CHD-associated enhancers shape human cardiomyocyte lineage commitment.
CHD-associated enhancers shape human cardiomyocyte lineage commitment.
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作者：
Armendariz DA;Goetsch SC;Sundarrajan A;Sivakumar S;Wang Y;Xie S;Munshi NV;Hon GC
增强子协调基因表达程序，驱动多细胞发育和谱系定型。因此，增强子处的遗传变异被认为通过改变细胞命运定型而促成发育疾病。然而，虽然已经鉴定了许多含有变体的增强子，但缺乏内源性测试这些增强子对谱系定型的影响的研究。我们进行了单细胞CRISPRi筛选，以评估25个增强子和假定的心脏靶基因在先天性心脏病（CHD）遗传研究中的内源性作用。我们确定了16个增强子，其抑制导致人类心肌细胞（CM）的分化不足。一项集中的CRISPRi验证筛选显示，TBX5增强子的抑制延迟了从中期到晚期CM状态的转录转换。两个TBX5增强子表型表观遗传扰动的内源性遗传缺失。总之，这些结果确定了心脏发育的关键增强子，并表明这些增强子的失调可能导致人类患者的心脏缺陷。
Enhancers orchestrate gene expression programs that drive multicellular development and lineage commitment. Thus, genetic variants at enhancers are thought to contribute to developmental diseases by altering cell fate commitment. However, while many variant-containing enhancers have been identified, studies to endogenously test the impact of these enhancers on lineage commitment have been lacking. We perform a single-cell CRISPRi screen to assess the endogenous roles of 25 enhancers and putative cardiac target genes implicated in genetic studies of congenital heart defects (CHDs). We identify 16 enhancers whose repression leads to deficient differentiation of human cardiomyocytes (CMs). A focused CRISPRi validation screen shows that repression of TBX5 enhancers delays the transcriptional switch from mid- to late-stage CM states. Endogenous genetic deletions of two TBX5 enhancers phenocopy epigenetic perturbations. Together, these results identify critical enhancers of cardiac development and suggest that misregulation of these enhancers could contribute to cardiac defects in human patients.