Sulforaphane-stimulated phase II enzyme induction inhibits cytokine production by airway epithelial cells stimulated with diesel extract

2007 ◽  
Vol 292 (1) ◽  
pp. L33-L39 ◽  
Author(s):  
Stacey A. Ritz ◽  
Junxiang Wan ◽  
David Diaz-Sanchez

Airborne particulate pollutants, such as diesel exhaust particles, are thought to exacerbate lung and cardiovascular diseases through induction of oxidative stress. Sulforaphane, derived from cruciferous vegetables, is the most potent known inducer of phase II enzymes involved in the detoxification of xenobiotics. We postulated that sulforaphane may be able to ameliorate the adverse effects of pollutants by upregulating expression of endogenous antioxidant enzymes. Stimulation of bronchial epithelial cells with the chemical constituents of diesel particles result in the production of proinflammatory cytokines. We first demonstrated a role for phase II enzymes in regulating diesel effects by transfecting the airway epithelial cell line (BEAS-2B) with the sentinel phase II enzyme NAD(P)H: quinine oxidoreductase 1 (NQO1). IL-8 production in response to diesel extract was significantly reduced in these compared with untransfected cells. We then examined whether sulforaphane would stimulate phase II induction and whether this would thereby ablate the effect of diesel extracts on cytokine production. We verified that sulforaphane significantly augmented expression of the phase II enzyme genes GSTM1 and NQO1 and confirmed that sulforaphane treatment increased glutathione S-transferase activity in epithelial cells without inducing cell death or apoptosis. Sulforaphane pretreatment inhibited IL-8 production by BEAS-2B cells upon stimulation with diesel extract. Similarly, whereas diesel extract stimulated production of IL-8, granulocyte-macrophage colony-stimulating factor, and IL-1β from primary human bronchial epithelial cells, sulforaphane pretreatment inhibited diesel-induced production of all of these cytokines. Our studies show that sulforaphane can mitigate the effect of diesel in respiratory epithelial cells and demonstrate the chemopreventative potential of phase II enzyme enhancement.

2005 ◽  
Vol 288 (3) ◽  
pp. L508-L513 ◽  
Author(s):  
Noriho Sakamoto ◽  
Hiroshi Mukae ◽  
Takeshi Fujii ◽  
Hiroshi Ishii ◽  
Sumako Yoshioka ◽  
...  

Defensins are cysteine-rich cationic antimicrobial peptides that play an important role in innate immunity and are known to contribute to the regulation of host adaptive immunity. In addition to direct antimicrobial activities, it has been recently reported that α-defensins, mainly present in neutrophils in the lung, have a cytotoxic effect and induce IL-8 production from airway epithelial cells. Although β-defensins are expressed in epithelial cells in various tissues, including lung, there are no reports of their effects on cytokine synthesis in airway epithelial cells. The aim of the present study was to determine the effects of both α- and β-defensins on the cytokine production, transcription factor binding activity, and cytotoxicity in primary cultured human bronchial epithelial cells (HBECs). We used human neutrophil peptide-1 (HNP-1; α-defensin) and human β-defensin-2 (HBD-2) to stimulate HBECs. The results showed that treatment of HBECs with HNP-1, but not HBD-2, increased IL-8 and IL-1β mRNA expression in a dose-dependent manner and also enhanced IL-8 protein secretion and NF-κB DNA binding activity. The 24-h treatments with >20 μg/ml of HNP-1 or >50 μg/ml of HBD-2 were cytotoxic to HBECs. These results suggest that α- and β-defensins have different effects on cytokine synthesis by airway epithelial cells, and we speculate that they play different roles in inflammatory lung diseases.


1999 ◽  
Vol 277 (3) ◽  
pp. L465-L471 ◽  
Author(s):  
Alessandro Celi ◽  
Silvana Cianchetti ◽  
Stefano Petruzzelli ◽  
Stefano Carnevali ◽  
Filomena Baliva ◽  
...  

Intercellular adhesion molecule-1 (ICAM-1) is the only inducible adhesion receptor for neutrophils identified in bronchial epithelial cells. We stimulated human airway epithelial cells with various agonists to evaluate whether ICAM-1-independent adhesion mechanisms could be elicited. Phorbol 12-myristate 13-acetate (PMA) stimulation of cells of the alveolar cell line A549 caused a rapid, significant increase in neutrophil adhesion from 11 ± 3 to 49 ± 7% (SE). A significant increase from 17 ± 4 to 39 ± 6% was also observed for neutrophil adhesion to PMA-stimulated human bronchial epithelial cells in primary culture. Although ICAM-1 expression was upregulated by PMA at late time points, it was not affected at 10 min when neutrophil adhesion was already clearly enhanced. Antibodies to ICAM-1 had no effect on neutrophil adhesion. In contrast, antibodies to the leukocyte integrin β-chain CD18 totally inhibited the adhesion of neutrophils to PMA-stimulated epithelial cells. These results demonstrate that PMA stimulation of human airway epithelial cells causes an increase in neutrophil adhesion that is not dependent on ICAM-1 upregulation.


2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Zhongjia Jiang ◽  
Fuyang Song ◽  
Yanan Li ◽  
Di Xue ◽  
Ning Zhao ◽  
...  

In an attempt to better understand the pathogen-host interaction between invadingMycoplasma ovipneumoniae(M. ovipneumoniae) and sheep airway epithelial cells, biological effects and possible molecular mechanism of capsular polysaccharide ofM. ovipneumoniae(CPS) in the induction of cell apoptosis were explored using sheep bronchial epithelial cells cultured in air-liquid interface (ALI). The CPS ofM. ovipneumoniaewas first isolated and purified. Results showed that CPS had a cytotoxic effect by disrupting the integrity of mitochondrial membrane, accompanied with an increase of reactive oxygen species and decrease of mitochondrial membrane potential (ΔΨm). Of importance, the CPS exhibited an ability to induce caspase-dependent cell apoptosis via both intrinsic and extrinsic apoptotic pathways. Mechanistically, the CPS induced extrinsic cell apoptosis by upregulating FAS/FASL signaling proteins and cleaved-caspase-8 and promoted a ROS-dependent intrinsic cell apoptosis by activating a JNK and p38 signaling but not ERK1/2 signaling of mitogen-activated protein kinases (MAPK) pathways. These findings provide the first evidence that CPS ofM. ovipneumoniaeinduces a caspase-dependent apoptosis via both intrinsic and extrinsic apoptotic pathways in sheep bronchial epithelial cells, which may be mainly attributed by a ROS-dependent JNK and p38 MAPK signaling pathways.


2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Christie F. Michael ◽  
Christopher M. Waters ◽  
Kim S. LeMessurier ◽  
Amali E. Samarasinghe ◽  
Chi Y. Song ◽  
...  

In asthmatic airways, repeated epithelial damage and repair occur. No current therapy directly targets this process. We aimed to determine the effects of mannan derived from S. cerevisiae (SC-MN) on airway epithelial wound repair, in vitro. The presence of functional mannose receptors in bronchial epithelial cells was shown by endocytosis of colloidal gold-Man BSA via clathrin-coated pits in 16HBE cells. In primary normal human bronchial epithelial cells (NHBEC), SC-MN significantly facilitated wound closure. Treatment with SC-MN stimulated cell spreading as indicated by a significant increase in the average lamellipodial width of wound edge 16HBE cells. In addition, NHBEC treated with SC-MN showed increased expression and activation of Krüppel-like factors (KLFs) 4 and 5, transcription factors important in epithelial cell survival and regulation of epithelial-mesenchymal transition. We conclude that SC-MN facilitates wound repair in human bronchial epithelium, involving mannose receptors.


2012 ◽  
Vol 303 (2) ◽  
pp. L97-L106 ◽  
Author(s):  
Shilpa Nimishakavi ◽  
Marina Besprozvannaya ◽  
Wilfred W. Raymond ◽  
Charles S. Craik ◽  
Dieter C. Gruenert ◽  
...  

Prostasin is a membrane-anchored protease expressed in airway epithelium, where it stimulates salt and water uptake by cleaving the epithelial Na+ channel (ENaC). Prostasin is activated by another transmembrane tryptic protease, matriptase. Because ENaC-mediated dehydration contributes to cystic fibrosis (CF), prostasin and matriptase are potential therapeutic targets, but their catalytic competence on airway epithelial surfaces has been unclear. Seeking tools for exploring sites and modulation of activity, we used recombinant prostasin and matriptase to identify substrate t-butyloxycarbonyl-l-Gln-Ala-Arg-4-nitroanilide (QAR-4NA), which allowed direct assay of proteases in living cells. Comparisons of bronchial epithelial cells (CFBE41o−) with and without functioning cystic fibrosis transmembrane conductance regulator (CFTR) revealed similar levels of apical and basolateral aprotinin-inhibitable activity. Although recombinant matriptase was more active than prostasin in hydrolyzing QAR-4NA, cell surface activity resisted matriptase-selective inhibition, suggesting that prostasin dominates. Surface biotinylation revealed similar expression of matriptase and prostasin in epithelial cells expressing wild-type vs. ΔF508-mutated CFTR. However, the ratio of mature to inactive proprostasin suggested surface enrichment of active enzyme. Although small amounts of matriptase and prostasin were shed spontaneously, prostasin anchored to the cell surface by glycosylphosphatidylinositol was the major contributor to observed QAR-4NA-hydrolyzing activity. For example, the apical surface of wild-type CFBE41o− epithelial cells express 22% of total, extractable, aprotinin-inhibitable, QAR-4NA-hydrolyzing activity and 16% of prostasin immunoreactivity. In conclusion, prostasin is present, mature and active on the apical surface of wild-type and CF bronchial epithelial cells, where it can be targeted for inhibition via the airway lumen.


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