The p38 Mitogen-activated Kinase Pathway Regulates the Human Interleukin-10 Promoter via the Activation of Sp1 Transcription Factor in Lipopolysaccharide-stimulated Human Macrophages

Abstract

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 EpsteinBarr 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 mitogenactivated 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.

The Sp1 transcription factor binds to the G-allele of the –1087 IL-10 gene polymorphism and enhances transcriptional activation

“…40 LPSinduced activation of Sp1 in turn regulates the transcription of the human IL-10 gene. 35,38,39,41 In conclusion, this study demonstrated that the transcription factors PU.1, Spi-B and Sp1 in B cells bound to the À1087 site in the IL-10 promoter region. Using transfection of the DG75 B-cell line, we showed differences in promoter activity for the ACC and GCC haplotypes.…”

Inhibition of p38 MAPK activity in B-NHL Raji cells by treatment with engineered CD20-specific T cells

“…Consequently, down-regulation of the autocrine/paracrine loop of IL-10/IL-10R signaling partially inhibited p-STAT3 and Bcl-2 expression (2). Sp1 transcription factor is activated by p38 MAPK and Sp1 is involved in the regulation of IL-10 expression in a number of cell lines (24). Moreover, our study showed that the treatment of Raji cells with engineered T cells expressing anti-CD20scFvFc/CD28/CD3ζ led to a stronger inhibition of p38 MAPK activity and down-regulation of Bcl-2 expression and IL-10 secretary than the treatment of Raji cells with engineered T cells expressing anti-CD20scFvFc.…”

Anti-inflammatory functions of glucocorticoid-induced genes

“…Expression of IL-10 is acutely dependent on p38 MAPK (Foey et al, 1998;Koprak et al, 1999;Ma et al, 2001) and dysregulated in DUSP1 -/-macrophages (Abraham et al, 2006;Chi et al, 2006;Hammer et al, 2006;Zhao et al, 2006). There may exist a pathway for GC-mediated downregulation of IL-10 expression via the induction of DUSP1…”