• Title/Summary/Keyword: time-dependent effect

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The Suppressive Effect on Th2 Cytokines Expression and the Signal Transduction Mechanism in MC/9 Mast Cells by PRAL (MC/9 비만세포에서 행인(杏仁) 추출물의 Th2 cytokine 발현 억제 효과 및 신호전달 기전 연구)

  • Kang, Ki Yeon;Han, Jae Kyung;Kim, Yun Hee
    • The Journal of Pediatrics of Korean Medicine
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    • v.28 no.2
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    • pp.23-39
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    • 2014
  • Objectives PRAL (Prunus armniaca Linne Var) is a herbal formula in Oriental Medicine, known for its anti-inflammatory and anti-allergenic properties. However, its mechanism of action and the cellular targets have not yet been found enough. The purpose of this study is to investigate the effects of PRAL on Th2 cytokines expression in MC/9 mast cells. Methods The effect of PRAL was analyzed by ELISA, Real-time PCR, Western blot in MC/9 mast cells. mRNA levels of GM-CSF, IL-4, IL-5, IL-6, IL-13, TNF-${\alpha}$ were analyzed with Real-time PCR. Levels of IL-13, MIP-$1{\alpha}$ were measured using enzyme-linked immunosorbent assays (ELISA). NFAT, AP-1 and NF-${\kappa}B$ p65 were examined by Western blot analysis. Results PRAL inhibited GM-CSF, IL-4, IL-5, IL-6, IL-13, TNF-${\alpha}$ mRNA expression in a dose dependent manner. GM-CSF, IL-4, IL-5 mRNA expression were inhibited significantly in comparison to DNP-IgE control group at concentration of 100 ${\mu}g/ml$ and IL-6, IL-13, TNF-${\alpha}$ mRNA expression were inhibited at concentration of 50 ${\mu}g/ml$, 100 ${\mu}g/ml$. PRAL also inhibited the IL-13, MIP-$1{\alpha}$ production significantly in comparison to DNP-IgE control group in a dose dependent manner. IL-13 production was inhibited at a concentration of 200 ${\mu}g/ml$, 400 ${\mu}g/ml$ and MIP-$1{\alpha}$ was inhibited at a concentration of 100 ${\mu}g/ml$, 200 ${\mu}g/ml$, 400 ${\mu}g/ml$. Western blot analysis of transcription factors involving Th2 cytokines expression revealed prominent decrease of the mast cell specific transcription factors including NFAT-1, c-Jun as well as NF-${\kappa}B$ p65 but not NFAT-2 and c-Fos. Conclusion These results indicate that PRAL has the effect of suppressing Th2 cytokines production in the MC/9 mast cells. These data represent that PRAL potentiates therapeutic activities to the allergic disease by regulating Th2 cytokines in the MC/9 mast cells.

Effect of Calmodulin on Ginseng Saponin-Induced $Ca^{2+}$-Activated $Cl^{-}$ Channel Activation in Xenopus laevis Oocytes

  • Lee Jun-Ho;Jeong Sang-Min;Lee Byung-Hwan;Kim Jong-Hoon;Ko Sung-Ryong;Kim Seung-Hwan;Lee Sang-Mok;Nah Seung-Yeol
    • Archives of Pharmacal Research
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    • v.28 no.4
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    • pp.413-420
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    • 2005
  • We previously demonstrated the ability of ginseng saponins (active ingredients of Panax ginseng) to enhance $Ca^{2+}$-activated $Cl^{-}$ current. The mechanism for this ginseng saponin-induced enhancement was proposed to be the release of $Ca^{2+}$ from $IP_{3}-sensitive$ intracellular stores through the activation of PTX-insensitive $G\alpha_{q/11}$ proteins and PLC pathway. Recent studies have shown that calmodulin (CaM) regulates $IP_{3}$ receptor-mediated $Ca^{2+}$ release in both $Ca^{2+}-dependent$ and -independent manner. In the present study, we have investigated the effects of CaM on ginseng saponin-induced $Ca^{2+}$-activated $Cl^{-}$ current responses in Xenopus oocytes. Intraoocyte injection of CaM inhibited ginseng saponin-induced $Ca^{2+}$-activated $Cl^{-}$ current enhancement, whereas co-injection of calmidazolium, a CaM antagonist, with CaM blocked CaM action. The inhibitory effect of CaM on ginseng saponin-induced $Ca^{2+}$-activated $Cl^{-}$ current enhancement was dose- and time-dependent, with an $IC_{50} of 14.9\pm3.5 {\mu}M$. The inhibitory effect of CaM on saponin's activity was maximal after 6 h of intraoocyte injection of CaM, and after 48 h the activity of saponin recovered to control level. The half-recovery time was calculated to be $16.7\pm4.3 h$. Intraoocyte injection of CaM inhibited $Ca^{2+}$-induced $Ca^{2+}$-activated $Cl^{-}$ current enhancement and also attenuated $IP_{3}$-induced $Ca^{2+}$-activated $Cl^{-}$ current enhancement. $Ca^{2+}$/CaM kinase II inhibitor did not inhibit CaM-caused attenuation of ginseng saponin-induced $Ca^{2+}$-activated $Cl^{-}$ current enhancement. These results suggest that CaM regulates ginseng saponin effect on $Ca^{2+}$-activated $Cl^{-}$ current enhancement via $Ca^{2+}$-independent manner.

Inhibition of Nitric Oxide-induced Neuronal Apoptosis in PC12 Cells by Epigallocatechin Gallate

  • Jung, Ji-Yeon;Jeong, Yeon-Jin;Han, Chang-Ryoung;Kim, Sun Hun;Kim, Hyun-Jin;Lee, Ki-Heon;Park, Ha-Ok;Kim, Won-Jae
    • The Korean Journal of Physiology and Pharmacology
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    • v.9 no.4
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    • pp.239-246
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    • 2005
  • In the central nervous system, nitric oxide (NO) is associated with many pathological diseases such as brain ischemia, neurodegeneration and inflammation. The epigallocatechin gallate (EGCG), a major compound of green tea, is recognized as protective substance against neuronal diseases. This study is aimed to investigate the effect of EGCG on NO-induced cell death in PC12 cells. Administration of sodium nitroprusside (SNP), a NO donor, decreased cell viability in a dose- and time-dependent manner and induced genomic DNA fragmentation with cell shrinkage and chromatin condensation. EGCG diminished the decrement of cell viability and the formation of apoptotic morphologenic changes as well as DNA fragmentation by SNP. EGCG played as an antioxidant that attenuated the production of reactive oxygen species (ROS) by SNP. The cells treated with SNP showed downregulation of Bcl-2, but upregulation of Bax. EGCG ameliorated the altered expression of Bcl-2 and Bax by SNP. The release of cytochrome c from mitochondria into cytosol and expression of voltage -dependent anion channel (VDAC)1, a cytochrome c releasing channel in mitochondria, were increased in SNP-treated cells, whereas were attenuated by EGCG. The enhancement of caspase-9, preceding mitochondria-dependent pathway, caspase-8 and death receptor-dependent pathway, as well as caspase-3 activities were suppressed by EGCG. SNP upragulated Fas and Fas-L, which are death receptor assembly, whereas EGCG ameliorated the expression of Fas enhanced by SNP. These results demonstrated that EGCG has a protective effect against SNP-induced apoptosis in PC12 cells, through scavenging ROS and regulating the mitocondria- and death receptor-mediated signal pathway. The present study suggest that EGCG might be a natural neuroprotective substance.

Diazoxide Suppresses Mitochondria-dependent Apoptotic Signaling in Endothelial Cells Exposed to High Glucose Media (고농도 당에 노출된 혈관 내피세포에서 미토콘드리아 의존성 세포사멸 기작 활성화에 미치는 diazoxide의 억제 효과)

  • Jung, Hyun Ju;Kim, Tae Hyun;Woo, Jae Suk
    • Journal of Life Science
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    • v.29 no.12
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    • pp.1393-1400
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    • 2019
  • In the present study, we examined the effect of mitochondrial K+ channel opener diazoxide on the mitochondria-dependent apoptotic signaling in endothelial cells exposed to high glucose (HG) media. Endothelial cells derived from human umbilical veins were exposed to HG media containing 30 mM glucose, and the degree of apoptotic cell death associated with activation of the mitochondria-dependent apoptotic signaling pathway was determined. Exposure to HG media was seen to enhance apoptotic cell death in a time-dependent manner. In these cells, activation of caspases 3, 8, and 9 was observed, and while caspase-3 and -9 inhibitors suppressed the HG-induced apoptotic cell death, a caspase-8 inhibitor did not. The HG-treated cells exhibited disruption of mitochondrial membrane potential, formation of permeability transition pores, and cytosolic release of cytochrome c. Subsequently, diazoxide was seen to attenuate the HG-induced apoptotic cell death; caspase-9 activation was suppressed but caspase 8 was not. Diazoxide also suppressed the depolarization of mitochondrial membrane potential, the formation of mitochondrial permeability transition pores, and the release of cytochrome c. These effects were significantly inhibited by 5-hydroxydecanoate, a selective blocker of ATP-sensitive K+ channels (KATP). The present results demonstrate that diazoxide exhibits a beneficial effect to ameliorate HG-induced endothelial cell apoptosis. Opening the KATP could help preserve the functional integrity of mitochondria and provide an underlying mechanism to suppress HG-triggered apoptotic signaling.

Modulation of Cellular Immune Response by Inosiplex (Inosiplex에 의한 세포성 면역반응의 변화)

  • Lee, Hern-Ku;Lee, Jeong-Ho;Kim, Hak-Kun;Ha, Tai-You
    • The Journal of the Korean Society for Microbiology
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    • v.21 no.2
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    • pp.251-259
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    • 1986
  • This study was performed to assess the effect of inosiplex(ISP) on the resistance of mice Candida albicans infection, the migration of chicken leukocytes, the production of leukocyte migration inhibitory factor(LIF), and the cell-mediated immunity(CMI) to lepomin in multibacillary lepromatous leprosy patients. The treatment with ISP before or on the time of infection with C. albicans had no or deliterious effect, and treatment with ISP after infection had no effect on the recovery of C. albicans from the kidneys of mice. The migratory ability of chicken leukocytes and the production of LIF from splenocytes of mice were not affected by ISP treatment. However, ISP decreased the migration of chicken leukocytes in vitro, and this decrease was dose-dependent. The therapy of lepromatous leprosy patients with ISP for 10 or 30 days clearly showed the increase of the significant positive rate of Mitsuda skin test to lepromin. The immune recovery as a result of the therapy was found to be the best in the group of patients treated for 30 days. This results suggest that (1) the effect of ISP in renal candidiasis can vary depending on the time of treatment relative to infection, (2) ISP can primarily change the migratory ability of chicken leukocytes but does not affect the production of LIF in mice, and (3) the classical therapy combined with ISP can reinforce or restore the defences of lepromatous leprosy patients against Mycobacterium leprae.

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Cryptotanshinone inhibits TNF-α-induced LOX-1 expression by suppressing reactive oxygen species (ROS) formation in endothelial cells

  • Ran, Xiaoli;Zhao, Wenwen;Li, Wenping;Shi, Jingshan;Chen, Xiuping
    • The Korean Journal of Physiology and Pharmacology
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    • v.20 no.4
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    • pp.347-355
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    • 2016
  • Cryptotanshinone (CPT) is a natural compound isolated from traditional Chinese medicine Salvia miltiorrhiza Bunge. In the present study, the regulatory effect and potential mechanisms of CPT on tumor necrosis factor alpha ($TNF-{\alpha}$) induced lectin-like receptor for oxidized low density lipoprotein (LOX-1) were investigated. Human umbilical vein endothelial cells (HUVECs) were cultured and the effect of $TNF-{\alpha}$ on LOX-1 expression at mRNA and protein levels was determined by Real-time PCR and Western blotting respectively. The formation of intracellular ROS was determined with fluorescence probe $CM-DCFH_2-DA$. The endothelial ox-LDL uptake was evaluated with DiI-ox-LDL. The effect of CPT on LOX-1 expression was also evaluated with SD rats. $TNF-{\alpha}$ induced LOX-1 expression in a dose- and time- dependent manner in endothelial cells. $TNF-{\alpha}$ induced ROS formation, phosphorylation of $NF-{\kappa}B$ p65 and ERK, and LOX-1 expression, which were suppressed by rotenone, DPI, NAC, and CPT. $NF-{\kappa}B$ inhibitor BAY11-7082 and ERK inhibitor PD98059 inhibited $TNF-{\alpha}-induced$ LOX-1 expression. CPT and NAC suppressed $TNF-{\alpha}-induced$ LOX-1 expression and phosphorylation of $NF-{\kappa}B$ p65 and ERK in rat aorta. These data suggested that $TNF-{\alpha}$ induced LOX-1 expression via ROS activated $NF-{\kappa}B/ERK$ pathway, which could be inhibited by CPT. This study provides new insights for the anti-atherosclerotic effect of CPT.

Study on the effect of Buthus martensi Karsch extract on thrombosis and brian damage (전갈(全蝎) 추출물(抽出物)이 혈전증(血栓症), 전뇌허혈(全腦虛血) 및 뇌세포독성(腦細胞毒性)에 미치는 영향(影響))

  • Baek, Myung-Hyun;Hwang, Yong-Geun;Jeong, Ji-Cheon;Kang, Jeong-Jun;Kim, Sung-Hoon
    • The Journal of Dong Guk Oriental Medicine
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    • v.8 no.1
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    • pp.171-190
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    • 1999
  • This following is effect of Buthus martensi Karsch(BMK) extract on dextran-thrombus model, KCN-induced coma, cytotoxicity of brain etc. BMK extract significantly increased number of platelet and fibrogen and significantly shortened the prothrombin time as compared with control group treated with dextran. BMK extract didn't affect the changes of hematocrit as compared with control group treated with dextran. BMK extract induced a significant inhibition of human platelet aggregation induced by thrombin and ADP but did not affect human platelet aggregation induced by collagen. BMK extract showed a protective effect on pulmonary thrombosis induced by collagen and epinephrine. BMK extract prolonged the duration of KCN-induced coma and showed a protective effect on cytotoxicity of PC12 cells induced by amyloid ${\beta}$ protein(25-35) in a dose dependent manner. These results suggested that BMK extract might be usefully applied for prevention and treatment of thrombosis and brain damage.

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Numerical experiment on driftwood dynamics considering rootwad effect and wood collision

  • Kang, Taeun;Kimura, Ichiro;Onda, Shinichiro
    • Proceedings of the Korea Water Resources Association Conference
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    • 2019.05a
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    • pp.267-267
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    • 2019
  • Driftwood is one of serious problems in a river environment. In several countries, such as Indonesia, Japan, and Italy, the driftwood frequently appears in a river basin, and it can alter the channel bed, flow configuration by wood deposition and jam formation. Therefore, the studies related to driftwood have been actively conducted by many researchers to understand the mechanism of driftwood dynamics. In particular, wood motion by collision is one of the difficult issues in the numerical simulation because the calculation for wood collision requires significantly expensive calculation time due to small time step. Thus, this study conducted the numerical simulation in consideration of the wood motion by water flow and wood collision to understand the wood dynamics in terms of computation. We used the 2D (two-dimensional) depth-averaged velocity model, Nays2DH, which is a Eulerian model to calculate the water flow on the generalized coordinate. A Lagrangian type driftwood model, which expresses the driftwood as connected sphere shape particles, was employed to Nays2DH. In addition, the present study considered root wad effect by using larger diameter for a particle at a head of driftwood. An anisotropic bed friction was considered for the sliding motion dependent on stemwise, streamwise and motion directions. We particularly considered changeable draft at each particle and projection area by an angle between stemwise and flow directions to precisely reproduce the wood motions. The simulation results were compared with experimental results to verify the model. As a result, the simulation results showed good agreement with experimental results. Through this study, it would be expected that this model is a useful tool to predict the driftwood effect in the river flow.

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Effect of Psychological Variables on Decision-making Time in the Online Centipede Game (온라인 지네 게임으로 알아본 심리적 변인이 의사결정 시간에 미치는 영향)

  • Kim, Bora;Kwon, Young-Mi
    • Journal of Digital Convergence
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    • v.15 no.12
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    • pp.169-185
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    • 2017
  • Given that nowadays things get very fast due to the pervasive use of the Internet and mobile devices, decision-making time can be an important variable in the online economic decisions. Although in experimental and behavioral economics, measures like scores or earnings are usually preferred, this study argues that the time variable can be dealt with as a new decision outcome. Thus, by selecting some psychological factors presumably impactful in the online context (i.e., incidental emotions, psychological distances, and individual's impulsivity), this study tested their effect on decision time in the online centipede game. As a result, the mean decision time in the game was longer (1) in the happiness condition than in the anger condition and (2) in the friend condition than in the stranger condition. The people with attention difficulties spent a short time in the decision and the people who dislike complex problems spent a short time in explaining their decision. This study can contribute to the field as it used the decision time as the dependent variable and it tested the effect of psychological factors in the context of online decision-making. Future studies can be conducted in other online decision situations or by considering other psychological variables.

Blockade of Kv1.5 channels by the antidepressant drug sertraline

  • Lee, Hyang Mi;Hahn, Sang June;Choi, Bok Hee
    • The Korean Journal of Physiology and Pharmacology
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    • v.20 no.2
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    • pp.193-200
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    • 2016
  • Sertraline, a selective serotonin reuptake inhibitor (SSRI), has been reported to lead to cardiac toxicity even at therapeutic doses including sudden cardiac death and ventricular arrhythmia. And in a SSRI-independent manner, sertraline has been known to inhibit various voltage-dependent channels, which play an important role in regulation of cardiovascular system. In the present study, we investigated the action of sertraline on Kv1.5, which is one of cardiac ion channels. The effect of sertraline on the cloned neuronal rat Kv1.5 channels stably expressed in Chinese hamster ovary cells was investigated using the whole-cell patch-clamp technique. Sertraline reduced Kv1.5 whole-cell currents in a reversible concentration-dependent manner, with an $IC_{50}$ value and a Hill coefficient of $0.71{\mu}M$ and 1.29, respectively. Sertraline accelerated the decay rate of inactivation of Kv1.5 currents without modifying the kinetics of current activation. The inhibition increased steeply between -20 and 0 mV, which corresponded with the voltage range for channel opening. In the voltage range positive to +10 mV, inhibition displayed a weak voltage dependence, consistent with an electrical distance ${\delta}$ of 0.16. Sertraline slowed the deactivation time course, resulting in a tail crossover phenomenon when the tail currents, recorded in the presence and absence of sertraline, were superimposed. Inhibition of Kv1.5 by sertraline was use-dependent. The present results suggest that sertraline acts on Kv1.5 currents as an open-channel blocker.