Tags

Type your tag names separated by a space and hit enter

Ectopic expression of the striatal-enriched GTPase Rhes elicits cerebellar degeneration and an ataxia phenotype in Huntington's disease.
Neurobiol Dis. 2015 Oct; 82:66-77.ND

Abstract

Huntington's disease (HD) is caused by an expansion of glutamine repeats in the huntingtin protein (mHtt) that invokes early and prominent damage of the striatum, a region that controls motor behaviors. Despite its ubiquitous expression, why certain brain regions, such as the cerebellum, are relatively spared from neuronal loss by mHtt remains unclear. Previously, we implicated the striatal-enriched GTPase, Rhes (Ras homolog enriched in the striatum), which binds and SUMOylates mHtt and increases its solubility and cellular cytotoxicity, as the cause for striatal toxicity in HD. Here, we report that Rhes deletion in HD mice (N171-82Q), which express the N-terminal fragment of human Htt with 82 glutamines (Rhes(-/-)/N171-82Q), display markedly reduced HD-related behavioral deficits, and absence of lateral ventricle dilatation (secondary to striatal atrophy), compared to control HD mice (N171-82Q). To further validate the role of GTPase Rhes in HD, we tested whether ectopic Rhes expression would elicit a pathology in a brain region normally less affected in HD. Remarkably, ectopic expression of Rhes in the cerebellum of N171-82Q mice, during the asymptomatic period led to an exacerbation of motor deficits, including loss of balance and motor incoordination with ataxia-like features, not apparent in control-injected N171-82Q mice or Rhes injected wild-type mice. Pathological and biochemical analysis of Rhes-injected N171-82Q mice revealed a cerebellar lesion with marked loss of Purkinje neuron layer parvalbumin-immunoreactivity, induction of caspase 3 activation, and enhanced soluble forms of mHtt. Similarly reintroducing Rhes into the striatum of Rhes deleted Rhes(-/-)Hdh(150Q/150Q) knock-in mice, elicited a progressive HD-associated rotarod deficit. Overall, these studies establish that Rhes plays a pivotal role in vivo for the selective toxicity of mHtt in HD.

Authors+Show Affiliations

Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida 33458, USA.Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida 33458, USA.Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida 33458, USA.Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida 33458, USA.Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida 33458, USA.Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida 33458, USA. Electronic address: ssubrama@scripps.edu.

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

26048156

Citation

Swarnkar, Supriya, et al. "Ectopic Expression of the Striatal-enriched GTPase Rhes Elicits Cerebellar Degeneration and an Ataxia Phenotype in Huntington's Disease." Neurobiology of Disease, vol. 82, 2015, pp. 66-77.
Swarnkar S, Chen Y, Pryor WM, et al. Ectopic expression of the striatal-enriched GTPase Rhes elicits cerebellar degeneration and an ataxia phenotype in Huntington's disease. Neurobiol Dis. 2015;82:66-77.
Swarnkar, S., Chen, Y., Pryor, W. M., Shahani, N., Page, D. T., & Subramaniam, S. (2015). Ectopic expression of the striatal-enriched GTPase Rhes elicits cerebellar degeneration and an ataxia phenotype in Huntington's disease. Neurobiology of Disease, 82, 66-77. https://doi.org/10.1016/j.nbd.2015.05.011
Swarnkar S, et al. Ectopic Expression of the Striatal-enriched GTPase Rhes Elicits Cerebellar Degeneration and an Ataxia Phenotype in Huntington's Disease. Neurobiol Dis. 2015;82:66-77. PubMed PMID: 26048156.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Ectopic expression of the striatal-enriched GTPase Rhes elicits cerebellar degeneration and an ataxia phenotype in Huntington's disease. AU - Swarnkar,Supriya, AU - Chen,Youjun, AU - Pryor,William M, AU - Shahani,Neelam, AU - Page,Damon T, AU - Subramaniam,Srinivasa, Y1 - 2015/06/03/ PY - 2014/11/04/received PY - 2015/04/02/revised PY - 2015/05/26/accepted PY - 2015/6/7/entrez PY - 2015/6/7/pubmed PY - 2016/8/20/medline KW - Ataxia KW - Cerebellar pathology KW - Ectopic expression KW - Huntington's disease KW - Knock-in HD mice KW - Neurodegeneration KW - Neuronal death KW - Rhes KW - Soluble Huntingtin KW - Stereotaxy KW - Transgenic HD mice SP - 66 EP - 77 JF - Neurobiology of disease JO - Neurobiol Dis VL - 82 N2 - Huntington's disease (HD) is caused by an expansion of glutamine repeats in the huntingtin protein (mHtt) that invokes early and prominent damage of the striatum, a region that controls motor behaviors. Despite its ubiquitous expression, why certain brain regions, such as the cerebellum, are relatively spared from neuronal loss by mHtt remains unclear. Previously, we implicated the striatal-enriched GTPase, Rhes (Ras homolog enriched in the striatum), which binds and SUMOylates mHtt and increases its solubility and cellular cytotoxicity, as the cause for striatal toxicity in HD. Here, we report that Rhes deletion in HD mice (N171-82Q), which express the N-terminal fragment of human Htt with 82 glutamines (Rhes(-/-)/N171-82Q), display markedly reduced HD-related behavioral deficits, and absence of lateral ventricle dilatation (secondary to striatal atrophy), compared to control HD mice (N171-82Q). To further validate the role of GTPase Rhes in HD, we tested whether ectopic Rhes expression would elicit a pathology in a brain region normally less affected in HD. Remarkably, ectopic expression of Rhes in the cerebellum of N171-82Q mice, during the asymptomatic period led to an exacerbation of motor deficits, including loss of balance and motor incoordination with ataxia-like features, not apparent in control-injected N171-82Q mice or Rhes injected wild-type mice. Pathological and biochemical analysis of Rhes-injected N171-82Q mice revealed a cerebellar lesion with marked loss of Purkinje neuron layer parvalbumin-immunoreactivity, induction of caspase 3 activation, and enhanced soluble forms of mHtt. Similarly reintroducing Rhes into the striatum of Rhes deleted Rhes(-/-)Hdh(150Q/150Q) knock-in mice, elicited a progressive HD-associated rotarod deficit. Overall, these studies establish that Rhes plays a pivotal role in vivo for the selective toxicity of mHtt in HD. SN - 1095-953X UR - https://www.unboundmedicine.com/medline/citation/26048156/Ectopic_expression_of_the_striatal_enriched_GTPase_Rhes_elicits_cerebellar_degeneration_and_an_ataxia_phenotype_in_Huntington's_disease_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0969-9961(15)00185-0 DB - PRIME DP - Unbound Medicine ER -