Impaired fetal myogenesis marks MDC1A onset in mice

Merosin-deficient congenital muscular dystrophy type 1A (MDC1A) is a devastating neuromuscular disease in which patients demonstrate hypotonia from birth. MDC1A involves muscle wasting, inflammation and fibrosis, but how the disease starts is presently unknown.

The group of Sólveig Thorsteinsdóttir at FCUL collaborated with the team of Dean J. Burkin at the University of Nevada and used the dyW mouse model for MDC1A to study the effect of laminin α2-chain deficiency on skeletal muscle development in vivo. They found that during secondary myogenesis, dyW-/- muscles exhibit impaired growth, fail to maintain the normal number of Pax7-positive muscle stem cells and experience a dramatic drop in the number of Myogenin-positive myoblasts.

The paper by Andreia Nunes et al. entitled “Impaired fetal muscle development and JAK-STAT activation mark disease onset and progression in a mouse model for merosin-deficient congenital muscular dystrophy” shows for the first time that MDC1A starts before birth in dyW-/-  mice and that the onset of the disease in utero is marked by impaired fetal myogenesis.