Down regulation of TRAIL and FasL on NK cells by Cyclosporin A in renal transplantation patients.

TNF-related apoptosis-inducing ligand (TRAIL) and FasL can participate in cell mediated cytotoxicity via their death domain-mediated apoptotic signaling in the host-versus-graft disease occurred after renal transplantation. However, the effect of Cyclosporin A (CsA) commonly used as a drug to prevent and to treat renal transplant rejection, on these molecules have not been fully determined. In the present study, we found that with CsA administration, the expression of TRAIL and FasL predominantly on NK cells from renal transplantation patients was increased at day 5 after operation and went down to normal level on day 13. While, the levels of soluble TRAIL (sTRAIL) and sFasL in the serum increased within 25 days and went down to normal level three month later. In addition, we showed that a remarkable increase of TRAIL and FasL expression both on the surface of activated lymphocytes especially on NK cells and in the supernatants generated from mixed lymphocytes culture (MLC). Furthermore, the enhancement of these two molecules was greatly decreased by adding 500 ng/mL CsA at the beginning of MLC. We conclude that CsA may inhibit the transplant rejection partially by down-regulating the expression of TRAIL and FasL on NK cells.

[Role of the activation of interleukin-6/STAT3 in cholangiocyte proliferation induced by cold ischemia reperfusion and injury].

OBJECTIVE: To investigate the role of IL-6/STAT3 pathway in the proliferation of cholangiocyte induced by cold ischemia and reperfusion injury. METHODS: Rats were randomized into CP 1 h and CP 12 h groups (supplied livers were preserved for 1 or 12 h), anti-IL-6R (rats in CP 12 h group were administrated with anti-rat soluble IL-6 receptor antibody), and control group. At 1, 3, 7, 14 d postoperative, IL-6 concentration in liver homogenate and cholangiocyte proliferation were detected by enzyme linked immunosorbent assay and histochemistry respectively. Expressions of IL-6 mRNA, phosphorylated-STAT3 and cyclin D1 protein in cholangiocytes were determined by real-time PCR or Western blot analysis. Serum concentrations of ALP and GGT and histology analysis were also performed. RESULTS: Minimal expressions of IL-6, p-STAT3 and cyclin D1 were detected in CP 1 h group, with a slight cholangiocytes proliferation. Cholangiocytes responded to extended cold preservation with severe bile duct injures and marked increase in IL-6 secretion, p-STAT3 and cyclin D1 protein expression, followed by compensatory cholangiocytes regeneration. Parallel to this observation, biochemical index and morphology indicated that bile duct injury was recovery at 14 d postoperative. However, anti-sIL-6R inhibited cholangiocytes proliferation and reduced the expressions of IL-6, STAT3 and cyclin D, with the cellular injury and increase of serum ALP or GGT. CONCLUSIONS: IL-6/STAT3 pathway might participate to initiate cholangiocytes regeneration after cold ischemia and preservation injury, which might benefit biliary recovery after liver transplantation.

[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.

Activation of interleukin-6/STAT3 in rat cholangiocyte proliferation induced by lipopolysaccharide.

BACKGROUND: Cholangiocytes are exposed to endotoxins (lipopolysaccharide, LPS) in a variety of biliary inflammations. It is known that LPS enhances the release of interleukin (IL)-6, a potent cholangiocyte mitogen. However, the role of LPS in cholangiocyte proliferation in vivo is unknown. Aims To investigate whether LPS stimulates cholangiocyte proliferation in vivo via the IL-6/STAT3 pathway. METHODS: Rats were randomized into four groups: the LPS group (injected intravenously with LPS 2.5 mg/kg), anti-IL-6 group (injected intravenously with anti-IL-6 0.5 mg/kg 1 h after LPS injection), RPM group (treated with RPM 0.4 mg/kg intraperitoneally 30 min before LPS injection), and control group. At 6, 12, 24, 48, and 72 h after LPS injection, LPS in plasma was detected by kinetic turbidimetric limulus test. IL-6 concentrations in liver homogenate and cholangiocyte proliferation were determined by ELISA or immunohistochemistry, respectively. Expression of IL-6 mRNA and phosphorylated-STAT3 (P-STAT3) protein in cholangiocytes was analyzed by real-time RT-PCR and 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 proliferation of cholangiocytes and decreased levels of IL-6 and STAT3. Furthermore, after being treated with RPM, STAT3 activation was also depressed, which resulted a decreased proliferation of cholangiocytes. CONCLUSIONS: LPS promotes cholangiocyte proliferation through the IL-6/STAT3 pathway, while RPM shows a depressive effect in this pathway.