title: Clonality of mouse and human cardiomyogenesis in vivo.
abstract: An analysis of the clonality of cardiac progenitor cells (CPCs) and myocyte turnover in vivo requires genetic tagging of the undifferentiated cells so that the clonal marker of individual mother cells is traced in the specialized progeny. CPC niches in the atria and apex of the mouse heart were infected with a lentivirus carrying EGFP, and the destiny of the tagged cells was determined 1-5 months later. A common integration site was identified in isolated CPCs, cardiomyocytes, endothelial cells (ECs), and fibroblasts, documenting CPC self-renewal and multipotentiality and the clonal origin of the differentiated cell populations. Subsequently, the degree of EGFP-lentiviral infection of CPCs was evaluated 2-4 days after injection, and the number of myocytes expressing the reporter gene was measured 6 months later. A BrdU pulse-chasing protocol was also introduced as an additional assay for the analysis of myocyte turnover. Over a period of 6 months, each EGFP-positive CPC divided approximately eight times generating 230 cardiomyocytes; this value was consistent with the number of newly formed cells labeled by BrdU. To determine whether, human CPCs (hCPCs) are self-renewing and multipotent, these cells were transduced with the EGFP-lentivirus and injected after acute myocardial infarction in immunosuppressed rats. hCPCs, myocytes, ECs, and fibroblasts collected from the regenerated myocardium showed common viral integration sites in the human genome. Thus, our results indicate that the adult heart contains a pool of resident stem cells that regulate cardiac homeostasis and repair.
authors.affiliation: Department of Anesthesia, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Toru
authors.initials: T
authors.lastname: Hosoda
authors.forename: Domenico
authors.initials: D
authors.lastname: D'Amario
authors.forename: Mauricio Castro
authors.initials: MC
authors.lastname: Cabral-Da-Silva
authors.forename: Hanqiao
authors.initials: H
authors.lastname: Zheng
authors.forename: M Elena
authors.initials: ME
authors.lastname: Padin-Iruegas
authors.forename: Barbara
authors.initials: B
authors.lastname: Ogorek
authors.forename: João
authors.initials: J
authors.lastname: Ferreira-Martins
authors.forename: Saori
authors.initials: S
authors.lastname: Yasuzawa-Amano
authors.forename: Katsuya
authors.initials: K
authors.lastname: Amano
authors.forename: Noriko
authors.initials: N
authors.lastname: Ide-Iwata
authors.forename: Wei
authors.initials: W
authors.lastname: Cheng
authors.forename: Marcello
authors.initials: M
authors.lastname: Rota
authors.forename: Konrad
authors.initials: K
authors.lastname: Urbanek
authors.forename: Jan
authors.initials: J
authors.lastname: Kajstura
authors.forename: Piero
authors.initials: P
authors.lastname: Anversa
authors.forename: Annarosa
authors.initials: A
authors.lastname: Leri
mesh_terms: D016475:3T3 Cells; D000818:Animals; D001483:Base Sequence; D002454:Cell Differentiation; D019070:Cell Lineage; D049109:Cell Proliferation; D002999:Clone Cells / Q000166:cytology / Q000378:metabolism; D042783:Endothelial Cells / Q000166:cytology / Q000378:metabolism; D005260:Female; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D005822:Genetic Vectors / Q000235:genetics; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D016086:Lentivirus / Q000235:genetics; D051379:Mice; D008969:Molecular Sequence Data; D009206:Myocardium / Q000166:cytology / Q000378:metabolism; D032383:Myocytes, Cardiac / Q000166:cytology* / Q000378:metabolism*; D018995:Myosin Heavy Chains / Q000235:genetics / Q000378:metabolism; D051381:Rats; D011916:Rats, Inbred F344; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors
chemical_list: D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; D018995:Myosin Heavy Chains