• Food Science of Animal Resources
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• v.30 no.5
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• pp.842-850
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• 2010

Sex steroids are known to be involved in skeletal muscle development (anabolic effect) and are frequently used in medicines. It has been known that pork contains a variety of steroids that are mainly synthesized in the gonads (testis and ovary). Thus, the present study was conducted to evaluate the effects of anabolic steroids of pork on the proliferation and differentiation of myogenic satellite cells (MSC). Three different methods (M1, M2, and M3) were developed for the isolation and purification of steroids from porcine tissues. Among three extraction methods that we developed, M3 was the best method with respect to the quantities of steroids and the induction of MSC proliferation. Hormonal analysis showed that the steroid hormone levels were the highest in muscle and fat of intact male than those of castrated males and females. In addition, the highest serum levels of nandrolone and testosterone were detected in intact males, whereas estrone and $17{\beta}$-estradiol levels were similar in the entire experimental serum samples. Expression of androgen receptor (AR), myoD, desmin, and myogenin in bovine muscle cells were significantly up-regulated by the treatment of steroid extracts. The highest increas of myogenin and AR mRNA abundance were observed in the MSCs treated with M3 extract (p<0.001). Altogether, the present research showed the positive effect of steroids on MSC proliferation and differentiation in vitro. These results would certainly imply a beneficial effect of pork consumption on human muscle development.

• Journal of Animal Science and Technology
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• v.47 no.6
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• pp.913-918
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• 2005

The development of marbling in cattle is closely associated with an increase in adipocyte size and number within muscle. The adipose precursor cells have the capacity to differentiate into adipocytes within the muscle during the formation of marbling. In this studies, we established the cell culture system for differentiation of intramuscular preadipocyte isolated from the sirloin of Hanwoo aged 12 months. The intramuscular preadipocyte cells exhibited a fibroblastic appearance and differentiated into adipocytes by treating confluent cells with differentiation medium containing insulin, dexamethasone, and troglitazone. When intramuscular preadipocyte cells were differentiated at 18 day, the triglyceride concentration was higher than control cells. Moreover, the thiazolidinedione treatment increased adipogenesis. RT-PCR analysis confirmed the significant expression of PPARγ mRNA during adipocyte differentiation. In conclution, our culture system used in this study allowed intramuscular preadipocyte cells to differentiated into adipocytes and intramuscular preadipocyte cells may be useful in the further study of differentiation mechanism of adipocytes in Hanwoo.

• Journal of Applied Biological Chemistry
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• v.66
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• pp.60-66
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• 2023

Lentinula edodes is one of the most produced mushrooms in the world. In this study, the effects of L. edodes water extracts and lentinan, a beta-glucan from this mushroom, on the proliferation of Bos taurus Hanwoo myosatellite cells were studied. The betaglucan content of the L. edodes water extract was approximately 15.20% at 85 ℃ for 4 h, 13.64% at 100 ℃ for 4 h, 9.48% at 40 ℃ for 8 h and 8.21% at room temperature for 24 h. L. edodes water extract was added to the culture of Hanwoo myosatellite cells. The expression of the MyoD gene increased in the addition of the extract at 40 ℃ for 8 h and 100 ℃ for 4 h, and the expression of the Myogenin gene increased in the addition of the extract at 40 ℃ for 8 h, but proliferation and activity did not increase compared to no addition. However, the addition of lentinan to the culture of Hanwoo myosatellite cells increased the expression of Myogenin gene related to muscle formation increased and the proliferation and viability of the cells. This study proved that the components of L. edodes can affect the proliferation of Hanwoo myosatellite cells, and further research will help develop the mushroom industry and cultured meat industry in the future.

• Journal of radiological science and technology
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• v.25 no.2
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• pp.77-82
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• 2002

It is well known that X-irradiation affects on maturing process of differentiated chondrocytes. Nevertheless, It has been remained elusively whether X-irradiation affects the process of differentiation of mesenchymal cells which differentiate into chondrocyte, fibroblast, or muscle cells. In this study, we examined the effect of X-irradiation (with 1 to 10 Gy) on chondrogenesis using the mesenchymal cells of chick limb bud. Our results show that X-irradiation dose-dependently inhibited chondrogenesis. This result suggests that immature chondroblast-like mesenchymal cells are sensitive to X-irradiation. Moreover, X-irradiation affects not only maturing process of chondrocytes, but also inhibits the chondrogenesis. Taken together, we demonstrate that the whole process of differentiation of mature chondrocytes from mesenchymal cells is affected by X-irradiation and undifferentiated cells were more affected by X-irradiation than mature cells.

• Journal of Life Science
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• v.31 no.2
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• pp.137-143
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• 2021

Muscle atrophy refers to a decrease in muscle cells due to damage to muscle fibers. It is reported that muscle atrophy is caused by heart disease, diabetes, and other chronic diseases related to aging. The purpose of this study is to reveal the inhibitory effects of seaweed extracts, which are widely consumed in Korea, and alginic acid on muscle cell damage in muscle atrophy and regeneration models. We found that seaweed extracts (U) and alginic acid (A) attenuated TNF-α-induced muscle atrophy in differentiated C2C12 myoblast cells and inhibited muscle atrophy markers such as MuRF1 and MAFbx. In addition, U and A also regulated ubiquitination marker FoxO1 protein. To confirm the muscle regeneration effect in animal tissue, cardiotoxin (CTX) was used for the regeneration model. Six hours after CTX injection, gastrocnemius muscle volume was increased compared to control. Otherwise, the muscle volume of the U and A treatment groups was not changed. U and A also upregulated regeneration markers MyHC and PGC-1α in a CTX mouse model. These results indicate that seaweed extracts and alginic acid, a seaweed component, are applicable to senile sarcopenia by inhibiting muscle loss and promoting muscle regeneration.

• The Science & Technology
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• v.33 no.10 s.377
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• pp.86-87
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• 2000

21세기를 주도하는 과학은 생물학으로 생명의 기원을 실험실에서 재생할 것이며 또 금속과 실리콘 신경과 근육이 함께 어우러져 일어나는 산업혁명이 시작될 것이다. 우리는 1백년 안에 소행성에 식민지를 건설하고 천년 후엔 인류도 다양하게 분화되며 1만년 단위로 보면 인간진화의 싸움터는 생물학에서 철학으로 옮겨갈 것이다.

• Journal of Life Science
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• v.27 no.12
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• pp.1479-1485
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• 2017

Muscle atrophy due to aging, starvation, and various chronic diseases leads to a decrease in muscle fiber area and density due to reduced muscle protein synthesis and increased protein breakdown. This study investigated the effect of dexamethasone and hydrogen peroxide on the induction of muscle atrophy and expression of atrophy-related genes in differentiated C2C12 myotubes. C2C12 myoblasts were differentiated into myotubes in differentiation medium. During myoblast differentiation, muscle-specific transcription factors, such as myogenin, and MyoD expression increased. Differentiated C2C12 myotubes exposed to noncytotoxic levels of dexamethasone and hydrogen peroxide showed a decrease in myotube diameter, which was associated with up-regulation of muscle-specific ubiquitin ligases, such as muscle atrophy F-box (MAFbx)/atrogin-1 and muscle RING finger-1 (MuRF1), and down-regulation of myogenin and MyoD. These results demonstrated that dexamethasone and hydrogen peroxide induced atrophy through regulation of muscle-specific ubiquitin ligases and muscle-specific transcription factors in C2C12 myotubes. In this study, we confirmed the process of differentiation of C2C12 myoblasts into myotubes in in vitro experiments in the presence of atrophy. This muscle atrophy model of C2C12 cells induced by dexamethasone or hydrogen peroxide seems suited to studies of the mechanism of muscle atrophy suppression and to exploit the experiment for excavating new muscle atrophy.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2004.10a
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• pp.132-136
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• 2004

본 연구는 근육 및 지방세포 분화에 관여하는 leptin, MYF5 및 H-FABP의 3개 기능성 후보 유전자가 한우의 도체특성 및 육질에 미치는 영향을 분석하기 위하여 이들 유전자의 PCR-RFLP marker와 도체형질과의 관련성을 분석하였다. Leptin, MYF5 및 H-FABP 유전자에서 AA, AB 및 BB 3종류의 RFLP 유전자형이 각각 검출되었고 A와 B 대립유전자 빈도는 각각 0.57과 0.43, 0.61과 0.39 그리고 0.90과 0.10으로 추정되었다. 육질 등급에 따라 고급육과 저급육으로 분리 선발한 두 그룹간의 대립유전자 출현빈도를 비교한 결과 leptin과 MYF5 유전자에서 각각 통계적 유의차(P< .05)가 인정되었다. 또한 각 후보유전자의 RFLP marker 유전자형이 도체형질에 미치는 효과를 분석한 결과 leptin 유전자는 등지방 두께 그리고 MYF5유전자는 배장근 단면적에 각각 유의적인 영향(P< .05)을 미치는 것으로 분석되었다. 그러나 H-FABP 유전자는 도체형질들과 유의성이 인정되지 않았다. 따라서, leptin과 MYF5 유전자는 한우의 도체특성 및 육질 개선을 위한 DNA marker로 이용 가능할 것으로 사료된다.

• Journal of Life Science
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• v.26 no.7
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• pp.758-763
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• 2016

Fatty acid transporters are key mediators of skeletal muscle lipid metabolism. Several protein groups have been implicated in cellular long-chain fatty acid uptake or oxidation, including fatty acid transporter proteins (FATPs), the plasma membrane fatty acid-binding protein (FABPpm), and the fatty acid translocase (FAT/CD36). FAT/CD36 is highly expressed in skeletal muscle and known to be regulated by various factors such as exercise and hormones. Insulin-like growth factor-I (IGF-I) is a well-known regulator of skeletal muscle cells. However, it has not been studied whether there is any interaction between IGF-I and FAT/CD36 in skeletal muscle cells. In this study, the effects of IGF-I treatment on FAT/CD36 induction were examined. Differentiated C2C12 cells were treated with 20 ng/ml of IGF-I at different time points. Treatment of C2C12 cells with IGF-I resulted in increased FAT/CD36 mRNA and protein expression. After 24 and 48 hr of IGF-I treatment, FAT/CD36 mRNA increased 89% and 24% respectively. The increase of both proteins returned to the control level after 72 hr of IGF-I treatment, suggesting that the FAT/CD36 gene is regulated pretranslationally by IGF-I in skeletal muscle cells. These results suggest that IGF-I can regulate the expression of FAT/CD36 in skeletal muscle cells. In conclusion, IGF-I induces a rapid transcriptional modification of the FAT/CD36 gene in C2C12 skeletal muscle cells and has modulating effects on fatty acid uptake proteins as well as oxidative proteins.

• Food Science and Preservation
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• v.31 no.2
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• pp.298-306
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• 2024

This study evaluated the differentiation and protective effects of mixed plant-extract powder in C2C12 muscle cells. Cells were differentiated into myotubes in 2% horse serum (HS)-containing medium with mixed plant-extract powder (MPEP) for 6 days. Treatment with MPEP increased the expression of myogenin and myosin heavy chain (MHC) protein in cells compared with non-treated cells. Differentiated cells were pretreated with MPEP, and hydrogen peroxide (H₂O₂). Our results revealed that treatment with MPEP before H₂O₂ treatment increased cell viability and decreased H₂O₂-induced lactate dehydrogenase (LDH) and creatine kinase (CK). In addition, MPEP attenuated H₂O₂-induced upregulation of Bax, downregulation of Bcl-2, and activation of caspase-9 and -3. These results suggest the MPEP can stimulate C2C12 muscle cell differentiation into myotubes and observe the protective effect of mixed plant-extract powder against muscle oxidative stress. In conclusion, MPEP may be useful as a prevention and treatment material for skeletal muscle disease caused by age-related diseases.