Sphingolipids and their Impact in Corneal Wound Healing

鞘脂及其对角膜伤口愈合的影响

基本信息

批准号：
10298908
负责人：
Dimitrios Karamichos
金额：
$ 6.15万
依托单位：
UNIVERSITY OF TENNESSEE HEALTH SCI CTR
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-07-01 至 2021-11-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10298908
关键词：
3-Dimensional Affect Animals Area Attention Blindness Cell Culture Techniques Ceramides Cicatrix Clinical Management Complex Cornea Corneal Diseases Corneal Injury Corneal Opacity Corneal dystrophy Data Development Disease Economics Enzymes Extracellular Matrix Feedback Fibroblasts Fibrosis Future G-Protein-Coupled Receptors GTP-Binding Protein alpha Subunits, Gs Genetic Transcription Growth Factor Human In Vitro Infection Injury Investigation Keratoconus Keratoplasty Knock-out Knockout Mice Knowledge Liver Fibrosis Mediating Mediator of activation protein Metabolism Modeling Mus Myofibroblast Operative Surgical Procedures Outcome Pathologic Pathway interactions Patients Pharmaceutical Preparations Phenotype Process Protein Isoforms Pulmonary Fibrosis Research Role SPHK1 enzyme Signal Pathway Signal Transduction Signaling Protein Site Sphingolipids Sphingosine-1-Phosphate Receptor Stromal Cells Testing Therapeutic Tissues Transcriptional Activation Transforming Growth Factor beta Receptors Transforming Growth Factors Trauma United States National Institutes of Health Up-Regulation Visual Acuity Wild Type Mouse base chemokine clinically significant corneal epithelial wound healing corneal scar coronary fibrosis cytokine design effective therapy experimental study fibrogenesis human disease human model in vitro Model in vivo in vivo Model inhibitor/antagonist migration new therapeutic target novel prevent receptor response small molecule inhibitor sphingosine 1-phosphate therapeutic development therapeutic evaluation three-dimensional modeling treatment strategy wound healing

项目摘要

Up to one fourth of all cases of blindness worldwide are attributable to corneal opacities generated by scarring, or fibrosis, representing a huge economic and societal burden. No effective therapies for corneal fibrosis have been developed and the most reliable treatment option is corneal transplantation, which has numerous limitations/ and complications, including post-surgical corneal fibrosis. Corneal fibrosis is characterized by the formation of corneal scars from over-accumulation of disorganized extracellular matrix (ECM) produced by fibroblasts and myofibroblasts after they are activated by injury or infection. The corneal wound-healing, as well as the process of fibrosis, is driven by multiple complex pathways involving many cytokines, growth factors, and chemokines, which are not completely understood. The lack of knowledge regarding this process is a critical barrier to developing new treatment strategies to minimize scarring and retain or restore corneal transparency. Our recent advances, with the aid of an NIH/NEI R21 (EY025256), have led us to discover a novel potential mechanism that combines sphingolipid (SPL) signaling with classical transforming growth factor-β (TGF-β) pathways to mediate corneal fibrosis via activation/differentiation of keratocytes into myofibroblasts. We have also demonstrated that SPL metabolism is altered in “injured” corneal stromal cells, and that stimulation of healthy corneal stromal cells with Sphingosine 1-Phosphate (S1P), a bioactive SPL, induces TGF-β1 expression and fibrosis, signaling through the S1P receptor 3 (S1P3). Furthermore, we found that TGF-β isoforms can increase S1P3 signaling by increasing expression of Sphingosine kinase 1 (SPHK1; an enzyme that synthesizes S1P) and S1P3. Based on these discoveries, we hypothesize that S1P is a key mediator of corneal fibrosis via activation of TGF-β, and TGF-β in turn induces expression of S1P signaling proteins and thus forms a positive feedback loop which drives irreversible activation of corneal fibroblasts and differentiation to myofibroblasts. The proposed studies are designed to clearly define the key players in these pathways and delineate how they interact in the context of corneal fibrosis using our in vitro 2D and 3D models of human and mouse corneal stromal cells (Aim 1); and in vivo models of corneal wound healing in wild type, Sphk1, and S1P3 knockout mice, along with testing the therapeutic potential of targeting S1P and TGF-β signaling using selective inhibitors in these models (Aim 2). The role of S1P in corneal fibrosis has not received substantial attention and we are currently the only group pursuing SPL-based processes as part of the potential mechanism. If successful, the results from the proposed studies could have far-reaching scientific and clinical significance, as the understanding of corneal fibrotic mechanisms and the role of S1P as an important mediator would not only be important for clinical management/treatment of corneal fibrosis, but could also be applicable to many diseases in which fibrosis is a major pathological outcome, such as liver, lung, and cardiac fibrosis.

全球失明病例中多达四分之一是由于角膜混浊造成的疤痕或纤维化，代表着巨大的经济和社会负担没有有效的角膜治疗方法。纤维化已经发展，最可靠的治疗选择是角膜移植，角膜纤维化有许多局限性/并发症，包括术后角膜纤维化。其特征是由于杂乱的细胞外基质过度积累而形成角膜疤痕 (ECM) 由成纤维细胞和肌成纤维细胞因损伤或感染而激活后产生。伤口愈合以及纤维化过程是由涉及许多因素的多种复杂途径驱动的细胞因子、生长因子和趋化因子，目前尚不完全了解。关于这一过程是开发新的治疗策略以最大程度地减少疤痕并保留疤痕的关键障碍或恢复角膜透明度，我们最近在 NIH/NEI R21 (EY025256) 的帮助下取得了进展。发现一种将鞘脂 (SPL) 信号传导与经典转化相结合的新型潜在机制生长因子-β (TGF-β) 途径通过角膜细胞的激活/分化介导角膜纤维化我们还证明，“受伤”的角膜基质细胞的 SPL 代谢发生了改变，使用 1-磷酸鞘氨醇 (S1P)（一种生物活性 SPL）刺激健康的角膜基质细胞，通过 S1P 受体 3 (S1P3) 信号传导，诱导 TGF-β1 表达和纤维化。此外，我们发现。 TGF-β 同种型可以通过增加鞘氨醇激酶 1 (SPHK1；SPHK1；基于这些发现，我们发现 S1P 是一个关键。通过激活 TGF-β 介导角膜纤维化，而 TGF-β 反过来诱导 S1P 信号传导的表达蛋白质，从而形成一个正反馈循环，驱动角膜成纤维细胞的不可逆激活拟议的研究旨在明确定义这些细胞的关键参与者。使用我们的体外 2D 和 3D 模型描述它们在角膜纤维化背景下如何相互作用人类和小鼠角膜基质细胞（目标 1）；以及野生型角膜伤口愈合的体内模型， Sphk1 和 S1P3 敲除小鼠，以及测试针对 S1P 和 TGF-β 的治疗潜力在这些模型中使用选择性抑制剂进行信号传导（目标 2）。S1P 在角膜纤维化中的作用尚未得到证实。受到极大的关注，我们是目前唯一一个追求基于 SPL 的流程作为潜力的一部分的团队如果成功，拟议研究的结果可能具有深远的科学和临床意义。意义，作为了解角膜纤维化机制和 S1P 作为重要介质的作用不仅对角膜纤维化的临床管理/治疗很重要，而且也适用许多以纤维化为主要病理结果的疾病，例如肝纤维化、肺纤维化和心脏纤维化。