Detecting the Effects of the Glucocorticoid Dexamethasone on Primary Human Skeletal Muscle Cells-Differences to the Murine Cell Line

• Published in: International journal of molecular sciences 2020-04, Vol.21 (7), p.2497
• Main Authors: Langendorf, Eva K, Rommens, Pol M, Drees, Philipp, Mattyasovszky, Stefan G, Ritz, Ulrike
• Format: Article
• Language: English
• Subjects: Animals; Atrophy; Back pain; Cell adhesion & migration; Cell Line; Cell lines; Cell Survival - drug effects; Cells, Cultured; Denervation; Dexamethasone; Dexamethasone - adverse effects; Dexamethasone - pharmacology; Dose-Response Relationship, Drug; Forkhead protein; Forkhead Transcription Factors - genetics; Forkhead Transcription Factors - metabolism; Gene expression; Gene Expression Regulation - drug effects; Glucocorticoids; Glucocorticoids - adverse effects; Glucocorticoids - pharmacology; Humans; Immobilization; MAFbx; Mice; MuRF-1; Muscle contraction; Muscle Proteins - genetics; Muscle Proteins - metabolism; Muscles; Muscular Atrophy - chemically induced; Muscular Atrophy - metabolism; Musculoskeletal system; Myoblasts; Myoblasts, Skeletal - cytology; Myoblasts, Skeletal - drug effects; Myoblasts, Skeletal - metabolism; Myosin; Myotubes; Primary Cell Culture; Protein biosynthesis; Protein synthesis; Proteins; Signal transduction; Signal Transduction - drug effects; Skeletal muscle; Steroids; Time Factors; Transcription factors; Tripartite Motif Proteins - genetics; Tripartite Motif Proteins - metabolism
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms21072497

Skeletal muscle atrophy is characterized by a decrease in muscle fiber size as a result of a decreased protein synthesis, which leads to degradation of contractile muscle fibers. It can occur after denervation and immobilization, and glucocorticoids (GCs) may also increase protein breakdown contributing to the loss of muscle mass and myofibrillar proteins. GCs are already used in vitro to induce atrophic conditions, but until now no studies with primary human skeletal muscle existed. Therefore, this study deals with the effects of the GC dexamethasone (dex) on primary human myoblasts and myotubes. After incubation with 1, 10, and 100 µM dex for 48 and 72 h, gene and protein expression analyses were performed by qPCR and Western blot. , , and were significantly upregulated by dex, and there was increased gene expression of myogenic markers. However, prolonged incubation periods demonstrated no Myosin protein degradation, but an increase of MuRF-1 expression. In conclusion, applying dex did not only differently affect primary human myoblasts and myotubes, as differences were also observed when compared to murine cells. Based on our findings, studies using cell lines or animal cells should be interpreted with caution as signaling transduction and functional behavior might differ in diverse species.