Constitutive phosphorylation of cardiac myosin regulatory light chain prevents development of hypertrophic cardiomyopathy in mice.
Constitutive phosphorylation of cardiac myosin regulatory light chain prevents development of hypertrophic cardiomyopathy in mice.
复制标题
心肌肌球蛋白调节轻链的组成型磷酸化可预防小鼠肥厚型心肌病的发生。
DOI：
10.1073/pnas.1505819112
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发表时间：
2015
影响因子：
11.1
通讯作者：
Szczesna-Cordary,Danuta
中科院分区：
文献类型：
--
作者：
Yuan,Chen-Ching;Muthu,Priya;Kazmierczak,Katarzyna;Liang,Jingsheng;Huang,Wenrui;Irving,ThomasC;Kanashiro-Takeuchi,RosemeireM;Hare,JoshuaM;Szczesna-Cordary,Danuta
众所周知，心肌肌凝蛋白调节轻链（RLC）的肌凝蛋白轻链激酶（MLCK）依赖性磷酸化在心脏病中发挥有益作用，但磷酸化介导的肥厚性心肌病（HCM）表型逆转的想法是新颖的。我们之前对转基因（Tg） HCM-RLC小鼠的研究表明，D166V （Aspartate166→Valine）突变诱导的心脏形态和功能的变化与RLC原位磷酸化的大量降低相一致。我们假设将组成性磷酸化丝氨酸15 （S15D）引入D166V小鼠的心脏可以阻止有害HCM表型的发展。为了支持这一观点，mlck诱导的d166v突变心脏的磷酸化被发现可以挽救它们的一些异常收缩特性。Tg-S15D-D166V小鼠用人心脏RLC- s15d - d166v构建物代替小鼠心脏RLC，并进行功能、结构和形态学评估。将结果分别与表达人心室RLC-WT或其D166V突变体的Tg-WT和Tg-D166V小鼠进行比较。超声心动图和有创血流动力学研究显示，与D166V相比，S15D-D166V小鼠的完整心功能有显著改善，收缩期和舒张期指标达到WT小鼠的监测值。在d166v突变的心脏中观察到的极大降低的最大张力和异常高的肌丝Ca2+敏感性在S15D-D166V小鼠中被逆转。低角度x射线衍射研究显示，在S15D-D166V救援小鼠中，HCM-D166V小鼠肌丝结构的改变得到了缓解。我们的集体结果表明，假磷酸化的RLC在HCM小鼠心脏中的表达足以阻止病理性HCM表型的发展。
Myosin light chain kinase (MLCK)-dependent phosphorylation of the regulatory light chain (RLC) of cardiac myosin is known to play a beneficial role in heart disease, but the idea of a phosphorylation-mediated reversal of a hypertrophic cardiomyopathy (HCM) phenotype is novel. Our previous studies on transgenic (Tg) HCM-RLC mice revealed that the D166V (Aspartate166 →Valine) mutation-induced changes in heart morphology and function coincided with largely reduced RLC phosphorylation in situ. We hypothesized that the introduction of a constitutively phosphorylated Serine15 (S15D) into the hearts of D166V mice would prevent the development of a deleterious HCM phenotype. In support of this notion, MLCK-induced phosphorylation of D166V-mutated hearts was found to rescue some of their abnormal contractile properties. Tg-S15D-D166V mice were generated with the human cardiac RLC-S15D-D166V construct substituted for mouse cardiac RLC and were subjected to functional, structural, and morphological assessments. The results were compared with Tg-WT and Tg-D166V mice expressing the human ventricular RLC-WT or its D166V mutant, respectively. Echocardiography and invasive hemodynamic studies demonstrated significant improvements of intact heart function in S15D-D166V mice compared with D166V, with the systolic and diastolic indices reaching those monitored in WT mice. A largely reduced maximal tension and abnormally high myofilament Ca2+sensitivity observed in D166V-mutated hearts were reversed in S15D-D166V mice. Low-angle X-ray diffraction study revealed that altered myofilament structures present in HCM-D166V mice were mitigated in S15D-D166V rescue mice. Our collective results suggest that expression of pseudophosphorylated RLC in the hearts of HCM mice is sufficient to prevent the development of the pathological HCM phenotype.