• Molecules and Cells
• /
• 제37권10호
• /
• pp.747-752
• /
• 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.

• 대한의생명과학회지
• /
• 제19권2호
• /
• pp.118-123
• /
• 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
• /
• 제19권2호
• /
• pp.111-118
• /
• 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
• /
• 제69권5호
• /
• pp.337-347
• /
• 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
• /
• 제35권2호
• /
• pp.43-49
• /
• 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
• /
• 제38권1호
• /
• pp.37-42
• /
• 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
• /
• 제34권2호
• /
• pp.87-95
• /
• 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.

• 생명과학회지
• /
• 제28권11호
• /
• pp.1361-1368
• /
• 2018

염증은 인체에서 가장 흔히 나타나는 증상으로 조직이 손상되면 염증 반응이 발생하고 염증 부위에서 혈관 확장과 혈류가 증가하여 부종이 생긴다. Lipopolysaccharide (LPS)는 Toll-like receptor 4에 의해 인식되고 염증 반응을 일으킨다. 열로 사멸시킨 Enterococcus faecalis 사균체(EF-2001)는 면역 조절 및 예방 활동을 하는 것으로 사전 보고되었고, 항 종양 효과가 있다고 보고되었지만 염증에 미치는 영향에 대해서는 지금까지 연구되지 않았다. 본 연구에서는 LPS에 의한 대식세포 염증 반응에 대한 EF-2001의 효과에 대해 연구하였다. 연구결과에서 EF-2001은 LPS에 의해 유도된 산화 질소의 생성을 감소시켰다. 우리는 EF-2001의 세포 독성이 있는지 확인했으며, 산화 질소의 감소는 세포독성에 의한 것이 아님을 확인하였다. 또한 이러한 EF-2001의 항염증 효과에 대한 분자기전을 연구하였다. LPS에 의한 유도된 iNOS와 COX-2의 발현은 EF-2001에 의해 감소되었다. 더해진 분자기작 분석에서 EF-2001은 LPS로 유도된 ERK, JNK 및 p38 인산화를 농도 의존적으로 억제하였다. 더해진 실험에서 EF-2001은 Akt 인산화를 억제하고 $NF-{\kappa}B$ 억제제인 $I{\kappa}B$ 단백질 발현을 증가시켰다. 또한, EF-2001은 p65의 핵으로의 이동을 억제함을 알수 있었다. 따라서, 이러한 결과는 EF-2001이 항염증 효과를 가지며 염증 질환 치료에 유용 할 수 활용될 수 있음을 시사한다.

• Biomolecules & Therapeutics
• /
• 제23권6호
• /
• pp.531-538
• /
• 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.

• 대한한방부인과학회지
• /
• 제33권3호
• /
• pp.40-59
• /
• 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.