Regulation of hypoxia-inducible factor 1alpha and induction of vascular endothelial growth factor in a rat neonatal stroke model

Neurobiol Dis. 2003 Dec;14(3):524-34. doi: 10.1016/j.nbd.2003.08.020.

Abstract

Stroke is a devastating condition occurring in at least 1 in 4000 live births in the neonatal period. Since hypoxia-inducible factor (HIF)-1alpha can modulate ischemic injury via induction of target genes that may protect cells against ischemia, and is induced after preconditioning by hypoxia in the neonatal rat brain hypoxia-ischemia model, we evaluated whether HIF-1alpha is induced after focal ischemia-reperfusion, a model for neonatal stroke. We developed an ischemia-reperfusion model in postnatal day 10 (P10) rats by transiently occluding the middle cerebral artery (MCA) for 1.5 h. The MCA territory was reperfused for 0, 4, 8, or 24 h and the expression of HIF-1alpha and its target gene, vascular endothelial growth factor (VEGF), were delineated. HIF-1alpha protein and VEGF protein peaked at 8 h, and declined subsequently at 24 h in injured cortex following 1.5 h of MCA occlusion. Double-immunolabeling indicated that both HIF-1alpha and VEGF are expressed together in neurons with a similar time course of expression. The presence of HIF-1alpha and VEGF after moderate ischemia-reperfusion injury suggests potential avenues to exploit for neuroprotection.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Animals, Newborn
  • Brain / metabolism
  • Brain / physiopathology
  • Disease Models, Animal*
  • Female
  • Gene Expression / physiology
  • Hypoxia-Inducible Factor 1, alpha Subunit
  • Hypoxia-Ischemia, Brain / metabolism*
  • Hypoxia-Ischemia, Brain / physiopathology
  • Infarction, Middle Cerebral Artery / metabolism
  • Infarction, Middle Cerebral Artery / physiopathology
  • Neurons / metabolism
  • Neurons / pathology
  • RNA, Messenger / metabolism
  • Rats
  • Rats, Sprague-Dawley
  • Reaction Time / physiology
  • Reperfusion Injury / metabolism
  • Reperfusion Injury / physiopathology
  • Stroke / metabolism*
  • Stroke / physiopathology
  • Transcription Factors / metabolism*
  • Up-Regulation / physiology
  • Vascular Endothelial Growth Factor A / genetics*
  • Vascular Endothelial Growth Factor A / metabolism

Substances

  • Hypoxia-Inducible Factor 1, alpha Subunit
  • RNA, Messenger
  • Transcription Factors
  • Vascular Endothelial Growth Factor A