title: Peroxidation of polyunsaturated fatty acids by lipoxygenases drives ferroptosis.
abstract: Ferroptosis is form of regulated nonapoptotic cell death that is involved in diverse disease contexts. Small molecules that inhibit glutathione peroxidase 4 (GPX4), a phospholipid peroxidase, cause lethal accumulation of lipid peroxides and induce ferroptotic cell death. Although ferroptosis has been suggested to involve accumulation of reactive oxygen species (ROS) in lipid environments, the mediators and substrates of ROS generation and the pharmacological mechanism of GPX4 inhibition that generates ROS in lipid environments are unknown. We report here the mechanism of lipid peroxidation during ferroptosis, which involves phosphorylase kinase G2 (PHKG2) regulation of iron availability to lipoxygenase enzymes, which in turn drive ferroptosis through peroxidation of polyunsaturated fatty acids (PUFAs) at the bis-allylic position; indeed, pretreating cells with PUFAs containing the heavy hydrogen isotope deuterium at the site of peroxidation (D-PUFA) prevented PUFA oxidation and blocked ferroptosis. We further found that ferroptosis inducers inhibit GPX4 by covalently targeting the active site selenocysteine, leading to accumulation of PUFA hydroperoxides. In summary, we found that PUFA oxidation by lipoxygenases via a PHKG2-dependent iron pool is necessary for ferroptosis and that the covalent inhibition of the catalytic selenocysteine in Gpx4 prevents elimination of PUFA hydroperoxides; these findings suggest new strategies for controlling ferroptosis in diverse contexts.
authors: Department of Biological Sciences, St. John's University, Queens, NY 11439; yangw@stjohns.edu bstockwell@columbia.edu.
authors: Wan Seok
authors: WS
authors: Yang
authors: Department of Biological Sciences, Columbia University, New York, NY 10027;
authors: Katherine J
authors: KJ
authors: Kim
authors: Department of Chemistry, Columbia University, New York, NY 10027;
authors: Michael M
authors: MM
authors: Gaschler
authors: Department of Medicine, New York University School of Medicine, New York, NY 10016;
authors: Milesh
authors: M
authors: Patel
authors: Retrotope, Inc., Los Altos, CA 94022.
authors: Mikhail S
authors: MS
authors: Shchepinov
authors: Department of Biological Sciences, Columbia University, New York, NY 10027; Department of Chemistry, Columbia University, New York, NY 10027; yangw@stjohns.edu bstockwell@columbia.edu.
authors: Brent R
authors: 0000-0002-3532-3868
authors: BR
authors: Stockwell
mesh_terms: D020134:Catalytic Domain; D016923:Cell Death / Q000187:drug effects* / Q000235:genetics; D045744:Cell Line, Tumor; D003903:Deuterium; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D005231:Fatty Acids, Unsaturated / Q000378:metabolism* / Q000494:pharmacology; D005786:Gene Expression Regulation; D005979:Glutathione Peroxidase / Q000235:genetics / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007501:Iron / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects; D008054:Lipid Peroxides / Q000096:biosynthesis; D058945:Lipoxygenases / Q000235:genetics / Q000378:metabolism*; D000080662:Phospholipid Hydroperoxide Glutathione Peroxidase; D010764:Phosphorylase Kinase / Q000235:genetics / Q000378:metabolism*; D021381:Protein Transport; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D017279:Selenocysteine / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D005231:Fatty Acids, Unsaturated; D008054:Lipid Peroxides; D011993:Recombinant Fusion Proteins; D017279:Selenocysteine; D049452:Green Fluorescent Proteins; D003903:Deuterium; D007501:Iron; D000080662:Phospholipid Hydroperoxide Glutathione Peroxidase; D005979:Glutathione Peroxidase; D058945:Lipoxygenases; D010764:Phosphorylase Kinase
keywords: Gpx4; PHKG2; PUFAs; ferroptosis; lipoxygenase