Strategies to Control Alternative Pathway Activation in Age-Related Sensory Loss.

项目摘要/摘要 双重感觉丧失被定义为年龄相关性视力丧失的组合，例如年龄相关性黄斑变性- 老年性耳聋(AMD)和年龄相关性听力损失(ARHL)共同发生在65岁以上的人群中。AMD，干的和湿的形式， 和ARHL是多因素疾病，具有相同的病因，如吸烟和补体调节失调。 重要的是，补体替代途径(AP)的扩增环对控制至关重要，因为它是 可自发激活细胞表面和胞外膜上的大部分补体。AP是 被循环补体蛋白因子H(Fh)抑制。补体激活的机制之一是- 天然抗体(NAB)与新的表位或损伤相关的分子模式结合在一起。 老化的组织对损伤的反应。补体效应分子和NAB激活巨噬细胞并 其他免疫细胞，加剧可导致神经退化的炎症状态。两个研究得很好的 融合蛋白CR2-Fh和B4-scFv-Fh将被用来将Fh的抑制结构域靶向组织的部位 损坏。补体受体2(CR2)结构域结合到补体片段沉积部位，并且 单链抗体B4(B4-scFv)结构域与暴露在受损组织上的修饰的膜联蛋白IV结合。两者都有 CR2-Fh和B4-ScFv-Fh在小鼠神经退行性疾病模型中被证明是有效的 当全身给药时，或局部或通过基因治疗用于CR2-FH。有趣的是这个补充物和 湿性AMD模型小鼠视网膜下间隙和耳蜗组织中巨噬细胞活性升高 关于衰老的小鼠。此外，吸烟诱导的促炎、神经退行性AP激活，以及异常 巨噬细胞活动活跃，已见眼部和耳蜗部。基于这些观察，我们假设 载体驱动的CR2-Fh和注射的B4-ScFv-Fh将Fh定位于受损的神经组织，并缓解湿性AMD和 ARHL病理，部分是通过减少巨噬细胞活化，从而减少补体- 巨噬细胞炎症反馈环。我将在两个具体目标上测试这一假设，其结果将 过渡到我的博士后研究。AIM 1将提供C3启动子被调控的概念证据 补体依赖的方式和循环B4-ScFv-Fh定位于受损的耳蜗组织 烟雾暴露的ARHL小鼠。在目标2中，我将测试AAV5-PC3-CR2-Fh和AAV5-PC3-CR2-Fh本地传递的假设 B4-scFv-Fh的耳蜗靶向治疗可减轻AMD的病理改变，预防耳蜗病的发生。 部分是通过减少巨噬细胞的激活。在《目标3》中，作为一名博士后实习生，我渴望在实验室里接受培训-- 研究老化的人类视觉和听觉系统，以扩大我在感官丧失方面的翻译研究。过了- 总之，我这个提议的目的是证明抑制AP在双重感觉丧失中可以改善病理。 部分是通过减少巨噬细胞的激活和减少促炎的微环境。我的长期生活 目标是扩大我在翻译感觉神经科学方面的研究和研究培训。

PROJECT SUMMARY/ABSTRACT Dual sensory loss is defined as a combination of age-related vision loss, e.g., age-related macular degenera- tion (AMD) and age-related hearing loss (ARHL) that co-occurs in people age >65. AMD, dry and wet forms, and ARHL are multifactorial diseases that share etiologies such as smoking and complement dysregulation. Importantly, the amplification loop of the complement alternative pathway (AP) is crucial to control, as it is re- sponsible for the majority of complement activation on cell surfaces and extracellular membranes. The AP is inhibited by circulating complement protein factor H (fH). One of the mechanisms by which complement is acti- vated is natural antibodies (nAbs) binding to neoepitopes, or damage-associated molecular patterns, on dam- aged tissues in response to injury. The complement effector molecules and nAbs activate macrophages and other immune cells, intensifying the inflammatory state that can lead to neurodegeneration. Two well-studied fusion proteins, CR2-fH and B4-scFv-fH, will be used to target the inhibitory domain of fH to sites of tissue damage. The complement receptor 2 (CR2) domain binds to complement fragment deposited sites, and the single chain antibody B4 (B4-scFv) domain binds to modified annexin IV exposed on damaged tissues. Both CR2-fH and B4-scFv-fH have been shown to be efficacious in mouse models of neurodegenerative diseases when administered systemically, or for CR2-fH locally and via gene therapy. Of interest is that complement and macrophage activation are elevated in the subretinal space of wet AMD mouse models and in cochlear tissue of aged mice. In addition, smoke-induced proinflammatory, neurodegenerative AP activation, and abnormal macrophage activity, have been seen the eye and cochlea. Based on these observations, we hypothesize that vector driven CR2-fH and injected B4-scFv-fH localize fH to damaged nerve tissues and mitigate wet AMD and ARHL pathology, in part by reducing macrophage activation, and thereby reducing the complement- macrophage inflammatory feedback loop. I will test this hypothesis in two specific aims, the results of which will transition to my postdoctoral research. Aim 1 will provide proof of concept that the C3 promoter is modulated in a complement-dependent manner and that circulating B4-scFv-fH localizes to damaged cochlear tissue in smoke-exposed ARHL mice. In Aim 2, I will test the hypothesis that local delivery of AAV5-pC3-CR2-fH and cochlear targeting of B4-scFv-fH can mitigate AMD pathology and prevent cochlear damage, respectively, in part by reducing macrophage activation. In Aim 3, as a postdoctoral trainee, I aspire to train in a lab with exper- tise in the aged human visual and auditory systems to expand my translational research in sensory loss. Over- all, my goal for this proposal is to demonstrate that AP inhibition in dual sensory loss can ameliorate pathology in part by reducing macrophage activation and reducing the proinflammatory microenvironment. My long-term goal is to expand my research and research training in translational sensory neuroscience.