application): While it is well recognized that the accumulation of extracellular amyloid is a hallmark of AD, many of the key pathological events of AD may also be directly related to the intracellular accumulation of this insoluble peptide. Recent studies in cell culture have indicated that A-beta1-42 (but not A-beta1-40), once accumulated inside cells, is resistant to degradation and can serve as a nidus for a prion-like replication model (the solid phase replication model for A-beta accumulation). Further studies in brain suggest that A-beta1-42 is the preferential form that accumulates in AD and that A-beta can be found within neurons though much less is known about its state and associated proteins. Once present in cultured cells, the aggregated amyloid induces the production of reactive oxygen species and lipid peroxidation products and ultimately results in the leakage of the lysosomal membrane. The breakdown of the lysosomal membrane may be a key pathological event, leading to the release of heparan sulfate and lysosomal hydrolysases. Taken together, these observations provide the novel view that amyloid deposits and some of the early events of amyloid pathogenesis initiate randomly within single cells in AD. This mechanism can explain some of the more enigmatic features of AD pathogenesis, like the focal nature of amyloid plaques, dystrophic neurites and neurofibrillary tangle pathology and the miscompartmentation of extracellular and cytosolic components observed in the AD brain. This project will use a combination of biochemical and light and electron microscopic, immunocytochemical approaches to study the accumulation of intracellular amyloid. The studies will be a combination of in vitro on cultured cells and in vivo studies on control and-AD brain, thereby combining the precision of in vitro studies with the need to evaluate predictions and findings in vivo. Select experiments will also be conducted on the aged canine brain that accumulates extensive amyloid and where the postmortem conditions can be precisely controlled. Preliminary data support the hypothesis that amyloid (""""""""preamyloid"""""""") accumulates in neurons in the aging and AD brain, can be shown to have a granular appearance in neurons and may be associated with a breakdown in intracellular compartmentation.

Agency
National Institute of Health (NIH)
Institute
National Institute on Aging (NIA)
Type
Specialized Center (P50)
Project #
1P50AG016573-01A1
Application #
6395417
Study Section
Special Emphasis Panel (ZAG1)
Project Start
2000-04-15
Project End
2005-03-31
Budget Start
Budget End
Support Year
1
Fiscal Year
2000
Total Cost
Indirect Cost
Name
University of California Irvine
Department
Type
DUNS #
161202122
City
Irvine
State
CA
Country
United States
Zip Code
92697
Torres, Maria D; Garcia, Octavio; Tang, Cindy et al. (2018) Dendritic spine pathology and thrombospondin-1 deficits in Down syndrome. Free Radic Biol Med 114:10-14
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
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
Largent, Emily A; Karlawish, Jason; Grill, Joshua D (2018) Study partners: essential collaborators in discovering treatments for Alzheimer's disease. Alzheimers Res Ther 10:101
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
Miranda, Andre M; Herman, Mathieu; Cheng, Rong et al. (2018) Excess Synaptojanin 1 Contributes to Place Cell Dysfunction and Memory Deficits in the Aging Hippocampus in Three Types of Alzheimer's Disease. Cell Rep 23:2967-2975
Haaksma, Miriam L; Calderón-Larrañaga, Amaia; Olde Rikkert, Marcel G M et al. (2018) Cognitive and functional progression in Alzheimer disease: A prediction model of latent classes. Int J Geriatr Psychiatry 33:1057-1064
Ramsey, Christine M; Gnjidic, Danijela; Agogo, George O et al. (2018) Longitudinal patterns of potentially inappropriate medication use following incident dementia diagnosis. Alzheimers Dement (N Y) 4:1-10
Melikyan, Zarui A; Greenia, Dana E; Corrada, Maria M et al. (2018) Recruiting the Oldest-old for Clinical Research. Alzheimer Dis Assoc Disord :
Hadjichrysanthou, Christoforos; McRae-McKee, Kevin; Evans, Stephanie et al. (2018) Potential Factors Associated with Cognitive Improvement of Individuals Diagnosed with Mild Cognitive Impairment or Dementia in Longitudinal Studies. J Alzheimers Dis 66:587-600

Showing the most recent 10 out of 518 publications