摘要
目的观察脑缺血急性期半暗带区Notch1活性的动态变化，探讨其与缺血后细胞凋亡的关系，为缺血性脑血管病临床治疗寻找可能的靶点。方法采用线栓中动脉闭塞（MCAO）法建立局灶性脑缺血模型。SD雄性成年大鼠随机分为假手术组（Sham组）、MCAO＋溶剂对照组（Vehicle组）、MCAO＋Notch1抑制剂组（DAPT组）。原位缺口末端标记法（TUNEL）检测凋亡指数，Western blot法检测Notch1活性片段（NICD）、聚腺苷二磷酸核糖聚合酶（PARP）裂解片段、蛋白激酶B（Akt）和Bad磷酸化。
结果缺血后1、3、7 d NICD含量较Sham组分别增加2.1、4.6、3.8倍。持续侧脑室注射DAPT抑制NICD产生后，1、3、7 d凋亡指数[分别为（32.71±5.20）%、（52.58±9.20）%、（49.53±8.40）%]较Vehicle组[分别为（23.21±4.66）%、（37.86±8.12）%、（34.87±7.30）%]增加，磷酸化Akt及Bad较Vehicle组明显下降。
结论脑缺血急性期半暗带区Notch1活性增加，可能具有抑制细胞凋亡的作用；抑制Notch1活化可加重缺血性脑损伤。
ObjectiveTo study the dynamic changes of Notch1 activity in penumbra area and its role in cell apoptosis during acute phase of cerebral ischemic injury and explore new therapeutic target for ischemia cerebrovascular disease.
MethodsFocal cerebral ischemic model was established by intraluminal middle cerebral artery occlusion （MCAO） method. Adult male SD rats were randomly divided into sham group （Sham）, MCAO＋ Notch1 inhibitor group （DAPT group）, and MCAO＋ vehicle control group （Vehicle group）. Cell apoptotic index was analyzed by TdT-mediated dUTP nick end labeling （TUNEL） staining. The poly adenosine diphosphate-ribose polymerase （PARP） cleavage fragment, activated Notch1 fragment, phosphorylation of protein kinase B （Akt） and Bad were detected by Western blotting.
ResultsThe Notch1 activity in ischemic penumbra area at 1, 3, 7 d after ischemia was increased by 2.1, 4.6, 3.8 folds, respectively, in comparison to sham group. Consecutive DAPT injection significantly reduced Notch1 activity. The apoptotic indices in DAPT group at 1, 3, 7 d [（32.71±5.20）%, （52.58±9.20）%, （49.53±8.40）%, respectively] were significantly higher than those in Vehicle group [（23.21±4.66）%, （37.86±8.12）%, （34.87±7.30）%, respectively], and the phosphorylation levels of Akt and Bad in DAPT group were lower than those in Vehicle group.
ConclusionIncreased Notch1 activity in ischemic penumbra following ischemic stroke maybe inhibit cell apoptosis and inhibition of Notch1 activity may exacerbate ischemic injury.
出处
《中华实验外科杂志》
CSCD
北大核心
2017年第10期1702-1704,共3页
Chinese Journal of Experimental Surgery
基金
武汉大学医学创新种子基金（266078）
