Disease-Modifying Effects of Filgastrim in a Mouse Model of AD

摘要/概要 Filgastrim（粒细胞集落刺激因子或G-CSF）是一种多模式造血生长因子 常规用于血液学/肿瘤学环境，但其对脑部疾病的益处的报告 出现在文学中。 我们在阿尔茨海默病（AD）小鼠模型中进行了初步研究， 实验室表明，它具有促进认知和改善疾病的作用。 的机制 对这些深远影响的原因尚不清楚，G-CSF作为治疗剂的开发 对AD患者的治疗需要进行临床前研究。 目的：本研究旨在通过以下方法阐明其细胞和分子机制： G-CSF减少淀粉样蛋白沉积/水平，刺激海马神经发生并恢复 AD小鼠模型中的突触功能活性。 目标1：假设贩运人口活动增加， 从血液到脑的骨髓来源细胞和/或增加的小胶质细胞和吞噬活性， 将在嵌合tg AD小鼠中测试导致β-淀粉样蛋白（A-<$）沉积减少的 其中骨髓来源的细胞表达绿色荧光蛋白（GFP）。 目标2：测试 假设G-CSF的促认知作用是通过对神经祖细胞的直接作用介导的 细胞和神经元，G-CSF促进神经发生和/或促进恢复的程度。 将用神经解剖学和神经病理学方法测试海马突触的功能和结构， 电生理技术。 目标3：在细胞内水平，机制研究将阐明 一种由G-CSF触发的新信号通路，涉及转换为 蛋白激酶C（PKC-δ 2），刺激海马神经发生并抑制多聚- Tau的磷酸化，这两者都被认为是改善海马突触的基础。 功能 方法：细胞和分子生物学技术，免疫组织化学，海马 将采用切片电生理学和行为分析。 嵌合tg AD小鼠，移植有 将产生表达绿色荧光蛋白（GFP+）的骨髓细胞，以确定 外周来源的小胶质细胞和其他骨髓来源的细胞在多大程度上有助于 淀粉样蛋白减少和/或神经发生。 迄今为止的发现：给予认知受损的tg AD小鼠（APP+PS1）G-CSF逆转了 认知能力受损，海马体中A？沉积显著减少， 内嗅皮层 G-CSF治疗的tg AD小鼠也显示总的小胶质细胞增生显著增加， 海马CA 1和CA 3区突触素免疫染色面积增加。 额外 从给予tg AD小鼠G-CSF获得的初步结果包括刺激 海马脑片神经发生和电生理功能的改善。 临床相关性：G-CSF常规且安全地用于治疗中性粒细胞减少症和刺激 在健康骨髓供体中造血干细胞生成。 认知增强和 G-CSF在AD小鼠模型中的潜在疾病修饰作用为以下研究提供了强大的动力： 临床试验来逆转或阻止AD患者痴呆的进展。 与VA的相关性使命：AD是一种无法治愈的年龄依赖性痴呆疾病，患病率为5 百万在美国。 随着退伍军人人口的老龄化，AD的患病率将增加， 对VA医疗保健系统的巨大需求。 从人道主义和社会经济两方面 因此，迫切需要疾病修饰药物，以延迟或逆转疾病。 进行性痴呆

Abstract/Summary Filgastrim (granulocyte colony stimulating factor or G-CSF) is a multi-modal hematopoietic growth factor used routinely in the hematology/oncology setting but reports of its benefits for brain diseases are appearing in the literature. Preliminary studies in a mouse model of Alzheimer's disease (AD) in our laboratory suggests it has both pro-cognitive and disease-modifying effects. The mechanisms responsible for these profound effects are not clear and development of G-CSF as a therapeutic agent for patients with AD warrants pre-clinical research. Objectives: The proposed studies are designed to elucidate the cellular and molecular mechanisms by which G-CSF reduces amyloid deposition/levels, stimulates hippocampal neurogenesis and restores synaptic functional activity in a mouse model of AD. Aim 1: The hypothesis that enhanced trafficking of bone-marrow derived cells from blood to brain and/or increased microglial and phagocytic activity is responsible for the decrease in beta-amyloid (A-¿) deposition will be tested in a chimeric tg AD mouse in which bone marrow derived cells express green fluorescent protein (GFP). Aim 2: To test the hypothesis that the pro-cognitive effects of G-CSF are mediated by direct actions on neural progenitor cells and neurons, the extent to which G-CSF promotes neurogenesis and/or promotes recovery of hippocamapal synaptic function and structure will be tested with neuroanatomical and electrophysiological techniques. Aim 3: At an intracellular level, mechanistic studies will elucidate a novel signaling pathway triggered by G-CSF that involves switching to an alternatively spliced variant of protein kinase C (PKC-delta2) that stimulates hippocampal neurogenesis and inhibits poly- phosphorylation of Tau, both which are postulated to underlie improved hippocampal synaptic function. Methods: Cellular and molecular biology techniques, immunohistochemistry, hippocampal slice electrophysiology and behavioral analysis will be employed. Chimeric tg AD mice engrafted with green fluorescent protein expressing (GFP+) bone marrow cells will be generated to determine the extent to which peripherally derived microglia and other bone marrow-derived cells contribute to amyloid reduction and/or neurogenesis. Findings to date: Administration of G-CSF to cognitively-impaired tg AD mice (APP+PS1) reversed the impaired cognitive performance and significantly decreased A¿ deposition in hippocampus and entorhinal cortex. G-CSF-treated tg AD mice also revealed a significant increase in total microgliosis and increased areas of synaptophysin immunostaining in hippocamal CA1 and CA3 regions. Additional preliminary results obtained from G-CSF administration to tg AD mice include stimulation of hippocampal neurogenesis and improvement of electrophysiological function in hippocampal slices. Clinical relevance: G-CSF is routinely and safely used to treat neutropenia and to stimulate hematopoietic stem cell generation in healthy bone marrow donors. The cognitive-enhancing and potential disease-modifying effects of G-CSF in a mouse model of AD provides a strong impetus for clinical trials to reverse or forestall progression of dementia in AD patients. Relevance to VA Mission: AD is an incurable, age-dependent dementing disease with a prevalence of 5 million in the US. As the veteran population ages, the prevalence of AD will increase, resulting in overwhelming demands on the VA health care system. From both humanitarian and socio-economic perspectives, there is an urgent need for disease-modifying medications that delay or reverse the progressive dementia of AD.