CHD7 Regulates Cardiac Neural Crest Cell Differentiation Through SOX5-Mediated Self-Activation

CHARGE syndrome, primarily caused by CHD7 haploinsufficiency, is a complex developmental disorder frequently associated with congenital heart defects. Our comprehensive single-cell RNA sequencing analysis of cardiac neural crest cells (cNCCs) with Chd7 inactivation reveals impaired myocyte differentiation by cNCCs as a major cellular defect; loss of Chd7 disrupts myogenic transcriptional programs, alters cell fate trajectories, and activates cellular stress responses. These results significantly advance our understanding of the NCC-autonomous role of CHD7 and the mechanisms underlying CHARGE-associated heart defects driven by cNCC dysfunction. We further discovered that CHD7 enhances its own expression through interaction with SOX5 at an upstream, evolutionarily conserved enhancer. Notably, SOX5 overexpression in cultured Chd7-haploinsufficient cNCCs restores Chd7 expression from the intact allele, and rescues myocyte differentiation. These findings uncover a SOX5-mediated Chd7 autoregulatory mechanism and suggest that enhancing the SOX5-CHD7 axis may represent a promising strategy to mitigate cardiovascular defects caused by CHD7 insufficiency. Overall design: GFP+ cells were isolated by fluorescence-activated cell sorting from the PA3–6 trunk and outflow tract (OFT) regions of control (Wnt1-Cre2; R26 +/mtmg; Chd7 +/+) and mutant (Wnt1-Cre2; R26 +/mtmg; Chd7 loxp/loxp) embryos at E10.5. Cells were pooled from three embryos of the same genotype. Single-cell transcriptome libraries were prepared using the 10x Genomics Chromium Single Cell 3' v3 Reagent Kits, following the manufacturer's standard protocol.