Figure 1.

Conserved pathways associated with longer lifespan identified in yeast, worms, flies, and mice. Altered metabolism involves signature changes related to energy saving, activation of lipid fuel use, and dampened growth and synthetic pathways. At the cellular level the delayed aging phenotype is associated with increased metabolite recycling, autophagy, reduced translation, protein turnover, and enhanced maintenance and repair linked to antioxidant and other stress response pathways. Interactions among organelles are influenced by energy status and associations shift to accommodate the metabolic state linked to lower nutrient availability and low growth signaling conditions. The overall outcome is a reprogrammed metabolism, enhanced repair and recycling mechanisms, and reduced growth and macromolecular synthesis.