Merosin-deficient congenital muscular dystrophy type 1A is a severe and fatal muscle wasting disease with no cure. MDC1A patients and the dyW-/- mouse model exhibit severe muscle weakness, demyelinating neuropathy, failed muscle regeneration and premature death. The authors of the present study have recently shown that laminin-111, a form of laminin found in embryonic skeletal muscle, can substitute for the loss of laminin-211/221 and prevent muscle disease progression in the dyW-/- mouse model. What is unclear from these studies is if laminin-111 can restore failed regeneration to laminin-α2 deficient muscle. To investigate the potential of laminin-111 protein therapy to improve muscle regeneration, laminin-111 or PBS treated laminin-α2 deficient muscle was damaged with cardiotoxin and muscle regeneration quantified. These results show laminin-111 treatment promoted an increase in myofiber size and number, and an increased expression of α7β1 integrin, Pax7, myogenin and embryonic myosin heavy chain, indicating a restoration of the muscle regenerative program. Together these results show laminin-111 restores muscle regeneration to laminin-α2 deficient muscle and further supports laminin-111 protein as a therapy for the treatment of MDC1A.
