Dae Kyun Chung

Publications of Dae Kyun Chung

• 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.

  Authors: Tae Hoon Lee, Mira Jung, Myun-Ho Bang, Dae Kyun Chung, Jiyoung Kim

  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 ofExtracts 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.

• Lactobacillus plantarum lipoteichoic acid alleviates TNF-α-induced inflammation in the HT-29 intestinal epithelial cell line.

  Authors: Hangeun Kim, Bong Jun Jung, Ji Hae Jung, Joo Yun Kim, Sung Kyun Chung, Dae Kyun Chung

  Molecules and cells. 04/2012;

  We recently observed that lipoteichoic acid (LTA) isolated from Lactobacillus plantarum inhibited endotoxin-mediated inflammation of the immune cells and septic shock in a mouse model. Here, weWe recently observed that lipoteichoic acid (LTA) isolated from Lactobacillus plantarum inhibited endotoxin-mediated inflammation of the immune cells and septic shock in a mouse model. Here, we examined the inhibitory role of L. plantarum LTA (pLTA) on the inflammatory responses of intestinal epithelial cells (IEC). The human colon cell line, HT-29, increased interleukin (IL)-8 expression in response to recombinant human tumor necrosis factor (TNF)-alpha, but not in response to bacterial ligands and interferon (IFN)-gamma. TNF-α also increased the produc-tion of inducible nitric oxide synthase (iNOS), nitric oxide (NO), and intercellular adhesion molecule 1 (ICAM-1) through activation of p38 mitogen-activated protein kinase (MAPK) from HT-29 cells. However, the inflammatory response of HT-29 on TNF-α stimulation was significantly inhibited by pLTA treatment. This pLTA-mediated inhibition accompanied the inhibition of nuclear factor (NF)-kappa B and MAPKs. Our data suggest that pLTA regulates cytokine-mediated immune responses and may be a good candidate for maintaining intestinal homeostasis against excessive inflammation.

• Lipoteichoic acid of Staphylococcus aureus enhances IL-6 expression in activated human basophils.

  Authors: Jun Ho Jeon, Sun Kyung Kim, Jung Eun Baik, Seok-Seong Kang, Cheol-Heui Yun, Dae Kyun Chung, Seung Hyun Han

  Comparative immunology, microbiology and infectious diseases. 03/2012;

  At allergic inflammation, cross-linking of FcɛRI with multivalent antigen-bound IgE triggers the signaling pathways via activation of protein kinase C (PKC) and mobilization of intracellular Ca(2+)At allergic inflammation, cross-linking of FcɛRI with multivalent antigen-bound IgE triggers the signaling pathways via activation of protein kinase C (PKC) and mobilization of intracellular Ca(2+) leading to the production of various mediators such as interleukin-6 (IL-6). Accumulating reports demonstrated that interaction of Toll-like receptor 2 (TLR2) expressed on basophils with a TLR2 ligand, lipoteichoic acid (LTA) of Staphylococcus aureus, exacerbated allergic inflammation. Here, we showed that staphylococcal LTA (Sa.LTA) substantially enhanced IL-6 expression at both the protein and the mRNA levels in the human basophil line, KU812, in the presence of a PKC activator (phorbol 12-myristrate 13-acetate; PMA), and a calcium ionophore (A23187), whereas Sa.LTA alone could not induce IL-6 expression. PMA/A23187 augmented the expression of CD14 and TLR2 on the surface of KU812 cells and concomitantly increased the binding of fluorochrome-labeled Sa.LTA to the cells. Sa.LTA enhanced the phosphorylation of mitogen-activated protein (MAP) kinases in PMA/A23187-stimulated KU812 cells. Notably, Sa.LTA could not enhance PMA/A23187-induced IL-6 expression in the presence of inhibitors of MAP kinases, reactive oxygen species, or protein kinase C. Furthermore, Sa.LTA enhanced the PMA/A23187-increased DNA-binding activities of the transcription factors NF-κB and AP-1. Experiments using human peripheral blood mononuclear cells demonstrated that not only PMA/A23187 but also Sa.LTA increased the intracellular IL-6 expression in the basophil population and Sa.LTA plus PMA/A23187 further enhanced the IL-6 expression. Collectively, these results suggest that Sa.LTA exacerbates allergic inflammation by potentiating IL-6 production from activated basophils.

• Probiotic genomic DNA reduces the production of pro-inflammatory cytokine tumor necrosis factor-alpha.

  Authors: Chung Hee Kim, Han Geun Kim, Joo Yun Kim, Na Ra Kim, Bong Jun Jung, Ji Hye Jeong, Dae Kyun Chung

  FEMS microbiology letters. 11/2011; 328(1):13-9.

  The effect of Lactobacillus plantarum genomic DNA on lipopolysaccharide (LPS)-induced mitogen-activated protein kinase (MAPK) activation, nuclear factor-kappa B activation, and the expressions ofThe effect of Lactobacillus plantarum genomic DNA on lipopolysaccharide (LPS)-induced mitogen-activated protein kinase (MAPK) activation, nuclear factor-kappa B activation, and the expressions of tumor necrosis factor-alpha, interleukin-1 receptor-associated kinase M, and the pattern recognition receptor were examined. Pretreatment of p-gDNA inhibited the phosphorylation of MAPKs and nuclear factor-kappa B, and also inhibited LPS-induced TNF-α production in response to subsequent LPS stimulation. L. plantarum genomic DNA-mediated inhibition of signaling pathway and tumor necrosis factor-alpha was accompanied by the suppression of toll-like receptor (TLR) 2, TLR4, and TLR9 and the induction of interleukin-1 receptor-associated kinase M, a negative regulator of TLR. This study can extend our understanding of the biological function of probiotic genomic DNA as an anti-inflammatory agent.

• Lipoteichoic acid from Lactobacillus plantarum induces nitric oxide production in the presence of interferon-γ in murine macrophages.

  Authors: Seok-Seong Kang, Young Hee Ryu, Jung Eun Baik, Cheol-Heui Yun, Kangseok Lee, Dae Kyun Chung, Seung Hyun Han

  Molecular immunology. 08/2011; 48(15-16):2170-7.

  Lipoteichoic acid (LTA) is a major immuno-stimulating component of Gram-positive bacteria. LTA from the beneficial bacterium Lactobacillus plantarum induces weak nitric oxide (NO) production inLipoteichoic acid (LTA) is a major immuno-stimulating component of Gram-positive bacteria. LTA from the beneficial bacterium Lactobacillus plantarum induces weak nitric oxide (NO) production in murine macrophages. Currently, it is not clear if LTA from L. plantarum is able to stimulate the innate immune response, even in the presence of inflammation. In the present study, we prepared highly pure and structurally intact LTA from L. plantarum and investigated its ability to induce NO in the presence of interferon (IFN)-γ in the RAW 264.7 murine macrophage cell line and bone marrow-derived macrophages (BMMs) from mice. L. plantarum LTA alone was unable to induce NO production, even at 30μg/ml. However, LTA in the presence of IFN-γ significantly induced NO production in RAW 264.7 cells. The observed NO production was inhibited by a NO synthase (NOS) inhibitor l-NAME and an inducible NOS (iNOS) inhibitor l-NIL, suggesting that iNOS is specifically required for this action. Western blot analysis and reverse transcription and polymerase chain reaction further confirmed that L. plantarum LTA increased protein and mRNA levels of iNOS, respectively. However, such induction was substantially inhibited in BMMs from Toll-like receptor 2 (TLR2)-deficient mice and the macrophages treated with an inhibitor blocking platelet-activating factor receptor. In addition, L. plantarum LTA plus IFN-γ induced IFN-β expression and STAT1 phosphorylation, which are key pathways for inducing iNOS expression. Electrophoretic mobility shift assay demonstrated that L. plantarum LTA in the presence of IFN-γ remarkably increased the DNA-binding activity of NF-κB transcription factor, which is known to be involved in the iNOS gene expression. Collectively, these results suggest that LTA from L. plantarum alone has no inflammatory potential but does induce NO production under conditions of inflammation, such as the presence of IFN-γ.

• Multi-spectrometric analyses of lipoteichoic acids isolated from Lactobacillus plantarum.

  Authors: Kyoung-Soon Jang, Jung Eun Baik, Seung Hyun Han, Dae Kyun Chung, Byung-Gee Kim

  Biochemical and biophysical research communications. 03/2011; 407(4):823-30.

  Lipoteichoic acid is a major cell wall virulence factor of gram-positive bacteria. LTAs from various bacteria have differential immunostimulatory potentials due to heterogeneity in their structures.Lipoteichoic acid is a major cell wall virulence factor of gram-positive bacteria. LTAs from various bacteria have differential immunostimulatory potentials due to heterogeneity in their structures. Although recent studies have demonstrated that LTA isolated from Lactobacillus plantarum (pLTA) has anti-inflammatory properties and is less inflammatory than LTAs from pathogenic bacteria, little is known about the structure of pLTA. In this study, high-field NMR spectra of the pLTA were compared with those of LTA from pathogenic bacterium, Staphylococcus aureus (aLTA). The 2D NMR results demonstrated that pLTA possesses α-linked hexose sugar substituents on the poly-glycerophosphate backbone instead of N-acetylglucosamine substituents, and unsaturated fatty acids in its glycolipids. The sugar substituents were revealed as an approximately 29:1 molar ratio of the glucose to galactose by HPAEC-PAD analysis. MALDI-TOF/TOF MS analyses identified the presence of unsaturated fatty acids in the glycolipid moieties of pLTA. In addition, the glycolipid structure was found to be composed of trihexosyl-diacyl- and/or trihexosyl-triacyl-glycerol ceramide units by means of unique fragment ions of the glycolipids. These results enabled us to elucidate the pLTA structure, which is distinctively different from canonical LTA structure, and suggest that the unique immunological property of pLTA might be caused by the pLTA structure.

• Lactobacillus plantarum lipoteichoic acid down-regulated Shigella flexneri peptidoglycan-induced inflammation.

  Authors: Han Geun Kim, Seung Yeon Lee, Na Ra Kim, Hea Young Lee, Mi Yeon Ko, Bong Jun Jung, Chul Min Kim, Jung Min Lee, Jong Hwan Park, Seung Hyun Han, Dae Kyun Chung

  Molecular immunology. 01/2011; 48(4):382-91.

  Bacterial peptidoglycans (PGNs) are recognized by the host's innate immune system. This process is mediated by the NOD/CARD family of proteins, which induces inflammation by activating nuclear factorBacterial peptidoglycans (PGNs) are recognized by the host's innate immune system. This process is mediated by the NOD/CARD family of proteins, which induces inflammation by activating nuclear factor (NF)-κB. Excessive activation of monocytes by Shigella flexneri PGN (flexPGN) leads to serious inflammatory diseases such as intestinal bowel diseases (IBD) and Crohn's disease. In this study, we examined whether Lactobacillus plantarum lipoteichoic acid (pLTA) could attenuate the pro-inflammatory signaling induced by flexPGN in human monocytic THP-1 cells. Compared to control THP-1 cells, pLTA-tolerant cells showed a significant reduction in TNF-α and IL-1β production in response to flexPGN. We also examined the inhibition of NF-κB and the activation of mitogen-activated protein kinase (MAPK) in pLTA-tolerant cells. We found that the expression of NOD2 in pLTA-tolerant cells was down-regulated at the mRNA and protein levels, suggesting that pLTA is a potent modulator of the pro-inflammatory NOD2-related signaling pathways induced by flexPGN. Together, these data indicate that pLTA induces cross-tolerance against flexPGN. Notably, these effects are related not only to IL-1 signaling, which is known to play a role in LPS tolerance, but also to NOD-Rick signaling. This study provides insight into how commensal microflora may contribute to homeostasis of the host intestinal tract.

• A glycosidic spinasterol from Koreana stewartia promotes procollagen production and inhibits matrix metalloproteinase-1 expression in UVB-irradiated human dermal fibroblasts.

  Authors: Tae Hoon Lee, Sang Min Lee, Dae-Young Lee, Youngsook Son, Dae Kyun Chung, Nam-In Baek, Jiyoung Kim

  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 successiveMethanol 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.

• Protein expression changes in human monocytic THP-1 cells treated with lipoteichoic acid from Lactobacillus plantarum and Staphylococcus aureus.

  Authors: Ri-Zhong Zeng, Han Geun Kim, Na Ra Kim, Hae Young Lee, Bong Jun Jung, Mi Yeon Ko, Seung Yeon Lee, Dae Kyun Chung

  Molecules and cells. 05/2010; 29(6):585-94.

  Lipoteichoic acid (LTA) from Staphylococcus aureus (aLTA) and from Lactobacillus plantarum LTA (pLTA) are both recognized by Toll-like receptor 2 (TLR2), but cause different stimulatory effects onLipoteichoic acid (LTA) from Staphylococcus aureus (aLTA) and from Lactobacillus plantarum LTA (pLTA) are both recognized by Toll-like receptor 2 (TLR2), but cause different stimulatory effects on the innate immune and inflammatory responses, and their underlying cellular mechanisms are unknown. In this study, comparative proteome analysis was performed using two-dimensional gel electrophoresis and mass spectrometry on protein extracts from human monocyte THP-1 cells stimulated with either aLTA or pLTA. Differentially expressed proteins might be involved in innate immunity and inflammation. Cells treated with aLTA and with pLTA showed different protein expression profiles. Of 60 identified proteins, 10 were present only in treated cells (8 in aLTA-treated only, and 2 in pLTA-treated only), 1 protein (IMPDH2) was suppressed by pLTA, and 49 were up- or down-regulated more than three-fold by aLTA- or pLTA- stimulation. Several proteins involved in immunity or inflammation, antioxidation, or RNA processing were significantly changed in expression by aLTA- or pLTA-stimulation, including cyclophilin A, HLA-B27, D-dopachrome tautomerase, Mn- SOD, hnRNP-C, PSF and KSRP. These data demonstrated that aLTA and pLTA had different effects on the protein profile of THP-1 cells. Comparison of the proteome alterations will provide candidate biomarkers for further investigation of the immunomodulatory effects of aLTA and pLTA, and the involvement of aLTA in the pathogenesis of Staphylococcus aureus sepsis.

• Molecular Cloning and Expression of the Trichoderma harzianum C4 Endo-beta-1,4-Xylanase Gene in Saccharomyces cerevisiae.

  Authors: Jung Min Lee, Ji-Won Shin, Jae-Kook Nam, Ji-Young Choi, Choon Soo Jeong, In Seob Han, Soo-Wan Nam, Yun-Jaie Choi, Dae Kyun Chung

  Journal of microbiology and biotechnology. 09/2009; 19(8):823-8.

  An endo-beta-1,4-xylanase (beta-xylanase) from Trichoderma harzianum C4 was purified without cellulase activity by sequential chromatographies. The specific activity of the purified enzymeAn endo-beta-1,4-xylanase (beta-xylanase) from Trichoderma harzianum C4 was purified without cellulase activity by sequential chromatographies. The specific activity of the purified enzyme preparation was 430 units/mg on D-xylan. The complementary DNA (cDNA) encoding beta-xylanase (xynII) was amplified by PCR and isolated from cDNA PCR libraries constructed from T. harzianum C4. The nucleotide sequence of the cDNA fragment contained an open reading frame of 663 bp that encodes 221 amino acids, of which the mature protein is homologous to several beta- xylanases II. An intron of 63 bp was identified in the genomic DNA sequence of xynII. This gene was expressed in Saccharomyces cerevisiae strains under the control of adh1 (alcohol dehydrogenase I) and pgk1 (phosphoglycerate kinase I) promoters in 2 mu-based plasmids, which could render recombinants able to secrete beta-xylanase into the media.

• Induction of IL-8 expression by bacterial flagellin is mediated through lipid raft formation and intracellular TLR5 activation in A549 cells.

  Authors: Jintaek Im, Jun Ho Jeon, Min Kyung Cho, Sang Su Woo, Seok-Seong Kang, Cheol-Heui Yun, Kangseok Lee, Dae Kyun Chung, Seung Hyun Han

  Molecular immunology. 09/2009;

  We investigated the mechanism for the induction of a chemokine, IL-8, by bacterial flagellins in the human alveolar type II epithelial cell line, A549. Bacterial flagellin induced expression of IL-8We investigated the mechanism for the induction of a chemokine, IL-8, by bacterial flagellins in the human alveolar type II epithelial cell line, A549. Bacterial flagellin induced expression of IL-8 mRNA and protein in dose- and time-dependent manners. IL-8 expression was inhibited by nystatin (a lipid rafts inhibitor) but not by chlorpromazine (a clathrin-coated pits inhibitor). Interestingly, Toll-like receptor 5 (TLR5) recognizing flagellins was found in the intracellular compartment of A549 but rarely on the cell surface. Flagellin-induced IL-8 expression appears to be mediated through TLR5 as determined by in vitro transient transfection experiment in HEK-293 cells expressing TLR5 using a reporter gene construct containing IL-8 promoter. IL-8 expression was attenuated by inhibitors for protein kinase C (PKC) and mitogen-activated protein (MAP) kinases. Furthermore, NF-kappaB and NF-IL6 transcription factors played an important role in the flagellin-induced IL-8 gene expression in A549 cells. Collectively, these results suggest that flagellin-induced IL-8 expression requires formation of lipid rafts, intracellular TLR activation, and subsequent activation of PKC and MAP kinases leading to the activation of the transcription factors NF-kappaB and NF-IL6 in human alveolar type II epithelial cells.

• Stewartia koreana extract stimulates proliferation and migration of human endothelial cells and induces neovasculization in vivo.

  Authors: Tae-Hoon Lee, Guy Wilhem Lee, Chan Woo Kim, Myun-Ho Bang, Nam-In Baek, Sung-Hoon Kim, Dae Kyun Chung, Jiyoung Kim

  Phytotherapy research : PTR. 06/2009;

  Angiogenesis, the growth of new blood vessels from preexisting vasculature, plays an important role in physiological and pathological processes such as embryonic development and wound healing. ThisAngiogenesis, the growth of new blood vessels from preexisting vasculature, plays an important role in physiological and pathological processes such as embryonic development and wound healing. This study investigated the effects of methanol extracts of Stewartia koreana leaves (SKE) on angiogenesis. Stewartia koreana significantly promoted the proliferation and migration of human umbilical vein endothelial cells in a dose-dependent manner. The SKE induced endothelial cell proliferation in the range of 50 microg/mL without cytotoxicity. Treatment of HUVECs resulted in the activation of the mitogen-activated protein kinases that was correlated with endothelial cell proliferation and migration. SKE also stimulated angiogenesis in a chick chorioallantoic membrane assay, demonstrating promotion of new blood vessel formation in vivo. Local administration of SKE onto skin punched wounds resulted in increased von Willebrand Factor antigen, indicating that it stimulated neovasculization in the wound region. The results suggest that Stewartia koreana extracts may potentially be useful for the development of agents to accelerate vascular wound healing or to promote the growth of collateral blood vessels in ischemic tissues. Copyright (c) 2009 John Wiley & Sons, Ltd.

• Differential immunostimulatory effects of Gram-positive bacteria due to their lipoteichoic acids.

  Authors: Young Hee Ryu, Jung Eun Baik, Jae Seung Yang, Seok-Seong Kang, Jintaek Im, Cheol-Heui Yun, Dong-Wook Kim, Kangseok Lee, Dae Kyun Chung, Hyang Ran Ju, Seung Hyun Han

  International immunopharmacology. 12/2008;

  Lipoteichoic acid (LTA) is a major immunostimulating component in the cell wall of Gram-positive bacteria as lipopolysaccharide of Gram-negative bacteria. However, LTA is expressed on not onlyLipoteichoic acid (LTA) is a major immunostimulating component in the cell wall of Gram-positive bacteria as lipopolysaccharide of Gram-negative bacteria. However, LTA is expressed on not only pathogenic but also nonpathogenic Gram-positive bacteria. In order to examine whether the immunostimulating potentials of Gram-positive bacteria are correlated with their LTAs, we prepared highly pure LTAs from Staphylococcus aureus (pathogenic), Bacillus subtilis (non-pathogenic), or Lactobacillus plantarum (beneficial). When a murine macrophage cell-line, RAW 264.7, was stimulated with heat-killed bacteria, both S. aureus and B. subtilis induced nitric oxide (NO) production in a dose-dependent manner while L. plantarum showed a minimal induction. Interestingly, purified LTAs from S. aureus and B. subtilis, but not from L. plantarum, were able to induce the production of NO. The differential inflammatory potentials of LTAs coincided with their abilities to activate Toll-like receptor 2 (TLR2), which is known to recognize Gram-positive bacteria and LTA, and transcription factors NF-kappaB and AP-1. Similar results were obtained with the expression of cytokines related to inflammation by RAW 264.7 and human peripheral blood mononuclear cells as well. The ability of LTA to induce TNF-alpha and NO production was abolished when the LTAs were treated with 0.2 N NaOH. Collectively, we suggest that the immunostimulating potentials of Gram-positive bacteria differ due to their LTAs with differential potencies in the stimulation of TLR2.

• A new lignan glycoside from the fruits of Cornus kousa Burg.

  Authors: Dae-Young Lee, Ki Hyun Yoo, In Sik Chung, Ji Young Kim, Dae Kyun Chung, Dae Keun Kim, Sung-Hoon Kim, Nam-In Baek

  Archives of pharmacal research. 08/2008; 31(7):830-3.

  A new lignan glycoside, (7'S, 8'R)-dihydrodehydrodiconiferyl alcohol-4'-O-beta-D-xylopyranoside (1), named cornuskoside A, was isolated from the fruits of Cornus kousa. The structure of the compoundA new lignan glycoside, (7'S, 8'R)-dihydrodehydrodiconiferyl alcohol-4'-O-beta-D-xylopyranoside (1), named cornuskoside A, was isolated from the fruits of Cornus kousa. The structure of the compound was determined by spectroscopy, including FABMS, UV, IR, (1)H-and 13C-NMR, DEPT and 2D-NMR (COSY, HSQC, and HMBC). This new lignan glycoside, along with its aglycone, (7'S, 8'R)-dihydrodehydrodiconiferyl alcohol (3), and another lignan with a similar skeleton, (-)-balanophonin (2), which have been previously isolated from this plant, were evaluated for cytotoxicity in human cancer cell lines such as HeLa, MCF-7, SK-MEL-5, and SK-OV-3. Compounds 2 and 3 showed cytotoxicity against HeLa [IC50 = 29.1 microM (2), 45.5 microM (3)], MCF-7 [IC50 = 29.2 microM (2), 28.2 microM (3)], SK-MEL-5 [IC50 = 31.3 microM (2), 32.3 microM (3)], and SK-OV-3 [IC50 = 33.4 microM (2), 43.4 microM (3)] cell lines.

• Mechanical stress induces tumor necrosis factor-alpha production through Ca2+ release-dependent TLR2 signaling.

  Authors: Han Geun Kim, Joo Yun Kim, Min Geun Gim, Jung Min Lee, Dae Kyun Chung

  American journal of physiology. Cell physiology. 07/2008;

  We studied centrifugation-mediated mechanical stress induced Tumor necrosis factor (TNF)-alpha production in the monocyte-like cell line THP-1. The induction of TNF-alpha by mechanical stress wasWe studied centrifugation-mediated mechanical stress induced Tumor necrosis factor (TNF)-alpha production in the monocyte-like cell line THP-1. The induction of TNF-alpha by mechanical stress was dependent on the centrifugation speed and produced the highest level of TNF-alpha after 1 h of stimulation. TNF-alpha production returned to normal levels after 24 h of stimulation. Mechanical stress also induced Toll-like Receptor (TLR) 2 mRNA in proportion to the expression of TNF-alpha. The inhibition of TLR2 signaling by dominant negative myeloid differentiation factor 88 (MyD88) blocked TNF-alpha expression response to mechanical stress. After transient over-expression of TLR2 in HEK293 cells, mechanical stress induced TNF-alpha mRNA production. Interestingly, mechanical stress activated the c-Src-dependent TLR2 phosphorylation, which is necessary to induce Ca(2+) fluxes. When THP-1 cells were pretreated with BAPTA-AM, thapsigargin, and NiCl2*6H2O followed by mechanical stimulation, both TLR2 and TNF-alpha production were inhibited, indicating that centrifugation-mediated mechanical stress induces both TLR2 and TNF-alpha production through Ca(2+) releases from intracellular Ca(2+) stores following TLR2 phosphorylation. In addition, TNF-alpha treatment in THP-1 cells induced TLR2 production in response to mechanical stress, whereas the pre-incubation of anti-TNF-alpha antibody scarcely induced the mechanical stress-mediated production of TLR2, indicating that TNF-alpha produced by mechanically simtulated-THP-1 cells affected TLR2 production. We concluded that TNF-alpha production induced by centrifugation-mediated mechanical stress is dependent on MyD88-dependent TLR2 signaling that is associated with Ca(2+) release and that TNF-alpha production induced by mechanical stress affects TLR2 production. Key words: Mechanical stress, Toll-like receptor, Calcium release, Tumor necrosis factor.

• Inhibitory Effects of Lactobacillus plantarum Lipoteichoic Acid (LTA) on Staphylococcus aureus LTA-induced Tumor Necrosis Factor-Alpha Production.

  Authors: Han Geun Kim, Seung Yeon Lee, Na Ra Kim, Mi Yeon Ko, Jung Min Lee, Tae-Hoo Yi, Sung Kyun Chung, Dae Kyun Chung

  Journal of microbiology and biotechnology. 07/2008; 18(6):1191-6.

  Staphylococcus aureus is a common etiologic agent for Gram-positive sepsis, and its lipoteichoic acid (LTA) may be important in causing Gram-positive bacterial septic shock. Here, we demonstrate thatStaphylococcus aureus is a common etiologic agent for Gram-positive sepsis, and its lipoteichoic acid (LTA) may be important in causing Gram-positive bacterial septic shock. Here, we demonstrate that highly purified LTA (pLTA) isolated from Lactobacillus plantarum inhibited aureus LTA (aLTA)-induced TNF-alpha production in THP- cells. Whereas pLTA scarcely induced TNF-alpha production, aLTA induced excessive TNF-alpha production. Interestingly, aLTA-induced TNF-alpha production was inhibited by pLTA pretreatment. Compared with pLTA, aLTA induced strong signal transduction through the MyD88, NF-kappaB, and MAP kinases. This signaling, however, was reduced by a pLTA pretreatment, and resulted in the inhibition of aLTA-induced TNF-alpha production. Whereas dealanylated LTAs, as well as native LTAs, contributed to TNF- induction or TNF-alpha reduction, deacylated LTAs did not, indicating that the acyl chain of LTA played an important role in the LTA-mediated immune regulation. These results suggest that pLTA may act as an antagonist for aLTA, and that an antagonistic pLTA may be a useful agent for suppressing the septic shock caused by Gram-positive bacteria.

• Inhibitory effect of dalbergioidin isolated from the trunk of Lespedeza cyrtobotrya on melanin biosynthesis.

  Authors: Seunghwa Baek, Jinhee Kim, Donghyun Kim, Chanyong Lee, Jiyoung Kim, Dae Kyun Chung, Choonghwan Lee

  Journal of microbiology and biotechnology. 05/2008; 18(5):874-9.

  Tyrosinase is a key enzyme for melanin biosynthesis, and hyperpigmentation disorders are associated with abnormal accumulation of melanin pigments, which can be reduced by treatment with depigmentingTyrosinase is a key enzyme for melanin biosynthesis, and hyperpigmentation disorders are associated with abnormal accumulation of melanin pigments, which can be reduced by treatment with depigmenting agents. The methanol extract of Lespedeza cyrtobotrya MIQ showed inhibitory activity against mushroom tyrosinase. The active compound was purified from the methanol extract of L cyrtobotrya, followed by several chromatographic methods, and identified as dalbergioidin (DBG) by spectroscopic methods. The results showed that DBG exhibited tyrosinase inhibitory activity with an IC50 of 20 mM. The kinetic analysis tyrosinase inhibition revealed that DBG acted as noncompetitive inhibitor. In addition, DBG showed a melanin biosynthesis inhibition zone in the culture plate of Streptomyces bikiniensis that has commonly been used as an indicator organism. Furthermore, 27 mM DBG decreased more than 50% of melanin contents on the pigmentation using immortalized mouse melanocyte, melan-a cell.

• Phenolic glycosides from Lindera fruticosa root and their inhibitory activity on osteoclast differentiation.

  Authors: Myoung-Chong Song, Fikru Nigussie, Hye-Joung Yang, Hong-Hee Kim, Ji Young Kim, Dae Kyun Chung, Nam-In Baek

  Chemical & pharmaceutical bulletin. 05/2008; 56(5):707-10.

  Two new compounds were found in the phenolic glycosides isolated from the roots of Lindera fruticosa: 5-O-[beta-D-apiofuranosyl-(1''-->2')-O-beta-D-xylopyranosyl]gentisic acid-7,5''-ester (3), namedTwo new compounds were found in the phenolic glycosides isolated from the roots of Lindera fruticosa: 5-O-[beta-D-apiofuranosyl-(1''-->2')-O-beta-D-xylopyranosyl]gentisic acid-7,5''-ester (3), named linderofruticoside A; and 5-O-[beta-D-apiofuranosyl-(1''-->3')-O-beta-D-xylopyranosyl]gentisic acid methyl ester (4), linderofruticoside B. Two previously known phenolic glycosides were also identified: beta-D-(3,4-disinapoyl)fructofuranosyl-alpha-D-(6-sinapoyl)glucopyranoside (1) and beta-D-(3-sinapoyl)fructofuranosyl-alpha-D-(6-sinapoyl)glucopyranoside (2). Compounds 1 and 2 inhibited osteoclast differentiation in a dose-dependent manner at concentrations higher than 1.04 microM and 0.132 microM, respectively.

• Peptidoglycan-mediated IL-8 expression in human alveolar type II epithelial cells requires lipid raft formation and MAPK activation.

  Authors: In Su Cheon, Sang Su Woo, Seok-Seong Kang, Jintaek Im, Cheol-Heui Yun, Dae Kyun Chung, Dong Ki Park, Seung Hyun Han

  Molecular immunology. 04/2008; 45(6):1665-73.

  Staphylococcus aureus, a major sepsis-causing Gram-positive bacterium, invades pulmonary epithelial cells and causes lung diseases. In the lung, alveolar type II epithelial cells play an importantStaphylococcus aureus, a major sepsis-causing Gram-positive bacterium, invades pulmonary epithelial cells and causes lung diseases. In the lung, alveolar type II epithelial cells play an important role in innate immunity by secreting chemokines and antimicrobial peptides upon bacterial infection whereas type I cells mainly function in gas-exchange. In this study, we investigated the ability of S. aureus peptidoglycan (PGN) to induce expression of a chemokine, IL-8, in a human alveolar type II epithelial cell line, A549. PGN induces IL-8 mRNA and protein expression in a dose- and time-dependent manner. Supplementation of soluble CD14 further enhanced the PGN-induced IL-8 expression. Interestingly, PGN-induced IL-8 expression was inhibited by nystatin, a specific inhibitor for lipid rafts, but not by chlorpromazine, a specific inhibitor for clathrin-coated pits. Furthermore, PGN-induced IL-8 expression was attenuated by inhibitors for MAP kinases such as ERK, p38 kinase, and JNK/SAPK, whereas no inhibitory effect was observed by inhibitors for reactive oxygen species or protein kinase C. Electrophoretic mobility shift assay demonstrates that PGN increased the DNA binding of the transcription factors, AP-1 and NF-kappaB while minimally, NF-IL6, all of which are involved in the transcription of IL-8. Taken together, these results suggest that PGN induces IL-8 expression in a CD14-enhanced manner in human alveolar type II epithelial cells, through the formation of lipid rafts and the activation of MAP kinases, which ultimately leads to activation of AP-1, NF-kappaB, and NF-IL6.

• Lipoteichoic acid isolated from Lactobacillus plantarum inhibits lipopolysaccharide-induced TNF-alpha production in THP-1 cells and endotoxin shock in mice.

  Authors: Han Geun Kim, Na Ra Kim, Min Geun Gim, Jung Min Lee, Seung Yeon Lee, Mi Yeon Ko, Joo Yun Kim, Seung Hyun Han, Dae Kyun Chung

  Journal of immunology (Baltimore, Md. : 1950). 03/2008; 180(4):2553-61.

  In this study, the effect of Lactobacillus plantarum lipoteichoic acid (pLTA) on LPS-induced MAPK activation, NF-kappaB activation, and the expression of TNF-alpha and IL-1R-associated kinase MIn this study, the effect of Lactobacillus plantarum lipoteichoic acid (pLTA) on LPS-induced MAPK activation, NF-kappaB activation, and the expression of TNF-alpha and IL-1R-associated kinase M (IRAK-M) was examined. The expression of the pattern recognition receptor and the survival rate of mice were also examined. pLTA pretreatment inhibited the phosphorylation of ERK, JNK, and p38 kinase. It also inhibited the degradation of IkappaBalpha and IkappaBbeta, as well as the activation of the LPS-induced TNF-alpha factor in response to subsequent LPS stimulation. These changes were accompanied by the suppression of the LPS-induced expression of TLR4, NOD1, and NOD2, and the induction of IRAK-M, with a concurrent reduction of TNF-alpha secretion. Furthermore, the overexpression of pattern recognition receptors such as TLR4, NOD1, and NOD2 and the degradation of IRAK-M by transient transfection were found to reinstate the production of TNF-alpha after LPS restimulation. In addition, the i.p. injection of pLTA suppressed fatality, and decreased the level of TNF-alpha in the blood, in LPS-induced endotoxin shock mice. In conclusion, these data extend our understanding of the pLTA tolerance mechanism, which is related to the inhibition of LPS-induced endotoxin shock, and suggest that pLTA may have promise as a new therapeutic agent for LPS-induced septic shock.