FUNCTIONAL CHARACTERIZATION OF NOVEL DETERMINANTS OF HOLOPROSENCEPHALY (HPE)

前脑无裂畸形 (HPE) 的新决定因素的功能特征

基本信息

批准号：
10366059
负责人：
Ernesto Guccione
金额：
$ 36.34万
依托单位：
ICAHN SCHOOL OF MEDICINE AT MOUNT SINAI
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-03-05 至 2026-02-28
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10366059
关键词：
Accounting Affect Anterior Automobile Driving Biological Process Brain Cause of Death Cells Cephalic Cessation of life Chromatin Clinical Collaborations Congenital Abnormality Craniofacial Abnormalities Critical Pathways Data Defect Development Developmental Process Diagnostic Disease Embryo Embryonic Development Embryonic Structures Epigenetic Process Erinaceidae Event Eye Failure Family Fingers Follow-Up Studies Forebrain Development Gene Expression Genes Genetic Genetic Determinism Genetic Transcription Goals Growth Head Healthcare Holoprosencephaly Human In Vitro Individual Infant Knowledge Link MAP Kinase Gene Mediating Microcephaly Mining Molecular Molecular Diagnosis Morbidity - disease rate Mus Mutate Mutation NOTCH3 gene Nature Newborn Infant Oncogene Deregulation Pathogenicity Pathway interactions Patients Pattern Phenotype Primitive Streaks Prosencephalon Proteins Regenerative Medicine Reporting Research Project Grants Risk Role SHH gene Science Shapes Signal Pathway Signal Transduction Structural defect Structure System Testing Therapeutic Transcriptional Regulation United States National Institutes of Health Variant Work base brain malformation cohort congenital anomaly defined contribution disability embryonic stem cell epigenomics genetic testing genetic variant improved in vivo malformation member mouse genetics novel prevent progenitor programs stem targeted sequencing transcription factor transcriptomics

项目摘要

SUMMARY Congenital defects are a leading cause of morbidity worldwide, accounting for the deaths of 330,000 new- born every year. Brain malformations appear to be the most common congenital anomalies and are a major cause of death and lifelong disability. In the majority of cases the cause remains uncertain, due to the complexity and the multi-genic origin of these anomalies. Genes encoding Transcription Factors (TFs) and epigenetic regulators have become relevant candidates given the central role of these proteins in integrating signalling cascades and orchestrating multiple biological processes. Deficiency in their function may disturb entire transcriptional programs, involving several genes and molecular pathways. Here we combine mouse genetics and epigenomic approaches to uncover the role of PRDM15, a previously unsuspected disease-associated epigenetic regulator, in congenital brain malformations. Moreover, by functionally characterizing PRDM15 downstream effectors (e.g. NOTCH and WNT/PCP pathways) we uncover hitherto underappreciated genes mutated in patients with brain malformations (i.e. HPE and microcephaly). Preliminary data: We have characterized the function of PRDM15 in regulating the mouse naïve ESC state. We have then expanded our findings to demonstrate that, in vivo, PRDM15 depletion leads to: 1) embryonic lethality at E12.5-E14.5; 2) patterning defects affecting Anterior/Posterior patterning and forebrain development. In particular we have observed a failure to properly form the Axial Mesendoderm (AME), an embryonic structure necessary for proper anterior specification; 3) Finally, in collaboration with the groups of M.Muenke (NIH) and F.Hildebrandt (Harvard), we have identified heterozygous and homozygous mutations in PRDM15 linked to Holoprocensephaly (HPE) and microcephaly, respectively and mutations in over 100 PRDM15-regulated genes (~20% likely to be damaging) in a large cohort of HPE patients (132 trios and 188 singletons). In AIM1 we propose to define the molecular basis of PRDM15 function, specifically to understand how it regulates, at the level of chromatin, the transcriptional program driving forebrain development. Next, in AIM2 we will establish a causative link between human PRDM15 mutations, HPE-associated genetic variants identified as PRDM15-transcriptional targets, and the associated spectrum of brain malformations (ranging from HPE, to Microcephaly). The significance of these studies is that PRDM15 is a so far uncharacterized critical regulator of embryonic development and knowledge of the downstream regulated pathways will be useful to the field of regenerative medicine and will have diagnostic and clinical implications for patients with holoprosencephaly and microcephaly. The clinical Impact of these studies is that given the multigenic origin of HPE, targeted sequencing of PRDM15, and its key downstream targets, can potentially be added to routine genetic testing in families at risk of carrying other HPE-causing mutations (e.g. SHH, ZIC2, TGIF).

概括先天性缺陷是全世界发病的主要原因，导致 330,000 名新生儿死亡每年出生的脑畸形似乎是最常见的先天性异常，也是一种主要的先天性异常。由于复杂性，大多数情况下，死亡原因和终身残疾仍然不确定。以及这些异常的多基因起源。编码转录因子（TF）和表观遗传的基因。鉴于这些蛋白质在整合信号传导中的核心作用，调节剂已成为相关候选者级联和协调多个生物过程的功能缺陷可能会扰乱整个过程。转录程序，涉及多个基因和分子途径。在这里，我们结合小鼠遗传学和表观基因组方法来揭示 PRDM15 的作用，PRDM15 是先前的一种先天性脑畸形中未被怀疑的与疾病相关的表观遗传调节因子。我们发现 PRDM15 下游效应器（例如 NOTCH 和 WNT/PCP 通路）的功能特征迄今为止，人们对脑畸形（即 HPE 和小头畸形）患者中基因突变的认识不足。初步数据：我们已经表征了 PRDM15 在调节小鼠幼稚 ESC 状态中的功能。然后，我们扩展了我们的研究结果，证明在体内，PRDM15 耗尽会导致：1) 胚胎 E12.5-E14.5 的致死率；2) 影响前/后图案和前脑发育的图案缺陷。特别是我们观察到未能正确形成轴向中内胚层（AME），这是一种胚胎结构 3) 最后，与 M.Muenke (NIH) 和 F. Hildebrandt（哈佛大学），我们已经鉴定出与 PRDM15 相关的杂合和纯合突变无前脑畸形 (HPE) 和小头畸形，以及超过 100 个 PRDM15 调控基因的突变（约 20% 的可能性是有害的）在一大群 HPE 患者（132 名三人组和 188 名单身患者）中。在 AIM1 中，我们建议定义 PRDM15 功能的分子基础，特别是了解它如何在染色质水平上调节驱动前脑发育的转录程序接下来，我们在 AIM2 中进行研究。将在人类 PRDM15 突变和已鉴定的 HPE 相关遗传变异之间建立因果关系作为 PRDM15 转录靶点，以及相关的脑畸形谱（从 HPE 到小头畸形）。这些研究的意义在于 PRDM15 是迄今为止尚未表征的胚胎发育的关键调节因子。下游调节途径的发展和知识将有助于再生领域医学并对前脑无裂畸形和小头畸形患者具有诊断和临床意义。这些研究的临床影响是，鉴于 HPE 的多基因起源，靶向测序 PRDM15 及其关键下游靶标有可能被添加到高危家庭的常规基因检测中携带其他引起 HPE 的突变（例如 SHH、ZIC2、TGIF）。