Centre for Psychiatric Research, Aarhus University Hospital, Risskov, Denmark.
Brain Res. 2011 Apr 18;1385:26-37. doi: 10.1016/j.brainres.2011.02.048. Epub 2011 Feb 24.
Prolonged stress has been associated with altered synaptic plasticity but little is known about the molecular components and mechanisms involved in the stress response. In this study, we examined the effect of chronic restraint stress (CRS) on the expression of genes associated with synaptic vesicle exocytosis in rat prefrontal cortex and hippocampus. Rats were stressed daily using a 21day restraint stress paradigm, with durations of half an hour or 6h. RNA and protein were extracted from the same tissue sample and used for real-time quantitative polymerase chain reaction (real-time qPCR) and immunoblotting, respectively. Focusing on the SNARE complex, we investigated the expression of the SNARE core components syntaxin 1A, SNAP-25, and VAMP2 at both transcriptional and protein levels. In addition, the expression of 10 SNARE regulatory proteins was investigated at the transcriptional level. Overall, the prefrontal cortex was more sensitive to CRS compared to the hippocampus. In prefrontal cortex, CRS induced increased mRNA levels of VAMP2, VAMP1, syntaxin 1A, snapin, synaptotagmins I and III, and synapsins I and II, whereas SNAP-25 was down-regulated after CRS. Immunoblotting demonstrated equivalent changes in protein levels of VAMP2, syntaxin 1A, and SNAP-25. In hippocampus, we found increased mRNA levels of VAMP2 and SNAP-29 and a decrease in VAMP1 levels. Immunoblotting revealed decreased VAMP2 protein levels despite increased mRNA levels. Changes in the expression of synaptic proteins may accompany or contribute to the morphological, functional, and behavioral changes observed in experimental models of stress and may have relevance to the pathophysiology of stress-related disorders.
慢性应激与突触可塑性改变有关，但对于应激反应中涉及的分子成分和机制知之甚少。在这项研究中，我们研究了慢性束缚应激（CRS）对大鼠前额叶皮层和海马突触小泡胞吐相关基因表达的影响。使用 21 天束缚应激范式每天对大鼠施加应激，时长半小时或 6 小时。从同一组织样本中提取 RNA 和蛋白质，分别用于实时定量聚合酶链反应（real-time qPCR）和免疫印迹。我们聚焦 SNARE 复合物，研究了 SNARE 核心成分突触融合蛋白 1A、SNAP-25 和 VAMP2 在转录和蛋白水平上的表达。此外，还在转录水平上研究了 10 种 SNARE 调节蛋白的表达。总体而言，前额叶皮层对 CRS 的敏感性高于海马体。在前额叶皮层中，CRS 诱导 VAMP2、VAMP1、突触融合蛋白 1A、snapin、突触素 I 和 III 以及突触素 I 和 II 的 mRNA 水平增加，而 SNAP-25 在 CRS 后下调。免疫印迹显示 VAMP2、突触融合蛋白 1A 和 SNAP-25 的蛋白水平发生了相同的变化。在海马体中，我们发现 VAMP2 和 SNAP-29 的 mRNA 水平增加，而 VAMP1 的水平降低。免疫印迹显示尽管 mRNA 水平增加，但 VAMP2 蛋白水平下降。突触蛋白表达的变化可能伴随或促成应激实验模型中观察到的形态、功能和行为变化，并且可能与应激相关疾病的病理生理学有关。
