Myosatellite cell

Myosatellite cells or satellite cells are small multipotent cells with very little cytoplasm found in mature muscle. They are precursors to skeletal muscle cells, capable of giving rise to satellite cells or differentiated skeletal muscle cells. They have the potential to provide additional nuclei to their parent muscle fiber, or return to a quiescent state.

Etymology

The term "myosatellite" is derived from the Greek words "myo-", meaning muscle, and "satellite", which refers to their position on the outside of the muscle fiber.

Structure

Myosatellite cells are located between the basal lamina (a layer of extracellular matrix secreted by the epithelial cells, on which the epithelium sits) and the sarcolemma (a thin membranous sheath that surrounds the muscle fiber cell). They are small, mononuclear progenitor cells that are in a quiescent state under normal conditions.

Function

The primary role of myosatellite cells is to aid in the repair and regeneration of damaged muscle tissue. They are activated in response to muscle injury or trauma. Once activated, they proliferate extensively and differentiate into myoblasts. These myoblasts can either fuse with existing muscle fibers to increase their size and protein content, or they can fuse with each other to form new muscle fibers.

Clinical significance

Myosatellite cells play a crucial role in muscle regeneration. Their dysfunction or depletion can lead to various muscle disorders, including muscular dystrophy and sarcopenia. Research is ongoing to explore the potential of myosatellite cells in muscle regeneration therapies.

See also

• Muscle tissue
• Muscle regeneration
• Stem cell

References

• Schematic of satellite cell myogenesis and markers typical of each stage
  Schematic of satellite cell myogenesis and markers typical of each stage