Cellular senescence, a state of irreversible cell cycle arrest, is implicated in age-related diseases. While it is well known that senescent cells resist apoptosis, studies on their resistance to ferroptosis are limited and not fully understood. Senescent cells remain sensitive to ferroptosis induced by direct inhibition of glutathione peroxidase 4 (GPX4) but resist ferroptosis from cystine starvation, suggesting a role for mitochondrial metabolism. Here, we found that this resistance is mediated by peroxisome proliferator-activated receptor α (PPARα)-dependent upregulation of pyruvate dehydrogenase kinase 4 (PDK4), which inactivates pyruvate dehydrogenase (PDH) and suppresses mitochondria-derived reactive oxygen species, a key driver of ferroptosis. Our findings identify the PPARα-PDK4-PDH axis as a metabolic switch regulating ferroptosis sensitivity in senescent cells and provide insight into the senescence-ferroptosis interaction.
Machii et al. (Sun,) studied this question.