Role of Lipoprotein Assembly in Maternal-Fetal Transport of Beta-Carotene

脂蛋白组装在 β-胡萝卜素母胎转运中的作用

• 批准号: 9913384
• 负责人: M Mahmood Hussain
• 金额: $ 37.66万
• 依托单位: RUTGERS, THE STATE UNIV OF N.J.
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-04-12 至 2024-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9913384
• 关键词: Adult; Affect; Anabolism; Animal Model; Apolipoproteins B; Beta Carotene; Biological Assay; Biological Process; Blood Circulation; Carotenoids; Cells; Cleaved cell; Congenital Abnormality; Data; Developed Countries; Developing Countries; Development; Diet; Dietary Component; Dietary Practices; Dose; Elements; Embryo; Embryonic Development; Event; Fetal health; Fetus; Generations; Genetic Transcription; HNF4A gene; Health; Human; In Vitro; Incidence; Intake; Intervention; Intraperitoneal Injections; Knowledge; Link; Lipoproteins; Mediating; Metabolism; Micronutrients; Molecular; Mothers; Mus; Nutrient; Oxides; Oxygenases; Placenta; Pregnancy; Pregnant Women; Premature Birth; Production; Public Health; Publishing; Regulation; Reporter; Retinaldehyde; Retinoids; Risk; Role; Small Interfering RNA; Source; Time; Tretinoin; Vitamin A; Vitamin A Deficiency; Vitamins; Work; base; chromatin immunoprecipitation; embryo tissue; enhancing factor; fetal; human model; in vivo; inhibitor/antagonist; insight; intervention program; knock-down; microsomal triglyceride transfer protein; mouse model; novel; promoter; transcription factor; trophoblast

Embryonic vitamin A deficiency or excess have been linked to congenital defects in humans and animal models, owing to the defective transcriptional action of retinoic acid (RA), the active form of vitamin A, during embryogenesis. β-carotene (BC) is the most abundant dietary vitamin A precursor. In the embryo, BCO1 cleaves intact BC, from the maternal circulation, to generate retinaldehyde, which is then oxidized to RA. Asymmetric cleavage of BC by BCO2, generates β-apo-10'-carotenal (apo10AL) which can serve as a precursor of retinoids (vitamin A and its derivatives), but also antagonize RA action. Our data suggest that lipoproteins synthesized within placenta mediate the transfer of BC towards the fetus. We hypothesize that apo10AL, generated in placenta by BCO2 from BC, upregulates microsomal triglyceride transfer protein (Mttp; MTP) through HNF4α and/or COUP-TFs, by antagonizing the action of RA. We propose three Specific Aims to understand the molecular mechanisms of BC placental-fetal transfer under a normal maternal vitamin A status. Aim 1. To investigate in vivo the regulation of placental lipoprotein biosynthesis by apo10AL and RA. We will assess placental carotenoids and retinoids levels and metabolism, and lipoprotein biosynthesis in WT, Bco1-/- and Bco2-/- mice. Aim 1A: To define the molecular events related to carotenoid metabolism and lipoprotein production that occur in placenta after a single maternal administration of BC. Dams will be sacrificed at various time points post-BC administration (at 13.5 dpc, by IP injection). Aim 1B: To establish the effects of a single maternal BC administration at various times during gestation on the molecular events related to carotenoid metabolism and lipoprotein production. Dams will be administered BC at various times during gestation and sacrificed after 4 and 24 h. Aim 2. To establish that placenta MTP deficiency abrogates accumulation of embryonic BC after its administration to the mother. A mouse model with placental-specific inactivation of Mttp will be used. Dams will be sacrificed 4 and 24 h after BC administration at 13.5 dpc, and placentas analyzed as in Aim 1. Aim 3. To investigate in vitro the regulation of human placental lipoprotein biosynthesis by apo10AL and RA. In this Aim, we will expand our studies to human models. Aim 3A: To study the apo10AL-mediated regulation of MTP function in human placenta explants and Bewo cells. We will: (i) determine the time course and dose-dependent effect of BC, apo10AL and RA on carotenoid and retinoid metabolism and lipoprotein biosynthesis; (ii) inactivate MTP by siRNA or an MTP inhibitor and (iii) Bco1 and Bco2 by siRNA; (iv) study the competing effects of apo10AL and RA on MTP expression. Aim 3B: To identify the cis-elements in the Mttp promoter and the transcription factors required for apo10AL-mediated increase in Mttp transcription. Promoter reporter assays, transcription factors knockdown, and ChIP assays will establish how placental Mttp expression is regulated by apo10AL through HNF4a and/or COUP-TFs.

胚胎维生素A缺乏症或超过与人类和动物模型中的先天性缺陷有关，这是由于视黄酸（RA）（RA）（RA）（在胚胎发生过程中）的活性形式的转录作用。 β-胡萝卜素（BC）是最丰富的饮食维生素A先生。在胚胎中，BCO1从母体循环中切开完整的BC，以产生视网膜醛，然后将其氧化为RA。 BCO2对BC的不对称切割会产生β-APO-10'-偶然（APO10AL），该元素可以用作类维生素A（维生素A及其衍生物）的前体，但也可以拮抗RA作用。我们的数据表明，脂蛋白在plapeta中合成的脂蛋白介导BC向胎儿的转移。我们假设由BC中的BCO2在plabeta中产生的Apo10al上调通过HNF4α和/或Coup-TFS上调微粒体甘油三酸酯转移蛋白（MTTP； MTP），通过拮抗RA的作用。我们提出了三个特定的目的，以了解正常母体维生素A状态下BC斑点 - 芬特转移的分子机制。目的1。在体内研究apo10al和ra的斑点脂蛋白生物合成的调节。我们将在WT，BCO1 - / - 和BCO2 - / - 小鼠中评估斑点类胡萝卜素和类视黄素水平和代谢水平以及代谢。 AIM 1A：定义与单一母亲给药后在Ploceta中发生的类胡萝卜素代谢和脂蛋白产生有关的分子事件。大坝将在BC给药后的不同时间点处置（在13.5 DPC，通过IP注入）。 AIM 1B：在妊娠期间，在不同时间建立单个基质BC给药的影响对与类胡萝卜素代谢和脂蛋白产生有关的分子事件。大坝将在妊娠期间的不同时间给予BC，并在4和24小时后处死。目的2。确定胎盘MTP缺乏症在给母亲的胚胎后，BC的积累。将使用具有MTTP的位置特异性灭活的小鼠模型。 BC在13.5 dpc给药后4和24小时处置大坝，如在AIM 1中分析的斑点。目的3。在体外通过Apo10al和RA调节人倍素脂蛋白脂蛋白生物合成。在此目标中，我们将把研究扩展到人类模型。 AIM 3A：研究人胎盘外植体和BEWO细胞中MTP功能的APO10AL介导的调节。我们将：（i）确定BC，APO10AL和RA对类胡萝卜素和类维生素性代谢以及脂蛋白生物合成的时间过程和剂量依赖性效应； （ii）由siRNA或MTP抑制剂灭活MTP，以及（iii）BCO1和BCO2 siRNA； （iv）研究APO10AL和RA对MTP表达的竞争影响。 AIM 3B：确定MTTP启动子中的顺式元素以及APO10AL介导的MTTP转录增加所需的转录因子。启动子记者测定，转录因子敲低和CHIP分析将确定如何通过HNF4A和/或COUP-TFS APO10AL调节Plotetal MTTP的表达。