發(fā)布時間：2018-10-21 12:34

【摘要】：目的探討褪黑素通過沉默信息調節(jié)因子1(SIRT1)減輕線粒體氧化應激機制對腦缺血-再灌注(IR)小鼠的作用。方法通過線栓法建立小鼠短暫性大腦中動脈阻塞(MCAO)IR模型,對190只小鼠經腹腔注射褪黑素和側腦室注射SIRT1抑制劑EX527,剔除死亡小鼠30只,按隨機數字表法分為IR組、褪黑素組、褪黑素+EX527組、EX527組各40只,通過2,3,5-氯化三苯基四氮唑(TTC)法測定腦梗死體積、干濕比重法測定腦水腫并進行神經功能缺損評分。通過Western blot檢測線粒體和胞質SIRT1、Ac-P53、Ac-核因子κB(Ac-NF-κB)、BCL2、BAX蛋白以及細胞色素C蛋白表達。多組間比較采用單因素方差分析。結果 (1)4組間腦梗死體積、神經功能障礙評分和腦水腫的差異均有統(tǒng)計學意義(F值分別為16.452、23.622和18.786,均P0.05)。4組SITR1、Ac-P53、Ac-NF-κB、BCL2、BAX表達差異均有統(tǒng)計學意義(F值分別為2 348.158、1 434.841、7 042.563、14 627.128和691.475,均P0.05)。4組小鼠線粒體膜電位、線粒體活性氧和復合體Ⅰ活性差異有統(tǒng)計學意義(F值分別為28.454、33.728和29.716,均P0.05)。(2)與IR組相比,褪黑素組的腦梗死體積縮小(32±5)mm~3比(57±5)mm~3,P0.05);神經功能障礙評分降低(2.4±0.3比3.5±0.3,P0.05);腦水腫減輕(80.2±0.9)%比(83.9±1.2)%,P0.05);SIRT1和抗凋亡蛋白BCL2的表達增加(P0.05);促凋亡蛋白BAX和Ac-P53、Ac-NF-κB的表達減少(P0.05);線粒體膜電位、線粒體復合體Ⅰ活性和細胞色素C水平提高(P0.05);胞質活性氧產物和細胞色素C水平降低(P0.05)。(3)與褪黑素組相比,褪黑素+EX527組的腦梗死體積增大[(42±5)mm~3比(32±5)mm~3,P0.05];神經功能障礙評分增高(3.2±0.3比2.4±0.3,P0.05);腦水腫加重[(83.4±0.8)%比(80.2±0.9)%,P0.05];SIRT1和抗凋亡蛋白BCL2的表達減少(P0.05);促凋亡蛋白BAX和Ac-P53、Ac-NF-κB的表達增加(P0.05);線粒體膜電位、線粒體復合體Ⅰ活性和細胞色素C水平降低(P0.05);胞質活性氧產物和胞質細胞色素C水平提高(P0.05)。結論在缺血性卒中模型小鼠中,褪黑素通過激活SIRT1信號通路,減輕線粒體氧化應激損傷和細胞死亡,從而發(fā)揮腦保護作用。
[Abstract]:Objective to investigate the protective effect of melatonin on cerebral ischemia-reperfusion (IR) mice by silencing information regulatory factor 1 (SIRT1). Methods the (MCAO) IR model of transient middle cerebral artery occlusion in mice was established by the method of thread occlusion. Thirty dead mice were killed by intraperitoneal injection of melatonin and injection of SIRT1 inhibitor EX527,. According to the method of random number table, they were divided into IR group and melatonin group. The volume of cerebral infarction was measured by (TTC) method in melatonin EX527 group and 40 rats in EX527 group. Brain edema was measured by dry-wet specific gravity method and neurological impairment score was evaluated. The expression of SIRT1,Ac-P53,Ac- nuclear factor 魏 B (Ac-NF- 魏 B), BCL2,BAX protein and cytochrome C protein) in mitochondria and cytoplasm was detected by Western blot. Single factor analysis of variance (ANOVA) was used for multi-group comparison. Results (1) the volume of diencephalic infarction in 4 groups, There were significant differences in neurological dysfunction score and cerebral edema (F = 16.452, 23.622 and 18.786, respectively, P0.05). There were significant differences in the expression of BCL2BAX in SITR1,Ac-P53,Ac-NF- 魏 B, BCL2BAX in 4 groups (F = 2 348.158 1 434.841 7 042.56314 627.128 and 691.475, respectively, P0.05). The activity of reactive oxygen species (Ros) and complex 鈪，

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