• 생명과학회지
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• 제26권6호
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• pp.633-639
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• 2016

고분자(polymer), 금속(metal), 세라믹(ceramic), 합성물(composite) 등과 같은 바이오소소재(Biomaterials)는 그들의 물리화학적 성질 때문에 의료용섬유(medical fibers), 인공혈관(artificial blood vessels), 인공관절(artificial joints), 임플란트(implants), 연조직(soft tissue), 인공성형물(plastic surgery materials) 등 의료용으로 많이 사용되며, 개발연구도 활발히 진행되고 있다. 그러나, 필름(film)이나 판(plate)형태의 바이오소재에 대한 생체적합성(biocompatibility)이나 독성(toxicity)을 포유동물세포를 이용하여 평가하는 것은 적절한 평가용 장치가 없기 때문에 매우 어려운 상황이다. 따라서 이러한 문제를 해결하기 위해서, 본 연구에서는 고분자필름이나 금속판에 유용하게 적용할 수 있는 실리콘링, 상판(top panel), 하판(bottom panel)으로 구성된 새로운 포유동물배양시스템을 개발하고, 이를 실제 적용하고자 하였다. 개발된 시스템은 평가하고자 하는 시료를 상판과 하판사이에 조립하는 샌드위치시스템을 기반으로 한다. 세포배양장치의 조립 후, SK-MEL-2세포를 3가지 시료; Styela Clava Tunic (SCT)- PF, NaHCO₃-added SCT (SCTN)-PF, magnesium MP (MMP)에 적용하고 37℃ 이산화탄소 배양기에서 24시간과 48시간 동안 배양하였다. MTT분석결과에서, 세포생존율(cell viability)은 24시간과 48시간 동안 SCT-PF배양그룹에서 정상적으로 유지되었지만 48시간 동안 SCTN-PF배양그룹에서는 급격하게 감소되었다. 더불어, MMP배양그룹에서 세포생존율은 24시간과 48시간 배양 후에 대조군과 유사하게 유지되었다. 이러한 결과는 본 연구에서 새롭게 개발된 샌드위치형태의 포유동물세포배양장치는 고분자필름이나 금속판형태의 바이오소재에 대한 독성이나 생체적합성을 평가하기 위한 우수한 잠재력을 보유하고 있음을 제시하고 있다.

• 대한한의학회지
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• 제28권2호통권70호
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• pp.213-223
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• 2007

Objective : Alzheimer's disease (AD) is a geriatric dementia that is widespread in old age. With an aging populace, AD is a looming problem in public health service. Alzheimer's disease is characterized by specific neuronal degeneration in certain areas of the brain. Mutations and abnormal expression of several genes are associated with ${\beta}-amyloid$ deposits and Alzheimer's disease; among them APP, PS1, and PS2, SOD, free radical, ROS. Methods:We studied herbal medicines that have a relationship to brain degeneration. From pre-modern times, although a variety of oriental prescriptions of Aster tataricus have been traditionally utilized for the treatment of AD, their pharmacological effects and action mechanisms have not yet been fully elucidated. Result : Based on morphological observations by phase-contrast microscope, TUNEL assay and MTT in the culture media, $H_20_2-induced$ cell death was significantly inhibited by Aticus. We examined by ROS formation, catalase activity and GSH activity. We studied the protective effect and inhibitory effects of neurotoxicity in $H_20_2-induced$ PC-12 cells by Aticus. Findings from our experiments show that Aticus inhibits apoptosis, which has neurotoxicities and cell damage in PC-12 cells. In addition, treatment with Aticus ($>25{\mu}g/ml$ for 6hrs) partially prevented $H_20_2-induced$ cytotoxicity in PC-12 cells, and induced a protective effect. Conclusion : As the result of this study, in the Aticus group, the apoptosis in the nervous system was inhibited, protected against the degeneration of PC-12 cells by $H_20_2$. Taken together, Aticus exhibited inhibition of $H_20_2-induced$ apoptotic cell death. Aticus was found to induce protective effect on GSH and catalase in PC-12 cells. Based on these findings, Aticus may be beneficial for the treatment of AD.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제32권3호
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• pp.218-228
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• 2010

발암물질로 알려진 Hydroquinone (HQ)은 치과용 합성수지를 구성하는 중요한 성분으로서 지금까지 치과용 재료영역에서 널리 사용되고 있으며 구강 내에서 HQ의 유출이 일어나는 것으로 확인 되었다. 따라서 구강암의 기원이 되는 인체상피세포의 발암화에 HQ가 미치는 영향을 평가하였다. HQ에 의한 인체세포 독성을 평가하기위해 LDH assay를 실시하고 세포 독성이 높지 않은 용량을 실험 용량으로 설정하였다. 인체 세포의 발암화를 평가하기 위해 세포 발암화 지표로서 cell saturation density, soft-agar colony formation 및 cell aggregation의 분석을 사용한 결과 고용량인 50 ${\mu}M$을 제외한 모든 용량에서 발암화 지표의 변화를 나타내지 않아 HQ의 발암력은 매우 낮은 것으로 추정된다. 그러나 발암촉진제인 TPA와 함께 투여 시 발암력의 증가를 보여 주변 환경의 여건에 따라 발암력이 증가할 수 있음을 입증하였다. HQ를 노출 후 세포사멸화를 측정하기 위해 DNA fragmentation변화를 분석한 결과 10 ${\mu}M$부터 50 ${\mu}M$까지 노출 시간 의존형의 증가를 나타내었으며 50 ${\mu}M$과 같은 고용량 농도에서는 노출시간 의존적 세포사멸 효과를 보였다. 따라서 세포 발암화를 일으킨 용량에서 세포사멸도 함께 일어나 HQ에 의한 발암화에 세포사멸이 관여함을 보였다. HQ는 ROS를 생성하였으며 Trolox, NAC와 같은 항산화물에 의한 ROS의 차단 효과와 BSO와 같은 GSH 고갈 유발 물질에 따른 ROS의 급격한 증가는 HQ가 인체세포에서 ROS를 효율적으로 생성함을 입증하는 결과이다. 세포간의 신호전달기작 조절에 중요한 역할을 하는 효소인 protein kinase C (PKC)를 immunoblot으로 분석한 결과 PKC-${\alpha}$의 활성이 증가 된 반면 PKC-${\beta}II$의 영향은 나타나지 않았다. 따라서 특정 이성질체에 대한 특이적인 효소반응이 발암화에 관여할 것으로 추정된다. 본 연구결과 치과용 합성수지 구성성분인 HQ 유출에 따른 인체상피세포의 발암성은 매우 낮은 것으로 추정되나 발암촉진제 등과의 상호작용에 의한 발암성 증가는 HQ의 구강암 발생 평가에 고려되어야 할 사항이다. 따라서 본 연구는 구강암의 예방을 위한 과학적인 접근 방법 및 기반 자료를 제시하였고 치과용 합성수지사용의 적정성에 대한 과학적인 판단을 할 수 있는 근거를 제공 하였다. 또한 본 연구 결과는 새로운 치과용 합성수지 개발의 필요성 및 개선방향을 제시 할 수 있는 근거로 활용될 수 있을 것으로 사료된다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권23호
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• pp.10281-10287
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• 2015

Background: Development of a nanosized polymeric delivery system for erlotinib was the main objective of this research. Materials and Methods: Poly caprolactone-polyethylene glycol-polycaprolactone (PCEC) copolymers with different compositions were synthesized via ring opening polymerization. Formation of triblock copolymers was confirmed by HNMR as well as FT-IR. Erlotinib loaded nanoparticles were prepared by means of synthesized copolymers with solvent displacement method. Results: Physicochemical properties of obtained polymeric nanoparticles were dependent on composition of used copolymers. Size of particles was decreased with decreasing the PCL/PEG molar ratio in used copolymers. Encapsulation efficiency of prepared formulations was declined by decreasing their particle size. Drug release behavior from the prepared nanoparticles exhibited a sustained pattern without a burst release. From the release profiles, it can be found that erlotinib release rate from polymeric nanoparticles is decreased by increase of CL/PEG molar ratio of prepared block copolymers. Based on MTT assay results, cell growth inhibition of erlotinib has a dose and time dependent pattern. After 72 hours of exposure, the 50% inhibitory concentration (IC50) of erlotinib hydrochloride was appeared to be $14.8{\mu}M$. Conclusions: From the obtained results, it can be concluded that the prepared PCEC nanoparticles in this study might have the potential to be considered as delivery system for erlotinib.

• Journal of Microbiology and Biotechnology
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• 제22권6호
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• pp.838-848
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• 2012

Orally administered herbal glycosides are metabolized to their hydrophobic compounds by intestinal microflora in the intestine of animals and human, not liver enzymes, and absorbed from the intestine to the blood. Of these metabolites, some, such as quercetin and kaempherol, are mutagenic. The fecal bacterial enzyme fraction (fecalase) of human or animals has been used for measuring the mutagenicity of dietary glycosides. However, the fecalase activity between individuals is significantly different and its preparation is laborious and odious. Therefore, we developed a fecal microbial enzyme mix (FM) usable in the Ames test to remediate the fluctuated reaction system activating natural glycosides to mutagens. We selected, cultured, and mixed 4 bacteria highly producing glycosidase activities based on a cell-free extract of feces (fecalase) from 100 healthy Korean volunteers. When the mutagenicities of rutin and methanol extract of the flos of Sophora japonica L. (SFME), of which the major constituent is rutin, towards Salmonella typhimurium strains TA 98, 100, 102, 1,535, and 1,537 were tested using FM and/or S9 mix, these agents were potently mutagenic. These mutagenicities using FM were not significantly different compared with those using Korean fecalase. SFME and rutin were potently mutagenic in the test when these were treated with fecalase or FM in the presence of S9 mix, followed by those treated with S9 mix alone and those with fecalase or FM. Freeze-dried FM was more stable in storage than fecalase. Based on these findings, FM could be usable instead of human fecalase in the Ames test.

• 한국해양생명과학회지
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• 제7권1호
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• pp.15-20
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• 2022

본 연구는 우리나라 해안에서 널리 서식 중인 해양 자원 중 하나인 전복(Haliotis discus hannai)의 차세대염기서열분석 데이터 기반으로 선별한 신규 펩타이드의 항암 활성을 평가한 연구이다. 펩타이드의 항암 활성은 교모세포종 세포주인 SNU-489에서 농도 의존적으로 처리 시간에 비례하여 증가하였으며, 200 µM로 48시간 처리하였을 때 암 세포 사멸율이 67%로 가장 높게 나타났다. 반면 정상 세포인 HaCaT에서 가장 높은 세포 사멸율은 18%로 농도 의존적이었으나 처리 시간과는 무관하였다. 또한 신규 펩타이드의 항암 메커니즘 과정을 밝히기 위해 세포자멸괴사(Necroptosis) 관련 유전자의 발현 변화를 qRT-PCR 방법을 통해 검증하였다. RIPK3는 신규 펩타이드 처리군에서 200 µM 처리 시 9배 이상 발현 증가, MLKL는 100 µM 처리군에서 대조군 대비 2배 이상 유의미하게 발현이 증가되었다. 이러한 결과로 미루어 볼 때, 전복 유래 신규 펩타이드는 암 세포 특이적으로 세포 독성을 가지며, 세포자멸괴사 메커니즘을 통해 암세포 사멸을 일으키는 것으로 추측되므로 신규 펩타이드가 추후 교모세포종 치료제의 후보 물질로 활용될 수 있을 것으로 사료된다.

• The Korean Journal of Physiology and Pharmacology
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• 제27권3호
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• pp.267-275
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• 2023

Cardiotoxicity, particularly drug-induced Torsades de Pointes (TdP), is a concern in drug safety assessment. The recent establishment of human induced pluripotent stem cell-derived cardiomyocytes (human iPSC-CMs) has become an attractive human-based platform for predicting cardiotoxicity. Moreover, electrophysiological assessment of multiple cardiac ion channel blocks is emerging as an important parameter to recapitulate proarrhythmic cardiotoxicity. Therefore, we aimed to establish a novel in vitro multiple cardiac ion channel screening-based method using human iPSC-CMs to predict the drug-induced arrhythmogenic risk. To explain the cellular mechanisms underlying the cardiotoxicity of three representative TdP high- (sotalol), intermediate- (chlorpromazine), and low-risk (mexiletine) drugs, and their effects on the cardiac action potential (AP) waveform and voltage-gated ion channels were explored using human iPSC-CMs. In a proof-of-principle experiment, we investigated the effects of cardioactive channel inhibitors on the electrophysiological profile of human iPSC-CMs before evaluating the cardiotoxicity of these drugs. In human iPSC-CMs, sotalol prolonged the AP duration and reduced the total amplitude (TA) via selective inhibition of I_Kr and I_Na currents, which are associated with an increased risk of ventricular tachycardia TdP. In contrast, chlorpromazine did not affect the TA; however, it slightly increased AP duration via balanced inhibition of I_Kr and I_Ca currents. Moreover, mexiletine did not affect the TA, yet slightly reduced the AP duration via dominant inhibition of I_Ca currents, which are associated with a decreased risk of ventricular tachycardia TdP. Based on these results, we suggest that human iPSC-CMs can be extended to other preclinical protocols and can supplement drug safety assessments.

• Bulletin of the Korean Chemical Society
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• 제30권12호
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• pp.2999-3005
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• 2009

Among the more than 120 different types of human papillomavirus (HPV), types 16 and 18 have been known to be high risk agents that cause cervical cancer. We examined, in an immuno-chromatographic analysis, the potential of using the early gene product, E7 protein, as a diagnostic marker of cervical cancer caused by HPV. We developed monoclonal antibodies specific to HPV-16 and 18 E7 proteins that were produced from bacterial cells using gene recombinant technology. For each E7 protein, the optimal antibody pair was selected using the immuno-chromatographic sandwichtype binding system based on the lateral flow through membrane pores. Under these conditions, this rapid testing assay had a detection capability as low as 2 ng/mL of E7 protein. Furthermore, since viral analysis required the host cell to be lysed using chemicals such as detergents, it was possible that the E7 protein was structurally damaged during this process, which would result in a decrease in detection sensitivity. Therefore, we examined the detrimental effects caused by different detergents on the E7 protein using HeLa cells as the host. In these experiments, we found that the damage caused by the detergent, nonylphenylpolyethylene glycol (NP-40), was minimal relative to Triton X-100 commonly used for the cell lysis. Temperature also affected the stability of the E7 protein, and we found that the E7 protein was stabilized at 4$^{\circ}C$ for about 2 h, which was 4 times longer than at room temperature. Finally, a HPV-infected cervical cancer cell line, which was used as a real sample model, was treated using the optimized conditions and the presence of E7 proteins were analyzed by immuno-chromatography. The results of this experiment demonstrated that this rapid test could specifically detect HPV-infected samples.

• Molecules and Cells
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• 제41권9호
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• pp.842-852
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• 2018

Notch signaling is an evolutionarily conserved pathway and involves in the regulation of various cellular and developmental processes. Ligand binding releases the intracellular domain of Notch receptor (NICD), which interacts with DNA-bound CSL [CBF1/Su(H)/Lag-1] to activate transcription of target genes. In the absence of NICD binding, CSL down-regulates target gene expression through the recruitment of various corepressor proteins including SMRT/NCoR (silencing mediator of retinoid and thyroid receptors/nuclear receptor corepressor), SHARP (SMRT/HDAC1-associated repressor protein), and KyoT2. Structural and functional studies revealed the molecular basis of these interactions, in which NICD coactivator and corepressor proteins competitively bind to ${\beta}-trefoil$ domain (BTD) of CSL using a conserved ${\varphi}W{\varphi}P$ motif (${\varphi}$ denotes any hydrophobic residues). To date, there are conflicting ideas regarding the molecular mechanism of SMRT-mediated repression of CSL as to whether CSL-SMRT interaction is direct or indirect (via the bridge factor SHARP). To solve this issue, we mapped the CSL-binding region of SMRT and employed a 'one- plus two-hybrid system' to obtain CSL interaction-defective mutants for this region. We identified the CSL-interaction module of SMRT (CIMS; amino acid 1816-1846) as the molecular determinant of its direct interaction with CSL. Notably, CIMS contains a canonical ${\varphi}W{\varphi}P$ sequence (APIWRP, amino acids 1832-1837) and directly interacts with CSL-BTD in a mode similar to other BTD-binding corepressors. Finally, we showed that CSL-interaction motif, rather than SHARP-interaction motif, of SMRT is involved in transcriptional repression of NICD in a cell-based assay. These results strongly suggest that SMRT participates in CSL-mediated repression via direct binding to CSL.

• KSBB Journal
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• 제22권6호
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• pp.393-400
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• 2007

현재 많은 대학과 기업에서 다양한 방법으로 상용화가 가능한 protein microarray의 개발을 위해 많은 연구를 집중하고 있다. Protein microarray의 제작 및 분석 조건을 최적화하기 위한 연구도 진행되고 있지만 protein microarray로 부터 얻은 분석 결과를 모든 연구자들이 공유하고 통합하기 위한 노력이 절실한 실정이다. 뿐만 아니라, PCR 같은 무한 확장 방법이 존재하지 않는 단백질의 특성을 고려할 때, 좀 더 실용적인 protein microarray를 많이 만들기 위해서는 수많은 단백질들과 결합할 수 있는 특이성이 높고 결합력이 강한 capture molecule들을 개발하는 것이 필수이다. 그러나 이러한 장애에도 불구하고 protein microarray는 아주 적은 시료량으로 high-throughput assay가 가능하다는 장점 때문에 현재의 생명과학의 발전 추세로 볼 때 앞으로 protein microarray가 조만간 실용화될 것이며 이의 시장성은 매우 클 것으로 기대된다. 보다 빠른 실용화를 위해서는 protein microarray의 개발에 필요한 기반 기술의 개발과 동시에 이를 활용하기 위한 contents의 개발도 절실히 요구된다.