title: Heterogeneic nature of adult cardiac side population cells.
abstract: Side population cells have been found in various types of adult tissue including heart and are presumed to be tissue-specific stem/progenitor cells. In the present study, we confirmed the presence of cardiac side population (cSP) cells, which showed both the Hoechst 33342 efflux ability and ABCG2 expression, in adult murine heart. Flow cytometric analysis showed that more than half of cSP cells expressed the endothelial marker VE-cadherin or the smooth muscle markers, alpha-smooth muscle actin and desmin. In addition, immunohistochemical analysis demonstrated that ABCG2(+) cells were mainly localized within vascular walls. Quantitative RT-PCR analysis demonstrated that VE-cadherin(-) cSP cells progressively expressed Nkx2.5 and cardiac troponin T with time in culture. VE-cadherin(-) cSP cells also expressed mesodermal-mesenchymal-associated markers and differentiated into osteocytes and adipocytes. These results highlight the heterogeneic nature of cSP cells, consisting of vascular endothelial cells, smooth muscle cells, and mesenchymal stem/progenitor cells including potential cardiomyogenic cells.
authors.affiliation: Harefield Heart Science Centre, Imperial College London, Middlesex, UK.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Yamahara
authors.forename: Satsuki
authors.initials: S
authors.lastname: Fukushima
authors.forename: Steven R
authors.initials: SR
authors.lastname: Coppen
authors.forename: Leanne E
authors.initials: LE
authors.lastname: Felkin
authors.forename: Anabel
authors.initials: A
authors.lastname: Varela-Carver
authors.forename: Paul J R
authors.initials: PJ
authors.lastname: Barton
authors.forename: Magdi H
authors.initials: MH
authors.lastname: Yacoub
authors.forename: Ken
authors.initials: K
authors.lastname: Suzuki
mesh_terms: D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D000199:Actins / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D000818:Animals; D001562:Benzimidazoles / Q000378:metabolism; D015820:Cadherins / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D002454:Cell Differentiation; D002469:Cell Separation; D002478:Cells, Cultured; D003893:Desmin / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D006321:Heart; D000072576:Homeobox Protein Nkx-2.5; D018398:Homeodomain Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D032386:Myoblasts, Cardiac / Q000737:chemistry / Q000166:cytology* / Q000378:metabolism*; D014157:Transcription Factors / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D020107:Troponin T / Q000032:analysis / Q000235:genetics / Q000378:metabolism
chemical_list: D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters; C501412:Abcg2 protein, mouse; D000199:Actins; D001562:Benzimidazoles; D015820:Cadherins; D003893:Desmin; D000072576:Homeobox Protein Nkx-2.5; D018398:Homeodomain Proteins; C484469:Nkx2-5 protein, mouse; D014157:Transcription Factors; D020107:Troponin T; C017807:bisbenzimide ethoxide trihydrochloride