Function of the Apela-APJ signaling axis in mammalian development.

Apela-APJ 信号轴在哺乳动物发育中的功能。

• 批准号: 8908290
• 负责人: Laina Freyer
• 金额: $ 5.8万
• 依托单位: SLOAN-KETTERING INST CAN RESEARCH
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-01 至 2017-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8908290
• 关键词: Behavior; Binding; Biological Assay; Cardiac; Cardiovascular system; Cells; Coculture Techniques; Congenital Heart Defects; Defect; Development; Disease; Disease Outcome; Disease Progression; Embryo; Embryonic Development; Endoderm; Exhibits; Failure; Foundations; Future; G-Protein-Coupled Receptors; Genetic; Germ Layers; Goals; Heart; Homeostasis; Image; In Vitro; Investigation; Knock-out; Knockout Mice; Knowledge; Left; Life; Ligands; Light; Maintenance; Mediating; Mesoderm; Modeling; Molecular; Morphogenesis; Morphology; Mus; Mutant Strains Mice; Mutation; Organ; Organogenesis; Outcome; Pathway interactions; Pattern; Peptides; Phenotype; Play; Pluripotent Stem Cells; Preclinical Drug Evaluation; Primitive Streaks; Primitive foregut structure; Process; Proteins; Reporter; Role; Signal Pathway; Signal Transduction; Signaling Molecule; Signaling Protein; Source; Stem cells; Testing; Therapeutic; Tissues; Vertebrates; Work; Zebrafish; base; cardiogenesis; cell behavior; cell motility; design; embryonic stem cell; gastrulation; interest; malformation; migration; mouse development; mutant; novel; progenitor; programs; public health relevance; receptor coupling; research study; tool

 DESCRIPTION (provided by applicant): Proper embryo formation and organogenesis relies on molecular signaling pathways that are used in a reiterated manner throughout development, and are essential for viability. The Apela-APJ signaling axis is a new pathway that was only recently discovered in zebrafish. Loss of apela in zebrafish causes early defects in germ layer formation as well as later malformations of various organs. Notably, these mutants often fail to form a heart. It is not clear whether defects in organogenesis are a consequence of earlier deficiencies in endoderm and mesoderm, or if Apela-APJ also functions in particular organs, such as the developing heart. Since the discovery of Apela as a signaling molecule occurred so recently, its role in mammalian development is yet to be determined, though evidence suggests conservation of the Apela-APJ signaling pathway among vertebrates. The aims of this project are designed to uncover and define the function and requirement for Apela-APJ signaling in mouse embryonic development and organogenesis. To accomplish this, the sponsor's lab has recently created mice lacking Apela. The phenotype of Apela null mutants will be characterized by analyzing morphology of vital organs as well as expression of various developmental markers important for heart development, endoderm/mesoderm specification, and left-right patterning. It has been shown that Apela signals via binding to the G protein-coupled receptor APJ. Another non-homologous molecule, Apelin, also activates APJ. Discrepancies between Apelin and APJ mutant phenotypes suggest that Apela may play a critical role in mouse development. Therefore overlapping roles between Apela versus Apelin mediated activation of APJ will be investigated using Apelin and APJ mouse mutants. Defects in endoderm and mesoderm progenitors will be assessed in Apela mutants using primitive streak explants, motility assays, and live imaging of fluorescent reporter mice. To test the requirements for Apela-APJ signaling with respect to the specification and behavior of endoderm and cardiac progenitors, mouse embryonic stem cells (mESCs) from Apela;Apelin, and APJ mutants will be derived for in vitro experiments. Apelin-APJ signaling promotes the differentiation and maintenance of mESC-derived cardiovascular progenitors, suggesting that Apela may exert similar effects. The role of Apela-APJ signaling in directed differentiation of mESCs into endoderm and cardiac progenitor cell fates will be investigated, thereby establishing its relevance to future therapeutic applications. To determine cell autonomous requirements for APJ-mediated signaling, mutant and control mESCs will be assayed in co-cultures, and will also be used to make chimeric embryos. Collectively, these studies will shed light on the critical functions of a novel signaling axis in mammalian development, and they will provide fundamental knowledge for building new genetic pathways that function in development or disease.

 描述（由适用提供）：正确的胚胎形成和器官发生取决于分子信号通路，这些途径在整个发育过程中以重复的方式使用，对于生存能力至关重要。 APELA-APJ信号轴是一种新的途径，直到最近才在斑马鱼中发现。斑马鱼中APELA的丧失会导致生殖层形成的早期缺陷，以及随后的各种器官的畸形。值得注意的是，这些突变体通常无法形成心脏。目前尚不清楚器官发生缺陷是内胚层和中胚层缺陷的结果，还是Apela-apj在尤其是内脏（例如发育中的心脏）中起作用。由于最近出现了APELA作为信号分子的发现，因此其在哺乳动物发育中的作用尚未确定，尽管有证据表明脊椎动物之间的Apela-APJ信号通路保存。该项目的目的旨在发现和定义小鼠胚胎发育和器官发生中APELA-APJ信号的功能和需求。为此，赞助商的实验室最近创造了缺乏Apela的老鼠。 Apela Null突变体的表型将以分析重要器官的形态以及对心脏发育，内胚层/中胚层规范和左右构图至关重要的各种发育标记的表达来表征。我们被证明是通过与G蛋白偶联受体APJ结合的APELA信号。另一个非同理分子Apelin也激活了APJ。 APELIN和APJ突变体表型之间的差异表明Apela可能在小鼠发育中起关键作用。因此，将使用APELIN和APJ小鼠突变体研究APELLA与APELIN介导的APJ激活之间的重叠作用。内胚层和中胚层祖细胞中的缺陷将在Apella突变体中使用原始条纹外植体，运动性评估和荧光报告小鼠的实时成像进行评估。为了测试有关内胚层和心脏祖细胞的规范和行为的APELLA-APJ信号传导的要求，将得出来自Apella; apelin的小鼠胚胎干细胞（MESC）； APELIN和APJ突变体将用于体外实验。 APELIN-APJ信号传导促进了MESC衍生的心血管祖细胞的分化和维护，这表明Apela可能会执行类似的影响。将研究APELA-APJ信号在指示MESC分化为内胚层和心脏祖细胞命运中的作用，从而确定其与未来的治疗应用的相关性。为了确定APJ介导的信号传导的细胞自主要求，将在共培养中分配突变体和对照MESC，并将用于制作嵌合胚。总的来说，这些研究将阐明哺乳动物发育中新型信号轴的关键功能，它们将为建立在发育或疾病中起作用的新遗传途径提供基本知识。