The important role of the neuromuscular junction in maintaining muscle mass and strength

Sarcopenia is an age-related decline of skeletal muscle mass and function, leading to reduced physical ability and difficulties in carrying out day-to-day tasks; it has become a major health concern in our aging society. The exact etiology of sarcopenia is not completely understood, but recent studies have focused on age-associated changes in the neuromuscular junction (NMJ). Using an animal model of myasthenia gravis with antibodies against muscle-specific kinase (MuSK), a disorder of the NMJ characterized by muscle weakness, we investigated the role of the NMJ in the pathogenesis of sarcopenia. Our studies indicate that the structure and function of the NMJ is important for maintaining muscle mass and strength, which suggests that the malfunction of the NMJ plays a role, at least in part, in the onset of sarcopenia. These findings suggest that the NMJ will become an important therapeutic target for sarcopenia in the future.