Biological pacemakers: characterization in an in vitro coculture model.
J Electrocardiol
; 41(6): 562-6, 2008.
Article
em En
| MEDLINE
| ID: mdl-18790503
ABSTRACT
BACKGROUND:
Biological pacemakers could be an alternative or complement to electronic pacemakers. Embryonic stem cells (ESCs) can be differentiated in vitro to spontaneously active cells. Although numerous studies show that ESC-derived cardiomyocytes (ESC-CMs) and other cell types are capable to exert pacemaker function in vivo, detailed analyses of pattern and safety of conduction on a tissue level are rare.METHODS:
Murine ESCs (mESCs) expressing enhanced green fluorescent protein and puromycin resistance under control of the promoter of alpha-myosin (heavy chain) were differentiated to cardiomyocytes (mESC-CMs) and purified by negative antibiotic selection. Ventricles of mouse embryonic hearts (embryonic day 16.5) were embedded in agarose and sliced along the short axis. Clusters of mESC-CMs and the murine, vital heart slices were cocultured on multielectrode arrays for 4 days. Field potentials and videos were recorded daily to investigate beating behavior and excitation spreading within the slice.RESULTS:
On the first day of coculture, the mean beating rate of the tissue slices cocultured with mESC-CMs (n = 19) did not differ significantly from the beating rate of control slices (n = 19) (37 +/- 10 versus 19 +/- 7 bpm, P = .133). After 4 days of coculture, beating rates were significantly higher in cocultures than in control slices (154 +/- 22 versus 49 +/- 8 bpm, P < .001). On day 4, 11 coupling could be found in 1 of 19 preparations; 21, 31, or 41 coupling in another 4 of 19 preparations; 14 of 19 propagation patterns were irregular.CONCLUSION:
In this in vitro model, the increase of the beating rate suggests that purified mESC-CMs can pace native heart tissue, albeit with low efficiency.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Relógios Biológicos
/
Potenciais de Ação
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Miócitos Cardíacos
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Células-Tronco Embrionárias
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Contração Miocárdica
Limite:
Animals
Idioma:
En
Ano de publicação:
2008
Tipo de documento:
Article