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1.
Neurobiol Dis ; 190: 106376, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38092268

RESUMO

In Huntington disease (HD), the mutant huntingtin (mtHTT) protein is the principal cause of pathological changes that initiate primarily along the cortico-striatal axis. mtHTT is ubiquitously expressed and there is, accordingly, growing recognition that HD is a systemic disorder with functional interplay between the brain and the periphery. We have developed a monoclonal antibody, C6-17, targeting an exposed region of HTT near the aa586 Caspase 6 cleavage site. As recently published, mAB C6-17 can block cell-to-cell propagation of mtHTT in vitro. In order to reduce the burden of the mutant protein in vivo, we queried whether extracellular mtHTT could be therapeutically targeted in YAC128 HD mice. In a series of proof of concept experiments, we found that systemic mAB C6-17 treatment resulted in the distribution of the mAB C6-17 to peripheral and CNS tissues and led to the reduction of HTT protein levels. Compared to CTRL mAB or vehicle treated mice, the mAB C6-17 treated YAC128 animals showed improved body weight and motor behaviors, a delayed progression in motor deficits and reduced striatal EM48 immunoreactivity. These results provide the first proof of concept for the feasibility and therapeutic efficacy of an antibody-based anti-HTT passive immunization approach and suggest this modality as a potential new HD treatment strategy.


Assuntos
Doença de Huntington , Camundongos , Animais , Doença de Huntington/metabolismo , Camundongos Transgênicos , Proteínas do Tecido Nervoso/metabolismo , Proteínas Nucleares/metabolismo , Proteína Huntingtina/genética , Imunoterapia , Modelos Animais de Doenças , Anticorpos Monoclonais/farmacologia , Anticorpos Monoclonais/uso terapêutico , Progressão da Doença
2.
J Neurosci ; 41(4): 780-796, 2021 01 27.
Artigo em Inglês | MEDLINE | ID: mdl-33310753

RESUMO

Huntington disease (HD) is a neurodegenerative disease caused by a CAG trinucleotide repeat expansion in the huntingtin (HTT) gene. Therapeutics that lower HTT have shown preclinical promise and are being evaluated in clinical trials. However, clinical assessment of brain HTT lowering presents challenges. We have reported that mutant HTT (mHTT) in the CSF of HD patients correlates with clinical measures, including disease burden as well as motor and cognitive performance. We have also shown that lowering HTT in the brains of HD mice results in correlative reduction of mHTT in the CSF, prompting the use of this measure as an exploratory marker of target engagement in clinical trials. In this study, we investigate the mechanisms of mHTT clearance from the brain in adult mice of both sexes to elucidate the significance of therapy-induced CSF mHTT changes. We demonstrate that, although neurodegeneration increases CSF mHTT concentrations, mHTT is also present in the CSF of mice in the absence of neurodegeneration. Importantly, we show that secretion of mHTT from cells in the CNS followed by glymphatic clearance from the extracellular space contributes to mHTT in the CSF. Furthermore, we observe secretion of wild type HTT from healthy control neurons, suggesting that HTT secretion is a normal process occurring in the absence of pathogenesis. Overall, our data support both passive release and active clearance of mHTT into CSF, suggesting that its treatment-induced changes may represent a combination of target engagement and preservation of neurons.SIGNIFICANCE STATEMENT: Changes in CSF mutant huntingtin (mHTT) are being used as an exploratory endpoint in HTT lowering clinical trials for the treatment of Huntington disease (HD). Recently, it was demonstrated that intrathecal administration of a HTT lowering agent leads to dose-dependent reduction of CSF mHTT in HD patients. However, little is known about how HTT, an intracellular protein, reaches the extracellular space and ultimately the CSF. Our findings that HTT enters CSF by both passive release and active secretion followed by glymphatic clearance may have significant implications for interpretation of treatment-induced changes of CSF mHTT in clinical trials for HD.


Assuntos
Química Encefálica , Proteína Huntingtina/líquido cefalorraquidiano , Doença de Huntington/líquido cefalorraquidiano , Animais , Astrócitos/metabolismo , Biomarcadores/líquido cefalorraquidiano , Feminino , Sistema Glinfático/metabolismo , Humanos , Proteína Huntingtina/genética , Doença de Huntington/genética , Masculino , Camundongos , Camundongos Transgênicos , Mutação , Neurônios/metabolismo , Expansão das Repetições de Trinucleotídeos
3.
Neurobiol Dis ; 166: 105652, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35143966

RESUMO

Huntington disease (HD) is a neurodegenerative disease caused by a trinucleotide repeat expansion in the HTT gene encoding an elongated polyglutamine tract in the huntingtin (HTT) protein. Expanded mutant HTT (mHTT) is toxic and leads to regional atrophy and neuronal cell loss in the brain, which occurs earliest in the striatum. Therapeutic lowering of mHTT in the central nervous system (CNS) has shown promise in preclinical studies, with multiple approaches currently in clinical development for HD. Quantitation of mHTT in the cerebrospinal fluid (CSF) is being used as a clinical pharmacodynamic biomarker of target engagement in the CNS. We have previously shown that the CNS is a major source of mHTT in the CSF. However, little is known about the specific brain regions and cell types that contribute to CSF mHTT. Therefore, a better understanding of the origins of CSF mHTT and whether therapies targeting mHTT in the striatum would be expected to be associated with significant lowering of mHTT in the CSF is needed. Here, we use complementary pharmacological and genetic-based approaches to either restrict expression of mHTT to the striatum or selectively deplete mHTT in the striatum to evaluate the contribution of this brain region to mHTT in the CSF. We show that viral expression of a mHTT fragment restricted to the striatum leads to detectable mHTT in the CSF. We demonstrate that targeted lowering of mHTT selectively in the striatum using an antisense oligonucleotide leads to a significant reduction of mHTT in the CSF of HD mice. Furthermore, using a transgenic mouse model of HD that expresses full length human mHTT and wild type HTT, we show that genetic inactivation of mHTT selectively in the striatum results in a significant reduction of mHTT in the CSF. Taken together, our data supports the conclusion that the striatum contributes sufficiently to the pool of mHTT in the CSF that therapeutic levels of mHTT lowering in the striatum can be detected by this measure in HD mice. This suggests that CSF mHTT may represent a pharmacodynamic biomarker for therapies that lower mHTT in the striatum.


Assuntos
Doença de Huntington , Doenças Neurodegenerativas , Animais , Biomarcadores/líquido cefalorraquidiano , Modelos Animais de Doenças , Proteína Huntingtina/genética , Proteína Huntingtina/metabolismo , Doença de Huntington/metabolismo , Camundongos , Camundongos Transgênicos , Doenças Neurodegenerativas/genética , Expansão das Repetições de Trinucleotídeos/genética
4.
Nucleic Acids Res ; 48(1): 36-54, 2020 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-31745548

RESUMO

Huntington disease (HD) is a fatal neurodegenerative disease caused by a pathogenic expansion of a CAG repeat in the huntingtin (HTT) gene. There are no disease-modifying therapies for HD. Artificial microRNAs targeting HTT transcripts for degradation have shown preclinical promise and will soon enter human clinical trials. Here, we examine the tolerability and efficacy of non-selective HTT lowering with an AAV5 encoded miRNA targeting human HTT (AAV5-miHTT) in the humanized Hu128/21 mouse model of HD. We show that intrastriatal administration of AAV5-miHTT results in potent and sustained HTT suppression for at least 7 months post-injection. Importantly, non-selective suppression of huntingtin was generally tolerated, however high dose AAV5-miHTT did induce astrogliosis. We observed an improvement of select behavioural and modest neuropathological HD-like phenotypes in Hu128/21 mice, suggesting a potential therapeutic benefit of miRNA-mediated non-selective HTT lowering. Finally, we also observed that potent reduction of wild type HTT (wtHTT) in Hu21 control mice was tolerated up to 7 months post-injection but may induce impairment of motor coordination and striatal atrophy. Taken together, our data suggests that in the context of HD, the therapeutic benefits of mHTT reduction may outweigh the potentially detrimental effects of wtHTT loss following non-selective HTT lowering.


Assuntos
Proteína Huntingtina/genética , Doença de Huntington/terapia , MicroRNAs/genética , Terapia de Alvo Molecular/métodos , Parvovirinae/genética , RNA Mensageiro/genética , Animais , Animais Geneticamente Modificados , Astrócitos/metabolismo , Astrócitos/patologia , Sequência de Bases , Corpo Estriado/metabolismo , Corpo Estriado/patologia , Dependovirus , Modelos Animais de Doenças , Dosagem de Genes , Vetores Genéticos/química , Vetores Genéticos/metabolismo , Humanos , Proteína Huntingtina/antagonistas & inibidores , Proteína Huntingtina/metabolismo , Doença de Huntington/genética , Doença de Huntington/metabolismo , Doença de Huntington/patologia , Camundongos , MicroRNAs/administração & dosagem , MicroRNAs/metabolismo , Neuroglia/metabolismo , Neuroglia/patologia , Neurônios/metabolismo , Neurônios/patologia , Parvovirinae/metabolismo , Desempenho Psicomotor , Estabilidade de RNA , RNA Mensageiro/antagonistas & inibidores , RNA Mensageiro/metabolismo , Repetições de Trinucleotídeos
5.
Hum Mol Genet ; 27(2): 239-253, 2018 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-29121340

RESUMO

Oxidative stress is a prominent feature of Huntington disease (HD), and we have shown previously that reduced levels of hace1 (HECT domain and Ankyrin repeat containing E3 ubiquitin protein ligase 1) in patient striatum may contribute to the pathogenesis of HD. Hace1 promotes the stability of Nrf2 and thus plays an important role in antioxidant response mechanisms, which are dysfunctional in HD. Moreover, hace1 overexpression mitigates mutant huntingtin (mHTT)-induced oxidative stress in vitro through promotion of the Nrf2 antioxidant response. Here, we show that the genetic ablation of hace1 in the YAC128 mouse model of HD accelerates motor deficits and exacerbates cognitive and psychiatric phenotypes in vivo. We find that both the expression of mHTT and the ablation of hace1 alone are sufficient to cause deficits in astrocytic mitochondrial respiration. We confirm the crucial role of hace1 in astrocytes in vivo, since its ablation is sufficient to cause dramatic astrogliosis in wild-type FVB/N mice. Astrogliosis is not observed in the presence of mHTT but a strong dysregulation in the expression of astrocytic markers in HACE1-/- x YAC128 striatum suggests an additive effect of mHTT expression and hace1 loss on this cell type. HACE1-/- x YAC128 mice and primary cells derived from these animals therefore provide model systems that will allow for the further dissection of Nrf2 pathways and astrocyte dysfunction in the context of HD.


Assuntos
Astrócitos/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Animais , Corpo Estriado/metabolismo , Modelos Animais de Doenças , Doença de Huntington/genética , Doença de Huntington/metabolismo , Camundongos , Mitocôndrias/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Neostriado/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Estresse Oxidativo/fisiologia
6.
J Neurosci Res ; 98(8): 1588-1604, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32495348

RESUMO

Hypoxic/ischemic insult, a leading cause of functional brain defects, has been extensively studied in both clinical and experimental animal research, including its etiology, neuropathogenesis, and pharmacological interventions. Transient sublethal hypoxia (TSH) is a common clinical occurrence in the perinatal period. However, its effect on early developing brains remains poorly understood. The present study was designed to investigate the effect of TSH on the dendrite and dendritic spine formation, neuronal and synaptic activity, and cognitive behavior of early postnatal Day 1 rat pups. While TSH showed no obvious effect on gross brain morphology, neuron cell density, or glial activation in the hippocampus, we found transient hypoxia did cause significant changes in neuronal structure and function. In brains exposed to TSH, hippocampal neurons developed shorter and thinner dendrites, with decreased dendritic spine density, and reduced strength in excitatory synaptic transmission. Moreover, TSH-treated rats showed impaired cognitive performance in spatial learning and memory. Our findings demonstrate that TSH in newborn rats can cause significant impairments in synaptic formation and function, and long-lasting brain functional deficits. Therefore, this study provides a useful animal model for the study of TSH on early developing brains and to explore potential pharmaceutical interventions for patients subjected to TSH insult.


Assuntos
Espinhas Dendríticas/metabolismo , Espinhas Dendríticas/patologia , Hipóxia/patologia , Hipóxia/fisiopatologia , Memória , Animais , Animais Recém-Nascidos , Córtex Cerebral/metabolismo , Feminino , Hipocampo/patologia , Hipocampo/fisiologia , Hipóxia-Isquemia Encefálica/patologia , Masculino , Aprendizagem em Labirinto , Plasticidade Neuronal , Ratos , Ratos Sprague-Dawley , Aprendizagem Espacial
8.
Hum Mol Genet ; 26(6): 1115-1132, 2017 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-28104789

RESUMO

Huntington disease (HD) is a neurodegenerative disease caused by a mutation in the huntingtin (HTT) gene. HTT is a large protein, interacts with many partners and is involved in many cellular pathways, which are perturbed in HD. Therapies targeting HTT directly are likely to provide the most global benefit. Thus there is a need for preclinical models of HD recapitulating human HTT genetics. We previously generated a humanized mouse model of HD, Hu97/18, by intercrossing BACHD and YAC18 mice with knockout of the endogenous mouse HD homolog (Hdh). Hu97/18 mice recapitulate the genetics of HD, having two full-length, genomic human HTT transgenes heterozygous for the HD mutation and polymorphisms associated with HD in populations of Caucasian descent. We have now generated a companion model, Hu128/21, by intercrossing YAC128 and BAC21 mice on the Hdh-/- background. Hu128/21 mice have two full-length, genomic human HTT transgenes heterozygous for the HD mutation and polymorphisms associated with HD in populations of East Asian descent and in a minority of patients from other ethnic groups. Hu128/21 mice display a wide variety of HD-like phenotypes that are similar to YAC128 mice. Additionally, both transgenes in Hu128/21 mice match the human HTT exon 1 reference sequence. Conversely, the BACHD transgene carries a floxed, synthetic exon 1 sequence. Hu128/21 mice will be useful for investigations of human HTT that cannot be addressed in Hu97/18 mice, for developing therapies targeted to exon 1, and for preclinical screening of personalized HTT lowering therapies in HD patients of East Asian descent.


Assuntos
Proteína Huntingtina/genética , Doença de Huntington/genética , Mutação/genética , Alelos , Animais , Modelos Animais de Doenças , Éxons/genética , Heterozigoto , Humanos , Doença de Huntington/patologia , Camundongos , Camundongos Transgênicos , Fenótipo
9.
Hum Mol Genet ; 25(17): 3654-3675, 2016 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-27378694

RESUMO

Huntington disease (HD) model mice with heterozygous knock-in (KI) of an expanded CAG tract in exon 1 of the mouse huntingtin (Htt) gene homolog genetically recapitulate the mutation that causes HD, and might be favoured for preclinical studies. However, historically these mice have failed to phenotypically recapitulate the human disease. Thus, homozygous KI mice, which lack wildtype Htt, and are much less relevant to human HD, have been used. The zQ175 model was the first KI mouse to exhibit significant HD-like phenotypes when heterozygous. In an effort to exacerbate HD-like phenotypes and enhance preclinical utility, we have backcrossed zQ175 mice to FVB/N, a strain highly susceptible to neurodegeneration. These Q175F mice display significant HD-like phenotypes along with sudden early death from fatal seizures. The zQ175 KI allele retains a floxed neomycin resistance cassette upstream of the Htt gene locus and produces dramatically reduced mutant Htt as compared to the endogenous wildtype Htt allele. By intercrossing with mice expressing cre in germ line cells, we have excised the neo cassette from Q175F mice generating a new line, Q175FΔneo (Q175FDN). Removal of the neo cassette resulted in a ∼2 fold increase in mutant Htt and rescue of fatal seizures, indicating that the early death phenotype of Q175F mice is caused by Htt deficiency rather than by mutant Htt. Additionally, Q175FDN mice exhibit earlier onset and a greater variety and severity of HD-like phenotypes than Q175F mice or any previously reported KI HD mouse model, making them valuable for preclinical studies.


Assuntos
Técnicas de Introdução de Genes/métodos , Proteína Huntingtina/genética , Doença de Huntington/genética , Mutação , Animais , Comportamento Animal , Cruzamentos Genéticos , Modelos Animais de Doenças , Heterozigoto , Humanos , Doença de Huntington/patologia , Camundongos , Fenótipo
10.
Hum Mol Genet ; 25(13): 2621-2632, 2016 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-27126634

RESUMO

White matter (WM) atrophy is a significant feature of Huntington disease (HD), although its aetiology and early pathological manifestations remain poorly defined. In this study, we aimed to characterize WM-related features in the transgenic YAC128 and BACHD models of HD. Using diffusion tensor magnetic resonance imaging (DT-MRI), we demonstrate that microstructural WM abnormalities occur from an early age in YAC128 mice. Similarly, electron microscopy analysis of myelinated fibres of the corpus callosum indicated that myelin sheaths are thinner in YAC128 mice as early as 1.5 months of age, well before any neuronal loss can be detected. Transcript levels of myelin-related genes in striatal and cortical tissues were significantly lower in YAC128 mice from 2 weeks of age, and these findings were replicated in differentiated primary oligodendrocytes from YAC128 mice, suggesting a possible mechanistic explanation for the observed structural deficits. Concordant with these observations, we demonstrate reduced expression of myelin-related genes at 3 months of age and WM microstructural abnormalities using DT-MRI at 12 months of age in the BACHD rats. These findings indicate that WM deficits in HD are an early phenotype associated with cell-intrinsic effects of mutant huntingtin on myelin-related transcripts in oligodendrocytes, and raise the possibility that WM abnormalities may be an early contributing factor to the pathogenesis of HD.


Assuntos
Doença de Huntington/genética , Bainha de Mielina/fisiologia , Substância Branca/fisiopatologia , Animais , Atrofia/patologia , Encéfalo/metabolismo , Corpo Caloso/metabolismo , Corpo Estriado/metabolismo , Imagem de Tensor de Difusão/métodos , Modelos Animais de Doenças , Expressão Gênica , Humanos , Doença de Huntington/etiologia , Camundongos , Camundongos Transgênicos , Bainha de Mielina/genética , Bainha de Mielina/metabolismo , Neostriado/metabolismo , Proteínas do Tecido Nervoso/genética , Neurônios/metabolismo , Oligodendroglia/metabolismo , Ratos
11.
BMC Genomics ; 16: 545, 2015 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-26204903

RESUMO

BACKGROUND: Nr2e1 (nuclear receptor subfamily 2, group e, member 1) encodes a transcription factor important in neocortex development. Previous work has shown that nuclear receptors can have hundreds of target genes, and bind more than 300 co-interacting proteins. However, recognition of the critical role of Nr2e1 in neural stem cells and neocortex development is relatively recent, thus the molecular mechanisms involved for this nuclear receptor are only beginning to be understood. Serial analysis of gene expression (SAGE), has given researchers both qualitative and quantitative information pertaining to biological processes. Thus, in this work, six LongSAGE mouse libraries were generated from laser microdissected tissue samples of dorsal VZ/SVZ (ventricular zone and subventricular zone) from the telencephalon of wild-type (Wt) and Nr2e1-null embryos at the critical development ages E13.5, E15.5, and E17.5. We then used a novel approach, implementing multiple computational methods followed by biological validation to further our understanding of Nr2e1 in neocortex development. RESULTS: In this work, we have generated a list of 1279 genes that are differentially expressed in response to altered Nr2e1 expression during in vivo neocortex development. We have refined this list to 64 candidate direct-targets of NR2E1. Our data suggested distinct roles for Nr2e1 during different neocortex developmental stages. Most importantly, our results suggest a possible novel pathway by which Nr2e1 regulates neurogenesis, which includes Lhx2 as one of the candidate direct-target genes, and SOX9 as a co-interactor. CONCLUSIONS: In conclusion, we have provided new candidate interacting partners and numerous well-developed testable hypotheses for understanding the pathways by which Nr2e1 functions to regulate neocortex development.


Assuntos
Neocórtex/crescimento & desenvolvimento , Neurogênese , Receptores Citoplasmáticos e Nucleares/biossíntese , Fatores de Transcrição/genética , Animais , Sítios de Ligação , Regulação da Expressão Gênica no Desenvolvimento , Microdissecção e Captura a Laser , Camundongos , Neocórtex/metabolismo , Receptores Citoplasmáticos e Nucleares/genética
12.
Neurobiol Dis ; 76: 46-56, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25662335

RESUMO

Huntington disease (HD) is an inherited, fatal neurodegenerative disease with no disease-modifying therapy currently available. In addition to characteristic motor deficits and atrophy of the caudate nucleus, signature hallmarks of HD include behavioral abnormalities, immune activation, and cortical and white matter loss. The identification and validation of novel therapeutic targets that contribute to these degenerative cellular processes may lead to new interventions that slow or even halt the course of this insidious disease. Semaphorin 4D (SEMA4D) is a transmembrane signaling molecule that modulates a variety of processes central to neuroinflammation and neurodegeneration including glial cell activation, neuronal growth cone collapse and apoptosis of neural precursors, as well as inhibition of oligodendrocyte migration, differentiation and process formation. Therefore, inhibition of SEMA4D signaling could reduce CNS inflammation, increase neuronal outgrowth and enhance oligodendrocyte maturation, which may be of therapeutic benefit in the treatment of several neurodegenerative diseases, including HD. To that end, we evaluated the preclinical therapeutic efficacy of an anti-SEMA4D monoclonal antibody, which prevents the interaction between SEMA4D and its receptors, in the YAC128 transgenic HD mouse model. Anti-SEMA4D treatment ameliorated neuropathological signatures, including striatal atrophy, cortical atrophy, and corpus callosum atrophy and prevented testicular degeneration in YAC128 mice. In parallel, a subset of behavioral symptoms was improved in anti-SEMA4D treated YAC128 mice, including reduced anxiety-like behavior and rescue of cognitive deficits. There was, however, no discernible effect on motor deficits. The preservation of brain gray and white matter and improvement in behavioral measures in YAC128 mice treated with anti-SEMA4D suggest that this approach could represent a viable therapeutic strategy for the treatment of HD. Importantly, this work provides in vivo demonstration that inhibition of pathways initiated by SEMA4D constitutes a novel approach to moderation of neurodegeneration.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Antígenos CD/imunologia , Doença de Huntington/terapia , Semaforinas/imunologia , Animais , Anticorpos Monoclonais/administração & dosagem , Encéfalo/metabolismo , Encéfalo/patologia , Transtornos Cognitivos/etiologia , Transtornos Cognitivos/terapia , Modelos Animais de Doenças , Doença de Huntington/complicações , Imunoterapia , Camundongos , Camundongos Transgênicos , Atividade Motora/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos
13.
Hum Mol Genet ; 22(1): 18-34, 2013 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-23001568

RESUMO

Silencing the mutant huntingtin gene (muHTT) is a direct and simple therapeutic strategy for the treatment of Huntington disease (HD) in principle. However, targeting the HD mutation presents challenges because it is an expansion of a common genetic element (a CAG tract) that is found throughout the genome. Moreover, the HTT protein is important for neuronal health throughout life, and silencing strategies that also reduce the wild-type HTT allele may not be well tolerated during the long-term treatment of HD. Several HTT silencing strategies are in development that target genetic sites in HTT that are outside of the CAG expansion, including HD mutation-linked single-nucleotide polymorphisms and the HTT promoter. Preclinical testing of these genetic therapies has required the development of a new mouse model of HD that carries these human-specific genetic targets. To generate a fully humanized mouse model of HD, we have cross-bred BACHD and YAC18 on the Hdh(-/-) background. The resulting line, Hu97/18, is the first murine model of HD that fully genetically recapitulates human HD having two human HTT genes, no mouse Hdh genes and heterozygosity of the HD mutation. We find that Hu97/18 mice display many of the behavioral changes associated with HD including motor, psychiatric and cognitive deficits, as well as canonical neuropathological abnormalities. This mouse line will be useful for gaining additional insights into the disease mechanisms of HD as well as for testing genetic therapies targeting human HTT.


Assuntos
Modelos Animais de Doenças , Doença de Huntington/genética , Animais , Inativação Gênica , Humanos , Doença de Huntington/psicologia , Camundongos , Camundongos Transgênicos , Mutação , Polimorfismo de Nucleotídeo Único , Regiões Promotoras Genéticas , Teste de Desempenho do Rota-Rod
14.
Mol Ther ; 22(12): 2093-2106, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25101598

RESUMO

Huntington disease (HD) is a dominant, genetic neurodegenerative disease characterized by progressive loss of voluntary motor control, psychiatric disturbance, and cognitive decline, for which there is currently no disease-modifying therapy. HD is caused by the expansion of a CAG tract in the huntingtin (HTT) gene. The mutant HTT protein (muHTT) acquires toxic functions, and there is significant evidence that muHTT lowering would be therapeutically efficacious. However, the wild-type HTT protein (wtHTT) serves vital functions, making allele-specific muHTT lowering strategies potentially safer than nonselective strategies. CAG tract expansion is associated with single nucleotide polymorphisms (SNPs) that can be targeted by gene silencing reagents such as antisense oligonucleotides (ASOs) to accomplish allele-specific muHTT lowering. Here we evaluate ASOs targeted to HD-associated SNPs in acute in vivo studies including screening, distribution, duration of action and dosing, using a humanized mouse model of HD, Hu97/18, that is heterozygous for the targeted SNPs. We have identified four well-tolerated lead ASOs that potently and selectively silence muHTT at a broad range of doses throughout the central nervous system for 16 weeks or more after a single intracerebroventricular (ICV) injection. With further validation, these ASOs could provide a therapeutic option for individuals afflicted with HD.


Assuntos
Encéfalo/patologia , Doença de Huntington/terapia , Proteínas Mutantes/metabolismo , Proteínas do Tecido Nervoso/genética , Oligonucleotídeos Antissenso/administração & dosagem , Tionucleotídeos/administração & dosagem , Animais , Encéfalo/metabolismo , Modelos Animais de Doenças , Inativação Gênica , Humanos , Proteína Huntingtina , Doença de Huntington/genética , Doença de Huntington/patologia , Injeções , Camundongos , Camundongos Endogâmicos C57BL , Terapia de Alvo Molecular , Proteínas do Tecido Nervoso/metabolismo , Oligonucleotídeos Antissenso/farmacologia , Polimorfismo de Nucleotídeo Único , Ratos , Ratos Sprague-Dawley , Tionucleotídeos/farmacologia
15.
Hum Mol Genet ; 21(10): 2219-32, 2012 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-22328089

RESUMO

The development of animal models of Huntington disease (HD) has enabled studies that help define the molecular aberrations underlying the disease. The BACHD and YAC128 transgenic mouse models of HD harbor a full-length mutant huntingtin (mHTT) and recapitulate many of the behavioural and neuropathological features of the human condition. Here, we demonstrate that while BACHD and YAC128 animals exhibit similar deficits in motor learning and coordination, depressive-like symptoms, striatal volume loss and forebrain weight loss, they show obvious differences in key features characteristic of HD. While YAC128 mice exhibit significant and widespread accumulation of mHTT striatal aggregates, these mHTT aggregates are absent in BACHD mice. Furthermore, the levels of several striatally enriched mRNA for genes, such as DARPP-32, enkephalin, dopamine receptors D1 and D2 and cannabinoid receptor 1, are significantly decreased in YAC128 but not BACHD mice. These findings may reflect sequence differences in the human mHTT transgenes harboured by the BACHD and YAC128 mice, including both single nucleotide polymorphisms as well as differences in the nature of CAA interruptions of the CAG tract. Our findings highlight a similar profile of HD-like behavioural and neuropathological deficits and illuminate differences that inform the use of distinct endpoints in trials of therapeutic agents in the YAC128 and BACHD mice.


Assuntos
Doença de Huntington/genética , Proteínas do Tecido Nervoso/genética , Neurônios/metabolismo , Animais , Modelos Animais de Doenças , Feminino , Proteína Huntingtina , Doença de Huntington/metabolismo , Doença de Huntington/patologia , Masculino , Camundongos , Camundongos Transgênicos , Proteínas do Tecido Nervoso/metabolismo , Neurônios/patologia , Transgenes
16.
Hum Mol Genet ; 21(9): 1954-67, 2012 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-22262731

RESUMO

Apoptosis, or programmed cell death, is a cellular pathway involved in normal cell turnover, developmental tissue remodeling, embryonic development, cellular homeostasis maintenance and chemical-induced cell death. Caspases are a family of intracellular proteases that play a key role in apoptosis. Aberrant activation of caspases has been implicated in human diseases. In particular, numerous findings implicate Caspase-6 (Casp6) in neurodegenerative diseases, including Alzheimer disease (AD) and Huntington disease (HD), highlighting the need for a deeper understanding of Casp6 biology and its role in brain development. The use of targeted caspase-deficient mice has been instrumental for studying the involvement of caspases in apoptosis. The goal of this study was to perform an in-depth neuroanatomical and behavioral characterization of constitutive Casp6-deficient (Casp6-/-) mice in order to understand the physiological function of Casp6 in brain development, structure and function. We demonstrate that Casp6-/- neurons are protected against excitotoxicity, nerve growth factor deprivation and myelin-induced axonal degeneration. Furthermore, Casp6-deficient mice show an age-dependent increase in cortical and striatal volume. In addition, these mice show a hypoactive phenotype and display learning deficits. The age-dependent behavioral and region-specific neuroanatomical changes observed in the Casp6-/- mice suggest that Casp6 deficiency has a more pronounced effect in brain regions that are involved in neurodegenerative diseases, such as the striatum in HD and the cortex in AD.


Assuntos
Caspase 6/fisiologia , Degeneração Neural/enzimologia , Envelhecimento/patologia , Envelhecimento/fisiologia , Doença de Alzheimer/enzimologia , Doença de Alzheimer/patologia , Animais , Apoptose/fisiologia , Sequência de Bases , Comportamento Animal/fisiologia , Encéfalo/enzimologia , Encéfalo/patologia , Caspase 6/deficiência , Caspase 6/genética , Humanos , Doença de Huntington/enzimologia , Doença de Huntington/patologia , Camundongos , Camundongos Knockout , Atividade Motora/fisiologia , Degeneração Neural/genética , Degeneração Neural/patologia , Neurônios/enzimologia , Neurônios/patologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores de N-Metil-D-Aspartato/fisiologia
17.
Neurobiol Dis ; 48(3): 282-9, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22796360

RESUMO

Huntington disease (HD), a neurodegenerative disorder caused by an expanded CAG repeat in the HTT gene, remains without a treatment to modify the course of the illness. Lithium, a drug widely used for the treatment of bipolar disorder, has been shown to exert neuroprotective effects in a number of models of neurological disease but may have various toxic effects at conventional therapeutic doses. We examined whether NP03, a novel low-dose lithium microemulsion, would improve the disease phenotypes in the YAC128 mouse model of HD. We demonstrate that NP03 improves motor function, ameliorates the neuropathological deficits in striatal volume, neuronal counts, and DARPP-32 expression, and partially rescues testicular atrophy in YAC128 mice. These positive effects were accompanied by improvements in multiple biochemical endpoints associated with the pathogenesis of HD, including normalization of caspase-6 activation and amelioration of deficits in BDNF levels, and with no lithium-related toxicity. Our findings demonstrate that NP03 ameliorates the motor and neuropathological phenotypes in the YAC128 mouse model of HD, and represents a potential therapeutic approach for HD.


Assuntos
Encéfalo/efeitos dos fármacos , Doença de Huntington/tratamento farmacológico , Lítio/administração & dosagem , Fármacos Neuroprotetores/administração & dosagem , Animais , Encéfalo/patologia , Modelos Animais de Doenças , Feminino , Humanos , Doença de Huntington/patologia , Immunoblotting , Lítio/efeitos adversos , Masculino , Camundongos , Atividade Motora/efeitos dos fármacos , Fármacos Neuroprotetores/efeitos adversos , Ratos , Ratos Wistar , Reação em Cadeia da Polimerase Via Transcriptase Reversa
18.
Hum Mol Genet ; 19(8): 1528-38, 2010 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-20097678

RESUMO

Levels of full-length huntingtin (FL htt) influence organ and body weight, independent of polyglutamine length. The growth hormone-insulin like growth factor-1 (GH-IGF-1) axis is well established as a regulator of organ growth and body weight. In this study, we investigate the involvement of the IGF-1 pathway in mediating the effect of htt on body weight. IGF-1 expression was examined in transgenic mouse lines expressing different levels of FL wild-type (WT) htt (YAC18 mice), FL mutant htt (YAC128 and BACHD mice) and truncated mutant htt (shortstop mice). We demonstrate that htt influences body weight by modulating the IGF-1 pathway. Plasma IGF-1 levels correlate with body weight and htt levels in the transgenic YAC mice expressing human htt. The effect of htt on IGF-1 expression is independent of CAG size. No effect on body weight is observed in transgenic YAC mice expressing a truncated N-terminal htt fragment (shortstop), indicating that FL htt is required for the modulation of IGF-1 expression. Treatment with 17beta-estradiol (17beta-ED) lowers the levels of circulating IGF-1 in mammals. Treatment of YAC128 with 17beta-ED, but not placebo, reduces plasma IGF-1 levels and decreases the body weight of YAC128 animals to WT levels. Furthermore, given the ubiquitous expression of IGF-1 within the central nervous system, we also examined the impact of FL htt levels on IGF-1 expression in different regions of the brain, including the striatum, cerebellum of YAC18, YAC128 and littermate WT mice. We demonstrate that the levels of FL htt influence IGF-1 expression in striatal tissues. Our data identify a novel function for FL htt in influencing IGF-1 expression.


Assuntos
Peso Corporal , Doença de Huntington/metabolismo , Fator de Crescimento Insulin-Like I/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Proteínas Nucleares/metabolismo , Animais , Encéfalo/metabolismo , Modelos Animais de Doenças , Expressão Gênica , Humanos , Proteína Huntingtina , Doença de Huntington/genética , Fator de Crescimento Insulin-Like I/genética , Masculino , Camundongos , Camundongos Transgênicos , Proteínas do Tecido Nervoso/genética , Proteínas Nucleares/genética , Transdução de Sinais
19.
World J Clin Cases ; 10(4): 1311-1319, 2022 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-35211564

RESUMO

BACKGROUND: Persistent vegetative state (PVS) is a devastating and long-lasting clinical condition with high morbidity and mortality; currently, there are no available effective interventions. CASE SUMMARY: We report the case of an 11-year-old boy with PVS caused by severe intracerebral bleeding in the left hemisphere following anticoagulation treatment. The patient's PVS severity showed no notable improvement after 2-mo neuroprotective treatment and rehabilitation, including nerve growth factor and baclofen, hyperbaric oxygen, and comprehensive bedside rehabilitation therapies. Daily inhalation treatment (4-6 h) of high-concentration hydrogen (H2) gas (66.6% H2 + 33.3% O2) was provided. Surprisingly, the patient's orientation, consciousness, ability to speak, facial expressions, and locomotor function were significantly restored, along with improvements in essential general health status, after H2 gas inhalation treatment, which was consistent with stabilized neuropathology in the left hemisphere and increased Hounsfield unit values of computed tomography in the right hemisphere. The patient finally recovered to a near normal conscious state with a Coma Recovery Scale-Revised Score of 22 from his previous score of 3. CONCLUSION: Phase 1 clinical trials are needed to explore the safety and efficacy of H2 gas inhalation in patients with PVS.

20.
PLoS One ; 17(10): e0276494, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36264861

RESUMO

Comprehending heavy mineral composition of the sandy land in Northeast China (NESL) is of great significance for interpreting generation, pathways, source and geochemistry of sediments in this area. To this end, the fine-grained (<63 µm) aeolian-fluvial sediments and loess deposits, which were taken from the Onqin Daga Sandy Land, the Horqin Sandy Land, the Hulun Buir Sandy Land and the Songnen Sandy Land, and from the downwind loess section (L1), respectively, were analyzed to construct the heavy mineral data set of NESL source and sink and to evaluate feasibility of the heavy mineral method in tracing the source of aeolian dust in Northeast China. Additionally, the <63 µm, 63-125 µm and 125-250 µm fractions of the fluvial sands from the different Balan River reaches having a same source, were analyzed to valuate the impact of the river transport-sedimentation process on the heavy mineral composition. The results show that the NESL shows moderate similarities in the heavy mineral composition, with ilmenite, epidote, zircon and amphibole as the primary minerals. In the source-to-sink system in the NESL, limited by sedimentary differentiation, post-deposition alteration and similar source material composition, the heavy mineral composition of the loess and that of sandy-land sources does not well correlate, indicating single heavy mineral method is incapable of unequivocally detecting loess sources when not considering the physical geographical conditions. The sediments in the different Balan River reaches show clear diversities and grain-size dependency in heavy minerals composition, indicating the river transport-deposition processes exert a clear control on the heavy-mineral composition in the sediment downstream. Both a wide grain-size window and more numbers of samples are needed to obtain a complete heavy-mineral picture in the source area.


Assuntos
Sedimentos Geológicos , Metais Pesados , Sedimentos Geológicos/química , Areia , Monitoramento Ambiental/métodos , Minerais/análise , Poeira/análise , Amiantos Anfibólicos , China , Metais Pesados/análise
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