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The influence of satellite cell‐depletion on glycosaminoglycan accumulation in aged skeletal muscle
Author(s) -
Hardyniec Zakkary James,
Lee Jonah D,
Peterson Charlotte A.
Publication year - 2013
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.27.1_supplement.1150.10
Subject(s) - satellite , extracellular matrix , skeletal muscle , tamoxifen , medicine , endocrinology , glycosaminoglycan , immunostaining , gastrocnemius muscle , biology , immunohistochemistry , microbiology and biotechnology , anatomy , cancer , aerospace engineering , breast cancer , engineering
We utilized the Pax7‐DTA mouse model to directly test the role of satellite cells in aged muscle fibrosis. The Pax7‐DTA mouse allows for the conditional depletion of satellite cells in adult muscle with tamoxifen treatment. Four month old mice were treated with tamoxifen or vehicle and sacrificed at 24 months of age. Pax7 immunohistochemistry of the gastrocnemius muscle demonstrated a reduction of 78% of the satellite cell pool in tamoxifen‐compared to vehicle‐treated aged mice. Thus, early‐adulthood tamoxifen treatment successfully reduces the satellite cell pool, which does not effectively recover during the course of the lifespan. Alpha‐wheat germ agglutinin immunostaining demonstrated a 40% increase in glycosaminoglycan expression from muscle depleted of satellite cells, with no differences in muscle cross‐sectional area compared to muscle from vehicle‐treated muscle. The robust increase in glycosaminoglycan expression in satellite cell depleted muscle provides strong evidence that satellite cells participate in the regulation of muscle extracellular matrix remodeling with age, however do not influence overall muscle size. Funding: NIH R01AR060701 and R21AG34453 (CAP); Ellison Foundation/American Federation of Aging Research EPD12102 (JDL); American Physiological Society undergraduate research fellowship (ZJH); University of Kentucky Center for Muscle Biology.