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Reduced skeletal muscle satellite cell number alters muscle morphology after chronic stretch but allows limited serial sarcomere addition
Author(s) -
Kinney Matthew C.,
Dayanidhi Sudarshan,
Dykstra Peter B.,
McCarthy John J.,
Peterson Charlotte A.,
Lieber Richard L.
Publication year - 2017
Publication title -
muscle and nerve
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.025
H-Index - 145
eISSN - 1097-4598
pISSN - 0148-639X
DOI - 10.1002/mus.25227
Subject(s) - sarcomere , anatomy , muscle architecture , skeletal muscle , extracellular matrix , chemistry , myocyte , biology , medicine , microbiology and biotechnology
: Muscles add sarcomeres in response to stretch, presumably to maintain optimal sarcomere length. Clinical evidence from patients with cerebral palsy, who have both decreased serial sarcomere number and reduced satellite cells (SCs), suggests a hypothesis that SCs may be involved in sarcomere addition. Methods : A transgenic Pax7‐DTA mouse model underwent conditional SC depletion, and their soleii were then stretch‐immobilized to assess the capacity for sarcomere addition. Muscle architecture, morphology, and extracellular matrix (ECM) changes were also evaluated. Results : Mice in the SC‐reduced group achieved normal serial sarcomere addition in response to stretch. However, muscle fiber cross‐sectional area was significantly smaller and was associated with hypertrophic ECM changes, consistent with fibrosis. Conclusions : While a reduced SC population does not hinder serial sarcomere addition, SCs play a role in muscle adaptation to chronic stretch that involves maintenance of both fiber cross‐sectional area and ECM structure. Muscle Nerve 55 : 384–392, 2017