Cell fate choices by Tbx1 in forming the mammalian heart

Tbx1 在形成哺乳动物心脏过程中的细胞命运选择

基本信息

批准号：
10451598
负责人：
BERNICE E MORROW
金额：
$ 60.56万
依托单位：
ALBERT EINSTEIN COLLEGE OF MEDICINE
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-08-20 至 2024-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10451598
关键词：
22q11 22q11.2 3-Dimensional APLN gene ATAC-seq Affect Alleles Anterior Aorta Binding Binding Proteins Binding Sites Biological Process Cardiac Cardiac development Cell Differentiation process Cell model Cells ChIP-seq Chromatin Chromosomes Data Data Set Defect DiGeorge Syndrome Ectopic Expression Embryo Embryonic Development Face Gene Expression Profile Gene Proteins General Population Genes Genetic Genetic Transcription Heart Heart Abnormalities Human Genetics Immunofluorescence Immunologic Individual Lung Mammals Maps Mesenchyme Mesoderm Mesoderm Cell Molecular Mus Muscle Muscle Fibers Mutant Strains Mice Mutation Myocardium Neck Neonatal Pathway interactions Patients Penetrance Persistent Truncus Arteriosus Pharyngeal Apparatus Phenocopy Population Population Sizes Process Regulatory Element Risk Factors Shprintzen syndrome Testing Time Tissues base cell behavior cell type conditional mutant congenital heart disorder embryo tissue experimental study functional genomics gastrulation gene network interest mouse model mutant precursor cell progenitor programs receptor single-cell RNA sequencing spatiotemporal stem cells transcription factor transcriptomics

项目摘要

TBX1 encodes a T-box transcription factor required for cardiac development. This gene maps to the chromosome 22q11.2 region that is deleted in patients with DiGeorge syndrome/velo-cardio- facial syndrome or 22q11.2 deletion syndrome (22q11.2DS). Approximately 60% of 22q11.2DS patients have congenital heart disease that mostly affects the cardiac outflow tract. A subset of individuals with a mutation of the TBX1 gene but not a deletion has been identified and they partially phenocopy patients with 22q11.2DS. Inactivation of one allele of Tbx1 in mice results in mild defects, but inactivation of both alleles results in neonatal lethality with a persistent truncus arteriosus, in which the aorta and pulmonary trunk fail to separate. This defect also occurs in 5- 10% of 22q11.2DS patients with congenital heart disease. To understand the function of Tbx1 in mammals, we performed single cell RNA-sequencing (scRNA-seq) of cardiopharyngeal mesoderm progenitor cells within the pharyngeal apparatus. We discovered a multilineage progenitor (MLP) population that expresses genes important for forming the cardiac outflow tract as well as branchiomeric muscles of the face and neck. The MLP population expands at the expense of more differentiated populations when Tbx1 is inactivated in the cardiopharyngeal mesoderm. Our main hypothesis is that Tbx1 is required in the MLP population for progression towards more differentiated states needed for cardiac development. We propose three specific aims to test this hypothesis. In the first aim, we will perform additional scRNA-seq experiments and analyze the complete dataset to understand how the progression of MLP cells are altered in Tbx1 conditional and global mutant mouse embryos. In Aim 2, we will determine where the MLP cells are localized in the embryo. Preliminary data suggests that these cells are localized to the nascent mesenchyme of the elongating pharyngeal apparatus. We will also inactivate Tbx1 specifically within the MLP cells to determine its particular functions. In Aim 3, we will turn to functional genomic studies and will identify open and accessible chromatin for which harbors TBX1 protein binding sites using ATAC-seq and ChIP-seq from embryo tissue. Preliminary data suggests that we are able to identify direct transcriptional target genes. By these three aims, we will understand the molecular functions of TBX1 in the progression of progenitor cells to more differentiated states to build the cardiac outflow tract.

TBX1编码心脏发育所需的T-box转录因子。这个基因地图 Digeorge综合征/Velo-Cardio-患者删除的22q11.2染色体区域面部综合征或22Q11.2缺失综合征（22q11.2ds）。大约22q11.2ds的60％患者患有先天性心脏病，主要影响心脏流出道。一个子集患有TBX1基因突变但没有缺失的个体已被鉴定出来，他们部分22q11.2ds的表观复制患者。小鼠中TBX1等位基因的失活导致轻度缺陷，但两个等位基因的失活会导致新生儿致死性，并持续动脉，主动脉和肺部躯干无法分离。该缺陷也发生在5- 在22q11.2ds患有先天性心脏病的患者中，有10％。了解tbx1在哺乳动物，我们进行了心咽的单细胞RNA-sequest（SCRNA-SEQ）中胚层祖细胞中的咽室内。我们发现了一个多线表达基因的祖先（MLP）种群对于形成心脏流出区很重要以及面部和颈部的分支肌肉。 MLP人口在当TBX1在心咽中灭活时，差异化的人群的费用更高中胚层。我们的主要假设是MLP人群需要TBX1进行进展迈向心脏发展所需的更明显的状态。我们提出了三个特定的旨在检验这一假设。在第一个目标中，我们将执行其他SCRNA-SEQ实验并分析完整的数据集，以了解如何改变MLP细胞的进展 TBX1条件和全局突变小鼠胚胎。在AIM 2中，我们将确定MLP的位置细胞位于胚胎中。初步数据表明，这些细胞位于伸长咽部装置的新生间充质。我们还将灭活tbx1 特别是在MLP细胞内确定其特定功能。在AIM 3中，我们将转向功能性基因组研究，并将识别开放式染色质，该染色质为此提供 TBX1蛋白结合位点使用胚胎组织的ATAC-SEQ和CHIP-SEQ。初步数据表明我们能够识别直接的转录靶基因。通过这三个目标，我们将了解祖细胞进展中TBX1的分子功能差异化状态以建立心脏流出区。