Molecular mechanisms of tissue interactions during coronal suture development

本应用程序的总体目标是检查冠状突起的基本机制。 缝合线的发展。我们将检验中央假设，即顶盖与横断之间的组织相互作用 (TTR)和冠状缝合在发育过程中相互作用，需要严格调节PDGFRA的活性 为他们的互动。PDGFRA在颅面发育中起关键作用，且PDGFRA表达升高 而活动与人类颅缝融合症有关。我们将研究以下具体目标： 1.研究胚胎发育过程中TTR与缝合细胞的相互作用。 在这个目标中，我们将检验TTR和缝合细胞在胚胎发育过程中相互作用的假设。在目标1a中，我们 将检查去除TTR后冠状缝合的发展情况。在目标1b中，我们将评估 TTR发育中的冠状缝合。我们将使用基因工具来消融特定的冠状缝合 评估小鼠模型中TTR值的发育。 2.研究PDGFRA调控TTR发育的机制。 TTR发展的调控机制尚未阐明。PDGFRA活性的变化 导致不同的TTR表型，表明PDGFRA在TTR的形成中起关键作用。转录组 我们确定Wnt9a和Sox9是PDGFRA的转录靶点。在这个目标中，我们将测试 PDGFRA通过调节Sox9表达调控软骨细胞祖细胞形成的假说 Wnt9a/β-连环蛋白信号转导。在目标2a中，我们将通过以下方式描述PDGFRA在TTR发展中的作用 分析PDGFRA功能丧失(LOF)和功能获得(GOF)模型中的TTR表型。在AIM 2B，我们将分析PDGFRA在控制软骨细胞祖细胞形成中的作用。在Aim 2c中，我们将 研究Wnt9a/β-catenin通路作为PDGFRA的潜在介导物在控制Sox9表达和 形成软骨细胞前体细胞。 3.探讨PDGFRA在冠状缝合细胞发育和维持中的作用。 研究表明，缝合线含有丰富的间充质干细胞(MSCs)。PDGFRA是公认的 MSCs标记物。我们的数据表明，PDGFRA在发育中的缝合线中表达。本构活化 PDGFRA导致发育中的缝合线分化异常。在目标3a中，我们将追踪缝合线 在PDGFRA LOF和GOF模型中通过操纵组织特异性PDGFRA活性的祖细胞 举止。在目标3b中，我们将研究PDGFRA在成人缝合间充质干细胞维护中的作用及其 采用颅骨损伤模型进行动态平衡实验。 随着拟议研究的完成，我们预计将回答TTR和TTR之间的组织相互作用 冠状缝合是正常缝合发育所必需的，PDGFRA在正常组织中的特殊作用是什么？ 骨缝发育与颅缝融合的形成。

The overall objective in this application is to examine the fundamental mechanisms underlying coronal suture development. We will test the central hypothesis that tissue interaction between tectum transversum (TTR) and coronal sutures interact during development, and a rigorous regulation of Pdgfra activity is required for their interaction. Pdgfra plays a crucial role in craniofacial development, and elevated PDGFRA expression and activity is implicated in human craniosynostosis. We will examine the following specific aims: 1. To examine interaction between TTR and suture cells during embryonic development. In this aim we will test the hypothesis that TTR and suture cells interact during embryogenesis. In aim 1a, we will examine the coronal suture development with removal of TTR. In aim 1b, we will assess the requirement of coronal sutures on TTR development. We will use genetic tools to ablate coronal sutures specifically and assess TTR development in mouse models. 2. To examine the mechanisms underlying Pdgfra regulation on TTR development. The regulatory mechanisms underlying TTR development has not been illustrated. Alteration of Pdgfra activity causes distinct TTR phenotype, indicating Pdgfra is a critical player in TTR formation. By transcriptome profiling we identified Wnt9a and Sox9 as transcriptional targets of Pdgfra. In this aim we will test the hypothesis that Pdgfra regulates chondrocyte progenitors formation by regulating Sox9 expression via Wnt9a/beta-catenin signaling. In aim 2a, we will characterize the role of Pdgfra in TTR development, by analyzing the TTR phenotype in both Pdgfra loss-of-function (LOF) and gain-of-function (GOF) models. In aim 2b, we will analyze the role of Pdgfra in controlling chondrocyte progenitor formation. In aim 2c, we will examine Wnt9a/beta-catenin pathway as a potential mediator of Pdgfra in controlling Sox9 expression and chondrocyte progenitor formation. 3. To examine the role of Pdgfra in coronal sutural cells development and maintenance. It has been shown that suture contains abundant mesenchymal stem cells (MSCs). Pdgfra is a recognized MSCs marker. Our data show that Pdgfra is expressed in the developing suture. Constitutive activation of Pdgfra leads to abnormal differentiation in the developing sutures. In aim 3a, we will trace the suture progenitor cells in both Pdgfra LOF and GOF models by manipulating Pdgfra activity in a tissue-specific manner. In aim 3b, we will examine the role for Pdgfra in adult suture MSCs maintenance and their homeostasis using calvarial injury model. By completion of the proposed study, we expect to answer whether tissue interaction between TTR and coronal suture is essential for normal suture development, and what is the specific role for Pdgfra in normal suture development and craniosynostosis formation.