title: Hypersensitivity of aryl hydrocarbon receptor-deficient mice to lipopolysaccharide-induced septic shock.
abstract: Aryl hydrocarbon receptor (AhR), a ligand-activated transcription factor, is known to mediate a wide variety of pharmacological and toxicological effects caused by polycyclic aromatic hydrocarbons. Recent studies have revealed that AhR is involved in the normal development and homeostasis of many organs. Here, we demonstrate that AhR knockout (AhR KO) mice are hypersensitive to lipopolysaccharide (LPS)-induced septic shock, mainly due to the dysfunction of their macrophages. In response to LPS, bone marrow-derived macrophages (BMDM) of AhR KO mice secreted an enhanced amount of interleukin-1beta (IL-1beta). Since the enhanced IL-1beta secretion was suppressed by supplementing Plasminogen activator inhibitor-2 (Pai-2) expression through transduction with Pai-2-expressing adenoviruses, reduced Pai-2 expression could be a cause of the increased IL-1beta secretion by AhR KO mouse BMDM. Analysis of gene expression revealed that AhR directly regulates the expression of Pai-2 through a mechanism involving NF-kappaB but not AhR nuclear translocator (Arnt), in an LPS-dependent manner. Together with the result that administration of the AhR ligand 3-methylcholanthrene partially protected mice with wild-type AhR from endotoxin-induced death, these results raise the possibility that an appropriate AhR ligand may be useful for treating patients with inflammatory disorders.
authors.affiliation: The Center for Tsukuba Advanced Research Alliance and Institute of Basic Medical Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba 305-8577, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Sekine
authors.forename: Junsei
authors.initials: J
authors.lastname: Mimura
authors.forename: Motohiko
authors.initials: M
authors.lastname: Oshima
authors.forename: Hiromi
authors.initials: H
authors.lastname: Okawa
authors.forename: Jun
authors.initials: J
authors.lastname: Kanno
authors.forename: Katsuhide
authors.initials: K
authors.lastname: Igarashi
authors.forename: Frank J
authors.initials: FJ
authors.lastname: Gonzalez
authors.forename: Togo
authors.initials: T
authors.lastname: Ikuta
authors.forename: Kaname
authors.initials: K
authors.lastname: Kawajiri
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Fujii-Kuriyama
mesh_terms: D000818:Animals; D051784:Aryl Hydrocarbon Receptor Nuclear Translocator / Q000235:genetics / Q000378:metabolism; D051792:Basic Helix-Loop-Helix Proteins; D001854:Bone Marrow Cells / Q000166:cytology / Q000378:metabolism; D002478:Cells, Cultured; D016207:Cytokines / Q000276:immunology; D020869:Gene Expression Profiling; D006801:Humans; D053583:Interleukin-1beta / Q000276:immunology; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008264:Macrophages / Q000166:cytology / Q000187:drug effects* / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D020411:Oligonucleotide Array Sequence Analysis; D017396:Plasminogen Activator Inhibitor 2 / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic; D018336:Receptors, Aryl Hydrocarbon / Q000235:genetics / Q000378:metabolism*; D012772:Shock, Septic / Q000139:chemically induced* / Q000276:immunology
chemical_list: D051784:Aryl Hydrocarbon Receptor Nuclear Translocator; D051792:Basic Helix-Loop-Helix Proteins; D016207:Cytokines; D053583:Interleukin-1beta; D008070:Lipopolysaccharides; D017396:Plasminogen Activator Inhibitor 2; D018336:Receptors, Aryl Hydrocarbon; C484722:Ahr protein, mouse; C497397:Arnt protein, mouse