Muscle satellite cells.
Skeletal muscle satellite cells are quiescent mononucleated myogenic cells, located between the sarcolemma and basement membrane of terminally-differentiated muscle fibres. These are normally quiescent in adult muscle, but act as a reserve population of cells, able to proliferate in response to injury and give rise to regenerated muscle and to more satellite cells. The recent discovery of a number of markers expressed by satellite cells has provided evidence that satellite cells, which had long been presumed to be a homogeneous population of muscle stem cells, may not be equivalent. It is possible that a sub-population of satellite cells may be derived from a more primitive stem cell. Satellite cell-derived muscle precursor cells may be used to repair and regenerate damaged or myopathic skeletal muscle, or to act as vectors for gene therapy. CELL FACTS: (1) Number of cells in body: 2 x 10(7) to 3 x 10(7) myonuclei/g, 20-25 kg muscle in average man; 2 x 10(5) to 10 x 10(5) satellite cells/g, i.e. approximately 1 x 10(10) to 2 x 10(10) satellite cells per person. (2) Main functions: repair and maintenance of skeletal muscle. (3) Turnover rate: close to zero in non-traumatic conditions-high in disease or severe trauma.
Morgan
Jennifer E
JE
Muscle Cell Biology Group, Faculty of Medicine, MRC Clinical Sciences Centre, Imperial College of Science, Technology and Medicine, Hammersmith Hospital, Du Cane Road, London W12 ONN, UK. jennifer.morgan@csc.mrc.ac.uk
Partridge
Terence A
TA
D000818:Animals; D006801:Humans; D051379:Mice; D018485:Muscle Fibers, Skeletal / Q000502:physiology / Q000648:ultrastructure; D018482:Muscle, Skeletal / Q000293:injuries / Q000502:physiology; D012038:Regeneration / Q000502:physiology*; D032496:Satellite Cells, Skeletal Muscle / Q000502:physiology* / Q000648:ultrastructure