• International Journal of Oral Biology
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• 제45권4호
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• pp.179-189
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• 2020

Green tea polyphenol (-)-epigallocatechin-3-gallate (EGCG) is a potent antioxidant with protective effects against neurotoxicity. However, it is currently unclear whether EGCG protects neuronal cells against radiation-induced damage. Therefore, the objective of this study was to investigate the effects of EGCG on ultraviolet (UV)-induced oxidative stress and apoptosis in PC12 cells. The effects of UV irradiation included apoptotic cell death, which was associated with DNA fragmentation, reactive oxygen species (ROS) production, enhanced caspase-3 and caspase-9 activity, and poly (ADP-ribose) polymerase cleavage. UV irradiation also increased the Bax/Bcl-2 ratio and mitochondrial pathway-associated cytochrome c expression. However, pretreatment with EGCG before UV exposure markedly decreased UV-induced DNA fragmentation and ROS production. Furthermore, the UV irradiation-induced increase in Bax/Bcl-2 ratio, cytochrome c upregulation, and caspase-3 and caspase-9 activation were each ameliorated by EGCG pretreatment. Additionally, EGCG suppressed UV-induced phosphorylation of p38 and rescued UV-downregulated phosphorylation of ERK. Taken together, these results suggest that EGCG prevents UV irradiation-induced apoptosis in PC12 cells by scavenging ROS and inhibiting the mitochondrial pathways known to play a crucial role in apoptosis. In addition, EGCG inhibits UV-induced apoptosis via JNK inactivation and ERK activation in PC12 cells. Thus, EGCG represents a potential neuroprotective agent that could be applied to prevent neuronal cell death induced by UV irradiation.

• 대한본초학회지
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• 제27권6호
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• pp.1-6
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• 2012

Objectives : ROS are involved in a wide spectrum of diseases including chronic inflammation and cancer. S.chinensis Baill, a perennial herb commonly called Chinese lizard's tail or Sam-baek-cho in Korea, is used for the treatment of edema and inflammatory diseases in the Oriental folk medicine. In this study, we investigated the antioxidant activities and anti-inflammatory effects of the two extracts, water(WE) and ethyl acetate(EAE) from S.chinensis Baill. Methods : Anti-oxidant activity was evaluated using Fe2+ chelating and hydroxyl radical scavenging assay. DNA cleavage assay, and western blot and immunostaining for phospho-p65 were performed to evaluate anti-oxidative effect. Anti-inflammatory effect was performed using NO generation assay and western blot in LPS-stimulated RAW264.7 cell. Results : In Fe2+ chelating activity and hydroxyl radical scavenging activity, WE showed more strong scavenging activity for hydroxyl radical than EAE. WE scavenged hydroxyl radical by 12% at 3.2 ${\mu}g/ml$, 21% at 16 ${\mu}g/ml$, 32% at 80 ${\mu}g/ml$, 66% at 400 ${\mu}g/ml$ and 82% at 2000 ${\mu}g/ml$, respectively. In addition, WE showed more strong chelating activity than EAE. WE chelated Fe2+ ion by 1.1% at 3.2 ${\mu}g/ml$, 8.2% at 16 ${\mu}g/ml$, 26.3% at 80 ${\mu}g/ml$, 72% at 400 ${\mu}g/ml$ and 89% at 2000 ${\mu}g/ml$, respectively. Also, WE inhibited oxidative damage via its anti-oxidant activity. In anti-inflammatory effect, EAE inhibited NO production and iNOS expression. In addition EAE suppressed the NF-${\kappa}B$ and MAPK signaling pathway in LPS-stimulated RAW 264.7 cells. Conclusions : Together, these data indicate that S. chinensis Baill, shows anti-oxidant activity and anti-inflammatory effect.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 1994년도 Proceedings of International Symposium on BIOLOGICAL CONTROL OF PLANT DISEASES Korean Society of Plant Pathology
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• pp.86-102
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• 1994

To understand the molecular structure and pathogenesis mechanism of Korean garlic viruses, we have isolate cDNA clones for garlic viruses. The partial nucleotide sequences of 24 cDNA clones were determined and that of six clones containing poly (A) tail were compared with those of other plant viruses. One of those clones, V9 has 81.8% similarity in nucleotide sequence and 93.0% in deduced amino acid sequence, respectively, to the coat protein gene for garlic mosaic virus (GMV). Northern blot analysis with the clone V9 demonstrated that the genome of GMV is 7.8 kb long and has poly (A) tail. The anti-coat protein antibody for GMV recognizes 35 kDa polypeptide which could be the coat protein of GMV from infected garlic leaf extract or virus preparation. Clone G7 has about 62% of deduced amino acid sequence identity with the members of potyvirus group. Northern blot analysis with the clone G7 demonstrated that the genome of the potyvirus I garlic is 9.0 kb long and has poly (A) tail. The third clone, S81, shows 42% amino acid identity to the potexvirus. The other clones are under the characterization. To test the possibility of producing garlic virus resistant plant, we have designed a hairpin type ribozyme to cleave V9 RNA at the middle of the coat protein gene. From the cleavage reactions in vitro with two different sizes of RNA substrates, V9SUB (144 nucleotides) and V9 RNA (1,361 nucleotides), the ribozyme can cleave V9 sequence effectively at the predicted site. To study the activity of the ribozyme in vivo, plant transformation is in progress. Further possibilities to produce garlic virus resistant plant will be discussed.

• 대한치과교정학회지
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• 제33권6호
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• pp.453-463
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• 2003

본 연구는 MC3T3El 조골세포가 저산소증에 반응하여 유발될 수 있는 세포 고사조절 기전을 구명하고자 함에 목적이 있다. $2\%$ 저산소증의 조건하에서 MC3T3El 조골세포는 DNA 사다리 분절 헝성을 보였으며 형광성 염료인 Hoechst 33258로 염색된 핵 구조 형태 관찰시 시간이 지남에 따라 세포고사 현상을 관찰할 수 있었다 Pancaspase 억제제인 Z-VAD-FMK나 특정한 caspase-3 억제제인 Z-DEVD-CHO로 사전 처치하였을 경우에는 저산소증에 의한 DNA 사다리 분절형성이 농축에 비례하여 억제되었다. caspase-3류의 프로테아제(DEVDase) 활성 증가가 세포고사 중에 관찰되었으나 caspase-1 (YVADase)의 활성은 없었다. 어떤 caspase가 세포고사에 관여하는지를 확인하기 위하여 anti-caspase-3 또는 anti-caspase-6의 항체를 이용한 western blotting이 시행되었다. caspase-3의 활성산물에 해당하는 17-KDa단백질과 caspase-6의 활성산물인 20-KDa 단백질이 세포용해물에서 발생되었다. 또한 시간 경과와 더불어 caspase-6의 활동의 상징인 Lamin A의 분열을 일으켰으며, 사이토크롬 C를 cytosol로 방출하였다. 이로써 저산소증에 의한 조골세포의 고사 과정에 사이토크롬 C의 방출이 포함된 caspase의 활성이 관여한다는 것을 확인할 수 있었다.

• 생명과학회지
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• 제18권8호
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• pp.1042-1048
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• 2008

전립선 암은 현대 남성에게 걸리기 쉬운 질환으로 매년 점점 증가하는 암 사망률 중 하나이다. 하지만 남성호르몬 비의존형 전립선 암 치료에 대한 효과가 거의 없어 이에 본 연구에서는 남성호르몬 비의존형 전립선 암세포인 PC-3 세포에서 감마선이 세포 성장 억제와 세포자멸사 기작에 대해 알아보고자 한다. 그리하여 본 연구에서는 5가지 방법으로 즉, 세포증식 억제, apoptotic cell의 형태학적 변화, DNA 분절 분석, AV/PI 염색, western blot 분석법을 사용하여 수행하였다. 본 연구의 결과로 감마선을 처리한 PC-3세포에서 형태학적(분절화) 변화와 DNA ladder가 관찰되었다. 또한 감마선을 처리한PC-3세포에서는 apoptosis와 관련된 Caspase3와 PARP cleavage가 유발되었고 Bax 단백질 증가도 보였다.

• 미생물학회지
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• 제30권1호
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• pp.53-59
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• 1992

자연계로부터 4-chlorobiphenyl (4CB) 을 분해하는 P08, P20, 027 그리고 P1242 균주를 불리하였다. 이들 분해 균주들의 4CB 분해 과정을 UV-spectrophotometry 방법으로 분석한 결과, 4-CB 로 부터 2-hydroxy-6-oxo-6-(4'-chlorophenyl)hexa-2, 4-dienoic acid 와 4-chlorobenzoate(4CBA) 가 생성되었다. 따라서 분해균주들은 공통적으로 meta-cleavage pathway에 의하여 4CB 를 분해하는 것으로 확인되었다. 그러나 DJ-12, P08 그리고 P27 균주는 4CBA 를 계속 분해하여 4-hydroxybenzoate 를 생성하였으나, P20 과 P1242 균주들은 4CBA 를 더이상 분해하지 못 하였다. 각 분해 균주에서 cbp 유전자군의 상동성을 분석하기 위하여 P. pseudoalcaligenes KF707 의 bphABC 유전자군을 DNA probe 로 이용하여 Southern hybridization 을 실시한 결과, DJ-12, P08 그리고 P27 균주들은 XhoI 에 의한 2.2kb 와 1.8 kb, 그리고 EcoRI 에 의한 11 kb 의 genomic DNA 의 절편에서 hybridization 이 일어났다. 따라서 본 연구에서 분리한 4CB 분해 균주들의 cbp 유전자군은 분해경로 및 bph 유전자군과의 상동성에 의거하여 부 group 으로 구분되었다.

• Genomics & Informatics
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• 제15권4호
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• pp.142-146
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• 2017

More effective production of human insulin is important, because insulin is the main medication that is used to treat multiple types of diabetes and because many people are suffering from diabetes. The current system of insulin production is based on recombinant DNA technology, and the expression vector is composed of a preproinsulin sequence that is a fused form of an artificial leader peptide and the native proinsulin. It has been reported that the sequence of the leader peptide affects the production of insulin. To analyze how the leader peptide affects the maturation of insulin structurally, we adapted several in silico simulations using 13 artificial proinsulin sequences. Three-dimensional structures of models were predicted and compared. Although their sequences had few differences, the predicted structures were somewhat different. The structures were refined by molecular dynamics simulation, and the energy of each model was estimated. Then, protein-protein docking between the models and trypsin was carried out to compare how efficiently the protease could access the cleavage sites of the proinsulin models. The results showed some concordance with experimental results that have been reported; so, we expect our analysis will be used to predict the optimized sequence of artificial proinsulin for more effective production.

• 대한본초학회지
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• 제22권2호
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• pp.65-72
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• 2007

Objectives : In this study, we investigate that Euphorbiae lathyridis Semen extract contributes to growth inhibitory effect and anti-cancer activity on the HT-29 human colon cancer cells. Methods : Euphorbiae lathyridis Semen was extracted from the Semen of the plant using 80% Methanol. The Euphorbiae lathyridis Semen extract was treated to different concentrations for 24 hr, 4Shr or 72hr. Growth inhibitory effect was analyzed by measuring FACS study and MTT assay. Cell apoptosis was confirmed by surveying caspases cascades activation using Westem blot. Results : Exposure to Euphorbiae lathyridis Semen extract (0.4mg/ml) results in an inhibitory effect on cell growth in HT-29 cells. Growth inhibition by Euphorbiae lathyridis Semen extract in HT-29 cells was related with the inhibition of proliferation and induction of apoptosis. The Euphorbiae lathyridis Semen extract induces DNA fragmentation in HT-29 cells. Furthermore, Euphorbiae lathyridis Semen extract induces cell apoptosis through the activation of caspases-3, caspase-9 and PARP cleavage. Conclusion : Euphorbiae lathyridis Semen extract induces apoptosis in human colon cancer cells, therefore, we suggest that Euphorbiae lathyridis Semen extract can be used as a novel class of anti-cancer drugs.

• 동국한의학연구소논문집
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• 제11권
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• pp.52-57
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• 2008

Objectives. In this study, we investigate that methanol extract of Euphorbiae lathyridis Semen contributes to growth inhibitory effect on the HT-29 human colon cancer cells. Methods. Euphorbiae lathyridis Semen (ELS) was extracted with 80% methanol. HT-29 cells were treated with different concentrations of ELS extract for 24-72 hrs. Growth inhibitory effect was determined by MTT assay. Cell apoptosis was determined by surveying caspases cascades activation using Western blot. Cell cycle arrest was analyzed by flow cytometry with PI staining. Results. Exposure to ELS extract showed in inhibitory effects on HT-29 cell growth as a dose-dependent manner. Cell growth inhibition by ELS extract was related with induction of cell apoptosis with DNA fragmentation through the activation of caspases-3, caspase-9 and PARP cleavage. Conclusion. ELS extract significantly inhibited cell growth and induced cell apoptosis in HT-29 human colon cancer cells, therefore, These results suggest that ELS extract can be used as chemoprevention agent of colon cancers.

• IMMUNE NETWORK
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• 제5권2호
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• pp.99-104
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• 2005

Background: Malignant gliomas are the most common primary tumors in the central nervous system. Methods: We investigated the combined effect of PG490 and LPS on the induction of the apoptotic pathway in human astroglioma cells. Results: Treatment of U87 cells with combination of 50nM of PG490 and $50{\mu}g/ml$ of LPS resulted in increased internucleosomal DNA fragmentation, cleavage of PLC-${\gamma}1$, and downregulation of cIAP1 and XIAP. The combination of LPS and PG490 treatment-induced apoptosis is mediated through the activation of caspase, which is inhibited by the caspase inhibitor, z-VAD-fmk. Also, release of cytochrome c was found in PG490 and LPS-cotreated U87 cell. Conclusion: Taken together, combination of PG490 and LPS appears to be a potent inducer of apoptosis in astrogliaoma cells, and might have some benefit in the treatment of glioma patients.