title: PM(10) impairs the antioxidant defense system and exacerbates oxidative stress driven cell death.
abstract: The aim of this study was to investigate the effect of airborne particulate matter with a mean aerodynamic diameter of < or =10microm (PM(10)) on oxidative stress markers and antioxidant enzymatic activity and its relevance in the face of acute oxidative challenge in a human lung epithelial cell line (A549). PM(10)-induced reactive oxygen species (ROS) generation and oxidative damage with no changes in cellular viability. In addition, PM(10) decreased glutathione (GSH) levels (54.9%) and the activity of the antioxidant enzymes superoxide dismutase (65%), catalase (31.2%), glutathione reductase (61.5%) and glutathione-S-transferase (42.39%). Trolox, a scavenger of reactive species, prevented the increase of ROS generation and the decrease in GSH levels but partially prevented PM(10)-induced oxidative damage. Interestingly, it was unable to avoid the decrease in the activity of antioxidant enzymes. Finally, the survival of the cells previously exposed to PM(10) and challenged with hydrogen peroxide was significantly lower. We conclude that the impairment in the antioxidant defense system induced by PM(10) weaken ROS detoxification which exacerbates cell death when these cells are exposed to an acute oxidative challenge.
authors.affiliation: Instituto Nacional de Cancerología, Tlalpan, Mexico D.F., Mexico.
authors.forename: Yolanda I
authors.initials: YI
authors.lastname: Chirino
authors.forename: Yesennia
authors.initials: Y
authors.lastname: Sánchez-Pérez
authors.forename: Alvaro R
authors.initials: AR
authors.lastname: Osornio-Vargas
authors.forename: Rocío
authors.initials: R
authors.lastname: Morales-Bárcenas
authors.forename: María Concepción
authors.initials: MC
authors.lastname: Gutiérrez-Ruíz
authors.forename: Yazmin
authors.initials: Y
authors.lastname: Segura-García
authors.forename: Irma
authors.initials: I
authors.lastname: Rosas
authors.forename: José
authors.initials: J
authors.lastname: Pedraza-Chaverri
authors.forename: Claudia M
authors.initials: CM
authors.lastname: García-Cuellar
mesh_terms: D000975:Antioxidants / Q000378:metabolism*; D016923:Cell Death / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D005978:Glutathione / Q000378:metabolism; D006801:Humans; D018384:Oxidative Stress / Q000187:drug effects*; D052638:Particulate Matter / Q000633:toxicity*; D017382:Reactive Oxygen Species / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D000975:Antioxidants; D052638:Particulate Matter; D017382:Reactive Oxygen Species; D013482:Superoxide Dismutase; D005978:Glutathione