AJP - Lung Cellular and Molecular Physiology, Vol 259, Issue 2 144-L150, Copyright © 1990 by American Physiological Society
Colony-stimulating factor induction of protooncogene expression in rat alveolar macrophages
T. Schaberg and A. E. Filderman
Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut 06510.
The effect of granulocyte-macrophage colony-stimulating factor (GM-CSF) and
macrophage colony-stimulating factor (M-CSF) on the expression of c-fos and
c-myc protooncogenes was studied in rat alveolar macrophages (AM). AM were
exposed in vitro to GM-CSF (100 U/ml) or M-CSF (1,000 U/ml) for 30-120 min,
and c-fos and c-myc mRNA expression was determined by in situ hybridization
and Northern blot analysis. GM-CSF caused a rapid induction of c-fos mRNA
after 30 min and c-myc mRNA after 60 min. Exposure to M-CSF stimulated
maximal expression of c-fos mRNA after 60 min and c-myc mRNA after 120 min.
Under the same experimental conditions lipopolysaccharide (100 ng/ml)
induced a comparable amount of c-fos and c-myc mRNA expression, whereas
culture of AM with medium alone did not induce c-fos or c-myc expression.
Thus GM-CSF and M-CSF induce AM in vitro to express the nuclear
protooncogenes c-fos and c-myc. This effect of colony-stimulating factors
on protooncogene expression may be of importance in the local regulation of
AM activation and/or proliferation in an inflammatory lung response.
