The role of Hippo signaling in palate development

项目摘要 继发腭裂是最常见的先天性畸形之一，患病率为1/1500 活产腭裂患者可以由专家团队治疗，达到功能和美学标准; 然而，目前的治疗需要在一生中多次手术，这与显著的 发病率，因此，有机会改善治疗和结果。人民进一步了解 腭发育的生物学过程将为改进干预措施提供基础 并为腭裂患者建立治疗方法。 次生腭的发育是一个复杂的多步骤的过程，其中腭架从 上颌突垂直生长，位于发育中的舌的侧面。腭架重新定向 在一个称为腭架提升的过程中，舌背侧的水平位置。架子变大了 水平地在中线处相遇并融合形成分开口腔和鼻腔的硬腭和软腭 蛀牙腭架上升的过程是腭发生中最不为人所知的方面之一。 在腭架发育过程中，腭架的组织张力和形态发生了巨大的变化 然而，细胞如何产生和解释张力以导致组织重塑并不清楚。 明白 海马通路是最近发现的一种机械感觉通路，其调节器官大小和组织 通过控制增殖、凋亡和分化进行修复。海马通路的下游靶点， 是相关蛋白（雅普）和具有PDZ结合基序的转录共激活因子（TAZ），易位到 细胞核和调节基因转录响应细胞几何形状的变化，细胞外基质（ECM） 硬化和物理拉伸。为了探讨张力与细胞形态变化之间的联系， 腭架上升过程中，本建议调查海马信号通路在次级腭 阵 在一个次级腭间充质细胞亚群中缺失雅普和Taz会导致腭裂， 特别是腭架抬高的缺陷。这项研究提案将确定雅普/TAZ在以下方面的作用： 腭架升高并检验雅普/TAZ由腭架中的张力激活的假设， 由ECM和细胞骨架重塑产生，以诱导升高所需的基因转录。目标1将 分析缺失雅普和Taz的腭间充质的变化，并确定Hippo的作用 腭发育中的信号传导。目的2建立雅普/TAZ在腭部作用的分子机制 通过确定雅普/TAZ的转录靶点来开发。这项工作将带来新的见解， 物理和细胞生物学基础腭隆起，将扩大我们的理解腭发生 以及继发腭裂的治疗，为腭裂患者的未来治疗提供指导。

PROJECT SUMMARY Clefting of the secondary palate is one of the most common congenital anomalies, with a prevalence of 1/1,500 live births. Individuals with cleft palate can be treated by a team of specialists to functional and esthetic norms; however, the current treatment requires multiple surgeries throughout life, which are associated with significant morbidities, and thus, there is an opportunity to improve therapies and outcomes. An increased understanding of the biological processes underlying palatogenesis will provide a foundation on which improved interventions and therapies will be built for patients with cleft palate. Secondary palate development is a complex, multi-step process in which the palatal shelves develop from the maxillary processes and grow vertically, lateral to the developing tongue. The palatal shelves then reorient into a horizontal position dorsal to the tongue in a process termed palatal shelf elevation. The shelves grow horizontally to meet at the midline and fuse to form the hard and soft palate that separate the oral and nasal cavities. The process of palatal shelf elevation is one of the least understood aspects of palatogenesis. Tremendous change in tissue tension and morphology occurs in the palatal shelves during palatal shelf elevation, yet how tension is generated and interpreted by the cells to result in tissue remodeling is not understood. The Hippo pathway is a recently discovered mechanosensory pathway that regulates organ size and tissue repair by controlling proliferation, apoptosis, and differentiation. The downstream targets of the Hippo pathway, Yes-associated protein (YAP) and transcriptional co-activator with PDZ-binding motif (TAZ), translocate to the nucleus and regulate gene transcription in response to change in cell geometry, extracellular matrix (ECM) stiffening, and physical stretching. In order to probe for a link between tension and morphological change in the palatal shelves during elevation, this proposal investigates the Hippo signaling pathway in secondary palate formation. Deletion of Yap and Taz in a subset of secondary palate mesenchymal cells results in cleft palate and, specifically, defects in palatal shelf elevation. This research proposal will determine the role of YAP/TAZ in palatal shelf elevation and test the hypothesis that YAP/TAZ are activated by tension in the palatal shelves, created by ECM and cytoskeleton remodeling, to induce gene transcription required for elevation. Aim 1 will analyze changes in the palatal mesenchyme with deletion of Yap and Taz and determine the role of Hippo signaling in palatogenesis. Aim 2 will establish the molecular mechanism of action of YAP/TAZ in palate development by determining transcriptional targets of YAP/TAZ. This work will bring new insight into the physical and cellular biology underlying palate elevation that will broaden our understanding of palatogenesis and clefting of the secondary palate, guiding future therapies for patients with cleft palate.