The potential to increase lifespan and healthspan by genetic, dietary, and/or other environmental means has been demonstrated across multiple organisms. In budding yeast, we recently discovered that mechanisms by which such interventions exert their effects can be mediated by extracellular compounds that are produced by one cell and act on another, so-called cell non-autonomous aging. Similarly, serum transfer and parabiosis experiments between young and old mice show that circulating factors confer and induce multiple health and aging benefits to the recipient cells or organism. Although a single cell organism, yeast cultures or colonies comprise a complex community of cells functioning in a coordinated fashion to adapt and survive in their respective environments, making them ideal for studies of cell-cell communication. Examples of coordinated developmental responses include mating, sporulation, and quorum sensing. Yeast are also ideal for high- throughput screening and analysis due to the large variety of available whole genome mutant collections. We hypothesize that ancient and conserved mechanisms of cell non-autonomous aging co-occur in yeast and metazoan organisms, and that these can be identified and thoroughly investigated using yeast chronological aging. Our group has developed a custom high-throughput quantitative method (Q-HTCP) for measuring chronological aging of the yeast gene knock out (YKO) collection in 384-well format, thus facilitating analysis at a systems level of understanding. We have also developed quantitative and cost-effective metabolomics approaches to combine with Q-HTCP and transcriptomics to investigate cell non-autonomous aging. We propose 2 specific aims designed to 1) identify and determine how cell non-autonomous aging factors are produced from yeast cells, and 2) determine how cells respond to such factors to modify chronological lifespan. Additionally, we will use the fruit fly, Drosophila melanogaster to screen candidate factors for evolutionary conservation of the non-autonomous aging effect by adding the factors to fly food and assaying for lifespan and healthspan markers. These experiments are anticipated to greatly advance our knowledge of cell non- autonomous aging mechanisms, and perhaps even identify conserved anti-aging interventions.
Studies in model organisms have significantly advanced our understanding of the biology of cellular aging, yet our understanding of the role cell-cell communication plays in aging processes remains incomplete. We have found that yeast cultures, under certain conditions, secrete compounds conferring longevity not only on other yeast, but also fruit flies. Using a systems biology approach, we will build upon these observations to verify the biochemical identities and identify the molecular pathways that underlie lifespan and healthspan influences of cell non-autonomous aging and anti-aging factors.
