Mechanisms of Vitamin E Function Studied in Zebrafish

斑马鱼维生素 E 功能的机制研究

基本信息

批准号：
7936207
负责人：
MARET G TRABER
金额：
$ 36万
依托单位：
OREGON STATE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-09-20 至 2012-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7936207
关键词：
Animal Experimentation Animals Antioxidants Apoptosis Apoptosis Regulator Arachidonate 15-Lipoxygenase Ascorbic Acid Biological Models Birth Cardiovascular Abnormalities Cardiovascular system Cell Culture Techniques Cell Death Cells Characteristics Complex Congenital neurologic anomalies Data Defect Development Diet Embryo Embryonic Development Exhibits Fertilization Functional disorder Gene Targeting Genes Glutathione Goals Greek Hour Human Hydrogen Peroxide LOX gene Link Lipid Peroxidation Lipids Mediating Mediator of activation protein Mind Modeling Molecular Molecular Target Mothers Names Nervous system structure Neurologic Nutrient Outcome Oxidants Oxidative Stress Phospholipids Plants Platelet Factor 4 Pregnancy Proteins Reaction Regulation Reproduction Review Literature Rodent Role Signal Transduction Site Solid Staging Study models System Testing Time Tissues Tocopherols Transgenic Model Translating Vertebrates Vitamin E Vitamin E Deficiency Vitamins Water Yolk Sac Zebrafish apoptosis inducing factor base biological systems craniofacial egg embryo tissue fetal glutathione peroxidase implantation knock-down lipid mediator malformation oxidized lipid preference prevent protein expression success zebrafish development

项目摘要

Vitamin E was discovered in 1922 as a lipid soluble factor necessary for reproduction and named -tocopherol from the Greek words for “birth” and for “to carry”. To date, - tocopherol’s role in reproduction has been impossible to approach experimentally because - tocopherol-deficient (E-) mothers do not produce embryonic tissues due to failed implantation. To circumvent this barrier, we have chosen to use the premier vertebrate model for studying development, the zebrafish, because they lay eggs; thus, implantation is not necessary. The zebrafish model is ideal for our studies because it, like humans, has a preference for - tocopherol, expresses the ttp gene and requires vitamin C, an important determinant in - tocopherol antioxidant function in humans. An additional strength of this model over traditional rodent transgenic models is that any gene can be knocked down during embryogenesis, a feature we plan to exploit. We have succeeded in developing the first defined zebrafish diet. Using our E- defined diet, we are able to produce E- eggs. By 48 hours post-fertilization (hpf), many E- embryos exhibit severe developmental malformations, which establishes for the first time that -tocopherol is required for fetal neurological and cardiovascular development, not just implantation. We also found that the -tocopherol transfer protein -TTP) is abundantly expressed by the 48 hpf zebrafish embryo and its expression increases with oxidative stress. Severe vitamin E deficiency with progressive neurologic degeneration occurs in humans with ttp gene defects, emphasizing the critical importance of this protein. -TTP expression in the zebrafish embryo suggests that during development -TTP directs -tocopherol from the yolk sac to specific sites in the developing embryo where it is especially required. We propose that -tocopherol is required to protect key oxidized lipid mediators from further oxidative degradation during specific developmental steps, especially those in the nervous system. Specifically, glutathione peroxidase 4 (GPx4), a detoxifier of phospholipid hydroperoxides, translates oxidative stress into cell death that is mediated by both 12/15-lipoxygenase (12/15 LOX) and apoptosis-inducing factor (AIF); -tocopherol prevents these abnormalities in vitro. We hypothesize that α-tocopherol provides antioxidant protection for specific, key lipid mediators necessary for embryonic development, including cell loss via programmed cell death. To explain the key developmental effects of -tocopherol deficiency, we propose the following Aim 1. Define the roles of oxidant and antioxidant apoptosis regulators during embryonic development; Aim 2. Define the role of -TTP during embryonic development. Completion of these specific aims will allow us to determine specific -tocopherol molecular functions and key antioxidant/oxidant signaling mechanisms. Defining the molecular targets altered by - tocopherol-deficiency in the zebrafish will provide a solid basis for understanding why humans require -tocopherol for reproduction as well as to maintain a healthy nervous system

维生素E于1922年被发现是繁殖必要的脂质固体因子从希腊语单词中命名为“出生”和“携带”的the。迄今为止，- 生育酚在繁殖中的作用是不可能在实验上接近的，因为-- 由于植入失败，缺乏生育酚（E-）母亲不会产生胚胎组织。为了避免这种障碍，我们选择使用主要的脊椎动物模型来研究斑马鱼的发展，因为它们产卵。因此，植入不是必需的。这斑马鱼模型是我们研究的理想选择，因为它像人类一样偏爱-- 生育酚表达TTP基因，并需要维生素C，这是-的重要决定剂人类的生育酚抗氧化功能。该模型对传统的额外优势啮齿动物转基因模型是，在胚胎发生过程中，任何基因都可以被击倒我们计划探索的功能。我们成功地开发了第一种定义的斑马鱼饮食。使用我们的电子定义饮食，我们能够产生e-eggs。施税后48小时（HPF），许多E-Embryos表现出严重的发育畸形，这是第一个胎儿神经系统和心血管发育所必需的生育酚是植入。我们还发现托酚转移蛋白-TTP大量由48 hpf斑马鱼胚胎表达，其表达随氧化应激而增加。患有TTP的人类发生严重的维生素E缺乏症和进行性神经性变性基因缺陷，强调该蛋白质的关键重要性。 -TTP表达斑马鱼的胚胎表明，在开发过程中-TTP在蛋黄中指导托酚囊囊到开发胚胎中的特定位置，特别需要。我们提出了这一点 托酚需要保护关键的氧化脂质介质免受进一步氧化的影响在特定的发育步骤中，尤其是神经系统中的发育步骤中的降解。具体而言，谷胱甘肽过氧化物酶4（GPX4），一种磷脂氢过氧化物的排毒剂，将氧化应激转化为由12/15-脂氧酶介导的细胞死亡（12/15 LOX）和凋亡诱导的因子（AIF）； 托酚在体外阻止这些异常。我们假设α-生育酚为特定的键脂质提供抗氧化剂保护胚胎发育所需的介质，包括通过编程细胞死亡的细胞损失。为了解释托酚缺乏的主要发育效果，我们提出以下目标1。定义胚胎调节剂的氧化剂和抗氧化剂凋亡的作用发展;目标2。定义-TTP在胚胎发育过程中的作用。完成这些特定目标将使我们能够确定特定的托酚分子函数和键抗氧化剂/氧化信号传导机制。定义由-改变的分子靶标斑马鱼中的生育酚缺陷将为理解人类提供扎实的基础需要托酚进行繁殖以及维持健康的神经系统