目的：探讨后负荷增加型大鼠不同时间点心脏全基因谱差异表达情况。方法纳入雄性SD大鼠70只，术前随机取10只进行处理，相关参数作为基线数据；其余60只，随机分为模型组（2周亚组、8周亚组、18周亚组）和假手术组（2周亚组、8周亚组、18周亚组），每组30只（每亚组10只）。模型组大鼠采用缩窄腹主动脉的方法建立心脏后负荷增加模型，假手术组大鼠腹主动脉只穿线不进行缩窄。各组大鼠分组后分别在术前、术后2周、8周、18周采用小动物超声实时影像系统及颈动脉插管检测大鼠心脏结构及血流动力学相关指标。完成上述步骤后，处死大鼠，取左心室，进行大鼠心脏RNA建库，使用Illumina HiSeqTM2500/MiseqTM对文库进行高通量测序，并进行生物信息分析。结果在术后第2周、第8周、第18周，模型组大鼠平均动脉压、左室重量、左室舒张末内径、左室舒张末压较基线显著升高（P均＜0.05），心脏每搏输出量、左室射血分数、左室内压最大上升速率较基线显著下降（P均＜0.05）；假手术组大鼠平均动脉压、左室舒张末内径、心脏每搏输出量、左室射血分数、左室内压最大上升速率与基线比较则无显著变化（P均＞0.05）；大鼠后负荷增加模型建立成功。模型组与假手术组大鼠在第2周、第8周相较基线时差异表达的基因个数有升高趋势，至第18周差异表达的基因个数有所回落。模型组较假手术组在同时间段差异表达的基因明显增加。在第2周、第8周、第18周，模型组与假手术组大鼠心脏差异表达的基因个数分别为119、43和49个基因，差异基因的个数随时间有显著下降。不同时间点模型组与假手术组大鼠心脏差异表达的基因功能富集（GO）及通路富集（KEGG）有很大差异。结论腹主动脉缩窄后负荷增加大鼠与假手术组比较，在术后早期差异基因明显增加，术后中晚期差异基因数量逐渐下降；不同时间点差异基因功能及相关通路有很大差异。%Objective To investigate the differential expression of cardiac whole gene at different time points after afterload increasing rats.Methods 10 of 70 male SD rats were randomly selected for the preoperative treatment, relevant parameters were collected as the baseline data; the rest of 60 rats were randomly divided into model group (2- weeks’ subgroup, 8- weeks’ subgroup, 18 weeks’ subgroup) and sham operation group (2-weeks’ subgroup, 8-weeks’ subgroup, 18 weeks’ subgroup) with 10 rats in each subgroup. Rats in the model group were treated with coarctation abdominal aorta to establish the model of cardiac afterload increase, and the abdominal aorta of the sham operation group was not constricted. Cardiac structure and hemodynamics were measured before operation, 2 weeks, 8 weeks and 18 weeks after operation by small animal ultrasound real-time imaging system and carotid artery cannulation. Then rats were sacrificed and the left ventricle was harvested. The rat cardiac RNA library was constructed. The library was sequenced using Illumina HiSeqTM 2500 / MiseqTM and the bioinformatics analysis was performed.Results At 2 weeks, 8 weeks, and 18 weeks after surgery, The mean arterial pressure, left ventricular mass, left ventricular end-diastolic dimension and left ventricular end-diastolic pressure of model group were significantly higher than those of baseline (P<0.05). Left ventricular ejection fraction (LVE) and left ventricular pressure (LVP) were significantly lower than baseline (P<0.05). There were no significant changes in mean arterial pressure, left ventricular end diastolic diameter, stroke volume, left ventricular ejection fraction, and left ventricular pressure in sham - operated rats compared with baseline (P>0.05). The rat model of afterload increase was established successfully. The number of genes differentially expressed between the model group and the sham-operated group increased at the 2nd week and the 8th week compared with the baseline, and the number of the differentially expressed genes decreased at the 18th week. Compared with the sham group, the expression of genes in the model group was significantly increased at the same time. At the 2nd week, 8th week and 18th week,the number of genes differentially expressed between the model group and the sham operation group were 119, 43 and 49 genes respectively, and the number of different genes decreased significantly with time. At different time points, there was a significant difference in gene functional enrichment (GO) and pathway enrichment (KEGG) between the model group and the sham-operated group.Conclusion Compared with the sham-operated group, the number of differentially expressed genes in the early postoperative period increased significantly, and the number of the differentially expressed genes in the middle and late post-operation decreased gradually. There were significant differences in the function of different genes and related pathways at different time points.
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