Sequenced response of extracellular matrix deadhesion and fibrotic regulators after muscle damage is involved in protection against future injury in human skeletal muscle

TY - JOUR

T1 - Sequenced response of extracellular matrix deadhesion and fibrotic regulators after muscle damage is involved in protection against future injury in human skeletal muscle

AU - Mackey, Abigail

AU - Brandstetter, Simon

AU - Schjerling, Peter

AU - Bojsen-Moller, Jens

AU - Qvortrup, Klaus

AU - Pedersen, Mette M

AU - Doessing, Simon

AU - Kjær, Michael

AU - Magnusson, S Peter

AU - Langberg, Henning

PY - 2011/6

Y1 - 2011/6

N2 - The purpose of this study was to test the hypothesis that remodeling of skeletal muscle extracellular matrix (ECM) is involved in protecting human muscle against injury. Biopsies were obtained from medial gastrocnemius muscles after a single bout of electrical stimulation (B) or a repeated bout (RB) 30 d later, or 30 d after a single stimulation bout (RBc). A muscle biopsy was collected from the control leg for comparison with the stimulated leg. Satellite cell content, tenascin C, and muscle regeneration were assessed by immunohistochemistry; real-time PCR was used to measure mRNA levels of collagens, laminins, heat-shock proteins (HSPs), inflammation, and related growth factors. The large responses of HSPs, CCL2, and tenascin C detected 48 h after a single bout were attenuated in the RB trial, indicative of protection against injury. Satellite cell content and 12 target genes, including IGF-1, were elevated 30 d after a single bout. Among those displaying the greatest difference vs. control muscle, ECM laminin-β1 and collagen types I and III were elevated ∼6- to 9-fold (P<0.001). The findings indicate that the sequenced events of load-induced early deadhesion and later strengthening of skeletal muscle ECM play a role in protecting human muscle against future injury.

AB - The purpose of this study was to test the hypothesis that remodeling of skeletal muscle extracellular matrix (ECM) is involved in protecting human muscle against injury. Biopsies were obtained from medial gastrocnemius muscles after a single bout of electrical stimulation (B) or a repeated bout (RB) 30 d later, or 30 d after a single stimulation bout (RBc). A muscle biopsy was collected from the control leg for comparison with the stimulated leg. Satellite cell content, tenascin C, and muscle regeneration were assessed by immunohistochemistry; real-time PCR was used to measure mRNA levels of collagens, laminins, heat-shock proteins (HSPs), inflammation, and related growth factors. The large responses of HSPs, CCL2, and tenascin C detected 48 h after a single bout were attenuated in the RB trial, indicative of protection against injury. Satellite cell content and 12 target genes, including IGF-1, were elevated 30 d after a single bout. Among those displaying the greatest difference vs. control muscle, ECM laminin-β1 and collagen types I and III were elevated ∼6- to 9-fold (P<0.001). The findings indicate that the sequenced events of load-induced early deadhesion and later strengthening of skeletal muscle ECM play a role in protecting human muscle against future injury.

U2 - 10.1096/fj.10-176487

DO - 10.1096/fj.10-176487

M3 - Journal article

C2 - 21368102

SN - 1530-6860

VL - 25

SP - 1943

EP - 1959

JO - FASEB Journal

JF - FASEB Journal

IS - 6

ER -