TIMD4^hiMHCⅡ^hi Macrophages Preserve Heart Function Through Retnla

Genetic fate mapping confirmed the existence of the TIMD4^hiMHCⅡ^hi macrophage subset and showed that they were resident macrophages with minimal input from peripheral monocytes. Further, single-cell RNA sequencing revealed that Retnla could serve as the signature gene for TIMD4^hiMHCⅡ^hi macrophages. Administration of recombinant protein of the Retnla gene, RELMα, delayed the onset of heart failure, whereas either deletion of TIMD4^hiMHCⅡ^hi macrophages or macrophage-specific loss of Retnla facilitated heart failure progression.