A group of researchers from Royal Holloway, University of London and the Institute of Psychiatry King’s College London have released a new study identifying a single-celled amoeba that helps them to better understand the proteins causing Alzheimer’s disease.
Published in the Journal of Cell Science, the study identified the amoeba Dictyostelium as a new way to better understand the role of presenilin proteins in Alzheimer’s. “This work on the amoeba Dictyostelium shows we can successfully use this simple model to try to better understand the normal roles of other proteins and genes in Alzheimer’s disease and other forms of neurodegeneration,” Dr. Richard Killick of the Institute of Psychiatry at King’s College London said in a press release.
Instead of testing the role of presenilin proteins in animals — which was often difficult — the scientists studied them in the amoeba. “Our data suggest that presenilin proteins perform an ancient non-proteolytic role in regulating intracellular signaling and development, and that Dictyostelium is a useful model for analyzing human presenilin function,” the authors wrote in the abstract.
Several years ago, scientists found that presenilin proteins were linked to Alzheimer’s. For decades, the presenilin 1 gene has been associated with early-onset familial form of Alzheimer’s, which runs in families; but scientists only recently were able to glean more information about how mutations in this gene caused the disease. “In mouse models of Alzheimer’s disease and in skin cell of patients with Alzheimer’s disease caused by presenilin mutations, we observed that the ability to break down and reuse normal proteins and to remove potentially toxic damaged proteins and organelles is severely impaired,” Dr. Ralph Nixon, an author of the 2010 study, said in a press release. In this study, the researchers suggested trying a new drug development route that would focus on eliminating toxic proteins before they do damage, rather than focusing on removing amyloid plaques from the brain.
Studying presenilin proteins in amoebas can help move researchers forward in developing this new drug route. “This discovery allows us to examine the role for the human presenilin 1 protein, without the use of animal testing,” Professor Robin Williams of the School of Biological Sciences at Royal Holloway said in the press release. “It is amazing that so simple an organism lends itself to the study of such a complex disease.”
Source: Ludtmann M, Otto G, Schilde C, et al. An ancestral non-proteolytic role for presenilin proteins in multicellular development of the social amoebaDictyostelium discoideum. Journal of Cell Science. 2014.