Heat Shock Proteins as Biomarkers of Aging
These researchers suggest that heat shock proteins might be used as a biomarker of aging, a way to determine biological age rather than chronological age, and hence predict life span or evaluate the effectiveness of potentially longevity-inducing therapies: "Since their discovery in Drosophila, the heat shock proteins (Hsps) have been shown to regulate both stress resistance and life span. Aging is characterized by increased oxidative stress and the accumulation of abnormal (malfolded) proteins, and these stresses induce Hsp gene expression through the transcription factor HSF. In addition, a subset of Hsps is induced by oxidative stress through the JNK signaling pathway and the transcription factor Foxo. The Hsps counteract the toxicity of abnormal proteins by facilitating protein refolding and turnover, and through other mechanisms including inhibition of apoptosis. The Hsps are up-regulated in tissue-specific patterns during aging, and their expression correlates with, and sometimes predicts, life span, making them ideal biomarkers of aging. The tools available for experimentally manipulating gene function and assaying healthspan in Drosophila provides an unparalleled opportunity to further study the role of Hsps in aging."