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Non-structural 5A protein of hepatitis C virus induces a range of liver pathology in transgenic mice
Wang, Ai-Guo,Lee, Dong-Seok,Moon, Hyung-Bae,Kim, Jin-Man,Cho, Kyung-Hyun,Choi, Soo-Ho,Ha, Hye-Lin,Han, Ying-Hao,Kim, Dae-Ghon,Hwang, Soon B.,Yu, Dae-Yeul John Wiley Sons, Ltd. 2009 The Journal of pathology Vol.219 No.2
<P>Hepatitis C virus (HCV) is a major cause of chronic hepatitis, liver cirrhosis and hepatocellular carcinoma (HCC). However, the mechanism of HCV pathogenesis is not well understood. Our previous in vitro studies suggested that non-structural 5A (NS5A) protein may play an important role in liver pathogenesis. To elucidate the mechanism of HCV-induced liver pathogenesis, we investigated the histopathological changes of liver in transgenic mice harbouring the NS5A gene. We generated transgenic mice harbouring HCV NS5A gene under the control of hepatitis B virus (HBV) enhancer. Pathological changes were analysed by immunohistochemical staining and western blot analysis. Lipid composition and reactive oxygen species (ROS) production in NS5A transgenic mice were analysed. HCV NS5A transgenic mice developed extraordinary steatosis over 6 months old and induced HCC in some mice. NS5A was co-localized with apolipoprotein A-I in fatty hepatocytes. In addition, the extraordinarily high levels of ROS, NF-κB and STAT3 were detected in hepatocytes of NS5A transgenic mice. These data suggest that NS5A, independent of other HCV viral proteins, may play an important role in the development of hepatic pathologies, including steatosis and hepatoceullular carcinoma in transgenic mice. Copyright © 2009 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.</P>
Microbiological Analysis of Rice Cake Processing in Korea
WANG, JUN,PARK, JOONG-HYUN,CHOI, NA-JUNG,HA, SANG-DO,OH, DEOG-HWAN International Association for Food Protection 2016 Journal of food protection Vol.79 No.1
<B>ABSTRACT</B><P>This study was conducted to evaluate the microbial contamination in rice cake materials and products during processing and in the operation environment in nonhazard analysis [and] critical control point factories. Furthermore, the environmental health of the processing facilities and the bacterial and fungal contamination on the workers' hands were investigated. Pour plate methods were used for enumeration of aerobic plate count (APC), yeast and molds (YM), Bacillus cereus, Staphylococcus aureus, and Clostridium perfringens, whereas Petrifilm count plates were used for enumeration of coliforms and Escherichia coli. The respective microbial levels of APC, coliforms, YM, and B. cereus were in the range of 2.6 to 4.7, 1.0 to 3.8, not detected (ND) to 2.9, and ND to 2.8 log CFU/g in the raw materials and in the range of 2.3 to 6.2, ND to 3.6, ND to 2.7, and ND to 3.7 log CFU/g during processing of the rice cake products. During the processing of rice cakes, APC, coliforms, YM, and B. cereus increased during soaking and smashing treatments and decreased after steaming treatment. E. coli, S. aureus, and C. perfringens were not detected in any of the raw materials and operating areas or during processing. B. cereus was detected on the operators' hands at microbial contamination levels of 1.9 ± 0.19 to 2.0 ± 0.19 log CFU/g. The results showed that B. cereus in the end product is presumably the main concern for rice cakes. In addition, the high contamination level of B. cereus during manufacturing processes, including soaking, smashing, and molding, and the absence of B. cereus from the air sampling plates indicated that the contaminated equipment showed the potential risk to cause cross-contamination.</P>
Hypoxic condition enhances chondrogenesis in synovium-derived mesenchymal stem cells
Hyun Cheol Bae,Hee Jung Park,Sun Young Wang,Ha Ru Yang,Myung Chul Lee,한혁수 한국생체재료학회 2018 생체재료학회지 Vol.22 No.4
Background: The chondrogenic differentiation of mesenchymal stem cells (MSCs) is regulated by many factors, including oxygen tensions, growth factors, and cytokines. Evidences have suggested that low oxygen tension seems to be an important regulatory factor in the proliferation and chondrogenic differentiation in various MSCs. Recent studies report that synovium-derived mesenchymal stem cells (SDSCs) are a potential source of stem cells for the repair of articular cartilage defects. But, the effect of low oxygen tension on the proliferation and chondrogenic differentiation in SDSCs has not characterized. In this study, we investigated the effects of hypoxia on proliferation and chondrogenesis in SDSCs. Method: SDSCs were isolated from patients with osteoarthritis at total knee replacement. To determine the effect of oxygen tension on proliferation and colony-forming characteristics of SDSCs, A colony-forming unit (CFU) assay and cell counting-based proliferation assay were performed under normoxic (21% oxygen) or hypoxic (5% oxygen). For in vitro chondrogenic differentiation, SDSCs were concentrated to form pellets and subjected to conditions appropriate for chondrogenic differentiation under normoxia and hypoxia, followed by the analysis for the expression of genes and proteins of chondrogenesis. qRT-PCR, histological assay, and glycosoaminoglycan assays were determined to assess chondrogenesis. Results: Low oxygen condition significantly increased proliferation and colony-forming characteristics of SDSCs compared to that of SDSCs under normoxic culture. Similar pellet size and weight were found for chondrogensis period under hypoxia and normoxia condition. The mRNA expression of types II collagen, aggrecan, and the transcription factor SOX9 was increased under hypoxia condition. Histological sections stained with Safranin-O demonstrated that hypoxic conditions had increased proteoglycan synthesis. Immunohistochemistry for types II collagen demonstrated that hypoxic culture of SDSCs increased type II collagen expression. In addition, GAG deposition was significantly higher in hypoxia compared with normoxia at 21 days of differentiation. Conclusion: These findings show that hypoxia condition has an important role in regulating the synthesis ECM matrix by SDSCs as they undergo chondrogenesis. This has important implications for cartilage tissue engineering applications of SDSCs.
Structural insight into the carboxylesterase BioH from <i>Klebsiella pneumoniae</i>
Wang, Lulu,Chen, Yuanyuan,Shang, Fei,Liu, Wei,Lan, Jing,Gao, Peng,Ha, Nam-Chul,Nam, Ki Hyun,Dong, Yuesheng,Quan, Chunshan,Xu, Yongbin Elsevier 2019 Biochemical and biophysical research communication Vol.520 No.3
<P><B>Abstract</B></P> <P>The BioH carboxylesterase which is a typical α/β-hydrolase enzyme involved in biotin synthetic pathway in most bacteria. BioH acts as a gatekeeper and blocks the further elongation of its substrate. In the pathogen <I>Klebsiella pneumoniae</I>, BioH plays a critical role in the biosynthesis of biotin. To better understand the molecular function of BioH, we determined the crystal structure of BioH from <I>K. pneumoniae</I> at 2.26 Å resolution using X-ray crystallography. The structure of KpBioH consists of an α-β-α sandwich domain and a cap domain. B-factor analysis revealed that the α-β-α sandwich domain is a rigid structure, while the loops in the cap domain shows the structural flexibility. The active site of KpBioH contains the catalytic triad (Ser82-Asp207-His235) on the interface of the α-β-α sandwich domain, which is surrounded by the cap domain. Size exclusion chromatography shows that KpBioH prefers the monomeric state in solution, whereas two-fold symmetric dimeric formation of KpBioH was observed in the asymmetric unit, the conserved Cys31-based disulfide bonds can maintain the irreversible dimeric formation of KpBioH. Our study provides important structural insight for understanding the molecular mechanisms of KpBioH and its homologous proteins.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Crystal structure of <I>K. pneumoniae</I>BioH consists of an α-β-αsandwish domain and acapsubdomain. </LI> <LI> The active site of KpBioH contains the catalytic triad (Ser82-Asp207-His235). </LI> <LI> The Arg138, Arg142, Arg155, and Arg159 of KpBioH may play an important role in the binding of the substrates like ACP. </LI> <LI> The Cys31-based disulfide bonds can maintain the irreversible dimeric formation of KpBioH. </LI> </UL> </P>
( Wang Lok Lee ),( Jun Hyun Jeong ),( Hee Geun Park ),( Youn Gran Lee ),( Soon Mi Kwon ),( Ha Kyoung Jang ),( Jong Kui Jun ),( Myung Hwa Kim ),( Sang Ki Lee ),( Kwang Mu Lee ) 한국운동영양학회 2012 Physical Activity and Nutrition (Phys Act Nutr) Vol.16 No.3
This study investigated the effect of moderate exercise training on macrophage immunocompetence in high fat diet-induced obese mice. To determine the differential effects of exercise training and low fat diet on macrophage, C57BL/6 male mice (4 week old, n=32) were fed high-fat diet for 5 weeks to induce obese. The high fat-induced obese mice were then divided into four groups and differently treated by high/low fat diet and exercise training for a further 8 weeks; HHC (13 weeks high-fat diet), HHE (13 weeks high-fat diet with 8 weeks Exercise training) and HLC (5 weeks high-fat diet and 8 weeks low-fat diet), HLE (5 weeks high-fat diet and 8 weeks low-fat diet with exercise training). The exercise groups were performed on a motorized treadmill, running for 30-60 min/day at 10-22 m/min, 0% grade for 8wks. Body weight was significantly decreased for those with a low-fat diet and exercise training (HLE). Macrophage phagocytosis was significantly increased by low-fat diet and exercise training (HLE). The percentage of stimulation of NO release induced by LPS was higher in HLE than in other groups. The percentage of stimulation of IL-1β release induced by LPS was higher in HHE and HLE than in other groups. The percentage of stimulation of IFN-γ release induced by LPS was higher in HLE than in other groups. These findings suggest that moderate exercise and low-fat diet have beneficial effects on macrophage immunocompetence in high fat diet-induced obese mice.
목하균(Ha-Kyun Mok),왕수현(Soo-Hyun Wang),성영모(Young-Mo Sung),이용태(Yong-Tae Lee),이용훈(Yong-Hoon Lee),김흥묵(Heung-Mook Kim) 한국방송·미디어공학회 2009 방송공학회논문지 Vol.14 No.4
To verify the performance of a Distributed Translator Network(DTxR) system in the real world conditions, 5 legacy DTV broadcasting repeater sites were implemented with 5 DTxR systems and field-tested by the DTV field test truck. The 4 DTV broadcasting repeater sites are selected in congested areas where their service areas are overlapped and the 5th site is deviated from the other sites to examine the effect of long-delayed multipath signals. First of all, we checked the receiving signal of the main station that used as a transmitting signal in 5 DTxR systems on the pre-selected 60 test points and tested every case of a DTxR system's on & off except 1 repeater site due to the already built-in DTV repeater system. The test items are received signal electric field strength, noise margin, ease of reception and subjective evaluation of the picture quality for received signals. We used 3rd, 5th, and 6th generation DTV receivers to examine the differences of the receivability by each generation of DTV receivers. Reviewing the test results, we conclude that the DTxR system can be adopted in the current DTV Repeater sites and it could improve the quality and receivability of the main signals by extending the service areas and enhancing the signal levels in the shadow areas without using the extra broadcasting channels.