Article

Dystrophin is expressed in mdx skeletal muscle fibers after normal myoblast implantation.

Neuromuscular Research Group, Montreal Neurological Institute, McGill University, Quebec, Canada.
American Journal Of Pathology (Impact Factor: 4.6). 08/1989; 135(1):27-32.
Source: PubMed

ABSTRACT In mdx mice, the dystrophin gene of the X chromosome is defective and, as a result, immunoreactive dystrophin is undetectable in all muscle fibers of all animals of this highly inbred strain. This study showed that implantation of suspensions of clonal cultures of normal human myoblasts into different regions of quadriceps muscles of 6-to-10-day-old mdx mice or 60-day-old mdx mice (whose muscles have been crushed 4 days before implantation) results in the appearance of scattered fiber segments containing microscopically demonstrable immunoreactive dystrophin. In the animals that received the normal myoblast implantation in the prenecrotic stage of the disease (6 to 10 days of age), the dystrophin-positive fiber segments (demonstrated at ages 35, 45, and 60 days) escaped necrosis. This was determined by the absence of the characteristic chains of central nuclei, a reliable marker of prior necrosis in mdx muscle fibers. By heavy labeling of the nuclear DNA of the transplantable human myoblasts with H3-thymidine during culturing, and by sequential performance of an immunocytochemical staining for dystrophin and autoradiography on the same sections, some dystrophin-positive fiber segments were shown to contain radiolabeled myonuclei. It was concluded that nondystrophic myoblasts fused with host muscle fibers to form mosaic muscle fibers in which the normal dystrophin gene of the implanted myoblasts was expressed. This approach may be employed for the mitigation of the deleterious consequences of a gene defect in recessively inherited human muscle diseases such as Duchenne dystrophy.

0 Followers
 · 
84 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Although the contribution of bone marrow-derived cells to regenerating skeletal muscle has been repeatedly documented, there remains considerable debate as to whether this incorporation is exclusively a result of inflammatory cell fusion to regenerating myofibers or whether certain populations of bone marrow-derived cells have the capacity to differentiate into muscle. The present study uses a dual-marker approach in which GFP(+) cells were intravenously transplanted into lethally irradiated beta-galactosidase(+) recipients to allow for simple determination of donor and host contribution to the muscle. FACS analysis of cardiotoxin-damaged muscle revealed that CD45(+) bone-marrow side-population (SP) cells, a group enriched in hematopoietic stem cells, can give rise to CD45(-)/Sca-1(+)/desmin(+) cells capable of myogenic differentiation. Moreover, after immunohistochemical examination of the muscles of both SP- and whole bone marrow-transplanted animals, we noted the presence of myofibers composed only of bone marrow-derived cells. Our findings suggest that a subpopulation of bone marrow SP cells contains precursor cells whose progeny have the potential to differentiate towards a muscle lineage and are capable of de novo myogenesis following transplantation and initiation of muscle repair via chemical damage.
    Journal of Cell Science 06/2008; 121(Pt 9):1426-34. DOI:10.1242/jcs.021675 · 5.33 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The recovery of injured muscle depends on several factors, such as muscle regeneration, revascularization, and reinnervation. Recovery can be improved with gene therapy procedures that deliver substances that promote the recovery of the injured muscle and may also prevent complications associated with muscle healing and contractures. Two different approaches have been employed to deliver genes to muscle: cell therapy based on myoblast transplantation (MT) and gene therapy (GT) using viral and nonviral vectors. These approaches are discussed in this chapter.
    Stem Cell Biology and Gene Therapy, 05/2002: pages 179 - 200; , ISBN: 9780471223955
  • [Show abstract] [Hide abstract]
    ABSTRACT: Duchenne muscular dystrophy (DMD) is a fatal disease caused by mutations in the dystrophin gene, which result in the complete absence of dystrophin protein throughout the body. Gene correction strategies hold promise to treating DMD. Our laboratory has previously demonstrated the ability of peptide nucleic acid single-stranded oligodeoxynucleotides (PNA-ssODNs) to permanently correct single-point mutations at the genomic level. In this study, we show that PNA-ssODNs can target and correct muscle satellite cells (SCs), a population of stem cells capable of self-renewing and differentiating into muscle fibers. When transplanted into skeletal muscles, SCs transfected with correcting PNA-ssODNs were able to engraft and to restore dystrophin expression. The number of dystrophin-positive fibers was shown to significantly increase over time. Expression was confirmed to be the result of the activation of a subpopulation of SCs that had undergone repair as demonstrated by immunofluorescence analyses of engrafted muscles using antibodies specific to full-length dystrophin transcripts and by genomic DNA analysis of dystrophin-positive fibers. Furthermore, the increase in dystrophin expression detected over time resulted in a significant improvement in muscle morphology. The ability of transplanted cells to return into quiescence and to activate upon demand was confirmed in all engrafted muscles following injury. These results demonstrate the feasibility of using gene editing strategies to target and correct SCs and further establish the therapeutic potential of this approach to permanently restore dystrophin expression into muscle of DMD patients. Stem Cells 2014.
    Stem Cells 07/2014; 32(7). DOI:10.1002/stem.1668 · 7.70 Impact Factor

Preview

Download
2 Downloads
Available from