Integrin Signaling in the Trabecular Meshwork

这是R01的新应用。这项资助的长期目标是识别整合素信号 可作为控制和降低眼压的治疗靶点的机制。青光眼， 导致视网膜神经节细胞不可逆转的损失，影响全球约6700万人。他们 通常与由于房水减少而引起的眼内压(IOP)升高有关 小梁网流出体液(TM)。尽管已知有许多生理因素 监管流出设施，这是作为一种重要的监管机制出现的关键因素之一 流出设备是TM的收缩特性。目前，还不清楚哪些分子事件 调节TM的收缩能力。我们实验室的研究表明，信号特性 细胞外基质(ECM)及其受体(整合素)中的生物活性片段可用于调节 在培养的前段，TM的收缩能力和流出能力增加。尤其是我们有 结果表明，纤维连接蛋白的一个生物活性结构域，称为HepII结构域，可以激活整合素信号。 在培养的TM细胞中降低细胞收缩能力的途径。我们的初步数据有力地支持 假设TM中整合素信号通路的操纵可以改变细胞的收缩能力 用于调节流出设施。这项研究的目的是确定靶向整合素的可能方法 TM中的信号通路，以增加流出设施。为此，我们提出了三种方法来 激活培养的前节细胞的？4？1信号通路。首先，使用慢病毒载体表达 TM中的Mini-HepII基因。第二，在TM中过表达一个结构性激活的整合素亚单位。 第三，从整合素结合蛋白的胞浆区或整合素结合蛋白中表达多肽。 这会破坏细胞黏附，降低细胞的收缩能力。本申请书中提出的研究将不会 这只会加深我们对整合素信号在TM中的作用的理解，但它将确定靶向的新方法 TM中的细胞收缩性能。

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.