• International Journal of Oral Biology
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• v.31 no.1
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• pp.21-26
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• 2006

Periodontopathogens including Porphyromonas gingivalis interact with host periodontal cells and the excessive subsequent host responses contribute a major part to the development of periodontal diseases. Cyclooxygenase(COX)-2-synthesized $PGE_2$ has detrimental activities in terms of periodontal pathogenesis. The present study investigated induction of COX-2 expression by P. gingivalis in human monocytic THP-1 cells. Live P. gingivalis increased expression of COX-2, but not that of COX-1, which was demonstrated at both mRNA and protein levels. Elevated levels of $PGE_2$ were released from P. gingivalis-infected THP-1 cells. Pharma-cological inhibition of p38 mitogen-activated protein kinase(MAPK) and extracellular signal-regulated kinase(ERK) substantially attenuated P. gingivalis-induced COX-2 mRNA expression. Indeed, activation of p38 MAPK and ERK was observed in P. gingivalis-infected THP-1 cells. Also, P. gingivalis induced activation of nuclear $factor-{\kappa}B\;(NF-{\kappa}B)$ which is an important transcription factor for COX-2. These results suggest that COX-2 expression is up regulated in P. gingivalis-infected monocytic cells, at least in part, via p38 MAPK, ERK, and $NF-{\kappa}B$.

• Parasites, Hosts and Diseases
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• v.54 no.6
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• pp.759-768
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• 2016

Cystic echinococcosis (CE) treatment urgently requires a novel drug. The p38 mitogen-activated protein kinases (MAPKs) are a family of Ser/Thr protein kinases, but still have to be characterized in Echinococcus granulosus. We identified a 1,107 bp cDNA encoding a 368 amino acid MAPK protein (Egp38) in E. granulosus. Egp38 exhibits 2 distinguishing features of p38-like kinases: a highly conserved T-X-Y motif and an activation loop segment. Structural homology modeling indicated a conserved structure among Egp38, EmMPK2, and H. sapiens $p38{\alpha}$, implying a common binding mechanism for the ligand domain and downstream signal transduction processing similar to that described for $p38{\alpha}$. Egp38 and its phosphorylated form are expressed in the E. granulosus larval stages vesicle and protoscolices during intermediate host infection of an intermediate host. Treatment of in vitro cultivated protoscolices with the p38-MAPK inhibitor ML3403 effectively suppressed Egp38 activity and led to significant protoscolices death within 5 days. Treatment of in vitro-cultivated protoscolices with $TGF-{\beta}1$ effectively induced Egp38 phosphorylation. In summary, the MAPK, Egp38, was identified in E. granulosus, as an anti-CE drug target and participates in the interplay between the host and E. granulosus via human $TGF-{\beta}1$.

• Molecules and Cells
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• v.21 no.2
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• pp.237-243
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• 2006

Brain-derived neurotrophic factor (BDNF) is a neuromodulator of nociceptive responses in the dorsal root ganglia (DRG) and spinal cord. BDNF synthesis increases in response to nerve growth factor (NGF) in trkA-expressing small and medium-sized DRG neurons after inflammation. Previously we demonstrated differential activation of multiple BDNF promoters in the DRG following peripheral nerve injury and inflammation. Using reporter constructs containing individual promoter regions, we investigated the effect of NGF on the multiple BDNF promoters, and the signaling pathway by which NGF activates these promoters in PC12 cells. Although all the promoters were activated 2.4-7.1-fold by NGF treatment, promoter IV gave the greatest induction. The p38 mitogen-activated protein kinase (MAPK) inhibitor, SB203580, phosphatidylinositol 3-kinase (PI-3K) inhibitor, LY294003, protein kinase A (PKA) inhibitor, H89, and protein kinase C (PKC) inhibitor, chelerythrine, had no effect on activation of promoter IV by NGF. However, activation was completely abolished by the MAPK kinase (MEK) inhibitors, U0126 and PD98059. In addition, these inhibitors blocked NGF-induced phosphorylation of extracellular signal-regulated protein kinase (ERK) 1/2. Taken together, these results suggest that the ERK1/2 pathway activates BDNF promoter IV in response to NGF independently of NGF-activated signaling pathways involving PKA and PKC.

• Clinical and Experimental Pediatrics
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• v.48 no.6
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• pp.580-587
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• 2005

New evidence is emerging that airway smooth muscle(ASM) may act as an immunomodulatory cell by providing pro-inflammatory cytokines and chemokines, polypeptide growth factors, extracellular matrix proteins, cell adhesion receptors and co-stimulatory molecules. ASM can promote the formation of the interstitial extracellular matrix, and potentially contribute to the alterations within the extracellular matrix in asthma. In addition, extracellular matrix components can alter the proliferative, survival, and cytoskeletal synthetic function of ASM cells through integrin-directed signaling. Increased ASM mass is one of the most important features of the airway wall remodeling process in asthma. Three different mechanisms may contribute to the increased ASM mass : cell proliferation, increased migration and decreased rate of apoptosis. The major signaling pathways of cell proliferation activated by ASM mitogens are those dependent on extracellular signal-regulated kinase and phosphoinositide 3'-kinase. The key signaling mechanisms of cell migration have been identified as the p38 mitogen-activated protein kinase and the p21-activated kinase 1 pathways. ASM cells contain ${\beta}2$-adrenergic receptors and glucocorticoid receptors. They may represent a key target for ${\beta}2$-adrenergic receptor agonist/corticosteroid interactions which have antiproliferative activity against a broad spectrum of mitogens.

• Journal of Applied Biological Chemistry
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• v.64 no.3
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• pp.277-284
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• 2021

The emergence and rapid spread of the potentially fatal coronavirus disease 2019, caused due to infection by severe acute respiratory syndrome coronavirus-2, has led to worldwide interest in developing functional bioactive ingredients that act as immunomodulatory agents. In this study, we aimed to characterize Carica papaya extract and explore its potential as an immunomodulator by performing in vitro cell screening. Papaya leaf water extract (PLW) was found to significantly increase the levels of nitric oxide (NO) and prostaglandin E₂ (PGE₂) by upregulating inducible nitric oxide synthase and cyclo-oxygenase-2 activity, respectively. Additionally, PLW increased the production of tumor necrosis factor-α and interleukin 1β in RAW 264.7 cells. Furthermore, PLW activated the expression of c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK) but not that of p38 mitogen-activated protein kinase. These results indicate that PLW increased the production of NO, PGE₂, and pro-inflammatory cytokines by activating the JNK and ERK pathways in macrophages, thus demonstrating immunomodulatory properties. Finally, high-performance liquid chromatography fingerprint analysis indicated the presence of rutin, narirutin, and ρ-coumaric acid in PLW (6.30, 119.76, and 47.25 ppm, respectively). Treating cells with these compounds at non-toxic concentrations had no effect on NO production. Taken together, these results suggest that PLW may have potential as an immunity-enhancing supplement.

• International Journal of Oral Biology
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• v.30 no.3
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• pp.85-90
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• 2005

Homeostatic pH is very important for various cellular processes, including metabolism, survival, and death. An imbalanced-pH might induce cellular acidosis, which is involved in many abnormal events such as apoptosis and malignancy. One of several factors contributing to the onset of metabolic acidosis is the production of lactate and protons by lactate dehydrogenase (LDH) in anaerobic glycolysis. LDH is an important enzyme that catalyzes the reversible conversion of pyruvate to lactate. This study sought to examine whether decreases in extracellular pH induce apoptosis of CHO cells, and to elucidate the role of mitogen-activated protein kinases (MAPKs) in acidification-induced apoptosis. To test apoptotic signaling by acidification we used CHO dhfr cells that were sensitive to acidification, and CHO/anti-LDH cells that are resistant to acidification-induced apoptosis and have reduced LDH activity by stable LDH antisense mRNA expression. In the present study, cellular lactic acid-induced acidification and the role of MAPKs signaling in acidification-induced apoptosis were investigated. Acidification, which is caused by $HCO{_3}^-$-free conditions, induced apoptosis and MAPKs (ERK, JNK, and p38) activation. However, MAPKs were slightly activated in acidic conditions in the CHO/anti-LDH cells, indicating that lactic acid-induced acidification induces activation of MAPKs. Treatment with a p38 inhibitor, PD169316, increased acidification-induced apoptosis but apoptosis was not affected by inhibitors for ERK (U0126) or JNK (SP600125). Thus, these data support the hypothesis that activation of the p38 MAPK during acidification-induced apoptosis contributes to cell survival.

• Proceedings of the Korean Society of Toxicology Conference
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• 2001.05a
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• pp.156-156
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• 2001

One of the most frequent defects in human cancer is the uncontroled activation of the ras-signaling pathway. We have previously shown that H-rasm but not N-ras, induces an invasiveness. Here, we show that cell motility was greatly increased by H-ras, but not by N-ras, suggesting that H-ras-induced invasive phnotype involves enhanced cell motility.(omitted)

• Proceedings of the Zoological Society Korea Conference
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• 2001.10a
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• pp.212.1-212
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• 2001

No Abstract, See Full Text

• Herbal Formula Science
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• v.27 no.1
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• pp.53-63
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• 2019

Objectives : In this study, we investigated the combination effects of Cinnamomi cortex Ethanol Extract (CcEE) and hyperthermia in the human AGS gastric cancer cell line. Methods : AGS cells were treated with the indicated concentrations of CcEE (0, 50 or $60{\mu}g/mL$) for 1h prior to hyperthermia. And then incubated for a further 30 min at the indicated temperatures (37, 42 or $43^{\circ}C$) in a humidified incubator containing 5% $CO_2$ or a thermostatically controlled water bath for hyperthermia. The cell viability was measured by MTT assay, Morphology assay and Trypan blue assay. To investigate the possible molecular signaling pathways, the activation of mitogen-activated protein kinase (MAPK) proteins (ERK, p38 and JNK) and expression of various anti-apoptotic proteins such as Caspase-3, Caspase-9, p53, Cyclin D1 and MMP-2 were assessed by Western blot analysis. In addition, Annexin V and 7-amino-actinomycin D (7-AAD) staining was performed to examine the apoptotic mechanism. Results : Combination of CcEE with hyperthermia effectively suppressed the cell viability and changed cellmorphology compared with CcEE or hyperthermia treatment alone. Combined treatment also abated the expression of Caspase-3, Caspase-9, Cyclin D1 and MMP-2. Whereas, the expression level of p53 was up-regulated by co-treatment. Moreover, combination treatment enhanced phosphorylation of ERK, p38 and JNK. In addition, this combination increased anti-cancer effect by inducing cell death through the apoptosis. Conclusions : Taken together, all these findings suggest that the combination treatment with CcEE and hyperthermia may have therapeutic potential as a promising approach to patients with stomach cancer.

• Journal of Microbiology and Biotechnology
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• v.28 no.10
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• pp.1635-1644
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• 2018

Asterias amurensis (starfish) is a marine organism that is harmful to the fishing industry, but is also a potential source of functional materials. The present study was conducted to analyze the profiles of fatty acids extracted from A. amurensis tissues and their anti-inflammatory effects on RAW264.7 macrophage cells. In different tissues, the component ratios of saturated fatty acids, monounsaturated fatty acids, and polyunsaturated fatty acids differed; particularly, polyunsaturated fatty acids such as dihomo-gamma-linolenic acid (20:3n-6) and eicosapentaenoic acid (20:5n-3) were considerably different. In lipopolysaccharide-stimulated RAW264.7 cells, fatty acids from A. amurensis skin, gonads, and digestive glands exhibited anti-inflammatory activities by reducing nitric oxide production and inducing nitric oxide synthase gene expression. Asterias amurensis fatty acids effectively suppressed the expression of inflammatory cytokines such as tumor necrosis $factor-{\alpha}$, interleukin-$1{\beta}$, and interleukin-6 in lipopolysaccharide-stimulated cells. Cyclooxygenase-2 and prostaglandin $E_2$, which are critical inflammation biomarkers, were also significantly suppressed. Furthermore, A. amurensis fatty acids reduced the phosphorylation of nuclear $factor-{\kappa}B$ p-65, p38, extracellular signal-related kinase 1/2, and c-Jun N-terminal kinase, indicating that these fatty acids ameliorated inflammation through the nuclear $factor-{\kappa}B$ and mitogen-activated protein kinase pathways. These results provide insight into the anti-inflammatory mechanism of A. amurensis fatty acids on immune cells and suggest that the species is a potential source of anti-inflammatory molecules.