APP in the Neuromuscular Junction for the Development of Sarcopenia and Alzheimer's Disease

Sarcopenia, an illness condition usually characterized by a loss of skeletal muscle mass and muscle strength or function, is often associated with neurodegenerative diseases, such as Alzheimer's disease (AD), a common type of dementia, leading to memory loss and other cognitive impairment. However, the underlying mechanisms for their associations and relationships are less well understood. The App, a Mendelian gene for early-onset AD, encodes amyloid precursor protein (APP), a transmembrane protein enriched at both the neuromuscular junction (NMJ) and synapses in the central nervous system (CNS). Here, in this review, we highlight APP and its family members' physiological functions and Swedish mutant APP (APP(swe))'s pathological roles in muscles and NMJ. Understanding APP's pathophysiological functions in muscles and NMJ is likely to uncover insights not only into neuromuscular diseases but also AD. We summarize key findings from the burgeoning literature, which may open new avenues to investigate the link between muscle cells and brain cells in the development and progression of AD and sarcopenia.

Automated summary

Sarcopenia, characterized by muscle mass and strength/function loss, is associated with neurodegenerative diseases like Alzheimer's disease (AD). The underlying mechanisms for their associations are not well understood. The APP gene encodes amyloid precursor protein (APP), enriched at neuromuscular junction (NMJ) and synapses in the central nervous system (CNS). This review highlights the physiological functions of APP and its family members and the pathological roles of Swedish mutant APP (APP(swe)) in muscles and NMJ, providing insights into neuromuscular diseases and AD.