Aggravation of post-ischemic liver injury by overexpression of A20, an NF-κB suppressor

Yu, J.,Lee, H.S.,Lee, S.M.,Yu, H.C.,Moon, W.S.,Chung, M.J.,Park, J.W.,Park, B.H. Elsevier Science Publishers 2011 Journal of hepatology Vol.55 No.2

Backgroud & Aims: A20 is an intracellular ubiquitin-editing enzyme that plays an important role in the negative feedback regulation of NF-κB activation in response to a diverse range of stimuli. Liver ischemia/reperfusion injury is associated with rapid activation of NF-κB signaling, but the role of NF-κB in hepatic ischemia/reperfusion injury remains controversial. The NF-κB signaling pathway mediates both protective and deleterious effects in the liver. Here, we examined whether A20 inhibited or aggravated hepatic ischemia/reperfusion injury. Methods: We used IκBα super-repressor as a positive control and overexpressed A20 and IκBα super-repressor in the liver of C57BL/6 mice. Mice underwent 45min of partial hepatic ischemia and were then reperfused. Results: Protein level of A20 was increased after reperfusion. Mice subjected to ischemia/reperfusion injury showed increased NF-κB activation, as evidenced by phosphorylation of IκBα and nuclear translocation of NF-κB. Prior transfection with Ad-A20 or Ad-IκBα super-repressor attenuated NF-κB activation and aggravated liver injury. Serum aminotransferases and proinflammatory cytokines, hepatocellular necrosis, and hepatic neutrophil infiltration were markedly increased compared to those of uninfected or control virus infected mice. In addition, A20 abolished the beneficial effect of ischemic preconditioning. Conclusions: Our results suggest that inhibition of NF-κB activation by A20 aggravated partial hepatic ischemia/reperfusion injury. Understanding how the NF-κB pathway plays a role in directing a clinical outcome may lead to better prospects of more rational approaches to reduce post-ischemic liver injury.

Enhanced strength and ductility in particulate-reinforced aluminum matrix composites fabricated by flake powder metallurgy

Kai, X.Z.,Li, Z.Q.,Fan, G.L.,Guo, Q.,Xiong, D.B.,Zhang, W.L.,Su, Y.S.,Lu, W.J.,Moon, W.J.,Zhang, D. Elsevier Sequoia 2013 Materials science & engineering. properties, micro Vol.587 No.-

Reinforcement agglomeration always leads to severe stress concentration and porosity, which is detrimental to the deformation ability and mechanical properties of particulate-reinforced metal matrix composites. In this study, uniform distribution of 32vol%B<SUB>4</SUB>C has been achieved in B<SUB>4</SUB>C/Al composite by means of flake powder metallurgy (Flake PM), in which flake Al powder is used as the starting material. The flake Al powder exhibits higher apparent volume than spherical powders of the same mass, and thus can provide more space to accommodate the B<SUB>4</SUB>C particles. Therefore, compared with conventional PM, Flake PM can lead to more uniform distribution of B<SUB>4</SUB>C particles in the composite powder as well as in the consolidated composite. Meanwhile, the flake Al powder has a nano skin of Al<SUB>2</SUB>O<SUB>3</SUB>, which could be fractured and dispersed inside the fine matrix grains during consolidation, and were found to induce a higher normalized strain hardening rate for the composite during deformation. As a result, the Flake PM 32vol%B<SUB>4</SUB>C/Al composite exhibits an ultimate tensile strength of 305MPa and a uniform elongation of 6.6%, 63% stronger and 13% more ductile than its counterpart fabricated by conventional PM.

Cloning and functional characterization of the p65 subunit of NF-κB from olive flounder (Paralichthys olivaceus)

Kong, H.J.,Moon, J.H.,Moon, J.Y.,Kim, J.M.,Nam, B.H.,Kim, Y.O.,Kim, W.J.,Lee, S.J. Academic Press 2011 Fish & shellfish immunology Vol.30 No.1

NF-κB is a master transcription factor found in almost all cell types that responds to diverse cellular stimuli by activating the expression of stress response genes, including immune-related genes. cDNA encoding the p65 subunit of olive flounder (Paralichthys olivaceus) NF-κB (Po-p65) was isolated through an EST analysis of an olive flounder cDNA library, a screen of BAC library, and rapid amplification of cDNA ends (RACE). The cDNA for Po-p65 encodes a polypeptide 626 amino acids in length containing a well-conserved Rel-homology domain (RHD). The primary sequence of Po-p65 showed strong homology with p65 from perch and zebrafish (82.7 and 64.4%, respectively), and shared 43.4-42.1% homology with p65 from other species, including mammals, while the N-terminal RHD of Po-p65 showed strong identity (95.6-67.8%) with that of other species. Po-p65 mRNA expression was detected in all flounder tissues examined. The over-expression of full-length Po-p65 (Po-p65f), but not of a Po-p65 C-terminus deletion mutant (Po-p65ΔC), stimulated κB element-driven reporter (κB-luc) activity in a dose-dependent manner and regulated the expression of p65 target genes, including TNF-α and IκB-α, in HINAE olive flounder cells. Po-p65f translocated to the nucleus following stimulation with poly I:C in HINAE cells. Together, these results suggest that Po-p65 is evolutionarily and functionally conserved in flounder and mammals and may provide clues to the detailed molecular mechanism(s) underlying immune response regulation in flounder.

심혈관질환의 위험인자로서의 endothelial nitric oxide synthase의 SNP 연구

윤수인,문제성,신철,박현영,이정복,조인호 국립보건연구원 2000 국립보건원보 Vol.37 No.-

Caspase-3 activation as a key factor for HBx-transformed cell death

Kim, A.,Kwon, O. S.,Kim, S. O.,He, L.,Bae, E. Y.,Lee, M. S.,Jeong, S. J.,Shim, J. H.,Yoon, D. Y.,Kim, C. H.,Moon, A.,Kim, K. E.,Ahn, J. S.,Kim, B. Y. Blackwell Publishing Ltd 2008 Cell proliferation Vol.41 No.5

<P>Abstract. </P><P><I>Objectives</I>: Nuclear factor-kappa B (NF-&kgr;B) activation has been associated with the tumorigenic growth of hepatitis B virus X protein (HBx)-transformed cells. This study was aimed to find a key target for treatment of HBx-mediated cancers. <I>Materials and methods</I>: NF-&kgr;B activation, endoplasmic reticulum-stress (ER-stress), caspase-3 activation, and cell proliferation were evaluated after Chang/HBx cells permanently expressing HBx viral protein were treated with inhibitors of NF-&kgr;B, proteasome and DNA topoisomerase. <I>Results</I>: Inhibition of NF-&kgr;B transcriptional activity by transient transfection with mutant plasmids encoding Akt1 and glycogen synthase kinase-3&bgr; (GSK-3&bgr;), or by treatment with chemical inhibitors, wortmannin and LY294002, showed little effect on the survival of Chang/HBx cells. Furthermore, I&kgr;Bα (S32/36A) mutant plasmid or other NF-&kgr;B inhibitors, 1-pyrrolidinecarbonidithioic acid and sulphasalazine, were also shown to have little effect on the cell proliferation. By contrast, proteasome inhibitor-1 (Pro1) and MG132 enhanced the HBx-induced ER-stress response and the subsequent activation of caspase-12, -9 and -3 and reduced cell proliferation. Camptothecin (CPT), however, triggered activation of caspase-3 without induction of caspase-12, and reduced cell proliferation. In addition, CPT-induced cell death was reversed by pre-treatment with z-DEVD, a caspase-3-specific inhibitor. <I>Conclusions</I>: Detailed exploitation of the regulators of caspase-3 activation could open the gate for finding an efficient target for development of anticancer therapeutics against HBx-transformed hepatocellular carcinoma.</P>

A METHOD OF COLOR EXCESS DETERMINATION FOR HIGH AMPLITUDE δ SCUTI STARS

Kim, Chul-Hee,Choi, J.H.,Moon, B.K.,Boonrucksar, Soonthornthum The Korean Astronomical Society 2009 Journal of The Korean Astronomical Society Vol.42 No.6

In order to determine color excess in the $uvby\beta$ color system for high amplitude $\delta$ Scuti stars, reddening free $[m_1]$, $[c_1]$, and $\beta$ indices data were obtained from the existing literature for 21 stars. Then, the three intrinsic relations of $(b-y)_0$ - $[m_1]$, $(b-y)_0$ - $[c_1]$, and $(b-y)_0$ - $\beta$ were investigated. Among these, it was shown that the $(b-y)_0$-$[c_1]$ relation is the most useful. By establishing intrinsic $(b-y)_0$-$[c_1]$ relations for six reddening calibration stars, color excesses of other stars were determined.

Growth inhibitory effects of obovatol through induction of apoptotic cell death in prostate and colon cancer by blocking of NF-κB

Lee, S.Y.,Yuk, D.Y.,Song, H.S.,Yoon, D.Y.,Jung, J.K.,Moon, D.C.,Lee, B.S.,Hong, J.T. North-Holland ; Elsevier Science Ltd 2008 european journal of pharmacology Vol.582 No.1

Biphenolic components in Magnolia obovata including magnolol and honokiol have shown several pharmacological activities such as anti-tumor, anti-oxidant and anti-inflammatory effects. Previously in cultured macrophage Raw264.7 cells and fibroblast, we found that obovatol, an active compound isolated from M. obovata inhibited NF-κB activity which has been known to be a significant transcriptional factor to control of cancer cell growth. We investigated here whether obovatol could inhibit NF-κB activity, and thereby inhibit cancer cell growth in prostate (LNCaP and PC-3) and colon cancer (SW620 and HCT116) cells. Treatment of obovatol (10, 15, 20, 25 μM) inhibits cancer cell growth in the absence or the presence of tumor necrosis factor-α (TNF-α , 10 ng/ml) and tetradecanoyl phorbol acetate (TPA 10 or 50 nM) in a concentration-dependent manner through induction of apoptotic cell death. Cytotoxic activity was not observed in normal cells with up to 50 μM obovatol. It was also found that obovatol inhibited TNF-α and TPA-induced transcriptional and DNA binding activities of NF-κB. In further study, obovatol decreased translocation p65 and p50 into nucleus via decrease of phosphorylation of IκB. Correlated well with the induction of apoptosis, obovatol increased the expression of the apoptotic genes; Bax, caspase-3, caspase-9, whereas inhibited expression of anti-apoptotic genes; Bcl-2, inhibitor of apoptosis protein (IAP-1) and X chromosome IAP (XIAP) as well as the cell proliferation marker genes; Cox-2, c-Fos, c-Jun and cyclin D1. These results suggest that obovatol inhibits prostate and colon cancer cell growth via induction of apoptotic cell death, and that inhibition of NF-κB may be a significant as its action mechanism.

식품의 제조 가공용 화학적 합성품의 국내 소비실태에 관한 연구

문범수,김복성,이재관,윤혜,신석우 國立保健硏究院 1972 국립보건연구원보 Vol.9 No.-

Dental restorative composites containing 2,2-bis-[4-(2-hydroxy-3-methacryloyloxy propoxy) phenyl] propane derivatives and spiro orthocarbonates

Moon, E.J.,Lee, J.Y.,Kim, C.K.,Cho, B.H. Wiley Subscription Services, Inc., A Wiley Company 2005 Journal of biomedical materials research. Part B, Vol.b73 No.2

<P>Various dental restorative composite resins containing 2,2-bis-[4-(2-hydroxy-3-methacryloyloxy propoxy) phenyl] propane (Bis-GMA) derivatives and spiro orthocarbonates (SOCs) were explored for minimizing the volumetric shrinkage that generally occurs during polymerization. Previous reports suggested mixing Bis-GMA with its derivative TMBis-GMA (2,2-bis[3,5-dimethyl-4-(2-hydroxy-3-methacryloyloxy propoxy) phenyl] propane) to obtain a dental composite with low volumetric shrinkage. It was hypothesized that spiro orthocarbonates would expand volumetrically during polymerization, because of their sophisticated ring-opening reactions; therefore several of them were added to the mixture of Bis-GMA and TMBis-GMA to bring about further reductions in volumetric shrinkage. It was indeed possible to reduce the extent of volumetric shrinkage of dental composites containing SOCs, and to do so without compromising these resins' mechanical properties. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater</P>

Tailoring metal-oxide interfaces of oxide-encapsulated Pt/silica hybrid nanocatalysts with enhanced thermal stability

Moon, S.Y.,Naik, B.,Jung, C.H.,Qadir, K.,Park, J.Y. Elsevier Science Publishers 2016 CATALYSIS TODAY - Vol.265 No.-

<P>We report the fabrication of metal-oxide (m-oxide) hybrid nanocatalysts with oxide encapsulation (Pt/SiO2@m-oxide; m-oxide =TiO2, Nb2O5, Ta2O5, CeO2) using a simple surface-modification chemical process. The synthesized m-oxide hybrid nanocatalysts with oxide encapsulation have two advantages: tailoring the metal-support interaction and achieving higher thermal and chemical stability. Briefly, Pt nanoparticles (NPs) capped with polyvinylpyrrolidone were successfully assembled on functionalized SiO2 via electrostatic interactions, and then an ultrathin layer of m-oxide was coated on the surface. Transmission electron microscopy studies confirmed that the Pt NPs were uniformly dispersed and distributed throughout the surface of the SiO2 with a thin layer of m-oxide. In particular, energy-dispersive X-ray spectroscopy line mapping was employed to ensure the presence of a uniformly coated thin oxide layer of constituent elements. The metal NPs were found well exposed to the outer surface, enabling surface characterization, including chemisorption and X-ray photoelectron spectroscopy. Even after calcination at 600 degrees C, the structure and morphology of the hybrid nanocatalysts remained intact, confirming high thermal stability. We investigated the effect of different types of m-oxide coating, an active support material, on the performance of catalytic activity for CO oxidation for the Pt/SiO2@m-oxide hybrid nanocatalysts with well-exposed Pt nanoparticles. We carried out CO oxidation over the hybrid nanocatalysts and found that metal-oxide interfaces play important roles that influence catalytic activity. Designing such metal-oxide hybrid structures with thin oxide encapsulation represents a critical step in the advancement of model catalytic systems for investigating the metal-support interaction with improved thermal stability. (C) 2015 Elsevier B.V. All rights reserved.</P>