Transplantation of myoblasts from a transgenic mouse overexpressing dystrophin prduced only a relatively small increase of dystrophin-positive membrane.
Myoblast cultures from normal and Tg-MDA (transgenic mouse overexpressing dystrophin 50-fold) mice were transplanted into dystrophin-deficient mdx mouse muscles. Four weeks after transplantation, dystrophin-positive fibers were observed four times more frequently in cross sections of muscles injected with Tg-MDA. Myoblasts from Tg-MDA mice also expressing the beta-gal transgene (Tg-MDA/beta-gal) and myoblasts from beta-gal transgenic mice containing one normal dystrophin gene (normal/beta-gal) were also transplanted into mdx mouse muscles. Four weeks after transplantation, the fiber length positive for dystrophin (nuclear domain) was shorter (439 +/- 326 microm) than the beta-gal nuclear domain (1466 +/- 713 microm) of the same fiber when normal/beta-gal myoblasts were transplanted, but increased (1302 +/- 487 microm) when Tg-MDA/beta-gal myoblasts were used. These experiments show that despite the presence in Tg-MDA myoblasts of constructions which lead in vivo in transgenic mice to an overexpression of dystrophin 50-fold, the membrane area over which dystrophin was expressed was increased only threefold. This observation is also expected for vector-mediated gene therapy.
Kinoshita
I
I
Centre de Recherche en Neurobiologie, Hôpital de l'Enfant-Jésus, Université Laval, Québec, Canada.
Vilquin
J T
JT
Asselin
I
I
Chamberlain
J
J
Tremblay
J P
JP
D000818:Animals; D017690:Cell Transplantation / Q000379:methods; D002478:Cells, Cultured; D003198:Computer Simulation; D017931:DNA Primers; D018076:DNA, Complementary; D016189:Dystrophin / Q000096:biosynthesis* / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D018101:Mice, Inbred mdx; D008822:Mice, Transgenic; D008954:Models, Biological; D018482:Muscle, Skeletal / Q000166:cytology / Q000502:physiology / Q000637:transplantation*; D009412:Nerve Fibers / Q000502:physiology / Q000648:ultrastructure; D016133:Polymerase Chain Reaction; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D012044:Regression Analysis; D001616:beta-Galactosidase / Q000096:biosynthesis
D017931:DNA Primers; D018076:DNA, Complementary; D016189:Dystrophin; D011993:Recombinant Fusion Proteins; D001616:beta-Galactosidase