trinucleotide repeat expansions are the cause of several muscular- and neuro-degenerative diseases, and further expansions during intergenerational inheritance often leads to an earlier age-of-onset in the offspring. Some intergenerational expansions appear to occur during germ cell replication, but how those replication-associated expansions arise is incompletely understood. Because there are many replication barriers in genomes, including the structure-forming repeats themselves, we investigated whether a repeat placed after such a barrier had altered instability. We discovered that a restarted replication fork traversing a CAG repeat tract is highly error prone and repeat expansions and contractions are more prevalent in this case compared to normal replication. These results reveal a mechanism for replication-associated repeat instability relevant to disease-associated trinucleotide repeat expansions.
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Affiliation(s)
- Michaela A. Gold
- Department of Biology, Tufts University, Medford, Massachusetts, United States of America
| | - Jenna M. Whalen
- Department of Biology, Tufts University, Medford, Massachusetts, United States of America
| | - Karine Freon
- Institut Curie, Université PSL, Orsay, France
- Université Paris-Saclay, Orsay, France
| | - Zixin Hong
- Department of Biology, Tufts University, Medford, Massachusetts, United States of America
| | - Ismail Iraqui
- Institut Curie, Université PSL, Orsay, France
- Université Paris-Saclay, Orsay, France
| | - Sarah A. E. Lambert
- Institut Curie, Université PSL, Orsay, France
- Université Paris-Saclay, Orsay, France
- Equipes Labélisées Ligue Nationale Contre Le Cancer, Orsay, France
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29
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Gusella JF, Lee JM, MacDonald ME. Huntington's disease: nearly four decades of human molecular genetics. Hum Mol Genet 2021; 30:R254-R263. [PMID: 34169318 PMCID: PMC8490011 DOI: 10.1093/hmg/ddab170] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2021] [Revised: 06/16/2021] [Accepted: 06/21/2021] [Indexed: 11/13/2022] Open
Abstract
Huntington's disease (HD) is a devastating neurogenetic disorder whose familial nature and progressive course were first described in the 19th century but for which no disease-modifying treatment is yet available. Through the active participation of HD families, this disorder has acted as a flagship for the application of human molecular genetic strategies to identify disease genes, understand pathogenesis and identify rational targets for development of therapies.
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Affiliation(s)
- James F Gusella
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
- Medical and Population Genetics Program, The Broad Institute of M.I.T. and Harvard, Cambridge, MA 02142, USA
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Jong-Min Lee
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
- Medical and Population Genetics Program, The Broad Institute of M.I.T. and Harvard, Cambridge, MA 02142, USA
- Department of Neurology, Harvard Medical School, Boston, MA 02115, USA
| | - Marcy E MacDonald
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
- Medical and Population Genetics Program, The Broad Institute of M.I.T. and Harvard, Cambridge, MA 02142, USA
- Department of Neurology, Harvard Medical School, Boston, MA 02115, USA
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30
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Hong EP, Chao MJ, Massey T, McAllister B, Lobanov S, Jones L, Holmans P, Kwak S, Orth M, Ciosi M, Monckton DG, Long JD, Lucente D, Wheeler VC, MacDonald ME, Gusella JF, Lee JM. Association Analysis of Chromosome X to Identify Genetic Modifiers of Huntington's Disease. J Huntingtons Dis 2021; 10:367-375. [PMID: 34180418 DOI: 10.3233/jhd-210485] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
BACKGROUND Huntington's disease (HD) is caused by an expanded (>35) CAG trinucleotide repeat in huntingtin (HTT). Age-at-onset of motor symptoms is inversely correlated with the size of the inherited CAG repeat, which expands further in brain regions due to somatic repeat instability. Our recent genetic investigation focusing on autosomal SNPs revealed that age-at-onset is also influenced by genetic variation at many loci, the majority of which encode genes involved in DNA maintenance/repair processes and repeat instability. OBJECTIVE We performed a complementary association analysis to determine whether variants in the X chromosome modify HD. METHODS We imputed SNPs on chromosome X for ∼9,000 HD subjects of European ancestry and performed an X chromosome-wide association study (XWAS) to test for association with age-at-onset corrected for inherited CAG repeat length. RESULTS In a mixed effects model XWAS analysis of all subjects (males and females), assuming random X-inactivation in females, no genome-wide significant onset modification signal was found. However, suggestive significant association signals were detected at Xq12 (top SNP, rs59098970; p-value, 1.4E-6), near moesin (MSN), in a region devoid of DNA maintenance genes. Additional suggestive signals not involving DNA repair genes were observed in male- and female-only analyses at other locations. CONCLUSION Although not genome-wide significant, potentially due to small effect size compared to the power of the current study, our data leave open the possibility of modification of HD by a non-DNA repair process. Our XWAS results are publicly available at the updated GEM EURO 9K website hosted at https://www.hdinhd.org/ for browsing, pathway analysis, and data download.
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Affiliation(s)
- Eun Pyo Hong
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA.,Department of Neurology, Harvard Medical School, Boston, MA, USA.,Medical and Population Genetics Program, the Broad Institute of M.I.T. and Harvard, Cambridge, MA, USA
| | - Michael J Chao
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA.,Department of Neurology, Harvard Medical School, Boston, MA, USA
| | - Thomas Massey
- Medical Research Council Centre for Neuropsychiatric Genetics and Genomics, Institute of Psychological Medicine and Clinical Neurosciences, School of Medicine, Cardiff University, Cardiff, UK
| | - Branduff McAllister
- Medical Research Council Centre for Neuropsychiatric Genetics and Genomics, Institute of Psychological Medicine and Clinical Neurosciences, School of Medicine, Cardiff University, Cardiff, UK
| | - Sergey Lobanov
- Medical Research Council Centre for Neuropsychiatric Genetics and Genomics, Institute of Psychological Medicine and Clinical Neurosciences, School of Medicine, Cardiff University, Cardiff, UK
| | - Lesley Jones
- Medical Research Council Centre for Neuropsychiatric Genetics and Genomics, Institute of Psychological Medicine and Clinical Neurosciences, School of Medicine, Cardiff University, Cardiff, UK
| | - Peter Holmans
- Medical Research Council Centre for Neuropsychiatric Genetics and Genomics, Institute of Psychological Medicine and Clinical Neurosciences, School of Medicine, Cardiff University, Cardiff, UK
| | | | - Michael Orth
- Department of Old Age Psychiatry and Psychotherapy, University of Bern, Switzerland
| | - Marc Ciosi
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Darren G Monckton
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Jeffrey D Long
- Department of Psychiatry, Carver College of Medicine and Department of Biostatistics, College of Public Health, and Department of Psychiatry, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - Diane Lucente
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - Vanessa C Wheeler
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA.,Department of Neurology, Harvard Medical School, Boston, MA, USA.,Medical and Population Genetics Program, the Broad Institute of M.I.T. and Harvard, Cambridge, MA, USA
| | - Marcy E MacDonald
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA.,Department of Neurology, Harvard Medical School, Boston, MA, USA.,Medical and Population Genetics Program, the Broad Institute of M.I.T. and Harvard, Cambridge, MA, USA
| | - James F Gusella
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA.,Medical and Population Genetics Program, the Broad Institute of M.I.T. and Harvard, Cambridge, MA, USA.,Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
| | - Jong-Min Lee
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA.,Department of Neurology, Harvard Medical School, Boston, MA, USA.,Medical and Population Genetics Program, the Broad Institute of M.I.T. and Harvard, Cambridge, MA, USA
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31
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Benn CL, Gibson KR, Reynolds DS. Drugging DNA Damage Repair Pathways for Trinucleotide Repeat Expansion Diseases. J Huntingtons Dis 2021; 10:203-220. [PMID: 32925081 PMCID: PMC7990437 DOI: 10.3233/jhd-200421] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
DNA damage repair (DDR) mechanisms have been implicated in a number of neurodegenerative diseases (both genetically determined and sporadic). Consistent with this, recent genome-wide association studies in Huntington’s disease (HD) and other trinucleotide repeat expansion diseases have highlighted genes involved in DDR mechanisms as modifiers for age of onset, rate of progression and somatic instability. At least some clinical genetic modifiers have been shown to have a role in modulating trinucleotide repeat expansion biology and could therefore provide new disease-modifying therapeutic targets. In this review, we focus on key considerations with respect to drug discovery and development using DDR mechanisms as a target for trinucleotide repeat expansion diseases. Six areas are covered with specific reference to DDR and HD: 1) Target identification and validation; 2) Candidate selection including therapeutic modality and delivery; 3) Target drug exposure with particular focus on blood-brain barrier penetration, engagement and expression of pharmacology; 4) Safety; 5) Preclinical models as predictors of therapeutic efficacy; 6) Clinical outcome measures including biomarkers.
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Affiliation(s)
- Caroline L Benn
- LoQus23 Therapeutics, Riverside, Babraham Research Campus, Cambridge, UK
| | - Karl R Gibson
- Sandexis Medicinal Chemistry Ltd, Innovation House, Discovery Park, Sandwich, Kent, UK
| | - David S Reynolds
- LoQus23 Therapeutics, Riverside, Babraham Research Campus, Cambridge, UK
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32
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Ciosi M, Cumming SA, Chatzi A, Larson E, Tottey W, Lomeikaite V, Hamilton G, Wheeler VC, Pinto RM, Kwak S, Morton AJ, Monckton DG. Approaches to Sequence the HTT CAG Repeat Expansion and Quantify Repeat Length Variation. J Huntingtons Dis 2021; 10:53-74. [PMID: 33579864 PMCID: PMC7990409 DOI: 10.3233/jhd-200433] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Background: Huntington’s disease (HD) is an autosomal dominant neurodegenerative disorder caused by the expansion of the HTT CAG repeat. Affected individuals inherit ≥36 repeats and longer alleles cause earlier onset, greater disease severity and faster disease progression. The HTT CAG repeat is genetically unstable in the soma in a process that preferentially generates somatic expansions, the proportion of which is associated with disease onset, severity and progression. Somatic mosaicism of the HTT CAG repeat has traditionally been assessed by semi-quantitative PCR-electrophoresis approaches that have limitations (e.g., no information about sequence variants). Genotyping-by-sequencing could allow for some of these limitations to be overcome. Objective: To investigate the utility of PCR sequencing to genotype large (>50 CAGs) HD alleles and to quantify the associated somatic mosaicism. Methods: We have applied MiSeq and PacBio sequencing to PCR products of the HTT CAG repeat in transgenic R6/2 mice carrying ∼55, ∼110, ∼255 and ∼470 CAGs. For each of these alleles, we compared the repeat length distributions generated for different tissues at two ages. Results: We were able to sequence the CAG repeat full length in all samples. However, the repeat length distributions for samples with ∼470 CAGs were biased towards shorter repeat lengths. Conclusion: PCR sequencing can be used to sequence all the HD alleles considered, but this approach cannot be used to estimate modal allele size or quantify somatic expansions for alleles ⪢250 CAGs. We review the limitations of PCR sequencing and alternative approaches that may allow the quantification of somatic contractions and very large somatic expansions.
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Affiliation(s)
- Marc Ciosi
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Sarah A Cumming
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Afroditi Chatzi
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Eloise Larson
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - William Tottey
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Vilija Lomeikaite
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Graham Hamilton
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.,Glasgow Polyomics, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Vanessa C Wheeler
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA.,Department of Neurology, Harvard Medical School, Boston, MA, USA
| | - Ricardo Mouro Pinto
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA.,Department of Neurology, Harvard Medical School, Boston, MA, USA
| | - Seung Kwak
- CHDI Management/CHDI Foundation, Princeton, NJ, USA
| | - A Jennifer Morton
- Department of Physiology, Development and Neuroscience, University of Cambridge, Tennis Court Road, Cambridge, UK
| | - Darren G Monckton
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
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33
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Jones L, Wheeler VC, Pearson CE. Special Issue: DNA Repair and Somatic Repeat Expansion in Huntington's Disease. J Huntingtons Dis 2021; 10:3-5. [PMID: 33554921 PMCID: PMC7990429 DOI: 10.3233/jhd-219001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Lesley Jones
- Division of Psychological Medicine and Clinical Neurosciences, MRC Centre for Neuropsychiatric Genetics and Genomics, School of Medicine, Cardiff University, Cardiff, UK
| | - Vanessa C Wheeler
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA.,Department of Neurology, Harvard Medical School, Boston, MA, USA
| | - Christopher E Pearson
- Program of Genetics & Genome Biology, The Hospital for Sick Children, The Peter Gilgan Centre for Research and Learning, Toronto, Ontario, Canada.,University of Toronto, Program of Molecular Genetics
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