The p38 mitogen-activated kinase pathway regulates the human interleukin-10 promoter via the activation of Sp1 transcription factor in lipopolysaccharide-stimulated human macrophages.
Interleukin-10 (IL-10), a pleiotropic cytokine that inhibits inflammatory and cell-mediated immune responses, is produced by a wide variety of cell types including T and B cells and monocytes/macrophages. Regulation of pro- and anti-inflammatory cytokines has been suggested to involve distinct signaling pathways. In this study, we investigated the regulation of the human IL-10 (hIL-10) promoter in the human monocytic cell line THP-1 following activation with lipopolysaccharide (LPS). Analysis of hIL-10 promoter sequences revealed that DNA sequences located between base pairs -652 and -571 are necessary for IL-10 transcription. A computer analysis of the promoter sequence between base pairs -652 and -571 revealed the existence of consensus sequences for Sp1, PEA1, YY1, and Epstein-Barr virus-specific nuclear antigen-2 (EBNA-2)-like transcription factors. THP-1 cells transfected with a plasmid containing mutant Sp1 abrogated the promoter activity, whereas plasmids containing the sequences for PEA1, YY1, and EBNA-2-like transcription factors did not influence hIL-10 promoter activity. To understand the events upstream of Sp1 activation, we investigated the role of p38 and extracellular signal-regulated kinase mitogen-activated protein kinases by using their specific inhibitors. SB202190 and SB203580, the p38-specific inhibitors, inhibited LPS-induced IL-10 production. In contrast, PD98059, a specific inhibitor of extracellular signal-regulated kinase kinases, failed to modulate IL-10 production. Furthermore, SB203580 inhibited LPS-induced activation of Sp1, as well as the promoter activity in cells transfected with a plasmid containing the Sp1 consensus sequence. These results suggest that p38 mitogen-activated protein kinase regulates LPS-induced activation of Sp1, which in turn regulates transcription of the hIL-10 gene.
Department of Pediatrics, University of Ottawa, Ottawa, Ontario K1H 8L1, Canada.
W
W
Ma
W
W
Lim
K
K
Gee
S
S
Aucoin
D
D
Nandan
M
M
Kozlowski
F
F
Diaz-Mitoma
A
A
Kumar
D029681:Arabidopsis Proteins; D001483:Base Sequence; D001665:Binding Sites; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000235:genetics; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004797:Enzyme-Linked Immunosorbent Assay; D019309:Epstein-Barr Virus Nuclear Antigens / Q000235:genetics; D050981:Erythroid-Specific DNA-Binding Factors; D005419:Flavonoids / Q000494:pharmacology; D005434:Flow Cytometry; D015971:Gene Expression Regulation, Enzymologic; D017930:Genes, Reporter; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology; D016753:Interleukin-10 / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism*; D018950:Lipopolysaccharide Receptors / Q000378:metabolism; D008070:Lipopolysaccharides / Q000378:metabolism*; D008156:Luciferases / Q000378:metabolism; D008264:Macrophages / Q000378:metabolism*; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000235:genetics; D010957:Plasmids / Q000378:metabolism; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D011725:Pyridines / Q000494:pharmacology; D015398:Signal Transduction; D016329:Sp1 Transcription Factor / Q000378:metabolism*; D013997:Time Factors; D014157:Transcription Factors / Q000235:genetics; D014158:Transcription, Genetic; D014162:Transfection; D014764:Viral Proteins; D050986:YY1 Transcription Factor; D048051:p38 Mitogen-Activated Protein Kinases
D029681:Arabidopsis Proteins; D004268:DNA-Binding Proteins; C402641:EBNA-2 protein, Human herpesvirus 4; D004791:Enzyme Inhibitors; D019309:Epstein-Barr Virus Nuclear Antigens; D050981:Erythroid-Specific DNA-Binding Factors; D005419:Flavonoids; D007093:Imidazoles; D018950:Lipopolysaccharide Receptors; D008070:Lipopolysaccharides; C084017:PEA1 protein, Arabidopsis; D010940:Plant Proteins; D011725:Pyridines; D016329:Sp1 Transcription Factor; D014157:Transcription Factors; D014764:Viral Proteins; D050986:YY1 Transcription Factor; C494698:YY1 protein, human; D016753:Interleukin-10; D008156:Luciferases; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; C093642:SB 203580; C090942:4-(4-fluorophenyl)-2-(4-hydroxyphenyl)-5-(4-pyridyl)imidazole; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one