scholarly journals Effects of E-Cigarette Flavoring Chemicals on Human Macrophages and Bronchial Epithelial Cells

Author(s):  
Anna M. Morris ◽  
Stephen S. Leonard ◽  
Jefferson R. Fowles ◽  
Theresa E. Boots ◽  
Anna Mnatsakanova ◽  
...  

E-cigarettes utilize a wide range of flavoring chemicals with respiratory health effects that are not well understood. In this study, we used pulmonary-associated cell lines to assess the in vitro cytotoxic effects of 30 flavoring chemicals. Human bronchial epithelial cells (BEAS-2B) and both naïve and activated macrophages (THP-1) were treated with 10, 100, and 1000 µM of flavoring chemicals and analyzed for changes in viability, cell membrane damage, reactive oxygen species (ROS) production, and inflammatory cytokine release. Viability was unaffected for all chemicals at the 10 and 100 µM concentrations. At 1000 µM, the greatest reductions in viability were seen with decanal, hexanal, nonanal, cinnamaldehyde, eugenol, vanillin, alpha-pinene, eugenol, and limonene. High amounts of ROS were elicited by vanillin, ethyl maltol, and the diketones (2,3-pentanedione, 2,3-heptanedione, and 2,3-hexanedione) from both cell lines. Naïve THP-1 cells produced significantly elevated levels of IL-1β, IL-8, and TNF-α when exposed to ethyl maltol and hexanal. Activated THP-1 cells released increased IL-1β and TNF-α when exposed to ethyl maltol, but many flavoring chemicals had an apparent suppressive effect on inflammatory cytokines released by activated macrophages, some with varying degrees of accompanying cytotoxicity. The diketones, L-carvone, and linalool suppressed cytokine release in the absence of cytotoxicity. These findings provide insight into lung cell cytotoxicity and inflammatory cytokine release in response to flavorings commonly used in e-cigarettes.

1996 ◽  
Vol 5 (3) ◽  
pp. 210-217
Author(s):  
M. M. Verheggen ◽  
H. I. M. de Bont ◽  
P. W. C. Adriaansen-Soeting ◽  
B. J. A. Goense ◽  
C. J. A. M. Tak ◽  
...  

In this study, we investigated the expression of lipocortin I and II (annexin I and I in the human bronchial epithelium, bothin vivoandin vitro. A clear expression of lipocortin I and II protein was found in the epithelium in sections of bronchial tissue. In cultured human bronchial epithelial cells we demonstrated the expression of lipocortin I and II mRNA and protein using Northern blotting, FACScan analysis and ELISA. No induction of lipocortin I or II mRNA or protein was observed after incubation with dexamethasone. Stimulation of bronchial epithelial cells with IL-1β, TNF-α or LPS for 24 h did not affect the lipocortin I or II mRNA or protein expression, although PGE2and 6-keto-PGF1αproduction was significantly increased. This IL-1β- and LPS-mediated increase in eicosanoids could be reduced by dexamethasone, but was not accompanied by an increase in lipocortin I or II expression. In human bronchial epithelial cells this particular glucocorticoid action is not mediated through lipocortin I or II induction.


1999 ◽  
Vol 277 (1) ◽  
pp. L58-L64 ◽  
Author(s):  
Ilja Striz ◽  
Tadashi Mio ◽  
Yuichi Adachi ◽  
Peggy Heires ◽  
Richard A. Robbins ◽  
...  

Interleukin (IL)-4 is thought to contribute to the Th2 type of immune response and hence the development of allergic reactions such as asthma. In asthmatic patients, the airway epithelium expresses increased amounts of the cell surface adhesion molecule intercellular adhesion molecule (ICAM)-1 (CD54). One cytokine capable of inducing ICAM-1 in airway epithelial cells, tumor necrosis factor-α (TNF-α), is present in asthma. This study evaluated if IL-4 either alone or together with TNF-α costimulation might modulate CD54 expression by human bronchial epithelial cells (HBECs). CD54 positivity increased in response to IL-4 (16 ± 2% positive vs. 3 ± 1%, P < 0.01); greater induction of CD54 resulted from TNF-α (45 ± 2%, P < 0.001). Costimulation with TNF-α plus IL-4 further augmented expression (56 ± 1%, P < 0.05). Immunoperoxidase results were confirmed by flow cytometry. RT-PCR revealed no increase in ICAM-1 mRNA expression under control conditions or after stimulation with IL-4 alone. TNF-α increased IL-4 mRNA, and IL-4 potentiated this. Functionally, IL-4 augmented the adhesion of THP-1 monocyte/macrophage cells to monolayers of HBECs both alone and in the presence of TNF-α. We conclude that 1) IL-4 augments epithelial cell ICAM-1 expression, 2) IL-4 potentiates the adhesion of THP-1 monocyte/macrophage cells to epithelial cells, and 3) modulation of epithelial cell ICAM-1 expression by IL-4 may play a role in the immunopathology of bronchial asthma.


2014 ◽  
Vol 307 (8) ◽  
pp. L643-L651 ◽  
Author(s):  
Todd A. Wyatt ◽  
Jill A. Poole ◽  
Tara M. Nordgren ◽  
Jane M. DeVasure ◽  
Art J. Heires ◽  
...  

Lung injury caused by inhalation of dust from swine-concentrated animal-feeding operations (CAFO) involves the release of inflammatory cytokine interleukin 8 (IL-8), which is mediated by protein kinase C-ε (PKC-ε) in airway epithelial cells. Once activated by CAFO dust, PKC-ε is responsible for slowing cilia beating and reducing cell migration for wound repair. Conversely, the cAMP-dependent protein kinase (PKA) stimulates contrasting effects, such as increased cilia beating and an acceleration of cell migration for wound repair. We hypothesized that a bidirectional mechanism involving PKA and PKC regulates epithelial airway inflammatory responses. To test this hypothesis, primary human bronchial epithelial cells and BEAS-2B cells were treated with hog dust extract (HDE) in the presence or absence of cAMP. PKC-ε activity was significantly reduced in cells that were pretreated for 1 h with 8-bromoadenosine 3′,5′-cyclic monophosphate (8-Br-cAMP) before exposure to HDE ( P < 0.05). HDE-induced IL-6, and IL-8 release was significantly lower in cells that were pretreated with 8-Br-cAMP ( P < 0.05). To exclude exchange protein activated by cAMP (EPAC) involvement, cells were pretreated with either 8-Br-cAMP or 8-(4-chlorophenylthio)-2'- O-methyladenosine-3',5'-cyclic monophosphate (8-CPT-2Me-cAMP) (EPAC agonist). 8-CPT-2Me-cAMP did not activate PKA and did not reduce HDE-stimulated IL-6 release. In contrast, 8-Br-cAMP decreased HDE-stimulated tumor necrosis factor (TNF)-α-converting enzyme (TACE; ADAM-17) activity and subsequent TNF-α release ( P < 0.001). 8-Br-cAMP also blocked HDE-stimulated IL-6 and keratinocyte-derived chemokine release in precision-cut mouse lung slices ( P < 0.05). These data show bidirectional regulation of PKC-ε via a PKA-mediated inhibition of TACE activity resulting in reduced PKC-ε-mediated release of IL-6 and IL-8.


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