Novel electrical stimulation sets the cultured myoblast contractile function to 'on'.
OBJECTIVE
In the present study, the effect of electrical stimulation was examined for the ability to induce morphological, physiological, and molecular biological effects on myoblasts during cell differentiation.


METHODS
L6 rat myoblasts were electrically stimulated by newly developed methods on culture days 6, 8, 10 and 12.


RESULTS
This electrical stimulation accelerated the appearance of myotubes, and subsequently produced spontaneously contracting muscle fibers. Measurement of membrane potential showed that the contracting cell had functional ion channels and gap junctional intercellular communication. In the electrically stimulated cells, an enhanced expression of MyoD family and M-cadherin was also observed. Expression of connexin 43 was increased and maintained at a high level in the electrically stimulated cells.


CONCLUSIONS
This is the first demonstration of in vitro induction of myoblasts in spontaneously contractile muscle fibers by intermittent stimulation. This novel method for induction of myoblast differentiation represents an important advance in cell therapy.
Kawahara
Yumi
Y
Division of Bio-Environmental Adaptation Sciences, Graduate School of Health Sciences, Hiroshima University, Hiroshima, Japan.
Yamaoka
Kaoru
K
Iwata
Masahiro
M
Fujimura
Masahiko
M
Kajiume
Teruyuki
T
Magaki
Takuro
T
Takeda
Masaaki
M
Ide
Toshinori
T
Kataoka
Katsuko
K
Asashima
Makoto
M
Yuge
Louis
L
D000818:Animals; D015153:Blotting, Western; D015820:Cadherins / Q000378:metabolism; D002450:Cell Communication; D002454:Cell Differentiation; D002460:Cell Line; D048430:Cell Shape; D018031:Connexin 43 / Q000378:metabolism; D004558:Electric Stimulation; D017629:Gap Junctions / Q000378:metabolism / Q000502:physiology; D007150:Immunohistochemistry; D008564:Membrane Potentials; D009119:Muscle Contraction; D017570:MyoD Protein / Q000096:biosynthesis; D032448:Myoblasts, Skeletal / Q000166:cytology* / Q000378:metabolism / Q000502:physiology; D018006:Myogenic Regulatory Factors / Q000096:biosynthesis; D051381:Rats; D013997:Time Factors; D015854:Up-Regulation
D015820:Cadherins; D018031:Connexin 43; D017570:MyoD Protein; D018006:Myogenic Regulatory Factors; C063403:myogenic factor 6; C070896:M-cadherin