Transcriptional Regulation of Phrenic Motor Neuron Identity

项目总结 呼吸对于陆地生命来说是必不可少的。在哺乳动物中，膈运动神经元(MN)形成单一的运动 柱(膈马达柱或PMC)，并以一种刻板的方式支配隔膜以控制其 收缩。发育过程中的改变可能是导致呼吸功能障碍的原因之一，因为 观察到睡眠呼吸暂停和婴儿猝死综合征(SIDS)。尽管隔膜型MNS起着重要作用， 建立膈MN同一性的分子决定因素尚不完全清楚。我们之前的研究 已证明Hox5(Hoxa5和Hoxc5)转录因子(TF)对PMC的规范至关重要， 但控制PMC表达的转录和调控机制尚不清楚。 破译Hox5蛋白如何选择性地控制它们的靶标是理解膈肌的基础 锰矿开发。HOX蛋白与特定辅因子的协同结合影响其靶点选择性。 我们已经确定了更多与Hoxa5相互作用的转录因子。在这项提案中，我将研究Hoxa5的功能 决定PMC特性的蛋白质及其与其他辅因子的相互作用。 在目标1中，我将确定Hoxa5如何在规范膈神经的过程中具体调节其靶效应器。 MNS。 在目标2中，我将绘制Hoxa5和其他辅助因子之间的相互作用图，并评估这种相互作用是否必要 用于激活假定的隔膜增强剂和启动子。 在目标3中，我将定义依赖于Hox5的膈MN多样性。 我开发了一种涵盖遗传模型、细胞和分子生物学的综合方法论。 技术和高通量测序，以便在体内解决这些问题。澄清 膈运动神经元身份转录调控的分子机制将使我们能够 确定潜在的治疗目标，使我们更接近开发有效的呼吸系统治疗方法 功能障碍。

PROJECT SUMMARY Breathing is essential for terrestrial life. In mammals, phrenic motor neurons (MNs) form a single motor column (Phrenic Motor Column or PMC) and innervate the diaphragm in a stereotypical manner to control its contraction. Alterations in the development of phrenic MNs are likely a cause of respiratory dysfunction, as observed in sleep apneas and sudden infant death syndrome (SIDS). Despite the essential role of phrenic MNs, the molecular determinants that establish phrenic MN identity are not fully understood. Our previous studies have shown that Hox5 (Hoxa5 and Hoxc5) transcription factors (TFs) are critical for the specification of PMC, but the transcriptional and regulatory mechanisms that control PMC specification are yet to be elucidated. Deciphering how Hox5 proteins can selectively control their targets is fundamental in order to understand phrenic MN development. Cooperative binding of Hox proteins with select cofactors influences their target site selectivity. We have identified additional TFs that interact with Hoxa5. In this proposal I will investigate the function of Hoxa5 protein and its interaction with other cofactors in determining PMC identity. In Aim 1 I will determine how Hoxa5 specifically regulates its target effectors during the specification of phrenic MNs. In Aim 2 I will map the interaction between Hoxa5 and other cofactors and evaluate if this interaction is essential for the activation of putative phrenic enhancers and promoters. In Aim 3 I will define Hox5-dependent phrenic MN diversity. I have developed an integrative methodology encompassing genetic models, cell and molecular biology techniques, and high throughput sequencing in order to address these questions in vivo. Elucidating the molecular mechanisms underlying transcriptional regulation of phrenic motor neuron identity will allow us to identify potential therapeutic targets and bring us closer to the development of effective treatments for respiratory dysfunction.