Innovative Therapeutic Targets for Fungal Keratitis

描述(由申请人提供)：我们报道了真菌抗氧化途径和铁结合分子(铁载体)对于哺乳动物角膜中的菌丝生长是必不可少的(J Clin Invest 2012，PMC3708856；PLoS Pathogens 2013，PMC3534057)。我们还证明，抗癌药物PX-12可以抑制硫氧还蛋白途径，辛伐他汀可以抑制铁质曲霉载体TAFC(9，10)的产生，可以针对这些途径。在目前的提案中，我们还显示了抑制锌运输会损害曲霉菌丝在体外的生长的初步数据。当前提案中概述的研究将检查PX-12、他汀类药物与其他针对这些通路的药物的比较，这些药物要么是在常规临床使用中，要么是已经通过第一阶段试验并被证明无毒(都是商业上可以买到的)。然后，我们将使用多目标方法组合最有效的化合物。在第一年，我们将在体外直接菌丝杀伤试验(AIM 1)、旨在增强人中性粒细胞对菌丝杀伤的体外试验(AIM 2)以及我们建立的创伤诱导和隐形眼镜/生物膜诱导的真菌性角膜炎小鼠模型(AIM 3)中确定最有效的药物。在第二年，我们将完成目标3，并基于在小鼠模型中的发现，我们将检验在一种新的隐形眼镜相关性真菌性角膜炎兔模型中的疗效。两性霉素B或纳他霉素，作为治疗真菌性角膜炎的常见疗法，也将包括在内，我们将检查每种药物及其组合的细胞毒性。这些新的方法针对角膜中菌丝生长的基本途径，没有预期的全身副作用，因为它们是局部给药，并有相当大的潜力作为这一重要疾病的新疗法。

DESCRIPTION (provided by applicant): We reported that fungal anti-oxidant pathways and iron binding molecules (siderophores) are essential for hyphal growth in the mammalian cornea (J Clin Invest 2012, PMC3708856; PLoS Pathogens 2013, PMC3534057). We also demonstrated that these pathways can be targeted using the anti-cancer drug PX-12, which inhibits the thioredoxin pathway, and by Simvastatin, which inhibits production of the Aspergillus siderophore TAFC (9, 10). In the current proposal, we also show preliminary data that inhibition of zinc transport impairs growth of Aspergillus hyphae in vitro. Studies outlined in the current proposal will examine PX-12, statins compared with other drugs that target these pathways, and which are either in routine clinical use, or which have gone through Phase I trials and shown to be non-toxic (all are commercially available). We will then combine the most effective compounds using a multi-target approach. In year 1, we will determine the most effective agents in a direct in vitro hyphal killing assay (Aim 1), in an in vitro assay designed to augment hyphal killing by human neutrophils (Aim 2), and in our established murine models of trauma induced and contact lens/biofilm induced fungal keratitis (Aim 3). In the second year, we will complete Aim 3 and based on findings in the murine models, we will examine efficacy in a new rabbit model of contact lens associated fungal keratitis. Amphotericin B or natamycin, as common therapies for fungal keratitis, will also be included, and we will examine cytotoxicity of each dru and combination. These novel approaches target essential pathways of hyphal growth in the cornea, have no anticipated systemic side effects as they are administered topically, and have considerable potential as novel therapies for this important disease.