摘要
目的探讨五味子乙素对心肌梗死小鼠心肌结构和心功能的影响及其机制。
方法C57BL/6J雄性小鼠56只,由南京医科大学动物中心提供。采用随机数字表法将小鼠分为3组,即假手术组(n=8)、五味子乙素组(n=24)和心肌梗死组(n=24)。采用冠状动脉结扎术建立小鼠心肌梗死模型,假手术组只开胸不结扎。术后五味子乙素组小鼠给予五味子乙素80 mg·kg-1·d-1灌胃治疗。术后3周观察各组小鼠存活率,通过二维超声心动图检测各组小鼠心功能指标,处死小鼠计算心脏质量/体重比,通过氯化三苯基四氮唑染剂(TTC)和伊文思蓝染色计算心肌梗死面积,制作心脏病理切片并行HE及Masson染色以观察小鼠心肌炎性浸润、结构及纤维化的情况,通过免疫荧光法检测小鼠缺血心肌组织细胞凋亡情况,通过酶联免疫吸附试验检测转化生长因子-β(TGF-β)、肿瘤坏死因子-α(TNF-α)、白细胞介素1β(IL-1β)蛋白的表达水平,Western blot法检测核因子-κB (NF-κB)、B淋巴细胞瘤-2(Bcl-2)相关蛋白X(Bax)、Bcl-2、内皮型一氧化氮合酶(eNOS)、磷酸化eNOS(p-eNOS)、蛋白激酶B (Akt)、磷酸化Akt(p-Akt)蛋白的表达水平。
结果术后3周,假手术组小鼠存活率为100%(8/8),五味子乙素组小鼠存活率为83.33%(20/24),心肌梗死组小鼠存活率为54.17%(13/24),五味子乙素组小鼠存活率明显高于心肌梗死组(P〈0.05)。五味子乙素组小鼠左心室舒张末期内径(LVEDD)和左心室收缩末期内径(LVESD)均明显低于心肌梗死组[分别为(4.13±0.40) mm比(4.44±0.46) mm和(3.07±0.39) mm比(3.46±0.52) mm),P均〈0.05],左心室射血分数(LVEF)和左心室短轴缩短率(LVFS)均明显高于心肌梗死组[(51.77±8.50)%比(40.23±8.30)%和(26.44±5.15)%比(19.53±4.56)%,P均〈0.05],心脏质量/体重比值明显低于心肌梗死组[(0.59±0.06)%比(0.68±0.10)%,P〈0.05]。五味子乙素组小鼠心肌梗死面积为(23.4±2.36)%明显小于心肌梗死组的(39.4±2.06)%(P〈0.05)。HE染色结果显示心肌梗死组小鼠梗死边缘区域心肌大量炎性浸润,排列结构非常紊乱,而五味子乙素组小鼠心肌病变情况则明显轻于心肌梗死组。Masson染色结果显示,五味子乙素组心肌纤维化范围明显小于心肌梗死组、程度明显轻于心肌梗死组。心肌梗死组小鼠心肌细胞凋亡指数[(45.33±2.02)%]明显高于假手术组[(5.00±1.83)%](P〈0.05),而五味子乙素组小鼠心肌细胞凋亡指数[(26.00±2.73)%]则明显低于心肌梗死组(P〈0.05)。五味子乙素组小鼠心肌组织抗凋亡蛋白Bcl-2明显高于心肌梗死组(P〈0.05),凋亡蛋白Bax则明显低于心肌梗死组(P〈0.05),Bcl-2/Bax比值明显高于心肌梗死组(P〈0.05)。心肌梗死组小鼠心肌组织NF-κB、TGF-β、TNF-α和IL-1β的表达水平均明显高于假手术组(P均〈0.05),而五味子乙素组上述炎症因子的表达水平均低于心肌梗死组(P均〈0.05)。假手术组、五味子乙素组、心肌梗死组小鼠心肌组织中eNos、Akt的表达差异均无统计学意义(P均〉0.05)。而五味子乙素组小鼠心肌组织p-eNOS和p-Akt的表达水平均明显高于心肌梗死组(P均〈0.05)。
结论五味子乙素具有改善梗死后心肌重构及心功能的作用,而其机制可能与其抗纤维化、抗炎、抗细胞凋亡和增强修复的作用有关。
ObjectiveTo investigate whether Schisandrin B (Sch B) could improve cardiac structure and function in myocardial infarction (MI) mice and related mechanisms.
MethodsMale C57BL/6J mice were randomized into sham (n=8), MI+ Sch B (n=24, 80 mg·kg-1·d-1 per gavage) or MI+ vehicle (n=24, equal volume). After treatment for 3 weeks, cardiac function was detected by echocardiography measurement.Infarction size was measured by Evans blue and TTC staining.HE and Masson trichrome staining were used to observe the myocardial inflammation, structure and fibrosis.TNF-α, TGF-β, IL-1β were detected by ELISA. The apoptosis index of ischemic myocardial cells was detected by immunofluorescence. NF-κB, Bcl-2, Bax, Akt phosphorylated Akt(p-Akt), eNOS, phosphorylated eNOS (p-eNOS) were detected by Western blot.
ResultsThree weeks after operation, survival rate (83.33% vs. 54.17%, P〈0.05), LVEF((51.77±8.50)% vs.(40.23±8.30)%, P〈0.05), LVFS((26.44±5.15)% vs. (19.53±4.56)%, P〈0.05)were significantly higher; LVEDD ((4.13±0.40) mm vs.(4.44±0.46)mm, P〈0.05), LVESD((3.07±0.39) mm vs. (3.46±0.52)mm, P〈0.05), the heart weight/body weight ratio((0.59±0.06)% vs. (0.68±0.10)%, P〈0.05)was significantly lower and infarct size ((23.4±2.36)% vs. (39.4±2.06)%, P〈0.05) was significantly reduced in MI+ Sch B group than those in MI+ vehicle group. In MI+ vehicle group, HE staining showed a large number of inflammatory cells in the peri-infarctl region, and the permutation structure was very disorganized, while above changes were significantly reduced in the MI+ Sch B group. Masson staining results showed that the degree of myocardial fibrosis in MI+ Sch B group was significantly less than that of MI+ vehicle group.Moreover, Sch B could down-regulate some inflammatory cytokines, like NF-κB、TGF-β、TNF-α and IL-1β, activate Akt-eNOS pathway, upgrade Bcl-2 and downgrade Bax and reduce cell apoptosis as compared with MI+ vehicle group (all P〈0.05).
ConclusionsOur results demonstrate that Sch B can reduce inflammation, inhibit apoptosis, and attenuate cardiac remodeling and improve cardiac function in this mice MI model.Sch B might serve as a potential novel therapeutic agent for ischemic heart disease.
出处
《中华心血管病杂志》
CAS
CSCD
北大核心
2017年第11期963-970,共8页
Chinese Journal of Cardiology
基金
国家自然科学基金[81170102(BA11)]
关键词
心肌梗死
细胞凋亡
五味子乙素
Myocardial infarction
Apoptosis
Schisandrin B