TMEM108和ErbB4在突触发育和突触传递中的作用

发布时间：2018-06-22 19:50

本文选题：ErbB4 + NRG1　；参考：《南昌大学》2016年博士论文

【摘要】：精神分裂症(Schizophrenia,SZ)是一种神经系统功能紊乱疾病,表现为大脑基本功能(如感觉、情绪、判断力等)异常,出现幻听、思维混乱、缺乏快感及认知功能障碍。由神经系统发育过程中的功能异常所导致的神经信息传递和突触可塑性的紊乱,被认为是精神分裂症的主要病征之一。神经调节素1(Neuregulin 1,NRG1)及其受体类表皮生长因子4(ErbB4)是精神分裂症易感基因。目前已知NRG1/ErbB4信号通路通过调控大脑皮质神经元迁移、分化和突触整合等过程,参与大脑皮质内的信息传递和脑高级功能,但该信号通路如何调控大脑皮质神经环路的发生发育及其内在机制却不甚清楚。已知ErbB4特异性表达在中间神经元中。一般认为,全长NRG1剪切生成活性NRG1配体,结合ErbB4并激活受体酪氨酸激酶活性,及其胞内下游信号通路,调控突触传递和神经系统发育。本文以ErbB4为研究靶点,探讨精神分裂症易感基因ErbB4是否调控大脑皮质中不同类型突触的形成?这些调控作用是否依赖ErbB4激酶活性?其内在机制是什么?本文第一部分利用ErbB4基因敲除小鼠、ErbB4报告基因小鼠和ErbB4酪氨酸激酶结构域基因突变(T796G-ErbB4)小鼠,通过细胞培养、免疫组织化学、免疫印迹及分子和生物化学等方法,在体内体外详细地研究了ErbB4对小鼠大脑皮质不同类型突触发生发育的调控作用。结果表明:1)敲除ErbB4,不影响锥体神经元上兴奋性突触发育,也不影响中间神经元上抑制性突触发育。2)敲除ErbB4,显著抑制GABA能中间神经元上兴奋性突触,及其锥体神经元上抑制性突触的发育。3)Erb B抑制剂AG1487和PD158780广泛影响锥体神经元和中间神经元的突触发生。4)利用1NMPP1特异性抑制ErbB4酪氨酸激酶,显著抑制GABA能中间神经元上兴奋性突触形成,但锥体神经元和中间神经元上抑制性突触的发育不受影响。提示锥体神经元上抑制性突触的发育机制受ErbB4蛋白调控,但不依赖受体激酶活性。以上结果从突触角度,研究了ErbB4及其激酶活性调控大脑皮质内多种类型突触的发生发育。我们发现ErbB4对不同类型突触发生和成熟的调控机制不同。提示在中枢神经系统,尤其是大脑皮质内,存在于中间神经元上ErbB4通过多种不同调节方式,精密地调控锥体神经元的活动,参与大脑皮质内神经信息的传递和整合。这些结果从突触水平上为研究精神分裂症的发病机制提供了实验学依据,也为开发治疗精神分裂症疾病的临床药物提供了新思路。精神分裂症受遗传、心理和环境等影响,其病因和发病机制还不十分清楚。一种普遍被接受的观点是精神分裂症与多基因细小突变协同作用相关。TMEM108,编码跨膜蛋白108(TMEM108),也是精神分裂症易感基因之一。然而,我们对TMEM108却知之甚少。本文第二部分利用TMEM108基因敲除Lac Z基因敲入小鼠(TMEM108-/-)对TMEM108在小鼠大脑中的表达分布和功能做了一系列研究。结果表明:1)TMEM108集中表达在大脑海马齿状回,并受发育调控;2)TMEM108-/-小鼠齿状回颗粒细胞的成熟树突棘数量减少;3)TMEM108-/-小鼠齿状回的突触传递受损,且颗粒细胞m EPSCs的幅度减小,主要是由于AMPA受体介导的电流减少;4)TMEM108可与AMPA受体亚基Glu A2相互作用,并调节其在膜上的表达。这些结果表明,TMEM108可调控海马齿状回兴奋性突触的成熟和功能,可能为精神分裂症的发病机制提供新视角。
[Abstract]:Schizophrenia (SZ) is a nervous system disorder characterized by abnormal brain function (such as sensation, emotion, judgment, etc.), auditory hallucination, confusion, lack of pleasure and cognitive dysfunction. Neural information transmission and synaptic plasticity are caused by dysfunction of the nervous system. Disorder, considered as one of the major signs of schizophrenia. Neuromodulin 1 (Neuregulin 1, NRG1) and its receptor class epidermal growth factor 4 (ErbB4) are susceptibility genes for schizophrenia. Currently, the NRG1/ErbB4 signaling pathway is known to participate in the information transmission in the cerebral cortex by regulating the migration, differentiation, and synaptic integration of the cerebral cortex neurons. It is not clear how the signaling pathway regulates the development and internal mechanism of the cerebral cortical nerve loop, but it is known that ErbB4 is specifically expressed in the intermediate neurons. It is generally believed that the full-length NRG1 shear generation of active NRG1 ligands, the binding of ErbB4 and the activation of the receptor tyrosine kinase, and the intracellular downstream signal Pathways, regulation of synaptic transmission and nervous system development. In this paper, ErbB4 is used as a target to explore whether schizophrenia susceptibility gene ErbB4 regulates the formation of different types of synapses in the cerebral cortex. Are these regulatory effects dependent on the activity of ErbB4 kinase? What is the intrinsic mechanism of this regulation? The first part of this article is the use of ErbB4 knockout mice, ErbB4 Probiotic mice and ErbB4 tyrosine kinase domain gene mutation (T796G-ErbB4) mice, through cell culture, immunohistochemistry, immunoblotting and molecular and biochemical methods, have studied in vitro and in vitro the regulatory effect of ErbB4 on the development of different types of sudden triggering in the cerebral cortex of mice. The results showed that: 1) knocking out ErbB4, Influence of excitatory synapse development on pyramidal neurons, nor inhibitory synapse development.2 in intermediate neurons, ErbB4, excitatory synapses on GABA intermediate neurons, and.3 of inhibitory synapses on pyramidal neurons. Erb B inhibitors AG1487 and PD158780 widely affect the process of pyramidal and intermediate neurons. Contact occurred.4) using 1NMPP1 specificity to inhibit ErbB4 tyrosine kinase, significantly inhibiting the formation of excitatory synapses on the GABA intermediate neurons, but the development of inhibitory synapses on the pyramidal and intermediate neurons is not affected. It suggests that the developmental mechanism of the inhibitory synapses on the pyramidal neurons is regulated by the ErbB4 protein, but does not depend on the receptor kinase activity. From the synaptic point of view, the results show that ErbB4 and its kinase activity regulate the occurrence and development of various types of synapses in the cerebral cortex. We have found that ErbB4 has different regulatory mechanisms for different types of synapses and maturation. It is suggested that ErbB4 exists in the central nervous system, especially in the cerebral cortex, through a variety of differences. These results provide an experimental basis for the study of the pathogenesis of schizophrenia, and provide a new idea for the development of clinical drugs for the treatment of schizophrenia. Schizophrenia is inherited. The causes and pathogenesis are not very clear in psychological and environmental effects. A widely accepted view is the synergistic effect of schizophrenia and multi gene mutation,.TMEM108, encoding transmembrane protein 108 (TMEM108), also one of the susceptibility genes of schizophrenia. However, we know little about TMEM108. The second part of this article is beneficial. The TMEM108 gene knocking Lac Z gene was knocked into mice (TMEM108-/-) to make a series of studies on the expression and function of TMEM108 in the brain of mice. The results showed that: 1) TMEM108 concentrated in the dentate gyrus of the brain, and was regulated by development; 2) the number of mature dendritic spines in the dentate granulocytes of TMEM108-/- mice decreased; 3) TMEM108-/- mice. The synaptic transmission of the dentate gyrus was damaged and the amplitude of M EPSCs in granular cells decreased, mainly due to the decrease of the AMPA receptor mediated current; 4) TMEM108 could interact with the AMPA receptor subunit Glu A2 and regulate its expression on the membrane. These results suggest that TMEM108 can regulate the maturation and function of the excitatory synapse of the dentate gyrus, which may be a spiritual component. The pathogenesis of cleft disease provides a new perspective.
【学位授予单位】：南昌大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：R749.3

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