Single-cell genomics reveals a novel cell state during smooth muscle cell phenotypic switching and potential therapeutic targets for atherosclerosis in mouse and human [mouse]

Smooth muscle cells (SMC) play significant roles in atherosclerosis via phenotypic switching, a pathological process in which SMC dedifferentiation, migration and transdifferentiation into other cell types. Yet, how SMC contribute to pathophysiology of atherosclerosis remains elusive. To reveal the trajectories of SMC transdifferentiation during atherosclerosis and to identify molecular targets for disease therapy, we combined SMC fate mapping and single-cell RNA sequencing of both mouse and human atherosclerotic plaques. Overall design: SMC-lineage tracing mice, ROSA26 ZsGreen1/+; Myh11-CreERT2 mice, were crossed onto athero-prone backgrounds (Ldlr-/- or ApoE-/-). Mouse single cells digested from arterial tissues (including ascending aorta, brachiocephalic artery and thoracic aorta) for scRNA-seq were prepared from three ROSA26 ZsGreen1/+; Ldlr-/-; Myh11-CreERT2 mice at the same timepoint of Western diet (WD) feeding (0, 8, 16, 26 weeks) and ROSA26 ZsGreen1/+; ApoE-/-; Myh11-CreERT2 mice at the same timepoint of WD feeding (8, 16, 22 weeks). Alive ZsGreen1+ cells (SMC-lineage cells) and ZsGreen1- cells were sorted separately and were immediately subjected to scRNA-seq using Chromium Single Cell Gene Expression system (10x Genomics) in parallel.