Redox regulation of reactive oxygen species-induced p38 MAP kinase activation and barrier dysfunction in lung microvascular endothelial cells.
Reactive oxygen species (ROS)-mediated compromise of endothelial barrier integrity has been implicated in a number of pulmonary disorders, including adult respiratory distress syndrome, pulmonary edema, and vasculitis. The mechanisms by which ROS increase endothelial permeability are unclear. We hypothesized that ROS-induced changes in cellular redox status (thiols) may contribute to endothelial barrier dysfunction. To test this hypothesis, we used N-acetylcysteine (NAC) and diamide to modulate intracellular levels of cellular glutathione (GSH) and investigated hydrogen peroxide (H(2)O(2))-mediated mitogen-activated protein kinase (MAPK) activation and transendothelial electrical resistance (TER). Exposure of bovine lung microvascular endothelial cells (BLMVECs) to H(2)O(2), in a dose- and time-dependent fashion, increased endothelial permeability. Pretreatment of BLMVECs with NAC (5 mM) for 1 h resulted in partial attenuation of H(2)O(2)-induced TER (a measure of increase in permeability) and GSH. Furthermore, treatment of BLMVECs with diamide, which is known to reduce the intracellular GSH, resulted in significant reduction in TER, which was prevented by NAC. To understand further the role of MAPKs in ROS-induced barrier dysfunction, we examined the role of extracellular signal-regulated kinase (ERK) and p38 MAPK on H(2)O(2)- and diamide-mediated permeability changes. Both H(2)O(2) and diamide, in a dose-dependent manner, activated ERK and p38 MAPK in BLMVECs. However, SB203580, an inhibitor of p38 MAPK, but not PD98059, blocked H(2)O(2)- and diamide-induced TER. Also, NAC prevented H(2)O(2)- and diamide-induced p38 MAPK, but not ERK activation. These results suggest a role for redox regulation of p38 MAPK in ROS-dependent endothelial barrier dysfunction.
Department of Medicine, Division of Pulmonary and Critical Care, Johns Hopkins University School of Medicine, Baltimore, MD 21224, USA.
Peter V
PV
Usatyuk
Suryanarayana
S
Vepa
Tonya
T
Watkins
Donghong
D
He
Narasimham L
NL
Parinandi
Viswanathan
V
Natarajan
D000111:Acetylcysteine / Q000378:metabolism; D000818:Animals; D015153:Blotting, Western; D002417:Cattle; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000166:cytology*; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005419:Flavonoids / Q000494:pharmacology; D005978:Glutathione / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007093:Imidazoles / Q000494:pharmacology; D008168:Lung / Q000098:blood supply*; D020935:MAP Kinase Signaling System; D008833:Microcirculation; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D010084:Oxidation-Reduction; D010539:Permeability; D011725:Pyridines / Q000494:pharmacology; D017382:Reactive Oxygen Species; D013997:Time Factors; D048051:p38 Mitogen-Activated Protein Kinases
D004791:Enzyme Inhibitors; D005419:Flavonoids; D007093:Imidazoles; D011725:Pyridines; D017382:Reactive Oxygen Species; D006861:Hydrogen Peroxide; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D005978:Glutathione; C093642:SB 203580; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one; D000111:Acetylcysteine