Potassium currents in human myogenic cells from healthy and congenital myotonic dystrophy foetuses.
The whole-cell patch clamp technique was used to record potassium currents in in vitro differentiating myoblasts isolated from healthy and myotonic dystrophy type 1 (DM1) foetuses carrying 2000 CTG repeats. The fusion of the DM1 myoblasts was reduced in comparison to that of the control cells. The dystrophic muscle cells expressed less voltage-activated K(+) (delayed rectifier and non-inactivating delayed rectifier) and inward rectifier channels than the age-matched control cells. However, the resting membrane potential was not significantly different between the control and the DM1 cells. After four days in a differentiation medium, the dystrophic cells expressed the fast-inactivating transient outward K(+) channels, which were not observed in healthy cells. We suggest that the low level of potassium currents measured in differentiated DM1 cells could be related to their impaired fusion.
Nurowska
Ewa
E
Department of Biophysics, Warsaw University of Life Sciences SGGW, Warsaw, Poland, ewa_nurowska@sggw.pl
Constanti
Andrew
A
Dworakowska
Beata
B
Mouly
Vincent
V
Furling
Denis
D
Lorenzon
Paola
P
Pietrangelo
Tiziana
T
Dołowy
Krzysztof
K
Ruzzier
Fabio
F
D002462:Cell Membrane / Q000502:physiology; D055724:Electrophysiological Phenomena; D005333:Fetus / Q000166:cytology*; D006801:Humans; D009223:Myotonic Dystrophy / Q000473:pathology / Q000503:physiopathology*; D018408:Patch-Clamp Techniques; D024642:Potassium Channels, Voltage-Gated / Q000502:physiology*; D032496:Satellite Cells, Skeletal Muscle / Q000473:pathology / Q000502:physiology*
D024642:Potassium Channels, Voltage-Gated