title: Evaluation of Oxidative Stress Markers in Human Conjunctival Epithelial Cells Exposed to Diesel Exhaust Particles (DEP).
abstract: OBJECTIVE
  The aim of this study was to evaluate oxidative stress markers in human conjunctival epithelial cells (IOBA-NHC) exposed to diesel exhaust particles (DEP).
  
  
  METHODS
  Reactive oxygen (ROS) and nitrogen (RNS) species production; hydrogen peroxide (H2O2) levels; protein oxidation; antioxidant enzymes activities (superoxide dismutase [SOD], catalase [CAT], glutathione peroxidase [GPx], glutathione S-transferase [GST], and glutathione reductase [GR]); total reactive antioxidant potential (TRAP); reduced (GSH) and oxidized glutathione (GSSG) were evaluated. Transmission electron microscopy was performed to evaluate DEP uptake.
  
  
  RESULTS
  Diesel exhaust particles were entrapped by membrane protrusions developed by IOBA-NHC. Cells exposed to DEP 50 and 100 μg/mL showed a significant increase in ROS, RNS, H2O2 levels, SOD, GPx, and GST compared with the control group. A significant decay in GR was observed in both groups, meanwhile CAT levels remained unchanged. The group exposed to DEP 100 μg/mL displayed a significant increase in protein oxidation. In both groups, TRAP was significantly reduced as well as the GSH/GSSG ratio.
  
  
  CONCLUSIONS
  The decrease in nonenzymatic antioxidants and the compensatory increase of SOD, GPX, and GST activities are consequence of the increase in ROS and RNS production due to DEP exposure and its accumulation inside the cells. The decay in GR activity leads to the decrease in GSH/GSSG recycling. These results suggest that oxidative stress could play an important role in the development of DEP effects on human conjunctival epithelial cells.
authors.affiliation: General and Inorganic Chemistry Division IBIMOL UBA-CONICET, School of Pharmacy and Biochemistry, University of Buenos Aires, Buenos Aires, Argentina.
authors.forename: Romina M
authors.initials: RM
authors.lastname: Lasagni Vitar
authors.affiliation: Ocular Investigation Laboratory, Pathology Department, School of Medicine, University of Buenos Aires, Buenos Aires, Argentina.
authors.forename: Julia
authors.initials: J
authors.lastname: Tau
authors.affiliation: General and Inorganic Chemistry Division IBIMOL UBA-CONICET, School of Pharmacy and Biochemistry, University of Buenos Aires, Buenos Aires, Argentina.
authors.forename: Claudia G
authors.initials: CG
authors.lastname: Reides
authors.affiliation: Ocular Investigation Laboratory, Pathology Department, School of Medicine, University of Buenos Aires, Buenos Aires, Argentina.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Berra
authors.affiliation: General and Inorganic Chemistry Division IBIMOL UBA-CONICET, School of Pharmacy and Biochemistry, University of Buenos Aires, Buenos Aires, Argentina.
authors.forename: Sandra M
authors.initials: SM
authors.lastname: Ferreira
authors.affiliation: General and Inorganic Chemistry Division IBIMOL UBA-CONICET, School of Pharmacy and Biochemistry, University of Buenos Aires, Buenos Aires, Argentina.
authors.forename: Susana F
authors.initials: SF
authors.lastname: Llesuy
mesh_terms: D015415:Biomarkers / Q000378:metabolism; D002478:Cells, Cultured; D003228:Conjunctiva / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D006801:Humans; D046529:Microscopy, Electron, Transmission; D018384:Oxidative Stress / Q000502:physiology*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D001335:Vehicle Emissions
chemical_list: D015415:Biomarkers; D017382:Reactive Oxygen Species; D001335:Vehicle Emissions