Protective Effects Of Intestinal Trefoil Factor (ITF) On Gastric Mucosal Epithelium Through Activation Of Extracellular Signal-regulated Kinase 1/2 (ERK1/2)

Background Acid, pepsin, drugs, food and stress can result in injury to gastric mucosal epithelium. Effective repair strategies is significant to restore the structure and function of the gastric mucosa. Repair of gastric mucosal epithelium is a complex biological process. Cell migration and proliferation plays a key role in the repair of gastric mucosal epithelium. A variety of regulatory peptides can regulate the repair of gastric mucosal epithelium.Intestinal trefoil factor (trefoil factor 3, ITF, TFF3)is a significant member of the trefoil factor family (TFFs). ITF can induce migration and proliferation of many cell line. ITF is crucial for repair of gastric mucosal epithelium. At same time, ITF has been shown to contribute to gastric cytoprotection against indomethacin, ethanol, aspirin, and stress. However, the underlying molecular mechanisms that are responsible for ITF-induced gastric epithelial repair remain unclear. Activation of downstream signaling pathways is one of molecular mechanisms for ITF-induced gastric mucosal epithelium. Extracellular signal-regulated kinase 1/2 (ERK1/2) is a significant member of the mitogen-activated protein kinase(MAPK). Since ERK1/2 is known to promote cell proliferation, migration, differentiation, and survival.Objective To investigate the role of ERK1/2 in ITF-induced proliferation, migration, and cytoprotection form NS398 (nonsteroidal anti-inflammatory drug) of GES-1 cells.Method Primary cultures of GES-1 human gastric epithelial cells in vitro. GES-1 were exposed to different concentrations of ITF and U0126(a specific inhibitor of the ERK1/2 signaling pathway) at different time point. A Cell Counting Kit-8 (CCK-8) was used to evaluate cell viability. A double-chamber migration system was used to measure cell migration. The expression of ERK1/2 and phospho-ERK1/2 was evaluated by Western blot analysis. GES-1 were exposed to ITF, U0126 and NS398. Necrotic cells was assessed with FDA and PI staining. Flow cytometry measurements of cell apoptosis were performed. Measurement data are expressed as the mean± standard deviation (SD). Statistical analysis was performed with one-way variance (ANOVA) followed by the Student-Newman-Keuls’test using SPSS software. Tests were considered statistically significant when P< 0.05 (*) and P< 0.01 (**).Results 1、ITF (100 ng/ml and 500 ng/ml) induces proliferation of GES-1 cells in a dose-dependent manner.2、ITF can activate the ERK1/2 signaling pathway in GES-1 cells. Peak expression of pERKl/2 occurred after a 5 min exposure to ITF (150 ng/ml) and was maintained for 10 min.3、ITF induces the proliferation, migration of GES-1 cells via activating ERK1/2 signaling pathway.4、ITF mediate protection of GES-1 cells against NS398-induced cell death through activation of ERK1/2 signaling pathway.Conclusion ITF induces the proliferation, migration, and survival of GES-1 cells via activating ERK1/2signaling pathway. Consequently, the activation of the ERK1/2 signaling pathway may present a new therapeutic strategy for repairing gastric mucosal epithelium.