title: Production of reactive oxygen and nitrogen species in phagocytes is regulated by taurine chloramine.
abstract: Taurine is abundantly present in phagocytic cells and provides protection against cytotoxicity caused by reactive oxygen species (ROS). The reaction between taurine and HOCl, a toxic product of the myeloperoxidase (MPO) system, generates a more stable and less toxic product, taurine chloramine (TauCl). TauCl has also been shown to inhibit the production of superoxide anion (O2-) and nitric oxide (NO). In this review, we compare the effect of taurine and TauCl on the production of these reactive species in phagocytes. First, TauCl inhibit PMA-derived O2- production and this is associated with inhibition of p47phox phosphorylation and of p47phox and p67phox translocation. Second, TauCl inhibits LPS-induced iNOS expression and NO production. This occurs by direct inhibition of Ras activation, ERK1/2 phosphorylation and NF-kappaB activation. Third, TauCl by itself increases the expression of heme oxygenase-1 (HO-1) and enhances HO activity. Carbon monoxide (CO), a product of HO activity, is able to inhibit both O2- and NO production. Combined, these effects of TauCl appear to provide cytoprotection against the inadvertent cytotoxicity caused by overproduction of O2- and NO.
authors.affiliation: Laboratory for Leukocyte Signaling Research and Center for Advanced Medical Education by BK21 Project, Incheon, Korea. chaekyun@inha.ac.kr
authors.forename: Chaekyun
authors.initials: C
authors.lastname: Kim
authors.forename: Young-Nam
authors.initials: YN
authors.lastname: Cha
mesh_terms: D000818:Animals; D002248:Carbon Monoxide / Q000378:metabolism; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D006801:Humans; D019255:NADPH Oxidases / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II / Q000096:biosynthesis; D010586:Phagocytes / Q000187:drug effects / Q000378:metabolism*; D010766:Phosphorylation; D021381:Protein Transport; D026361:Reactive Nitrogen Species / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013654:Taurine / Q000031:analogs & derivatives* / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
chemical_list: D016328:NF-kappa B; D026361:Reactive Nitrogen Species; D017382:Reactive Oxygen Species; D013654:Taurine; C043410:N-chlorotaurine; D002248:Carbon Monoxide; D052247:Nitric Oxide Synthase Type II; D019255:NADPH Oxidases; C060505:neutrophil cytosolic factor 1; D048049:Extracellular Signal-Regulated MAP Kinases; D013755:Tetradecanoylphorbol Acetate