Glycosylation with O-linked beta-N-acetylglucosamine induces vascular dysfunction via production of superoxide anion/reactive oxygen species

Author(s)

Souza-Silva, Leonardo ^[1] ; Alves-Lopes, Rheure ^{[2, 3]} ; Miguez, Jessica Silva ^[1] ; Dela Justina, Vanessa ^[1] ; Neves, Karla Bianca ^{[2, 3]} ; Mestriner, Fabiola Leslie ^[3] ; Tostes, Rita de Cassia ^[3] ; Giachini, Fernanda Regina ^[1] ; Lima, Victor Vitorino ^[1]

Affiliation

^[1] Univ Fed Mato Grosso, Inst Biol & Hlth Sci, Barra Do Garcas, MT - Brazil

^[2] Univ Glasgow, BHF Glasgow Cardiovasc Res Ctr, Inst Cardiovasc & Med Sci, Glasgow, Lanark - Scotland

^[3] Univ Sao Paulo, Ribeirao Preto Med Sch, Dept Pharmacol, Ribeirao Preto - Brazil

• Document type: Journal article
• Source: Canadian Journal of Physiology and Pharmacology; v. 96, n. 3 MAR 2018.
• Web of Science Citations: 0

Abstract

Overproduction of superoxide anion (center dot O-2(-)) and O-linked beta-N-acetylglucosamine (O-GlcNAc) modification in the vascular system are contributors to endothelial dysfunction. This study tested the hypothesis that increased levels of O-GlcNAc-modified proteins contribute to center dot O-2(-) production via activation of NADPH oxidase, resulting in impaired vasodilation. Rat aortic segments and vascular smooth muscle cells (VSMCs) were incubated with vehicle (methanol) or O-(2-acetamido-2-deoxy-D-glucopyranosylidenamino) N-phenylcarbamate (PUGNAc) (100 mu M). PUGNAc produced a time-dependent increase in O-GlcNAc levels in VSMC and decreased endothelium-dependent relaxation, which was prevented by apocynin and tiron, suggesting that O-2(-) contributes to endothelial dysfunction under augmented O-GlcNAc levels. Aortic segments incubated with PUGNAc also exhibited increased levels of reactive oxygen species, assessed by dihydroethidium fluorescence, and augmented center dot O-2(-) production, determined by lucigenin-enhanced chemiluminescence. Additionally, PUGNAc treatment increased Nox-1 and Nox-4 protein expression in aortas and VSMCs. Translocation of the p47(phox) subunit from the cytosol to the membrane was greater in aortas incubated with PUGNAc. VSMCs displayed increased p22(phox) protein expression after PUGNAc incubation, suggesting that NADPH oxidase is activated in conditions where O-GlcNAc protein levels are increased. In conclusion, O-GlcNAc levels reduce endothelium-dependent relaxation by overproduction of center dot O-2(-) via activation of NADPH oxidase. This may represent an additional mechanism by which augmented O-GlcNAc levels impair vascular function. (AU)

• FAPESP's process: 13/08216-2 - CRID - Center for Research in Inflammatory Diseases
• Grantee: Fernando de Queiroz Cunha
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC