Expression And Significance Of NF-κB-ERK Signaling Pathway In Liver Of Mice With Primary Biliary Cholangitis

[Objective]Primary biliary cholangitis(PBC),also known as primary biliary cirrhosis,is an autoimmune-induced chronic inflammatory and biliary cholestatic liver disease of unknown cause.Its pathogenesis is not fully understood.So we used female mice named C57BL/6 to establish the PBC animal model.Based on this,we investigated the expression of p65,p50 and p-ERK level of PBC.Moreover,We used PDTC and PD98059,which are specific inhibitors of NF-κB and ERK,to explored whether NF-κB-ERK signaling pathway were involved in the development of PBC.Aiming at providing experimental foundation and theoretical evidence of explaining the pathogenesis of PBC,we investigated the mechanism of which NF-κB-ERK signaling pathway playing roles.[Methods]In the present study,the female C57BL/6 mice were intraperitoneally injected with 2-octynedioic acid-bovine serum albumin coupled with polyinosinic-polycytidylic acid.The foreign matter-induced PBC model was established,and the mice in control group didn’t do anything.During the establishment cycle,the serum were collected from mice for detection of liver biochemistry,and the liver tissues were collected from mice for pathological testing.We chose the liver tissues with twelfth week mice to detect the expression of p65,p50 and p-ERK level by immunohistochemistry and western blotting-The data analysis was using t test and linear correlation analysis.The statistical data was interpreted using mean and standard deviation and expressed as x±s.P<0.05 indicated significantly different.Based on this,PBC mice were intraperitoneal injection with PDTC(100mg/kg),other PBC mice were PD98059(10mg/kg).And experimental components of PDTC were into PBC,PBC+PDTC12h and PBC+PDTC24h groups.The experimental components of PD98059 were the same as before.The mice in control group were intraperitoneal injection with equal physiological saline solution.The liver tissues were collected from mice for immunohistochemistry and western blotting,to detection the expression of p65 and p50 level in experimental of PDTC and p-ERK level level in experimental of PD98059.The data analysis was using variance analysis and linear correlation analysis.The statistical data was interpreted using mean and standard deviation and expressed as x×s.P<0.05 indicated significantly different.[Results]1.Establishment of PBC animal model:(1)The detection of liver biochemistry:The model group got higher expression of ALP.There was no significant change in the control group.(2)The results of liver tissue HE staining:In the model group,around the portal area and bile duct have obvious inflammatory cell infiltration and infiltration increased along with the prolongation of time,bile duct injury obviously.While there was no obsvious inflammatory cells around the portal area and bile duct in the control group.2.Expression of NF-κB-ERK signaling pathway in liver of PBC mice:(1)Result of immunohistochemical:the p65、p50 and p-ERK had high expression in the model group,while the expression of p65、p50 and p-ERK in the control group was low or negative.p65 and p50 were mainly expressed on the surface of Kupffer cells in the model group,and them were mainly located in the area of the bile duct and porta hepatis.p-ERK in the model group were mainly expressed on the surface of Kupffer cells,the hepatocyte surface also has partial expression.The control group was also not obvious.The scores of the p65、p50 and p-ERK in model group were significantly higher than the control group,the difference was statistically significant(P<0.05);the expression levels of p-ERK and p65 were positively correlated(r=0.942,P=0.000),the expression levels of p-ERK and p50 were positively correlated(r=0.906,P=0.002).(2)Result of western blotting of p65、p50 and p-ERK in the liver of PBC:The model group got higher expression of p65、p50 and p-ERK.The difference is statistically significant(p65:t=-2.616,P=0.026;p50:t=-4.860,P=0.001;p-ERK:t=-4.813,P=0.001).the expression levels of p-ERK and p65 were positively correlated(r=0.929,P=0.000),the expression levels of p-ERK and p50 were positively correlated(r=0.677,P=0.016).3.Expression of NF-κB-ERK signaling pathway which was blocked in liver of PBC mice:(1)Result of western blotting of p65 and p50 in the experimental components of PDTC:The experimental components of PDTC got lower expression of p65 and p50.The difference is statistically significant(p65:F=11.01,P=0.02;p50:F=13.76,P=0.000).There was no significant change in the NS treatment group.(2)Result of western blotting of p-ERK in the experimental components of PD98059:The experimental components of PD98059 got lower expression of p-ERK.The difference is statistically significant(F=14.51,P=0.000).There was no significant change in the NS treatment group.[Conclusion]1.The animal model of PBC is successfully established through injection of 20A-BSA coupled with poly I:C.2.The PBC mice had p65、p50 and p-ERK high expression in liver of mice,indicating that NF-κB-ERK signaling pathway are playing an important role in the development of PBC.3.The PBC mice had p65 and p50 low expression in liver of mice after dealing with PDTC,and the PD98059 was same as before,indicating that blocking the NF-κB-ERK signaling pathway can reduce the expression of NF-κB-ERK signaling pathway in PBC mice.