• Animal cells and systems
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• 제5권3호
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• pp.205-209
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• 2001

Mesenchymal cells from the leg buds of stage 24-chick embryos differentiated into chondrocytes when plated at high density. Treatment of high density micromass culture of chick mesenchymal cells with cytochalasin D(CD, 2 $\mu$M for 24 h) resulted in inhibition of chondrogenesis. CD treatment was found to affect the expression of the contractile protein $\alpha$-smooth muscle actin ($\alpha$-SM actin). In control cultures, $\alpha$-SM actin uniformly expressed from culture day 2, but the CD-treated cells induced expression of $\alpha$-SM actin from the first day of culture followed by a continuous increase. Expression of pan-cadherin (P-cadherin) decreased as chondrogenesis proceeded in the control culture, whereas the CD-treated cells showed sustained expression. These results propose a close connection of chondrogenic differentiation with expression of $\alpha$-SM actin and P-cadherin.

• 한국동물위생학회지
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• 제31권4호
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• pp.449-456
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• 2008

The differentiation of mouse embryonic stem(ES) cell into smooth muscle cells(SMC) may play a major role in cardiovascular development and under pathophysiological conditions. Therefore, in the present study, we have examined the differentiation of ES cells and its related gene expression. SMC differentiation was indicated by cellular morphology and time-dependent induction of dibutyryl adenosine 3,5-cyclic monophosphate(DBcAMP)and retinoic acid(RA) on smooth muscle ${\alpha}$-actin($SM{\alpha}A$), smooth muscle myosin heavy chain(SMMHC) gene expression. The control was undifferentiated ES cells(protein expressions represent 50-60kDaOct-4). The results of this study show that morphology of embryoid body and confirmation of $SM{\alpha}A$ expression by immunocytochemistry. Moreover, SMMHC and desmin expression was significantly increased by time dependent manner(5, 7, 15 days), in contrast to $SM{\alpha}A$ expression was slightly decreased on 15days. In conclusion, DBcAMP and RA stimulate mouse ES cells differentiation into SMC and enhanced $SM{\alpha}A$, SMMHC and desmin expression.

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

• BMB Reports
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• 제33권6호
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• pp.531-536
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• 2000

Tropomyosin (TM) is an important actin binding protein involved in regulation of muscle contraction. Unacetylated striated tropomyosin failed to bind to actin whereas unacetylated smooth tropomyosin bound well to actin. It has been demonstrated that high actin affinity of unacetylated ${\alpha}-tropomyosin$ was ascribed to the carboxyl terminal amino acid residues. In order to define the role of the carboxyl terminal residues of tropomyosin molecule on actin binding, two mutant tropomyosins were constructed. TM11 is identical to the striated tropomyosin except that the carboxyl terminal last three amino acids was replaced with $^{282}NNM^{284}$ whereas in TM14 $^{276}HA^{277}$ was substituted with smooth specific $^{276}QT^{277}$. TM11 and TM14 were overproduced in Escherichia coli and analyzed for actin affinity. The apparent binding constants (Kapp) of unacetylated tropomyosins were $2.2{\times}10^6M^{-1}$ for sm9, $1.03{\times}10^6M^{-1}$ for TM14, $0.19{\times}10^6M^{-1}$ for TM11, $>0.1{\times}10^6M^{-1}$ for striated, respectively. This result indicated that higher actin affinity of the unacetylated smooth tropomyosin was primarily attributed to the presence of QT residues in the smooth sequence. In case of the Ala-Ser (AS) dipeptide extension of the amino terminus of tropomyosin, Kapp were $21.1{\times}10^6M^{-1}$ for AS-sm9, $8.0{\times}10^6M^{-1}$ for AS-11, $4.7{\times}10^6M^{-1}$ for AS-14, $3.8{\times}10^6M^{-1}$ for AS-striated. AS-TM11 showed considerably higher actin affinity than AS-TM14, implying that interaction of Ala-Ser of the amino terminus with the carboxyl terminal residues. Since Kapp of AS-TM11 was significantly lower than that of AS-sm9, the presence of QT might be required for restoration of high actin affinity of the smooth ${\alpha}-tropomyosin$. These results suggested that the carboxyl terminal amino acid residues Glutamine275-Threonine276 are important for actin affinity of the recombinant smooth ${\alpha}-tropomyosin$, particularly of unacetylated smooth ${\alpha}-tropomyosin$.

• Journal of Korean Biological Nursing Science
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• 제8권2호
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• pp.41-59
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• 2006

Chronic liver diseases and hepatic cancer have been reported as 10% of cause of death in Koreans. Regardless of various causes, chronic liver disease accompanies commonly hepatic fibrosis. But still the mechanism of hepatic fibrosis remains poorly understood. Using the dimethylnitrosamine(DMN)-induced hepatic fibrosis rat model, We performed to evaluate the possible therapeutic effect of RIP(extracts of Phellodendron amurense and Patrinia scabiosaefolia) and to investigate the changes in referential connective tissue proteins($TGF-{\beta}_1$, ${\alpha}$-smooth muscle actin, and vimentin) as a marker of fibrogenesis. For these purposes, liver tissues were stained with H & E, and Azan staining for estimation of developing fibrosis. In the DMN-treated rat liver tissue, fibrosis were developed forming incomplete septal fibrosis. Whereas, in the RIP-treated rat liver tissues, the fibrosis were decreased recovering to normal morphology. The expressions of $TGF-{\beta}_1$, ${\alpha}$-smooth muscle actin($\alpha-SMA$), and vimetin were increased in the DMN-treated rat liver tissues, but decreased in the various areas of RIP-treated rat liver tissues. According to these results, RIP could be a possible therapeutic agent to reduce hepatic fibrosis, and the $TGF-{\beta}_1$, ${\alpha}$-SMA, and vimentin could be possible indicative markers of hepatic fibrosis development and recovery.

• 생명과학회지
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• 제17권2호통권82호
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• pp.204-210
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• 2007

평활근 ${\alpha}$-트로포마이오신의 높은 액틴 친화력은 아미노산 잔기 Gln276 및 Thr277에 기인한다는 이전 보고에 따라, 2 잔기 중 어느 잔기가 액틴 친화력에 더 중요한 가를 알아보기 위하여 골격근 트로포마이오신의 His 혹은 Ala 단일 잔기를 각각 Gln 혹은 Thr으로 치환한 돌연변이 트로포마이오신을 제작하여 대장균에서 대량발현 시킨 후 정제하여 액틴 결합력을 측정하였다. 비록 비아세틸화된 트로포마이오신의 경우 Gln 및 Thr 잔기가 최고 액틴친화력을 위해 모두 필요하나, 돌연변이 트로포마이신 중 Gln 잔기를 가진 돌연변이 트로포마이오신들이 다른 돌연변이 트로포마이오신들에 비하여 3에서 4배 높은 액틴친화력을 보였다. 이러한 결과는 평활근 ${\alpha}$-트로포마이오신의 높은 액틴 친화력은 Thr277 잔기보다 Gln276 잔기에 주로 기인한다는 것을 의미한다.

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

• Molecules and Cells
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• 제24권3호
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• pp.441-444
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• 2007

Despite the importance of cell fate decisions regulated by epigenetic programming, no experimental model has been available to study transdifferentiation from myoblasts to smooth muscle cells. In the present study, we show that myoblast cells can be induced to transdifferentiate into smooth muscle cells by modulating their epigenetic programming. The DNA methylation inhibitor, zubularine, induced the morphological transformation of C2C12 myoblasts into smooth muscle cells accompanied by de novo synthesis of smooth muscle markers such as smooth muscle ${\alpha}$-actin and transgelin. Furthermore, an increase of p21 and decrease of cyclinD1 mRNA were observed following zebularine treatment, pointing to inhibition of cell cycle progression. This system may provide a useful model for studying the early stages of smooth muscle cell differentiation.

• 생명과학회지
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• 제23권1호
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• pp.137-142
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• 2013

인체 중간엽 줄기세포는 지방세포, 골세포, 연골세포, 근육세포 등 여러 형태의 세포로의 분화되는 것이 특징이다. 특히, 최근 연구 결과를 살펴 보면, 중간엽 줄기세포는 생체 내에서 조직 특이적인 세포 형태로 분화 된다. 본 연구에서는 염증 상태에 존재하는 중간엽 줄기 세포가 혈관 형성에 관여하는지 알아보고, 염증 상태에 존재하는 줄기세포의 역할을 규명하고자 본 연구를 진행하였다. 생체 내 염증 상태와 유사한 환경을 만들고자, 강력한 염증 유발 물질인 LPS를 대식세포에 처리하여 그 배양액을 중간엽 줄기세포에 처리하여 변화를 관찰하였다. LPS 배양액을 처리한 중간엽 줄기세포는 평활근 세포로 분화가 촉진되는 것을 확인하였으며, LPS 배양액에 존재하는 분화 유도 물질이 $PGF2{\alpha}$임을 확인하였다. 이에 본 연구결과를 통해 염증 상태에서 존재하는 중간엽 줄기세포는 평활근 세포로의 분화가 촉진되는 것을 확인하였다. 본 연구는 염증성 미세환경 내에 존재하는 중간엽 줄기세포가 평활근 세포로 분화가 유도됨을 확인하였고, 혈관 형성을 촉진하는데 영향을 미칠 수 있음을 제시한다.

• 한국동물위생학회지
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• 제35권2호
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• pp.153-157
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• 2012

A 7-year-old, castrated male dachshund dog with tumor of the spleen portion was referred to the Kangwon National University. The tumor removed surgically and tumor size was 6~7 cm. Histopathologically, this neoplasm was the presence of perivascular whorls of fusiform cells. The cells also arranged in interlacing bundles or storiform patterns. And this neoplasm consisted of spindle cells that often formed distinct whorls around a central capillary. Immunohistochemical analysis revealed multi-focally immunoreactivity for ${\alpha}$-smooth muscle actin, whereas not immunoreactive for desmin, S-100, von Willebrand factor. On the base of the histological and immunohistochemical results, this neoplasm was diagnosed as a canine hemangiopericytoma.