APStracts 2:0058L, 1995.

Correlation of expression of the transcription factor c/ebp-[alpha] and surfactant protein genes in lung cells. Li, Feng, Elizabeth Rosenberg, Candyce I. Smith, Kathleen Notarfrancesco, Samuel R. Reisher, Henry Shuman, and Sheldon I. Feinstein. Institute for Environmental Medicine and Departments of Genetics and Physiology, University of Pennsylvania School of Medicine, Philadelphia, PA. and Deborah Research Institute, Brown's Mills, NJ.

APStracts 2:0058L, 1995.

C/EBP-[alpha] is a transcription factor which can stimulate expression of genes in lipid-metabolizing epithelial cells. We have detected an increase in mRNA for C/EBP-[alpha] in lungs of fetal rats between days 18 and 20 of gestation, correlating with events occurring during the maturation of the surfactant system such as an increase in the amount of surfactant protein A mRNA. We have found that C/EBP-[alpha] mRNA levels are substantially enriched in type II alveolar epithelial cells purified from adult lung and that the C/EBP-[alpha] protein is present in type II cell nuclei. When the type II cells are removed from the lung and purified, the protein is rapidly lost. However, both surfactant protein gene expression and C/EBP-[alpha] reappear when cells are plated on Matrigel. Levels of C/EBP-[alpha] mRNA from purified cells decline much more slowly than the protein and are still detectable 48 hours after cells have been plated on standard tissue culture plastic. We have also detected the C/EBP-[alpha] protein in nuclear extracts of NCI-H441, a lung-derived cell line which expresses surfactant proteins A and B, but not in A549, a lung -derived cell line which does not express the surfactant proteins. Our data suggest that C/EBP-[alpha] is involved in the development and maintenance of the surfactant system in lung type II cells.

Received 4 August 1994; accepted in final form 6 April 1995.
APS Manuscript Number L222-4.
Article publication pending Am. J. Physiol. (Lung Cell. Mol.
Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 25 April 1995.