Elucidating signaling networks in Anterior Segment development, repair and diseases

前段(AS)组织的缺陷导致一组高度衰弱的眼部疾病，称为前部 节段性发育不良(ASD)。ASD是导致先天性角膜混浊并导致青光眼的主要原因之一 在约50%的病例中，并经常与近视有关。尽管几乎没有发现致病基因，但几乎没有发现。 了解此类疾病中潜在的组织畸形的分子和细胞机制。几个 包括Meckel、Bardet Biedl和Joubert综合征在内的纤毛疾病显示的影响AS组织的条件包括 严重近视。我们最近报道，有条件地消融神经脊细胞(NCC)的初级纤毛导联 在小鼠模型上发生ASD，条件与在人类中观察到的情况相似。我们已经证明了主纤毛 神经沟来源的POM介导Hedgehog(HH)通路。然而，我们的初步结果表明，纤毛 在AS的形态发生和修复过程中，以一种组织特异性的方式发挥不同的作用。该计划的目标是 拟开展的研究旨在阐明纤毛蛋白调控的信号通路和细胞机制。 角膜和其他AS结构的形态发生。具体地说，我们将测试我们的中心工作假设，即主要 纤毛使POM的神经脊来源的细胞能够解释局部的形态发生线索并引发不同的细胞行为 在AS的不同结构的形态发生和修复过程中。为了验证这一假设，我们产生了特定的基因 和计算工具，并开发了一种活体成像方法，使我们能够a)阐明重叠和 初级纤毛和HH通路在AS组织发育和修复中的不同作用；b)识别信号 初级纤毛下游与AS形态发生相关的网络，以及c)进行 具有软骨形成能力的PNC谱系中一种新的纤毛依赖细胞群。总体而言，这一结果 工作将揭示初级纤毛信号的整合作用，这是实现正常AS形态发生所必需的。重要的是 纤毛相关信号级联的描绘将有助于确定治疗ASD的新治疗策略 和创伤。

Defects of the anterior segment (AS) tissue lead to a group of highly debilitating eye disorders referred to as Anterior Segment Dysgenesis (ASD). ASD represents one of the leading causes of congenital corneal opacity and leads to glaucoma in ~50% of the cases and are often associated with myopia. Although few causative genes have been identified, little is known about the molecular and cellular mechanisms underlying tissue malformation in this class of diseases. Several ciliopathies including Meckel, Bardet Biedl, and Joubert syndromes display conditions affecting tissues of the AS including severe myopia. We have recently reported that conditional ablation of the primary cilium in neural crest cells (NCC) leads to ASD in the mouse model with conditions similar to those observed in humans. We have shown that primary cilia of the neural crest derived POM mediate the Hedgehog (Hh) pathway. However, our preliminary results suggest that the cilium could play distinct roles in a tissue specific manner important for AS morphogenesis and repair. The objective of the proposed study is to elucidate the signaling pathways and cellular mechanisms orchestrated by ciliary proteins during morphogenesis of the cornea and other AS structures. Specifically, we will test our central working hypothesis that primary cilia enable neural crest-derived cells of the POM to interpret local morphogenetic cues and elicit distinct cellular behaviors during morphogenesis and repair of different structures of the AS. To test this hypothesis, we have generated specific genetic and computational tools and developed an in vivo imaging approach that will allow us to a) elucidate overlapping and distinct roles of primary cilia and the Hh pathway during the development and repair of AS tissues; b) To identify signaling networks downstream of the primary cilium relevant for AS morphogenesis, and c) conduct a functional characterization of a novel cilia-dependent cell population of the pNC lineage with chondrogenic capabilities. Collectively, the outcome of this work will reveal the integrative role of primary cilia signaling necessary to achieve normal AS morphogenesis. Importantly, delineation of the cilia-related signaling cascades will enable the identification of new therapeutic strategies to treat ASD and trauma.