Calprotectin is released from human skeletal muscle tissue during exercise.
Research output: Contribution to journal › Journal article › Research › peer-review
Skeletal muscle has been identified as a secretory organ. We hypothesized that IL-6, a cytokine secreted from skeletal muscle during exercise, could induce production of other secreted factors in skeletal muscle. IL-6 was infused for 3 h into healthy young males (n = 7) and muscle biopsies obtained at time points 0, 3 and 6 h in these individuals and in resting controls. Affymetrix microarray analysis of gene expression changes in skeletal muscle biopsies identified a small set of genes changed by IL-6 infusion. RT-PCR validation confirmed that S100A8 and S100A9 mRNA were up-regulated 3-fold in skeletal muscle following IL-6 infusion compared to controls. Furthermore, S100A8 and S100A9 mRNA levels were up-regulated 5-fold in human skeletal muscle following cycle ergometer exercise for 3 h at approximately 60% of in young healthy males (n = 8). S100A8 and S100A9 form calprotectin, which is known as an acute phase reactant. Plasma calprotectin increased 5-fold following acute cycle ergometer exercise in humans, but not following IL-6 infusion. To identify the source of calprotectin, healthy males (n = 7) performed two-legged dynamic knee extensor exercise for 3 h with a work load of approximately 50% of peak power output and arterial-femoral venous differences were obtained. Arterial plasma concentrations for calprotectin increased 2-fold compared to rest and there was a net release of calprotectin from the working muscle. In conclusion, IL-6 infusion and muscle contractions induce expression of S100A8 and S100A9 in skeletal muscle. However, IL-6 alone is not a sufficient stimulus to facilitate release of calprotectin from skeletal muscle.
Original language | English |
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Journal | Journal of Physiology |
Volume | 586 |
Issue number | 14 |
Pages (from-to) | 3551-62 |
Number of pages | 11 |
ISSN | 0022-3751 |
DOIs | |
Publication status | Published - 2008 |
Bibliographical note
Keywords: Adult; Biopsy; Exercise; Gene Expression Profiling; Gene Expression Regulation; Humans; Interleukin-6; Leukocyte L1 Antigen Complex; Male; Muscle Proteins; Muscle, Skeletal; RNA, Messenger
ID: 8465908