Regulation of upper lip development by PDGFR Alpha andRac1 signaling

PDGFR Alpha 和 Rac1 信号传导对上唇发育的调节

• 批准号: 8768336
• 负责人: Fenglei He
• 金额: $ 8.91万
• 依托单位: ICAHN SCHOOL OF MEDICINE AT MOUNT SINAI
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-07-16 至 2016-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8768336
• 关键词: Affect; Alleles; Automobile Driving; Binding; Birth; Cell Proliferation; Cell physiology; Cells; Cleaved cell; Cleft Lip; Congenital Abnormality; Data; Defect; Development; Disease; Distal; Down-Regulation; Embryonic Development; Event; Exhibits; Face; Future; Gene Targeting; Generations; Genes; Genetic; Genetic Transcription; Goals; Guanosine Triphosphate; Health; Human; In Vitro; Knockout Mice; Knowledge; Laboratories; Lateral; Ligands; Link; Lip structure; Maxilla; Medial; Mediating; Mediator of activation protein; Methods; Minor; Molecular; Monomeric GTP-Binding Proteins; Morphogenesis; Mus; Mutant Strains Mice; Mutation; Neural Crest Cell; Newborn Infant; Nose; PDGFA gene; PDGFRB gene; Palate; Pathogenesis; Pathway interactions; Pattern; Phenotype; Platelet-Derived Growth Factor; Platelet-Derived Growth Factor Receptor; Platelet-Derived Growth Factor alpha Receptor; Play; Prevention; Process; Proteins; Receptor Protein-Tyrosine Kinases; Regulation; Research; Role; Series; Signal Pathway; Signal Transduction; Testing; Therapeutic; Tissues; Work; cell motility; cleft lip and palate; craniofacial; design; in vitro Assay; in vivo; innovation; interest; lip morphogenesis; mouse model; mutant; novel; orofacial; post-doctoral training; rapid growth; research study; response; transcriptome sequencing

DESCRIPTION (provided by applicant): Cleft lip represents one of most common birth defects and affects approximately 1 in every 700 newborns worldwide. It is caused by disruption of normal upper lip development with environmental or genetic factors. The long term goal of this proposed research is to understand the mechanisms of upper lip development and of orofacial cleft pathogenesis. Mutations of Platelet Derived Growth Factor Receptor α (PDGFRα) signaling have been tightly linked to cleft lip/palate in humans and mice, suggesting an evolutionarily conserved role in craniofacial development. During embryo development, the upper lip is formed by highly coordinated development of medial nasal process (MNP), lateral nasal process (LNP) and maxillary processes (MxP), all of which are originating from neural crest cells (NCCs). My previous study reveals that PDGFRα signaling is required to maintain MNP cell proliferation and regulate NCC migration, and indicates a role for small GTPase Rac1 in these processes downstream of PDGFRα. This proposed research is aimed at characterizing the role of Rac1 signaling in mediating PDGFRα regulation on MNP and NCC development. In aim one, I will use a newly generated unbiased Wnt1-Cre2 allele, to ablate Rac1 function specifically in NCCs, and characterize the mutant craniofacial phenotype at histological, cellular and molecular levels. The epistatic effect between Rac1 and PDGFRα will be tested by inactivating a single allele of each gene in NCCs. I will further rescue the craniofacial phenotype of PDGFRα fl/fl; Wnt1-Cre2 mice by driving expression a constitutively active form of Rac1 in NCCs in vivo. In aim two, I will examine how PDGFRα signaling regulates Rac1 activity during MNP morphogenesis. I will analyze the activity of immediate downstream signaling pathways in PDGFRα deficient MNP, and examine of the interaction between the identified signaling pathways and Rac1 activity. Aim three is designed to characterize the expression of PDGFRα transcriptional targets Cdc42ep3 (CEP3) and its role in craniofacial development. CEP3 will be examined with in vitro assays and gene-targeting method. Results of the proposed works will delineate the signaling cascade by which PDGFRα regulates NCC and MNP development, at the levels of signaling transduction and transcription. The results of proposed research will provide novel information to understand the fundamental mechanisms of MNP development and upper lip morphogenesis. This study will hold important benefit in treatment of cleft lip, to ultimately reduce the occurrence of this birth defect in humans.

描述（由申请人提供）：唇裂是最常见的出生缺陷之一，全世界大约每 700 名新生儿中就有 1 人患有唇裂。它是由于环境或遗传因素破坏了正常上唇发育而引起的。这项研究的长期目标是了解上唇发育和口面裂发病机制。血小板衍生生长因子受体 α (PDGFRα) 信号突变与人类和小鼠的唇裂/腭裂密切相关，表明其在颅面发育中的进化保守作用。在胚胎发育过程中，上唇是由内侧鼻突（MNP）、外侧鼻突（LNP）和上颌突（MxP）高度协调发育形成的，所有这些都起源于神经嵴细胞（NCC）。我之前的研究表明，PDGFRα 信号传导是维持 MNP 细胞增殖和调节 NCC 迁移所必需的，并表明小 GTPase Rac1 在 PDGFRα 下游的这些过程中的作用。这项研究旨在表征 Rac1 信号传导在介导 PDGFRα 对 MNP 和 NCC 发育的调节中的作用。在目标一中，我将使用新生成的无偏 Wnt1-Cre2 等位基因，专门消除 NCC 中的 Rac1 功能，并在组织学、细胞和分子水平上表征突变颅面表型。 Rac1 和 PDGFRα 之间的上位效应将通过灭活 NCC 中每个基因的单个等位基因来测试。我将进一步抢救颅面表型 PDGFRα fl/fl； Wnt1-Cre2 小鼠通过在体内 NCC 中驱动 Rac1 的组成型活性形式的表达。在目标二中，我将研究 PDGFRα 信号如何在 MNP 形态发生过程中调节 Rac1 活性。我将分析 PDGFRα 缺陷 MNP 中直接下游信号通路的活性，并检查已识别的信号通路与 Rac1 活性之间的相互作用。目标三旨在表征 PDGFRα 转录靶点 Cdc42ep3 (CEP3) 的表达及其在颅面发育中的作用。 CEP3 将通过体外测定和基因靶向方法进行检查。拟议工作的结果将描述 PDGFRα 在信号转导和转录水平上调节 NCC 和 MNP 发育的信号级联。所提出的研究结果将为理解 MNP 发育和上唇形态发生的基本机制提供新的信息。这项研究将为唇裂的治疗带来重要益处，最终减少人类这种先天缺陷的发生。