• Journal of Microbiology and Biotechnology
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• 제22권5호
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• pp.622-627
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• 2012

Mast cells and basophils are important effector cells in immunoglobulin-E (IgE)-mediated allergic reactions. Using the human basophilic KU812F cells, we assessed the inhibitory effects of 6-methoxyluteolin, isolated from Chrysanthemum zawadskii, in the $Fc{\varepsilon}RI$-mediated allergic reaction. We determined that 6-methoxyluteolin inhibited anti-$Fc{\varepsilon}RI$ ${\alpha}$ chain antibody (CRA-1)-induced histamine release, as well as elevation of intracellular calcium concentration $[Ca^{2+}]_i$ in a dose-dependent manner. Moreover, the inhibitory effects of 6-methoxyluteolin on the cell surface expression and the mRNA level of the $Fc{\varepsilon}RI$ ${\alpha}$ chain were determined by flow cytometric analysis and reverse transcription-polymerase chain reaction (RT-PCR), respectively. Therefore, these results show that 6-methoxyluteolin is a potent inhibitor of histamine release and calcium influx via down-regulation of the $Fc{\varepsilon}RI$ ${\alpha}$ chain.

• BMB Reports
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• 제47권7호
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• pp.393-398
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• 2014

The role of Bax inhibitor-1 (BI-1) in the protective mechanism against apoptotic stimuli has been studied; however, as little is known about its role in death receptor-mediated cell death, this study was designed to investigate the effect of BI-1 on Fas-induced cell death, and the underlying mechanisms. HT1080 adenocarcinoma cells were cultured in high concentration of glucose media and transfected with vector alone (Neo cells) or BI-1-vector (BI-1 cells), and treated with Fas. In cell viability, apoptosis, and caspase-3 analyses, the BI-1 cells showed enhanced sensitivity to Fas. Fas significantly decreased cytosolic pH in BI-1 cells, compared with Neo cells, and this decrease correlated with BI-1 oligomerization, mitochondrial $Ca^{2+}$ accumulation, and significant inhibition of sodium-hydrogen exchanger (NHE) activity. Compared with Neo cells, a single treatment of BI-1 cells with the NHE inhibitor EIPA or siRNA against NHE significantly increased cell death, which suggests that the viability of BI-1 cells is affected by the maintenance of intracellular pH homeostasis through NHE.

• 대한전기학회논문지:전력기술부문A
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• 제48권8호
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• pp.1046-1053
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• 1999

The musculotendon model is presented to show the declines in muscle force and shortening velocity during muscle fatigue due to the repeated functional electrical stimulation (FES). It consists of the nonlinear activation and contraction dynamics including physiological concepts of muscle fatigue. The activation dynamics represents $Ca^{2+}$ binding and unbinding mechanism with troponins of cross-bridges in sarcoplasm. It has the constant binding rate or activation time constant and two step nonlinear unbinding rate or inactivation time constant. The contraction dynamics is the modified Hill type model to represent muscle force - length and muscle force - velocity relations. A muscle fatigue profile as a function of the intracellular acidification, pH is applied into the contraction dynamics to represent the force decline. The computer simulation shows that muscle force and shortening velocity decline in stimulation time. And we validate the model. The model can predicts the proper muscle force without changing its parameters even when existing the estimation errors of the optimal fiber length. The change in the estimate of the optimal fiber length has an effect only on muscle time constant in transient period not on the tetanic force in the steady-state and relaxation periods.

• Animal cells and systems
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• 제7권1호
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• pp.57-62
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• 2003

Flounder B lymphocytes isolated from different tissues were studied in terms of cell proliferation, apoptosis and the effects of cortisol on these processes. B lymphocytes, isolated from the flounder head kidney and spleen, were characterized by higher proliferation and lower intracellular calcium ($Ca^2$) response to lgcrosslinking compared with peripheral blood B lymphocytes. Cortisol induced high levels of apoptosis (150% of control levels) in peripheral blood B lymphocytes, in combination with a stimulatory LPS signal. Head kidney and to a lesser extent spleen B lymphocytes, although less sensitive than their equivalent in peripheral blood, underwent cortisol-induced apoptosis irrespective of extra stimulation up to 142% of control levels. Also proliferation with and without LPS stimulation was suppressed by cortisol (compared to plasma values measured during stress conditions) that is effective in inducing a significant increase in apoptosis in all three populations of B-cells, suggesting that cortisol may be important for immunoregulation in both stressed and non-stressed conditions. This implies possible severe impact of stress on lymphocyte development and activity, Different sensitivity of B-cells to the corticosteroid, with respect to developmental stage and activity, may prevent excessive and long lasting depletion of B-lymphocytes.

• 대한한방부인과학회지
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• 제25권3호
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• pp.1-15
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• 2012

Objectives: The purpose of this study was to investigate the effects of Chaenomelis Fructus Herba Water Extract(CF) on the production of inflammatory mediators in RAW 264.7 cell mouse macrophages stimulated with LPS. Methods: We have not examined effect of CF on the cell viability of RAW 264.7 cell until we investigated effects of CF on LPS-induced productions of NO, Ca and various cytokines in RAW 264.7 cell. And when p-value is below 0.05, it is judged to have the significant difference statistically(P<0.05). Results: 1. CF increased the cell viability in the RAW 264.7 cell at the density of 25, 50, 100 and 200 ${\mu}g/ml$. 2. CF inhibited significantly increasing the production of NO in LPS-induced RAW 264.7 cell at the density of 25, 50, 100 and 200 ${\mu}g/ml$. 3. CF inhibited significantly increasing the production of Intracellular Ca in LPS-induced RAW 264.7 cell at the density of 25, 50, 100 and 200 ${\mu}g/ml$. 4. CF inhibited significantly the IL-2, IL-10, IL-12p70, TNF-${\alpha}$, GM-CSF, M-CSF, LIF and VEGF of the RAW 264.7 cell induced by LPS at the density of 25, 50, 100 and 200 ${\mu}g/ml$. 5. CF inhibited significantly the IL-4 at the density of 25, 50 ${\mu}g/ml$, the IL-5, IL-15 and MIG at the density of 25, 50 and 200 ${\mu}g/ml$ and IFN-${\gamma}$ at the density of 25, 100 ${\mu}g/ml$ respectively in the RAW 264.7 cell increased by LPS. Conclusions: CF inhibited significantly increasing IL-2, IL-10, IL-12p70, TNF-${\alpha}$, GM-CSF, M-CSF, LIF, VEGF, NO and Ca in LPS-induced RAW 264.7 cell at the density of more than 25 ${\mu}g/ml$ without causing the toxicity. These results signify that CF has antiinflammatory effect on controlling the over inflammatory reaction by the RAW 264.7 cell.

• Journal of Applied Biological Chemistry
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• 제65권4호
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• pp.239-245
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• 2022

지혈이 일어나는 과정에서 혈소판의 정상적인 활성화가 중요하지만, 혈소판의 과도하거나 비정상적인 활성화는 뇌졸중, 죽상동맥 경화증 및 혈전증과 같은 심혈관 질환을 유발할 수 있다. 따라서, 혈소판 활성화를 조절하거나 억제할 수 있는 새로운 물질의 발견은 심혈관 질환의 예방 및 치료에 도움이 될 수 있다. Artemether는 Artemisia annua의 유효성분으로 알려진 artemisinin의 유도체로서 말라리아 치료에 효과적이라고 보고된 바 있고, 항산화 및 대사 효소 억제를 통해 기능하는 것으로 알려져 있다. 그런데, 혈소판 활성화 및 응집에 있어서의 artemether의 역할과 collagen으로 유도한 사람 혈소판에서 artemether의 작용기전은 현재까지 알려진 바가 없다. 본 연구는 artemether가 collagen에 의해 유도된 혈소판 활성화와 혈전 형성에 어떤 영향을 미치는 지 연구하였다. 그 결과, cAMP level이 artemether에 의해 유의하게 증가되었고, cAMP-의존성 kinase의 기질인 VASP 및 IP₃R이 인산화되었다. Artemether에 의한 IP₃R 인산화는 세포질 내로의 Ca²⁺ 동원을 억제하였고, 인산화된 VASP는 혈소판 막에 위치한 αIIb/β₃ 불활성화를 일으켜 fibrinogen 결합을 억제하였다. 결과적으로, artemether는 thrombin으로 유도한 fibrin clot의 형성을 억제하였다. 따라서, 우리는 artemether가 과도한 혈소판 활성화 및 혈전 형성으로 인한 심혈관 질환의 효과적인 예방 및 치료제로 작용할 수 있음을 제안한다.

• 한국응용과학기술학회지
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• 제34권3호
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• pp.536-544
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• 2017

생태계 교란 식물로 알려진 가시박 추출물을 활용하여 생리 활성 효과를 알아보고, 기능성 화장품 소재로써의 활용 가능성을 확인하고자 하였다. 본 실험 방법으로는, 총 폴리페놀 함량, 총 플라보노이드 함량을 측정하고, DPPH radical 소거능, 세포 내 ROS 생성 억제, NO 및 COX-2 발현 억제 효과를 평가하고자 하였다. 본 실험 결과, 가시박 추출물의 21 mg/g, 0.72 mg/g의 총 폴리페놀과 총 플라보노이드 함량을 확인하였으며, 높은 라디칼 소거 활성을 통한 항산화 활성을 확인 하였다. RAW 264.7세포와 HDF세포에서 $100{\mu}g/mL$ 농도까지 유의한 세포 독성은 확인되지 않았으며, HDF세포에서의 농도 의존적인 ROS 생성 억제와 RAW 264.7 세포에서의 높은 NO 생성 억제와 COX-2 단백질 발현 억제 효과를 확인 하였다. 이와 같은 결과를 통하여 항산화 효과가 우수하고, 세포 내 ROS 생성 억제와 NO 생성 억제, COX-2 단백질 발현 억제 활성을 통하여 항산화 및 항염증의 효과를 가진 기능성 화장품 소재로써의 활용 가능성을 확인 하였다.

• 대한수의학회지
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• 제38권1호
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• pp.29-42
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• 1998

$Mg^{2+}$ is one of the most abundant divalent cations in mammalian body(0.2~1.0mM) and the important physiological roles are : first, the cofactor of many enzyme activities, second, the regulator of glycolysis and DNA synthesis, third, the important role of bioenergetics by regulating of phosphorylation, fourth, the influence of cardiac metabolism and function. In this work we have investigated the regulation of the $Mg^{2+}$ induced by ${\alpha}_1-adrenoceptor$ stimulation in perfused guinea pig hearts and isolated myocytes. The $Mg^{2+}$ content of the perfusate or the supernatant was measured by atomic absorbance spectrophotometry. The elimination of $Mg^{2+}$ in the medium increased the force of contraction of right ventricular papillary muscles, and the left ventricular pressure. Phenylephrine also enhanced the force of contraction in the presence of $Mg^{2+}-free$ medium. ${\alpha}_1-Agonists$ such as phenylephrine and methoxamine were found to induce $Mg^{2+}$ efflux in both perfused hearts and myocytes. These effects were blocked by prazosin, an ${\alpha}_1-adrenoceptor$ antagonist. The $Mg^{2+}$ influx could also be induced by phenylephrine and R59022, a diacylglycerol kinase inhibitor. In the presence of protein kinase C(PKC) inhibitors, phenylephrine produced an increase in $Mg^{2+}$ efflux from perfused hearts. Furthermore, $Mg^{2+}$ efflux by phenylephrine was amplified by phorbol 12-myristate 13-acetate(PMA). This enhancement of $Mg^{2+}$ efflux by PMA was blocked by prazosin in perfused hearts. By contrast, the $Mg^{2+}$ influx could be induced by verapamil, nifedipine, ryanodine in perfused hearts, but not in myocytes. $W^7$, a $Ca^{2+}$/calmodulin antagonist, completely blocked the phenylephrine-induced $Mg^{2+}$ efflux in perfused hearts. In conclusion, $Mg^{2+}$ is responsible for the cardiac activity associated with ${\alpha}_1-adrenoceptor$ stimulation. The mobilization of $Mg^{2+}$ is decreased or increased by ${\alpha}_1-adrenoceptor$ stimulation in guinea pig hearts. These responses may be related specifically to the respective pathways of signal transduction. A decrease in $Mg^{2+}$ efflux by ${\alpha}_1-adrenoceptor$ stimulation in hearts can be through PKC dependent and intracellular $Ca^{2+}$ levels.

• Journal of Microbiology and Biotechnology
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• 제7권4호
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• pp.229-236
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• 1997

A gene, $phbC_{2.4.1}$ encoding poly-3-hydroxybutyric acid (PHB) synthase of Rhodobacter sphaeroides 2.4.1 was cloned by employing heterologous expression in Escherichia coli. R. sphaeroides chromosomal DNA partially digested with MboI was cloned in pUC19 followed by mobilization into E. coli harbouring $phbA,B_{AC}$ in pRK415, which code for ${\beta}$-ketothiolase and acetoacetyl CoA reductase of Alcaligenes eutrophus, respectively. Two E. coli clones carrying R. sphaeroides chromosomal fragment of $phbC_{2.4.1}$ in pUC19 were selected from ca. 10,000 colonies. The PHB-producing colonies had an opaque white appearance due to the intracellular accumulation of PHB. The structure of PHB produced by the recombinant E. coli as well as from R. sphaeroides 2.4.1 was confirmed by [$H^{+}$]-nuclear magnetic resonance (NMR) spectroscopy. Restriction analysis of the two pUC19 clones revealed that one insert DNA fragment is contained as a part of the other cloned fragment. An open reading frame of 601 amino acids of $phbC_{2.4.1}$ with approximate M.W. of 66 kDa was found from nucleotide sequence determination of the 2.8-kb SaiI-PstI restriction endonuclease fragment which had been narrowed down to support PHB synthesis through heterologous expression in the E. coli harbouring $phbA,B_{AC}$. The promoter (s) of the $phbC_{2.4.1}$ were localized within a 340-bp DNA region upstream of the $phbC_{2.4.1}$ start codon according to heterologous expression analysis.

• Molecules and Cells
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• 제42권2호
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• pp.143-150
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• 2019

Chronic neuropathic pain is one of the primary causes of disability subsequent to spinal cord injury. Patients experiencing neuropathic pain after spinal cord injury suffer from poor quality of life, so complementary therapy is seriously needed. Dehydrocorybulbine is an alkaloid extracted from Corydalis yanhusuo. It effectively alleviates neuropathic pain. In the present study, we explored the effect of dehydrocorybulbine on neuropathic pain after spinal cord injury and delineated its possible mechanism. Experiments were performed in rats to evaluate the contribution of dehydrocorybulbine to P2X4 signaling in the modulation of pain-related behaviors and the levels of pronociceptive interleukins and proteins after spinal cord injury. In a rat contusion injury model, we confirmed that chronic neuropathic pain is present on day 7 after spinal cord injury and P2X4R expression is exacerbated after spinal cord injury. We also found that administration of dehydrocorybulbine by tail vein injection relieved pain behaviors in rat contusion injury models without affecting motor functions. The elevation in the levels of pronociceptive interleukins ($IL-1{\beta}$, IL-18, MMP-9) after spinal cord injury was mitigated by dehydrocorybulbine. Dehydrocorybulbine significantly mitigated the upregulation of P2X4 receptor and reduced ATP-evoked intracellular $Ca^{2+}$ concentration. Both P2XR and dopamine receptor2 agonists antagonized dehydrocorybulbine's antinociceptive effects. In conclusion, we propose that dehydrocorybulbine produces antinociceptive effects in spinal cord injury models by inhibiting P2X4R.