Saín Juliana, González Marcela Aída, Lavandera Jimena Verónica, Scalerandi María Victoria, Bernal Claudio Adrián
1Cátedra de Bromatología y Nutrición, Facultad de Bioquímica y Ciencias Biológicas,Universidad Nacional del Litoral,Ciudad Universitaria, Paraje el Pozo S/N, C.C. 242,C.P. 3000, Santa Fe,Argentina.
Br J Nutr. 2016 Aug;116(4):611-20. doi: 10.1017/S0007114516002415.
The aim of this study was to investigate the effects of trans-fatty acids (TFA) on liver and serum TAG regulation in mice fed diets containing different proportions of n-3, n-6 and n-9 unsaturated fatty acids (UFA) from olive (O), maize (C) or rapeseed (R) oils partially substituted or not with TFA (Ot, Ct and Rt, respectively). Male CF1 mice were fed (30 d) one of these diets. The effects of the partial substitution (1 %, w/w) of different UFA with TFA on the activity and expression of hepatic enzymes involved in lipogenesis and fatty acids oxidation were evaluated, as well as their transcription factor expressions. Some of the mechanisms involved in the serum TAG regulation, hepatic VLDL rich in TAG (VLDL-TAG) secretion rate and lipoprotein lipase (LPL) activity were assessed. In liver, TFA induced an increase in TAG content in the Ot and Rt groups, and this effect was associated with an imbalance between lipogenesis and β-oxidation. In the Ot group, exacerbated lipogenesis may be one of the mechanisms responsible for the liver steatosis induced by TFA, whereas in Rt it has been related to a decreased β-oxidation, compared with their respective controls. The enhanced hepatic VLDL-TAG secretion in the Ot and Rt groups was compensated with a differential removal of TAG by LPL enzyme in extrahepatic tissues, leading to unchanged serum TAG levels. In brief, the effects of low levels of TFA on liver and serum TAG regulation in mice depend on the dietary proportions of n-3, n-6 and n-9 UFA.
本研究旨在调查反式脂肪酸（TFA）对喂食含有不同比例n-3、n-6和n-9不饱和脂肪酸（UFA）的小鼠肝脏和血清甘油三酯（TAG）调节的影响，这些不饱和脂肪酸分别来自橄榄油（O）、玉米油（C）或菜籽油（R），部分被TFA替代（分别为Ot、Ct和Rt）或未被替代。雄性CF1小鼠喂食（30天）这些饮食中的一种。评估了用TFA部分替代（1%，w/w）不同不饱和脂肪酸对参与脂肪生成和脂肪酸氧化的肝脏酶活性和表达的影响，以及它们的转录因子表达。评估了血清TAG调节、富含TAG的肝脏极低密度脂蛋白（VLDL-TAG）分泌率和脂蛋白脂肪酶（LPL）活性所涉及的一些机制。在肝脏中，TFA导致Ot组和Rt组的TAG含量增加，这种影响与脂肪生成和β-氧化之间的失衡有关。在Ot组中，脂肪生成加剧可能是TFA诱导肝脏脂肪变性的机制之一，而在Rt组中，与各自的对照组相比，这与β-氧化减少有关。Ot组和Rt组肝脏VLDL-TAG分泌增强，通过肝外组织中LPL酶对TAG的差异清除得到补偿，导致血清TAG水平不变。简而言之，低水平TFA对小鼠肝脏和血清TAG调节的影响取决于n-3、n-6和n-9不饱和脂肪酸的饮食比例。
