Bronchial epithelial cells regulate fibroblast proliferation. Nakamura, Yoichi, Leroy Tate, Ronald F. Ertl, Masashi Kawamoto, Tadashi Mio, Yuichi Adachi, Debra J. Romberger, Shin Koizumi, Gail Gossman, Richard A. Robbins, John R. Spurzem, Stephen I. Rennard. Third Department of Internal Medicine First Department of Surgery, University of Tokushima Nippon Medical School, School of Medicine 1 -1-5 Sendagi, Bunkyo-ku, Kuramoto-cho, 3 Tokyo 113, Japan, Tokushima 770, Japan, Department of Pathology, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, Tokyo 113, Japan
APStracts 2:0071L, 1995.
Chronic bronchitis frequently leads to irreversible airways obstruction. Alteration of airways architecture with abnormal airway connective tissue is thought to play an important role in this process. We hypothesized that the epithelial cells which line the airways modulate the development of peribronchial fibrosis and fixed airway obstruction by directing fibroblast proliferation. To assess this, we examined stimulatory activities for human lung fibroblast proliferation in bovine bronchial epithelial cell-conditioned medium. The conditioned medium stimulated the proliferation of fibroblasts in a serum free culture system in a concentration dependent manner. The fibroblast growth stimulatory activity was heterogenous with molecular weights of >50 kD and approximately 10 kD. Bronchial epithelial cell-conditioned medium also contained fibroblast growth inhibitory factors including both transforming growth factor (TGF) -[beta] and, based on indomethacin sensitivity, cyclo-oxygenase products. TGF-[beta] appeared to contribute to the morphological change of fibroblasts induced by the conditioned medium. Co-culture of human lung fibroblasts with bronchial epithelial cells resulted in a stimulation of fibroblast proliferation. In summary, airway epithelial cells appear to regulate fibroblast proliferation and may play a role in peribronchial fibrosis in chronic bronchitis. 

Received 24 March 1994; accepted in final form 25 April 1995.
APS Manuscript Number L90-4.
Article publication pending Am. J. Physiol. (Lung Cell. Mol.
Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on  9 May 1995.