The Comparison Research Of Changes And Mechanism Of Autophagy In Different Acute Liver Injury Models

Beckgroud:Autophagy always exists as a critical lysosomal pathway involved in the degradition of long-lived proteins and cellular organelles in eukaryon cells for the homeostasis and plays an important role in celluar growth, differentiation, secescence and apotosis.Autophagy keeps the regular cellular metabolism and function of liver.Many researchs reported that there was an clear change of autophagy levels in various kinds of liver injury,such as alcohol liver disease, drug-induced liver disease,viral hepatitis and ischemic reperfusion injury.Many drugs can induce liver injury via different mechanisms. Acetaminophen and tetrachloromethane are the most frequent used to induce liver injury.This research will explore the changes of autophagy levels and the mechanism of autophagy in both acute liver injury models and compared their the similarities and differences for the sake of in-depth research.Objective:This research will explore the level changes of autophagy in different acute liver injury models induced by acetaminophen and carbon tetrachloride and compare the differerces of changes of autophagy related cytokines, further explore the celluar mechanism of autophagy in the liver injury. We will explore the effect of autophagy in liver injury by increasing and reducing autophagy to improve our understanding of acute liver injury so that providing new methods of treatment in clincal works.Methods: 56 male C57 mice were randomly divided into control group, model group and treatment group.The control group of normal group injected by normal saline and oil group injected by plant oil, were scrificed after the injection of 6 hours.Model group include APAP group and CC14 group.APAP group were divided into APAP 2h group, APAP 6h group, APAP 12h group and APAP 24h group and so as the CC14 group.APAP and CC14 group were respectively intraperitoneal injected by acetaminophen and carbon tetrachloride and get the specimens in mice at the corresponding time.Treatment group were consist of rapamycin treatment group and chloroquine treatment group. Rapamycin treatment group were injected rapamycin immediately after the intraperitoneal injection of APAP or CC14,while chloroquine treatment group were injected chloroquine at the same time.Then kill these mice after 6 hours.Testing the serum ALT level of mice in each group and evaluating the extent of liver injury by haematoxylin-eosin staining.The expression of LC3 and p62 were detected by immunohistochemical and western blot.The expression of Beclinl and mTOR were detceted by western blot.Results:1. The serum ALT level and the degree of liver injury in the model group were higher than the control group, and much higher as time went on.Compared with the 6h model group(APAP 6h group and CC14 6h group), The serum ALT level and the degree of liver injury were apparently reduced in rapamycin treatment group and increased in chloroquine treatment group.2. The expression of LC3 in the model group was time-depedented more than that in the control group detected by immunohistochemical and western blot.And compared with the 6h model group, the LC3 expression in the rapamycin group and the chloroquine group was increased. The expression of p62 in the model group was less than that in the control group.But compared with the 6h model group, p62 expression in rapamycin group was increased and reduced in chloroquine group.3. According to the results of western blot, the expression of mTOR in the model group was time-depedented less than the control group no matter in APAP group or CC14 group.The expression of beclinl in the model group was time-dependented increased when compared with control group, but there is no apparent differences between model group and control group.Conclusion:1. The level of autophagy was increased in both kinds of acute liver injury, and should be detected as early as in two hours.This change should be more with time went on.2. After promoting autophagy, the extent of liver injury was reduced, and inhibit autophagy, the extent of liver injury was increased. This indicate autophagy plays a positive effect in both kinds of liver injury.3. Acetaminophen increase autophagy via both mTOR and beclinl pathways, while tetrachloromethane increase autophagy mainly through mTOR pathway but beclinl pathway.