Certain neuropathological lesions characterize the brains of normal aged humans and monkeys, and particularly Alzheimer's disease patients, where the lesions occur much earlier and in far greater numbers. The substantial minority (between 15 and 50%) of Alzheimer cases which appear to be the result of the inheritance of an autosomal dominant mutation indicate that a single genetic defect can cause the neuropathology. Using an immunochemical/ molecular genetic approach, the gene coding for one component of the extracellular protein deposits (termed """"""""amyloid"""""""") of normal aged and Alzheimer's disease brain was cloned, and found to code for a protease inhibitor, alpha 1-antichymotrypsin. Further experiments confirmed the intimate association of this protease inhibitor with the proteinaceous amyloid filaments of normal aged and Alzheimer's disease brain. Most of the next five years will be devoted to determining how alpha 1-antichymotrypsin contributes to amyloid deposition, either directly as a structural amyloid component, or indirectly as a protease inhibitor. For example, the fact that alpha 1- antichymotrypsin is overexpressed in Alzheimer brain suggests that it may prevent the normal clearing of amyloid deposits. Studies will determine the protease targets of alpha 1-antichymotrypsin inhibition in the brain, the cells expressing alpha 1- antichymotrypsin, and any alterations which may arise in the alpha 1-antichymotrypsin gene, its expression, or its encoded protein, during normal aging or Alzheimer's disease. Transgenic mice will be made in which alpha 1-antichymotrypsin will be overexpressed in a regulated manner to determine whether such over-expression leads to neuropathology, and to provide an animal model for testing potential therapeutic approaches to Alzheimer's disease and 'normal' senile neuropathy.

Agency
National Institute of Health (NIH)
Institute
National Institute on Aging (NIA)
Type
Research Project (R01)
Project #
5R01AG008084-02
Application #
3119482
Study Section
Neurology C Study Section (NEUC)
Project Start
1989-02-01
Project End
1992-01-31
Budget Start
1990-02-01
Budget End
1991-01-31
Support Year
2
Fiscal Year
1990
Total Cost
Indirect Cost
Name
Harvard University
Department
Type
Schools of Medicine
DUNS #
082359691
City
Boston
State
MA
Country
United States
Zip Code
02115
Geller, L N; Potter, H (1999) Chromosome missegregation and trisomy 21 mosaicism in Alzheimer's disease. Neurobiol Dis 6:167-79
DeFranco, C; Chicurel, M E; Potter, H (1998) A general RNA-binding protein complex that includes the cytoskeleton-associated protein MAP 1A. Mol Biol Cell 9:1695-708
Kayyali, U S; Zhang, W; Yee, A G et al. (1997) Cytoskeletal changes in the brains of mice lacking calcineurin A alpha. J Neurochem 68:1668-78
Li, J; Xu, M; Zhou, H et al. (1997) Alzheimer presenilins in the nuclear membrane, interphase kinetochores, and centrosomes suggest a role in chromosome segregation. Cell 90:917-27
Li, J; Ma, J; Potter, H (1995) Identification and expression analysis of a potential familial Alzheimer disease gene on chromosome 1 related to AD3. Proc Natl Acad Sci U S A 92:12180-4
Potter, H (1993) Application of electroporation in recombinant DNA technology. Methods Enzymol 217:461-78
Nelson, R B; Siman, R; Iqbal, M A et al. (1993) Identification of a chymotrypsin-like mast cell protease in rat brain capable of generating the N-terminus of the Alzheimer amyloid beta-protein. J Neurochem 61:567-77
Chicurel, M E; Terrian, D M; Potter, H (1993) mRNA at the synapse: analysis of a synaptosomal preparation enriched in hippocampal dendritic spines. J Neurosci 13:4054-63
Potter, H; Nelson, R B; Das, S et al. (1992) The involvement of proteases, protease inhibitors, and an acute phase response in Alzheimer's disease. Ann N Y Acad Sci 674:161-73
Abraham, C R; Driscoll, J; Potter, H et al. (1991) A calcium-activated protease from Alzheimer's disease brain cleaves at the N-terminus of the amyloid beta-protein. Biochem Biophys Res Commun 174:790-6