Designed Proteins to Treat Muscular Dystrophy

Muscular dystrophy is a term used to describe many different muscular diseases caused by genetic defects. To date, there are no treatments available to stop disease progression. In their study, the scientists led by Prof. Markus Rüegg have investigated a specific type of muscular dystrophy, called congenital muscular dystrophy. In an animal model, they demonstrated for the first time that two proteins designed by the researchers not only recover muscle force and increase body weight in the sick animals but also significantly prolong survival.

Severe impairments due to congenital muscular dystrophy

Congenital muscular dystrophy is a rare and severe form of a muscular dystrophy that presents at birth or during infancy. “The children born with this disease are also called ′floppy infants′ because of the poor muscle tone and weakness,” says Judith Reinhard, first author of the study. “The disease becomes more severe with increasing age, as the muscle wasting progresses.” Affected children are often unable to walk independently or they lose this ability with age. The respiratory muscles are also affected. The lifespan is often short and many patients die before reaching adulthood.

Defective gene – defective cell scaffolding

This form of muscular dystrophy results from a genetic defect in laminin-α2. This protein is a key component of the cell scaffolding and connects it with the inner part of the muscle fiber, ensuring the stability of the tissue. Consequently, as a result of gene defects in laminin-α2 the muscles are extremely unstable and even normal use of the muscles leads to muscle injuries, inflammation and finally to the degeneration of muscle fibers. In these diseased muscles, which are unable to produce laminin-α2, another laminin takes over. This protein, called laminin-α4, however, is only a poor replacement because it is not well integrated into the cell scaffolding.