Proteomics of the astrocyte secretome reveals changes in their response to soluble oligomeric Abeta

Astrocytes associate with amyloid plaques in Alzheimers disease (AD). Astrocytes react to changes in the brain environment, including to increasing concentrations of amyloid-{beta} (A{beta}). However, the precise response of astrocytes to soluble small A{beta} oligomers at concentrations similar to those present in the human brain has not been addressed. In this study, we exposed astrocytes to neuronal media containing soluble human A{beta} oligomers and used proteomics to investigate changes in the astrocyte secretome. Our data shows dysregulated secretion of astrocytic proteins involved in the extracellular matrix and cytoskeletal organization and increase secretion of proteins involved in oxidative stress responses and those with chaperone activity. Several of these proteins have been identified in previous transcriptomic and proteomic studies using brain tissue from human AD and cerebrospinal fluid (CSF). Our work highlights the relevance of studying astrocyte secretion to understand the brain response to AD pathology and the potential use of these proteins as biomarkers for the disease.