scholarly journals Global Rhes knockout in the Q175 Huntington’s disease mouse model

PLoS ONE ◽  
2021 ◽  
Vol 16 (10) ◽  
pp. e0258486
Author(s):  
Taneli Heikkinen ◽  
Timo Bragge ◽  
Juha Kuosmanen ◽  
Teija Parkkari ◽  
Sanna Gustafsson ◽  
...  
Keyword(s):  
Mouse Model ◽  
Huntington's Disease ◽  
Huntington’S Disease ◽  
The Body ◽  
Mutant Huntingtin ◽  
Polyglutamine Tract ◽  
Severe Pathology ◽  
Expansion Mutation ◽  
Q175 Mice ◽  
Mixed Gender

Huntington’s disease (HD) results from an expansion mutation in the polyglutamine tract in huntingtin. Although huntingtin is ubiquitously expressed in the body, the striatum suffers the most severe pathology. Rhes is a Ras-related small GTP-binding protein highly expressed in the striatum that has been reported to modulate mTOR and sumoylation of mutant huntingtin to alter HD mouse model pathogenesis. Reports have varied on whether Rhes reduction is desirable for HD. Here we characterize multiple behavioral and molecular endpoints in the Q175 HD mouse model with genetic Rhes knockout (KO). Genetic RhesKO in the Q175 female mouse resulted in both subtle attenuation of Q175 phenotypic features, and detrimental effects on other kinematic features. The Q175 females exhibited measurable pathogenic deficits, as measured by MRI, MRS and DARPP32, however, RhesKO had no effect on these readouts. Additionally, RhesKO in Q175 mixed gender mice deficits did not affect mTOR signaling, autophagy or mutant huntingtin levels. We conclude that global RhesKO does not substantially ameliorate or exacerbate HD mouse phenotypes in Q175 mice.

scholarly journals Caspase-6 does not contribute to the proteolysis of mutant huntingtin in the HdhQ150 knock-in mouse model of Huntington’s disease

PLoS Currents ◽  
2012 ◽  
Vol 4 ◽  
pp. e4fd085bfc9973 ◽  
Author(s):  
Christian Landles ◽  
Andreas Weiss ◽  
Sophie Franklin ◽  
David Howland ◽  
Gill Bates
Keyword(s):  
Mouse Model ◽  
Huntington's Disease ◽  
Huntington’S Disease ◽  
Mutant Huntingtin ◽  
Caspase 6

scholarly journals Bim contributes to the progression of Huntington’s disease-associated phenotypes

2019 ◽  
Vol 29 (2) ◽  
pp. 216-227
Author(s):  
Sheridan L Roberts ◽  
Tracey Evans ◽  
Yi Yang ◽  
Yuhua Fu ◽  
Robert W Button ◽  
...  
Keyword(s):  
Mouse Model ◽  
Huntington's Disease ◽  
Huntington’S Disease ◽  
Neuronal Death ◽  
Neurodegenerative Disorder ◽  
Neuronal Degeneration ◽  
Brain Regions ◽  
Post Mortem ◽  
Polyglutamine Tract

Abstract Huntington’s disease (HD) is a neurodegenerative disorder caused by an expanded polyglutamine tract in the huntingtin (HTT) protein. Mutant HTT (mHTT) toxicity is caused by its aggregation/oligomerization. The striatum is the most vulnerable region, although all brain regions undergo neuronal degeneration in the disease. Here we show that the levels of Bim, a BH3-only protein, are significantly increased in HD human post-mortem and HD mouse striata, correlating with neuronal death. Bim reduction ameliorates mHTT neurotoxicity in HD cells. In the HD mouse model, heterozygous Bim knockout significantly mitigates mHTT accumulation and neuronal death, ameliorating disease-associated phenotypes and lifespan. Therefore, Bim could contribute to the progression of HD.

scholarly journals Targeted Genetic Reduction of Mutant Huntingtin Lessens Cardiac Pathology in the BACHD Mouse Model of Huntington's Disease

2021 ◽  
Vol 8 ◽  
Author(s):  
Saemi Park ◽  
Shu Hon Christopher Luk ◽  
Raj S. Bains ◽  
Daniel S. Whittaker ◽  
Emily Chiem ◽  
...  
Keyword(s):  
Mouse Model ◽  
Huntington's Disease ◽  
Huntington’S Disease ◽  
Treatment Strategies ◽  
The Body ◽  
Activity Levels ◽  
Protein Levels ◽  
Pathological Cardiac Hypertrophy ◽  
Expression Of Genes ◽  
Wide Range

Individuals affected by Huntington's disease (HD) present with progressive degeneration that results in a wide range of symptoms, including cardiovascular (CV) dysfunction. The huntingtin gene (HTT) and its product are ubiquitously expressed, hence, the cardiomyopathy could also be driven by defects caused by its mutated form (mHTT) in the cardiomyocytes themselves. In the present study, we sought to determine the contribution of the mHTT expressed in the cardiomyocytes to CV symptoms. We utilized the BACHD mouse model, which exhibits many of the HD core symptoms, including CV dysfunction. This model allows the targeted genetic reduction of mHTT expression in the cardiomyocytes while maintaining the expression of the mHTT in the rest of the body. The BACHD line was crossed with a line of mice in which the expression of Cre recombinase is driven by the cardiac-specific alpha myosin-heavy chain (Myh6) promoter. The offspring of this cross (BMYO mice) exhibited a dramatic reduction in mHTT in the heart but not in the striatum. The BMYO mice were evaluated at 6 months old, as at this age, the BACHD line displays a strong CV phenotype. Echocardiogram measurements found improvement in the ejection fraction in the BMYO line compared to the BACHD, while hypertrophy was observed in both mutant lines. Next, we examined the expression of genes known to be upregulated during pathological cardiac hypertrophy. As measured by qPCR, the BMYO hearts exhibited significantly less expression of collagen1a as well as Gata4, and brain natriuretic peptide compared to the BACHD. Fibrosis in the hearts assessed by Masson's trichrome stain and the protein levels of fibronectin were reduced in the BMYO hearts compared to BACHD. Finally, we examined the performance of the mice on CV-sensitive motor tasks. Both the overall activity levels and grip strength were improved in the BMYO mice. Therefore, we conclude that the reduction of mHtt expression in the heart benefits CV function in the BACHD model, and suggest that cardiomyopathy should be considered in the treatment strategies for HD.

scholarly journals Neuronal targets for reducing mutant huntingtin expression to ameliorate disease in a mouse model of Huntington's disease

2014 ◽  
Vol 20 (5) ◽  
pp. 536-541 ◽  
Author(s):  
Nan Wang ◽  
Michelle Gray ◽  
Xiao-Hong Lu ◽  
Jeffrey P Cantle ◽  
Sandra M Holley ◽  
...  
Keyword(s):  
Mouse Model ◽  
Huntington's Disease ◽  
Huntington’S Disease ◽  
Mutant Huntingtin

Huntington's disease: from pathology and genetics to potential therapies

2008 ◽  
Vol 412 (2) ◽  
pp. 191-209 ◽  
Author(s):  
Sara Imarisio ◽  
Jenny Carmichael ◽  
Viktor Korolchuk ◽  
Chien-Wen Chen ◽  
Shinji Saiki ◽  
...  
Keyword(s):  
Huntington's Disease ◽  
Huntington’S Disease ◽  
Trinucleotide Repeat ◽  
Mutant Protein ◽  
Mutant Huntingtin ◽  
Genetic Screens ◽  
Wild Type ◽  
Biological Studies ◽  
Polyglutamine Tract

Huntington's disease (HD) is a devastating autosomal dominant neurodegenerative disease caused by a CAG trinucleotide repeat expansion encoding an abnormally long polyglutamine tract in the huntingtin protein. Much has been learnt since the mutation was identified in 1993. We review the functions of wild-type huntingtin. Mutant huntingtin may cause toxicity via a range of different mechanisms. The primary consequence of the mutation is to confer a toxic gain of function on the mutant protein and this may be modified by certain normal activities that are impaired by the mutation. It is likely that the toxicity of mutant huntingtin is revealed after a series of cleavage events leading to the production of N-terminal huntingtin fragment(s) containing the expanded polyglutamine tract. Although aggregation of the mutant protein is a hallmark of the disease, the role of aggregation is complex and the arguments for protective roles of inclusions are discussed. Mutant huntingtin may mediate some of its toxicity in the nucleus by perturbing specific transcriptional pathways. HD may also inhibit mitochondrial function and proteasome activity. Importantly, not all of the effects of mutant huntingtin may be cell-autonomous, and it is possible that abnormalities in neighbouring neurons and glia may also have an impact on connected cells. It is likely that there is still much to learn about mutant huntingtin toxicity, and important insights have already come and may still come from chemical and genetic screens. Importantly, basic biological studies in HD have led to numerous potential therapeutic strategies.

scholarly journals A YAC Mouse Model for Huntington’s Disease with Full-Length Mutant Huntingtin, Cytoplasmic Toxicity, and Selective Striatal Neurodegeneration

Neuron ◽  
1999 ◽  
Vol 23 (1) ◽  
pp. 181-192 ◽  
Author(s):  
J.Graeme Hodgson ◽  
Nadia Agopyan ◽  
Claire-Anne Gutekunst ◽  
Blair R Leavitt ◽  
Fred LePiane ◽  
...  
Keyword(s):  
Mouse Model ◽  
Huntington's Disease ◽  
Huntington’S Disease ◽  
Full Length ◽  
Mutant Huntingtin
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