title: Protection of human keratinocyte mtDNA by low-level nitric oxide.
abstract: This study was designed to evaluate the DNA damaging effects of nitric oxide and to determine whether the endogenous generation of nitric oxide at low levels in the cell exerts a protective effect against this damage. Damage to mitochondrial and nuclear DNA in normal human epidermal keratinocytes (NHEK) was assessed after treatment of these cells with varying concentrations of S-nitroso-N-acetylpenicillamine, which decomposes to release nitric oxide. The results showed that mitochondrial DNA was more vulnerable to nitric oxide-induced damage than was a similarly sized fragment of the beta-globin gene. To evaluate the effects on DNA damage by pretreatment of cells with low-levels of nitric oxide, NHEK cells were treated with the prodrug V-PYRRO/NO. This agent is metabolized inside these cells and releases small quantities of nitric oxide. The cells then were exposed to damaging amounts of nitric oxide produced by S-nitroso-N-acetylpenicillamine. The results of these studies showed that pretreatment of NHEK cells with V-PYRRO/NO attenuated the mtDNA damage and loss of cell viability produced by exposure to S-nitroso-N-acetylpenicillamine.
authors.affiliation: Department of Cell Biology and Neuroscience, University of South Alabama, Mobile, Alabama 36688-0002, USA.
authors.forename: I
authors.initials: I
authors.lastname: Shokolenko
authors.forename: T M
authors.initials: TM
authors.lastname: Oberyszyn
authors.forename: S M
authors.initials: SM
authors.lastname: D'Ambrosio
authors.forename: J E
authors.initials: JE
authors.lastname: Saavedra
authors.forename: L K
authors.initials: LK
authors.lastname: Keefer
authors.forename: S P
authors.initials: SP
authors.lastname: LeDoux
authors.forename: G L
authors.initials: GL
authors.lastname: Wilson
authors.forename: F M
authors.initials: FM
authors.lastname: Robertson
mesh_terms: D001483:Base Sequence; D002460:Cell Line; D004249:DNA Damage; D017931:DNA Primers; D004272:DNA, Mitochondrial / Q000502:physiology*; D006801:Humans; D015603:Keratinocytes / Q000378:metabolism*; D009569:Nitric Oxide / Q000502:physiology*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D010396:Penicillamine / Q000031:analogs & derivatives* / Q000494:pharmacology
chemical_list: D017931:DNA Primers; D004272:DNA, Mitochondrial; D020030:Nitric Oxide Donors; C110881:S-nitro-N-acetylpenicillamine; D009569:Nitric Oxide; D010396:Penicillamine