Duchenne muscular dystrophy (DMD) is a recessive X-linked
form of muscular dystrophy, a neuromuscular condition caused by mutations in
the dystrophin gene.  Symptoms of DMD
include muscle degeneration, breathing and walking difficulties, and first
appear in affected children before the age of 5.

The advent of stem cell studies holds much promise for the
treatment and repair of dystrophic muscle in this condition.  In an article published in Skeletal Muscle, Parker et al. develop an improved pre-clinical
model of myogenic stem cell transplantation, and test this in both canine-mouse
and canine-canine assays.  Previous
experiments using murine-murine transplantation have demonstrated that adult
murine satellite stem cells with engraftment potential in dystrophin deficient
(mdx) mice express CXCR4.  In the current
study, Parker
et al demonstrate that although
CXCR4 expressing cells are important for donor muscle engraftment, FACS sorted
CXCR4-positive cells actually display decreased engraftment.  They found engraftment and proliferation of
donor cells to be significantly increased in the presence of diprotin A, a
positive enhancer of CXCR4-SDF-1 binding. 
The study clearly demonstrates the importance of diprotin A in muscle
cell engraftment, and highlights the use of xenotransplantation to assess the
efficacy of muscle stem cell populations in a pre-clinical setting.

Skeletal Muscle is a peer
reviewed, open access, online journal that publishes articles investigating
molecular mechanisms underlying the biology of skeletal muscle.  A wide range of skeletal muscle biology is
included: development, metabolism, the regulation of mass and function, aging,
degeneration, dystrophy and regeneration. 
The emphasis is on understanding adult skeletal muscle, its maintenance and
its interactions with non-muscle cell types and regulatory modulators.