柚皮苷调节NAFLD小鼠脂代谢紊乱机制研究

Down-regulation of hepatic SREBP1 and PPAR-γexpression by naringin in mice with high-fat diet-induced NAFLD

目的探讨柚皮苷(nar)对高脂饮食(HFD)诱导的非酒精性脂肪性肝病(NAFLD)小鼠肝组织脂代谢紊乱的影响。方法将24只C57BL/6J小鼠随机分为对照组(n=8)、高脂饮食组(HFD组,n=8)和柚皮苷干预组(HFD/Nar干预组,n=8)。采用转录组测序寻找药物干预差异基因富集通路,采用qPCR和Western Blot法检测肝组织脂代谢相关基因及其蛋白表达。结果与对照组比,模型组小鼠体质量增加了57.8%(P<0.01),而经柚皮苷干预后,小鼠体质量较模型组降低了13.5%(P<0.01);模型组小鼠肝组织TG和TC水平分别为(3.5±0.4)mmol/g protein和(3.1±0.5)mmol/g protein,均显著高于对照组[分别为(1.0±0.3)mmol/g protein和(0.8±0.1)mmol/g protein,P<0.01],而HFD/Nar干预组肝组织TG和TC较模型组显著下降[分别为(2.1±0.4)mmol/g protein和(1.11±0.3)mmol/g protein,P<0.05];转录组测序KEGG富集分析显示柚皮苷对与脂代谢通路相关的9条通路有显著影响,表现为柚皮苷干预可显著下调肝组织固醇调节元件结合蛋白1(SREBP1)、过氧化物酶体增殖激活受体(PPAR-γ)、CD36和肝型脂肪酸结合蛋白1(FABP1)表达(P<0.05),而上调PPAR-α和重组肉毒碱棕榈酰转移酶1a(CPT-1A)表达(P<0.05)。结论柚皮苷可明显改善NAFLD小鼠肝内脂质沉积,可能影响了有关基因表达而减少了脂质摄取、合成,加快脂肪酸氧化有关。

Objective The purpose of this experiment was to investigate effects of naringin(Nar)on lipid metabolism in mice with high-fat diet(HFD)induced non-alcoholic fatty liver diseases(NAFLD).Methods Twenty-four C57BL/6J mice were randomly divided into control,model and HFD/Nar-intervention groups,with eight mice in each group.The model of NAFLD was established by HFD intake,and the intervention was carried out by naringin gavage at dose of 100 mg.kg^(-1) for four weeks.Drug intervention with differential gene enrichment pathways was determined by transcriptome sequencing.Hepatic lipid metabolism related genes and their protein expression were detected by qPCR and Western blot.Results Body mass of mice in model group increased by 57.8%(P<0.01)as compared with in the control,while in naringin-intervention group,it decreased by 13.5%(P<0.01);hepatic TG and TC levels in the model were(3.5±0.4)mmol/g protein and(3.1±0.5)mmol/g protein,both much higher than[(1.0±0.3)mmol/g protein and(0.8±0.1)mmol/g protein,P<0.01]in the control,while in HFD/Nar-intervention group,they significantly decreased to[(2.1±0.4)mmol/g protein and(1.11±0.3)mmol/g protein,P<0.05];KEGG enrichment analysis by transcriptome sequencing showed obvious impacts of naringin on nine pathways related to lipid metabolism,presenting with hepatic sterol regulatory element binding protein 1(SREBP1),peroxisome proliferator-activated receptor-γ(PPAR-γ),thrombospondin receptor(CD36)and liver-type fatty acid-binding protein 1(FABP1)down-regulation(P<0.05),and PPAR-αand recombinant carnitine palmitoyltransferase 1A(CPT-1A)up-regulation(P<0.05).Conclusion Naringin could significantly ameliorate hepatic lipid deposition,the mechanisms by which it work might be related to regulation of some gene expression and inhibit lipid uptake and synthesis,and accelerate fatty acid oxidation.