Huntington's disease (HD) is one of nine fatal neurodegenerative disorders without effective treatment or cure, caused by an expanded CAG/polyglutamine repeat. The roles of the normal and mutant HD gene product, huntingtin remain uncertain. The objective of the proposed Mentored Clinical Scientist Development Award is to explore huntingtin mediated neurodegeneration. We propose to evaluate the roles of transcriptional dysregulation and protein processing in HD by pursuing the following Specific Aims:
Specific Aim 1 : Define the role of the NMDA receptor subunit NR2B, CBP, histone acetylation, and BDNF in aberrant neurite outgrowth and decreased survival of embryonic stem (ES) cells with expanded CAG repeats.
Specific Aim 2 : Identify transcripts involved in expanded polyglutamine-mediated transcriptional dysregulation.
Specific Aim 3 : Characterize the processing of polyglutamine containing proteins in undifferentiated and neuronally differentiated ES cells. We will pursue these Specific Aims utilizing an accurate, easily accessible, murine ES cell model. We find that neuronally differentiated ES cells with expanded CAG repeat domains develop features consistent with polyglutamine-mediated toxicity. Proposed experiments are expected to characterize full-length huntingtin protein processing and identify if the NMDA receptor subunit NR2B, CBP, histone acetylation, or BDNF are mediating neuronal dysfunction that precedes neurodegeneration in HD. Comparison of transcriptional profiles from neuronally differentiated ES cells with and without CAG repeats will be utilized to identify novel factors involved in HD pathogenesis. Once the pathologic mechanisms of mutant huntingtin are understood it will become possible to design rational therapeutics.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Clinical Investigator Award (CIA) (K08)
Project #
5K08NS045180-04
Application #
7121538
Study Section
NST-2 Subcommittee (NST)
Program Officer
Oliver, Eugene J
Project Start
2003-09-01
Project End
2008-08-31
Budget Start
2006-09-01
Budget End
2007-08-31
Support Year
4
Fiscal Year
2006
Total Cost
$173,340
Indirect Cost
Name
University of Michigan Ann Arbor
Department
Neurology
Type
Schools of Medicine
DUNS #
073133571
City
Ann Arbor
State
MI
Country
United States
Zip Code
48109
Lorincz, Matthew T; Zawistowski, Virginia A (2009) Expanded CAG repeats in the murine Huntington's disease gene increases neuronal differentiation of embryonic and neural stem cells. Mol Cell Neurosci 40:1-13
Lorincz, Matthew T (2006) Optimized neuronal differentiation of murine embryonic stem cells: role of cell density. Methods Mol Biol 330:55-69
Lorincz, Matthew T (2006) Geriatric chorea. Clin Geriatr Med 22:879-97, vii
Lorincz, Matthew T (2006) Clinical implications of Parkinson's disease genetics. Semin Neurol 26:492-8
Lorincz, Matthew T; Rainier, Shirley; Thomas, Donald et al. (2005) Cerebrotendinous xanthomatosis: possible higher prevalence than previously recognized. Arch Neurol 62:1459-63
Lorincz, Matthew T (2005) Embryonic stem cell models of CAG repeat disease. Cerebellum 4:25-30