Proteomic Analysis of Protein Expression Throughout Disease Progression in a Mouse Model of Alzheimer's Disease

Alzheimer's disease (AD) is the most common cause of dementia. Mice in the transgenic A beta PPswe/PS1dE9 mouse line express a chimeric mouse/human amyloid-beta protein precursor (Mo/HuA beta PP695swe) and mutant human presenilin 1 (PS1-dE9) associated with early-onset AD. Knowing the protein expression in these mice may offer better understanding of the pathological changes in AD. In this study, we used two-dimensional gel electrophoresis combined with mass spectrometry techniques to compare protein expression in A beta PPswe/PS1dE9 mice with age-matched wild-type mice throughout the disease progression. We identified 15 proteins that were significantly different between the A beta PPswe/PS1dE9 mice and age-matched controls and also changed with disease development. Among those, the expression levels of the following proteins in A beta PPswe/PS1dE9 mice were at least 1.5 times higher than those in normal mice: DCC-interacting protein 13-beta, serum albumin, creatine kinase B-type, heat shock 70 kDa protein 1A, T-complex protein 1 subunit beta, adenylate kinase isoenzyme 1, pyruvate dehydrogenase E1 component subunit beta mitochondrial, and V-type proton ATPase catalytic subunit A. Levels of the following proteins in A beta PPswe/PS1dE9 mice were at least 1.5 times lower than those in normal mice: dihydropyrimidinase-related protein 2, actin cytoplasmic 2, isoform 1 of V-type proton ATPase catalytic subunit, tubulin alpha-1C chain, F-actin-capping protein subunit alpha-2, ubiquitin carboxyl-terminal hydrolase isozyme L1, and actin cytoplasmic 1. These proteins are involved in regulating various cellular functions, including cytoskeletal structure, energy metabolism, synaptic components, and protein degradation. These findings indicate altered protein expression in the pathogenesis of AD and illuminate novel therapeutic avenues for treatment in AD.