Integrin Signaling in the Trabecular Meshwork

描述（由申请人提供）：这是R 01的新申请。这项资助的长期目标是确定整合素信号传导机制，可用作控制和降低眼内压的治疗靶点。青光眼导致视网膜神经节细胞的不可逆损失，影响全球约6700万人。它们通常与眼内压（IOP）水平升高相关，这是由于小梁网（TM）的房水流出减少。尽管已知许多生理因素调节流出功能，但作为流出功能的重要调节机制出现的关键因素之一是TM的收缩特性。目前，还不清楚是什么分子事件调节TM的收缩性。我们实验室的研究表明，来自细胞外基质（ECM）及其受体（整合素）的生物活性片段的信号传导特性可用于调节TM的收缩性，并增加培养的前段的流出设施。特别是，我们已经表明，从纤连蛋白的生物活性域称为HepII域激活？四个？1整联蛋白信号通路，降低培养的TM细胞的细胞收缩性。我们的初步数据有力地支持了这一假设，即操纵整合素信号通路的TM，修改细胞的收缩性，可用于调节流出设施。本研究的目的是确定可能的方法来靶向整合素信号通路的TM，以增加流出设施。为此，我们提出了三种方法来激活？四个？1信号通路。首先，使用慢病毒载体在TM中表达mini-HepII基因。第二，过度表达是一种本能的激活？4整合素亚基。第三，表达肽从胞质结构域的？4-亚基或整联蛋白结合蛋白桩蛋白，破坏细胞粘附并降低细胞收缩性。本申请中提出的研究不仅将增强我们对整合素信号传导在TM中的作用的理解，而且将确定靶向TM中细胞收缩性的新方法。 公共卫生相关性：青光眼是美国第二大常见的致盲原因，也是非洲裔美国人最常见的致盲原因。眼内压（IOP）升高是青光眼的常见危险因素。该项目的目标是确定可以被激活以降低IOP并用作治疗青光眼的潜在靶点的信号通路。

DESCRIPTION (provided by applicant): This is a new application for a R01. The long-term objective of this grant is to identify integrin signaling mechanisms that can be used as therapeutic targets to control and lower intraocular pressure. The glaucomas, which lead to irreversible loss of retinal ganglion cells, affect approximately 67 million people worldwide. They are commonly associated with elevated levels of intraocular pressure (IOP) due to a reduction in aqueous humor outflow from the trabecular meshwork (TM). Although a number of physiological factors are known to regulate outflow facility, one of the key factors that have emerged as an important regulatory mechanism for outflow facility is the contractile properties of the TM. At the present, it is unclear what molecular events regulate contractility in the TM. Studies from our laboratory have shown that the signaling properties of bioactive fragments from the extracellular matrix (ECM) and their receptors (integrins) can be used to regulate the contractility of the TM and increase outflow facility in cultured anterior segments. In particular we have shown that a bioactive domain from fibronectin called the HepII domain activates a ?4?1 integrin signaling pathway that decreases cell contractility in cultured TM cells. Our preliminary data strongly supports the hypothesis that manipulation of integrin signaling pathways in the TM that modify cellular contractility can be used to regulate outflow facility. The objective of this research is to identify possible ways to target integrin signaling pathways in the TM in order to increase outflow facility. To this end, we propose three approaches to activate the ?4?1 signaling pathway in cultured anterior segments. First, use lentiviral vectors to express a mini-HepII gene in the TM. Second, over express a constitutively activated ?4 integrin subunit in the TM. Third, express peptides from the cytoplasmic domain of the ?4-subunit or the integrin binding protein, paxillin which disrupt cell adhesion and decrease cell contractility. The studies proposed in this application will not only enhance our understanding of the role of integrin signaling in the TM, but it will identify new ways to target cell contractility in the TM. PUBLIC HEALTH RELEVANCE: Glaucoma is the second most common cause of blindness in the U.S. and the most common cause of blindness among African-Americans. Increased intraocular pressure (IOP) is a common risk factor for glaucoma. The goal of this project is to identify signaling pathway(s) that can be activated to reduce IOP and be used as potential targets to treat glaucoma.