title: AhR deficiency impairs expression of LPS-induced inflammatory genes in mice.
abstract: Recent reports suggest the participation of the aryl hydrocarbon receptor (AhR) in the induction mechanism of the NF-κB signaling pathway. In the current study we challenged C57BL/6 wild-type (WT) and AhR deficient (AhR(-/-)) mice with bacterial lipopolysaccharide (LPS) to investigate the role of the AhR in expression profiles of LPS and NF-κB target genes. Further, we analyzed the effect of LPS on the DNA binding activity of NF-κB, C/EBP and AP-1 transcription factors in liver and lung from WT and AhR(-/-) mice. The results show that the LPS-induced expression of several target genes was impaired in AhR(-/-) mice compared to WT mice. Depending on the target gene, the target tissue as well as the time of treatment, the deficiency of AhR may cause an inhibition or increase of the LPS-induced gene expression. The binding activity of NF-κB, C/EBP and AP-1 transcription factors was also affected in a time- and tissue-dependent manner. The current study shows that the AhR is implemented in LPS-induced inflammatory gene expression in vivo even in the absence of exogenous ligands of the AhR. The main implication of this finding is that the AhR functions in Toll-like receptor (TLR) and NF-κB signaling after activation by a classical stimulus, such as LPS.
authors.affiliation: Center for Health and the Environment, University of California Davis, One Shields Avenue, Davis, CA 95616, USA.
authors.forename: Dalei
authors.initials: D
authors.lastname: Wu
authors.forename: Wen
authors.initials: W
authors.lastname: Li
authors.forename: Patty
authors.initials: P
authors.lastname: Lok
authors.forename: Fumio
authors.initials: F
authors.lastname: Matsumura
authors.forename: Christoph Franz Adam
authors.initials: CF
authors.lastname: Vogel
mesh_terms: D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000172:deficiency* / Q000235:genetics; D005260:Female; D005786:Gene Expression Regulation; D007249:Inflammation / Q000235:genetics* / Q000276:immunology; D008070:Lipopolysaccharides / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D008817:Mice, Mutant Strains; D016328:NF-kappa B / Q000378:metabolism; D018336:Receptors, Aryl Hydrocarbon / Q000172:deficiency* / Q000235:genetics; D051193:Toll-Like Receptors / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D008070:Lipopolysaccharides; D016328:NF-kappa B; D018336:Receptors, Aryl Hydrocarbon; D051193:Toll-Like Receptors; D014157:Transcription Factors; C484722:Ahr protein, mouse