Birth and Death of Choriocapillaris.

脉络膜毛细血管的出生和死亡。

• 批准号: 8290655
• 负责人: Gerard Anthony Lutty
• 金额: $ 48.84万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-09-01 至 2017-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8290655
• 关键词: Affect; Age; Albumins; Architecture; Birth; Blood Vessels; Blood capillaries; Bruch' s basal membrane structure; Cause of Death; Caveolae; Cell Death; Cessation of life; Charge; Choroid; Chronology; Collection; Defect; Deposition; Development; Drusen; Endothelial Cells; Epithelial; Excision; Exudative age-related macular degeneration; Eye; Functional disorder; Gold; Grant; Human; In Vitro; Knock-out; Knowledge; Label; Lipids; Lipoproteins; Lobular; Manuscripts; Membrane; Mus; Nonexudative age-related macular degeneration; Nutrient; Oxygen; Photoreceptors; Positioning Attribute; Property; Proteins; Publishing; Respiratory Diaphragm; Retina; Retinal; Retinal Degeneration; Serum; Serum Proteins; Side; Specimen; Structure of retinal pigment epithelium; System; Therapeutic; Third Pregnancy Trimester; Tight Junctions; Time; Toxic effect; Transmission Electron Microscopy; Transport Process; Up-Regulation; Vascular Endothelial Growth Factors; aged; alpha 2-Glucoproteins; capillary; caveolin 1; coated pit; cohort; crosslink; cytotoxic; glycation; in vivo; macromolecule; monolayer; nanoparticle; neovascular; prevent; vasculogenesis; wasting

DESCRIPTION (provided by applicant): The choriocapillaris (CC) is a lobular, fenestrated vasculature that provides all of the oxygen and serum nutrients to the RPE and photoreceptors. We have elaborated the birth of human CC by hemo-vasculogenesis and the death of CC in wet and dry AMD in the last grant period. In dry AMD, CC cell death is related to loss of adjacent RPE. In wet AMD, loss of CC occurs in advance of choroidal neovascular membrane (CNV) formation, which is unexplained to date. We have observed high concentrations of serum proteins around CC in dry and wet AMD. The reason for this accumulation and influence of these proteins on CC is unknown. Although it is assumed that CC provides the nutrients for RPE and photoreceptors and removes waste, the exact mechanisms of transport are unknown. The proposed studies will characterize CC's normal transport mechanisms via fenestrations, caveolae, and coated pits. These mechanisms will be evaluated using gold nanoparticles of defined sizes, tagged serum proteins, and tagged serum lipids. We will determine if dysregulation in CC transport affects protein accumulation by using mice lacking caveolae (knock out cav-1, the major component in the caveolae system), or fenestrations (RPE-produced VEGF knocked out or neutralized), or mice with RPE over expressing VEGF, or producing basal laminar deposits. The proposed studies will determine the effects of Bruchs membrane deposits on CC transport and the effects of CC transport defects on deposit formation. We hypothesize that dysfunction in CC transport results in the serum protein accumulation in choroid we observe, which is toxic to CC and may be the reason that CC die in AMD. We will evaluate the toxicity of serum proteins (albumin, CRP, and alpha-2 macroglobulin with and without glycation) on choroidal endothelial cells (CEC) in vitro and determine if those serum proteins cause loss of tight junctions, changes in numbers of caveolae or fenestrations in CEC. It is also assumed that CC dysfunction is involved in AMD. Our preliminary studies demonstrated that loss in fenestrations is associated with Bruchs membrane deposits and RPE loss. In a large collection of AMD eyes that Greg Hageman has prepared for TEM, we will determine if CC fenestrations, caveolae, coated pits and/or tight junctions change in human AMD and the association of basal deposits, drusen, and RPE loss with these changes. In conclusion, this proposal will define the normal transport processes used by CC to supply nutrients to retina. We will also determine if these transport processes are altered in AMD. We will determine if serum proteins that accumulate with age in choroid contribute to dysfunction in CC transport and the death of CC we have observed in AMD. We will investigate how reduced or elevated VEGF changes CC transport. This new knowledge of CC transport and how it changes in AMD will be invaluable in developing new systemic therapeutic nanoparticles for preventing retinal degeneration and CNV that occurs in AMD. PUBLIC HEALTH RELEVANCE: This study will determine how the choriocapillaris (CC) transports nutrients to retinal pigment epithelium (RPE) and photoreceptors and if the CC transport systems are dysregulated in the presence of too little or too much VEGF. This will be accomplished in mice using uniform size and charge gold nanoparticles, and labeled albumin and lipoprotein to evaluate caveolae, fenestrations, coated pits, and tight junction. CC transport will also be evaluated in mice lacking fenestrations and caveolae, or with deposits on Bruch's membrane. These results will be compared to transmission electron microscopy of a well-characterized cohort of AMD and aged subjects. These studies will determine mechanisms of CC transport and how they are affected in AMD, both of which are unknown.

描述（由申请人提供）：脉络膜毛细血管（CC）是一种小叶，染色的脉管系统，可为RPE和感光体提供所有氧气和血清营养素。我们已经通过血流生成详细阐述了人CC的诞生，以及在最后一个赠款期间湿和干燥AMD中CC的死亡。在干燥AMD中，CC细胞死亡与相邻RPE的丧失有关。在湿AMD中，CC的丧失发生在脉络膜新生血管膜（CNV）形成之前，迄今为止无法解释。我们已经观察到干燥和湿AMD中CC周围的高浓度血清蛋白。这些蛋白质对CC的积累和影响的原因尚不清楚。 尽管假定CC为RPE和感光器提供了营养并消除废物，但运输的确切机制却未知。拟议的研究将通过Fenestrations，Caveolae和涂层坑来表征CC的正常运输机制。这些机制将使用定义大小，标记的血清蛋白和标记的血清脂质的金纳米颗粒进行评估。我们将通过使用缺少小鼠（敲除CAV-1，Cave-1，Caveolae系统中的主要成分）或Fenestrations（RPE生产的VEGF敲除或中和）或用RPE在表达VEGGF或生产蔬菜的底层层层的载体（RPE）或鼠标中。拟议的研究将确定BRUCHS膜沉积物对CC运输的影响以及CC转运缺陷对沉积形成的影响。 我们假设CC转运中的功能障碍会导致我们观察到的脉络膜中血清蛋白的积累，这对CC有毒，可能是CC在AMD中死亡的原因。我们将在体外评估血清蛋白（白蛋白，CRP和Alpha-2型大球蛋白）对脉络膜内皮细胞（CEC）的体外评估，并确定这些血清蛋白是否会导致紧密连接的损失，CEC中的Caveolae或Caveolae或Fenestrations的变化。还假定CC功能障碍参与AMD。我们的初步研究表明，Fenrestration的损失与Bruchs膜沉积物和RPE损失有关。在格雷格·哈格曼（Greg Hageman）为TEM准备的大量AMD眼中，我们将确定人类AMD的CC，Caveolae，Caveolae，涂层坑和/或紧密连接的变化以及基础沉积物，DRUSEN和RPE损失的关联。 总之，该提案将定义CC用来向视网膜供应营养的正常运输过程。我们还将确定这些运输过程是否在AMD中发生了变化。我们将确定随着脉络膜年龄而积聚的血清蛋白是否导致CC转运的功能障碍以及我们在AMD中观察到的CC死亡。我们将调查VEGF减少或升高如何改变CC运输。对于CC运输及其在AMD中的变化的新知识对于开发新的系统性治疗纳米颗粒将是无价的，以防止AMD中发生的视网膜变性和CNV。 公共卫生相关性：这项研究将确定绒毛膜毛细血管（CC）如何将养分运输到视网膜色素上皮（RPE）和感光体上，以及在太少或太多VEGF的情况下，CC传输系统是否失调。这将在使用均匀尺寸和电荷金纳米颗粒的小鼠中完成，并标记为白蛋白和脂蛋白，以评估小窝，燃料，涂层，涂层坑和紧密连接。还将评估缺乏燃烧和小窝的小鼠或Bruch膜上的沉积物中的CC运输。这些结果将与特征良好的AMD和老年受试者的透射电子显微镜进行比较。这些研究将确定CC运输的机制以及它们在AMD中的影响，这两者都是未知的。