Single-cell transcriptome of the murine carotid artery following acute injury
Acute vascular injury is an unwelcome consequence of invasive treatments designed to alleviate symptoms of vascular stenosis. Resulting fibrotic scarring and neointima formation may result in loss of lumen diameter and diminished vascular function. Understanding of the key phases of acute inflammation, resolution and remodeling has the potential to minimise unwanted effects on the vasculature and therefore improve patient outcomes. The cellular landscape of blood vessels is highly hetergeneous in nature, and therefore data at single-cell resolution is of high relevance to this problem. Herein, the cellularity of murine carotid artery tissue is described in a cell- and time-resolved manner. Single-cell RNA-sequencing of carotid tissue isolated at time-points ranging from uninjured vessel to 14 days post-injury enabled the recapitulation of all stages of vascular injury. In these data, a sub-population of smooth muscle cells which also arises in atherosclerosis and myocardial infarction was identified. So-called stem cells/endothelial cells/monocytes (SEM) cells are candidates for repopulating injured vessels, and were amongst the most proliferative cell clusters following wire-injury of the carotid artery. Transcriptional signatures reflecting SEM gene expression patterns could also be detected in bulk RNA-sequencing of neointimal tissue isolated by laser capture microdissection. These data indicate that phenotypic plasticity of smooth muscle cells is highly important to the progression of lumen loss following acute vascular insult. Overall design: Murine carotid arteries were isolated at different time points post-injury, digested, and submitted for single-cell RNA-sequencing.