• Proceedings of the Korean Society of Applied Pharmacology
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• 한국응용약물학회 2003년도 Annual Meeting of KSAP : International Symposium on Pharmaceutical and Biomedical Sciences on Obesity
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• pp.84-84
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• 2003

Lead has long been considered as a toxic environmental pollutant, which severely damages central nervous system. Lead can cause hypo- and de-myelination, and glial cells are closely related with myelination or demyelination. Matrix metalloproteinases (MMPs) are proteolytic enzymes that are involved in the remodelling of the extracellular matrix in a variety of physiological and pathological processes. MMPs also seem to be important in the pathogenesis of inflammatory demyelinating diseases of the central and peripheral nervous system. In this study, we investigated whether lead affects MMP-9 expression in rat primary glial cells. Treatment of 0.1-5 ${\mu}$M lead dose- and time-dependently increased MMP-9 expression in rat primary glial cells. The activity of MMPs was determined using zymography. Lead activated Erk(1/2) but neither of the other endogenous MAP kinases, p38 or JNK. Inhibition of Erk(1/2) activation by PD98059, a MEK inihibitor, prevented lead-induced expression of MMP-9. The results of the present study suggest that lead intoxication may adversely affect brain function at least in part by inducing MMP-9 expression through Erk(1/2) activation in primary glial cells.

• Molecules and Cells
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• 제26권1호
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• pp.12-17
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• 2008

The TrkA tyrosine kinase is activated by autophosphorylation in response to NGF, and plays an important role in cell survival, differentiation, and apoptosis. To investigate its role in cell fate determination, we produced stable TrkA-inducible SK-N-MC and U2OS cell lines using the Tet-On system. Interestingly, TrkA overexpression induced substantial cell death even in the absence of NGF, by stimulating ERK phosphorylation and caspase-7 activation leading to PARP cleavage. TrkA-mediated cell death was shown by the annexin-V binding assay to be, at least in part, apoptotic in both SK-N-MC and U2OS cells. Furthermore, the truncated form (p18) of Bax accumulated in the TrkA-induced cells, suggesting that TrkA induces mitochondria-mediated apoptosis. NGF treatment augmented the cell death induced by TrkA overexpression. This TrkA-induced cell death was blocked by the tyrosine kinase inhibitors, K-252a and GW441756. Moreover, TrkA overexpression inhibited long-term proliferation of both the neuronal SK-N-MC cells and the non-neuronal U2OS cells, suggesting a potential role of TrkA as a tumor suppressor.

• Archives of Pharmacal Research
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• 제28권11호
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• pp.1257-1262
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• 2005

MMP-9 is a metalloproteinase capable of basement membrane degradation in vivo. Expression of MMP-9 can be found in normal conditions such as trophoblasts, osteoclasts, and leukocytes and their precursors. They also occur as well as in pathological conditions, such as the invasive growth of primary tumors, metastasis, angiogenesis, rheumatoid arthritis, and periodontal diseases. MMP-9 upregulation can be highly induced by a wide range of agents. These agents include growth factors, cytokines, cell-cell, and cell-ECM adhesion molecules, and agents altering cell shape. Here, we observed that TNF-$\alpha$ stimulated human monocytic cell line, HL-60 produced MMP-9 in a dose and time dependent manner. Real time PCR results indicated transcriptional upregulation of MMP-9 as early as 3 h post TNF-$\alpha$ stimulation. To investigate the signaling pathway underlined in TNF-$\alpha$ induced MMP-9 expression, three MAP kinase inhibitors were added to cells 1 h prior to TNF-$\alpha$ treatment. The ERK inhibitor completely abolished MMP-9 expression by TNF-$\alpha$. But neither p38 MAP kinase nor JNK inhibitor had an effect on TNF-$\alpha$ induced MMP-9 expression, suggesting that ERK activation is required for the MMP-9 induction by TNF-$\alpha$. Taken together, we found that TNF-$\alpha$ stimulation facilitates ERK activation, which results in the transcriptional upregulation of MMP-9 gene and subsequent MMP-9 production and secretion.

• Natural Product Sciences
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• 제13권2호
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• pp.169-173
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• 2007

Luteolin is a major flavonoid of Lonicera japonica and has anti-inflammatory effect. The activation of proteinase-activated receptor (PAR)-2 and -4 by trypsin appears to play a role in inflammation, In the present study, we examined the inhibitory effects of luteolin on activation of trypsin-induced human leukemic mast cells (HMC-1). HMC-1 cells were stimulated with trypsin, PAR-2 and PAR-4 agonist, in the presence or absence of luteolin. The level of TNF-${\alpha}$ secretion was measured by enzyme-linked immunosorbent assay (ELISA). The expression of tryptase and phosphorylated-extracellular signal-regulated kinase (ERK) were assessed by Westem blot analysis. Moreover, trypsin activity was measured by the substrate Bz-DL-Arg-p-nitroanilide (BAPNA). TNF-${\alpha}$ secretion and Tryptase expression in trypsin-stimulated HMC-1 cells were markedly inhibited by pretreatment of luteolin. Furthermore, the pretreatment of luteolin resulted in the reduction of ERK phosphorylation and trypsin activity. These results suggest that luteolin might has the inhibitory effects on the PAR-2 and -4-dependent inflammation.

• Korean Journal of Plant Resources
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• 제31권3호
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• pp.202-210
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• 2018

Abeliophyllum distichum is a medicinal plant used in regional traditional medicine to relieve pain in inflammatory processes. In this study, anti-inflammatory effects of Abeliophyllum distichum flower (ADF) extract were examined. Furthermore, possible molecular mechanisms of the anti-inflammatory effects were dissected. The anti-inflammatory activity was investigated by inhibition of lipopolysaccharide (LPS) induced pro-inflammatory cytokine production in murine macrophage-like cell line Raw264.7 cells. The measurement of the induced pro-inflammatory cytokine levels were carried out by ELISA. The phosphorylation of ERK1/2, JNK, and MAPK, and the nuclear expression of nuclear factor NF-${\kappa}B$ p65 were investigated by Western blot analysis. The extract of ADF significantly decreased the production of pro-inflammatory cytokines. In addition, the extract suppressed the phosphorylation of ERK1/2, JNK, and p38 MAPK, and the nuclear translocation of NF-${\kappa}B$ p65 in activated cells. Our findings provide evidence for the popular use of Abeliophylli distichum in inflammation around Goesan region and also suggest that the flower extract has potential therapeutic benefits against various inflammatory diseases.

• IMMUNE NETWORK
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• 제6권3호
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• pp.123-127
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• 2006

Background: Caveolin-1 is a principal component of caveolae membranes in vivo. Although expression of caveolae structure and expression of caveolin family, caveolin-1, -2 and -3, was known in chondrocytes, the functional role of caveolae and caveolins in chondrocytes remains unknown. In this study, we investigated the role of caveolin-1 in articular chondrocytes. Methods: Rabbit articular chondrocytes were prepared from cartilage slices of 2-week-old New Zealand white rabbits by enzymatic digestion. Caveolin-1 cDNA was transfected to articular chondrocytes using LipofectaminePLUS. The cyclooxygenase-2 (COX-2) expression levels were determined by immunoblot analysis, immunostaining, immunohistochemistry, and prostaglandin $E_2\;(PGE_2)$ assay was used to measure the COX-2 activity. Results: Ectopic expression of caveolin-1 induced COX-2 expression and activity, as indicated by immunoblot analysis and $PGE_2$ assay. And also, overexpression of caveolin-1 stimulated activation of p38 kinase and ERK-1/-2. Inhibition of p38 kinase and ERK-1/-2 with SB203580 and PD98059, respectively, led to a dose-dependent decrease COX-2 expression and $PGE_2$ production in caveolin-1-transfected cells. Conclusion: Taken together, our data suggest that ectopic expression of caveolin-1 contributes to the expression and activity of COX-2 in articular chondrocytes through MAP kinase pathway.

• Proceedings of the Plant Resources Society of Korea Conference
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• 한국자원식물학회 2018년도 춘계학술발표회
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• pp.89-89
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• 2018

Abeliophyllum distichum is a medicinal plant used in regional traditional medicine to relieve pain in inflammatory processes. In this study, anti-inflammatory effects of Abeliophyllum distichum stem (ADS) ethyl acetate extract were examined. Furthermore, possible molecular mechanisms of the anti-inflammatory effects were dissected. The anti-inflammatory activity was investigated by inhibition of lipopolysaccharide (LPS) induced pro-inflammatory cytokine production in murine macrophage-like cell line Raw264.7 cells and human microglial cell line BV2 cells. The measurement of the induced pro-inflammatory cytokine levels were carried out by ELISA. The phosphorylation of ERK1/2, JNK, and MAPK, and the nuclear expression of nuclear factor $NF-{\kappa}B$ p65 were investigated by Western blot analysis. The extract of ADS significantly decreased the production of pro-inflammatory cytokines. In addition, the extract suppressed the phosphorylation of ERK1/2, JNK, and p38 MAPK, and the nuclear translocation of $NF-{\kappa}B$ p65 in activated cells. Our findings provide evidence for the popular use of Abeliophylli distichum in inflammation around Goesan region and also suggest that the stem extract has potential therapeutic benefits against several inflammatory diseases.

• Proceedings of the Plant Resources Society of Korea Conference
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• 한국자원식물학회 2018년도 춘계학술발표회
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• pp.90-90
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• 2018

Kochiae Fructus is a medicinal plant used as medicine of the urinary organs, skin disease and inflammation. In this study, anti-inflammatory activity of Kochiae Fructus extract and its possible mechanisms of action were examined. The anti-inflammatory activity was investigated by inhibition of lipopolysaccharide (LPS) induced nitric oxide (NO), pro-inflammatory cytokine production and matrix metalloprotease-9 (MMP-9) in murine macrophage-like cell line Raw 264.7 cells. The measurement of the induced pro-inflammatory cytokine levels were carried out by ELISA. The phosphorylation of ERK1/2, JNK and MAPK and the nuclear expression of nuclear factor $NF-{\kappa}B$ p65 were investigated by Wesern blot analysis. The extract suppressed the phosphorylation of ERK1/2, JNK, and p38 MAPK, and the nuclear translocation of $NF-{\kappa}B$ p65 in activated cells. As a result, we suggest that the extract of Kochiae Fructus decreased the production of pro-inflammatory cytokines ($TNF-{\alpha}$, IL-6), nitric oxide, MMP-9 in LPS-induced Raw264.7 cells. Kochiae Fructus has possibility to be used as therapeutic benefits against inflammatory diseases.

• YAKHAK HOEJI
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• 제52권2호
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• pp.111-116
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• 2008

Diethylstilbestrol (DESB) is a synthetic estrogen not only that routinely prescribed, but also that known to be a teratogen. In this study, we found a novel pharmacological feature that DESB is able to positively modulate CD29 $({\beta}1-integrin)$ function. Thus, DESB up-regulated homotypic cell-cell adhesion of monocytic U937 cells mediated by CD29. However, DESB did not increase the surface level of CD29 and its binding activity to ligand (fibronectin), according to flow cytometric analysis and cell-fibronectin adhesion assay. Instead, the DESB-mediated up-regulation of cell-cell adhesion was blocked by several signaling enzyme inhibitors. Treatment of U0126 [an extracellular signal-regulated kinase (ERK) inhibitor], SB20358 (a p38 inhibitor) or Rp-8-pCPT-cGMP (a protein kinase G inhibitor) clearly inhibited DESB-mediated up-regulation of cell-cell adhesion induced by CD29. However, estrogen receptor antagonist ICI 182,780 failed to abrogate DESB effect. Therefore, our data suggest that DESB may up-regulate CD29-mediated cell-cell adhesion via modulating intracellular signaling enzymes such as ERK, PKG, and p38, independent of estrogen receptor function.

• Biomolecules & Therapeutics
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• 제19권4호
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• pp.460-465
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• 2011

The present study was undertaken to investigate the influence of quercetin on vascular smooth muscle contractility and to determine the mechanism involved. Denuded aortic rings from male rats were used and isometric contractions were recorded and combined with molecular experiments. Quercetin at a low concentration (0.01-0.03 mM) directly and more significantly relaxed fluoride or thromboxane $A_2$-induced vascular contraction than phorbol ester-induced contraction suggesting as a possible anti-hypertensive on the agonist-induced vascular contraction regardless of endothelial nitric oxide synthesis. Furthermore, quercetin more significantly inhibited thromboxane $A_2$-induced increases in pMYPT1 levels than phorbol ester-induced increases. It also more significantly inhibited thromboxane $A_2$-induced increases in pMYPT1 levels than pERK1/2 levels suggesting the mechanism involving the primarily inhibition of Rho-kinase activity and the subsequent phosphorylation of MYPT1. This study provides evidence regarding the mechanism underlying the relaxation effect of quercetin on agonist-induced vascular contraction regardless of endothelial function.