Search Spit for Signs of Aging

By comparing the salivary proteomes of younger and older women, John Yates and his colleagues find that protein expression is age-dependent. As they report in the Journal of Proteome Research, they fractionated parotid saliva from 14 women and then analyzed the samples using mass spec and MudPIT. They identified 532 proteins, but found that half were only expressed in a particular age group. "It is critical to take into consideration these normal differences in protein expression when searching for clinically relevant, disease specific biomarkers," the authors write. In a related news story, author James Melvin adds, "Because several diseases that affect women, in particular autoimmune disorders, are age-dependent, we wanted to determine the background levels of protein changes that you'd expect to see in normal aging."