Han min hee
Publications
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2.21Impact points
Inhibitory effects of a spinasterol glycoside on lipopolysaccharide-induced production of nitric oxide and proinflammatory cytokines via down-regulating MAP kinase pathways and NF-κB activation in RAW264.7 macrophage cells.
International immunopharmacology. 05/2012;
Extracts from the leaves of Stewartia koreana are known to exhibit strong anti-inflammatory activity. Investigation of bioactive compounds from S. koreana has led to the isolation of 3-O-β-d-glucopyanosylspinasterol (spinasterol-Glc), a spinasterol glycoside. In the present study, we examined the ef... [more] Extracts from the leaves of Stewartia koreana are known to exhibit strong anti-inflammatory activity. Investigation of bioactive compounds from S. koreana has led to the isolation of 3-O-β-d-glucopyanosylspinasterol (spinasterol-Glc), a spinasterol glycoside. In the present study, we examined the effects of spinasterol-Glc on production of nitric oxide (NO) and proinflammatory cytokines in LPS-treated RAW264.7 macrophage cells and in mouse models. Our results showed that spinasterol-Glc inhibited the production of NO and proinflammatory cytokines such as TNF-α, IL-6 and IL-1β in dose-dependent manners in LPS-treated RAW264.7 cells. Spinasterol-Glc inhibited the expression of iNOS and the proinflammatory cytokine genes. Spinasterol-Glc also inhibited phosphorylation of IκB-α and IKKα/β as well as translocation of NF-κB to the nucleus. We demonstrated that spinasterol-Glc reduced transcription of the NF-κB minimal promoter and NF-κB DNA binding activity. Administration of the spinasterol-Glc significantly decreased the plasma levels of these inflammatory mediators including TNF-α, IL-6 and IL-1β in LPS-injected mice and improved survival of septic mice with lethal endotoxemia. These results suggest that spinasterol-Glc has effective inhibitory effects on production of inflammatory mediators via inhibition of MAP kinases/NF-κB activities, and can be used as a potential anti-inflammatory agent for the prevention and treatment of inflammatory diseases.
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Comparative proteomic analysis for the insoluble fractions of colorectal cancer patients.
Journal of proteomics. 04/2012;
We used label-free quantitative proteomics with the insoluble fractions from colorectal cancer (CRC) patients to gain further insight into the utility of profiling altered protein expression as a potential biomarker for cancer. The insoluble fractions were prepared from paired tumor/normal biopsies ... [more] We used label-free quantitative proteomics with the insoluble fractions from colorectal cancer (CRC) patients to gain further insight into the utility of profiling altered protein expression as a potential biomarker for cancer. The insoluble fractions were prepared from paired tumor/normal biopsies from 13 patients diagnosed with CRC (stages I to IV). Fifty-six proteins identified in data pooled from the 13 cases were differentially expressed between the tumor and adjacent normal tissue. The connections between these proteins are involved in reciprocal networks related to tumorigenesis, cancer incidence based on genetic disorder, and skeletal and muscular disorders. To assess their potential utility as biomarkers, the relative expression levels of the proteins were validated using personal proteomics and a heat map to compare five individual CRC samples with five normal tissue samples. Further validation of a panel of proteins (KRT5, JUP, TUBB, and COL6A1) using western blotting confirmed the differential expression. These proteins gave specific network information for CRC, and yielded a panel of novel markers and potential targets for treatment. It is anticipated that the experimental approach described here will increase our understanding of the membrane environment in CRC, which may provide direction for making diagnoses and prognoses through molecular biomarker targeting.
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1.44Impact points
Comparison of Different Grafting Techniques in Type I Tympanoplasty in Cases of Significant Middle Ear Granulation.
Otology & neurotology : official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology. 03/2012;
OBJECTIVE: To assess anatomical and hearing results after different reconstruction methods of tympanic membrane in cases of severe middle ear granulation. STUDY DESIGN: Retrospective review. SETTING: Secondary care medical center. PATIENTS: Forty patients with severe middle ear granulation were incl... [more] OBJECTIVE: To assess anatomical and hearing results after different reconstruction methods of tympanic membrane in cases of severe middle ear granulation. STUDY DESIGN: Retrospective review. SETTING: Secondary care medical center. PATIENTS: Forty patients with severe middle ear granulation were included. INTERVENTIONS: Canal wall-up mastoidectomy with Type I tympanoplasty. Temporalis fascia was used in 22 patients, cartilage island flap was used in 10 patients, and cartilage palisade was used in 8 patients. MAIN OUTCOME MEASURES: Graft take, air-bone gap, and air-bone gap closure ratio of 50% or more. RESULTS: In the fascia group, the graft take rate was 91%, whereas the graft take rate for the cartilage island group and the cartilage palisades group was 100% (p = 0.617). Mean ± SD preoperative air-bone gaps for the fascia, island flap, and cartilage palisades were 30 ± 9.4, 26 ± 11.7, and 25 ± 10.8 dB, respectively. Postoperative air-bone gaps were 17 ± 10.2, 14 ± 8.4, and 19 ± 7.5 dB, respectively, in the same order. The cartilage palisades group failed to show statistically significant difference between preoperative and postoperative air-bone gaps (p = 0.195). Air-bone gap closure ratio of 50% or more was found in 11 cases (50%) of the fascia group, in 5 cases (50%) of the island flap group, and in 1 case (13%) of the cartilage palisades group. CONCLUSION: Cartilage palisades showed reliable graft take but slightly poor hearing results. Thus, fascia or cartilage island grafting might be better for tympanoplasty in cases of severe middle ear granulation tissue.
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3.54Impact points
Human lactoferrin suppresses TNF-α-induced intercellular adhesion molecule-1 expression via competition with NF-κB in endothelial cells.
FEBS letters. 02/2012; 586(3):229-34.
Lactoferrin (Lf) is known to have anti-inflammatory activity, but the mechanisms of action by Lf remain to be elucidated. Here, we demonstrated that TNF-α-induced expression of intercellular adhesion molecule-1 (ICAM-1) was down-regulated by Lf in a DNA-binding dependent manner at transcriptional le... [more] Lactoferrin (Lf) is known to have anti-inflammatory activity, but the mechanisms of action by Lf remain to be elucidated. Here, we demonstrated that TNF-α-induced expression of intercellular adhesion molecule-1 (ICAM-1) was down-regulated by Lf in a DNA-binding dependent manner at transcriptional level in endothelial cells. Our results showed that Lf bound to a DNA region in the ICAM-1 promoter in vitro as well as in chromatin context. Lf inhibited binding of NF-κB to a proximal NF-κB site in ICAM-1 promoter. This type of repression represents an additional mechanism for the action of Lf in regulation of gene expression.
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2.27Impact points
Chlamydophila pneumonia inhibits the corticosteroid-induced suppressions of metalloproteinase-9 and tissue inhibitor metalloproteinase-1 secretion by human peripheral blood mononuclear cells.
Journal of medical microbiology. 01/2012;
Chlamydophila pneumoniae infection has been suggested to be associated with severe asthma characterized by persistent airway limitation, which may be related to airway remodeling. We investigated whether C. pneumoniae infection affected the secretion of metalloproteinase-9 (MMP9) and tissue inhibito... [more] Chlamydophila pneumoniae infection has been suggested to be associated with severe asthma characterized by persistent airway limitation, which may be related to airway remodeling. We investigated whether C. pneumoniae infection affected the secretion of metalloproteinase-9 (MMP9) and tissue inhibitor metalloproteinase-1 (TIMP1), and altered the responsiveness of inflammatory cells to corticosteroids. Human peripheral blood mononuclear cells (PBMC) were cultured in vitro in the presence or absence of C. pneumoniae. Secretion of both MMP9 and TIMP1 was strongly suppressed by dexamethasone treatment in uninfected cells. MMP9 secretion was also significantly inhibited by dexamethasone in C. pneumoniae-infected cells, but TIMP1 secretion was not; hence the MMP9 to TIMP1 ratio decreased. Interestingly, expression of human glucocorticoid receptor (GR)β, which is believed to confer resistance to corticosteroids, was enhanced by dexamethasone treatment in C. pneumoniae-infected PBMC. We conclude that C. pneumoniae infection may promote airway remodeling by decreasing the ratio of MMP9 to TIMP1 secreted by inflammatory cells, and by altering cellular responsiveness to corticosteroids.
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1.16Impact points
Lignans from the flowers of Osmanthus fragrans var. aurantiacus and their inhibition effect on NO production.
Archives of pharmacal research. 12/2011; 34(12):2029-35.
A new lignan, (7R,7'R,8R,8'R)-8-hydroxypinoresinol 8-O-β-D-glucopyranoside 4'-methyl ether (7), was isolated from the flowers of Osmanthus fragrans var. aurantiacus along with six known lignans: (+)-phillygenin (1), phillyrin (2), (-)-phillygenin (3), (-)-epipinoresinol-β-D-glucoside (4)... [more] A new lignan, (7R,7'R,8R,8'R)-8-hydroxypinoresinol 8-O-β-D-glucopyranoside 4'-methyl ether (7), was isolated from the flowers of Osmanthus fragrans var. aurantiacus along with six known lignans: (+)-phillygenin (1), phillyrin (2), (-)-phillygenin (3), (-)-epipinoresinol-β-D-glucoside (4), taxiresinol (5), and (-)-olivil (6). The structure of the new compound was elucidated on the basis of 1D- and 2D-NMR spectroscopic analysis and specific rotation data. The compounds isolated from the flowers of O. fragrans var. aurantiacus were evaluated for inhibitory activities on nitric oxide production in lipopolysaccharide-stimulated macrophage RAW 264.7 cells. (+)-Phillygenin (1), phillyrin (2), and (-)-phillygenin (3) exerted the strongest inhibitory activities on NO production with IC(50) values of 25.5, 18.9, and 25.5 μM, respectively. These compounds may prove beneficial in the development of natural agents for prevention and treatment of inflammatory diseases.
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4.43Impact points
In-depth analysis of cysteine oxidation by the RBC proteome: advantage of peroxiredoxin II knockout mice.
Proteomics. 11/2011; 12(1):101-12.
Peroxiredoxin II (Prdx II, a typical 2-Cys Prdx) has been originally isolated from erythrocytes, and its structure and peroxidase activity have been adequately studied. Mice lacking Prdx II proteins had heinz bodies in their peripheral blood, and morphologically abnormal cells were detected in the d... [more] Peroxiredoxin II (Prdx II, a typical 2-Cys Prdx) has been originally isolated from erythrocytes, and its structure and peroxidase activity have been adequately studied. Mice lacking Prdx II proteins had heinz bodies in their peripheral blood, and morphologically abnormal cells were detected in the dense red blood cell (RBC) fractions, which contained markedly higher levels of reactive oxygen species (ROS). In this study, a labeling experiment with the thiol-modifying reagent biotinylated iodoacetamide (BIAM) in Prdx II-/- mice revealed that a variety of RBC proteins were highly oxidized. To identify oxidation-sensitive proteins in Prdx II-/- mice, we performed RBC comparative proteome analysis in membrane and cytosolic fractions by nano-UPLC-MSE shotgun proteomics. We found oxidation-sensitive 54 proteins from 61 peptides containing cysteine oxidation, and analyzed comparative expression pattern in healthy RBCs of Prdx II+/+ mice, healthy RBCs of Prdx II-/- mice, and abnormal RBCs of Prdx II-/- mice. These proteins belonged to cellular functions related with RBC lifespan maintain, such as cytoskeleton, stress-induced proteins, metabolic enzymes, signal transduction, and transporters. Furthermore, protein networks among identified oxidation-sensitive proteins were analyzed to associate with various diseases. Consequently, we expected that RBC proteome might provide clues to understand redox-imbalanced diseases.
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0.98Impact points
Effect of fibrin-coated collagen fleece (TachoComb) on pain and bleeding after adenotonsillectomy in children.
Acta oto-laryngologica. 09/2011; 131(12):1293-8.
Even though the use of TachoComb does not decrease pain after tonsillectomy, it is safe and useful to reduce bleeding after tonsillectomy. Sealing the post-tonsillectomy wound would be expected to reduce pain and bleeding by decreasing the exposure of the traumatized tissue and sensory nerves. Tacho... [more] Even though the use of TachoComb does not decrease pain after tonsillectomy, it is safe and useful to reduce bleeding after tonsillectomy. Sealing the post-tonsillectomy wound would be expected to reduce pain and bleeding by decreasing the exposure of the traumatized tissue and sensory nerves. TachoComb is a powerful topical hemostatic agent. The objectives of this study were to evaluate the effect of TachoComb on reduction of pain and bleeding after tonsillectomy. A prospective randomized double-blind study was performed on 120 pediatric patients undergoing adenotonsillectomy. The patients were randomized into two groups: use/non-use of TachoComb. In the study group, each tonsillar bed was covered with a TachoComb strip at the end of operation. No hemostatic agents were used in the control group. After surgery, patients were monitored for pain, bleeding, oral intake, medication administration, activity, and complications using a 10-day diary. In all, 110 patients returned and filled in the diary. The use of TachoComb did not decrease pain, reduce the use of analgesic drugs or speed recovery to normal everyday life. Post-surgery bleeding was not experienced by any of the TachoComb patients, but occurred in five of the control patients. The result had borderline statistical significance (p < 0.1).
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0.58Impact points
Acute supraglottitis in adults: What's the optimal airway intervention?
Auris, nasus, larynx. 09/2011; 39(2):204-7.
To validate the Friedman stage and define the proper timing for airway intervention in adult cases of acute supraglottitis, we evaluated the clinical courses and management of adult patients. 202 adult patients with acute supraglottitis were included in this study. The diagnosis of supraglottitis wa... [more] To validate the Friedman stage and define the proper timing for airway intervention in adult cases of acute supraglottitis, we evaluated the clinical courses and management of adult patients. 202 adult patients with acute supraglottitis were included in this study. The diagnosis of supraglottitis was established by flexible nasolaryngoscopic examination. Friedman stages were classified in each patient. In this study, the first three days of serial nasolaryngoscopic findings for each patient were evaluated. All patients were treated successfully with only conservative methods. There were no significant differences between patients with Friedman stages I or II/III. Among the patients that had serial nasolaryngoscopic findings, only one patient presented with progressive swelling of the epiglottis, and there were no cases of persistent swelling. The airway intervention threshold should be raised from Friedman stages II-III. And, airway intervention should not be needed if patients are tolerant of their respiratory discomfort.
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A P300-Based Hangul Input System with a Hierarchical Stimulus Presentation Paradigm
Pattern Recognition in NeuroImaging (PRNI), 2011 International Workshop on; 06/2011
We propose a hierarchical stimulus presentation paradigm for a P300-based Hangul (Korean script) input system. A P300-based input system is one of the most promising noninvasive brain-computer interface (BCI) applications based on its direct applicability in many computer programs. While the previou... [more] We propose a hierarchical stimulus presentation paradigm for a P300-based Hangul (Korean script) input system. A P300-based input system is one of the most promising noninvasive brain-computer interface (BCI) applications based on its direct applicability in many computer programs. While the previous row/column stimulus presentation paradigm has been well-suited to the English input, it may not be optimal for a Hangul input because Hangul has a distinct hierarchical structure. To overcome the limitation of the previous paradigms, we developed a new P300-based Hangul input system by taking the unique hierarchical structure of Hangul into account for creating a hierarchical stimulus presentation paradigm. By using the hierarchical structure, we can effectively reduce the window size of the interface without loss of classification accuracy. A performance comparison shows that the hierarchical paradigm exhibits higher classification accuracy than the row/column paradigm even with a smaller window size. Thus the proposed hierarchical paradigm is more efficient to spell Hangul and will be more useful for BCI-based Hangul input for a text messenger, e-mail program, word processor, and so on.
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1.48Impact points
The role of peroxiredoxin V in (-)-epigallocatechin 3-gallate-induced multiple myeloma cell death.
Oncology research. 01/2011; 19(8-9):391-8.
(-)-Epigallocatechin 3-gallate (EGCG) is a potent antioxidant polyphenol in green tea that acts as an anticancer agent via both direct and indirect pathways. Although the relationship between EGCG's anticancer effects and its antioxidant activity is not fully understood, it is known that EGCG st... [more] (-)-Epigallocatechin 3-gallate (EGCG) is a potent antioxidant polyphenol in green tea that acts as an anticancer agent via both direct and indirect pathways. Although the relationship between EGCG's anticancer effects and its antioxidant activity is not fully understood, it is known that EGCG stimulates production of reactive oxygen species (ROS), which induce oxidative stress leading to cell death. In IM9 multiple myeloma cells, EGCG acted in a dose- and time-dependent manner to induce apoptotic cell death. Among the antioxidant enzymes expressed in IM9 cells, levels of peroxiredoxin V (PrdxV) were selectively and significantly reduced by EGCG. Moreover, the ROS scavenger NAC completely inhibited EGCG-induced apoptosis and PrdxV reduction, while overexpression of PrdxV, but not a Prdx(VC48S) mutant, protected IM9 cells from EGCG-induced apoptosis. EGCG-induced reductions in cell viability and PrdxV levels were also observed in primary CD138+ multiple myeloma cells from patients. These results suggest that PrdxV is a key target via which EGCG mediates its anticancer effects.
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1.81Impact points
A glycosidic spinasterol from Koreana stewartia promotes procollagen production and inhibits matrix metalloproteinase-1 expression in UVB-irradiated human dermal fibroblasts.
Biological & pharmaceutical bulletin. 01/2011; 34(5):768-73.
Methanol extract of Koreana stewartia leaves (SKE) stimulated collagen production in ultraviolet-B (UVB)-irradiated human fibroblast cells. An active compound was isolated from SKE by successive partitioning and chromatography, and the chemical structure was determined to be 3-O-β-D-glucopyranosylsp... [more] Methanol extract of Koreana stewartia leaves (SKE) stimulated collagen production in ultraviolet-B (UVB)-irradiated human fibroblast cells. An active compound was isolated from SKE by successive partitioning and chromatography, and the chemical structure was determined to be 3-O-β-D-glucopyranosylspinasterol (spinasterol-Glc) by spectroscopic characterization. Spinasterol-Glc increased collagen production in the supernatant of UVB-irradiated dermal fibroblast cell cultures in a dose-dependent manner. The effects of spinasteol-Glc on expression of procollagen and matrix metalloproteinase-1 (MMP-1) were further evaluated. We found that the compound stimulated collagen production in UVB-treated fibroblasts than in vehicle-treated control cells by about 3-fold. In addition, we also demonstrate that the compound increased the mRNA and protein levels of procollagen in UVB-treated fibroblast cells, while it inhibited expression of MMP-1. These results indicate that spinasterol-Glc protects fibroblast cells from the adverse effects of UV radiation via stimulation of procollagen synthesis as well as inhibition of MMP-1 expression. Spinasterol-Glc may be useful in the future development of therapeutic and cosmetic applications.
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Characteristics analysis in a pole changing memory motor using coupled FEM & Preisach modeling
Electrical Machines and Systems (ICEMS), 2010 International Conference on; 11/2010
This paper deals with the PM performance evaluations in a pole changing memory motor (PCMM) using a coupled transient finite element method (FEM) and Preisach modeling, which is presented to analyze the magnetic characteristics of permanent magnets. The focus of this paper is the characteristics eva... [more] This paper deals with the PM performance evaluations in a pole changing memory motor (PCMM) using a coupled transient finite element method (FEM) and Preisach modeling, which is presented to analyze the magnetic characteristics of permanent magnets. The focus of this paper is the characteristics evaluation relative to magnetizing direction and the pole number of machine on re-demagnetization condition in a pole changing memory motor.
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Optimum design criteria for maximum torque density & minimum torque ripple of Flux Switching Motor using response surface methodology
Electrical Machines and Systems (ICEMS), 2010 International Conference on; 11/2010
This paper deals with optimum design criteria for maximum torque density & minimum torque ripple of Flux Switching Motor (FSM) using response surface methodology (RSM) & finite element method (FEM). The focus of this paper is to find a design solution through the comparison of torque density... [more] This paper deals with optimum design criteria for maximum torque density & minimum torque ripple of Flux Switching Motor (FSM) using response surface methodology (RSM) & finite element method (FEM). The focus of this paper is to find a design solution through the comparison of torque density and torque ripple according to rotor shape variations. And then, new type winding method & optimum turns of armature/field winding is introduced, and numerical analysis & experiment is conducted to confirm the appropriate solution for the optimized model. The proposed procedure allows the definition of the optimum rotor dimensions and armature/ field turns starting from an existing motor or a preliminary design.
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1.46Impact points
Immune response induced by ppGpp-defective Salmonella enterica serovar Gallinarum in chickens.
Journal of microbiology (Seoul, Korea). 10/2010; 48(5):674-81.
To protect chickens from typhoid caused by Salmonella enterica serovar Gallinarum (S. Gallinarum), the attenuated 9R strain has been used in the field as a vaccine. However, safety concerns have been raised because the mutations in 9R are undefined while its efficacy is still a question under debate... [more] To protect chickens from typhoid caused by Salmonella enterica serovar Gallinarum (S. Gallinarum), the attenuated 9R strain has been used in the field as a vaccine. However, safety concerns have been raised because the mutations in 9R are undefined while its efficacy is still a question under debate. A global regulator, ppGpp, synthesized by RelA and SpoT, has been shown to induce various virulence genes in S. Gallinarum (Jeong et al., 2008). In this study, two mutant strains defective in ppGpp-synthesis were constructed in wild-type S. Gallinarum (ΔppGpp) and 9R strain (9R-ΔppGpp) backgrounds and tested as live vaccines in chickens. After oral inoculation, the LD(50) values of ΔppGpp and 9R-ΔppGpp were approximately 5×10(10) colony forming unit (CFU) similarly as 9R strain, which was ∼10(5)-fold higher than that of the wildtype S. Gallinarum strain. Immunological analyses revealed immunization with either of the two attenuated ppGpp-defective strains induced significant antibody responses, the production of antibody-secreting B cells in blood, proliferation of CD4+ and CD8+ T cells in the spleen, and splenic expression of proinflammatory cytokines, such as IFN-γ and TGF-β4, at levels comparable to the 9R strain. Chickens immunized with the mutants (1×10(8) CFU) were 80% protected against oral challenge with 1×10(9) wild-type virulent bacteria (4,000-fold LD(50) dose), similar to the level of protection achieved by 9R immunization. Based on these data, live attenuated ΔppGpp-defective strains may serve as novel vaccines to control fowl typhoid in chickens.
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4.59Impact points
Caenorhabditis elegans mitofilin homologs control the morphology of mitochondrial cristae and influence reproduction and physiology.
Journal of cellular physiology. 09/2010; 224(3):748-56.
Human mitofilin is a mitochondrial protein that controls cristae formation. Here, we investigated the role of the Caenorhabditis elegans mitofilin homologs, IMMT-1 and -2, in reproduction, physiology, and mitochondrial cristae formation. Mutation of either immt-1 or immt-2 produced defects in germli... [more] Human mitofilin is a mitochondrial protein that controls cristae formation. Here, we investigated the role of the Caenorhabditis elegans mitofilin homologs, IMMT-1 and -2, in reproduction, physiology, and mitochondrial cristae formation. Mutation of either immt-1 or immt-2 produced defects in germline development and egg-laying. These defects were exacerbated by the double mutation, which greatly reduced motility, increased levels of reactive oxygen species, decreased mitochondrial mass, and imparted resistance to oxidative stress. Cryo-electron microscopy and electron tomography revealed that each of the single mutations resulted in curved and stacked mitochondrial crista tubules as well as a reduced number of crista junctions. The immt-2 mutation was also associated with the presence of outer mitochondrial membrane pores, which were larger in the double mutant. IMMT-1 and IMMT-2 proteins were localized to the inner mitochondrial membrane, as seen by immunoelectron microscopy, and they behaved as oligomers or large complexes with F(1)F(0) ATP synthase in native polyacrylamide gel electrophoresis. These findings suggest that the two C. elegans mitofilin isoforms have non-overlapping functions in controlling mitochondrial cristae formation.
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5.13Impact points
Proteomic analysis of protein expression affected by peroxiredoxin V knock-down in hypoxic kidney.
Journal of proteome research. 08/2010; 9(8):4003-15.
Peroxiredoxin V, an atypical thioredoxin peroxidase, is widely expressed in mammalian tissues. In addition, Prdx V is localized in mitochondria, peroxisome, cytosol, and the nucleus. Prdx V has been reported to protect a wide range of cellular environments as an antioxidant enzyme, and its dysfuncti... [more] Peroxiredoxin V, an atypical thioredoxin peroxidase, is widely expressed in mammalian tissues. In addition, Prdx V is localized in mitochondria, peroxisome, cytosol, and the nucleus. Prdx V has been reported to protect a wide range of cellular environments as an antioxidant enzyme, and its dysfunctions may be implicated in several diseases, such as cancer, inflammation, and neurodegenerative disease. Identification and relative quantification of proteins affected by Prdx V may help identify novel signaling mechanisms that are important for oxidative stress response. However, the role of Prdx V in the modulation of hypoxia-related cellular response is not studied yet. To examine the function of endogenous Prdx V in hypoxic condition in vivo, we generated a transgenic mouse model with Prdx V siRNA expression controlled by U6 promoter. Of many tissues, the knockdown of Prdx V expression was displayed in the kidney, lung, and liver but not the spleen and skin. We conducted on the basis of nano-UPLC-MS(E) proteomic study to identify the Prdx V-affected protein networks in hypoxic kidneys. In this study, we identified protein networks associated with oxidative stress, fatty acid metabolism, and mitochondrial dysfunction. Our results indicated that Prdx V affected to regulation of kidney homeostasis under hypoxia stress.
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4.00Impact points
Microglial peroxiredoxin V acts as an inducible anti-inflammatory antioxidant through cooperation with redox signaling cascades.
Journal of neurochemistry. 03/2010; 114(1):39-50.
Reactive oxygen species (ROS) actively participate in microglia-mediated pathogenesis as pro-inflammatory molecules. However, little is known about the involvement of specific antioxidants in maintaining the microglial oxidative balance. We demonstrate that microglial peroxiredoxin (Prx) 5 expressio... [more] Reactive oxygen species (ROS) actively participate in microglia-mediated pathogenesis as pro-inflammatory molecules. However, little is known about the involvement of specific antioxidants in maintaining the microglial oxidative balance. We demonstrate that microglial peroxiredoxin (Prx) 5 expression is up-regulated by lipopolysaccharide (LPS) through activation of the ROS-sensitive signaling pathway and is involved in attenuation of both microglial activation and nitric oxide (NO) generation. Unlike in stimulation of oxidative insults with paraquat and hydrogen peroxide, Prx V expression is highly sensitive to LPS-stimulation in microglia. Reduction of ROS level by treatment with either NADPH oxidase inhibitor or antioxidant ablates LPS-mediated Prx V up-regulation in BV-2 microglial cells and is closely associated with the activation of the c-jun N-terminal kinase (JNK) signaling pathway. This suggests the involvement of ROS/JNK signaling in LPS-mediated Prx V induction. Furthermore, NO induces Prx V up-regulation that is ablated by the addition of inducible nitric oxide synthase inhibitor or deleted mutation of inducible nitric oxide synthase in LPS-stimulated microglia. Therefore, these results suggest that Prx V is induced by cooperative action among the ROS, RNS, and JNK signaling cascades. Interestingly, knockdown of Prx V expression causes the acceleration of microglia activation, including augmented ROS generation and JNK-dependent NO production. In summary, we demonstrate that Prx V plays a key role in the microglial activation process through modulation of the balance between ROS/NO generation and the corresponding JNK cascade activation.
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1.59Impact points
Application of a Self-Multiplication Correction Method to a Neutron Coincidence Counter and Its Calibration for Spent Fuel
Nuclear Science, IEEE Transactions on. 11/2009;
A passive neutron coincidence counter was developed for the nondestructive measurements of the nuclear materials in the Advanced Spent Fuel Conditioning Process (ACP) facility at the Korea Atomic Energy Research Institute (KAERI). A hot test of the neutron counter was performed with spent fuel rod-c... [more] A passive neutron coincidence counter was developed for the nondestructive measurements of the nuclear materials in the Advanced Spent Fuel Conditioning Process (ACP) facility at the Korea Atomic Energy Research Institute (KAERI). A hot test of the neutron counter was performed with spent fuel rod-cuts to obtain the calibration curve for <sup>244</sup>Cm in 2007. The source terms were analyzed by using the ORIGEN-ARP code. There was a considerable difference in the neutron counting rates between the measurements and the MCNPX simulation results. This difference was systematic and came from the errors in the declared <sup>244</sup>Cm mass obtained by using the burnup code. To correct the calibration curve, a self-multiplication correction method was applied, and the corrected singles and doubles rates as well as the expected <sup>244</sup>Cm mass of each rod-cut were obtained as a result. The differences in the calibration constants between the measurements and the MCNPX results were - 33% and - 34% for the singles and doubles rates, respectively. However, those differences between the self-multiplication correction and MCNPX results were reduced to - 1% and - 5% for the singles and doubles rates, respectively.
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5.87Impact points
RtxA1-Induced Expression of the Small GTPase Rac2 Plays a Key Role in the Pathogenicity of Vibrio vulnificus.
The Journal of infectious diseases. 11/2009;
Infection with the human pathogen Vibrio vulnificus leads to the generation of reactive oxygen species (ROS) via NAD(P)H oxidase (Nox) in host cells. In the present study, we employed mutant V. vulnificus strains to identify an essential virulence factor responsible for this ROS generation. We found... [more] Infection with the human pathogen Vibrio vulnificus leads to the generation of reactive oxygen species (ROS) via NAD(P)H oxidase (Nox) in host cells. In the present study, we employed mutant V. vulnificus strains to identify an essential virulence factor responsible for this ROS generation. We found that repeats-in-toxin A1 (RtxA1) expressed by V. vulnificus acts via Nox1 to induce significant ROS generation in the intestine epithelial cells, which ultimately results in cell death. Furthermore, RtxA1 modulates the small GTPase Rac2, which is known to play an important role in the activation of Nox. When mice were infected by the oral method, in contrast with the wild-type bacteria, an RtxA1-deficient V. vulnificus mutant was unable to induce ROS generation within the intestine and failed to cause death. These findings strongly suggest that RtxA1-induced Rac2 expression is a critical step underlying the pathogenicity of V. vulnificus.
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