Phosphatidylglycerol as a Therapy for Corneal Injury

项目摘要/摘要 因损伤、化学烧伤、手术、戴隐形眼镜而造成的角膜损伤和擦伤 和干眼综合症是痛苦的，并可能使个人容易感染。尽管这些伤口往往 迅速愈合，在某些情况下，如糖尿病，愈合可能延迟，甚至可能失败；在其他情况下 尽管损伤或感染已痊愈，但患者可能会继续表现出持续性或慢性炎症。 这种持续的无菌炎症会干扰角膜的透明度，从而影响视力；因此， 需要在促进角膜伤口愈合的同时抑制炎症的治疗。在令人兴奋的新奇结果中 我们发现，一种天然存在的磷脂，二油酰磷脂酰甘油(DOPG)，可以增强角膜 野生型小鼠和实验性角膜损伤小鼠上皮伤口的愈合 在活体内治愈。这些数据表明使用DOPG促进角膜伤口愈合的可能性 从治疗上讲。文献中的信息也支持DOPG在抑制 发炎。因此，我们最近证明DOPG通过抑制皮肤炎症而抑制皮肤炎症 模式识别受体，如Toll样受体-2(TLR2)和Toll样受体-4(TLR4)，在 对损伤相关分子模式(DAMP)的反应，即损伤后释放的内源分子 细胞提醒先天免疫系统危险的存在，这样保护性免疫反应就可以 被挂载。事实上，最近一篇研究无菌炎症的活体啮齿动物模型的文章表明 角膜基质细胞释放的热休克蛋白B4(HSPB4，又称晶状体蛋白Alpha A) 对受损角膜上皮细胞的反应是激活角膜巨噬细胞上TLR2的潮湿因素 导致角膜发炎。在创新性的初步研究中，我们发现DOPG可以抑制 巨噬细胞炎症介质的产生对HSPB4的反应，提示这种脂质 会抑制这种角膜炎症。根据我们的初步结果，我们假设DOPG将采取行动 不仅促进角膜伤口愈合，而且通过抑制TLR2和/或TLR4抑制炎症 激活。在提出的研究中，我们将测试DOPG将：(1)剂量依赖，安全和 生理上促进角膜上皮伤口愈合，无不良反应，最佳剂量为 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)抑制中性粒细胞 通过抑制TLR2/4在体小鼠角膜损伤模型中的浸润和炎症 激活。在第三个目标中，我们还将确定DOPG发挥这些作用的机制 促进角膜上皮损伤愈合，抑制TLR2/4活化和炎症。如果我们的假设 证明是正确的，这将表明开发DOPG作为一种安全有效的治疗方法的可能性 角膜伤口的愈合和防止因损伤、感染、眼科手术或其他原因引起的炎症 疾病需要角膜上皮伤口愈合，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.