背根节神经元细胞表面Delta阿片受体表达与调控机制的研究

发布时间：2018-09-06 11:07

【摘要】：背根神经节是痛觉信息传递的第一站,其神经元细胞表面阿片受体的表达与调控对于阿片类药物的镇痛效果具有重要的意义。本论文主要以小鼠背根节神经元为研究对象,以细胞表面的Delta阿片受体(DOR)的调控为核心,通过细胞生物学、电生理学和药理学等方法研究了DOR在细胞表面的表达与调控机制。受体插入到细胞表面的途径可以分为两类:与刺激耦联的可调节分泌途径和与刺激无关的持续分泌途径。背根节小神经元中,Mu阿片受体通过持续分泌途径上膜,而大部分DOR与神经肽类物质共存于大致密芯囊泡中。我们发现细胞受到伤害性刺激时胞内钙浓度升高,细胞发生胞吐,DOR插入到细胞膜表面,增加了膜表面受体总量,即DOR的上膜以依赖于钙浓度升高的方式受伤害性刺激的调控。我们进一步发现DOR进入可调节分泌途径依赖于P物质前体蛋白的表达,前速激肽原-A基因敲除导致刺激无法诱导DOR插入到细胞膜表面,而且DOR激动剂所诱发的大致密芯囊泡胞吐也大为减弱。此外,我们还发现可穿膜的DOR拮抗剂作为药理学伴娘可以增强DOR上膜,这一方式是通过持续分泌途径和可调节分泌途径中的DOR同时增加来实现的,且不依赖于细胞内钙浓度的升高。这些结果表明背根节神经元细胞表面DOR表达受多种因素调控,理解这些调控机理对于合理使用阿片类药物镇痛和发展新的阿片类药物具有重要意义。
[Abstract]:Dorsal root ganglion (DRG) is the first station for the transmission of pain. The expression and regulation of opioid receptors on the surface of neurons are of great significance to the analgesic effect of opioid drugs. In this paper, the expression and regulation mechanism of Delta opioid receptor (DOR) on the surface of mouse dorsal root ganglion (DRG) neurons was studied by means of cell biology, electrophysiology and pharmacology. The receptors inserted into the cell surface can be divided into two types: the stimulus-coupled adjustable secretory pathway and the stimulation-independent persistent secretion pathway. In the small neurons of dorsal root ganglion (DRG), the MU opioid receptor is secreted through the supermembrane through a continuous secretion pathway, and most of the DOR and neuropeptides coexist in the large dense core vesicles. We found that the intracellular calcium concentration increased when the cells were stimulated by nociceptive stimulation, and the DOR was inserted into the surface of the cell membrane, which increased the total number of the membrane surface receptors, that is, the supermembrane of DOR was regulated by the nociceptive stimulation in a manner dependent on the increase of calcium concentration. We further found that the regulated secretory pathway of DOR was dependent on the expression of substance P precursor protein, and that prokallikrein A gene knockout resulted in stimulation that could not induce DOR insertion into the surface of the cell membrane. Moreover, the large dense core vesicle exocytosis induced by DOR agonist was also weakened. In addition, we also found that transmembrane DOR antagonists as pharmacological bridesmaids can enhance the DOR supermembrane, which is achieved by the simultaneous increase of DOR in both persistent and adjustable secretion pathways. And does not depend on the increase of intracellular calcium concentration. These results suggest that the expression of DOR on the surface of dorsal root ganglion neurons is regulated by many factors. Understanding these mechanisms is of great significance for the rational use of opioid drugs for analgesia and the development of new opioid drugs.
【学位授予单位】：中国科学院研究生院（上海生命科学研究院）
【学位级别】：博士
【学位授予年份】：2005
【分类号】：R33

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