Transcriptional and posttranscriptional modulation of myeloid colony-stimulating factor expression by tumor necrosis factor and other agents.
Granulocyte (G) and granulocyte-macrophage (GM) colony-stimulating factors (CSF) are necessary for proliferation and differentiation of myeloid hematopoietic cells. Fibroblasts stimulated by tumor necrosis factor alpha (TNF alpha) and several other agents are a rich source of these CSF. The GM-CSF synthesized by these cells had the same molecular weight and glycosylation pattern as that produced by activated T lymphocytes, as shown by [35S]methionine labeling studies. Northern (RNA) blot analysis showed that the fibroblasts had trace levels of G- and GM-CSF mRNA. Both G- and GM-CSF mRNA concentrations coordinately increased after exposure of the cells to TNF alpha (greater than or equal to 5 ng/ml), 12-O-tetradecanoylphorbol 13-acetate (TPA) (greater than or equal to 5 x 10(-10) M), or cycloheximide (20 micrograms/ml). Both TNF alpha and TPA increased levels of G- and GM-CSF mRNA in the absence of new protein synthesis. Transcriptional run-on studies demonstrated that fibroblasts constitutively transcribed GM-CSF, and transcription was enhanced 3.0-fold by TNF alpha and 2.5-fold by TPA and was unchanged by cycloheximide. The stability of G- and GM-CSF transcripts was determined after exposure of the cells to actinomycin D; the half-lives of G- and GM-CSF mRNA in unstimulated cells were less than 0.25 h and were increased 2- to 16-fold in cells cultured with TNF, TPA, or cycloheximide. In summary, both transcriptional and posttranscriptional signals acted coordinately to modulate the levels of G- and GM-CSF mRNAs in fibroblasts.
Koeffler
H P
HP
Department of Medicine, University of California, Los Angeles 90024.
Gasson
J
J
Tobler
A
A
D001853:Bone Marrow / Q000378:metabolism; D001854:Bone Marrow Cells; D002460:Cell Line; D002478:Cells, Cultured; D003115:Colony-Stimulating Factors / Q000096:biosynthesis / Q000235:genetics*; D003513:Cycloheximide / Q000494:pharmacology*; D005796:Genes / Q000187:drug effects; D016179:Granulocyte Colony-Stimulating Factor; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D006133:Growth Substances / Q000096:biosynthesis / Q000235:genetics*; D006412:Hematopoietic Stem Cells / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D012323:RNA Processing, Post-Transcriptional / Q000187:drug effects*; D012333:RNA, Messenger / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D011994:Recombinant Proteins / Q000494:pharmacology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D014158:Transcription, Genetic / Q000187:drug effects*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D003115:Colony-Stimulating Factors; D006133:Growth Substances; D012333:RNA, Messenger; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; D016179:Granulocyte Colony-Stimulating Factor; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D003513:Cycloheximide; D013755:Tetradecanoylphorbol Acetate