Genetic modification of PUFA biosynthesis and CHD

描述(申请人提供)：多不饱和脂肪酸(PUFA)在膜结构、细胞信号和基因表达调节方面发挥重要作用。多不饱和脂肪酸是几种不同二十烷类化合物的前体，这些二十烷类化合物在炎症、调节血压和凝血等许多功能中具有多种作用。通过这些功能，多不饱和脂肪酸无疑与预防冠心病的发展联系在一起。亚油酸(n-6)和α-亚麻酸(n-3)是必需脂肪酸，可在转录因子的调节下，通过伸长、脱饱和和强反馈作用转化为长链多不饱和脂肪酸，参与这一生物合成的甾醇脱饱和酶受转录因子、类固醇调节元件结合蛋白-1c(SREBP-1c)和过氧化物酶体增殖物激活受体-α(PPAR-α)的调节。我们假设这些基因的突变会影响FA的生物合成和CHD的风险。我们的总体目标是通过检测参与其生物合成途径的基因，评估饮食中多不饱和脂肪酸对ML影响的个体差异。我们将从正在进行的研究中研究2,150例ML幸存者和2,150名基于人群的对照。具体假设将检验FA[1)n-3 FA：α-亚麻酸、二十碳五烯酸(EPA)和二十二碳六烯酸(DMA)的摄入与ML风险的遗传机制；2)n-6 FA：亚油酸和花生四烯酸，以及3)反式FA]。这些基因包括：脂肪酸去饱和酶(FADS)2(Delta6-去饱和酶)、FADS1(Delta5-去饱和酶)和FADS3、ELOVL-1、2、3、4、5、6、7(7个延长酶基因)、PPAR-α和SREBP-1c。进一步的假设将通过其他参与从花生四烯酸和环境保护局合成二十碳二烯酸的基因来验证：环氧合酶(COX)-2，S-溶氧合酶(LOX)和细胞色素P450 2J2(CYP2J2)。脂肪组织中的Fas将被用作摄入量的生物标志物。生化测量、饮食数据和一般信息都适用于这一人群。这项拟议的研究提供了一个难得的机会来扩大我们对遗传和环境条件如何影响CHD的理解。人群的饮食提供了所有主要类型脂肪酸的广泛变化，特别是低范围的饱和脂肪和n-3脂肪酸。这加强了对风险的评估，并适用于当前的饮食目标。被提议进行最终分析的大量SNPs将增加识别CHD背后基因的分辨率和能力。

DESCRIPTION (provided by applicant): Polyunsaturated fatty acids (PUFA) exert vital functions on membrane structure, cell signaling, and regulation of gene expression. PUFA are the precursors of several different eicosanoids, which have multiple roles in inflammation, regulation of blood pressure, and blood clotting, among many other functions. Through these functions, PUFA are undoubtedly linked to the prevention of development of coronary heart disease (CHD). Linoleic (n-6) and alpha-linolenic acid (n-3) are essential fatty acids (FA) that can be converted into long- chain PUFA through elongation, desaturation, and strong feedback regulated by transcription factors, sterol desaturases enzymes involved in this biosynthetic pathway are regulated by transcription factors, sterol regulatory element-binding protein-1c (SREBP-1c) and peroxisome proliferators-activated receptor-alpha (PPAR-alpha). We hypothesize that mutations in these genes affect FA biosynthesis and risk of CHD. Our overall objective is to assess individual variability in the effect of dietary PUFA on Ml, by examining genes involved in their biosynthetic pathway. We will study 2,150 case survivors of Ml and 2,150 population-based controls from out ongoing study. Specific hypothesis will examine the genetic mechanisms that link intake of FA [1) n-3 FAs: alpha-linolenic acid, eicosapentaenoic acid (EPA), and docsahexaenoic acid, (DMA); 2) n-6 FAs: linoleic acid, and arachidonic acid, and 3) trans FA] to risk of Ml. The proposed genes include: fatty acid desaturase (FADS)2 (delta6-desaturase), FADS1 (delta5-desaturase), and FADS3, ELOVL-1,2,3,4,5,6,7 (7 elongase genes), PPAR-alpha, and SREBP-1c. Further hypothesis will be tested with other genes involved in the synthesis of eicosanoids from arachidonic acid and EPA: cycloxygenase(COX)-2, S-lypoxygenase(LOX), and cytochrome P450 2J2 (CYP2J2). FAs in adipose tissue will be used as biomarkers of intake. Biochemical measurements, dietary data, and general information are available for this population. The proposed study offers and unusual opportunity to expand our understanding of how genetic and environmental conditions can influence CHD. The diet of the population offers a wide range in variation of all the major types of FAs, particularly with low ranges of saturated fat and n-3 FAs represented. This strengthens evaluation of risk, and application to current dietary goals. The large number of SNPs proposed for final analysis will add to the resolution and power to identify the genes that underlie CHD.