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Item Type: | Article |
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Title: | Skeletal muscle 11beta-HSD1 controls glucocorticoid-induced proteolysis and expression of E3 ubiquitin ligases atrogin-1 and MuRF-1 |
Creators Name: | Biedasek, K., Andres, J., Mai, K., Adams, S., Spuler, S., Fielitz, J. and Spranger, J. |
Abstract: | Recent studies demonstrated expression and activity of the intracellular cortisone-cortisol shuttle 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) in skeletal muscle and inhibition of 11beta-HSD1 in muscle cells improved insulin sensitivity. Glucocorticoids induce muscle atrophy via increased expression of the E3 ubiquitin ligases Atrogin-1 (Muscle Atrophy F-box (MAFbx)) and MuRF-1 (Muscle RING-Finger-1). We hypothesized that 11beta-HSD1 controls glucocorticoid-induced expression of atrophy E3 ubiquitin ligases in skeletal muscle. Primary human myoblasts were generated from healthy volunteers. 11beta-HSD1-dependent protein degradation was analyzed by [(3)H]-tyrosine release assay. RT-PCR was used to determine mRNA expression of E3 ubiquitin ligases and 11beta-HSD1 activity was measured by conversion of radioactively labeled [(3)H]-cortisone to [(3)H]-cortisol separated by thin-layer chromatography. We here demonstrate that 11beta-HSD1 is expressed and biologically active in interconverting cortisone to active cortisol in murine skeletal muscle cells (C2C12) as well as in primary human myotubes. 11Beta-HSD1 expression increased during differentiation from myoblasts to mature myotubes (p < 0.01), suggesting a role of 11beta-HSD1 in skeletal muscle growth and differentiation. Treatment with cortisone increased protein degradation by about 20% (p < 0.001), which was paralleled by an elevation of Atrogin-1 and MuRF-1 mRNA expression (p < 0.01, respectively). Notably, pre-treatment with the 11beta-HSD1 inhibitor carbenoxolone (Cbx) completely abolished the effect of cortisone on protein degradation as well as on Atrogin-1 and MuRF-1 expression. In summary, our data suggest that 11beta-HSD1 controls glucocorticoid-induced protein degradation in human and murine skeletal muscle via regulation of the E3 ubiquitin ligases Atrogin-1 and MuRF-1. |
Keywords: | 11-beta-Hydroxysteroid Dehydrogenase Type 1, Cultured Cells, Glucocorticoids, Muscle Cells, Muscle Proteins, Myoblasts, Messenger RNA, Skeletal Muscle, Skeletal Muscle Fibers, SKP Cullin F-Box Protein Ligases, Ubiquitin-Protein Ligases |
Source: | PLoS ONE |
ISSN: | 1932-6203 |
Publisher: | Public Library of Science |
Volume: | 6 |
Number: | 1 |
Page Range: | e16674 |
Date: | 31 January 2011 |
Official Publication: | https://doi.org/10.1371/journal.pone.0016674 |
PubMed: | View item in PubMed |
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