小檗胺对糖尿病心肌病心肌损伤的保护作用及其机制

Protective effects of berbamine against diabetic cardiomyopathy and its underlying mechanism

目的观察小檗胺(BBM)对糖尿病心肌病心肌损伤的保护作用并初步探讨其保护机制。方法将60只雄性C57BL/6小鼠(8周龄)随机分为4组:正常对照组(control组),单纯药物处理组(Con+BBM组),糖尿病心肌病组(DCM组)和糖尿病心肌病+药物处理组(DCM+BBM组),每组15只。DCM组和DCM+BBM组小鼠采用腹腔注射链脲佐菌素(STZ)联合高热量饮食法建立糖尿病心肌病模型,control组和DCM组灌胃生理盐水12周,Con+BBM组灌胃BBM(100 mg/kg)12周,DCM+BBM组小鼠在STZ注射2周后,每天通过灌胃补充小檗胺处理(100 mg/kg)共12周。待实验结束后,用小动物超声仪检测小鼠心脏收缩功能;HE染色法观察小鼠左心室心肌细胞横截面积;计算各组小鼠全心质量指数(HMI)和左心室质量指数(LVMI);Masson染色法观察心肌组织纤维化程度;免疫组化染色法检测心肌组织Collagen-1表达程度;分光光度法检测心肌组织中超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)和丙二醛(MDA)的含量;RT-PCR法检测心肌肥厚相关基因α-MHC和β-MHC的表达水平;Western blot法检测SIRT3、Ac-FOXO3a和gp91 phox的蛋白表达水平。结果与control组相比,DCM组小鼠心脏收缩功能显著降低,HMI和LVMI值明显升高,心肌肥厚相关基因的表达水平显著上升,心肌组织纤维化程度和氧化应激水平显著升高,且心肌SIRT3/FOXO3a信号通路被显著抑制(均P<0.05)。与DCM组比较,DCM+BBM组小鼠心脏收缩功能障碍及心肌肥厚情况得到显著改善,心肌组织纤维化程度明显缓解,氧化应激损伤显著减轻,并且心肌SIRT3/FOXO3a信号通路也显著上调(均P<0.05)。而Con+BBM组小鼠与control组相比,在心功能、心肌肥厚情况、心肌纤维化程度、氧化应激损伤和心肌SIRT3通路表达上的差异均无统计学意义(均P>0.05)。结论小檗胺通过减轻心肌组织氧化应激损伤发挥抗糖尿病心肌病心肌损伤的作用,其分子机制可能与激活心肌SIRT3/FOXO3a信号有关。

Objective To investigate the effects of berbamine(BBM)on streptozotocin(STZ)-induced diabetic cardiomyopathy(DCM)and explore its molecular mechanism.Methods Sixty male 8-week old C57BL/6 mice were randomly divided into four groups:control group,Con+BBM group,DCM group and DCM+BBM group.The model of diabetic cardiomyopathy in DCM group and DCM+BBM group was established by intraperitoneal injection of STZ combined with high calorie diet.The mice in control group and DCM group were treated with normal saline by intragastric supplementation for 12 weeks,and the mice in Con+BBM group were treated with BBM(100 mg/kg)by intragastric supplementation for 12 weeks.Mice in DCM+BBM group were treated with BBM(100 mg/kg)by intragastric supplementation every day for 12 weeks.Echocardiography was used to detect the contractile function,and HE staining was used to observe the cross-sectional area of left ventricular cardiomyocyte.Heart mass index(HMI)and left ventricular mass index(LVMI)were calculated.Masson staining and immunohistochemical staining were used to determine the degree of myocardial fibrosis,spectrophotometry was used to estimate the contents of superoxide dismutase(SOD),glutathione peroxidase(GSH-Px)and malondialdehyde(MDA)in myocardium,real-time PCR(RT-PCR)analysis was used to detect the gene expression ofα-MHC andβ-MHC,and Western blot assay was used to detect the protein expression levels of SIRT3,Ac-FOXO3a and gp91 phox.Results Compared with control group,cardiac systolic function was significantly decreased,HMI and LVMI values were significantly increased,and the expression levels of cardiac hypertrophy-related genes were significantly elevated in DCM group.Besides,the degree of myocardial tissue fibrosis and oxidative stress were aggravated,accompanied by the inhibited myocardial SIRT3/FOXO3a signaling pathway in DCM group(all P<0.05).Compared with DCM group,BBM treatment improved the systolic function and cardiac hypertrophy in DCM+BBM group,alleviated the degree of myocardial tissue fibrosis and oxidative stress,and up-regulated the myocardial SIRT3/FOXO3a signaling pathway(all P<0.05).Compared with control group,there was no significant difference in cardiac function,cardiac hypertrophy,myocardial fibrosis,oxidative stress injury and myocardial SIRT3 pathway expression in Con+BBM group(all P>0.05).Conclusion Berbamine could protect against diabetic cardiomyopathy by exhibiting its anti-oxidative stress effect via activating SIRT3/FOXO3a signaling pathway.