应用由CRMP2衍生的ST2-104多肽调控CRMP2/NMDAR对AD的干预作用机制研究

The axon guidance and outgrowth protein collapsin response mediator protein 2 (CRMP2) is an abundant brain-enriched protein that is highly phosphorylated in AD brain. CRMP2 is a novel binding partner of NMDARAs (N-Methyl-D-Aspartate receptors). It has shown that calcium surges triggered by toxic level of glutamate can be blocked by knockdown of CRMP2，suggesting that modulation of NMDAR by CRMP2 is critical for the establishment of endogenous protective mechanism in neurons.In cultured hippocampal neurons and in cerebral ischemia and traumatic brain injury models, the introduction of CRMP2-derived ST2-104 peptide is neuroprotective in the face of glutamate mediated neurotoxicity. Here we will apply this information in the strategic design of a conceptually innovative approach to neuroprotection in AD that has never been considered. We will test the hypothesis that targeting the NMDAR with ST2-104 peptide is a neuroprotective strategy in AD. We will manipulate CRMP2 level embryonic hippocampal neurons with our toolbox CRMP2 construction and test effects of Aβ on neurons of overexpression or knockdown of CRMP2 with or without ST2-104. To determine if ST2-104 is neuroprotective and prevent memory loss in vivo in an animal model of AD. We anticipate that ST2-104 will be efficacious in preventing against Aβ-induced cell death and Alzheimer’s-like memory deficits. Results from our studies may give rise to novel therapeutic treatment for AD.

CRMP2在海马神经元表达丰富，对神经系统发育具有重要作用。磷酸化的CRMP2与NMDAR作用增强，促进细胞外Ca2+通过NMDAR内流，导致突触后神经元Ca2+过载，引发神经毒性。敲除CRMP2或应用CRMP2蛋白衍生的ST2-104多肽干扰 CRMP2与NMDAR结合，能够阻断Ca2+内流，抵抗脑创伤和脑缺血后谷氨酸增高介导的神经毒性。故我们推测：ST2-104多肽可通过拮抗磷酸化的CRMP2的毒性作用治疗AD。本课题拟应用Aβ诱导高表达及敲除CRMP2大鼠海马神经元毒性的细胞模型并建立Aβ25-35 多肽诱导AD动物模型，应用ST2-104多肽阻断CRMP2与NMDAR相互作用，研究NMDAR与CRMP2在AD中发生发展中的相互作用，探讨ST2-104多肽保护神经元免予Aβ毒性的可能分子机制，评估ST2-104多肽临床治疗AD的可行性。

CRMP2在海马神经元表达丰富，对神经系统发育具有重要作用。磷酸化的CRMP2与NMDAR作用增强，促进细胞外Ca2+通过NMDAR内流，导致突触后神经元Ca2+过载，引发神经毒性。敲除CRMP2或应用CRMP2蛋白衍生的ST2-104多肽干扰 CRMP2与NMDAR结合，能够阻断Ca2+内流，抵抗脑创伤和脑缺血后谷氨酸增高介导的神经毒性。故我们推测：ST2-104多肽可通过拮抗磷酸化的CRMP2的毒性作用治疗AD。本课题通过建立Aβ25-35多肽诱导AD动物模型及应用Aβ诱导过表达及敲除的SH-SY5Y细胞损伤模型，并应用ST2-104进行干预治疗，研究ST2-104多肽保护神经元免予Aβ毒性的可能分子机制。结果表明ST2-104具有神经保护作用，能够减轻阿尔茨海默病的记忆缺陷，其机制与ST2-104多肽干扰 CRMP2与NMDAR结合，阻断Ca2+内流有关。该研究将为ST2-104用于AD临床治疗提供了一定的理论依据。