甜菜碱对肥胖小鼠肝脏脂质沉积的影响

Effect of Betaine on High Fat Diet-Induced Lipid Accumulation in the Liver of Mice

【目的】探究甜菜碱对高脂饮食诱导的肥胖小鼠肝脏脂质沉积的影响效应。【方法】对高脂饮食喂养的小鼠进行为期2个月的甜菜碱补饲,随后利用组织学分析、实时荧光定量PCR、谷丙转氨酶(ALT)和谷草转氨酶(AST)检测及气相色谱对小鼠肝脏变性和脂肪酸组成进行分析。【结果】与对照组相比:甜菜碱组肝重和脂质沉积减少,ALT和AST血清水平降低;甜菜碱组的甘油三酯水解酶(ATGL和HSL)含量极显著降低(P<0.01);肝内C13∶0、C14∶0、C15∶0、C16∶0、C18∶1n9c、C18∶2n6c水平下降,但差异不显著(P>0.05);C12∶0、C22∶0水平显著下降(P<0.05),多不饱和脂肪酸(PUFA)比例上升(P>0.05);脂质生成相关基因(SREBP-1c、LPL、PPARγ、SCD-1、FAS)表达水平极显著下降(P<0.01),脂肪酸β氧化调控基因(PPARɑ、CD36和ACSS1)表达水平极显著上升(P<0.01)。【结论】甜菜碱补充可预防高脂饮食诱导小鼠的肝内脂质沉积,其机制可能与脂肪酸代谢调控相关。

【Objective】The objective of this study was to identify the effect of betaine on lipids accumula-tion in hepatic tissues of high fat diet(HFD)-induced obese mice.【Method】Mice fed a high-fat diet were fed betaine supplements for 2 months.Subsequently,we evaluated histological degeneration and fatty acids composition in liver by histological analysis,real-time quantitative PCR,the detection of alanine transaminase(ALT)and aspartate aminotransferase(AST),and liquid chromatography.【Result】When compared with control group,liver weight,lipids accumulation and serum levels of ALT and AST were observed decreasing in betaine group.The expression of genes associated with triglyceride hydroly-sis(ATGL and HSL)were significantly down-regulated in betaine group(P<0.01).In addition,betaine group showed more C13∶0,C14∶0,C15∶0,C16∶0,C18∶1n9c,C18∶2n6c in liver,but the difference was insignificant(P>0.05);In the betaine group,we observed a marked reduction in both C12∶0 and C22∶0(P<0.05),while increased ratio in polyunsaturated fatty acids(PUFA)(P>0.05).When compared with control group,lipid-generating genes(SREBP-1c,LPL,PPARγ,SCD-1 and FAS;P<0.01)and regulators involved in fatty acidβoxidation(PPARɑ,CD36 and ACSS1;P<0.01)were significantly down-regulated or up-regulated in the betaine group,respectively.【Conclusion】Supplementation of betaine may contribute to protect against high fat diet-induced lipids accumulation in liver,and its underlying mechanism might be associated with regulation of fatty acids metabolism.