ABSTRACT
Objective To investigate the mechanism of bone morphogenetic protein 4(BMP4) in the genesis of Barrett′s esophagus.Methods Human esophageal epithelial cell (HEEC) and MRC-5 were cultured.The effects of different concentration of BMP4 and different pH value of hydrochloric acid or glycocholic acid on the expression of caudal-related homeobox transcription factor 2(CDX2) in HEEC were detected by real time polymerase chain reaction.The effects of different pH value of hydrochloric acid or glycocholic acid on BMP4 expression in MRC-5 were also investigated.Independent sample t test was performed for statistical analysis.Results After HEEC stimulated by BMP4 at 0.1, 1.0, 10.0 and 100.0 ng/mL, the relative quantity expressions of CDX2 were 1.617±0.246, 2.489±0.455, 5.629±0.449 and 13.670±1.689, respectively, which were higher than those of control group (1.000±0.043, 1.029±0.094, 1.001±0.002 and 1.049±0.051, respectively), and the differences were statistically significant (t=2.47, 3.14, 10.31, 7.47;all P<0.05).After MRC-5 stimulated by acid at pH four or five, or glycocholic acid at pH four or five, the relative quantity expressions of BMP4 were 2.430±0.105, 2.394±0.145, 125.900±12.620 and 2.128±0.215, respectively, which were higher than those of control group(1.025±0.095, 0.999±0.007, 1.060±0.138 and 0.893±0.110,respectively), and the differences were statistically significant (t=9.94, 9.59, 9.89, 5.11;all P<0.01).Conclusion BMP4 can increase the expression of CDX2 in HEEC, which promote the genesis of Barrett′s esophagus.
ABSTRACT
In this study, we focused to identify whether eupatilin (5,7-dihydroxy-3',4',6-trimethoxyflavone), an extract from Artemisia argyi folium, prevents H2O2-induced injury of cultured feline esophageal epithelial cells. Cell viability was measured by the conventional MTT reduction assay. Western blot analysis was performed to investigate the expression of 5-lipoxygenase by H2O2 treatment in the absence and presence of inhibitors. When cells were exposed to 600 microM H2O2 for 24 hours, cell viability was decreased to 40%. However, when cells were pretreated with 25~150 microM eupatilin for 12 hours, viability was significantly restored in a concentration-dependent manner. H2O2-treated cells were shown to express 5-lipoxygenase, whereas the cells pretreated with eupatilin exhibited reduction in the expression of 5-lipoxygenase. The H2O2-induced increase of 5-lipoxygenase expression was prevented by SB202190, SP600125, or NAC. We further demonstrated that the level of leukotriene B4 (LTB4) was also reduced by eupatilin, SB202190, SP600125, NAC, or nordihydroguaiaretic acid (a lipoxygenase inhibitor) pretreatment. H2O2 induced the activation of p38MAPK and JNK, this activation was inhibited by eupatilin. These results indicate that eupatilin may reduce H2O2-induced cytotoxicity, and 5-lipoxygenase expression and LTB4 production by controlling the p38 MAPK and JNK signaling pathways through antioxidative action in feline esophageal epithelial cells.
Subject(s)
Anthracenes , Arachidonate 5-Lipoxygenase , Artemisia , Blotting, Western , Cell Survival , Epithelial Cells , Flavonoids , Hydrogen , Hydrogen Peroxide , Imidazoles , Leukotriene B4 , Lipoxygenase , MAP Kinase Signaling System , Masoprocol , p38 Mitogen-Activated Protein Kinases , PyridinesABSTRACT
Quercetin-3-O-beta-D-glucuronopyranoside (QGC) is a flavonoid glucoside extracted from Rumex Aquaticus Herba. We aimed to explore its protective effect against ethanol-induced cell damage and the mechanism involved in the effect in feline esophageal epithelial cells (EEC). Cell viability was tested and 2',7'-dichlorofluorescin diacetate assay was used to detect intracellular H2O2 production. Western blotting analysis was performed to investigate MAPK activation and interleukin 6 (IL-6) expression. Exposure of cells to 10% ethanol time-dependently decreased cell viability. Notably, exposure to ethanol for 30 min decreased cell viability to 43.4%. When cells were incubated with 50 microM QGC for 12 h prior to and during ethanol treatment, cell viability was increased to 65%. QGC also inhibited the H2O2 production and activation of ERK 1/2 induced by ethanol. Pretreatment of cells with the NADPH oxidase inhibitor, diphenylene iodonium, also inhibited the ethanol-induced ERK 1/2 activation. Treatment of cells with ethanol for 30 or 60 min in the absence or presence of QGC exhibited no changes in the IL-6 expression or release compared to control. Taken together, the data indicate that the cytoprotective effect of QGC against ethanol-induced cell damage may involve inhibition of ROS generation and downstream activation of the ERK 1/2 in feline EEC.