胡椒碱对胆囊胆固醇结石模型小鼠肝脏组织LRH-1相关信号通路蛋白表达的影响

Effect of Piperine on Expression of LRH-1 Related Signal Pathway in Liver Tissue of Cholesterol Gallstone Mice

目的:观察胡椒碱对胆囊胆固醇结石模型小鼠肝脏组织肝脏核受体类似物-1(LRH-1)相关信号通路蛋白表达的影响,并探讨其相关机制。方法:将90只雄性C57BL/6小鼠随机分成正常组,模型组,熊去氧胆酸组(90 mg·kg-1),胡椒碱低、中、高剂量组(20,40,60 mg·kg-1),每组15只,灌胃给药4周。除正常组外,其余各组均采用含2%胆固醇的高脂饲料喂养4周建立胆囊胆固醇结石模型。肉眼观察各组结石形成情况;测量胆囊容积,检测血清中总胆固醇(TC),甘油三酯(TG),低密度脂蛋白胆固醇(LDL-C)及高密度脂蛋白胆固醇(HDL-C)的含量;蛋白免疫印迹法(Western blot)检测各组大鼠肝脏组织LRH-1,B类-Ⅰ型清道夫受体(SRBI),腺苷三磷酸结合盒转运体G5(ABCG5),ABCG8的蛋白表达;实时荧光定量聚合酶链式反应(Real-time PCR)检测各组大鼠肝脏组织LRH-1,SRBI,ABCG5,ABCG8 mRNA表达。结果:与正常组比较,模型组小鼠成石率明显升高(P <0. 05),胆囊容积明显升高(P <0. 05),血清中TC,TG和LDL-C含量明显升高(P <0. 05),血清中HDL-C含量明显下降(P <0. 05),肝脏组织中LRH-1,SRBI,ABCG5,ABCG8的蛋白和mRNA表达明显升高;与模型组比较,熊去氧胆酸组和胡椒碱中、高剂量组小鼠成石率明显降低(P <0. 05),胆囊容积均明显降低(P <0. 05),血清中TC,TG和LDL-C含量明显降低(P <0. 05),血清中HDL-C含量明显升高(P <0. 05),肝脏组织中LRH-1,SRBI,ABCG5,ABCG8的蛋白和mRNA表达明显降低(P <0. 05)。结论:胡椒碱中、高剂量组可能通过抑制肝脏组织LRH-1/SRBI及LRH-1/ABCG5/ABCG8信号通路的表达,改善脂质代谢异常,进而能够抑制高胆固醇饲料诱导的C57BL/6小鼠胆囊胆固醇结石的形成,且胡椒碱高剂量组优于胡椒碱中剂量组。

Objective:To investigate the inhibitory effect of piperine on liver receptor homolog^-1 (LRH-1)related signal pathway in liver tissues of mice with cholesterol gallston.Method:A total of 90male C57BL/6J mice were randomly divided into six groups,namely normal group,model group,ursodeoxycholic acid (UDCA)group (90mg·kg^-1),and low-dose,middle-dose,high-dose piperine groups (20,40,60mg·kg^-1 respectively),15mice in each group.The mice received intragastrical administration for 4weeks.Except for the normal group,the mice of other groups were fed with high-fat diet containing 2%cholesterol for 4weeks to establish cholesterol gallston models.The stone formation was observed with naked eyes;gallbladder volume wasmeasured,and the levels of serum total cholesterol (TC),triglyceride (TG),low-density lipoprotein cholesterol (LDL-C),and high-density lipoprotein cholesterol (HDL-C)were detected.The protein expression levels of LRH-1,scavenger receptor B I (SRBI),ATP binding cassette transport-G5(ABCG5),ABCG8in Ever tissues of each group were detected by Western blot,and the mRNA expression levels of LRH-1,SRBI,ABCG5and ABCG8in Ever tissues of each group were detected by real time polymerase chain reaction (Real-time PCR). Result:As compared with the normal group,the rate of stone formation in the model group was significantly increased (P <0.05);the volume of gallbladder was increased significantly (P <0.05);the contents of TC,TG and LDL-C in serum were increased significantly (P <0.05);the content of HDL-C in serum was decreased significantly (P <0.05),and the protein and mRNA expression levels of LRH-1,SRBI,ABCG5and ABCG8 in liver tissues were increased significantly (P <0.05).As compared with the model group,the rate of stone formation in ursodeoxycholic acid group and piperine medium and high dose groups was significantly lower (P < O.05);the volume of gallbladder was decreased significantly (P <0.05);the contents of TC,TG and LDL-C in serum were decreased significantly (P <O.05);the content of HDL-C in serum was increased significantly (P < 0.05);the protein and mRNA expression levels of LRH-1,SRBI,ABCG5and ABCG8 in Ever tissue were decreased significantly (P <0.05).Conclusion:Medium and high dose (40,60mg'kg-1)piperine can inhibit the formation of cholesterol gallstones in the gallbladder of C57BL/6 mice induced by high cholesterol diet,which may be related to the improvement of lipid metabolism abnormality and inhibition of the expression of LRH-1/SRBI and LRH-1/ABCG5/ABCG8signaling pathways in the Ever tissue;moreover,piperine high dose group had better effects than piperine medium dose group.