Year: 2023
Type: article
Abstract: ABSTRACT 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 (CHD). 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. HIGHLIGHTS Single-cell enhancer perturbation screens during human cardiomyocyte differentiation. Perturbation of CHD-linked enhancers/genes causes deficient CM differentiation. Repression or knockout of TBX5 enhancers delays transition from mid to late CM states. Deficient differentiation coincides with reduced expression of known cardiac genes.
Source: eLife
Authors: Daniel A. Armendariz, Sean C. Goetsch, Anjana Sundarrajan, Sushama Sivakumar, Yihan Wang, Shiqi Xie, Nikhil Munshi, Gary C. Hon
Institution: The University of Texas Southwestern Medical Center
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $2,500
Funders: U.S. Department of Defense, Burroughs Wellcome Fund, Welch Foundation, Cancer Prevention and Research Institute of Texas, University of Texas Southwestern Medical Center, National Institutes of Health, National Heart, Lung, and Blood Institute, National Human Genome Research Institute, National Institute of General Medical Sciences
Awards: G2325851841, G390011392, G3943524290, G4395170721, G4967353114, Comprehensive Evaluation of Functional Enhancers in Breast Cancer Risk Susceptibility Loci, G6245228462, G6413612278, G6781771585, Defining regenerative potential in the cardiac conduction system, G9000054229, G9000112556, G9000228567, G9000232788, G9000284670, Exploring Mechanisms of Cardiac Pacemaker Cell Fate Determination
OpenAlex ID: W4366986744