CRMP4/Sema3A介导的突触分枝形成和可塑性调控在抑郁症中的作用机制研究

Major depression (MDD) is a chronic and debilitating mood disorder which affects public health seriously. Previous studies suggest that synaptic plasticity was highly correlated to major depressive disorder. Our study demonstrated that CRMP4 was significantly increased in the prefrontal cortex of depressive mice, a number of studies have confirmed that CRMP4 is associated with several neuropsychiatric disorders, some experiments have also demonstrated that CRMP4 regulates the process of neuronal dendritic growth and synaptic plasticity mediated by axon growth factor Sema3A, but the relationship among CRMP4,Sema3A and synaptic plasticity in MDD is unclear. We plan to explore the effect of CRMP4/Sema3A pathway on dendritic branch formation, synaptic plasticity of depressive animals, through up-regulation /down-regulation of expression of CRMP4 in vitro and in vivo, by employing electron microscopy, WB and electrophysiology techniques. And this study will clarify the key mechanisms of CRMP4 regulating Sema3A-mediated dendritic branch formation, synaptic plasticity in depression from a new perspective and thinking, and further explore the molecular pathway of "CRMP4-Sema3A-synaptic plasticity-depressive behavior", to provide new ideas and clues for understanding the mechanism of major depressive disorder.

抑郁症严重危害公共健康，前期研究提示其发生发展与突触可塑性改变存在紧密联系。课题组前期研究证实抑郁样大鼠前额叶皮层中坍塌反应调节蛋白（CRMP4）的表达显著上调，且有多项研究证实CRMP4与数种神经精神疾病密切相关，亦有实验证明CRMP4可调控轴突生长导向因子（Sema3A）介导的神经元树突发育及突触可塑性过程，但CRMP4与Sema3A及突触可塑性在抑郁症中的关系尚不明确。本研究拟在细胞和动物水平通过上调或下调CRMP4的表达，利用电镜、WB以及神经电生理等技术，观察在抑郁样动物中CRMP4/Sema3A对树突分支形成和突触可塑性的影响，并从全新的角度和思路阐明CRMP4调控Sema3A介导的神经元树突发育及突触可塑性参与抑郁症的关键机制，深入探讨“CRMP-Sema3A-突触可塑性-抑郁样行为”的分子通路，为了解抑郁症的病理生理提供新的思路和线索。

抑郁症和焦虑症患病率逐年上升，对个人乃至社会造成了严重的危害。这两种疾病通常共同出现，但又有其特有的临床表现和机制。本研究采用慢性温和应激(CMS)动物模型成功构建了抑郁易感、焦虑易感以及应激抵抗模型，并且进一步采用基于 iTRAQ 的鸟枪定量方法来对三组大鼠的嗅球进行了比较定量蛋白质组学分析，并采用平行反应监测(PRM)以及Western blot (WB)对蛋白表达进行独立分析，并进行生物信息学分析。蛋白组学分析共鉴定出133个差异表达蛋白。随后基于PRM或WB的分析显示，Nefl、Mtmr7和Tk2；Prkaca、Coa3、Cox6c2、Lamc1和Tubal3；以及Pabpn1、Nme3、Sos1和Lum的变化分别与抑郁易感、焦虑易感以及应激抵抗组存在独特的相关性。这些特异表达的差异蛋白主要参与多种代谢和信号转导通路，表明完全相同的CMS刺激条件下，抑郁应激以及焦虑应激过程对嗅觉蛋白调控系统和生物过程具有不同的影响，因此可能作为潜在的疾病标志物生物靶点。