Direct contact with endoderm-like cells efficiently induces cardiac progenitors from mouse and human pluripotent stem cells.
BACKGROUND
Pluripotent stem cell-derived cardiac progenitor cells (CPCs) have emerged as a powerful tool to study cardiogenesis in vitro and a potential cell source for cardiac regenerative medicine. However, available methods to induce CPCs are not efficient or require high-cost cytokines with extensive optimization due to cell line variations.


OBJECTIVE
Based on our in-vivo observation that early endodermal cells maintain contact with nascent pre-cardiac mesoderm, we hypothesized that direct physical contact with endoderm promotes induction of CPCs from pluripotent cells.


RESULTS
To test the hypothesis, we cocultured mouse embryonic stem (ES) cells with the endodermal cell line End2 by co-aggregation or End2-conditioned medium. Co-aggregation resulted in strong induction of Flk1(+) PDGFRa(+) CPCs in a dose-dependent manner, but the conditioned medium did not, indicating that direct contact is necessary for this process. To determine if direct contact with End2 cells also promotes the induction of committed cardiac progenitors, we utilized several mouse ES and induced pluripotent (iPS) cell lines expressing fluorescent proteins under regulation of the CPC lineage markers Nkx2.5 or Isl1. In agreement with earlier data, co-aggregation with End2 cells potently induces both Nkx2.5(+) and Isl1(+) CPCs, leading to a sheet of beating cardiomyocytes. Furthermore, co-aggregation with End2 cells greatly promotes the induction of KDR(+) PDGFRa(+) CPCs from human ES cells.


CONCLUSIONS
Our co-aggregation method provides an efficient, simple and cost-effective way to induce CPCs from mouse and human pluripotent cells.
Division of Cardiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
Hideki
H
Uosaki
Peter
P
Andersen
Lincoln T
LT
Shenje
Laviel
L
Fernandez
Sofie Lindgren
SL
Christiansen
Chulan
C
Kwon
D000818:Animals; D018920:Coculture Techniques; D017077:Culture Media, Conditioned; D004707:Endoderm / Q000166:cytology*; D005434:Flow Cytometry; D006801:Humans; D051379:Mice; D009206:Myocardium / Q000166:cytology*; D039904:Pluripotent Stem Cells / Q000166:cytology*; D020133:Reverse Transcriptase Polymerase Chain Reaction
D017077:Culture Media, Conditioned