Tumor necrosis factor alpha (TNF alpha)-induced ICAM-1 surface expression in airway epithelial cells in vitro: possible signal transduction mechanisms.
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.
Department of Anatomy, Physiological Sciences, and Radiology, College of Veterinary Medicine, North Carolina State University, Raleigh 27606, USA.
T M
TM
Krunkosky
B M
BM
Fischer
N J
NJ
Akley
K B
KB
Adler
D000328:Adult; D015703:Antigens, CD / Q000378:metabolism; D000975:Antioxidants / Q000494:pharmacology; D001980:Bronchi / Q000166:cytology* / Q000378:metabolism; D002460:Cell Line; D004848:Epithelium / Q000378:metabolism; D005434:Flow Cytometry; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism*; D011493:Protein Kinase C / Q000378:metabolism; D018124:Receptors, Tumor Necrosis Factor / Q000378:metabolism; D047888:Receptors, Tumor Necrosis Factor, Type I; D015398:Signal Transduction; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D015703:Antigens, CD; D000975:Antioxidants; D018124:Receptors, Tumor Necrosis Factor; D047888:Receptors, Tumor Necrosis Factor, Type I; D014409:Tumor Necrosis Factor-alpha; D018799:Intercellular Adhesion Molecule-1; D011493:Protein Kinase C