To determine the differential genes in ischemic myocardium of Wistar rats with acute myocardial in- farction (AMI), we constructed two differential gene expression profiles. AMI model was generated by ligation of the left anterior descending coronary artery in Wistar rats. Total RNA was extracted from the normal and the ischemic heart tissues under the ligation point at the 8th day after the operation. Dif- ferential gene expression profiles of the two samples were constructed by using long serial analysis of gene expression (LongSAGE). Real time fluorescence quantitative PCR (Q-PCR) was used to confirm the expression changes of partial target genes. The main results were as follows: a total of 15966 tags were screened from the normal and the ischemic LongSAGE maps, and 9646 tags in the normal tissue and 9563 tags in the ischemic tissue were obtained. Among them, 7665 novel tags were identified by NCBI BLAST search. In the ischemic tissue, 142 genes significantly changed compared to those in the normal tissue (P<0.05). These differentially expressed genes may play important roles in the pathways of oxidation and phosphorylation, ATP synthesis and glycolysis and so on. Partial genes identified by the LongSAGE were confirmed by Q-PCR. The results show that AMI causes a series of gene expres- sion changes in the regulation of the pathways related to energy metabolism.
GUO ChunYu YIN HuiJun JIANG YueRong XUE Mei SHI DaZhuo
为寻找梗死后大鼠缺血心肌差异表达基因,采用结扎Wistar大鼠冠状动脉左前降支的方法,建立急性心肌梗死(AMI)模型,饲养7d后处死大鼠,提取正常和缺血心肌总RNA,应用长标签基因表达系列分析(long serial analysis of gene expression,LongSAGE)构建AMI后大鼠缺血心肌基因差异表达谱,荧光定量PCR鉴定部分差异基因的表达.结果显示,在建立的AMI后缺血心肌和正常心肌组织LongSAGE标签库中,共获得标签15966个,正常心肌获得9646个,梗死后缺血心肌获得9563个.通过NCBI网站BLAST同源性分析后,发现新核苷酸序列标签7665个.与正常组比较,142个基因在AMI大鼠心肌组织中的表达有显著性差异(P<0.05),这些差异基因主要与氧化磷酸化、三磷酸腺苷(ATP)合成、糖异生等能量代谢通路相关.荧光定量PCR的鉴定结果与LongSAGE差异表达结果基本一致.结果表明,AMI可引起多基因表达异常,能量代谢作用通路相关基因的异常表达是造成AMI后心肌损伤的重要分子机制.
This study was conducted to investigate the effects of Chinese herbs capable of replenishing qi, nourishing yin and activating blood circulation and their compatibility on differentially expressed genes of ischemic myocardium which were selected from differential expression profile we had established before, and to explore the underlying mechanism. The acute myocardial infarction (AMI) model was established by ligating the left anterior descending (LAD) coronary artery, then the model rats were randomly divided into the model group, the Metoprolol group, the replenishing qi nourishing yin (RN) group, the activating blood circulation (AB) group, and the replenishing qi, nourishing yin and activating blood circulation (RA) group. In addition, the normal group and the sham group were set up. The rats of medication groups were administered by intragastric gavage with corresponding drugs on the second day after operations, and the rats of the normal group and the sham group were given normal saline as the same time.Then the ischemic hearts were harvested on the 8th day after operation. The myocardial pathomorphological changes were observed under a light microscope. The mRNA changes of target genes such as COX5a and ATP5e were detected using Realtime fluorescence quantitative PCR (QPCR), and the activities of related enzymes were detected by colorimetric assay. The main results were as follows: the histological changes were observed by HE staining, and cardiocyte swelling, inflammatory cell infiltration and cytolysis were showed in regional ischemic myocardium of the model group, while the pathomorphological changes in all medication groups did not show obvious changes. Two genes related to energy metabolism, COX5a and ATP5e, were selected as the target genes which were downregulated at the mRNA level in the medication groups. The activities of correlative functional enzymes also decreased in the RA group compared to that in the model group accordingly (P<0.05). The results indicated that the abnormal expression of ge
