淀粉样前体蛋白及其代谢产物Aβ对神经元兴奋性的影响
发布时间：2019-06-13 22:31
【摘要】：目的：阿尔茨海默病(Alzheimer disease,AD),是一种中枢神经系统退行性疾病。主要表现为进行性记忆障碍、认知功能障碍、人格改变及语言障碍等神经精神症状,严重影响社交、职业与生活质量。AD的病因及发病机制尚未阐明,特征性病理改变为p淀粉样蛋白(β-amyloid,Aβ)沉积形成的细胞外老年斑和Tau蛋白过度磷酸化形成的细胞内神经原纤维缠结。Ap的代谢前体为淀粉样前体蛋白(Amyloid Precursor Protein, APP)。因其剪切产物Ap是构成老年斑的主要成分,长期以来人们对APP的研究大部分集中在其代谢途径异常对AD发病机制的影响方面。APP作为一种管家基因在人体多种组织中均有表达,但对其功能却知之甚少,尤其APP对神经元兴奋性以及与电压门控性钠通道的功能联系至今未见报道。尽管有报道称Ap可影响神经兴奋,但多数研究集中在Ap提高谷氨酸兴奋性毒性上,鲜有探讨Ap影响钠通道及神经元本身的兴奋性。本实验室前期实验结果显示APP与电压门控钠通道特异地汇聚在中枢神经系统郎飞氏结上,影响神经传导,因此本研究的主要目的是从功能水平上进一步研究APP及其产物Ap与神经元兴奋性和电压门控钠通道之间的关系,为揭示APP的生理功能及AD的发病机制提供新的理论依据。方法：APP/PS1转基因鼠体外原代神经元培养,电流钳探讨神经元兴奋性的变化：APP转染不同亚型电压门控钠通道(Nav1.6, Nav1.2)HEK 293细胞系,全细胞膜片钳探讨APP和钠通道的功能联系；Aβ_(1-42)干预体外原代培养神经元,全细胞膜片钳探讨神经元兴奋性和电压门控钠通道的变化。结果：1.APP可提高神经元动作电位峰值。2.APP可降低神经元动作电位的阈电位。3.APP可增加神经元动作电位的发放频率。4.APP可增大HEK 293 Nav1.6细胞系电流幅值。5.APP可加快HEK 293 Nav1.6钠通道的激活。6.APP可减慢HEK 293 Nav1.6钠通道的失活。7.APP对HEK 293 Nav1.2细胞系钠通道没有调控作用。8.Aβ_(1-42)可降低神经元动作电位的阈电位。9.Aβ_(1-42)可增加神经元动作电位的发放频率。10.Aβ_(1-42)对钠通道电流似乎无影响。结论：1.APP过表达可提高神经元兴奋性。2.APP可特异增强Nav1.6通道的电流,而对Nav1.2电流无调控作用。3.Aβ_(1-42)亦可增加神经元兴奋性,但对钠通道电流似乎无影响。
[Abstract]:Objective: Alzheimer's disease (Alzheimer disease,AD) is a degenerative disease of central nervous system. The main manifestations are progressive memory impairment, cognitive impairment, personality changes and language disorders, which seriously affect social interaction, occupation and quality of life. The etiology and pathogenesis of AD have not been clarified, and the characteristic pathological changes are p-amyloid,. A 尾) deposited extracellular plaques and intracellular neurofibrillar tangles formed by hyperphosphorylation of Tau protein. The metabolic precursor of AP is starch precursor protein (Amyloid Precursor Protein, APP). Because its shear product Ap is the main component of elderly plaques, most of the research on APP has been focused on the effect of abnormal metabolic pathway on the pathogenesis of AD. App, as a housekeeper gene, is expressed in a variety of human tissues, but little is known about its function, especially the relationship between APP and voltage-gated sodium channel has not been reported. Although it has been reported that Ap can affect nerve excitation, most of the studies have focused on the enhancement of glutamate excitotoxicity by Ap. Few studies have discussed the effects of Ap on sodium channels and the excitability of neurons themselves. The results of previous experiments in our laboratory show that APP and voltage-gated sodium channel converge specifically on Langfei's node of central nervous system, which affects nerve conduction. Therefore, the main purpose of this study is to further study the relationship between APP and its product Ap and neuron excitability and voltage-gated sodium channel at functional level, so as to provide a new theoretical basis for revealing the physiological function of APP and the pathogenesis of AD. Methods: the primary neurons of APP/PS1 transgenic mice were cultured in vitro, and the changes of neuron excitability were investigated by current clamp: APP was transfected into different subtypes of voltage gated sodium channel (Nav1.6, Nav1.2) HEK 293cell line, the functional relationship between APP and sodium channel was discussed by whole cell patch clamp, A 尾 _ (1 鈮，
本文编号：2498868
[Abstract]:Objective: Alzheimer's disease (Alzheimer disease,AD) is a degenerative disease of central nervous system. The main manifestations are progressive memory impairment, cognitive impairment, personality changes and language disorders, which seriously affect social interaction, occupation and quality of life. The etiology and pathogenesis of AD have not been clarified, and the characteristic pathological changes are p-amyloid,. A 尾) deposited extracellular plaques and intracellular neurofibrillar tangles formed by hyperphosphorylation of Tau protein. The metabolic precursor of AP is starch precursor protein (Amyloid Precursor Protein, APP). Because its shear product Ap is the main component of elderly plaques, most of the research on APP has been focused on the effect of abnormal metabolic pathway on the pathogenesis of AD. App, as a housekeeper gene, is expressed in a variety of human tissues, but little is known about its function, especially the relationship between APP and voltage-gated sodium channel has not been reported. Although it has been reported that Ap can affect nerve excitation, most of the studies have focused on the enhancement of glutamate excitotoxicity by Ap. Few studies have discussed the effects of Ap on sodium channels and the excitability of neurons themselves. The results of previous experiments in our laboratory show that APP and voltage-gated sodium channel converge specifically on Langfei's node of central nervous system, which affects nerve conduction. Therefore, the main purpose of this study is to further study the relationship between APP and its product Ap and neuron excitability and voltage-gated sodium channel at functional level, so as to provide a new theoretical basis for revealing the physiological function of APP and the pathogenesis of AD. Methods: the primary neurons of APP/PS1 transgenic mice were cultured in vitro, and the changes of neuron excitability were investigated by current clamp: APP was transfected into different subtypes of voltage gated sodium channel (Nav1.6, Nav1.2) HEK 293cell line, the functional relationship between APP and sodium channel was discussed by whole cell patch clamp, A 尾 _ (1 鈮，
本文编号：2498868
本文链接：https://www.wllwen.com/yixuelunwen/jsb/2498868.html
最近更新
教材专著
