Release of nerve growth factor by human pulmonary epithelial cells: role in airway inflammatory diseases

Elevated levels of nerve growth factor (NGF) have been detected in the bron choalveolar lavage fluid of patients with asthma. However, the source of th is enhanced mediator production is not known. Here, we investigate the prod uction of NGF from a human airway epithelial cell line (A549). Under basal conditions, A549 cells generated NGF in a time-dependent fashion. However, basal release was significantly augmented in a concentration-dependent mann er in cells treated with interleukin-1 beta (IL-1 beta) or tumour necrosis factor-alpha (TNF-alpha) and inhibited by dexamethasone. These data suggest that NGF released from structural cells may be an important target for the anti-inflammatory effects of steroids in asthma therapy. (C) 2001 Elsevier Science B.V. All rights reserved.