Acid ceramidase modulates the lipid profile and exacerbates sensitivity to ferroptosis in senescent cells.

Cellular senescence, a complex biological process characterized by irreversible cell cycle arrest and the senescence-associated secretory phenotype, has emerged as a critical target for therapeutic development for age-related diseases. Ferroptosis, an iron-dependent regulated cell death pathway driven by the accumulation of lipid peroxidation in cell membranes, has been implicated in neurodegenerative diseases and other age-related disorders. This study investigated the relationship between cellular senescence and ferroptosis. Using human fetal lung Wi-38 fibroblasts induced to senesce via replicative exhaustion, we report a novel role for acid ceramidase (ACase), which breaks down ceramides into sphingosine and free fatty acids, in regulating the sensitivity of senescent cells to lipid peroxidation and ferroptosis through the modulation of polyunsaturated fatty acid composition of membrane phospholipids. Furthermore, we demonstrate a cell non-autonomous paracrine sensitization of non-senescent cells to ferroptosis by senescent cells. Together, these findings unveil ACase as a novel regulator of the ferroptosis pathway and open promising therapeutic avenues for targeting senescence-linked disorders and advancing healthy aging strategies.