Spinocerebellar ataxia type 1 (SCA1) is one of nine fatal inherited neurodegenerative diseases caused by expansion of an inframe CAG trinucleotide repeat. Each repeat tract encodes a stretch of glutamine residues in the affected protein, in the case of SCA1 the protein is ataxin-1 (ATXN1). Symptoms of SCA1 include loss of motor coordination and balance, slurred speech, swallowing difficulty, spasticity, and some cognitive impairment. A characteristic feature of SCA1 pathology is atrophy and eventual loss of Purkinje cells from the cerebellar cortex. Like many neurodegenerative disorders, SCA1 is typically a late onset disease suggesting that physiological changes due to aging contribute to the onset of the disease. There is currently no effective treatment. Identifying signaling pathways and cellular mediators of SCA1 pathogenesis in the cerebellum leading to ataxia and in the brainstem that underlie lethality are critical in the search for therapeutics and are the focus of the research outlined in this application for continued support.

Public Health Relevance

A challenge facing understanding pathogenesis of SCA1, and neurodegenerative diseases in general, is elucidating the relative contribution of each molecular pathway altered has in pathogenesis in the different regions of the brain affected. We will - 1) assess relative contributions of a) a gain-of- CIC function, and the ATXN1/Rbm17 complex have in Purkinje cell SCA1 disease; 2) assess the extent to which the SCA1 Purkinje cell pathogenic pathway drives disease outside of the cerebellum, focusing on the brainstem; 3) use RNA-seq to profile brainstem (medulla) transcriptome and identify changes correlating with lethality in Sca1154Q/2Q mice.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS022920-31
Application #
9618682
Study Section
Cellular and Molecular Biology of Neurodegeneration Study Section (CMND)
Program Officer
Miller, Daniel L
Project Start
1986-09-30
Project End
2023-02-28
Budget Start
2019-03-01
Budget End
2020-02-29
Support Year
31
Fiscal Year
2019
Total Cost
Indirect Cost
Name
University of Minnesota Twin Cities
Department
Pathology
Type
Schools of Medicine
DUNS #
555917996
City
Minneapolis
State
MN
Country
United States
Zip Code
55455
Rubinsztein, David C; Orr, Harry T (2016) Diminishing return for mechanistic therapeutics with neurodegenerative disease duration?: There may be a point in the course of a neurodegenerative condition where therapeutics targeting disease-causing mechanisms are futile. Bioessays 38:977-80
Nelson, David L; Orr, Harry T; Warren, Stephen T (2013) The unstable repeats--three evolving faces of neurological disease. Neuron 77:825-43
Ebner, Blake A; Ingram, Melissa A; Barnes, Justin A et al. (2013) Purkinje cell ataxin-1 modulates climbing fiber synaptic input in developing and adult mouse cerebellum. J Neurosci 33:5806-20
Orr, Harry T (2012) Cell biology of spinocerebellar ataxia. J Cell Biol 197:167-77
Ingram, Melissa A C; Orr, Harry T; Clark, H Brent (2012) Genetically engineered mouse models of the trinucleotide-repeat spinocerebellar ataxias. Brain Res Bull 88:33-42
Orr, Harry T (2012) Polyglutamine neurodegeneration: expanded glutamines enhance native functions. Curr Opin Genet Dev 22:251-5
Fryer, John D; Yu, Peng; Kang, Hyojin et al. (2011) Exercise and genetic rescue of SCA1 via the transcriptional repressor Capicua. Science 334:690-3
Gehrking, Kristin M; Andresen, J Michael; Duvick, Lisa et al. (2011) Partial loss of Tip60 slows mid-stage neurodegeneration in a spinocerebellar ataxia type 1 (SCA1) mouse model. Hum Mol Genet 20:2204-12
Oz, G├╝lin; Vollmers, Manda L; Nelson, Christopher D et al. (2011) In vivo monitoring of recovery from neurodegeneration in conditional transgenic SCA1 mice. Exp Neurol 232:290-8
Barnes, Justin A; Ebner, Blake A; Duvick, Lisa A et al. (2011) Abnormalities in the climbing fiber-Purkinje cell circuitry contribute to neuronal dysfunction in ATXN1[82Q] mice. J Neurosci 31:12778-89

Showing the most recent 10 out of 62 publications