• Asian Pacific Journal of Cancer Prevention
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• 제15권17호
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• pp.7363-7369
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• 2014

The present study aimed to prepare and evaluate polymeric micelles conjugated with folic acid through ${\alpha}$- or ${\gamma}$-carboxyl groups for antitumor efficacy. The isomeric block copolymers, ${\alpha}$- and ${\gamma}$-folate-polyethyleneglycol-distearoyl phosphatidylethanolamine (${\alpha}$- and ${\gamma}$-Fol-PEG-DSPE), were produced by solid phase peptide synthesis. Three types of doxorubicin (DOX)-loaded polymeric micelles (MPEG-DSPE-DOX and ${\alpha}$- / ${\gamma}$-Fol-PEG-DSPEDOX micelles) were prepared via the film formation method. Compared with MPEG-DSPE-DOX micelles, the ${\alpha}$- / ${\gamma}$-Fol-PEG-DSPE-DOX micelles presented a higher cellular uptake behavior in the live cell study. Cell viability percentages were 81.8%, 57.3%, 56.6% at 2 hours for MPEG-DSPE-DOX, ${\alpha}$- and ${\gamma}$-Fol-PEG-DSPE-DOX micelles, respectively (p<0.05). Using the KB xenograft tumor model, both ${\alpha}$- and ${\gamma}$-folate-conjugated micelles were found to have better antitumor effects with lower toxicity in comparison with MPEG-DSPE-DOX micelles. No difference in in vivo antitumor efficacy was found between ${\alpha}$- and ${\gamma}$-Fol-PEG-DSPE-DOX micelles. The folate-conjugated micelles might be a potentially useful strategy for tumor targeting of therapeutic agents, whether grafting with folic acid through ${\alpha}$- or ${\gamma}$-carboxyl groups.

• 한국식물생명공학회:학술대회논문집
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• 한국식물생명공학회 2005년도 추계학술대회 및 한일 식물생명공학 심포지엄
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• pp.71-80
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• 2005

Effects of low temperature ($8^{\circ}C$) on the hydraulic conductivity of young roots of a chilling-sensitive (cucumber; Cucumis sativus L.) and a chilling-resistant (figleaf gourd; Cucurbita ficifolia Bouche) crop have been measured at the levels of whole root systems (root hydraulic conductivity, $Lp_r$) and of individual cortical cells (cell hydraulic conductivity, Lp). In figleaf gourd, there was a reduction only in hydrostatic $Lp_r$ but not in osmotic $Lp_r$ suggesting that the activity of water channels was not much affected by low root temperature (LRT)treatment in this species. Changes in cell Lp in response to chilling and recovery were similar asroot level, although they were more intense at the root level. Roots of figleaf gourd recovered better from LRT treatment than those of cucumber. In figleaf gourd, recovery (both at the root and cell level) often resulted in Lp and $Lp_r$ values which were even bigger than the original, i.e. there was an overshoot in hydraulic conductivity. These effects were larger forosmotic (representing the cell-to-cell passage of water) than for hydrostatic $Lp_r$. After a short term (1 d) exposure to $8\;^{\circ}C$ followed by 1 d at $20\;^{\circ}C$, hydrostatic $Lp_r$ of cucumber nearly recovered and that of figleaf gourd still remained higher due to the overshoot. On the contrary, osmotic $Lp_r$ and cell Lp in both species remained high by a factor of 3 as compared to the control, possibly due to an increased activity of water channels. After pre-conditioning of roots at LRT, increased hydraulic conductivitywas completely inhibited by $HgCl_2$ at both the root and cell levels. Different from figleaf gourd, recovery from chilling was not complete in cucumber after longer exposure to LRT. It is concluded that at LRT, both changes in the activity of aquaporins and alterations of root anatomy determine the water uptake in both species. To better understand the aquaporin function in plants under various stress conditions, we examined the transgenic Arabidopsisand tobacco plants that constitutively overexpress ArabidopsisPIP1;4 or PIP2;5 under various abiotic stress conditions. No significant differences in growth rates were found between the transgenic and wild-type plants under favorable growth conditions. By contrast, overexpression of PIP1;4 or PIP2;5 had a negative effect on seed germination and seedling growth under drought stress, whereas it had a positive effect under cold stress and no effect under salt stress. Measurement of water transport by cell pressure probe revealed that these observed phenotypes under different stress conditions were closely correlated with the ability of water transport by each aquaporin in the transgenic plants. Together, our results demonstrate that PIP-type aquaporins play roles in seed germination, seedling growth, and stress response of Arabidopsis and tobacco plants under various stress conditions, and emphasize the importance of a single aquaporin-mediated water transport in these cellular processes.

• Asian Pacific Journal of Cancer Prevention
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• 제16권14호
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• pp.6039-6046
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• 2015

Aims: To investigate effect of metallic nanoparticles, silver (AgNPs) and gold nanoparticles (AuNPs) as antitumor treatment in vitro against human breast cancer cells (MCF-7) and their associated mechanisms. This could provide new class of engineered nanoparticles with desired physicochemical properties and may present newer approaches for therapeutic modalities to breast cancer in women. Materials and Methods: A human breast cancer cell line (MCF-7) was used as a model of cells. Metallic nanoparticles were characterized using UV-visible spectra and transmission electron microscopy (TEM). Cytotoxic effects of metallic nanoparticles on MCF-7 cells were followed by colorimetric SRB cell viability assays, microscopy, and cellular uptake. Nature of cell death was further investigated by DNA analysis and flow cytometry. Results: Treatment of MCF-7 with different concentrations of 5-10nm diameter of AgNPs inhibited cell viability in a dose-dependent manner, with IC50 value of $6.28{\mu}M$, whereas treatment of MCF-7 with different concentrations of 13-15nm diameter of AuNPs inhibited cell viability in a dose-dependent manner, with IC50 value of $14.48{\mu}M$. Treatment of cells with a IC50 concentration of AgNPs generated progressive accumulation of cells in the S phase of the cell cycle and prevented entry into the M phase. The treatment of cells with IC50 concentrations of AuNPs similarly generated progressive accumulation of cells in sub-G1 and S phase, and inhibited the entrance of cells into the M phase of the cell cycle. DNA fragmentation, as demonstrated by electrophoresis, indicated induction of apoptosis. Conclusions: Our engineered silver nanoparticles effectively inhibit the proliferation of human breast carcinoma cell line MCF-7 in vitro at high concentration ($1000{\mu}M$) through apoptotic mechanisms, and may be a beneficial agent against human carcinoma but further detailed study is still needed.

• 한국식품영양과학회지
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• 제34권9호
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• pp.1367-1374
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• 2005

사람의 정상 골모세포 FOB에서 아미노산 수송계 L의 발현 및 이들 수송계 L을 통한 아미노산 수송특성을 밝히기 위하여, FOB 세포에서 RT-PCR, western blot 분석 및 아미노산 uptake 실험 등을 수행하여 다음과 같은 결과들을 얻었다. FOB 세포에서 아미노산 수송계 L의 두 아형인 LAT1, LAT2및 그들의 보조인자 4F2hc의 발현을 확인할 수 있었다. FOB 세포에서 $_{L}-leucine$의 수송은 $Na^+$-비의존적이었다. FOB 세포에서 $_{L}-leucine$의 수송은 아미노산 수송계 L의 선택적 억제제인 BCH에 의해 완전히 차단되었다. FOB 세포에서 여러 아미노산들에 의한 L-leucine수송억제 실험결과는 Xenopus oocyte에서 시행되어 보고되어진 LAT1과 LAT2 수송억제 실험 결과의 특성을 모두 포함하였다. 본 연구의 결과로 사람의 정상 골모세포주인 FOB에서 는 세포성장 및 증식을 위한 중성 아미노산의 수송에 아미노산 수송계 L의 두 아형인 LAT1과 LAT2가 중요한 역할을 하고 있음을 확인할 수 있었다.

• Applied Microscopy
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• 제40권4호
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• pp.201-209
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• 2010

한방에서 사용되는 약재 중 가자와 지모, 단삼은 면역조절 및 항암효과, 항염증효과가 있다고 알려졌다. 그러나 비만세포와 관련된 아나필락스를 이해할 수 있는 세포학적 기전에 대한 가자와 지모, 단삼의 효과에 대해서는 알려진 바 없다. 본 연구에서는 가자와 지모, 단삼의 메탄올 추출물이 아나필락시스 반응에 대해 어떠한 영향을 끼치는지를 조사하였다. 시험관내 실험과 생체 실험을 통하여, 가자와 지모, 단삼의 메탄올 추출물이 compound 48/80에 의한 아나필락시스와 비만세포 활성화 및 IgE에 의한 피부반응을 관찰하였다. 실험결과는 다음과 같다. 1) 가자와 지모, 단삼의 메탄올 추출물은 compound 48/80에 의한 전신성 아나필락시스와 귀부종 반응, IgE에 의한 피부반응을 억제하였다. 2) Compound 48/80에 의한 비만세포 탈과립과 흰쥐 복강 비만세포로부터 히스타민 유리가 가자와 지모, 단삼의 메탄올 추출물 전처리에 의해 억제되었다. 3) Compound 48/80에 의한 흰쥐 복강 비만세포내로의 칼슘 유입이 가자와 지모, 단삼의 메탄올 추출물 전처리에 의해 현저하게 억제되었다. 이상의 결과로 가자와 지모, 단삼의 메탄올 추출물은 비만세포 탈과립과 비만세포로부터 히스타민 유리, 비만세포내로 칼슘유입을 억제함으로써 compound 48/80에 의한 아나필락시스와 IgE에 의한 피부반응을 억제한다는 것을 알 수 있었다. 이로써 가자와 지모, 단삼은 알레르기 질환에 대한 효과적인 치료제로 이용될 수 있을 것으로 생각된다.

• 생명과학회지
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• 제26권12호
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• pp.1470-1476
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• 2016

바이러스성 출혈성 패혈증 바이러스(VHSV)는 넙치를 포함한 어류 양식의 막대한 피해를 일으키는 바이러스 병원체이며, VHSV가 생성하는 6개의 바이러스 단백질들 중에서 NV 단백질이 병원성에 관여하는 것으로 알려져 있다. VHSV-감염 넙치를 이용한 전사체 마이크로 어레이의 선행 분석 결과에 의하면 VHSV 감염이 해당과정 효소들의 mRNA 발현을 억제함으로써 넙치 세포에서 ATP 생성을 감소시켰음을 알 수 있었다. 이들 결과를 토대로, 본 연구에서는 VHSV NV 단백질이 해당과정 효소인 glucokinase의 발현에 미치는 영향을 검토하였다. 본 연구의 결과에 의하면, NV 단백질은 넙치 세포에서 glucokinase의 mRNA 발현을 감소시켰으며, 새롭게 동정한 glucokinase의 유전자 프로모터의 활성 실험결과, NV 단백질이 glucokinase의 프로모터 활성을 저해함을 알 수 있었다. 이와 같은 작용 결과들로 인하여 VHSV NV 단백질의 발현이 세포 내로의 포도당 흡수 또한 감소시켰다. 이러한 결과들은 VHSV NV 단백질이 유전자 발현의 전사 수준에서 음성적으로 해당과정의 효소 발현을 조절함을 의미하며, 결국 세포 내 에너지의 결핍으로 넙치의 폐사로 이어질 가능성을 보여주는 것이다.

• 한국축산식품학회지
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• 제37권1호
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• pp.123-133
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• 2017

The development of a new manufacturing process, a two-step temperature treatment, to modulate the physicochemical properties of nanoparticles including the size is critical. This is because its physicochemical properties can be key factors affecting the cellular uptake and the bioavailability of bioactive compounds encapsulated in nanoparticles. The aims of this study were to produce (beta-lactoglobulin) ${\beta}-lg$ nanoparticles and to understand how two-step temperature treatment could affect the formation and physicochemical properties of ${\beta}-lg$ nanoparticles. The morphological and physicochemical properties of ${\beta}-lg$ nanoparticles were determined using atomic force microscopy and a particle size analyzer, respectively. Circular dichroism spectroscopy was used to investigate the secondary structure of ${\beta}-lg$. The surface hydrophobicity and free thiol groups of ${\beta}-lg$ were increased with a decrease in sub-ambient temperature and an increase in mild heat temperature. As sub-ambient temperature was decreased, a decrease in ${\alpha}-helical$ content and an increase in ${\beta}-sheet$ content were observed. The two-step temperature treatment firstly involved a sub-ambient temperature treatment from 5 to $20^{\circ}C$ for 30 min, followed secondly by a mild heat temperature treatment from 55 to $75^{\circ}C$ for 10 min. This resulted in the production of spherically-shaped particles with a size ranging from 61 to 214 nm. Two-way ANOVA exhibited the finding that both sub-ambient and mild heat temperature significantly (p<0.0001) affected the size of nanoparticles. Zeta-potential values of ${\beta}-lg$ nanoparticles were reduced with increasing mild heat temperature. In conclusion, two-step temperature treatment was shown to play an important role in the manufacturing process - both due to its inducement of the conformational changes of ${\beta}-lg$ during nanoparticle formation, and due to its modulation of the physicochemical properties of ${\beta}-lg$ nanoparticles.

• 생명과학회지
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• 제22권9호
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• pp.1159-1165
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• 2012

${\gamma}$-Aminobutyric acid (GABA)는 신경세포 밖으로 분비된 후 GABA 수송체들(GATs)에 의하여 다시 신경세포 안으로 재흡수 된다. 그러나, GABA 수송체들이 어떻게 연접전막의 위치에 안정적으로 존재하는지 또한 어떤 단백질과 결합하여 조절을 받는지는 알려져 있지 않다. 본 연구에서 효모 two-hybrid system을 이용하여 betaine-${\gamma}$-aminobutyric acid transporter 1 (BGT-1/mGAT2)의 C-말단과 특이적으로 결합하는 Munc-18-interacting (Mint) 단백질을 분리하였다. BGT-1/mGAT2의 C-말단에 존재하는 "T-H-L" 아미노산배열은 Mint2와의 결합에 필수적으로 관여하였다. Mint2은 BGT-1/mGAT2와는 결합하지만, 다른 종류의 GAT와는 결합하지 않았다. 또한 HEK-293T 세포에 Mint2와 BGT-1/mGAT2을 동시에 발현시켜 면역침강한 결과 두 단백질은 같이 면역침강하였으며, 두 단백질은 세포 내에서 세포막 부위에 같이 존재함도 확인하였다. 이러한 결과들은 Mint2가 BGT-1/mGAT2와 결합하여 BGT-1/mGAT2을 조절하는 역할을 함을 시사한다.

• Journal of Microbiology and Biotechnology
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• 제22권12호
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• pp.1782-1789
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• 2012

We have developed a novel type of polymer nanogel loaded with anticancer drug based on bio-derived poly(${\gamma}$-glutamic acid) (${\gamma}$-PGA). ${\gamma}$-PGA is a highly anionic polymer that is synthesized naturally by microbial species, most prominently in various bacilli, and has been shown to have excellent biocompatibility. Thiolated ${\gamma}$-PGA was synthesized by covalent coupling between the carboxyl groups of ${\gamma}$-PGA and the primary amine group of cysteamine. Doxorubicin (Dox)-loaded ${\gamma}$-PGA nanogels were fabricated using the following steps: (1) an ionic nanocomplex was formed between thiolated ${\gamma}$-PGA as the negative charge component, and Dox as the positive charge component; (2) addition of poly(ethylene glycol) (PEG) induced hydrogen-bond interactions between thiol groups of thiolated ${\gamma}$-PGA and hydroxyl groups of PEG, resulting in the nanocomplex; and (3) disulfide crosslinked ${\gamma}$-PGA nanogels were fabricated by ultrasonication. The average size and surface charge of Dox-loaded disulfide cross-linked ${\gamma}$-PGA nanogels in aqueous solution were $136.3{\pm}37.6$ nm and $-32.5{\pm}5.3$ mV, respectively. The loading amount of Dox was approximately 38.7 ${\mu}g$ per mg of ${\gamma}$-PGA nanogel. The Dox-loaded disulfide cross-linked ${\gamma}$-PGA nanogels showed controlled drug release behavior in the presence of reducing agents, glutathione (GSH) (1-10 mM). Through fluorescence microscopy and FACS, the cellular uptake of ${\gamma}$-PGA nanogels into breast cancer cells (MCF-7) was analyzed. The cytotoxic effect was evaluated using the MTT assay and was determined to be dependent on both the concentration and treatment time of ${\gamma}$-PGA nanogels. The bio-derived ${\gamma}$-PGA nanogels are expected to be a well-designed delivery carrier for controlled drug delivery applications.

• 생명과학회지
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• 제32권3호
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• pp.256-262
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• 2022

옥시스테롤은 담즙산 합성 동안 일련의 효소 반응에 의해 생성된 콜레스테롤의 산화물로써, 콜레스테롤과 유사하게 세포내 영역으로 빠르게 이동하여 면역 세포 반응, 지질 대사 및 콜레스테롤 항상성과 같은 다양한 세포 과정을 조절한다. 글루코코르티코이드 수용체(GR), 에스트로겐 수용체(ER) 및 간 X 수용체(LXR)와 같은 종류의 핵 수용체는 여러 조직에서 옥시스테롤에 의해 조절될 수 있다. 가장 풍부한 옥시스테롤인 27-하이드록시콜레스테롤(27-OHC)은 조직 특이적 방식에 의해 에스트로겐 수용체 활성을 활성화하거나 억제하기 때문에 선택적 에스트로겐 수용체 조절자로 규명되었다. 특히 27-하이드록시콜레스테롤이 동맥 경화증 플라크에서 많이 발견되고 대식세포가 거품 세포로 변형되는 것을 가속화하기 때문에 동맥 경화증 발병에 기여하는 것이 분명해 보이나, 다른 연구들에서는 27-하이드록시콜레스테롤이 간 및 지방 조직을 포함한 다양한 대사 기관에 미치는 영향에 대해 반대 의견이 존재한다. 따라서 본 총설을 통해 대사 조직에서의 27-하이드록시콜레스테롤 역할에 대한 논의와 함께, 죽상 동맥 경화증 및 대사 증후군에 영향을 주는 27-하이드록시콜레스테롤의 세부 기전에 대해 논의하고자 한다.