MYOSIN HEAVY-CHAIN MESSENGER-RNA AND PROTEIN ISOFORM TRANSITIONS DURING CARDIAC-HYPERTROPHY - INTERACTION BETWEEN HEMODYNAMIC AND THYROID-HORMONE INDUCED SIGNALS
MYOSIN HEAVY-CHAIN MESSENGER-RNA AND PROTEIN ISOFORM TRANSITIONS DURING CARDIAC-HYPERTROPHY - INTERACTION BETWEEN HEMODYNAMIC AND THYROID-HORMONE INDUCED SIGNALS
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DOI：
10.1172/jci112908
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发表时间：
1987-03-01
影响因子：
15.9
通讯作者：
MAHDAVI, V
中科院分区：
文献类型：
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作者：
IZUMO, S;LOMPRE, AM;MAHDAVI, V
心脏肌球蛋白同工酶的表达在发育过程中受到激素刺激和血流动力学负荷的调节。在该研究中，两种同种型（α.和β）从mRNA和蛋白质水平研究了心肌肥大时肌球蛋白重链（MHC）的变化。在正常对照和假手术大鼠中，α- MHC mRNA主要分布于心室肌。响应于主动脉缩窄，存在β-SMA的快速诱导。MHC mRNA随后出现相当水平的β- MHC蛋白的增加与左心室重量的增加平行。对缩窄的动物施用甲状腺素引起β-甲状腺素的快速去诱导。MHC和α-MHC的诱导尽管左心室肥大进展，但在mRNA和蛋白水平上均存在MHC。这些结果表明，在血流动力学过载的MHC同工酶的转变主要是由翻译前机制，并在MHC基因表达的血流动力学和激素刺激之间存在着复杂的相互作用。
Expression of the cardiac myosin isozymes is regulated during development, by hormonal stimuli and hemodynamic load. In this study, the levels of expression of the two isoforms (.alpha. and .beta.) of myosin heavy chain (MHC) during cardiac hypertrophy were investigated at the messenger RNA (mRNA) and protein levels. In normal control and sham-operated rats, the .alpha.-MHC mRNA predominated in the ventricular myocardium. In response to aortic coarctation, there was a rapid induction of the .beta.-MHC mRNA followed by the appearance of comparable levels of the .beta.-MHC protein in parallel to an increase in the left ventricular weight. Administration of thyroxine to coarctated animals caused a rapid deinduction of .beta.-MHC and induction of .alpha.-MHC, both at the mRNA and protein levels, despite progression of left ventricular hypertrophy. These results suggest that the MHC isozyme transition during hemodynamic overload is mainly regulated by pretranslational mechanisms, and that a complex interplay exists between hemodynamic and hormonal stimuli in MHC gene expression.