What causes the accumulation of toxic amyloid aggregates? An article by Rimal et al. published in the journal Acta Neuropathologica Communications might have found the answer to this question. Their work shows that a defective ribosome quality control (RQC) causes the C-terminal fragment (APP.C99) of the Amyloid precursor protein (APP) to accumulate. This might be one of the earliest pathogenic events of amyloid aggregation. Labeling such aggregates in HeLa cells with Amytracker 680 shows that they have amyloid-like properties.

Image:🔬 Ribosome stall-induced aberrant APP.C99 seeds amyloid ß-42 aggregation in HeLa cells after addition of Aß42 AT tails. Fluorescent microscope images showing aggregation of Aß42 as detected with the aggregation-specific dye Amytracker (in blue). Rimal et al. Fig. S6D (CC-BY-4.0).