The injection of Wnt7a into muscles has been shown to speed up muscle repair and improve muscle health in a mouse model of Duchenne muscular dystrophy (DMD). However, it's not clear if Wnt7a is necessary for muscle repair.

In this study, we looked at mice with and without Wnt7a in their muscles to see how well their muscles could heal after injury. We found that both normal mice and those with DMD, lacking Wnt7a in their muscles, had trouble regenerating their muscles after injury.

Interestingly, the mice with DMD and without Wnt7a had weaker muscles even before the injury. However, both types of mice showed weaker muscles after the injury.

Importantly, when we gave the mice with DMD and lacking Wnt7a a single injection of Wnt7a, their muscle regeneration improved. This suggests that the body naturally increases Wnt7a after muscle injury, and giving Wnt7a externally could be a potential treatment for DMD.