Pathogenesis of Enterohemorrhagic <i>Escherichia coli</i> O157:H7 is mediated by the cytochrome P450 family in <i>Caenorhabditis elegans</i> animal model

Ryu, S.,Oh, S.,Park, M.R.,Lee, W.J.,Yun, B.,Choi, H.J.,Oh, M.H.,Oh, N.S.,Song, M.H.,Kim, Y. BUTTERWORTH-HEINEMANN 2019 FOOD CONTROL Vol.103 No.-

<P><B>Abstract</B></P> <P>Foodborne pathogens, including enterohemorrhagic <I>Escherichia coli</I> (EHEC) O157:H7, may enter from the farm environment and foods via several different vectors and influence human health. Here, we employed <I>Caenorhabditis elegans</I> as a host model system and compared specific host responses during EHEC O157:H7 infection using whole-transcriptome analysis. To elucidate the immune pathways stimulated by EHEC O157:H7, we employed quantitative real-time polymerase chain reaction (qRT-PCR), transgenic worms, and RNAi. Whole-transcriptome analysis revealed that genes encoding the cytochrome P450 (CYP450) family were induced more than 10-fold during EHEC O157:H7 infection in <I>C. elegans</I> host models. Importantly, <I>C. elegans</I> mutants lacking CYP450 genes were highly susceptible to EHEC O157:H7 infection compared with wild-type N2 worms. Consistent with susceptibility tests, qRT-PCR results indicated that CYP450 loss-of-function mutations significantly affected the transcriptional induction of antimicrobial peptide genes, such as <I>clec-60</I>. Together, our results provide critical insights into host strategies for avoiding EHEC O157:H7 pathogenesis in the gastrointestinal tract via the cytochrome P450 family and highlights potential molecular targets for preventing the virulence of EHEC O157:H7 in foods.</P>

유착에 의한 AGS 및 Hep-G2 세포 표면 구조의 변화

박동규 ( D. K. Park ),전훈재 ( H. J. Chun ),박재홍 ( J. H. Park ),박철희 ( C. H. Park ),진윤태 ( Y. T. Jeen ),이홍식 ( H. S. Lee ),이상우 ( S. W. Lee ),엄순호 ( S. H. Um ),최재현 ( J. H. Choi ),김창덕 ( C. D. Kim ),류호상 ( H. S. Ryu 대한소화기학회 2002 대한소화기학회 춘계학술대회 Vol.2002 No.-

<목적> 최근 H. pylori 유착에 의한 세포 표면 구조의 변화에 관한 연구가 시도되어지고 있으나 actin 의 변화여부 및 그 특성에 관해서는 아직 명확히 정립되지 못한 실정이다. Rho GTPase는 세포 표면의 미세돌기인 microvilli, filopodia 및 membrane ruffle의 형성과 관련이 있으며, 최근 AGS 세포에서 H. pylori가 Rac activation에 의하여 membrane ruffle을 형성한다는 것과 Rac

Dipeptidyl petidase-IV inhibitor (gemigliptin) inhibits tunicamycin-induced endoplasmic reticulum stress, apoptosis and inflammation in H9c2 cardiomyocytes

Hwang, H.J.,Jung, T.W.,Ryu, J.Y.,Hong, H.C.,Choi, H.Y.,Seo, J.A.,Kim, S.G.,Kim, N.H.,Choi, K.M.,Choi, D.S.,Baik, S.H.,Yoo, H.J. North-Holland 2014 Molecular and cellular endocrinology Vol.392 No.1

The direct effects of dipeptidyl peptidase-IV (DPP-IV) inhibitors on endoplasmic reticulum (ER) stress-induced apoptosis and inflammation in cardiomyocytes have not been elucidated. H9c2 cell viability, which was reduced by tunicamycin, was increased after DPP-IV inhibitor gemigliptin treatment. Gemigliptin significantly decreased the tunicamycin-mediated increase in glucose regulated protein 78 (GRP78) expression and ER stress-mediated signaling molecules such as protein kinase RNA-like endoplasmic reticulum kinase (PERK)/C-EBP homologous protein (CHOP) and inositol-requiring enzyme 1α (IRE1α)/c-Jun N-terminal kinase (JNK)-p38. Furthermore, gemigliptin effectively induced Akt phosphorylation in a dose-dependent manner. Using flow cytometry and Hoechst staining, we showed that treatment with Akt inhibitor significantly blocked the anti-apoptotic effects mediated by gemigliptin. The reduction in tunicamycin-induced GRP78 level and PERK/CHOP pathway activity by gemigliptin was reversed after treatment with Akt inhibitor. In conclusion, gemigliptin effectively inhibited ER stress-induced apoptosis and inflammation in cardiomyocytes via Akt/PERK/CHOP and IRE1α/JNK-p38 pathways, suggesting its direct protective role in cardiovascular diseases.

초기성인의 생활습관과 당뇨에 대한 지식

소선이,마지은,고지윤,김은혜,박현화,서유진,서형은,유은미,이하늬,이혜인,정지연,현혜리,이자형,정덕유,강지숙 이화여자대학교 간호과학대학 2009 이화간호학회지 Vol.- No.43

Purposes :The purposes of this study was to investigate the self-managing status according to the life styles and the diabetic knowledge of early adulthood. The subjects in this study were 240people, the early adult aged twenties to thirties living in the metropolitan area. Data were collected by using self-administered questionnaires that measure about the knowledge of diabetes; the dietetic behavior; the knowledge of diet; the exercise behavior; the knowledge of exercise. Descriptive statistics, t-test, ANOVA, and correlation were used for data analysis. Result :1. At the knowledge of diabetes degree based on the general character, the subjects who had experiences of diabetic education have higher degree of the diabetic knowledge. 2. At the knowledge of diabetes degree according to the life style, the subjects who have regular diet are appeared highly. Also the subjects who don't take much food of animal origin have higher degree. 3. At the knowledge of diet based on the life style, the subjects who don't keep three times meals a day are appeared highly. Also the subjects who have regular diet have higher degree. 4. At the knowledge of exercise according to the life style, the subjects who take extra nutritions 3-4 times a week are appeared highly. Although the subjects tend to know about dietary, exercise and health management, it showed that they actually don't perform what they know in their everyday of life. The reason for this could be the lack of perceived seriousness about diabetes mellitus. Thus as nursing professionals, we should provide them proper health education and support. Moreover, advanced research on the empowerment is warranted.

The inability of Bacillus licheniformis perR mutant to grow is mainly due to the lack of PerR-mediated fur repression

Kim, J. H.,Yang, Y. M.,Ji, C. J.,Ryu, S. H.,Won, Y. B.,Ju, S. Y.,Kwon, Y.,Lee, Y. E.,Youn, H.,Lee, J. W. MICROBIOLOGICAL SOCIETY OF KOREA 2017 JOURNAL OF MICROBIOLOGY -SEOUL- Vol. No.

<P>PerR, a member of Fur family protein, is a metal-dependent H2O2 sensing transcription factor that regulates genes involved in peroxide stress response. Industrially important bacterium Bacillus licheniformis contains three PerR-like proteins (PerR(BL), PerR2, and PerR3) compared to its close relative Bacillus subtilis. Interestingly, unlike other bacteria including B. subtilis, no authentic perR (BL) null mutant could be established for B. licheniformis. Thus, we constructed a conditional perR (BL) mutant using a xylose-inducible promoter, and investigated the genes under the control of PerR(BL). PerR(BL) regulon genes include katA, mrgA, ahpC, pfeT, hemA, fur, and perR as observed for PerR(BS). However, there is some variation in the expression levels of fur and hemA genes between B. subtilis and B. licheniformis in the derepressed state. Furthermore, katA, mrgA, and ahpC are strongly induced, whereas the others are only weakly or not induced by H2O2 treatment. In contrast to the B. subtilis perR null mutant which frequently gives rise to large colony phenotype mainly due to the loss of katA, the suppressors of B. licheniformis perR mutant, which can form colonies on LB agar, were all catalase-positive. Instead, many of the suppressors showed increased levels of siderophore production, suggesting that the suppressor mutation is linked to the fur gene. Consistent with this, perR fur double mutant could grow on LB agar without Fe supplementation, whereas perR katA double mutant could only grow on LB agar with Fe supplementation. Taken together, our data suggest that in B. licheniformis, despite the similarity in PerR(BL) and PerR(BS) regulon genes, perR is an essential gene required for growth and that the inability of perR null mutant to grow is mainly due to elevated expression of Fur.</P>

Coumarins reduce biofilm formation and the virulence of Escherichia coli O157:H7

Lee, J.H.,Kim, Y.G.,Cho, H.S.,Ryu, S.Y.,Cho, M.H.,Lee, J. G. Fischer 2014 Phytomedicine Vol.21 No.8

E. coli O157:H7 is the most common cause of hemorrhagic colitis, and no effective therapy exists for E. coli O157:H7 infection. Biofilm formation is closely related to E. coli O157:H7 infection and constitutes a mechanism of antimicrobial resistance. Hence, the antibiofilm or antivirulence approach provides an alternative to antibiotic strategies. Coumarin and its derivatives have a broad range of biological effects, and in this study, the antibiofilm activities of nine coumarins were investigated against E. coli O157:H7. Coumarin or umbelliferone at 50μg/ml was found to inhibit biofilm E. coli O157:H7 formation by more than 80% without affecting bacterial growth. Transcriptional analysis showed that coumarins repressed curli genes and motility genes in E. coli O157:H7, and these findings were in-line with observed reductions in fimbriae production, swarming motility, and biofilm formation. In addition, esculetin repressed Shiga-like toxin gene stx2 in E. coli O157:H7 and attenuated its virulence in vivo in the nematode Caenorhabditis elegans. These findings show that coumarins have potential use in antivirulence strategies against persistent E. coli O157:H7 infection.

다운증후군의 산전진단을 위한 다양한 선별검사의 기여율 비교 - 산전 및 신생아때 진단된 96 례 분석 -

한정열(J . Y . Han),김문영(Y. M . Kim),조준형(J . H . Cho),안현경(H . K . Ahn),류현미(H . M . Ryu),김진미(J . M . Kim),김영미(Y . M . Kim),박소연(S . Y . Park),한혜경(H . K . Han),이영호(Y . H . Lee),양재혁(J . H . Yang) 대한산부인과학회 2000 Obstetrics & Gynecology Science Vol.43 No.10

연구의 목적은 다운증후군을 산전진단하기 위한 다양한 산전선별검사 (나이; 35세 이상, 임산부 혈청 marker를 이용한 triple test, 초음파; 비정상 소견, 후경부 투명대 (nuchal translucency), 후경부두께 (nuchal fold thickness))의 기여율를 비교하기 위한 것이다. 1990년 1월부터 1999년 9월까지 본원에서 산전 및 산후에 진단된 례는 총 96례 이었다. 산전 및 신생아기에 진단된 다운증후군의 빈도는 각각 68례 (71 %), 28례 (29 %)였다. 다운증후군 태아를 임신했던 임산부의 평균연령은 33±5.7세이다. 다운증후군의 1,000분만당 연도별 빈도율은 1990년부터 1999년까지 각각 0.4, 1.3, 0.7, 0.7, 1.6, 0.7, 1.2, 2.2, 2.0, 그리고 2.3 (Y=0.28±0.18 year, P=0.01)이었다. 산전진단된 다운증후군의 비율 (%)은 지난 10년간 각각 0 (0/2), 43 (3/7), 50 (2/4), 25 (1/4), 56 (5/9), 100 (5/5), 71 (5/7), 78 (14/18), 78 (14/18), 그리고 89 (17/19) (Y=12.9±8.9 year, P=0.000) 이었다. 다운증후군을 산전진단하기 위한 다양한 산전선별 검사에 따른 기여율은 35세이상의 연령에 의하면 30.2±5.6 %, triple test의 경우 18.2±3.4 %, 초음파에 의한 경우 51.7±6.3 % 이며, 초음파에 의한 산전 선별 검사가 통계적으로 유의하게 연령이나 triple test에 의한 경우 보다 다운증후군의 산전진단에 기여율이 높았다. (P=0.008) 결론적으로 본 연구에 의하면 지난 10년 동안 다운증후군을 산전 진단하기 위한 여러 선별 검사방법의 적용은 효율적이었으며, 특히 초음파에서 다양한 소견을 이용한 다운증후군의 산전선별검사는 연령이나 triple test 보다는 더욱더 의미가 있다고 추론된다. Objective : The purpose of this study was comparison of the contribution rate for prenatal diagnosis of Down syndrome using various screening methods (Age: greater than or equal to 35 years old, Serum markers: Triple test, Ultrasonography: abnormal sonographic findings, nuchal translucency, nuchal fold thickness).Methods : Total 96 cases of Down syndrome, prenatally or postnatally diagnosed between Jan. 1990 and Sept. 1999, made up the study population. We got the contribution rate of various prenatal screening methods of down syndrome, and obtained the efficiency of various screening program applied for last 10 years. Results : The frequencies of Down syndrome confirmed in prenatal and postnatal were 68 (71%) and 28 (29%) in respectively. The mean age of mother of Down syndrome fetus was 33.0±5.7 years old. The frequency rate of Down syndrome was 0.4, 1.3, 0.7, 0.7, 1.6, 0.7, 1.2, 2.2, 2.0 and 2.3 a 1,000 deliveries from 1990 to 1999 (Y= 0.28+0.18 year, P=0.01). The percentage of Down syndrome diagnosed prenatally was 0 (0/2), 43 (3/7), 50 (2/4), 25 (1/4), 56 (5/9), 100 (5/5), 71 (5/7), 78 (14/18), 78 (14/18) and 89 (17/19) from 1990 to 1999 (Y= 12.9+8.9 year, P=0.000). The contribution rate of prenatal diagnosis for Down syndrome was 30.2±5.6% by age, 18.2±3.4% by triple test and 51.7±6.3% by ultrasonography, and was significantly difference among each screen methods (P=0.008). Conclusions : This study shows that our prenatal screening program is highly effective to detect Down syndrome and especially ultrasonographic findings (abnormal sono findings, Nuchal translucency, Nuchal fold thickness) may be more important than that of age or Triple test to detect the Down syndrome prenatally.

Sanitizing radish seeds by simultaneous treatments with gaseous chlorine dioxide, high relative humidity, and mild heat

Bang, J.,Choi, M.,Son, H.,Beuchat, L.R.,Kim, Y.,Kim, H.,Ryu, J.H. Elsevier Science Publishers 2016 International journal of food microbiology Vol.237 No.-

<P>Sanitizing radish seeds intended for edible sprout production was achieved by applying simultaneous treatments with gaseous chlorine dioxide (ClO2), high relative humidity (RH, 100%), and mild heat (55 degrees C). Gaseous ClO2 was produced from aqueous ClO2 (0.66 ml) by mixing sulfuric acid (5% w/v) with sodium chlorite (10 mg/mL) in a sealed container (1.8 L). Greater amounts of gaseous ClO2 were measured at 23% RH (144 ppm after 6 h) than at 100% RH (66 ppm after 6 h); however, the lethal activity of gaseous ClO2 against naturally occurring mesophilic aerobic bacteria (MAB) on radish seeds was significantly enhanced at 100% RH. For example, when exposed to gaseous ClO2 at 23% RH, the number of MAB on radish seeds decreased from 3.7 log CFU/g to 2.6 log CFU/g after 6 h. However, when exposed to gaseous ClO2 at 100% RH for 6 h, the MAB population decreased to 0.7 log CFU/g after 6 h. Gaseous ClO2 was produced in higher amounts at 55 degrees C than at 25 degrees C, but decreased more rapidly over time at 55 degrees C than at 25 degrees C. The lethal activity of gaseous ClO2 against MAB on radish seeds was greater at 55 degrees C than at 25 degrees C. When radish seeds were treated with gaseous ClO2 (peak concentration: 195 ppm) at 100% RH and 55 degrees C, MAB were reduced to populations below the detectable level (<-0.7 log CFU/g) within 2 h without decreasing the seed germination rate (97.7%). The lethality of combined treatments against artificially inoculated Escherichia coli O157:H7 was also evaluated. When exposed to gaseous ClO2 at 100% RH and 55 degrees C for 6 h, the initial number of E. coli O157:H7 (3.5 log CFU/g) on radish seeds decreased to below the detection limit (0.7 log CFU/g) by direct plating but it was not eliminated from seeds. The germination rate of radish seeds was not significantly (P> 0.05) decreased after treatment for 6 h. The information reported here will be useful when developing decontamination strategies for producing microbiologically safe radish seed sprouts. (C) 2016 Published by Elsevier B.V.</P>

Functionality improvement of fungal lignin peroxidase by DNA shuffling for 2,4-dichlorophenol degradability and H₂O₂ stability

Ryu, K.,Hwang, S.Y.,Kim, K.H.,Kang, J.H.,Lee, E.K. Elsevier Science Publishers 2008 Journal of biotechnology Vol.133 No.1

One of the major problems of wild-type lignin peroxidase (LiP) is its inactivity at the presence of excess H<SUB>2</SUB>O<SUB>2</SUB> and high concentration of aromatic compounds. Little is known about the substrate-binding site of LiP, and functionality improvement of LiP was not actively tried by genetic engineering and directed evolution. In order to improve LiPs functionality, we performed directed evolution with a colorimetric screening method. Finally, three types of LiP mutants were screened. The catalytic efficiency of the variants toward 2,4-dichlorophenol (DCP) degradation activity and the stability against H<SUB>2</SUB>O<SUB>2</SUB> was increased over the wild type. The K<SUB>m</SUB> value of the variants toward H<SUB>2</SUB>O<SUB>2</SUB> was increased, but K<SUB>m</SUB> value toward 2,4-DCP degradation was reduced. Overall, The K<SUB>cat</SUB>/K<SUB>m</SUB> values of the mutants toward 2,4-DCP was increased ca. 4-fold, and that toward H<SUB>2</SUB>O<SUB>2</SUB> was increased ca. 89-fold. Amino acid sequence analysis indicated that the most of the mutations were located on the enzyme surface. We expect that these results coupled with recombining mutation can be successfully applied to the molecular evolution cycles for screening of LiPs and other oxidative enzymes with improved functionality and stability.

Effect of additives on redox behavior of iron oxide for chemical hydrogen storage

Ryu, J.C.,Lee, D.H.,Kang, K.S.,Park, C.S.,Kim, J.W.,Kim, Y.H. Korean Society of Industrial and Engineering Chemi 2008 Journal of industrial and engineering chemistry Vol.14 No.2

The redox behaviors of iron oxides, which were modified with Pd, Pt, Rh, Ru, Al, Ce, Ti and Zr as additives, were investigated using temperature-programmed reaction (TPR) technique. The modified iron oxides were prepared by co-precipitation method using urea precipitant. The role of additives was also examined using XRD and SEM analysis in detail. As a result, Pd, Pt, Rh and Ru additives have an effect on promoting the reduction and lowering the re-oxidation temperature of iron oxide. Especially, it is revealed that the effect of Rh species on lowering the reduction temperature is attributed to decrease of activation energy for H<SUB>2</SUB> reduction according to Fe<SUB>2</SUB>O<SUB>3</SUB>->Fe<SUB>3</SUB>O<SUB>4</SUB> course. Meanwhile, Al, Ce, Ti and Zr additives played an important role in prevention of deactivation of iron oxide by repeated redox cycles. Redox performances of iron oxides were also enhanced due to cooperative effects by co-addition of Rh and another species such as Al, Ce and Zr. Finally, Fe-O/(Rh, Ce, Zr) sample exhibited good performance for H<SUB>2</SUB> evolution by water-splitting through synergistic effect of component additives.