title: Dynamic haematopoietic cell contribution to the developing and adult epicardium.
abstract: The epicardium is a cellular source with the potential to reconstitute lost cardiovascular tissue following myocardial infarction. Here we show that the adult epicardium contains a population of CD45+ haematopoietic cells (HCs), which are located proximal to coronary vessels and encased by extracellular matrix (ECM). This complex tertiary structure is established during the regenerative window between post-natal days 1 and 7. We show that these HCs proliferate within the first 24 h and are released between days 2 and 7 after myocardial infarction. The ECM subsequently reforms to encapsulate HCs after 21 days. Vav1-tdTomato labelling reveals an integral contribution of CD45+ HCs to the developing epicardium, which is not derived from the proepicardial organ. Transplantation experiments with either whole bone marrow or a Vav1+ subpopulation of cells confirm a contribution of HCs to the intact adult epicardium, which is elevated during the first 24 weeks of adult life but depleted in aged mice.
authors.affiliation: 1] Molecular Medicine Unit, UCL-Institute of Child Health, London WC1N 1EH, UK [2].
authors.forename: Gemma M
authors.initials: GM
authors.lastname: Balmer
authors.affiliation: 1] Regenerative Medicine Laboratory, University of Genoa & IRCCS AOU San Martino-IST, Largo Rosanna Benzi, 16132 Genoa, Italy [2].
authors.forename: Sveva
authors.initials: S
authors.lastname: Bollini
authors.affiliation: Molecular Medicine Unit, UCL-Institute of Child Health, London WC1N 1EH, UK.
authors.forename: Karina N
authors.initials: KN
authors.lastname: Dubé
authors.affiliation: Neural Development Unit, UCL-Institute of Child Health, London WC1N 1EH, UK.
authors.forename: Juan Pedro
authors.initials: JP
authors.lastname: Martinez-Barbera
authors.affiliation: Molecular Haematology and Cancer Biology Unit, UCL-Institute of Child Health, London WC1N 1EH, UK.
authors.forename: Owen
authors.initials: O
authors.lastname: Williams
authors.affiliation: Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK.
authors.forename: Paul R
authors.initials: PR
authors.lastname: Riley
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D002478:Cells, Cultured; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000276:immunology; D017493:Leukocyte Common Antigens / Q000276:immunology; D051379:Mice; D010496:Pericardium / Q000166:cytology*
chemical_list: D017493:Leukocyte Common Antigens; C516770:Ptprc protein, mouse