树豆酮酸A抑制3T3-L1细胞脂肪合成与分解的作用研究

Inhibitory effect of cajanonic acid A on lipogenesis and lipolysis in 3T3-L1 adipocytes

目的探讨树豆酮酸A(caianonic acid A,CAA)对小鼠3T3-L1脂肪细胞脂质代谢的影响及其机制。方法诱导分化成熟的3T3-L1脂肪细胞加入不同浓度的CAA作用48 h后进行总脂肪、甘油三酯、游离脂肪酸和甘油含量测定。实时荧光定量PCR法检测脂质代谢相关基因的表达。结果CAA明显降低3T3-L1脂肪细胞总脂肪和甘油三酯含量,抑制游离脂肪酸和甘油的释放,下调乙酰辅酶A羧化酶(acetyl CoA carboxylase,ACC)、脂肪酸合成酶(fatty acid synthase,FAS)、脂蛋白脂酶(lipoprotein lipase,LPL)、激素敏感性脂肪酶(hormone sensitive lipase,HSL)和脂肪甘油三酯脂酶(adipose triglyceride lipase,ATGL)基因的表达,但增加乙酰辅酶A氧化酶(acyl CoA oxidase,ACOX)和肉碱棕榈酰转移酶-1(carnitine palmitoyl transferase 1,CPT-1)基因的mRNA水平。结论 CAA通过抑制脂肪吸收与合成相关基因(ACC、FAS、LPL)的表达,减少脂肪细胞甘油三酯的合成,抑制细胞过度肥大。同时,下调脂肪分解限速酶基因(HSL、ATGL)mRNA水平,促进脂肪酸氧化关键基因(ACOX和CPT-1)的表达减少游离脂肪酸的释放,改善脂肪细胞的脂质代谢平衡。

Aim To investigate the effects of cajanonic acid A(CAA) on lipid metabolism in murine 3T3-L1 adipocytes.Methods 3T3-L1 cells induced to differentiated into mature adipocytes were treated with CAA in different dosages for 48 h,then total lipids as well as triglyceride,free fatty acid and glycerol were measured.The expression levels of genes related to lipid metabolism were quantitatively analyzed by real-time fluorescent quantitative polymearase chain reaction(RTFQ-PCR).Results Total lipids and triglyceride in 3T3-L1 adipocytes were markedly reduced by CAA.The release of free fatty acid and glycerol was lower than that of control.This coincided with decreased mRNA levels of the key enzymes involved in de novo lipogenesis(acetyl CoA carboxylase and fatty acid synthase),fatty acid uptake(lipoprotein lipase),and lipolysis(hormone sensitive lipase and adipose triglyceride lipase).While the expression of fatty acid oxidative genes including acyl CoA oxidase and carnitine palmitoyl transferasel was increased after CAA treatment.Conclusion CAA may inhibit lipogenesis and lipolysis,reduce circulating free fatty acid and improve the lipid metabolism in adipocytes by regulating gene expressions.