Hypoglycemic signaling targets in astrocytes

星形胶质细胞中的降血糖信号靶标

• 批准号: 6667268
• 负责人: James William Mandell
• 金额: $ 18.5万
• 依托单位: UNIVERSITY OF VIRGINIA
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-09-30 至 2004-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6667268
• 关键词: astrocytes; biological signal transduction; cell communication molecule; expression cloning; glucose metabolism; hypoglycemia; laboratory mouse; mass spectrometry; nerve injury; proteomics; tissue /cell culture; two dimensional gel electrophoresis

DESCRIPTION (provided by applicant): Hypoglycemia is a common complication in the management of diabetes. Severe hypoglycemia can cause seizures, unconsciousness, and irreversible cognitive impairment, presumably because of neuronal injury and death. Astrocytes, the star-shaped glial cells found throughout the brain, perform important roles to support and protect neurons. Recent work indicates that in hypoglycemia, astrocytes are capable of rapidly generating substrates to feed energy-depleted neurons, probably by breakdown of intracellular glycogen. The mechanisms by which astrocytes sense dropping glucose levels, and the downstream signaling pathways controlling glycogen metabolism, are poorly understood. We propose a discovery-based, but focused approach to identify components of astrocytic hypoglycemic signaling pathways, utilizing two powerful and complementary methodologies: proteomics and a novel method of expression cloning. We will test a general hypothesis: Astrocytes possess specialized glucose signaling molecules and mechanisms enabling rapid regulation of substrates for neuronal metabolism in hypoglycemia. The specific aims of the project are: 1) Identify molecular targets of acute, subacute and episodic hypoglycemia in astrocytes using two independent and complementary approaches: a) proteomics (two-dimensional gel electrophoresis with protein identification by mass spectrometry); and b) FIMS, a novel expression cloning method developed in our laboratory. 2) Validate targets using cell culture and in vivo models of hypoglycemia. The entire set of identified hypoglycemia-regulated proteins will be made available as a database for the research community. A subset of the targets identified will be the subject of future hypothesis-driven research projects in our laboratory. The longterm goal is to develop pharmacologic or molecular methods to augment or modulate neuroprotective aspects of the astrocytic response to hypoglycemia.

描述（由申请人提供）：低血糖是糖尿病治疗中的常见并发症。严重低血糖可导致癫痫发作、意识不清和不可逆的认知障碍，可能是由于神经元损伤和死亡。星形胶质细胞是遍布大脑的星形神经胶质细胞，在支持和保护神经元方面发挥着重要作用。最近的研究表明，在低血糖情况下，星形胶质细胞能够快速产生底物来喂养能量耗尽的神经元，这可能是通过细胞内糖原的分解来实现的。人们对星形胶质细胞感知血糖水平下降的机制以及控制糖原代谢的下游信号通路知之甚少。我们提出了一种基于发现但重点突出的方法来识别星形胶质细胞低血糖信号通路的组成部分，利用两种强大且互补的方法：蛋白质组学和表达克隆的新方法。我们将测试一个普遍的假设：星形胶质细胞拥有专门的葡萄糖信号分子和机制，能够快速调节低血糖时神经元代谢的底物。该项目的具体目标是： 1) 使用两种独立且互补的方法识别星形胶质细胞中急性、亚急性和阵发性低血糖的分子靶点： a) 蛋白质组学（二维凝胶电泳，通过质谱法鉴定蛋白质）； b) FIMS，我们实验室开发的一种新型表达克隆方法。 2) 使用细胞培养和低血糖体内模型验证目标。整套已确定的低血糖调节蛋白将作为数据库提供给研究界。所确定的目标的子集将成为我们实验室未来假设驱动研究项目的主题。长期目标是开发药理学或分子方法来增强或调节星形胶质细胞对低血糖反应的神经保护作用。