O-GlcNAcylation contributes to the vascular effects of ET-1 via activation of the RhoA/Rho-kinase pathway

Victor V. Lima, Fernanda R. Giachini, Fernando S. Carneiro, Maria Helena C. Carvalho, Zuleica B. Fortes, R. Clinton Webb, Rita C. Tostes

Research output: Contribution to journalArticlepeer-review

44 Scopus citations

Abstract

AimsGlycosylation with β-N-acetylglucosamine (O-GlcNAcylation) is one of the most complex post-translational modifications. The cycling of O-GlcNAc is controlled by two enzymes: UDP-NAc transferase (OGT) and O-GlcNAcase (OGA). We recently reported that endothelin-1 (ET-1) augments vascular levels of O-GlcNAcylated proteins. Here we tested the hypothesis that O-GlcNAcylation contributes to the vascular effects of ET-1 via activation of the RhoA/Rho-kinase pathway.Methods and resultsIncubation of vascular smooth muscle cells (VSMCs) with ET-1 (0.1 μM) produces a time-dependent increase in O-GlcNAc levels. ET-1-induced O-GlcNAcylation is not observed when VSMCs are previously transfected with OGT siRNA, treated with ST045849 (OGT inhibitor) or atrasentan (ETA antagonist). ET-1 as well as PugNAc (OGA inhibitor) augmented contractions to phenylephrine in endothelium-denuded rat aortas, an effect that was abolished by the Rho kinase inhibitor Y-27632. Incubation of VSMCs with ET-1 increased expression of the phosphorylated forms of myosin phosphatase target subunit 1 (MYPT-1), protein kinase C-potentiated protein phosphatase 1 inhibitor protein (protein kinase C-potentiated phosphatase inhibitor-17), and myosin light chain (MLC) and RhoA expression and activity, and this effect was abolished by both OGT siRNA transfection or OGT inhibition and atrasentan. ET-1 also augmented expression of PDZ-Rho GEF (guanine nucleotide exchange factor) and p115-Rho GEF in VSMCs and this was prevented by OGT siRNA, ST045849, and atrasentan.ConclusionWe suggest that ET-1 augments O-GlcNAcylation and this modification contributes to increased vascular contractile responses via activation of the RhoA/Rho-kinase pathway.

Original languageEnglish (US)
Pages (from-to)614-622
Number of pages9
JournalCardiovascular Research
Volume89
Issue number3
DOIs
StatePublished - Feb 15 2011
Externally publishedYes

Keywords

  • Endothelin-1
  • RhoA/Rho-kinase pathway
  • Vascular reactivity
  • β-N-acetylglucosamine

ASJC Scopus subject areas

  • Physiology
  • Cardiology and Cardiovascular Medicine
  • Physiology (medical)

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