Cell Type- and Exposure-Specific Modulation of CD63/CD81-Positive and Tissue Factor-Positive Extracellular Vesicle Release in response to Respiratory Toxicants.

Frank R M Stassen,Emiel F M Wouters,Niki L Reynaert,Gernot G U Rohde,Pascalle H Van Eijck,Paul H M Savelkoul,Birke J Benedikter,Jacco J Briedé,Theo M De Kok

doi:10.1155/2019/5204218

Frank R M Stassen, Emiel F M Wouters + Show 7 more

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https://doi.org/10.1155/2019/5204218

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Abstract

Chronic exposure to respiratory stressors increases the risk for pulmonary and cardiovascular diseases. Previously, we have shown that cigarette smoke extract (CSE) triggers the release of CD63+CD81+ and tissue factor (TF)+ procoagulant extracellular vesicles (EVs) by bronchial epithelial cells via depletion of cell surface thiols. Here, we hypothesized that this represents a universal response for different pulmonary cell types and respiratory exposures. Using bead-based flow cytometry, we found that bronchial epithelial cells and pulmonary fibroblasts, but not pulmonary microvascular endothelial cells or macrophages, release CD63+CD81+ and TF+ EVs in response to CSE. Cell surface thiols decreased in all cell types upon CSE exposure, whereas depletion of cell surface thiols using bacitracin only triggered EV release by epithelial cells and fibroblasts. The thiol-antioxidant NAC prevented the EV induction by CSE in epithelial cells and fibroblasts. Exposure of epithelial cells to occupational silica nanoparticles and particulate matter (PM) from outdoor air pollution also enhanced EV release. Cell surface thiols were mildly decreased and NAC partly prevented the EV induction for PM10, but not for silica and PM2.5. Taken together, induction of procoagulant EVs is a cell type-specific response to CSE. Moreover, induction of CD63+CD81+ and TF+ EVs in bronchial epithelial cells appears to be a universal response to various respiratory stressors. TF+ EVs may serve as biomarkers of exposure and/or risk in response to respiratory exposures and may help to guide preventive treatment decisions.

Highlights

The human lungs are covered with a vast epithelial surface, which makes them very efficient for gas exchange, and highly vulnerable to inhaled exposures [1]
Using bead-based flow cytometry, we found that bronchial epithelial cells and pulmonary fibroblasts, but not pulmonary microvascular endothelial cells or macrophages, release CD63+CD81+ and tissue factor (TF)+ extracellular vesicles (EVs) in response to cigarette smoke extract (CSE)
Despite a significant CSE-induced decrease in cell surface thiols for all cell types (Figure 1(b)), a concentration-dependent increase in EV release was only observed in BEAS-2B, HEL-299, and MRC-5 cells, but not in THP-1 cells or HPMEC (Figure 1(c))

Summary

Introduction

The human lungs are covered with a vast epithelial surface, which makes them very efficient for gas exchange, and highly vulnerable to inhaled exposures [1]. Such exposures include cigarette smoke, as well as gases, volatile compounds, and particulates from outdoor and indoor sources of air pollution. Respiratory exposures are associated with increased risks of lung cancer [8,9,10] and cardiovascular diseases (CVD) [11,12,13]. While the cellular and molecular mechanisms underlying the development of respiratory exposure-associated diseases are still incompletely understood, inflammation is known to play an important role

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