Schaberg T, Filderman A E
Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut 06510.
Am J Physiol. 1990 Aug;259(2 Pt 1):L144-50. doi: 10.1152/ajplung.1990.259.2.L144.
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.
