A chemical dye that lights up the protein clumps characteristic of Alzheimer's disease also slows ageing in worms. The lifespan-boosting effects of the dye — called Thioflavin T or Basic Yellow 1 — support the idea that the build-up of misshapen proteins underlies ageing. Drugs that recognize such toxic detritus and alert the cell's natural repair and protein-recycling systems could, therefore, be used to treat diseases of old age, says Gordon Lithgow, a molecular geneticist at the Buck Institute in Novato, California, who led the study, published today in Nature1.
Proteins are essential for almost everything a cell does, from communicating with other cells to generating energy. But sometimes proteins form the wrong three-dimensional shapes. Misfolded proteins don't function properly and, worse, tend to accumulate and gum up other cellular systems. To prevent this from happening, cells deploy 'chaperones', whose job it is to refold misshapen proteins. In more extreme cases, cells can degrade these potentially dangerous proteins. “There's a growing appreciation that protein misfolding may be one of the very fundamental events of ageing,” says Richard Morimoto, a molecular biologist at Northwestern University in Evanston, Illinois, who was not involved with the study. Worms genetically engineered to have a revved-up protein-recycling system, for instance, live longer than normal worms23.