Role of Chemorepellants during Neural Crest Migration in the Eye

在角膜发育和再生过程中促进细胞迁移的分子信号是 很大程度上不是现在。神经脊细胞从眼周区域迁移到发育中的眼睛，并产生 到角膜基质和内皮细胞。神经脊发育缺陷与Wltii Peter 畸形和AXENFEID-Rieger综合征，而他们的角质细胞后代参与了伤口 导致瘢痕形成的愈合过程，cheoKireatedSemaphorinSA之间的相互作用 (SemaSA)及其受体Neuropllin-1(Npn-1)在发育过程中被重复利用，并在发育过程中发挥作用。 在引导细胞迁移和轴突投射方面发挥重要作用。然而，它们在眼睛发育过程中的作用 而且还没有检查伤口愈合情况。我们已经证明晶状体来源的SemaSA调节角膜 发育过程中的神经支配，这是角膜神经和结构正常配对所必需的 腹侧神经丛。我们还观察到Sema3A和Npn-1在晶状体中表达，并且 眼周神经峰分别在眼睛发育早期，但Npn-1在眼睛发育过程中下调 神经脊移入原始眼睛。此外，Npn-1和SemaSA是不同的 在角膜再生过程中表达。因此，我们假设Sema3/^Npn-1信号是重要的 用于调节角膜发育过程中眼周神经脊和L等细胞的迁移 再生。为了验证这一假设，我们将结合经典的胚胎学技术、遗传分析、 分子生物学和视频显微镜研究Npn-1和SemaSA的作用并可视化神经 在这些事件期间实时进行CREST迁移。实验将在小白鼠和小白鼠身上进行 该模型提供了独特的实验优势。将实现以下具体目标：1)检查 用在体延时视频显微镜观察神经脊细胞向角膜的迁移。2)描述和 研究Npn-1和SemaSA在小鼠眼睛发育过程中的作用。3)研究Npn的作用-- 1/Sema3A在角膜伤口愈合过程中的相互作用。

The molecular signals that guitde cell migration during development and regeneration of the cornea are largely unl<nown. Neural crest cells migrate from the periocular region Into the developing eye and give rise to the cornea stroma and endothelium. Defects In neural crest development are associated wltii Peter's anomaly and Axenfeid-Rieger syndrome, whereas their keratocyte progeny are Involved In the wound healing process that results in scar formation, interactions between the cheoKirepetient SemaphorinSA (SemaSA) and its receptor Neuropllin-1 (Npn-1) are utilized repeatedly throughout development and play a significant role in directing ceil migration and axon projections. However their role during eye development and wound healing has not been examined. We have shown that lens derived SemaSA regulates corneal innervation during development, which is required for the proper partening oif corneal nerves and formation of the ventral plexus. We have also observed that Sema3A and Npn-1 are expressed in the lens and periocular neural crest respectively, early during eye development, but Npn-1 is down-regulated during neural crest migration into the rudimentary eye. Furthermore, Npn-1 and SemaSA are differentially expressed during cornea regeneration. We therefore hypothesize that Sema3/^Npn-1 signaling is important for regulating migration of periocular neural crest and l<eratocytes during cornea development and regeneration. To test this hypothesis, we will combine classical embryological techniques, genetic analysis, molecular biology and video microscopy to examine the role of Npn-1 and SemaSA and visualize neural crest migration in real-time during these events. Experiments will be carried out in chicl< and mouse, as each model offers unique experimental advantages. The following specific aims will be peri'ormed: 1) Examine the migration of neural crest cells Into the cornea by in vivo time-lapse video microscopy. 2) Characterize and examine the role of Npn-1 and SemaSA during mouse eye development. 3) Examine the role of Npn- 1/Sema3A interactions during cornea wound healing.