缺血预处理对小鼠心肌缺血再灌注损伤的保护作用研究

发布时间：2018-07-03 16:07

本文选题：缺血再灌注损伤 + 缺血预处理　；参考：《生命科学研究》2017年02期

【摘要】：通过建立C57/B6雄性小鼠心肌缺血再灌注(ischemia-reperfusion,I/R)模型,探讨缺血预处理对小鼠心肌缺血再灌注损伤的保护作用。首先,将36只6~8周C57/B6雄性小鼠随机分为3组(n=12):假手术组(Sham组)、缺血再灌注组(I/R组)及缺血预处理组(Ipost组)。然后,利用苏木素伊红(hematoxylin and eosin,HE)染色、脱氧三磷酸尿苷缺口末端标记(Td T-mediated d UTP-biotin nick end labeling,TUNEL)染色、免疫组化及蛋白质印迹方法,对比3组小鼠的心肌病理学改变、心肌细胞凋亡情况、梗死心肌边缘区微血管密度(microvessel density,MVD)的变化,以及肿瘤相关蛋白质PTEN(phosphatase and tensin homolog deleted from chromosome 10,即人第10号染色体缺失的磷酸酶及张力蛋白同源基因的编码产物)、自噬相关蛋白质LC3I/II和腺苷酸活化蛋白激酶(5-AMP activated protein kinase,AMPK)的表达水平。结果显示,I/R组心肌组织细胞水肿、炎症细胞浸润等组织病理学变化情况较Sham组明显,而Ipost组中的情况相比I/R组有明显改善;同时,Ipost组心肌凋亡率高于Sham组,但显著低于I/R组(P0.01);Ipost组梗死心肌边缘区域的微血管密度显著高于I/R组(P0.01)。此外,缺血预处理后,PTEN的表达水平降低,AMPK磷酸化水平以及LC3I/II蛋白的表达水平均增强。由此可见,缺血预处理可减轻I/R损伤,减少心肌梗死面积,减轻心肌水肿,对心肌细胞有明显的保护作用,其机制可能与梗死心肌中PTEN表达下调、AMPK磷酸化水平增强、心肌细胞自噬增强和凋亡减少有关。
[Abstract]:The protective effect of ischemic preconditioning on myocardial ischemia-reperfusion injury in C57 / B6 male mice was studied by establishing the ischemia reperfusion I / R model. First, 36 C57 / B6 male mice were randomly divided into three groups: sham group (sham group), ischemia reperfusion group (I / R group) and ischemic preconditioning group (Ipost group). Then, using hematoxylin eosin (HE) staining, deoxyuridine triphosphate Nick end labeling (TD T-mediated d UTP-biotin nick end labelingn Tunel) staining, immunohistochemistry and Western blotting methods, the myocardial pathological changes and myocardial cell apoptosis in the three groups were compared. Changes of microvessel density in the marginal area of infarcted myocardium. And the expression levels of tumor-associated protein PTEN (phosphatase and tensin homolog deleted from chromosome 10, the encoding product of homologous genes of phosphatase and tensin missing on chromosome 10, autophagy associated protein LC3I / II and adenylate activated protein kinase (5-AMP activated protein kinase- AMPK). The results showed that the histopathological changes of myocardial tissue edema and inflammatory cell infiltration in the I / R group were significantly higher than those in the Sham group, while the myocardial apoptosis rate in the Ipost group was higher than that in the Sham group, while that in the Ipost group was better than that in the I / R group. But the microvessel density in the marginal area of the infarcted myocardium was significantly lower than that in the I / R group (P0.01) and in the Ipost group significantly higher than that in the I / R group (P0.01). In addition, the expression level of PTEN decreased after ischemic preconditioning, and the phosphorylation level of AMPK and the expression level of LC3I / II protein were increased. It can be seen that ischemic preconditioning can attenuate I / R injury, reduce myocardial infarction size, reduce myocardial edema and protect cardiomyocytes, and its mechanism may be related to the increase of PTEN expression down-regulation and AMPK phosphorylation in infarcted myocardium. The increase of myocardial autophagy is related to the decrease of apoptosis.
【作者单位】：南方医科大学第二临床学院;广东省人民医院广东省医学科学院广东省心血管病研究所;中南大学生命科学学院;中南大学湘雅三医院儿科;
【基金】：中南大学湘雅三医院“新湘雅人才工程”资助项目(JY201524)
【分类号】：R542.2

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