Oxidative stress induction by short time exposure to ozone on THP-1 cells.

Ozone is a major component of air pollution mainly formed by photochemical reactions of nitrogen oxides with volatile organic compounds and/or carbon monoxide. Numerous studies have shown the association between ozone exposure with pulmonary injuries. This pollutant is a strong oxidant exerting its biological action either by direct reaction with target molecules or by generating reactive oxygen species which result in its biological effects and its toxicity. In order to study the effects of an induced oxidative stress by ozone on THP-1 cell, a human macrophage-like cell line, we used an in vitro system which has been previously used to study the rapid responses to ozone exposure. Using this system, THP-1 cells were subjected to short time exposure (30 min) followed by different incubation times ranging from 4 to 24 h. Our results show that ozone exposure provokes an alteration of the cell membrane translating an induction of lipid peroxidation resulting in a 3.2-fold increase of thiobarbituric reactive substances (TBARS), an increase by 35% of heme oxygenase-1 (HO-1) expression, and significant modifications of the redox status evaluated by glutathione measurement and of antioxidant enzyme activities in THP-1 cells. Our in vitro model constitutes a very interesting tool for the measurement of ozone effect on rapid modifications induced by this pollutant as well as intracellular modifications due to an oxidative stress.