Ultrafine and nanoparticles-induced oxidative stress: The role of heme oxygenase-1 and carbon monoxide as anti-inflammatory pathways

Introduction. Particulate matter (PM) is an environmental factor that has been associated with increased respiratory morbidity and mortality. The major effect of ambient PM on the pulmonary system is that it promotes inflammation in susceptible people. One of the mechanisms by which ambient PM exerts its proinflammatory effects is by generating increased oxidative stress induced by chemical compounds and metal constituents. Cellular responses to PM-induced oxidative stress include activation of antioxidant defense. Objective. To investigate the anti-inflammatory and anti-apoptotic roles of heme oxygenase-1 (HO-1) and carbon monoxide (CO) in the PM-induced oxidative stress arm, inflammation, and toxicity. Methods. Particle size analyses were performed according to a laser technique based on the time of transition theory using an Eyetech Analyzer (Donner Technologies Ltd., Israel). HO-1 was analyzed by quantitative reverse transcriptase polymerase chain reaction (RT-PCR) in induced sputum (IS) samples. Results. We demonstrate the feasibility of measuring micro- and nanoparticles in IS samples of exposed individuals in and out of the workplace to determine the protective role of HO-1 and CO. Conclusions. Ongoing studies will further elucidate the protective role of HO-1 and CO in the PM-induced oxidative stress model.