Protective Effect Of IL-22 On Small-for-size Liver Graft In Rats

?Objective? To establish a rat model of liver transplantation, 50% of the reduced-size liver transplantation and 30% small for size liver transplantation model to study the expression of IL-22 in different size of liver transplantation; building 30s% small for size liver transplantation in rat to explore the protective effect of IL-22.?Methods? The first part, selecting SD rats to build rat liver transplantation model(n = 30), 50% reduced-size liver transplantation(n = 30) and 30% small for size liver transplantation(n = 30), recording the operation time of operation of donor and recipient, cold ischemic time, anhepatic and inferior vena cava occlusion time, observing the survival rate of rats in 7 days. The second part, to establishment of full size liver transplantation model in group?(n = 48), 50% of liver transplantation model in group?(n = 48) and 30% of liver transplantation model in group?(n = 48), respectively, each in the postoperative 6 hours, 1 day, 3 days and 7 days, 6 rats were sacrificed. The serum of ALT and AST levels, the rate of liver regeneration, HE staining and immunohistochemical staining of PCNA, using RT-PCR to detect IL-22mRNA; using Western blot method to detect IL-22 and STAT3 were compared. The third part, the model of 30% of liver transplantation in rats were randomly divided into two groups: groupA(n = 56), intraoperative injection of recombinant rats IL-22; groupB(n = 56), intraoperative injection of saline as control group. Recording donor and recipient operation time, cold ischemic time, anhepatic, inferior vena cava occlusion time, five rats were sacrificed after 6 hours, 1 day, 3 days, 7 days in each group, serum ALT, AST, the rate of liver regeneration, HE staining and immunohistochemical staining of PCNA were compared, eight rats were selected randomly for survival rates analysis in each group.?Results? The first part: the indicators recorded in the three group had no significant difference, 100%,50% and 30% of liver transplantation for 7 days survival rates were 93.3%(14/15), 86.7%(13/15) and 46.7%(7/15). The second part: the serum ALT and AST level in group? were significantly higher than in group? at 6 hours and1 day after operation(P<0.05); HE staining of liver tissue structural showed more severe damage in group? than other two groups; the rate of liver regeneration analysis showed lower in group? than group?(P<0.01); the rate of PCNA positive cells in group? suggest the rapid regeneration at 1d after operation; a significant increase in IL-22 mRNA at 1 day after operation in group? than the other two groups(P <0.01). Western blot analysis showed, the expression of IL-22 in group? at 6 hours, 1 day after operation gradually increased; the expression p-STAT3 in group? began to increase at 6h after operation, the expression in group? could observed at 6 hours. Part III: There were no statistical differences in recording relevant information; the levels of serum ALT and AST were lower in groupA than in groupB at 1d after operation(P<0.05); the rate of liver regeneration in groupA were higher than groupB; PCNA suggest that regeneration in groupA was earlier than groupB(P<0.05). rats the 7 days survival rate was 62.5%(5/8) in groupA and 37.5%(3/8) in groupB.? Conclusion ? 1. Liver transplantation in rats is a difficulty, skilled microsurgical procedures, focusing on the details of operation and you can obtain a good survival rate. In this study, the operation time of operation of donor and recipient, cold ischemic time, anhepatic and inferior vena cava occlusion time had no statistical difference between the groups suggest that the models tends to be stable, so it can be used for further study. 2. Expression of IL-22 was earlier in 50% partial liver transplantation group than 30% liver transplantation group; the injury and regeneration of liver had the correlation with the expression of IL-22, and the expression of p-STAT3 had the correlation with expression of IL-22, therefore it suggest that the IL-22 may protect liver by improving liver function and promoting liver regeneration through STAT3 pathway. 3. The injection of recombinant IL-22 intraoperative in small for size liver transplantation in rats can promote liver function in the early postoperative, while promoting the regeneration of liver. Thus it suggest that the injection of recombinant IL-22 in rats could promote the recovery of liver function and liver regeneration in early after transplantation so that it play a role in protecting graft liver.