Laboratory of Molecular Biology, Nutrition and Biotechnology, Universitat de les Illes Balears, CIBER de Fisiopatología de la Obesidad y Nutrición (CIBERobn), Cra. Valldemossa, Km 7.5, 07122 Palma de Mallorca, Spain.
Br J Nutr. 2011 Apr;105(8):1226-34. doi: 10.1017/S0007114510004885. Epub 2011 Jan 5.
Trans-fatty acids (TFA) and cis-monounsaturated fat appear to exert detrimental and beneficial effects, respectively, on glucose metabolism and insulin sensitivity. Adipose tissue and skeletal muscle are a source of signalling proteins (adipokines and myokines), some of which have been related to the control of insulin sensitivity. Here, we investigated the possible differential effects of elaidic acid (EA; trans-9-18 : 1) - the major component in industrially produced TFA - and oleic acid (OA; cis-9-18 : 1) - its cis-isomer naturally present in food - on cellular glucose uptake and the expression of selected myokines and adipokines using cell models. Differentiated C2C12 myotubes and 3T3-L1 adipocytes were pretreated with the vehicle (control cells) or fatty acids for 24 h, after which basal and insulin-stimulated 2-deoxyglucose uptake and the expression of selected signalling proteins were measured. In C2C12 myotubes, pretreatment with OA, but not with EA, led to increased insulin-stimulated 2-deoxyglucose uptake and IL-6 expression levels, while pretreatment with EA, but not with OA, led to reduced IL-15 mRNA levels and increased TNF-α expression levels. In 3T3-L1 adipocytes, exposure to OA, but not to EA, resulted in reduced resistin gene expression and increased adiponectin gene expression. The results show evidence of distinct, direct effects of OA and EA on muscle glucose uptake and the expression of target myokines and adipokines, thus suggesting novel mechanisms by which cis- and trans-monounsaturated fat may differentially affect systemic functions.
反式脂肪酸（TFA）和顺式单不饱和脂肪分别对葡萄糖代谢和胰岛素敏感性产生有害和有益的影响。脂肪组织和骨骼肌是信号蛋白（脂肪因子和肌因子）的来源，其中一些与胰岛素敏感性的控制有关。在这里，我们研究了反油酸（EA；反式 9-18:1）——工业生产的 TFA 的主要成分——和油酸（OA；顺式 9-18:1）——其顺式异构体天然存在于食物中——对细胞葡萄糖摄取和选定的肌因子和脂肪因子表达的可能差异影响，使用细胞模型。分化的 C2C12 肌管和 3T3-L1 脂肪细胞用载体（对照细胞）或脂肪酸预处理 24 小时，然后测量基础和胰岛素刺激的 2-脱氧葡萄糖摄取和选定信号蛋白的表达。在 C2C12 肌管中，OA 预处理而非 EA 预处理导致胰岛素刺激的 2-脱氧葡萄糖摄取和 IL-6 表达水平增加，而 EA 预处理而非 OA 预处理导致 IL-15 mRNA 水平降低和 TNF-α表达水平升高。在 3T3-L1 脂肪细胞中，暴露于 OA 而非 EA 导致抵抗素基因表达减少和脂联素基因表达增加。这些结果表明 OA 和 EA 对肌肉葡萄糖摄取以及目标肌因子和脂肪因子表达具有明显的直接影响，从而为顺式和反式单不饱和脂肪可能以不同方式影响全身功能提供了新的机制。
