• Archives of Pharmacal Research
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• v.22 no.5
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• pp.454-458
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• 1999

TR8 is a recently identified member of the tumor necrosis factor (TNF) receptor superfamily. TR8 seems to play important roles in bone metabolism as stimulation of this receptor with its ligand, TL8 or osteoclast differentiation factor (ODF), induced the differentiation and activation of osteoclasts. Despite its important biological functions, the biochemcial events ensuing form TR8 activation have not been revealed in detail. Most of TNF receptor family proteins provoke the activation of the NF-$textsc{k}$B transcription factor. In the present study, we examined the signaling potential of TR8 to induce NF-B activation. When overexpressed in a human embryonic kidney cell line by transient transfection, TR8 caused a strong activation of NF-$textsc{k}$B, which was further increased upon stimulation with TL8. The TR8-induced NF-B activation was abrogated by the co-expression of the TRAF6 mutnat lacking the Ring and zinc finger domains and that of the kinase-inactive mutant NIK. Taken together, our study suggests that the presence of intact TRAF6 and the kiase activity of NIK may be essential for TR8 to induce NF-$textsc{k}$B activation.

• Development and Reproduction
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• v.15 no.3
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• pp.197-204
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• 2011

Egg activation is a crucial step that initiates embryo development upon breaking the meiotic arrest. In mammalian, egg activation is accomplished by fusion with sperm, which induces the repeated intracellular $Ca^{2+}$- increases ($[Ca^{2+}]_i$ oscillation). Researches in mammals support the view of the $[Ca^{2+}]_i$ oscillation and egg activation is triggered by a protein factor from sperm that causes $[Ca^{2+}]_i$ release from endoplasmic reticulum, intracellular $[Ca^{2+}]_i$ store, by persistently activation of phosphoinositide pathway. It represents that the sperm factor generates production of inositol trisphosphate ($IP_3$). Recently a sperm specific form of phospholipase C zeta, referred to as PLCZ was identified. In this paper, we confer the evidence that PLCZ represent the sperm factor that induces $[Ca^{2+}]_i$ oscillation and egg activation and discuss the correlation of PLCZ and infertility.

• Korean Journal of Animal Reproduction
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• v.26 no.4
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• pp.369-375
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• 2002

A sperm factor(s) for oocyte activation during fertilization has not been clearly identified. In this study to elucidate an oocyte activation factor(s), mouse sperm were sonicated and ultra-filtered with a 30 kilo-daltons (KD) cutoff membrane and the ultra-filtrate was then sequentially fractionated over Suporose 12 column and Superdex column, The recovered fractions were micro-injected into Mⅱmouse oocytes and second polar body formation (PBF) was examined. Suporose fraction RV2.10 prepared from sperm extract significantly increased PBF. Of Superdex fractions re-separated from Suporose fraction RV2.10, fraction RV2.12 also had the strongest PBF activity. By analyzing with micro-reverse phase column (URPC), the Superdex fraction RV2.12 appeared to be glutamic acid. In microinjection test, glutamic acid significantly increased PBF. This study suggests that glutamic acid should be a type of sperm factor for second polar body formation related to oocyte activation.

• Korean Journal of Pharmacognosy
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• v.34 no.2 s.133
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• pp.150-155
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• 2003

The nuclear factor of activated T cells (NFAT) protein induce transcription of cytokine genes required for T-cell activation, including the IL-2 gene. Activation of NFAT normally plays a significant role in inducing immune response. However, excessive activation provokes immunopathological reactions including autoimmunity, transplant rejection and inflammation. Thus, several natural products were screened on the inhibitory activity against the NFAT transcription factor. Among them, Euonymus sieboldiana showed strong inhibitory activity against the NFAT transcription factor without affecting cell viability.

• YAKHAK HOEJI
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• v.54 no.2
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• pp.102-105
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• 2010

Our previous results showed that hypoxia inducible factor-1 (HIF-1) activated estrogen receptor (ER) in the absence of ligand. In this study, we have studied the effect ER overexpression on the activation of HIF-1. ER overexpression induced transcription activation of hypoxia response element driven luciferase and vascular endothelial growth factor. As a negative control, the effect of ER on androgen receptor response element was used. Our result indicate that the two ER$\alpha$ and HIF-1 signaling pathways shares part of the activation pathway.

• Bulletin of the Korean Chemical Society
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• v.34 no.11
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• pp.3405-3409
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• 2013

The activation of heat shock factor 1 (HSF1) can be induced by the changes in environmental pH, but the mechanism of HSF1 activation by acidification is not completely understood. This paper reports that a low pH (pH~6.0) can trigger human HSF1 activation. Considering the involvement of the imidazole group of histidine residues under acid pH stress, an in vitro EMSA experiment, Trp-fluorescence spectroscopy, and protein structural analysis showed that the residue, His83, is the essential for pH-dependent human HSF1-activation. To determine the roles of His83 in the HSF1-mediated stress response affecting the cellular acid resistance, mouse embryo fibroblasts with normal wild-type or mutant mouse HSF1 expression were preconditioned by heating or pH stress. The results suggest that His83 is essential for HSF1 activation or the HSF1-mediated transcription of heat shock proteins, in protecting cells from acid pH stress.

• Journal of the Semiconductor & Display Technology
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• v.3 no.1
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• pp.35-39
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• 2004

Statistical design of experiments was successfully employed to investigate the effect of alternating magnetic field on activation of polycrystalline Si (p-Si) doped as n-type using $\textrm{PH}_3$, by full factorial design of three factors with two levels. In this design, the input variables are graphite size, alternating current, and activation time. The output parameter, sheet resistance, is analyzed in terms of the primary effects and multi-factor interactions. Notably, the three-factor interaction is calculated to be a dominant interaction. The interaction between graphite size and activation time and the main effect of current are important effects compared to the other variables and relevant interactions. Alternating magnetic flux activation is proved a significantly beneficial processing technique.

• Molecules and Cells
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• v.25 no.2
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• pp.253-257
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• 2008

Acrolein is a highly electrophilic ${\alpha},{\beta}$-unsaturated aldehyde present in a number of environmental sources, especially cigarette smoke. It reacts strongly with the thiol groups of cysteine residues by Michael addition and has been reported to inhibit nuclear $factor-{\kappa}B$ ($NF-{\kappa}B$) activation by lipopolysaccharide (LPS). The mechanism by which it inhibits $NF-{\kappa}B$ is not clear. Toll-like receptors (TLRs) play a key role in sensing microbial components and inducing innate immune responses, and LPS-induced dimerization of TLR4 is required for activation of downstream signaling pathways. Thus, dimerization of TLR4 may be one of the first events involved in activating TLR4-mediated signaling pathways. Stimulation of TLR4 by LPS activates both myeloid differential factor 88 (MyD88)- and TIR domain-containing adapter inducing $IFN{\beta}$ (TRIF)-dependent signaling pathways leading to activation of $NF-{\kappa}B$ and IFN-regulatory factor 3 (IRF3). Acrolein inhibited $NF-{\kappa}B$ and IRF3 activation by LPS, but it did not inhibit $NF-{\kappa}B$ or IRF3 activation by MyD88, inhibitor ${\kappa}B$ kinase $(IKK){\beta}$, TRIF, or TNF-receptor-associated factor family member-associated $NF-{\kappa}B$ activator (TANK)-binding kinase 1 (TBK1). Acrolein inhibited LPS-induced dimerization of TLR4, which resulted in the down-regulation of $NF-{\kappa}B$ and IRF3 activation. These results suggest that activation of TLRs and subsequent immune/inflammatory responses induced by endogenous molecules or chronic infection can be modulated by certain chemicals with a structural motif that enables Michael addition.

• Proceedings of the KSPS conference
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• 2003.05a
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• pp.93-96
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• 2003

The present study was conducted to investigate the difference of cortical activation in naming the picture in Korean and English. Experimental design was 2(Korean, English) language condition x 4(no distractor, semantic related distractor, semantic unrelated distrator, corresponding distractor) distractor condition. language condition was between subject factor and distractor condition was within subject factor. The result was that Korean naming condition showed less cortical activation than English naming condition. The activation region was reported in each condition.

• KIEE International Transactions on Electrophysics and Applications
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• v.3C no.2
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• pp.48-54
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• 2003

To evaluate the radiation degradation of ethylene propylene rubber (EPR), radiation effects on EPR were investigated by using dielectric analysis and thermal-gravimetric analysis. Permittivity, loss factor, tan$\delta$, and thermal decomposition temperature were observed for ${\gamma}$-ray irradiated EPR. As the radiation dose was increased, the peak temperature of the loss factor and tans of EPR were increased and loss factor and tan$\delta$ at peak temperature were decreased. Activation energies were calculated using loss factor and thermal decomposition for ${\gamma}$-ray irradiated EPR as well. The trends of both calculated activation energies showed the same tendencies as radiation dose was increased.