Alzheimer's disease (AD) is the most common form of dementia and is characterized neuropathologically by the presence of ?-amyloid (A?)-containing plaques and neurofibrillary tangles (NFTs) composed of phosphorylated tau protein. Symptomatic treatments for AD have been developed, but effective disease- modifying intervention is still needed. Targets have been identified for disease-modifying drugs, but the results of clinical trials have been disappointing. Biomarkers of AD may improve clinical trial design and analysis, increasing the likelihood of successful drug development. The precise mechanisms of Tau release in AD are not completely understood, however some studies indicates that Tau might be released as aggregates in clear vesicles or membrane free. Of them, recent studies suggest that pathogenic forms of Tau might be released in exosomal vesicles that are positive for the L1 cell adhesion protein (LI CAM), suggesting that they are shed from neuronal cells from where they can traffic to the CSF and blood. Without specific preparation and handling for isolation of exosomes, these neuronally-derived exosomes (L1NE) containing Tau are not detectible in blood. We hypothesize that the trafficking of Tau in exosomes from the CNS to CSF and/or blood is an important pathway in identifying stages of AD and can serve to identify patients in preclinical stages when pathology is developing and no overt cognitive effects are seen.

Public Health Relevance

Biomarkers of Alzheimer's disease (AD) can dramatically clinical trial design and analysis, increasing the likelihood of successful drug development and although work has focused on tau phosphorylation, another important intermediate to consider is neuronally derived exosomes (L1NE). Better understanding of the trafficking of L1NE from CNS to CSF and blood could be important to clarify the pathogenic significance of Tau containing exosomes in AD and might contribute to validate the detection of exosomes as biomarkers of AD; which in turn could improve clinical trial design and analysis, increasing the likelihood of successful drug development. In this context, the main objectives of this study will be to investigate the trafficking and pathogenic activity of Tau containing L1NE's in Tau transgenic animal models and patients with AD present in human CSF and if levels of this truncated protein can serve as a viable biomarker of AD.

Agency
National Institute of Health (NIH)
Institute
National Institute on Aging (NIA)
Type
Exploratory/Developmental Grants (R21)
Project #
5R21AG051839-02
Application #
9336219
Study Section
Cell Death in Neurodegeneration Study Section (CDIN)
Program Officer
Yang, Austin Jyan-Yu
Project Start
2016-09-01
Project End
2018-04-30
Budget Start
2017-08-01
Budget End
2018-04-30
Support Year
2
Fiscal Year
2017
Total Cost
Indirect Cost
Name
University of California, San Diego
Department
Neurosciences
Type
Schools of Medicine
DUNS #
804355790
City
La Jolla
State
CA
Country
United States
Zip Code
92093
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