Protein O-N-acetylglucosaminylation modulates promoter activities of cyclic AMP response element and activator protein 1 and enhances E-selectin expression on HuH-7 human hepatoma cells.

Abstract

High glucose accelerates O-N-acetylglucosaminylation (O-GlcNAcylation) of proteins and causes diabetic complications. In the present study, we found that treatment of HuH-7 human hepatoma cells with high glucose or the protein O-N-acetylglucosaminidase (O-GlcNAcase) inhibitor O-(2-acetoamide-2-deoxy-D-glucopyranosylidene)amino-N-phenylcarbamate (PUGNAc) increased the cell surface expression of E-selectin. A dual luciferase reporter assay indicated that high glucose and PUGNAc suppressed promoter activities of the cyclic AMP response element (CRE) and enhanced those of activator protein 1 (AP-1). Enhanced CRE promoter activities in HuH-7 cells treated with dibutyryl cAMP or co-transfected with a protein kinase A expression vector pFC-PKA that enhances the phosphorylation of CRE binding protein (CREB) were suppressed by PUGNAc. In contrast, PUGNAc further increased the enhanced AP-1 promoter activity in cells transfected with a mitogen-activated protein kinase kinase kinase expression vector pFC-MEKK that enhances c-Jun phosphorylation. Immuno-blotting using an anti-O-GlcNAc antibody revealed that high glucose and PUGNAc accelerated protein O-GlcNAcylation and that there were substantial differences in the O-GlcNAcylated proteins in the cytoplasmic and nuclear fractions. In addition, PUGNAc increased the nuclear import of O-GlcNAcylated CREB. These results suggest that protein O-GlcNAcylation modulates the promoter activities of E-selectin gene, suppression of CRE and enhancement of AP-1, and enhances E-selectin protein expression on hepatocytes.

• Authors: Yutaro Azuma, Kana Miura, Koji Higai, Kojiro Matsumoto
• Journal: Biological & pharmaceutical bulletin (Biol Pharm Bull) Vol. 30 Issue 12 Pg. 2284-9 (Dec 2007) ISSN: 0918-6158 [Print] Japan
• PMID: 18057713 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• E-Selectin
• Interleukin-1beta
• Receptors, Cell Surface
• Transcription Factor AP-1
• Cyclic AMP Response Element Modulator
• Luciferases
• CREB-Binding Protein
• Glucose
• Acetylglucosamine

Topics

• Acetylglucosamine (metabolism)
• CREB-Binding Protein (metabolism)
• Carcinoma, Hepatocellular (metabolism)
• Cell Line, Tumor
• Cyclic AMP Response Element Modulator (biosynthesis, genetics)
• E-Selectin (biosynthesis)
• Glucose (pharmacology)
• Humans
• Immunoblotting
• Interleukin-1beta (pharmacology)
• Liver Neoplasms (metabolism)
• Luciferases (metabolism)
• Promoter Regions, Genetic (genetics, physiology)
• Receptors, Cell Surface
• Transcription Factor AP-1 (biosynthesis, genetics)