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Extracellular matrix remodeling and its contribution to protective adaptation following lengthening contractions in human muscle
Author(s) -
Hyldahl Robert D.,
Nelson Brad,
Xin Ling,
Welling Tyson,
Groscost Logan,
Hubal Monica J.,
Chipkin Stuart,
Clarkson Priscilla M.,
Parcell Allen C.
Publication year - 2015
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/fj.14-266668
Subject(s) - extracellular matrix , transcriptome , extracellular , skeletal muscle , medicine , endocrinology , chemistry , andrology , microbiology and biotechnology , gene expression , biology , biochemistry , gene
This study determined the contribution of extracellular matrix (ECM) remodeling to the protective adaptation of human skeletal muscle known as the repeated‐bout effect (RBE). Muscle biopsies were obtained 3 hours, 2 days, and 27 days following an initial bout (B1) of lengthening contractions (LCs) and 2 days following a repeated bout (B2) in 2 separate studies. Biopsies from the nonexercised legs served as controls. In the first study, global transcriptomic analysis indicated widespread changes in ECM structural, deadhesive, and signaling transcripts, 3 hours following LC. To determine if ECM remodeling is involved in the RBE, we conducted a second study by use of a repeated‐bout paradigm. TNC immunoreactivity increased 10.8‐fold following B1, was attenuated following B2, and positively correlated with LC‐induced strength loss ( r 2 = 0.45; P = 0.009). Expression of collagen I, III, and IV ( COL1A1, COL3A1, CO‐L4A1 ) transcripts was unchanged early but increased 5.7 ± 2.5‐, 3.2 ± 0.9‐, and 2.1 ± 0.4‐fold ( P < 0.05), respectively, 27 days post‐B1 and were unaffected by B2. Likewise, TGF‐β signaling demonstrated a delayed response following LC. Satellite cell content increased 80% ( P < 0.05) 2 days post‐B1 ( P < 0.05), remained elevated 27 days post‐B1, and was unaffected by B2. Collectively, the data suggest sequential ECM remodeling characterized by early deadhesion and delayed reconstructive activity that appear to contribute to the RBE.—Hyldahl, R. D., Nelson, B., Xin, L., Welling, T., Groscost, L., Hubal, M. J., Chipkin, S., Clarkson, P. M., Parcell, A. C. Extracellular matrix remodeling and its contribution to protective adaptation following lengthening contractions in human muscle. FASEB J . 29, 2894‐2904 (2015). www.fasebj.org