Phosphomimetic cardiac myosin-binding protein C partially rescues a cardiomyopathy phenotype in murine engineered heart tissue
Phosphomimetic cardiac myosin-binding protein C partially rescues a cardiomyopathy phenotype in murine engineered heart tissue
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DOI：
10.1038/s41598-019-54665-2
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发表时间：
2019-12-03
影响因子：
4.6
通讯作者：
Mearini, Giulia
中科院分区：
文献类型：
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作者：
Dutsch, Alexander;Wijnker, Paul J. M.;Mearini, Giulia
由MYBPC 3编码的心肌肌球蛋白结合蛋白C（cMyBP-C）的磷酸化增加了肌球蛋白头部与肌动蛋白相互作用的可用性，从而增强收缩。肥厚型心肌病（HCM）患者的隔肌切除术中cMyBP-C磷酸化水平低于非衰竭心脏。在这里，我们比较了磷酸化模拟物（D282）和野生型（S282）cMyBP-C基因转移对从携带Mybpc 3突变（KI）的小鼠模型产生的工程心脏组织（EHT）的HCM表型的影响。与野生型（WT）EHT相比，KI EHT显示出较低水平的突变Mybpc 3 mRNA和蛋白质，以及改变的基因表达。此外，KI EHTs在起搏下表现出更快的自发收缩和更高的最大力和对外部[Ca 2 +]的敏感性。腺相关病毒介导的D282和S282基因转移同样恢复了Mybpc 3 mRNA和蛋白水平，并抑制了突变Mybpc 3转录。此外，两种外源性cMyBP-C蛋白都被适当地掺入肌节中。KI EHTs的过度收缩性也同样被两种治疗所阻止，但S282在使力-Ca 2 +-关系和失调基因的表达正常化方面的作用比D282强。体外模型中的这些发现表明，S282是比D282更好的恢复HCM EHT表型的选择。这些结果在多大程度上适用于人类HCM仍有待观察。
Phosphorylation of cardiac myosin-binding protein C (cMyBP-C), encoded by MYBPC3, increases the availability of myosin heads for interaction with actin thus enhancing contraction. cMyBP-C phosphorylation level is lower in septal myectomies of patients with hypertrophic cardiomyopathy (HCM) than in non-failing hearts. Here we compared the effect of phosphomimetic (D282) and wild-type (S282) cMyBP-C gene transfer on the HCM phenotype of engineered heart tissues (EHTs) generated from a mouse model carrying a Mybpc3 mutation (KI). KI EHTs showed lower levels of mutant Mybpc3 mRNA and protein, and altered gene expression compared with wild-type (WT) EHTs. Furthermore, KI EHTs exhibited faster spontaneous contractions and higher maximal force and sensitivity to external [Ca2+] under pacing. Adeno-associated virus-mediated gene transfer of D282 and S282 similarly restored Mybpc3 mRNA and protein levels and suppressed mutant Mybpc3 transcripts. Moreover, both exogenous cMyBP-C proteins were properly incorporated in the sarcomere. KI EHTs hypercontractility was similarly prevented by both treatments, but S282 had a stronger effect than D282 to normalize the force-Ca2+-relationship and the expression of dysregulated genes. These findings in an in vitro model indicate that S282 is a better choice than D282 to restore the HCM EHT phenotype. To which extent the results apply to human HCM remains to be seen.