Production of (S)-3-hydroxybutyrate by metabolically engineered Saccharomyces cerevisiae

Yun, E.J.,Kwak, S.,Kim, S.R.,Park, Y.C.,Jin, Y.S.,Kim, K.H. Elsevier Science Publishers 2015 Journal of biotechnology Vol.209 No.-

(S)-3-Hydroxybutyrate (S-3HB) can be used as a precursor for the synthesis of biodegradable polymers such as polyhydroxyalkanoate and stereo-specific fine chemicals such as antibiotics, pheromones, and drugs. For the production of S-3HB in yeast, the biosynthetic pathway of S-3HB from acetyl-CoA, consisting of the three enzymes, acetyl-CoA C-acetyltransferase (ACCT), acetoacetyl-CoA reductase (ACR), and 3-hydroxybutyryl-CoA thioesterase (HBT), was introduced into Saccharomyces cerevisiae. An engineered yeast strain overexpressing ERG10, hbd, and tesB genes not only exhibited enzyme activities of AACT, ACR, and HBT, but also produced S-3HB from ethanol. In order to increase the titer of S-3HB, a fed-batch fermentation based on pulse feeding of ethanol as a carbon source was performed, and a final S-3HB titer of 12.0g/L was achieved. This is the first report on the production of 3HB by engineered yeast, utilizing ethanol as the carbon source, suggesting that the industrially preferred S. cerevisiae can be a promising host for producing S-3HB.

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.

Melatonin enhances arsenic trioxide-induced cell death via sustained upregulation of Redd1 expression in breast cancer cells

Yun, S.M.,Woo, S.H.,Oh, S.T.,Hong, S.E.,Choe, T.B.,Ye, S.K.,Kim, E.K.,Seong, M.K.,Kim, H.A.,Noh, W.C.,Lee, J.K.,Jin, H.O.,Lee, Y.H.,Park, I.C. North-Holland 2016 Molecular and cellular endocrinology Vol.422 No.-

Melatonin is implicated in various physiological functions, including anticancer activity. However, the mechanism(s) of its anticancer activity is not well understood. In the present study, we investigated the combined effects of melatonin and arsenic trioxide (ATO) on cell death in human breast cancer cells. Melatonin enhanced the ATO-induced apoptotic cell death via changes in the protein levels of Survivin, Bcl-2, and Bax, thus affecting cytochrome c release from the mitochondria to the cytosol. Interestingly, we found that the cell death induced by co-treatment with melatonin and ATO was mediated by sustained upregulation of Redd1, which was associated with increased production of reactive oxygen species (ROS). Combined treatment with melatonin and ATO induced the phosphorylation of JNK and p38 MAP kinase downstream from Redd1 expression. Rapamycin and S6K1 siRNA enhanced, while activation of mTORC1 by transfection with TSC2 siRNA suppressed the cell death induced by melatonin and ATO treatment. Taken together, our findings suggest that melatonin enhances ATO-induced apoptotic cell death via sustained upregulation of Redd1 expression and inhibition of mTORC1 upstream of the activation of the p38/JNK pathways in human breast cancer cells.

등가응력 접근법을 통한 SLS 3D 프린팅으로 제작 된 PA2200 폴리머코어의 피로 특성에 관한 연구

박준수(J. S. Park),정의철(E. C. Jeong),최한솔(H. S. Choi),김미애(M. A. Kim),윤언경(E. G. Yun),김진수(J. S. Kim),김용대(Y. D. Kim),원시태(S. T. Won),이성희(S. H. Lee) 한국소성가공학회 2019 한국소성가공학회 학술대회 논문집 Vol.2019 No.10

High lipid composition of particulate organic matter in the northern Chukchi Sea, 2011

Kim, B.K.,Lee, J.H.,Yun, M.S.,Joo, H.,Song, H.J.,Yang, E.J.,Chung, K.H.,Kang, S.H.,Lee, S.H. Pergamon Press 2015 Deep-sea research. Part II, Topical studies in oce Vol.120 No.-

We investigated the biochemical compositions (lipids, proteins, and carbohydrates) of particulate organic matter (POM) as a potential food source in the northern Chukchi Sea. We aimed to understand physiological status of phytoplankton, determine important controlling factors, and estimate the energetic contents of POM. The major inorganic nutrients were generally depleted at upper mixed-layer depth (>20m). The average chlorophyll a (chl-a) concentration was 31.9mgm<SUP>-2</SUP> (S.D.=+/-31.3mgm<SUP>-2</SUP>) in this study, significantly higher than that reported previously in the northern Chukchi Sea. Small phytoplankton (0.7-5@?m) accounted for 65.9% of total chl-a concentration. The overall average compositions of lipids, carbohydrates, and proteins were 50% (S.D.=+/-10.7%), 35% (S.D.=+/-11.0%), and 15% (S.D.=+/-11.2%) for POM, respectively. Along with other evidence (e.g., low N:P and protein-carbohydrate ratios), the high lipid and low protein compositions of POM in this study suggests that phytoplankton might have had a nitrogen limitation and/or stationary growth phase in the northern Chukchi Sea during the cruise period, 2011. The overall average calorific content of food material (FM) was 149.2μgL<SUP>-1</SUP> (S.D.=+/-36.5μgL<SUP>-1</SUP>) or 1.0Kcalm<SUP>-3</SUP> (S.D.=+/-0.2Kcalm<SUP>-3</SUP>). The relatively higher calorific contents in the northern Chukchi Sea were due to high lipid contributions and the considerably high calorific content of FM per POC.

Streptococcus gordonii induces nitric oxide production through its lipoproteins stimulating Toll-like receptor 2 in murine macrophages

Kim, H.Y.,Baik, J.E.,Ahn, K.B.,Seo, H.S.,Yun, C.H.,Han, S.H. Pergamon Press 2017 Molecular immunology Vol.82 No.-

<P>Streptococcus gordonii, a Gram-positive commensal in the oral cavity, is an opportunistic pathogen that can cause endodontic and systemic infections resulting in infective endocarditis. Lipoteichoic acid (LTA) and lipoprotein are major virulence factors of Gram-positive bacteria that are preferentially recognized by Toll-like receptor 2 (TLR2) on immune cells. In the present study, we investigated the effect of S. gordonii LTA and lipoprotein on the production of the representative inflammatory mediator nitric oxide (NO) by the mouse macrophages. Heat-killed S. gordonii wild-type and an LTA-deficient mutant (Delta ltaS) but not a lipoprotein-deficient mutant (Delta lgt) induced NO production in mouse primary macrophages and the cell line, RAW 264.7.S. gordonii wild-type and Delta ItaS also induced the expression of inducible NO synthase (iNOS) at the mRNA and protein levels. In contrast, the Delta lgt mutant showed little effect under the same condition. Furthermore, S. gordonii wild-type and Delta ItaS induced NF-kappa B activation, STAT1 phosphorylation, and IFN-beta expression, which are important for the induction of iNOS gene expression, with little activation by Delta lgt. S. gordonii wild-type and Delta ltaS showed an increased adherence and internalization to RAW 264.7 cells compared to Delta lgt. In addition, S. gordonii wild-type and AIMS, but not Delta lgt, substantially increased TLR2 activation while none of these induced NO production in TLR2-deficient macrophages. Triton X-114-extracted lipoproteins from S. gordonii were sufficient to induce NO production. Collectively, we suggest that lipoprotein is an essential cell wall component of S. gordonii to induce NO production in macrophages through TLR2 triggering NF-kappa B and STAT1 activation. (C) 2016 Elsevier Ltd. All rights reserved.</P>

WWW 상에서의 CGI를 이용한 농업용 전문가 시스템의 추론엔진과 사용자 인터페이스의 개발

조성인,이종수,박은우,황헌,윤진일 한국농업정보과학회 1999 농업정보과학 Vol.1 No.1

Tuday's agriculture mainly relies on agricultural chemicals, mechanical power, and electronics. Efficiencies if labor, capital, productivity and quality are also major issues in today's agriclilture. Not only mechanization to replace human labor but information process becomes important to achieve the efficiencies. Agricultural informations consist of numerical data, text data and images. Lots of the informations come from human experiences and are in non-numerical forms. Therefore, they are difficult to be processed properly for the information process such as expert systems. This problem would be solved by using CGI (Common Cateway Interface) in WWW (World Wide Web). We developed a forward chaining inference engine for a heuristic rule-based expert system to process knowledges in agriculture. It managed many rule bases with recursion using low memory capacity. User interfaces of the expert system using the CGI improved processing specialized agricul-tural knowledges from experts in agricultural domains. By networking the expert systems in WWW, farmers could use expert systems at remote sites with ease.

Comparison of mRNA, Protein, and Urinary Nucleic Acid Levels of S100A8 and S100A9 between Prostate Cancer and BPH

Yun, S. J.,Yan, C.,Jeong, P.,Kang, H. W.,Kim, Y. H.,Kim, E. A.,Lee, O. J.,Kim, W. T.,Moon, S. K.,Kim, I. Y. Springer Science + Business Media 2015 Annals of Surgical Oncology Vol.22 No.7

Contribution of small phytoplankton to total primary production in the Chukchi Sea

Lee, S.H.,Sun Yun, M.,Kyung Kim, B.,Joo, H.,Kang, S.H.,Keun Kang, C.,Whitledge, T.E. Pergamon Press ; Elsevier Science Ltd 2013 Continental shelf research Vol.68 No.-

Given a projection of thriving small phytoplankton in the Arctic Ocean under climate-induced environmental changes, it is important to estimate the contribution of small phytoplankton (0.7-5μm) to the total primary production in the Chukchi Sea, which is an important conduit of organic matter from the North Pacific to the Arctic Ocean. Based on a <SUP>13</SUP>C-<SUP>15</SUP>N dual isotope tracer technique, small phytoplankton productivity measurements were taken during two consecutive cruises in the Chukchi Sea in 2004. The total phytoplankton carbon uptake rates ranged from 0 to 25.38mgCm<SUP>-3</SUP>h<SUP>-1</SUP>, whereas the uptake rates of small phytoplankton ranged from 0 to 2.87mgCm<SUP>-3</SUP>h<SUP>-1</SUP>. In comparison with the carbon uptake rates, total phytoplankton nitrate uptake rates ranged from 0 to 4.40mgNm<SUP>-3</SUP>h<SUP>-1</SUP> while small phytoplankton nitrate uptake rates ranged from 0 to 0.39mgNm<SUP>-3</SUP>h<SUP>-1</SUP>. Ammonium uptake rates ranged from 0 to 8.34mgNm<SUP>-3</SUP>h<SUP>-1</SUP> and from 0.01 to 2.18mgNm<SUP>-3</SUP>h<SUP>-1</SUP>, for total and small phytoplankton, respectively. Small phytoplankton contributed 24.80% (S.D.=+/-23.0%) to the total chlorophyll-a concentration, and 59.41% (S.D.=+/-52.12%) to the total carbon biomass due to its higher particulate organic carbon per chlorophyll-a unit during the two cruises in 2004. In the Chukchi Sea, the average contributions of small phytoplankton to carbon and total nitrogen (nitrate+ammonium) uptake rates were 31.72% (S.D.=+/-23.59%) and 37.31% (S.D.=+/-26.06%), respectively.

Lipoteichoic acid of Streptococcus mutans interacts with Toll-like receptor 2 through the lipid moiety for induction of inflammatory mediators in murine macrophages

Hong, S.W.,Baik, J.E.,Kang, S.S.,Yun, C.H.,Seo, D.G.,Han, S.H. Pergamon Press 2014 Molecular immunology Vol.57 No.2

Streptococcus mutans is a pathogenic Gram-positive bacterium that is closely associated with dental caries and subsequent pulpal inflammation. Although lipoteichoic acid (LTA) is considered a major virulence factor of Gram-positive bacteria, little is known about the innate immunity to S. mutans LTA. In this study, we purified LTA from S. mutans (Sm.LTA) through n-butanol extraction, hydrophobic interaction column chromatography, and ion-exchange column chromatography to investigate its immunological properties using murine macrophages. The Sm.LTA preparation had no detectable contamination with endotoxins, proteins, or nucleic acids. Upon exposure to Sm.LTA, the murine macrophage cell-line RAW 264.7 cells produced TNF-α and nitric oxide (NO) in a dose-dependent manner. Sm.LTA preferentially bound to and activated CHO/CD14/TLR2 cells rather than CHO/CD14/TLR4 cells, which are stable transfectants expressing CD14 and TLR2 or CD14 and TLR4, respectively. Sm.LTA could not induce TNF-α or NO production in macrophages derived from TLR2-deficient mice whereas it dose-dependently induced those inflammatory mediators in wild-type macrophages. TLR2-dependent induction of NO by Sm.LTA was also confirmed in RAW 264.7 cells using specific antibodies blocking TLR2. Furthermore, Sm.LTA deacylated by alkaline hydrolysis neither stimulated TLR2 nor induced TNF-α or NO production, suggesting that Sm.LTA lipid moieties are crucial for the immuno-stimulatory activity of Sm.LTA. Unlike Staphylococcus aureus LTA, which has potent immuno-stimulating activity, Sm.LTA showed a modest induction of NO production comparable to LTAs of other oral bacteria Enterococcus faecalis and Lactobacillus plantarum. In conclusion, our results suggest that the Sm.LTA interacts with TLR2 through the lipid moiety for the induction of inflammatory mediators in macrophages.