NF-kappaB and c-Jun-dependent regulation of macrophage inflammatory protein-2 gene expression in response to lipopolysaccharide in RAW 264.7 cells.
Macrophage inflammatory protein-2 (MIP-2) is a mouse C-X-C chemokine that plays an important role in the recruitment of neutrophils. Transcription of the MIP-2 gene is rapidly induced by lipopolysaccharide (LPS) stimulation in cells of macrophage lineage. We show here that the MIP-2 promoter is transcriptionally activated in a macrophage cell line RAW 264.7 by LPS through a sequence located between -450 and -54 and this region contains two copies of activator protein-1 (AP-1) and one copy of nuclear factor-kappaB (NF-kappaB) binding site. A MIP-2 promoter-reporter was activated by ectopical expression of NF-kappaB p65 or c-Jun transcription factors. Inhibition of NF-kappaB nuclear localization by co-expression of a mutant IkappaBalpha protein (IkappaBalpha super repressor, IkappaBalphaSR) blocked LPS-induced transcription from a MIP-2 promoter-reporter construct, showing that NF-kappaB activation is required for MIP-2 gene expression in the LPS-signaling pathway. By deletion analysis of the MIP-2 promoter region, we show that NF-kappaB and c-Jun binding sites are essential for LPS-induced MIP-2 gene expression. Using transient transfection, NF-kappaB and c-Jun transcription factors were found to synergistically activate the MIP-2 promoter. In summary, our data suggest that both NF-kappaB and c-Jun contribute to LPS-induced mouse MIP-2 gene expression in RAW 264.7 cells.
Kim
Doo-Sik
DS
Institute of Life Science and Biotechnology, College of Science, New Science Building, Room #S127, Yonsei University, Seoul 120-749, South Korea.
Han
Jung Ho
JH
Kwon
Hyung-Joo
HJ
D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D054426:Chemokine CXCL2; D005786:Gene Expression Regulation; D016758:Genes, jun; D006801:Humans; D016209:Interleukin-8 / Q000235:genetics; D008070:Lipopolysaccharides / Q000494:pharmacology; D051379:Mice; D015846:Monokines / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D016328:NF-kappa B / Q000502:physiology*; D011401:Promoter Regions, Genetic; D014162:Transfection
D054426:Chemokine CXCL2; D016209:Interleukin-8; D008070:Lipopolysaccharides; D015846:Monokines; D016328:NF-kappa B