Characterization of EGCG-receptors: Role in mediating the effects of green tea

EGCG 受体的表征：在调节绿茶作用中的作用

• 批准号: 7523919
• 负责人: Mark Lundquist
• 金额: $ 4.12万
• 依托单位: WEILL MEDICAL COLL OF CORNELL UNIV
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-01-01 至 2010-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7523919
• 关键词: Antibodies; Apoptosis; Apoptotic; Axon; Binding Proteins; Biological Assay; Cell Line; Cells; Consumption; Dietary Supplementation; Disease; Epigallocatechin Gallate; Genes; Green tea; Growth Cones; Health Benefit; Hippocampus (Brain); Knock-out; LAMR1 gene; Malignant Neoplasms; Mediating; Modeling; Molecular; Neurodegenerative Disorders; Neurons; Pathogenesis; Phenocopy; Physiological; Proteins; Rattus; Reagent; Role; Safety; Semaphorin-3A; Signal Transduction; Signaling Molecule; Small Interfering RNA; Spinal cord injury; Squalene monooxygenase; Subfamily lentivirinae; Traumatic Nerve Injury; cancer type; excitotoxicity; gallocatechol; knock-down; nerve injury; nervous system disorder; neuron loss; neuroprotection; overexpression; prevent; protein function; receptor; research study; tool

DESCRIPTION (provided by applicant): (-)-Epigallocatechin-3-gallate (EGCG) is a component of green tea, a widely used herbal remedy. Green tea has been consumed for its health benefits for thousands of years, yet the molecular mechanism by which EGCG mediates its effects is not fully understood. EGCG has been intensively studied for its anti-cancer effects. EGCG inhibits the proliferation and induces apoptosis in many types of cancer lines. Several EGCG-binding proteins have been identified, and a subset of these has been shown to mediate the pro- apoptotic effects of EGCG in different cell lines. However, EGCG also has potent and potentially medically useful effects on neurons. EGCG prevents neuronal cell death in various models of neurodegenerative disease as well as in excitotoxicity models. Additionally, EGCG is able to inhibit the effects of certain molecules, such as Semaphorin 3A (SemaSA), that promote axonal retraction. This effect could make EGCG useful as a CAM for disorders such as spinal cord injury or other traumatic nerve injuries. However, it is unknown if the receptors that mediate the antiapoptotic effects of EGCG also mediate the effects of EGCG on neurons. Alternatively, other EGCG-proteins, such as squalene monooxygenase, MICAL, or 67LR might mediate the effects of EGCG in neurons. To identify the mechanisms by which EGCG mediates its effects in neurons, the specific aims of this proposal are: (1) To develop reagents and assay candidate EGCG receptors for neuroprotection. In this aim, I describe experiments to ascertain if siRNA-mediated knockdown of the putative EGCG receptors phenocopies the effect of EGCG treatment in an assay for neuronal excitotoxicity using cultured rat hippocampal neurons; and (2) To determine whether candidate EGCG receptors mediate the effects of EGCG on axons. In this aim, I describe experiments using knockout and overexpression strategies to determine if known EGCG-binding proteins mediate the ability of EGCG to block SemaSA signaling in axons. Together, the experiments in these two aims will clarify whether the putative EGCG receptors mediate the well-documented actions of EGCG in neurons. Because of the widespread consumption of EGCG, the identification of biologically relevant EGCG receptors is important for understanding the mechanism of action, appropriateness, and safety of EGCG dietary supplementation. Additionally, the identification of biologically relevant receptors for the actions of EGCG in neurons will help to clarify the suitability of EGCG as a CAM for neurological diseases and disorders associated with nerve injury.

描述（由申请人提供）： (-)-表没食子儿茶素-3-没食子酸酯 (EGCG) 是绿茶的一种成分，绿茶是一种广泛使用的草药。绿茶因其对健康的益处而被人们食用数千年，但 EGCG 介导其作用的分子机制尚不完全清楚。 EGCG 的抗癌作用已被深入研究。 EGCG 抑制多种癌细胞系的增殖并诱导细胞凋亡。已鉴定出几种 EGCG 结合蛋白，其中的一个子集已被证明可以介导 EGCG 在不同细胞系中的促凋亡作用。然而，EGCG 对神经元也具有有效且潜在的医学用途。 EGCG 可防止各种神经退行性疾病模型以及兴奋性毒性模型中的神经细胞死亡。此外，EGCG 能够抑制某些分子的作用，例如促进轴突回缩的信号蛋白 3A (SemaSA)。这种效应可以使 EGCG 作为一种 CAM 来治疗脊髓损伤或其他创伤性神经损伤等疾病。然而，介导 EGCG 抗凋亡作用的受体是否也介导 EGCG 对神经元的作用尚不清楚。或者，其他 EGCG 蛋白，例如角鲨烯单加氧酶、MICAL 或 67LR 可能介导 EGCG 在神经元中的作用。为了确定 EGCG 在神经元中介导其作用的机制，本提案的具体目标是：（1）开发用于神经保护的试剂和检测候选 EGCG 受体。为了这个目的，我描述了实验，以确定 siRNA 介导的推定 EGCG 受体的敲低是否在使用培养的大鼠海马神经元进行神经元兴奋性毒性测定中复制了 EGCG 治疗的效果； (2)确定候选EGCG受体是否介导EGCG对轴突的作用。为此，我描述了使用敲除和过表达策略的实验，以确定已知的 EGCG 结合蛋白是否介导 EGCG 阻断轴突中 SemaSA 信号传导的能力。这两个目标的实验将共同阐明假定的 EGCG 受体是否介导 EGCG 在神经元中的有据可查的作用。由于 EGCG 的广泛消费，鉴定生物学相关的 EGCG 受体对于了解 EGCG 膳食补充剂的作用机制、适当性和安全性非常重要。此外，鉴定 EGCG 在神经元中的作用的生物学相关受体将有助于阐明 EGCG 作为神经系统疾病和神经损伤相关疾病的 CAM 的适用性。