Molecular targets of Corneal Anti-fibrosis

描述（由申请人提供）：角膜盲是世界上第二大视力丧失原因。暴露的角膜首先也会引起眼部感染， 化学或爆炸损伤，并迅速发展血管生成和纤维化，最终导致疤痕和角膜失明。仅在美国，每年就有超过5万例与工作有关的眼部损伤，而在战场上，伊拉克和阿富汗的美国士兵死于眼部和面部损伤的比例是躯干损伤的四倍。为了解开这个普遍存在的谜团， 在抗血管纤维化药物方面，我们建立了一个高通量药物筛选平台，从中筛选出了多能抑制剂withaferin A（WFA）。第二个创新的发现，由化学遗传学方法提供，照亮波形蛋白，III型中间丝（IF）蛋白，作为WFA的结合靶点。分子模拟研究揭示了四聚体波形蛋白中的WFA结合位点，并首次显示了保留在III型IF成员中的高度保守的可药用位点。这一前所未有的IF蛋白药理学分子洞察结合对靶缺陷（Vim KO）小鼠的研究产生了波形蛋白作为纤维化转换的关键调节因子。在目前提出的研究中，我们将研究III型IF蛋白是角膜抗纤维化药物靶点的假设。我们将测试三个具体目标：（1）激活的角膜驻留细胞通过过表达波形蛋白参与角膜纤维化转换细胞。然后，我们将验证波形蛋白的遗传和药理学下调所产生的抗纤维化的分子机制。此外，我们计划通过在这些小鼠中诱导波形蛋白缺乏来拯救小鼠免于眼部疾病无虹膜。(2)研究结蛋白表达在角膜组织修复中的作用，并证明结蛋白与波形蛋白结合加剧角膜纤维化，通过遗传或药理学手段协调下调结蛋白表达可改善创伤性损伤后角膜的恢复。(3)开发具有改善的溶解度的WFA类似物用于局部眼部治疗。使用这些新的WFA类似物将增强我们对基于WFA的药物开发的治疗方式的理解，以及靶向角膜纤维化中III型IF的合理性。

DESCRIPTION (provided by applicant): Corneal blindness is the second leading cause of vision loss in the world. The exposed cornea is first to also become involved in ocular infections, chemical or blast injuries, and rapidly develops angiogenesis and fibrosis, which ultimately leads to scarring and corneal blindness. In the US alone, work-related eye injuries account for over 50,000 cases per year, while on the battlefield, US soldiers in Iraq and Afghanistan succumb to eye and face injuries at four times the rate of torso injuries. To tackle the prevailing enigma for angio-fibrotic drugs, we developed a high throughput screening platform for drug discovery, from which was borne out the pluripotent inhibitor withaferin A (WFA). A second innovative discovery, afforded by the chemical genetic approach, illuminated vimentin, a type III intermediate filament (IF) protein, as the binding target of WFA. Molecular modeling studies have unraveled the WFA-binding site in tetrameric vimentin and showed, for the first time, a highly conserved druggable site that is retained in members of type III IFs. This unprecedented molecular insight into IF-protein pharmacology combined with studies on target deficient (Vim KO) mice yielded vimentin as a critical regulator of the fibrotic switch. In this current proposed study, we will investigate the hypothesis that type III IF proteins are druggable targets for corneal anti- fibrosis. We will test three specific aims: (1) Activated corneal resident cells engage the corneal fibrotic switch cells by overexpressing vimentin. We will then validate the molecular mechanism of anti-fibrosis exerted by genetic and pharmacological downregulation of vimentin. Additionally, we plan to rescue mice from the ocular disease Aniridia, by inducing vimentin deficiency in these mice. (2) Investigate the role of desmin expression in corneal tissue repair, and demonstrate that desmin combines with vimentin to exacerbate corneal fibrosis and their coordinate downregulation by genetic or pharmacological means can improve corneal recovery after traumatic injury. (3) Develop WFA analogs with improved solubility for topical ocular treatment. Use of these novel WFA analogs will enhance our understanding of therapeutic modalities for WFA-based drug development and the rational to target type III IFs in corneal fibrosis.