Endothelin-1 impairs nitric oxide signaling in endothelial cells through a protein kinase cδ-dependent activation of STAT3 and decreased endothelial nitric oxide synthase expression

Neetu Sud, Stephen M. Black

Research output: Contribution to journalArticle

22 Scopus citations

Abstract

In an ovine model of persistent pulmonary hypertension of the newborn (PPHN), endothelin-1 (ET-1) expression is increased, while endothelial nitric oxide synthase (eNOS) expression is decreased. However, the molecular mechanisms by which ET-1 attenuates eNOS expression in endothelial cells are not completely understood. Thus, the goal of this study was to determine if the overexpression of ET-1 decreases eNOS expression in pulmonary arterial endothelial cells isolated from fetal lambs. To increase the ET-1 expression, cells were transfected with a plasmid coding for Prepro-ET-1, a precursor of ET-1. After overexpression of Prepro-ET-1, ET-1 levels in the culture medium were significantly increased (control=805.3±69.8; Prepro-ET-1 overexpression=1351±127.9). eNOS promoter activity, protein levels, and NO generation were all significantly decreased by the overexpression of Prepro-ET-1. The decrease in transcription correlated with increased activity of protein kinase Cδ (PKCδ) and STAT3. Further, DNA binding activity of STAT3 was also increased by Prepro-ET-1 overexpression. The increase in STAT3 activity and decrease in eNOS promoter activity were inhibited by the overexpression of dominant negative mutants of PKCδ or STAT3. Further, a 2bp mutation in the STAT3 binding site in the eNOS promoter inhibited STAT3 binding and led to enhanced promoter activity in the presence of Prepro-ET-1 overexpression. In conclusion, ET-1 secretion is increased by Prepro-ET-1 overexpression. This results in activation of PKCδ, which phosphorylates STAT3, increasing its binding to the eNOS promoter. This in turn decreases eNOS promoter activity, protein levels, and NO production. Thus, ET-1 can reduce eNOS expression and NO generation in fetal pulmonary artery endothelial cells through PKCδ-mediated activation of STAT3.

Original languageEnglish (US)
Pages (from-to)543-553
Number of pages11
JournalDNA and cell biology
Volume28
Issue number11
DOIs
Publication statusPublished - Nov 1 2009

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ASJC Scopus subject areas

  • Molecular Biology
  • Genetics
  • Cell Biology

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