Silencing of CCR4-NOT complex subunits affects heart structure and function
Silencing of CCR4-NOT complex subunits affects heart structure and function
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DOI：
10.1242/dmm.044727
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发表时间：
2020-07-01
影响因子：
4.3
通讯作者：
Bodmer, Rolf
中科院分区：
文献类型：
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作者：
Elmen, Lisa;Volpato, Claudia B.;Bodmer, Rolf
鉴定使个体易患心血管疾病的遗传变异并更好地了解其靶点将是非常有利的。全基因组关联研究已经确定了与QT间期长度（心肌复极的测量）相关的变异。三个最强的关联变体（单核苷酸多态性）位于hocT 1的推定启动子区域，hocT 1是编码CCR 4-NOT的中心hocT 1亚基的基因：一种多功能的保守复合物，调节基因表达和mRNA稳定性和周转。我们从QT风险等位基因纯合子个体中分离出包含所有三种变体的hocT 1启动子的最小片段，并证明与较长QT间期相关的单倍型导致心脏细胞系中报告基因表达减少，这表明hocT 1表达减少可能导致QT间期异常。在人诱导多能干细胞衍生的心肌细胞（hiPSC-CM）中，系统性siRNA介导的CCR 4-NOT组分的敲除揭示了hocT 1和其他CCR 4-NOT基因的沉默降低了它们的增殖能力。沉默hocT 7也缩短了动作电位时程。此外，心脏特异性敲低果蝇体内CCR 4-NOT基因直系同源物（hocT 1/Not 1和hocT 7/8/Pop 2）是致命的，或导致扩张性心肌病，收缩力降低或心律失常的倾向。沉默hocT 2/Not 2、hocT 4/Not 4和hocT 6/6L/twin也影响心腔大小和收缩力。发育研究表明，hocT 1/Not 1和hocT 7/8/Pop 2在从幼虫到成虫的心脏重塑过程中是必需的。总之，我们已经证明了如何通过结合基于人心肌细胞的模型和全生物体的体内心脏模型来研究GWAS鉴定的疾病相关基因。我们的研究结果还表明了hocT 1和hocT 7/8与QT改变的潜在联系，并进一步确立了CCR 4-NOT复合体在心脏发育和功能中的关键作用。
The identification of genetic variants that predispose individuals to cardiovascular disease and a better understanding of their targets would be highly advantageous. Genome-wide association studies have identified variants that associate with QT-interval length (a measure of myocardial repolarization). Three of the strongest associating variants (single-nucleotide polymorphisms) are located in the putative promotor region of CNOT1, a gene encoding the central CNOT1 subunit of CCR4-NOT: a multifunctional, conserved complex regulating gene expression and mRNA stability and turnover. We isolated the minimum fragment of the CNOT1 promoter containing all three variants from individuals homozygous for the QT risk alleles and demonstrated that the haplotype associating with longer QT interval caused reduced reporter expression in a cardiac cell line, suggesting that reduced CNOT1 expression might contribute to abnormal QT intervals. Systematic siRNA-mediated knockdown of CCR4-NOT components in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) revealed that silencing CNOT1 and other CCR4-NOT genes reduced their proliferativ e capacity. Silencing CNOT7 also shortened action potential duration. Furthermore, the cardiac-specific knockdown of Drosophila orthologs of CCR4-NOT genes in vivo (CNOT1/Not1 and CNOT7/8/Pop2) was either lethal or resulted in dilated cardiomyopathy, reduced contractility or a propensity for arrhythmia. Silencing CNOT2/Not2, CNOT4/Not4 and CNOT6/6L/twin also affected cardiac chamber size and contractility. Developmental studies suggested that CNOT1/Not1 and CNOT7/8/Pop2 are required during cardiac remodeling from larval to adult stages. To summarize, we hav e demonstrated how disease-associated genes identified by GWAS can be investigated by combining human cardiomyocyte cell-based and whole-organism in vivo hear t models. Our results also suggest a potential link of CNOT1 and CNOT7/8 to QT alterations and further establish a crucial role of the CCR4-NOT complex in heart development and function.This article has an associated First Person interview with the first author of the paper.