辛伐他汀对慢性心力衰竭兔人第10号染色体缺失的磷酸酶及张力蛋白同源基因和β-catenin表达的影响

摘要

Objective To study the effect of simvastatin on the expression of phosphatase and tensin homologue deleted on chromosome 10 (PTEN) and β-catenin in myocardial cells of rabbits with chronic heart failure (CHF).Methods Twenty-four male New Zealand rabbits were randomly divided into control group,CHF model group and simvastatin treatment group,with 8 rabbits in each group.The rabbits in CHF model group and simvastatin treatment group were injected with adriamycin (2.0 mg · kg-1) ria ear rein once a week for six weeks,and from the seventh week were injected with adriamycin (1.5 mg · kg-1)once a week for another six weeks to establish the CHF model;the rabbits in control group were injected with the same volume saline.The rabbits in simvastatin treatment group were given simvastatin (1.5 mg · kg-1 · d-1) by intragastric administration at the time point of first injection of adriamycin for 12 weeks;the rabbits in CHF model group and control group were given the same volume saline for 12 weeks.The left ventricular structure and function were determined by color doppler uhrasonography after the modeling.Then the rabbits were sacrificed and the left ventricular walls were taken to observe the changes of myocardial cell structures by hematoxylin-eosin staining.The positive expression rate of PTEN and β-catenin protein was calculated by immunohistochemistry staining.The expression of PTEN and β-catenin mRNA was detected real-time quantitative polymerase chain reaction.Results Compared with the control group,the left ventricular end-systolic dimension (LVESD),left ventricular end-diastolic dimension(LVEDD) were increased and the left ventricular ejection fraction(LVEF) was decreased in the CHF model group and simvastatin treatment group(P ＜ 0.05).Compared with the CHF model group,the LVESD,LVEDD were decreased and the LVEF was increased in the simvastatin treatment group(P ＜ 0.05).The positive expression rate of PTEN protein in myocardial cells of rabbits in control group,CHF model group and simvastatin treatment group was (16.36 ± 0.54) ％,(41.63 + 0.72) ％ and (24.17 ± 0.51) ％ respectively;the positive expression rate of β-catenin protein in myocardial cells of rabbits in control group,CHF model group and simvastatin treatment group was (21.73 ± 0.46)％,(52.26 ±+ 0.72) ％ and (38.42 + 0.56) ％ respectively.The positive expression rates of PTEN and β-catenin protein in myocardial cells of rabbits in CHF model group and simvastatin treatment group were significanlty higher than those in the control group(P ＜ 0.05);the positive expression rates of PTEN and β-catenin protein of myocardial cell in simvastatin treatment group were significantly lower than those in the CHF model group (P ＜ 0.05).The epression of PTEN mRNA and β-catenin mRNA in myocardial cells of rabbits in control group,CHF model group and simvastatin treatment group was 1.91 ± 0.30,4.61 ± 0.71,3.49 ± 0.64 and 1.51 ± 0.21,2.48 ± 0.34,1.51 ±+ 0.25.The expression of PTEN and β-catenin mRNA in myocardial cells of rabbits in CHF model group and simvastatin treatment group were significanlty higher than those in the control group (P ＜ 0.05);the expression of PTEN and β-catenin mRNA in myocardial cells of rabbits in simvastatin treatment group were significantly lower than those in the CHF model group (P ＜ 0.05).Conclusion Simvastatin can inhibit myocardial apoptosis,improve cardiac function of CHF rabbits.It may be related to inhibiting the expression of PTEN and β-catenin.%目的 探讨辛伐他汀对慢性心力衰竭兔心肌细胞中人第10号染色体缺失的磷酸酶及张力蛋白同源基因(PTEN)和β-catenin表达的影响.方法 将24只雄性新西兰大耳白兔随机分为对照组、心力衰竭模型组和辛伐他汀组,每组8只.心力衰竭模型组和辛伐他汀组兔经耳缘静脉注射盐酸阿霉素2.0 mg·kg-1,每周1次,连续6周,第7周起经耳缘静脉注射盐酸阿霉素1.5 mg·kg-1,连续6周,建立慢性心力衰竭兔模型;对照组兔给予等量的生理盐水.辛伐他汀组兔在首次注射盐酸阿霉素时给予辛伐他汀灌胃(1.5 mg·kg-1·d-1),连续12周;对照组和心力衰竭模型组兔给予等量生理盐水灌胃12周.造模结束后通过心脏超声测量兔左心室结构和功能.处死动物留取左心室室壁,苏木精-伊红染色观察心肌细胞结构,免疫组织化学染色检测心肌细胞中PTEN、β-catenin蛋白的表达,实时荧光定量聚合酶链反应检测PTEN、β-catenin mRNA的表达.结果 与对照组比较,心力衰竭模型组、辛伐他汀组兔的左心室收缩末期内径(LVESD)和左心室舒张末期内径(LVEDD)增大,左心室射血分数(LVEF)降低(P＜0.05);与心力衰竭模型组比较,辛伐他汀组兔的LVESD、LVEDD减小,LVEF升高(P＜0.05).对照组、心力衰竭模型组、辛伐他汀组兔心肌细胞PTEN蛋白阳性表达率分别为(16.36 +0.54)％、(41.63±0.72)％、(24.17±0.51)％,对照组、心力衰竭模型组、辛伐他汀组兔心肌细胞β-catenin蛋白阳性表达率分别为(21.73±0.46)％、(52.26±0.72)％、(38.42±0.56)％;心力衰竭模型组和辛伐他汀组兔心肌细胞PTEN、β-catenin蛋白阳性表达率高于对照组(P＜0.05),辛伐他汀组兔心肌细胞PTEN、β-catenin蛋白阳性表达率低于心力衰竭模型组(P＜0.01).对照组、心力衰竭模型组、辛伐他汀组兔心肌细胞中PTEN mRNA相对表达量分别为1.91 ±0.30、4.61 ±0.71、3.49±0.64,对照组、心力衰竭模型组、辛伐他汀组兔心肌细胞中β-catenin mRNA相对表达量分别为1.51 ±0.21、2.48±0.34、1.51 ±0.25;心力衰竭模型组和辛伐他汀组兔心肌细胞中PTEN、β-catenin mRNA相对表达量高于对照组(P＜0.05),辛伐他汀组兔心肌细胞中PTEN、β-catenin mRNA相对表达量低于心力衰竭模型组(P＜0.05).结论 辛伐他汀可抑制慢性心力衰竭兔心肌凋亡,提高心功能,其机制可能与抑制PTEN、β-catenin表达有关.