Regulation of C/EBPβ mRNA expression and C/EBPβ promoter activity by protein kinases A and C in a myelomonocytic cell line (HD11)
Rent the article at a discountRent now
* Final gross prices may vary according to local VAT.Get Access
The transcription factor CCAAT/enhancer- binding protein (C/EBP) β is involved in inflammatory responses in immune cells, including myelomonocytic cells. In this study, signal transduction pathways regulating C/EBPβ expression were investigated.
The expression of C/EBPβ mRNA in cells treated with various activators and inhibitors of PKA and PKC was analyzed by Northern blot hybridization. C/EBPβ promoter activity was investigated by transient transfection assays with C/EBPβ promoter CAT constructs.
Phorbol 12-myristate 13-acetate (PMA), forskolin and 3-isobutyl-1-methyl-xanthine (IBMX), an inhibitor of cAMP and cGMP phosphodiesterases, but not cGMP, when added to chicken myelomonocytic HD11 cells, markedly stimulated the C/EBPβ mRNA expression. However, transfection experiments using HD11 cells showed that CAT constructs controlled by the 5′ flanking sequence from –704 to +24 of chicken C/EBPβ gene were activated by PMA, but not by forskolin. In contrast to forskolin, IBMX was able to activate the C/EBPβ promoter CAT constructs. Further transient transfection experiments using other cell lines demonstrated that the chicken C/EBPβ promoter was responsive to forskolin in mouse fibroblasts NIH3T3, but not in human hepatoma HepG2 cells. Increase in C/EBPβ mRNA stability in HD11 cells was induced by forskolin and PMA.
The results indicate that the C/EBPβ gene is regulated transcriptionally as well as post-transcriptionally in response to forskolin and PMA, and the forskolin responsiveness of the C/EBPβ promoter seems to depend on cellular cAMP turnover.
- Regulation of C/EBPβ mRNA expression and C/EBPβ promoter activity by protein kinases A and C in a myelomonocytic cell line (HD11)
Volume 56, Issue 7 , pp 274-281
- Cover Date
- Print ISSN
- Online ISSN
- Additional Links
- myelomonocytic cells
- Industry Sectors
- Author Affiliations
- 1. Institute for Microbiology, Department of Infectious Diseases, University of Veterinary Medicine, Bischofsholer Damm 15, 30173, Hannover, Germany
- 2. Federal Agricultural Research Centre, Institute for Animal Welfare and Animal Husbandry, Dörnbergstr. 25–27, 29223, Celle, Germany