Multiple mechanisms control the expression of granulocyte-macrophage colony-stimulating factor by human fibroblasts.
Human granulocyte-macrophage colony-stimulating factor (GM-CSF) has in vitro and in vivo effects on hemopoiesis and enhances the function of circulating mature myeloid cells. Unstimulated fibroblasts show low level GM-CSF transcription but no accumulation of GM-CSF mRNA or protein, whereas fibroblasts stimulated by TNF-alpha, IL-1, and phorbol diester have been shown to produce and secrete GM-CSF. To determine the mechanisms controlling the expression of GM-CSF in human fibroblasts, we used a transient transfection assay to look at the effect of TNF-alpha, IL-1 and phorbol diester on GM-CSF promoter sequences. Our results demonstrate that the phorbol diester, 12-O-tetradecanoylphorbol 13-acetate, can stimulate GM-CSF transcription via sequences located within 53 bp upstream of the GM-CSF cap site. TNF-alpha and IL-1 had no effect on GM-CSF transcription, suggesting that these cytokines act predominantly post-transcriptionally to stimulate production of GM-CSF. Our results demonstrate that multiple mechanisms can be used by human fibroblasts to produce GM-CSF in response to various inflammatory stimuli.
Nimer
S D
SD
Division of Hematology-Oncology, UCLA School of Medicine, Los Angeles, CA 90024-1678.
Gates
M J
MJ
Koeffler
H P
HP
Gasson
J C
JC
D001483:Base Sequence; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics; D003115:Colony-Stimulating Factors / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D005347:Fibroblasts / Q000201:enzymology / Q000502:physiology*; D005786:Gene Expression Regulation; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D006133:Growth Substances / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D012045:Regulatory Sequences, Nucleic Acid; D014162:Transfection
D003115:Colony-Stimulating Factors; D006133:Growth Substances; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D015500:Chloramphenicol O-Acetyltransferase