Peroxisome proliferator-activated receptor activators inhibit thrombin-induced endothelin-1 production in human vascular endothelial cells by inhibiting the activator protein-1 signaling pathway

Circ Res. 1999 Sep 3;85(5):394-402. doi: 10.1161/01.res.85.5.394.

Abstract

Endothelin-1 (ET-1), a 21-amino acid vasoactive peptide mainly produced by vascular endothelial cells, is involved in the regulation of vascular tone and smooth muscle cell proliferation. Peroxisome proliferator-activated receptors (PPARs), key players in lipid and glucose metabolism, have been implicated in metabolic disorders that are predisposing to atherosclerosis. Because of the potential role of ET-1 in vascular disorders such as hypertension and atherosclerosis, we investigated the regulation of ET-1 expression by PPAR activators. Western blot and reverse transcription-polymerase chain reaction analyses demonstrated that both PPARalpha and PPARgamma are expressed in human coronary artery endothelial cells as well as in endothelial cell lines such as HMEC-1 and ECV304. In bovine aortic endothelial cells and HMEC-1 cells, both PPARalpha and PPARgamma ligands inhibited thrombin-induced ET-1 secretion, whereas basal ET-1 secretion was only slightly suppressed. Reverse transcription-polymerase chain reaction experiments showed that this inhibition of ET-1 production occurs at the gene expression level. Using transient transfection assays, we demonstrated that PPARs downregulate thrombin-activated transcription of the human ET-1 promoter. Transactivation studies with c-Jun and c-Fos expression plasmids indicated that PPARs negatively interfere with the activator protein-1 signaling pathway, which mediates thrombin activation of ET-1 gene transcription. Furthermore, electrophoretic mobility shift assays demonstrated that PPAR activators reduce the thrombin-stimulated binding activity of bovine aortic endothelial cell nuclear extracts as well as c-Jun binding to an activator protein-1 consensus site. Taken together, these data indicate that (1) both PPARalpha and PPARgamma are expressed in human vascular endothelial cells and (2) PPAR activators inhibit thrombin-induced ET-1 biosynthesis, indicating a novel role for PPARs in vascular endothelial function.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Aorta / cytology
  • Arteriosclerosis / physiopathology
  • Capillaries / cytology
  • Cattle
  • Coronary Vessels / cytology
  • DNA / genetics
  • DNA / metabolism
  • Endothelin-1 / biosynthesis*
  • Endothelin-1 / genetics
  • Endothelin-1 / metabolism
  • Gene Expression Regulation / drug effects*
  • Humans
  • Peroxisome Proliferators / pharmacology*
  • Promoter Regions, Genetic
  • Protein Binding / drug effects
  • Proto-Oncogene Proteins c-fos / physiology
  • Receptors, Cytoplasmic and Nuclear / drug effects
  • Receptors, Cytoplasmic and Nuclear / physiology*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Signal Transduction / drug effects*
  • Thrombin / antagonists & inhibitors*
  • Thrombin / pharmacology
  • Transcription Factor AP-1 / antagonists & inhibitors*
  • Transcription Factor AP-1 / physiology
  • Transcription Factors / drug effects
  • Transcription Factors / physiology*
  • Transcription, Genetic
  • Transfection

Substances

  • Endothelin-1
  • Peroxisome Proliferators
  • Proto-Oncogene Proteins c-fos
  • Receptors, Cytoplasmic and Nuclear
  • Transcription Factor AP-1
  • Transcription Factors
  • DNA
  • Thrombin