Sphingolipid and methionine metabolism in aging.

Sphingolipids are essential for cell membrane structure and the regulation of organelle functions. Sphingolipid synthesis requires the coordinated activity of multiple organelles, including the endoplasmic reticulum, Golgi, lysosomes and mitochondria, which are connected via membrane contact sites. Metabolic remodeling of sphingolipid pathways is observed in aging and numerous age-related disorders. However, numerous studies have highlighted the complex and species-specific roles of sphingolipid metabolism in aging. In budding yeast, inhibition of sphingolipid synthesis extends lifespan by a mechanism that is poorly understood. Recent findings suggest that inhibition of sphingolipid synthesis in cells mimics methionine restriction, a condition known to extend lifespan across different experimental models. However, how sphingolipid remodeling alters cellular methionine levels, and whether this directly influences aging, remains unclear. In this Review, we explore the roles of sphingolipids in organelle function, highlighting their metabolic connections to methionine restriction and aging.