Oxidative stress and innate immunity impair the visual cycle

项目摘要 老年性黄斑变性(AMD)是导致老年人失明的主要原因。目前，没有 任何形式的AMD都可以通过治疗恢复视力。为了解决这一缺陷，这项提案将重点放在 可以恢复视力的机制。11顺式视网膜(11-CRAL)的视觉循环是一种RPE 对视力至关重要的功能。而氧化应激和补体是AMD不可或缺的因素 病理生理学方面，它们对视觉周期的影响尚不明确。这项提案的目标是定义如何 氧化应激和先天免疫损害了AMD的视觉周期，从而降低了视力。假设是 测试表明，氧化应激和受损的补体调节因子CFH和CD46会降低视觉周期 网络。提出的具体目标是：1.确定氧化应激I)损害CFH诱导的程度 减少视觉周期基因表达的炎症，以及ii)诱导Ptx3，并通过调节CFH 丰富，防止视觉周期下降。这一目标将测试CFH降低所产生的程度 通过增加补体或丙二醛介导的细胞因子表达来激活STAT3的炎症，这是 减少视觉周期基因的表达、功能和视力，以及Ptx3对CFH丰度的影响 调节CFH介导的炎症反应。2.确定慢性氧化应激对视力的损害程度 循环通过Notch信令。氧化应激激活Notch信号，从而诱导转录 因子Sox9控制由6个视觉周期基因组成的网络的表达。而急性Notch信号 增加Sox9，慢性Notch信令降低Sox9。这一目标将探索慢性氧化的程度 应激激活Notch信号，以及Notch如何通过Sox9影响视觉周期功能。3.确定 CD46对Notch信号和Sox9介导的视觉周期基因功能的调节程度。除了它的 作为调节作用的补充，CD46结合Jag1来阻碍Notch信号转导。因此，CD46的减少使 Jag1可用于激活Notch信令作为替代的非补体功能。这一目标将探索 CD46的降低通过Jag1影响Notch信号和视周期功能的程度。由于CD46是 不在体细胞中表达，我们将使用具有关键CD46结构域突变的iPS RPE细胞来 实现这一目标。这些贡献是重要的，因为如果成功，新的途径将被确定为 治疗老年性黄斑变性视力丧失的目标。这项研究是创新的，因为我们将调查未被研究的领域 包括氧化应激和先天免疫的协同影响导致视力丧失的机制， STAT3、Notch和Sox9的作用以及补体调节因子的非常规、非补体功能 视觉周期使用独特的、最先进的遗传小鼠，具有新鲜但决定性的因素，尚未 以前测试过的。靶向治疗中和了降低视觉周期基因表达的途径， 这项工作预计将产生氧化应激和过度活跃的先天免疫的视觉功能。

Project Summary Age-related macular degeneration (AMD) is the leading cause of blindness among the elderly. At present, no therapy will restore vision with any form of AMD. To address this shortcoming, this proposal will focus on mechanisms that could restore vision. The recycling of 11-cis-retinal (11-cRAL) by the visual cycle is an RPE function that is essential for vision. While oxidative stress and complement are integral factors in AMD pathophysiology, their impact on the visual cycle is undefined. The objective of this proposal is to define how oxidative stress and innate immunity impair the visual cycle to decrease vision in AMD. The hypothesis to be tested is that oxidative stress and impaired complement regulators Cfh and CD46 decrease the visual cycle network. The proposed specific aims are: 1. Determine the extent that oxidative stress i) impairs Cfh to induce inflammation which decreases visual cycle gene expression, and ii) induces Ptx3, and by regulating Cfh abundance, prevents visual cycle decline. This aim will test the extent that decreased Cfh generates inflammation from increased complement or MDA mediated cytokine expression to activate Stat3, which decreases visual cycle gene expression, function, and vision, and the impact of Ptx3 on Cfh abundance to regulate Cfh mediated inflammation. 2. Determine the extent that chronic oxidative stress impairs the visual cycle through Notch signaling. Oxidative stress activates Notch signaling, which can induce the transcription factor Sox9 to control the expression of a network of 6 visual cycle genes. While acute Notch signaling increases Sox9, chronic Notch signaling decreases Sox9. This aim will explore the extent that chronic oxidative stress activates Notch signaling, and how Notch influences visual cycle function through Sox9. 3. Determine the extent that CD46 regulates Notch signaling and Sox9 mediated visual cycle gene function. Besides its complement regulatory action, CD46 binds Jag1 to impede Notch signaling. Thus, decreased CD46 makes Jag1 available to activate Notch signaling as an alternative, non-complement function. This aim will explore the extent that decreased CD46 influences Notch signaling and visual cycle function through Jag1. Since CD46 is not expressed in somatic rodent cells, we will use iPS RPE cells with mutations in key CD46 domains to address this aim. These contributions are significant because if successful, novel pathways will be identified as targets to treat vision loss in AMD. The research is innovative since we will investigate understudied areas including mechanisms of vision loss from the synergistic impact of oxidative stress and innate immunity, the role of Stat3, Notch, and Sox9, and unconventional, non-complement functions of complement regulators on the visual cycle using unique, state-of-the-art genetic mice with fresh, but decisive factors that have not been previously tested. Targeted therapy that neutralizes pathways that degrade visual cycle gene expression, function, and vision from oxidative stress and overactive innate immunity is expected to result from this work.