Nonmuscle myosins in craniofacial morphogenesis and orofacial clefting

描述(申请人提供)：唇腭裂是非常常见的先天性畸形，对受影响的个人及其家庭具有毁灭性的后果。形成面部正常发育所必须完成的发育过程是多步骤和复杂的。例如，为了形成完整的次级腭部或口腔顶部，称为腭架的胚胎原基垂直突出到口腔中，重新定位。 到舌头上方的位置，然后在中线融合。目前，我们拥有丰富的关于信号通路和转录因子的知识，这些信号通路和转录因子控制着发育中的这些步骤，但实际上对施加力量塑造面部发育的分子以及信号通路如何连接到这些效应器是神秘的。根据我们的初步数据，结合最近发表的人类遗传学研究，我们认为非肌肉肌球蛋白是头面部形态发生的优秀候选驱动因素。非肌肉肌球蛋白是一种分子马达，在肌动蛋白细胞骨架上行走、滑动或产生张力，对细胞迁移、黏附和胞质分裂等细胞过程至关重要，但它们在颅面发育和疾病中的功能尚不清楚。在这里，我们提出了一系列实验来研究非肌肉肌球蛋白在颅面发育和口面部裂开中的发育作用。我们建议使用小鼠遗传学方法，在这种方法中，非肌肉肌球蛋白的功能在特定的细胞类型中被破坏来定义它们的作用。此外，我们将使用先进的成像方法来观察它们在小鼠体内丧失功能的细胞后果。然后，我们建议确定在腭部融合的背景下调节这些马达活动的信号通路。因此，这些实验将把已知的调节器与下游的效应器联系起来，提供更完整的图景，说明唇腭裂等先天性畸形是如何发生正常发育的，以及这些事件是如何受到干扰的。我们期望这些研究对这种常见的先天性畸形的预防和治疗策略的设计具有重要的意义。 公共卫生相关性：唇腭裂是最常见的先天性畸形之一，但潜在的形态发生的影响因素在很大程度上尚不清楚。本申请旨在表征NMIIA和NMIIB，这两种肌动蛋白在发育过程中具有不同的细胞和组织特异性功能，其在颅面形态发生中的功能尚未被研究。这项工作应该提供对口腔裂隙的病因的洞察，并为设计预防或治疗策略提供方向。

DESCRIPTION (provided by applicant): Cleft lip and palate are extremely common congenital anomalies that have devastating consequences for affected individuals and their families. The developmental events that must be completed to shape normal development of the face are multistep and complex. For example, in order to form an intact secondary palate or roof of the mouth, embryonic primordia called palatal shelves project vertically into the oral cavity, reorient to a position above the tongue, and then fuse at the midline. Currently, we possess a wealth of knowledge about signaling pathways and transcription factors that control these steps in development, but have practically no knowledge of the molecules that exert the forces to shape the development of the face, and how signaling pathways connect to these effectors is mysterious. Based on our preliminary data, combined with recently published human genetics studies, we believe that non-muscle myosins are excellent candidate drivers of craniofacial morphogenesis. The non-muscle myosins are molecular motors that walk along, propel sliding, or produce tension on the actin cytoskeleton and are crucial for a number of cellular processes including cell migration, adhesion and cytokinesis, but their functions in craniofacial development and disease are not known. Here we propose a series of experiments to investigate the developmental roles for nonmuscle myosins in craniofacial development and orofacial clefting. We propose to use mouse genetics approaches in which the function of the nonmuscle myosins is disrupted in specific cell types to define their action. Further, we will use advanced imaging methods to observe the cellular consequences of their loss of function in mice. We then propose to identify the signaling pathways that regulate the activity of these motors in the context of palate fusion. These experiments will therefore connect known regulators with the downstream effectors providing a more complete picture of how normal development of the lip and palate occurs, and how these events are perturbed in congenital anomalies such as cleft lip and palate. We expect these studies to hold significant implications for the design of preventative and therapeutic strategies for this common class of congenital anomaly. PUBLIC HEALTH RELEVANCE: Cleft lip and palate are among the most common congenital anomalies but the effectors of the underlying morphogenesis are largely unknown. This application seeks to characterize NMIIA and NMIIB, actin motors with distinct cellular and tissue-specific functions during development, whose function has not been studied in craniofacial morphogenesis. This work should provide insight into the etiology of orofacial clefting, and directions for designing preventative or therapeutic strategies.