[Role of IL-6/STAT3 in rat cholangiocyte proliferation induced by lipopolysaccharide].

Objective: To investigate whether lipopolysaccharide (LPS) stimulates cholangiocyte proliferation via the IL-6/STAT3 pathway in vivo.
Methods: Rats were randomized into three groups: LPS group (injected intravenously with LPS 2.5 mg/kg), anti-IL-6 group (injected intravenously with anti-IL-6 0.5 mg/kg 1hr after LPS injection), and control group. At 6, 12, 24, 48 and 72 h after LPS injection, LPS concentration in plasma was detected by kinetic turbidimetric limulus test. IL-6 concentrations in liver homogenate was determinded by ELISA, cholangiocyte proliferation was checked by immunohistochemistry, expression of IL-6 mRNA was quantified by real-time RT-PCR, the level of phophorylated-STAT3 (P-STAT3) protein was analyzed by western blotting.
Results: Cholangiocytes responded to LPS by a marked increase in cell proliferation, IL-6 secretion and P-STAT3 expression. Anti-IL-6 neutralizing antibody inhibited LPS-induced cholangiocytes proliferation, and decreased levels of IL-6 and p-STAT3.
Conclusions: LPS promotes cholangiocyte proliferation through the IL-6/STAT3 pathway.