• Journal of Ginseng Research
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• v.46 no.3
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• pp.444-453
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• 2022

Background: Compound K (CK) is among the protopanaxadiol (PPD)-type ginsenoside group, which produces multiple pharmacological effects. Herein, we examined the effects of CK on muscle atrophy under hyperlipidemic conditions along with its pro-myogenic effects. Further, the molecular pathways underlying the effects of CK on skeletal muscle have been justified. Methods: C2C12 myotubes were treated with palmitate and CK. C2C12 myoblasts were differentiated using CK for 4-5 days. For the in vivo experiments, CK was administered to mice fed on a high-fat diet for 8 weeks. The protein expression levels were analyzed using western blotting analysis. Target protein suppression was performed using small interfering (si) RNA transfection. Histological examination was performed using Jenner-Giemsa and H&E staining techniques. Results: CK treatment attenuated ER stress markers, such as eIF2a phosphorylation and CHOP expression and impaired myotube formation in palmitate-treated C2C12 myotubes and skeletal muscle of mice fed on HFD. CK treatment augmented AMPK along with autophagy markers in skeletal muscle cells in vitro and in vivo experiments. AMPK siRNA or 3-MA, an autophagy inhibitor, abrogated the impacts of CK in C2C12 myotubes. CK treatment augmented p38 and Akt phosphorylation, leading to an enhancement of C2C12 myogenesis. However, AMPK siRNA abolished the effects of CK in C2C12 myoblasts. Conclusion: These findings denote that CK prevents lipid-induced skeletal muscle apoptosis via AMPK/autophagy-mediated attenuation of ER stress and induction of myoblast differentiation. Therefore, we may suggest the use of CK as a potential therapeutic approach for treating muscle-wasting conditions associated with obesity.

• The Korea Journal of Herbology
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• v.35 no.3
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• pp.25-32
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• 2020

Objectives : At present, aging-related degenerative muscle diseases are considered a serious problem. However, the effects on muscles regarding the efficacy of blueberry have not been studied. In this study, we tried to find out the correlation between blueberry and muscle. Methods : 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS) assay was performed to confirm the antioxidant efficacy of blueberry hydrothermal extract. To determine the effect of blueberry hydrothermal extracts (BHE) on myoblast activity, 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay was performed. To confirm the effect of blueberry hydrothermal extracts on the differentiation of myoblast into myotubes, protein expression levels of myosin heavy chain 3 (Myh3) and paired box 3/7 (pax3/7) were confirmed by immunoblot analysis. In addition, immunofluorescence microscopy was performed to confirm the effect on myotube formation of blueberry hydrothermal extracts. Results : Antioxidative efficacy and low toxicity were confirmed through ABTS assay and MTS assay of blueberry extract for myoblasts. As a result of immunoblot analysis and immunofluorescence analysis, the decrease in myogenic marker Pax3/7 was not confirmed, but myotubes The specific expression inhibitory activity of the forming protein Myh3 was confirmed. Through this, it was confirmed that the blueberry extract has a negative activity against myoblast differentiation. Conclusion : This experiment confirmed that blueberry hydrothermal extract has excellent antioxidant efficacy and negative results in inhibiting the differentiation and proliferation of myoblast. This requires deep study of certain ingredients and requires reassessment of the dietary intake of blueberries.

• Food Science of Animal Resources
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• v.42 no.6
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• pp.942-952
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• 2022

To establish a pre-plating method of chicken satellite cells with high purity, pre-plating was performed under culture conditions of 37℃ and 41℃, and the pre-plating time was set from a total of 3 hours to 6 hours in consideration of the cell attachment time. The purity of the cells was confirmed by staining paired box protein 7 (Pax7) after proliferation, and Pax7 expression was the highest in culture flasks shaken for 2 hours after incubation at 41℃ for 2 hours to prevent the attachment of satellite cells (p<0.05). Also, when pre-plating and proliferation were performed at 37℃ and 41℃, the Pax7 expression rate was higher at 41℃. The differentiation capabilities of the three groups (T3, T6, and T7) with high Pax7 expression were compared and the fusion index (%) and myotube formation area (%) determined by myosin heavy chain (MHC) staining was calculated. The T6 and T7 groups, which were cultured at 41℃, showed significantly higher values than the T3 group (p<0.05). There was no significant difference in the expression of Pax7 and MHC between the T6 and T7 groups (p>0.05). These results suggest that pre-plating at 41℃ for a total of 4 hours was the most efficient in terms of cost and time for purifying chicken satellite cells for cultured meat.

• Biomedical Science Letters
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• v.13 no.4
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• pp.251-261
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• 2007

A myofiber of skeletal muscle is composed of myofibrils, sarcolemma (plasma membrane), and constameres, which anchor the myofibrils to the sarcolemma. Achvillin is a recently identified F-actin binding muscle protein, co-isolates with dystrophin and caveolin-3 in low-density sarcolemma of striated muscle, and colocalizes with dystrophin at costameres, the specialized adhesion sites in muscle. Archvillin also binds to nebulin and localizes at myofibrillar Z-discs, the lateral boundaries of the sarcomere in muscle. However other roles of archvillin on the dynamics of myofibrillogenesis remain to be defined. The goal of this study is, by using siRNA-mediated gene silencing technique, to investigate the effect of archvillin on the dynamics of myofibrillogenesis in cell culture of a mouse skeletal myogenic cell line (C2C12), where presumptive myoblasts withdraw from the cell cycle, fuse, undergo de novo myofibrillogenesis, and differentiate into mature myotubes. The roles of archvillin in the assembly and maintenance of myofibril and during the progression of myofibrillogenesis induced in skeletal myoblast following gene silencing in the cell culture were investigated. Fluorescence microscopy demonstrated that the distribution of archvillin was changed along the course of myofibril assembly with nebulin, vinculin and F-actin and then located at Z-lines with nebulin. Fluorescence microscopy demonstrated that knockdown of mouse archvillin expression led to an impaired assembly of new myofibrillar clusters and delayed fusion and myofibrillogenesis although the mouse archvillin siRNA did not affect those expressions of archvillin binding proteins, such as nebulin and F-actin. This result is corresponded with that of RT-PCR and western blots. When the perturbed archvillin was rescued by co-transfection with GFP or Red tagged human archvillin construct, the inhibited cell fusion and myotube formation was recovered. By using siRNA technique, archvillin was found to be involved in early stage of myofibrillogenesis. Therefore, the current data suggest the idea that archvillin plays critical roles on cell fusion and dynamic myofibril assembly.

• Korean Journal of Clinical Laboratory Science
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• v.55 no.3
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• pp.184-194
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• 2023

In this study, we investigated whether p-anisaldehyde (PAA), the main component of essential oils derived from anise seeds, influences the differentiation of mouse C2C12 myoblasts. Cells were induced to differentiate over 5 days using a differentiation medium with or without PAA (50 or 200 mg/mL). Myotube length and diameter were measured, and the expressions of myogenic markers (myoblast determination protein 1, myogenin, myocyte enhancer factor 2, muscle creatine kinase, and myosin heavy chain) and atrophy-related genes (atrogin-1 and muscle ring finger-1 [MuRF-1]) were assessed by quantitative real-time polymerase chain reaction. Additionally, protein kinase B (Akt) phosphorylation was monitored by western blotting. PAA significantly induced the formation of smaller and thinner myotubes and reduced myogenic marker expression. Furthermore, PAA increased the expressions of atrogin-1 and MuRF-1 and simultaneously reduced Akt phosphorylation. Our findings indicate that PAA inhibits the myogenic differentiation of C2C12 cells by reducing the phosphorylation and activation of Akt.