Abrupt reoxygenation of microvascular endothelial cells after hypoxia activates ERK1/2 and JNK1, leading to NADPH oxidase-dependent oxidant production

Microcirculation. 2007 Feb;14(2):125-36. doi: 10.1080/10739680601131218.


Objective: Mitogen-activated protein kinases (MAPK) in microvascular endothelial cells (EC) may participate in organ pathophysiology following hypoxia/reoxygenation (H/R). The authors aimed to determine the role of MAPK in H/R-induced reactive oxygen species (ROS) generation in mouse microvascular EC.

Methods: Cultured EC derived from skeletal muscle of male wild-type (WT), gp91phox-/- or p47phox-/- mice were subjected to hypoxia (0.1% O2, 1 h) followed by abrupt reoxygenation, H/RA (hypoxic medium quickly replaced by normoxic medium), or slow reoxygenation, H/RS (O2 diffused to cells through hypoxic medium). Cells were analyzed for ERK, JNK, and p38 MAPK phosphorylation, NADPH oxidase activation, and ROS generation.

Results: In WT cells, H/RA but not H/RS rapidly phosphorylated ERK1/2 and JNK1 and subsequently increased ROS production. H/RA did not affect p38. MAPK phosphorylation persisted despite inhibition of NADPH oxidase, mitochondrial respiration, protein tyrosine kinase, or PKC. ROS increase during H/RA was prevented by deletion of gp91phox or p47phox, or MAPK inhibition.

Conclusions: Abrupt reoxygenation after hypoxia activates ERK1/2 and JNK1 in mouse microvascular endothelial cells via a tyrosine kinase-, PKC-, and NADPH oxidase-insensitive mechanism, leading to increased NADPH oxidase-dependent ROS production. The results suggest that MAPK activation in the microvascular endothelium is O2-sensitive, contributing critically to tissue pathophysiology after H/R.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Endothelial Cells / metabolism*
  • Hypoxia / metabolism*
  • MAP Kinase Signaling System / drug effects
  • MAP Kinase Signaling System / physiology*
  • Male
  • Membrane Glycoproteins / metabolism
  • Mice
  • Mice, Inbred C57BL
  • Mice, Mutant Strains
  • Microcirculation / physiology*
  • Mitogen-Activated Protein Kinase 1 / metabolism
  • Mitogen-Activated Protein Kinase 3 / metabolism
  • Mitogen-Activated Protein Kinase 8 / metabolism
  • Muscle, Skeletal / blood supply
  • Muscle, Skeletal / metabolism
  • NADPH Oxidase 2
  • NADPH Oxidases / metabolism
  • Oxidative Stress / physiology*
  • Oxygen / metabolism
  • Phosphorylation
  • Protein Kinase Inhibitors / pharmacology
  • Reactive Oxygen Species / metabolism


  • Membrane Glycoproteins
  • Protein Kinase Inhibitors
  • Reactive Oxygen Species
  • Cybb protein, mouse
  • NADPH Oxidase 2
  • NADPH Oxidases
  • neutrophil cytosolic factor 1
  • Mitogen-Activated Protein Kinase 1
  • Mitogen-Activated Protein Kinase 3
  • Mitogen-Activated Protein Kinase 8
  • Oxygen