For each experimental condition, heart tissues were first rinsed and minced into 1 mm pieces on ice, then the minced tissues were pooled and digested in tissue dissociation media (0.1% Collagenase with 2.5 U/mL Dispase II, 9:1 in volume) for 40 minutes in 37°C water bath, pipetted every 5 minutes, to ensure an adequate number of cells and a robust representation of cardiac cell types. Single-cell suspension was passed through a 40 µm filter. Cell suspension was stained with PE Rat anti mouse CD31 (BD Pharmingen, 553373) or APC Rat anti mouse CD45 (BD Pharmingen, 559864), then followed incubated with anti-PE microbeads (MACS,130-105-639) or Anti-APC microbeads (MACS,130-090-855). Single cells from CD31+ or CD45+ cell populations were collected by FACS sorting. The DNBelab C Series Single-Cell Library Prep Set (MGI, 1000021082) was used as previously described. In brief, single cell suspensions were used for droplet generation, emulsion breakage, bead collection, reverse transcription and cDNA amplification to generate barcoded libraries. Libraries were sequenced on DNBSEQ-T1 sequencers with the following sequencing strategy: 41-bp read length for read 1 and 100-bp read length for read 2.