Abstract
The hallmarks of Alzheimer’s disease (AD) are characterized by cognitive decline and behavioral changes. The most prominent brain region affected by the progression of AD is the hippocampal formation. The pathogenesis involves a successive loss of hippocampal neurons accompanied by a decline in learning and memory consolidation mainly attributed to an accumulation of senile plaques. The amyloid precursor protein (APP) has been identified as precursor of Aβ-peptides, the main constituents of senile plaques. Until now, little is known about the physiological function of APP within the central nervous system. The allocation of APP to the proteome of the highly dynamic presynaptic active zone (PAZ) highlights APP as a yet unknown player in neuronal communication and signaling. In this study, we analyze the impact of APP deletion on the hippocampal PAZ proteome. The native hippocampal PAZ derived from APP mouse mutants (APP-KOs and NexCreAPP/APLP2-cDKOs) was isolated by subcellular fractionation and immunopurification. Subsequently, an isobaric labeling was performed using TMT6 for protein identification and quantification by high-resolution mass spectrometry. We combine bioinformatics tools and biochemical approaches to address the proteomics dataset and to understand the role of individual proteins. The impact of APP deletion on the hippocampal PAZ proteome was visualized by creating protein-protein interaction (PPI) networks that incorporated APP into the synaptic vesicle cycle, cytoskeletal organization, and calcium-homeostasis. The combination of subcellular fractionation, immunopurification, proteomic analysis, and bioinformatics allowed us to identify APP as structural and functional regulator in a context-sensitive manner within the hippocampal active zone network.
Highlights
Alzheimer’s disease (AD), characterized by a massive loss of synapses, cognitive decline and behavioral changes, is mainly associated with an accumulation of neurofibrillary tangles and senile plaques [1,2,3]
We combine bioinformatics tools and biochemical approaches to address the dataset provided by proteomics
Our findings offer a new perspective on the physiological function of amyloid precursor protein (APP) in the central nervous system and may provide a molecular link to the pathogenesis of Alzheimer’s disease
Summary
Alzheimer’s disease (AD), characterized by a massive loss of synapses, cognitive decline and behavioral changes, is mainly associated with an accumulation of neurofibrillary tangles and senile plaques [1,2,3]. We compared the PAZ proteomes of wild type controls, single APP-KO mice, and conditional APP/APLP2 double knockout mice for creating a common core proteome of hippocampal neurotransmitter release sites. The impact of APP deletion and APP/APLP2 deletion within the CNS point to general physiological role in synaptic plasticity and synaptic maintenances [6,7,8,9,10] In this context, we addressed the question of the cellular function of APP at synaptic release sites by comparing wild type and knockout mice and creating protein-protein interaction networks. Our novel experimental design for the isolation and purification of the native hippocampal PAZ [14] along with quantitative biochemical and proteomic approaches allowed us to compare APP-mutants to their controls and to unravel the proximate impact of APP deletion. Results derived from the combination of multidisciplinary biological techniques suggest that APP is as structural and functional regulator in a context-sensitive manner within the hippocampal active zone network
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
