• Journal of Ginseng Research
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• 제22권2호
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• pp.126-132
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• 1998

In the present study, we examined effects of ginseng saponins (ginsenosides) on pp60c-src protein tyrosine kinase (PTK) activity, intracellular calcium concentration ([$Ca^{2+}$]i), and cell proliferation in NIH3T3 cells. Eight different ginsenosides [ginsenoside-Rb1 (G-$Rb_1$), -$Rb_2$, -Rc, -Rd, -Re, -Rf, -$Rg_1$, -$Rg_2$) and ginseng total saponin (GTS) were used for these experiments. All ginsenosides and GTS tested stimulated the activation of $pp60^{c-src}$ kinase, and especially G-$Rb_1$,-Rd,-$Rg_1$, and -$Rg_1$ showed a higher stimulatory effect than others at 16.7 $\mu\textrm{g}$/ml of ginsenosides with a 18 hr-incubation, increasing the activity by 4.5, 3.5, 3.5, and 3.0-fold, respectively, over that of untreated control. In addition, both G-Rd and -$Rg_2$)Rg2 increased ($Ca^{2+}$), to 202 and 334 nM, respectively, about 2-3-fold above the basal level within 7min at 250 $\mu\textrm{g}$/yml of ginsenosides. The increases of ($Ca^{2+}$), were eliminated by Pretreatment of EGTA, an extracellular calcium chelator, suggtasting that they result from an influx of calcium ion from extracellular medium rather than an efflux from intracellular calcium store, endoplasmic reticulum (ER). All ginsenosides studied enhanced cell proliferation to 1.2-1.4-fold over that of untreated control at 5~250 $\mu\textrm{g}$/ml of concentrations. Interestingly the promotion of cell proliferation by ginsenosides corresponded with the activation of c-src kinase, which is an early step in the mitogenic signaling cascade. Taken together, we suggest that some ginsenosides may lead to cellProliferation via the activation of cellular signal transduction Pathway involving $pp60^{c-src}$ kinase.

• Journal of Korean Dental Science
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• 제10권2호
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• pp.45-52
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• 2017

Calcium has versatile roles in diverse physiological functions. Among these functions, intracellular $Ca^{2+}$ plays a key role during the secretion of salivary glands. In this review, we introduce the diverse cellular components involved in the saliva secretion and related dynamic intracellular $Ca^{2+}$ signals. Calcium acts as a critical second messenger for channel activation, protein translocation, and volume regulation, which are essential events for achieving the salivary secretion. In the secretory process, $Ca^{2+}$ activates $K^+$ and $Cl^-$ channels to transport water and electrolyte constituting whole saliva. We also focus on the $Ca^{2+}$ signals from intracellular stores with discussion about detailed molecular mechanism underlying the generation of characteristic $Ca^{2+}$ patterns. In particular, inositol triphosphate signal is a main trigger for inducing $Ca^{2+}$ signals required for the salivary gland functions. The biphasic response of inositol triphosphate receptor and $Ca^{2+}$ pumps generate a self-limiting pattern of $Ca^{2+}$ efflux, resulting in $Ca^{2+}$ oscillations. The regenerative $Ca^{2+}$ oscillations have been detected in salivary gland cells, but the exact mechanism and function of the signals need to be elucidated. In future, we expect that further investigations will be performed toward better understanding of the spatiotemporal role of $Ca^{2+}$ signals in regulating salivary secretion.

• Natural Product Sciences
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• 제12권4호
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• pp.175-192
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• 2006

Screening for the cytotoxicity from plant origin is the first stage for anti-cancer drug development. A variety of terpenoids with exomethylene, epoxide, allyl, $\alpha,\beta-unsaturated$ carbonyl, acetylenes, and $\alpha-methylene-\gamma-lactone$ induces apoptosis and/or differentiation as well as cytotoxicity through the ROS signal transduction pathways. These are found among monoterpenes, sesquiterpenes, triterpenes, flavonoids, coumarins, diarylheptanoids, and even organosulfuric compounds. The most essential characteristics of natural cytotoxic substances is to possess the strong electrophilicity that is susceptible to nucleophilic biomolecules in the cell. Thiol-reductants and superoxide dismutase can block or delay apoptosis. Thus, ROS and the resulting cellular redox-potential changes can be parts of the signal transduction pathway during apoptosis. Disturbance of the balance of oxireduction by the pigment of natural quinones also caused the induction of the differentiation and apoptosis. Saponins with the cytotoxicity are restricted to their monodesmosides, rather than to bisdesmosides. Those saponins exhibited calcium ion-mediated apoptosis in addition to cytotoxicity whereas they showed also differentiation without extracellular calcium ion. The properties on cytotoxicity, apoptosis, and differentiation were assumed to depend on resultant oxidative stress to the cells. In this review, we describe a spectrum of cytotoxic compounds with various action mechanisms.

• Molecular Medicine Reports
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• 제20권3호
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• pp.2476-2483
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• 2019

Atopic dermatitis (AD ) is an inflammatory skin disorder caused by immunological dysregulation and genetic factors. Whether the expression levels of cytokine and skin barrier protein were altered by S100 calcium binding protein A8 (S100A8) and S100A9 in human keratinocytic HaCaT cells was examined in the present study. Alterations of cytokine expression were examined by ELI SA following treatment with S100A8/9 and various signal protein-specific inhibitors. Activation of the mitogen activated protein kinase (MAPK) pathway and nuclear factor (NF)-κB was evaluated by using western blotting and an NF-κB activity test, respectively. The expression levels of interleukin (IL )-6, IL- 8 and monocyte chemoattractant protein-1 increased following treatment with S100A8 and S100A9, and the increase was significantly blocked by specific signaling pathway inhibitors, including toll-like receptor 4 inhibitor (TLR 4i), rottlerin, PD98059, SB203580 and BAY-11-7085. Extracellular signal-regulated kinase (ER K) and p38 MAPK pathways were activated in a time-dependent manner following treatment with S100A8 and S100A9. Phosphorylation of ER K and p38 MAPK were blocked by TLR 4i and rottlerin. S100A8 and S100A9 induced translocation of NF-κB in a time-dependent manner, and the activation of NF-κB was inhibited by TLR 4i, rottlerin, PD98059 and SB203580. In addition, S100A8 and S100A9 decreased the expression of skin barrier proteins, filaggrin and loricrin. These results may help to elucidate the pathogenic mechanisms of AD and develop clinical strategies for controlling AD.

• Biomolecules & Therapeutics
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• 제18권2호
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• pp.152-158
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• 2010

Melanin concentrating hormone is a neuropeptide highly expressed in the brain that regulates several physiological functions mediated by receptors in the G-protein coupled receptor family, especially plays an important role in the complex regulation of energy balance and body weight mediated by the melanin concentrating hormone receptor subtype 1 (MCH1). Compelling pharmacological evidence implicating MCH1 signaling in the regulation of food intake and energy expenditure has generated a great deal of interest by pharmaceutical companies as MCH1 antagonists may have potential therapeutic benefit in the treatment of obesity and metabolic syndrome. Although fluorescence-based calcium mobilization assay platform has been one of the most widely accepted tools for receptor research and drug discovery, fluorescence interference and shallow assay window limit their application in high throughput screening and have led to a growing interest in alternative, luminescence-based technologies. Herein, a luminescence-based functional assay system for the MCH1 receptor was developed and validated with the mitochondrial targeted aequorin. Aequorin based functional assay system for MCH1 presented excellent Z' factor (0.8983) and high signal-to-noise ratio (141.9). The nonpeptide MCH1 receptor antagonist, SNAP 7941 and GSK 803430, exhibited $IC_{50}$ values of 0.62 ${\pm}$ 0.11 and 12.29 ${\pm}$ 2.31 nM with excellent correlation coefficient. These results suggest that the aequorin based assay system for MCH1 is a strong alternative to the traditional GPCR related tools such as radioligand binding experiments and fluorescence functional determinations for the compound screening and receptor research.

• Journal of Plant Biotechnology
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• 제6권4호
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• pp.259-264
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• 2004

The present study describes the ameliorating effect of $Ca^{++}\;on\;Cd^{++}$ toxicity on the germination, early growth of mungbean seedlings, nitrogen assimilation enzyme. s-nitrate reductase (NR), nitrite reductase (NIR), anti-oxidant enzymes (POD, CAT and SOD) and on the accumulation of hydrogen peroxide and sulphydryls. $Cd^{++}$ inhibited seed germination and root and shoot length of seedlings. While NR activity was down- regulated, the activities of NIR, POD and SOD were up- regulated with $Cd^{++}$ treatment. $Cd^{++}$ treatment also increased the accumulation of sulphydryls and peroxides, which is reflective of increased thiol rich proteins and oxidative stress. $Ca^{++}$ reversed the toxic effects of $Cd^{++}$ on germination and on early growth of seedlings as well as on the enzyme activities, which were in turn differentially inhibited with a combined treatment with calcium specific chelator EGTA. The results indicate that the external application of $Ca^{++}$ may increase the tolerance capacity of plants to environmental pollutants by both up and down regulating metabolic activities. Abbreviations: $Cd^{++}= cadmium,\;Ca^{++} = calcium$, NR= nitrate reductase, NIR=nitrite reductase, POD = peroxidse, SOD= superoxide dismutase, CAT= catalase, EGTA= ethylene glycol-bis( $\beta-aminoethyl ether$)-N,N,N,N-tetraacetic acid.

• BMB Reports
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• 제46권12호
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• pp.600-605
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• 2013

Interplay between calcium ions ($Ca^{2+}$) and reactive oxygen species (ROS) delicately controls diverse pathophysiological functions of vascular smooth muscle cells (VSMCs). However, details of the $Ca^{2+}$ and ROS signaling network have been hindered by the absence of a method for dual measurement of $Ca^{2+}$ and ROS. Here, a real-time monitoring system for $Ca^{2+}$ and ROS was established using a genetically encoded hydrogen peroxide indicator, HyPer, and a ratiometric $Ca^{2+}$ indicator, fura-2. For the simultaneous detection of fura-2 and HyPer signals, 540 nm emission filter and 500 nm~ dichroic beamsplitter were combined with conventional exciters. The wide excitation spectrum of HyPer resulted in marginal cross-contamination with fura-2 signal. However, physiological $Ca^{2+}$ transient and hydrogen peroxide were practically measurable in HyPer-expressing, fura-2-loaded VSMCs. Indeed, distinct $Ca^{2+}$ and ROS signals could be successfully detected in serotonin-stimulated VSMCs. The system established in this study is applicable to studies of crosstalk between $Ca^{2+}$ and ROS.

• 한국식생활문화학회지
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• 제37권3호
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• pp.248-255
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• 2022

Spinach (Spinacia oleracea L.), a green leafy vegetable, is well known as a functional food due to its biological activities. Vascular calcification is associated with several disease conditions including atherosclerosis, diabetes, and chronic kidney disease (CKD), and is known to raise the risk of cardiovascular diseases related morbidity and mortality. However, there are no previous studies that have investigated the effects of fermented spinach exract (FSE) against aortic and its underlying mechanisms. Therefore, this study investigated the effects and action of possible mechanisms of FSE on inorganic phosphate (PI)-induced vascular calcification in ex vivo mouse aortic rings. PI increased vascular calcification through calcium deposition in ex vivo aortic rings. FSE inhibited calcium accumulation and osteogenic key marker, runt-related transcription factor 2 (Runx2), and bone Morphogenetic Protein 2 (BMP-2) protein expression in ex vivo aortic rings. And, FSE inhibited PI-induced extracellular signal-regulated kinase (ERK) and p38 phosphorylation in ex vivo aortic rings. These results show that FSE can prevent vascular calcification which may be a crucial way for the prevention and treatment of vascular disease association with vascular calcification.

• 한국수정란이식학회지
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• 제24권4호
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• pp.237-247
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• 2009

Melatonin (N-acetyl-5-methoxytryptamine) is the major neurohormone secreted during the night by the vertebrate pineal gland. The circadian pattern of pineal melatonin secretion is related to the biological clock within the suprachiasmatic nucleus (SCN) of the hypothalamus in mammals. The SCN coordinates the body's rhythms to the environmental light-dark cycle in response to light perceived by the retina, which acts mainly on retinal ganglion cells that contain the photopigment melanopsin. Calbindin-D9k (CaBP-9k) is a member of the S100 family of intracellular calcium- binding proteins, and in this review, we discuss the involvement of melatonin and CaBP-9k with respect to calcium homeostasis and apoptotic cell death. In future studies, we hope to provide important information on the roles played by CaBP-9k in cell signal transduction, cell proliferation, and $Ca^{2+}$ homeostasis in vivo and in vitro.

• 한국발생생물학회지:발생과생식
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• 제12권3호
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• pp.267-274
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• 2008

포배의 분화는 배아의 착상에 있어 핵심적인 단계로 배아 자체 또는 생식수관에서 유래하는 조절요인의 조절을 받는다. 이들 조절요인과 포배와의 순차적인 신호의 주고 받음은 분화의 중요한 단계로 인식되고 있다. 한편, 포배기 때 자유 칼슘을 통한 신호전달경로가 포배의 분화에 중요한 축의 하나로 제안되어 왔다. Concanavalin A(Con A)가 포배의 자유 칼슘 농도 증감을 유도한다는 것을 밝혀졌으나, 포배 내 자유 칼슘 농도를 변형시켜 부화와 그 이후의 발생을 촉진하는 것으로 알려진 heparin-binding epidermal growth factor-like growth factor(HB-EGF)와는 달리 팽창 이후의 부화를 억제하였다. 따라서 본 연구에서는 착상과정에서 중요한 역할을 하는 것으로 알려진 prostaglandin $E_2(PGE_2)$가 포배의 분화에 관여하는지를 Con A와 연계하여 알아보았다. Con A는 그 처리 시간에 관계없이 1시간 처리군 그리고 계속처리군에서 팽창은 촉진하고 부화는 유의하게 억제하였다. 특히 계속처리군에서 부화율이 1시간 처리군에 비하여 유의하게 감소하였다. 또한, $PGE_2$도 포배 내 자율 칼슘 농도를 증가시켰으나 팽창과 부화를 촉진하지 않았다. 또한, $10{\mu}m\;PGE_2$ 농도에서는 부화가 억제되는 경향을 보였다. 그러나 흥미롭게도 $PGE_2$는 Con A가 처리된 포배의 부화를 촉진하였다. Con A를 전처리한 포배에 $PGE_2$를 처리할 경우 포배 내 자유 칼슘의 농도 증감이 진행됨을 공촛점현미경을 이용하여 분석할 수 있었다. 이러한 결과는 신호물질에 의해 유도된 자유 칼슘 농도의 증감이 신호물질에 따른 각기 다른 칼슘 매개로 활성화되는 신호경로를 조절하는 것을 추정할 수 있다. 또한, 순차적 신호물질 조절에 의한 자유 칼슘의 농도 증감이 포배의 분화에 있어 중요함을 제안한다.