• Journal of Life Science
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• v.20 no.7
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• pp.1093-1099
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• 2010

Little is known about the cardiovascular effects of Lycopene, an anti-cancer and anti-oxidative agent. In this study, we executed a series of experiments with vascular endothelial cells to disclose the cardiovascular functions of lycopene. From our in vitro experiments, lycopene was determined to act as a stimulant to induce endothelial cell proliferation and migration. In addition, lycopene was shown to inhibit lipopolysaccharide (LPS)-induced adhesion of THP-1 leukocytes to endothelial cells, as well as activating mitogen activated protein kinase (MAPK) family members, ERK, JNK and p38 MAPK. Both ERK and p38 MAPK were involved in lycopene-induced cell proliferation, while JNK was involved in lycopene-dependent cell migration. Taken together, lycopene activates MAPK family members which regulate cell proliferation and migration. Lycopene differentially blocks LPS-dependent adhesion for THP-1 to endothelial cells, indicating that lycopene is likely to regulate a variety of vascular functions.

• Korean Journal of Animal Reproduction
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• v.19 no.1
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• pp.15-34
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• 1995

1970년말부터 뇌하수체 성선자극호르몬(gonadotropic hormone ; GTH)의 유전자 구조(FSH$\beta$, LH$\beta$ 및 공동의 $\alpha$쇄)가 다양한 종에서 밝혀지기 시작하였으나 이러한 유전자의 조직/세포 특이적 분비양식과 세포외 신호에 의한 조절양식은 정확히 밝혀져 있지 않다. 그러나 최근 들어 형질전환 맞추스 제작기법에 의해 $\alpha$쇄 유전자 상류에 세포특이적 발현을 조절하는 특이부위가 존재함이 보고됨을 시작, FSH$\beta$ 및 LH$\beta$쇄 유전자발현을 조절하는 특이부위 또한 가까운 시기내 발견되리라 기대된다. 한편, 성선자극 호르몬 방출호르몬(GnRH), 스테로이드 호르몬 및 여러 결합단백질과 같은 세포의 신호는 각기 다른 신호전달체계를 통하여 GTH유전자 발현을 일으킨다. 또한 뇌하수체에서도 그 존재가 확인된 전사인자들 (cFos, cJun)과 미지의 인자들은 상호간에 다양한 이량체를 형성하여 유전자 발현을 조절하는 각 특이부위에 결합함으로써 전사단계에서의 다양한 제어가 존재함이 밝혀지고 있으며 이러한 유전자상의 특이발현영역과 세포의 신호별 전사인자에 관한 연구는 번식에 있어 중요한 성선자극호르몬에 관한 분자수준의 조절기전을 밝혀내리라 기대되어진다.

• Journal of Plant Biology
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• v.38 no.1
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• pp.87-93
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• 1995

For understanding physiological nature of phototaxis in Synechocystis sp. PCC 6803 PTX(S. 6803 PTX), we examined the effects of some metabolic inhibitors and cation ionophore on the phototactic movement. In the presence of DCMU, which blocks the photosynthetic electron transport just after photosystem II acceptor, there was no inhibitory effect on the phototaxis up to $100\;\mu\textrm{M}$. Instead, the respiratory electron chain inhibitor such as sodium azide dramatically impaired the phototaxis in S. 6803 PTX. These observations indicate that the phototaxis is linked not to photo-phosphorylation, but to respiratory phosphorylation. When the cells were treated with un couplers such as CCCP or DNP, which dissipate the electrochemical gradient of proton($\Delta\mu_{H}+$) across the cytoplasmic membrane, these chemicals did not affect phototaxis. In contrast, when cells were treated with DCCD or NBD which deprive cells of A TP but leave $\Delta\mu_{H}+$ intact across the membrane, the phototactic movement was severly reduced. These results imply that ATP production, not proton motive force, is involved in the phototactic movement in this organism as a driving motive force. The application of specific calcium ionophore A23187 strongly impaired positive phototaxis. Calcium fluxes should be engaged in the sensory trans-duction of phototactic orientation. Finally, when ethionine was supplimented to culture media, the photomovement of this organism was inhibited. This implies that methylation/demethylation mechanism controls the process of phototaxis in S. 6803 PTX like chemotaxis in E. coli and Salmonella typhimurium.murium.

• Development and Reproduction
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• v.6 no.2
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• pp.77-82
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• 2002

In ascidians, a primitive chordate, maternal cytoplasmic factors and inductive interactions are involved in the specification of cell fates in early embryos. The larval structure of ascidians is relatively simple, and the major mesodermal tissues of the tadpole larva are notochord, muscle, and mesenchyme. Formation of muscle cells is a cell-autonomous process, and localized maternal macho-l mRNA specify muscle fate in the posterior marginal zone of the early embryo. In contrast, inductive influence from endoderm precursors plays important roles in the specification of notochord and mesenchyme fates. FGF-Ras-MAPK signaling is involved In the induction of both tissues. The difference in responsiveness of the posterior mesenchyme and anterior notochord precursors to FGF signaling is caused by the presence or absence of intrinsic factors that inherited from the posterior-vegetal egg cytoplasm, respectively. In these inductions, directed signal polarizes the induced cells and promotes asymmetric cell divisions to produce two daughter cells with distinct fates.

• Journal of Life Science
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• v.34 no.9
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• pp.666-672
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• 2024

Plants recognize pathogens through intracellular receptors that trigger defense signaling. Nucleotide-binding leucine-rich repeat (NLR) proteins within a cell specifically recognize pathogenic molecules (effectors), leading to signal transduction that ultimately triggers the cell death pathway, thereby inducing effector-triggered immunity in plants. NLR proteins are broadly categorized into two types based on their N-terminal domains: coiled-coil domain NLRs (CNLs) and toll/interleukin-1 receptor (TIR) domain NLRs (TNLs) are defined by their unique N-terminal domains. The TIR domain, which is responsible for activates nicotinamide adenine dinucleoside hydrolases (NADases), is crucial for the degradation of the NAD+ cofactor. TNL-dependent immune signaling involves lipase-like proteins known as Enhanced Disease Susceptibility 1 (EDS1) and its partners Phytoalexin Deficient 4 (PAD4) and Senescence-Associated Gene 101 (SAG101). This immune system also requires helper NLR subfamilies, such as activated disease resistance 1 (ADR1) and N requirement gene 1 (NRG1). The catalytic activity of TIR domain proteins generates various small molecules reported to activate plant's immune responses. These small molecules bind to specific sites on EDS1-PAD4 and EDS1-SAG101, inducing structural changes in the EP domain, and subsequently enabling interaction with ADR1 or NRG1. Here, we will discuss the characteristics of these small molecules and describe their relationships with protein complexes based on their structural and biochemical characteristics. We will also discuss how these small molecules can activate immune pathways.

• Journal of Embryo Transfer
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• v.20 no.3
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• pp.191-200
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• 2005

Many studies have shown that the development of mouse early 2-cell embryos in vitro is related with the intracellular $Ca^{2+}$ changes. In ICR strain mouse, the development of embryos arrests at early 2-cell stage, but the arrested early 2-cell embryos can be rescued by the addition of $Ca^{2+}$-related materials. Acetylcholine (ACh) increases intracellular $Ca^{2+}$ concentration ([$Ca^{2+}$]i) via the mAChR-PLC-IP3 pathway in mouse oocytes. We examined whether ACh rescues 2-cell block in mouse. In early 2-cell embryos, ACh increased [$Ca^{2+}$]i in a dose-dependent manner (p<0.001), and had an effect on rescue of 2-cell block and embryonic development. To identify the signal pathway involved in ACh-induced rescue of 2-cell block, we first applied an agonist of ACh receptor (AChR). Like ACh, carbachol increased intracellular $Ca^{2+}$ concentration ([$Ca^{2+}$]i) and atropine, an antagonist of ACh receptor, blocked the ACh-induced $Ca^{2+}$ increase. In $Ca^{2+}$-free medium, ACh also increased [$Ca^{2+}$]i, indicating that $Ca^{2+}$ increased by ACh is mainly released from the intracellular $Ca^{2+}$ store. The ACh-induced $Ca^{2+}$ increase was blocked by PLC inhibitor (U73122), ryanodine receptor (RyR) antagonist (dantrolene), and CaM KII inhibitor (KN-93), but not by IP3R antagonists (xestospongin C). These results show that ACh increases intracellular $Ca^{2+}$ concentration via mAChR/PLC/RyR, and this contributes to the rescue of 2-cell block.

• Journal of Marine Bioscience and Biotechnology
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• v.1 no.4
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• pp.305-310
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• 2006

Abnormal activation of the Wnt/${\beta}$-catenin pathway and subsequent up-regulation of ${\beta}$-catenin response transcription (CRT) are associated with the development of colon cancer. Thus, the Wnt/${\beta}$-catenin pathway is an attractive target for chemoprevention and treatment of this cancer. In this study, we used a cell-based screen to identify a methanol extract of Dictyota dichotoma (EDD) that suppresses the Wnt/${\beta}$-catenin pathway without altering the level of ${\beta}$-catenin protein and reduces the expression of cyclin D1, which is a known ${\beta}$-catenin/T cell factor (TCF)-dependent gene. EDD inhibited the growth of various colon cancer cells. Our findings suggest that EDD can potentially be used as a chemopreventive agent against colon cancer.

• Journal of Life Science
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• v.31 no.9
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• pp.787-795
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• 2021

Eupatorium chinensis var. simplicifolium (EUC) has anti-inflammatory and antioxidant effects. Young sprouts of EUC have been used as food for a long time, and the whole EUC plant has been used as an herbal remedy in oriental medicine. Arteriosclerosis, or chronic inflammation in arterial vessels, is a cardiovascular disease and is involved in various disorders. Cardiovascular diseases such as restenosis and neuropathic hyperplasia are mainly caused by abnormal growth and movement due to multiple growth factors in vascular smooth muscle cells (VSMCs). Platelet-derived growth factor (PDGF) is a mitogen released from damaged vessel walls and is involved in the proliferation and migration of VSMCs. To determine the effects of EUC on the abnormal proliferation and migration of VSMCs, the present study investigated intracellular signaling pathways in PDGF-BB-induced VSMCs treated with and without EUC. Pretreating PDGF-BB-induced VSMCs with EUC tended to effectively decrease cell proliferation and migration. Subsequently, the intracellular growth-related signaling pathways of AKT, phospholipase C gamma (PLC-γ), and mitogen-activated protein kinase (MAPK) were investigated using western blotting to confirm inhibited phosphorylation. Furthermore, flow cytometry data showed that EUC blocked the cell cycle of VSMCs. These results suggest that EUC can inhibit the proliferation and migration of VSMCs by controlling the cell cycle and growth factor receptors. Furthermore, this indicates that EUC can be used as a preventative against cardiovascular disease resulting from abnormal proliferation and migration of VSMCs.

• Korean Journal of Food Science and Technology
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• v.50 no.5
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• pp.555-563
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• 2018

Barley has nutritional benefits due to its high dietary fiber content; therefore, the intake of whole barley grains is recommended. However, barley is often consumed in the fermented form because of the improved texture and digestibility. The present study was designed to elucidate the intracellular signaling pathway for macrophage activation by the polysaccharide BF-CP from fermented barley. BF-CP is a neutral polysaccharide, composed of neutral sugars, including glucose (70.7%), xylose (11.4%), and arabinose (9.0%). BF-CP exhibited macrophage-stimulatory activity by inducing the production of interleukin (IL)-6, tumor necrosis factor $(TNF)-{\alpha}$, and nitric oxide in RAW 264.7 macrophages. Further, BF-CP treatment strongly increased the IL-6 and $TNF-{\alpha}$ gene expression in a concentration-dependent manner. Signal transduction experiments using immunoblotting showed that BF-CP phosphorylated mitogen-activated protein kinases (MAPKs), such as c-Jun N-terminal kinase, extracellular signal-regulated kinase, and p38, and nuclear factor $(NF)-{\kappa}B$, in RAW 264.7 cells in a concentration-dependent manner. These results suggest that BF-CP activates the macrophages via MAPK and $NF-{\kappa}B$ pathways, and also induces an increase in the production of cytokines.

• The Korean Journal of Food And Nutrition
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• v.26 no.4
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• pp.806-813
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• 2013

Agrimonia pilosa Ledeb. is a medicinal plant with anti-tumor, anti-oxidant, anti-inflammatory and anti-hyperglycemic activities. However, few studies of the anti-diabetic effect of A. pilosa on insulin resistance status have been performed. In the present study, the anti-diabetic effect of A. pilosa water extract (AP) was determined by investigating its ${\alpha}$-glucosidase inhibitory property, glucose utilization, and uptake, as well as insulin resistance mechanism of action in C2C12 skeletal muscle cells. Compared to positive control (acarbose), AP ($10mg/m{\ell}$) showed a similar ${\alpha}$-glucosidase inhibitory capacity. Glucose uptake was significantly increased by $1{\mu}m$ insulin treatment (p<0.05). However, palmitic acid (FFA, 1 mM) induced muscle insulin resistance and glucose uptake dysfunction. On the other hand, AP ($10{\mu}g/m{\ell}$) was capable of reversing the FFA-induced insulin resistance in C2C12 myotubes. Compared to control, AP ($100{\mu}g/m{\ell}$ without insulin) significantly increased the utilization of glucose (p<0.05) in C2Cl2 myotubes cultured in normal glucose (7 mM). AP treatment significantly increased the relative mRNA and protein expression levels of Akt. In particular, the effect of A. pilosa on the insulin signaling system is associated with the up-regulation of Akt genes and glucose uptake in C2Cl2 myotubes. These results suggest that A. pilosa is useful in the prevention of diabetes and the treatment of hyperglycemic disorders.