Molecular mechanisms of corneal recurrent erosion formation

角膜反复糜烂形成的分子机制

• 批准号: 9312813
• 负责人: Mary Ann Stepp
• 金额: $ 56.15万
• 依托单位: GEORGE WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-07-01 至 2021-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9312813
• 关键词: Adhesions; Aging; Alpha Cell; Anterior; Appearance; Axon; Basal Cell; Basement membrane; Biological Models; Burr hole procedure; Cell Proliferation; Cell membrane; Complex; Cornea; Corneal Injury; Data; Debridement; Defect; Denervation; Development; Disease; Ephrins; Epithelial; Epithelial Cells; Epithelium; Extracellular Matrix; Eye; Eye diseases; Funding; Gene Expression; Goals; Herpesviridae Infections; Homeostasis; Hour; Human; In Vitro; Individual; Infection; Injury; Keratitis; Lead; Lesion; MMP9 gene; Mediating; Mitomycins; Molecular; Mus; NTN1 gene; Natural regeneration; Nerve; Nervous system structure; Neuroglia; Neurons; Operative Surgical Procedures; Pain; Pathology; Patients; Phagocytosis; Pharmaceutical Preparations; Play; Proteins; Recurrence; Research; Role; Running; Schwann Cells; Secondary to; Sensory; Site; Stem cells; Stroke; Structure of retinal pigment epithelium; Structure of trigeminal ganglion; Study models; Supporting Cell; Surface; Surgical Injuries; Testing; Time; Topical application; Trauma; Vision; afferent nerve; axon injury; axon regeneration; cell motility; conditioning; corneal epithelium; corneal scar; density; effective therapy; experimental study; eye dryness; healing; heat injury; improved; in vivo; insight; laminin A; limbal; mRNA Expression; nerve supply; ocular surface; painful neuropathy; prevent; reinnervation; response; response to injury; restoration; senescence; wound

Corneal surface injuries are painful and expose the eye to infections that can destroy vision. During our previous funding period, we characterized a model for the study of recurrent corneal erosions in mice and showed that subbasal nerves (SBNs) fail to reinnervate the cornea prior to erosion formation. In addition, we showed that we could induce SBN reinnervation by treating debridement wounded corneas with mitomycin C (MMC). The long-term goal of our research is to identify the factors that prevent the corneal epithelium from reforming an intact stable barrier after trauma. One factor is failed reinnervation of the SBNs. Our data lead us to propose two hypotheses. The first (Aim A) is that corneal epithelial basal cells adhere to, protect, organize, and maintain the subbasal nerves (SBNs) that originate from the trigeminal ganglion. The corneal epithelial cells protect individual SBNs by secreting a laminin-rich ECM to insulate them from one another, organize SBNs by enclosing clusters of several SBNs within infoldings of their basal and basolateral cell membranes forming epithelial cell:axon adhesions, and maintain optimal SBN function by removing damaged SBN stubs during homeostasis and after injury by phagocytosis. We will test this hypothesis by conducting experiments to answer the following questions: 1. Do corneal epithelial cells adhere to and provide support to SBNs using adhesion complexes and proteins similar to those used by non-myelinating Schwann cells? 2. Do corneal epithelial cells phagocytose axonal debris during homeostasis and in response to SBN damage? 3. Do corneal epithelial cells respond to SBN denervation by altering expression of genes that regulate axon regeneration in Schwann cells? A second hypothesis (Aim B) proposed is to resolve corneal pathology after trauma or disease, adhesion between corneal epithelial cells, SBNs, and the basement membrane must be restored to levels present prior to development of pathology. This hypothesis is supported by preliminary data showing that MMC reduces corneal epithelial cell migration in vitro and MMP9 expression in vivo. We will test this hypothesis by conducting experiments to answer the following questions: 1. Do corneal epithelial cells at the center of the wounded mouse cornea undergo senescence? 2. Can reinnervation be accelerated by treating crush (trephine only) wounded corneas with MMC? 3. Can erosions be eliminated after they form by treating mouse corneas with MMC? 4. Can MMC improve reinnervation of corneas in mice with dry eye disease? 5. Does a prior injury (conditioning lesion) improve reinnervation after crush or debridement wounds? Comparing reinnervation after different wound types allows us to differentiate between mechanisms that permit reinnervation after crush wounds from those that prevent reinnervation after debridement wounds and will give us insight into how MMC enhances reinnervation.

角膜表面的损伤是痛苦的，并使眼睛暴露在可能破坏视力的感染中。在我们的 在之前的资助期，我们描述了一个用于研究小鼠和 显示在侵蚀形成之前，基底下神经(SBN)不能重新支配角膜。此外，我们 显示我们可以通过用丝裂霉素C治疗角膜清创损伤来诱导SBN的再支配 (MMC)。我们研究的长期目标是确定阻止角膜上皮细胞生长的因素 重建创伤后完整稳定的屏障。其中一个因素是SBN的神经再支配失败。我们的数据引领着我们 提出两个假设。第一个(目标A)是角膜上皮基底层细胞黏附、保护、 组织和维护起源于三叉神经节的基础下神经(SBN)。角膜 上皮细胞通过分泌富含层粘连蛋白的细胞外基质来保护单个SBN，使它们相互隔离， 通过将几个SBN的簇包围在其基细胞和基侧细胞的内折内来组织SBN 形成上皮细胞的膜：轴突粘连，并通过去除受损的SBN来维持最佳的SBN功能 SBN在动态平衡和损伤后通过吞噬形成的短桩。我们将通过以下方式验证这一假设： 实验回答了以下问题：1.角膜上皮细胞是否附着并提供支持 使用与非髓鞘雪旺细胞相似的黏附复合体和蛋白质的SBN？2.做 在动态平衡和对SBN损伤的反应中，角膜上皮细胞吞噬轴突碎片？3。 角膜上皮细胞通过改变调控轴突的基因表达而对SBN失神经作出反应 雪旺细胞的再生？提出的第二个假说(目标B)是解决术后角膜病理。 创伤或疾病，角膜上皮细胞、SBN和基底膜之间的粘连必须 恢复到病理学发展之前的水平。这一假设得到了 初步数据显示，MMC减少了角膜上皮细胞的体外迁移和MMP9的表达 活着。我们将通过实验来验证这一假设，以回答以下问题：1.做角膜 损伤小鼠角膜中央的上皮细胞经历衰老？2.再神经是否可以 用丝裂霉素治疗(仅限环钻)损伤的角膜加速？3.术后能消除腐蚀物吗？ 它们是通过用MMC处理小鼠角膜而形成的。4.MMC能否促进小鼠角膜的神经再生 干眼病？5.先前的损伤(条件性损伤)能改善挤压或清创后的神经再支配吗 伤口？比较不同创伤类型后的再神经支配，可以区分不同的机制 允许在挤压伤后再神经再生，而不是在清创伤口后阻止神经再支配 并将使我们深入了解MMC如何增强神经再支配。