A synthetic amyloid lawn system for high-throughput analysis of amyloid toxicity and drug screening

Abstract

Amyloid-β (Aβ) is the major constituent of senile plaques in the brains of Alzheimer's disease patients. In order to develop an efficient in vitro system for studying the interaction of cells with Aβ aggregates, we have prepared a synthetic amyloid lawn by immobilizing Aβ peptides over a functionalized glass surface and subsequently incubating the template in a fresh Aβ solution. On the top of different types of amyloid lawns (e.g. monomeric, oligomeric, and fibrillar), we cultivated PC12 cells, creating physical contacts between the cells and the lawns. Results indicated that cell viability was differentially affected when grown atop different Aβ lawns while cells were well adhered onto the surface of these Aβ lawns. The mode of cell death by Aβ lawn was confirmed to be apoptotic rather than necrotic, showing that cells undergo suicide by just contact with Aβ lawn. While conventional 'solution-based' methods for testing amyloid toxicity suffer from problems such as lot-to-lot variations, continued fibrillation, and heterogeneous population of aggregates, our 'surface-based' lawn system is suitable for high-throughput analysis of amyloid toxicity, which may enable high-throughput screening of potential drug candidates for treating amyloid diseases with the goal of reducing the cell death on the lawn.