BETA AMYLOID-INDUCED RNA OXIDATION AS A MEDIATOR OF AD PATHOGENESIS

阿尔茨海默病(AD)是美国和我们人口的主要健康问题之一 随着年龄的增长，它将变得更加突出，除非找到治疗或预防措施。了解 阿尔茨海默病选择性神经元变性的发病机制是确定预防或治疗的关键 措施。有越来越多的知识表明自由基介导的氧化 损伤参与了AD的发病机制。我们最近的研究证明了显著的氧化 遗忘性轻度认知障碍最早对脑脂类、蛋白质、DMA和RNA的损害 AD的可检测阶段，表明氧化损伤是AD的早期事件，而不是继发性的 神经退行性变。这一建议的主要假设是，AD早期的RNA氧化是在 部分是由促进蛋白质合成障碍和神经元功能障碍的淀粉样β蛋白(AP)引起的。在……里面 特定的目标1和2，我们将量化在神经元中的RNA氧化和醛修饰 AD从正常到MCI再到晚期AD(LAD)的进展，以及APP/PS1敲入转基因小鼠的进展 使用免疫组织化学、共聚焦显微镜和抗8-OHG、丙烯醛/鸟嘌呤抗体的时间 加合物和MC-1。在正常对照组、疾病对照组(额颞区)的相同脑区 痴呆)，MCI和LAD，以及来自APP/PS-1小鼠的脑标本，我们将量化 用GC-MS-SIM和丙烯醛修饰的鸟嘌呤在这些池中纯化rRNA、tRNA和mRNA池中使用 LC-MS-MS在具体目标3中，我们将确定核心B的有毒和无毒AP的能力，以定义 培养神经元中的RNA氧化和丙烯醛/鸟嘌呤加合物及其与RNA氧化的比较 在体内观察到的特定目标1和2。在特定目标4中，我们将确定单个mRNAs 在体外对AP反应的氧化也在对照组和MCI、LAD和MCI的大脑中被氧化 额颞部痴呆患者。然后我们将确定预测的蛋白质是否由 氧化的mRNAs在从正常到MCI再到LAD的过程中表现出表达和功能的降低。 特定目标5将确定组蛋白脱乙酰酶抑制剂减轻AP诱导的神经毒性的能力 在体外和在APP/PS1转基因小鼠中。我们有所有具体目标的初步数据表明 这些研究的可行性。通过以公正的方式进行这些研究，并允许神经元 和脑标本来指导我们，我们将定义AP如何促进AD中的神经元功能障碍。这项研究有 识别分子靶点的潜力，用于开发旨在减少神经元的治疗药物 损害和减缓AD的进展或潜在地预防AD。

Alzheimer's disease (AD) is one of the major health problems in the United States and as our population ages it will become more prominent unless measures to treat or prevent it are found. Understanding the pathogenesis of selective neuron degeneration in AD is the key to defining preventive or therapeutic measures. There is a rapidly increasing body of knowledge that indicates free radical-mediated oxidative damage is involved in the pathogenesis of AD. Our recent studies have demonstrated significant oxidative damage to brain lipids, proteins, DMA, and RNA in amnestic mild cognitive impairment, the earliest detectable phase of AD, indicating that oxidative damage is an early event in AD and not secondary to neurodegeneration. The major hypothesis of this proposal is that RNA oxidation in early AD is mediated in part by amyloid-beta peptide (AP) that promotes impairment of protein synthesis and neuron dysfunction. In Specific Aims 1 and 2, we will quantify RNA oxidation and aldehydic modifications in neurons in the progression of AD from normal to MCI to late AD (LAD), and in the APP/PS1 knock-in transgenic mice over time using immunohistochemistry, confocal microscopy, and antibodies against 8-OHG, acrolein/guanine adducts, and MC-1. In the same brain regions of normal controls, disease controls (frontotemporal dementia), MCI and LAD, and brain specimens from APP/PS-1 mice, we will quantify RNA oxidation in purified pools of rRNA, tRNA, and mRNA by GC-MS-SIM and acrolein-modified guanine in these pools using LC-MS-MS. In Specific Aim 3, we will determine the ability of toxic and non-toxic Ap from Core B to define RNA oxidation and acrolein/guanine adducts in cultured neurons and compare this with the RNA oxidation observed in vivo in Specific Aims 1 and 2. In Specific Aim 4, we will determine if the individual mRNAs oxidized in response to Ap in vitro are also oxidized in the brains of control subjects and MCI, LAD, and frontotemporal dementia patients. We will then determine whether the predicted proteins encoded by the oxidized mRNAs exhibit decreased expression and function in the progression from normal to MCI to LAD. Specific Aim 5 will define the ability of histone deacetylase inhibitors to ameliorate Ap-induced neurotoxicity in vitro and in the APP/PS1 transgenic mice. We have preliminary data in all specific aims indicating the feasibility of these studies. By conducting these studies in an unbiased manner and allowing the neurons and brain specimens to guide us, we will define how Ap promotes neuron dysfunction in AD. This study has the potential of identifying molecular targets for development of therapeutic agents aimed at reducing neuron injury and slowing the progression of or potentially preventing AD.