Exploration of the Role of Porcupine in Chick Neural Development

描述（申请人提供）：由于神经管缺陷是最常见的出生缺陷之一，因此了解神经管发育的分子机制至关重要。Wnt信号通路在神经管闭合和脊髓背侧的模式/扩张中发挥着充分的作用；然而，对wnt的上游调控因子如何影响神经管发育知之甚少。豪猪（Porcn）是Wnt配体的重要上游调节剂，与局灶性皮肤发育不全患者的神经管缺陷有关。Porcn在Wnt配体的脂质修饰中有明确的作用，这是一种影响其活性和分布的翻译后修饰。本研究的目的是确定Porcn在神经管发育的两个不同阶段的发育作用，同时分析Porcn在下游Wnt信号通路中的具体作用，使用小鸡神经管作为体内模型系统。为了实现这一提议的目标，我们计划验证我们的中心假设，即Porcn通过b-连环蛋白依赖的Wnt信号调节神经管的关闭和脊髓背侧的扩张和模式。

DESCRIPTION (provided by applicant): As neural tube defects are amongst the most common birth defects, it is vitally important to understand the molecular mechanisms underlying neural tube development. Wnt signaling pathways have well-documented roles in neural tube closure and patterning/expansion of the dorsal spinal cord; however, little is known about how upstream regulators of Wnts affect neural tube development. Porcupine (Porcn) is an important upstream regulator of Wnt ligands and has been linked to neural tube defects in patients with Focal Dermal Hypoplasia. Porcn has a demonstrated role in the lipid modification of Wnt ligands, a post-translational modification that affects their activity and distribution. The objectve of the proposed work is to define the developmental role of Porcn in two distinct stages of neural tube development while assaying the specific roles of Porcn in downstream Wnt signaling pathways, using the chick neural tube as an in vivo model system. To attain the objective of this proposal, we plan to test our central hypothesis that Porcn regulates the closure of the neural tube and for the expansion and patterning of the dorsal spinal cord via b-catenin-dependent Wnt signaling. PUBLIC HEALTH RELEVANCE: As neural tube defects are amongst the most common birth defects, it is vitally important to understand the molecular mechanisms underlying neural tube development. The objective of the proposed work is to define the developmental role of Porcn, an upstream regulator of Wnt signaling, in two distinct stages of chick neural tube development while assaying the specific roles of Porcn in downstream Wnt signaling pathways. These experiments are expected to yield significant insights about the physiological roles of Wnt lipidation in neural tube development and to provide novel insights about a regulatory mechanism for Wnt ligands, which play key roles in the development of the CNS.