大鼠心肌梗死后心脏中肌酸激酶基因表达的变化

Changes of creatine kinase gene expression in rat heart post-myocardial infarction.

作者信息

Neubauer S, Frank M, Hu K, Remkes H, Laser A, Horn M, Ertl G, Lohse M J

机构信息

Department of Medicine, Universität Würzburg, Germany.

出版信息

J Mol Cell Cardiol. 1998 Apr;30(4):803-10. doi: 10.1006/jmcc.1998.0645.

DOI:10.1006/jmcc.1998.0645

PMID:9602429

Abstract

Creatine kinase (CK) plays a crucial role in cardiac energy transduction. During chronic cardiac stress conditions leading to hypertrophy and/or heart failure, the profile of CK isoenzyme activities changes towards a fetal pattern with increases of BB- and MB-CK and decreases of MM-CK and mito-CK. Changes of myocardial CK gene expression are only indirectly reflected by measurements of CK activities. The purpose of this work was, therefore, to determine myocardial expression of B-, M- and sarcomeric mito-CK genes in an animal model of heart failure where hemodynamic alterations and CK system changes are well defined, that is, in the rat heart post-myocardial infarction. Intact residual left ventricular myocardium was harvested 2 months following infarction (MI; n = 7) or sham operation (sham; n = 6) after in vivo left-ventricular end-diastolic pressure (LVEDP) was recorded. Total CK activity was measured spectrophotometrically, CK isoenzyme distribution with agarose gel electrophoresis. Steady state mRNA levels coding for B-, M- and mito-CK genes were measured with quantitative PCR and were normalized for GAPDH expression. Total CK activity tended to be reduced in MI (5.51 +/- 0.62 IU/mg protein) compared to sham (6.77 +/- 0.24; P = 0.55). CK isoenzyme distribution showed an increase of fetal BB- + MB-CK (MI 22.0 +/- 3.1%, sham 15.1 +/- 1.0%; P < 0.05), no change of MM-CK and a decrease of mito-CK (27.0 +/- 1.5% sham, 20.8 +/- 2.0% MI: P < 0.05). Relative B-CK mRNA levels increased (sham 0.46 +/- 0.06, MI 1.03 +/- 0.09; P < 0.05) and M-CK mRNA levels decreased (sham 1.06 +/- 0.08. MI 0.66 +/- 0.09; P < 0.05) significantly post-MI. The increase of B-CK mRNA (r = 0.72; P = 0.009) and the decrease of M-CK mRNA (r = 0.76; P = 0.003) correlated significantly with in vivo LVEDP. Mito-CK mRNA levels remained unchanged after MI (sham 0.94 +/- 0.16, MI 0.98 +/- 0.09). Intact residual left-ventricular myocardium post-MI is characterized by increased B-CK-mRNA and reduced M-CK-mRNA expression.

摘要

肌酸激酶（CK）在心脏能量转导中起着至关重要的作用。在导致心肌肥厚和/或心力衰竭的慢性心脏应激状态下，CK同工酶活性谱向胎儿模式转变，BB型和MB型CK增加，MM型CK和线粒体CK减少。心肌CK基因表达的变化仅通过CK活性测量间接反映。因此，本研究的目的是在心力衰竭动物模型中确定B型、M型和肌节线粒体CK基因的心肌表达，该模型中血流动力学改变和CK系统变化已明确界定，即心肌梗死后的大鼠心脏。在记录体内左心室舒张末期压力（LVEDP）后，在心肌梗死（MI；n = 7）或假手术（假手术；n = 6）2个月后收集完整的残余左心室心肌。用分光光度法测量总CK活性，用琼脂糖凝胶电泳分析CK同工酶分布。用定量PCR测量编码B型、M型和线粒体CK基因的稳态mRNA水平，并针对甘油醛-3-磷酸脱氢酶（GAPDH）表达进行标准化。与假手术组（6.77±0.24；P = 0.55）相比，MI组的总CK活性有降低趋势（5.51±0.62 IU/mg蛋白）。CK同工酶分布显示胎儿型BB + MB-CK增加（MI组为22.0±3.1%，假手术组为15.1±1.0%；P < 0.05），MM-CK无变化，线粒体CK减少（假手术组为27.0±1.5%，MI组为20.8±2.0%：P < 0.05）。MI后，相对B-CK mRNA水平显著升高（假手术组为0.46±0.06，MI组为1.03±0.09；P < 0.05），M-CK mRNA水平显著降低（假手术组为1.06±0.08，MI组为0.66±0.09；P < 0.05）。B-CK mRNA的增加（r = 0.72；P = 0.009）和M-CK mRNA的减少（r = 0.76；P = 0.003）与体内LVEDP显著相关。MI后线粒体CK mRNA水平保持不变（假手术组为0.94±0.16，MI组为0.98±0.09）。MI后完整的残余左心室心肌的特征是B-CK-mRNA表达增加和M-CK-mRNA表达减少。