Intermittent hypoxia-induced endothelial barrier dysfunction requires ROS-dependent MAP kinase activation.
The objective of the present study was to determine the impact of simulated apnea with intermittent hypoxia (IH) on endothelial barrier function and assess the underlying mechanism(s). Experiments were performed on human lung microvascular endothelial cells exposed to IH-consisting alternating cycles of 1.5% O2 for 30s followed by 20% O2 for 5 min. IH decreased transendothelial electrical resistance (TEER) suggesting attenuated endothelial barrier function. The effect of IH on TEER was stimulus dependent and reversible after reoxygenation. IH-exposed cells exhibited stress fiber formation and redistribution of cortactin, vascular endothelial-cadherins, and zona occludens-1 junction proteins along with increased intercellular gaps at cell-cell boundaries. Extracellular signal-regulated kinase (ERK) and c-jun NH2-terminal kinase (JNK) were phosphorylated in IH-exposed cells. Inhibiting either ERK or JNK prevented the IH-induced decrease in TEER and the reorganization of the cytoskeleton and junction proteins. IH increased reactive oxygen species (ROS) levels, and manganese (III) tetrakis (1-methyl-4-pyridyl) porphyrin pentachloride, a membrane-permeable antioxidant, prevented ERK and JNK phosphorylation as well as IH-induced changes in endothelial barrier function. These results demonstrate that IH via ROS-dependent activation of MAP kinases leads to reorganization of cytoskeleton and junction proteins resulting in endothelial barrier dysfunction.
University of Chicago, Institute For Integrative Physiology and Center for Systems Biology of O2 Sensing, Chicago, Illinois; and.
Vladislav V
VV
Makarenko
Peter V
PV
Usatyuk
Guoxiang
G
Yuan
May M
MM
Lee
Jayasri
J
Nanduri
Viswanathan
V
Natarajan
Ganesh K
GK
Kumar
Nanduri R
NR
Prabhakar
D002478:Cells, Cultured; D003599:Cytoskeleton / Q000502:physiology; D017097:Electric Impedance; D042783:Endothelial Cells / Q000187:drug effects* / Q000502:physiology*; D004789:Enzyme Activation; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D000860:Hypoxia / Q000378:metabolism; D007365:Intercellular Junctions / Q000378:metabolism; D008168:Lung / Q000098:blood supply; D020929:Mitogen-Activated Protein Kinase Kinases / Q000378:metabolism*; D018384:Oxidative Stress; D010100:Oxygen / Q000378:metabolism / Q000494:pharmacology*; D010766:Phosphorylation; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013997:Time Factors
D017382:Reactive Oxygen Species; D020929:Mitogen-Activated Protein Kinase Kinases; D010100:Oxygen
cytoskeleton proteins; junction proteins; microvascular endothelial cells; oxidative stress