Abstract 9929: Inhibition of Receptor for Advanced Glycation End Products (RAGE) Reduces E-Cigarette-Induced Increase in Endothelial Permeability

Abstract

Introduction: A growing body of research has linked e-cigarette (e-cig) use and vascular dysfunction. However, the molecular mechanism of endothelial function impairment from e-cig use is relatively unknown. We investigated how e-cig use affects endothelial permeability and its regulation by the receptor for advanced glycation end products (RAGE) pathway. Hypothesis: E-cig use increases endothelial permeability compared to both cigarette users and non-users via increasing ligands of RAGE. Methods: We recruited 120 healthy participants who either chronically use e-cigs (n=42), cigarettes (n=28), or no products (n=50), with no dual users. Serum levels of the RAGE ligand subunit S100A8 and the complete RAGE ligand calprotectin were quantified by Luminex and ELISA. Endothelial permeability was measured in cultured human lung microvascular endothelial cells (HMVEC-Ls) that were incubated in all participants’ sera individually by using electric cell-substrate impedance sensing (ECIS). 1 ug/mL of FPS-ZM1 (RAGE inhibitor) and TAK-242 (TLR4 inhibitor) diluted in DMSO were administered to HMVEC-Ls with individual sera. 200 pg/mL of calprotectin and DMSO were administered as positive and negative controls. Results: Incubation of HMVEC-Ls with e-cig users’ sera significantly increased endothelial permeability compared to sera from cigarette smokers and non-users. There was no significant difference in calprotectin serum levels, but S100A8 level was significantly and substantially higher in e-cig users’ sera than in smokers’ and non-user’s sera. Inhibition of RAGE, but not of TLR4, significantly reduced permeability only in e-cig users’ sera compared to vehicle. Conclusions: Endothelial permeability resulting from e-cig use relies on activation of the RAGE pathway and can be partially prevented by inhibition of RAGE.