title: PGE2 induced in and released by dying cells functions as an inhibitory DAMP.
abstract: Cellular components released into the external milieu as a result of cell death and sensed by the body are generally termed damage-associated molecular patterns (DAMPs). Although DAMPs are conventionally thought to be protective to the host by evoking inflammatory responses important for immunity and wound repair, there is the prevailing notion that dysregulated release of DAMPs can also underlie or exacerbate disease development. However, the critical issue for how resultant DAMP-mediated responses are regulated has heretofore not been fully addressed. In the present study, we identify prostaglandin E2 (PGE2) as a DAMP that negatively regulates immune responses. We show that the production of PGE2 is augmented under cell death-inducing conditions via the transcriptional induction of the cyclooxygenase 2 (COX2) gene and that cell-released PGE2 suppresses the expression of genes associated with inflammation, thereby limiting the cell's immunostimulatory activities. Consistent with this, inhibition of the PGE2 synthesis pathway potentiates the inflammation induced by dying cells. We also provide in vivo evidence for a protective role of PGE2 released upon acetaminophen-induced liver injury as well as a pathogenic role for PGE2 during tumor cell growth. Our study places this classically known lipid mediator in an unprecedented context-that is, an inhibitory DAMP vis-à-vis activating DAMPs, which may have translational implications for designing more effective therapeutic regimens for inflammation-associated diseases.
authors.affiliation: Department of Molecular Immunology, Institute of Industrial Science, The University of Tokyo, Komaba 4-6-1, Meguro-ku, Tokyo 153-8505, Japan; Max Planck-The University of Tokyo Center for Integrative Inflammology, Komaba 4-6-1, Meguro-ku, Tokyo 153-8505, Japan;
authors.forename: Sho
authors.initials: S
authors.lastname: Hangai
authors.affiliation: Department of Molecular Immunology, Institute of Industrial Science, The University of Tokyo, Komaba 4-6-1, Meguro-ku, Tokyo 153-8505, Japan;
authors.forename: Tomoka
authors.initials: T
authors.lastname: Ao
authors.affiliation: Department of Molecular Immunology, Institute of Industrial Science, The University of Tokyo, Komaba 4-6-1, Meguro-ku, Tokyo 153-8505, Japan;
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Kimura
authors.affiliation: Department of Molecular Immunology, Institute of Industrial Science, The University of Tokyo, Komaba 4-6-1, Meguro-ku, Tokyo 153-8505, Japan;
authors.forename: Kosuke
authors.initials: K
authors.lastname: Matsuki
authors.affiliation: Laboratory for System Biology and Medicine, Research Center for Advanced Science and Technology, The University of Tokyo, Komaba 4-6-1, Meguro-ku, Tokyo 153-8904, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kawamura
authors.affiliation: Department of Molecular Immunology, Institute of Industrial Science, The University of Tokyo, Komaba 4-6-1, Meguro-ku, Tokyo 153-8505, Japan; Max Planck-The University of Tokyo Center for Integrative Inflammology, Komaba 4-6-1, Meguro-ku, Tokyo 153-8505, Japan;
authors.forename: Hideo
authors.initials: H
authors.lastname: Negishi
authors.affiliation: Department of Molecular Immunology, Institute of Industrial Science, The University of Tokyo, Komaba 4-6-1, Meguro-ku, Tokyo 153-8505, Japan; Max Planck-The University of Tokyo Center for Integrative Inflammology, Komaba 4-6-1, Meguro-ku, Tokyo 153-8505, Japan;
authors.forename: Junko
authors.initials: J
authors.lastname: Nishio
authors.affiliation: Laboratory for System Biology and Medicine, Research Center for Advanced Science and Technology, The University of Tokyo, Komaba 4-6-1, Meguro-ku, Tokyo 153-8904, Japan.
authors.forename: Tatsuhiko
authors.initials: T
authors.lastname: Kodama
authors.affiliation: Department of Molecular Immunology, Institute of Industrial Science, The University of Tokyo, Komaba 4-6-1, Meguro-ku, Tokyo 153-8505, Japan; Max Planck-The University of Tokyo Center for Integrative Inflammology, Komaba 4-6-1, Meguro-ku, Tokyo 153-8505, Japan; tada@m.u-tokyo.ac.jp.
authors.forename: Tadatsugu
authors.initials: T
authors.lastname: Taniguchi
authors.affiliation: Department of Molecular Immunology, Institute of Industrial Science, The University of Tokyo, Komaba 4-6-1, Meguro-ku, Tokyo 153-8505, Japan; Max Planck-The University of Tokyo Center for Integrative Inflammology, Komaba 4-6-1, Meguro-ku, Tokyo 153-8505, Japan;
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Yanai
mesh_terms: D000082:Acetaminophen / Q000009:adverse effects; D000067531:Alarmins / Q000378:metabolism*; D000818:Animals; D016923:Cell Death / Q000276:immunology* / Q000502:physiology; D045744:Cell Line, Tumor; D056486:Chemical and Drug Induced Liver Injury / Q000276:immunology; D051546:Cyclooxygenase 2 / Q000096:biosynthesis*; D015232:Dinoprostone / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D007249:Inflammation / Q000276:immunology / Q000473:pathology*; D008070:Lipopolysaccharides; D051379:Mice; D008810:Mice, Inbred C57BL
chemical_list: D000067531:Alarmins; D008070:Lipopolysaccharides; D000082:Acetaminophen; C077623:Ptgs2 protein, mouse; D051546:Cyclooxygenase 2; D015232:Dinoprostone
keywords: DAMP; PGE2; cell death; inflammation; tumor regulation