biostudies-literatureLi RNHLBINHLBI NIH HHSUS Department of Defense152-167https://www.ebi.ac.uk/biostudies/studies/S-EPMC11534516biostudies-literatureUnknown196Although some studies have suggested that macrophages may secrete structural collagens, and convert to fibroblast-like cells, macrophage to fibroblast transdifferentiation in infarcted and remodeling hearts remains controversial. Our study uses linage tracing approaches and single cell transcriptomics to examine whether macrophages undergo fibroblast conversion, and to characterize the extracellular matrix expression profile of myeloid cells in myocardial infarction. To examine whether infarct macrophages undergo fibroblast conversion, we identified macrophage-derived progeny using the inducible CX3CR1^CreER mice crossed with the PDGFRα^EGFP reporter line for reliable fibroblast identification. The abundant fibroblasts that infiltrated the infarcted myocardium after 7 aJournal of molecular and cellular cardiologyMacrophages in the infarcted heart acquire a fibrogenic phenotype, expressing matricellular proteins, but do not undergo fibroblast conversion.PMC11534516R01 HL076246R01 HL085440R01 HL149407Hanna AHumeres CLiu YFrangogiannis NGHuang SHernandez SCLi RKubota ATuleta IChen BZheng DfalseMacrophages in the infarcted heart acquire a fibrogenic phenotype, expressing matricellular proteins, but do not undergo fibroblast conversion.Although some studies have suggested that macrophages may secrete structural collagens, and convert to fibroblast-like cells, macrophage to fibroblast transdifferentiation in infarcted and remodeling hearts remains controversial. Our study uses linage tracing approaches and single cell transcriptomics to examine whether macrophages undergo fibroblast conversion, and to characterize the extracellular matrix expression profile of myeloid cells in myocardial infarction. To examine whether infarct macrophages undergo fibroblast conversion, we identified macrophage-derived progeny using the inducible CX3CR1^CreER mice crossed with the PDGFRα^EGFP reporter line for reliable fibroblast identification. The abundant fibroblasts that infiltrated the infarcted myocardium after 7 a2024-01-01T00:00:00Z2024 Nov2026-06-05T09:24:49.939Z2026-05-15T03:12:15.418ZS-EPMC115345163908957010.1016/j.yjmcc.2024.07.010