Abstracts

Abstract

Introduction/Background Cigarette smoking (CS) is the major cause of Chronic Obstructive Pulmonary Disease (COPD). Ecigarettes are considered by some as a safer alternative; however, inhalation of nicotine-containing e-cigarettes can also cause pathophysiologic changes, and 'vaping' of some substances has led to severe lung damage. Our group has previously identified the effect of CS or e-cigarettes in lung endothelial apoptosis and mitochondrial dysfunction. Objective(s) This study seeks to characterize the effects of CS or E-cig in lung endothelial dysfunction. Methods An important marker of mitochondrial dysfunction is excess mitochondrial ROS (mitoROS), and its production in lung ECs was assessed using MitoSOX reagent. Cytoskeleton rearrangement of ECs upon e-cigarette was assessed by immunofluorescence. Lung EC was exposed to E-cigarette extract (50 mg/ml), resulting in disruption of endothelial permeability assessed by Electric Cell Substrate Impedance (ECIS) and Transwell assay. Atomic Force Microscopy (AFM) was used to probe the biomechanical responses of the manipulated ECs upon e-cigarette challenge. Results Blocking mitoROS with Mito-TEMPO (10 mM, 3 h), a cell-permeable antioxidant, decreased mitochondrial superoxide production. We next assessed the role of Mito-TEMPO on Ecigarette-induced endothelial permeability. Pretreatment with Mito-TEMPO provided barrier protection upon e-cigarette challenge. These results suggest a key role of mitoROS in ecigarette-induced endothelial permeability. E-cigarette exposure induces cytoskeleton rearrangement leading to gap formation in lung EC, as well as alters elastic properties of ECs as measured by AFM. Conclusion This study provides novel mitochondrial and biophysical characterization of the effects of e-cigarette exposure on lung EC and advances our understanding of its pathophysiologic effects.