Mechanisms That Mediate The Absence of Lymphatics in the Retina

描述（由申请方提供）：淋巴系统起着双重作用：1）从组织中排出间质液并将其返回血液，2）参与免疫反应。除中枢神经系统（CNS）外，所有血管化组织都覆盖有淋巴管。虽然最近在了解调节淋巴管生成的分子方面取得了重大进展，但对阻止淋巴管生长的因素或条件知之甚少。因此，我们建议调查这个问题，并测试的假设，即在中枢神经系统中的淋巴管的情况下，是一个积极的抑制过程的结果。我们提出CNS中淋巴管的抑制是由Sema 3F与NRP 2结合介导的，其作用是阻断VEGF-C和VEGF-D的促淋巴管效应。我们建议用以下三个目标来检验这一假设。(1)检测Sema 3F、NRP 2和VEGF-C在视网膜中的表达，并进一步表征视网膜中的视网膜样结构。Sema 3F和3B将在出生后的小鼠视网膜和成人原位杂交检查。将使用NRP 2-LacZ小鼠并通过原位杂交评估NRP 2表达。从P0开始，随时间推移检查淋巴样结构，并评估其他淋巴标志物的表达，包括NRP 2、VEGFR 3、podoplanin和Prox-1。(2)确定阻断Sema 3F是否会导致视网膜中淋巴管的形成。Sema 3F的作用将通过施用可溶性NRP 2或中和Sema 3F来中和。此外，将评估VEGF-C过表达的影响。(3)确定Sema 3F给药是否可以抑制角膜炎症/伤口愈合模型中的淋巴管生成。将通过在充分表征的角膜缝合模型中注射Sema 3F蛋白来检查Sema 3F阻断视网膜外淋巴管形成的能力。

DESCRIPTION (provided by applicant): The lymphatic system plays a dual role: 1) draining interstitial fluid from tissues and returning it to the blood and, 2) participating in the immune response. All vascularized tissues, except the central nervous system (CNS), are invested with lymphatic vessels. Although significant progress has recently been made in understanding the molecules that regulate lymphangiogenesis, very little is known about factors or conditions that deter lymphatic growth. We, thus, propose to investigate this question and to test the hypothesis that the absence of lymphatic vessels in the CNS is the result of an active inhibitory process. We propose that suppression of lymphatic vessels in the CNS is mediated by Sema3F binding to NRP2, which acts to block the pro-lymphatic effects of VEGF-C and VEGF-D. We propose to test this hypothesis with the following aims three aims. (1) To examine the expression of Sema3F, NRP2 and VEGF-C in the retina and to further characterize the lymphatic-like structures in the retina. Sema3F and 3B will be examined by in situ hybridization in postnatal mouse retinas and in the adult. NRP2 expression will be assessed using NRP2-LacZ mice and by in situ hybridization. Lymphatic-like structures will be examined over time, beginning at P0, and will be assessed for expression of other lymphatic markers, including NRP2, VEGFR3, podoplanin and Prox-1. (2) To determine if blocking Sema3F leads to the formation of lymphatic vessels in the retina. The action of Sema3F will be neutralized by administration of soluble NRP2 or neutralizing Sema3F. In addition, the effect of VEGF- C overexpression will be assessed. (3) To determine if the Sema3F administration can suppress lymphangiogenesis in a model of corneal inflammation/wound healing. The ability of Sema3F to block the formation of lymphatic vessels outside of the retina will be examined by injection of Sema3F protein in a well-characterized corneal suture model.