The aim of this study was to provide a set of data on mechanisms involved in the
calcium homeostasis of
facioscapulohumeral muscular dystrophy (FSHD) co-cultured myotubes. In fact, abnormal regulation of
calcium have been shown in deficient
dystrophin cells like
Duchenne muscular dystrophy (DMD) cells, and it seemed interesting to study the
calcium regulation in a pathologic cellular model which express
dystrophin. T- and L-type
calcium currents and contractile responses induced by membrane depolarisations as well as intracellular
calcium transients induced by three kinds of stimulus (superfusions of
acetylcholine, high K+ or
caffeine containing media) were recorded by means of whole-cell patch-clamp and ratiometric cytofluorimetry in co-cultured FSHD myotubes which presented a sarcolemmal localisation of
dystrophin. As judged from
calcium currents properties, voltage-dependency of contractile responses or amplitude of evoked
calcium transients, no clear difference in the
calcium handling or
calcium signalling was observed between this type of cell and the control cells, at least with the means and the conditions used in the present study. Since FSHD cells, contrary to DMD (
Duchenne muscular dystrophy) cells, seemed to display both
dystrophin expression and unaltered
calcium regulation, the FSHD co-cultured cells appeared as a useful model of
dystrophin-expressing pathological muscle cells to further investigate the link between
dystrophin expression and intracellular
calcium level regulation.