Abstract：
Mutations of NKX2-5 largely contribute to congenital heart diseases (CHDs), especially atrial septal defect (ASD). We identified a novel heterozygous splicing mutation c.335-1G > A in NKX2-5 gene in an ASD family via whole exome sequencing (WES) and linkage analysis. Utilizing the human induced pluripotent stem cell (hiPSC)-derived cardiomyocytes (hiPSC-CMs) as a disease model, we showed that haploinsufficiency of NKX2-5 contributed to aberrant orchestration of apoptosis and proliferation in ASD patient-derived hiPSC-CMs. RNA-seq profiling and dual-luciferase reporter assay revealed that NKX2-5 acts upstream of PYK2 via miR-19a and miR-19b (miR-19a/b) to regulate cardiomyocyte apoptosis. Meanwhile, miR-19a/b are also downstream mediators of NKX2-5 during cardiomyocyte proliferation. The novel splicing mutation c.335-1G > A in NKX2-5 and its potential pathogenic roles in ASD were demonstrated. Our work provides clues not only for deep understanding of NKX2-5 in cardia development, but also for better knowledge in the molecular mechanisms of CHDs.
摘要：
NKX2-5的突变在很大程度上有助于先天性心脏病（CHD）。尤其是房间隔缺损（ASD）。通过全外显子组测序（WES）和连锁分析，我们在ASD家族的NKX2-5基因中鉴定了一个新的杂合剪接突变c.335-1G>A。利用人类诱导多能干细胞（hiPSC）衍生的心肌细胞（hiPSC-CM）作为疾病模型，我们发现NKX2-5单倍体不足导致ASD患者来源的hiPSC-CM细胞凋亡和增殖的异常排列。RNA-seq分析和双荧光素酶报告基因分析显示，NKX2-5通过miR-19a和miR-19b（miR-19a/b）作用于PYK2的上游，从而调节心肌细胞凋亡。同时,miR-19a/b也是心肌细胞增殖过程中NKX2-5的下游介质。证明了NKX2-5中的新剪接突变c.335-1G>A及其在ASD中的潜在致病作用。我们的工作不仅为深入理解NKX2-5在贲门发育中的作用提供了线索，也是为了更好地了解冠心病的分子机制。
