GDF11对II型糖尿病小鼠心肌损伤的保护作用

目的 观察GDF11对Ⅱ型糖尿病C57BL/6J小鼠心肌损伤的保护作用及心肌凋亡水平的变化情况。方法 60只体重20~25 g的雄性C57BL/6J小鼠,随机分为3个组：正常对照组（control）、Ⅱ型糖尿病模型组（DM）和GDF11干预组（DM+GDF11）。高脂高糖饲料饲养4周后,连续3次腹腔注射60 mg/kg链脲佐菌素（STZ）,建立Ⅱ型糖尿病小鼠模型,持续高脂高糖饲料饲养4周后,小动物超声检测心功能,取心肌组织,TUNEL染色检测心肌组织凋亡比例,Western blot法检测凋亡相关蛋白cleaved-caspase-3、Bcl-2和Bax的表达。结果 糖尿病损伤显著下调左室射血分数和左室短轴缩短率,增加心肌凋亡率,而给予重组GDF11蛋白能够明显改善心功能并减轻心肌凋亡。结论 外源性的GDF11可以显著减轻糖尿病损伤后心肌凋亡水平,改善心功能。

Protective effect of growth differentiation factor 11 on myocardial injury in type II diabetic mice

Objective To observe the protective effect of growth differentiation factor 11(GDF11) on myocardial injury and the changes of myocardial apoptosis in type 2 diabetic C57BL/6J mice. Methods Sixty male C57BL/6J mice weighing 20-25 g were randomly divided into three groups:control group (control), type 2 diabetes mellitus group (DM) and GDF11 intervention group (DM + GDF11). To establish mouse model of type 2 diabetes, the mice were fed with high fat and high sugar diet for 4 weeks, and i.p. injected consecutively three times of streptozotocin (STZ) in a dose of 60 mg/kg. After the continuous high-fat and high-sugar diet for 4 weeks, the cardiac function was detected by small animal ultrasound, TUNEL staining was used to detect the apoptosis in myocardium, and the expressions of cleaved-caspase-3, Bcl-2, Bax were measured. Results Diabetic injury significantly reduced the left ventricular ejection fraction and left ventricular short axis shortening rate, and increased myocardial apoptosis. Recombinant GDF11 protein significantly improved cardiac function and reduced myocardial apoptosis. Conclusions Exogenous GDF11 can significantly reduce myocardial apoptosis and improve heart function after diabetic injury.