• International Journal of Oral Biology
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• v.44 no.1
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• pp.20-26
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• 2019

Periodontal diseases have been associated with the development of cardiovascular diseases. Accumulating evidences have indicated that Porphyromonas gingivalis, a major periodontopathic pathogen, plays a critical role in the pathogenesis of atherosclerosis. In the present study, we demonstrated that P. gingivalis lipopolysaccharide (LPS) increases the mRNA and protein expression of matrix metalloproteinase-9 (MMP-9) in rat vascular smooth muscle cells. We showed that the MMP-9 expression induced by P. gingivalis LPS is mediated by the activation of signal transducer and activator of transcription 3 (STAT3) in vascular smooth muscle cells. Furthermore, the inhibition of STAT3 activity reduced P. gingivalis LPS-induced migration of vascular smooth muscle cells. Overall, our findings indicate that P. gingivalis LPS stimulates the migration of vascular smooth muscle cells via STAT3-mediated MMP-9 expression.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.9
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• pp.1226-1234
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• 2012

3,4,3',5'-Tetrahydroxy-trans-stilbene (piceatannol) is a derivative of resveratrol with a variety of biological activities, including anti-inflammatory, anti-proliferative, and anti-cancer activities. We assessed the mechanisms by which piceatannol inhibits inflammatory responses using lipopolysaccharide (LPS)-treated Raw264.7 murine macrophages. Piceatannol (0~10 ${\mu}mol/L$) decreased LPS-induced release of nitric oxide, tumor necrosis factor (TNF)-${\alpha}$, interleukin (IL)-6, IL-$1{\beta}$, and inhibited LPS-induced protein expression of inducible nitric oxide synthase (iNOS). Activation of nuclear factor-kappaB (NF-${\kappa}B$), activator protein (AP)-1, and signal transducer and activator of transcription 3 (STAT3) are crucial steps during an inflammatory response. Piceatannol prevented LPS-induced degradation of inhibitor of ${\kappa}B$ ($I{\kappa}B$), translocation of p65 to the nucleus, and phosphorylation of stress-activated protein kinase/c-Jun NH2-terminal kinase (SAPK/JNK). Additionally, piceatannol inhibited LPS-induced phosphorylation of STAT3 and IL-6-induced translocation of STAT3 to the nucleus. Furthermore, piceatannol increased the protein and mRNA levels of hemeoxygenase (HO)-1, the rate-limiting enzyme of heme catabolism that plays a critical role in mediating antioxidant and anti-inflammatory effects. Piceatannol further induced antioxidant response elements (ARE)-driven luciferase activity in Raw264.7 cells transfected with an ARE-luciferase reporter construct containing the enhancer 2 and minimal promoter region of HO-1. These results suggest that piceatannol exerts anti-inflammatory effects via the down-regulation of iNOS expression and up-regulation of HO-1 expression.

• Parasites, Hosts and Diseases
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• v.51 no.5
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• pp.589-594
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• 2013

In intestinal helminth infections, Th2 immune respones are generally associated with mucin secretion for worm expulsion from the host intestine. In particular, IL-4 and IL-13 are the important cytokines related with intestinal mucus production via STAT6 signalling in nematode infections. However, this perspective has never been studied in Gymnophalloides seoi infection. The present study aimed to observe the STAT6 signalling and cytokine responses in C57BL/6 mice, a mouse strain resistant to infection with this trematode. The results showed that worm expulsion occurred actively during days 1-2 post-infection (PI), when goblet cells began to proliferate in the small intestine. The STAT6 gene expression in the mouse spleen became remarkable from day 2 PI. Moreover, G. seoi infection induced a significant increase of IL-13 from day 4 PI in the spleen of infected mice. Our results suggested that goblet cell hyperplasia and worm expulsion in G. seoi-infected mice should be induced by STAT6 signalling, in which IL-13 may be involved as a dominant triggering cytokine.

• BMB Reports
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• v.34 no.6
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• pp.578-583
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• 2001

As a prototypic Thl vs Th2 cytokine, IFN-$\gamma$ and IL-4 activate distinct STAT proteins, STAT1 and STATE, respectively. In cytokine-producing Jurkat T cells, IL-4 is effectively rescued from cell death that is induced by dexamethasone, but IFN-$\gamma$ failed to do so. Since the Ras/MAPK pathway is known to play an important role in cytokine-induced cell survival, we investigated the mechanism of T cell survival through the analysis of functional cross-talk between Ras/MAPK and distinct STAT proteins that are activated by IL-4 and IFN-$\gamma$. Although IL-4 and IFN-$\gamma$ each induced the activation of STATE and STATI. in Jurkat T cells, respectively, only IL-4 was capable of inducing MAPK. Along with tyrosine kinase inhibitors, MEK/MAPK inhibitors also caused a significant suppression of the IL-4-induced STATE activity. This suggests a positive regulation of STATE by MAPK during IL-4 signal transduction. Furthermore, transfection studies with dominant active (da) vs dominant negative (dn) Ras revealed that daRas, but not dnRas, selectively up-regulated the expression and activity of STATE with a concomitant increase in MAPK activity. These results, therefore, suggest that there is a functional cross-talk between the Ras/MAPK and Jak/STAT6 pathways, which may have a role in the IL-4-induced T cell survival.

• Korean Journal of Medicinal Crop Science
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• v.17 no.3
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• pp.217-222
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• 2009

The purpose of this study evaluated the immunoregulatory effect of phellinus linteus ethanol (PLE) extracts on liver damage on carbon tetrachloride ($CCl_4$) induced in rats. Four-week old Male Sprague-Dawley rats were divided into the three experimental groups randomly; Control group, $CCl_4$ group, $CCl_4$ + PLE group. We found that effect of PLE on $IFN-\gamma$, STAT1 and pSTAT1 was decrease in vivo. Several genes were demonstrated to be IL-4 inducible prior to the discovery of STAT6. IL-4, STAT6 and pSTAT6 decreased significantly lower in $CCl_4$ + PLE than the $CCl_4$ group. Our data indicated that cytokine protein production were increased in $CCl_4$ group with $CCl_4$ + PLE group. In our data indicate that IgA levels in MLN lymphocytes were low, while IgE was high in $CCl_4$ + PLE group compared with $CCl_4$ group. Therefore, the results of this study show that PLE can be proposed to protect the liver against $CCl_4$-induced immunoregulatory activity in rats.

• International Journal of Oncology
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• v.55 no.1
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• pp.203-210
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• 2019

To overcome the poor prognosis of patients with ovarian cancer, attempting to target ovarian cancer with effective antitumor compounds has been conducted for numerous years. Although the 3,4-dihydroquinazoline derivative KYS05090S was known to exert antitumor effects in A549 and ovarian cancer cells by inhibition of T-type Ca²⁺ channels, the complete underlying antitumor mechanism of this compound remains unclear. Thus, in the present study, the potential apoptotic mechanism of KYS05090S was elucidated in SKOV3 and OVCAR3 ovarian cancer cells. KYS05090S exerted significant cytotoxicity in SKOV3 and OVCAR3 ovarian cancer cells, and also increased the number of apoptotic bodies, and the number of terminal deoxynucleotidyl transferase dUTP nick end labeling positive cells and the sub-G1 population as a feature of apoptosis. Consistently, KYS05090S induced cleavage of poly(ADP-ribose) polymerase and caspase-9/3 in ovarian cancer cells. Notably, KYS05090S attenuated the expression of anti-apoptotic proteins, including cyclin D1 and B-cell lymphoma-2 (Bcl-2), and reduced the phosphorylation of Janus kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3) in ovarian cancer cells. Additionally, KYS05090S blocked the nuclear translocation of STAT3 and suppressed the signaling of JAK2/STAT3 in interleukin-6-treated SKOV3 cells, as a STAT3 activator. Overall, these observations indicated that inhibition of JAK2/STAT3 signaling and activation of caspase-9/3 are critically involved in the effects of KYS05090S on apoptosis in ovarian cancer types, and the compound may be beneficial as a potent antitumor agent.

• The Korean Journal of Physiology and Pharmacology
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• v.15 no.5
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• pp.251-258
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• 2011

Here we have investigated how lactosylceramide (LacCer) modulates gene expression of adhesion molecules in TNF-${\alpha}$ and IFN ${\gamma}$ (CM)-stimulated astrocytes. We have observed that stimulation of astrocytes with CM increased the gene expression of ICAM-1 and VCAM-1. D-Threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol (PDMP) and N-butyldeoxynojirimycin (NBDNJ), inhibitors of glucosylceramide synthase (GLS) and LacCer synthase (galactosyltransferase, GalT-2), inhibited the gene expression of ICAM-1 and VCAM-1 and activation of their gene promoter induced by CM, which were reversed by exogenously supplied LacCer. Silencing of GalT-2 gene using its antisense oligonucleotides also attenuated CM-induced ICAM-1 and VCAM-1 expression, which were reversed by LacCer. PDMP treatment and silencing of GalT-2 gene significantly reduced CM-induced luciferase activities in NF-${\kappa}B$, AP-1, GAS, and STAT-3 luciferase vectors-transfected cells. In addition, LacCer reversed the inhibition of NF-${\kappa}B$ and STAT-1 luciferase activities by PDMP. Taken together, our results suggest that LacCer may play a crucial role in the expression of ICAM-1 and VCAM-1 via modulating transcription factors, such as NF-${\kappa}B$, AP-1, STAT-1, and STAT-3 in CM-stimulated astrocytes.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.6
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• pp.2453-2459
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• 2014

Ginsenoside Rg1 is one effective anticancer and antioxidant constituent of total saponins of Panax ginseng (TSPG), which has been shown to have various pharmacological effects. Our previous study demonstrated that Rg1 had anti-tumor activity in K562 leukemia cells. The aim of this study was designed to investigate whether Rg1 could induce apoptosis in TF-1/Epo cells and further to explore the underlying molecular mechanisms. Here we found that Rg1 could inhibit TF-1/Epo cell proliferation and induce cell apoptosis in vitro in a concentration and time dependent manner. It also suppressed the expression of EpoR on the surface membrane and inhibited JAK2/STAT5 pathway activity. Rg1 induced up-regulation of Bax, cleaved caspase-3 and C-PAPR protein and down-regulation of Bcl-2 and AG490, a JAK2 specific inhibitor, could enhance the effects of Rg1. Our studies showed that EpoR-mediated JAK2/STAT5 signaling played a key role in Rg1-induced apoptosis in TF-1/Epo cells. These results may provide new insights of Rg1 protective roles in the prevention a nd treatment of leukemia.

• Korean Journal of Medicinal Crop Science
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• v.17 no.4
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• pp.273-279
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• 2009

GATA-binding protein-3 (GATA-3) and T-box expressed in T-cells (T-bet) are now considered as master transcription factors involving Th cell differentiation, but the roles of these factors are still uncertain in vivo. This study was conducted to investigate the expression of these transcription factors in the liver damage induced by carbon tetrachloride ($CCl_4$) in rats. In this study, liver damage were induced with Scutellaria baicalensis Georgi water extracts (SBW) and followed for 4 weeks. The expression of GATA-3 and T-bet protein in liver damage induced by $CCl_4$ and the serum levels of immunoglobulin A (IgA), IgE were studied after 4 weeks of treatment. We found that effect of SBW on IFN-$\gamma$, STAT1, pSTAT1 and T-bet was decreased in vivo. Several genes were demonstrated to be IL-4 inducible prior to the discovery of STAT6. $CCl_4$+SBW group was significantly lower than $CCl_4$ group in IL-4, STAT6, pSTAT6 and GATA-3. Our data indicate that cytokine protein production were increased in $CCl_4$ group and $CCl_4$+SBW group. From these results, water extracts obtained from Scutellaria baicalensis Georgi may have an immunoregulatory effect in the liver induced by $CCl_4$ of rats.

• Biomolecules & Therapeutics
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• v.26 no.5
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• pp.464-473
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• 2018

Cripto is a small glycosylphosphatidylinositol-anchored signaling protein that can detach from the anchored membrane and stimulate proliferation, migration, differentiation, vascularization, and angiogenesis. In the present study, we demonstrated that Cripto positively affected proliferation and survival of mesenchymal stem cells (MSCs) without affecting multipotency. Cripto also increased expression of phosphorylated janus kinase 2 (p-JAK2), phosphorylated signal transducer and activator of transcription 3 (p-STAT3), 78 kDa glucose-regulated protein (GRP78), c-Myc, and cyclin D1. Notably, treatment with an anti-GRP78 antibody blocked these effects. In addition, pretreatment with STAT3 short interfering RNA (siRNA) inhibited the increase in p-JAK2, c-Myc, cyclin D1, and BCL3 levels caused by Cripto and attenuated the pro-survival action of Cripto on MSCs. We also found that incubation with Cripto protected MSCs from apoptosis caused by hypoxia or $H_2O_2$ exposure, and the level of caspase-3 decreased by the Cripto-induced expression of B-cell lymphoma 3-encoded protein (BCL3). These effects were sensitive to down-regulation of BCL3 expression by BCL3 siRNA. Finally, we showed that Cripto enhanced expression levels of vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF), and hepatocyte growth factor (HGF). In summary, our results demonstrated that Cripto activated a novel biochemical cascade that potentiated MSC proliferation and survival. This cascade relied on phosphorylation of JAK2 and STAT3 and was regulated by GRP78. Our findings may facilitate clinical applications of MSCs, as these cells may benefit from positive effects of Cripto on their survival and biological properties.