Molecular mechanism and functional consequences of lansoprazole-mediated heme oxygenase-1 induction.
OBJECTIVE
To investigate the molecular mechanism and functional consequences of heme oxygenase-1 (HO-1) activation by lansoprazole in endothelial cells and macrophages.


METHODS
Expression of HO-1 mRNA was analyzed by Northern blotting. Western blotting was used to determine the HO-1 and ferritin protein levels. NADPH-dependent reactive oxygen species (ROS) formation was measured with lucigenin-enhanced chemiluminescence. HO-1 promoter activity in mouse fibroblasts, stably transfected with a 15-kb HO-1 gene that drives expression of the reporter gene luciferase, was assessed using in vivo bioluminescence imaging.


RESULTS
Lansoprazole increased HO-1 mRNA levels in endothelial cells and HO-1 protein levels in macrophages. In addition, lansoprazole-induced ferritin protein levels in both cell systems. Moreover, induction of the antioxidant proteins HO-1 and ferritin by lansoprazole was followed by a decrease in NADPH-mediated ROS formation. The radical scavenging properties of lansoprazole were diminished in the presence of the HO inhibitor, chromium mesoporphyrin IX. Induction of HO-1 gene expression by lansoprazole was not related to oxidative stress or to the activation of the mitogen-activated protein kinase pathway. However, the phosphatidylinositol 3-kinase inhibitor LY294002 showed a concentration-dependent inhibition of HO-1 mRNA and promoter activity.


CONCLUSIONS
Activation of HO-1 and ferritin may account for the gastric protection of lansoprazole and is dependent on a pathway blocked by LY294002.
Schulz-Geske
Stephanie
S
Department of Pharmacology and Toxicology, School of Pharmacy, Martin Luther University Halle-Wittenberg, 06099 Halle, Germany.
Erdmann
Kati
K
Wong
Ronald J
RJ
Stevenson
David K
DK
Schröder
Henning
H
Grosser
Nina
N
D053799:2-Pyridinylmethylsulfinylbenzimidazoles / Q000494:pharmacology*; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D015152:Blotting, Northern; D015153:Blotting, Western; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism*; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005293:Ferritins / Q000235:genetics / Q000378:metabolism*; D015971:Gene Expression Regulation, Enzymologic; D017506:H(+)-K(+)-Exchanging ATPase; D051547:Heme Oxygenase-1 / Q000187:drug effects / Q000378:metabolism*; D064747:Lansoprazole; D049449:Luminescence; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D011401:Promoter Regions, Genetic; D054328:Proton Pump Inhibitors; D012333:RNA, Messenger / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism
D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D000975:Antioxidants; D004791:Enzyme Inhibitors; D054328:Proton Pump Inhibitors; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; D064747:Lansoprazole; D005293:Ferritins; D051547:Heme Oxygenase-1; D017506:H(+)-K(+)-Exchanging ATPase