Amyloid β accelerates age-related proteome-wide protein insolubility

Could the abundance of proteins be increasing in the lysate and that's why you see more insolublity?

This is a good observation. We did not measure the lysate proteome. We did address this in the supplementary by looking at expression changes in publicly available RNAseq datasets from aging wild type and the GMC101 model. We found that insoluble proteins don't change at the level of RNA in either case so they're unlikely to be "over-expressed" at the protein level leading to insolubility.