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Komamura, Kazuo; Shirotani-Ikejima, Hiroko; Tatsumi, Rei; Tsujita-Kuroda, Yuko; Kitakaze, Masafumi; Miyatake, Kunio; Sunagawa, Kenji; Miyata, Toshiyuki

doi:10.1023/a:1027352703783

Cited by 53 publications

(17 citation statements)

References 31 publications

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“…In contrast to our results ( Figure 5) MAFbx was repressed while Myosin expression was increased [57]. Foxo expression clearly indicates an induction of muscle atrophy in murine as well as in human muscle cells in vitro [50][51][52][53][54]. With regard to the supplements in the growth medium of myoblasts, the growth factor bFGF (basic fibroblast growth factor) was added which could also be a reason for delayed differentiation [68].…”

Section: Dex Has Developmental-stage-dependent Effects On Myotubes Ancontrasting

confidence: 93%

“…In consequence, it can be assumed that Foxo is also dephosphorylated in human myotubes by dex. This is associated with the suppression of Akt and mTOR, and the translocation of Foxo into the nucleus [33], where the expression of the E3 ligases MuRF-1 and MAFbx will be induced [50][51][52][53][54].…”

Section: Dex Induces the Expression Of The Atrophy-related Genes Murfmentioning

confidence: 99%

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

Langendorf

Rommens

Drees

et al. 2020

IJMS

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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. Foxo, MuRF-1, and MAFbx 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.

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Section: Dex Has Developmental-stage-dependent Effects On Myotubes Ancontrasting

confidence: 93%

Section: Dex Induces the Expression Of The Atrophy-related Genes Murfmentioning

confidence: 99%

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

Langendorf

Rommens

Drees

et al. 2020

IJMS

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“…For example, previous studies suggest that calcium-calpain-dependent cleavage of myofibrillar proteins is an important “upstream” mechanism of sepsis-induced muscle proteolysis [5, 6, 38, 39]. Other studies suggest that lysosomal protein degradation, in particular cathepsin L-dependent proteolysis, is also involved in muscle wasting [3, 4]. …”

Section: Resultsmentioning

confidence: 99%

The NF-κB Inhibitor Curcumin Blocks Sepsis-Induced Muscle Proteolysis

Poylin

Fareed

O’Neal

et al. 2008

Mediators of Inflammation

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We tested the hypothesis that treatment of rats with curcumin prevents sepsis-induced muscle protein degradation. In addition, we determined the influence of curcumin on different proteolytic pathways that are activated in septic muscle (i.e., ubiquitin-proteasome-, calpain-, and cathepsin L-dependent proteolysis) and examined the role of NF-κB and p38/MAP kinase inactivation in curcumin-induced inhibition of muscle protein breakdown. Rats were made septic by cecal ligation and puncture or were sham-operated. Groups of rats were treated with three intraperitoneal doses (600 mg/kg) of curcumin or corresponding volumes of solvent. Protein breakdown rates were measured as release of tyrosine from incubated extensor digitorum longus muscles. Treatment with curcumin prevented sepsis-induced increase in muscle protein breakdown. Surprisingly, the upregulated expression of the ubiquitin ligases atrogin-1 and MuRF1 was not influenced by curcumin. When muscles from septic rats were treated with curcumin in vitro, proteasome-, calpain-, and cathepsin L-dependent protein breakdown rates were reduced, and nuclear NF-κB/p65 expression and activity as well as levels of phosphorylated (activated) p38 were decreased. Results suggest that sepsis-induced muscle proteolysis can be blocked by curcumin and that this effect may, at least in part, be caused by inhibited NF-κB and p38 activities. The results also suggest that there is not an absolute correlation between changes in muscle protein breakdown rates and changes in atrogin-1 and MuRF1 expression during treatment of muscle wasting.

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“…Many studies have shown that glucocorticoids not only cause muscle atrophy through the IGF-1/PI-3K/Akt/mTOR and myostatin/Smad2/3 pathways [7, 8], but also through the regulation of muscle transcription factors, atrogenes, and cathepsins [8, 9]. Some of these mechanisms involve the reduction in mTOR activity induced by an increase of REDD1 (regulated in development and DNA damage responses 1) [10], and an increase in the GSK3 β protein.…”

Section: Introductionmentioning

confidence: 99%

The Effects of Omega-3 Fatty Acid Supplementation on Dexamethasone-Induced Muscle Atrophy

Fappi

Godoy

Maximino

et al. 2014

BioMed Research International

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Corticosteroids cause muscle atrophy by acting on proteasomal and lysosomal systems and by affecting pathways related to muscular trophysm, such as the IGF-1/PI-3k/Akt/mTOR. Omega-3 fatty acid (n-3) has been used beneficially to attenuate muscle atrophy linked to sepsis and cachexia; however, its effect on dexamethasone-induced muscle atrophy has not been evaluated. Objectives. We evaluated whether n-3 supplementation could mitigate the development of dexamethasone-induced muscle atrophy. Methods. Two groups of Wistar rats were orally supplemented with n-3 or vehicle solution for 40 days. In the last 10 days, dexamethasone, or saline solution, was administrated establishing four groups: control, dexamethasone, n-3, and dexamethasone + n-3. The cross-sectional areas of muscle fibers, gene expression (MyoD, Myogenin, MuRF-1, and Atrogin-1), and protein expression (Akt, GSK3β, FOXO3a, and mTOR) were assessed. Results. Dexamethasone induced a significant loss in body and muscle weight, atrophy in type 2B fibers, and decreased expression of P-Akt, P-GSK3β, and P-FOXO3a. N-3 supplementation did not attenuate the negative effects of dexamethasone on skeletal muscle; instead, it caused atrophy in type 1, 2A, reduced the expression of Myogenin, and increased the expression of Atrogin-1. Conclusion. Food supplements containing n-3 are usually healthful, but they may potentiate some of the side effects of glucocorticoids.

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Untitled

Cited by 53 publications

References 31 publications

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

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

The NF-κB Inhibitor Curcumin Blocks Sepsis-Induced Muscle Proteolysis

The Effects of Omega-3 Fatty Acid Supplementation on Dexamethasone-Induced Muscle Atrophy

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