Effects of modified erythropoietin on cognition and neuropathology

对记忆的有效评估可能是创作一部小说的最重要的组成部分 阿尔茨海默氏症的治疗。然而，记忆只是行为障碍中的一种 阿尔茨海默氏症患者表现出。他们也有情感和感觉运动缺陷，以及社交问题 行为。与其他过度表达APP的小鼠不同，5xFAD转基因小鼠通过以下方式表现出强大的神经变性 9个月大。像其他阿尔茨海默病模型一样，它们在空间测试中表现出严重的认知缺陷 学习和记忆。然而，5xFAD小鼠表现出许多其他行为异常。例如, 与野鼠一样，它们对笼友表现出更多的社交行为，但不会表现出 某些品系的实验小鼠包括野生型小鼠的理发现象 紧张。尽管已发表的报告显示，5xFAD小鼠在加号迷宫的张开双臂上花费的时间更多， 焦虑减少的迹象，我们已经表明这可归因于习惯性和 第四层胡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 先前研究表明，突变的非促红细胞生成素(EPO)对急性髓细胞白血病模型有神经保护作用。 青光眼、黄斑变性和MPTP神经毒性，无红细胞压积升高。这种改装的EPO， EpoR76E是由重组腺相关病毒(RAAV)载体注射到 腓肠肌(腿)肌肉。我们的初步数据显示，淀粉样斑块几乎完全清除。 在12个月大的5xFAD转基因婴儿肌肉注射rAAV.EpoR76E几个月后， 开始时大脑皮质和海马区有广泛的斑块。此应用程序的目标是确定 RAAV.EpoR76E是否具有神经保护作用并能预防或逆转认知功能障碍和异常 5xFAD小鼠表现出社会行为。拟议研究的一般假设是，欧洲专利局 VARIANT将成功减少斑块形成，防止神经变性和记忆障碍 突变的小鼠。我们还期望5xFAD小鼠的社会行为表型能够正常化 RAAV.EpoR76E，基于预期它是神经退行性变的影响。在拟议的实验中， 小鼠在4或13个月龄时注射EpoR76E或rAAV.eGFP对照载体。社会行为 并将评估记忆，以及焦虑和感觉运动功能的控制测试。验尸报告 分析将评估与阿尔茨海默氏症相关的神经病理和细胞死亡。最后，我们将检查已知的因素 参与β的生产和批准，如BACE1、IDE和奈普利辛，以确定 β被rAAV.EpoR76E从5xFAD大脑中清除的原因。细胞培养在原代神经元中发挥作用 从5xFAD和野生型小鼠将决定突变的EPO结构如何影响APP的处理。 成功地减少转基因小鼠的淀粉样蛋白负荷、细胞死亡和记忆损伤可能 提供对可以减少或预防阿尔茨海默病患者痴呆的新治疗策略的洞察。

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.