New strategies for prevention of posterior capsule opacification

项目总结 后囊混浊(PCO)是最常见和最昂贵的损害视力的并发症 白内障手术。NEI晶状体与白内障项目的一项主要研究重点是“研究 转化生长因子β−介导晶状体纤维化的机制探讨预防后发性白内障的有效方法 在过去的25年里，我们已经完善了无血清原代鸡晶状体细胞培养系统(DCDMLs)，该系统已经 已经被证实是适合哺乳动物晶状体的模型。使用该系统，我们发现转化生长因子β可以 不仅诱导晶状体细胞纤维化(即上皮-间充质转化为肌成纤维细胞；EMyT)，而且还诱导晶状体 纤维细胞分化。后者是临床上有害的后囊混浊的主要原因。在此应用程序中，我们建议 针对不同途径的三种预防多囊卵巢综合征的新策略。每一个都有可能阻止 在不增加时间、复杂性或成本的情况下开发纤维性和/或晶状体纤维型PCO 标准的白内障手术。它们还为批准的或研究中的人类提供了新的临床应用 治疗，另一个NIH计划的目标(NCATS的药物重新用途/救援计划)。 (1)我们史无前例地发现了FDA批准的一种小分子多激酶抑制剂 2012年，为了对抗白血病，阻止转化生长因子β诱导的DCDML细胞分化为EMyT和晶状体纤维细胞，以及 对后囊混浊的发展至关重要的另外两个过程(晶状体细胞增殖和迁移)。有效 这种药物的浓度可以在一小时内被加载到标准的人工晶状体中，并从标准的人工晶状体中释放出来。 (IOL)，在兔眼内或玻璃体内注射均为无毒。目标1是评估 这种释药人工晶状体在最常用和被接受的临床前动物中预防后发性白内障的能力 建立兔后发性白内障模型，即模拟白内障手术。这些研究将在 与多囊卵巢及其在兔身上的临床前评估的全球权威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可以阻断 转化生长因子β诱导DCDMLs肌间充质形成。据我们所知，这些研究首次揭示了一项强制性的 转化生长因子β和erbB信号通路在晶状体细胞纤维化中的协同作用目标2是确定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 这种互动的影响。我们还将测试FDA批准的ErbB R抑制剂是否可以通过IOL给药。 (3)白内障手术的一个明显但被低估的后果是，存活下来的前晶状体 上皮细胞几乎完全失去了细胞与细胞的接触。在非镜片系统中，两种类型的可用药 转录效应物已被证明调节转化生长因子β诱导的细胞密度依赖的纤维化 举止。根据本申请书中提出的初步证据，我们建议进行第一次 MRTF-A(Aim#3A)和YAP/TAZ(Aim#3B)在低密度诱导中作用的分子研究 转化生长因子β依赖的晶状体细胞纤维化。

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.