• 한국동물학회지
• /
• 제35권3호
• /
• pp.322-331
• /
• 1992

To investigate the svnthyesis of muscle proteins during differentiation of chicken myoblast, cvtosolic and membrane fractions were used for both sodium dodecvl sulfate polvcrylamide gel eBectrophoresis and two-dimensional gel electrophoresis. An extensive cell fusion was observed in 4 day culture. In the protein pattern of the cvtosolic fraction from SDS-PAGE. several protein bands including 250 kDa and 46 kDa showed remarkable changes during culture. the protein of 46 kDa was the most prominent one ann its optical density was the highest in 5 day culture (OD = 1.30). In the membrane fraction, band of 19.8 kDa showed the highest absorbance with 0.93 OD at 12 hr after initial plating and decreased gradually thereafter to 0.23 in 5 nay culture. From the results of two-dimensional gel electrophoresis of cytosolic fraction, the 46 kDa spot was observed as ko separated forms from culture 2 nary culture, and the sixte of this spot was the largest in 5 nay culture. In the pattern of membrane protein, the extensive appearance of newiv synthesized Proteins was found in a naut culture, but no Prominent spot was observed throughout culture. From the results of the present clay, we found that, during myoblast differentiation, the most prominent proteins were bands of 46 kDa and 19.8 kDa in cvtosolic and membrane fraction, respectively, and the appearance of new proteins was initiated at 48 hr after initial plating, and the 46 kDa protein was predominant in the cytoplasm of late culture in which extensive cell fusion was observed.

• 한국동물학회지
• /
• 제27권3호
• /
• pp.151-164
• /
• 1984

근원세포의 융합에 관여하는 융합유도물질의 존재를 구명하기 위하여 계배의 근세포를 배양하면서, muscle-conditioned medium (MCM) 이 근원세포의 융합에 미치는 영향을 조사하고, 근원세포로부터 배양액 내로 방출되는 단백질을 분석하여 다음과 같은 결과를 얻었다. (1) MCM은 뚜렷한 융합촉진 효과를 나타냈으며, 이러한 효과는 첨가된 MCM의 농도가 층가함에 따라 증가하였다. (2) MCM의 융합촉진 효과는 주로 근원세포로부터 방출되는 융합유도물질에 의하여 일어나는 것으로 판단된다. (3) 배양근원세포로부터 분비되는 45,000달톤과 65,000달톤의 단백질이 융합 유도물질일 가능성이 높다.

• 한국동물학회:학술대회논문집
• /
• 한국동물학회 1999년도 한국생물과학협회 학술발표대회
• /
• pp.175.1-175
• /
• 1999

No Abstract, See Full Text

• 한국동물학회:학술대회논문집
• /
• 한국동물학회 1999년도 한국생물과학협회 학술발표대회
• /
• pp.176.1-176
• /
• 1999

No Abstract, See Full Text

• 한국당과학회:학술대회논문집
• /
• 한국당과학회 2006년도 제1회 연례학술대회
• /
• pp.46-46
• /
• 2006

• 생명과학회지
• /
• 제17권7호통권87호
• /
• pp.976-982
• /
• 2007

본 연구는 분화 전단계인 C2C12 myoblast세포에 중요한 후천적 기작의 하나인 DNA 히스톤 단백질의 아세틸화를 조절하였을 때 일어나는 변화를 살펴본 결과, 히스톤 탈아세틸화 효소를 trichostatin A로서 억제시키자 C2C12 myoblast 세포가 smooth muscle로 분화하였다. 이는 immunofluorescentstaining을 통해 smooth muscle ${\alpha}-actin$의 발현 증가를 trishostatin A로 처리한 세포에서 관찰하였으며, DAPI 염색을 통해 대조군 세포와 비교하여 세포의 증식이 많이 억제됨을 관찰하였다. 또한 real-time PCR 결과는 smooth muscle ${\alpha}$-actin과 transgelin mRNA의 발현이 trichostatin A 처리군 세포에서 현저히 증가함을 보여주었다. 이러한 결과를 바탕으로 히스톤 단백질의 탈아세틸화 억제는 C2C12 myoblast 세포의 분화에 매우 중요한 역할을 하며, 또한 C2C12 myoblast 세포를 골격근인 다핵의 myotube로 분화시키지 않고, smooth muscle로 분화시킴을 알 수 있었다. 이것은 분명히 HDAC억제제 인 trichostatin A가 DNA 히스톤 단백질의 HDAC 효소에 의한 탈아세틸화를 강력히 억제하고, 이러한 HDAC효소의 억제는 세포주기에 있어서 증식과 분화를 조절하는 유전자들의 발현을 조절하였음을 시사한다. 이를 검증하기 위해 세포주기 조절인자인 p21과 cyclin Dl mRNA의 발현을 조사한 결과 세포를 증식단계로 진행하는데 있어서 필수적인 cdk 억제제인 p21 mRNA의 발현이 trichostatin A로 처리한 세포에서 현저히 증가함을 보였으며, 세포 증식을 유도하는 cyclin Dl mRNA의 발현은 trichostatin A를 처 리 한 후 24시간 후 유의하게 감소함을 보였는데 이는 trichostatin A가 세포증식을 억제하는 초기단계에서 cyclin Dl 유전자의 발현을 조절함을 보여준다. 향후 연구에서는 또 하나의 중요한 후천적 기작인 DNA 메틸화와 히스톤 아세틸화가 유전자 발현을 조절하는데 있어서 상호작용에 대한 연구가 필요할 것으로 생각된다.

• 생명과학회지
• /
• 제17권3호통권83호
• /
• pp.420-426
• /
• 2007

본 연구에서는 유전자 발현에 중요한 조절 역할을 하는 DNA 메틸화를 식이성 폴리페놀의 하나인 녹차의 대표적인 추출물 EGCG로 억제하였을 때 C2C12 myoblast 세포에 일어나는 현상을 살펴보았다. 그 결과 smooth muscle의 지표인 transgelin, smooth muscle ${\alpha}-actin$ mRNA와 단백질이 현저히 증가함을 보였고, 형태학적으로도 smooth muscle의 전형적인 모습을 보였다. 식이에 포함된 DNA 메틸화 억제제인 EGCG가 C2C12 myoblast를 smooth muscle로 분화를 유도하였으며, 암 예방 차원에서의 EGCG의 역할 외에 혈관질환과 같은 smooth muscle에 관련된 예방과 치료차원에서 EGCG의 역할이 있을 것으로 사료된다. 본 연구는 C2C12 myoblast를 smooth muscle로 유도하는 결정적인 신호전달 역할을 하는 유전자에 대한 연구는 수행하지 못하였다. 따라서 EGCG에 의해 변화되는 유전자에 대한 기전연구가 필요하다고 하겠다.

• 대한한방내과학회지
• /
• 제28권2호
• /
• pp.333-345
• /
• 2007

Determination and differentiation of cells in the skeletal muscle lineage is positively regulated by cell-cell contact. differentiation proteins proposed to mediate this effect include both classical MyoD and MEF members : potential interactions between the promyogenic activities of these classes of protein, however, are unknown. We show here that MyoD and MEF, two promyogenic family members that determine to each other in a cis fashion, form ineraction with MyoD- and MEF. These proteins contain myosin heavy chains and are enriched at sites of cell-cell contact between myoblasts, Therefore, In differentiation of MyoD MEF from CST (Chungsimyeonjatang) interact dependently, suggesting that the interactions occur in a cis fashio : consistent with this conclusion, MyoD-mediated differentiation is required for myoblast to occur by CST. Inhibition in myoblasts of a MyoD by STP in its ability to associate with MEF interferes with differentiation as assessed by morphological and transcription level, suggesting that this interaction is functionally important in myogenesis. Also, some of the differentiation-mediated proteins that are required for myogenesis seem to be based on interdependent activities of promyogenic classical SMAD-subfamilly.

• Animal cells and systems
• /
• 제14권3호
• /
• pp.147-154
• /
• 2010

It is well-established that phosphoinositide 3-kinase (PI3-kinase) regulates myogenesis by inducing transcription of myogenin, a key muscle regulatory factor, at the initiation of myoblast differentiation. In this study, we investigated the role of PI3-kinase in cells that have committed to differentiation. PI3-kinase activity increases during myogenesis, and this increase is sustained during the myogenic process; however, its function after the induction of differentiation has not been investigated. We show that LY294002, a PI3-kinase inhibitor, blocked myoblast fusion even after myogenin expression initially increased. In contrast to the inhibitory effects of LY294002 on myogenin mRNA levels during the initiation of differentiation, LY294002 blocked the accumulation of myogenin protein without affecting its mRNA level after differentiation was induced. Treatment with cycloheximide, a translation inhibitor, or actinomycin D, a transcription inhibitor, indicated that the stability of myogenin protein is lower than that of its mRNA. LY294002 inhibited the activities of several important translation factors, including eukaryotic elongation factor-2(eEF2), by altering their phosphorylation status. In addition, LY294002 blocked the incorporation of [$^{35}S$]methionine into newly synthesized proteins. Since myogenin has a relatively short half-life, LY294002-mediated inhibition of post-transcriptional processes resulted in a rapid depletion of myogenin protein. In summary, these results suggest that PI3-kinase plays an important role in regulating the expression of myogenin through post-transcriptional mechanisms after differentiation has been induced.

• Asian-Australasian Journal of Animal Sciences
• /
• 제20권7호
• /
• pp.1115-1119
• /
• 2007

This study was conducted to determine the difference between satellite cells (porcine) and myoblasts (C2C12) in their differentiation under the influence of 2, 4-thiazolidindion. C2C12 myoblast cells and porcine satellite cells (isolated from 10 d old $Landrace{\times}Duroc$ piglets) were grown to absolute confluency. Post confluent cells (day 0) were further exposed to adipogenic induction medium along with 2, 4-thiazolidindion ($8{\mu}M$) for 2 d. Thereafter, cells were exposed to 2, 4-thiazolidindion alone every 2 d till day 10 and analysed. The control was cultured in differentiation medium without any treatment. Increased (p<0.05) expression of transcriptional factors i.e. C/EBP-${\alpha}$ and PPAR-${\gamma}$ and transition of cells to adipocyte morphology was noticed from 2 d and 4 d onwards in satellite cells (Porcine) and myoblasts (C2C12) respectively. Myogenesis was observed to be suppressed completely in case of satellite cells compared to myoblasts in response to 2, 4-thiazolidindion. Pax-7 (transcriptional factor) appeared as a sole entity to satellite cells only, as it was not identified in case of myoblasts. Although both the cells were converting to adipoblasts, the degree of their conversion was different in response to 2, 4-thiazolidindion. Therefore, the hypothesis that satellite cells contribute various domains to the growing myoblasts appeared obscured and found to be dependent on the proliferative energy/or degree of fusion. However, it revealed satellite cells as currency to myoblasts/muscle.