Lansoprazole, a proton pump inhibitor, mediates anti-inflammatory effect in gastric mucosal cells through the induction of heme oxygenase-1 via activation of NF-E2-related factor 2 and oxidation of kelch-like ECH-associating protein 1.
Induction of heme oxygenase-1 (HO-1) expression has been associated with cytoprotective and anti-inflammatory actions of lansoprazole, a proton pump inhibitor, but the underlying molecular mechanisms remain largely unresolved. In this study, we investigate the role of transcriptional NF-E2-related factor 2 (Nrf2), its phosphorylation/activation, and oxidation of Kelch-like ECH-associating protein 1 (Keap1) in lansoprazole-induced HO-1 up-regulation using cultured gastric epithelial cells (rat gastric mucosal cell line, RGM-1). HO-1 expression of RGM-1 cells was markedly enhanced in a time- and dose-dependent manner by the treatment with lansoprazole, and this up-regulation of HO-1 contributed to the inhibition of chemokine production from stimulated RGM-1 cells. Transfection of Nrf2-siRNA suppressed the lansoprazole-induced HO-1. An electrophoretic mobility shift assay showed increases in the nuclear translocation and stress-response elements (StRE) binding activity of Nrf2 proteins in RGM-1 cells treated with lansoprazole. Furthermore, in RGM-1 cells transfected with HO-1 enhancer luciferase reporter plasmid containing mutant StRE, lansoprazole-induced HO-1 reporter gene activity was diminished. Lansoprazole promoted the phosphorylation of extracellular signal-regulated kinase (ERK), and lansoprazole-induced HO-1 up-regulation was suppressed by U0126, an ERK-specific inhibitor. Phosphorylated Nrf2 protein was detected in the phosphoprotein fraction purified by a Pro-Q Diamond Phosphoprotein Enrichment kit. Finally, an oxidative form of the Keap1 protein was detected in lansoprazole-treated RGM-1 cells by analyzing S-oxidized proteins using biotinylated cysteine as a molecular probe. These results indicate that lansoprazole up-regulates HO-1 expression in rat gastric epithelial cells, and the up-regulated HO-1 contributes to the anti-inflammatory effects of the drug. Phosphorylation of ERK and Nrf2, activation and nuclear translocation of Nrf2, and oxidation of Keap1 are all involved in the lansoprazole-induced HO-1 up-regulation.
Takagi
Tomohisa
T
Kyoto Prefectural University of Medicine, Japan.
Naito
Yuji
Y
Okada
Hitomi
H
Ishii
Takeshi
T
Mizushima
Katsura
K
Akagiri
Satomi
S
Adachi
Satoko
S
Handa
Osamu
O
Kokura
Satoshi
S
Ichikawa
Hiroshi
H
Itoh
Ken
K
Yamamoto
Masayuki
M
Matsui
Hirofumi
H
Yoshikawa
Toshikazu
T
D053799:2-Pyridinylmethylsulfinylbenzimidazoles / Q000494:pharmacology*; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D002460:Cell Line; D004790:Enzyme Induction / Q000187:drug effects / Q000502:physiology; D005753:Gastric Mucosa / Q000166:cytology / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D051547:Heme Oxygenase-1 / Q000096:biosynthesis*; D007313:Insecta; D047908:Intracellular Signaling Peptides and Proteins; D000072019:Kelch-Like ECH-Associated Protein 1; D064747:Lansoprazole; D051379:Mice; D051267:NF-E2-Related Factor 2 / Q000378:metabolism* / Q000502:physiology; D010084:Oxidation-Reduction / Q000187:drug effects; D011506:Proteins / Q000378:metabolism*; D054328:Proton Pump Inhibitors / Q000494:pharmacology*; D051381:Rats
D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D000894:Anti-Inflammatory Agents, Non-Steroidal; D047908:Intracellular Signaling Peptides and Proteins; C486610:KEAP1 protein, rat; D000072019:Kelch-Like ECH-Associated Protein 1; D051267:NF-E2-Related Factor 2; D011506:Proteins; D054328:Proton Pump Inhibitors; D064747:Lansoprazole; D051547:Heme Oxygenase-1