新型粉防己碱纳米脂质体通过激活Nrf2/HO-1信号通道预防糖尿病心肌病的实验研究

Preventive Effect of Tetrandrine-loaded Nanoliposomes on Diabetic Cardiomyopathy by Activating Nrf2/HO-1 Signaling Pathway

目的:考察包载粉防己碱(Tet)新型纳米脂质体(Tet-lips)对于糖尿病心肌病(DCM)的预防作用及其机制。方法:应用薄膜分散法结合超声水合技术制备Tet-lips并对其进行质量表征。腹腔注射链脲佐菌素(STZ)建立1型糖尿病(DM)实验动物模型后,将实验动物随机分为正常对照组、DM组、Tet溶液组及Tet-lips组分别接受相应形式药物干预。药物干预结束后分别应用超声心动图、HE染色及透射电镜评价各组大鼠心功能及心肌细胞结构。ELISA及Western blot技术分析各组大鼠的氧化应激水平及分子机制。结果:Tet-lips形态圆整,分散均匀,包封率高达(87.23±2.21)%且稳定好。常规超声心功能检查结果显示DM组大鼠心功能指标包括左心室舒张末内径(LVEDD)、左心室收缩末内径(LVESD)、左心室舒张末期容积(LVEDV)、左心室收缩末期容积(LVESV)较正常组对照大鼠显著升高(P<0.05),而短轴短缩率(FS)及射血分数(EF)显著下降(P<0.05),同时HE染色及透射电镜观察也证实DM组大鼠心肌细胞排列紊乱、肌原纤维断裂,线粒体空泡化。而Tet-lips干预组大鼠的各项心功能指标及心肌细胞结构较DM组明显改善,接近正常对照组水平。同时,分子生物学检测显示,Tet-lips组大鼠心肌超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-px)含量和核因子E-2相关因子2(Nrf-2)、血红素氧合酶-1(HO-1)蛋白表达较DM组显著升高(P<0.05),同时丙二醛(MDA)含量显著下降(P<0.05)。结论:新型粉防己碱纳米脂质体能够激活Nrf2/HO-1信号通道从而发挥抗氧化应激损伤作用,改善DCM大鼠的心功能。

Objective: To investigate the preventive effect of tetrandrine-loaded nanoliposomes(Tet-lips) on diabetic cardiomyopathy(DCM) and underlying mechanism. Methods: Tet-lips were prepared by thin film dispersion combined with ultrasonic hydration,and their qualities were characterized. Type 1 diabetes mellitus(DM) experimental animal model was established by intraperitoneal injection of streptozotocin(STZ). Experimental animals were then randomly divided into normal control group,DM group,Tet solution group and Tet-lips group to receive the corresponding drug intervention. After drug intervention,echocardiography,HE staining and transmission electron microscopy were used to evaluate the cardiac function and myocardial cell structure of rats in each group. The level of oxidative stress and its molecular mechanism were analyzed by ELISA and Western blot. Results: The Tet-lips were round in shape,evenly dispersed,and stable with a encapsulation efficiency up to(87.23± 2.21) %. The results of echocardiogram indicated that the indices including left ventricular end-diastolic diameter(LVEDD),left ventricular systolic diameter(LVESD),at the end of the left ventricular end-diastolic volume(LVEDV) and left ventricular end systolic volume(LVESV) were significantly higher(P <0.05) in DM group when compared with those in the normal control group. The short axis shortening rate(FS) and ejection fraction(EF) in DM group were significantly lower(P<0.05) than those in the normal control group. Meanwhile,HE staining and transmission electron microscopy also confirmed that the myocardial cells of DM group were disordered,myofibrils were broken,and mitochondria were vacuolated. The cardiac function indices and the myocardial cell structure of Tet-lips group were significantly improved when compared with those in DM group,which were close to the levels of the normal control group. Molecular biological tests showed that the contents of SOD and GSH-PX,and the protein expressions of NRF-2 and HO-1 in Tet-lips group were significantly increased when compared with those in DM group(P<0.05),while MDA content was significantly decreased(P<0.05). Conclusion: The novel tetrandrine-loaded nanoliposomes can activate Nrf2/HO-1 signaling pathway to play the role of anti-oxidative stress and improve the cardiac function of DCM rats.