Alterations in mitochondrial function in endothelial and epithelial cells by plasma from E-cigarette users

Abstract

Background: Mitochondria play vital roles in cellular function and homeostasis. Inhalation of aerosols generated by E-cigarettes (E-Cig) may affect mitochondrial physiology. Data on risks of E-Cigs and vaping devices on mitochondria physiology remain incomplete. Our objective was to investigate novel effects of E-Cig plasma mediators on mitochondrial physiology in human endothelial (EA.hy 926) and lung epithelial cells (A549). Hypothesis: Plasma from E-Cig users will induce alterations in mitochondrial physiology. Methods: A longitudinal cohort study was conducted on subjects who used E-cigarettes (n=21) and 10 non-smoking, non-vaping controls. Inclusion criteria were active E-Cig use without known lung disease and with normal lung function, between the ages of 18-30 years. E-Cig use was confirmed with in-person interviews and plasma cotinine levels. Active E-Cig use was defined as use of >0.5-1 mL e-liquid/day or 3.5-7 mL/week for >6 months. Plasma was isolated and stored at -70°C. The metabolic stress effects of E-Cig plasma (1%, 1h conditioning) mediators were assessed in vitro on endothelial cells (8x104/well) and epithelial cells (5x104/well) using the Seahorse XF Energy phenotype Test. The mitochondrial copy number in E-Cig user plasma was estimated by digital droplet PCR. Membrane potentials and reactive oxygen species (ROS) were quantified by Cytation5. Results: E-Cig plasma altered the metabolic stress phenotype of mitochondria of EA.hy 926 and A549 cells. Metabolic stress was evidenced by increased oxygen consumption and glycolytic rates in both cell types. The mitochondria membrane potential and ROS levels significantly increased in E-Cig plasma subjected cells. Mitochondrial gene copy number levels were significantly increased in E-Cig user plasma suggesting mitochondrial stress in vivo. Conclusions: Plasma of E-cig users enhances maximal metabolic stress on human endothelial and lung cells in vitro and shows evidence for mitochondrial stress in vivo. These results may have important implications regarding the effects of E-Cig use on mitochondrial function and eventual public health recommendations. T31IP1929 and R21 AG058174-01A1 This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.