Purified cardiomyocytes from bone marrow mesenchymal stem cells produce stable intracardiac grafts in mice.
OBJECTIVE
We have previously isolated cardiomyogenic cells from murine bone marrow (CMG cells). Regenerated cardiomyocytes are important candidates for cell transplantation, but as they are stem cell derived, they can be contaminated with various cell types, thereby requiring characterization and purification. Our objectives were to increase the efficiency of cell transplantation and to protect the recipients from possible adverse effects using an efficient and effective purification process as well as to characterize regenerated cardiomyocytes.


METHODS
Noncardiomyocytes were eliminated from a mixture of stem-cell-derived cells using a fluorescence-activated cell sorter to specifically isolate CMG cells transfected with a recombinant plasmid containing enhanced green fluorescent protein (EGFP) cDNA under the control of the myosin light chain-2v (MLC-2v) promoter. Gene expression and the action potential were investigated, and purified cells were transplanted into the heart of adult mice.


RESULTS
Six percent to 24% of transfected CMG cells expressed EGFP after differentiation was induced, and a strong EGFP-positive fraction was selected. All the sorted cells began spontaneous beating after 3 weeks. These cells expressed cardiomyocyte-specific genes such as alpha-skeletal actin, beta-myosin heavy chain, MLC-2v, and CaV1.2 and incorporated bromodeoxyuridine for 5 days. The isolated EGFP-positive cells were expanded for 5 days and then transplanted into the left ventricle of adult mouse hearts. The transplanted cells survived for at least 3 months and were oriented in parallel to the cardiomyocytes of the recipient heart.


CONCLUSIONS
The purification and transplantation of differentiated cardiomyocytes from adult stem cells provides a viable model of tissue engineering for the treatment of heart failure.
Hattan
Naoichiro
N
Department of Physiology, Tokai University School of Medicine, Japan.
Kawaguchi
Haruko
H
Ando
Kiyoshi
K
Kuwabara
Eriko
E
Fujita
Jun
J
Murata
Mitsushige
M
Suematsu
Makoto
M
Mori
Hidezo
H
Fukuda
Keiichi
K
D000200:Action Potentials; D000818:Animals; D002454:Cell Differentiation; D002469:Cell Separation / Q000379:methods; D004247:DNA / Q000096:biosynthesis; D004562:Electrocardiography; D005260:Female; D015870:Gene Expression; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006333:Heart Failure / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D059630:Mesenchymal Stem Cells / Q000166:cytology*; D051379:Mice; D016513:Mice, SCID; D008854:Microscopy, Electron; D009206:Myocardium / Q000378:metabolism / Q000473:pathology; D032383:Myocytes, Cardiac / Q000637:transplantation*; D018994:Myosin Light Chains / Q000235:genetics; D011401:Promoter Regions, Genetic
D018994:Myosin Light Chains; D049452:Green Fluorescent Proteins; D004247:DNA