• Title/Summary/Keyword: Activation Model

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Inhibitory Effects of Ginsenoside-Rb2 on Nicotinic Stimulation-Evoked Catecholamine Secretion

  • Lim, Hyo-Jeong;Lee, Hyun-Young;Lim, Dong-Yoon
    • The Korean Journal of Physiology and Pharmacology
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    • v.18 no.5
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    • pp.431-439
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    • 2014
  • The aim of the present study was to investigate whether ginsenoside-Rb2 (Rb2) can affect the secretion of catecholamines (CA) in the perfused model of the rat adrenal medulla. Rb2 ($3{\sim}30{\mu}M$), perfused into an adrenal vein for 90 min, inhibited ACh (5.32 mM)-evoked CA secretory response in a dose- and time-dependent fashion. Rb2 ($10{\mu}M$) also time-dependently inhibited the CA secretion evoked by DMPP ($100{\mu}M$, a selective neuronal nicotinic receptor agonist) and high $K^+$ (56 mM, a direct membrane depolarizer). Rb2 itself did not affect basal CA secretion (data not shown). Also, in the presence of Rb2 ($50{\mu}g/mL$), the secretory responses of CA evoked by veratridine (a selective $Na^+$ channel activator ($50{\mu}M$), Bay-K-8644 (an L-type dihydropyridine $Ca^{2+}$ channel activator, $10{\mu}M$), and cyclopiazonic acid (a cytoplasmic $Ca^{2+}$-ATPase inhibitor, $10{\mu}M$) were significantly reduced, respectively. Interestingly, in the simultaneous presence of Rb2 ($10{\mu}M$) and L-NAME (an inhibitor of NO synthase, $30{\mu}M$), the inhibitory responses of Rb2 on ACh-evoked CA secretory response was considerably recovered to the extent of the corresponding control secretion compared with the inhibitory effect of Rb2-treatment alone. Practically, the level of NO released from adrenal medulla after the treatment of Rb2 ($10{\mu}M$) was greatly elevated compared to the corresponding basal released level. Collectively, these results demonstrate that Rb2 inhibits the CA secretory responses evoked by nicotinic stimulation as well as by direct membrane-depolarization from the isolated perfused rat adrenal medulla. It seems that this inhibitory effect of Rb2 is mediated by inhibiting both the influx of $Ca^{2+}$ and $Na^+$ into the adrenomedullary chromaffin cells and also by suppressing the release of $Ca^{2+}$ from the cytoplasmic calcium store, at least partly through the increased NO production due to the activation of nitric oxide synthase, which is relevant to neuronal nicotinic receptor blockade.

Inhibitory Mechanism of Polyphenol Compounds Isolated from Red Wine on Catecholamine Release in the Perfused Rat Adrenal Medulla

  • Yu, Byung-Sik;Ko, Woo-Seok;Lim, Dong-Yoon
    • Biomolecules & Therapeutics
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    • v.16 no.2
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    • pp.147-160
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    • 2008
  • The present study was designed to examine effects of polyphenolic compounds isolated from red wine (PCRW) on the release of catecholamines (CA) from the isolated perfused model of the rat adrenal medulla, and to clarify its mechanism of action. PCRW (20${\sim}$180 ${\mu}$g/mL), given into an adrenal vein for 90 min, caused inhibition of the CA secretory responses evoked by ACh (5.32 mM), high $K^+$ (a direct membrane-depolarizer, 56 mM), DMPP (a selective neuronal nicotinic $N_N$ receptor agonist, 100 ${\mu}$M) and McN-A-343 (a selective muscarinic $M_1$ receptor agonist, 100 ${\mu}$M) in dose- and time-dependent fashion. PCRW itself did not affect basal CA secretion (data not shown). Following the perfusion of PCRW (60 ${\mu}$g/mL), the secretory responses of CA evoked by Bay-K-8644 (a L-type dihydropyridine $Ca^{2+}$ channel activator, 10 ${\mu}$M), cyclopiazonic acid (a cytoplasmic $Ca^{2+}$-ATPase inhibitor, 10 ${\mu}$M) and veratridine (an activator of voltage-dependent $Na^+$ channels, 10 ${\mu}$M) were also markedly blocked, respectively. Interestingly, in the simultaneous presence of PCRW (60 ${\mu}$g/mL) and L-NAME (a selective inhibitor of NO synthase, 30 ${\mu}$M), the inhibitory responses of PCRW on the CA secretion evoked by ACh, high $K^+$, DMPP, McN-A-343, Bay-K-8644 and cyclpiazonic acid were recovered to considerable level of the corresponding control release compared with those effects of PCRW-treatment alone. Practically, the amount of NO released from adrenal medulla after loading of PCRW (180 ${\mu}$g/mL) was significantly increased in comparison to the corresponding basal released level. Collectively, these results obtained here demonstrate that PCRW inhibits the CA secretory responses evoked by stimulation of cholinergic (both muscarinic and nicotinic) receptors as well as by direct membrane-depolarization from the isolated perfused adrenal gland of the normotensive rats. It seems that this inhibitory effect of PCRW is mediated by blocking the influx of both ions through $Na^+$ and $Ca^+{2$} channels into the rat adrenomedullary chromaffin cells as well as by inhibiting the release of $Ca^{2+}$ from the cytoplasmic calcium store, which are due at least partly to the increased NO production through the activation of nitric oxide synthase. Based on these data, it is also thought that PCRW may be beneficial to prevent or alleviate the cardiovascular diseases, such as hypertension and angina pectoris.

The Stability of p53 in Ras-mediated Senescent Cells in Response to Nucleolar Stress (Ras에 의해 유도된 노화세포에서 핵인 스트레스에 의한 p53 안정화 연구)

  • Sihn, Choong-Ryoul;Park, Gil-Hong;Lee, Kee-Ho;Kim, Sang-Hoon
    • Journal of Life Science
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    • v.19 no.4
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    • pp.436-441
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    • 2009
  • B23/nucleophosmin, a nucleolar protein, translocates into the nucleus from the nucleolus when cells are damaged by extracellular stresses. Recently, it was shown that such translocation of B23/nucleophosmin in normal fibroblasts under stress conditions increases both the stability and activation of the p53 protein by disrupting its interaction with MDM2. Senescent cells have a single large nucleolus and a diminished capacity to induce p53 stability upon exposure to various DNA damaging agents. To investigate the role of B23/nucleophosmin in p53 stability in senescent cells, we established a senescence model system by expressing the ras oncogene in IMR90 cells. The stability of p53 was reduced in these cells in response to nucleolar stress, although the level of B23/nucleophosmin protein was not changed. In addition, p53 did not accumulate in the nucleus and B23/nucleophosmin did not translocate into the nucleoplasm. The binding affinity of B23/nucleophosmin with p53 was reduced in senescent cells, whereas the interaction between MDM2 and p53 was stable. Taken together, the stability of p53 in ras-induced senescent cells may be influenced by the ability of B23/nucleophosmin to interact with p53 in response to nucleolar stress.

Development of intranet-based Program Management Information System of multi-complex project with application of BIM (BIM을 활용한 다중복합 프로젝트의 인트라넷 기반 통합사업관리체계 구축 방안)

  • Song, Il-Bab;Hur, Young-Ran;Seo, Jong-Won
    • Journal of KIBIM
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    • v.2 no.1
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    • pp.27-39
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    • 2012
  • Public construction projects need complex and multi-functional management skill, since the most of public construction projects are comprised of multi-project and mega-projects. In order to effectively manage construction projects, PMIS is widely used. However the majority of the current PMIS have been developed as a single project-oriented business management system. Thus compatibility problems are encountered during the process of integrating the entire systems to manage the multi-complex projects. In addition, the form of orders applying BIM are increased recently, but the research and development of BIM based PMIS are still lacking. In this study, therefore, the functions of PMIS main objectives based on the analysis of PMIS As-Is and To-Be of PMIS, the dual management system utilizing Internet and Intranet will be proposed to integrate the individual PMIS with Integrated Program Management System. Rather than combining commercial BIM tool and PMIS directly, which is the common method of failure, the sequential process model to adopt BIM based PMIS is also explained. Step-by-step development method of BIM based PMIS is suggested to prepare for the activation of BIM technology in the nearest future.

Electrical Characterization of Ultrathin Film Electrolytes for Micro-SOFCs

  • Shin, Eui-Chol;Ahn, Pyung-An;Jo, Jung-Mo;Noh, Ho-Sung;Hwang, Jaeyeon;Lee, Jong-Ho;Son, Ji-Won;Lee, Jong-Sook
    • Journal of the Korean Ceramic Society
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    • v.49 no.5
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    • pp.404-411
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    • 2012
  • The reliability of solid oxide fuel cells (SOFCs) particularly depends on the high quality of solid oxide electrolytes. The application of thinner electrolytes and multi electrolyte layers requires a more reliable characterization method. Most of the investigations on thin film solid electrolytes have been made for the parallel transport along the interface, which is not however directly related to the fuel cell performance of those electrolytes. In this work an array of ion-blocking metallic Ti/Au microelectrodes with about a $160{\mu}m$ diameter was applied on top of an ultrathin ($1{\mu}m$) yttria-stabilized-zirconia/gadolinium-doped-ceria (YSZ/GDC) heterolayer solid electrolyte in a micro-SOFC prepared by PLD as well as an 8-${\mu}m$ thick YSZ layer by screen printing, to study the transport characteristics in the perpendicular direction relevant for fuel cell operation. While the capacitance variation in the electrode area supported the working principle of the measurement technique, other local variations could be related to the quality of the electrolyte layers and deposited electrode points. While the small electrode size and low temperature measurements increaseed the electrolyte resistances enough for the reliable estimation, the impedance spectra appeared to consist of only a large electrode polarization. Modulus representation distinguished two high frequency responses with resistance magnitude differing by orders of magnitude, which can be ascribed to the gadolinium-doped ceria buffer electrolyte layer with a 200 nm thickness and yttria-stabilized zirconia layer of about $1{\mu}m$. The major impedance response was attributed to the resistance due to electron hole conduction in GDC due to the ion-blocking top electrodes with activation energy of 0.7 eV. The respective conductivity values were obtained by model analysis using empirical Havriliak-Negami elements and by temperature adjustments with respect to the conductivity of the YSZ layers.

Physiological Roles of Phospholipase Cγ and Its Mutations in Human Disease (Phospholipase Cγ의 생리적 기능과 질병과 연관된 돌연변이)

  • Jang, Hyun-Jun;Choi, Jang Hyun;Chang, Jong-Soo
    • Journal of Life Science
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    • v.30 no.9
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    • pp.826-833
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    • 2020
  • Phospholipase C gamma (PLCγ) has critical roles in receptor tyrosine kinase- and non-receptor tyrosine kinase-mediated cellular signaling relating to the hydrolysis of phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] to produce inositol 1,4,5 trisphosphate (IP3) and diacylglycerol (DAG), which promote protein kinase C (PKC) and Ca2+ signaling to their downstream cellular targets. PLCγ has two isozymes called PLCγ1 and PLCγ2, which control cell growth and differentiation. In addition to catalytically active X- and Y-domains, both isotypes contain two Src homology 2 (SH2) domains and an SH3 domain for protein-protein interaction when the cells are activated by ligand stimulation. PLCγ also contains two pleckstrin homology (PH) domains for membrane-associated phosphoinositide binding and protein-protein interactions. While PLCγ1 is widely expressed and appears to regulate intracellular signaling in many tissues, PLCγ2 expression is restricted to cells of hematopoietic systems and seems to play a role in the regulation of immune response. A distinct mechanism for PLCγ activation is linked to an increase in phosphorylation of specific tyrosine residue, Y783. Recent studies have demonstrated that PLCγ mutations are closely related to cancer, immune disease, and brain disorders. Our review focused on the physiological roles of PLCγ by means of its structure and enzyme activity and the pathological functions of PLCγ via mutational analysis obtained from various human diseases and PLCγ knockout mice.

Vitrification, in vitro fertilization, and development of Atg7 deficient mouse oocytes

  • Bang, Soyoung;Lee, Geun-Kyung;Shin, Hyejin;Suh, Chang Suk;Lim, Hyunjung Jade
    • Clinical and Experimental Reproductive Medicine
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    • v.43 no.1
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    • pp.9-14
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    • 2016
  • Objective: Autophagy contributes to the clearance and recycling of macromolecules and organelles in response to stress. We previously reported that vitrified mouse oocytes show acute increases in autophagy during warming. Herein, we investigate the potential role of Atg7 in oocyte vitrification by using an oocyte-specific deletion model of the Atg7 gene, a crucial upstream gene in the autophagic pathway. Methods: Oocyte-specific Atg7 deficient mice were generated by crossing Atg7 floxed mice and Zp3-Cre transgenic mice. The oocytes were vitrified-warmed and then subjected to in vitro fertilization and development. The rates of survival, fertilization, and development were assessed in the Atg7 deficient oocytes in comparison with the wildtype oocytes. Light chain 3 (LC3) immunofluorescence staining was performed to determine whether this method effectively evaluates the autophagy status of oocytes. Results: The survival rate of vitrified-warmed $Atg7^{f/f}$;Zp3-Cre ($Atg7^{d/d}$) metaphase II (MII) oocytes was not significantly different from that of the wildtype ($Atg7^{f/f}$) oocytes. Fertilization and development in the $Atg7^{d/d}$ oocytes were significantly lower than the $Atg7^{f/f}$ oocytes, comparable to the $Atg5^{d/d}$ oocytes previously described. Notably, the developmental rate improved slightly in vitrified-warmed $Atg7^{d/d}$ MII oocytes when compared to fresh $Atg7^{d/d}$ oocytes. LC3 immunofluorescence staining showed that this method can be reliably used to assess autophagic activation in oocytes. Conclusion: We confirmed that the LC3-positive signal is nearly absent in $Atg7^{d/d}$ oocytes. While autophagy is induced during the warming process after vitrification of MII oocytes, the Atg7 gene is not essential for survival of vitrified-warmed oocytes. Thus, induction of autophagy during warming of vitrified MII oocytes seems to be a natural response to manage cold or other cellular stresses.

Slope Failure Prediction through the Analysis of Surface Ground Deformation on Field Model Experiment (현장모형실험 기반 표층거동분석을 통한 사면붕괴 예측)

  • Park, Sung-Yong;Min, Yeon-Sik;Kang, Min-seo;Jung, Hee-Don;Sami, Ghazali-Flimban;Kim, Yong-Seong
    • Journal of the Korean Geosynthetics Society
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    • v.16 no.3
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    • pp.1-10
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    • 2017
  • Recently, one of the natural disasters, landslide is causing huge damage to people and properties. In order to minimize the damage caused by continuous landslide, a scientific management system is needed for technologies related to measurement and monitoring system. This study aims to establish a management system for landslide damage by prediction of slope failure. Ground behavior was predicted by surface ground deformation in case of slope failure, and the change in ground displacement was observed as slope surface. As a result, during the slope failure, the ground deformation has the collapse section, the after collapse precursor section, the acceleration section and the burst acceleration section. In all cases, increase in displacement with time was observed as a slope failure, and it is very important event of measurement and maintenance of risky slope. In the future, it can be used as basic data of slope management standard through continuous research. And it can contribute to reduction of landslide damage and activation of measurement industry.

The Effects of Alismatis Rhizoma Extract on Allergic Inflammation in RBL-2H3 Mast Cells and OVA/alum-Sensitized Mice (택사 (澤瀉, Alismatis Rhizoma) 추출물이 RBL-2H3 비만세포와 OVA/alum 감작 생쥐의 알레르기 염증 반응에 미치는 영향)

  • Song, Ji Hyun;Lee, Jin Hwa;Kim, Eun Jin;Kim, Yun Hee
    • The Journal of Pediatrics of Korean Medicine
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    • v.32 no.3
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    • pp.1-15
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    • 2018
  • Objectives Alismatis Rhizoma has been known to suppress inflammation and allergic reaction. However, the cellular target of Alismatis Rhizoma and its mechanism of action remain unclear. This study was designed to examine the effect of Alismatis Rhizoma extract (ALC) on the RBL-2H3 mast cells in vitro and on the OVA/alum sensitized mice ex vivo. Methods In the study, RBL-2H3 mast cells were cultured in minimal essential medium (MEM) for 24 hours, and treated separately with cyclosporin A and varying doses of ALC, and then stimulated with Phorbol 12-myristate 13-acetate (PMA) (50 ng/ml) and Ionomycin ($0.5{\mu}M$). The levels of IL-13, IL-4 were measured by ELISA analysis. The mRNA levels of IL-4, IL-5, IL-6, IL-13, GM-CSF, $TNF-{\alpha}$ were analyzed with Real-time PCR. Also, manifestations of MAPKs transcription factors and $NF-{\kappa}B$ p65 translocation were analyzed by western blotting in vitro. Subsequently, for ex vivo experiment, we induced allergic inflammation on Balb/c mice by OVA/alum and administered ALC orally. And we measured serum OVA-specific IgE level and IL-4, IL-13 in the splenocyte culture supernatant by ELISA analysis. Results ALC was shown to suppress mRNA expression of IL-4, IL-5, IL-6, IL-13, GM-CSF, $TNF-{\alpha}$, and to inhibit the IL-13, IL-4 production. Also ALC reduced an activation of mast cells specific signal MAPKs transcription factors and $NF-{\kappa}B$ p65 from the western blot analysis in in vitro experiment. In ex vivo, ALC oral adminstration decreased the level of OVA-specific IgE in serum, and IL-4, IL-13 in the splenocyte culture supernatant. Conclusions ALC is shown to reduce inflammation and allergic response by suppressing Th2 cytokines through the regulation of transcription factors MAPKs and $NF-{\kappa}B$ p65 in mast cells. Administration of ALC suppressed OVA-specific IgE in ovalbumin allergy model through the inhibition of Th2 cytokine. In conclusion, ALC can be considered as an effective treatment for allergic diseases such as atopic dermatitis.

Inhibition of Phorbol 12-myristate-13-acetate Induced Cyclooxygenase-2 Activity by Three-step Fermented Soybeans (PMA에 의해 유도된 cycooxygenase-2 활성에 대한 새로운 발효법에 의한 대두산물의 억제 효능)

  • Park, Cheol;Lee, Jeong-Ok;Ryu, Chung-Ho;Choi, Yung-Hyun
    • Journal of Life Science
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    • v.18 no.2
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    • pp.180-186
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    • 2008
  • In this study, we examined the effects of the fermented soybeans by Bacillus subtilis (FSB) and the novel three-step fermented soybeans (TFS) on the expression and activity of COX-2 in human leukemic U937 cell model. Treatment of phorbol 12-myristate 13-acetate (PMA) significantly induced pro-inflammatory mediators such as COX-2 expression and prostaglandin $E_2\;(PGE_2)$ production, whereas the levels of COX-1 remained unchanged. However, pre-treatment with FSB and TFS significantly attenuated the PMA-induced COX-2 protein as well as mRNA, which was associated with inhibition of $PGE_2$ production. Moreover, TFS exerts a much better inhibitory activity than FSB against PMA-induced activation of COX-2 and production of $PGE_2$ in U937 cells. Taken together, these findings provide important new insights into the possible molecular mechanisms of the anti-inflammatory activity of FSB and TFS.