慢性情绪应激对急性心肌梗死后骨髓c-kit~＋干细胞动员的影响

Impact of Chronic Emotional Stress On the Bone Marrow c-kit^+ Stem Cell Mobilization After Acute Myocardial Infarction in Rats

目的:探讨慢性情绪应激(焦虑和抑郁)对急性心肌梗死后骨髓c-kit+干细胞动员的影响。方法:根据随机数字表将SD大鼠分为假手术组、心肌梗死组、心肌梗死合并焦虑组、心肌梗死合并抑郁组,每组6只。采用两种慢性情绪应激方案,分别建立焦虑和抑郁的慢性情绪应激模型,并与冠状动脉左前降支结扎建立心肌梗死模型相结合,分别建立心肌梗死合并焦虑、心肌梗死合并抑郁的大鼠模型。超声心动图评价大鼠心功能,旷野试验评价大鼠活动能力,高架十字迷宫评价大鼠焦虑状态,强迫游泳评价大鼠抑郁状态,HE染色观察心脏和大脑病理改变,Masson染色观察心肌纤维化程度,酶联免疫吸附法(ELISA)检测外周血核转录因子-κB(NF-κB)的表达,流式细胞术检测外周血和骨髓c-kit^+干细胞的阳性细胞数。结果:(1)心肌梗死组、心肌梗死合并焦虑组、心肌梗死合并抑郁组的左心室射血分数低于假手术组,心肌梗死合并焦虑组和心肌梗死合并抑郁组的左心室射血分数低于心肌梗死组,差异均有统计学意义(P均<0.05)。(2)相比于心肌梗死组,心肌梗死合并焦虑组大鼠倾向于停留在高架十字迷宫中闭合臂,心肌梗死合并抑郁组的大鼠强迫游泳试验中漂浮不动的时间延长,且两组大鼠在旷野试验中的运动能力均减弱(P均<0.05)。(3)病理染色结果显示,心肌梗死组、心肌梗死合并焦虑组和心肌梗死合并抑郁组大鼠的心肌出现心肌坏死和纤维化,心肌梗死合并焦虑组和心肌梗死合并抑郁组大鼠的大脑海马CA3区细胞排列紊乱。(4)心肌梗死合并焦虑组和心肌梗死合并抑郁组的大鼠外周血NF-κB含量高于心肌梗死组(P<0.05)。相比于心肌梗死组,心肌梗死合并焦虑组大鼠骨髓c-kit^+干细胞数减少,心肌梗死合并抑郁组大鼠外周血c-kit^+干细胞数减少(P均<0.05)。结论:结扎冠状动脉左前降支联合空瓶刺激法、孤养+慢性不可预知性刺激分别可建立心肌梗死合并焦虑大鼠模型、心肌梗死合并抑郁大鼠模型;焦虑和抑郁可抑制心肌梗死后骨髓和外周血c-kit^+干细胞的动员,其原因可能与焦虑抑郁导致心肌梗死后NF-κB升高有关。

Objectives： To investigate the impact of chronic emotional stress（anxiety and depression） on bone marrow c-kit~＋ stem cell mobilization after acute myocardial infarction（AMI） in rats.Methods： Male SD rats were randomly divided into four groups（n=6 each）： sham group（SH）, AMI group（MI）, AMI complicated with anxiety group（MA）, AMI complicated with depression group（MD）. AMI was performed at 15 th day of various stimulation. One week later, cardiac function was evaluated by echocardiography, mobility status evaluated by open field test（OFT）, depression-like behaviors was evaluated by forced swim test（FST）, anxiety-like behaviors was evaluated by elevated plus-maze（EPM） test. Rats were then sacrificed and HE pathological staining was used to evaluate the pathological change of heart and brain. Masson pathological staining was used to evaluate the degree of cardiac fibrosis. NF-κB level in the peripheral blood was measured by ELISA. The number of the c-kit~＋ stem cells in bone marrow and peripheral blood weredetected by flow cytometry.Results： Left ventricular ejection fraction（LVEF） was significantly lower in MI, MA and MD groups than in SH group and significantly lower in MA and MD groups than in MI group（all P〈0.05）. The rats of MA group preferred to stay at the closed arm in EPM and the immobility time in FST was significantly longer in MD group than in MI group, and poorer mobility status was evidenced in MA and MD groups as compared to MI group in OFT（all P〈0.05）. HE and Masson staining of heart tissue evidenced myocardial necrosis and myocardial fibrosis in MI group, MA group and MD group. HE stained brain tissue showed the disordered arrangement of cells in hippocampal CA3 area in MA group and MD group. NF-κB level in the peripheral blood was significantly higher in MA group and MD group than in MI group（both P〈0.05）, while the number of the c-kit~＋ stem cells was significantly lower in bone marrow of MA group and lower in peripheral blood of MD group compared to MI group（all P〈0.05）. Conclusions： Ligation of left anterior descending（LAD） complicated with stimulation of empty bottle could establish the rat model of AMI with anxiety while the ligation of LAD complicated with separation and chronic unpredictable mild stress could establish the model of AMI with depression. Anxiety and depression may inhibit the mobilization capacity of bone marrow c-kit~＋ stem cell after AMI,which may be linked with the higher level of NF-κB in MI rats complicating with anxiety or depression.