The asymmetric cleavage of beta-carotene in mammalian embryonic development

哺乳动物胚胎发育中β-胡萝卜素的不对称裂解

• 批准号: 9029615
• 负责人: Loredana Quadro
• 金额: $ 31.61万
• 依托单位: RUTGERS, THE STATE UNIV OF N.J.
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9029615
• 关键词: Address; Affect; Alcohols; Aldehydes; All-Trans-Retinol; Beta Carotene; Binding; Binding Sites; Breeding; C10; Carotenoids; Cell Line; Cell Respiration; Cell Survival; Child; Citric Acid Cycle; Cleaved cell; Congenital Abnormality; Data; Developing Countries; Development; Diet; Dose; Embryo; Embryonic Development; Enzymes; Experimental Animal Model; Experimental Models; Female; Female of child bearing age; Fetal Death; Fetus; Fibroblasts; Genes; Genetic Transcription; Geographic Locations; Growth and Development function; Health; Homeostasis; Human; In Vitro; Intake; Intervention; Knock-out; Knockout Mice; Lead; Ligands; Link; Malnutrition; Metabolism; Mitochondria; Modeling; Morphology; Mothers; Mus; Mutant Strains Mice; Mutation; Nutrient; Nutritional status; Output; Oxidation-Reduction; Oxidative Phosphorylation; Oxidative Stress; Oxygenases; Pathway interactions; Phenotype; Phosphotransferases; Physiology; Play; Population; Pregnancy; Pregnant Women; Production; Protein Isoforms; Proteins; Public Health; Pyruvate Dehydrogenase Complex; Reaction; Reagent; Regulation; Respiration; Retinaldehyde; Retinoids; Retinol Binding Proteins; Role; Signal Transduction; Source; Supplementation; Testing; Tissues; Toxic effect; Tretinoin; Vitamin A; Vitamin A Deficiency; Woman; Work; World Health Organization; apocarotenal; base; in vivo; innovation; mouse model; novel; prevent; programs; public health relevance

 DESCRIPTION (provided by applicant): Vitamin A is required for proper mammalian embryonic development, owing to defective transcriptional action of retinoic acid (RA), its active form. Deficient or excessive maternal vitamin A intake of this essential nutrient results in congenital abnormalities or fetal death in experimental animal models and humans. Notably, vitamin A deficiency (VAD) is the third most prevalent nutritional deficiency, and is an overwhelming public health issue, affecting hundreds of millions of people (predominantly women and children) in developing countries. The majority of the world population, especially in the above-mentioned geographic areas, relies on the vitamin A precursor β-carotene (BC) as a source of retinoids (vitamin A and its derivatives). In the embryo, BC obtained from the maternal diet can significantly contribute to the retinoid needs of the developing tissues upon conversion to retinaldehyde via the symmetric BC cleavage enzyme β,β-carotene-15,15'-oxygenase, CMO1. Retinaldehyde is then oxidized to retinoic acid, the master regulator of many genes that are crucial to embryogenesis. BC is also cleaved asymmetrically by β,β-carotene-9',10'-oxygenase, CMO2, generating C10 β-apocarotenal (C10 apoAL). While retinaldehyde could also be generated from C10 apoAL, the role of CMO2 and its reaction product during mammalian embryonic development is unknown. Our preliminary data indicate that the well-known detrimental effects of VAD on mouse embryogenesis are aggravated when CMO2 is inactive and BC is administered to the dams, despite expression of CMO1. We showed that the embryonic phenotype of mice lacking CMO2 on the retinol-binding protein (RBP) knockout background, an established model of VAD, was due to the low levels of C10 apoAL along with limited availability of retinoids. Supplementing CMO2-/-RBP-/- mice on a vitamin A deficient diet with C10 apoAL reduced congenital malformations. We propose that C10 apoAL serves as a ligand for PKCδ. This mitochondria-localized PKC isoform signals to the pyruvate dehydrogenase complex (PDHC), increasing its activity, with the purpose of coordinating the fuel flux to the citric acid cycle with the demands for ATP production. PKCδ is activated by redox mechanisms, with a mandatory catalytic role of vitamin A (retinol) that binds the activation domains of the kinase. CMO2 localizes to mitochondria and C10 aopAL is structurally similar to retinol. We showed that C10 apoAL interacts with the retinol-binding domain of PKCδ and modulates respiration in mouse embryonic fibroblasts, in a PKCδ-dependent manner. Overall, our data suggest that disruption of PKC signaling and mitochondrial functions when C10 apoAL and vitamin A are limiting could be the underlying cause of the exacerbated phenotypes of mice lacking CMO2 in the presence of BC. With this application we seek to further understand the function of CMO2 and the mechanisms of C10 apoAL action during mammalian embryogenesis. Specifically, we will test whether C10 apoAL is essential for embryonic survival under conditions of VAD (Aim 1) and we will define the interaction between CMO2/β- apocarotenoids and PKCδ signaling network during embryonic development (Aim 2), both in vitro and ex vivo (Aim 2A) and in vivo (Aim 2B). Unique reagents, such as pure synthetic β-apocarotenoid compounds, and new mouse models, with inactivation of the PKCδ and carotenoid metabolism pathways, will be used to address the above-mentioned questions. Understanding the role of CMO2/β-apocarotenoids in embryogenesis is relevant to human health, as it will lead to novel interventions to ameliorate VAD-associated congenital defects.

 描述（由适用提供）：由于视黄酸（RA）（其活性形式）的不良转录作用，维生素A是适当的哺乳动物胚胎发育所必需的。缺乏或过量的材料维生素这种基本营养素的摄入导致先天性异常或实验动物模型和人类的胎儿死亡。值得注意的是，维生素A缺乏症（VAD）是第三大普遍的营养缺乏症，是一个压倒性的公共卫生问题，影响了发展中国家数亿人（主要是妇女和儿童）。世界上的大多数人口，尤其是在上述地理区域中，依赖于维生素A前体β-胡萝卜素（BC）作为类视黄素（维生素A及其衍生物）的来源。在胚胎中，从母体饮食获得的卑诗省可以通过对称的BC裂解酶β，β-胡萝卜素15,15'-氧合酶CMO1在转化为视网膜甲基时的开发组织的类视角需求。然后将视网膜醛氧化为视黄酸，维甲酸是许多对胚胎发生至关重要的基因的主要调节剂。 BC还通过β，β-胡萝卜素-9'，10'-氧合酶，CMO2不对称地裂解，产生C10β-阿普托元素（C10 apoal）。虽然也可以通过C10 apoal产生视网膜氢，但CMO2及其在哺乳动物胚胎发育过程中的反应产物的作用尚不清楚。我们的初步数据表明，当CMO2不活跃并且将BC施用到大坝时，VAD对小鼠胚胎发生的众所周知的有害作用是聚集的，即所需的CMO1表达。我们表明，在视黄醇结合蛋白（RBP）敲除背景上缺少CMO2的小鼠的胚胎表型是一种已建立的VAD模型，是由于C10 apoal的低水平以及视黄素的可用性较少所致。补充CMO2 - / - RBP - / - 小鼠在维生素上是一种缺乏饮食的饮食，C10 apoal降低了先天性畸形。我们建议C10 apoal用作PKCδ的配体。该线粒体定位的PKC同工型信号与丙酮酸脱氢酶络合物（PDHC），增加了其活性，目的是将燃料通量与柠檬酸周期协调，并需要对ATP产生。 PKCδ被氧化还原激活 机制，具有结合激酶活化域的维生素A（视黄醇）的强制性催化作用。 CMO2定位于线粒体，C10 aopal在结构上与视黄醇相似。我们表明，C10 apoal与PKCδ的视黄醇结合结构域相互作用，并以PKCδ依赖性方式调节小鼠胚胎成纤维细胞中的呼吸。总体而言，我们的数据表明，当C10 Apoal和维生素A限制时，PKC信号传导和线粒体功能的破坏可能是在卑诗省存在下缺乏CMO2的小鼠表型的根本原因。通过此应用，我们试图进一步了解CMO2的功能以及在哺乳动物胚胎发生过程中C10 apoal作用的机制。具体而言，我们将测试在VAD条件下C10 Apoal对于胚胎生存是否至关重要（AIM 1），我们将在胚胎发育过程中定义CMO2/β-apocar​​otendoids和PKCδ信号网络之间的相互作用（AIM 2）（AIM 2），即体外和EX VIVO和EX VIVO（AIM 2A）和VIVO（AIM 2A）和VIVO（AIM 2A）和INVIVO（AIM 2B）。独特的试剂，例如纯合成β-apoarotendoid化合物，以及新的小鼠模型，具有PKCδ和类胡萝卜素代谢途径的灭活，将用于解决上述问题。了解CMO2/β-apocar​​otendoids在胚胎发生中的作用与人类健康有关，因为这将导致新的干预措施改善与VAD相关的先天性缺陷。