title: Bone marrow cells differentiate in cardiac cell lineages after infarction independently of cell fusion.
abstract: Recent studies in mice have challenged the ability of bone marrow cells (BMCs) to differentiate into myocytes and coronary vessels. The claim has also been made that BMCs acquire a cell phenotype different from the blood lineages only by fusing with resident cells. Technical problems exist in the induction of myocardial infarction and the successful injection of BMCs in the mouse heart. Similarly, the accurate analysis of the cell populations implicated in the regeneration of the dead tissue is complex and these factors together may account for the negative findings. In this study, we have implemented a simple protocol that can easily be reproduced and have reevaluated whether injection of BMCs restores the infarcted myocardium in mice and whether cell fusion is involved in tissue reconstitution. For this purpose, c-kit-positive BMCs were obtained from male transgenic mice expressing enhanced green fluorescence protein (EGFP). EGFP and the Y-chromosome were used as markers of the progeny of the transplanted cells in the recipient heart. By this approach, we have demonstrated that BMCs, when properly administrated in the infarcted heart, efficiently differentiate into myocytes and coronary vessels with no detectable differentiation into hemopoietic lineages. However, BMCs have no apparent paracrine effect on the growth behavior of the surviving myocardium. Within the infarct, in 10 days, nearly 4.5 million biochemically and morphologically differentiated myocytes together with coronary arterioles and capillary structures were generated independently of cell fusion. In conclusion, BMCs adopt the cardiac cell lineages and have an important therapeutic impact on ischemic heart failure.
authors.affiliation: Cardiovascular Research Institute, Department of Medicine, New York Medical College, Valhalla, NY 10595, USA. jan_kajstura@nymc.edu
authors.forename: Jan
authors.initials: J
authors.lastname: Kajstura
authors.forename: Marcello
authors.initials: M
authors.lastname: Rota
authors.forename: Brian
authors.initials: B
authors.lastname: Whang
authors.forename: Stefano
authors.initials: S
authors.lastname: Cascapera
authors.forename: Toru
authors.initials: T
authors.lastname: Hosoda
authors.forename: Claudia
authors.initials: C
authors.lastname: Bearzi
authors.forename: Daria
authors.initials: D
authors.lastname: Nurzynska
authors.forename: Hideko
authors.initials: H
authors.lastname: Kasahara
authors.forename: Elias
authors.initials: E
authors.lastname: Zias
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Bonafé
authors.forename: Bernardo
authors.initials: B
authors.lastname: Nadal-Ginard
authors.forename: Daniele
authors.initials: D
authors.lastname: Torella
authors.forename: Angelo
authors.initials: A
authors.lastname: Nascimbene
authors.forename: Federico
authors.initials: F
authors.lastname: Quaini
authors.forename: Konrad
authors.initials: K
authors.lastname: Urbanek
authors.forename: Annarosa
authors.initials: A
authors.lastname: Leri
authors.forename: Piero
authors.initials: P
authors.lastname: Anversa
mesh_terms: D000818:Animals; D001160:Arterioles / Q000166:cytology; D016477:Artifacts; D001854:Bone Marrow Cells / Q000166:cytology*; D002196:Capillaries / Q000166:cytology; D002454:Cell Differentiation; D002459:Cell Fusion; D019070:Cell Lineage; D042783:Endothelial Cells / Q000166:cytology; D005260:Female; D017930:Genes, Reporter; D006085:Graft Survival; D049452:Green Fluorescent Proteins / Q000032:analysis; D006321:Heart / Q000502:physiology; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D015552:Injections, Intralesional; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D009200:Myocardial Contraction; D009203:Myocardial Infarction / Q000601:surgery*; D032383:Myocytes, Cardiac / Q000166:cytology; D032389:Myocytes, Smooth Muscle / Q000166:cytology; D009928:Organ Specificity; D019899:Paracrine Communication; D019009:Proto-Oncogene Proteins c-kit / Q000032:analysis; D012038:Regeneration; D033581:Stem Cell Transplantation; D016277:Ventricular Function, Left; D014998:Y Chromosome
chemical_list: C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; D019009:Proto-Oncogene Proteins c-kit