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.

권역심뇌혈관질환센터 사업의 비용-편익 분석

김병호 ( Byung Ho Kim ),감신 ( Sin Kam ),배상근 ( Sang Geun Bae ),김건엽 ( Keon-yeop Kim ),이원기 ( Won Kee Lee ),홍남수 ( Nam-soo Hong ),박형근 ( Hyeung-keun Park ),이혜진 ( Heyjean Lee ),조은정 ( Eun-jung Cho ),채성철 ( Shung C 한국보건정보통계학회(구 한국보건통계학회) 2017 보건정보통계학회지 Vol.42 No.1

Objectives: This study was conducted to investigate economic feasibility of operating Regional Cardiocerebrovascular Centers using cost-benefit analysis. Methods: The current study assessed cost and benefit data collected from nine hospitals which were designated as Regional Cardiocerebrovascular Centers between 2008 and 2010. Results: The operation of Regional Cardiocerebrovascular Centers reduced mortality rate and length of stay due to acute myocardial infarction and stroke and also decreased disability occurred after stroke. The total calculated cost of operating nine Regional Cardiocerebrovascular Centers was 19.85-22.30 billion won and the minimum benefit calculated was 23.98 billion won. Applying the maximum cost and the minimum benefit, the net benefit was 1.68 billion won, which is estimated to 190 million won per Regional Cardiocerebrovascular Center. Conclusions: The present study revealed that the operation of Regional Cardiocerebrovascular Centers was economically beneficial. The benefit would be larger if intangible benefit such as the long-term effects to community hospitals and enhancement of quality of life of patients and their families are considered.

Hypoxia-Responsive MicroRNA-101 Promotes Angiogenesis <i>via</i> Heme Oxygenase-1/Vascular Endothelial Growth Factor Axis by Targeting Cullin 3

Kim, Ji-Hee,Lee, Kwang-Soon,Lee, Dong-Keon,Kim, Joohwan,Kwak, Su-Nam,Ha, Kwon-Soo,Choe, Jongseon,Won, Moo-Ho,Cho, Byung-Ryul,Jeoung, Dooil,Lee, Hansoo,Kwon, Young-Guen,Kim, Young-Myeong Mary Ann Liebert 2014 Antioxidants & redox signaling Vol.21 No.18

<P>Aims: Hypoxia induces expression of various genes and microRNAs (miRs) that regulate angiogenesis and vascular function. In this study, we investigated a new functional role of new hypoxia-responsive miR-101 in angiogenesis and its underlying mechanism for regulating heme oxygenase-1 (HO-1) and vascular endothelial growth factor (VEGF) expression. Results: We found that hypoxia induced miR-101, which binds to the 3 ' untranslated region of cullin 3 (Cul3) and stabilizes nuclear factor erythroid-derived 2-related factor 2 (Nrf2) via inhibition of the proteasomal degradation pathway. miR-101 overexpression promoted Nrf2 nuclear accumulation, which was accompanied with increases in HO-1 induction, VEGF expression, and endothelial nitric oxide synthase (eNOS)-derived nitric oxide (NO) production. The elevated NO-induced S-nitrosylation of Kelch-like ECH-associated protein 1 and subsequent induction of Nrf2-dependent HO-1 lead to further elevation of VEGF production via a positive feedback loop between the Nrf2/HO-1 and VEGF/eNOS axes. Moreover, miR-101 promoted angiogenic signals and angiogenesis both in vitro and in vivo, and these events were attenuated by inhibiting the biological activity of HO-1, VEGF, or eNOS. Moreover, these effects were also observed in aortic rings from HO-1(+/-) and eNOS(-/-) mice. Local overexpression of miR-101 improved therapeutic angiogenesis and perfusion recovery in the ischemic mouse hindlimb, whereas antagomiR-101 diminished regional blood flow. Innovation: Hypoxia-responsive miR-101 stimulates angiogenesis by activating the HO-1/VEGF/eNOS axis via Cul3 targeting. Thus, miR-101 is a novel angiomir. Conclusion: Our results provide new mechanistic insights into a functional role of miR-101 as a potential therapeutic target in angiogenesis and vascular remodeling. Antioxid. Redox Signal. 21, 2469-2482.</P>

Clinical Research Article : The effect of Low fresh gas flow rate on sevoflurane consumption

( Ho Geol Ryu ),( Ji Hyun Lee ),( Kyung Ku Lee ),( Nam Su Gil ),( Chong Soo Kim ),( Sung Eun Sim ),( Sang Chul Lee ),( Seong Won Min ) 대한마취과학회 2011 Korean Journal of Anesthesiology Vol.60 No.2

Background: In an era of medical cost containment, cost-effectiveness has become a major focus in healthcare. The effect of a new policy on the use of low fresh gas flow during maintenance of general anesthesia with volatile anesthetics was evaluated. Methods: The numbers and duration of general anesthesia cases using sevoflurane 5 weeks prior to and 15 weeks after policy implementation were retrieved from the electronic medical records database. The number of sevoflurane bottles consumed was also assessed. The anesthesia hours per bottle of sevoflurane were compared before and after policy implementation. Results: The number of anesthesia hours performed per bottle of sevoflurane increased by 38.3%. The effect varied over time and tended to fade with time. Conclusions: The implementation of a low fresh gas flow rate policy effectively reduces the amount of sevoflurane consumed for the same duration of anesthesia. (Korean J Anesthesiol 2011; 60: 75-77)

Biochemical and Structural Analysis of Hormone-sensitive Lipase Homolog EstE7: Insight into the Stabilized Dimerization of HSL-Homolog Proteins

Nam, Ki-Hyun,Park, Sung-Ha,Lee, Won-Ho,Hwang, Kwang-Yeon Korean Chemical Society 2010 Bulletin of the Korean Chemical Society Vol.31 No.9

Hormone sensitive lipase (HSL) plays a major role in energy homeostasis and lipid metabolism. Several crystal structures of HSL-homolog proteins have been identified, which has led to a better understanding of its molecular function. HSL-homolog proteins exit as both monomer and dimer, but the biochemical and structural basis for such oligomeric states has not been successfully elucidated. Therefore, we determined the crystal structure of HSL-homolog protein EstE7 from a metagenome library at $2.2\;{\AA}$ resolution and characterized the oligomeric states of EstE7 both structurally and biochemically. EstE7 protein prefers the dimeric state in solution, which is supported by its higher enzymatic activity in the dimeric state. In the crystal form, EstE7 protein shows two-types of dimeric interface. Specifically, dimerization via the external ${beta}8$-strand occurred through tight association between two pseudosymmetric folds via salt bridges, hydrogen bonds and van der Waals interactions. This dimer formation was similar to that of other HSL-homolog protein structures such as AFEST, BEFA, and EstE1. We anticipate that our results will provide insight into the oligomeric state of HSL-homolog proteins.

Enhancement of efficient incorporation of Unnatural Amino Acid by control of translation key factors

Nam Young Kim(김남영),Jin Ho Ahn(안진호),Tae Wan Kim(김태완),In Seok Oh(오인석),Jung won Keum(금정원),Jeong Mi Son(손정미),Dong Myung Kim(김동명),Chang Kil Park(박창길),Cha Yong Choi(최차용) 한국생물공학회 2004 한국생물공학회 학술대회 Vol.2004 No.10

Results of Primary Total Hip Arthroplasty Using 36 mm Femoral Heads on 1st Generation Highly Cross Linked Polyethylene in Patients 50 Years and Less with Minimum Five Year Follow-up

( Won Kee Choi ),( Myung Rae Cho ),( Hee Soo Kim ),( Jun Ho Nam ),( Seung Bum Chae ) 대한고관절학회 2016 Hip and Pelvis Vol.28 No.2

Purpose: We evaluated the clinical and radiographic midterm results of primary total hip arthroplasty (THA) using a 36 mm diameter femoral head on 1st generation highly cross-linked polyethylene (HXLPE) in patients 50 years and less with minimum five year follow-up. Materials and Methods: We retrospectively reviewed 31 patients (41 hips) aged 50 years and less underwent primary THA with a 36 mm diameter femoral head on HXLPE between 2004 and 2010. Clinical follow-ups included specific measurements like modified Harris hip scores (HHS) and Merle d`Aubigne and Postel score. For radiologic evaluations, together with position of acetabular cup at six weeks later of postoperation, we separately calculated the penentrations of femoral head into polyethylene liners during postoperation and one year later check-ups, and during one year later check-ups and final check-ups. Results: There were no major complications except for one case of dislocation. Average modified HHS at final follow-up was 88 (81-98), and Merle d`Aubigne and Postel scores were more than 15. Mean acetabular cup inclination and anteversion were 45.81。(36.33。-54.91。) and 13.26。(6.72。-27.71。), respectively. Average femoral head penetration of steady-state wear rate determined using radiographs taken at one-year postoperatively and at latest follow-up was 0.042±0.001 mm/year. Conclusion: Based on minimum 5 years clinical results, we think 36 mm metal head coupling with HXLPE as the good alternate articulation surface when planning THA for patients aged 50 years and less.

Developing the vegetation drought response index for South Korea (VegDRI-SKorea) to assess the vegetation condition during drought events

Nam, Won-Ho,Tadesse, Tsegaye,Wardlow, Brian D.,Hayes, Michael J.,Svoboda, Mark D.,Hong, Eun-Mi,Pachepsky, Yakov A.,Jang, Min-Won TaylorFrancis 2018 International journal of remote sensing Vol.39 No.5

<P>South Korea has experienced severe droughts and water scarcity problems that have influenced agriculture, food prices, and crop production in recent years. Traditionally, climate-based drought indices using point-based meteorological observations have been used to help quantify drought impacts on the vegetation in South Korea. However, these approaches have a limited spatial precision when mapping detailed vegetation stress caused by drought. For these reasons, the development of a drought index that provides detailed spatial-resolution information on drought-affected vegetation conditions is essential to improve the country's drought monitoring capabilities, which are needed to help develop more effective adaptation and mitigation strategies. The objective of this study was to develop a satellite-based hybrid drought index called the vegetation drought response index for South Korea (VegDRI-SKorea) that could improve the spatial resolution of agricultural drought monitoring on a national scale. The VegDRI-SKorea was developed for South Korea, modifying the original VegDRI methodology (developed for the USA) by tailoring it to the available local data resources. The VegDRI-SKorea utilizes a classification and regression tree (CART) modelling approach that collectively analyses remote-sensing data (e.g. normalized difference vegetation index (NDVI)), climate-based drought indices (e.g. self-calibrated Palmer drought severity index (PDSI) and standardized precipitation index (SPI)), and biophysical variables (e.g. elevation and land cover) that influence the drought-related vegetation stress. This study evaluates the performance of the recently developed VegDRI-SKorea for severe and extreme drought events that occurred in South Korea in 2001, 2008, and 2012. The results demonstrated that the hybrid drought index improved the more spatially detailed drought patterns compared to the station-based drought indices and resulted in a better understanding of drought impacts on the vegetation conditions. The VegDRI-SKorea model is expected to contribute to the monitoring of drought conditions nationally. In addition, it will provide the necessary information on the spatial variations of those conditions to evaluate local and regional drought risk assessment across South Korea and assist local decision-makers in drought risk management.</P>

Study on Local and Year Variation of QTLs relating to Heading Date, Culm Length and Panicle Length in Rice

Ho Il Kim,Jae Ki Chang,Young Tae Lee,Soon Jong Seok,Hyun Jung Kang,Jae Keun Sohn,Gi Hwan Yi,Jeong Kweon Nam,Young Soon Cha,Do Won Yun,Kang Sub Lee,Yong Sam Kwon,Moo Young Moo 한국육종학회 2002 한국육종학회 학술발표회 발표요지 Vol.34 No.2

Modification of an Analysis Algorithm for DC Power Systems Considering Scalable Topologies

Won-Poong Lee,Jin-Young Choi,Young-Ho Park,Soo-Nam Kim,Dong-Jun Won 대한전기학회 2018 Journal of Electrical Engineering & Technology Vol.13 No.5

Direct current(DC) systems have recently attracted attention due to the increase in DC loads and distributed generations, such as renewable energy sources. Among these technologies, there has been much research into DC distribution systems or DC microgrids. Within this body of research, the main topics have been about optimum control and operation methods in terms of improving power efficiency. When DC systems are controlled and operated using power electronic devices such as converters, it is necessary to design and analyze them by considering the power electronics sections. For this reason, we propose a scalable DC system analysis algorithm, which considers various system configurations depending on the operating mode and location of the converter. The algorithm consists of power flow fault current calculations, and the results of the algorithm can be used for designing DC systems. The algorithm is implemented using MATLAB with defined input and output data. The verification of the algorithm is mainly performed using ETAP software, and the accuracy of the algorithm analysis can be confirmed through the results.