Endothelin-converting enzyme is a plausible target gene for hypoxia-inducible factor

Kidney Int. 2015 Apr;87(4):761-70. doi: 10.1038/ki.2014.362. Epub 2014 Dec 3.

Abstract

Renal endothelin-converting enzyme (ECE)-1 is induced in experimental diabetes and following radiocontrast administration, conditions characterized by renal hypoxia, hypoxia-inducible factor (HIF) stabilization, and enhanced endothelin synthesis. Here we tested whether ECE-1 might be a HIF-target gene in vitro and in vivo. ECE-1 transcription and expression increased in cultured vascular endothelial and proximal tubular cell lines, subject to hypoxia, to mimosine or cobalt chloride. These interventions are known to stabilize HIF signaling by inhibition of HIF-prolyl hydroxylases. In rats, HIF-prolyl-hydroxylase inhibition by mimosine or FG-4497 increased HIF-1α immunostaining in renal tubules, principally in distal nephron segments. This was associated with markedly enhanced ECE-1 protein expression, predominantly in the renal medulla. A progressive and dramatic increase in ECE-1 immunostaining over time, in parallel with enhanced HIF expression, was also noted in conditional von Hippel-Lindau knockout mice. Since HIF and STAT3 are cross-stimulated, we triggered HIF expression by STAT3 activation in mice, transfected by or injected with a chimeric IL-6/IL-6-receptor protein, and found a similar pattern of enhanced ECE-1 expression. Chromatin immunoprecipitation sequence (ChIP-seq) and PCR analysis in hypoxic endothelial cells identified HIF binding at the ECE-1 promoter and intron regions. Thus, our findings suggest that ECE-1 may be a novel HIF-target gene.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Aspartic Acid Endopeptidases / genetics*
  • Aspartic Acid Endopeptidases / metabolism*
  • Cell Hypoxia / physiology
  • Cells, Cultured
  • Cobalt / pharmacology
  • Dioxygenases / antagonists & inhibitors
  • Endothelin-Converting Enzymes
  • Human Umbilical Vein Endothelial Cells
  • Humans
  • Hypoxia-Inducible Factor 1, alpha Subunit / metabolism*
  • Introns
  • Kidney Tubules, Proximal / cytology
  • Kidney Tubules, Proximal / metabolism
  • Male
  • Metalloendopeptidases / genetics*
  • Metalloendopeptidases / metabolism*
  • Mice
  • Mice, Inbred BALB C
  • Mice, Knockout
  • Mimosine / pharmacology
  • Oligonucleotide Array Sequence Analysis
  • Prolyl-Hydroxylase Inhibitors / pharmacology
  • Promoter Regions, Genetic
  • Rats
  • Rats, Sprague-Dawley
  • STAT3 Transcription Factor / metabolism
  • Signal Transduction / drug effects
  • Signal Transduction / physiology
  • Transcription, Genetic
  • von Hippel-Lindau Disease / genetics
  • von Hippel-Lindau Disease / metabolism

Substances

  • Hif1a protein, rat
  • Hypoxia-Inducible Factor 1, alpha Subunit
  • Prolyl-Hydroxylase Inhibitors
  • STAT3 Transcription Factor
  • Stat3 protein, mouse
  • Cobalt
  • Mimosine
  • Dioxygenases
  • HIF prolyl hydroxylase, rat
  • Aspartic Acid Endopeptidases
  • Metalloendopeptidases
  • ECE1 protein, human
  • Ece1 protein, mouse
  • Endothelin-Converting Enzymes
  • cobaltous chloride