[Effect of Helicobacter pylori lipopolysaccharide on expression of Gli and Ptch-1 proteins in sonic hedgehog signaling pathway of gastric mucosa GES-1 cells]

To investigate the effect of Helicobacter Pylori lipopolysaccharide (Hp-LPS) on expression of Gli and Ptch-1 proteins in sonic hedgehog (Shh) signaling pathway of gastric mucosa GES-1 cells.The LPS was extracted from Hp by hot phenol water method, and then the concentration of LPS was detected by the kinetic turbidimetric assay. GES-1 cells were stimulated by different concentrations of Hp-LPS (0, 1, 10, 20, 30 and 40 μg/ml). The inhibition rates of cell growth were measured by MTT assay after treated with Hp-LPS for 24 h. The expression of Gli and Ptch-1 proteins were determined by Western Blot.MTT assay showed that the inhibition rates of GES-1 cell growth after treatment by different concentrations of Hp-LPS (1, 10, 20, 30 and 40μg/ml) were 25.8% ± 2.7%, 34.2% ± 3.1 %, 46.3% 3.4%, 60.8% ± 2.1% and 82.9% ± 2.8% respectively (r=0.985, P0.001). Western blot showed that the expressions of Gli and Ptch-1 proteins were decreased after Hp-LPS treatment (0, 1, 10, 20, 30 and 40 μg/ml): the relative expression values of Gli were 1.286 ± 0.180, 0.963 ± 0.067, 0.850 ± 0.085, 0.566 ± 0.058, 0.549 ± 0.056 and 0.377 ± 0.047, respectively (r=-0.945, P0.001); those of Ptch-1 were 1.688 ± 0.088, 1.466 ± 0.061, 1.170 ± 0.065, 1.042 ± 0.064, 0.648 ± 0.057 and 0.482 ± 0.074, respectively (r=-0.985, P0.001).Hp-LPS can decrease the related protein expression of Shh signaling pathway, which indicates that Hp may interfere with the function of Shh signaling pathway in gastric mucosa via the effect of its LPS.