Fig. 4. Lipophagy alters cell death responses.

a, b Oxidative stress decreases the rate of mitochondrial β-oxidation, resulting in a decrease in cell ATP content. Severe reductions in ATP can lead to necrosis and cell death. Decreased levels of ATP promote mitochondrial dysfunction and trigger apoptotic cell death by affecting the release of cytochrome c. Lipophagy mediates resistance to these two forms of cell death by degrading lipid droplets into fatty acids and participating in the synthesis of ATP. c Lipotoxic molecules can cause apoptosis directly or by inhibiting lipophagy, which degrades lipotoxic molecules by enveloping triglycerides in lipid droplets and degrading them.