Role of Chemorepellants during Neural Crest Migration in the Eye

描述（由申请人提供）：尽管它们在发育过程中具有重要意义，并且由于神经嵴异常发育而引起的视觉缺陷数量惊人，但在眼睛发育或角膜再生过程中控制它们迁移的分子信号知之甚少。在眼周区域，神经嵴细胞在迁移到眼睛之前表达Neuropilin-1 (Npn-1)，而晶状体表达SemaphorinSA （SemaSA）。有趣的是，Npn-1和SemaSA在创面愈合过程中随着角膜再生也有差异表达。然而，Npn-1/SemaSA信号在眼睛发育和伤口愈合中的作用尚未得到研究。因此，识别和表征在角膜内调节眼周神经嵴细胞及其角化细胞后代迁移的引导分子的作用是至关重要的。本项目将研究Npn-1/SemaSA相互作用在眼部神经嵴迁移中的作用。我们将特别强调眼周神经嵴向眼基底的侵袭，它们与晶状体的相互作用和向角膜内皮和基质的分化，以及在角膜再生过程中神经嵴来源的角化细胞的关系。本研究将经典胚胎学技术与分子生物学和视频显微镜相结合，实时观察神经嵴迁移，并研究Npn-1和SemaSA在这些事件中的作用。实验将在小鸡和老鼠身上进行，每种模型都有其独特的实验优势。以下具体目的将实现：1)在体内和体外实验中，研究Npn-1/SemaSA相互作用在神经嵴对角膜的贡献过程中的作用。2)用活体延时视频显微镜观察神经嵴细胞向角膜的迁移。3)表征小鼠眼睛发育过程中Npn-1和SemaSA的表达。4)研究Npn-1/SemaSA相互作用在小鼠眼睛发育中的作用。5)研究Npn-1/SemaSA相互作用在角膜创面愈合中的作用。意义：本研究旨在揭示发育过程中神经嵴迁移到眼内的引导分子及其在角膜再生过程中的角化细胞后代的作用。了解引导分子在这些过程中的作用可能为先天性眼病中神经嵴细胞的迁移模式如何被破坏提供线索。

DESCRIPTION (provided by applicant): Despite of their developmental importance and the striking number of visual defects that arise from aberrant neural crest development, little is known of the molecular signals that control their migration during eye development or during the regeneration of the cornea. In the periocular region, neural crest cells express Neuropilin-1 (Npn-1) prior to their migration into the eye, while the lens expresses SemaphorinSA (SemaSA). Interestingly, Npn-1 and SemaSA are also differentially expressed as the cornea regenerates during wound healing. However the role of Npn-1/SemaSA signaling during eye development and wound healing has not been examined. Therefore it is critical to identify and characterize the role of guidance molecules that regulate the migration of periocular neural crest cells and their keratocyte progeny in the cornea. This project will study the role of Npn-1/SemaSA interactions during neural crest migration in the eye. There will be special emphasis on the invasion of periocular neural crest into the eye rudiment, their interaction with the lens and differentiation into corneal endothelium and stroma, and relationship to neural crest-derived keratocytes during regeneration of the cornea. This proposal combines classical embryological techniques with molecular biology and video microscopy to visualize neural crest migration in real-time and examine the role of Npn-1 and SemaSA during these events. Experiments will be carried out in chick and mouse, as each model offers unique experimental advantages. The following specific aims will be performed: 1) Examine the role of Npn-1/SemaSA interactions during neural crest contribution to the cornea in vivo and in vitro. 2) Examine the migration of neural crest cells into the cornea by in vivo time-lapse video microscopy. 3) Characterize the expression of Npn-1 and SemaSA during mouse eye development. 4) Examine the role of Npn-1/SemaSA interactions during mouse eye development. 5) Examine the role of Npn-1/SemaSA interactions during cornea wound healing. Significance: The proposed research aims to provide an insight into the role of guidance molecules during neural crest migration into the eye during development and of their keratocyte progeny during cornea regeneration. Understanding the role of guidance molecules during -these processes may provide clues on how the migration pattern of neural crest cells is disrupted in congenital eye disorders.