Phosphatidylglycerol as a Therapy for Corneal Injury

项目概要/摘要 因受伤、化学烧伤、手术、配戴隐形透镜而导致的角膜创伤和擦伤 和干眼综合征是痛苦的，并可使个体易于感染。虽然这些伤口 愈合迅速，在某些情况下，如糖尿病，愈合可能会延迟，甚至可能失败;在其他情况下， 尽管损伤或感染已消退，但个体可能继续表现出持续性或慢性炎症。 这种持续的无菌性炎症会干扰角膜清晰度，从而损害视力;因此， 需要抑制炎症同时改善角膜伤口愈合的治疗。令人兴奋的新结果 我们已经发现，天然存在的磷脂，二油酰磷脂酰甘油（DOPG）， 野生型小鼠和角膜损伤实验小鼠模型中的上皮伤口愈合 体内愈合这些数据表明使用DOPG促进角膜伤口愈合的可能性 治疗上文献中的信息也支持DOPG在抑制 炎症因此，我们最近证明DOPG通过抑制皮肤炎症， 模式识别受体，如toll样受体-2（TLR 2）和toll样受体-4（TLR 4）的激活， 损伤相关分子模式（DAMPs）反应，即损伤后释放的内源性分子， 细胞，以提醒先天免疫系统危险的存在，使保护性免疫反应， 上马。事实上，最近的一篇研究无菌炎症的体内啮齿动物模型的文章表明， 热休克蛋白B4（HSPB 4，也称为晶状体蛋白α A）在角膜基质细胞中释放， 对受损角膜上皮细胞的反应作为DAMP激活角膜巨噬细胞上的TLR 2， 引起角膜炎症。在创新的初步研究中，我们发现DOPG可以抑制 巨噬细胞炎症介质的生产响应HSPB 4，这表明这种脂质的可能性， 会抑制角膜炎症根据我们的初步结果，我们假设DOPG将采取行动， 不仅加速角膜伤口愈合，而且通过抑制TLR 2和/或TLR 4来抑制炎症 activation.在这项研究中，我们将测试DOPG将：（1）剂量依赖性，安全性和 在生理上加速角膜上皮伤口愈合而没有副作用， 在正常和糖尿病受损的角膜伤口愈合小鼠模型中测定，和（2）抑制嗜中性粒细胞 通过其抑制TLR 2/4的能力在体内小鼠角膜损伤模型中的浸润和炎症 activation.在第三个目标中，我们还将确定DOPG发挥这些作用的机制， 刺激角膜上皮伤口愈合并抑制TLR 2/4活化和炎症。如果我们的假设 证明是正确的，这将表明发展DOPG作为一种安全有效的治疗方法的可能性， 愈合角膜伤口和预防损伤、感染、眼科手术或其他手术后的炎症 需要角膜上皮伤口愈合的疾病，从而改善这些患者的生活质量。

Project Summary/Abstract Corneal wounds and abrasions occurring as a result of injury, chemical burns, surgery, contact lens wear and dry eye syndrome are painful and can predispose individuals to infection. Although these wounds tend to heal rapidly, in some cases, such as in diabetes, the healing may be delayed or may even fail; in other cases individuals may continue to show persistent or chronic inflammation despite resolution of the injury or infection. This persistent sterile inflammation can interfere with corneal clarity thereby compromising vision; therefore, treatments to inhibit inflammation while improving corneal wound healing are needed. In exciting novel results we have found that a naturally occurring phospholipid, dioleoylphosphatidylglycerol (DOPG), enhances corneal epithelial wound healing in wild-type mice and in an experimental mouse model of impaired corneal wound healing in vivo. These data suggest the possibility of using DOPG to enhance corneal wound healing therapeutically. Information in the literature also supports a potential role for DOPG in suppressing inflammation. Thus, we have recently demonstrated that DOPG suppresses skin inflammation by inhibiting the activation of pattern recognition receptors, such as toll-like receptor-2 (TLR2) and toll-like receptor-4 (TLR4), in response to damage-associated molecular patterns (DAMPs), endogenous molecules released from injured cells to alert the innate immune system to the presence of danger so that a protective immune response can be mounted. Indeed, a recent article examining an in vivo rodent model of sterile inflammation demonstrated that heat shock protein B4 (HSPB4, also known as crystallin Alpha A) released from corneal keratocytes in response to damaged corneal epithelial cells serves as a DAMP to activate TLR2 on corneal macrophages and induce corneal inflammation. In innovative preliminary studies we have found that DOPG can inhibit macrophage inflammatory mediator production in response to HSPB4, suggesting the likelihood that this lipid will suppress this corneal inflammation. Based on our preliminary results, we hypothesize that DOPG will act not only to accelerate corneal wound healing but also to suppress inflammation by inhibiting TLR2 and/or TLR4 activation. In the research proposed, we will test the idea that DOPG will: (1) dose-dependently, safely and physiologically accelerate corneal epithelial wound healing without adverse effects, at an optimal dose to be determined, in normal and diabetes-impaired corneal wound healing mouse models, and (2) inhibit neutrophil infiltration and inflammation in in vivo mouse models of corneal injury through its ability to inhibit TLR2/4 activation. In a third aim we will also determine the mechanism by which DOPG exerts these effects to stimulate corneal epithelial wound healing and inhibit TLR2/4 activation and inflammation. If our hypothesis proves correct, it would suggest the possibility of developing DOPG as a safe and effective treatment to hasten healing of corneal wounds and to prevent inflammation following injury, infection, ophthalmic surgery or other disorders necessitating corneal epithelial wound healing, thereby improving the quality of life for these patients.