The specific heparin sulfate proteoglycan, perlecan, is a constant companion and integral component of beta-amyloid protein (Abeta)- containing amyloid deposits in Alzheimer's disease (AD) brain. The overall objective of this proposal is to elucidate and define the mechanisms involving perlecan in the normal function of the beta-amyloid precursor protein (betaPP), in its association with Abeta, and in the pathogenesis of AD.
In Aim #1, antibody-mediated cell surface capping of betaPP, double labelled immunofluorescence and confocal microscopy, will be used in rat primary cultures of microglia, astrocytes and neurons to assess whether betaPP functions in association with perlecan on the cell surface or in the extracellular matrix during neurite outgrowth (by morphometry) or cell adhesion (by adhesion assays).
In Aim #2, we will characterize the mechanisms of perlecan-Abeta interactions by 1) identifying perlecan (and other PGs) in isolated amyloid plaque cores and neurofibrillary tangles using specific solubilization techniques and PG structural biochemistry, and 2) identifying specific perlecan core protein domain(s) and GAG chain structure(s) involved in Abeta-binding (by analyzing tryptic digestions of SASD-125 I-perlecan coupled to Abeta peptides, and by affinity coelectrophoresis, affinity chromatography and solid phase binding assays). In addition, we will use the latter two techniques to assess the interaction of perlecan with Apolipoprotein E4 versus E3.
In Aim #3, we will determine the levels (by Northern analysis and mRNA slot blots) and sites (by in situ hybridization) of perlecan synthesis in AD and normal aged brain, and in primary cultures will identify perlecan producing cells (by structural PG biochemistry, Western and Northern analysis) which bind Abeta or betaPP (by affinity column chromatography).
In Aim #4, we will determine 1) the effects of formation of perlecan-Abeta/betaPP or GAG-Abeta complexes (using aggregation assays analyzed by electron microscopy, congo red staining, Thioflavin T spectrofluorometry, X-ray diffraction and infrared spectroscopy) and 2) whether perlecan protects Abeta/betaPP degradation using HPLC, SDS-PAGE, Western blotting and scanning densitometry. Additionally, we will use chemical modulators of PG synthesis, and introduce exogenous PGs/GAGs into primary cultures to assess the consequences of altered PG synthesis on betaPP metabolism and Abeta production. Furthermore, we will infuse Abeta or perlecan into rat brain to determine (by immunocytochemistry, Northern analysis and structural biochemistry) whether Abeta causes an upregulation in perlecan expression and synthesis, and whether perlecan influences betaPP expression and synthesis in vivo. Deciphering the mechanisms underlying perlecan's interaction with Abeta/betaPP will be essential to understand several key steps in the pathogenesis of AD and may provide relevant targets for therapeutic intervention in the future.

Agency
National Institute of Health (NIH)
Institute
National Institute on Aging (NIA)
Type
Specialized Center (P50)
Project #
5P50AG005136-14
Application #
6234053
Study Section
Project Start
1997-05-01
Project End
1998-04-30
Budget Start
1996-10-01
Budget End
1997-09-30
Support Year
14
Fiscal Year
1997
Total Cost
Indirect Cost
Name
University of Washington
Department
Type
DUNS #
135646524
City
Seattle
State
WA
Country
United States
Zip Code
98195
Gray, Shelly L; Anderson, Melissa L; Hanlon, Joseph T et al. (2018) Exposure to Strong Anticholinergic Medications and Dementia-Related Neuropathology in a Community-Based Autopsy Cohort. J Alzheimers Dis 65:607-616
Reed, May J; Damodarasamy, Mamatha; Pathan, Jasmine L et al. (2018) Increased Hyaluronan and TSG-6 in Association with Neuropathologic Changes of Alzheimer's Disease. J Alzheimers Dis :
Barnes, Josephine; Bartlett, Jonathan W; Wolk, David A et al. (2018) Disease Course Varies According to Age and Symptom Length in Alzheimer's Disease. J Alzheimers Dis 64:631-642
Suchy-Dicey, Astrid M; Muller, Clemma J; Madhyastha, Tara M et al. (2018) Telomere Length and Magnetic Resonance Imaging Findings of Vascular Brain Injury and Central Brain Atrophy: The Strong Heart Study. Am J Epidemiol 187:1231-1239
Burke, Shanna L; Maramaldi, Peter; Cadet, Tamara et al. (2018) Decreasing hazards of Alzheimer's disease with the use of antidepressants: mitigating the risk of depression and apolipoprotein E. Int J Geriatr Psychiatry 33:200-211
Nafikov, Rafael A; Nato Jr, Alejandro Q; Sohi, Harkirat et al. (2018) Analysis of pedigree data in populations with multiple ancestries: Strategies for dealing with admixture in Caribbean Hispanic families from the ADSP. Genet Epidemiol 42:500-515
Qian, Winnie; Fischer, Corinne E; Schweizer, Tom A et al. (2018) Association Between Psychosis Phenotype and APOE Genotype on the Clinical Profiles of Alzheimer's Disease. Curr Alzheimer Res 15:187-194
Davis, Jeremy J (2018) Performance validity in older adults: Observed versus predicted false positive rates in relation to number of tests administered. J Clin Exp Neuropsychol 40:1013-1021
Young, Jessica E; Fong, Lauren K; Frankowski, Harald et al. (2018) Stabilizing the Retromer Complex in a Human Stem Cell Model of Alzheimer's Disease Reduces TAU Phosphorylation Independently of Amyloid Precursor Protein. Stem Cell Reports 10:1046-1058
Gallagher, Damien; Kiss, Alex; Lanctot, Krista et al. (2018) Depression and Risk of Alzheimer Dementia: A Longitudinal Analysis to Determine Predictors of Increased Risk among Older Adults with Depression. Am J Geriatr Psychiatry 26:819-827

Showing the most recent 10 out of 753 publications