摘要
目的 探究大鼠心肌梗死后心力衰竭左心室机械卸载心肌微小RNA(miRNA)-mRNA的调控网络.方法 将SD大鼠按照随机数表法分为对照组、心力衰竭组和左心室机械卸载组(卸载组),每组8只.采用前降支结扎和主动脉弓缩窄方法构建大鼠心肌梗死后心力衰竭模型,造模后第3天进行左心室机械卸载,观察至造模后第7天.超声心动图评估大鼠心脏结构和功能,血清学酶联免疫吸附试验评估心肌炎症反应,采用高内涵成像分析系统评估心肌成纤维细胞增殖率.选取基因表达总库(GEO)数据库中缺血性心肌病患者应用左心室辅助装置进行机械卸载前后的心肌表达谱数据进行生物信息学分析,筛选出核心miRNA及其可能的下游效应mRNA.利用qRT-PCR验证心肌中核心miRNA的表达情况.结果 与心力衰竭组大鼠相比,卸载组大鼠左心室射血分数提升20.0％(F=35.37,P=0.027),血清心肌损伤标志物心肌肌钙蛋白I水平下降52.5％(F=118.9,P＜0.001)、B型利钠肽水平下降18.2％(F=112.6,P=0.001);血清中炎症因子白细胞介素1β、白细胞介素6和肿瘤坏死因子a的水平分别下降58.5％(F=62.16,P＜0.001)、27.8％(F=26.44,P=0.010)和 31.2％(F=40.42,P＜0.001);心肌细胞横截面积降低 31.6％(F=204.7,P＜0.001)、心肌胶原纤维面积下降29.1％(F=34.19,P=0.026);心肌成纤维细胞增殖率显著降低(F=7.387,P=0.003).通过生物信息学分析共筛选出 4 个核心 miRNA(hsa-miR-205-3p、hsa-miR-205-5p、hsa-miR-335-3p 和 hsa-miR-335-5p).miR-335-3p(F=20.72,P=0.020)和 miR-335-5p(F=26.36,P=0.005)在卸载后的心肌中表达显著上调,miR-335的潜在下游靶基因(APOOL、ERBB4和WWTR1)表达水平显著下调(F=14.22、10.13和8.69,P=0.011、0.015和0.033).结论 左心室机械卸载可以有效逆转大鼠心肌梗死后的心肌重构,并降低急性期心肌成纤维细胞增殖率,miR-335在这一过程中可能发挥关键作用.
Abstract
Objective To investigate the regulatory network of myocardial microRNA(miRNA)-mRNA in post-infarction heart failure with left ventricular mechanical unloading.Methods The rats were divided into the control group,heart failure group,left ventricular mechanical unloading group(unloading group)(n=8,each group)according to the random number table method.A rat post-infarction heart failure model was constructed by using anterior descending branch ligation and aortic arch narrowing methods,and mechanical unloading of the left ventricle was performed 3 days after modeling,with follow-up until postoperative 7th day.Echocardiography was used to assess the structure and function of the rat heart,serological ELISA was used to assess the myocardial inflammatory response,and the myocardial fibroblast value-added rate was assessed by using a high-content imaging analysis system.Myocardial expression profiling data before and after mechanical unloading under application of left ventricular assist device(LVAD)in patients with ischemic cardiomyopathy from the GEO database were selected for bioinformatics analysis,and core miRNAs and their possible downstream effector mRNAs were screened.qRT-PCR was used to validate the expression of core miRNAs in the myocardium.Results Compared with rats in the heart failure group,rats in the unloaded group had a 20.0％of elevation in LVEF(F=35.37,P=0.027),a 52.5％of decrease in serum myocardial injury marker cardiac troponin I levels(F=118.9,P＜0.001),and an 18.2％of decrease in B-type natriuretic peptide levels(F=112.6,P=0.001);and serum levels of the inflammatory factors levels of interleukin-1 β,interleukin-6 and tumor necrosis factor-α decreased by 58.5％(F=62.16,P＜0.001),27.8％(F=26.44,P=0.010)and 31.2％(F=40.42,P＜0.001),respectively.Myocardial cell cross-sectional area decreased by 31.6％(F=204.7,P＜0.001),myocardial collagen fiber area decreased by 29.1％(F=34.19,P=0.026),and myocardial fibroblast proliferation rate was significantly reduced(F=7.387,P=0.003).A total of 4 core miRNAs(hsa-miR-205-3p,hsa-miR-205-5p,hsa-miR-335-3p,and hsa-miR-335-5p)were screened through bioinformatics analysis.miR-335-3p(F=20.72,P=0.020)and miR-335-5p(F=26.36,P=0.005)expression was significantly upregulated in unloaded myocardium,and the expression levels of potential downstream target genes of miR-335(APOOL,ERBB4 and WWTR1)were significantly downregulated(F=14.22,10.13 and 8.69;P=0.011,0.015 and 0.033).Conclusions Left ventricular mechanical unloading effectively reverses myocardial remodeling after myocardial infarction and reduces myocardial fibroblasts value-added rate in the acute phase,and miR-335 may play a key role in this process.
维普
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