神经突触传递稳态的Rab3GAP调控机制及其在抗抑郁研究中的作用

Neuron synaptic homeostasis changes have become a popular target of antidepressant research. This research not only need to consider drug-based antidepression as a regular pattern, but also with the aid of the stress resilience as a new study carrier. Several studies have found that there are some commonalities and correlations between stress resilience and drug-based antidepression in terms of synaptic transmission homeostasis, however, their corresponding comprehensive analysis and deep excavation have not yet been carried out. In our previous synaptic membrane proteome research, abnormal expression of Rab3a-GTP and syntaxin 1 in presynaptic active zone of the stress resilient rat hippocampus were found, which subjected to potential induction of synaptic Rab3GAP. On the basis of the finding, in this study we attempt to seize the key scientific problems--“how Rab3GAP to regulate synaptic transmission homeostasis and its antidepressant effect”. Through a combination of broad-spectrum and targeted analysis, we intend to systematically construct the molecule networks of Rab3GAP regulating neurotransmission in the cellular and animal models. At the same time, the patch-clamp and HPLC-ECD chromatography will be employed to analyze the corresponding changes of neurotransmitters. Then, by means of the neural circuitry of fear and reward, the commonalities and correlations between stress resilience and drug anti-depression in terms of synaptic transmission homeostasis will be explored to discover the potential and new antidepressant ways. Further, the regulation of Rab3GAP to synaptic homeostasis changes of neural circuits as an antidepressant new way will be consolidated using brain region targeted intervention strategy.

神经突触自稳态变化已成为抗抑郁研究的热门靶标，此类研究不仅需以药物抗抑郁作为常规切入模式，还可借助应激抵抗这一新研究载体。研究已发现应激抵抗与药物抗抑郁的突触传递稳态变化存在诸多共性和关联，但尚未得到全面剖析和深度挖掘。前期突触膜蛋白质组研究发现应激抵抗大鼠海马突触前活性区Rab3a-GTP和Syntaxin 1表达异常，受到突触蛋白Rab3GAP的潜在诱导。籍此基础上，本项目拟围绕“Rab3GAP如何调控突触传递稳态及其抗抑郁作用”这一关键科学问题，有机整合蛋白质靶向和广谱分析策略，在细胞和动物水平系统构建Rab3GAP调节突触传递稳态的分子网络；同时利用膜片钳和高效液相色谱电化学等技术分析相应神经递质变化；从恐惧和奖赏神经环路层面探讨应激抵抗与药物抗抑郁突触传递稳态的共性和关联，发现抗抑郁新机制；并采用脑区靶向干预策略以期夯实Rab3GAP调节神经环路突触传递稳态变化的抗抑郁新途径。

抑郁症作为一种常见的情绪障碍，可由各种原因引起，具有严重的危害性。应激性事件通常被认为是抑郁症的主要促发因素，但在日常生活中有部分人群即使饱受压抑仍可保持正常心理状态，导致该现象发生的分子机制目前尚不清晰。已有研究表明，海马突触可塑性改变已成抑郁症发生的最终共同途径，而这在抵抗应激机制中所扮演角色需深入剖析。本项目首先采用慢性温和应激模式建立了抑郁大鼠模型，依据行为学评估结果得到了对照、应激抵抗和应激敏感三个组别；随后利用稳定同位素标记的相对和绝对定量（iTRAQ）技术结合二维液相色谱串联质谱对各组大鼠海马突触连接的蛋白质组进行定量分析；通过生物信息学和免疫印迹分析，发现在应激抵抗大鼠的海马突触活性区存在应激保护相关的分子适应性表征，可能是潜在的抗抑郁新机制。进一步选取了感兴趣蛋白Rab3GAP1并对其调控机制进行了解析，在体外培养神经元中稳定过表达和低表达Rab3GAP1后，使用基于iTRAQ标记的定量蛋白质组技术对Rab3GAP1所引起的蛋白质表达变化进行比较分析，并通过生物信息学分析初步探讨了Rab3GAP1调节的分子机制，增进了我们对突触可塑性机制的理解。另外，我们还借助糖水偏好和高架十字迷宫实验对应激敏感大鼠进行抑郁/焦虑敏感亚组分析，并利用定量蛋白质组学和生物信息学技术发现了一些涉及各种代谢途径的潜在蛋白质表达变化，可作为疾病研究的潜在新靶点，该分子基础将有助于更好理解应激诱导的抑郁/焦虑和应激抵抗的病理生理机制的共性和特异性。本项目利用定量蛋白质组学技术发现的所有差异数据，将给抑郁症的诊治、抗抑郁药物的研发和临床使用提供新的理论依据。