cAMP-induced Interleukin-10 Promoter Activation Depends on CCAAT/Enhancer-binding Protein Expression and Monocytic Differentiation

• Published in: The Journal of biological chemistry 2003-02, Vol.278 (8), p.5597-5604
• Main Authors: Brenner, S, Proesch, S, Schenke-Layland, K, Riese, U, Gausmann, U, Platzer, C
• Format: Article
• Language: English
• Subjects: Animals; Base Sequence; Bucladesine - pharmacology; CCAAT-Enhancer-Binding Proteins - genetics; CCAAT-Enhancer-Binding Proteins - metabolism; Cell Differentiation; Codon, Initiator; Cyclic AMP - physiology; Gene Expression Regulation - drug effects; Gene Expression Regulation - immunology; HL-60 Cells; Humans; Interleukin-10 - genetics; Mice; Molecular Sequence Data; Monocytes - cytology; Monocytes - immunology; Muridae; Oligodeoxyribonucleotides; Promoter Regions, Genetic; Protein Biosynthesis; Recombinant Proteins - immunology; TATA Box; Transcription, Genetic - immunology; Transfection
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M207448200

The molecular mechanisms underlying the regulation of interleukin (IL)-10 transcription in monocytic cells by various stimuli during inflammation and the stress reaction are not fully understood. Recently, we provided evidence that stress-induced IL-10 promoter activation in monocytic cells is mediated by catecholamines via a cAMP-dependent signaling pathway including CREB/ATF (cAMP-responsive element binding protein/activating transcription factor) binding to two CRE motifs. However, the mutation of these sites diminished cAMP responsiveness by only 50%, suggesting a role for additional transcription factors and elements in the cAMP-dependent regulation of the human IL-10 promoter. Here, we analyze the functional role of one such factor, C/EBP, in two cell lines of myelomonocytic origin, THP-1 and HL-60, which are known to differ in their differentiation status and C/EBP protein content. We show that the level of basal as well as cAMP-stimulated IL-10 transcription depends on the expression of C/EBPα and β and their binding to three motifs in the promoter/enhancer region. The C/EBP5 motif, which is located between the TATA-box and the translation start point, is essential for the C/EBP-mediated constitutive and most of the cAMP-stimulated expression as its mutation nearly abolished IL-10 promoter activity. Our results suggest a dominant role of C/EBP transcription factors relative to CREB/ATF in tissue-specific and differentiation-dependent IL-10 transcription.