An optimal condition of bronchial cell proliferation stimulated by insulin-like growth factor-I

Background: It is known that growth hormones such as insulin-like growth fa ctor-I (IGF-I) and several kinds of cytokines are involved in the regenerat ion process of injured epithelial cells in chronic respiratory inflammatory diseases such as bronchial asthma, Repetitive degeneration/regeneration pr ocesses of the airway epithelial layer is supposed to be responsible for th e remodeling and irreversible organic changes of the airway in bronchial as thma, The purpose of this study is to establish a simple and reliable in vi tro method for studying airway epithelial cell growth and proliferation usi ng IGF-I, Method: By altering the number of cultured epithelial cells (stra in NCI-H-292), culture duration before stimulation with IGF-I, concentratio n of IGF-I, and duration of IGF-I stimulation, the optimum conditions for e pithelial cell growth was determined. The epithelial cell growth was evalua ted using [methyl-H-3]thymidine uptake. Result: Among various culture condi tions, the epithelial cells cultured at 1 x 10(3) cells/well for 24 h follo wed by 24 h of stimulation by 10(-8) M of IGF-I showed the highest growth. Conclusion: The method for the evaluation of epithelial cell growth establi shed in this study requires a small number of cells and has no complicated procedure. This simple model enables us to investigate the effect of variou s substances on bronchial epithelial cell growth in the presence of IGF-I, Copyright (C) 2000 S. Karger AG, Basel.