OP9 Single Cell RNA-sequencing reveals novel targets with a potential role in vascular regeneration in the ischaemic adult heart

Ischaemic heart disease remains a leading global cause of death. Restoring blood perfusion in the peri-infarct border region may limit further infarct expansion and promote cardiac regeneration. However, the pathways driving endogenous vascular regeneration following myocardial infarction (MI) remain poorly understood. We aimed to investigate the origin, clonal dynamics and transcriptional profiles of resident coronary endothelial cells (EC) in the post-ischaemic adult mouse heart and to apply single cell RNA-sequencing (scRNAseq) to identify and validate novel targets with a potential role in neovasculogenesis following MI. MI was induced in an EC-specific multispectral lineage-tracing mouse, ‘Pdgfb-iCreERT2-R26R-Brainbow2.1’ by permanent ligation of the left anterior descending coronary artery. Blood vessel formation via clonal proliferation by resident coronary vascular EC was significantly upregulated in the ischaemic border at 7 days post-MI, compared to the healthy heart (Pdgfb-Confetti+ EC per clone = 4.0 ± 2.1 versus 10.3 ± 10.6, P