• The korean journal of orthodontics
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• v.33 no.3 s.98
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• pp.199-210
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• 2003

Tooth movement is the result of bone metabolism in the periodontium, where various cytokines take important roles. Interleukin-6(II-6) and nitrous oxide (NO) were reported to be secreted from osteoblasts in the process of bone resorption. The mechanism of the process has not been clearly understood, but the activation of mitogen-activated protein kinase (MAPK) was known to be an important process in the release of the inflammatory cytotines in macrophages. In this regard, to prove the role of MAPK in the release of IL-6 and NO in MC3T3E-1 osteoblasts, Northern blot analysis, Western blot analysis and immune complex kinase assay were used. As a result, the treatment of MC3T3E-1 osteoblast cultures with combined $interferon-\gamma(IFN-\gamma)$, lipopolysaccharide (LPS) and tumor necrosis $factor-\alpha(TNF-\alpha)$ induces expressions of inducible nitric oxide synthase (iNOS) and IL-6, resulting in sustained releases of large amounts of NO and IL-6. However, $IFN-\gamma,\;LPS,\;and\;TNF-\alpha$ individually induce a non-detectable or small amount of NO and IL-6 in MC3T3E-1 osteoblasts. The role of MAPK activation in the early intracellular signal transduction involved in iNOS and IL-6 transcription in the combined agents-stimulated osteoblasts has been investigated. The p38 MAPK pathway is specifically involved in the combined agents-induced NO and IL-6 release, since NO and IL-6 release in the presence of a specific inhibitor of p38 MAPK, 4-(4-fluorophenyl)-2-(4-metylsulfinylphenyl)-5-(4-metylsulfinylphenyl)-5-(4-pyridyl)imidazole) (SB203580), were significantly diminished. In contrast, PD98059, a specific inhibitor of MEK1, had no effect on NO and IL-6 release. Northern blot analysis showed that the p3a MAPK pathway controlled the iNOS and IL-6 transcription level. These data suggest that p38 MAPK play an important role in the secretion of NO and IL-6 in $LPS/IFN{\gamma}-or\;TNF-\gamma-treated\;MC3T3E-1$ osteoblasts.

• The Korean Journal of Pharmacology
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• v.29 no.1
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• pp.97-105
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• 1993

Adenosine receptors in rat adipose tissues have been reported to be of $A_{1}$ subclass, and their stimulation leads to inhibition of adenylyl cyclase, resulting in inhibition of lipolysis. In the present study we investigated changes in $A_{1}$ adenosine receptor-adenylyl cyclase system of adipocytes following induction of experimental diabetes in rats. One week following experimental diabetes were induced by intravenous injection of streptozotocin (50 mg/kg body wt.), adipocytes from rats $(170{\sim}230g)$ fed ad libitum were isolated using collagenase. When adipocytes were incubated for 1 h with 1 unit/ml adenosine deaminase and $1\;{\mu}M$ isoproterenol, and assayed for glycerol formation, it was found that the inhibition of lipolysis in diabetic adipocytes by $(-)-N^{6}-(R-phenylisopropyl)adenosine$ (PIA), an $A_{1}$, adenosine receptor agonist, was twice that of control adipocytes. In an effort to delineate the mechanism(s), $[^{3}H]PIA$ binding to adipocytic membranes from diabetic and control rats were determined. Neither the affinities nor numbers of $A_{1}$ adenosine receptor were significantly different from each other (Best fit parameters for the one-site model are: $K_{d}=0.51{\pm}0.09nM$ and $B_{max}=1.60{\pm}0.12\;pmoles/mg$ protein for control membranes; $K_{d}=0.54{\pm}0.21\;nM$ and $B_{max}=1.72{\pm}0.31\;pmoles/mg$ protein for diabetic membranes). However, the inhibiton by PIA of the isoproterenol-stimulated adenylyl cyclase activities was found to be 1.9 times higher in adipocytic membranes from diabetic rats than those from controls. These results suggest that the increased sensitivity of inhibition of lipolysis to PIA in adipocytic membranes from diabetic rats is due to changes in signal transduction pathways, rather than alterations of $A_{1}4 adenosine receptor molecules themselves.

• Korean Journal of Biological Psychiatry
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• v.14 no.2
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• pp.115-121
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• 2007

Objetives : Identification of target genes for ethanol in neurons is important for understanding its molecular and cellular mechanism of action and the neuropathological changes seen in alcoholics. The purpose of this study is to identify of altered gene expression after acute treatmet of ethanol in rat gliom cells. Methods : We used high density cDNA microarray chip to measure the expression patterns of multiple genes in cultured rat glioma cells. DNA microarrays allow for the simultaneous measurement of the expression of several hundreds of genes. Results : After comparing hybridized signals between control and ethanol treated groups, we found that treatment with ethanol increased the expression of 15 genes and decreased the expression of 12 genes. Upregulated genes included Orthodenticle(Drosophila) homolog 1, procollagen type II, adenosine A2a receptor, GATA bindning protein 2. Downregulated genes included diacylglycerol kinase beta, PRKC, Protein phosphatase 1, clathrin-associated protein 17, nucleoporin p58, proteasome. Conclusion : The gene changes noted were those related to the regulation of transcription, signal transduction, second messenger systems. modulation of ischemic brain injury, and neurodengeneration. Although some of the genes were previously known to be ethanol responsive, we have for the most part identified novel genes involved in the brain response to ethanol.

• Tuberculosis and Respiratory Diseases
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• v.49 no.3
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• pp.332-342
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• 2000

Background : The importance of pro-inflammatory cytokines, especially tumor necrosis factor $\alpha$ (INF-$\alpha$) and interleukin-1$\beta$ (IL-1$\beta$), have been extensively documented in the generation of inflammatory lung disease. Lung epithelial cells are also actively involved in initiating and maintaining inflammation by producing pro-inflammatory mediators. Understanding the mechanism of pro-inflammatory cytokine expression in lung epithelial cells is crucial to the development of new therapeutic modalities for inflammatory lung disease. Transcription of most pro-inflammatory cytokines is dependent on the activation of NF-${\kappa}B$. However, the relationship between pro-inflammatory cytokine expression and NF-${\kappa}B/I{\kappa}B$ pathway in lung epithelial cells is not clear. Methods : BEAS-2B, A549, Na-H157, NCI-H719 cells were stimulated with IL-$1{\beta}$ or TNF-$\alpha$ at various times, and then IL-8 and TNF-$\alpha$mRNA expressions were assayed by Northern blot analysis. IL-$1{\beta}$ or TNF-$\alpha$-induced NF-${\kappa}B$ activation was assessed by the nuclear translocation of p65 NF-${\kappa}B$ subunit. The degradation of $I{\kappa}B{\alpha}$ and $I{\kappa}B{\beta}$ by IL-$1{\beta}$ or TNF-$\alpha$stimulation was assayed by Western blot analysis. The phosphorylation of $I{\kappa}B{\alpha}$ was evaluated by Western blot analysis after pre-treating cells with proteasome inhibitor followed by IL-$1{\beta}$ or TNF-$\alpha$ stimulation. The basal level of IKK $\alpha$ expression was evaluated by Western blot analysis. Results: $I{\kappa}B{\alpha}$ and $I{\kappa}B{\alpha}$ was rapidly degraded after 5 minutes of incubation with IL-$1{\beta}$ or TNF-$\alpha$ in BEAS-2B, A549, and NCI-H157 cells. The activation of NF-${\kappa}B{\alpha}$ and the induction of IL-8 and TNF-$\alpha$ mRNA expression were observed by IL-$1{\beta}$ or TNF-$\alpha$ stimulation in these cells. In contrast, neither the changes in NF-${\kappa}B/I{\kappa}B$ pathway nor IL-8 and TNF-$\alpha$mRNA expression was induced by IL-$1{\beta}$ or TNF-$\alpha$ stimulation in NCI-H719 cells. IL-$1{\beta}$ and TNF-$\alpha$-induced $I{\kappa}B$ phosphorylation was observed in BEAS-2B, A549, and NCI-H157 cells, but not in NCI-H719 cells. The basal level of IKK$\alpha$ expression was not different between cell. Conclusion : NF-${\kappa}B/I{\kappa}B$ pathway plays an important role in the expression of pro-inflammatory cytokine in most lung epithelial cells. The absence of the effect on NF-${\kappa}B/I{\kappa}B$ pathway in NCI-H719 cells sæms to be due to the defect in the intracellular signal transduction pathway upstream to IKK.