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Am J Physiol Lung Cell Mol Physiol. 2015 Jul 15;309(2):L175-87. doi: 10.1152/ajplung.00411.2014. Epub 2015 May 15.

Endothelial disruptive proinflammatory effects of nicotine and e-cigarette vapor exposures.

Author information

1
Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana;
2
Department of Clinical Pharmacology, The Johns Hopkins University, Baltimore, Maryland;
3
Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana;
4
Department of Chemistry and Chemical Biology; Indiana University-Purdue University, Indianapolis, Indiana;
5
Department of Physics, Indiana University-Purdue University, Indianapolis, Indiana;
6
Queens College, City University of New York, Flushing, New York; and.
7
Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana; Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana; Richard L. Roudebush Veterans Affairs Medical Center, Indianapolis, Indiana ipetrach@iu.edu.

Abstract

The increased use of inhaled nicotine via e-cigarettes has unknown risks to lung health. Having previously shown that cigarette smoke (CS) extract disrupts the lung microvasculature barrier function by endothelial cell activation and cytoskeletal rearrangement, we investigated the contribution of nicotine in CS or e-cigarettes (e-Cig) to lung endothelial injury. Primary lung microvascular endothelial cells were exposed to nicotine, e-Cig solution, or condensed e-Cig vapor (1-20 mM nicotine) or to nicotine-free CS extract or e-Cig solutions. Compared with nicotine-containing extract, nicotine free-CS extract (10-20%) caused significantly less endothelial permeability as measured with electric cell-substrate impedance sensing. Nicotine exposures triggered dose-dependent loss of endothelial barrier in cultured cell monolayers and rapidly increased lung inflammation and oxidative stress in mice. The endothelial barrier disruptive effects were associated with increased intracellular ceramides, p38 MAPK activation, and myosin light chain (MLC) phosphorylation, and was critically mediated by Rho-activated kinase via inhibition of MLC-phosphatase unit MYPT1. Although nicotine at sufficient concentrations to cause endothelial barrier loss did not trigger cell necrosis, it markedly inhibited cell proliferation. Augmentation of sphingosine-1-phosphate (S1P) signaling via S1P1 improved both endothelial cell proliferation and barrier function during nicotine exposures. Nicotine-independent effects of e-Cig solutions were noted, which may be attributable to acrolein, detected along with propylene glycol, glycerol, and nicotine by NMR, mass spectrometry, and gas chromatography, in both e-Cig solutions and vapor. These results suggest that soluble components of e-Cig, including nicotine, cause dose-dependent loss of lung endothelial barrier function, which is associated with oxidative stress and brisk inflammation.

KEYWORDS:

cell proliferation; inflammation; permeability; sphingosine-1-phosphate; tobacco

PMID:
25979079
PMCID:
PMC4504977
DOI:
10.1152/ajplung.00411.2014
[Indexed for MEDLINE]
Free PMC Article

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