Helicobacter bilis infection induces oxidative stress in and enhances the proliferation of human cholangiocytes.

BACKGROUND: Helicobacter bilis, an enterohepatic Helicobacter species, represents a carcinogenic risk factor for cholangiocytes owing to the prevalence of infections in patients with biliary tract cancer, cholecystitis, and pancreaticobiliary maljunction. However, the effect of H. bilis infection on cholangiocytes and the process and mechanism of carcinogenesis are not known. We aimed to determine the effects of H. bilis on cholangiocytes, focusing on inflammation and oxidative stress. MATERIALS AND METHODS: Helicobacter bilis and MMNK-1 cells were cocultured for 24 h and inflammatory cytokine secretion was evaluated. Furthermore, MMNK-1 cell proliferation, intracellular reactive oxidant species (ROS) production, and DNA damage caused by ROS were investigated. All factors were compared with and without H. bilis infection. RESULTS: Interleukin (IL)-6 and IL-8 secretion were significantly increased in MMNK-1 cocultures with H. bilis (IL-6, 24.3 ± 12.2 vs. 271.1 ± 286.4 pg/ml; IL-8, 167.6 ± 78.7 vs. 1085.1 ± 1047.1 pg/ml, p < .05). MMNK-1 proliferation was also significantly higher in H. bilis cocultures (1.05 ± 0.02 vs. 1.00-fold, respectively; p < .05). Coculturing enhanced the production of ROS in MMNK-1 cells depending on the cell concentration of H. bilis (1.0 vs. 1.17 ± 0.06, p < .05); however, DNA injury was not observed in cocultures with H. bilis (5.35 ± 0.87 vs. 6.08 ± 0.55 pg/µl, p = .06). CONCLUSIONS: Helicobacter bilis infection induced ROS production in and enhanced the proliferation of cholangiocytes.

The effect of selective neutrophil elastase inhibitor on pancreatic islet yields and functions in rat with hypercytokinemia.

BACKGROUND: It is well known that to achieve insulin independence requires a high number of islets, but at present, isolation techniques can recover 50% or less of the islets present in the pancreas. Brain death is characterized by a cytokine storm that takes place in the body, and this condition reduces the islet yields and functions. In this study, we used selective neutrophil elastase inhibitor, sivelestat sodium to prevent damage to the islets for transplantation. MATERIAL/METHODS: We used three groups of rats, group 1 were transfused with only saline, group 2 received sivelestat sodium (10 mg/kg/h) and group 3 received a higher dose of sivelestat sodium (30 mg/kg/h). Thirty minutes after the treatment, lipopolysaccharide was injected to induce hypercytokinemia. We examined serum cytokine levels, derivatives of reactive oxygen metabolites (d-ROMs), islet yields and viability and 24 hours after static incubation, the islet yields, viability, functions (insulin stimulation index and ADP/ATP ratio). RESULTS: The levels of serum cytokines, IL-1ß, IL-6 and IFN-γ were significantly different between groups 1 and 3. The islet yields and the 24 h recovery rate of islets and insulin stimulation index were significantly higher in group 3 compared with group 1. The d-ROMs and ADP/ATP ratio were decreased by dose dependently in group 2 and 3. CONCLUSIONS: The islet yields and functions in vitro were significantly improved by the treatment with sivelestat sodium. These experiments may lead to marginal donors, pre-treated with sivelestat sodium becoming acceptable for islet transplantation.