Normal and high eNOS levels are detrimental in both mild and severe cardiac pressure-overload

Elza D. van Deel, Yanti Octavia, Martine de Boer, Rio P. Juni, Dennie Tempel, Rien van Haperen, Rini de Crom, An L. Moens, Daphne Merkus, Dirk J. Duncker*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

10 Citations (Web of Science)

Abstract

Nitric oxide (NO) produced by endothelial NO synthase (eNOS) exerts beneficial effects in a variety of cardiovascular disease states. Studies on the benefit of eNOS activity in pressure-overload cardiac hypertrophy and dysfunction produced by aortic stenosis are equivocal, which may be due to different expression levels of eNOS or different severities of pressure-overload. Consequently, we investigated the effects of eNOS-expression level on cardiac hypertrophy and dysfunction produced by mild or severe pressure-overload. To unravel the impact of eNOS on pressure-overload cardiac dysfunction we subjected eNOS deficient, wildtype and eNOS overexpressing transgenic (eNOS-Tg)mice to 8 weeks of mild or severe transverse aortic constriction (TAC) and studied cardiac geometry and function at the whole organ and tissue level. In both mild and severe TAC, lack of eNOS ameliorated, whereas eNOS overexpression aggravated, TAC-induced cardiac remodeling and dysfunction. Moreover, the detrimental effects of eNOS in severe TAC were associated with aggravation of TAC-induced NOS-dependent oxidative stress and by further elevation of eNOS monomer levels, consistent with enhanced eNOS uncoupling. In the presence of TAC, scavenging of reactive oxygen species with N-acetylcysteine reduced eNOS S-glutathionylation, eNOS monomer and NOS-dependent superoxide levels in eNOS-Tg mice to wildtype levels. Accordingly, N-acetylcysteine improved cardiac function in eNOS-Tg but not in wildtype mice with TAC. In conclusion, independent of the severity of TAC, eNOS aggravates cardiac remodeling and dysfunction, which appears due to TAC-induced eNOS uncoupling and superoxide production.
Original languageEnglish
Pages (from-to)145-154
JournalJournal of Molecular and Cellular Cardiology
Volume88
DOIs
Publication statusPublished - Nov 2015

Keywords

  • Cardiac pressure-overload
  • eNOS uncoupling
  • Oxidative stress
  • Cardiac remodeling
  • Cardiac dysfunction

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