Effects of modified erythropoietin on cognition and neuropathology

对记忆的有效评估也许是奋进发展一部小说的最重要组成部分 阿尔茨海默病的治疗方法然而，记忆只是行为障碍之一， 老年痴呆症患者的展览。他们也有情感和感觉运动缺陷，以及社交问题。 行为与其他APP过表达小鼠不同，5xFAD转基因小鼠表现出强烈的神经变性， 9个月大。与其他阿尔茨海默病模型一样，他们在空间认知测试中表现出严重的认知缺陷。 学习和记忆。然而，5xFAD小鼠显示出许多其他行为异常。比如说， 它们对笼友表现出更多的社会行为，就像野生型小鼠一样，但不表现出 某些品系的实验室小鼠（包括其野生型）特有的毛发生长现象 株尽管已发表的报告显示，5xFAD小鼠在十字迷宫的开放臂上花费更多时间， 表明焦虑减少，我们已经表明，这是归因于受损的习惯， IV层须桶中抑制性中间神经元的退化（即，使闭合的手臂令人厌恶）。我们有 先前表明，突变的非促红细胞生成素（Epo）在模型中具有神经保护作用， 青光眼、黄斑变性和MPTP神经毒性，而不升高红细胞压积。这种改良的促红细胞生成素 EpoR76 E通过将重组腺相关病毒（rAAV）载体注射到EpoR76 E中无限产生。 腓肠肌（腿部）肌肉。我们的初步数据显示，淀粉样斑块几乎完全清除2 在单次肌内注射rAAV.EpoR76E后3个月，在12个月大的5xFAD转基因动物中， 一开始是大脑皮层和海马体出现大量斑块本申请的目的是确定 rAAV.EpoR76E是否具有神经保护作用，是否能够预防或逆转认知缺陷和异常 5xFAD小鼠表现出的社会行为。这项研究的一般假设是， 变异将成功地减少斑块的形成，防止神经退行性变和记忆障碍， 突变小鼠我们还期望在接受了以下治疗的5xFAD小鼠中社会行为表型正常化： rAAV.EpoR76E，预期它是神经变性的作用。在拟议的实验中， 在4或13月龄时给小鼠注射EpoR76E或rAAV.eGFP对照构建体。社会行为 和记忆力，以及焦虑和感觉运动功能的控制测试。验尸 分析将评估阿尔茨海默病相关的神经病理学和细胞死亡。最后，我们将研究已知的因素， 参与Aβ的产生和清除，如BACE1、IDE和脑啡肽酶，以确定 Aβ被rAAV.EpoR76E从5xFAD脑中清除的原因。原代神经元的细胞培养工作 将确定突变Epo构建体如何影响APP加工。 成功地减少转基因小鼠的淀粉样蛋白负荷、细胞死亡和记忆障碍， 提供了新的治疗策略，可以减少或预防阿尔茨海默病患者的痴呆症的见解。

A valid assessment of memory is perhaps the most important component of an endeavor to develop a novel treatment for Alzheimer's disease. However, memory is only one of the behavioral impairments that Alzheimer's patients exhibit. They also have affective and sensorimotor deficits, and problems with social behavior. Unlike other APP-overexpressing mice, the 5xFAD transgenics exhibit robust neurodegeneration by 9 months of age. Like other Alzheimer models, they exhibit profound cognitive deficits on tests of spatial learning and memory. However, the 5xFAD mice show a host of other behavioral anomalies. For example, they exhibit much more social behavior toward their cage-mates as do wild-type mice, but do not exhibit the barbering phenomenon characteristic of some strains of laboratory mice, including wild-types of the same strain. Although published reports show that 5xFAD mice spend more time on open arms of a plus maze, indicative of decreased anxiety, we have shown that this is attributable to impaired habituation and degeneration of inhibitory interneurons in layer IV whisker barrels (i.e., making closed arms aversive). We have shown previously that a mutant, non-erythropoietic erythropoietin (Epo) is neuroprotective in models of glaucoma, macular degeneration, and MPTP neurotoxicity, without raising hematocrit. This modified Epo, EpoR76E, is generated indefinitely by a recombinant adeno-associated viral (rAAV) vector injected into the gastrocnemius (leg) muscle. Our preliminary data show that amyloid plaque is nearly completely cleared 2 months after a single intramuscular injection of rAAV.EpoR76E, in 12-month-old 5xFAD transgenics that started with extensive plaque in the cortex and hippocampus. The objective of this application is to determine whether rAAV.EpoR76E is neuroprotective and able to prevent or reverse the cognitive deficits and abnormal social behaviors exhibited by 5xFAD mice. The general hypothesis of the proposed research is that the Epo variant will successfully reduce plaque formation and prevent neurodegeneration and memory impairments in the mutant mice. We also expect the social behavior phenotype to be normalized in 5xFAD mice receiving rAAV.EpoR76E, on the expectation that it is an effect of neurodegeneration. In the proposed experiments, mice will be injected at 4 or 13 months of age with EpoR76E or rAAV.eGFP control construct. Social behavior and memory will be assessed, as well as control tests for anxiety and sensorimotor function. Post-mortem analyses will assess Alzheimer-related neuropathology and cell death. Finally, we will examine factors known to be involved in the production and clearance of Aβ, such as BACE1, IDE, and neprilysin, to determine the reason why Aβ is being cleared from 5xFAD brain by rAAV.EpoR76E. Cell culture work in primary neurons from 5xFAD and wild-type mice will determine how the mutant Epo construct affects APP processing. Successfully reducing amyloid burden, cell death, and memory impairments in the transgenic mice may provide insight into new treatment strategies that could reduce or prevent dementia in Alzheimer patients.