Transcription of stem cell factor (SCF) is potentiated by glucocorticoids and interleukin-1beta through concerted regulation of a GRE-like and an NF-kappaB response element.
Expression of stem cell factor SCF, a major mast cell growth factor, is potentiated shortly after co-treatment with interleukin (IL)-1beta and glucocorticoids. SCF promoter contains a GRE-like sequence and a putative kappaB site. We assessed the mechanisms of the regulation of SCF transcription in human lung fibroblasts in culture. Chromatin immunoprecipitation showed that co-treatment with IL-1beta and the glucocorticoid budesonide increased the SCF promoter occupancy by NF-kappaB and GR, as compared with IL-1beta and budesonide alone. In reporter gene assays, IL-1beta time-dependently increased the promoter activity, which was abolished by either pre-treatment with the MAP kinase inhibitors PD98059 (MEK) and SB203580 (p38), pre-treatment with the NF-kappaB inhibitor PDTC, or deletion of the kappaB site. Budesonide time-dependently decreased the promoter activity, an effect requiring the GRE-like element. Co-treatment with IL-1beta and budesonide potentiated the promoter activity at 30 min, an effect blocked by PD98059 and SB203580, PDTC, or deletion of the kappaB or GRE-like element. In conclusion, the GRE-like sequence mediating the repression of SCF expression, thus acting as a negative-responsive element, is turned into a positive element in an NF-kappaB site-dependent manner, indicating a concerted action of these two regulatory elements in the potentiation of SCF gene expression.
Da Silva
Carla Alexandra
CA
INSERM U425, Université Louis Pasteur Strasbourg I, France. carla.dasilva@pharma.u-strasbg.fr
Heilbock
Christine
C
Kassel
Olivier
O
Frossard
Nelly
N
D019819:Budesonide / Q000494:pharmacology*; D002478:Cells, Cultured; D004357:Drug Synergism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism; D005938:Glucocorticoids / Q000494:pharmacology*; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology*; D015735:Mifepristone / Q000494:pharmacology; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors; D008957:Models, Genetic; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011759:Pyrrolidines / Q000494:pharmacology; D011965:Receptors, Glucocorticoid / Q000037:antagonists & inhibitors / Q000378:metabolism; D020218:Response Elements; D019089:Stem Cell Factor / Q000096:biosynthesis / Q000235:genetics*; D013859:Thiocarbamates / Q000494:pharmacology; D015533:Transcriptional Activation
D004791:Enzyme Inhibitors; D005938:Glucocorticoids; D007375:Interleukin-1; D016328:NF-kappa B; D011759:Pyrrolidines; D011965:Receptors, Glucocorticoid; D019089:Stem Cell Factor; D013859:Thiocarbamates; C020972:pyrrolidine dithiocarbamic acid; D015735:Mifepristone; D019819:Budesonide; D020928:Mitogen-Activated Protein Kinases