Flk1(+) cardiac stem/progenitor cells derived from embryonic stem cells improve cardiac function in a dilated cardiomyopathy mouse model.
OBJECTIVE
Flk1(+) cells derived from embryonic stem (ES) cells are known to differentiate into mesodermal lineages such as hematopoietic and endothelial cells. Here we demonstrate that they can develop into cardiomyocytes that support functional recovery in a dilated cardiomyopathy (DCM) C57/BL6 mouse model.


METHODS
Flk1(+) and Flk1(-) cells were sorted at day 4 of differentiation, and cardiomyogenesis was assessed in vitro. Next, we transplanted these cells into the hearts of cardiomyopathy mice to assess improvement in cardiac function.


RESULTS
Flk1(+) cells, but not Flk1(-) cells, isolated on day 4 after differentiation were efficiently converted into contractile cardiomyocytes. RT-PCR analysis and immunohistological assays demonstrated that contractile cells derived from Flk1(+) cells in vitro expressed mature cardiac markers on day 10 after differentiation. Transplantation of sorted Flk1(+) cells into DCM model mouse hearts improved cardiac function, as determined by echocardiography and cardiac catheterization. The in vivo differentiated Flk1(+) cells expressed cardiac markers and had gap junctions, as demonstrated by immunohistochemistry. Furthermore, these cells generated ventricular type action potentials similar to those of adult ventricle.


CONCLUSIONS
These results indicate that Flk1 is a good marker for sorting cardiac stem/progenitor cells which can differentiate into mature cardiomyocytes both in vitro and in vivo.
Baba
Shiro
S
Department of Pediatrics, Graduate School of Medicine, Kyoto University, Kyoto, Japan, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan. shibaba@kuhp.kyoto-u.ac.jp
Heike
Toshio
T
Yoshimoto
Momoko
M
Umeda
Katsutsugu
K
Doi
Hiraku
H
Iwasa
Toru
T
Lin
Xue
X
Matsuoka
Satoshi
S
Komeda
Masashi
M
Nakahata
Tatsutoshi
T
D000200:Action Potentials / Q000502:physiology; D000818:Animals; D002311:Cardiomyopathy, Dilated / Q000503:physiopathology / Q000628:therapy*; D018929:Cell Culture Techniques; D002454:Cell Differentiation; D004317:Doxorubicin; D004452:Echocardiography; D004562:Electrocardiography; D042783:Endothelial Cells / Q000502:physiology; D006412:Hematopoietic Stem Cells / Q000502:physiology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D023421:Models, Animal; D032383:Myocytes, Cardiac / Q000502:physiology; D018408:Patch-Clamp Techniques; D033581:Stem Cell Transplantation / Q000379:methods*; D013234:Stem Cells / Q000502:physiology*; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000378:metabolism*
D004317:Doxorubicin; D040301:Vascular Endothelial Growth Factor Receptor-2