• Asian-Australasian Journal of Animal Sciences
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• 제20권8호
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• pp.1285-1291
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• 2007

This research investigated variation in the improvement of the texture of chicken and pork sausages induced by microbial transglutaminase (MTG). The extractability of myofibrillar proteins from these sausages as well as the ${\varepsilon}-({\gamma}-glutamyl)$lysine (G-L)　content were also investigated. MTG treatment of sausages significantly increased the breaking strength values in both meat types, especially for samples incubated at $40^{\circ}C$. However, values of the breaking strength in both meat types were increased differently. The variation in protein extractability of samples incubated at $40^{\circ}C$ for both meat types could lead to some consideration of the mechanisms and the high accessions of myosin heavy chain (MHC) to MTG. SDS-PAGE analysis showed significant changes in the density of the bands after adding MTG, especially for the pork samples in which the bands disappeared totally. The G-L content in the presence of MTG was double that in control samples of both meat types. This study suggests that the binding ability of myofibrillar proteins with MTG is strong. This leads us to suggest that MTG functions positively with different improvements in the texture of chicken and pork products that are treated mechanically, such as sausages. Variability in gel improvement level between chicken and pork sausages was observed; this resulted from the variation in meat proteins in response to MTG, as well as to the original glutamyl and lysine content.

• BMB Reports
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• 제51권7호
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• pp.350-355
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• 2018

HnRNPK is a multifunctional protein that participates in chromatin remodeling, transcription, RNA splicing, mRNA stability and translation. Here, we uncovered the function of hnRNPK in regulating the proliferation and differentiation of myoblasts. hnRNPK was mutated in the C2C12 myoblast cell line using the CRISPR/Cas9 system. A decreased proliferation rate was observed in hnRNPK-mutated cells, suggesting an impaired proliferation phenotype. Furthermore, increased G2/M phase, decreased S phase and increased sub-G1 phase cells were detected in the hnRNPK-mutated cell lines. The expression analysis of key cell cycle regulators indicated mRNA of Cyclin A2 was significantly increased in the mutant myoblasts compared to the control cells, while Cyclin B1, Cdc25b and Cdc25c were decreased sharply. In addition to the myoblast proliferation defect, the mutant cells exhibited defect in myotube formation. The myotube formation marker, myosin heavy chain (MHC), was decreased sharply in hnRNPK-mutated cells compared to control myoblasts during differentiation. The deficiency in hnRNPK also resulted in the repression of Myog expression, a key myogenic regulator during differentiation. Together, our data demonstrate that hnRNPK is required for myoblast proliferation and differentiation and may be an essential regulator of myoblast function.

• Animal cells and systems
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• 제1권4호
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• pp.641-646
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• 1997

Lysophosphatidic acid (LPA; 1-acyl-glycerol-3-phosphate) has been known as an intercellular phospholipid messenger with a wide range of biological activities. In this study, the effect of LPA on both the proliferation and differentiation of rat E63 myoblasts has been investigated. In the serum-free Insulin-Transferrin-Selenium (ITS) media, the proliferation of E63 cells was largely restricted. Addition of LPA into the ITS media strongly promoted the cell proliferation and resulted in two to four fold increase of cell number. Furthermore, it appeared to increase the percent fusion in a dose-dependent manner up to 15 ug/ml. The synthesis of myosin heavy chain (MHC) was increased by LPA as well. These results indicate that LPA is able to promote both cell proliferation and differentiation in rat E63 myoblasts. Suramin, known to have uncoupling activity on growth factor-receptor interaction, was tested for antagonistic activity in myoblast proliferation and differentiation. Myoblasts grown in the ITS medium containing LPA were able to proliferate well even in the presence high concentration of suramin whereas myoblast differentiation was completely blocked by 30 ug/ml of suramin. The inhibitory effect of suramin on the myoblast differentiation was completely reversible by removing the suramin. This result indicates that the intracellular signaling pathway of LPA leading to cell proliferation might be distinct from that leading to cell differentiation on E63 myoblasts. Also, the antagonistic effect of suramin suggests that the differentiation activity elicited by LPA might be mediated by a specific G protein-coupled receptor.

• Animal Bioscience
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• 제36권2호
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• pp.295-306
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• 2023

Objective: Inhibiting the p38 mitogen-activated protein kinase (MAPK) signaling pathway delays differentiation and increases proliferation of muscle stem cells in most species. Here, we aimed to investigate the effect of p38 inhibitor (p38i) treatment on the proliferation and differentiation of chicken muscle stem cells. Methods: Chicken muscle stem cells were collected from the muscle tissues of Hy-line Brown chicken embryos at embryonic day 18, then isolated by the preplating method. Cells were cultured for 4 days in growth medium supplemented with dimethyl sulfoxide or 1, 10, 20 μM of p38i, then subcultured for up to 4 passages. Differentiation was induced for 3 days with differentiation medium. Each treatment was replicated 3 times. Results: The proliferation and mRNA expression of paired box 7 gene and myogenic factor 5 gene, as well as the mRNA expression of myogenic differentiation marker gene myogenin were significantly higher in p38i-treated cultures than in control (p<0.05), but immunofluorescence staining and mRNA expression of myosin heavy chain (MHC) were not significantly different between the two groups. Oil red O staining of accumulated lipid droplets in differentiated cell cultures revealed a higher lipid density in p38i-treated cultures than in control; however, the expression of the adipogenic marker gene peroxisome proliferator activated receptor gamma was not significantly different between the two groups. Conclusion: p38 inhibition in chicken muscle stem cells improves cell proliferation, but the effects on myogenic differentiation and lipid accumulation require additional analysis. Further studies are needed on the chicken p38-MAPK pathway to understand the muscle and fat development mechanism.

• 운동영양학회지
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• 제24권2호
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• pp.11-21
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• 2020

[Purpose] Doxorubicin (DOX) is a potent anti-cancer drug that appears to have severe myotoxicity due to accumulation. The skeletal muscle has a regeneration capacity through satellite cell activation when exposed to extracellular stimulus or damage. Endurance exercise (EXE) is a therapeutic strategy that improves pathological features and contributes to muscle homeostasis. Thus, this study investigated the effect of EXE training in mitigating chronic DOX-induced myotoxicity. [Methods] Male C57BL/6J mice were housed and allowed to acclimatize with free access to food and water. All the mice were randomly divided into four groups: sedentary control (CON, n=9), exercise training (EXE, n=9), doxorubicin treatment (DOX, n=9), doxorubicin treatment and exercise training (DOX+EXE, n=9) groups. The animals were intraperitoneally injected with 5 mg/kg/week of DOX treatment for 4 weeks, and EXE training was initiated for treadmill adaptation for 1 week and then performed for 4 weeks. Both sides of the soleus (SOL) muscle tissues were dissected and weighed after 24 hours of the last training sessions. [Results] DOX chemotherapy induced an abnormal myofiber's phenotype and transition of myosin heavy chain (MHC) isoforms. The paired box 7 (PAX7) and myoblast determination protein 1 (MYOD) protein levels were triggered by DOX, while no alterations were shown for the myogenin (MYOG). DOX remarkably impaired the a-actinin (ACTN) protein, but the EXE training seems to repair it. DOX-induced myotoxicity stimulated the expression of the forkhead box O3 (FOXO3a) protein, which was accurately controlled and adjusted by the EXE training. However, the FOXO3a-mediated downstream markers were not associated with DOX and EXE. [Conclusion] EXE postconditioning provides protective effects against chronic DOX-induced myotoxicity, and should be recommended to alleviate cancer chemotherapy-induced late-onset myotoxicity.

• 대한본초학회지
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• 제34권6호
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• pp.79-89
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• 2019

Objective : This study investigated the anti-diabetic effects of DM1, a herbal mixture with Atractylodis Rhizoma, Anemarrhenae Rhizoma, and Cinnamomi Cortex in high fat diet (HFD)-induced diabetic mice and the mechanism in C2C12 mouse skeletal muscle cells. Methods : The C57B/6 mice were fed high fat for 12 weeks, and then administrated DM1 extract (500 mg/kg, p.o.) for 4 weeks. The changes of body weight, calorie and water intakes, fasting blood glucose levels and the serum levels of glucose, insulin, triglyceride, HDL-cholesterol, AST and ALT were measured in mice. The histological changes of liver and pancreas tissues were also observed by H&E stain. C2C12 myoblasts were differentiated into myotubes and then treated with DM1 extract (0.5, 1, and 2 mg/㎖) for 24 hr. The expression of myosin heavy chain (MHC), PGC1α, Sirt1 and NRF1, and the AMPK phosphorylation were determined in the myotubes by western blot, respectively. Results : The DM1 extract administration significantly decreased the calorie and water intakes, glucose, triglyceride, AST and ALT levels and increased insulin and HDL-cholesterol in HFD-induced diabetic mice. DM1 extract inhibited lipid accumulation in liver tissue and improved glucose tolerance. In C2C12 myotubes, DM1 treatment increased the expression of MHC, PGC1α, Sirt-1, NRF-1 and the AMPK phosphorylation. Conclusion : In our results indicate that DM1 can improve diabetic symptoms by decreasing the obesity, glucose tolerance and fatty liver in HFD-induced diabetic mice, and responsible mechanism is might be related with energy enhancement.

• 한국식품저장유통학회지
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• 제31권2호
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• pp.298-306
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• 2024

본 연구에서는 식물 추출물 혼합 분말의 근육세포 분화 및 산화적 스트레스에 대한 세포 보호 효과를 확인하고자 하였다. 추출물을 최대 1,000 ㎍/mL 농도까지 세포에 처리한 결과, 세포 생존율이 감소하지 않음을 확인되었다. 식물 추출물 혼합분말이 근육세포 분화 인자에 미치는 영향을 확인하기 위해 myogenin과 MHC의 발현 여부를 확인한 결과, 무처리군에 비해 발현이 증가함을 확인하였다. H₂O₂에 의해 유도된 산화적 스트레스에 대한 세포 보호 효과를 확인한 결과, 식물 추출물 혼합 분말 처리에 의해 H₂O₂ 단독 처리군보다 세포 생존율이 증가하였으며, LDH와 creatine kinase의 활성이 감소하였다. 또한, Bax와 Bcl-2의 발현을 조절하여 caspase-9와 -3 활성화를 억제함을 확인하였다. 이를 통해 식물 추출물 혼합 분말의 근육세포 분화 효과 및 H₂O₂에 의해 유도된 산화적 스트레스에 대한 세포 보호 효과가 있음을 확인하였다. 따라서 식물 추출물 혼합 분말은 근감소증 개선을 위한 기능성 소재로써 활용이 가능할 것으로 판단되며, 향후 근감소증 개선을 위한 기능성 소재로서의 유효성 확보를 위해서 근감소증 세포 및 동물모델을 이용한 효능 및 기전 분석 연구가 더 필요할 것으로 사료된다.

• Journal of Nutrition and Health
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• 제56권6호
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• pp.602-614
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• 2023

본 연구는 근생성 및 근위축 완화효능을 가진 유효소재 발굴의 필요성에 의해 polygalacin D가 근원세포 분화 및 미토콘드리아에 미치는 영향과 항암제 유도 근위축에 대한 완화효과를 각각 세포 및 동물실험을 통해 확인하고자 하였다. 그 결과, polygalacin D는 다핵을 지닌 근관세포의 수와 분화 종결인자인 MHC isoforms의 발현량을 증가시켰고 근육 내 단백질 분해 인자인 MuRF1, Smad2/3의 발현량은 유의적으로 감소시켰다. 또한 미토콘드리아 생합성 조절인자인 Pgc1α의 발현은 증가시키고 미토콘드리아 분열인자인 Drp1과 Fis1의 발현은 감소시켰다. 한편 zebrafish 동물모델을 통해 항암제 유도 근위축에 대한 개선효과를 확인한 결과, polygalacin D는 항암제에 의해 유도된 근위축과 미토콘드리아 손상을 완화시켰다. 이상의 결과들은 polygalacin D가 미토콘드리아 기능 증진을 매개로 근원세포 분화 촉진 및 근육 단백질 분해 저하 효과를 지닐 뿐만 아니라, 미토콘드리아 손상을 개선하여 항암제로 유도된 근위축에 대한 완화 효과를 나타냄을 시사한다. 따라서 본 연구를 통해 polygalacin D가 근생성 및 근위축 예방과 치료를 위한 잠재적인 유효소재로서의 가능성을 제시하였다.

• 대한물리치료과학회지
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• 제8권1호
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• pp.745-758
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• 2001

The purpose of study to phenomenological examine and the mechanism regarding the gene(DNA, RNA, Protein) and sports to studied, analyzed. and evaluated. This review considers the evidence for genetic effects in several determinants of endurance performance and resistance performance, namely: body measurements and physique, body fat pulmonary functions, cardiac and circulatory functions, muscle characteristics. substrate utilization, maximal aerobic power and other. Moreover, the response to aerobic training of indicators aerobic work metabolism and endurance performance is reviewed, with emphasis on the specificity of the response and the individual differences observed in training ability. This study indicate that improvement of 'Enhancer Action' in RNA genes changed by exercise or sports. Moreover exercise was effect on Central Dogma with DNA makes RNA makes Protein. and think that occurred with exercise influence on skeletal muscle into cell have to Myosin Heavy Chain (MHC) changed was after exercise performance, which accompanied into skeletal muscle that were exercise-induces gene-modulation that is, take gene mutations. This study known that existed hormone(epinephrine)-immune system with interaction. Exercise were altered insulin binding and MAP Kinase signaling increased into immune cells. This review suggested that the high rate of glutamine utilization by cells of the immune system serves to maintain a high intra cellular concentration of the intermediates of biosynthetic pathways such that optimal rates of DNA, RNA and protein synthesis can be maintained. In the absence of glutamine, lymphocytes do not proliferate in vitro: proliferation increase greatly as the glutamine concentration increase. Glutamine is synthesized in skeletal muscle. Skeletal muscle and plasma glutamine levels are lowered by sepsis, injury, bums, surgery and endurance exercise and in the overtrained athlete. The study of result show that production of ET-1 is markedly increased tissue specifically in the heart by exercise without appreciable changes in endothelin-converting enzyme and endothelial receptor expressions, suggest that myocardial ET-1 may participate in modulation of cardiac function during exercise. Conclusionally, this study indicate that improvement of 'Enhancer Action' in RNA genes changed by exercise or sports. Moreover exercise was effect on Central Dogma with DNA makes RNA makes Protein. This study is expected to contribute the area of sports science, medicine, hereafter more effort is required to establish the relation between gene alters and exercise amount.

• Reproductive and Developmental Biology
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• 제37권4호
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• pp.219-224
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• 2013

Muscular satellite cell (SC), which is stem cell of postnatal pig, is an important for study of differentiation into adipogenesis, myogenesis, and osteoblastogenesis. In this study, we isolated and examined from pig muscle tissue to determine capacity in proliferate, differentiate, and expression of various genes. Porcine satellite cells (PSC) were isolated from semimembranosus (SM) muscles of 90~100 days old pigs according to standard conditions. The cell proliferation increased in multi-potent cell by Masson's, oil red O, and Alizarin red staining respectively. We performed the expression levels of differentiation related genes using real-time PCR. We found that the differentiation into adipocyte increased expression levels of both fatty acid binding protein 4 (FABP4) and peroxisome proliferator-activated receptor gamma ($PPAR{\gamma}$) genes (p<0.01). Myocyte increased the expression levels of the myosin heavy chain (MHC), myogenic factor 5 (Myf5), myogenic regulatory factor (MyoD), and Myogenic factor 4 (myogenin) (p<0.01). Osteoblast increased the expression levels of alkaline phosphatase (ALP) (p<0.01). Finally, porcine satellite cells were induced to differentiate towards adipogenic, myogenic, and osteoblastogenic lineages. Our results suggest that muscle satellite cell in porcine may influence cell fate. Understanding the progression of PSC may lead to improved strategies for augmenting meat quality.