Role of Cholesterol Biosynthesis in Development

胆固醇生物合成在发育中的作用

• 批准号: 9767244
• 负责人: SHAILENDRA BHANUBHAI PATEL
• 金额: $ 11.76万
• 依托单位: CINCINNATI CHILDRENS HOSP MED CTR
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-01 至 2021-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9767244
• 关键词: 7-dehydrocholesterol reductase; Address; Affect; Alleles; Basic Science; Biochemical; Birth; Brain; Cholesterol Homeostasis; Clinical; Clinical Sciences; Collaborations; Congenital Abnormality; Defect; Desmosterol; Development; Dorsal; Dysmorphology; Embryo; Embryology; Embryonic Development; Enzymes; Face; Genes; Genetic; Goals; Human; Hydroxysteroids; Lead; Membrane Microdomains; Metabolism; Molecular; Mus; Mutation; Neuraxis; Oxidoreductase; Pathway interactions; Perinatal mortality demographics; Phenotype; Positioning Attribute; Proteins; Proteome; Research Personnel; Role; Squalene; Sterols; Structural Congenital Anomalies; Structure; Syndrome; Telencephalon; Tissues; brain tissue; cholesterol biosynthesis; craniofacial; craniofacial tissue; enzyme biosynthesis; experimental study; interdisciplinary approach; interest; malformation; mutant; myelination; nervous system development; neurogenesis; novel; postnatal; prevent; skeletal; tool

Genetic defects in the cholesterol bio-synthesis pathway lead to a spectrum of human dysmorphology syndromes with a key common theme of altered craniofacial, skeletal and central nervous system (CNS) development. A deep mechanistic understanding of how these malformations arise will require a multi- disciplinary approach. As part of this R03 to “establish basic science-clinical collaborations to understand structural birth defects,” we will merge the expertise of three teams at the interface of genetics, embryology and sterol metabolism. We will combine clinical acumen and biochemical expertise with molecular embryology to synergistically approach the question of how sterol metabolism defects lead to brain and craniofacial birth defects. We will focus specifically on three enzymes in the post-squalene portion of the cholesterol biosynthesis pathway: hydroxysteroid (17-beta) dehydrogenase 7 (Hsd17b7), 24-dehydrocholesterol reductase (Dhcr24) and 7-dehydrocholesterol reductase (Dhcr7). These are neighboring enzymes in the latter portion of the pathway, but have very different phenotypes when ablated. The rationale for this proposal is that the molecular basis for these structural birth defects in mouse and humans has not been fully elucidated. Furthermore, detailed analysis of the mouse CNS phenotypes after birth has been prevented by perinatal death of the null mutants. Our central hypothesis is that the differing phenotypes within the spectrum of cholesterol metabolism errors occur because defects at different steps of the pathway lead to the accumulation of different sterol intermediates and/or altered lipid raft composition, which then affect embryonic development differently. We have collected and generated 5 mouse alleles (Hsd17b7rudolph, Dhcr24null, Dhcr7null, Dhcr24flox, Dhcr7flox and) to specifically address this hypothesis in this exploratory proposal. In addition, we propose to generate new tools to further develop our overarching hypothesis. We propose to address this hypothesis with two specific aims: (1). Analysis of sterols and lipid rafts in developing brains and faces upon loss of Hsd17b7, Dhcr24, and Dhcr7. (2). Determine the consequences for loss of cholesterol biosynthesis genes Hsd17b7, Dhcr24, and Dhcr7 in the cortex. The experiments in this proposal will accomplish two goals: (1) We will substantially increase our understanding of the effects of loss of three crucial cholesterol biosynthesis enzymes on CNS development. These preliminary studies and the novel Hsd17b7 allele will position us to address even more mechanistic hypotheses about the role of these enzymes, and sterol metabolism more broadly, in congenital structural brain defects, (2) We will establish an effective and demonstrable collaboration between an embryologist, a clinician researcher and an expert in sterol analysis with a shared interest in the role of sterol metabolism in structural birth defects. !

胆固醇生物合成途径的遗传缺陷导致一系列人类形态异常 以颅面、骨骼和中枢神经系统 (CNS) 改变为主要共同主题的综合征 对这些畸形如何产生的深入机制的理解需要多方面的研究。 作为 R03 的一部分，“建立基础科学与临床合作以理解 结构性出生缺陷”，我们将融合遗传学、胚胎学领域三个团队的专业知识 我们将临床智慧和生化专业知识与分子胚胎学结合起来。 协同解决甾醇代谢缺陷如何导致大脑和颅面出生的问题 我们将特别关注胆固醇角鲨烯后部分的三种酶。 生物合成途径：羟基类固醇 (17-β) 脱氢酶 7 (Hsd17b7)、24-脱氢胆固醇 还原酶 (Dhcr24) 和 7-脱氢胆固醇还原酶 (Dhcr7) 这些是后者的邻近酶。 该提议的基本原理是： 小鼠和人类这些结构性出生缺陷的分子基础尚未完全阐明。 此外，围产期检查阻碍了对出生后小鼠中枢神经系统表型的详细分析。 我们的中心假设是，范围内的不同表型。 胆固醇代谢错误的发生是因为途径不同步骤的缺陷导致 不同甾醇中间体和/或脂筏组成的积累，然后影响 我们收集并生成了 5 个小鼠等位基因（Hsd17b7rudolph， Dhcr24null、Dhcr7null、Dhcr24flox、Dhcr7flox 和）在本探索性研究中专门解决这一假设 此外，我们建议生成新的工具来进一步发展我们的总体假设。 提出通过两个具体目标来解决这一假设：（1）分析发育中的甾醇和筏脂质。 确定 Hsd17b7、Dhcr24 和 Dhcr7 缺失后的大脑和面部 (2)。 皮质中的胆固醇生物合成基因 Hsd17b7、Dhcr24 和 Dhcr7 本提案中的实验。 将实现两个目标：（1）我们将大大加深对失去三个人的影响的理解 这些初步研究和新颖的胆固醇生物合成酶对中枢神经系统的发育至关重要。 Hsd17b7 等位基因将使我们能够解决有关这些作用的更多机制假设 酶和更广泛的甾醇代谢，在先天性结构性脑缺陷中，（2）我们将建立一个 胚胎学家、临床研究人员和专家之间有效且可证明的合作 甾醇分析，对甾醇代谢在结构性出生缺陷中的作用有着共同的兴趣。 ！