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Characterization of the role of maternal effect gene Nlrp2 in reproduction

母体效应基因 Nlrp2 在生殖中作用的表征

基本信息

批准号：
10404542
负责人：
IGNATIA B VAN DEN VEYVER
金额：
$ 38.39万
依托单位：
BAYLOR COLLEGE OF MEDICINE
依托单位国家：
美国
项目类别：
财政年份：
2018
资助国家：
美国
起止时间：
2018-08-15 至 2024-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10404542
关键词：
Affect Beckwith-Wiedemann Syndrome Binding Cell Culture Techniques Cells Child Complement Complex Congenital Abnormality DNA Binding DNA Methylation DNA Modification Methylases Data Defect Dependence Development Disease Embryo Embryo Transfer Embryonic Development Environment Epigenetic Process Event Female Fertilization Fertilization failure Fertilization in Vitro Foundations Future Gametogenesis Gene Expression Genes Genetic Transcription Genome Germ Cells Goals Growth Haploidy Health Homologous Gene Human Hydatidiform Mole In Vitro Infertility Knockout Mice Knowledge Link Modeling Molecular Mus Mutant Strains Mice Mutation Nuclear Oocytes Parents Phenotype Placenta Pregnancy Process Proteins RNA Reader Recurrence Regulation Reproduction Rodent Role Time Totipotent Transcript Translations Work blastocyst demethylation embryo cell experimental study follow-up gene function genome-wide histone modification imprint in utero in vivo loss of function maternal imprint member methylome methylomics molecular phenotype mouse model mutant mutant mouse model neonatal death novel offspring phenotypic data protein complex reproductive reproductive system disorder therapeutic target transcriptome transcriptome sequencing transcriptomics zygote

项目摘要

PROJECT SUMMARY Maternal mutations in human NLRP7 cause pregnancies recurrent hydatidiform molar pregnancies with imprinting defects. Maternal mutations in its highly homologous neighboring gene NLRP2, cause a multi-locus imprinting disorder (MLID) that manifests as Beckwith-Wiedemann syndrome in offspring. Both are associated with abnormal DNA methylation of maternally imprinted genes. Rodents have the Nlrp2 gene, but no Nlrp7. We hypothesized that Nlrp2 may combine functions of both human homologs and generated a Nlrp2-mutant mouse model to study the mechanisms by which its maternal inactivation causes the observed offspring and placental abnormalities. We found that NLRP2 protein is a new member of the subcortical maternal complex (SCMC), a cytoplasmic complex in oocytes that persists in preimplantation embryos with a presumed role in maternal-to- zygote transition and zygotic genome activation, which are the processes by which embryos switch from reliance on maternally contributed transcripts and proteins to their own transcription and translation. We found that a maternal-effect mutation in Nlrp2 disrupts the SCMC, causing Nlrp2-null females to produce fewer and smaller litters with offspring that have birth defects, growth abnormalities, and imprinting defects. In vitro cultured embryos of these Nlrp2-null females have a more severe phenotype with early cleavage-stage arrest. These data for the first time link the SCMC to imprinting reprogramming and indicate that Nlrp2-null mice are an excellent model to study the mechanisms of this interaction. They support the overarching goal of this project, to characterize how maternal loss of NLRP2, a new SCMC protein, alters imprinting in offspring, and how this leads to a range of reproductive phenotypes. Towards this goal, for specific aim 1, we will characterize the cellular and developmental events in the zygote and preimplantation embryo that are at the origin of the reproductive and imprinting phenotypes. For specific aim 2, we will investigate the molecular mechanisms that underlie the reproductive phenotypes of maternal inactivation of Nlrp2 by following up on other interesting early observations, which include that NLRP2 and DNA-methyltransferase 1 (DNMT1) co-localize in preimplantation embryos, and that Nlrp2-deficient oocytes have altered gene expression profiles. For specific aim 3 we will characterize in vivo the variable later developmental abnormalities of embryos and placentas resulting from maternal loss of Nlrp2. This will increase knowledge on the reproductive disorders caused by maternal effect mutations. All phenotyping will be complemented by transcriptomics, methylomics and profiling of DNMT1 binding to fully integrate molecular and phenotypic data. We predict that this work will uncover important new principles of genome reprogramming during gametogenesis and after fertilization and will clarify how the SCMC affects this process. The long-term benefit for human health will include better understanding of multi-locus imprinting disorders and some forms of infertility and in vitro fertilization failures.

项目概要人类 NLRP7 的母体突变导致妊娠复发性葡萄胎妊娠压印缺陷。其高度同源的邻近基因 NLRP2 的母体突变，导致多位点印记障碍（MLID），在后代中表现为贝克威斯-维德曼综合征。两者都有关联母系印记基因的 DNA 甲基化异常。啮齿动物有 Nlrp2 基因，但没有 Nlrp7。我们假设 Nlrp2 可能结合了两种人类同源物的功能并产生了 Nlrp2 突变小鼠模型来研究其母体失活导致观察到的后代和胎盘的机制异常。我们发现NLRP2蛋白是皮质下母体复合体（SCMC）的新成员，是一种卵母细胞中的细胞质复合物，在植入前胚胎中持续存在，推测在母体到母体的过程中发挥作用合子转变和合子基因组激活，这是胚胎从依赖转变的过程母体为自己的转录和翻译贡献转录本和蛋白质。我们发现一个 Nlrp2 的母体效应突变会破坏 SCMC，导致 Nlrp2 缺失的雌性产生更少和更小具有出生缺陷、生长异常和印记缺陷的后代的窝。体外培养这些 Nlrp2 缺失雌性的胚胎具有更严重的表型，早期卵裂期停滞。这些数据首次将 SCMC 与印记重编程联系起来，并表明 Nlrp2 缺失小鼠是一种研究这种相互作用机制的优秀模型。他们支持该项目的总体目标，描述母体失去 NLRP2（一种新的 SCMC 蛋白）如何改变后代的印记，以及这如何导致一系列生殖表型。为了实现这一目标，对于具体目标 1，我们将描述细胞和受精卵和植入前胚胎的发育事件是生殖和生殖的起源印记表型。对于具体目标 2，我们将研究其背后的分子机制通过跟踪其他有趣的早期观察结果，了解母体 Nlrp2 失活的生殖表型，其中包括 NLRP2 和 DNA 甲基转移酶 1 (DNMT1) 在植入前胚胎中共定位，以及 Nlrp2 缺陷的卵母细胞已经改变了基因表达谱。对于具体目标 3，我们将在体内表征由于母体 Nlrp2 缺失而导致胚胎和胎盘的后期发育异常。这将增加对母体效应突变引起的生殖障碍的了解。所有表型分析将得到转录组学、甲基组学和 DNMT1 结合分析的补充，以完全整合分子和表型数据。我们预测这项工作将揭示基因组的重要新原理配子发生期间和受精后的重编程将阐明 SCMC 如何影响这一过程。对人类健康的长期利益将包括更好地了解多位点印记疾病和某些形式的不孕症和体外受精失败。