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目的:研究c-kit与microRNA-21基因在大鼠左室重构中的动态表达,探讨其内在联系和作用机制。方法:SD雄性大鼠随机分为正常对照组和心衰模型组。心衰模型制作:4 mg/kg阿霉素腹腔注射,每周1次,共6周。正常对照组给予等量0.9%氯化钠溶液。在8周时对大鼠进行心功能检测,证明心衰形成。取心脏组织,冰冻切片,利用免疫组织化学、免疫荧光显色、RT-PCR等技术检测心肌组织中microRNA-21和c-kit的基因表达变化。结果:HE染色示:各个时间点呈现不同的病理学变化;对照组未出现心肌梗死表现。免疫组织化学和免疫荧光显示:在正常和心衰心肌中microRNA-21阳性细胞主要表达于血管内皮,少量心肌细胞和干细胞,而在心衰心肌组织中的表达量明显减少;c-kit阳性细胞常成群分布,主要聚集于心外膜及其附近,心衰后表达量较正常心肌明显减少。在两组心肌组织中均有少数细胞存在microRNA-21和c-kit共表达。RT-PCR结果显示:心衰模型组c-kit和microRNA-21表达比正常对照组明显减少(P<0.05)。结论:阿霉素致大鼠左室重构的心肌内c-kit和microRNA-21阳性干细胞减少,其表达异常与左室重构具有高度的相关性且存在一定的内在联系。
Objective: To study the dynamic expression of c-kit and microRNA-21 in rat left ventricular remodeling and to explore its intrinsic relationship and mechanism. Methods: SD male rats were randomly divided into normal control group and heart failure model group. Heart failure model: 4 mg / kg doxorubicin intraperitoneal injection once a week for 6 weeks. The normal control group was given the same amount of 0.9% sodium chloride solution. Cardiac function tests were performed at 8 weeks in rats demonstrating heart failure. Cardiac tissues and frozen sections were taken for immunohistochemistry, immunofluorescence and RT-PCR to detect the gene expression changes of microRNA-21 and c-kit. Results: HE staining showed different pathological changes at various time points; no myocardial infarction appeared in the control group. Immunohistochemistry and immunofluorescence showed that microRNA-21 positive cells were mainly expressed in vascular endothelium, a small amount of cardiomyocytes and stem cells in normal and heart failure myocardium, while the expression of microRNA- Often distributed in groups, mainly in the epicardium and its vicinity, after heart failure, the expression was significantly reduced compared with normal myocardium. A few cells in both groups had microRNA-21 and c-kit coexpressed. The results of RT-PCR showed that the expression of c-kit and microRNA-21 in heart failure model group was significantly lower than that in normal control group (P <0.05). CONCLUSION: Adriamycin induced a decrease in c-kit and microRNA-21 positive stem cells in left ventricular remodeling in rats. The expression of c-kit and microRNA-21 positive stem cells is highly correlated with left ventricular remodeling and has some intrinsic relationships.