Mechanism of oxidative DNA damage induction in a strict anaerobe, Prevotella melaninogenica.
We investigated the mechanism of the oxidative DNA damage induction by exposure to O(2) in Prevotella melaninogenica, a strict anaerobe. Flow cytometry with hydroethidine and dichlorofluorescein diacetate showed that O(2) exposure generated O(2)*-) and H(2)O(2). Results of electron spin resonance with alpha-(4-pyridyl-1-oxide)-N-tert-butylnitrone and ethanol showed that O(2) exposure also induced *OH radical generation in P. melaninogenica loaded with FeCl(2) but not in samples without FeCl(2) loading. In P. melaninogenica, O(2) exposure increased 8-hydroxydeoxyguanosine (8OHdG), typical of oxidative DNA damage. Catalase inhibited the increase, but the *OH radical scavengers did not. Phenanthroline, a membrane-permeable Fe and Cu chelator, increased the 8OHdG induction. In FeCl(2)-loaded samples, induction of 8OHdG decreased. Addition of H(2)O(2) markedly increased 8OHdG levels. These results indicate that in P. melaninogenica, exposure to O(2) generated and accumulated O(2)* and H(2)O(2), and that a crypto-OH radical generated through H(2)O(2) was the active species in the 8OHdG induction.
Takeuchi
T
T
Department of Hygiene, Faculty of Medicine, Kagoshima University, Kagoshima, Japan. takeuchi@m.kufm.kagoshima-u.ac.jp
Kato
N
N
Watanabe
K
K
Morimoto
K
K
D000080242:8-Hydroxy-2'-Deoxyguanosine; D000693:Anaerobiosis; D004249:DNA Damage; D003849:Deoxyguanosine / Q000031:analogs & derivatives* / Q000378:metabolism; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods; D005434:Flow Cytometry / Q000379:methods; D006861:Hydrogen Peroxide / Q000378:metabolism; D017665:Hydroxyl Radical / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism / Q000494:pharmacology*; D001443:Prevotella melaninogenica / Q000187:drug effects / Q000235:genetics* / Q000502:physiology; D017382:Reactive Oxygen Species / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism
D017382:Reactive Oxygen Species; D013481:Superoxides; D017665:Hydroxyl Radical; D000080242:8-Hydroxy-2'-Deoxyguanosine; D006861:Hydrogen Peroxide; D003849:Deoxyguanosine; D010100:Oxygen