title: Isolation of cardiac cells from E8.5 yolk sac by ALCAM (CD166) expression.
abstract: It is known that the adhesion molecule ALCAM (CD166) mediates metastasis of malignant cells and organogenesis in embryos. We show here that embryonic day 8.5 (E8.5) murine yolk sac cells express ALCAM protein and that ALCAM expression can be used to define endothelial and cardiac precursors from hematopoietic precursors in E8.5 yolk sacs. ALCAM high+ cells exclusively give rise to endothelial and cardiac cells in matrigel assays but generate no hematopoietic colonies in methylcellulose assays. ALCAM low+ and ALCAM- populations predominantly give rise to hematopoietic cells in methylcellulose, but do not generate any cell clusters in matrigel. The ALCAM high+ population contains both Flk-1+ and Flk-1- cells. The former population exclusively contains endothelial cells whereas the latter give rise to cardiac cells when cultured on OP9 stromal cells. We also show that cardiac lineage marker genes such as Nkx-2.5, and the endothelial marker VE-cadherin are expressed in the ALCAM high+ fraction, whereas the hematopoietic marker GATA1 and Runx1 are expressed in the ALCAM low+/- fraction. However, we did not detect expression of the cardiac structural protein cTn-T in cells from yolk sac cells until these had had been differentiated on OP9 for 5 days. Altogether, these results indicate that cells retaining a potential to differentiate to the cardiac lineage are present in E8.5 yolk sacs and can be isolated as ALCAM high+, Flk-1- cells. Our report provides novel insights into the origin and differentiation process of cardiac cells in the formation of the circulatory system.
authors.affiliation: Foundation of Biomedical Research and Innovation, 2-2 Minatojima-Minamimachi, Chuo-ku, Kobe 650-0047, Japan.
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Murakami
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Hirata
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Miyamoto
authors.forename: Ayako
authors.initials: A
authors.lastname: Nagahashi
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Sawa
authors.forename: Martin
authors.initials: M
authors.lastname: Jakt
authors.forename: Takayuki
authors.initials: T
authors.lastname: Asahara
authors.forename: Shin
authors.initials: S
authors.lastname: Kawamata
mesh_terms: D020410:Activated-Leukocyte Cell Adhesion Molecule / Q000235:genetics* / Q000378:metabolism*; D000818:Animals; D002454:Cell Differentiation; D002458:Cell Fractionation; D019070:Cell Lineage; D002469:Cell Separation; D018920:Coculture Techniques; D003094:Collagen / Q000378:metabolism; D004338:Drug Combinations; D042783:Endothelial Cells / Q000166:cytology / Q000378:metabolism; D005260:Female; D005434:Flow Cytometry; D018507:Gene Expression Regulation, Developmental; D006413:Hematopoietic System / Q000166:cytology / Q000378:metabolism; D007797:Laminin / Q000378:metabolism; D008747:Methylcellulose / Q000378:metabolism; D051379:Mice; D009206:Myocardium / Q000166:cytology*; D011509:Proteoglycans / Q000378:metabolism; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000378:metabolism; D015017:Yolk Sac / Q000166:cytology*
chemical_list: D020410:Activated-Leukocyte Cell Adhesion Molecule; D004338:Drug Combinations; D007797:Laminin; D011509:Proteoglycans; C059485:matrigel; D008747:Methylcellulose; D003094:Collagen; D040301:Vascular Endothelial Growth Factor Receptor-2