title: C/EBPβ is a transcriptional key regulator of IL-36α in murine macrophages.
abstract: Interleukin (IL)-36α - one of the novel members of the IL-1 family of cytokines - is a potent regulator of dendritic and T cells and plays an important role in inflammatory processes like experimental skin inflammation in mice and in mouse models for human psoriasis. Here, we demonstrate that C/EBPβ, a transcription factor required for the selective expression of inflammatory genes, is a key activator of the Il36A gene in murine macrophages. RNAi-mediated suppression of C/EBPβ expression in macrophages (C/EBPβ(low) cells) significantly impaired Il36A gene induction following challenge with LPS. Despite the presence of five predicted C/EBP binding sites, luciferase reporter assays demonstrated that C/EBPβ confers responsiveness to LPS primarily through a half-CRE•C/EBP element in the proximal Il36A promoter. Electrophoretic mobility shift assays showed that C/EBPβ but not CREB proteins interact with this critical half-CRE•C/EBP element. In addition, overexpression of C/EBPβ in C/EBPβ(low) cells enhanced the expression of Il36A whereas CREB-1 had no effect. Finally, chromatin immunoprecipitation confirmed that C/EBPβ but neither CREB-1, ATF-2 nor ATF4 is directly recruited to the proximal promoter region of the Il36A gene. Together, these findings demonstrate an essential role of C/EBPβ in the regulation of the Il36A gene via the proximal half-CRE•C/EBP element in response to inflammatory stimuli.
authors.affiliation: Institute for Microbiology, Department of Infectious Diseases, University of Veterinary Medicine, Foundation Hannover, 30173 Hannover, Germany. Electronic address: andreas.nerlich@charite.de.
authors.forename: Andreas
authors.initials: A
authors.lastname: Nerlich
authors.affiliation: Institute for Microbiology, Department of Infectious Diseases, University of Veterinary Medicine, Foundation Hannover, 30173 Hannover, Germany.
authors.forename: Nanthapon
authors.initials: N
authors.lastname: Ruangkiattikul
authors.affiliation: Institute for Microbiology, Department of Infectious Diseases, University of Veterinary Medicine, Foundation Hannover, 30173 Hannover, Germany.
authors.forename: Kristin
authors.initials: K
authors.lastname: Laarmann
authors.affiliation: Institute for Microbiology, Department of Infectious Diseases, University of Veterinary Medicine, Foundation Hannover, 30173 Hannover, Germany.
authors.forename: Nina
authors.initials: N
authors.lastname: Janze
authors.affiliation: Institute of Biochemistry, Medical School Hannover, 30625 Hannover, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Dittrich-Breiholz
authors.affiliation: Rudolf -Buchheim-Institute of Pharmacology, Justus-Liebig-University Giessen, 35392 Giessen, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Kracht
authors.affiliation: Institute for Microbiology, Department of Infectious Diseases, University of Veterinary Medicine, Foundation Hannover, 30173 Hannover, Germany.
authors.forename: Ralph
authors.initials: R
authors.lastname: Goethe
mesh_terms: D000818:Animals; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D022782:CCAAT-Enhancer-Binding Protein-beta / Q000502:physiology*; D002478:Cells, Cultured; D018387:Codon, Initiator / Q000235:genetics; D005786:Gene Expression Regulation / Q000187:drug effects; D007249:Inflammation / Q000235:genetics*; D007375:Interleukin-1 / Q000235:genetics* / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D011565:Psoriasis / Q000235:genetics; D050436:Regulatory Elements, Transcriptional
chemical_list: D022782:CCAAT-Enhancer-Binding Protein-beta; D018387:Codon, Initiator; D007375:Interleukin-1; D008070:Lipopolysaccharides; C543716:interleukin 1F6, mouse
keywords: C/EBPβ; Gene regulation; Half-CRE element; IL-36 cytokines; Lipopolysaccharide; Macrophages