We evaluated the expression of the FLK1, one of the lateral mesoderm early markers where cardiogenesis occurs, to characterize and isolate cardiac stem/progenitor cells from ES cells. Dissociated cells from embryoid bodies (EBs) on day 3, 4, or 5 were collected into two subpopulations with or without FLK1 expression and coculture on OP9 stromal cells was continued to examine whether contracting colonies came out or not. FLK1+ cells from EBs at days 3 and 4 formed spontaneous contracting colonies more efficiently than FLK1- cells on the same days, but not at day 5. Most contracting cardiac colonies derived from FLK1+ cells mainly on day 4 were detected on endothelial cells along with hematopoietic cells. Further characterization of cells with these capabilities into three lineages revealed the FLK1+ CD31-VE-cadherin- phenotype. Our findings indicate that FLK1+ cells, especially FLK1+ CD31-VE-cadherin- cells, could act as cardiohemangioblasts to form cardiac cells as well as endothelial cells and hematopoietic cells.
- Cardiomyocyte differentiation
- ES cells
- Embryoid bodies
ASJC Scopus subject areas
- Molecular Biology