title: Persistent expression of the ATP-binding cassette transporter, Abcg2, identifies cardiac SP cells in the developing and adult heart.
abstract: Stem cells are important in the maintenance and repair of adult tissues. A population of cells, termed side population (SP) cells, has stem cell characteristics as they have been shown to contribute to diverse lineages. In this study, we confirm that Abcg2 is a determinant of the SP cell phenotype. Therefore, we examined Abcg2 expression during murine embryogenesis and observed robust expression in the blood islands of the E8.5 yolk sac and in developing tissues including the heart. During the latter stages of embryogenesis, Abcg2 identifies a rare cell population in the developing organs. We further establish that the adult heart contains an Abcg2 expressing SP cell population and these progenitor cells are capable of proliferation and differentiation. We define the molecular signature of cardiac SP cells and compare it to embryonic stem cells and adult cardiomyocytes using emerging technologies. We propose that the cardiac SP cell population functions as a progenitor cell population for the development, maintenance, and repair of the heart.
authors.affiliation: Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390-8573, USA.
authors.forename: Cindy M
authors.initials: CM
authors.lastname: Martin
authors.forename: Annette P
authors.initials: AP
authors.lastname: Meeson
authors.forename: Scott M
authors.initials: SM
authors.lastname: Robertson
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Hawke
authors.forename: James A
authors.initials: JA
authors.lastname: Richardson
authors.forename: Susan
authors.initials: S
authors.lastname: Bates
authors.forename: Sean C
authors.initials: SC
authors.lastname: Goetsch
authors.forename: Teresa D
authors.initials: TD
authors.lastname: Gallardo
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Garry
mesh_terms: D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters / Q000235:genetics / Q000502:physiology*; D000818:Animals; D015153:Blotting, Western; D002478:Cells, Cultured; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D006321:Heart / Q000502:physiology*; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D051379:Mice; D009206:Myocardium / Q000166:cytology*; D009363:Neoplasm Proteins / Q000235:genetics / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013234:Stem Cells / Q000502:physiology*; D015017:Yolk Sac / Q000502:physiology
chemical_list: C116614:ABCG2 protein, human; D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters; D009363:Neoplasm Proteins