Role of Chemorepellants during Neural Crest Migration in the Eye

描述(申请人提供)：尽管它们对发育具有重要意义，而且由于异常的神经脊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期间控制它们迁移的分子信号知之甚少。在眼周区域，神经脊细胞在迁移到眼睛之前表达Neuropilin-1(Npn-1)，而晶状体则表达Semaphorin SA(SemaSA)。有趣的是，当角膜在伤口愈合过程中再生时，Npn-1和SemaSA也有不同的表达。然而，Npn-1/SemaSA信号在眼睛发育和伤口愈合中的作用尚未被研究。因此，识别和表征引导分子在调节眼周神经脊细胞及其角膜基质细胞后代在角膜中迁移的作用至关重要。本项目将研究Npn-1/SemaSA相互作用在眼部神经脊迁移过程中的作用。将特别强调眼周神经脊对眼球雏形的侵袭，它们与晶状体的相互作用以及在角膜再生过程中向角膜内皮和基质的分化，以及与神经脊来源的角膜基质细胞的关系。这项建议结合了经典的胚胎学技术、分子生物学和视频显微镜来实时观察神经脊的迁移，并研究Npn-1和SemaSA在这些事件中的作用。实验将在小鸡和小鼠身上进行，因为每种模型都有独特的实验优势。1)研究Npn-1/SemaSA相互作用在体内和体外神经脊对角膜的贡献过程中的作用。2)用在体延时视频显微镜观察神经脊细胞向角膜的迁移情况。3)研究Npn-1和SemaSA在小鼠眼部发育过程中的表达。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相互作用在角膜伤口愈合中的作用。意义：这项拟议的研究旨在深入了解引导分子在发育过程中神经脊迁移到眼睛中的作用，以及在角膜再生过程中其角质细胞后代的作用。了解引导分子在这些过程中的作用可能会提供线索，说明神经脊细胞的迁移模式在先天性眼病中是如何被破坏的。

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.