title: Genome-wide identification and characterization of transcripts translationally regulated by bacterial lipopolysaccharide in macrophage-like J774.1 cells.
abstract: Although Escherichia coli LPS is known to elicit various proinflammatory responses in macrophages, its effect on the translational states of transcripts has not yet been explored on a genome-wide scale. To address this, we investigated the mRNA profiles in polysomal and free messenger ribonucleoprotein particle (mRNP) fractions of mouse macrophage-like J774.1 cells, using Affymetrix Mouse Genome 430 2.0 GeneChips. Comparison of the mRNA profiles in total cellular, polysomal, and free mRNP fractions enabled us to identify transcripts that were modulated at the translational level by LPS: among 19,791 transcripts, 115 and 418 were up- and downregulated at 1, 2, or 4 h after LPS stimulation (100 ng/ml) in a translation-dependent manner. Interestingly, gene ontology-based analysis suggested that translation-dependent downregulated genes frequently include those encoding proteins in the mitochondrial respiratory chain. In fact, the mRNA levels of some transcripts for complexes I, IV, and V in the mitochondrial respiratory chain were translationally downregulated, eventually contributing to the decline of their protein levels. Moreover, the amount of metabolically labeled cytochrome oxidase subunit Va in complex IV was decreased without any change of its mRNA level in total cellular fraction after LPS stimulation. Consistently, the total amounts and activities of complexes I and IV were attenuated by LPS stimulation, and the attenuation was independent of nitric oxide. These results demonstrated that translational suppression may play a critical role in the LPS-mediated attenuation of mitochondrial oxidative phosphorylation in a nitric oxide-independent manner in J774.1 cells.
authors.affiliation: Laboratories for Immunogenomics, RIKEN Research Center for Allergy and Immunology, Yokohama, Japan. ktmr@rcai.riken.jp
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kitamura
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Ito
authors.forename: Tomoko
authors.initials: T
authors.lastname: Yuasa
authors.forename: Chisato
authors.initials: C
authors.lastname: Kikuguchi
authors.forename: Atsushi
authors.initials: A
authors.lastname: Hijikata
authors.forename: Michiyo
authors.initials: M
authors.lastname: Takayama
authors.forename: Yayoi
authors.initials: Y
authors.lastname: Kimura
authors.forename: Ryo
authors.initials: R
authors.lastname: Yokoyama
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Kaji
authors.forename: Osamu
authors.initials: O
authors.lastname: Ohara
mesh_terms: D000818:Animals; D002460:Cell Line; D004579:Electron Transport / Q000187:drug effects / Q000235:genetics; D004926:Escherichia coli / Q000737:chemistry; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000187:drug effects; D016678:Genome; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008264:Macrophages / Q000187:drug effects* / Q000378:metabolism; D051379:Mice; D008954:Models, Biological; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D020411:Oligonucleotide Array Sequence Analysis; D014176:Protein Biosynthesis / Q000187:drug effects*; D012333:RNA, Messenger / Q000145:classification / Q000187:drug effects / Q000378:metabolism*
chemical_list: D008070:Lipopolysaccharides; D012333:RNA, Messenger; D019331:NG-Nitroarginine Methyl Ester