• 한국전자현미경학회:학술대회논문집
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• 2005.11a
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• pp.127-129
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• 2005

Bacterial lipopolysaccharide(LPS) is can stimulate the most LPS-responsive cells in the mammalian host. The macrophage response to LPS can protect the host from infection but high levels, contribute to systemic inflammatory response syndrome and destruction of host itself, The previously study, secretory leukocyte pretense inhibitor (SLPI) was known LPS-induced product of macrophage and had the function that antagonizes their LPS-induced activation of pro-inflammation signaling factors. Purpose of this study was to identify the expression of SLPI involving the infection in various cell lines including odontoblast cell line. Therefore, we conducted in vitro researches, which treated the LPS to the MDPC-23, and compared to NIH3T3, RAW264.7. To investigate the expressionof SLPI in mRNA level, the methods was used RT-PCR and western blotting for protein expression of SLPI. Moreover, we performed the scanning electron microscopic (SEM) observation for the morphological change. This work was supported by Korea Science and Engineering Foundation.

• Journal of the Korean Society of Food Culture
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• v.33 no.4
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• pp.337-344
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• 2018

Germinated brown rice (GBR, Orysa sartiva L.) has been reported to have anti-obesity and anti-inflammatory effects. However, the mechanisms underlying these effects in adipocytes are not fully understood. Therefore, this study was conducted to explore the anti-inflammatory mechanisms of GBR on lipopolysaccharide (LPS)-stimulated 3T3-L1 adipocytes. 3T3-L1 adipocytes were pretreated with GBR extracts (0-20 mg/mL) 1 h before LPS stimulation. The mRNA expression of adipokines and Toll-like receptor 4 (TLR4) were measured by RT-PCR. The protein expressions of TLR4-related molecules were detected by western blotting and nuclear factor-${\kappa}B$ ($NF-{\kappa}B$) activation was measured. Our results showed that GBR extract dose-dependently inhibited mRNA expression of LPS-induced tumor necrosis factor-${\alpha}$ ($TNF-{\alpha}$), interleukin-6 (IL-6), and monocyte chemoattractant protein-1 (MCP-1). GBR extract was found to inhibit LPS-induced mRNA expression of TLR4 and protein expression of both myeloid differentiation factor 88 (MyD88) and TNF receptor-associated factor 6 (TRAF6). Furthermore, GBR extract significantly inhibited extracellular receptor-activated kinase (ERK) phosphorylation and $NF-{\kappa}B$ activation. These results suggest that GBR extract has the anti-inflammatory effects on LPS-induced inflammation via inhibition of TLR4 signaling, includingthe ERK and $NF-{\kappa}B$ signaling pathways, in adipocytes.

• Tuberculosis and Respiratory Diseases
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• v.65 no.4
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• pp.343-350
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• 2008

PD-L1 is expressed in a variety of antigen-presenting cells and provides T cell tolerance via ligation with its receptor PD-1 and B7-1 on T cells. Stimulation with lipopolysaccharide (LPS) can increase the level of PD-L1 expression in B cells and macrophages, which suggests that this molecule plays a role in the immunosuppression observed in severe sepsis. The aim of this study was to identify which of the downstream pathways of TLR4 are involved in the up-regulation of PD-L1 by LPS in macrophages. Flow cytometry was used to examine the expression of PD-L1 in RAW 264.7 macrophages stimulated with LPS. The following chemical inhibitors were used to evaluate the role of each pathway: LY294002 for PI3K/Akt, SB202190 for p38 MAPK, and U0126 for MEK. LPS induced the expression of PD-L1 in a time- and dose-dependent manner. Transfection of siRNA for TLR4 suppressed the induction of PD-L1. Pretreatment with LY294002 and SB202190 decreased the level of PD-L1 expression but U0126 did not. Overall, the PI3K/Akt and p38 MAPK pathways are involved in the up-regulation of PD-L1 expression in RAW 264.7 macrophages stimulated with LPS.

• International Journal of Oral Biology
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• v.49 no.3
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• pp.79-86
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• 2024

Periodontal disease (PD) is strongly linked to increased risk of oral squamous cell carcinoma (OSCC); however, the specific mechanism through which the development of PD and OSCC is simultaneously promoted remains unclear. This study explored the impact of periodontal pathogens on OSCC progression and the contribution of periodontal pathogen-stimulated OSCC to PD development. The expression of osteoclastogenesis-inducing factors was assessed using quantitative reverse transcription polymerase chain reaction analysis following stimulation of OSCC with lipopolysaccharide (LPS) derived from the periodontal pathogen Porphyromonas gingivalis (Pg), a pathogen commonly responsible for PD. The cell counting kit-8 assay was used to determine the effects of Pg-LPS on OSCC proliferation and drug resistance to cisplatin and 5-fluorouracil. The effects of conditioned medium (CM) derived from Pg-LPS-stimulated OSCC on osteoclastogenesis was evaluated using tartrate-resistant acid phosphatase (TRAP) staining on bone marrow-derived macrophages (BMMs). Pg-LPS administration in SCC-25 and YD-8 OSCC cell lines induced a significant increase in receptor activator of nuclear factor kappa-B ligand mRNA expression; however, it did not affect cell proliferation. Treatment with CM derived from Pg-LPS-stimulated SCC-25 or YD-8 cells markedly enhanced the formation of TRAP-positive multinucleated cells during osteoclast differentiation of BMMs. Altogether, these findings demonstrate that Pg-LPS-stimulated OSCC promoted osteoclastogenesis through a paracrine mechanism.

• The Korean Journal of Physiology and Pharmacology
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• v.19 no.3
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• pp.263-268
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• 2015

5-Lipoxygenase (5-LO) plays a pivotal role in the progression of atherosclerosis. Therefore, this study investigated the molecular mechanisms involved in 5-LO expression on monocytes induced by LPS. Stimulation of THP-1 monocytes with LPS ($0{\sim}3{\mu}g/ml$) increased 5-LO promoter activity and 5-LO protein expression in a concentration-dependent manner. LPS-induced 5-LO expression was blocked by pharmacological inhibition of the Akt pathway, but not by inhibitors of MAPK pathways including the ERK, JNK, and p38 MAPK pathways. In line with these results, LPS increased the phosphorylation of Akt, suggesting a role for the Akt pathway in LPS-induced 5-LO expression. In a promoter activity assay conducted to identify transcription factors, both Sp1 and NF-${\kappa}B$ were found to play central roles in 5-LO expression in LPS-treated monocytes. The LPS-enhanced activities of Sp1 and NF-${\kappa}B$ were attenuated by an Akt inhibitor. Moreover, the LPS-enhanced phosphorylation of Akt was significantly attenuated in cells pretreated with an anti-TLR4 antibody. Taken together, 5-LO expression in LPS-stimulated monocytes is regulated at the transcriptional level via TLR4/Akt-mediated activations of Sp1 and NF-${\kappa}B$ pathways in monocytes.

• Applied Biological Chemistry
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• v.48 no.4
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• pp.411-417
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• 2005

Aqueous extracts were prepared from 21 medicinal herbs including Herba Pogostemi (Agastache rugosa) to examine their modulatory effects on NO production in mouse macrophage cell line RAW264.7 cells. While almost all medicinal herb extracts failed to show marked scavenging activities to NO produced by LPS stimulation, only Herba Pogostemi showed a rather strong induction of NO production in RAW264.7 cells without stimulation with LPS. When we treated the cell with $200{\mu}M\;of\;N^G-monomethyl-L-arginine\;(N^GMMA)$, a NOS2 inhibitor, a significant reduction in NO production could be observed. Moreover, a treatment of $100{\mu}M$ pyrrolidine dithiocarbamate (PDTC) led to about a 79% reduction of NO production. These results demonstrated that the aqueous extract of Herba Pogostemi might provide a second signal for the expression of NOS2 in RAW264.7 cells, and suggested that Herba Pogostemi induces NO production through L-argininedependent pathway.

• The Journal of Korean Medicine
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• v.22 no.2
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• pp.109-119
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• 2001

Objective : There are many reports that acupuncture has thermoregulatory effects on human and animals. To investigate the effect and mechanism of antipyretic action of acupuncture, we observed the body temperature and cytokine expressions in the hypothalamus of rats. Methods : Lipopolysaccharide (LPS, i.p., 2.5mg/kg) was injected to conscious rats (Sprague-Dawley, male, n=4l) to cause hyperthermia and simple needling (stainless steel, 0.25 mm o.d., 5 mm insertion for 10 sec with no manipulation) was performed bilaterally with the measurement of rectal temperature. Next, we sacrificed rats to remove brain and determined the level of mRNA for interleukin-6 (IL-6), $interleukin-1{\beta}{\;}(IL-1{\beta})$, interleukin-2 (IL-2) and $interferon-{\gamma}{\;}(IFN-{\gamma})$ in the hypothalamus by using reverse transcriptase-polymerase chain reaction (RT-PCR). Resul1s : Needling on forepaw (acupoint HT8) and needling on hindpaw (acupoint BL66 and acupoint LR2) significantly inhibited LPS-induced fever of rats (P<0.01, 10 min after treatment respectively), but same treatment on proximal tail (non-acupoint) did not cause any change on fever. The levels of IL-6 and $IL-1{\beta}$ mRNA in the hypothalamus was significantly enhanced by LPS-injection, while the level of IL-6 and $IL-1{\beta}$ mRNA was markedly reduced after treatment on BL66 (P<0.01). Treatment on forepaw reduced it slightly, but not significantly. Equivalent stimulation on proximal tail did not cause any changes. Conclusions : Our results indicate that acupuncture stimulation on various body parts has differential thermoregulatory effects on LPS-induced fever of rats with site-specificity. And, we suggest that its antipyretic action might be accompanied with the suppression of hypothalamic production of pro-inflammatory cytokine of immune system, IL-6 and $IL-1{\beta}$.

• Mycobiology
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• v.38 no.2
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• pp.144-148
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• 2010

$\beta$-Glucans have been known to exhibit antitumor activities by potentiating host immunity by an unknown mechanism. The C-type lectin dectin-1, a $\beta$-glucan receptor, is found on the macrophage and can recognize various $\beta$-glucans. Previously, we demonstrated the presence of $\beta$-glucan receptor, dectin-1, on the Raw 264.7 cells as well as on murine mucosal organs, such as the thymus, the lung, and the spleen. In order to investigate immunopotentiation of innate immunity by $\beta$-glucan, we stimulated a murine macrophage Raw 264.7 cell line with $\beta$-glucans from Pleurotus ostreatus, Saccharomyces cerevisiae, and Laminaria digitata. Then, we analyzed cytokines such as tumor necrosis factor (TNF)-$\alpha$ and interleukin (IL)-6 by reverse transcription-polymerase chain reaction (RT-PCR). In addition we analyzed gene expression patterns in $\beta$-glucan-treated Raw 264.7 cells by applying total mRNA to cDNA microarray to investigate the expression of 7,000 known genes. When stimulated with $\beta$-glucans, the macrophage cells increased TNF-$\alpha$ expression. When co-stimulation of the cells with $\beta$-glucan and lipopolysaccharide (LPS), a synergy effect was observed by increased TNF-$\alpha$ expression. In IL-6 expression, any of the $\beta$-glucans tested could not induce IL-6 expression by itself. However, when co-stimulation occurred with $\beta$-glucan and LPS, the cells showed strong synergistic effects by increased IL-6 expression. Chip analysis showed that $\beta$-glucan of P. ostreatus increased gene expressions of immunomodulating gene families such as kinases, lectin associated genes and TNF-related genes in the macrophage cell line. Induction of TNF receptor expression by FACS analysis was synergized only when co-stimulated with $\beta$-glucan and LPS, not with $\beta$-glucan alone. From these data, $\beta$-glucan increased expressions of immunomodulating genes and showed synergistic effect with LPS.

• Journal of Marine Life Science
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• v.3 no.2
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• pp.45-50
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• 2018

Rock bream iridovirus (RBIV) is a megalocytivirus widely infected in various fish species in Korea, causing symptoms of acute inflammation and enlargement of spleen. In our previous study, RBIV induced the initial upregulation but later down-regulation of proinflammatory cytokines and IFN1 gene expression. Signal transducers and activators of transcriptions (STAT) are transcription factors involved in the regulation of immune genes including IFNs. This study was conducted to analyse the expression of STAT2. The expressional study of STAT2 gene was performed in head kidney and spleen upon RBIV infection and immune stimulants like LPS or poly I:C in vitro. Consequently, STAT2 gene expression pattern was different in head kidney and spleen as it was significantly up-regulated by LPS from 4 h to 8 h but down-regulated at 24 h while up-regulated by poly I:C at 8 h in head kidney while, in spleen, STAT2 gene expression was down regulated by LPS but significantly up-regulated by poly I:C. Upon RBIV stimulation, STAT2 gene expression was significantly down-regulated by high dose RBIV at 4 h but up-regulated at 8 h and 24 h in head kidney. In spleen cells, it was up-regulated by medium dose RBIV at 4 h and by high dose RBIV at 4 h and 8 h but down regulated later then. In vivo, STAT2 gene expression was not significantly affected by RBIV infection while significant up-regulated by vaccination at day 7 post-vaccination, indicating STAT2 gene can be involved in adaptive immune response in rock bream.

• IMMUNE NETWORK
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• v.21 no.5
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• pp.37.1-37.17
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• 2021

Hepatitis B virus X (HBx) protein has been reported as a key protein regulating the pathogenesis of HBV-induced hepatocellular carcinoma (HCC). Recent evidence has shown that HBx is implicated in the activation of autophagy in hepatic cells. Nevertheless, the precise molecular and cellular mechanism by which HBx induces autophagy is still controversial. Herein, we investigated the molecular and cellular mechanism by which HBx is involved in the TRAF6-BECN1-Bcl-2 signaling for the regulation of autophagy in response to TLR4 stimulation, therefore influencing the HCC progression. HBx interacts with BECN1 (Beclin 1) and inhibits the association of the BECN1-Bcl-2 complex, which is known to prevent the assembly of the pre-autophagosomal structure. Furthermore, HBx enhances the interaction between VPS34 and TRAF6-BECN1 complex, increases the ubiquitination of BECN1, and subsequently enhances autophagy induction in response to LPS stimulation. To verify the functional role of HBx in liver cancer progression, we utilized different HCC cell lines, HepG2, SK-Hep-1, and SNU-761. HBx-expressing HepG2 cells exhibited enhanced cell migration, invasion, and cell mobility in response to LPS stimulation compared to those of control HepG2 cells. These results were consistently observed in HBx-expressed SK-Hep-1 and HBx-expressed SNU-761 cells. Taken together, our findings suggest that HBx positively regulates the induction of autophagy through the inhibition of the BECN1-Bcl-2 complex and enhancement of the TRAF6-BECN1-VPS34 complex, leading to enhance liver cancer migration and invasion.