P2Y(2) receptor expression is regulated by C/EBPβ during inflammation in intestinal epithelial cells.

Abstract

Inflammatory bowel diseases are characterized by relapses and remission periods during which numerous factors, including stress factors and nucleotides, are mobilized to re-establish intestinal mucosal homeostasis. We have previously found that expression of the P2Y(2) nucleotide receptor is increased in colonic tissue isolated from inflammatory bowel disease patients as well as in a mouse model of colitis, and that P2Y(2) transcription is regulated in part by nuclear factor κB (NF-κB) p65. Transcription factor DNA-binding site analysis identified three potential CCAAT/enhancer-binding protein β (C/EBPβ) binding sites in the P2Y(2) proximal promoter. We then assessed the role of C/EBP transcription factors in the regulation of P2Y(2) in intestinal epithelial cells (IECs). We identified a region between -229 and -220 bp upstream of the transcription initiation site as a DNA-binding site for C/EBPβ, by electrophoretic mobility and supershift assays. Mutagenesis of this site decreased C/EBPβ-dependent P2Y(2) expression, as assessed by luciferase assays. In vivo, C/EBPβ as well as P2Y(2) expression was increased in colonic IECs isolated from mice with dextran sulfate sodium-induced acute colitis. In contrast, P2Y(2) expression was decreased in C/EBPβ-deficient mice treated with dextran sulfate sodium. Although C/EBPβ was sufficient to induce P2Y(2) transcription, the effect of C/EBPβ and NF-κB p65 on receptor transcription was synergistic. Chromatin immunoprecipitation assays revealed that both proteins simultaneously bind to the P2Y(2) promoter. Thus, we have identified C/EBPβ as a novel regulator of P2Y(2) expression.

• Authors: Emilie Degagné, Naomie Turgeon, Julie Moore-Gagné, Claude Asselin, Fernand-Pierre Gendron
• Journal: The FEBS journal (FEBS J) Vol. 279 Issue 16 Pg. 2957-65 (Aug 2012) ISSN: 1742-4658 [Electronic] England
• PMID: 22742194 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2012 The Authors Journal compilation © 2012 FEBS.

Chemical References

• CCAAT-Enhancer-Binding Protein-beta
• NF-kappa B
• Receptors, Purinergic P2Y2
• Dextran Sulfate

Topics

• Animals
• Binding Sites (genetics)
• CCAAT-Enhancer-Binding Protein-beta (physiology)
• Caco-2 Cells
• Colitis (chemically induced)
• Dextran Sulfate
• Epithelial Cells (metabolism)
• Gene Expression Regulation
• Humans
• Inflammation (physiopathology)
• Mice
• NF-kappa B (physiology)
• Promoter Regions, Genetic (physiology)
• Rats
• Receptors, Purinergic P2Y2 (biosynthesis)