• 동의생리병리학회지
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• 제19권5호
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• pp.1363-1369
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• 2005

Previously we have shown that shikonin has strong anti-tumor activities via inducing apoptosis and suppressing metastasis on LLC cells in vivo and in vitro. Here we have investigated anti-angiogenic potential of shikonin and its possible mechanism of action in HSE cells. Shikonin inhibited the proliferation of HSE cells in a concentration-dependent manner. It was shown that this proliferation inhibition was caused by apoptosis induced by shikonin via BrdU incorporation and Western blotting analysis. Shikonin treatment was caused that decrease of activation of caspases and cleavage of PARP. And shikonin induced that the activation of mitogen-activated protein kinases (MAPKs), such as extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK) and p38. Moreover, shikonin showed anti-angiogenic activities inhibiting tube-like formation of HSE cells in vitro and vascular formation of LLC cells in vivo. These findings suggest that shikonin may a possible candidate not only anti-metastatic agent but also anti-angiogenic agent.

• Biomolecules & Therapeutics
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• 제19권4호
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• pp.425-430
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• 2011

In this study, we found that Forsythiae fructus (FF) and one of its main compounds, arctigenin, significantly inhibited nitric oxide production in lipopolysaccharide (LPS)-stimulated BV-2 microglial cells. Arctigenin also suppressed the expression of inducible nitric oxide synthase and cyclooxygenase-2, and inhibited the activation of extracellular signal-regulated kinase, c-Jun N-terminal kinase and p38. Moreover, it also reduced levels of proinflammatory cytokines, interleukin $1{\beta}$, tumor necrosis factor ${\alpha}$ and prostaglandin E2, and inhibited neuronal death in LPS-treated organotypic hippocampal cultures. Therefore, we suggest that arctigenin may confer a neuroprotective effect via the inhibition of neuroinflammation.

• 약학회지
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• 제52권3호
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• pp.182-187
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• 2008

Salicylate (SA) was shown to alleviate insulin resistance. Here, we showed that SA inhibited Ser731 phosphorylation of insulin receptor substrate 1 (IRS1) and S6 kinase activation, and enhanced tyrosine phosphorylation of IRS1 in response to insulin or amino acid. Experiments using a cJun N-terminal kinase (JNK)-deficient cell and an IRS1 JNK-binding mutant showed that JNK is not required for Ser731 phosphorylation. A two-week treatment of obese mice with SA resulted in decreased Ser731 phosphorylation and enhanced insulin signaling. These results suggest that SA enhances insulin signaling by inhibiting Ser731 phosphorylation of IRS1.

• International Journal of Oral Biology
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• 제45권4호
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• pp.218-224
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• 2020

The antitumor effects of octyl gallate (OG) were investigated on FaDu human hypopharyngeal squamous carcinoma cells. At various concentrations, OG inhibited the proliferation of FaDu cells by suppressing cell cycle regulators and induced apoptosis by activating caspase 3 and its downstream poly (ADP-ribose) polymerase, thereby damaging DNA. Immunoblotting demonstrated that OG significantly suppressed the expression of integrin family proteins (integrin α4, αv, β3, β4), hindering cell adhesion. The reduced expression of integrins subsequently mediated the mitogen-activated protein kinase signaling pathway to stimulate the activation of extracellular signal-regulated kinases and c-jun N-terminal kinases, leading to apoptosis. Thus, OG demonstrated antitumor activity on hypopharyngeal squamous carcinoma cells by suppressing cell proliferation and inducing apoptosis.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.165.3-166
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• 2003

The c-Jun N-terminal kinase (JNK) plays essential roles in apoptosis and cell survival. Because apoptosis is promoted by blocking the MEK kinase1-mediated activation of JNK1, we tested whether JNK1 plays dual roles in apoptosis. We show here that JNK1 activity is differentially up-regulated in a two-tiered fashion by specific mechanisms during taxol- or ginsenoside Rh2-induced apoptosis. The early phase of JNK1 activation, but not apoptosis is prevented by expressing the dominant negative SEK1 mutant. (omitted)

• BMB Reports
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• 제56권7호
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• pp.410-415
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• 2023

Breast cancer has become the most common cancer among women worldwide. Among breast cancers, metastatic breast cancer is associated with the highest mortality rate. Twist1, one of the epithelial-mesenchymal transition-regulating transcription factors, is known to promote the intravasation of breast cancer cells into metastatic sites. Therefore, targeting Twist1 to develop anti-cancer drugs might be a valuable strategy. In this study, LY-290181 dose-dependently inhibited migration, invasion, and multicellular tumor spheroid invasion in breast cancer cell lines. These anti-cancer effects of LY-290181 were mediated through the down-regulation of Twist1 protein levels. LY-290181 inhibited extracellular signal-regulated kinase and c-Jun N-terminal kinase signaling pathways. Therefore, our findings suggest that LY-290181 may serve as a basis for future research and development of an anti-cancer agent targeting metastatic cancers.

• International Journal of Industrial Entomology and Biomaterials
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• 제48권1호
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• pp.13-18
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• 2024

The rice field grasshopper, Oxya chinensis sinuosa (OC), has traditionally been utilized in Korea for various purposes; however, its potential benefits in the context of osteoporosis remain unclear. The results revealed that OC ethanol extract (OCE) significantly inhibited the formation and activity of tartrate-resistant acid phosphatase (TRAP)-positive cells in receptor activator of nuclear factor-κB ligand (RANKL)-stimulated RAW264.7 cells. Furthermore, OCE, at concentrations ranging from 100 to 400 ㎍/mL, demonstrated a dose-dependent reduction in the protein expression of osteoclast-specific markers, including nuclear factor of activated T cell cytoplasmic 1, c-Src, and TRAP, when compared to RANKL stimulation alone. Additionally, OCE significantly inhibited RANKL-induced activation of p38 mitogen-activated protein kinase (MAPK) and c-Jun N-terminal kinase (JNK) but not the activation of extracellular signal-regulated kinase. Collectively, these results indicate that OCE suppresses osteoclastogenesis by attenuating the phosphorylation of p38 MAPK and JNK. Consequently, these findings suggest that OCE holds promise for the prevention of osteoporosis.

• The Korean Journal of Physiology and Pharmacology
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• 제11권5호
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• pp.163-169
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• 2007

The neurotoxicity of amyloid $\beta(A\beta)$ is associated with an increased production of reactive oxygen species and apoptosis, and it has been implicated in the development of Alzheimer's disease. While(-)-epigallocatechin-3-gallate(EGCG) suppresses $A\beta$-induced apoptosis, the mechanisms underlying this process have yet to be completely clarified. This study was designed to investigate whether EGCG plays a neuroprotective role by activating cell survival system such as protein kinase C(PKC), extracellular-signal-related kinase(ERK), c-Jun N-terminal kinase(JNK), and anti-apoptotic and pro-apoptotic genes in SH-SY5Y human neuroblastoma cells. One ${\mu}M\;A{\beta}_{1-42}$ decreased cell viability, which was correlated with increased DNA fragmentation evidenced by DAPI staining. Pre-treatment of SH-SY5Y neuroblastoma cells with EGCG($1{\mu}M$) significantly attenuated $A{\beta}_{1-42}$-induced cytotoxicity. Potential cell signaling candidates involved in this neuroprotective effects were further examined. EGCG restored the reduced PKC, ERK, and JNK activities caused by $A{\beta}_{1-42}$ toxicity. In addition, gene expression analysis revealed that EGCG prevented both the $A{\beta}_{1-42}$-induced expression of a pro-apoptotic gene mRNA, Bad and Bax, and the decrease of an anti-apoptotic gene mRNA, Bcl-2 and Bcl-xl. These results suggest that the neuroprotective mechanism of EGCG against $A{\beta}_{1-42}$-induced apoptotic cell death includes stimulation of PKC, ERK, and JNK, and modulation of cell survival and death genes.

• 생명과학회지
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• 제20권11호
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• pp.1603-1610
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• 2010

Fucoidan은 갈조류의 세포벽에 존재하는 황산화 다당류이다. 본 연구에서는 자외선 B를 인체각질형성세포에 조사하여 matrix metalloproteinase-1 (MMP-1)을 발현 시킨 후 Fucus evanescens fucoidan이 MMP-1 promoter, mRNA, 단백 발현과 mitogen-activated protein kinases (MAPKs)의 인산화에 미치는 영향을 확인하고자 하였다. 자외선 B에 의해 생성된 MMP-1의 promoter activity와 mRNA, 단백 발현은 fucoidan $10\;{\mu}g/ml$와 $100\;{\mu}g/ml$를 투여하였을 때 fucoidan을 투여하지 않고 자외선만 조사한 군에 비하여 유의하게 억제되었다. 그리고 F. evanescens fucoidan은 extracellular signal regulated kinase (ERK)의 활성은 현저히 억제시켰으나 c-JUN N-terminal kinase (JNK)와 p38의 활성에 미치는 영향은 약하였다. 따라서 이 연구결과들은 F. evanescens fucoidan이 피부 광노화의 예방과 치료에 도움이 될 가능성을 확인할 수 있었다.

• The Korean Journal of Physiology and Pharmacology
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• 제8권4호
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• pp.187-194
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• 2004

Middle cerebral artery occlusion (MCAO) results in cell death by activation of complex signal pathways for cell death and survival. Hypothermia is a robust neuroprotectant, and its effect has often been attributed to various mechanisms, but it is not yet clear. Upstream from the cell death promoters and executioners are several enzymes that may activate several transcription factors involved in cell death and survival. In this study, we immunohistochemically examined the phosphorylation of mitogen-activated protein kinase, extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK) and p38 kinase during early period of the ischemic injury, following 2 hours (h) of transient MCAO. Increased phosphorylation of ERK and p38 was observed in the vessels at 3 h, neuron-like cells at 6 and 12 h and glia-like cells at 12 h. Activation of JNK was not remarkable, and a few cells showed active JNK following ischemia. Phosphorylation of Elk-1, a transcription factor, was reduced by ischemic insult. Hypothermia attenuated the activation of ERK, p38 and JNK, and inhibited reduction of Elk-1. These data suggest that signals via different MAPK family members converge on the cell damage process and hypothermia protects the brain by interfering with these pathways.