| Background: Liver transplantation is the most effective method for the treatment of end-stage liver disease,but the incidence of metabolic complications(such as dyslipidemia,diabetes,etc.)after liver transplantation is high,which seriously affects the long-term effect of liver transplantation.At present,it is believed that the use of immunosuppressants and donor liver gene polymorphism are important risk factors for the disorder of glucose and lipid metabolism after liver transplantation,but its potential molecular mechanism is not clear.It has been found that mi R-33 a plays an important role in regulating the homeostasis of glucose and lipid metabolism,but the liver microenvironment of liver transplant recipients changes significantly after ischemia-reperfusion injury and liver regeneration.In addition,the application of immunosuppressants will also affect the function of mi R-33 a.In this context,it is not clear how mi R-33 a participates in the homeostasis regulation of glucose and lipid metabolism.Therefore,it is of great significance to study the role and molecular mechanism of mi R-33 a in maintaining the homeostasis of glucose and lipid metabolism in recipients after liver transplantation.Aim:The purpose of this study is to explore the role and molecular mechanism of mi R-33 a in maintaining the homeostasis of glucose and lipid metabolism after liver transplantation.Method: Section 1:The expression levels of mi R-33 a and its lipid metabolism related target genes were quantitatively detected in tacrolimus-treated cells and mouse models.Non-coding RNA databases(Circ Base,mi R-Base)and their algorithms were used to predict mi R-33a-related Circ RNA.Luciferase report experiment was used to reveal the interaction between circ FASN and mi R-33 a.Functional experiments were used to confirm the relationship between circ FASN and mi R-33 a and their role in regulating lipid metabolism.The mechanism of triglyceride imbalance induced by tacrolimus was studied by silencing mi R-33.The clinical data and samples of 73 liver transplant recipients were collected to verify the leading role of mi R-33 a in tacrolimus-related dyslipidemia.Section 2:Through the detection of clinical data of liver transplantation recipients and corresponding donor liver samples,the correlation between mi R-33 a and metabolic complications after liver transplantation was confirmed.The second generation sequencing was used to find the key metabolic regulatory factors regulated by mi R-33 a.At the same time,functional experiments,such as lipid droplet observation,glucose production,glucose uptake and insulin sensitivity test,were used to further clarify the effect of liver mi R-33 a on glucose and lipid metabolism and its potential molecu Lar mechanism.The culture medium was collected from liver cells treated with mi R-33 a mimics.Tumor cells were co-cultured with the culture medium.CCK-8 and transwell assays were used to detect the changes of proliferation and migration of hepatocellular carcinoma cells.Results: Section 1:In tacrolimus-treated cells and mouse models,it was observed that tacrolimus could induce triglyceride accumulation in hepatocytes by stimulating sterol response element binding proteins(SREBPs)and mi R-33 a.It is proved that mi R-33 a is the direct target of Circ FASN in silico and experimental analyses.Tacrolimus can down-regulate Circ FASN,increase mi R-33 a,and inhibit mi R-33 a target gene expression in vivo and in vitro,resulting in triglyceride deposition in the liver.Overexpression of Circ FASN or silencing of mi R-33 a could reduce the promoting effect of tacrolimus on triglyceride accumulation.It was found that the content of serum mi R-33 a in patients with dyslipidemia after liver transplantation was higher than that in patients with normal blood lipids,but there was no significant correlation between the increase of mi R-33 a and the blood concentration of tacrolimus(R2=0.021).In the mouse model,it was confirmed that mi R-33 a could be used as a potential therapeutic target for lipid metabolic disorders caused by tacrolimus.Section 2:It was found that the expression level of mi R-33 a was associated with postoperative dyslipidemia and recurrence of intrahepatic liver cancer.A series of key regulatory molecules of glucose and lipid metabolism regulated by mi R-33 a,such as ABCA1,ABCG1,G6 PC and CPT1 A,were found.It was found that the number of lipid droplets in the liver cells overexpressing mi R-33 a was significantly more than that in the control group.After the activation of liver X receptor(LXR),the function of mi R-33 a was activated at the same time.In addition,the ability of glucose production and glucose uptake of hepatocytes overexpressing mi R-33 a increased significantly.The abnormal increase of mi R-33 a expression in liver will destroy the homeostasis of liver metabolic microenvironment,and it was found that the proliferation and invasion ability of hepatoma cells increased significantly in such microenvironment.Conclusion: 1.Circ FASN/mi R-33 a signal pathway plays an important role in the destruction of lipid homeostasis induced by tacrolimus,in which mi R-33 a can be used as a potential therapeutic target for lipid metabolic disorders caused by tacrolimus.2.The expression level of mi R-33 a in donor liver is closely related to the occurrence of metabolic disease and intrahepatic recurrence of liver cancer after liver transplantation.3.The target genes of mi R-33 a include a series of key molecules regulating glucose and lipid metabolism,and LXR/mi R-33 a pathway is involved in maintaining the homeostasis of liver glucose and lipid metabolism microenvironment.4.When the expression level of mi R-33 a in donor liver is abnormally increased,the metabolic microenvironment of donor liver is more likely to attract liver cancer cells and cause intrahepatic recurrence of liver cancer after liver transplantation. |
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