The Study On Emodin Prevents Sever Acute Pancreatitis' Acinar Cells Necroptosis By Regulating The RIP3 And MLKL Complex

Objetive: To observe the therapeutic effect of emodin on SAP in a mouse model of severe acute pancreatitis(SAP);to explore the function of receptor interacting protein 3(RIP3)in the necroptosis of SAP pancreatic acinar cells;and to expound the impact of emodin on the RIP3-MLKL complex.Method: 1.Therapeutic effect of emodin on SAP mouse model: SAP mouse model(SAP group)was induced by cerulein combined with lipopolysaccharide,emodin(Emodin group)and Dachengqi decoction(DCQD group)were given for intervention,it was compared with the control group(Control group)to observe pancreatic necrosis after modeling,and pathological scoring of the pancreatic inflammation was conducted;meanwhile,serum amylase,serum inflammatory factors IL-1?,IL-6,IL-18 and TNF-? level were detected.The therapeutic effect of emodin on SAP was clarified by comparing the therapeutic effect with Dachengqi Decoction.2.Role of RIP3 in SAP cell model: SAP model(SAP group)of CCK-induced pancreatic acinar cell injury was established and RIP3 inhibitor-GSK'872 was given for intervention(GSK group)to observe the necrosis of cells after modeling by referring to the control group(Control group);meanwhile,the expression of RIP3 protein and m RNA in cells was detected,m RNA and protein levels of necrosis interacting pathway proteins RIP1,MLKL and Bax were examined,as well as cell supernatant amylase,inflammatory factors IL-1?,IL-6,IL-18 and TNF-? levels,in order to observe the role of RIP3 in SAP pancreatic acinar cell necroptosis.3.Impact of emodin on the expression of RIP3-MLKL in SAP mouse model: a control group(Control group)is established,mouse SAP model group(SAP group)was induced by cerulein combined with lipopolysaccharide,and emodin was given for intervention(Emodin group)to detect the m RNA and protein expression of RIP1 and RIP3 in pancreatic tissue and the m RNA and protein levels of necrotic pathway interacting proteins MLKL and Bax.Finally,the level of RIP3-MLKL was detected by immunoprecipitation,and the regulating effect of emodin on RIP3-MLKL was observed.Result: 1.Therapeutic effect of emodin on SAP mouse model: Compared with Control group,the levels of mouse serum Amy,IL-1?,IL-6,IL-18 and TNF-? in SAP group are significantly increased(P<0.05),and the pathological scores of pancreatic tissue under light microscope are also significantly increased(P<0.05);compared with SAP group,the above indicators in Emodin group and DCQD group are both reduced significantly(P<0.05);compared with DCQD group,the decline level of IL-6 and necrosis score in the Emodin group are not as good as those in the DCQD group.2.The role of RIP3 in SAP cellular model: Compared with the Control group,the levels of cell supernatant Amy,IL-1?,IL-6,IL-18 and TNF-? in the SAP group are significantly increased(P<0.05),the m RNA and protein levels of RIP3,RIP1,MLKL and Bax are also increased significantly(P<0.05).Compared with SAP group,no significant difference is seen regarding the m RNA and protein levels of RIP1 in GSK group,while the other indicators are reduced significantly(P<0.05).3.The impact of emodin on the expression of RIP3-MLKL in SAP mouse model: Compared with Control group,the m RNA and protein levels of RIP3,RIP1,MLKL and Bax in SAP mouse pancreas are significantly increased(P<0.05),immunohistochemical data also show the same trend;compared with SAP group,no significant difference is seen regarding the m RNA and protein levels of RIP1 and MLKL in Emodin group,but the m RNA and protein levels of RIP3 and Bax decrease significantly,and immunohistochemical data also show the same trend.After co-immunoprecipitation,the level of RIP3-MLKL in the Emodin group is significantly lower than that in the SAP group(P<0.05).Conclusion: 1.Emodin can significantly reduce the expression of amylase and interacting inflammatory factors in SAP mouse and alleviate pancreatic injury;2.RIP3 level will be elevated when necroptosis occurs in SAP pancreatic acinar cells.Necroptosis of SAP can be alleviated when RIP3 is inhibited,indicating that RIP3 plays a key role in SAP necroptosis;3.Emodin can improve the condition of SAP by inhibiting the necroptosis of pancreatic acinar cells mediated by RIP3-MLKL complex.