Conantokins抑制小鼠吗啡依赖功能的发现及机理的初步研究

发布时间：2018-03-22 01:02

本文选题：NMDA受体　切入点：conantokins　出处：《中国人民解放军军事医学科学院》2010年硕士论文　论文类型：学位论文

【摘要】： Conantokins (Con-)是芋螺活性肽的一个重要家族,能特异性作用于N-甲基-天门冬氨酸受体(NMDAR)及其亚型,是目前发现的该受体的唯一一类多肽抑制剂。NMDA受体NR2B亚基与镇痛、神经保护、戒毒等密切相关,NR2B亚基特异抑制剂对研发低副作用的镇痛、神经保护、戒毒药具有诱人前景。前期本实验室发现con-G及其突变体对吗啡依赖小鼠的催促戒断跳跃具有显著抑制作用,且抑制活性与其对NR2B亚基的选择性密切相关,但该类抑制剂对小鼠吗啡精神依赖没有研究。本论文在前期工作基础上,开展了对NMDA受体NR2B亚基选择性抑制剂Conantokins的进一步筛选并初步研究了其抑制吗啡身体依赖发展、精神依赖发展、表达的新功能的作用机理,获得了如下新结果： (1)筛选了21个conantokins天然肽及其突变体,找到了一种副作用低且特异性作用于NMDA受体NR2B亚基的抑制剂con-T-[M8Q],不仅能有效抑制小鼠的吗啡身体依赖的表达与发展,而且不影响小鼠的运动功能及自发活动。 (2) Con-T-[M8Q]对小鼠的吗啡精神依赖的表达与发展具有显著抑制作用,5nmol/kg的剂量con-T[M8Q]几乎能完全抑制小鼠吗啡精神依赖的表达及发展。 (3)研究了吗啡依赖小鼠在给不同剂量con-T-[M8Q]抑制剂后主要相关信号通路的变化,结果表明：Con-T[M8Q]能够抑制吗啡依赖小鼠NMDA受体NR2B亚基1472位酪氨酸的磷酸化水平,下调非磷酸化NR2B亚基的表达水平；除CaMKI mRNA的表达量和抑制剂剂量之间没有明显规律性变化外,CaMKIIa、β单体及CaMKIV mRNA的表达量均随抑制剂剂量的增高而降低；Con-T[M8Q]同时还下调ERK、c-fos蛋白的表达水平。该工作为吗啡依赖相关机理研究提供了一个很好的研究工具,并为相关抑制剂的应用提供了机理支持。
[Abstract]:Conantokins Con-Con-is an important family of conoc active peptides, which can act specifically on N-methyl-aspartate receptor (NMDAR) and its subtypes. It is the only type of polypeptide inhibitor. NMDA receptor NR2B subunit and analgesia, neuroprotection. Detoxification and other closely related NR2B subunit specific inhibitors have attractive prospects for the development of analgesic, neuroprotective and abstinent poisons with low side effects. It was found in our laboratory that con-G and its mutants had a significant inhibitory effect on withdrawal jumping in morphine dependent mice, and the inhibitory activity was closely related to their selectivity to NR2B subunits. On the basis of previous work, this thesis has carried out further screening of Conantokins, a selective inhibitor of NMDA receptor NR2B subunit, and studied its inhibition on the development of morphine physical dependence. The mechanism of the new function of spiritual dependence development and expression has obtained the following new results:. We screened 21 conantokins natural peptides and their mutants, and found an inhibitor con-T- [M8Q], which has low side effect and specific effect on NR2B subunit of NMDA receptor, which can not only effectively inhibit the expression and development of morphine physical dependence in mice. Moreover, the motor function and spontaneous activity of mice were not affected. (2) Con-T- [M8Q] had a significant inhibitory effect on the expression and development of morphine dependence in mice. Con-T (5 nmol / kg) [M8Q] could almost completely inhibit the expression and development of morphine dependence in mice. The changes of the main related signaling pathways in morphine dependent mice after different doses of con-T- [M8Q] inhibitor were studied. The results showed that: Con-T [M8Q] could inhibit tyrosine phosphorylation of NMDA receptor NR2B subunit 1472 in morphine dependent mice. The expression of non-phosphorylated NR2B subunits was down-regulated. The expression of CaMKIIa, 尾 monomer and CaMKIV mRNA decreased with the increase of inhibitor dose, and decreased the expression level of ERK c-fos protein with the increase of inhibitor dose. This work provides a good tool for the study of morphine dependence mechanism and provides mechanism support for the application of related inhibitors.
【学位授予单位】：中国人民解放军军事医学科学院
【学位级别】：硕士
【学位授予年份】：2010
【分类号】：R341

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