title: Carbon monoxide-releasing antibacterial molecules target respiration and global transcriptional regulators.
abstract: Carbon monoxide, a classical respiratory inhibitor, also exerts vasodilatory, anti-inflammatory, and antiapoptotic effects. CO-releasing molecules have therapeutic value, increasing phagocytosis and reducing sepsis-induced lethality. Here we identify for the first time the bacterial targets of Ru(CO)(3)Cl(glycinate) (CORM-3), a ruthenium-based carbonyl that liberates CO rapidly under physiological conditions. Contrary to the expectation that CO would be preferentially inhibitory at low oxygen tensions or anaerobically, Escherichia coli cultures were also sensitive to CORM-3 at concentrations equimolar with oxygen. CORM-3, assayed as ruthenium, was taken up by bacteria and rapidly delivered CO intracellularly to terminal oxidases. Microarray analysis of CORM-3-treated cells revealed extensively modified gene expression, notably down-regulation of genes encoding key aerobic respiratory complexes. Genes involved in metal metabolism, homeostasis, or transport were also differentially expressed, and free intracellular zinc levels were elevated. Probabilistic modeling of transcriptomic data identified the global transcription regulators ArcA, CRP, Fis, FNR, Fur, BaeR, CpxR, and IHF as targets and potential CO sensors. Our discovery that CORM-3 is an effective inhibitor and global regulator of gene expression, especially under aerobic conditions, has important implications for administration of CO-releasing agents in sepsis and inflammation.
authors.affiliation: Department of Molecular Biology and Biotechnology, The University of Sheffield, Firth Ct., Western Bank, Sheffield S10 2TN, United Kingdom.
authors.forename: Kelly S
authors.initials: KS
authors.lastname: Davidge
authors.forename: Guido
authors.initials: G
authors.lastname: Sanguinetti
authors.forename: Chu Hoi
authors.initials: CH
authors.lastname: Yee
authors.forename: Alan G
authors.initials: AG
authors.lastname: Cox
authors.forename: Cameron W
authors.initials: CW
authors.lastname: McLeod
authors.forename: Claire E
authors.initials: CE
authors.lastname: Monk
authors.forename: Brian E
authors.initials: BE
authors.lastname: Mann
authors.forename: Roberto
authors.initials: R
authors.lastname: Motterlini
authors.forename: Robert K
authors.initials: RK
authors.lastname: Poole
mesh_terms: D000693:Anaerobiosis / Q000187:drug effects / Q000502:physiology; D000900:Anti-Bacterial Agents / Q000378:metabolism / Q000494:pharmacology*; D002248:Carbon Monoxide / Q000378:metabolism / Q000494:pharmacology*; D048168:Escherichia coli K12 / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000096:biosynthesis* / Q000235:genetics; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects*; D020411:Oligonucleotide Array Sequence Analysis; D009942:Organometallic Compounds / Q000378:metabolism / Q000494:pharmacology*; D014157:Transcription Factors / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D029968:Escherichia coli Proteins; D009942:Organometallic Compounds; D014157:Transcription Factors; C476530:tricarbonylchloro(glycinato)ruthenium(II); D002248:Carbon Monoxide