Reactive oxygen species (ROS) such as hydrogen peroxide and hydroxyl radicals are generated intracellularly or when cells are being exposed to exogenous agents, for example, air pollutants. Results from previous studies have demonstrated that prolonged exposure to excess ROS can induce oxidative stress and cause DNA damages, of which some may eventually lead to various human diseases like cancers and cardiopulmonary diseases. 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dG), one of the major and abundant DNA oxidation products, may serve as a biological dosimeters of exposure to oxidative stress induced from particulate matter 2.5 (PM2.5) and for risk assessment. LC-MS/MS with isotope dilution method of high sensitivity and selectivity and HPLC-DAD method for respectively quantitat...[ Read more ]

Reactive oxygen species (ROS) such as hydrogen peroxide and hydroxyl radicals are generated intracellularly or when cells are being exposed to exogenous agents, for example, air pollutants. Results from previous studies have demonstrated that prolonged exposure to excess ROS can induce oxidative stress and cause DNA damages, of which some may eventually lead to various human diseases like cancers and cardiopulmonary diseases. 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dG), one of the major and abundant DNA oxidation products, may serve as a biological dosimeters of exposure to oxidative stress induced from particulate matter 2.5 (PM2.5) and for risk assessment. LC-MS/MS with isotope dilution method of high sensitivity and selectivity and HPLC-DAD method for respectively quantitating the levels of 8-oxo-dG and 2'-deoxyguanosine (dG) were developed, and applied for the oxidative stress response studies. The research aims to explore the responses of Ct-DNA and cells exposed to the oxidative stress induced by Fe(II)-EDTA and PM2.5, through quantitating 8-oxo-dG in the genomic DNA and extracellular fluid (ECF) of toxicants exposed cells. The results improve our understanding on the roles of different organic and aqueous fraction components in PM2.5 toxicity, thus filling the gap of poorly understood chemical toxicology of human exposure to ambient particulate matters, including iron and other trace transition metals in PM2.5.