小鼠社会挫败模型前额叶中谷氨酸能神经递质的初步研究

发布时间：2018-07-15 22:43

【摘要】：背景抑郁症是一种严重的具有高发病率和死亡率的复杂性精神障碍,世界卫生组织发文称全球抑郁症患者数已达3.22亿。到目前为止,已被报道的发病机制包括HPA轴障碍,单胺能和GABA能神经递质紊乱,以及BDNF异常表达等学说。尽管如此,抑郁症的发病机制仍然是复杂和未知的。因此,积极寻找抑郁症的发病机制至关重要。过去研究发现谷氨酸能递质在神经精神疾病的研究方面具有重要的作用,值得考虑成为揭示新的抑郁症发病机制和用药靶点的新方向。前额叶是一个调节情绪,记忆和认知的关键神经脑区,已参与抑郁症发病机理研究数十年。虽然既往有研究采用普筛代谢物在抑郁症中测量神经递质的改变,但是上述非定量分析方法不能准确量化代谢过程中的变化。为了克服这个问题,我们采用LC-MS/MS方法定量检测了三条与抑郁症高度相关的代谢通路中的25个关键神经递质。目的基于小鼠社会挫败模型模拟抑郁症表型,采用LC-MS/MS方法,在前额叶皮质中定量检测色氨酸通路,GABA通路和儿茶酚胺通路三条通路的关键神经递质。并进一步对差异的代谢物质进行相关机制验证和探讨。方法1.构建小鼠社会挫败抑郁模型,对其行为学进行评估,根据社会交互比值将挫败造模后的老鼠分为抑郁组,抵抗组和对照组。2.取抑郁组,抵抗组和对照组三组小鼠各10只的前额叶组织进行LC-MS/MS检测分析,分析物质为色氨酸通路,GABA通路和儿茶酚胺通路三条通路的关键神经递质。3.根据LC-MS/MS结果选取差异性递质谷氨酸进行该递质的关键酶,转运体和受体进行RT-q PCR和Western Blotting的验证。结果1.应用社会交互试验来评价挫败小鼠的抑郁和抵抗表型。13只(46.4%)小鼠表现为抑郁抵抗表型。抑郁小鼠的SI值低于对照组和抵抗组,抵抗组的SI值显著地高于对照组和抑郁组。2.在抑郁和抵抗组中谷氨酸水平显着降低,L-DOPA和VMA显示抑郁组比对照组和抵抗组显着增加。3.谷氨酸代谢通路验证,在基因表达水平Glul,Gad1,Gad2和m Glu R1的m RNA表达在CSDS组中与对照组相比显着改变。在蛋白质水平,与对照组相比在CSDS小鼠中Glu A1有改变,而在EAAT2和Glu1中没有发现显着的改变。结论研究结果表明兴奋性神经递质谷氨酸的代谢途径对社会挫败模型具有重要的影响。本实验中的定量代谢组学检测揭示了在不同表型中谷氨酸,L-DOPA和VMA水平的显着变化。其检测结果中谷氨酸的改变与该蛋白代谢通路中基因和蛋白质的分子水平相关。虽然需要进一步的研究确认这些发现,关键谷氨酸能递质的调控可能揭示产生抑郁障碍的药理应用,并且可以帮助找到更多帮助这种疾病的诊断工具及治疗药物靶点。
[Abstract]:Background Depression is a serious complex mental disorder with high morbidity and mortality. The World Health Organization (WHO) reports that the number of depression patients in the world has reached 322 million. So far, the pathogenesis has been reported including HPA axis disorders, monoaminergic and GABA neurotransmitter disorders, and BDNF abnormal expression theory. Nevertheless, the pathogenesis of depression remains complex and unknown. Therefore, it is very important to actively search for the pathogenesis of depression. Previous studies have found that glutaminergic transmitters play an important role in the study of neuropsychiatric disorders, which is worthy of consideration as a new direction to reveal the pathogenesis of depression and drug targets. The prefrontal lobe, a key neurobrain region that regulates mood, memory and cognition, has been involved in the pathogenesis of depression for decades. Although previous studies have used screening metabolites to measure neurotransmitter changes in depression, the above non-quantitative methods cannot accurately quantify the changes in metabolic processes. To overcome this problem, we used the LC-MS / MS method to quantitatively detect 25 key neurotransmitters in three highly related metabolic pathways for depression. Objective based on the social frustration model of mice, the key neurotransmitters of the tryptophan pathway, GABA pathway and catecholamine pathway, were quantitatively detected by LC-MS / MS method in the prefrontal cortex. Furthermore, the related mechanism of different metabolites was verified and discussed. Method 1. The model of social frustration depression in mice was established, and its behavior was evaluated. The mice were divided into depression group, resistance group and control group according to the social interaction ratio. 2. The prefrontal lobe tissues of 10 mice in depression group, resistance group and control group were detected by LC-MS / MS. The results showed that the substance was the key neurotransmitter of the three pathways of tryptophan pathway, GABA pathway and catecholamine pathway. According to the LC-MS / MS results, the differential transporter glutamate was selected to perform the key enzyme, transporter and receptor for RT-Q PCR and Western blotting. Result 1. Social interaction test was used to evaluate the depression and resistance phenotype of thwarted mice. 13 (46.4%) mice showed depression resistance phenotype. The SI value of depression mice was lower than that of control group and resistance group, and the SI value of resistance group was significantly higher than that of control group and depression group. The levels of glutamate in depression and resistance group were significantly lower than those in control group and resistance group. The levels of L-DOPA and VMA in depression group were significantly higher than those in control group and resistance group. Glutamate metabolic pathway confirmed that the mRNA expression of Glulus Gad1Cad 2 and mGlu R1 in CSDS group was significantly different from that in the control group at the gene expression level. At protein level Glu A1 was changed in CSDS mice compared with control group but no significant change was found in EAAT2 and Glu1. Conclusion the results suggest that the metabolic pathway of excitatory neurotransmitter glutamate plays an important role in social frustration model. Quantitative metabonomics in this study revealed significant changes in L-DOPA and VMA levels in different phenotypes. The changes of glutamate were related to the molecular level of gene and protein in the protein metabolic pathway. While further research is needed to confirm these findings, the regulation of key glutamate transmitters may reveal the pharmacological application of depressive disorders and may help to identify more diagnostic tools and therapeutic targets for the disease.
【学位授予单位】：重庆医科大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R749.4

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