Ethanol extract of Prunus mume fruit attenuates hydrogen peroxide-induced oxidative stress and apoptosis involving Nrf2/HO-1 activation in C2C12 myoblasts

Kang, J.S.,Kim, D.J.,Kim, G.Y.,Cha, H.J.,Kim, S.,Kim, H.S.,Park, C.,Hwang, H.J.,Kim, B.W.,Kim, C.M.,Choi, Y.H. Sociedade Brasileira de Farmacognosia 2016 Revista brasileira de farmacognosia Vol.26 No.2

<P>The fruit of the Prunus mume (Siebold) Siebold & Zucc., Rosaceae (Korean name: Maesil) has long been used as a health food or valuable medicinal material in traditional herb medicine in Southeast Asian countries. In this study, we determined the potential therapeutic efficacy of the ethanol extract of P. mume fruits (EEPM) against H2O2-induced oxidative stress and apoptosis in the murine skeletal muscle myoblast cell line C2C12, and sought to understand the associated molecular mechanisms. The results indicated that exposure of C2C12 cells to H2O2 caused a reduction in cell viability by increasing the generation of intracellular reactive oxygen species and by disrupting mitochondrial membrane permeability, leading to DNA damage and apoptosis. However, pretreatment of the cells with EEPM before H2O2 exposure effectively attenuated these changes, suggesting that EEPM prevented H2O2-induced mitochondria-dependent apoptosis. Furthermore, the increased ex-pression and phosphorylation of nuclear factor erythroid 2-related factor 2 (Nrf2) and up-regulation of heme oxygenase-1 (HO-1), a phase II antioxidant enzyme, were detected in EEPM-treated C2C12 cells. We also found that zinc protoporphyrin IX, an HO-1 inhibitor, attenuated the protective effects of EEPM against H2O2-induced reactive oxygen species accumulation and cytotoxicity. Therefore, these results indicate that the activation of the Nrf2/HO-1 pathway might be involved in the protection of EEPM against H2O2-induced cellular oxidative damage. In conclusion, these results show that EEPM contributes to the prevention of oxidative damage and could be used as a nutritional agent for oxidative stress-related diseases. (C) 2016 Sociedade Brasileira de Farmacognosia. Published by Elsevier Editora Ltda. All rights reserved.</P>

C language를 위한 Concurrent Programming 환경의 개발

윤용익(Y I Yoon),조주현(J H Cho),정영조(Y C Chung),강석열(S Y. Kang) 한국정보과학회 1988 한국정보과학회 학술발표논문집 Vol.15 No.1

Multiprocessor system이 널리 보급되고 사용됨에 따라 concurrent programming은 더욱 더 중요한 feature가 되어가고 있다. 기존의 C 언어는 concurrent programming을 위한 feature들을 가지고 있지 못하나, 본 논문에서는 concurrent processing이 가능한 Concurrent-C 언어를 설계, 구현하였다. Concurrent feature들을 첨가하는 방법으로는 여러 종류의 runtime library routine들을 제공하여 C program 내에서 이 routine들을 call하는 방식을 사용하였다. Concurrent-C는 UNIX 환경하에서 구현되었으며, 실제로 C compiler를 제공하는 어떠한 OS 상에서도 host machine의 종류에 관계없이 구현될 수 있다.

An exploration of the antioxidant effects of garlic saponins in mouse-derived C2C12 myoblasts

Kang, J. S.,Kim, S. O.,Kim, G.-Y.,Hwang, H. J.,Kim, B. W.,Chang, Y.-C.,Kim, W.-J.,Kim, C. M.,Yoo, Y. H.,Choi, Y. H. Spandidos Publications 2016 INTERNATIONAL JOURNAL OF MOLECULAR MEDICINE Vol.37 No.1

<P>In this study, we aimed to confirm the protective effects of garlic saponins against oxidative stress-induced cellular damage and to further elucidate the underlying mechanisms in mouse-derived C2C12 myoblasts. Relative cell viability was determined by 3-(4.5-dimethylthiazol-2-yl)-2.5 diphenyltetrazolium bromide assay. Comet assay was used to measure DNA damage and oxidative stress was determined using 2 ',7 '-dichlorofluorescein diacetate to measure intracellular reactive oxygen species (ROS) generation. Western blot analysis and small interfering RNA (siRNA)-based knockdown were used in order to investigate the possible molecular mechanisms. Our results revealed that garlic saponins prevented hydrogen peroxide (H2O2)-induced growth inhibition and exhibited scavenging activity against intracellular ROS. We also observed that garlic saponins prevented H2O2-induced comet tail formation and decreased the phosphorylation levels of gamma H2AX expression, suggesting that they can prevent H2O2-induced DNA damage. In addition, garlic saponins increased the levels of heme oxygenase-1 (HO-1), a potent antioxidant enzyme associated with the induction and phosphorylation of nuclear factor erythroid 2-related factor 2 (Nrf2) and the translocation of Nrf2 from the cytosol into the nucleus. However, the protective effects of garlic saponins on H2O2-induced ROS generation and growth inhibition were significantly reduced by zinc protoporphyrin IX, an HO-1 competitive inhibitor. In addition, the potential of garlic saponins to mediate HO-1 induction and protect against H2O2-mediated growth inhibition was adversely affected by transient transfection with Nrf2-specific siRNA. Garlic saponins activated extracellular signal-regulated kinase (ERK) signaling, whereas a specific ERK inhibitor was able to inhibit HO-1 upregulation, as well as Nrf2 induction and phosphorylation. Taken together, the findings of our study suggest that garlic saponins activate the Nrf2/HO-1 pathway by enabling ERK to contribute to the induction of phase II antioxidant and detoxifying enzymes, including HO-1 in C2C12 cells.</P>

고분자 전구체 용액으로부터 분무열분해법에 의해 합성되어진 구형 형상의 Y₂SiO₅:Ce 형광체

강희상,강윤찬,박희동,설용건,Kang, H.S.,Kang, Y.C.,Park, H.D.,Shul, Y.G. 한국재료학회 2003 한국재료학회지 Vol.13 No.3

Ce-doped $Y_2$SiO$_{5}$ phosphor particles of spherical morphology, fine size, high crystallinity and high photoluminescence (PL) intensity were prepared by spray pyrolysis. When nitrate precursor solution is adopted, hollow particles were formed by uneven drying rate between surface and inside of droplet. Citric acid and ethylene glycol were introduced as polymeric precursor to control the morphology of particles. When polymeric solution is adopted, polymeric chain is formed by the esterification reaction between carboxyl and hydroxy groups of citric acid and ethylene glycol, and considered as controlling the drying characteristics of droplet. $Y_2$$SiO_{5}$ :Ce phosphor particles prepared from polymeric precursor solution were spherical, filled, fine size and not agglomerate before and after post heat treatment. The optimum doping concentration of cerium was 0.5 mol% of overall solution concentration. The optimum amount of TBOS of high PL intensity and pure crystallinity of X2-type $Y_2$$SiO _{5}$ was 105% of stoichiometric amount. The PL intensity of $Y_2$X$/_{5}$ :Ce phosphor particles prepared using the polymeric precursor solution was 164% of that of the nitrate precursor solution due to homogeneous composition and good morphology.y.

열처리에 따른 Y₂O₃박막의 미세 구조 변화와 전기적 특성 변화에 대한 고찰

정윤하(Y. H. Jung),강성관(S. K. Kang),김은하(E. H. Kim),고대홍(D. H. Ko),조만호(M. H. Cho),황정남(C. N. Whang) 한국진공학회(ASCT) 1999 Applied Science and Convergence Technology Vol.8 No.3(1)

p-type Si (100) 기판 위에 습식 산화법으로 SiO₂ 층을 형성한 후, Ionized Cluster Beam(ICB) 증착 방법으로 200 Å 두께의 Y₂O₃ 박막을 증착 하였다. Y₂O₃ 박막이 증착 된 시편을 산소, 아르곤 분위기에서 열처리한 후, Atomic Force Microscopy(AFM)과 Transmission Electron Microscopy(TEM)을 사용하여 Y₂O₃ 박막의 표면과 계면을 관찰하였다. 열처리를 수행한 후 Y₂O₃ 박막과 Si 기판 사이에서 SiO₂층이 성장하고, 이트륨실리 케이트 층이 형성되는 것을 관찰할 수 있었다. 산소 분위기에서 열처리를 수행한 시편의 Y₂O₃ 박막 표면을 관찰한 결과, 표면 상부에 아르곤 분위기에서 열처리한 시편에서는 보이지 않았던 새로운 상이 형성되었음을 알 수 있었다. 또한 전기적 특성을 측정하기 위하여 Al/Y₂O₃/p-type Si (100) 의 캐패시턴스-전압 특성을 관찰하였고, 그 결과 Y₂O₃ 박막의 유전 상수 값이 약 9정도임을 알 수 있었다. We investigated the interfacial reactions between the Y₂O₃ film deposited by ICB processing and p-type (100) Si substrates upon annealing treatments in O₂ and Ar gas ambients. We also investigated the evolution of surface morphology of ICB deposited Y₂O₃ films upon annealing treatments. We observed that the root-mean-square (RMS) value of surface roughness measured by AFM increased with annealing time at 800℃ in O₂ ambient, while the change of surface roughness was not observed in Ar ambient. We also found the growth of SiO₂ layer and the formation of yttrium silicate layer. From the capacitance values (C_(acc)) measured by C-V measurements, the relative dielectric constant of Y₂O₃ film in metal-insulator-semiconductor (MIS) structure was estimated to be about 9.

Comprehensive study on critical role of surface oxygen vacancies for 2DEG formation and annihilation in LaAlO3/SrTiO3 heterointerfaces

Moon, S. Y.,Moon, C. W.,Chang, H. J.,Kim, T.,Kang, C. Y.,Choi, H. J.,Kim, J. S.,Baek, S. H.,Jang, H. W. Springer Science + Business Media 2016 ELECTRONIC MATERIALS LETTERS Vol.12 No.2

<P>Here we report comprehensive study of 2DEG at a-LAO/STO interfaces in comparison with 2DEG at crystalline LaAlO3 (c-LAO)/STO interfaces. We observe that the oxygen deficient environment during the deposition of LAO overlayer is essentially required to create 2DEG at LAO/STO interface regardless of growth temperature from 25 degrees C to 700 degrees C, indicating that the oxygen-poor condition in the system is more important than the crystallinity of LAO layer. The critical thickness (2.6 nm) of 2DEG formation at a-LAO/STO heterostructure is thicker than (1.6 nm) that at c-LAO/STO. Upon ex-situ annealing at 300 degrees C under 300 mTorr of oxygen pressure, 2DEG at a-LAO/STO interface is annihilated, while that in c-LAO/STO interface is still maintained. With combing these findings and scanning transmission electron microscope (STEM) analysis, we suggest that oxygen vacancies at the LAO surface is attributed to the origin of 2DEG formation at the LAO/STO and the crystallinity of the LAO overlayer plays a critical role in the annihilation of 2DEG at a-LAO/STO interface rather than in the formation of 2DEG. This work provides a framework to understand the importance of prohibiting the LAO surface from being oxidized for achieving thermally stable 2DEG at a-LAO/STO interface.</P>

DMF effect on the morphology and the luminescence properties of Y₂O₃:Eu³⁺ red phosphor prepared by spray pyrolysis

Jung, K.Y.,Kang, Y.C.,Park, Y.K. Korean Society of Industrial and Engineering Chemi 2008 Journal of industrial and engineering chemistry Vol.14 No.2

N,N-Dimethylformamide (DMF) was used as a drying control chemical additive (DCCA) in spray pyrolysis in order to improve the luminous properties of Y<SUB>2</SUB>O<SUB>3</SUB>:Eu particles. It was found that the addition of DMF to the spray solution containing citric acid (CA) and ethylene glycol (EG) greatly enhances the photoluminescence intensity as well as the morphology of Y<SUB>2</SUB>O<SUB>3</SUB>:Eu particles. According to BET analysis, the surface area of Y<SUB>2</SUB>O<SUB>3</SUB>:Eu particles prepared from the solution containing only the organic additives was not reduced, whereas, the surface area of the Y<SUB>2</SUB>O<SUB>3</SUB>:Eu particles prepared from the solution containing both DMF and organic additives was decreased gradually as increasing the concentration of DMF. From these results, it was concluded that the adding of DMF to the spray solution containing the organic additives is a very effective way to reduce the porosity of phosphor particles, keeping the spherical morphology. As a result, the densification of porous structure led to greatly improve the photoluminescence intensity of Y<SUB>2</SUB>O<SUB>3</SUB>:Eu particles under ultraviolet (254nm) excitation. Finally, the prepared Y<SUB>2</SUB>O<SUB>3</SUB>:Eu particles with dense structure showed about 208% improved photoluminescence intensity compared with the particles which have a spherical shape but porous structure.

SIGN-R1, a C-type lectin, enhances apoptotic cell clearance through the complement deposition pathway by interacting with C1q in the spleen

Prabagar, M G,Do, Y,Ryu, S,Park, J-Y,Choi, H-J,Choi, W-S,Yun, T J,Moon, J,Choi, I-S,Ko, K,Ko, K,Young Shin, C,Cheong, C,Kang, Y-S Macmillan Publishers Limited 2013 Cell death and differentiation Vol.20 No.4

Complements, such as C1q and C3, and macrophages in the splenic marginal zone (MZMs) play pivotal roles in the efficient uptake and processing of circulating apoptotic cells. SIGN-R1, a C-type lectin that is highly expressed in a subpopulation of MZMs, regulates the complement fixation pathway by interacting with C1q, to fight blood-borne Streptococcus pneumoniae. Therefore, we examined whether the SIGN-R1-mediated classical complement pathway plays a role in apoptotic cell clearance and immune tolerance. SIGN-R1 first-bound apoptotic cells and this binding was significantly enhanced in the presence of C1q. SIGN-R1–C1q complex then immediately mediated C3 deposition on circulating apoptotic cells in the MZ, leading to the efficient clearance of them. SIGN-R1-mediated C3 deposition was completely abolished in the spleen of SIGN-R1 knockout (KO) mice. Given that SIGN-R1 is not expressed in the liver, we were struck by the finding that C3-deposited apoptotic cells were still found in the liver of wild-type mice, and dramatically reduced in the SIGN-R1 KO liver. In particular, SIGN-R1 deficiency caused delayed clearance of apoptotic cells and aberrant secretion of cytokines, such as TNF-α, IL-6, and TGF-β in the spleen as well as in the liver. In addition, anti-double- and single-stranded DNA antibody level was significantly increased in SIGN-R1-depleted mice compared with control mice. These findings suggest a novel mechanism of apoptotic cell clearance which is initiated by SIGN-R1 in the MZ and identify an integrated role of SIGN-R1 in the systemic clearance of apoptotic cells, linking the recognition of apoptotic cells, the opsonization of complements, and the induction of immune tolerance.

SIGN-R1, a C-type lectin, enhances apoptotic cell clearance through the complement deposition pathway by interacting with C1q in the spleen

MG Prabagar,Y Do,S Ryu,J-Y Park,H-J Choi,W-S Choi,TJ Yun,J Moon,I-S Choi,K Ko,K Ko,C Young Shin,C Cheong,Y-S Kang 한국당과학회 2013 한국당과학회 학술대회 Vol.2013 No.1

Complements, such as C1q and C3, and macrophages in the splenic marginal zone (MZMs) play pivotal roles in the efficient uptake and processing of circulating apoptotic cells. SIGN-R1, a C-type lectin that is highly expressed in a subpopulation of MZMs, regulates the complement fixation pathway by interacting with C1q, to fight blood-borne Streptococcus pneumoniae. Therefore, we examined whether the SIGN-R1-mediated classical complement pathway plays a role in apoptotic cell clearance and immune tolerance. SIGN-R1 first-bound apoptotic cells and this binding was significantly enhanced in the presence of C1q. SIGN-R1-C1q complex then immediately mediated C3 deposition on circulating apoptotic cells in the MZ, leading to the efficient clearance of them. SIGN-R1-mediated C3 deposition was completely abolished in the spleen of SIGN-R1 knockout (KO) mice. Given that SIGN-R1 is not expressed in the liver, we were struck by the finding that C3-deposited apoptotic cells were still found in the liver of wild-type mice, and dramatically reduced in the SIGN-R1 KO liver. In particular, SIGN-R1 deficiency caused delayed clearance of apoptotic cells and aberrant secretion of cytokines, such as TNF-α, IL-6, and TGF-β in the spleen as well as in the liver. In addition, anti-double- and single-stranded DNA antibody level was significantly increased in SIGN-R1-depleted mice compared with control mice. These findings suggest a novel mechanism of apoptotic cell clearance which is initiated by SIGN-R1 in the MZ and identify an integrated role of SIGN-R1 in the systemic clearance of apoptotic cells, linking the recognition of apoptotic cells, the opsonization of complements, and the induction of immune tolerance.

Novel dentin phosphoprotein frameshift mutations in dentinogenesis imperfecta type II

Lee, K‐,E,Kang, H‐,Y,Lee, S‐,K,Yoo, S‐,H,Lee, J‐,C,Hwang, Y‐,H,Nam, KH,Kim, J‐,S,Park, J‐,C,Kim, J‐,W Blackwell Publishing Ltd 2011 Clinical genetics Vol.79 No.4

<P>Lee K‐E, Kang H‐Y, Lee S‐K, Yoo S‐H, Lee J‐C, Hwang Y‐H, Nam KH, Kim J‐S, Park J‐C, Kim J‐W. Novel dentin phosphoprotein frameshift mutations in dentinogenesis imperfecta type II.</P><P>The dentin sialophosphoprotein (<I>DSPP</I>) gene encodes the most abundant non‐collagenous protein in tooth dentin and DSPP protein is cleaved into several segments including the highly phosphorylated dentin phosphoprotein (DPP). Mutations in the <I>DSPP</I> gene have been solely related to non‐syndromic form of hereditary dentin defects. We recruited three Korean families with dentinogenesis imperfecta (DGI) type II and sequenced the exons and exon–intron boundaries of the <I>DSPP</I> gene based on the candidate gene approach. Direct sequencing of PCR products and allele‐specific cloning of the highly repetitive exon 5 revealed novel single base pair (bp) deletional mutations (c.2688delT and c.3560delG) introducing hydrophobic amino acids in the hydrophilic repeat domain of the DPP coding region. All affected members of the three families showed exceptionally rapid pulp chambers obliteration, even before tooth eruption. Individuals with the c.3560delG mutation showed only mild, yellowish tooth discoloration, in contrast to the affected individuals from two families with c.2688delT mutation. We believe that these results will help us to understand the molecular pathogenesis of DGI type II as well as the normal process of dentin biomineralization.</P>