Role of fibro-adipogenic progenitors in skeletal muscle aging

Maintaining muscle mass is of paramount importance from a clinical perspective as it supports the flexibility, strength, and essential daily tasks that the body requires. Furthermore, muscle plays a role in regulating the body’s metabolic system. Unfortunately, aging can lead to a loss of muscle mass, which can reduce personal independence and quality of life while increasing the risk of developing disease. Fibro-adipogenic progenitor cells (FAPs) are muscle-resident progenitor cells that are essential for maintaining skeletal muscle fiber size and muscle regeneration. These vital FAP functions are mediated by a complex secretome that interacts in a paracrine manner to promote the division and differentiation of muscle satellite cells. Dysregulated differentiation of FAPs can lead to fibrosis, fatty infiltration, muscle atrophy, and poor muscle regeneration. In this article, we review what is currently known about how FAPs function in aging muscle and how they may prevent the onset of muscle wasting and degeneration. Finally, we discuss how FAPs represent a population of cells that can be used as therapeutic targets to improve the health of skeletal and muscle tissues as they age.