TGFB signaling as a therapeutic target in cataract and PCO

项目摘要 国家眼科研究所的透镜和白内障项目的核心目标是 白内障的防治。眼生长因子TGF？参与了 前囊下白内障（ASC）和后囊膜混浊的发生 (PCO)，视力受损的条件下，纤维分化和上皮细胞到- 透镜细胞的间充质转化（EMT）在病理上被上调。虽然它是好的 建立了TGF β在体外和体内诱导透镜细胞中的EMT，其在纤维样 与PCO和ASC相关的变化未知。我们开发了一种创新的 模型系统，以研究生长因子介导的信号转导在透镜，解离细胞- 原代鸡胚透镜细胞（DCDMLs）的衍生单层培养物。在本申请中， 我们发现DCDMLs是第一个TGF β诱导EMT的培养系统， 以及纤维分化可以研究，提供了一个前所未有的机会， 确定控制这两种细胞命运的分子机制，以及一种新的系统， 发现潜在的抗PCO/ASC药物。小分子酪氨酸激酶抑制剂作为 靶向治疗已经彻底改变了某些癌症的治疗。我们已经发现 在临床使用的浓度下，一种这样的抑制剂阻断EMT和纤维样 DCDMLs中TGF β下游的变化，即使在单次1小时处理后。这些 研究结果首次提出了耐受性良好的小分子激酶 抑制剂可用于对抗引起ASC的透镜细胞的两种病理结局 和PCO。拟议研究的目的是了解 这种化合物的作用，发现其他潜在的抗PCO/ASC治疗使用一种新的 筛选小分子激酶抑制剂，并在建立离体模型中测试这些化合物 人类透镜细胞纤维化的证据。这项工作将阐明信号转导途径， TGF β可增强透镜细胞的EMT和纤维分化，并开辟了一种新的方法， PCO和ASC的预防。此外，它还可能为药物提供新的应用 已经或正在获得FDA批准用于人类的药物。

PROJECT SUMMARY A core goal of the Lens and Cataract Program of the National Eye Institute is the prevention and treatment of cataract. The ocular growth factor TGF¿ is involved in the development of anterior subcapsular cataracts (ASC) and of posterior capsule opacification (PCO), vision-impairing conditions in which both fiber differentiation and epithelial-to- mesenchymal transition (EMT) of lens cells are pathologically upregulated. Although it is well established that TGF¿ induces EMT in lens cells in vitro and in vivo, its role in the fiber-like changes associated with PCO and ASC are unknown. We have developed an innovative model system to study growth factor-mediated signal transduction in the lens, dissociated cell- derived monolayer cultures of primary embryonic chick lens cells (DCDMLs). In this application, we show that DCDMLs are the first culture system in which the ability of TGF¿ to induce EMT as well as fiber differentiation can be studied, providing an unprecedented opportunity to identify the molecular mechanisms that govern these two cell fates and a novel system to discover potential anti-PCO/ASC drugs. The use of small molecule tyrosine kinase inhibitors as targeted therapeutics has revolutionized the treatment of certain cancers. We have discovered that at clinically used concentrations, one such inhibitor blocks both the EMT- and fiber-like changes downstream of TGF¿ in DCDMLs, even after a single, 1 hour treatment. These findings raise, for the first time, the possibility that a well-tolerated small molecule kinase inhibitor could be used to combat both of the pathological fates of lens cells that cause ASC and PCO. The aims of the proposed studies are to understand the mechanistic basis of the effects of this compound, discover other potential anti-PCO/ASC therapeutics using a novel small molecule kinase inhibitor screen, and test these compounds in established ex vivo models of human lens cell fibrosis. This work will elucidate the signal transduction pathways by which TGF¿ enhances EMT and fiber differentiation in lens cells, and open up a novel approach for the prevention of PCO and ASC. Moreover, it will potentially provide new applications for drugs that have, or are in the process of acquiring, FDA approval for human use.