Effects of epigallocatechin gallate on CoCl_(2)-induced apoptosis in PC12 cells

Yang, Kyu-Ho,Mo, Hyun-Chul,Choi, Nam-Ki,Kim, Seon-Mi,Kim,Won-Jae 大韓小兒齒科學會 2006 大韓小兒齒科學會誌 Vol.33 No.1

Neuronal apoptotic events, consequently resulting in neuronal cell death, are occurred in hypoxic/ischemic condition. This cell death has been shown to be accompanied with the production of reactive oxygen species (ROS), which can attack cellular components such as nucleic acids, proteins and phospholipid. However, the underlying mechanisms of apoptosis induced in hypoxic/ischemic condition and its treatment methods are unsettled. Cobalt chloride (CoCl_(2)) has been known to mimic hypoxic condition including the production of ROS. Epigallocatechin gallate (EGCG). a green tea polyphenol, has diverse pharmacologial activities in cell growth and death. This study was aimed to investigate the apoptotic mechanism by CoCl_(2) and effects of EGCG on CoCl_(2)-induced apoptosis in PC12 cells. Administration of CoCl_(2) decreased cell survival in dose- and time-dependent manners and induced genomic DNA fragmentation. Treatment with 100 µM EGCG for 30 min before PC12 cells were exposed to 150 µM CoCl_(2), being resulted in the cell viability and DNA fragmentation being rescued. CoCl_(2) caused morphologic changes such as cell swelling and condensed nuclei, whereas EGCG attenuated morphologic changes by CoCl_(2). EGCG suppressed the apoptotic peak and a loss of Δψ_(m) induced by CoCl_(2). CoCl_(2) decreased Bcl-2 expression but Bax expression was not changed in CoCl_(2)-treated cells. EGCG attenuated the Bcl-2 underexpression by CoCl_(2). CoCl_(2) augumented the cytochrome c release from mitochondria into cytoplasm and increased caspase-8, -9 and caspase-3 activity, a marker of the apoptotic executing stage. EGCG ameliorated the incruement in caspase-8, -9 and -3 activity, and cytochrome c release by CoCl_(2). NAC (N-acetyl-cysteine), a scavenger of ROS, attenuated CoCl_(2)-induced apoptosis in consistent with those of EGCG. These results suggest, that CoCl_(2) induces apoptotic cell death through both mitochondria- and death receptor-dependent pathway and EGCG has neuroprotective effects against CoCl_(2)-induced apoptosis in PC12 cells. 신경세포자멸사는 저산소 및 허혈환경에서 일어나며 이러한 세포죽은 reactive oxidant species (ROS) 생성을 동반함이 알려져있다. 그러나, 저산소 및 허혈환경에서 일어나는 세포자멸사의 기전 및 그 치료방법은 아직 정립되어 있지 않다. CoCl_(2)는 ROS를 생성하는 등 저산소환경과 유사한 조건을 초래하는 것으로 알려져 있다. Epigallocatechin gallate (EGCG)는 녹차의 polyphenol 성분으로서 세포성장과 죽음에 다양한 약리학적 효과를 나타냄이 알려져 있다. 본 연구는 PC12 세포에서 CoCl_(2)에 의한 세포자멸사기전을 밝히고 이에 미치는 EGCG의 효과를 조사하는데 목적이 있다. Cell viability는 MTT 측정으로 조사되었고, DNA fragmentation은 DNA laddering으로 조사되었다. Bcl-2와 Bax발현 정도는 RT-PCR로, caspase-3와 -9의 활성은 spectrophotometer, caspase-8의 활성은 flow cytometry에 의해 측정되었다. 미토콘드리아에서 세포질로 분비된 cytochrome c는 western blot으로, 분해된 DNA 양과 미토콘드리아 세포막전위 (Δψ_(m))는 FACScan으로 조사되었다. CoCl_(2)투여로 PC12 세포수는 용량 및 시간 의존형태로 감소하였고, genomic DNA fragmentation이 발생하였다. CoCl_(2)투여로 야기된 cell viability의 감소와 DNA fragmentation은 EGCG 전처치에 의해 억제되었다. CoCl_(2)은 세포용적팽창과 condensed nuclei 같은 형태적 변화를 일으켰으며, apoptotic peak, Δψ_(m)감소 및 cytochrome c 유리를 야기하였다. EGCG는 CoCl_(2)에 의한 세포형태변화, apoptotic peak, Δψ_(m)소실 및 cytochrome c 유리를 억제시켰다. CoCl_(2)는 Bcl-2 발현을 감소시켰지만, Bax 발현에는 영향을 미치지 않았다. EGCG는 CoCl_(2)에 의해 야기된 Bcl-2 발현 감소를 억제시켰다. CoCl_(2)는 caspase-3, -8, 그리고 -9의 활성을 증가시켰으며, EGCG는 CoCl_(2)에 의한 세포자멸사를 억제시켰다. 본 실험결과는 PC12 세포에서 CoCl_(2)가 미토콘드리아 의존 및 death receptor의존 기전으로 세포자멸사를 일으키며, EGCG는 세포자멸사기전을 억세지킴으로 신경보호기능을 가짐을 시사하였다.

고장초 추출물의 t-BHP로 산화적 손상이 유도된 HepG2 세포 보호 효과

박세호(Se-Ho Park),이재열(Jae-Yeul Lee),양선아(Seun-Ah Yang),방대석(Daesuk Bang),지광환(Kwang-Hwan Jhee) 한국생명과학회 2021 생명과학회지 Vol.31 No.3

고장초는 오랫동안 식용 및 의약 목적으로 차를 만드는 데 사용되어 왔다. 그러나 고장초를 고부가가치 식용재료로 사용하는 연구는 불충분하다. 이전 연구에서 우리는 tricin이 고장초의 주요 화합물임을 확인했다. 본 연구에서는 고장초 추출물의 HepG2 세포 보호 효과를 조사하였다. 고장초 추출물 또는 tricin의 HepG2 세포에 대한 독성 실험 결과, 사용한 모든 농도에서 고장초 추출물 또는 tricin에 대한 독성은 나타나지 않았다. 또한 tert-butyl hydroperoxide (t-BHP)에 의해 감소된 세포 생존율은 고장초 추출물(100 μg/ml에서 69.23%) 또는 tricin (100 ng/ml에서 74.47%)에 의해 증가되었다. 또한 고장초 추출물(250 μg/ml) 또는 tricin (250 ng/ml)은 산화적 손상에 의한 활성 산소종(ROS) 생성을 효과적으로 억제했다. 또한 항산화 효소로 알려진 superoxide dismutase 1(SOD1), catalase, heme oxygenase-1 (HO-1), nuclear factor erythroid-related factor 2 (Nrf2)의 단백질 발현은 고장초 추출물(100 μg/ml에서 2.1, 1.6, 1.7, 1.5배) 또는 tricin (250 ng/ml에서 2.6, 1.8, 2.2, 2.0배) 처리로 증가했으며, 이는 고장초 추출물의 HepG2 세포 보호 효과는 tricin의 활성과 관련이 있다는 것을 시사한다. 종합하면 고장초는 간 기능개선 관련 기능성 식품 소재로 개발이 가능할 것으로 기대된다. Zizania latifolia has long been used as a tea for both edible and medicinal purposes. However, research into the use of Z. latifolia as a high value-added edible material is lacking. In a previous study, we confirmed that tricin is the major component in Z. latifolia. In this study, we investigated the protective effect of a Z. latifolia extract (ZLE). Toxicity tests of ZLE or tricin on HepG2 cells revealed no toxicity due to ZLE or tricin at all concentrations used. The reduction in cell viability by tert-butyl hydroperoxide (t-BHP) was suppressed by treatment with ZLE or tricin. In addition, ZLE or tricin effectively inhibited the production of reactive oxygen species (generation of hydrogen peroxide, alkoxy free radicals, and peroxyl free radicals by t-BHP) and oxidative damage. ZLE or tricin treatments also increased the protein expression of superoxide dismutase 1 (SOD1), catalase, heme oxygenase-1 (HO-1), and nuclear factor erythroid-related factor 2 (Nrf2), which are known as antioxidant enzymes, suggesting that the protective effect of ZLE is related to activation of tricin. Taken together, the results indicate that Z. latifolia can be developed as a functional food material for improving liver function.

방사선 측정 및 해석 연구 : 원자로 냉각수중의 방사능해석에 의한 결함핵연료봉의 평가 Assessment of Defected Fuel by Analysis of Reactor Coolant Activities

양재춘,오희필,전재식,이호연,오헌진,정문규,박해용 충남대학교 기초과학연구소 1987 연구논문집 Vol.7 No.-

중성자와 우라늄의 핵반응에 의해 생성된 핵분열생성물의 물리적 특성을 이용하여 원자로 내의 핵연료 상태를 해석하는 모델을 개선하였다. 이 모델에서는 고체 핵연료 내에서 특정핵종의 핵분열생성물의 생성과 이것이 원자로 냉각재까지 방출되는 과정을 계산하고 추적하여 방사능농도와 결함 핵연료봉의 수를 관계짓는 방정식의 계수들을 결정한다. 핵분열생성물의 거동은 이탈(knock out)과 이동(migration) 두 부분으로 나누어 해석하였으며 트램프 우라늄의 영향을 분리할 수 있도록 하였다. 실측자료로는 가압 경수형 원자로인 고리 원자력발전소 1호기의 1차 냉각재를 분석해서 얻은 I-131과 I-133의 방사능 강도를 이용하였다. 이 실험자료와 위 방정식에서 구한 방사능 강도로부터 구한 결함 핵연료의 수는 제3주기에서 9.34±1.13개 제6주기에서 0.294±0.092개로 나타났다. An improved mothod of assessing fuel status by analyzsis of the fission product in the reactor coolant system is proposed. The release mechanism of specific fission products is established for determination of the coefficients in the equations which relate the radioactivities with the amount of detected fuel. Knock-out and migration models are employed in the formulation of the release mechanism. The influence of the tramp uranium is quantified. Sample calculations were made for KNU 1 reactor system using the I-131 and I-133 concentrations in the primary coolant. The estimated number of defected fuel pins in the third and sixth cycles appeared to be 9.34±1.13 and 0.294±0.092, respectively.

실증연구를 위한 주택용 태양열 온수기 모니터링 시스템 개발

양동조,김재열,한재호,송경석,김우진 한국공작기계학회 2004 한국공작기계학회 추계학술대회논문집 Vol.2004 No.-

The application of solar energy, in the field of alternative energy, was on the increase tendency. In the case of advanced nations, through continuous R&D, solar hot water heater with high efficiency has been used for the house and the industrial process on business, advanced nations were reached up the experimental stage of solar generation system. But, the actual circumstance of the domestic has been not accomplished the popularization of solar hot water heater and the settlement of it which is the fundamental stage of the solar energy usage. This trouble, the domestic was flooded with small enterprise for producing solar hot water heater, was caused by the popularization and the production without verification of performance. To supply the monitoring program for evaluating solar hot water heater, this research was purpose to improve the technical development of the enterprise for producing solar-heat hot-water-boiler and served as an aid for the enlargement and the popularization on solar energy.

액상요구르트의 沈澱安定化를 위한 硏究

양지영,이호재 釜山工業大學校 1994 論文集 Vol.36 No.-

In order to process the liquid yogurt without stabilizing agents, addition of rice bran extracts to medium, single or mixed cultures of various lactic acid bacteria were investigated. Addition of rice bran extracts stimulated acid production and propagation of L. casei N.Y. and its optimum concentration was 0.1%. Cultures prepared using 0.1% of rice bran extracts could be produced stable liquid yogurt product without stabilizing agents. But the use of rice bran extracts to liquid yogurt manufacture in a pilot scale was problematical in view of cost and law. The single or mixed cultures of L.casei L-14 and L. bulgaricus B-5b couldn't be produced stable product without stabilizing agents. L. casei J.Y. was produced 2.7 of acidity at 37℃ for 36 hrs to obtain cultures with high acidity and high number of viable cells. The liquid yogurt product prepared using cooled cultures of L. casei J.Y. was stable without stabilizing agents. But the liquid yogurt product prepared using stabilizing agents was unstable because of charge imbalane.

인간배아의 공동배양 : REVIEW

양회생,이은주,김종호,최석철,심재철 동국대학교 경주대학 1999 東國論集 Vol.18 No.-

One of the contributory causes to poor pregnancy rates in assisted reproduction has been the decreased viability of transferred embryos and the transfer of four-cell embryos into and environment that naturally would be receptive only to 5-day-old blastocysts. In this paper, we have reviewed on the role of helper cells(cocultures) to mimic the in vivo, environment to bring about improved embryo quality and an increased number of blastocysts for replacement in IVF patients. The behavior of helper cell is first presented, followed by their use as cocultures for fertilization and cleavage of embryos. The mode of action and specificity of helper cells are also discussed. The currently available results of pregnancies after cocultures are presented together with future aspects of research that are necessary to refine the coculture system, The ultimate aim is to mimic in vivo conditions in vitro, so that at least the pregnancy rates of assisted conception can be parallel to normal fecundity in the human. Therefore, a very attractive future includes the freezing of blastocysts generated from coculture, thawing, and replacing them in natural cycles.

^60Co γ-선 조사에 의한 TBP 추출제의 방사선 분해 특성

양한범,이일희,한선호,김원호,유재형 한국공업화학회 2003 공업화학 Vol.14 No.3

방사성 액체폐기물에 함유되어 있는 방사성 핵종의 회수 및 처리에 사용되는 용매 추출제인 tributyl phosphate(TBP)를 인위적인 방법인 ^60Co γ-방사선을 조사시킨 다음 TBP 및 분해생성물을 기체 크로마토그래피-질량 분석법, 액체 크로마토그래피-질량 분석법, 핵 자기공명법(^31P-NMR), 이온 크로마토그래피, 적외선 분광법으로 측정하여 방사선 분해 생성물의 종류와 농도를 정량분석하고, TBP 추출제의 방사선 분해 특성에 대해 기술하였다. 실험결과로부터 TBP는 방사선에 의해 TBP에 결합되어 있는 3개의 butyl 기가 한 개씩 순차적으로 분해되거나, 두 개, 또는 3개의 butyl 기가 동시에 떨어지면서 TBP→HDBP→H_2MBP→H_3PO_4가 생성되는 반응기구로 분해되는 것으로 생각된다. This study was carried out to evaluate the radiation stability of tributyl phosphate (TBP) extractant by irradiation of ^60Co γ -rays. The degradation products of TBP leads to a decrease of extraction yields and/or formation of the third phase in the solvent extraction system of radioactive waste. TBP was irradiated with ^60Co γ -rays and the degradation products were analysed with gas chromatography - mass spectrometer (GC-MS), liquid chromatography - mass spectrometer (LC-MS), nuclear magnetic resonance (NMR) spectrometer, ion chromatography (IC) and infrared (IR) spectrometer. It was found that the major degradation products from gamma radiolysis of TBP were dibutyl phosphate (HDBP), monobutyl phosphate (H_2MBP) and phosphoric acid. The main radiolysis pathway of TBP may be decomposed to the H_3PO_4 by losing on3 butyl radical step by step in subsequent reactions or losing two~tree but radicals simultaneously like the following ways, that is TBP→HDBP→H_2MBP→H_3PO_4.

청신경종의 크기에 따른 어지러움의 양상 및 전정기능 검사의 특징

정원호,홍성화,조양선,김성민,장병찬,최재연,이승진 대한이비인후과학회 2000 대한이비인후과학회지 두경부외과학 Vol.43 No.1

핵연료에서 핵분열 생성물의 방출 기구에 관한 연구

양재춘,이호연,정문규 충남대학교 기초과학연구소 1986 연구논문집 Vol.6 No.-

중성자와 우라늄의 핵 반응에 의해 생성된 핵분열 생성물의 물리적 특성을 이용하여 원자로 내의 핵연료 상태를 해석하는 새로운 모델을 도입하였다. 고체 핵연료 내에서 핵분열 생성물의 생성과 이것의 원자로 냉각재까지 방출되는 과정을 계산하는 방정식을 세웠다. 이 방정식으로 핵분열 생성물의 source term을 계산하고, 이것이 고체 핵연료 내에서 방출되어 gap과 핵연료 피복재를 통하여 원자로 냉각재까지 방출하는 양을 계산하였으며, 원자로 1차 냉각재에서의 tramp uranium양을 계산하였다. 이 방정식을 computer로 계산하기 위하여 전산화 하였다. 실험 자료로는 가압 수형 원자로 (Pressurized Water Reactor)인 고리 원자력 발전소 1호기의 제 3주기 동안에 핵연료의 상태를 감시하기 위해 1차 냉각재를 분석해서 얻은 핵분열 생성물의 방사능 강도를 이용하였다. 이 실험 자료와 위 방정식에서 계산한 방사능 강도를 비교하여 결함 핵연료 수와 tramp uranium 양을 구하였다. 이렇게 구한 결과와 고리 1호기의 제 3주기 말에 핵연료 재장진을 위해 수행한 sipping test 결과를 비교해 보았다. 그 결과 본 연구에서 도입한 모델이 잘 맞는 것을 알 수 있었다. We propose the new model which analyzes the nuclear fuel state of the reactor from the physical characteristics of nuclear fission products which are produced by reactions between neutron and uranium 235. The main feature of this model is to calculate the generation of fission products inside the solid nuclear fuel and the release mechanism of fission products into the reactor coolant. Using the computer we solved the equation of the model and put the experimental activity data of the fission products to determine the number of failed fuel rods and amount of tramp uranium. These data had been taken from the primary coolant of the Kori Nuclear Generating Station, Unit 1. This result of our calculation is in a fairly good agreement with the result of the sipping test during the refueling period for cycle 3 of the Kori Nuclear Generating Station, Unit 1. As a result of this research we conclude that our model for the release mechanism of unclear fission products in reactor fuel is well describing the actual processes.

ULSI 금속배선용 구리 도금층의 성질에 미치는 첨가제의 영향

梁在國,李宰鎬 弘益大學校 科學技術硏究所 2001 科學技術硏究論文集 Vol.11 No.-

The effects of additives on characteristics of electroplated copper for ULSI metallization application has been investigated. The grain size of DC electroplated copper is coarse and the addition of organic additives made smaller grain size. Pulse plating showed similar effects of organic additives. The higher ratio of pulse plating time made finer grains. The optimum ratio of pulse was 8:2. The effects of PEG and chloride ions were also investigated when pulse plating was applied. The addition of PEG made finer grains, however chloride ions didn't show recognizabel effects on grain size. The effects of chloride ions should be reconsidered in narrow trench copper metallization.