Using giant plasma membrane vesicles (GMPVs) to study age-dependent changes in amyloid-β oligomer toxicity.

Abstract

Aging is a major risk factor associated with several human ailments, including some forms of cancer, autoimmunity, and neurodegeneration. Longitudinal changes in the multicellular organisms, including issues with genomic stability and protein oxidation, have been extensively reported. However, age-dependent changes in plasma membrane lipids and how they contribute to age-related phenotypes are less understood. Moreover, mechanistic understanding about how age-dependent lipidic changes can seed or exacerbate the toxicity of aggregating protein, such as amyloid-β (Aβ) in Alzheimer's disease, is of particular interest. Indeed, certain isolated detergents, fatty acids, and lipids have been shown to nucleate soluble Aβ oligomers (Aβos) with notable cytotoxicity, but little has been done to understand how changes in complex mixtures such as plasma membrane lipids scaffold toxic oligomers in a longitudinal manner. To deconvolute how cellular age can influence the cytotoxic properties of Aβos, giant-plasma membrane derived vesicles (GPMVs) will be collected from cultured cells at various passage numbers and at senescence. Those GMPVs will then be used as lipidic scaffolds for soluble Aβos and the Aβo-GPMV complexes will be treated to cultured cells to monitor their responses. Specifically, Aβo-GPMV toxicity will be monitored by observing changes in cellular respiration, senescence, and/or cell death. The driving hypothesis is that GPMVs derived from aged cells (at high-passage numbers) will seed enhanced toxicity of Aβ oligomers compared to the young (low/medium passage number) counterparts.