Regulating retinal microvascular morphogenesis

描述（由申请人提供）：视网膜微血管形态发生是一个复杂且高度协调的过程，发生在胚胎发育期间、出生后，并与几种视力损害疾病相关，包括早产儿视网膜病变（ROP）、年龄相关性黄斑变性和糖尿病视网膜病变。最近在主要研究者的实验室进行的工作表明，isoactin为基础的细胞骨架重塑是不可或缺的发育和病理性血管生成过程中观察到的微血管迁移和增殖，包括视网膜微血管成熟过程中看到的周细胞为基础的重塑。在一个集中的，跨学科的研究计划，将利用体外和体内模型，使用一系列完善的分子，细胞生物学为基础的和分子遗传学的方法，我们的目标是揭示分子机制和isoactin为基础的信号级联调节（i）视网膜内皮细胞迁移驱动正常和病理性血管生成，和（ii）基于周细胞的内皮增殖和毛细血管收缩性的控制。视网膜微血管内皮细胞培养物的定量分析将与旨在过度表达实验室发现的新型β-肌动蛋白特异性结合和丝帽蛋白betacap73的实验结合进行。为了揭示驱动基于isoactin的发育和病理性血管生成控制的分子机制，我们将利用"双小鼠"转基因方法，在该方法中，我们将特异性地诱导出生后血管内皮内的betacap73过表达。这些组合的结果，揭示了内皮运动和受损的血管生成的改变，将有助于指导cDNA表达阵列分析，旨在确定控制这些关键的微血管事件的关键信号效应。此外，为了揭示调节周细胞收缩性和视网膜内皮生长的分子信号传导机制，我们将表征Rho GTdR家族成员在微血管形态发生过程中在信号传导血管细胞骨架重塑和isoactin动力学中发挥的作用。基于最近获得的初步数据和提出的实验方法，我们预计，我们的研究计划将提供重要的新的见解调节视网膜微血管形态发生的分子机制，在正常发育过程中，并与病理性血管生成伴随糖尿病视网膜病变。

DESCRIPTION (provided by applicant): Retinal microvascular morphogenesis is a complex and highly coordinated process, which occurs during embryonic development, post-natally and in association with several visually-impairing diseases, including retinopathy of prematurity (ROP), age-related macular degeneration and diabetic retinopathy. Recent work carried out in the principal investigator's laboratory has revealed that isoactin-based cytoskeletal remodeling is integral to the microvascular migration and proliferation observed during developmental and pathologic angiogenesis, including the pericyte-based remodeling seen during retinal microvascular maturation. In a focused, inter-disciplinary research plan that will take advantage of in vitro and in vivo models using a spectrum of well-established molecular, cell biology-based and molecular genetic approaches, we aim to reveal the molecular mechanisms and the isoactin-based signaling cascades regulating (i) retinal endothelial migration driving normal and pathologic angiogenesis, and (ii) pericyte-based control of endothelial proliferation and capillary contractility. Quantitative analyses of retinal microvascular endothelial cell cultures will be performed in conjunction with experiments aimed at over-expressing the novel beta-actin specific binding and filament capping protein, betacap73, discovered in the lab. To reveal the molecular mechanisms driving isoactin-based control of developmental and pathologic angiogenesis, we will take advantage of a 'two-mouse' transgenic approach, where we will specifically induce betacap73 over-expression within the post-natal vascular endothelium. These combined results, revealing alterations in endothelial motility and impaired angiogenesis, will serve to guide cDNA expression array analyses aimed at identifying key signaling effectors controlling these pivotal microvascular events. Further, to reveal the molecular signaling mechanisms regulating pericyte contractility and retinal endothelial growth, we will characterize the role that Rho GTPase family members play in signaling vascular cytoskeletal remodeling and isoactin dynamics during microvascular morphogenesis. Based on the preliminary data recently obtained and the experimental approaches proposed, we anticipate that our research plan will provide important new insights into the molecular mechanisms regulating retinal microvascular morphogenesis during normal development and in association with the pathologic angiogenesis accompanying diabetic retinopathy.