摘要
目的评价沉默调节蛋白1（SIRT1）介导糖尿病大鼠心肌线粒体自噬的机制与线粒体融合蛋白2（Mfn2）的关系。方法SPF级健康成年雄性SD大鼠24只，体重210～220 g，采用随机数字表法分为3组（n＝8）：对照组（C组）、糖尿病组（DM组）、糖尿病＋SIRT1激动剂SRT1720组（DM＋SRT组）。采用腹腔注射1%链脲佐菌素60 mg/kg的方法建立大鼠糖尿病模型。DM＋SRT组连续7 d尾静脉注射SIRT1激动剂SRT1720 1 mg/kg。随后采用超声法测定心功能指标：左室舒张末期容积（LVEDV）、左室收缩末期容积（LVESV）、左室射血分数（LVEF）、心率（HR）、舒张早期心室充盈速度最大值（E）、舒张晚期心室充盈速度最大值（A）和峰值流速比值（E/A比值）；取心肌组织，采用免疫共沉淀法检测SIRT1与Mfn2的结合水平、Mfn2乙酰化水平；Western blot法检测SIRT1、Mfn2、微管相关蛋白1轻链3Ⅱ（LC3Ⅱ）、LC3Ⅰ、Beclin1和P62的表达，计算LC3Ⅱ与LC3Ⅰ的比值（LC3Ⅱ/Ⅰ）。结果与C组比较，DM组LVEDV、LVEF、HR、E和E/A比值降低，A升高，LC3Ⅱ/Ⅰ比值降低，Beclin1、SIRT1和Mfn2表达下调，P62表达上调，Mfn2-SIRT1结合水平降低（P〈0.05）。与DM组比较，DM＋SRT组LVEDV、LVEF、E和E/A比值升高，A降低，LC3Ⅱ/Ⅰ比值升高，Beclin1和SIRT1表达上调，P62表达下调，Mfn2-SIRT1结合水平升高，Mfn2乙酰化水平降低（P〈0.05）。结论SIRT1介导糖尿病大鼠心肌线粒体自噬的机制与其对Mfn2的去乙酰化作用有关。
ObjectiveTo evaluate the relationship between the mechanism of silent information regulator factor 2-related enzyme 1（SIRT1）-mediated mitophagy in the myocardium and mitofusin 2（Mfn2）in diabetic rats.MethodsTwenty-four SPF healthy adult male Sprague-Dawley rats, weighing 210-220 g, were allocated into 3 groups（n=8 each）using a random number table： control group（group C）, diabetes mellitus group（group DM）and diabetes mellitus plus SIRT1 activator SRT1720 group（group DM＋ SRT）. Diabetes mellitus was induced by intraperitoneal 1% streptozotocin 60 mg/kg and confirmed by blood glucose ≥16.7 mmol/L 3 days later.SRT1720 1 mg/kg was injected via the caudal vein for 7 consecutive days in group DM＋ SRT.The ultrasonic method was used to measure the parameters of heart function including left ventricular end-diastolic volume（LVEDV）, left ventricular end-systolic volume（LVESV）, left ventricular ejection fraction（LVEF）, heart rate（HR）, E wave velocity（E）, A wave velocity（A）and E/A ratio.Myocardial specimens were obtained for determination of the interaction between SIRT1 and Mfn2 and acetylation of Mfn2（by co-immuno-precipitation）and expression of SIRT1, Mfn2, microtubule-associated protein 1 light chain 3 Ⅱ（LC3Ⅱ）, LC3Ⅰ, Beclin1 and P62（by Western blot）. The ratio LC3Ⅱ to LC3Ⅰ（LC3Ⅱ/Ⅰ ratio）was calculated.ResultsCompared with group C, LVEDV, LVEF, HR, E and E/A ratio were significantly decreased, A was increased, LC3Ⅱ/Ⅰ ratio was decreased, the expression of Beclin1, SIRT1 and Mfn2 was down-regulated, the expression of P62 was up-regulated, and the interaction between SIRT1 and Mfn2 was decreased in group DM（P〈0.05）. Compared with group DM, LVEDV, LVEF, E and E/A ratio were significantly increased, A was decreased, LC3Ⅱ/Ⅰ ratio was increased, the expression of Beclin1 and SIRT1 was up-regulated, the expression of P62 was down-regulated, the interaction between SIRT1 and Mfn2 was increased, and the acetylation of Mfn2 was decrease
出处
《中华麻醉学杂志》
CSCD
北大核心
2017年第8期993-996,共4页
Chinese Journal of Anesthesiology
基金
国家自然科学基金（81471844,81671891）
中央高校基本科研业务费专项基金（2042017kf0147）
