COMPARISON OF EFFECTS OF EPIDERMAL AND INSULIN-LIKE GROWTH-FACTORS, GASTRIN RELEASING PEPTIDE AND RETINOIC ACID ON FETAL LUNG-CELL GROWTH AND MATURATION INVITRO

被引:54
作者
FRASLON, C [1 ]
BOURBON, JR [1 ]
机构
[1] CNRS,CTR BIOL CELLULAIRE,67 RUE MAURICE GUNSBOURG,F-94205 IVRY,FRANCE
关键词
GROWTH FACTOR; GASTRIN RELEASING PEPTIDE; RETINOIC ACID; LUNG SURFACTANT; LUNG DEVELOPMENT;
D O I
10.1016/0005-2760(92)90172-R
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
The role in cell multiplication and maturation of several factors present in the late fetal lung was explored on isolated fetal rat pulmonary fibroblasts and alveolar epithelial type II cells cultivated in serum-free medium. The low degree of reciprocal contamination of each cell population was assessed by immunocytochemistry. Epidermal Growth Factor (EGF) stimulated thymidine incorporation and DNA accumulation in both cell types. In type II cells, it increased labeled-choline incorporation into surfactant phosphatidylcholine (PC), consistently with previous data obtained with lung explant cultures, but not into non-surfactant PC. Insulin-like growth factor (IGF)-I slightly stimulated DNA accumulation in fibroblasts although it did not significantly stimulate thymidine incorporation, contrary to IGF-II which presented a dose-dependent stimulating activity of thymidine incorporation. Neither IGF-I nor IGF-IL stimulated type II cell growth. IGFs thus appear to primarily control the growth of lung mesenchyme. In type II cells, they stimulated the most non-surfactant PC biosynthesis. Gastrin releasing peptide (GRP) which was recently reported to promote fetal lung growth in vivo and to stimulate surfactant biosynthesis in lung organ culture revealed as a growth factor for type II cells only, at concentrations below 10(-9) M. At concentration 10(-8)M, although it did not affect DNA synthesis, GRP tended to increase surfactant and non-surfactant-PC biosynthesis. Retinoic acid inhibited thymidine incorporation into type II cells on a dose-dependent manner but nevertheless enhanced surfactant-PC biosynthesis to a similar extent as EGF. It is suggested that retinoic acid may represent a differentiation or maturation factor for the alveolar epithelium.
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页码:65 / 75
页数:11
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