大鼠心肌梗死后心肌干细胞的动态变化

发布时间：2018-09-01 11:28

【摘要】：背景近年来,干细胞移植治疗心肌梗死成为一大研究热点。动员心肌内自身干细胞再生和修复成为了目前争论和研究的焦点,同时也决定了未来干细胞治疗心脏病方法的多样性。目前关于心肌干细胞研究较多的有sca-1阳性心肌干细胞,c-kit阳性心肌干细胞以及nanog阳性心肌干细胞。它们具有分化成心肌细胞的潜能。但心肌梗死后心肌干细胞的动态变化如何?它们在干细胞标记表达方面是否存在共表达情况?这些问题均有待进一步研究探讨。目的探讨大鼠急性心肌梗死后不同时段心肌梗死区域心肌干细胞的动态变化及其标记物共表达情况。方法健康成年SD大鼠25只,随机分为正常对照组(n=5)和急性心肌梗死组(n=20)。结扎大鼠冠状动脉前降支制备急性心肌梗死模型,术前和术后1w、2w、3w和4w分别检测左室射血分数(EF)、左室短轴缩短率(FS)、左室舒张末期内径(LVID;d)、左室舒张末期容积(LV Vol;d)和左室舒张末期后壁厚度(LVPW;d)。利用免疫组化技术对各组心脏切片进行免疫显色,观察sca-1阳性心肌干细胞的动态变化并进行计数分析。利用免疫荧光双标技术观察sca-1、c-kit、nanog的共表达情况。运用Western Blotting技术检测c-kit、nanog、sca-1蛋白的表达水平。结果1心肌梗死模型组EF、FS、LVPW;d均下降(P0.05)。LVID;d、LV Vol;d逐渐上升(P0.05)。2免疫组化结果显示nanog、c-kit、sca-1阳性心肌干细胞数量在2w时上升至高峰,随后下降。在梗死早期阳性细胞散在表达,3w时在梗死区聚集成团或条带状。3免疫荧光结果显示,梗死区域nanog和c-kit蛋白、sca-1和c-kit蛋白、sca-1和nanog蛋白之间在部分细胞上存在共表达。4 Western Blotting结果显示c-kit、nanog、sca-1蛋白含量于2w时达高峰,与免疫组化结果基本一致。结论1心肌干细胞随梗死时程的变化而变化,干细胞有向梗死区域迁移和聚集的倾向。2一种干细胞可表达两种干细胞的表面标记,提示心肌干细胞的亚群可能存在交叉重叠,其功能可能具有多样性。
[Abstract]:Background in recent years, stem cell transplantation has become a hot topic in the treatment of myocardial infarction. Mobilization of myocardial stem cells regeneration and repair has become the focus of debate and research, but also determine the future diversity of stem cells in the treatment of heart disease. At present, there are more sca-1 positive myocardial stem cells, c kit positive myocardial stem cells and nanog positive myocardial stem cells. They have the potential to differentiate into cardiomyocytes. But what about the dynamic changes of myocardial stem cells after myocardial infarction? Do they co-express stem cell markers? These problems need to be further studied and discussed. Objective to investigate the dynamic changes of myocardial stem cells and co-expression of markers in myocardial infarction region after acute myocardial infarction in rats. Methods 25 healthy adult SD rats were randomly divided into two groups: normal control group (n = 5) and acute myocardial infarction group (n = 20). Acute myocardial infarction model was established by ligating anterior descending coronary artery in rats. Left ventricular ejection fraction (EF), left ventricular short-axis shortening rate (FS), left ventricular end-diastolic volume (LV Vol;d), left ventricular end-diastolic volume (LV Vol;d) and left ventricular posterior wall thickness (LVPW;d) were measured before and 1 week after operation. Immunohistochemical technique was used to detect the dynamic changes of sca-1 positive myocardial stem cells in each group. The co-expression of sca-1,c-kit,nanog was observed by immunofluorescence double labeling technique. Western Blotting technique was used to detect the expression level of c-kitoku nanogCa-1 protein. Results 1in myocardial infarction model group, EF,FS,LVPW;d decreased (P0.05). LV Vol;d increased gradually (P0.05). 2 the results of immunohistochemistry showed that the number of nanog,c-kit,sca-1 positive myocardial stem cells increased to the peak at 2 weeks and then decreased. The results of immunofluorescence showed that the positive cells were clustered or banded in the infarct area at 3w after the positive cells were expressed in the early stage of infarction. There was coexpression of 4. 4 Western Blotting in some cells between nanog and c-kit protein, sca-1 and nanog protein in the infarcted area. The results showed that the content of c-kitacia nanogogsca-1 protein reached its peak at 2 weeks, which was consistent with the immunohistochemical results. Conclusion 1 Myocardial stem cells change with the change of infarct duration. 2. One kind of stem cells can express the surface markers of two kinds of stem cells, suggesting that the subsets of myocardial stem cells may have overlapping. Its functions may be diverse.
【学位授予单位】：新乡医学院
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R542.22

【参考文献】