Particulate air pollutants and asthma

In vitro exposure to isoprene-derived secondary organic aerosol by direct deposition and its effects on <i>COX-2</i> and <i>IL-8</i> gene expression

“…The Electrostatic Aerosol in Vitro Exposure System (EAVES) used in this study deposits particles, generated in our outdoor photochemical chamber, directly onto lung cells by electrostatic precipitation (de Bruijne et al, 2009). Similar techniques and devices have been used to expose cells to diesel exhaust particles (Lichtveld et al, 2012;Hawley et al, 2014b), but our study is the first to utilize the EAVES to explore the potential adverse effects of isoprene SOA on human lung cells. Additionally, for a more atmospherically relevant exposure, isoprene SOA was photochemically generated in an outdoor chamber to mimic its formation in the atmosphere.…”

“…The outdoor chamber is a 120 m 3 triangular cross-section Teflon chamber located on the roof of the Gillings School of Global Public Health, University of North Carolina at Chapel Hill. The chamber facility has been described in detail elsewhere by Lichtveld et al (2012). The outdoor chamber facility is equipped with sampling lines that allow direct deposition exposure of cells, online chemical measurements, and filter collection for offline chemical analysis.…”

“…Compared to exposure of cells in culture media to resuspended particles, direct particle deposition likely provides a more biologically relevant exposure model and enhances sensitivity of cells to air pollution particle exposures (Volckens et al, 2009;Lichtveld et al, 2012;Hawley et al, 2014a, b;Zavala et al, 2014;Hawley and Volckens, 2013). The Electrostatic Aerosol in Vitro Exposure System (EAVES) used in this study deposits particles, generated in our outdoor photochemical chamber, directly onto lung cells by electrostatic precipitation (de Bruijne et al, 2009).…”

“…An in vitro study that followed supported the potential for isoprene SOA to affect the levels of oxidative stress genes . In this study we chose to examine the gene expression levels of interleukin-8 (IL-8) and cyclooxygenase-2 (COX-2), not only for their links to inflammation and oxidative stress (Kunkel et al, 1991;Uchida, 2008) but also because both have been examined in previous studies using the EAVES for fresh and aged diesel exhaust (Lichtveld et al, 2012). Other studies on air pollution mixtures have also examined IL-8 as a biological endpoint due to its involvement with inflammation (Zavala et al, 2014;Ebersviller et al, 2012a, b;Doyle et al, 2004Doyle et al, , 2007.…”

“…We have recently demonstrated through a chemical assay that isoprene-derived SOA has the potential for inducing reactive oxygen species (ROS) (Kramer et al, 2016), which are linked to oxidative stress and inflammation (Reuter et al, 2010;Li et al, 2003). An in vitro study that followed supported the potential for isoprene SOA to affect the levels of oxidative stress genes .…”