• 응용통계연구
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• 제31권3호
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• pp.417-426
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• 2018

최근 동물실험의 대체방법 중 하나로 쥐의 줄기세포 유래 배상체를 이용하여 독성을 시험하는 방법이 개발되었다. 이는 동물에 직접 약물을 주입하는 것이 아닌 배상체 세포에 약물을 투입하여 세포의 변화에 따른 측정값들을 얻는 방법이다. 본 연구에서는 다범주 세포독성 자료를 이용해 통계적 기법인 판별분석(discriminant analysis)과 머신러닝 기법인 서포트 벡터 머신(support vector machine), 인공신경망(artificial neural network), k-인접이웃분류(k-nearest neighbor)의 성능을 비교하였다. 알고리즘의 성능은 분류 정확도(accuracy)와 가중카파계수(weighted Cohen's kappa coefficient)로 비교하였다.

• Journal of Ginseng Research
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• 제41권4호
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• pp.608-614
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• 2017

Background: Ginsenoside Rg1 belongs to protopanaxatriol-type ginsenosides and has diverse pharmacological activities. In this report, we investigated whether Rg1 could upregulate muscular stem cell differentiation and muscle growth. Methods: C2C12 myoblasts, MyoD-transfected 10T1/2 embryonic fibroblasts, and HEK293T cells were treated with Rg1 and differentiated for 2 d, subjected to immunoblotting, immunocytochemistry, or immunoprecipitation. Results: Rg1 activated promyogenic kinases, p38MAPK (mitogen-activated protein kinase) and Akt signaling, that in turn promote the heterodimerization with MyoD and E proteins, resulting in enhancing myogenic differentiation. Through the activation of Akt/mammalian target of rapamycin pathway, Rg1 induced myotube growth and prevented dexamethasone-induced myotube atrophy. Furthermore, Rg1 increased MyoD-dependent myogenic conversion of fibroblast. Conclusion: Rg1 upregulates promyogenic kinases, especially Akt, resulting in improvement of myoblast differentiation and myotube growth.

• 한국수정란이식학회지
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• 제33권4호
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• pp.343-348
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• 2018

Although the efforts to establish fish embryonic stem cells (ESCs) have been made for a long time, derivation of authentic ESCs that possess pluripotency is still difficult suggesting a need for the stepwise optimization of the methods to establish fish ESCs. Primary culture of the blastomeres from the embryos at blastula stage is a critical step for establishing continuous ESC lines. Here, we evaluated the effects of temperatures and basal media on primary culture of blastula embryo-derived blastomeres in marine medaka (Oryzias dancena). The blastomeres were isolated from the blastula embryos and cultured in various conditions designed by the combination of 4 temperatures including $28^{\circ}C$, $31^{\circ}C$, $34^{\circ}C$, and $37^{\circ}C$ and 2 basal media including Dulbecco's modified eagle's medium (DMEM) and Leibovitz's L-15 medium (L15). With the exception of a case cultured in L15 at $31^{\circ}C$, the rate of primary cell adherence reached 100% when the blastomeres were cultured over $31^{\circ}C$. The period for primary adherence was significantly shorter in the groups cultured in $34^{\circ}C$ and $37^{\circ}C$ than in the ones in $28^{\circ}C$ and $31^{\circ}C$. The proportion of subculture was significantly high in the group cultured in DMEM at $31^{\circ}C$ compared to the other groups. Collectively, we demonstrated that the culture in DMEM at $31^{\circ}C$ was effective to primary culture of the blastomeres derived from blastula embryos.

• Laboraroty Animal Research
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• 제34권4호
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• pp.279-287
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• 2018

Placenta specific 8 (PLAC8, also known as ONZIN) is a multi-functional protein that is highly expressed in the intestine, lung, spleen, and innate immune cells, and is involved in various diseases, including cancers, obesity, and innate immune deficiency. Here, we generated a Plac8 knockout mouse using the CRISPR/Cas9 system. The Cas9 mRNA and two single guide RNAs targeting a region near the translation start codon at Plac8 exon 2 were microinjected into mouse zygotes. This successfully eliminated the conventional translation start site, as confirmed by Sanger sequencing and PCR genotyping analysis. Unlike the previous Plac8 deficient models displaying increased adipose tissue and body weights, our male Plac8 knockout mice showed rather lower body weight than sex-matched littermate controls, though the only difference between these two mouse models is genetic context. Differently from the previously constructed embryonic stem cell-derived Plac8 knockout mouse that contains a neomycin resistance cassette, this knockout mouse model is free from a negative selection marker or other external insertions, which will be useful in future studies aimed at elucidating the multi-functional and physiological roles of PLAC8 in various diseases, without interference from exogenous foreign DNA.

• Laboraroty Animal Research
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• 제34권4호
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• pp.257-263
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• 2018

Trefoil factor 1 (TFF1, also known as pS2) is strongly expressed in the gastrointestinal mucosa and plays a critical role in the differentiation of gastric glands. Since approximately 50% of all human gastric cancers are associated with decreased TFF1 expression, it is considered a tumor suppressor gene. Tff1 deficiency in mice results in histological changes in the antral and pyloric gastric mucosa, with severe hyperplasia and dysplasia of epithelial cells, resulting in the development of antropyloric adenoma. Here, we generated Tff1-knockout (KO) mice, without a neomycin resistant ($Neo^R$) cassette, using the clustered regularly interspaced short palindromic repeats/CRISPR-associated nuclease 9 (CRSIPR/Cas9) system. Though our Tff1-KO mice showed phenotypes very similar to the previous embryonic stem (ES)-cell-based KO mice, they differed from the previous reports in that a reduction in body weight was observed in males. These results demonstrate that these newly established Tff1-KO mice are useful tools for investigating genetic and environmental factors influencing gastric cancer, without the effects of artificial gene insertion. Furthermore, these findings suggest a novel hypothesis that Tff1 expression influences gender differences.

• Reproductive and Developmental Biology
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• 제29권1호
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• pp.19-24
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• 2005

저밀도 리포단백질 수용체 관련 단백질 5(LRP5)는 간과 췌장을 포함하여 많은 조직에서 발현하며 아포리포단백질 E와 결합한다. 이와 같은 LRP5 유전자의 체내 기능을 규명하기 위하여 LRP5 유전자가 결손된 생쥐를 개발하였다. 먼지 LRP5 genomic DNA는 TT2 ES 세포로부터 분리하였으며 LRP5 유전자의 엑손 18에 neo 유전자를 삽입한 vector를 구축하고 TT2 ES 세포에 도입하였다. 178개의 G418 내성을 보인 세포 중 상동유전자 재조합에 의하여 targeting vector가 LRP5 유전자 위치에 삽입된 clone은 3개였다. 키메라 생쥐는 상실배기 수정을 ES 세포와 응집시켜 생산하였으며 생산된 키메라 생쥐는 C57BL/6 생쥐와 교미를 유도하여 heterozygous를 얻었다. 또한 이들 heterozygous간의 교배에 의하여 LRP5 유전자 결손 생쥐를 생산하였다. 이러한 생쥐는 LRP5 유전자의 체내 기능연구에 있어서 모델로 이용될 것으로 생각된다.

• 한국수정란이식학회지
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• 제32권4호
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• pp.257-265
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• 2017

Ferulic Acid (FA) is a metabolite of phenylalanine and tyrosine, a phenolic compound commonly found in fruits and vegetables. Several studies have shown that FA has various functions such as antioxidant effect, prevention of cell damage from irradiation, protection from cell damage caused by oxygen deficiency, anti-inflammatory action, anti-aging action, liver protective effect and anti-cancer action. In this study, we investigated the maturation rate, intracellular glutathione (GSH) and reactive oxygen species (ROS) of porcine oocytes by adding FA to the in vitro maturation (IVM) medium and examined subsequent embryonic developmental competence at 5% oxygen through parthenogenesis. There is no significant difference between the control group ($0{\mu}M$) and treatment groups ($5{\mu}M$, $10{\mu}M$, $20{\mu}M$) on maturation rates. Intracellular GSH levels in oocyte treated with $5{\mu}M$ of FA significantly increased (P < 0.05), and $20{\mu}M$ of FA revealed significant decrease (P < 0.05) in intracellular ROS levels compared with the control group. Oocytes treated with FA exhibited significantly higher cleavage rates (79.01% vs 89.19%, 92.20%, 90.89%, respectively) than the control group. Oocytes treated with $10{\mu}M$ showed significantly higher blastocyst formation rates (28.3% vs 40.3%, respectively) after PA than the control group. Total cell numbers in blastocyst of $10{\mu}M$ FA displayed significantly higher (39.4 vs 51.9, respectively) than the control group. In conclusion, these results suggested that treatment with FA during IVM improved the developmental potential of porcine embryos by increasing intracellular GSH synthesis and reducing ROS levels. Also, there was an improvement of cleavage rate, blastocyst formation and total cell numbers in blastocysts. It might be associated with Keap1-Nrf2 pathway as an antioxidant regulate pathway that plays a crucial role in determining the sensitivity of cells to oxidative damages by regulating the basal and inducible expression of enzymes which is related to detoxification and anti-oxidative effects, stress response enzymes and/or proteins and ABC transporters.

• Asian Pacific Journal of Cancer Prevention
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• 제16권16호
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• pp.6813-6823
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• 2015

Glioblastoma, also known as glioblastoma multiforme (GBM), is the most aggressive of human brain tumors and has a stunning progression with a mean survival of one year from the date of diagnosis. High cell proliferation, angiogenesis and/or necrosis are histopathological features of this cancer, which has no efficient curative therapy. This aggressiveness is associated with particular heterogeneity of the tumor featuring multiple genetic and epigenetic alterations, but also with implications of aberrant signaling driven by growth factors. The transforming growth factor ${\beta}$ ($TGF{\beta}$) superfamily is a large group of structurally related proteins including $TGF{\beta}$ subfamily members Nodal, Activin, Lefty, bone morphogenetic proteins (BMPs) and growth and differentiation factor (GDF). It is involved in important biological functions including morphogenesis, embryonic development, adult stem cell differentiation, immune regulation, wound healing and inflammation. This superfamily is also considered to impact on cancer biology including that of GBM, with various effects depending on the member. The $TGF{\beta}$ subfamily, in particular, is overexpressed in some GBM types which exhibit aggressive phenotypes. This subfamily impairs anti-cancer immune responses in several ways, including immune cells inhibition and major histocompatibility (MHC) class I and II abolishment. It promotes GBM angiogenesis by inducing angiogenic factors such as vascular endothelial growth factor (VEGF), plasminogen activator inhibitor (PAI-I) and insulinlike growth factor-binding protein 7 (IGFBP7), contributes to GBM progression by inducing metalloproteinases (MMPs), "pro-neoplastic" integrins (${\alpha}v{\beta}3$, ${\alpha}5{\beta}1$) and GBM initiating cells (GICs) as well as inducing a GBM mesenchymal phenotype. Equally, Nodal promotes GICs, induces cancer metabolic switch and supports GBM cell proliferation, but is negatively regulated by Lefty. Activin promotes GBM cell proliferation while GDF yields immune-escape function. On the other hand, BMPs target GICS and induce differentiation and sensitivity to chemotherapy. This multifaceted involvement of this superfamily in GBM necessitates different strategies in anti-cancer therapy. While suppressing the $TGF{\beta}$ subfamily yields advantageous results, enhancing BMPs production is also beneficial.

• 한국발생생물학회지:발생과생식
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• 제14권2호
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• pp.123-129
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• 2010

배아 줄기세포는 미분화상태에서 자가 재생을 유지할 수 있다. 자가 재생은 OCT4, SOX2와 NANOG와 같은 많은 인자들이 작용한다. 생쥐 배아 줄기세포에서 OCT4와 SOX2가 Nanog 프로모터에 결합하여 Nanog 유전자의 발현을 촉진한다는 사실은 생쥐 promoter에 관한 정밀분석으로 알려져 있다. 본 연구에서는 인간 Nanog promoter를 정밀 분석하기 위해 연속적인 결손 돌연변이를 가진 promoter-reporter construct를 제조하였다. Promoter의 최대 활성은 0.6 kb(-253/+365) promoter-reporter construct에서 발견되었으며, 이 construct에는 OCT4 및 SOX2의 결합부위가 포함된다. OCT4와 SOX2의 기여도를 확인하기 위하여 OCT4 및 SOX2의 결합부위에 자리 특이적 돌연변이를 유도하고 promoter 활성에 미치는 영향을 조사한 결과, OCT4나 SOX2 어느 한 군데라도 돌연변이가 존재하면 promoter 활성이 현저히 저해되었다. 본 연구 결과를 통해 인간 Nanog 유전자 발현에 있어 OCT4 및 SOX2가 필수적임을 직접적으로 확인할 수 있었다.

• 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.