Negative modulation of inositol 1,4,5-trisphosphate type 1 receptor expression prevents dystrophin-deficient muscle cells death.
Evidence for a modulatory effect of cyclosporin A (CsA) on calcium signaling and cell survival in dystrophin-deficient cells is presented. Our previous works strongly supported the hypothesis of an overactivation of Ca(2+) release via inositol 1,4,5-trisphosphate (IP3) receptors (IP3R) in dystrophin-deficient cells, both during membrane depolarization and at rest, through spontaneous Ca(2+) release events. Forced expression of mini-dystrophin in these cells contributed, during stimulation and in resting condition, to the recovery of a controlled calcium homeostasis. In the present work, we demonstrate that CsA exposure displayed a dual-modulator effect on calcium signaling in dystrophin-deficient cells. Short-time incubation induced a decrease of IP3-dependent calcium release, leading to patterns of release similar to those observed in myotubes expressing mini-dystrophin, whereas long-time incubation reduced the expression of the type I of IP3 receptors (IP3R-1) RNA levels. Moreover, both IP3R-1 knockdown and blockade through 2-aminoethoxydiphenyle borate or CsA induced improved survival of dystrophin-deficient myotubes, demonstrating the cell death dependence on the IP3-dependent calcium signaling as well as the protective effect of CsA. Inhibition of the IP3 pathway could be a very interesting approach for reducing the natural cell death of dystrophin-deficient cells in development.
Mondin
Ludivine
L
Institut de Physiologie et Biologie Cellulaires, Centre National de la Recherche Scientifique UMR 6187, Université de Poitiers, 86022 Poitiers, France.
Balghi
Haouaria
H
Constantin
Bruno
B
Cognard
Christian
C
Sebille
Stéphane
S
D000818:Animals; D015153:Blotting, Western; D020013:Calcium Signaling / Q000187:drug effects / Q000502:physiology*; D016923:Cell Death / Q000187:drug effects / Q000502:physiology; D016572:Cyclosporine / Q000494:pharmacology; D016189:Dystrophin / Q000172:deficiency*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015870:Gene Expression; D005786:Gene Expression Regulation / Q000187:drug effects; D007091:Image Processing, Computer-Assisted; D053496:Inositol 1,4,5-Trisphosphate Receptors / Q000096:biosynthesis* / Q000187:drug effects / Q000235:genetics; D051379:Mice; D018613:Microscopy, Confocal; D018485:Muscle Fibers, Skeletal / Q000187:drug effects / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis; D034741:RNA, Small Interfering; D020133:Reverse Transcriptase Polymerase Chain Reaction
D016189:Dystrophin; D004791:Enzyme Inhibitors; D053496:Inositol 1,4,5-Trisphosphate Receptors; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D016572:Cyclosporine