• 대한의생명과학회지
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• 제19권3호
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• pp.266-269
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• 2013

Hox genes encode transcription factors important for anterior-posterior body patterning at early stages of embryonic development. However, the precise mechanisms by which signal pathways are stimulated to regulate Hox gene expression are not clear. In the previous study, protein kinase B alpha (Akt1) has been identified as a putative upstream regulator of Hox genes, and Akt1 has shown to regulate Gcn5, a prototypical histone acetyltransferase (HAT), in a negative way in mouse embryonic fibroblast (MEF) cells. Since the activity of HAT such as the CBP/p300, and PCAF (a Gcn5 homolog), was down-regulated by Akt through a phosphorylation at the Akt consensus substrate motif (RXRXXS/T), the amino acid sequence of Gcn5 protein was analyzed. Mouse Gcn5 contains an Akt consensus substrate motif as RQRSQS sequence while human Gcn5 does not have it. In order to see whether Akt1 directly binds to Gcn5, immunoprecipitation with anti-Akt1 antibody was carried out in wild-type (WT) mouse embryonic fibroblast (MEF) cells, and then western blot analysis was performed with anti-Akt1 and anti-Gcn5 antibodies. Gcn5 protein was detected in the Akt1 immunoprecipitated samples of MEFs. This result demonstrates that Akt1 directly binds to Gcn5, which might have contributed the down regulation of the 5' Hoxc gene expressions in wild type MEF cells.

• Clinical and Experimental Reproductive Medicine
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• 제33권4호
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• pp.265-272
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• 2006

목 적: 본 연구는 생쥐 포배기 배아로부터 내세포괴를 분리하는 방법과 지지세포의 종류와 mitomycin C 처리 시간이 내세포괴 colony 형성률에 미치는 영향을 관찰하기 위해 시행되었다. 연구방법: 일반적인 면역절제술, 주사바늘을 이용한 부분 영양막세포 절개법, 포배기 배아 공배양법으로 내세포괴를 분리한 후, 상업적으로 구입이 가능한 STO 또는 직접 제조한 생쥐 배아섬유아세포 (pMEF)를 지지세포로 이용하여 배양하였다. 또한, mitomycin C를 1, 2, 3시간 동안 처리한 각각의 지지세포에서 7일 동안 배양한 후, 내세포괴 colony 형성률을 살펴보았다. 결 과: STO 지지세포에서는 부분 영양막세포 절개법을 사용한 경우 (52%)가 면역절제술 (12%)이나 포배기 배아 공배양법 (16%)을 사용한 경우보다 내세포괴 colony 형성률이 유의하게 높았다 (p<0.05). pMEF 지지세포에서의 형성률은 부분 영양막세포 절개법을 사용한 경우 (88%)와 포배기 배아 공배양법 (82%)을 사용한 경우가 면역절제술 (16%)을 사용한 경우보다 높았다 (p<0.05). STO와 pMEF 모두에서, 2시간 mitomycin C 처리군 (52%, 88%)이 1시간 처리군 (9%, 42%)과 3시간 처리군 (18%, 76%)보다 높은 내세포괴 colony 형성률을 보여주었다 (p<0.05). 결 론: 이상의 결과는 부분 영양막세포 절개법이 생쥐 포배기 배아로부터 내세포괴를 분리하는 가장 효과적인 방법이며, 가장 적절한 mitomycin C 처리 시간은 2시간이라는 것을 보여준다. 그러나 이와 같은 부분 영양막세포 절개법의 효용성을 보다 명확하게 확인하기 위해서는 분리한 내세포괴를 계대배양하여 줄기세포주로서의 특성을 확인하는 실험이 추가적으로 필요할 것으로 생각된다.

• 한국가금학회지
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• 제27권1호
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• pp.73-78
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• 2000

Embryonic stem (ES) cells are pluripotent cell lines, which derived from preimplantation embryo. These cells have been used as a vehicle of foreign DNA for production of transgenic mammals. this experiment was performed to examined the possible use of blastodermal cells derived from hen's egg for germline manipulation. Stage X blsdtodermal cells isolated from fertilized eggs were cultured in DMEM containing 15% fetal calf serum. Blastodermal cells wre co-cultured on the chicken embryonic fibroblast (CEF) or mouse embryonic fibroblast(MEF) cells. to examine the effects of growth factors on stem cell growth, bFGF and LIF were added. There was no significant difference in colony formation of putative ES cells between CEF and MEF as a feederlayer, but the addition of growth factors enhanced the proliferation and inhibited differentiation of blastodermal cells. To characterize the cell colonies as a putative ES cells, putative embryonic cell colonies were stained by periodic acid Schiffs (PAS) reagent. The putative ES cell colonies showed intensive positive reaction similar to the property of undifferentiated PGC upto 20days in vitro, but not in other cell types. this result demonstrates that PAS-positive cell colonies may be used for the study of establishment of chicken ES cell lines for the production of transgenic chicken.

• 한국동물학회지
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• 제28권2호
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• pp.108-119
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• 1985

Stress protein (SP) 遺傳子發現의 調節機構를 밝히기 위한 한가지 방편으로 환경의 stress와 pH가 SP의 合成誘導에 어떤 作用을 하는지를 SDS-PAGE를 이용해서 分析하였다. 蛋白質合成의 전반적 양상은 MEF와 SCK 세포에서 달랐으나 SP의 양상은 동일하였다. 그중에서 $SP_70$의 誘導와 感衰의 kinetics는 특히 흥미로웠다. $SP_70$의 kinetics는 酸性 pH와 正常 pH에서 類似하였으나 最大量의 SP 合成에 필요한 溫度와 그 處理時間은 pH에 의해 달리 나타나서, 酸性 pH 에서는 자은 溫度와 짧은 處理時間에서 나타나고 더욱 오래 지속되는 경향을 보였다. SP의 合成誘導와 SP mRNA의 축적은 actinomycin D에 의해 阻止되는 사실로 미루어 SP의 合成이 誘導되기 위해서는 새로운 mRNA의 合成이 필요함을 알수 있었고, cycloheximide 처리의 결과는 SP의 合成誘導에 앞서서 어떤 特異한 蛋白質의 合成은 일어나지는 않음을 알수 있었다. 이상과 같은 몇가지 實驗結果는 MEF와 SCK 세포에서 SP의 合成誘導는 일차적으로 轉寫水潗에서 調節되며, $SP_70$의 合成은 自動調節됨과 아울러 SP의 水潗은 세포늬 stress 상태와 相關關係가 있는 것으로 推論할수 있음을 보여주었다.

• 한국발생생물학회지:발생과생식
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• 제21권3호
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• pp.335-342
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• 2017

While adipose-derived stem cell-conditioned medium (ADSC-CM) has been demonstrated to promote skin wound healing, the mechanism regulating this effect remains unelucidated. In this study, we aimed to investigate the role of Ell3 in the wound healing activity of ADSC-CM. In vitro analysis revealed that Ell3 suppression in ADSCs impairs the promotive activity of ADSC-CM on the proliferation and migration of mouse embryonic fibroblasts (MEF) and normal human dermal fibroblasts (NHDF). Consistently, the expression of MMP family genes, which regulate cell proliferation and migration, was significantly suppressed in MEF and NHDF treated with siEll3-transfected ADSC-CM. Proinflammatory cytokines, such as interleukin-1 and interleukin-6, were highly expressed in MEF treated with siEll3-transfected ADSC-CM. The wound healing activity of siEll3-transfected ADSC-CM was significantly lower than that of the control in vivo. Our results suggest that Ell3 may contribute to the inhibition of inflammatory response during skin wound healing.

• 대한미생물학회지
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• 제17권1호
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• pp.7-14
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• 1982

A model of induction of neoplasia by viruses has develpoed from experimental studies in animals and in cultured cells and oncogenic transformation of cells is the result of integration of viral genetic information into the cellular DNA. The evidence for these associations was derived primarily from seroepidemiologic investigation. However, data indicating that the relation between HSV-2 and cervical cancer fits the model derived from experimental animal studies are not yet sufficient to draw conclusion with regard to the etiologic role the virus in the development of the neoplasms. In other hand, the K562 tumor cell is highly susceptible target for natural killer cell lysis by the lymphocytes of human and murine periperal blood. The characteristics of this effector cell type has been investigated. A study on natural killer cell mediated cytotoxicity(NKMC) against $^{51}Cr$-K562 as target cell was studed in HSV-2 infected ICR mouse. We have studied for susceptibility of HSV-2 against mouse embryo fibroblast(MEF) cells and NKMC from HSV-2 infected mouse. The results obtained that the mouse embryo fibroblast cells culture, the number and size of the cells were markedly increased and formed a monolayers relatively rapid, and become complete monolayer sheet around 72 hrs. Duration of cytopathic effect on MEF cells was rapid by serial passing of HSV-2. The morphology of the HSV-2 infected cells appear to be mainly round, ovium, spindle form and some of them was forming large giant cells. The NKMC was decrease in mouse with HSV-2 and comparison between effector/target cells ratio as 25:1 and 50:1 respectively, the NKMC was found to be more significantly decreased than normal control we have concluded that the natural killer cell activity of the viral infected mouse was shown as a suppressed during the HSV-2 infection, day 7th and 14th.

• Reproductive and Developmental Biology
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• 제36권4호
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• pp.291-294
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• 2012

Embryonic stem cell classically cultured on feeder layer with FBS contained ES medium. Feeder-free mouse ES cell culture systems are essential to avoid the possible contamination of nonES cells. First we determined the difference between ES cell and MEF by Oct4 population. We demonstrate to culture and to induce differentiation on feeder free condition using a commercially available mouse ES cell lines.

• Restorative Dentistry and Endodontics
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• 제32권5호
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• pp.459-468
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• 2007

이 연구에서는 법랑모세포 분화과정에서 APin의 기능을 알아보고자 APin-protein microarray를 시행한 후 치아발생과 관련이 있는 MEF2, Aurora kinase A, BMPR-IB와 EF-hand calcium binding protein을 분석하여 다음과 같은 결과를 얻었다. 1 CMV-APin construct를 transfection하여 APin의 과발현을 유도한 경우에는 MEF2와 Aurora kinase A 둘 모두에서 발현이 현저히 감소한 반면에, APin의 발현억제를 유도한 경우에는 둘 모두 변화가 없었다. 2. APin의 과발현을 유도한 경우에는 BMPR-IB와 EF-hand calcium binding protein 모두에서 발현이 크게 증가한 반면, APin을 발현억제 시킨 경우에는 BMPR-IB는 변화가 없었고, EF-hand calcium binding protein은 현저히 감소하였다. 위의 결과들로 보아 APin 단백질은 MEF2, Aurora kinase A, BMPR-IB, EF-hand calcium binding protein과 상호작용하여 법랑모세포의 분화와 석회화 과정 중에 중요한 역할을 하는 것으로 사료된다.

• Journal of Microbiology and Biotechnology
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• 제32권10호
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• pp.1245-1252
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• 2022

Induced pluripotent stem cells (iPSCs) can be generated from somatic cells using Oct4, Sox2, Klf4, and c-Myc (OSKM). Small molecules can enhance reprogramming. Licochalcone D (LCD), a flavonoid compound present mainly in the roots of Glycyrrhiza inflata, acts on known signaling pathways involved in transcriptional activity and signal transduction, including the PGC1-α and MAPK families. In this study, we demonstrated that LCD improved reprogramming efficiency. LCD-treated iPSCs (LCD-iPSCs) expressed pluripotency-related genes Oct4, Sox2, Nanog, and Prdm14. Moreover, LCD-iPSCs differentiated into all three germ layers in vitro and formed chimeras. The mesenchymal-to-epithelial transition (MET) is critical for somatic cell reprogramming. We found that the expression levels of mesenchymal genes (Snail2 and Twist) decreased and those of epithelial genes (DSP, Cldn3, Crb3, and Ocln) dramatically increased in OR-MEF (OG2^+/+/ROSA26^+/+) cells treated with LCD for 3 days, indicating that MET effectively occurred in LCD-treated OR-MEF cells. Thus, LCD enhanced the generation of iPSCs from somatic cells by promoting MET at the early stages of reprogramming.

• 약학회지
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• 제52권1호
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• pp.67-72
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• 2008

The use of doxorubicin, which is one of the most effective anticancer agents, is often limited by occurrence of acquired resistance in tumor cells. GSH has been shown to be involved in the development of this drug resistance. Transcription factor Nrf2 governs the expression of GSH synthesizing glutamylcysteine ligase (GCL), as well as multiple phase 2 detoxifying enzymes. Here we show that Nrf2 is one of factors determining doxorubicin sensitivity. Nrf2-deficient fibroblasts (murine embryonic fibroblasts, MEF) were more susceptible to doxorubicin mediated cell death than wild-type cells. Doxorubicin treatment elevated levels of Nrf2-regulated genes including NAD(P)H: quinone oxidoreductase (Nqo1) and GCL in wild-type fibroblasts, while no induction was observed in Nrf2-deficient cells. Doxorubicin resistance in human ovarian SK-OV cells was reversed by treatment with L-buthionine-sulfoxamine (BSO), which is depleting intracellular GSH. Finally, transfection of SK-OV cells with Nrf2 siRNA resulted in exacerbated cytotoxicity following doxorubicin treatment compared to scrambled RNA control. These results indicate that the Nrf2 pathway, which plays a protective role in normal cells, can be a potential target to control cancer cell resistance to anticancer agents.