PLoS Biol. 8, e1000450 (2010)

Ageing worms accumulate protein clumps similar to those observed in humans with Alzheimer's and Huntington's disease.

Cynthia Kenyon and her colleagues at the University of California, San Francisco, searched for proteins made by the nematode Caenorhabditis elegans that would not dissolve in detergents — a sign that the proteins would aggregate into insoluble clumps. The researchers found 461 proteins that become more insoluble as the worms age. Several of the proteins were similar to those that are found clumped and tangled in the brains of patients with Alzheimer's disease.

Furthermore, mutations that slow ageing in C. elegans by interfering with an insulin-signalling pathway also delayed the accumulation of insoluble proteins. The results suggest that disease is not the only factor to blame for protein aggregation, with ageing playing a part as well.