Mesoderm Formation and the Role of Repression by FoxD3

中胚层形成和 FoxD3 的抑制作用

• 批准号: 6827812
• 负责人: Daniel S Kessler
• 金额: $ 31.37万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-01-01 至 2006-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6827812
• 关键词: Xenopus; antisense nucleic acid; biological signal transduction; chimeric proteins; embryogenesis; gene expression; gene induction /repression; mesoderm; nonmammalian vertebrate embryology; oligonucleotides; transcription factor

DESCRIPTION (provided by applicant): Formation of the mesodermal germ layer is a critical step in the initiation of vertebrate embryogenesis. In addition to forming muscle, heart, blood and kidney, embryonic mesoderm drives the morphogenetic movements of gastrulation and induces formation of the central nervous system. The study of mesodermal development in the amphibian, Xenopus laevis, has demonstrated the importance of cell interactions in establishing mesoderm and has identified signaling pathways that control mesoderm formation. Experiments in Xenopus and other systems have identified Nodal-related members of the TGFBeta superfamily as key regulators of mesoderm formation, but the regulation of Nodal gene expression and the transcriptional response to Nodal signals are not fully understood. It is these transcriptional events that result in the determination and precise patterning of the mesodermal lineage. We have identified FoxD3, a forkhead family member, as a transcriptional repressor with potent mesoderm-inducing activity. FoxD3 is coexpressed with Nodal genes in Spemann?s organizer and induces a mesodermal response identical to Nodal. Using molecular and embryological approaches, the following hypothesis will be tested: FoxD3 is an essential transcriptional regulator of mesoderm formation that activates the Nodal signaling pathway. Toward this end we propose to: 1) Determine the requirement for FoxD3 in Xenopus mesoderm formation using activator fusion proteins that antagonize FoxD3 activity and morpholino antisense oligonucleotides that inhibit FoxD3 translation; 2) Determine the functional interaction of FoxD3 with the Nodal pathway using specific inhibitors to define the dependence of FoxD3 function on the Nodal pathway and the dependence of Nodal signaling on FoxD3; and 3) Identify the functional domains of FoxD3 required for mesoderm induction and transcriptional repression, and examine the role of Groucho corepressors in FoxD3 activity. These studies will elucidate the embryonic and molecular function of FoxD3 in the process of mesoderm formation. In addition, the activity of FoxD3 suggests that mesoderm formation in Xenopus involves repression of an inhibitor of mesoderm induction, and such a disinhibition model of mesoderm induction, not proposed previously, will be assessed in this proposal. Mesodermal defects are implicated in embryonic malformations and pathologies of childhood and the adult. Therefore, the study of FoxD3 may shed light on mesodermally based congenital abnormalities and disease states. Furthermore, as a regulator of mesodermal determination, the study of FoxD3 may have an impact on advances in tissue regeneration and organ culture.

描述（由申请人提供）：中胚层的形成是 是脊椎动物胚胎发生的关键一步除了 胚胎中胚层形成肌肉、心脏、血液和肾脏， 原肠胚形成的形态发生运动，并诱导中央 神经系统两栖动物爪蟾中胚层发育的研究 已经证明了细胞相互作用在建立 中胚层，并确定了控制中胚层形成的信号通路。 在非洲爪蟾和其他系统中的实验已经确定了Nodal相关成员 作为中胚层形成的关键调节因子，但 Nodal基因表达调控及对Nodal的转录应答 信号并不完全清楚。正是这些转录事件 导致中胚层谱系的确定和精确图案化。 我们已经确定FoxD 3，叉头家族成员，作为转录因子， 具有有效的中胚层诱导活性的阻遏物。FoxD 3与 Spemann的节点基因？的组织者和诱导中胚层反应相同 到Nodal利用分子和胚胎学方法， 假设将被测试：FoxD 3是一个重要的转录调节因子， 中胚层形成，激活Nodal信号通路。为此目的 我们建议：1）确定非洲爪蟾中胚层对FoxD 3的需求 使用拮抗FoxD 3活性的激活剂融合蛋白形成， 抑制FoxD 3翻译的吗啉代反义寡核苷酸; 2） 使用以下方法确定FoxD 3与Nodal途径的功能性相互作用： 特异性抑制剂，以确定FoxD 3功能对Nodal的依赖性 途径和Nodal信号传导对FoxD 3的依赖性;以及3）鉴定Nodal信号传导的信号传导途径。 中胚层诱导和转录所需的FoxD 3功能结构域 抑制，并检查Groucho辅阻遏物在FoxD 3活性中的作用。 这些研究将阐明FoxD 3在胚胎和分子中的功能， 中胚层形成的过程。此外，FoxD 3的活性表明， 非洲爪蟾中胚层的形成涉及到抑制 中胚层诱导，并且中胚层诱导的这种去抑制模型，不 之前提出的，将在本提案中进行评估。 中胚层缺陷与胚胎畸形和胚胎发育的病理学有关。 童年和成人。因此，对FoxD 3的研究可能有助于阐明 基于中胚层的先天性异常和疾病状态。此外如 作为中胚层决定的调节剂，FoxD 3的研究可能会产生影响， 组织再生和器官培养的进展