Live Cell FRET Imaging Reveals Amyloid β-Peptide Oligomerization in Hippocampal Neurons

Amyloid beta-peptide (A beta) oligomerization is believed to contribute to the neuronal dysfunction in Alzheimer disease (AD). Despite decades of research, many details of A beta oligomerization in neurons still need to be revealed. Forster resonance energy transfer (FRET) is a simple but effective way to study molecular interactions. Here, we used a confocal microscope with a sensitive Airyscan detector for FRET detection. By live cell FRET imaging, we detected A beta 42 oligomerization in primary neurons. The neurons were incubated with fluorescently labeled A beta 42 in the cell culture medium for 24 h. A beta 42 were internalized and oligomerized in the lysosomes/late endosomes in a concentration-dependent manner. Both the cellular uptake and intracellular oligomerization of A beta 42 were significantly higher than for A beta 40. These findings provide a better understanding of A beta 42 oligomerization in neurons.