• Journal of Oriental Neuropsychiatry
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• v.19 no.3
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• pp.117-127
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• 2008

Objective: Bee venom (BV) has been used for the treatment of inflammatory diseases such as rheumatoid arthritis and relief of pain in Oriental medicine. The two main components of BV are melittin and phospholipase A2 (PLA2). Of these, melittin, the major active ingredient of BV, has been reported to induce apoptosis and to possess anti tumor effects. Several studies have established that the agents inducing apoptosis in target organs suppress tumorigenesis. As the other component, PLA2 has been reported to induce neurite outgrowth in PC12 cells. However, there was no report about proliferative effect of BV in neuronal cells. In order to examine the effect of BV on glioma cell, human glioma cell line, U87 was used. Methods: Analysis of proliferation was confirmed by MTT assay. BV increased cell number through dose and duration dependent manner and these effects are apparent at a concentration of 10 ug/ml. To observe which signaling molecules will be activated by BV, phosphorylation of Akt, MAPK, PYK2 or CREB were examined by Western blot analysis. To study the long term effect of BV in U87 cells, the image of cells treated with BV for 4 days were obtained. Results: The phosphorylation levels of PYK2 and Akt were increased at 5 min after addition of 10 ug/ml of BV and sustained to 2 hours. On the other hand, phosphorylation of MAPK and CREB were increased at 5 min, maximum at 10 min, and returned to 30 min. These imply that BV may activate two different signaling pathways, PYK2/Akt and MAPK/CREB. BV treated cells showed increased neurite number and length. Conclusion: These results propose that BV may induce differentiation as well as proliferation of U87 cells through the activation of PYK2/ Akt and MAPK/ CREB.

• Journal of Microbiology
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• v.35 no.2
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• pp.103-108
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• 1997

To improve the detection of methicillin resistant staphylococci, lowered incubation temperature (30.deg.) and inclusion of sodium chloride in media have been empirically recommended. However, in this study, we found that sodium chloride in Peptone-Yeast Extract-K$\_$2/HPO$\_$4/ (PYK) medium decreased methicillin minimum inhibitory concentrations. Divalent cations were shown to restore the expression of staphylococcal methicillin resistance. However, when it was determined by efficiency of plating, sodium chloride increased methicillin resistance expression on agar medium in which higher divalent cations were contained in the agar medium. The decrease of minimum inhibitory concentrations at 30.deg.C by sodium chloride occurred in Brain Heart Infusion but did not occur in other media investigated. Interestingly, both PYK and Brain Heart Infusion media had peptone, which contain cholic acids having detergent activities. Inclusion of sodium chloride in PYK caused a higher rate of autolysis. Penicillin binding protein 2a that has a low affinity to beta-lactam antibiotics, was highly inducible in methicillin resistant Staphylococcus epidermidis strains. In this study, we found that autolysins that are activated by the sodium chloride decreased the minimum inhibitory concentration at 30.deg.C, and peptidoglycan is weakened due to the presence of methicillin. Peptone in the media may aggravate the fragile cells. However, stabilization due to the presence of divalent cations and production of penicilin binding protein 2a increase the survival of staphylococci.

• International Journal of Oral Biology
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• v.30 no.1
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• pp.9-15
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• 2005

Recently, we reported that high extracellular calcium increased receptor activator of nuclear factor-${\kappa}B$ ligand (RANKL) expression via p44/42 mitogen-activated protein kinase (p44/42 MAPK) activation in mouse osteoblasts. However, the mechanism for p44/42 MAPK activation by high extracellular calcium is unclear. In this study, we examined the role of intracellular calcium increase in high extracellular calcium-induced RANKL induction and p44/42 MAPK activation. Primary cultured mouse calvarial osteoblasts were used. RANKL expression was highly induced by 10 mM calcium treatment. Ionomycin, a calcium ionophore, also increased RANKL expression and activated p44/42 MAPK. U0126, an inhibitor of MEK1/2, an upstream activator of p44/42 MAPK, blocked the RANKL induction by both high extracellular calcium and ionomycin. High extracellular calcium increased the phosphorylation of proline-rich tyrosine kinase 2 (Pyk2), one of the known upstream regulators of p44/42 MAPK activation. Bisindolylmaleimide, an inhibitor of protein kinase C, did not block RANKL induction and p44/42 MAPK activation induced by high extracellular calcium. 2-Aminoethoxydiphenyl borate, an inhibitor of inositol 1,4,5-trisphosphate (IP3) receptor, blocked the RANKL induction by high extracellular calcium. It also partially suppressed the activation of Pyk2 and p44/42 MAPK. Cyclosporin A, an inhibitor of calcineurin, also inhibited high calcium-induced RANKL expression in dose dependent manner. However, cyclosporin A did not affect the activation of Pyk2 and p44/42 MAPK by high extracellular calcium treatment. These results suggest that 1) the increase in intracellular calcium via IP3-mediated calcium release is necessary for RANKL induction by high extracellular calcium treatment, 2) Pyk2 activation, but not protein kinase C, following the increase in intracellular calcium might be involved in p44/42 MAPK activation, and 3) calcineurin-NFAT activation by the increase in intracellular calcium is involved in RANKL induction by high extracellular calcium treatment.

• 대한약리학회:학술대회논문집
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• 2006.10a
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• pp.104.1-104.1
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• 2006

• Journal of Radiation Industry
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• v.4 no.3
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• pp.227-231
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• 2010

The purpose of this study was to investigate the expression mechanism of MCP-1 in gamma-irradiated RAW 264.7 macrophage cells. MCP-1 plays an important role in attracting monocyte to injured site at the early inflammation stage. However the production mechanism of MCP-1 by gamma-irradiation in RAW 264.7 macrophage cells was almost undiscovered. We found that MCP-1 was produced in RAW 264.7 macrophage cells by irradiation with 5 Gy. And these inceases were attenuated by specific inhibitors treatment, such as $NF-{\kappa}B$, JNK, ERK, JAK2, and Pyk2. These results indicate that radiation-induced MCP-1 production is mediated by MyD88- and TRIF-dependent pathways in RAW 264.7 macrophage cells. Furthermore, gamma-irradiation induced heme oxygenase-1 (HO-1) expression in RAW 264.7 macrophage cells. However this induction level was reduced before MCP-1 and $IFN-{\beta}$ production.

• Molecules and Cells
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• v.43 no.11
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• pp.921-934
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• 2020

Lck-interacting transmembrane adaptor 1 (LIME) has been previously identified as a raft-associated transmembrane protein expressed predominantly in T and B lymphocytes. Although LIME is shown to transduce the immunoreceptor signaling and immunological synapse formation via its tyrosine phosphorylation by Lck, a Src-family kinase, the in vivo function of LIME has remained elusive in the previous studies. Here we report that LIME is preferentially expressed in effector T cells and mediates chemokine-mediated T cell migration. Interestingly, in LIME^-/- mice, while T cell receptor stimulation-dependent proliferation, differentiation to effector T cells, cytotoxic T lymphocyte (CTL) function and regulatory T lymphocyte (Treg) function were normal, only T cell-mediated inflammatory response was significantly defective. The reduced inflammation was accompanied by the impaired infiltration of leukocytes and T cells to the inflammatory sites of LIME^-/- mice. More specifically, the absence of LIME in effector T cells resulted in the reduced migration and defective morphological polarization in response to inflammatory chemokines such as CCL5 and CXCL10. Consistently, LIME^-/- effector T cells were found to be defective in chemokine-mediated activation of Rac1 and Rap1, and dysregulated phosphorylation of Pyk2 and Cas. Taken together, the present findings show that LIME is a critical regulator of inflammatory chemokine-mediated signaling and the subsequent migration of effector T cells to inflammatory sites.