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Fibre type‐specific satellite cell content in two models of muscle disease
Author(s) -
Bankolé LandryCyrille,
Feasson Léonard,
Ponsot Elodie,
Kadi Fawzi
Publication year - 2013
Publication title -
histopathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.626
H-Index - 124
eISSN - 1365-2559
pISSN - 0309-0167
DOI - 10.1111/his.12231
Subject(s) - duchenne muscular dystrophy , polymyositis , skeletal muscle , fibre type , myocyte , basal lamina , muscular dystrophy , muscle fibre , medicine , chemistry , anatomy , pathology , ultrastructure
Aims Muscle satellite cells ( SC s) are responsible for the regenerative events following muscle fibre injury. This study aimed to improve our understanding of SC behaviour in two models of muscle disorder with different pathological mechanisms and onset of disease. Methods and results Pax7 + SC content was assessed in types I and II fibres of patients with Duchenne muscular dystrophy ( DMD ; n = 9; age 13 ± 2 years), polymyositis/dermatomyositis ( PM / DM ; n = 9; age 52 ± 12 years) and in controls ( n = 5; age 26 ± 5 years). Pax7 + SC s number in type I and II fibres was higher ( P < 0.05) in DMD and in PM / DM compared to controls. Type I fibres were associated with a higher number of Pax7 + SC s compared to type II fibres only in DMD ; Pax7 + SC s number in type I fibres was about threefold higher in DMD compared to PM / DM ( P < 0.05). In DMD , Pax7 + SC content in small regenerating fibres (0.09 ± 0.09 SC s/fibre) was similar to that in fibres from healthy skeletal muscle. The proportion of activated SC s (Ki‐67 + SC s) was fivefold lower in DMD (0.4 ± 0.4%) compared to PM / DM (2.8 ± 2%). Pax7 + cells located outside the basal lamina were observed in DMD muscles only. Conclusion The capacity to generate new SC s is increased even in severely impaired muscles and a fibre type‐specific enhancement of SC occurs in type I muscle fibres in DMD .