Transcriptional Evaluation of the Ductus Arteriosus at the Single-Cell Level Uncovers a Requirement for Vim (Vimentin) for Complete Closure

OBJECTIVEFailure to close the ductus arteriosus immediately post-birth, patent ductus arteriosus (PDA), accounts for up to 10% of all congenital heart defects. Despite significant advances in PDA management options, including pharmacological treatment targeting the prostaglandin pathway, a proportion of patients fail to respond and must undergo surgical intervention. Thus, further refinement of the cellular and molecular mechanisms that govern vascular remodeling of this vessel is required.APPROACH AND RESULTSAs anticipated, single-cell RNA sequencing on the ductus arteriosus in mouse embryos at E18.5, P0.5, and P5, revealed broad transcriptional alterations in the endothelial, smooth muscle, and fibroblast cell compartments. Making use of these data sets, vimentin emerged as an interesting candidate for further investigation. Subsequent studies demonstrated that, in fact, mice with genetic deletion of vimentin fail to complete vascular remodeling of the ductus arteriosus, as per presence of a functional lumen.CONCLUSIONSThrough single-cell RNA-sequencing and by tracking closure of the ductus arteriosus postnatally in mice, we uncovered the unexpected contribution of vimentin in driving complete closure of the ductus arteriosus potentially through regulation of the Notch signaling pathway.HIGHLIGHTSSingle-cell RNA-sequencing on the ductus arteriosus at E18.5, P0.5, and P5 reveals how the ductus arteriosus undergoes drastic transcriptional changes at the single-cell level.Endothelial cells increase levels of Vimentin, Notch1 and Jag1 transcripts soon after birth (P0.5), concurrent with ductus arteriosus closure.Loss of vimentin, the major intermediate filament protein of endothelial cells, prevents proper permanent closure of the ductus arteriosus.