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Biomedical subjects

Young-Mi Lee

Publications and source records attributed to Young-Mi Lee.

At least 37 records · Page 2Linked to original sources
PubMed2005

Analysis of 686 expressed sequence tags (ESTs) from the intertidal harpacticoid copepod Tigriopus japonicus (Crustacea, Copepoda).

The intertidal harpacticoid copepod Tigriopus japonicus is an important species in the study of marine pollution. To facilitate molecular biomonitoring using T. japonicus, we constructed a T. japonicus unidirectional cDNA library using lambdaZAP expression vector, excised to pBluescript vector with the aid of helper phage, and analyzed 686 randomly picked expressed sequence tags (ESTs) from this species. From the 686 ESTs sequenced, we found several functional genes such as vitellin, kinases and potential detoxification-related genes. We are now preparing a T. japonicus cDNA chip for molecular ecotoxicological studies. In this paper, we discuss the potential use of T. japonicus ESTs and their importance in ecotoxicology.

Animals↗
PubMed2005

Hepatocyte growth factor suppresses vascular endothelial growth factor-induced expression of endothelial ICAM-1 and VCAM-1 by inhibiting the nuclear factor-kappaB pathway.

Vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) are potent angiogenic factors that have been used clinically to induce angiogenesis. However, concerns have been raised about VEGF because of its proinflammatory actions, which include enhancing the adhesion of leukocytes to endothelial cells. We have examined the possible antiinflammatory effects of HGF on the vasculature. HGF, unlike VEGF, did not alter leukocyte adhesion to endothelial cells. Instead it inhibited VEGF-induced leukocyte-endothelial cell interactions and the endothelial expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1). In a skin inflammation model, VEGF-treated mice showed a significant increase of leukocytes infiltrated or adherent to the luminal surface of blood vessels, as compared with vehicle- or HGF-treated mice. The VEGF effect was markedly suppressed by coadministration of HGF. RT-PCR and promoter analysis revealed that HGF downregulated VEGF-mediated expression of ICAM-1 and VCAM-1 at the transcriptional level. Furthermore, these inhibitory effects coincided with suppression of IkappaB kinase activity, and this in turn prevented the activation of the inflammatory transcription factor NF-kappaB. Taken together, our results demonstrate that HGF suppresses VEGF-induced inflammation presumably by inhibiting the endothelial NF-kappaB pathway. This suggests that combined treatment with HGF and VEGF could be superior to treatment with either factor alone for enhancing therapeutic angiogenesis while avoiding inflammation.

Animals↗
PubMed2005

Inhibitory effect on TNF-alpha-induced IL-8 production in the HT29 cell of constituents from the leaf and stem of Weigela subsessilis.

Twelve compounds were isolated from the MeOH extract of the leaf and stem of the Korean endemic plant Weigela subsessilis L. H. Bailey. Their chemical structures were elucidated on the basis of physicochemical and spectroscopic data and by comparison with those of published literatures. These compounds were identified as three sterols, beta-sitosterol acetate (2), betasitosterol (3), daucosterol (11), eight triterpenoids, squalene (1), ursolic acid (4), ilekudinol A (5), corosolic acid (6), ilekudinol B (7), esculentic acid (8), pomolic acid (9), asiatic acid (10), and one iridoid glycoside, alboside I (12). This is the first report pertaining to the isolation of these compounds from Weigela subsessilis L. H. Bailey. In addition, three compounds 7, 9, and 12 were found to display a strong inhibitory effect on the production of IL-8 in the HT29 cells stimulated by TNF-alpha.

Caprifoliaceae↗
PubMed2005

Inhibitory effect of luteolin on TNF-alpha-induced IL-8 production in human colon epithelial cells.

Interleukin (IL)-8 plays a central role in the initiation and maintenance of inflammatory responses in the inflammatory bowel disease. The proinflammatory cytokine-mediated production of IL-8 requires activation of various kinases, which leads to the IkappaB degradation and NF-kappaB activation. In this study, we investigated the role of luteolin, a major flavonoid of Lonicera japonica, on TNF-alpha-induced IL-8 production in human colonic epithelial cells. HT29 cells were stimulated with TNF-alpha in the presence or absence of luteolin. IL-8 production was measured by enzyme-linked immunosorbent assay (ELISA) and reverse transcriptase-polymerase chain reaction (RT-PCR) analysis, and the mitogen-activated protein kinases (MAPKs) activation and IkappaB degradation were determined by Western blot analysis. NF-kappaB activation was assessed by the electrophoretic motility shift assay (EMSA). Luteolin suppressed TNF-alpha-induced IL-8 production in dose-dependent manner. In addition, luteolin inhibited TNF-alpha-induced phosphorylation of p38 MAPK and extracellular-regulated kinases (ERK), IkappaB degradation, and NF-kappaB activation. These results suggest that luteolin has the inhibitory effects on TNF-alpha-induced IL-8 production in the intestinal epithelial cells through blockade in the phosphorylation of MAPKs, following IkappaB degradation and NF-kappaB activation.

Anti-Inflammatory Agents↗
PubMed2005

The complete mitochondrial genome of the rayfish Raja porosa (Chondrichthyes, Rajidae).

We isolated mitochondrial DNA from the rayfish Raja porosa by long-polymerase chain reaction (Long-PCR) with conserved primers, and sequenced it by primer walking method using flanking sequences as sequencing primers. R. porosa mitochondrial DNA consists of 16,972 bp and its structural organization is conserved in comparison with other fishes and mammals. Based on the mitochondrial cytochrome b (cyt b) sequence, the phylogenetic position of R. porosa among cartilaginous fishes was inferred using different phylogenetic methods (ML-based quartet puzzling, Neighbor-joining (NJ) and Bayesian approaches). In this paper, we report the characteristics of the R. porosa mitochondrial genome including structural organization, base composition of rRNAs, tRNAs and protein-encoding genes and characteristics of mitochondrial tRNAs. These findings are applicable to comparative mitogenomics of R. porosa with other related taxa.

Amino Acid Motifs↗
PubMed2005

cDNA cloning and expression of ferritin heavy chain 1, ferritin heavy chain 2 and hemoglobin genes from the fire-bellied frog Bombina orientalis.

We cloned two Bombina orientalis ferritin heavy chains (ferritin heavy chains 1 and 2) and one hemoglobin beta-chain gene from a B. orientalis oviduct cDNA library, and the length of transcripts was 882, 858 and 611 bp encoding 177, 177 and 148 aa, respectively. B. orientalis ferritin heavy chain genes showed high similarity to those of amphibia (88-93%), mammals (70-71%), and fishes (70-72%), and the hemoglobin beta-chain gene showed moderate similarity to amphibian (65-68%) and mammalian (54-57%) hemoglobin beta-chain genes, respectively. Based on phylogenetic analysis, the genes were clustered to the same clade in amphibia. The two B. orientalis ferritin heavy chain genes showed different tissue-specific gene expression patterns. Thus, ferritin heavy chain 1 gene was highly expressed in intestine and oviduct but ferritin heavy chain 2 gene was ubiquitously expressed in most of the examined tissues. The hemoglobin beta-chain gene was more highly expressed in liver than in oviduct. These findings indicate that the genes may play different roles in different tissues. In this paper, we discuss the basic characteristics of B. orientalis ferritin heavy chain genes and hemoglobin beta-chain gene.

Amino Acid Sequence↗
PubMed2005

Triphenylmethane reductase from Citrobacter sp. strain KCTC 18061P: purification, characterization, gene cloning, and overexpression of a functional protein in Escherichia coli.

We purified to homogeneity an enzyme from Citrobacter sp. strain KCTC 18061P capable of decolorizing triphenylmethane dyes. The native form of the enzyme was identified as a homodimer with a subunit molecular mass of about 31 kDa. It catalyzes the NADH-dependent reduction of triphenylmethane dyes, with remarkable substrate specificity related to dye structure. Maximal enzyme activity occurred at pH 9.0 and 60 degrees C. The enzymatic reaction product of the triphenylmethane dye crystal violet was identified as its leuco form by UV-visible spectral changes and thin-layer chromatography. A gene encoding this enzyme was isolated based on its N-terminal and internal amino acid sequences. The nucleotide sequence of the gene has a single open reading frame encoding 287 amino acids with a predicted molecular mass of 30,954 Da. Although the deduced amino acid sequence displays 99% identity to the hypothetical protein from Listeria monocytogenes strain 4b H7858, it shows no overall functional similarity to any known protein in the public databases. At the N terminus, the amino acid sequence has high homology to sequences of NAD(P)H-dependent enzymes containing the dinucleotide-binding motif GXXGXXG. The enzyme was heterologously expressed in Escherichia coli, and the purified recombinant enzyme showed characteristics similar to those of the native enzyme. This is the first report of a triphenylmethane reductase characterized from any organism.

Amino Acid Sequence↗
PubMed2005

Inhibition of interleukin-8 production in the human colonic epithelial cell line HT-29 by 18 beta-glycyrrhetinic acid.

Interleukin (IL)-8 plays a central role in the initiation and maintenance of inflammatory responses in the inflammatory bowel disease. The proinflammatory cytokine-mediated production of IL-8 requires activation of various kinases, which leads to the I kappa B degradation and NF-kappa B activation. We investigated the role of 18 beta-glycyrrhetinic acid (GA), a saponin isolated from licorice roots, on TNF-alpha-induced IL-8 production in human colonic epithelial cells. HT29 cells were stimulated with TNF-alpha in the presence or absence of GA (1, 5 or 10 microM). IL-8 production was measured by enzyme-linked immunosorbent assay (ELISA) and reverse transcriptase-polymerase chain reaction analysis, and the mitogen-activated protein kinases (MAPKs) activation and I kappa B alpha degradation were determined by Western blot analysis. GA suppressed TNF-alpha-induced IL-8 production in a concentration-dependent manner. In addition, GA inhibited TNF-alpha-induced phosphorylation of p38 MAPK and extracellular-regulated kinases (ERK), I kappa B alpha degradation, and NF-kappa B activation. These results suggest that GA has the inhibitory effects on TNF-alpha-induced IL-8 production in the intestinal epithelial cells through blockade in the phosphorylation of MAPKs, following I kappa B alpha degradation and NF-kappa B activation.

Blotting, Western↗
PubMed2005

Effect of processed Scutellaria baicalensis on dextran sulfate sodium-induced colitis in mice.

Scutellaria baicalensis Georgi (Labiatae) has been used in the treatment of inflammatory diseases. Drug processing (Poje) is the process of treating crude drugs by several methods before use. The aim of this study was to determine the effect of processed Scutellaria baicalensis on experimental ulcerative colitis induced by dextran sulfate sodium (DSS). The types of processed Scutellaria baicalensis used in this study were parched Scutellaria baicalensis (PS) and rice wine-baked Scutellaria baicalensis (RWBS). Experimental colitis was induced in mice using a daily treatment of 5% DSS in the drinking water for 7 days. The water extracts of processed Scutellaria baicalensis (1 g/kg) were administered orally once a day for 7 days. The mice were divided in four groups: i) water plus DSS group, ii) crude Scutellaria baicalensis (CS) plus DSS group, iii) PS plus DSS group, and iv) RWBS plus DSS group. RWBS ameliorated all of the inflammatory symptoms, such as body weight loss, rectal bleeding and histological damage, compared to CS. Furthermore, RWBS significantly reduced the mucosal myeloperoxidase activity, and TNF-alpha (tumor necrosis factor-alpha), COX-2 (cyclooxygenase-2), NF-kappaB (nuclear factor-kappa B) and chymase expression more than CS. But these effects were not shown in the PS plus DSS group. Efficacy of Scutellaria baicalensis was increased after rice wine baking, but not after parching. The findings in this study suggest that RWBS may be a useful therapeutic agent for ulcerative colitis.

Animals↗
PubMed2005

A case of adrenal gland dependent hyperadrenocorticism with mitotane therapy in a Yorkshire terrier dog.

Hyperadrenocorticism, a disorder characterized by excessive production of cortisol by the adrenal cortex, is well-recognized in dogs. A 10-year-old, intact male, Yorkshire terrier dog was evaluated because of corneal ulceration and generalized alopecia. Diagnosis was made based on history taking, clinical signs, physical examination, and results of routine laboratory testing (complete blood count, serum biochemical analysis, and urinalysis). In addition, adrenocorticotropic hormone (ACTH) stimulation test and abdominal ultrasonography were also used to diagnose this case. The patient was diagnosed as adrenal gland neoplasia and medical therapy using the adrenocorticolytic agent, mitotane, was initiated. An ACTH stimulation test was performed after initial therapy. After successful induction was obtained, maintenance therapy with mitotane still continued.

Adrenal Gland Neoplasms↗
PubMed2005

Overexpression and characterization of a novel chitinase gene from a marine bacterium Pseudomonas sp. BK1.

The chitinase A (ChiA)-coding gene of Pseudomonas sp. BK1, which was isolated from a marine red alga Porphyra dentata, was cloned and expressed in Escherichia coli. The structural gene consists of 1602 bp encoding a protein of 534 amino acids, with a predicted molecular weight of 55,370 Da. The deduced amino acid sequence of ChiA showed low identity (less than 32%) with other bacterial chitinases. The ChiA was composed of multiple domains, unlike the arrangement of domains in other bacterial chitinases. Recombinant ChiA overproduced as inclusion bodies was solubilized in the presence of 8 M urea, purified in a urea-denatured form and re-folded by removing urea. The purified enzyme showed maximum activity at pH 5.0 and 40 degrees C. It exhibited high activity towards glycol chitosan and glycol chitin, and lower activity towards colloidal chitin. The enzyme hydrolyzed the oligosaccharides from (GlcNAc)4 to (GlcNAc)6, but not GlcNAc to (GlcNAc)3. The results suggest that the ChiA is a novel enzyme, with different domain structure and action mode from bacterial family 18 chitinases.

Chitin↗
PubMed2004

Requirement of c-jun transcription factor on the mouse mast cell protease-6 expression in the mast cells.

Mast cell tryptases may be a key mediator in mast cell-mediated inflammatory reactions, and these expressions can be regulated by microenvironmental factors of tissues, particularly stem cell factor. In the present study, we investigated whether the transcription of mouse mast cell protease-6 (mMCP-6) gene was caused by SCF-mediated c-jun. We observed that mMCP-6 mRNA was expressed by overexpression of c-jun in the immature mast cell line in which both mMCP-6 and c-kit receptor are negative. The c-jun increased synergistically the luciferase activity of mMCP-6 promoter through the direct interaction with mi transcription factor (MITF). The synergic effect of c-jun with MITF was abolished by deletion of sequence between nt -171 and -151 in the mMCP-6 promoter. Furthermore, the level of mMCP-6 mRNA in mast cells was attenuated by the introduction of dominant negative c-jun (TAM-67) and the treatment of Jun N-terminal kinase inhibitor, SP600125. These results show that c-jun might play a role in regulating the transcription of mMCP-6 gene in mast cells stimulated by SCF.

Animals↗
PubMed2004

The complete mitochondrial genome of the floating goby, Gymnogobius petschiliensis (Perciformes, Gobiidae).

We isolated floating goby Gymnogobius petschiliensis mitochondrial DNA by long-polymerase chain reaction (Long-PCR) with conserved primers, and sequenced the mitogenome by primer walking using flanking sequences. The G. petschiliensis mitochondrial DNA has 16,424 bp and its structural organization is similar to the mitochondrial DNAs of other fish, and mammals. We analyzed phylogenetic relationships derived from the mitochondrial cytochrome b gene. We report the basic characteristics of the G. petschiliensis mitochondrial genome including its structural organization and the base composition of the rRNAs, tRNAs and protein-coding genes as well as characteristics of tRNAs. These features are used to analyze phylogenetic relationship among the 60 species of the genus Gymnogobius.

Animals↗
PubMed2004

Isolation of Citrobacter sp. mutants defective in decolorizing malachite green.

To identify genes involved in the decolorization of malachite green, random mutants generated by transposon insertion in the malachite green-decolorizing bacterium, Citrobacter sp. were isolated. The resulting mutant bank yielded 24 mutants with complete defects in their abilities to decolorize malachite green. Southern hybridization with a Tn5 fragment as a probe showed a single hybridized band in 7 mutants, which appeared to have insertions at different sites of the chromosome. The Tn5-inserted genes were isolated and the DNA sequence flanking Tn5 was determined. Based on a sequence database, the putative protein products encoded by the mg genes were identified as follows. mg3, an ABC transporter homolog; mg6, a LysR-type regulatory protein; m11, an oxidoreductase; mg17, a MalG protein in the maltose transport system; and mg21, a sugar kinase. The deduced sequences from two mg genes (mg7 and mg18) showed no significant similarity to any protein with a known function, suggesting that these two mg genes encode unidentified proteins that are responsible for the decolorization of malachite green.

Bacterial Proteins↗
PubMed2004

Inhibition of trypsin-induced mast cell activation by water fraction of Lonicera japonica.

Lonicera japonica Thunb.(Caprifoliaceae) has long been known as an anti-inflammatory. In the present study, the effect of water fraction of Lonicera japonica (LJ) on trypsin-induced mast cell activation was examined. HMC-1 cells were stimulated with trypsin (100 nM) in the presence or absence of LJ (10, 100, and 1000 microg/mL). TNF-alpha and tryptase production were measured by enzyme-linked immunosorbent assay (ELISA) and reverse transcription-PCR. Extracellular signal-regulated kinase (ERK) phosphorylation was assessed by Western blot. Trypsin activity was measured by using Bz-DL-Arg-p-nitroanilide (BAPNA) as substrate. LJ (10, 100, and 1000 microg/mL) inhibited TNF-alpha secretion in a dose-dependent manner. LJ (10, 100, and 1000 microg/mL) also inhibited TNF-alpha and tryptase mRNA expression in trypsin-stimulated HMC-1. Furthermore, LJ inhibited trypsin-induced ERK phosphorylation. However, LJ did not affect the trypsin activity even 1000 microg/mL. These results indicate that LJ may inhibit trypsin-induced mast cell activation through the inhibition of ERK phosphorylation than the inhibition of trypsin activity.

Cell Line, Tumor↗
PubMed2004

Acanthoic acid inhibits IL-8 production via MAPKs and NF-kappaB in a TNF-alpha-stimulated human intestinal epithelial cell line.

BACKGROUND: Intestinal epithelial cells (IECs) can produce cytokines and chemokines that play an important role in the mucosal immune response. Regulation of this production is important to prevent inflammatory tissue damage. The root and stem barks of Acanthopanax species have been used as a tonic and sedative as well as in the treatment of rheumatism and diabetes. The aim of this study was to examine the inhibitory effect of acanthoic acid isolated from Acanthopanax koreanum (Araliaceae), on IL-8 production via mitogen-activated protein kinases (MAPKs) and nuclear factor-kappa B (NF-kappaB) in TNF-alpha-stimulated human colon epithelial cells. METHODS: HT29 cells were stimulated with TNF-alpha in the presence or absence of acanthoic acid. IL-8 production was measured by enzyme-linked immunosorbent assay (ELISA) and reverse transcription-PCR (RT-PCR). MAPK activation and IkappaB/NF-kappaB expression were assessed by Western blot analysis. NF-kappaB activation was determined using immunofluorescence localization and electrophoretic mobility shift assay (EMSA). RESULTS: Acanthoic acid suppressed TNF-alpha-induced IL-8 production in a dose-dependent manner. Furthermore, acanthoic acid inhibited TNF-alpha-induced MAPKs (p38, JNK1/2, and ERK1/2) activation, IkappaB degradation, NF-kappaB nuclear translocation, and NF-kappaB/DNA binding activity. CONCLUSION: Acanthoic acid might inhibit TNF-alpha-mediated IL-8 production by blocking in both the MAPKs and NF-kappaB pathways in HT29 cells.

Cell Line↗
PubMed2004

CDNA cloning and expression of ATP synthase subunit b from the fire-bellied frog Bombina orientalis (Anura: Discoglossidae).

We cloned the Bombina orientalis adenosine triphosphate (ATP) synthase subunit b gene from a B. orientalis oviduct cDNA library. The transcript was 997 bp long and encoded 250 amino acid residues. It showed high similarity to amphibian (84-85%), mammalian (56-62%) and invertebrate (46-50%) sequences. In phylogenetic analyses, it clustered with other amphibian sequences. This gene was highly expressed in brain, intestine and oviduct but not in muscle and liver. In this paper, we report the basic characteristics of B. orientalis ATP synthase subunit b gene.

Amino Acid Sequence↗