New strategies for prevention of posterior capsule opacification

项目摘要 后囊膜混浊（PCO）是最常见和昂贵的视力破坏并发症， 白内障手术NEI的透镜和白内障项目的一个主要研究重点是"研究 TGF β −介导的透镜纤维化的机制，以开发预防PCO的有效方法。"在 在过去的25年里，我们已经完善了无血清原代鸡透镜细胞培养系统（DCDMLs）， 已被确认为哺乳动物透镜的适当模型。使用这个系统，我们发现TGF β可以 不仅诱导透镜细胞纤维化（即，上皮-间充质转化为肌成纤维细胞; EMyT），但也包括透镜 纤维细胞分化后者是临床上有害的PCO的主要原因。在本申请中，我们提出 针对不同途径的三种预防PCO的新策略。每一个都有可能阻止 纤维化和/或透镜纤维型PCO的发展，而不增加当前的时间、复杂性或成本。 标准白内障手术它们还为已批准或研究的人类 这是另一个NIH项目（NCATS的药物再利用/拯救计划）的目标。 (1)我们史无前例地发现一种小分子多激酶抑制剂 在2012年，用于对抗白血病的药物阻断了DCDMLs中TGF β诱导的EMyT和透镜纤维细胞分化，以及 PCO发展所必需的另外两个过程（透镜细胞增殖和迁移）。有效 一定水平的这种药物可以装载到标准的人类眼内透镜中，并在一小时内从其释放 (IOL)兔眼前房注射或玻璃体注射后均无毒性反应。目标#1是评估 此类药物释放IOL在最常用和可接受的临床前动物中预防PCO的能力 PCO模型，即进行模拟白内障手术的兔。这些研究将在 与全球PCO及其在家兔中的临床前评估权威Liliana Werner博士合作。 (2)我们最近发现，10/10的ErbB（EGF）家族受体的小分子抑制剂阻断了 TGF β诱导DCDMLs中的EMyT。据我们所知，这些研究首次揭示了一种强制性的 透镜细胞纤维化中TGF β和ErbB通路之间的协同作用。目标#2是识别ErbB 这一过程所需的受体和配体，是阐明分子机制的重要第一步 of this interaction互动.我们还将测试FDA批准的ErbB R抑制剂是否可以通过IOL递送。 (3)白内障手术的一个明显但被低估的后果是， 上皮细胞失去了几乎所有的细胞间接触。在非晶状体系统中，两种类型的可药物 已经显示转录效应子以细胞密度依赖性方式调节TGF β诱导的纤维化。 方式根据本申请中提出的初步证据，我们建议进行第一次 MRTF-A（Aim#3A）和雅普/TAZ（Aim#3B）在低密度诱导的， 透镜细胞中的TGF β依赖性纤维化。

PROJECT SUMMARY Posterior capsule opacification (PCO) is the most common and costly vision-disrupting complication of cataract surgery. A stated major research priority of the Lens and Cataract Program at NEI is "to study the mechanism of TGFβ−mediated lens fibrosis in order to develop effective means of preventing PCO." During the past 25 years, we have perfected a serum-free primary chick lens cell culture system (DCDMLs) that has been validated as an appropriate model for the mammalian lens. Using this system, we found that TGFβ can induce not only lens cell fibrosis (i.e., epithelial-mesenchymal transition to myofibroblasts; EMyT), but also lens fiber cell differentiation. The latter is a major cause of clinically deleterious PCO. In this application, we propose three novel strategies to prevent PCO that target different pathways. Each has the potential to block the development of fibrotic and/or lens fiber-type PCO without increasing the time, complexity, or cost of current standard cataract surgery. They also provide new clinical applications for approved or investigational human therapeutics, a goal of another NIH program (the drug repurposing/rescue initiative at NCATS). (1) We have made the unprecedented discovery that a small molecule multikinase inhibitor FDA-approved in 2012 to fight leukemia blocks TGFβ-induced EMyT and lens fiber cell differentiation in DCDMLs, as well as two other processes essential for the development of PCO (lens cell proliferation and migration). Effective levels of this drug can be loaded into, and be released within an hour from, a standard human intraocular lens (IOL), and were non-toxic in rabbits after either intracameral or intravitreal injection. Aim #1 is to assess the ability of such drug-releasing IOLs to prevent PCO in the most commonly used and accepted preclinical animal model for PCO, namely rabbits subjected to mock cataract surgery. These studies will be conduced in collaboration with Dr. Liliana Werner, a worldwide authority on PCO and its preclinical assessment in rabbits. (2) We have recently discovered that 10/10 small molecule inhibitors of ErbB (EGF) family receptors block TGFβ from inducing EMyT in DCDMLs. To our knowledge, these studies are the first to reveal an obligatory cooperation between the TGFβ and ErbB pathways in fibrosis in lens cells. Aim #2 is to identify the ErbB receptors and ligands required for this process, the essential first step in elucidating the molecular mechanisms of this interaction. We will also test if an FDA-approved ErbB R inhibitor can be delivered via IOL. (3) An obvious but underappreciated consequence of cataract surgery is that the surviving anterior lens epithelial cells loose almost all of their cell-cell contacts. In non-lens systems, two types of druggable transcriptional effectors have been shown to regulate TGFβ-induced fibrosis in a cell density-dependent manner. On the basis of preliminary evidence presented in this application, we propose to carry out the first molecular investigation of the role of MRTF-A (Aim #3A) and YAP/TAZ (Aim #3B) in low density-induced, TGFβ-dependent fibrosis in lens cells.