• Molecules and Cells
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• v.37 no.10
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• pp.747-752
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• 2014

Protein kinase C (PKC) family members phosphorylate a wide variety of protein targets and are known to be involved in diverse cellular signaling pathways. However, the role of PKC in receptor activator of NF-${\kappa}B$ ligand (RANKL) signaling has remained elusive. We now demonstrate that $PKC{\beta}$ acts as a positive regulator which inactivates glycogen synthase kinase-$3{\beta}$ (GSK-$3{\beta}$) and promotes NFATc1 induction during RANKL-induced osteoclastogenesis. Among PKCs, $PKC{\beta}$ expression is increased by RANKL. Pharmacological inhibition of $PKC{\beta}$ decreased the formation of osteoclasts which was caused by the inhibition of NFATc1 induction. Importantly, the phosphorylation of GSK-$3{\beta}$ was decreased by $PKC{\beta}$ inhibition. Likewise, down-regulation of $PKC{\beta}$ by RNA interference suppressed osteoclast differentiation, NFATc1 induction, and GSK-$3{\beta}$ phosphorylation. The administration of PKC inhibitor to the RANKL-injected mouse calvaria efficiently protected RANKL-induced bone destruction. Thus, the $PKC{\beta}$ pathway, leading to GSK-$3{\beta}$ inactivation and NFATc1 induction, has a key role in the differentiation of osteoclasts. Our results also provide a further rationale for $PKC{\beta}$'s therapeutic targeting to treat inflammation-related bone diseases.

• Biomedical Science Letters
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• v.19 no.2
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• pp.118-123
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• 2013

Tumor necrosis factor-alpha (TNF-${\alpha}$) is a proinflammatory cytokine that mediates the inflammatory response and immune functions, and modulates the proliferation, differentiation and cell death of cancer cells. The differential functions of TNF-${\alpha}$ in various human cells due to the formation of different stimulating pathway upon the binding of TNF-${\alpha}$ to its receptors. In the present study, we examined the different effects of TNF-${\alpha}$ on the survival and apoptosis between normal granulocytes and human myeloid leukemia HL-60 cells. Although TNF-${\alpha}$ did not affect on the constitutive apoptosis of granulocytes, TNF-${\alpha}$ strongly induced the apoptosis of HL-60 cells in a dose- and a time-dependent manner. TNF-${\alpha}$-induced apoptosis was occurred via the activation of caspase 8, caspase 9 and caspase 3/7 and the induction of ROS production in HL-60 cells. Also, BAY-11-7085, a NF-${\kappa}B$ inhibitor, blocked the TNF-${\alpha}$-induced apoptosis in HL-60 cells. NF-${\kappa}B$ may be involved in TNF-${\alpha}$-induced apoptotic signaling pathway in HL-60 cells. These results suggest that TNF-${\alpha}$ activates apoptotic pathways and its process depends on cell type and many cellular factors. A better understanding of the differential effect of TNF-${\alpha}$ on cell apoptosis and survival may provide important information that can be used to elucidate the specific inhibitory effect of TNF-${\alpha}$ on the cancer dis.

• The Korean Journal of Physiology and Pharmacology
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• v.19 no.2
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• pp.111-118
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• 2015

Osteoprotegerin (OPG), receptor activator of NF-${\kappa}B$ ligand (RANKL)/receptor activator of NF-${\kappa}B$ (RANK) axis, and TNF-related apoptosis-inducing ligand (TRAIL) participate in vascular calcification process including atherosclerosis, but their contributions under high glucose (HG) and phosphate (HP) condition for a long-term period (more than 2 weeks) have not been fully determined. In this study, we evaluated the effects of HG and HP levels over 2 or 4 weeks on the progression of vascular calcification in rat vascular smooth muscle cells (VSMCs). Calcium deposition in VSMCs was increased in medium containing HG (30 mmol/L D-glucose) with ${\beta}$-glycerophosphate (${\beta}$-GP, 12 mmol/L) after 2 weeks and increased further after 4 weeks. OPG mRNA and protein expressions were unchanged in HG group with or without ${\beta}$-GP after 2 weeks. However, after 4 weeks, OPG mRNA and protein expressions were significantly lower in HG group with ${\beta}$-GP. No significant expression changes were observed in RANKL, RANK, or TRAIL during the experiment. After 4 weeks of treatment in HG group containing ${\beta}$-GP and rhBMP-7, an inhibitor of vascular calcification, OPG expressions were maintained. Furthermore, mRNA expression of alkaline phosphatase (ALP), a marker of vascular mineralization, was lower in the presence of rhBMP-7. These results suggest that low OPG levels after long term HG and phosphate stimulation might reduce the binding of OPG to RANKL and TRAIL, and these changes could increase osteo-inductive VSMC differentiation, especially vascular mineralization reflected by increased ALP activity during vascular calcification.

• Tuberculosis and Respiratory Diseases
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• v.69 no.5
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• pp.337-347
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• 2010

Background: Transglutaminase-2 (TG-2) has been reported to play an important role in the process of fibrosis. However, TG-2 studies on fibroproliferation of acute lung injury (ALI) are absent. The purpose of this study was to investigate the role of TG-2 in the fibroproliferation of lipopolysaccharide (LPS)-induced ALI. Methods: The male C57BL/6 mice of 5 weeks age were divided into 3 groups; control group (n=30) in which $50{\mu}L$ of saline was given intratracheally (IT), LPS group (n=30) in which LPS 0.5 mg/kg/$50{\mu}L$ of saline was given IT, and LPS+Cyst group treated with intraperitoneal 200 mg/kg of cystamine, competitive inhibitor of TG-2, after induction of ALI by LPS. TG-2 activity and nuclear factor $(NF)-{\kappa}B$ were measured in lung tissue homogenate. Tumor necrosis factor (TNF)-${\alpha}$, interleukin (IL)-$1{\beta}$, IL-6, myeloperoxidase (MPO), and transforming growth factor (TGF)-${\beta}1$ were measured using bronchoalveolar lavage fluids. Histopathologic ALI score and Mallory's phosphotunistic acid hematoxylin (PTAH) for collagen and fibronectin deposition were performed. Results: The TG-2 activities in the LPS group were significantly higher than the control and LPS+Cyst groups (p<0.05). The TNF-${\alpha}$ and IL-$1{\beta}$ concentrations and $NF-{\kappa}B$ activity were lower in the LPS+Cyst group than the LPS group (p<0.05). The LPS+Cyst group showed lower MPO, ALI score, TGF-${\beta}1$ concentration, and Mallory's PTAH stain than the LPS group, but the differences were not significant (p>0.05). Conclusion: Inhibition of TG-2 activity in the LPS-induced ALI prevented early inflammatory parameters, but had limited effects on late ALI and fibroproliferative parameters.

• International Journal of Oral Biology
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• v.35 no.2
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• pp.43-49
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• 2010

Enterococcus faecalis, a gram-positive bacterium, has been implicated in endodontic infections, particularly in chronic apical periodontitis. Proinflammatory cytokines, including tumor necrosis factor-$\alpha$ (TNF-$\alpha$), are involved in the pathogenesis of these apical lesions. E. faecalis has been reported to stimulate macrophages to produce TNF-$\alpha$. The present study investigated the mechanisms involved in TNF-$\alpha$ production by a murine macrophage cell line, RAW 264.7 in response to exposure to E. faecalis. Both live and heat-killed E. faecalis induced high levels of gene expression and protein release of TNF-$\alpha$. Treatment of RAW 264.7 cells with cytochalasin D, an inhibitor of endocytosis, prevented the mRNA up-regulation of TNF-$\alpha$ by E. faecalis. In addition, antioxidant treatment reduced TNF-$\alpha$ production to baseline levels. Inhibition of extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein (MAP) kinase also significantly attenuated E. faecalis-induced TNF-$\alpha$ expression by RAW 264.7 cells. Furthermore, activation of NF-${\kappa}B$ and AP-1 in RAW 264.7 cells was also stimulated by E. faecalis. These results suggest that the phagocytic uptake of bacteria is necessary for the induction of TNF-$\alpha$ in E. faecalis-stimulated macrophages, and that the underlying intracellular signaling pathways involve reactive oxygen species, ERK, p38 MAP kinase, NF-${\kappa}B$, and AP-1.

• International Journal of Oral Biology
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• v.38 no.1
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• pp.37-42
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• 2013

Receptor activator of NF-${\kappa}B$ ligand (RANKL) is an essential cytokine for osteoclast differentiation, activation and survival. T lymphocytes such as $T_{17}$ cells, a subset of T helper cells that produce IL-17, play an important role in rheumatoid arthritic bone resorption by producing inflammatory cytokines and RANKL. It has not yet been clearly elucidated how T cell activation induces RANKL expression. T cell receptor activation induces the activation of nuclear factor of activated T cell (NFAT) and expression of its target genes. In this study, we examined the role of NFAT in T cell activation-induced RANKL expression. EL-4, a murine T lymphocytic cell line, was used. When T cell activation was induced by phorbol 12-myristate 13-acetate (PMA) and ionomycin, RANKL expression increased in a time-dependent manner. In the presence of cyclosporin, an inhibitor of NFAT activation, this PMA/ionomycin-induced RANKL expression was blocked. Overexpression of either NFATc1 or NFATc3 induced RANKL expression. Chromatin immunoprecipitation results demonstrated that PMA/ionomycin treatment induced the binding of NFATc1 and NFATc3 to the mouse RANKL gene promoter. These results suggest that NFATc1 and NFATc3 mediates T cell receptor activation-induced RANKL expression in T lymphocytes.

• International Journal of Oral Biology
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• v.34 no.2
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• pp.87-95
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• 2009

Porphyromonas gingivalis is a major etiologic agent of chronic periodontitis and cytokines produced by macrophages play important roles in the pathogenesis of periodontal diseases. In this study we investigated the cytokine response of phorbol myristate acetatedifferentiated THP-1 cells exposed to P. gingivalis. Compared with the prominent cell wall components of P. gingivalis (lipopolysaccharide and the major fimbrial protein FimA), live P. gingivalis stimulated much higher levels of cytokine production. In addition, whereas low multiplicity of infection challenges (MOI=10) of P. gingivalis 381 stimulated high levels of monocyte chemoattractant protein-1 (MCP-1), tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), interleukin-6 (IL-6), and IL-1${\beta}$, high dose challenges with this bacterium (MOI = 100) resulted in a substantially diminished production of MCP-1 and IL-6. Moreover, high MOI P. gingivalis challenges achieved only low levels of induction of MCP-1 and IL-6 mRNA. The decreased production of MCP-1 and IL-6 appeared to be mediated by P. gingivalis proteases, because high MOI challenges with congenic protease mutant strains of this microorganism (MT10 and MT10W) did not result in a diminished production of MCP-1 and IL-6. Similar to its protease mutant strains, leupeptin (a protease inhibitor)- treated P. gingivalis at high doses induced high levels of MCP-1 production. To examine the mechanisms underlying the diminished production of MCP-1 by P. gingivalis proteases, the activation of mitogen-activated protein (MAP) kinases and NF-${\kappa}$B was compared between the 381 and MT10W strains. Whilst high doses of both 381 and MT10W similarly activated the three members of the MAP kinase family, the DNA binding activity of NF-${\kappa}$B, as revealed by gel shift assays, was greatly increased only by MT10W. Taken together, our data indicate that P. gingivalis stimulates the production of high levels of TNF-${\alpha}$, IL-1${\beta}$, IL-6, and MCP-1 but that high dose challenges with this bacterium result in a diminished production of MCP-1 and IL-6 via the protease-mediated suppression of NF-${\kappa}$B activation in THP-1 macrophagic cells.

• Journal of Life Science
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• v.28 no.11
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• pp.1361-1368
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• 2018

Inflammation is the most common condition in the human body. Tissue damage triggers inflammation, together with vasodilation and increased blood flow at the inflamed site, resulting in edema. Inflammatory responses are also triggered by lipopolysaccharide (LPS), a Toll-like receptor Enterococcus faecalis, a gram-positive organism, has been reported to possess immunomodulatory and preventive activities; however, its use may present risks of sepsis and other systemic infections. Heat-killed Enterococcus faecalis (EF-2001) has been reported to induce antitumor activity, but its effects on inflammation are not known. In the present study, we investigated the effect of EF-2001 on LPS-induced macrophage inflammatory responses. EF-2001 treatment reduced nitric oxide (NO) production, indicating suppression of inflammatory reactions. EF-2001 showed no cytotoxicity in macrophages. Further investigation of the anti-inflammatory mechanism of EF-2001 indicated that EF-2001 reduced the LPS-induced expression of inducible nitric oxide synthase and cyclooxygenase-2. EF-2001 also reduced f the LPS induction of several inflammatory molecules involved in the nuclear factor-${\kappa}B$ ($NF-{\kappa}B$) and mitogen-activated protein kinase pathways, including ERK, JNK, and p38 phosphorylation, in a concentration-dependent manner. Additionally, EF-2001 inhibited Akt phosphorylation and increased the expression of the inhibitory ${\kappa}B$ ($I{\kappa}B$) protein, an inhibitor of $NF-{\kappa}B$. EF-2001 also inhibited the nuclear translocation of p65. These results suggest that EF-2001 has anti-inflammatory properties and may be useful for treating inflammatory diseases.

• Biomolecules & Therapeutics
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• v.23 no.6
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• pp.531-538
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• 2015

Preceding infection or inflammation such as bacterial meningitis has been associated with poor outcomes after stroke. Previously, we reported that intracorpus callosum microinjection of lipopolysaccharides (LPS) strongly accelerated the ischemia/reperfusionevoked brain tissue damage via recruiting inflammatory cells into the ischemic lesion. Simvastatin, 3-hydroxy-3-methylgultaryl (HMG)-CoA reductase inhibitor, has been shown to reduce inflammatory responses in vascular diseases. Thus, we investigated whether simvastatin could reduce the LPS-accelerated ischemic injury. Simvastatin (20 mg/kg) was orally administered to rats prior to cerebral ischemic insults (4 times at 72, 48, 25, and 1-h pre-ischemia). LPS was microinjected into rat corpus callosum 1 day before the ischemic injury. Treatment of simvastatin reduced the LPS-accelerated infarct size by 73%, and decreased the ischemia/reperfusion-induced expressions of pro-inflammatory mediators such as iNOS, COX-2 and IL-$1{\beta}$ in LPS-injected rat brains. However, simvastatin did not reduce the infiltration of microglial/macrophageal cells into the LPS-pretreated brain lesion. In vitro migration assay also showed that simvastatin did not inhibit the monocyte chemoattractant protein-1-evoked migration of microglial/macrophageal cells. Instead, simvastatin inhibited the nuclear translocation of NF-${\kappa}B$, a key signaling event in expressions of various proinflammatory mediators, by decreasing the degradation of $I{\kappa}B$. The present results indicate that simvastatin may be beneficial particularly to the accelerated cerebral ischemic injury under inflammatory or infectious conditions.

• The Journal of Korean Obstetrics and Gynecology
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• v.33 no.3
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• pp.40-59
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• 2020

Objectives: The purpose of this study was to investigate the anti-inflammatory effects of ethanol extracts from Forsythia viridissima Lindley's fructus and Lonicera japonica Thunberg's flos in vitro, which has been frequently used in inflammatory diseases. Methods: In this experiment, the anti-inflammatory effects of ethanol extracts from Forsythia viridissima Lindley's fructus and Lonicera japonica Thunberg's flos were evaluated by checking the following substances of LPS-activated Raw264.7 cell: Prostaglandin E₂ (PGE₂), Nitric oxide (NO), Cyclooxygenase-2 (COX-2), inducible Nitric oxide synthase (iNOS), Interlukine-1β (IL-1β), Interlukine-6 (IL-6), Tumor necrosis factor-α (TNF-α), mitogen-activated protein kinase (MAPK), Inhibitor of kappa B-α (IκBα), Nuclear factor kappa B (NF-κB). And additionally measured reactive oxygen species (ROS) and free radicals to check the antioxidant effect of ethanol extracts from Forsythia viridissima Lindley's fructus and Lonicera japonica Thunberg's flos which affect inflammatory responses. Results: As a result of measuring anti-inflammatory efficacy, PGE2, NO, IL-1β, IL-6, TNF-α production amounts were reduced in the ethanol extracts from Forsythia viridissima Lindley's fructus and Lonicera japonica Thunberg's flos groups compared with the control group, and decreased the amount of COX-2 mRNA, iNOS mRNA gene expression. Expression of MAPK (ERK, JNK, p38) pathway was decreased. Expression of IκBα was increased and NF-κB was decreased. It is demonstrated that ethanol extracts from Forsythia viridissima Lindley's fructus and Lonicera japonica Thunberg's flos, by reducing NF-κB, regulate the expression of the inflammatory genes and reduce the inflammatory mediators. Ethanol extracts from Forsythia viridissima Lindley's fructus and Lonicera japonica Thunberg's flos also decreased ROS production and free radicals, which shown to have antioxidant efficacy and influence anti-inflammatory effects. Conclusions: These data suggest that ethanol extracts from Forsythia viridissima Lindley's fructus and Lonicera japonica Thunberg's flos can be used to treat various inflammatory diseases.