Reference - Detail
|Author||Miyazaki Y, Hiraoka S, Tsutsui S, Kitamura S, Shinomura Y, Matsuzawa Y.|
|Title||Epidermal growth factor receptor mediates stress-induced expression of its ligands in rat gastric epithelial cells.|
BACKGROUND & AIMS:Epidermal growth factor (EGF)-like growth factors are induced after acute gastric injury and may play an important role in mucosal repair. However, the mechanisms that trigger these growth factors are poorly understood. We determined the role of EGF receptor (EGFR) in stress-induced expression of heparin-binding EGF-like growth factor (HB-EGF) in a rat gastric epithelial cell line (RGM1 cells).
METHODS:RGM1 cells were transfected with a plasmid containing complementary DNA encoding a dominant-negative human EGFR (HERCD533). Cells were treated with hydrogen peroxide (0-400 micromol/L) or sorbitol (600 mmol/L). Tyrosine phosphorylation of EGFR was determined by immunoprecipitation and Western blotting with an antiphosphotyrosine antibody. HB-EGF messenger RNA and protein were determined with Northern and Western blotting, respectively. Cell growth was evaluated by cell number and [(3)H]thymidine incorporation.
RESULTS:Oxidative stress and osmotic stress induced tyrosine phosphorylation of EGFR within 2 minutes, followed by a marked increase in HB-EGF and amphiregulin transcripts in RGM1 cells. Introduction of HERCD533 into the cells inhibited not only tyrosine phosphorylation of EGFR but also growth response to EGF. Furthermore, oxidative stress-induced HB-EGF messenger RNA expression was impaired in HERCD533-expressing cells.
CONCLUSIONS:EGFR plays a crucial role in the stress-induced expression of EGF-like growth factors in gastrointestinal epithelial cells.
|MeSH||Amphiregulin Animals Blotting, Western Culture Media, Serum-Free / pharmacology DNA, Complementary EGF Family of Proteins Epidermal Growth Factor / analysis Epidermal Growth Factor / genetics* Epidermal Growth Factor / metabolism Epidermal Growth Factor / pharmacology ErbB Receptors / genetics* ErbB Receptors / metabolism* Gastric Mucosa / cytology Gastric Mucosa / drug effects Gastric Mucosa / metabolism* Gene Expression Regulation / drug effects Gene Expression Regulation / physiology Glycoproteins / genetics Growth Substances / genetics Heparin-binding EGF-like Growth Factor Intercellular Signaling Peptides and Proteins* Ligands Oxidative Stress / physiology* Phosphorylation Promoter Regions, Genetic / physiology Proto-Oncogene Proteins c-met / metabolism RNA, Messenger / metabolism Rats Rats, Wistar Receptor, ErbB-2 / metabolism Receptor, ErbB-3 / metabolism Transfection Transforming Growth Factor alpha / genetics Tyrosine / metabolism|
|Human and Animal Cells||RGM1(RCB0876)|