O-GlcNAcylation of amyloid-β precursor protein at threonine 576 residue regulates trafficking and processing

Chun, Y.S.,Kwon, O.H.,Chung, S. Academic Press 2017 Biochemical and biophysical research communication Vol. No.

The pathological hallmark of Alzheimer's disease (AD) is associated with the accumulation of amyloid-β (Aβ) derived from proteolytic processing of amyloid-β precursor protein (APP). APP undergoes post-translational modification including N- and O-glycosylation. O-GlcNAcylation is a novel type of O-glycosylation, mediated by O-GlcNAc transferase attaching O-β-N-acetylglucosamine (O-GlcNAc) to serine/threonine residues of the target proteins. O-GlcNAc is removed by O-GlcNAcase. We have previously reported that increasing O-GlcNAcylated APP using the O-GlcNAcase inhibitor, PUGNAc, increases its trafficking rate to the plasma membrane and decreases its endocytosis rate, resulting in decreased Aβ production. However, O-GlcNAc modification sites in APP are unknown. In this study, we mutated three predicted O-GlcNAc modification threonine residues of APP into alanines (T291A, T292A, and T576A) and expressed them in HeLa cells. These APP mutants showed reduced O-GlcNAcylation levels, indicating that these sites were endogenously O-GlcNAcylated. Thr 576 was the major O-GlcNAcylation site when cell was treated with PUGNAc. We also showed that the effects of PUGNAc on APP trafficking to the plasma membrane and Aβ production were prevented in the T576A mutant. These results implicate Thr 576 as the major O-GlcNAcylation site in APP and indicate that O-GlcNAcylation of this residue regulates its trafficking and processing. Thus, specific O-GlcNAcylation of APP at Thr 576 may be a novel and promising drug target for AD therapeutics.

단세포군 항체를 이용한 Shigella serotyping serum 개발(Ⅱ) : S. flexneri type Ⅰ,Ⅱ & type Ⅰ:6, group 6

정의범,이영희,김순남,박강수,이명숙,성원근,김종욱,홍승의,박정우 국립보건연구원 1994 국립보건원보 Vol.31 No.1

Cu 기판위에 성장한 MgO, MgAl₂O₄와 MgAl₂O₄/MgO 박막의 집속이온빔을 이용한 스퍼터링수율 측정과 이차전자방출계수 측정

정강원(K. W. Jung),이혜정(H. J. Lee),정원희(W. H. Jung),오현주(H. J. Oh),박철우(C. W. Park),최은하(E. H. Choi),서윤호(Y. H. Seo),강승언(S. O. Kang) 한국진공학회(ASCT) 2006 Applied Science and Convergence Technology Vol.15 No.4

MgAl₂O₄ 막은 MgO 보호막 보다 단단하며 수분 흡착 오염문제에 상당히 강한 특성을 가진다. 본 연구에서 AC-PDP의 유전체보호막으로 사용되는 MgO 보호막의 특성을 개선하기 위해 MgAl₂O₄/MgO 이중층 보호막을 제작하여 특성을 조사하였다. 전자빔 증착기를 사용하여 Cu 기판에 MgO와 MgAl₂O₄을 각각 1000 Å 두께로 증착, MgAl₂O₄/MgO을 200/800 Å 두께로 적층 증착 후, 이온빔에 의한 충전현상을 제거하기 위해 Al을 1000 Å 두께로 증착하였다. 집속 이온빔(focused ion beam ; FIB)장치를 이용하여 10 ㎸에서 14 ㎸까지 이온빔 에너지에 따라 MgO는 0.364 ~ 0.449 값의 스퍼터링 수율에서 MgAl₂O₄/MgO을 적층함으로 24 ~ 30 % 낮아진 0.244 ~ 0.357 값의 스퍼터링 수율이 측정되었으며, MgAl₂O₄는 가장 낮은 0.088 ~ 0.109 값의 스퍼터링 수율이 측정되었다. g-집속이온빔(g-FIB)장치를 이용하여 Ne? 이온 에너지를 50 V에서 200 V까지 변화 시켜 MgAl₂O₄/MgO와 MgO는 0.09 ~ 0.12의 비슷한 이차전자방출 계수를 측정 하였다. AC-PDP셀의 72시간 열화실험 후 SEM 및 AFM으로 열화된 보호막의 표면을 관찰하여 기존의 단일 MgO 보호막과 MgAl₂O₄/MgO의 적층보호막의 열화특성을 살펴보았다. It is known that MgAl₂O₄ has higher resistance to moisture than MgO, in humid ambient MgO is chemically unstable. It reacts very easily with moisture in the air. In this study, the characteristic of MgAl₂O₄ and MgAl₂O₄/MgO layers as dielectric protection layers for AC-PDP (Plasma Display Panel) have been investigated and analysed in comparison for conventional MgO layers. MgO and MgAl₂O₄ films both with a thickness of 1000 Å and MgAl₂O₄/MgO film with a thickness of 200/800 Å were grown on the Cu substrates using the electron beam evaporation. 1000 Å thick aluminium layers were deposited on the protective layes in order to avoid the charging effect of Ga? ion beam while the focused ion beam(FIB)is being used. We obtained sputtering yieds for the MgO, MgAl₂O₄ and MgAl₂O₄/MgO films using the FIB system. MgAl₂O₄/MgO protective layers have been found th show 24 ~ 30% lower sputtering yield values from 0.244 up to 0.357 than MgO layers with the values from 0.364 up to 0.449 for irradiated Ga? ion beam with energies ranged from 10 ㎸ to 14 ㎸. And MgAl₂O₄ layers have been found to show lowest sputtering yield values from 0.88 up to 0.109. Secondary electron emission coefficient(g) using the γ-FIB. MgAl₂O₄/MgO and MgO have been found to have similar g values from 0.09 up to 0.12 for indicated Ne+ ion with energies ranged from 50 V to 200 V. Observed images for the surfaces of MgO and MgAl₂O₄/MgO protective layers, after discharge degradation process for 72 hours by SEM and AFM. It is found that MgAl₂O₄/MgO protective layer has superior hardness and degradation resistance properties to MgO protective layer.

Diagnostic usefulness of a T cell-based assay for latent tuberculosis infection in kidney transplant candidates before transplantation

Kim, S.-H.,Lee, S.-O.,Park, I.-A.,Park, S.J.,Choi, S.-H.,Kim, Y.S.,Woo, J.H.,Park, S.-K.,Park, J.S.,Kim, S.C.,Han, D.J. Blackwell Publishing Inc 2010 Transplant infectious disease Vol.12 No.2

<P>S.-H. Kim, S.-O. Lee, I.-A. Park, S.J. Park, S.-H. Choi, Y.S. Kim, J.H. Woo, S.-K. Park, J.S. Park, S.C. Kim, D.J. Han. Diagnostic usefulness of a T cell-based assay for latent tuberculosis infection in kidney transplant candidates before transplantation.Transpl Infect Dis 2010: <B>12:</B> 113–119. All rights reserved</P><P>Background</P><P>The presence of latent tuberculosis (TB) infection (LTBI) should be evaluated before kidney transplantation. Although a new T cell-based assay for diagnosing LTBI gave promising results, this assay has not yet been compared with the tuberculin skin test (TST) for diagnosing LTBI in renal transplant candidates before transplantation.</P><P>Patients and methods</P><P>All adult patients admitted to a single institute for renal transplantation over a 1-year period were prospectively enrolled. A clinically predictive risk of LTBI was defined as: (i) recent close contact with a person with pulmonary TB; (ii) abnormal chest radiography; (iii) a history of untreated or inadequately treated TB; or (iv) a new infection (i.e., a recent conversion of TST).</P><P>Results</P><P>Of 209 renal recipients, 47 (22%) had a positive TST≥5 mm, 21 (10%) had a positive TST≥10 mm, 65 (30%) had a positive T-SPOT.<I>TB</I> test, and 25 (12%) had an indeterminate T-SPOT.<I>TB</I> test. The induration size of TST was significantly associated with a high positivity rate on T-SPOT.<I>TB</I> (<I>P</I><0.001). Agreement between T-SPOT.<I>TB</I> test and TST≥10 mm was fair (<I>k</I>=0.24, 95% confidence interval 0.11–0.36). However, neither univariate nor multivariate analysis showed any association between the clinical risk for LTBI and positivity on T-SPOT.<I>TB</I> or TST.</P><P>Conclusion</P><P>T-SPOT.<I>TB</I> test was more frequently positive than TST in renal transplant candidates. However, further longitudinal studies are awaited to determine whether the ability of T-SPOT.<I>TB</I> assay to detect LTBI in renal transplant recipients can better predict the development of TB than can TST after transplantation.</P>

Development of a system for S locus haplotyping based on the polymorphic SLL2 gene tightly linked to the locus determining self-incompatibility in radish (Raphanus sativus L.)

Kim, D.,Jung, J.,Choi, Y. O.,Kim, S. Springer Netherlands 2016 Euphytica Vol.209 No.2

<P>To develop a reliable system for identifying multiple S haplotypes controlling self-incompatibility (SI) in radish (Raphanus sativus L.), the genomic organization of the S locus region was identified from radish draft genome sequences. An initial attempt to find the S receptor kinase (SRK) gene, the female determinant of SI, failed due to presence of 15 homologous genes. Using synteny between the radish and Chinese cabbage genomes, the putative S locus region was identified in the radish R7 linkage group. One scaffold anchored to this R7 region contained the S-locus glycoprotein (SLG) gene, which is one of the S locus genes. Using the high homology between the SLG and S domain of SRK, the full-length radish SRK gene containing the largest 6861-bp intron1 was assembled by connecting two scaffolds harboring the S receptor and kinase domains, respectively. A scaffold containing the full-length S-locus cysteine-rich protein (SCR)/S locus protein 11 (SP11) gene, the male-determinant of SI, was identified using information reported previously. Finally, 53,785, 42,804, and 10,165 bp sequences containing the S locus genes and their flanking sequences were obtained. Unlike the various orientations of the SRK or SCR/SP11 genes, the position of SLL2 located at the border region of the S locus was conserved among haplotypes. Sequencing of the SLL2 gene from 31 inbred lines showing differential SI responses revealed 26 polymorphic alleles. Four additional SLL2 alleles were identified from analysis of diverse breeding lines. Based on the polymorphic SLL2 sequences, a new S haplotyping system was developed for efficient marker-assisted selection of the S haplotypes in radish.</P>

A study of nerve agent model organophosphonate binding with manganese-A₂B-corrole and -A₂B₂-porphyrin systems

Kim, K.,Kim, I.,Maiti, N.,Kwon, S.J.,Bucella, D.,Egorova, O.A.,Lee, Y.S.,Kwak, J.,Churchill, D.G. Pergamon Press 2009 Polyhedron Vol.28 No.12

Herein the synthesis and binding studies of novel trans-A<SUB>2</SUB>B-corrole and trans-A<SUB>2</SUB>B<SUB>2</SUB>-porphyrin derivatives are presented in comparing manganese(III)-organophosphonate (OP) binding (e.g., M<SUP>n+</SUP>←O?PR(OR)<SUB>2</SUB>) capabilities. H<SUB>3</SUB>(PFP-VC) [PFP-VC=5,15-di(pentafluorophenyl)-10-(3-vinylphenyl)corrolate] was synthesized by way of literature procedures and was characterized by a variety of 2-D NMR spectroscopic techniques and single-crystal X-ray diffraction. These compounds represent the first example of 3-vinyl-phenyl-containing meso-substituted corroles or porphyrins. Mn(PFP-VC) (3) was treated separately with (CH<SUB>3</SUB>CH<SUB>2</SUB>O)<SUB>2</SUB>P?O(C<SUB>3</SUB>H<SUB>6</SUB>NMe<SUB>2</SUB>), (C<SUB>4</SUB>H<SUB>9</SUB>O)<SUB>2</SUB>P?O(Me), (C<SUB>2</SUB>H<SUB>5</SUB>O)<SUB>2</SUB>P?O(CH<SUB>2</SUB>COCH<SUB>3</SUB>), (CH<SUB>3</SUB>CH<SUB>2</SUB>O)<SUB>2</SUB>P?O(Me), to give 1:1 adducts, as determined by UV-Vis spectroscopy (Job Plot), giving a red shift; Ph<SUB>3</SUB>P?O, was also found to bind, but very weakly. The trans-A<SUB>2</SUB>B<SUB>2</SUB>-porphyrin analogue Mn(PFP-VP) (4) was also prepared by way of a literature procedure; related binding studies gave 1:1 organophosphonate-Mn(PFP-VP) adducts (Job Plot). A clean blue shift occurred for the Mn-porphyrins at higher organophosphonate loadings (K<SUB>a</SUB> values: 6.7 (0.9)-11.9 (0.4)M<SUP>-1</SUP>). DFT geometry optimizations of O?P(OMe)<SUB>2</SUB>Me binding and formal Mn-O or P-O cleavage products in the unsubstituted neutral Mn-corrolato and -porphyrinato systems with a range of metal-based spin states revealed greatest stability in formal phosphoryl oxygen binding (energies: 11-13kcal/mol) for the Mn-corrole (singlet); the Mn-porphyrin (sextet) was also quite stable.

RF-O₂ Plasma 처리한 MgO 박막의 스퍼터링 수율 측정

정원희(W. H .Jeoung),정강원(K. W. Jeong),임연찬(Y. C. Lim),오현주(H. J. Oh),박철우(C. W. Park),최은하(E. H. Choi),서윤호(Y. H. Seo),김윤기(Y. K. Kim),강승언(S. O. Kang) 한국진공학회(ASCT) 2006 Applied Science and Convergence Technology Vol.15 No.3

RF-O₂ plasma 처리한 MgO 박막의 스퍼터링 수율을 집속이온빔 장치를 이용하여 측정하였다. 가속 전압 10 ㎸의 Ga 이온빔을 주사했을 때 plasma 처리하지 않은 MgO 박막의 스퍼터링 수율은 0.33 atoms/ion, RF-O₂ plasma 처리한 MgO 박막의 스퍼터링 수율은 0.20 atoms/ion 으로 RF-O₂ plasma 처리한 경우 스퍼터링 수율이 낮아졌다. 또한 XPS, AFM을 통해 plasma 처리로 인한 MgO 표면의 변화를 관찰하였다. MgO 박막에 RF-O₂ plasma 처리 한 후 XPS O 1s spectra의 binding energy와 FWHM 값이 각각 2.36 eV와 0.6167 eV 작아졌고 표면거칠기의 RMS 값 또한 0.32 ㎚ 작아졌다. We measured sputtering yield of RF O₂-plasma treated MgO protective layer for AC-PDP(plasma display panel) using a Focused Ion Beam System(FIB). A 10 ㎸ acceleration voltage was applied. The sputtering yield of the untreated sample and the treated sample were 0.33 atoms/ion and 0.20 atoms/ion, respectively. The influence of the plasma-treatment of MgO thin film was characterized by XPS and AFM analysis. We observed that the binding energy of the O 1s spectra, the FWHM of O 1s spectra and the RMS(root-mean-square) of surface roughness decreased to 2.36 eV, 0.6167 eV and 0.32 ㎚, respectively.

S100A2 promoter-driven conditionally replicative adenovirus targets non-small-cell lung carcinoma

Lee, K,Yun, S-T,Yun, C-O,Ahn, B-Y,Jo, E-C Macmillan Publishers Limited 2012 Gene Therapy Vol.19 No.10

S100A2, a member of the S100 family of calcium-binding proteins, has been implicated in carcinogenesis as both a tumor suppressor and stimulator. Here, we characterized promoter activity of S100A2, generated an S100A2 promoter-driven conditionally replicative adenovirus (Ad/SA), and evaluated its anti-tumor activity in vitro and in vivo. Promoter activity of S100A2 was greatly restricted to tumor cells, and the S100A2 promoter bound with typical nuclear targets of epidermal growth factor receptor (EGFR) signaling. EGF-stimulated EGFR phosphorylation induced S100A2 expression and further activated E1A expression of Ad/SA, which was restored by EGFR signal inhibition in a concentration-dependent manner in non-small-cell lung carcinoma (NSCLC). In two EGFR-activated tumor xenograft animal models, Ad/SA exhibited potent anti-tumor activity, whereas cetuximab, an EGFR-targeting anticancer drug, was active transiently or ineffective. Combined treatment with cetuximab or cisplatin plus Ad/SA resulted in enhanced anti-tumor activity. Immunohistochemical analysis of tumor sections showed moderate-to-high grade signals for EGFR and adenovirus, and a reduction in viable cells in Ad/SA-treated tumors. Collectively, these results demonstrate that the S100A2 promoter-driven adenovirus is a potent inhibitor of cancers, and further suggest that S100A2 is a target gene of EGFR signaling pathway in NSCLC.

<i>S100A9</i> and <i>EGFR</i> gene signatures predict disease progression in muscle invasive bladder cancer patients after chemotherapy

Kim, W. T.,Kim, J.,Yan, C.,Jeong, P.,Choi, S. Y.,Lee, O. J.,Chae, Y. B.,Yun, S. J.,Lee, S. C.,Kim, W. J. Oxford University Press 2014 Annals of Oncology Vol.25 No.5

<P>In our previous gene expression profile analysis, IL1B, S100A8, S100A9, and EGFR were shown to be important mediators of muscle invasive bladder cancer (MIBC) progression. The aim of the present study was to investigate the ability of these gene signatures to predict disease progression after chemotherapy in patients with locally recurrent or metastatic MIBC. Patients with locally advanced MIBC who received chemotherapy were enrolled. The expression signatures of four genes were measured and carried out further functional analysis to confirm our findings. Two of the four genes, S100A9 and EGFR, were determined to significantly influence disease progression (P = 0.023, 0.045, respectively). Based on a receiver operating characteristic curve, a cut-off value for disease progression was determined. Patients with the good-prognostic signature group had a significantly longer time to progression and cancer-specific survival time than those with the poor-prognostic signature group (P < 0.001, 0.042, respectively). In the multivariate Cox regression analysis, gene signature was the only factor that significantly influenced disease progression [hazard ratio: 4.726, confidence interval: 1.623-13.763, P = 0.004]. In immunohistochemical analysis, S100A9 and EGFR positivity were associated with disease progression after chemotherapy. Protein expression of S100A9/EGFR showed modest correlation with gene expression of S100A9/EGFR (r = 0.395, P = 0.014 and r = 0.453, P = 0.004). Our functional analysis provided the evidence demonstrating that expression of S100A9 and EGFR closely associated chemoresistance, and that inhibition of S100A9 and EGFR may sensitize bladder tumor cells to the cisplatin-based chemotherapy. The S100A9/EGFR level is a novel prognostic marker to predict the chemoresponsiveness of patients with locally recurrent or metastatic MIBC.</P>

In vitro antibacterial activity and major bioactive components of Cinnamomum verum essential oils against cariogenic bacteria, Streptococcus mutans and Streptococcus sobrinus

Choi, O.,Cho, S.K.,Kim, J.,Park, C.G.,Kim, J. China Humanity Technology Publishing House 2016 Asian Pacific journal of tropical biomedicine Vol.6 No.4

Objective: To evaluate the antibacterial activity of Cinnamomum verum (C. verum) from 32 different essential oils against cariogenic bacteria, Streptococcus mutans (S. mutans) and Streptococcus sobrinus (S. sobrinus). Methods: The antibacterial activities of each essential oil were individually investigated against S. mutans and S. sobrinus. The essential oil of C. verum was selected for further evaluation against S. mutans and S. sobrinus. Gas chromatography mass spectrometry was used to determine the major constituents of C. verum essential oil. In addition, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration of the most effective constituent was investigated. Results: The essential oil from C. verum exhibited the greatest antibacterial activity. Gas chromatography mass spectrometry analysis revealed that the major components of C. verum essential oil were cinnamaldehyde (56.3%), cinnamyl acetate (7.1%) and β-phellandrene (6.3%). The MIC of cinnamaldehyde was measured using broth dilution assays. The MIC of cinnamaldehyde was 0.02% (v/v) against both bacterial strains tested. The minimum bactericidal concentration of cinnamaldehyde against S. mutans and S. sobrinus were 0.2% and 0.1% (v/v), respectively. Conclusions: The essential oil of C. verum and its major component cinnamaldehyde possessed considerable in vitro antibacterial activities against cariogenic bacteria, S. mutans and S. sobrinus strains. These results showed that the essential oil of C. verum and its bioactive component, cinnamaldehyde, have potential for application as natural agents for the prevention and treatment of dental caries.