scholarly journals Contribution of Pulmonary CYP-mediated Bioactivation of Naphthalene to Airway Epithelial Injury in the Lung

2020 ◽  
Vol 177 (2) ◽  
pp. 334-346
Author(s):  
Nataliia Kovalchuk ◽  
Qing-Yu Zhang ◽  
Laura Van Winkle ◽  
Xinxin Ding

Abstract Previous studies have established that cytochrome P450 enzymes (CYPs) in both liver and lung are capable of bioactivating naphthalene (NA), an omnipresent air pollutant and possible human carcinogen, in vitro and in vivo. The aim of this study was to examine the specific contribution of pulmonary CYPs in airway epithelial cells to NA-induced airway toxicity. We used a lung-Cpr-null mouse model, which undergoes doxycycline-induced, Cre-mediated deletion of the Cpr (a redox partner of all microsomal CYPs) gene specifically in airway epithelial cells. In 2-month-old lung-Cpr-null mice, Cpr deletion occurred in 75%–82% of epithelial cells of conducting airways. The extent of NA-induced acute lung toxicity (as indicated by total protein concentration and lactate dehydrogenase activity in bronchoalveolar lavage fluid collected at 24-h after initiation of a 4-h, nose-only, 10-ppm NA inhalation exposure) was substantially lower (by 37%–39%) in lung-Cpr-null mice, compared with control littermates. Moreover, the extent of cellular proliferation (as indicated by 5-bromo-2′-deoxyuridine incorporation) was noticeably lower in both proximal and distal airways (by 59% and 65%, respectively) of NA-treated lung-Cpr-null mice, compared with control littermates, at 2-day post-NA inhalation exposure. A similar genotype-related difference in the extent of postexposure cell proliferation was also observed in mice exposed to NA via intraperitoneal injection at 200 mg/kg. These results directly validate the hypothesis that microsomal CYP enzymes in airway epithelial cells play a large role in causing injury to airway epithelia following exposure to NA via either inhalation or intraperitoneal route.

Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 509 ◽  
Author(s):  
Meenakshi Tiwary ◽  
Robert J. Rooney ◽  
Swantje Liedmann ◽  
Kim S. LeMessurier ◽  
Amali E. Samarasinghe

Eosinophils, previously considered terminally differentiated effector cells, have multifaceted functions in tissues. We previously found that allergic mice with eosinophil-rich inflammation were protected from severe influenza and discovered specialized antiviral effector functions for eosinophils including promoting cellular immunity during influenza. In this study, we hypothesized that eosinophil responses during the early phase of influenza contribute to host protection. Using in vitro and in vivo models, we found that eosinophils were rapidly and dynamically regulated upon influenza A virus (IAV) exposure to gain migratory capabilities to traffic to lymphoid organs after pulmonary infection. Eosinophils were capable of neutralizing virus upon contact and combinations of eosinophil granule proteins reduced virus infectivity through hemagglutinin inactivation. Bi-directional crosstalk between IAV-exposed epithelial cells and eosinophils occurred after IAV infection and cross-regulation promoted barrier responses to improve antiviral defenses in airway epithelial cells. Direct interactions between eosinophils and airway epithelial cells after IAV infection prevented virus-induced cytopathology in airway epithelial cells in vitro, and eosinophil recipient IAV-infected mice also maintained normal airway epithelial cell morphology. Our data suggest that eosinophils are important in the early phase of IAV infection providing immediate protection to the epithelial barrier until adaptive immune responses are deployed during influenza.


2018 ◽  
Vol 112 ◽  
pp. 163-168 ◽  
Author(s):  
Cynthia M. Schwartz ◽  
Braedyn A. Dorn ◽  
Selam Habtemariam ◽  
Cynthia L. Hill ◽  
Tendy Chiang ◽  
...  

Pharmaceutics ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1281
Author(s):  
Shan Guan ◽  
Max Darmstädter ◽  
Chuanfei Xu ◽  
Joseph Rosenecker

In vitro-transcribed (IVT) mRNA has come into focus in recent years as a potential therapeutic approach for the treatment of genetic diseases. The nebulized formulations of IVT-mRNA-encoding alpha-1-antitrypsin (A1AT-mRNA) would be a highly acceptable and tolerable remedy for the protein replacement therapy for alpha-1-antitrypsin deficiency in the future. Here we show that lipoplexes containing A1AT-mRNA prepared in optimum conditions could successfully transfect human bronchial epithelial cells without significant toxicity. A reduction in transfection efficiency was observed for aerosolized lipoplexes that can be partially overcome by increasing the initial number of components. A1AT produced from cells transfected by nebulized A1AT-mRNA lipoplexes is functional and could successfully inhibit the enzyme activity of trypsin as well as elastase. Our data indicate that aerosolization of A1AT-mRNA therapy constitutes a potentially powerful means to transfect airway epithelial cells with the purpose of producing functional A1AT, while bringing along the unique advantages of IVT-mRNA.


1994 ◽  
Vol 266 (6) ◽  
pp. L612-L619 ◽  
Author(s):  
R. B. Devlin ◽  
K. P. McKinnon ◽  
T. Noah ◽  
S. Becker ◽  
H. S. Koren

Acute exposure of animals and humans to ozone results in decrements in lung function, development of airway hyperreactivity, inflammation, edema, damage to pulmonary cells, and production of several compounds with tissue damaging, fibrinogenic or fibrotic potential. The contribution of airway epithelial cells and alveolar macrophages to these processes is unclear. In this study we have directly exposed human alveolar macrophages and human airway epithelial cells to ozone in vitro and measured the cytotoxic effects of ozone, as well as the production of the inflammatory cytokines interleukin-6 (IL-6) and interleukin-8 (IL-8), and fibronectin, all of which are substantially elevated in the bronchoalveolar lavage fluid of humans exposed to ozone. Cells were grown on rigid, collagen-impregnated filter supports, and the interaction of cells with ozone facilitated by exposing them to the gas with medium below the support but no medium on top of the cells. The results show that, although macrophages are much more sensitive to ozone than epithelial cells, they do not produce increased amounts of IL-6, IL-8, or fibronectin following ozone exposure. In contrast, epithelial cells produce substantially more of all three proteins following ozone exposure, and both IL-6 and fibronectin are secreted vectorially. An immortalized human airway epithelial cell line (BEAS 2B) was used in these experiments since human airway epithelial cells are infrequently available for in vitro studies. Data from this study extend previous findings which suggest that the BEAS cell line is a useful model to study the interaction between airway epithelial cells and environmental toxicants.


1992 ◽  
Vol 262 (2) ◽  
pp. L183-L191 ◽  
Author(s):  
C. M. Liedtke

A role for phospholipase C (PLC) hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP2) as a mechanism of alpha 1-adrenergic signal transduction in human airway epithelial cells (AEC) was investigated in isolated normal tracheal and cystic fibrosis (CF) nasal epithelial cells grown in in vitro culture and prelabeled with 3 muCi myo-[3H]inositol/ml for 72 h. Breakdown of polyphosphoinositides was measured using thin-layer chromatography to detect phosphatidylinositol, phosphatidylinositol 4-phosphate (PIP), and PIP2. Inositol phosphates were separated by ion-exchange column chromatography. In normal AEC, the addition of the endogenous catecholamine l-epinephrine produced a rapid, transient accumulation of inositol 1,4,5-trisphosphate (IP3) and inositol 1,4-bisphosphate (IP2) and breakdown of PIP and PIP2. IP3 increased 1.7-fold and IP2 1.6-fold after 20 and 40 s, respectively. A maximal decrease of 35% PIP2 and 30% PIP is observed after 20 and 40 s, respectively. The effects of l-epinephrine were not blocked by the beta-adrenergic antagonist dl-propranolol but were mimicked by the alpha 1-adrenergic agonist methoxamine. Prazosin, an alpha 1-adrenergic antagonist, and pertussis toxin (PTX) blocked the effects of l-epinephrine and methoxamine. Addition of l-epinephrine and methoxamine to CF nasal epithelial cells also induced prazosin-sensitive polyphosphoinositide breakdown and inositol phosphate accumulation. A 2.2-fold accumulation of IP3 was observed after 10 s and 2.0-fold increase in IP2 after 20 s. Maximal decreases of 32% PIP2 and 23% PIP levels were observed after 20-s incubation with l-epinephrine. PTX reduced the effects of l-epinephrine and significantly blocked the effects of methoxamine.(ABSTRACT TRUNCATED AT 250 WORDS)


Blood ◽  
1999 ◽  
Vol 94 (8) ◽  
pp. 2827-2835 ◽  
Author(s):  
Garry M. Walsh ◽  
Darren W. Sexton ◽  
Morgan G. Blaylock ◽  
Catherine M. Convery

Eosinophils, which are prominent cells in asthmatic inflammation, undergo apoptosis and are recognized and engulfed by phagocytic macrophages in vitro. We have examined the ability of human small airway epithelial cells (SAEC) to recognize and ingest apoptotic human eosinophils. Cultured SAEC ingested apoptotic eosinophils but not freshly isolated eosinophils or opsonized erythrocytes. The ability of SAEC to ingest apoptotic eosinophils was enhanced by interleukin-1 (IL-1) or tumor necrosis factor  (TNF) in a time- and concentration-dependent fashion. IL-1 was found to be more potent than TNF and each was optimal at 10−10 mol/L, with a significant (P < .05) effect observed at 1 hour postcytokine incubation that was maximal at 5 hours. IL-1 stimulation not only increased the number of SAEC engulfing apoptotic eosinophils, but also enhanced their capacity for ingestion. The amino sugars glucosamine, n-acetyl glucosamine, and galactosamine significantly inhibited uptake of apoptotic eosinophils by both resting and IL-1–stimulated SAEC, in contrast to the parent sugars glucose, galactose, mannose, and fucose. Incubation of apoptotic eosinophils with the tetrapeptide RGDS, but not RGES, significantly inhibited their uptake by both resting and IL-1–stimulated SAEC, as did monoclonal antibody against vβ3 and CD36. Thus, SAEC recognize apoptotic eosinophils via lectin- and integrin-dependent mechanisms. These data demonstrate a novel function for human bronchial epithelial cells that might represent an important mechanism in the resolution of eosinophil-induced asthmatic inflammation.


Sign in / Sign up

Export Citation Format

Share Document