GD3 synthase gene therapy to improve memory and prevent neurodegeneration

描述（由申请人提供）：阿尔茨海默病的特征是β -淀粉样蛋白（Abeta）在大脑中聚集，广泛的神经变性和认知能力下降。我们的工作重点是通过减少或消除GD3合成酶（GD3S）来改善阿尔茨海默氏症的病理，GD3S是一种负责合成四种主要脑神经节苷中的两种的酶。我们的初步数据表明，敲除编码GD3S的基因（St8sia1）可以显著降低A2聚集和氧化应激，并防止携带淀粉样蛋白前体蛋白（App）和早老素1 （Psen1）突变基因的小鼠的记忆缺陷。然而，这些小鼠在出生时就缺乏GD3S，并且它们缺乏许多参与正常发育的神经节苷脂。我们的目标是了解神经节苷类在阿尔茨海默病中的作用，以及它们与记忆障碍（阿尔茨海默病最早的认知症状）之间的关系。本应用的目的是确定在5xFAD小鼠模型中，使用基因沉默（shRNA）敲除GD3S是否与敲除GD3S一样有效，以减轻阿尔茨海默病的特征。本研究提出的一般假设是，shRNA敲除GD3S将成功减少斑块形成，防止成年突变小鼠的神经变性和记忆障碍。我们已经构建了三种病毒载体介导的GD3S- shrna结构，它们将GD3S的表达降低了80%，并在大脑中持续存在。在拟议的实验中，shRNA构建体将被施用于5xFAD和对照小鼠。将评估空间记忆，以及焦虑和感觉运动功能的对照测试。死后分析将评估阿尔茨海默病相关的神经病理学和细胞死亡。成功减少转基因小鼠的淀粉样蛋白负担、细胞死亡和记忆障碍，可能为阿尔茨海默病的新治疗策略提供见解，这些治疗方法可以减少或预防阿尔茨海默病患者的痴呆症。

DESCRIPTION (provided by applicant): Alzheimer's disease is characterized by the aggregation of beta-amyloid (Abeta) protein in the brain, widespread neurodegeneration, and cognitive decline. Our work focuses on amelioration of Alzheimer's pathology by reducing or eliminating GD3 synthase (GD3S), an enzyme responsible for synthesis of two of the four major brain gangliosides. Our preliminary data demonstrate that knocking out the gene that codes for GD3S (St8sia1) drastically reduces A2 aggregation and oxidative stress, and prevents memory deficits in mice carrying mutant human transgenes for amyloid precursor protein (App) and presenilin 1 (Psen1). However, GD3S is absent from birth in these mice, and they lack many of the gangliosides involved in normal development. Our goal is to understand the role of gangliosides in Alzheimer's disease and how they relate to memory impairment, the earliest cognitive symptom of the disease. The objective of this application is to determine whether knocking down GD3S using gene silencing (shRNA) is as effective as knocking out GD3S in alleviating features of Alzheimer's disease in the 5xFAD mouse model. The general hypothesis of the proposed research is that shRNA knock-down of GD3S will successfully reduce plaque formation and prevent neurodegeneration and memory impairments in adult mutant mice. We have already made three viral- vector-mediated GD3S-shRNA constructs that reduce GD3S expression ~80 percent and persist in the brain. In the proposed experiments, shRNA constructs will be administered to 5xFAD and control mice. Spatial 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. Successfully reducing amyloid burden, cell death, and memory impairment in the transgenic mice may provide insight into new treatment strategies for Alzheimer's disease--treatments that could reduce or prevent dementia in Alzheimer patients.