Sex Differences in Fatty Acid Metabolism

血液和组织中的脂肪酸在女性和男性中是不同的。本研究的长期目的是确定人类脂肪酸代谢的性别差异，从而导致不同水平的二十二碳六烯酸(DHA)，一种omega-3多不饱和脂肪酸以及n-7至n-9单不饱和脂肪酸水平的差异，我们在啮齿动物模型中证实了这些差异。我们将检查控制脂肪酸水平的各种因素，包括脂肪酸合成、脂肪酸融入复合脂质、脂肪酸氧化和饮食。在啮齿动物模型中，我们观察到参与这些脂肪酸合成的基因表达的性别差异，但雌激素等性激素在控制这种表达方面的作用不是通过直接激活的。因此，我们将研究脂肪生成途径中的性别差异，以确定可能间接激活啮齿动物和细胞培养模型中DHA和n-7单不饱和脂肪酸合成的性激素相互作用。特别是，我们将研究雌激素在细胞膜磷脂合成和能量储存三酰甘油合成中的作用。我们预计，脂肪酸合成的性别差异主要发生在肝脏，雌激素通过改变涉及类固醇调节元件结合蛋白-1c、过氧化体增殖物激活受体a和碳水化合物反应元件结合蛋白的途径，反式激活肝脏X受体反应元件，从而增加脂肪酸的脱饱和和延长。从这项研究中获得的理解可以洞察人类和动物生理学中不同系统中的性别差异，以及脂肪酸的摄取和结合。例如，n-7单不饱和脂肪酸代谢的性别差异可以部分解释胰岛素敏感性的性别差异。更好地了解n-3多不饱和脂肪酸的代谢和生物合成对于确定人类的营养需求和帮助制定增加食品供应中n-3多不饱和脂肪酸的策略至关重要。

Fatty acids in blood and tissues are different in women and men. The long term of the present research is to determine the sex differences in fatty acid metabolism that result in different levels of docosahexaenoic acid (DHA), an omega-3 polyunsaturated fatty acids and differences in levels of n-7 to n-9 monounsaturated fatty acids in humans and we have confirmed these differences in rodent models. We will examine various factors that control the levels of fatty acids including fatty acid synthesis, fatty acid incorporation into complex lipids, fatty acid oxidation and diet. In the rodent models, we have observed sex differences in the expression of genes involved in the synthesis of these fatty acids, but the role of sex hormones such as estrogen in the control of this expression is not by direct activation. Therefore, we will examine sex differences in lipogenesis pathways to identify sex hormone interactions that might be indirectly activating DHA and n-7 monounsaturated fatty acid synthesis in rodents and in cell culture models. In particular, we will be examining the role of estrogen on the synthesis of phospholipids for cell membranes, and the synthesis of triacylglycerols for energy storage. We expect that the sex differences in fatty acid synthesis mainly occur in the liver and that estrogen is transactivating liver X receptor response elements that increases desaturation and elongation of fatty acids through changes in pathways involving sterol regulatory element binding protein-1c, peroxisome proliferator activated receptor a, and carbohydrate responsive element binding protein. The understanding gained from this research can provide insight on sex differences in various systems in human and animal physiology and on fatty acid uptake and incorporation. For example, sex differences in n-7 monounsaturated fatty acids metabolism my partially explain sex difference in insulin sensitivity. A greater understanding of the metabolism and biosynthesis of n-3 polyunsaturated fatty acids is critical to determine nutritional requirements in humans, and to assist in strategies to increase n-3 polyunsaturated fatty acids in the food supply.