Pbx-Directed Control of Cellular Behaviors that Drive Midface Morphogenesis

Pbx 定向控制驱动中面部形态发生的细胞行为

基本信息

批准号：
10451656
负责人：
Licia Selleri
金额：
$ 57.3万
依托单位：
UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
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：
2021-07-15 至 2026-05-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10451656
关键词：
Antibodies Apoptosis Apoptotic Behavioral Genetics Bioinformatics Biological Assay Bromodeoxyuridine Cell Cycle Cell Cycle Arrest Cell Cycle Progression Cell Cycle Regulation Cells Cephalic Cleft Palate Cleft lip with or without cleft palate Congenital Abnormality Development Diagnostic Effector Cell Embryo Epithelial Epithelial Cells Exhibits Face Fostering Frontonasal Prominence Genes Genetic Genetic Transcription Grant Histone H3 Human Image Immunofluorescence Immunologic Impairment In Situ Hybridization Individual Lip structure Live Birth Maxilla Maxillary Prominence Mediating Mesenchyme Microdissection Molecular Molecular Profiling Morphogenesis Mus Neural Crest Pathogenesis Pathway interactions Population Pregnancy Premaxillary palate Process Proliferating Publishing Quantitative Reverse Transcriptase PCR Reporting Research Societies Stains Testing Time Tissues Transcript WNT5A gene Work base cdc Genes cell behavior craniofacial epithelial to mesenchymal transition experimental study in vivo inhibitor mouse model mutant orofacial cleft palate repair prenatal progenitor programs repair strategy single-cell RNA sequencing spatiotemporal tissue repair transcription factor transcriptome wound healing

项目摘要

PROJECT SUMMARY Human cleft lip with or without cleft palate (CL/P), the most common craniofacial birth defect, is caused by im- paired fusion of the facial prominences. During normal morphogenesis, the frontonasal and maxillary promi- nences fuse at a three-way seam, the lambdoidal junction (l), to form the upper lip/primary palate. If the epithe- lium that covers the prominences persists at the l, orofacial clefting ensues, as we previously reported in mouse embryos deficient for PBX transcription factors (TFs). We described that: 1) prominence fusion requires coordi- nation of two distinct cellular behaviors, apoptosis and epithelial-to-mesenchymal transition (EMT), respectively, in two discrete subpopulations within the l epithelium; 2) these two subpopulations are characterized by different molecular signatures; and 3) mice deficient for PBX TFs with CL/P lack both of these epithelial subpopulations. Our preliminary evidence in the mouse indicates that: I) the λ epithelium is heterogeneous and comprises 6 main cell subpopulations prior to prominence fusion, as demonstrated by single cell RNA sequencing; II) one of the subpopulations, that we termed “l fusion effectors”, is enriched for genes that have been associated with human or mouse orofacial clefting, for genes encoding pro-apoptotic factors, and for inhibitors of cell cycle progression; III) “l fusion effector” cells are located at the tip of the prominences; and IV) the proportion of “l fusion effectors” is perturbed in compound Pbx1/2 mutant embryos with CL/P compared to controls. Based on these results, we posit that the “l fusion effector” cluster comprises cells that are prime executors of prominence fusion; is halted in the cell cycle, a prerequisite for subsequent cellular changes, like apoptosis and EMT, to achieve fusion; and is quantitatively and/or qualitatively perturbed in mouse models of CL/P. We will test this hypothesis via the following Specific Aims: 1) Determine the spatiotemporal dynamics of the epithelial “l fusion effector” subpopulation throughout midface prominence fusion. We will establish whether the “l fusion effector” clus- ter is transient or if it persists after fusion, as well as track the progenitors and descendants of “l fusion effector” cells in vivo across space and developmental time. 2) Establish the molecular mechanisms underlying cell cycle arrest in “l fusion effector” cells during upper lip/primary palate fusion. We will uncover in vivo cell cycle dynamics of “l fusion effector” cells and assess whether PBX-dependent regulation of cell cycle genes mediates cell cycle control in this cluster. 3) Determine whether the perturbations of the “λ fusion effector” cluster in Pbx1/2 mutants are recapitulated in p63- or Bmpr1a-deficient mice with CL/P. We will establish whether the cellular and transcriptional changes of the l epithelium resulting in CL/P in Pbx1/2 mutants are recapitulated in all three mouse models, or if they are distinct. This research will lead to discover new genes for prenatal diagnostics of CL/P and open strategies for CL/P repair through reactivation of developmental programs that are defective in orofacial clefting. Broadly, this work will foster mechanistic studies testing whether other fusion processes are mediated by cell cycle arrest.

项目概要人类唇裂伴或不伴腭裂（CL/P）是最常见的颅面出生缺陷，是由免疫缺陷引起的。面部突出的成对融合在正常形态发生过程中，额鼻和上颌前突。 nences 在三向接缝处融合，即人字形接合处 (l)，形成上唇/主腭。覆盖突出物的 lium 持续存在于 l 处，随之而来的是口面部裂隙，正如我们之前在小鼠中报道的那样 PBX转录因子（TF）缺陷的胚胎我们描述：1）突出融合需要协调。两种不同细胞行为的国家，分别是细胞凋亡和上皮间质转化（EMT）， l 上皮内的两个离散亚群；2) 这两个亚群的特征不同分子特征；3) 具有 CL/P 的 PBX TF 缺陷的小鼠缺乏这两种上皮亚群。我们在小鼠身上的初步证据表明： I) λ 上皮是异质的，包含 6 个主要部分突出融合之前的细胞亚群，如单细胞 RNA 测序所证明的 II) 其中之一；我们称之为“l融合效应子”的亚群富含与人类相关的基因或小鼠口颌面裂，用于编码促凋亡因子的基因，以及细胞周期进程的抑制剂； III)“l融合效应子”细胞位于突起的尖端；以及IV)“l融合效应子”的比例；与对照相比，CL/P 复合 Pbx1/2 突变体胚胎受到干扰。假设“l 融合效应器”簇包含突出融合的主要执行者细胞；在细胞周期中，是随后细胞变化（如凋亡和 EMT）实现融合的先决条件；在 CL/P 小鼠模型中受到定量和/或定性的干扰，我们将通过以下具体目标：1）确定上皮“l融合效应器”的时空动力学我们将确定“l 融合效应器”是否属于中面部突出融合的亚群。 ter 是短暂的，或者如果它在融合后持续存在，以及跟踪“l 融合效应器”的祖先和后代体内细胞跨越空间和发育时间 2) 建立细胞的分子机制。我们将在体内细胞中发现上唇/初级腭融合过程中“l融合效应器”细胞的周期停滞。 “l融合效应”细胞的周期动力学，并评估细胞周期基因是否依赖PBX调节介导该簇中的细胞周期控制 3) 确定“λ融合效应子”是否受到扰动。我们将在 p63 或 Bmpr1a 缺陷小鼠中用 CL/P 重现 Pbx1/2 突变体中的簇。 L 上皮的细胞和转录变化是否导致 Pbx1/2 突变体中的 CL/P 在所有三种小鼠模型中进行概括，或者如果它们是不同的，这项研究将导致发现新的基因。 CL/P 的产前诊断以及通过重新激活发育程序进行 CL/P 修复的开放策略从广义上讲，这项工作将促进机制研究，测试其他因素是否存在。融合过程由细胞周期停滞介导。