Phospholipids with two polyunsaturated fatty acyl tails promote ferroptosis

Abstract

Phospholipids containing a single polyunsaturated fatty acyl tail (PL-PUFA₁s) are considered the driving force behind ferroptosis, whereas phospholipids with diacyl-PUFA tails (PL-PUFA₂s) have been rarely characterized. Dietary lipids modulate ferroptosis, but the mechanisms governing lipid metabolism and ferroptosis sensitivity are not well understood. Our research revealed a significant accumulation of diacyl-PUFA phosphatidylcholines (PC-PUFA₂s) following fatty acid or phospholipid treatments, correlating with cancer cell sensitivity to ferroptosis. Depletion of PC-PUFA₂s occurred in aging and Huntington's disease brain tissue, linking it to ferroptosis. Notably, PC-PUFA₂s interacted with the mitochondrial electron transport chain, generating reactive oxygen species (ROS) for initiating lipid peroxidation. Mitochondria-targeted antioxidants protected cells from PC-PUFA₂-induced mitochondrial ROS (mtROS), lipid peroxidation, and cell death. These findings reveal a critical role for PC-PUFA₂s in controlling mitochondria homeostasis and ferroptosis in various contexts and explain the ferroptosis-modulating mechanisms of free fatty acids. PC-PUFA₂s may serve as diagnostic and therapeutic targets for modulating ferroptosis.

Keywords: PUFA; ROS; complex I; diacyl-PUFA phosphatidylcholine; electron transport chain; ferroptosis; lipids; mitochondria; phospholipid; polyunsaturated fatty acid.