PPAR-α受体激动剂对肝脏缺血再灌注损伤的保护作用

Protection of PPAR-αagonists on the liver ischemia-reperfusion injury of rats

目的探讨过氧化物酶体增殖物激活受体α(PPAR-α)激动剂非诺贝特(FEN)对肝脏缺血再灌注损伤(HI/R)的保护作用。方法将40只SD大鼠随机分成对照组、模型组、PPAR-α激动剂FEN组(FEN组)和PPAR-α抑制剂GW6471组(GW组),每组10只。全自动生化分析仪检测各组大鼠血清中丙氨酸氨基转移酶(ALT),天门冬氨酸氨基转移酶(AST)和碱性磷酸酶(ALP)水平;通过苏木精-尹红(HE)染色观察各组大鼠肝脏组织病理形态;TUNEL法检测肝脏细胞凋亡;利用Western blot检测各组肝脏沉默信息调节因子1(SIRT1)、叉头转录因子1(FOXO1)、乙酰化FOXO1(AceFOXOI)、裂解型天冬氨酸蛋白水解酶(C-caspase3)和细胞质中细胞色素C(CytC)表达水平。结果与模型组相比,PPAR-α激动剂FEN预处理可明显减轻肝脏病理损伤,减少肝脏AceFOXO1、C-caspase3、TUNEL和细胞质CytC的表达水平及增加肝脏SIRT1表达水平。而FEN组血清中AST[(90.15±11.21)U/L],ALT[(135.18±20.46)U/L]和ALP[(211.12±22.75)U/L]水平较模型组血清中AST[(189.37±21.55)U/L],ALT[(378.15±36.78)U/L]和ALP[(495.93±31.14)U/L]水平明显降低。而予以PPAR-α抑制剂GW6471预处理可明显增加肝脏病理损伤,上调肝脏AceFOXO1、C-caspase3、TUNEL和细胞质CytC的表达水平及减少肝脏SIRT1表达水平。GW组血清中AST[(177.21±18.54)U/L],ALT[(199.46±28.54)U/L]和ALP[(286.12±24.51)U/L]水平较FEN组血清中AST,ALT和ALP水平明显增高(P<0.05)。结论 PPAR-ɑ受体激动剂FEN对大鼠HI/R具有保护作用,该作用可能与FEN能促进SIRT1去乙酰化修饰FOXO1,减少FOXO1介导线粒体凋亡,改善肝功能有关。

Objective To investigate the protective effect of PPAR-αagonist Fenofibrate(FEN)on liver ischemia-reperfusion injury.Methods 40 SD rats were randomly divided into the control group,the model group(HI/R),the PPAR-αagonist FEN group(the FEN group)and the PPAR-αinhibitor GW6471 group(the GW group).The content of alanine aminotransferase(ALT),glutamic oxaline aminotransferase(AST)and alkaline phosphatase(ALP)in serum of each group were detected by automatic biochemical analyzer.The pathological changes of liver tissues were observed by hematoxylin-eosin(HE)staining,the apoptosis of liver cells was detected using TUNEL assay,and Western blot was used to detect the regulation factor of liver silencing information 1(SIRT1),forkhead transcription factor 1(FOXO1),acetylation of FOXO1(Acetyl FOXO1),Cleaved-caspase3(C-caspase3)and cytoplasm of cytochrome C(CytC)expression level.Results Compared with the model group,fenofibrate pretreatment could significantly attenuate the liver pathological damage and down-regulate the expression of C-caspase3,TUNEL and cytoplasmic cytochrome C in liver with increasing the expression of SIRT1 in liver.In addition,the levels of AST [(90.15±11.21)U/L],ALT[(135.18±20.46)U/L]and ALP [(211.12±22.75)U/L]in the FEN group were significantly lower than those in the model group AST [(189.37±21.55)U/L],ALT [(378.15±36.78)U/L]and ALP[(495.93±31.14)U/L].PPAR-αinhibitor GW6471 precondition could exacerbate the pathological damage of liver and up-regulate the expression of Acetyl FOXO1,C-caspase3,TUNEL and cytochrome C in liver with reducing the expression of liver SIRT1.Moreover,the levels of AST [(177.21±18.54)U/L],ALT [(199.46±28.54)U/L]and ALP[(286.12±24.51)U/L]in the GW group were significantly higher than those in the FEN group.Conclusion FEN,the PPAR-αreceptor agonist,h as a protective effect on liverischemia-reperfusion injury in rats.This effect may be associated with promoting SIRT1 deacetylation of FOXO1,reducing FOXO1-mediated mitochondrial apoptosis and improving liver function.