|
|
||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
MUCOSAL BIOLOGY
1Second Department of Internal Medicine; 2Department of Anatomy and Cell Biology, Wakayama Medical University, Wakayama; 3Department of Legal Medicine, Graduate School of Medicine, University of Tokyo; and 4Department of Forensic Medicine, Juntendo University School of Medicine, Tokyo, Japan
Submitted 6 May 2007 ; accepted in final form 8 July 2008
Disturbance of the microcirculation and generation of reactive oxygen species are crucial in producing acute gastric mucosal lesions (AGML). To understand the protective mechanism against mucosal injury and oxidative stress in the stomach, we investigated sequential expression and localization of a product of lipid peroxidation and a chemical mediator of the oxidative response array, 4-hydroxynonenal (HNE), transcriptional factor, NF-E2-related factor (Nrf2), and the inducible heme oxygenase (HO-1) in the injured stomach. AGML was produced by intragastric administration of 0.6 N HCl in male rats. Expression and localization of HNE, Nrf2, and HO-1 were investigated by Western blotting, immunohistochemistry, real-time RT-PCR, and in situ hybridization histochemistry. Mucosal lesions and expression of HNE and HO-1 were assessed by prior treatment with the PGI2 analog beraprast or after sensory denervation by pretreatment with capsaicin. Mucosal lesions were assessed by prior treatment with a HO-1 inhibitor, zinc protoporphyrin (ZnPP). After AGML, increased generation of HNE was observed in the injured mucosa and the surrounding submucosa, followed by nuclear translocation of Nrf2 and upregulation of HO-1 in the macrophages located in the margin of the injured mucosa and in the submucosa. Pretreatment with beraprost attenuated AGML and downregulated the expression of HNE and HO-1, while sensory denervation aggravated AGML and upregulated the expression of HNE and HO-1. Pretreatment with ZnPP also aggravated AGML. The sequential HNE-Nrf2-HO-1 pathway in the gastric mucosal cells and the macrophages is involved in an adaptive mechanism against oxidative stress after AGML.
heat shock protein 32; reactive oxygen species; microcirculation; macrophages; 4-hydroxynonenal; heme oxygenase
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |