Notch1激活减轻小鼠糖尿病心肌再灌注损伤  

Notch1 activation attenuates myocardial reperfusion injury in diabetic mice

作　　者：杨怡[1,2] 裴海峰[2] 李秀川[2] 邱琛茗 宋晓峰[3] 杨永健[1,2] 

机构地区：[1]西南医科大学,四川泸州646000 [2]成都军区总医院心内科,四川成都610083 [3]成都军区总医院保健办,四川成都610083

出　　处：《基础医学与临床》2016年第9期1211-1215,共5页Basic and Clinical Medicine

基　　金：国家自然科学基金(81500208);全军医学科技青年培育项目(14QNP050);四川省科技支持计划(2015JY0277)

摘　　要：目的研究Notch1激活能否减轻糖尿病小鼠心肌再灌注(MI/R)损伤及肿瘤坏死因子α抑制剂(TNF-α)在其中的作用。方法用高脂饮食加腹腔注射链脲菌素(STZ)制备2型糖尿病小鼠模型,利用心肌点注射siRNA(20μg/只)技术敲低心肌Notch1信号。心肌点注射48 h后,制备心肌缺血(30 min)/再灌注模型。再灌注前10 min通过腹腔注射依那西普(8 mg/kg)给予治疗。再灌注3 h后,用ELISA测定血浆中TNF-α含量,Western blot测定心肌中TNF-α含量及Notch1激活程度,caspase-3检测心肌细胞凋亡水平;再灌注24 h后,通过Evan蓝和TTC双染及小动物超声观察心肌梗死面积和心脏功能。结果糖尿病小鼠血浆与心肌组织中的TNF-α水平均升高,而心肌组织中的Notch1活性明显被抑制(P<0.05)。依那西普治疗明显地减轻糖尿病小鼠乳酸脱氢酶(LDH)释放、改善心脏功能、减少心肌梗死面积、降低心肌细胞凋亡水平(P<0.01)。另外,依那西普显著降低了糖尿病小鼠TNF-α水平,同时明显地上调心肌Notch1的活性;而下调Notch1能够逆转依那西普的心肌保护作用(P<0.05)。结论 TNF-α抑制剂能够通过激活心肌Notch1来减轻糖尿病MI/R损伤。Objective To find whether Notchl can attenuates myocardial ischemia/reperfusion （MI/R） injury after diabetes, and to clarify the role of TNF-α inhibitor in it. Methods A murine model of type 2 diabetes mellitus was induced by STZ intraperitoneal injection along with a high fat diet. And Notchl specific small in- terfering RNA（siRNA, 20 μg） was delivered through intramyocardial injection to knockdown cardiac Notchl levels. After 48 hours, myocardial ischemia/reperfusion （30 minutes） mice model was prepared. Then, etan- ercept （8 mg/kg） was administrated by intraperitoneal injection 10 minute before reperfusion. Mice were subjected to 30 minutes of myocardial ischemia followed by 3 hours （for TNF-α contents determined by ELISA, Notchl activation and LDH release measured by western blot and cell apoptosis detected by caspase-3 activity assay ） or 24 hours （for myocardial infarct size assessed by Evans blue/（TTC） doubles staining and cardiac function determined by ultrasound） reperfusion. Results TNF-α level of plasma and the myocardial tissue in diabetes mice increased, while cardiac Notchl was significantly suppressed （ P 〈 0.05 ）. Etanercept apparently mitiga- ted MI/R injury in mice subjected to diabetic, evidenced by decreased release of LDH, improved cardiac function, lessened myocardial infarct size and reduced myocardial apoptosis （ P 〈 0. 01 ）. In addition, etaner- cept obviously reduced the contents of TNF-α in both plasma and myocardium, but enhanced the expression of Notchl intracellular domain （ Notchl ICD） in cardiac tissues （ P 〈 0.05 ）. The disturbance of Notchl path- way partly reversed etanercept＇s cardioprotection. Conclusions TNF-α inhibitor attenuates MI/R injury via activating Notchl in diabetic mice.

关 键 词：糖尿病 心肌再灌注损伤 NOTCH1 肿瘤坏死因子α抑制剂 

分 类 号：R587.2[医药卫生—内分泌] R542.2[医药卫生—内科学]