可卡因-苯丙胺调节转录肽对缺血-再灌注模型小鼠皮质突触可塑性的影响

发布时间：2018-12-28 08:12

【摘要】：目的观察可卡因-苯丙胺调节转录肽(CART)对缺血-再灌注(I/R)小鼠皮质突触可塑性的影响。方法选用10~12周龄的健康雄性清洁级昆明小鼠288只,按照随机数字表法完全随机分为I/R组(81只)、I/R+CART组(81只)和假手术组(63只)、假手术+CART组(63只)。建立大脑中动脉阻塞(MCAO)2h再灌注模型。I/R+CART组于再灌注前经尾静脉注射CART(0.5μg,200μl),假手术+CART组予以等剂量CART;每24小时重复给药1次。在实现再灌注后不同时间点(24h、72h和7d)采用2,3,5-氯化三苯基四氮唑染色检测I/R组和I/R+CART组脑梗死体积;采用透射电镜观察各组不同时间点突触超微结构变化,并对突触形态学参数进行定量分析;采用Western Blot法观察再灌注72h皮质梗死周围区突触后致密物95(PSD-95)蛋白表达水平。结果(1)与假手术组比较,I/R组小鼠造模后24、72h和7d皮质切片中突触数量明显减少[3.37±0.38)个/μm~2比(7.04±0.55)个/μm~2,(2.89±0.22)个/μm~2比(6.89±0.04)个/μm~2,(3.25±0.18)个/μm~2比(6.78±0.42)个/μm~2;均P0.05],PSD密度明显下降[24.4±2.8)nm比(47.3±6.1)nm,(23.8±3.7)nm比(46.5±7.5)nm,(24.6±2.2)nm比(48.1±5.1)nm:均P0.05],突触间隙宽度增大[25.2±2.1)nm比(21.5±1.6)nm、(25.2±1.4)nm比(21.3±1.0)nm,(23.7±2.6)nm比(21.6±1.6)nm;均P0.05];再灌注后72h时间点PSD-95蛋白表达水平下降(P0.05);(2)与I/R组比较,I/R+CART组小鼠I/R后24、72h和7d脑梗死体积缩小[分别为(29.0±1.9)%比(36.3±1.4)%,(38.1±1.4)%比(47.6±2.7)%,(36.0±2.8)%比(42.5±2.0)%;均P0.05];再灌注后72h时间点突触数量[4.32±0.35)个/μm~2]明显增多(P0.05),PSD-95蛋白表达水平增加(P0.05);再灌注后24、72 h和7d各时间点PSD密度[分别为(33.8±3.4)、(34.2±4.6)、(38.2±4.0)nm]增厚(均P0.05);而各时间点突触间隙宽度差异无统计学意义(均P0.05)。结论CART可缩小I/R小鼠脑梗死体积,改善缺血损伤后小鼠脑皮质神经细胞突触可塑性。
[Abstract]:Aim to investigate the effect of cocaine-amphetamine regulated transcription peptide (CART) on synaptic plasticity in ischemic reperfusion (I / R) mice. Methods 288 healthy male Kunming mice were randomly divided into I / R group (n = 81), I / R CART group (n = 81), sham operation group (n = 63) and CART group (n = 63). To establish the model of (MCAO) 2 h reperfusion in middle cerebral artery occlusion, I / R CART group was injected with CART via caudal vein before reperfusion (0. 5 渭 g / 200 渭 l),) CART group was given CART; at the same dose once every 24 hours. At different time points after reperfusion (24 h, 72 h and 7 d), the infarct volumes of I / R group and I / R CART group were measured by using 2-titriphenyl tetrazolium chloride staining. The ultrastructural changes of synapses at different time points were observed by transmission electron microscope and the morphological parameters of synapses were quantitatively analyzed. The expression of postsynaptic dense substance 95 (PSD-95) protein was observed by Western Blot method. Results (1) compared with the sham-operated group, the synapses in the cortex sections of the I / R group were significantly decreased [3.37 卤0.38] / 渭 m ~ (2) / 渭 m ~ (2) / (7.04 卤0.55) / 渭 m ~ (2). (2.89 卤0.22) / 渭 m ~ (2) vs (6.89 卤0.04) / 渭 m ~ (2), (3.25 卤0.18) / 渭 m ~ (2) / 渭 m ~ (2), (6.78 卤0.42) / 渭 m ~ (2); The density of PSD decreased significantly [24.4 卤2.8 nm vs (47.3 卤6.1) nm, (23.8 卤3.7) nm vs (46.5 卤7.5) nm, (24.6 卤2.2) nm vs (48.1 卤5.1) nm: P0.05]. Increased gap width [25.2 卤2.1) nm ratio (21.5 卤1.6) nm, (25.2 卤1.4) nm to (21.3 卤1.0) nm, (23.7 卤2.6) nm ratio (21.6 卤1.6) nm; The expression of PSD-95 protein decreased at 72 h after reperfusion (P0.05). (2) compared with the I / R group, the volume of cerebral infarction in the I / R CART group decreased at 2472 h and 7 d after I / R [(29.0 卤1.9)% vs (36.3 卤1.4)%, (38.1 卤1.4)% vs (47.6 卤2.7)%, respectively]. (36.0 卤2.8)% vs (42.5 卤2.0)%; At 72 h after reperfusion, the number of synapses [4.32 卤0.35] / 渭 m-2 increased significantly (P0.05), and the expression of PSD-95 protein increased (P0.05). The PSD density at 24 h and 7 d after reperfusion [(33.8 卤3.4), (, 34.2 卤4.6), (, 38.2 卤4.0) nm, respectively] was thickened (P0.05). There was no significant difference in the width of synaptic space at each time point (P0.05). Conclusion CART can reduce the volume of cerebral infarction in I / R mice and improve the synaptic plasticity of cortical neurons after ischemia injury in mice.
【作者单位】：南京大学医学院附属南京鼓楼医院急诊医学科;
【基金】：国家自然科学基金项目(81571122)
【分类号】：R743.3

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