The long term goal of the proposed research is to develop effective treatment for spinobulbar muscular atrophy (SBMA), a neurodegenerative disease caused by expansion of a polyglutamine (polyQ) tract in the androgen receptor (AR). My laboratory has recently published compelling evidence that native functions of the androgen receptor are essential mediators of toxicity. Specifically, we used a combination of Drosophila genetics and functional genomics to learn that interaction of the AF-2 domain of AR with nuclear hormone co-regulatory protein is an essential step in pathogenesis. This exciting finding suggests that modulation of native AR function with existing anti-androgen therapies may be effective in the treatment of this devastating neurodegenerative disease. The critical next steps are corroboration of this mechanism of pathogenesis in a mammalian model of SBMA and further elucidation of the specific AR functions that are perturbed by polyglutamine expansion, as outlined in the accompanying proposal. A related question is determination of the most important component of the motor unit to be targeted in therapy: motor neuron or muscle. Toward that end we have initiated experiments to address three specific aims. First, we have generated a novel series of transgenic mice that conditionally express wild type or mutant forms of human androgen receptor to corroborate these findings in a mammalian model. Second, we will pursue proteomic approaches to characterize how polyglutamine expansion influences native interactions of the androgen receptor. Third, we will engineer conditional expression exclusively in motor neuron or muscle to gauge the relative contributions of these tissues to the degenerative phenotype in SBMA mice.

Public Health Relevance

Mutations in the androgen receptor gene cause an inherited neurodegenerative disorder called spinobulbar muscular atrophy. This project seeks to understand the molecular basis of this disease and provide detailed characterization of a promising therapeutic target. These insights will be used to guide therapeutic intervention for this disease and related degenerative diseases.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS053825-09
Application #
8448750
Study Section
Cellular and Molecular Biology of Neurodegeneration Study Section (CMND)
Program Officer
Gubitz, Amelie
Project Start
2005-12-01
Project End
2016-04-30
Budget Start
2013-05-01
Budget End
2014-04-30
Support Year
9
Fiscal Year
2013
Total Cost
$369,415
Indirect Cost
$158,321
Name
St. Jude Children's Research Hospital
Department
Type
DUNS #
067717892
City
Memphis
State
TN
Country
United States
Zip Code
38105
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