De-differentiation and Proliferation of Artery Endothelial Cells Drive Coronary Collateral Development

We have earlier observed that upon myocardial infarction, pre-existing coronary arteries give rise to new collateral arteries via Artery Reassembly (AR) in neonatal mice, but not in adults. To understand this age dependent phenomenon, Gja5 (Cx40), an established artery endothelial cell marker, was used to lineage trace artery cells with TdTomato expression. For the neonatal mice, Tamoxifen was induced at postnatal (P)0, Myocardial Infarction (MI)/sham was performed at P2 and hearts were harvested at either P4 or P5. Whereas, for the adults, mice aged ~2months were used. Tamoxifen was induced at Day (D)0, MI/sham was performed at D2 and hearts were harvested at either D9 or D11. Ventricles from hearts were digested and FACS sorted for DAPI-, Ter199- and TdTomato+ cells. Single Cell RNA sequencing data was obtained from neonatal and adult mice heart ventricles using 10X genomics, and further processed on Cell Ranger.