Role of mitogen-activated protein kinases in 4-hydroxy-2-nonenal-induced actin remodeling and barrier function in endothelial cells.
In vivo and in vitro studies indicate that 4-hydroxy-2-nonenal (4-HNE), generated by cellular lipid peroxidation or after oxidative stress, affects endothelial permeability and vascular tone. However, the mechanism(s) of 4-HNE-induced endothelial barrier function is not well defined. Here we provide evidence for the first time on the involvement of mitogen-activated protein kinases (MAPKs) in 4-HNE-mediated actin stress fiber formation and barrier function in lung endothelial cells. Treatment of bovine lung microvascular endothelial cells with hydrogen peroxide (H(2)O(2)), as a model oxidant, resulted in accumulation of 4-HNE as evidenced by the formation of 4-HNE-Michael protein adducts. Exposure of cells to 4-HNE, in a dose- and time-dependent manner, decreased endothelial cell permeability measured as transendothelial electrical resistance. The 4-HNE-induced permeability changes were not because of cytotoxicity or endothelial cell apoptosis, which occurred after prolonged treatment and at higher concentrations of 4-HNE. 4-HNE-induced changes in transendothelial electrical resistance were calcium independent, as 4-HNE did not alter intracellular free calcium levels as compared with H(2)O(2) or diperoxovanadate. Stimulation of quiescent cells with 4-HNE (1-100 microm) resulted in phosphorylation of ERK1/2, JNK, and p38 MAPKs, and actin cytoskeleton remodeling. Furthermore, pretreatment of bovine lung microvascular endothelial cells with PD 98059 (25 microm), an inhibitor of MEK1/2, or SP 600125 (25 microm), an inhibitor of JNK, or SB 202190 (25 microm), an inhibitor of p38 MAPK, partially attenuated 4-HNE-mediated barrier function and cytoskeletal remodeling. These results suggest that the activation of ERK, JNK, and p38 MAP kinases is involved in 4-HNE-mediated actin remodeling and endothelial barrier function.
Usatyuk
Peter V
PV
Division of Pulmonary and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland 21224, USA.
Natarajan
Viswanathan
V
D000199:Actins / Q000187:drug effects* / Q000378:metabolism; D000447:Aldehydes / Q000494:pharmacology*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002118:Calcium / Q000378:metabolism; D002417:Cattle; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism; D004789:Enzyme Activation; D008168:Lung / Q000098:blood supply; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D018384:Oxidative Stress
D000199:Actins; D000447:Aldehydes; D020928:Mitogen-Activated Protein Kinases; C027576:4-hydroxy-2-nonenal; D002118:Calcium