• Journal of Life Science
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• v.29 no.2
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• pp.215-222
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• 2019

Muscle dysfunction may arise from skeletal muscle atrophy caused by aging, injury, oxidative stress, and hereditary disease. Powdered heat-killed Enterococcus faecalis (EF-2001) has anti-allergy, anti-inflammatory, and anti-tumor effects. However, its antioxidant and anti-atrophy effects are poorly characterized. In this study, we examined the effects of EF-2001 on muscle atrophy. To determine the protective effect of EF-2001 on oxidative stress, C2C12 myoblasts were treated with $H_2O_2$ to induce oxidative stress. This induced cell damage, which was reduced by treatment with EF-2001. The mechanism of EF-2001's effect was examined in response to oxidative stress. Treatment with EF-2001 reversed the expression of HSP70 and SOD1 proteins. Also, mRNA levels of Atrogin-1/MAFbx and MuRF1 increased under oxidative stress conditions but decreased following EF-2001 treatment. To evaluate muscle volume, two and three dimensional models of the muscles were analyzed using micro-CT. As expected, muscle volume decreased after sciatic denervation and recovered after oral administration of EF-2001. Therefore, EF-2001 is a candidate for the treatment of muscular atrophy, and future discovery of the additional effects of EF-2001 may yield further applications as a functional food with useful activities in various fields.

• Journal of Ginseng Research
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• v.41 no.4
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• pp.608-614
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• 2017

Background: Ginsenoside Rg1 belongs to protopanaxatriol-type ginsenosides and has diverse pharmacological activities. In this report, we investigated whether Rg1 could upregulate muscular stem cell differentiation and muscle growth. Methods: C2C12 myoblasts, MyoD-transfected 10T1/2 embryonic fibroblasts, and HEK293T cells were treated with Rg1 and differentiated for 2 d, subjected to immunoblotting, immunocytochemistry, or immunoprecipitation. Results: Rg1 activated promyogenic kinases, p38MAPK (mitogen-activated protein kinase) and Akt signaling, that in turn promote the heterodimerization with MyoD and E proteins, resulting in enhancing myogenic differentiation. Through the activation of Akt/mammalian target of rapamycin pathway, Rg1 induced myotube growth and prevented dexamethasone-induced myotube atrophy. Furthermore, Rg1 increased MyoD-dependent myogenic conversion of fibroblast. Conclusion: Rg1 upregulates promyogenic kinases, especially Akt, resulting in improvement of myoblast differentiation and myotube growth.

• The Korean Journal of Physiology and Pharmacology
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• v.15 no.6
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• pp.363-369
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• 2011

The present study elucidated the effect of the selective inducible nitric oxide synthase (iNOS) inhibitor $N^6$-(1-iminoethyl)-L-lysine (L-NIL) on monosodium urate (MSU) crystal-induced inflammation and edema in mice feet. L-NIL (5 or 10 mg/kg/day) was administered intraperitoneally 4 h before injection of MSU (4 mg) into the soles of mice hindlimb feet. Twenty-four hours after MSU injection, foot thickness was increased by 160% and L-NIL pretreatment reduced food pad swelling in a dose dependent manner. Pretreatment of 10 mg/kg/day L-NIL significantly suppressed the foot pad swelling by MSU. Plasma level of nitric oxide (NO) metabolites and gene expression and protein level of iNOS in feet were increased by MSU, which was suppressed by L-NIL pretreatment. Similar pattern of change was observed in nitrotyrosine level. MSU increased the gene expression of tumor necrosis factor (TNF)-${\alpha}$ and interleukin (IL)-$1{\beta}$ and L-NIL pretreatment suppressed MSU-induced cytokines expression. The mRNA levels of superoxide dismutase and glutathione peroxidase1 were increased by MSU and L-NIL pretreatment normalized the gene expression. Phosphorylation of extracellular signal-regulated kinase 1/2 and p38 was increased by MSU, which was suppressed by L-NIL pretreatment. The mRNA levels of iNOS, TNF-${\alpha}$, and IL-$1{\beta}$ were increased by MSU in human dermal fibroblasts, C2C12 myoblasts, and human fetal osteoblasts in vitro, which was attenuated by L-NIL in a dose dependent manner. This study shows that L-NIL inhibits MSU-induced inflammation and edema in mice feet suggesting that iNOS might be involved in MSU-induced inflammation.

• Molecules and Cells
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• v.28 no.2
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• pp.119-124
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• 2009

Anti cancer agent 5-FU (Fluoro Uracil) is a prodrug that can be metabolized and then activated to interfere with RNA and DNA homeostasis. However, the majority of administered 5-FU is known to be catabolized in vivo in the liver where Dihydropyrimidine dehydrogenase (DPD) is abundantly expressed to degrade 5-FU. The biological factors that correlate with the response to 5-FU-based chemotherapy have been proposed to include uridine phosphorylase (UPP), thymidine phosphorylase (TPP), p53 and microsatellite instability. Among these, the expression of UPP is known to be controlled by cytokines such as $TNF-{\alpha}$, IL1 and $IFN-{\gamma}$. Our preliminary study using a DNA microarray technique showed that basic fibroblast growth factor (bFGF) markedly induced the expression of UPP1 at the transcription level. In the present study, we investigated whether bFGF could modulate the expression of UPP1 in osteo-lineage cells and examined the sensitivity of these cells to 5-FU mediated apoptosis.

• 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.

• Journal of Nutrition and Health
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• v.57 no.1
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• pp.53-64
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• 2024

Purpose: Mitochondria play a crucial role in preserving skeletal muscle mass, and damage to mitochondria leads to muscle mass loss. This study investigated the effects of oxypeucedanin hydrate, a furanocoumarin isolated from Angelica dahurica radix, on myogenesis and mitochondrial function in vitro and in zebrafish models. Methods: C2C12 myotubes cultured in media containing 0.1, 1, 10, or 100 ng/mL oxypeucedanin hydrate were immunostained with myosin heavy chain (MHC), and then multinucleated MHC-positive cells were counted. The expressions of markers related to muscle differentiation, muscle protein degradation, and mitochondrial function were determined by quantitative reverse transcription polymerase chain reaction. To investigate the effects of oxypeucedanin hydrate on mitochondrial dysfunction, Tg(Xla.Eef1a1:mito-EGFP) zebrafish embryos were treated with 5-fluorouracil, leucovorin, and irinotecan (FOLFIRI) with or without oxypeucedanin hydrate and analyzed for mito-EGFP intensity and mitochondrial length. Results: Oxypeucedanin hydrate significantly increased MHC-positive multinucleated myotubes (≥ 3 nuclei) and increased the expression of the myogenic marker myosin heavy chain 4. However, it decreased the expressions of muscle-specific RING finger protein 1 and muscle atrophy f-box (markers of muscle protein degradation). Furthermore, oxypeucedanin hydrate enhanced the expressions of markers of mitochondrial biogenesis (peroxisome proliferator-activated receptor-gamma coactivator 1 alpha, transcription factor a mitochondrial, succinate dehydrogenase complex flavoprotein subunit A, and cytochrome c oxidase subunit 1) and mitochondrial fusion (optic atrophy 1). However, it reduced the expression of dynamin-related protein 1 (a mitochondrial fission regulator). Consistently, oxypeucedanin hydrate reduced FOLFIRI-induced mitochondrial dysfunction in the skeletal muscles of zebrafish embryos. Conclusion: The study indicates that oxypeucedanin hydrate promotes myogenesis by improving mitochondrial function, and thus, suggests oxypeucedanin hydrate has potential use as a nutritional supplement that improves muscle mass and function.

• Journal of Nutrition and Health
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• v.56 no.6
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• pp.602-614
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• 2023

Purpose: The balance between synthesis and degradation of proteins plays a critical role in the maintenance of skeletal muscle mass. Mitochondrial dysfunction has been closely associated with skeletal muscle atrophy caused by aging, cancer, and chemotherapy. Polygalacin D is a saponin derivative isolated from Platycodon grandiflorum (Jacq.) A. DC. This study aimed to investigate the effects of polygalacin D on myoblast differentiation and muscle atrophy in association with mitochondrial function in in vitro and in zebrafish models in vivo. Methods: C2C12 myoblasts were cultured in differentiation media containing different concentrations of polygalacin D, followed by the immunostaining of the myotubes with myosin heavy chain (MHC). The mRNA expression of markers related to myogenesis, muscle atrophy, and mitochondrial function was determined by real-time quantitative reverse transcription polymerase chain reaction. Wild type AB^* zebrafish (Danio rerio) embryos were treated with 5-fluorouracil, leucovorin, and irinotecan (FOLFIRI) with or without polygalacin D, and immunostained to detect slow and fast types of muscle fibers. The Tg(Xla.Eef1a1:mitoEGFP) zebrafish expressing mitochondria-targeted green fluorescent protein was used to monitor mitochondrial morphology. Results: The exposure of C2C12 myotubes to 0.1 ng/mL of polygalacin D increased the formation of MHC-positive multinucleated myotubes (≥ 8 nuclei) compared with the control. Polygalacin D significantly increased the expression of MHC isoforms (Myh1, Myh2, Myh4, and Myh7) involved in myoblast differentiation while it decreased the expression of atrophic markers including muscle RING-finger protein-1 (MuRF1), mothers against decapentaplegic homolog (Smad)2, and Smad3. In addition, polygalacin D promoted peroxisome proliferator-activated receptor-gamma coactivator (Pgc1α) expression and reduced the level of mitochondrial fission regulators such as dynamin-1-like protein (Drp1) and mitochondrial fission 1 (Fis1). In a zebrafish model of FOLFIRI-induced muscle atrophy, polygalacin D improved not only mitochondrial dysfunction but also slow and fast muscle fiber atrophy. Conclusion: These results demonstrated that polygalacin D promotes myogenesis and alleviates chemotherapy-induced muscle atrophy by improving mitochondrial function. Thus, polygalacin D could be useful as nutrition support to prevent and ameliorate muscle wasting and weakness.