• International Journal of Oral Biology
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• v.39 no.4
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• pp.221-228
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• 2014

Glucosamine is commonly taken by the elderly without prescription as a nutritional supplement to attenuate the progression or symptoms of osteoarthritis. Previous studies demonstrated that glucosamine shows anti-inflammatory effects in tissues such as blood vessels and the heart. However, there have been few reports about the effects of glucosamine on oral inflammatory diseases. Therefore, in this study, the effects of glucosamine on lipopolysaccharide (LPS)-induced inflammatory responses were investigated using human periodontal ligament fibroblasts (HPDLFs). HPDLFs were incubated in the presence and absence of glucosamine (10 mM) for 24 h, followed by treatment with E. coli LPS (100 ng/ml) or vehicle. Quantitative RT-PCR and ELISA results showed that LPS exposure significantly increased the levels of IL-6 and IL-8 mRNA and protein, while the effect was significantly suppressed by glucosamine treatment. Glucosamine did not attenuate, but slightly increased, the LPS-induced activation of mitogen activated kinases (ERK, p38, JNK). However, it suppressed the LPS-induced increase in the DNA binding affinity and transcriptional activity of NF-${\kappa}B$. These results suggest that glucosamine exerts anti-inflammatory effects on HPDLFs exposed to LPS via inhibition of NF-${\kappa}B$ activity, necessitating further studies using animal periodontitis models.

• The Microorganisms and Industry
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• v.19 no.4
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• pp.32-35
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• 1993

ras는 활성화 형태인 GTP bound form과 비활성화 형태인 GDP bound form의 두 형태로 존재하며 두 형태를 매개하는 regulatory protein들에 의해 그 activity가 조절된다. 또한 ras는 GTP와 GDP에 강한 친화성이 있으며 세포내에는 GTP보다 GDP가 더 많이 있어서 평소에는 ras가 GDP와 결합하고 있다가 활성화될때만 GTP와 결합하는 것으로 추정된다. GDP bound ras는 guanine nucloetide exchange protein(GEP)에 의해 활성화된 GTP bound form으로 전환되며 ras의 기능이 발휘된 후에는 GTPase activating protein(GAP)에 의해 비활성화된다. Yeast의 경우 IRA1과 2의 product가 GAP의 역할을 하는 것으로 알려져 있고 CDC25 gene의 product가 GEP의 기능을 담당하는 것으로 알려져 있다. NF1 gene은 Von Recklinghausen Neurofibromatosis Type I 질병을 가진 환자에게서 발견되었는데 부분적으로 sequencing한 결과에 따르면 yeast의 IRA1/2, mammalian GAP gene product와 protein homology가 높은 것으로 나타났다. Yeast의 경우 IRA1/2 gene의 손실이나 mammalian ras gene의 transformation으로 인한 heat shock sensitivity가 NF1 gene(2,3) 혹은 GAP(4)의 expression으로 suppression된 것으로 보아 NF1이 GAP protein으로서 ras를 불활성화 시킨다는 것이 판명되었다. 결론적으로 ras의 활성은 GTP bound 혹은 GDP bound의 양쪽형태를 이동하면서 조절되는데 이 기능은 GAP과 GEP 또는 그의 유사 protein들에 의해 수행되며 이러한 regulatory protein들은 growth factor, cytokine 그리고 protein kinase 같은 signal에 의해 활성화된다고 생각된다. 본 총설에서는 ras protein의 여러가지 성질보다는 ras의 modification과 관련하여 항암제로 사용할 수 있는 ras에 specific한 약품개발의 가능성과 현재 알려진 ras의 inhibitor를 중심으로 논하고자 한다.

• Bulletin of the Korean Chemical Society
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• v.34 no.4
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• pp.1165-1169
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• 2013

To elucidate the role of PKG isoforms in transcriptional control of cyclin D1, we employed a series of expression vectors of PKG $1{\alpha}$ and PKG $1{\beta}$ which encode HA-tagged wild type and constitutively active (SD and ${\Delta}N$) mutants. Our present study demonstrates that both the constitutively active mutants of PKG $1{\beta}$ downregulate the transcription of cyclin D1 when transiently transfected in NIH3T3 cells, whereas PKG $1{\alpha}$ mutants show weak inhibition. We further studied the transcriptional regulators of cyclin D1, such as, c-fos, NF-${\kappa}B$, and CRE by using the luciferase reporter assay. Constitutively active mutants of PKG $1{\beta}$ showed marked transcriptional downregulation of c-fos in NIH3T3 cells, whereas PKG $1{\alpha}$ downregulated c-fos to a lesser extent. We also found that the constitutively active mutants of PKG negatively regulated the activation of NF-${\kappa}B$ and CRE, suggesting their involvement in the regulation of cyclin D1.

• International Journal of Oral Biology
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• v.42 no.4
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• pp.149-153
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• 2017

Cyclooxygenase-2 (COX-2)-mediated prostaglandin $E_2$ ($PGE_2$) plays a key role in development and progression of inflammatory responses and Porphyromonas gingivalis is a common endodontic pathogen. In this study, we investigated induction of COX-2 and $PGE_2$ by P. gingivalis in human dental pulp cells (HDPCs). P. gingivalis increased expression of COX-2, but not that of COX-1. Increased levels of $PGE_2$ were released from P. gingivalis-infected HDPCs and this $PGE_2$ increase was blocked by celecoxib, a selective COX-2 inhibitor. P. gingivalis activated all three types of mitogen-activated protein kinases (MAPKs). P. gingivalis-induced activation of nuclear $factor-{\kappa}B$ ($NF-{\kappa}B$) was demonstrated by the results of phosphorylation of $NF-{\kappa}B$ p65 and degradation of inhibitor of ${\kappa}B-{\alpha}$ ($I{\kappa}B-{\alpha}$). Pharmacological inhibition of each of the three types of MAPKs and $NF-{\kappa}B$ substantially attenuated P. gingivalis-induced $PGE_2$ production. These results suggest that P. gingivalis should promote endodontic inflammation by stimulating dental pulp cells to produce $PGE_2$.

• Biomedical Science Letters
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• v.26 no.4
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• pp.267-274
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• 2020

The larva of Protaetia brevitarsis Lewis (P. brevitarsis), edible insect, is traditionally consumed as alternative source of nutrients and has various health benefits. However, the exact pharmaceutical effects of P. brevitarsis on inflammatory response are still not well understood. Thus, we investigated the anti-inflammatory effects and mechanisms of P. brevitarsis in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. We investigated the effects of P. brevitarsis on the expression levels of inflammatory-related genes, including inflammatory cytokines, prostaglandin E2 (PGE2), cyclooxygenase (COX)-2 and inducible nitric oxide synthase (iNOS) in LPS-stimulated RAW264.7 cells. To understand the anti-inflammatory mechanism of P. brevitarsis, we explored the regulatory effect of P. brevitarsis on nuclear factor (NF)-κB and caspase-1 activation. The findings of this study demonstrated that P. brevitarsis inhibits the LPS-induced inflammatory cytokine and PGE2 levels, as well as COX-2 and iNOS expression. Moreover, we confirmed that the anti-inflammatory effect of P. brevitarsis occurs via suppression of the activation of NF-κB and caspase-1. Conclusively, these findings provide experimental evidence that P. brevitarsis may be useful candidate for the treatment of inflammatory-related diseases.

• Biomedical Science Letters
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• v.27 no.4
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• pp.248-254
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• 2021

Ulcerative colitis (UC), chronic inflammatory bowel disease, is characterized by severe inflammation in the colon. Tea is one of the most popular beverages consumed worldwide. Pu-erh tea, a unique Chinese tea produced by microbial activities, possesses a broad range of health-promoting effects, including anti-aging, anti-Alzheimer's disease, antioxidation and anti-obesity. However, the inhibitory effect of Pu-erh tea on intestinal inflammation and the underlying mechanism remain unclear. The present study was designed to evaluate the regulatory effect of Pu-erh tea extract (PTE) on dextran sulfate sodium (DSS)-induced colitis clinical signs by analyzing the weight loss and colon length in mice. The inhibitory effects of PTE on inflammatory mediators, such as interleukin (IL)-6 and tumor necrosis factor (TNF)-α, and the activation of nuclear factor-κB (NF-κB) were also determined in DSS-treated colitis tissue. We observed that PTE treatment significantly inhibited the DSS-induced clinical symptoms of weight loss, decrease,in colon length, and colon tissue damage in mice. Moreover, PTE attenuated the DSS-induced levels of IL-6 and TNF-α in colon tissue. We also demonstrated the anti-inflammatory mechanism of PTE by suppressing the activation of NF-κB in DSS-treated colon tissues. Collectively, the findings provide experimental evidence that PTE may be effective in preventing and treatment of intestinal inflammatory disorders, including UC.

• Food Science of Animal Resources
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• v.43 no.5
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• pp.938-947
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• 2023

In the present study, we aimed to examine the inhibition of genomic DNA from Lactiplantibacillus plantarum (LpDNA) on Porphyromonas gingivalis lipopolysaccharide (PgLPS)-induced inflammatory responses in RAW264.7 cells. Pretreatment with LpDNA for 15 h significantly inhibited PgLPS-induced mRNA expression and protein secretion of interleukin (IL)-1β, IL-6, and monocyte chemoattractant protein-1. LpDNA pretreatment also reduced the mRNA expression of Toll-like receptor (TLR)2 and TLR4. Furthermore, LpDNA inhibited the phosphorylation of mitogen-activated protein kinases (MAPKs) and the activation of nuclear factor-κB (NF-κB) induced by PgLPS. Taken together, these findings demonstrate that LpDNA attenuates PgLPS-induced inflammatory responses by regulating MAPKs and NF-κB signaling pathways through the suppression of TLR2 and TLR4 expression.

• Geomechanics and Engineering
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• v.32 no.4
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• pp.361-373
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• 2023

This study aimed to investigate the engineering properties and mechanical behaviors of polymer-fibers treated sand. Para rubber (PR), natural fiber (NF), and geosynthetic fiber (GF) were used to reinforce poorly graded sand. A series of unconfined compressive and splitting tensile strength tests were performed to analyze the engineering behaviors and strength enhancement mechanism. The experiment results indicated that the PR-fibers mixture could firmly enhance the strength properties of sand. The stress-strain characteristics and failure patterns have been changed due to the increase of PR and fibers content. The presence of PR and fibers strengthened the sand and enhanced the stiffness and ductility behavior of the mixture. The stiffness of reinforced sand reaches an optimum state when both NF and GF are 0.5%, while the optimum PR contents are 20% and 22.5% for the mixture with NF and GF, respectively. An addition of PR and fiber into sand contributed to increasing interlocking zone and bonding of PR-sand interfacial.

• Asian Journal of Turfgrass Science
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• v.22 no.2
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• pp.185-196
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• 2008

This Study was conducted to evaluate the effect of liquid fertilizer containing medium of on growth of shoot and root in creeping bentgrass (Agrostis palustris Huds. cv. Pennlixs). According to application method of liquid fertilizer, the experiment plot was designed as follows; NF : non-fertilizer; CF : compound fertilizer(21-17-17) only; T500, T300, T100 : compound fertilizer +liquid fertilizer solution diluted 500, 300, 100 folds, respective; L500 : only liquid fertilizer solution which contained the medium of Lactobacillus confusa and Pichia anomala diluted 500 folds. The every treatments was arranged by a completely randomized complete block designs with three replications. The order of turf qualities like leaf color index and chlorophyll content in treatments showed T500 T300 T100 $\geq$ CF > NF. In treatment applied with compound fertilizer, the dry weight of shoot increased by about 13% in T500, T300 and T100 than CF, and that of root about 25% in just T300. Dry weight of shoot and root increased by 88% and 44% in L500 than NF, respectively. As compared with CF, T/R ratio in T500, T300 and T100 increased by 20%, 11% and 21%, respectively and root length 7%, 8% and 3%. In comparison with NF, T/R ratio and root length in L500 increased by 39% and 74%. These results suggested that the application of liquid fertilizer containing medium of Lactobacillus confusa and Pichia anomala induced the development of turf quality and growth by promoting root growth in creeping bentgrass.

• Environmental Engineering Research
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• v.17 no.4
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• pp.185-190
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• 2012

Rejection characteristics of perchlorate ($ClO_4^-$) were examined for commercially available reverse osmosis (RO) and nanofiltration (NF) membranes. A bench-scale dead-end stirred-cell filtration system was employed to determine the toxic ion rejection and the membrane flux. Model water solutions were used to prepare $ClO_4^-$ solutions (approximately, $1,000{\mu}g/L$) in the presence of background salts (NaCl, $Na_2SO_4$, and $CaCl_2$) at various pH values (3.5, 7, and 9.5) and solution ionic strengths (0.001, 0.01, and 0.01 M NaCl) in the presence of natural organic matter (NOM). Rejection by the membranes increased with increasing solution pH owing to increasingly negative membrane charge. In addition, the rejection of the target ion by the membranes increased with increasing solution ionic strength. The rejection of $ClO_4^-$ was consistently higher for the RO membrane than for the NF membrane and $ClO_4^-$ rejection followed the order $CaCl_2$ < NaCl < $Na_2SO_4$ at conditions of constant pH and ionic strength for both the RO and NF membranes. The possible influence of NOM on $ClO_4^-$ rejection by the membranes was also explored.