• 한국재료학회:학술대회논문집
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• 한국재료학회 2011년도 추계학술발표대회
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• pp.2.1-2.1
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• 2011

Biomedical applications of electrospun nanofibrous meshes have been receive tremendous attentions because of their unique structures and versatilities as novel biomaterials. Incorporation of growth factors in fibrous meshes can be performed by surface-modification and encapsulation. Those growth factors stimulate differentiation and proliferation of specific types of cells and thus lead tissue regenerations of specific cell types. Topographical cues of electrospun nanofibrous meshes also increase differentiation of specific cell types according to alignments of fibrous structures. Wound healing treatments of diabetic ulcers were performed using nanofibrous meshes encapsulating multiple growth factors. Aligned nanofibrous meshes and those with random configuration were compared for differentiating mesenchymal stem cells into neuronal cells. Thus, nanofibrous meshes can be applied to novel drug delivery carriers and matrix for promoting cellular proliferation.

• BMB Reports
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• 제56권9호
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• pp.496-501
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• 2023

Elongation of most bones occur at the growth plate through endochondral ossification in postnatal mammals. The maturation of chondrocyte is a crucial factor in longitudinal bone growth, which is regulated by a complex network of paracrine and endocrine signaling pathways. Here, we show that a phytochemical sulfuretin can stimulate hypertrophic chondrocyte differentiation in vitro and in vivo. We found that sulfuretin stabilized nuclear factor (erythroid-derived 2)-like 2 (Nrf2), stimulated its transcriptional activity, and induced expression of its target genes. Sulfuretin treatment resulted in an increase in body length of zebrafish larvae and induced the expression of chondrocyte markers. Consistently, a clinically available Nrf2 activator, dimethyl fumarate (DMF), induced the expression of hypertrophic chondrocyte markers and increased the body length of zebrafish. Importantly, we found that chondrocyte gene expression in cell culture and skeletal growth in zebrafish stimulated by sulfuretin were significantly abrogated by Nrf2 depletion, suggesting that such stimulatory effects of sulfuretin were dependent on Nrf2, at least in part. Taken together, these data show that sulfuretin has a potential use as supporting ingredients for enhancing bone growth.

• Animal cells and systems
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• 제7권2호
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• pp.127-132
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• 2003

Effects of genotype, settlement density and irradiane on the growth, mortality and population structure of Fucus serratus germlings were examined in the laboratory. The growth of F. serratus germlings was influenced by genotype of parent plants, which is likely to occur by microclimatic differentiation of substrata. The growth of germlings were greater at lower densities than higher densities indicating that intraspecific competition between germlings occurred within three weeks. Also, the growth of F. serratus germlings was better at $120\mumol\;m^-2/s^-1$ than at $60\mumol\;m^-2/s^-1$. However, mortality of germlings was determined by settlement density rather than irradiance. In population structure, skewness was increased at low irradiance and high density indicating that population structure could be changed by intraspecific competition. Thus, it is concluded that genotypic differentiation of F. serratus germlings occurred in a microgeographic scale, and the experimental density and irradiance level affected the growth of germlings.

• Nutrition Research and Practice
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• 제15권4호
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• pp.444-455
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• 2021

BACKGROUND/OBJECTIVES: Adipocytes undergo angiogenesis to receive nutrients and oxygen needed for adipocyte' growth and differentiation. No study relating quercetin with angiogenesis in adipocytes exists. Therefore, this study investigated the role of quercetin on adipogenesis in 3T3-L1 cells, acting through matrix metalloproteinases (MMPs). MATERIALS/METHODS: After proliferating preadipocytes into adipocytes, various quercetin concentrations were added to adipocytes, and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays were performed to evaluate cell proliferation. Glycerol-3-phosphate dehydrogenase (GPDH) activity was investigated as an indicator of fat accumulation. The mRNA expressions of transcription factors related to adipocyte differentiation, CCAAT/enhancer-binding proteins (C/EBPs), peroxisomal proliferatoractivated receptors (PPAR)-γ, and adipocyte protein 2 (aP2), were investigated. The mRNA expressions of proteins related to angiogenesis, vascular endothelial growth factor (VEGF)-α, vascular endothelial growth factor receptor (VEGFR)-2, MMP-2, and MMP-9, were investigated. Enzyme activities and concentrations of MMP-2 and MMP-9 were also measured. RESULTS: Quercetin treatment suppressed fat accumulation and the expressions of adipocyte differentiation-related genes (C/EBPα, C/EBPβ, PPAR-γ, and aP2) in a concentration-dependent manner in 3T3-L1 cells. Quercetin treatments reduced the mRNA expressions of VEGF-α, VEGFR-2, MMP-2, and MMP-9 in 3T3-L1 cells. The activities and concentrations of MMP-2 and MMP-9 were also decreased significantly as the concentration of quercetin increased. CONCLUSIONS: The results confirm that quercetin inhibits adipose tissue differentiation and fat accumulation in 3T3-L1 cells, which could occur through inhibition of the angiogenesis process related to MMPs.

• 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.

• 농업과학연구
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• 제45권4호
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• pp.715-723
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• 2018

The present study was done to investigate the effect of co-culturing muscle satellite cells (MSCs) and intramuscular preadipocytes (IPs) on the differentiation of adipocytes and muscle cells isolated from Korean native cattle. MSCs and IPs were single-cultured in 10% fetal bovine serum/Dulbecco's modified Eagles medium (FBS/DMEM) for 48 h followed by culturing in 5% FBS/DMEM as the growth media. Then, the growth media was replaced by differentiation media composed of 2% FBS/DMEM without any additives for the single- or co-culture of muscle cells and intramuscular adipocytes to induce the differentiation of both cell types. Cell differentiation was measured by morphological investigation and cytosolic enzyme analysis of glycerol-3-phosphate dehydrogenase (GPDH) for the adipocytes and creatine kinase (CK) for the muscle cells. In the morphological test, the presence of muscle cells did not stimulate adipocyte differentiation showing more differentiation of the adipocytes in the single-culture compared to the co-culture condition. However, the differentiation of muscle cells was promoted by adipocytes in the co-culture. The results of the enzymatic analysis were highly associated with the morphological results with a statistically higher GPDH activity (p < 0.05) appearing in the single-culture than in the co-culture, whereas the opposite was true for the CK activity of the muscle cells (p < 0.05). By manipulating in vivo the milieu using a co-culture, we could detect the difference in the rate of cell differentiation and suggest that a co-culture system is a more reliable and precise technique compared to a single-culture. Further studies on various co-culture trials including supplementation of differentiating substances, gene expression analysis, etc. should be done to obtain practical and fundamental data.

• Journal of Microbiology and Biotechnology
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• 제22권6호
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• pp.806-813
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• 2012

Adipocyte differentiation is strongly associated with obesity, which causes metabolic disorders. In this study, we investigated the inhibitory effects of widdrol on 3T3-L1 preadipocyte growth and differentiation. Widdrol decreased lipid droplet accumulation and down-regulated adipogenic transcription factors such as C/$EBP{\alpha}$, C/$EBP{\beta}$, and $PPAR{\gamma}$. Widdrol blocked preadipocyte proliferation and differentiation through the inhibition of mitotic clonal expansion, which was accompanied by the failure of degradation of p21, a cyclin-dependent kinase inhibitor. Cell-cycle analysis clearly indicated that widdrol actively induces cell-cycle arrest at the G1-S phage transition, causing cells to remain in the preadipocyte state. Moreover, widdrol increased p21 expression and inhibited Rb phosphorylation in preadipocyte incubated in a hormone medium. Therefore, these findings clearly suggest that widdrol blocks preadipocyte growth and differentiation through the inhibition of mitotic clonal expansion by p21-and Rb-dependent G1 arrest and can be developed as a potent anti-adipogenic agent for reducing obesity.

• 치위생과학회지
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• 제13권2호
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• pp.158-164
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• 2013

임플란트 식립 시 가장 빈번하게 맞게 되는 문제점으로 임플란트 식립 부위에서의 불충분한 골량과 해부학적 구조에 의한 접근성의 문제를 들 수 있다. 일반적으로 성장 인자들은 치유 과정이나 조직 형성에 있어서 가장 기본적인 필수 요소로 인정되고 있다. 이러한 이유로 골 이식 재료의 효과를 증진시키기 위한 성장 인자들이 최근에 주목을 받고 있다. 혈소판 내 granules에는 높은 농도의 다양한 성장 인자들이 포함되어 있다. 특히, platelet-rich fibrin (PRF)는 2세대 혈소판 농축 인자로 항응고제가 들어있지 않은 상태로 얻을 수가 있고, 혈소판과 많은 성장 인자들이 풍부한 섬유소 막을 포함하고 있다. 이번 연구의 목적은 in vitro 상에서 골아 세포에 대한 PRF의 영향을 알아보고자 하였다. 특히 치유와 재생에 연관된 주요 기능으로써 증식과 분화에 대한 영향을 조사하고자 하였다. 이를 위해서, PRF 내에서 방출되는 성장 인자(platelet-derived growth factor subunit B와 transforming growth factor-${\beta}1$)의 농도, 세포의 생존능력, alkaline phosphatase (ALP) activity, type 1 collagen 합성, 골아 세포의 분화 지표로써 ALP와 Runx2의 발현 정도와 골 기질 단백질로써 type 1 collagen의 발현 정도에 대해서 조사하였다. 이 실험을 통하여 PRF는 치유 시 필요한 타당한 기간 동안에 충분히 자가 성장 인자의 방출을 유지하고 있음을 알 수 있었고, 골아 세포의 증식과 분화에 대해서 긍정적인 효과가 있음을 보여 주였다. 제한적인 실험이지만, 골재생을 위한 PRF의 사용은 골 치유와 골 개조에 있어서 증진 효과를 가져다줄 수 있는 촉망되는 방법 중 하나가 될 수 있을 것이다.

• Clinical and Experimental Reproductive Medicine
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• 제31권1호
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• pp.19-27
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• 2004

Objective: This study was to examine the in vitro neural cell differentiation patterns of human embryonic stem (hES) cells following treatment of various neurotrophic factors [basic fibroblast growth factor (bFGF), retinoic acid (RA), brain derived neurotrophic factor (BDNF) and transforming growth factor (TGF)-$\alpha$], particulary in dopaminergic neuron formation. Methods: The hES cells were induced to differentiate by bFGF and RA. Group I) In bFGF induction method, embryoid bodies (EBs, for 4 days) derived from hES were plated onto gelatin dish, selected for 8 days in ITSFn medium and expanded at the presence of bFGF (10 ng/ml) for another 6 days followed by a final differentiation in N2 medium for 7, 14 and 21 days. Group II) For RA induction, EBs were exposed of RA ($10^{-6}M$) for 4 days and allowed to differentiate in N2 medium for 7, 14 and 21 days. Group III) To examine the effects of additional neurotrophic factors, bFGF or RA induced cells were exposed to either BDNF (10 ng/ml) or TGF-$\alpha$ (10 ng/ml) during the 21 days of final differentiation. Neuron differentiation and dopamine secretion were examined by indirect immunocytochemistry and HPLC, respectively. Results: The bFGF or RA treated hES cells were resulted in similar neural cell differentiation patterns at the terminal differentiation stage, specifically, 75% neurons and 11% glial cells. Additionally, treatment of hES cells with BDNF or TGF-$\alpha$ during the terminal differentiation stage led to significantly increased tyrosine hydroxylase (TH) expression of a dopaminergic neuron marker, compared to control (p<0.05). In contrast, no effect was observed on the rate of mature neuron (NF-200) or glutamic acid decarboxylase-positive neurons. Immunocytochemistry and HPLC analyses revealed the higher levels of TH expression (20.3%) and dopamine secretion (265.5 $\pm$ 62.8 pmol/mg) in bFGF and TGF-sequentially treated hES cells than those in $\alpha$ RA or BDNF treated hES cells. Conclusion: These results indicate that the generation of dopamine secretory neurons from in vitro differentiated hES cells can be improved by TGF-$\alpha$ addition in the bFGF induction protocol.

• 생명과학회지
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• 제26권3호
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• pp.331-337
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• 2016

섬유모세포성장인자-23(fibroblast growth factor 23, FGF23)은 뼈를 형성하는 세포에서 주로 생성되지만 그 작용은 신장에서 이루어진다. FGF23은 신장의 나트륨-인산염 공동수송체(Na-phosphate cotransporter)를 억제하여 인산염 재흡수를 감소시킨다. 이렇게 함으로써 인산염 항상성을 조절하는 작용과는 별개로 이것은 in vivo에서 뼈 형성을 억제하는 것으로 알려져 있다. 두개골 조골세포를 이용한 연구에서도 FGF23은 조골세포의 발달, 즉 분화 및 기질의 광화(mineralization)에 악영향을 미쳤다. 본 연구는 FGF23이 골수 유래 간엽줄기세포에서 조골세포로의 발달에 있어서도 유사한 영향을 줄 것인지를 조사한 것이다. 간엽줄기세포주인 D1 세포를 β-glycerophosphate, ascorbic acid, dexamethazone이 포함된 조골배(osteogenic medium)에 배양하여 alkaline phosphatase (Alp) 염색으로 분화를, Alizarin red 염색과 기질의 칼슘 함량의 분석을 통해 광화를 평가하였다. 분화 촉진 유전자인 Runx2, osteocalcin, Alp와 광화 억제 유전자인 Enpp1, Ank의 발현은 RT-PCR로 분석하였다. D1 세포의 증식과 조골세포로의 분화는 생리학적 농도를 훨씬 초과하는 FGF23의 농도에 의해서도 달라지지 않았다. FGF23 처치 1주, 2주, 3주 후 Alizarin red 염색에 의한 광화 정도의 평가에서도 대조군과 실험군의 차이는 발견되지 않았다. 그러나 두 군 모두 시간이 경과함에 따라 광화는 증가되었다. 기질에 침착된 칼슘의 양 또한 차이가 없었다. 분화 촉진 유전자와 광화 억제 유전자의 발현도 양 군 간에 다르지 않았다. 이러한 부정적인(negative) 결과는 FGF23에 의한 세포 내 신호전달의 장애가 아님이 Erk 인산화로 확인되었다. 이상의 결과로 미루어 두개골의 조골세포와 달리 FGF23은 간엽줄기세포에서 조골세포로의 분화와 광화에는 영향을 미치지 않을 것으로 사료된다.