Birth and Death of Choriocapillaris.

项目摘要： 脉络膜毛细血管（CC）是一个小叶，有孔的脉管系统，提供所有的氧气和血清 视网膜色素上皮和感光细胞的营养物质。我们已经阐述了人类CC的诞生通过血液血管发生 以及在上一个资助期内，CC因湿性和干性AMD死亡。在干性AMD中，CC细胞死亡与损失有关。 相邻的RPE。在湿性AMD中，CC的丧失发生在脉络膜新生血管膜（CNV）之前。 形成，这是无法解释的日期。我们观察到CC周围的血清蛋白浓度很高 干性和湿性AMD。这种积累的原因和这些蛋白质对CC的影响尚不清楚。 虽然认为CC为RPE和光感受器提供营养并去除废物， 确切的运输机制尚不清楚。拟议的研究将描述CC的正常运输 机制通过开窗，小窝，和涂层坑。这些机制将使用黄金进行评估 确定尺寸的纳米颗粒、标记的血清蛋白和标记的血清脂质。我们将确定是否 CC转运的失调通过使用缺乏小窝的小鼠（敲除cav-1， 小窝系统中的主要成分）或开窗（RPE产生的VEGF敲除或 中和的），或RPE过表达VEGF或产生基底层沉积物的小鼠。拟议 研究将确定Bruchs膜沉积物对CC转运的影响以及CC 存款形成的运输缺陷。 我们推测CC转运功能障碍导致脉络膜中的血清蛋白积聚 我们观察到，这是有毒的CC，可能是原因，CC死亡的AMD。我们将评估 脉络膜内皮细胞上的血清蛋白（白蛋白、CRP和α-2巨球蛋白，伴和不伴糖化） 细胞（CEC），并确定这些血清蛋白是否会导致紧密连接的丧失， CEC中的小窝或开窗。还假设CC功能障碍涉及AMD。我们的初步 研究表明开窗的损失与Bruchs膜沉积和RPE损失有关。在 Greg Hageman为TEM准备的大量AMD眼睛，我们将确定CC是否 人AMD中的开窗、小窝、被膜凹陷和/或紧密连接的变化以及基底膜的相关性。 视网膜色素沉着、玻璃疣和RPE损失。 总之，本提案将确定CC用于向以下区域提供营养物质的正常运输过程： 视网膜。我们还将确定这些运输过程是否在AMD中改变。我们将确定血清是否 随着年龄的增长，脉络膜中积累的蛋白质导致CC转运功能障碍和CC死亡， 在AMD中观察到。我们将研究如何减少或升高VEGF改变CC运输。这个新 CC运输的知识以及它在AMD中如何变化将是非常宝贵的，在开发新的系统 用于预防AMD中发生的视网膜变性和CNV的治疗性纳米颗粒。

Project Summary: 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.