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Looking Beyond the Epithellium: Identifying Trans-Exposure Effects in the Vascular Endothellium
Citation:
Vitucci, E. AND S. McCullough. Looking Beyond the Epithellium: Identifying Trans-Exposure Effects in the Vascular Endothellium. 2018 Genetics and Environmental Mutagenesis Fall Meeting, Durham, NC, November 07, 2018.
Impact/Purpose:
Presentation of data collected from the development and use of a novel three-cell organotypic in vitro model of the small airways to explore the mechanisms responsible for the adverse effects of air pollutant exposure.
Description:
An estimated 3.5-million people die every year from air pollution-induced cardiovascular disease (API-CVD); however, while this induced CVD is associated with systemic oxidative stress, the causative molecular mechanisms driving API-CVD are still unconfirmed. To identify the mechanisms driving API-CVD, we developed a tri-culture in-vitro model that represents the interface of the alveolar epithelial barrier (AEB) and the cardiovascular system. We hypothesized that air pollutant exposure of human alveolar-like epithelial cells (H441s) would induce oxidative stress in human pulmonary vasculature cells leading to vascular damage. To test this hypothesis, we exposed confluent monolayers of H441s, grown on the apical surface of Transwell permeable membranes, to the air pollutant, diesel exhaust particulates (DEP), with human lung fibroblasts on the underside of the Transwell membrane and human microvascular lung endothelial cells (HULEC) in the basal compartment. Upon DEP exposure, we identified a variety of oxidative stress-responsive genes induced in the directly exposed H441s and in the indirectly exposed HULEC, including heme oxygenase 1 (HMOX-1) and NAD(P)H dehydrogenase [quinone] 1 (NQO1). These changes in gene expression occurred despite a lack of change in trans-epithelial electrical resistance (TEER) and small molecule (20kDa fluorescein isothiocyanate (FITC)-dextran) permeability of the H441s. Collectively, these data suggest that induction of oxidative stress in endothelial cells may be mediated by factors released from airway epithelial/fibroblast cells and may be a mechanism of API-CVD. We conclude that we have developed a relevant in-vitro model of the AEB-cardiovascular system interface which can be used to identify the elusive molecular mechanisms driving API-CVD.