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Shirguppe S, Gapinske M, Swami D, Gosstola N, Acharya P, Miskalis A, Joulani D, Szkwarek MG, Bhattacharjee A, Elias G, Stilger M, Winter J, Woods WS, Anand D, Lim CKW, Gaj T, Perez-Pinera P. In vivo CRISPR base editing for treatment of Huntington's disease. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.05.602282. [PMID: 39005280 PMCID: PMC11245100 DOI: 10.1101/2024.07.05.602282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/16/2024]
Abstract
Huntington's disease (HD) is an inherited and ultimately fatal neurodegenerative disorder caused by an expanded polyglutamine-encoding CAG repeat within exon 1 of the huntingtin (HTT) gene, which produces a mutant protein that destroys striatal and cortical neurons. Importantly, a critical event in the pathogenesis of HD is the proteolytic cleavage of the mutant HTT protein by caspase-6, which generates fragments of the N-terminal domain of the protein that form highly toxic aggregates. Given the role that proteolysis of the mutant HTT protein plays in HD, strategies for preventing this process hold potential for treating the disorder. By screening 141 CRISPR base editor variants targeting splice elements in the HTT gene, we identified platforms capable of producing HTT protein isoforms resistant to caspase-6-mediated proteolysis via editing of the splice acceptor sequence for exon 13. When delivered to the striatum of a rodent HD model, these base editors induced efficient exon skipping and decreased the formation of the N-terminal fragments, which in turn reduced HTT protein aggregation and attenuated striatal and cortical atrophy. Collectively, these results illustrate the potential for CRISPR base editing to decrease the toxicity of the mutant HTT protein for HD.
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2
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Lemarié FL, Sanders SS, Nguyen Y, Martin DDO, Hayden MR. Full-length huntingtin is palmitoylated at multiple sites and post-translationally myristoylated following caspase-cleavage. Front Physiol 2023; 14:1086112. [PMID: 36711022 PMCID: PMC9880554 DOI: 10.3389/fphys.2023.1086112] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 01/02/2023] [Indexed: 01/15/2023] Open
Abstract
Introduction: Huntington disease is an autosomal dominant neurodegenerative disorder which is caused by a CAG repeat expansion in the HTT gene that codes for an elongated polyglutamine tract in the huntingtin (HTT) protein. Huntingtin is subjected to multiple post-translational modifications which regulate its cellular functions and degradation. We have previously identified a palmitoylation site at cysteine 214 (C214), catalyzed by the enzymes ZDHHC17 and ZDHHC13. Reduced palmitoylation level of mutant huntingtin is linked to toxicity and loss of function. Moreover, we have described N-terminal myristoylation by the N-myristoyltransferases of a short fragment of huntingtin (HTT553-586) at glycine 553 (G553) following proteolysis at aspartate 552 (D552). Results: Here, we show that huntingtin is palmitoylated at numerous cysteines: C105, C433, C3134 and C3144. In addition, we confirm that full-length huntingtin is cleaved at D552 and post-translationally myristoylated at G553. Importantly, blocking caspase cleavage at the critical and pathogenic aspartate 586 (D586) significantly increases posttranslational myristoylation of huntingtin. In turn, myristoylation of huntingtin promotes the co-interaction between C-terminal and N-terminal huntingtin fragments, which is also protective. Discussion: This suggests that the protective effect of inhibiting caspase-cleavage at D586 may be mediated through post-translational myristoylation of huntingtin at G553.
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Cattaneo M, Maciag A, Milella MS, Ciaglia E, Bruno A, Puca AA. Longevity-Associated Variant of BPIFB4 Confers Neuroprotection in the STHdh Cell Model of Huntington Disease. Int J Mol Sci 2022; 23:ijms232315313. [PMID: 36499641 PMCID: PMC9737551 DOI: 10.3390/ijms232315313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 11/30/2022] [Indexed: 12/12/2022] Open
Abstract
Huntington's disease (HD) is caused by the production of mutant Huntingtin (mHTT), characterized by long polyglutamine repeats with toxic effects. There are currently no clinically validated therapeutic agents that slow or halt HD progression, resulting in a significant clinical unmet need. The striatum-derived STHdh cell line, generated from mHTT knock-in mouse embryos (STHdhQ111/Q111), represents a useful model to study mechanisms behind pathogenesis of HD and to investigate potential new therapeutic targets. Indeed, these cells show susceptibility to nucleolar stress, activated DNA damage response and apoptotic signals, and elevated levels of H3K9me3 that all together concur in the progressive HD pathogenesis. We have previously shown that the adeno-associated viral vector-mediated delivery of the longevity-associated variant (LAV) of BPIFB4 prevents HD progression in a mouse model of HD. Here, we show that LAV-BPIFB4 stably infected in STHdhQ111/Q111 cells reduces (i) nucleolar stress and DNA damage through the improvement of DNA repair machinery, (ii) apoptosis, through the inhibition of the caspase 3 death signaling, and (iii) the levels of H3K9me3, by accelerating the histone clearance, via the ubiquitin-proteasome pathway. These findings pave the way to propose LAV-BPIFB4 as a promising target for innovative therapeutic strategies in HD.
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Affiliation(s)
- Monica Cattaneo
- Cardiovascular Department, IRCCS MultiMedica, 20138 Milan, Italy
| | - Anna Maciag
- Cardiovascular Department, IRCCS MultiMedica, 20138 Milan, Italy
| | | | - Elena Ciaglia
- Department of Medicine, Surgery and Dentistry “Scuola Medica Salernitana”, University of Salerno, 84081 Salerno, Italy
| | - Antonino Bruno
- Laboratory of Innate Immunity, Unit of Molecular Pathology, Biochemistry and Immunology, IRCCS MultiMedica, 20138 Milan, Italy
- Laboratory of Immunology and General Pathology, Department of Biotechnologies and Life Sciences (DBSV), University of Insubria, 20138 Varese, Italy
| | - Annibale Alessandro Puca
- Cardiovascular Department, IRCCS MultiMedica, 20138 Milan, Italy
- Department of Medicine, Surgery and Dentistry “Scuola Medica Salernitana”, University of Salerno, 84081 Salerno, Italy
- Correspondence:
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Zhao X, Sun Y, Wang Z, Chen L, Li S, Li XJ. Huntingtin exon 1 deletion does not alter the subcellular distribution of huntingtin and gene transcription in mice. Front Cell Neurosci 2022; 16:1021592. [DOI: 10.3389/fncel.2022.1021592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Accepted: 10/25/2022] [Indexed: 11/11/2022] Open
Abstract
Huntington disease (HD) is caused by the expansion of CAG triplet repeats in exon 1 of the huntingtin (HTT) gene, which also encodes the first 17 amino acids (N-17) that can modulate the toxicity of the expanded polyQ repeat. N-17 are conserved in a wide range of species and are found to influence the subcellular distribution of mutant Htt. Moreover, N-17 is subject to many posttranslational modifications that may regulate the function, stability, and distribution of HTT. However, the function of Htt exon 1 and its influence on the normal Htt remains to be fully investigated. By investigating a knock-in mouse model that lacks Htt exon1, we found that deletion of Htt exon1 does not affect the survival of mice and differentiation of cultured mouse neurons. Furthermore, the lack of Htt exon 1 does not alter the subcellular distribution of Htt, autophagy protein expression, and global gene transcription in the mouse brain. These results suggest that removing the entire exon 1 of Htt could be a therapeutic approach to eliminate expanded polyQ toxicity.
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5
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Therapeutic Strategies in Huntington’s Disease: From Genetic Defect to Gene Therapy. Biomedicines 2022; 10:biomedicines10081895. [PMID: 36009443 PMCID: PMC9405755 DOI: 10.3390/biomedicines10081895] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 07/29/2022] [Accepted: 08/03/2022] [Indexed: 12/14/2022] Open
Abstract
Despite the identification of an expanded CAG repeat on exon 1 of the huntingtin gene located on chromosome 1 as the genetic defect causing Huntington’s disease almost 30 years ago, currently approved therapies provide only limited symptomatic relief and do not influence the age of onset or disease progression rate. Research has identified various intricate pathogenic cascades which lead to neuronal degeneration, but therapies interfering with these mechanisms have been marked by many failures and remain to be validated. Exciting new opportunities are opened by the emerging techniques which target the mutant protein DNA and RNA, allowing for “gene editing”. Although some issues relating to “off-target” effects or immune-mediated side effects need to be solved, these strategies, combined with stem cell therapies and more traditional approaches targeting specific pathogenic cascades, such as excitotoxicity and bioavailability of neurotrophic factors, could lead to significant improvement of the outcomes of treated Huntington’s disease patients.
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Molecular Pathophysiological Mechanisms in Huntington's Disease. Biomedicines 2022; 10:biomedicines10061432. [PMID: 35740453 PMCID: PMC9219859 DOI: 10.3390/biomedicines10061432] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 06/12/2022] [Accepted: 06/14/2022] [Indexed: 12/11/2022] Open
Abstract
Huntington’s disease is an inherited neurodegenerative disease described 150 years ago by George Huntington. The genetic defect was identified in 1993 to be an expanded CAG repeat on exon 1 of the huntingtin gene located on chromosome 4. In the following almost 30 years, a considerable amount of research, using mainly animal models or in vitro experiments, has tried to unravel the complex molecular cascades through which the transcription of the mutant protein leads to neuronal loss, especially in the medium spiny neurons of the striatum, and identified excitotoxicity, transcriptional dysregulation, mitochondrial dysfunction, oxidative stress, impaired proteostasis, altered axonal trafficking and reduced availability of trophic factors to be crucial contributors. This review discusses the pathogenic cascades described in the literature through which mutant huntingtin leads to neuronal demise. However, due to the ubiquitous presence of huntingtin, astrocytes are also dysfunctional, and neuroinflammation may additionally contribute to Huntington’s disease pathology. The quest for therapies to delay the onset and reduce the rate of Huntington’s disease progression is ongoing, but is based on findings from basic research.
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7
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Srinivasan E, Ram V, Rajasekaran R. A review on Huntington protein Insight into protein aggregation and therapeutic interventions. Curr Drug Metab 2022; 23:260-282. [PMID: 35319359 DOI: 10.2174/1389200223666220321103942] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 12/13/2021] [Accepted: 01/15/2022] [Indexed: 11/22/2022]
Abstract
Huntington disease (HD) is a distressing, innate neurodegenerative disease that descends from CAG repeat expansion in the huntingtin gene causing behavioral changes, motor dysfunction, and dementia in children and adults. Mutation in huntingtin (HTT) protein has been suggested to cause neuron loss in the cortex and striatum through various mechanisms including abnormal regulation of transcription, proteasomal dysfunction, post-translational modification, and other events, regulating toxicity. Pathogenesis of HD involves cleavage of the huntingtin protein followed by the neuronal accumulation of its aggregated form. Several research groups made possible efforts to reduce huntingtin gene expression, protein accumulation, and protein aggregation using inhibitors and molecular chaperones as developing drugs against HD. Herein, we review the mechanism proposed towards the formation of HTT protein aggregation and the impact of therapeutic strategies for the treatment of HD.
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Affiliation(s)
- E Srinivasan
- Department of Biotechnology, School of Bio Sciences and Technology, Vellore Institute of Technology, Vellore - 632014, Tamil Nadu, India
- Department of Bioinformatics, Saveetha School of Engineering, Saveetha Institute of Medical and Technical Sciences (SIMATS), Thandalam, Chennai - 602105, Tamil Nadu, India
| | - Vavish Ram
- Bioinformatics Lab, Department of Biotechnology, School of Bio Sciences and Technology, Vellore Institute of Technology, Vellore - 632014, Tamil Nadu, India
| | - R Rajasekaran
- Bioinformatics Lab, Department of Biotechnology, School of Bio Sciences and Technology, Vellore Institute of Technology, Vellore - 632014, Tamil Nadu, India
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8
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Wang R, Wu Y, Liu R, Liu M, Li Q, Ba Y, Huang H. Deciphering therapeutic options for neurodegenerative diseases: insights from SIRT1. J Mol Med (Berl) 2022; 100:537-553. [PMID: 35275221 DOI: 10.1007/s00109-022-02187-2] [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] [Received: 12/15/2021] [Revised: 03/01/2022] [Accepted: 03/03/2022] [Indexed: 12/23/2022]
Abstract
Silent information regulator 1 (SIRT1) is a nicotinamide adenine dinucleotide (NAD +)-dependent protein deacetylase that exerts biological effects through nucleoplasmic transfer. Recent studies have highlighted that SIRT1 deacetylates protein substrates to exert its neuroprotective effects, including decreased oxidative stress and inflammatory, increases autophagy, increases levels of nerve growth factors (correlated with behavioral changes), and maintains neural integrity (affects neuronal development and function) in aging or neurological disorder. In this review, we highlight the molecular mechanisms underlying the protective role of SIRT1 in modulating neurodegeneration, focusing on protein homeostasis, aging-related signaling pathways, neurogenesis, and synaptic plasticity. Meanwhile, the potential of targeting SIRT1 to block the occurrence and progression of neurodegenerative diseases is also discussed. Taken together, this review provides an up-to-date evaluation of our current understanding of the neuroprotective mechanisms of SIRT1 and also be involved in the potential therapeutic opportunities of AD and related neurodegenerative diseases.
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Affiliation(s)
- Ruike Wang
- Department of Environmental Health, College of Public Health, Zhengzhou University, No.100 Kexue Avenue, Henan province, Zhengzhou, 450001, China.,Environment and Health Innovation Team, College of Public Health, Zhengzhou University, Henan province, Zhengzhou, 450001, China
| | - Yingying Wu
- Department of Environmental Health, College of Public Health, Zhengzhou University, No.100 Kexue Avenue, Henan province, Zhengzhou, 450001, China.,Environment and Health Innovation Team, College of Public Health, Zhengzhou University, Henan province, Zhengzhou, 450001, China
| | - Rundong Liu
- Department of Environmental Health, College of Public Health, Zhengzhou University, No.100 Kexue Avenue, Henan province, Zhengzhou, 450001, China.,Environment and Health Innovation Team, College of Public Health, Zhengzhou University, Henan province, Zhengzhou, 450001, China
| | - Mengchen Liu
- Department of Environmental Health, College of Public Health, Zhengzhou University, No.100 Kexue Avenue, Henan province, Zhengzhou, 450001, China.,Environment and Health Innovation Team, College of Public Health, Zhengzhou University, Henan province, Zhengzhou, 450001, China
| | - Qiong Li
- Department of Environmental Health, College of Public Health, Zhengzhou University, No.100 Kexue Avenue, Henan province, Zhengzhou, 450001, China.,Environment and Health Innovation Team, College of Public Health, Zhengzhou University, Henan province, Zhengzhou, 450001, China
| | - Yue Ba
- Department of Environmental Health, College of Public Health, Zhengzhou University, No.100 Kexue Avenue, Henan province, Zhengzhou, 450001, China.,Environment and Health Innovation Team, College of Public Health, Zhengzhou University, Henan province, Zhengzhou, 450001, China
| | - Hui Huang
- Department of Environmental Health, College of Public Health, Zhengzhou University, No.100 Kexue Avenue, Henan province, Zhengzhou, 450001, China. .,Environment and Health Innovation Team, College of Public Health, Zhengzhou University, Henan province, Zhengzhou, 450001, China.
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9
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Deng Y, Wang H, Joni M, Sekhri R, Reiner A. Progression of basal ganglia pathology in heterozygous Q175 knock-in Huntington's disease mice. J Comp Neurol 2021; 529:1327-1371. [PMID: 32869871 PMCID: PMC8049038 DOI: 10.1002/cne.25023] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 08/07/2020] [Accepted: 08/26/2020] [Indexed: 12/29/2022]
Abstract
We used behavioral testing and morphological methods to detail the progression of basal ganglia neuron type-specific pathology and the deficits stemming from them in male heterozygous Q175 mice, compared to age-matched WT males. A rotarod deficit was not present in Q175 mice until 18 months, but increased open field turn rate (reflecting hyperkinesia) and open field anxiety were evident at 6 months. No loss of striatal neurons was seen out to 18 months, but ENK+ and DARPP32+ striatal perikarya were fewer by 6 months, due to diminished expression, with further decline by 18 months. No reduction in SP+ striatal perikarya or striatal interneurons was seen in Q175 mice at 18 months, but cholinergic interneurons showed dendrite attenuation by 6 months. Despite reduced ENK expression in indirect pathway striatal perikarya, ENK-immunostained terminals in globus pallidus externus (GPe) were more abundant at 6 months and remained so out to 18 months. Similarly, SP-immunostained terminals from striatal direct pathway neurons were more abundant in globus pallidus internus and substantia nigra at 6 months and remained so at 18 months. FoxP2+ arkypallidal GPe neurons and subthalamic nucleus neurons were lost by 18 months but not prototypical PARV+ GPe neurons or dopaminergic nigral neurons. Our results show that striatal projection neuron abnormalities and behavioral abnormalities reflecting them develop between 2 and 6 months of age in Q175 male heterozygotes, indicating early effects of the HD mutation. The striatal pathologies resemble those in human HD, but are less severe at 18 months than even in premanifest HD.
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Affiliation(s)
- Yunping Deng
- Department of Anatomy and NeurobiologyThe University of Tennessee Health Science CenterMemphisTennesseeUSA
| | - Hongbing Wang
- Department of Anatomy and NeurobiologyThe University of Tennessee Health Science CenterMemphisTennesseeUSA
| | - Marion Joni
- Department of Anatomy and NeurobiologyThe University of Tennessee Health Science CenterMemphisTennesseeUSA
| | - Radhika Sekhri
- Department of PathologyThe University of Tennessee Health Science CenterMemphisTennesseeUSA
| | - Anton Reiner
- Department of Anatomy and NeurobiologyThe University of Tennessee Health Science CenterMemphisTennesseeUSA
- Department of OphthalmologyThe University of Tennessee Health Science CenterMemphisTennesseeUSA
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10
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Burrus CJ, McKinstry SU, Kim N, Ozlu MI, Santoki AV, Fang FY, Ma A, Karadeniz YB, Worthington AK, Dragatsis I, Zeitlin S, Yin HH, Eroglu C. Striatal Projection Neurons Require Huntingtin for Synaptic Connectivity and Survival. Cell Rep 2021; 30:642-657.e6. [PMID: 31968243 DOI: 10.1016/j.celrep.2019.12.069] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 11/07/2019] [Accepted: 12/17/2019] [Indexed: 12/19/2022] Open
Abstract
Huntington's disease (HD) is caused by an autosomal dominant polyglutamine expansion mutation of Huntingtin (HTT). HD patients suffer from progressive motor, cognitive, and psychiatric impairments, along with significant degeneration of the striatal projection neurons (SPNs) of the striatum. HD is widely accepted to be caused by a toxic gain-of-function of mutant HTT. However, whether loss of HTT function, because of dominant-negative effects of the mutant protein, plays a role in HD and whether HTT is required for SPN health and function are not known. Here, we delete Htt from specific subpopulations of SPNs using the Cre-Lox system and find that SPNs require HTT for motor regulation, synaptic development, cell health, and survival during aging. Our results suggest that loss of HTT function in SPNs could play a critical role in HD pathogenesis.
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Affiliation(s)
- Caley J Burrus
- Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA; Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Spencer U McKinstry
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Namsoo Kim
- Department of Psychology and Neuroscience, Trinity College of Arts and Sciences, Duke University, Durham, NC 27710, USA
| | - M Ilcim Ozlu
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Aditya V Santoki
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Francia Y Fang
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Annie Ma
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Yonca B Karadeniz
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Atesh K Worthington
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Ioannis Dragatsis
- Department of Physiology, The University of Tennessee, Health Science Center, Memphis, TN 38163, USA
| | - Scott Zeitlin
- Department of Neuroscience, University of Virginia, School of Medicine, Charlottesville, VA 22908, USA
| | - Henry H Yin
- Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA; Department of Psychology and Neuroscience, Trinity College of Arts and Sciences, Duke University, Durham, NC 27710, USA; Duke Institute for Brain Sciences, Durham, NC 27710, USA
| | - Cagla Eroglu
- Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA; Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA; Duke Institute for Brain Sciences, Durham, NC 27710, USA; Regeneration Next Initiative, Duke University, Durham, NC 27710, USA.
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11
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Eshraghi M, Karunadharma PP, Blin J, Shahani N, Ricci EP, Michel A, Urban NT, Galli N, Sharma M, Ramírez-Jarquín UN, Florescu K, Hernandez J, Subramaniam S. Mutant Huntingtin stalls ribosomes and represses protein synthesis in a cellular model of Huntington disease. Nat Commun 2021; 12:1461. [PMID: 33674575 PMCID: PMC7935949 DOI: 10.1038/s41467-021-21637-y] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 01/29/2021] [Indexed: 02/08/2023] Open
Abstract
The polyglutamine expansion of huntingtin (mHTT) causes Huntington disease (HD) and neurodegeneration, but the mechanisms remain unclear. Here, we found that mHtt promotes ribosome stalling and suppresses protein synthesis in mouse HD striatal neuronal cells. Depletion of mHtt enhances protein synthesis and increases the speed of ribosomal translocation, while mHtt directly inhibits protein synthesis in vitro. Fmrp, a known regulator of ribosome stalling, is upregulated in HD, but its depletion has no discernible effect on protein synthesis or ribosome stalling in HD cells. We found interactions of ribosomal proteins and translating ribosomes with mHtt. High-resolution global ribosome footprint profiling (Ribo-Seq) and mRNA-Seq indicates a widespread shift in ribosome occupancy toward the 5' and 3' end and unique single-codon pauses on selected mRNA targets in HD cells, compared to controls. Thus, mHtt impedes ribosomal translocation during translation elongation, a mechanistic defect that can be exploited for HD therapeutics.
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Affiliation(s)
- Mehdi Eshraghi
- grid.214007.00000000122199231The Scripps Research Institute, Department of Neuroscience, Jupiter, FL USA
| | - Pabalu P. Karunadharma
- grid.214007.00000000122199231The Scripps Research Institute, Genomic Core, Jupiter, FL USA
| | - Juliana Blin
- grid.462957.b0000 0004 0598 0706Laboratory of Biology and Cellular Modelling at Ecole Normale Supérieure of Lyon, RNA Metabolism in Immunity and Infection Lab, LBMC, Lyon, France
| | - Neelam Shahani
- grid.214007.00000000122199231The Scripps Research Institute, Department of Neuroscience, Jupiter, FL USA
| | - Emiliano P. Ricci
- grid.462957.b0000 0004 0598 0706Laboratory of Biology and Cellular Modelling at Ecole Normale Supérieure of Lyon, RNA Metabolism in Immunity and Infection Lab, LBMC, Lyon, France
| | | | | | - Nicole Galli
- grid.214007.00000000122199231The Scripps Research Institute, Department of Neuroscience, Jupiter, FL USA
| | - Manish Sharma
- grid.214007.00000000122199231The Scripps Research Institute, Department of Neuroscience, Jupiter, FL USA
| | - Uri Nimrod Ramírez-Jarquín
- grid.214007.00000000122199231The Scripps Research Institute, Department of Neuroscience, Jupiter, FL USA
| | - Katie Florescu
- grid.214007.00000000122199231The Scripps Research Institute, Department of Neuroscience, Jupiter, FL USA
| | - Jennifer Hernandez
- grid.214007.00000000122199231The Scripps Research Institute, Department of Neuroscience, Jupiter, FL USA
| | - Srinivasa Subramaniam
- grid.214007.00000000122199231The Scripps Research Institute, Department of Neuroscience, Jupiter, FL USA
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12
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Cepeda C, Levine MS. Synaptic Dysfunction in Huntington's Disease: Lessons from Genetic Animal Models. Neuroscientist 2020; 28:20-40. [PMID: 33198566 DOI: 10.1177/1073858420972662] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The understanding of the functional and structural changes occurring in the cerebral cortex and basal ganglia in Huntington's disease (HD) has benefited considerably from the generation of genetic animal models. Most studies of synaptic alterations in HD models have focused on the striatum, but a more complete picture of synaptic dysfunction in the cortico-basal ganglia-cortical loop is emerging. Here, we provide a review and analysis of current developments in the study of synaptic alterations in these areas using HD rodent models. Recent evidence indicates that cortical maldevelopment plays a role in synaptic dysfunction along the corticostriatal pathway that may have its roots in the way mutant huntingtin interacts with synaptic proteins. Furthermore, a progressive disconnection in the corticostriatal pathway leads to abnormal function engaging extrasynaptic N-methyl-D-aspartate glutamate receptors that contribute to eventual cell degeneration. In addition, biphasic increases followed by decreases in glutamate and dopamine release in the striatum could explain contrasting symptomatology in early and late stages of the disease. Changes in striatal output regions also are beginning to be examined. Finally, we highlight some therapeutic avenues aimed at rescuing synaptic dysfunction.
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Affiliation(s)
- Carlos Cepeda
- IDDRC, Jane and Terry Semel Institute for Neuroscience & Human Behavior, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Michael S Levine
- IDDRC, Jane and Terry Semel Institute for Neuroscience & Human Behavior, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
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13
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Piras IS, Picinelli C, Iennaco R, Baccarin M, Castronovo P, Tomaiuolo P, Cucinotta F, Ricciardello A, Turriziani L, Nanetti L, Mariotti C, Gellera C, Lintas C, Sacco R, Zuccato C, Cattaneo E, Persico AM. Huntingtin gene CAG repeat size affects autism risk: Family-based and case-control association study. Am J Med Genet B Neuropsychiatr Genet 2020; 183:341-351. [PMID: 32652810 DOI: 10.1002/ajmg.b.32806] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 04/20/2020] [Accepted: 05/04/2020] [Indexed: 11/10/2022]
Abstract
The Huntingtin (HTT) gene contains a CAG repeat in exon 1, whose expansion beyond 39 repeats consistently leads to Huntington's disease (HD), whereas normal-to-intermediate alleles seemingly modulate brain structure, function and behavior. The role of the CAG repeat in Autism Spectrum Disorder (ASD) was investigated applying both family-based and case-control association designs, with the SCA3 repeat as a negative control. Significant overtransmission of "long" CAG alleles (≥17 repeats) to autistic children and of "short" alleles (≤16 repeats) to their unaffected siblings (all p < 10-5 ) was observed in 612 ASD families (548 simplex and 64 multiplex). Surprisingly, both 193 population controls and 1,188 neurological non-HD controls have significantly lower frequencies of "short" CAG alleles compared to 185 unaffected siblings and higher rates of "long" alleles compared to 548 ASD patients from the same families (p < .05-.001). The SCA3 CAG repeat displays no association. "Short" HTT alleles seemingly exert a protective effect from clinically overt autism in families carrying a genetic predisposition for ASD, while "long" alleles may enhance autism risk. Differential penetrance of autism-inducing genetic/epigenetic variants may imply atypical developmental trajectories linked to HTT functions, including excitation/inhibition imbalance, cortical neurogenesis and apoptosis, neuronal migration, synapse formation, connectivity and homeostasis.
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Affiliation(s)
- Ignazio Stefano Piras
- Neurogenomics Division, The Translational Genomics Research Institute, Phoenix, Arizona, USA
| | - Chiara Picinelli
- Mafalda Luce Center for Pervasive Developmental Disorders, Milan, Italy
| | - Raffaele Iennaco
- Department of Biosciences, Università degli Studi di Milano, Milan, Italy.,Istituto Nazionale di Genetica Molecolare "Romeo ed Enrica Invernizzi", Milan, Italy
| | - Marco Baccarin
- Mafalda Luce Center for Pervasive Developmental Disorders, Milan, Italy
| | - Paola Castronovo
- Mafalda Luce Center for Pervasive Developmental Disorders, Milan, Italy
| | - Pasquale Tomaiuolo
- Interdepartmental Program "Autism 0-90", "Gaetano Martino" University Hospital, University of Messina, Messina, Italy
| | - Francesca Cucinotta
- Interdepartmental Program "Autism 0-90", "Gaetano Martino" University Hospital, University of Messina, Messina, Italy
| | - Arianna Ricciardello
- Interdepartmental Program "Autism 0-90", "Gaetano Martino" University Hospital, University of Messina, Messina, Italy
| | - Laura Turriziani
- Interdepartmental Program "Autism 0-90", "Gaetano Martino" University Hospital, University of Messina, Messina, Italy
| | - Lorenzo Nanetti
- Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Caterina Mariotti
- Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Cinzia Gellera
- Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Carla Lintas
- Unit of Child and Adolescent NeuroPsychiatry & Laboratory of Molecular Psychiatry and Neurogenetics, University Campus Bio-Medico, Rome, Italy
| | - Roberto Sacco
- Unit of Child and Adolescent NeuroPsychiatry & Laboratory of Molecular Psychiatry and Neurogenetics, University Campus Bio-Medico, Rome, Italy
| | - Chiara Zuccato
- Department of Biosciences, Università degli Studi di Milano, Milan, Italy.,Istituto Nazionale di Genetica Molecolare "Romeo ed Enrica Invernizzi", Milan, Italy
| | - Elena Cattaneo
- Department of Biosciences, Università degli Studi di Milano, Milan, Italy.,Istituto Nazionale di Genetica Molecolare "Romeo ed Enrica Invernizzi", Milan, Italy
| | - Antonio M Persico
- Interdepartmental Program "Autism 0-90", "Gaetano Martino" University Hospital, University of Messina, Messina, Italy
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14
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Epigenomic Remodeling in Huntington's Disease-Master or Servant? EPIGENOMES 2020; 4:epigenomes4030015. [PMID: 34968288 PMCID: PMC8594700 DOI: 10.3390/epigenomes4030015] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 07/15/2020] [Accepted: 07/27/2020] [Indexed: 12/03/2022] Open
Abstract
In light of our aging population, neurodegenerative disorders are becoming a tremendous challenge, that modern societies have to face. They represent incurable, progressive conditions with diverse and complex pathological features, followed by catastrophic occurrences of massive neuronal loss at the later stages of the diseases. Some of these disorders, like Huntington’s disease (HD), rely on defined genetic factors. HD, as an incurable, fatal hereditary neurodegenerative disorder characterized by its mid-life onset, is caused by the expansion of CAG trinucleotide repeats coding for glutamine (Q) in exon 1 of the huntingtin gene. Apart from the genetic defect, environmental factors are thought to influence the risk, onset and progression of HD. As epigenetic mechanisms are known to readily respond to environmental stimuli, they are proposed to play a key role in HD pathogenesis. Indeed, dynamic epigenomic remodeling is observed in HD patients and in brains of HD animal models. Epigenetic signatures, such as DNA methylation, histone variants and modifications, are known to influence gene expression and to orchestrate various aspects of neuronal physiology. Hence, deciphering their implication in HD pathogenesis might open up new paths for novel therapeutic concepts, which are discussed in this review.
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15
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Kay C, Collins JA, Caron NS, Agostinho LDA, Findlay-Black H, Casal L, Sumathipala D, Dissanayake VHW, Cornejo-Olivas M, Baine F, Krause A, Greenberg JL, Paiva CLA, Squitieri F, Hayden MR. A Comprehensive Haplotype-Targeting Strategy for Allele-Specific HTT Suppression in Huntington Disease. Am J Hum Genet 2019; 105:1112-1125. [PMID: 31708117 PMCID: PMC6904807 DOI: 10.1016/j.ajhg.2019.10.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 10/11/2019] [Indexed: 11/20/2022] Open
Abstract
Huntington disease (HD) is a fatal neurodegenerative disorder caused by a gain-of-function mutation in HTT. Suppression of mutant HTT has emerged as a leading therapeutic strategy for HD, with allele-selective approaches targeting HTT SNPs now in clinical trials. Haplotypes associated with the HD mutation (A1, A2, A3a) represent panels of allele-specific gene silencing targets for efficient treatment of individuals with HD of Northern European and indigenous South American ancestry. Here we extend comprehensive haplotype analysis of the HD mutation to key populations of Southern European, South Asian, Middle Eastern, and admixed African ancestry. In each of these populations, the HD mutation occurs predominantly on the A2 HTT haplotype. Analysis of HD haplotypes across all affected population groups enables rational selection of candidate target SNPs for development of allele-selective gene silencing therapeutics worldwide. Targeting SNPs on the A1 and A2 haplotypes in parallel is essential to achieve treatment of the most HD-affected subjects in populations where HD is most prevalent. Current allele-specific approaches will leave a majority of individuals with HD untreated in populations where the HD mutation occurs most frequently on the A2 haplotype. We further demonstrate preclinical development of potent and selective ASOs targeting SNPs on the A2 HTT haplotype, representing an allele-specific treatment strategy for these individuals. On the basis of comprehensive haplotype analysis, we show the maximum proportion of HD-affected subjects that may be treated with three or four allele targets in different populations worldwide, informing current allele-specific HTT silencing strategies.
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Affiliation(s)
- Chris Kay
- Center for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, BC V5Z4H4, Canada
| | - Jennifer A Collins
- Center for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, BC V5Z4H4, Canada
| | - Nicholas S Caron
- Center for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, BC V5Z4H4, Canada
| | - Luciana de Andrade Agostinho
- PPGNEURO, Universidade Federal do Estado do Rio de Janeiro (UNIRIO), Rio de Janeiro, RJ 20270-004, Brazil; Centro Universitário UNIFAMINAS, Muriaé, MG 36880-000, Brazil; Hospital do Câncer de Muriaé, Muriaé, MG 36880-000, Brazil
| | - Hailey Findlay-Black
- Center for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, BC V5Z4H4, Canada
| | - Lorenzo Casal
- Center for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, BC V5Z4H4, Canada
| | | | | | - Mario Cornejo-Olivas
- Neurogenetics Research Center, Instituto Nacional de Ciencias Neurologicas, Lima 15003, Peru; Center for Global Health, Universidad Peruana Cayetano Heredia, Lima 15102, Peru
| | - Fiona Baine
- Division of Human Genetics, National Health Laboratory Service and School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2001, South Africa; Division of Human Genetics, Department of Pathology, University of Cape Town, Observatory 7925, South Africa
| | - Amanda Krause
- Division of Human Genetics, National Health Laboratory Service and School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2001, South Africa
| | - Jacquie L Greenberg
- Division of Human Genetics, Department of Pathology, University of Cape Town, Observatory 7925, South Africa
| | - Carmen Lúcia Antão Paiva
- PPGNEURO, Universidade Federal do Estado do Rio de Janeiro (UNIRIO), Rio de Janeiro, RJ 20270-004, Brazil
| | - Ferdinando Squitieri
- Fondazione IRCCS Casa Sollievo della Sofferenza, 71013 San Giovanni Rotondo (FG), Italy
| | - Michael R Hayden
- Center for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, BC V5Z4H4, Canada.
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16
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Cepeda C, Oikonomou KD, Cummings D, Barry J, Yazon VW, Chen DT, Asai J, Williams CK, Vinters HV. Developmental origins of cortical hyperexcitability in Huntington's disease: Review and new observations. J Neurosci Res 2019; 97:1624-1635. [PMID: 31353533 PMCID: PMC6801077 DOI: 10.1002/jnr.24503] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 07/12/2019] [Accepted: 07/15/2019] [Indexed: 12/13/2022]
Abstract
Huntington's disease (HD), an inherited neurodegenerative disorder that principally affects striatum and cerebral cortex, is generally thought to have an adult onset. However, a small percentage of cases develop symptoms before 20 years of age. This juvenile variant suggests that brain development may be altered in HD. Indeed, recent evidence supports an important role of normal huntingtin during embryonic brain development and mutations in this protein cause cortical abnormalities. Functional studies also demonstrated that the cerebral cortex becomes hyperexcitable with disease progression. In this review, we examine clinical and experimental evidence that cortical development is altered in HD. We also provide preliminary evidence that cortical pyramidal neurons from R6/2 mice, a model of juvenile HD, are hyperexcitable and display dysmorphic processes as early as postnatal day 7. Further, some symptomatic mice present with anatomical abnormalities reminiscent of human focal cortical dysplasia, which could explain the occurrence of epileptic seizures in this genetic mouse model and in children with juvenile HD. Finally, we discuss recent treatments aimed at correcting abnormal brain development.
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Affiliation(s)
- Carlos Cepeda
- IDDRC, Jane and Terry Semel Institute for Neuroscience and Human Behavior and Department of Neurology, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, CA, USA
| | - Katerina D. Oikonomou
- IDDRC, Jane and Terry Semel Institute for Neuroscience and Human Behavior and Department of Neurology, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, CA, USA
| | - Damian Cummings
- IDDRC, Jane and Terry Semel Institute for Neuroscience and Human Behavior and Department of Neurology, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, CA, USA
| | - Joshua Barry
- IDDRC, Jane and Terry Semel Institute for Neuroscience and Human Behavior and Department of Neurology, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, CA, USA
| | - Vannah-Wila Yazon
- IDDRC, Jane and Terry Semel Institute for Neuroscience and Human Behavior and Department of Neurology, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, CA, USA
| | - Dickson T. Chen
- IDDRC, Jane and Terry Semel Institute for Neuroscience and Human Behavior and Department of Neurology, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, CA, USA
| | - Janelle Asai
- IDDRC, Jane and Terry Semel Institute for Neuroscience and Human Behavior and Department of Neurology, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, CA, USA
| | - Christopher K. Williams
- Section of Neuropathology, Department of Pathology and Laboratory Medicine and Department of Neurology, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, CA, USA
| | - Harry V. Vinters
- Section of Neuropathology, Department of Pathology and Laboratory Medicine and Department of Neurology, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, CA, USA
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17
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Loss-of-Huntingtin in Medial and Lateral Ganglionic Lineages Differentially Disrupts Regional Interneuron and Projection Neuron Subtypes and Promotes Huntington's Disease-Associated Behavioral, Cellular, and Pathological Hallmarks. J Neurosci 2019; 39:1892-1909. [PMID: 30626701 DOI: 10.1523/jneurosci.2443-18.2018] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Revised: 12/21/2018] [Accepted: 12/29/2018] [Indexed: 12/23/2022] Open
Abstract
Emerging studies are providing compelling evidence that the pathogenesis of Huntington's disease (HD), a neurodegenerative disorder with frequent midlife onset, encompasses developmental components. Moreover, our previous studies using a hypomorphic model targeting huntingtin during the neurodevelopmental period indicated that loss-of-function mechanisms account for this pathogenic developmental component (Arteaga-Bracho et al., 2016). In the present study, we specifically ascertained the roles of subpallial lineage species in eliciting the previously observed HD-like phenotypes. Accordingly, we used the Cre-loxP system to conditionally ablate the murine huntingtin gene (Httflx) in cells expressing the subpallial patterning markers Gsx2 (Gsx2-Cre) or Nkx2.1 (Nkx2.1-Cre) in Httflx mice of both sexes. These genetic manipulations elicited anxiety-like behaviors, hyperkinetic locomotion, age-dependent motor deficits, and weight loss in both Httflx;Gsx2-Cre and Httflx;Nkx2.1-Cre mice. In addition, these strains displayed unique but complementary spatial patterns of basal ganglia degeneration that are strikingly reminiscent of those seen in human cases of HD. Furthermore, we observed early deficits of somatostatin-positive and Reelin-positive interneurons in both Htt subpallial null strains, as well as early increases of cholinergic interneurons, Foxp2+ arkypallidal neurons, and incipient deficits with age-dependent loss of parvalbumin-positive neurons in Httflx;Nkx2.1-Cre mice. Overall, our findings indicate that selective loss-of-huntingtin function in subpallial lineages differentially disrupts the number, complement, and survival of forebrain interneurons and globus pallidus GABAergic neurons, thereby leading to the development of key neurological hallmarks of HD during adult life. Our findings have important implications for the establishment and deployment of neural circuitries and the integrity of network reserve in health and disease.SIGNIFICANCE STATEMENT Huntington's disease (HD) is a progressive degenerative disorder caused by aberrant trinucleotide expansion in the huntingtin gene. Mechanistically, this mutation involves both loss- and gain-of-function mechanisms affecting a broad array of cellular and molecular processes. Although huntingtin is widely expressed during adult life, the mutant protein only causes the demise of selective neuronal subtypes. The mechanisms accounting for this differential vulnerability remain elusive. In this study, we have demonstrated that loss-of-huntingtin function in subpallial lineages not only differentially disrupts distinct interneuron species early in life, but also leads to a pattern of neurological deficits that are reminiscent of HD. This work suggests that early disruption of selective neuronal subtypes may account for the profiles of enhanced regional cellular vulnerability to death in HD.
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