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.

소아 알레르기비염의 경제적 부담 평가를 위한 다기관 조사

공도연 ( Do Youn Kong ),김경원 ( Kyung Won Kim ),김우경 ( Woo Kyung Kim ),민택기 ( Taek Ki Min ),박용민 ( Yong Mean Park ),안재억 ( Jae Ouk Ahn ),양현종 ( Hyeon Jong Yang ),염혜영 ( Hye Yung Yum ),윤혜선 ( Hae Sun Yoon ),전유훈 ( 대한소아알레르기호흡기학회(구 대한소아알레르기 및 호흡기학회) 2012 소아알레르기 및 호흡기학회지 Vol.22 No.2

목적: 알레르기비염의 유병률은 전 세계적으로 급격히 증가하고 있으며, 그에 따른 경제적 부담도 증가하고 있다. 그러나, 소아 알레르기 질환이 미치는 경제적 부담에 관한 국내 연구는 제한적이어서 소아 알레르기비염이 환자와 그 가족에게 미치는 경제적 부담을 산출하고자 본 연구를 진행하였다. 방법: 2008년 7월 1일부터 9월 31일까지 서울시 6개 2-3차 의료기관을 방문한 18세 이하 소아 알레르기비염 환자 및 보호자를 대상으로 설문 조사를 진행하였다. 설문을 통해 직접 의료비 (병·의원 진료비, 및 약제비 한방 진료비 및 약제비, 보완/대체요법비), 직접비의료비 (교통비, 환경개선비), 그리고 간접비용 (월 평균 노동 손실)을 조사하였고 그 결과를 질환의 중증도 및 유병 기간에 따라 분석하여 그 차이를 비교하였다. 결과: 모집된 262명의 대상 중 174명(66.4%)이 남자였고, 평균 연령은 6.54세였다. 대상군의 연간 평균 직접 의료비는 177만 원이었고 직접비 의료비는 57만 원이었다. 비록 통계학적 유의성은 없었지만, 알레르기비염의 중증도가 증가할수록 직접 의료비가 증가하는 경향을 보였고, (P=0.053) 유병 기간 또한 직접 의료비의 증가와 유의한 양의 상관 관계를 보였다. (R=0.195, P=0.002) 대상 환자 보호자의 약 17%가 아이의 알레르기비염으로 인해 직장에 결근 또는 조퇴를 경험한 것으로 조사되어 사회적 간접비용을 미루어 생각할 수 있었다. 결론: 알레르기비염이 미치는 경제적 부담은 질환의 중증도가 심할수록, 그리고 유병 기간이 길수록 증가하며, 이는 특히 한방 진료 및 치료비와 보완/대체요법비의 증가에 기인한 것으로 조사되었다. 따라서 알레르기비염으로 인한 경제적 부담을 줄이기 위해서는 환자와 보호자를 대상으로 근거 중심의 치료를 할 수 있도록 지속적이고 체계적인 교육이 필요할 것으로 사료된다. Purpose: The prevalence of allergic rhinitis is rapidly increasing and results in relatively high socio-economic burden on their family and community. However, studies on the economic burden of pediatric allergic rhinitis in Korea are limited. Therefore, we conducted this study to investigate the impact of pediatric allergic rhinitis on economic burden. Methods: Two hundred sixty two children with allergic rhinitis were enrolled in 6 secondary or tertiary medical centers in Seoul from July to September, 2008. We collected data of the economic burden of allergic rhinitis (direct medical costs, direct nonmedical costs, and indirect costs) by face to face questionnaire survey. We compared the economic burden according to the severity and the duration of allergic rhinitis. Results: The mean age of subjects was 6.54 years, and male were 174 (66.4%). Direct medical costs (10,000 Korean Won/yr) were 177.75, and direct nonmedical costs were 57.92. Although, there was no statistical significance, direct medical costs showed increasing trends in severe allergic rhinitis. (P=0.053) In addition, direct medical costs were positively correlated with duration of allergic rhinitis.( R=0.195, P=0.002). About 17% of the parents who care the allergic rhinitis children experienced the work absence due to their child s illness. Conclusion: The economic burdens of allergic rhinitis were positively correlated with the severity and duration of illness. Particularly costs for alternative medicine including oriental medicine` were related with severity and duration allergic rhinitis. Therefore, special efforts for education with evidence based treatment strategy are necessary to decrease the economic burden of allergic rhinitis.

Estimation of Air Exchange Rate and Source Strength of Indoor Air Quality

Won-ho Yang,Ki-young Lee,Moon-ho Chung,Moon-shik Zong 한국보건교육건강증진학회 1999 한국보건교육·건강증진학회 학술대회 발표논문집 Vol.- No.-

Antioxidant activity and cell protective effect of loliolide isolated from Sargassum ringgoldianum subsp. coreanum

Yang, Xiudong,Kang, Min-Cheol,Lee, Ki-Wan,Kang, Sung-Myung,Lee, Won-Woo,Jeon, You-Jin The Korean Society of Phycology 2011 ALGAE Vol.26 No.2

A monoterpene lactone, loliolide was successively isolated from brown seaweed, Sargassum ringgoldianum subsp. coreanum using column chromatography and high-performance liquid chromatography. The structure of the isolated compound was determined by comparison of EIMS and NMR spectral data with the previously published data. The antioxidant activities of loliolide were also evaluated by DPPH and $H_2O_2$ radical and intracellular reactive oxygen species scavenging assays, and it showed moderate activities in all antioxidant assays. Furthermore, loliolide was found to exert positive dose-dependent effects in the protective effects against $H_2O_2$-induced cell damage which were determined via MTT, Hoechst staining assays and cell cycle analysis. This is the first study on chemical constituent of this seaweed according to our best knowledge. These results clearly indicated that loliolide isolated from Sargassum ringgoldianum subsp. coreanum can protect the cells against $H_2O_2$-induced cell damage or apoptosis.

Re-examination of the Standard Cultivation Practices of Rice in Response to Climate Change in Korea

Yang, Woonho,Cho, Hyeoun Suk,Kim, Mihyang,Seong, Ki Yeong,Park, Tae Seon,Seo, Myung Chul,Kang, Hang Won 한국작물학회 2013 Journal of crop science and biotechnology Vol.16 No.2

The impact of climate change has been simulated or estimated to bring about yield decline and quality deterioration of rice in Korea, a temperate country. To cope with these negative impacts, here we propose likely changes in the standard cultivation practices of rice in consideration of the current information on the progress/prediction of climate change and related physiological aspects of rice. Shifting grain-filling period could be a promising choice to optimize temperature for rice grain-filling, a crucial growth stage to productivity, hence providing rice plants with sufficient duration and solar radiation for the period. This choice, however, shortens days to flowering by the additive combined effects of high temperature by delayed transplanting, temperature rise itself by climate change, and accelerated phase change of rice by high temperature and short day-length. These combined effects may delay the time of transplanting in a great extent, hence reducing biomass accumulation of rice before flowering. In these conditions, recovering decreased biomass production is the key concern for rice productivity. This includes raising healthy seedlings by omitting the covering process, dense planting, and nutrient management to enhance plant's uptake activity. Current standard water management, especially mid-term drainage and intermittent irrigation, would have more importance in the future since they mitigate methane emission from the paddy. Field monitoring for weeds and pests would be an important first step to identify newly developing or thriving species for establishing subsequent controlling strategies. Earlier weed control should be emphasized through adjusting time of herbicide application.

Differential Expressions of Gap Junction Proteins during Differentiation of Rat Neuronal Stem Cells

Yang, Se-Ran,Cho, Sung-Dae,Ahn, Nam-Shik,Jung, Ji-Won,Park, Joon-Suk,Tiep, Nguyen Ba,Park, Ki-Su,Hong, In-Sun,Jo, Eun-Hye,Seo, Min-Seo,Yoon, Byong-Su,Lee, Yong-Soon,Kang, Kyung-Sun Korean Environmental Mutagen Society 2003 한국환경성돌연변이·발암원학회지 Vol.23 No.1

Gap junctional intercellular communication (GJIC) plays a key role during development, process of tissue differentiation, and in maintenance of adult tissue homeostasis. Neural stem cells leading to formation of cell clusters termed 'neurospheres', can differentiate into neurons, oligodendrocytes, and astrocytes. We investigated the expression levels and distribution of connexin43 (Cx43) and connexin32 (Cx32), abundant gap junctional protein in neural cells and in neurospheres isolated from rat fetus embryonic day (ED) 17. During differentiation of neurospheres, expression of Cx43 and 32 were increased time-dependently within 72 h, and then decreased at 7 day in western blot analysis. TPA-induced inhibition of GJIC was confirmed by decreased fluorescence by SL/DT assay, and induced hyperphosphorylation of Cx43 while no changes in Cx32 levels in western blot assay. Our results indicate that GJIC may be a crucial role in the differentiation of neuronal stem cell. And this GJIC can be inhibited by TPA through the hyperphosphorylation of Cx43.

7,8,4"-Trihydroxyisoflavone Attenuates DNCB-Induced Atopic Dermatitis-Like Symptoms in NC/Nga Mice

Ki Won Lee,Jiyoung Kim,Sam-Sung An,Pomjoo Lee,Hee Yang,Jinhwan Choi,Jong Rhan Kim,Heejung Kim,Heerim Kang 한국식품영양과학회 2014 한국식품영양과학회 학술대회발표집 Vol.2014 No.10

Multi-Sectional Coil Design for Wireless Power Transfer

Yang-bae Chun,Ki-won Hwang,Nam Kim,Seung-young Ahn 한국도시철도학회 2013 IJAR Vol.1 No.2

In this paper, we introduced wireless power transfer system for railway applications and proposed efficient multi-sectional coil design for maximal transfer power with minimal leakage electromagnetic field. In contrast to electric vehicle applications, the horizontal movement of the pickup coil and the airgap are assumed ignorable in railway system. In this condition, the design of dual coil for transmitter and receiver has very efficient magnetic field for power transfer, and the dual coil showed 43% increase of induced voltage and 85% decrease of electromagnetic field level when compared with general single coil wireless power transfer system.

Orbital Elements of Comet C1490 Y1 and the Quadrantid Shower

Ki-Won Lee,Hong-Jin Yang,Myeong-Gu Park 한국천문학회 2008 天文學會報 Vol.33 No.1

Synthesis and Evaluation of Hydroquinone Derivatives as Inhibitors of Isocitrate Lyase

Yang, Hyeong-Cheol,Yu, Ji-Su,Oh, Ki-Bong,Shin, Dong-Sun,Cho, Won-Jea,Shin, Jong-Heon,Kim, Sang-Hee 대한약학회 2007 Archives of Pharmacal Research Vol.30 No.8

Isocitrate lyase (ICL) is envisaged as an attractive drug target for the development of antimicrobial agents. We have prepared a series of hydroquinone derivatives on the basis of the structure of halisulfates, a naturally occurring inhibitor of ICL. The obtained derivatives were evaluated against ICL of C. albicans. The preliminary structure-activity relationships and the minimal structural requirements for potency were established through structural modifications.