Short-term effects of pharmacologic HIF stabilization on vasoactive and cytotrophic factors in developing mouse brain

Brain Res. 2009 Jul 14:1280:43-51. doi: 10.1016/j.brainres.2009.05.023. Epub 2009 May 18.

Abstract

Hypoxia-inducible transcription factors (HIFs) are crucially involved in brain development and cellular adaptation to hypoxia and ischemia. Degradation of HIF is regulated under normoxia by oxygen-dependent hydroxylation of specific prolyl residues on the labile alpha-subunit by HIF prolyl hydroxylases (PHD). Prolyl-4-hydroxylase inhibitors (PHI) have shown protective effects in vitro and in vivo in adult kidney and brain. The aim of the present study was to investigate in vivo short-term effects of a novel low molecular weight PHI, FG-4497, on HIF-regulated cytotrophic and vasoactive factors in developing mouse brain. Neonatal (P7, n=26) C57/BL6 mice were treated with PHI FG-4497 (30-100 mg/kg, i.p., duration 6 h). Gene expression was analyzed by TaqMan RT-PCR in kidney and developing brain in comparison to controls (NaCl 0.9% and non-treated animals). HIF-1alpha protein was quantified by Western blot analysis. Dose-response studies revealed prominent effects of FG-4497 at a dose of 100 mg/kg as assessed by significant up-regulation of mRNA in both kidney and brain of the following HIF-dependent genes: vascular endothelial growth factor, adrenomedullin and erythropoietin. Organ-specific transcriptional regulation was evident from analysis of hexokinase 2, inducible NO synthase and PHD3 mRNA concentrations. In the brain, HIF-1alpha and HIF-2alpha protein markedly accumulated in response to FG-4497. Besides vasoactive factors, PHI significantly increased cerebral chemokine receptor CXCR-4 mRNA levels. In conclusion, the novel PHI FG-4497 activates HIFs at an early stage of brain maturation and modulates neurotrophic processes known to be crucially involved in brain development and hypoxia-induced brain pathology.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adrenomedullin / metabolism
  • Animals
  • Animals, Newborn
  • Basic Helix-Loop-Helix Transcription Factors / metabolism*
  • Brain / drug effects
  • Brain / growth & development*
  • Brain / metabolism
  • Dose-Response Relationship, Drug
  • Enzyme Inhibitors / pharmacology*
  • Erythropoietin / metabolism
  • Gene Expression / drug effects
  • Hexokinase / metabolism
  • Hypoxia-Inducible Factor 1, alpha Subunit / genetics
  • Hypoxia-Inducible Factor 1, alpha Subunit / metabolism*
  • Kidney / drug effects
  • Kidney / growth & development
  • Kidney / metabolism
  • Mice
  • Mice, Inbred C57BL
  • Nitric Oxide Synthase Type II / metabolism
  • Procollagen-Proline Dioxygenase / antagonists & inhibitors*
  • Procollagen-Proline Dioxygenase / metabolism
  • RNA, Messenger / metabolism
  • Receptors, CXCR4 / metabolism
  • Vascular Endothelial Growth Factor A / metabolism

Substances

  • Basic Helix-Loop-Helix Transcription Factors
  • CXCR4 protein, mouse
  • Enzyme Inhibitors
  • Hif1a protein, mouse
  • Hypoxia-Inducible Factor 1, alpha Subunit
  • RNA, Messenger
  • Receptors, CXCR4
  • Vascular Endothelial Growth Factor A
  • Erythropoietin
  • Adrenomedullin
  • endothelial PAS domain-containing protein 1
  • Procollagen-Proline Dioxygenase
  • Nitric Oxide Synthase Type II
  • Hexokinase