Cholinergic neurons and memory in GFP-AD mouse: a novel neurotrophic therapy

GFP-AD 小鼠的胆碱能神经元和记忆：一种新型神经营养疗法

• 批准号: 8811325
• 负责人: ALPASLAN DEDEOGLU
• 金额: --
• 依托单位: VA BOSTON HEALTH CARE SYSTEM
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8811325
• 关键词: Acetylcholine; Adult; Affect; Age; Age-Months; Agonist; Alzheimer' s Disease; Alzheimer' s disease model; Amyloid; Amyloid beta-Protein Precursor; Amyotrophic Lateral Sclerosis; Animal Model; Animals; Asses; Attention; Axotomy; Biology; Blood - brain barrier anatomy; Brain; Brain-Derived Neurotrophic Factor; Cell Culture Techniques; Cells; Cerebral cortex; Cerebrum; Choline; Choline O-Acetyltransferase; Cholinergic Fibers; Code; Cognition; Cognitive; Cognitive deficits; Computer Assisted; Crossbreeding; Data; Dementia; Dendritic Spines; Densitometry; Development; Disease; Drug Kinetics; Elderly; Enzyme-Linked Immunosorbent Assay; Enzymes; Evaluation; Exhibits; Family Caregiver; Family member; Fluorescence-Activated Cell Sorting; Functional disorder; Future; Gene Expression; Gene Expression Profile; Genes; Genetic; Glutamine; Golgi Apparatus; Green Fluorescent Proteins; Healthcare Systems; High Pressure Liquid Chromatography; Hippocampus (Brain); Human; Immunohistochemistry; Individual; Inositol; Learning; Life; Magnetic Resonance Spectroscopy; Measures; Memory; Memory Loss; Memory impairment; Messenger RNA; Metabolic; Metabolism; Modeling; Mouse Strains; Mus; Mutate; Neocortex; Nerve Degeneration; Nerve Growth Factors; Neurofibrillary Tangles; Neurons; Neurotransmitters; Neurotrophic Tyrosine Kinase Receptor Type 2; Parkinson Disease; Pathology; Patients; Pattern; Peptides; Pharmacology; Population; Post-Traumatic Stress Disorders; Process; Production; Prosencephalon; Proteins; Psyche structure; Rattus; Reporting; Reverse Transcriptase Polymerase Chain Reaction; Role; Senile Plaques; Signal Transduction; Slice; Staining method; Stains; Synapses; Synaptophysin; System; Techniques; Testing; Therapeutic; Tissue Stains; Tissues; Transgenic Organisms; Veterans; Wild Type Mouse; age related; aged; amyloid pathology; basal forebrain; basal forebrain cholinergic neurons; brain tissue; cholinergic; cholinergic neuron; computerized; design; extracellular; familial Alzheimer disease; functional disability; gamma-Aminobutyric Acid; in vivo; indexing; mRNA Expression; morris water maze; mouse model; mutant; neurochemistry; neurogenesis; neurotrophic factor; novel; postnatal; presenilin-1; prevent; public health relevance; receptor; small molecule; tau Proteins; tau-1; trimethylamine

DESCRIPTION (provided by applicant): Alzheimer's disease (AD) is an age dependent neurodegenerative disorIer and the most common form of dementia affecting the elderly. The neuropathological hallmarks of AD include extracellular ss-amyloid- containing plaques and intracellular neurofibrillary tangles composed of phosphorylated tau protein in the hippocampus and neocortex, and degeneration and loss of basal forebrain cholinergic neurons (BFCN). BFCN project to the hippocampus and cerebral corte where the release of their neurotransmitter, acetylcholine (ACh), is central to cognition. A decline in BFCN function and cholinergic marker is apparent in AD patients and in animal models of AD. Thus, it has been postulated that the dysfunction and/or degeneration of BFCN contributes to the memory deficits associated with AD. Many of the available treatments for AD are designed to inhibit the breakdown of ACh, though the administration of trophic factors that support the function and survival of cholinergic neurons has also been explored. One such neurotrophin is brain derived neurotrophic factor (BDNF) that signals via the TrkB receptor. The reduced expression of mRNAs encoding TrkB in purified BFCN from AD patients, suggests that BDNF therapy could prevent or restore the functional impairments of these neurons in AD. This approach has been hampered by to the poor pharmacokinetics of BDNF that does not cross the blood-brain barrier. Recently a potent and selective TrkB agonist that readily enters the brain when administered peripherally was discovered 7,8-dihydroxyflavone (7,8-DHF). Beneficial effects of 7,8-DHF have been reported in models of Parkinson's disease, AD and post-traumatic stress disorder and we are presenting preliminary data of DHF treatment in mouse models of AD and amyotrophic lateral sclerosis that strongly support these reports. We hypothesize that 7,8-DHF, a TrkB agonist, will delay or lessen memory loss and reduce amyloid pathology through its neurotrophic effects on hippocampal and basal forebrain cholinergic neurons. To test our hypothesis APP.PS1/CHGFP mice will be treated with 7,8-DHF from 1 to 6 months (early pathology) or 12 months (late pathology). We will measure the effects of 7,8-DHF treatment on animals' memory and learning using Morris water maze test, BFCN gene expression pattern by microarray and RT-PCR of FACS purified BFCN, hippocampal ACh content and release by high-performance liquid chromatography (HPLC), amyloid pathology by immunohistochemistry (IHC) and ELISA and indices of hippocampal and cerebral cortical function assessed by IHC techniques including cholinergic neurons and cholinergic fibers, neurogenesis and synapses and dendritic spines. We will also measure neurochemical profile using magnetic resonance spectroscopy (MRS). Our proposed studies incorporate principals of rational pharmacology with state-of-the-art neuropathological, neurochemical, gene-analysis and MR techniques with cognitive evaluation to comprehensively assess the brain of a unique Alzheimer mouse model that expresses green fluorescent protein specifically in cholinergic cells. These studies will help further define the therapeutic benefits of a novel neurotrophic compound that crosses the blood-brain barrier but also will provide an entirely new level of understanding of the basic biology of BFCN and their function in AD and characterize a novel model for future use to test therapeutics relevant to patients with AD.

描述（由申请人提供）： 阿尔茨海默氏病 (AD) 是一种年龄依赖性神经退行性疾病，也是影响老年人的最常见的痴呆症。 AD 的神经病理学特征包括海马和新皮质中含有细胞外 ss-淀粉样蛋白的斑块和由磷酸化 tau 蛋白组成的细胞内神经原纤维缠结，以及基底前脑胆碱能神经元 (BFCN) 的变性和丧失。 BFCN 投射到海马体和大脑皮层，其中神经递质乙酰胆碱 (ACh) 的释放对于认知至关重要。 AD 患者和 AD 动物模型中 BFCN 功能和胆碱能标志物的下降很明显。因此，推测 BFCN 的功能障碍和/或退化会导致与 AD 相关的记忆缺陷。许多现有的 AD 治疗方法都是为了抑制 ACh 的分解，尽管也探索了支持胆碱能神经元功能和存活的营养因子的施用。其中一种神经营养因子是脑源性神经营养因子 (BDNF)，它通过 TrkB 受体发出信号。 AD 患者纯化的 BFCN 中编码 TrkB 的 mRNA 表达减少，表明 BDNF 治疗可以预防或恢复 AD 中这些神经元的功能损伤。由于 BDNF 不能穿过血脑屏障，药代动力学较差，这一方法受到阻碍。最近发现了一种有效的选择性 TrkB 激动剂，当外周给药时，它很容易进入大脑，即 7,8-二羟基黄酮 (7,8-DHF)。据报道，7,8-DHF 在帕金森病、AD 和创伤后应激障碍模型中具有有益作用，我们正在提供 DHF 在 AD 和肌萎缩侧索硬化症小鼠模型中治疗的初步数据，这些数据有力地支持了这些报告。我们假设 7,8-DHF（一种 TrkB 激动剂）将通过其对海马和基底前脑胆碱能神经元的神经营养作用来延迟或减轻记忆丧失并减少淀粉样蛋白病理。为了检验我们的假设，APP.PS1/CHGFP 小鼠将接受 7,8-DHF 治疗 1 至 6 个月（早期病理学）或 12 个月（晚期病理学）。我们将使用莫里斯水迷宫测试测量7,8-DHF治疗对动物记忆和学习的影响，通过微阵列和FACS纯化BFCN的RT-PCR检测BFCN基因表达模式，通过高效液相色谱（HPLC）检测海马ACh含量和释放，通过免疫组织化学（IHC）和ELISA检测淀粉样蛋白病理学以及海马和大脑指数 通过 IHC 技术评估皮质功能，包括胆碱能神经元和胆碱能纤维、神经发生、突触和树突棘。我们还将使用磁共振波谱 (MRS) 测量神经化学特征。我们提出的研究将理性药理学原理与最先进的神经病理学、神经化学、基因分析和磁共振技术以及认知评估相结合，以全面评估独特的阿尔茨海默小鼠模型的大脑，该模型在胆碱能细胞中特异性表达绿色荧光蛋白。这些研究将有助于 进一步明确了一种跨越血脑屏障的新型神经营养化合物的治疗益处，同时也将为 BFCN 的基本生物学及其在 AD 中的功能提供全新水平的理解，并表征未来用于测试与 AD 患者相关的治疗方法的新模型。