The major components of amyloid in Alzheimer's disease (AD) brain are Abeta peptides that are derived by proteolytic cleavage of amyloid precursor protein (APP). Our preliminary data demonstrates that the X11alpha protein strongly influences APP metabolism in transfected HEK 293 cells. Specifically, X11alpha prolongs the half-life of cellular APP and retards recovery of its metabolic fragments, including the secreted amino-terminal fragments APPs, as well as Abeta40 and Abeta42 in conditioned medium. These effects are mediated by direct binding of the PTB-PI domain of Xllalpha to the YENPTY motif in the intracellular carboxy-terminus of APP. In addition, to a PTB-PI domain, X11alpha also contains two PDZ domains as well as an extended amino-terminus that may modulate Xllalpha effects on APP processing. We have recently found that Xllalpha exists as a heterotrimeric complex in mouse brain complexed with the mammalian homologues of the C. elegans Lin-2 and Lin-7 proteins. We propose to determine the potential modulatory influence of mammalian Lin-2 and Lin-7 on the inhibitory effects of X11alpha on cellular APP metabolism. We will study these effects by over-expression of wild type and dominant negative constructs of X11alpha, mLin-2 and mLin-7. Initial studies will be performed with transfected Hek 293 cells. Since APP metabolism is to some degree cell-type specific and Xllalpha is primarily a neuronal protein, we will also analyze the effects of Xllalpha, mLin-2 and mLin-7 on APP processing in neurons. We will perform these experiments in NT2 neurons infected with Semliki Forest Virus expressing the wild type and dominant negative constructs. We hypothesize that Xllalpha influences PP metabolism by altering its cellular trafficking. Thus, we will examine the cellular localization of PP, Xllalpha, mLin-2, and mLin-7 in wild type and infected cells. Finally, we hypothesize that the regional expression of APP, X11alpha, mLin-2, and mLin-7 in brain may inversely correlate with the regional neuropathology of AD, particular amyloid plaques. We will determine the regional expression and localization of these genes/proteins in normal and AD brain sections by immunohistochemistry and in situ hybridization. Collectively, this data will provide insights into the regulation of cellular APP trafficking and metabolism via these specific protein-protein interactions, and their potential roles in the development of AD. This information may lead to novel therapeutic strategies to delay the onset or slow the progression of amyloid deposition, dementia, and AD.

Agency
National Institute of Health (NIH)
Institute
National Institute on Aging (NIA)
Type
Specialized Center (P50)
Project #
5P50AG008671-14
Application #
6600390
Study Section
Special Emphasis Panel (ZAG1)
Project Start
2002-07-01
Project End
2003-05-31
Budget Start
Budget End
Support Year
14
Fiscal Year
2002
Total Cost
Indirect Cost
Name
University of Michigan Ann Arbor
Department
Type
DUNS #
791277940
City
Ann Arbor
State
MI
Country
United States
Zip Code
48109
Sims, Rebecca (see original citation for additional authors) (2017) Rare coding variants in PLCG2, ABI3, and TREM2 implicate microglial-mediated innate immunity in Alzheimer's disease. Nat Genet 49:1373-1384
Michaud, Tzeyu L; High, Robin; Charlton, Mary E et al. (2017) Dependence Stage and Pharmacoeconomic Outcomes in Patients With Alzheimer Disease. Alzheimer Dis Assoc Disord 31:209-217
Monin, Joan K; Poulin, Michael J; Brown, Stephanie L et al. (2017) Spouses' daily feelings of appreciation and self-reported well-being. Health Psychol 36:1135-1139
Jun, Gyungah R; Chung, Jaeyoon; Mez, Jesse et al. (2017) Transethnic genome-wide scan identifies novel Alzheimer's disease loci. Alzheimers Dement 13:727-738
Cary, Brian P; Brooks, Allen F; Fawaz, Maria V et al. (2016) Synthesis and Evaluation of [(18)F]RAGER: A First Generation Small-Molecule PET Radioligand Targeting the Receptor for Advanced Glycation Endproducts. ACS Chem Neurosci 7:391-8
Karch, Celeste M; Ezerskiy, Lubov A; Bertelsen, Sarah et al. (2016) Alzheimer's Disease Risk Polymorphisms Regulate Gene Expression in the ZCWPW1 and the CELF1 Loci. PLoS One 11:e0148717
Mez, Jesse; Mukherjee, Shubhabrata; Thornton, Timothy et al. (2016) The executive prominent/memory prominent spectrum in Alzheimer's disease is highly heritable. Neurobiol Aging 41:115-121
Ridge, Perry G; Hoyt, Kaitlyn B; Boehme, Kevin et al. (2016) Assessment of the genetic variance of late-onset Alzheimer's disease. Neurobiol Aging 41:200.e13-200.e20
Hohman, Timothy J; Bush, William S; Jiang, Lan et al. (2016) Discovery of gene-gene interactions across multiple independent data sets of late onset Alzheimer disease from the Alzheimer Disease Genetics Consortium. Neurobiol Aging 38:141-150
Jun, G; Ibrahim-Verbaas, C A; Vronskaya, M et al. (2016) A novel Alzheimer disease locus located near the gene encoding tau protein. Mol Psychiatry 21:108-17

Showing the most recent 10 out of 274 publications