Helicobacter bilis Gamma-Glutamyltranspeptidase Enhances Inflammatory Stress Response via Oxidative Stress in Colon Epithelial Cells
Figure 1
Superoxide production induced by HBgGT in colon cancer cells.
A) NBT assay visualization of formazan crystal formation in HCT116 and DLD-1 cells in response to wild type and gGT deficient H. bilis infection for 20 hours at MOI 50. Cells were also treated with recombinant HBgGT (5µg/ml) or inactive HBgGT (5µg/ml) for 20 hours. Following treatment, cells were stained for formazan crystals (dark blue) and counterstained with safranin. TNFα (20ng/ml) was used as a positive control.
B) Quantification of crystal formation in HCT116 and DLD-1 cell lysates at OD 650. Results are expressed as mean of three independent experiments normalized to the untreated control. *p<0.05, **p<0.005, ***p<0.0005. Asterisks on top of bars indicate significance relative to untreated control; asterisks on bars indicate significance level between indicated conditions.