Nancy J. Akley

Tumor Necrosis Factor Alpha (TNFα)‐Induced ICAM‐1 Surface Expression in Airway Epithelial Cells in vitro: Possible Signal Transduction Mechanismsa

Within the past several years research on the interaction of cytokines and adhesion molecules with airway epithelium in diseases has allowed us to develop a better understanding of the disease process. The cytokine, TNF alpha and the adhesion molecule ICAM-1 are important mediators in the pathogenesis of airway diseases such as asthma, chronic bronchitis, and adult respiratory distress syndrome. Effects of TNF alpha on ICAM-1 surface expression was investigated in both primary cultures of normal human bronchial epithelial (NHBE) cells and immortalized human bronchial epithelial cell line BEAS-2B. TNF alpha (0.015-150 ng/mL) significantly enhanced ICAM-1 surface expression (measured by flow cytometry) in a dose and time-dependent manner, with peak expression seen at 24 hours. This response was negated by heat inactivation of the TNF alpha prior to incubation. TNF alpha-induced ICAM-1 expression also was inhibited by pre- and coincubation of TNF alpha with 3 micrograms/mL soluble TNF-R1 or by the PKC inhibitor, Calphostin C (0.1 and 0.5 microM). The ROI scavengers, dimethylthiourea (4 mM), and dimethyl sulfoxide (0.001%), enhanced TNF alpha-induced ICAM-1 expression. Collectively, these results indicate that TNF alpha-induced ICAM-1 surface expression is a specific receptor-mediated response (TNF-R1), which is mediated by mechanisms dependent on PKC and intracellular reactive oxygen species.

MODELING THE AIRWAY EPITHELIUM IN ALLERGIC ASTHMA: INTERLEUKIN-13- INDUCED EFFECTS IN DIFFERENTIATED MURINE TRACHEAL EPITHELIAL CELLS

SummaryMucous cells of the airway epithelium play a crucial role in the pathogenesis of human inflammatory airway diseases. Therefore, it is of importance to complement in vivo studies that use murine models of allergic asthma with in vitro mechanistic studies that use murine airway epithelial cells, including mucus-containing cells. In this study, we report the development and characterization of an in vitro culture system for primary murine tracheal epithelial (MTE) cells comprising ciliated cells and a substantial number of mucous cells. The increase in mucous cell number over that observed in the native murine airway, or in previously described murine cultures, creates a culture intermediate between the in vivo murine airway epithelium and in vitro cultures of human airway epithelial cells. To establish the usefulness of this culture system for the study of epithelial effects during inflammatory airway diseases, the cells were exposed to interleukin (IL)-13, a central inflammatory mediator in allergic asthma. The IL-13 induced two characteristic epithelial effects, proliferation and modulation of MUC5AC gene expression. There was a concentration dependence of these events, wherein high concentrations of IL-13 (10 ng/ml) induced proliferation, whereas lower concentrations (1 ng/ml) increased MUC5AC mRNA (where mRNA is messenger RNA). Interestingly, these effects occurred in an inverse manner, with the high concentration of IL-13 also provoking a significant decrease in MUC5AC gene expression. Thus, MTE cells cultured in this manner may provide an important link between experimental findings from animal models of allergic asthma and their application to human disease.

Secretion-competent mouse tracheal epithelial cell culture from the genetically altered mouse: Pathway analysis via gene array

2002;121;79S-80S Chest V. Romberger John Spurzem, Ji Zhang PhD, Xiang-der Liu, Stephan I. Rennard and Debra * Epithelial Repair Model of In Vitro Gene Expression in an http://chestjournal.chestpubs.org/content/121/3_suppl/79S.2.full.html can be found online on the World Wide Web at: The online version of this article, along with updated information and services ) ISSN:0012-3692 http://chestjournal.chestpubs.org/site/misc/reprints.xhtml ( distributed without the prior written permission of the copyright holder. All rights reserved. No part of this article or PDF may be reproduced or College of Chest Physicians, 3300 Dundee Road, Northbrook, IL 60062. has been published monthly since 1935. Copyright2002by the American is the official journal of the American College of Chest Physicians. It Chest