• The korean journal of orthodontics
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• v.33 no.3 s.98
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• pp.169-183
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• 2003

Tooth movement by orthodontic force effects great tissue changes within the periodontium, especially by shifting the blood flow in the pressure side and resulting in a hypoxic state of low oxygen tension. The aim of this study is to elucidate the possible mechanism of apoptosis in response to hypoxia in MC3T3El osteoblasts, the main cells in bone remodeling during orthodontic tooth movement. MC3T3El osteoblasts under hypoxic conditions ($2\%$ orygen) resulted in apoptosis in a time-dependent manner as estimated by DNA fragmentation assay and nuclear morphology stained with fluorescent dye, Hoechst 33258. Pretreatment with Z-VAD-FMK, a pancaspase inhibitor, or Z-DEVD-CHO, a specific caspase-3 inhibitor, completely suppressed the DNA ladder in response to hypoxia. An increase in caspase-3-like protease (DEVDase) activity was observed during apoptosis, but no caspase-1 activity (YVADase) was detected. To confirm what caspases are involved in apoptosis, Western blot analysis was performed using anti-caspase-3 or -6 antibodies. The 10-kDa protein, corresponding to the active products of caspase-3, and the 10-kDa protein of the active protein of caspase-6 were generated in hypoxia-challenged cells in which the processing of the full length form of caspase-3 and -6 was evident. While a time course similar to this caspase-3 and -6 activation was evident, hypoxic stress caused the cleavage of lamin A, which was typical of caspase-6 activity. In addition, the stress elicited the release of cytochrome c into the cytosol during apoptosis. Furthermore, we observed that pre-treatment with SB203580, a selective p38 mitogen activated protein kinase inhibitor, attenuated the hypoxia-induced apoptosis. The addition of SB203S80 suppressed caspase-3 and -6-like protease activity by hypoxia up to $50\%$. In contrast, PD98059 had no effect on the hypoxia-induced apoptosis. To confirm the involvement of MAP kinase, JNK/SAPK, ERK, or p38 kinase assay was performed. Although p38 MAPK was activated in response to hypoxic treatment, the other MAPK -JNK/SAPK or ERK- was either only modestly activated or not at all. These results suggest that p38 MAPK is involved in hypoxia-induced apoptosis in MC3T3El osteoblasts.

• Journal of Acupuncture Research
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• v.21 no.3
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• pp.107-119
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• 2004

Objective : The purpose of this study was to investigate the effect of Bee Venom and melittin on the lipopolysaccharide(LPS) and sodium nitroprusside(SNP)-induced expressions of Cell viability, nitric oxide(NO), inducible nitric oxide synthase(iNOS), extra-signal response kinase(ERK), jun N-terminal Kinase(JNK) and p38 kinase(p38)- mitogen activated protein kinase(MAPK) Family- in RAW 264.7 cells, a murine macrophage cell line. Methods : The expressions of cell viability by MTT assay, NO by Nitrite assay and iNOS, ERK, JNK and p38 were determined by Western blotting. Results : 1. Compared with the control group, 0.5, 1, $5{\mu}g/m{\ell}$ bee venom and 5, $10{\mu}g/m{\ell}$ melittin increased cell viability of RAW 264.7 induced by LPS and SNP significantly respectively. 2. Compared with the control group, 0.5, 1, $5{\mu}g/m{\ell}$ bee venom and 5, $10{\mu}g/m{\ell}$ melittin inhibited expression of NO induced by LPS and SNP significantly respectively. 3. Compared with the control group, 1, $5{\mu}g/m{\ell}$ bee venom and 5, $10{\mu}g/m{\ell}$ melittin inhibited expression of iNOS induced by LPS significantly and 0.5, 1, $5{\mu}g/m{\ell}$ bee venom and 5, $10{\mu}g/m{\ell}$ melittin inhibited expression of iNOS induced by SNP significantly. 4. Compared with the control group, the expression of ERK induced by LPS and SNP decreased significantly in the treatment groups of $5{\mu}g/m{\ell}$ bee venom and 5, $10{\mu}g/m{\ell}$ melittin, which of p-ERK by LPS also did in 1, $5{\mu}g/m{\ell}$ bee venom and 5, $10{\mu}g/m{\ell}$ melittin, but which of p-ERK by SNP did not decrease. 5. Compared with the control group, the. expression of JNK induced by LPS and SNP decreased significantly in the treatment groups of 5, $10{\mu}g/m{\ell}$ melittin, which of p-JNK by LPS in 5, $10{\mu}g/m{\ell}$ melittin and by SNP in $1{\mu}g/m{\ell}$ bee venom and $10{\mu}g/m{\ell}$ melittin decreased significantly. 6. Compared with the control group, the expression of p38 induced by LPS did not have significant difference, which induced by SNP decreased significantly in the treatment groups of 1, $5{\mu}g/m{\ell}$ bee venom and 5, $10{\mu}g/m{\ell}$ melittin. p-p38 induced by LPS decreased significantly in the treatment group of $10{\mu}g/m{\ell}$ of melittin, which induced by SNP also decreased significantly in 0.5, 1, $5{\mu}g/m{\ell}$ bee venom and 5, $10{\mu}g/m{\ell}$ melittin.

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2002.05a
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• pp.110-110
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• 2002

• Proceedings of the Korean Society of Toxicology Conference
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• 2002.05a
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• pp.110-110
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• 2002

15-Deoxy-$\Delta$12, 14-prostaglandin J2 (15-deoxy-PGJ2), a naturally occurring ligand activates the peroxisome proliferator-activated receptor-$\gamma$(PPAR-$\gamma$). It was known to have promoting ability of nerve growth factor(NGF)-induced neurite extension. However, it is not clear yet as to what signaling pathway is involved in its promoting ability of neurite extension.(omitted)

• Journal of the Korean Applied Science and Technology
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• v.30 no.1
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• pp.173-182
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• 2013

Atopic dermatitis is a chronic, relapsing inflammatory skin disease associated with dysfunction of skin barrier and cutaneous hyper-reactivity to environmental triggers. In the previous study, cytotoxicity, antioxidant, anti-inflammatory and anti-allergic activities were investigated for various herbal extracts such as Aloe vera L. (AV), Viola mandshurica W. Becker (VM), Punica granatum L. (PG), and Dendrobium nobile L. (DN) in order to develop effective therapeutic herbal extracts for atopic dermatitis, In this study, anti-inflammatory activities of these herb extracts in lipopolysaccharide (LPS)-induced macrophage RAW264.7 cells were further examined to find the underlying molecular mechanisms. The RT-PCR (reverse transcription polymerase chain reaction) analysis showed that PG, DN and AV inhibited effectively the gene expression of pro-inflammatory cytokines IL-6 and IL-$1{\beta}$ in LPS-stimulated macrophages, while VM did not. The transfection and luciferase analysis exhibited that all herbal extracts hindered the activation of transcription nuclear factor kappa B (NF-${\kappa}B$). The western blot analysis indicated that AV blocked the activation of only JNK MAP (c-Jun N-terminal kinase mitogen-activated protein) kinase not p38 MAP kinase, while VM, PG and DN did not show the activation of both JNK and p38 MAP kinases. These results suggest that AV, VM, PG, and DN have anti-inflammatory activities and thus have the potential to reduce and alleviate the symptoms of atopic dermatitis.

• Animal cells and systems
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• v.10 no.2
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• pp.79-83
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• 2006

Tissue plasminogen activator (tPA) is used to lyse clots and reperfuse brain in ischemic stroke. However, sideeffects of intracerebral hemorrhage (ICH) and edema limit their clinical application. In part, these phenomena has been linked with elevations in matrix metalloproteinase-9 (MMP-9) in neurovascular unit. However little is known about their regulatory signaling pathways in brain cells. Here, I examine the role of MAP kinase pathways in tPA-induced MMP-9 regulation in rat cortical astrocytes. tPA $(1-10\;{\mu}g/ml)$ induced dose-dependent elevations in MMP-9 and MMP-2 in conditioned media. Although tPA increased phosphorylation in two MAP kinases (ERK, JNK), only inhibition of the JNK pathway by the JNK inhibitor SP600126 significantly reduced MMP-9 upregulation. Neither ERK inhibition with U0126 nor p38 inhibition with SB203580 had any significant effects. Taken together, these results suggest that c-jun N-terminal kinase (JNK) plays an essential role for tPA-induced MMP-9 upregulation.

• Archives of Pharmacal Research
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• v.28 no.11
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• pp.1257-1262
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• 2005

MMP-9 is a metalloproteinase capable of basement membrane degradation in vivo. Expression of MMP-9 can be found in normal conditions such as trophoblasts, osteoclasts, and leukocytes and their precursors. They also occur as well as in pathological conditions, such as the invasive growth of primary tumors, metastasis, angiogenesis, rheumatoid arthritis, and periodontal diseases. MMP-9 upregulation can be highly induced by a wide range of agents. These agents include growth factors, cytokines, cell-cell, and cell-ECM adhesion molecules, and agents altering cell shape. Here, we observed that TNF-$\alpha$ stimulated human monocytic cell line, HL-60 produced MMP-9 in a dose and time dependent manner. Real time PCR results indicated transcriptional upregulation of MMP-9 as early as 3 h post TNF-$\alpha$ stimulation. To investigate the signaling pathway underlined in TNF-$\alpha$ induced MMP-9 expression, three MAP kinase inhibitors were added to cells 1 h prior to TNF-$\alpha$ treatment. The ERK inhibitor completely abolished MMP-9 expression by TNF-$\alpha$. But neither p38 MAP kinase nor JNK inhibitor had an effect on TNF-$\alpha$ induced MMP-9 expression, suggesting that ERK activation is required for the MMP-9 induction by TNF-$\alpha$. Taken together, we found that TNF-$\alpha$ stimulation facilitates ERK activation, which results in the transcriptional upregulation of MMP-9 gene and subsequent MMP-9 production and secretion.

• BMB Reports
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• v.45 no.7
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• pp.414-418
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• 2012

Triglycerides (TG) are implicated in the development of atherosclerosis through formation of foam cells and induction of macrophage cell death. In this study, we report that addition of exogenous TG induced cell death in phorbol 12-myristate 13-acetate-differentiated THP-1 human macrophages. TG treatment induced a dramatic decrease in interleukin-$1{\beta}$ (IL-$1{\beta}$) mRNA expression in a dose- and time-dependent manner. The expression of granulocyte macrophage colony-stimulating factor and platelet endothelial cell adhesion molecule remained unchanged. To identify signaling pathways involved in TG-induced downregulation of IL-$1{\beta}$, we added p38 MAPK, protein kinase C (PKC) or c-Raf1 specific inhibitors. We found that inhibition of p38 MAPK alleviated the TG-induced downregulation of IL-$1{\beta}$, whereas inhibition of PKC and c-Raf1 had no effect. This is the first report showing decreased IL-$1{\beta}$ expression during TG-induced cell death in a human macrophage line. Our results suggest that downregulation of IL-$1{\beta}$ expression by TG-treated macrophages may play a role during atherogenesis.

• The Korean Journal of Physiology and Pharmacology
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• v.22 no.3
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• pp.225-234
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• 2018

Adenosine is a naturally occurring breakdown product of adenosine triphosphate and plays an important role in different physiological and pathological conditions. Adenosine also serves as an important trigger in ischemic and remote preconditioning and its release may impart cardioprotection. Exogenous administration of adenosine in the form of adenosine preconditioning may also protect heart from ischemia-reperfusion injury. Endogenous release of adenosine during ischemic/remote preconditioning or exogenous adenosine during pharmacological preconditioning activates adenosine receptors to activate plethora of mechanisms, which either independently or in association with one another may confer cardioprotection during ischemia-reperfusion injury. These mechanisms include activation of $K_{ATP}$ channels, an increase in the levels of antioxidant enzymes, functional interaction with opioid receptors; increase in nitric oxide production; decrease in inflammation; activation of transient receptor potential vanilloid (TRPV) channels; activation of kinases such as protein kinase B (Akt), protein kinase C, tyrosine kinase, mitogen activated protein (MAP) kinases such as ERK 1/2, p38 MAP kinases and MAP kinase kinase (MEK 1) MMP. The present review discusses the role and mechanisms involved in adenosine preconditioning-induced cardioprotection.

• YAKHAK HOEJI
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• v.54 no.6
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• pp.461-465
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• 2010

We investigated the role of L-type $Ca^{2+}$ channel in receptor activator of nuclear factor-kappaB ligand (RANKL)-induced osteoclast formation. BayK 8644, a L-type $Ca^{2+}$ channel agonist, was shown to increase the RANKLinduced osteoclastogenesis and actin ring formation in mouse bone marrow-dereived macrophage (BMM) culture system. BayK 8644 stimulated RANKL-induced extracellular signal-regulated kinase (ERK) and p38 MAP kinase (MAPK) activation, which leads to increased nuclear factor of activated T cells (NFAT)c1 expression. Taken together, these data indicate that L-type $Ca^{2+}$ channel regulates osteoclast formation possibly through ERK- and p38-mediated NFATc1 expression.