慢性应激损伤大鼠海马突触传递异常的初步研究

Primary research on abnormal hippocampal synaptic transmission induced in a chronic mild stressed rat model

目的 本研究采用双向电泳的方法,分析抑郁模型大鼠海马突触差异表达蛋白,以探索抑郁症的突触发病机制.方法 根据糖水消耗基线值,随机将58只健康雄性Sprague-Dawley（SD）大鼠分为慢性轻度应激（Chronic Mild Stress,CMS）组和对照组（每组29只）,通过CMS实验模式建立大鼠抑郁模型后,运用蔗糖密度梯度离心法提取CMS组和对照组大鼠的海马突触,使用PH 5-8胶条进行传统的双向凝胶电泳,并用基质辅助激光解析电离飞行时间串联质谱进行差异蛋白鉴定.结果 CMS模型组较对照组大鼠糖水消耗量和偏好度均降低（P＜0.05）,提示成功建立大鼠抑郁模型.同时,通过双向凝胶电泳和质谱分析,得到了16个差异表达的海马突触蛋白质,其中,在CMS组中有4个蛋白表达下调,12个蛋白表达上调,这些差异蛋白质的功能主要分为四类,即能量代谢、物质代谢、细胞骨架和囊泡转运.结论 本研究发现的差异蛋白可能是抑郁症海马突触传递异常的重要分子病理基础,从而为抑郁症突触发病机制的研究提供了有价值的线索.

Objective The differential proteins of hippocampal synapses in depression model rat was analyzed by two-dimensional gel electrophoresis.To provide clues for studies on the synaptic pathogenesis of depression.Methods According to the baseline of sucrose consumption,58 male Sprague-Dawley rats were divided into Chronic Mild Stress （CMS） and control groups randomly （n=29 per group）.After establishment of rat depression model via CMS experimental mode,rat hippocampal synapses from the CMS and control groups were prepared by discontinuous sucrose density gradient centrifugation.Subsequently,the differential proteomics analysis were performed by conventional two-dimensional gel electrophoresis （2DE） and matrix-assisted laser desorption/ionization tandem time-of-flight mass spectrometry （MALDI-TOF/TOF-MS）.Results The results from the sucrose consumption test showed consistent decreases of sucrose intake and preference in the CMS group （P＜0.05）,suggesting that the depression model rat had been successfully established.Furthermore,by 2DE combined with mass spectrometry analysis （2DE-MS）,16 differentially expressed proteins were obtained,of which 12 were up-regulated and 4 were down-regulated in the chronic mild stressed group as compared with the control group.These proteins were mainly classified into four functional categories including energy metabolism,substance metabolism,cytoskeleton and vesicular transport.Conclusion Differential proteins found in this study may participate in an important mechanism that underlies the abnormal transmission of hippocampal synapses found in the chronic mild stressed rat,thereby providing valuable clues for studies on the pathogenesis of depression.