Parole chiave: Hydrogen Peroxide, Nitric Oxide, Article, Bacterial Gene, Bactericidal Activity, Controlled Study, Cytotoxicity, Dna Strand Breakage, Escherichia Coli, Macrophage, Nonhuman, Priority Journal, Catalase, Cell Hypoxia, Comparative Study, Deferoxamine, Diethylamines, Dna Damage, Drug Synergism, Glutathione, Isoenzymes, Neutrophils, Siderophores, Superoxide Dismutase,
Radiation Biology Branch, National Cancer Institute, Bethesda, MD 20892-1002, United States Laboratory of Pathology, National Cancer Institute, Bethesda, MD 20892-1002, United States Molecular Biology Department, Hebrew University Medical School, Jerusalem 91010, Israel
Previously, we reported that nitric oxide (NO) provides significant protection to mammalian cells from the cytotoxic effects of hydrogen peroxide (H2O2). Murine neutrophils and activated macrophages, however, produce NO, H2O2, and other reactive oxygen species to kill microorganisms, which suggests a paradox. In this study, we treated bacteria (Escherichia coli) with NO and H2O2 for 30 min and found that exposure to NO resulted in minimal toxicity, but greatly potentiated (up to 1,000-fold) H2O2-mediated killing, as evaluated by a clonogenic assay. The combination of NO/H2O2 induced DNA double strand breaks in the bacterial genome, as shown by field-inverted gel electrophoresis, and this increased DNA damage may correlate with cell killing. NO was also shown to alter cellular respiration and decrease the concentration of the antioxidant glutathione to a residual level of 15-20% in bacterial cells. The iron chelator desferrioxamine did not stop the action of NO on respiration and glutathione decrease, yet it prevented the NO/H2O2 synergistic cytotoxicity, implicating metal ions as critical participants in the NO/H2O2 cytocidal mechanism. Our results suggest a possible mechanism of modulation H2O2-mediated toxicity, and we propose a new key role in the antimicrobial macrophagic response for NO.
Testino G, Leone S, Fagoonee S, Del Bas JM, Rodriguez B, Puiggros F, Marine S, Rodriguez MA, Morina D, Armengol L, Caimari A, Arola L, Cimini FA, Barchetta I, Carotti S, Bertoccini L, Baroni MG, Vespasiani-gentilucci U, Cavallo MG, Morini S, Nelson JE, Roth CL, Wilson LA, Yates KP, Aouizerat B, Morgan-stevenson V, Whalen E, Hoofnagle A, Mason M, Gersuk V, Yeh MM, Kowdley KV, Lee SM, Jun DW, Cho YK, Jang KS, Kucukazman M, Ata N, Dal K, Yeniova AO, Kefeli A, Basyigit S, Aktas B, Akin KO, Agladioglu K, Ure OS, Topal F, Nazligul Y, Beyan E, Ertugrul DT, Catena C, Cosma C, Camozzi V, Plebani M, Ermani M, Sechi LA, Fallo F, Goto Y, Ray MB, Mendenhall CL, French SW, Gartside PS Serum vitamin A deficiency and increased intrahepatic expression of cytokeratin antigen in alcoholic liver disease(6 visite) Hepatology (ISSN: 1827-1669electronic, 0026-4806linking), 1988 Sep; 83120693611123109(5): 1019-1026. Impact Factor:0.913 DettagliEsporta in BibTeXEsporta in EndNote
309 Records (303 escludendo Abstract e Conferenze). Impact factor totale: 1161.098 (1131.365 escludendo Abstract e Conferenze). Impact factor a 5 anni totale: 1258.923 (1220.371 escludendo Abstract e Conferenze).