• The Korean Journal of Zoology
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• v.34 no.2
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• pp.173-180
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• 1991

The objective of this experiment was to examine the effect of polyamine depletion by polyamine biosynthesis inhibitors on microbicidal activity and tumoricidal activity in mouse mac-rophages. $\alpha$ -Difluoromethylomithine (DFMO), inhibitor of putrescine and spernidine biosynthesis, treatment in vivo for 6-8 days reduced chemiluminescence levels in thioglycollate-, lipo-polysaccharide (LPS), and BCG-treated mouse macrophages. An DFMO treatment in vitro inhibited production of tumor necrosis factor (TNF), in dose-dependent manner, and tumoricidal activity by macrophages. The effect of polyamine depletion by MO on ThF production and tumoricidal activity could be reversed by the addition of exogenous putrescine. These result indicated that the obserbed effect of DFMO on macrophage activities were mediated through inhibition of polyamines are, must be, required for optimal activities of macrophages.

• Preventive Nutrition and Food Science
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• v.16 no.3
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• pp.242-247
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• 2011

The methanolic extract of Rosa davurica Pall. roots exhibited strong antioxidant activity in a 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging assay and was found to be a dose-dependent inhibitor of non-enzymatic formation of advanced glycation end products (AGEs), which are relevant to diabetes complications. HPLC-diode array detector (DAD) analysis of the R. davurica Pall. root extract led to the identification of four compounds: hydrocaffeic acid, catechin, epicatechin, and ellagic acid. Catechin was present in the largest amount and exhibited high antiglycation activity. A CYP3A4 assay was used to investigate potential interactions between drugs and the extract, and results suggest that the R. davurica Pall. root extract had moderate potential for interfering with drug metabolism. The R. davurica Pall. extract did not display anti-inflammatory activity on the level of that for tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) in a lipopolysaccharide (LPS)-stimulated macrophage assay; however, the extract did exhibit low to moderate immunostimulatory activity in a pro-inflammatory macrophage assay. Therefore, we conclude that R. davurica Pall. root is a promising anti-AGE agent with low to moderate risks of associated inflammation or drug interaction.

• YAKHAK HOEJI
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• v.46 no.4
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• pp.258-264
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• 2002

Zinc plays an important role in immunobiological responses, while excessive zinc attenuates immune functions in a dose-dependent manner. Zinc excess has been reported to increase levels of plasma prostaglandin E$_2$ (PGE$_2$), which is known to inhibit production of Th (helper T) 1-associated cytokines and to induce inflammatory responses. Thus, this study was investigated the effects of indomethacin, a potent inhibitor of PGE$_2$ synthesis, on the proinflammatory cytokine and lymphokine production in ICR mice exposed to excessive zinc. Indomethacin at doses of 5 mg/kg was administered i.p. 30 minutes before zinc chloride (Zn) 30 mg/kg orally daily for 10 days. Excessive Zn remarkedly increased tumor necrosis factor (TNF)-$\alpha$ and interleukin (IL)-1$\beta$ levels in both serum and splenic supernatants compared with those in controls, while indomethacin significantly reduced the excessive Zn-induced levels of IL-1$\beta$. In serum, excessive Zn significantly decreased the levels of IL-2 and interferon (IFN)-${\gamma}$ compared with those in controls, whereas indomethacin significantly enhanced the excessive Zn-decreased levels of IFN-${\gamma}$ but did not affect the Zn-decreased levels of serum IL-2. In splenic supernatants, All of excessive Zn, indomethacin, and combination of Zn and indomethacin significantly enhanced IL-2 levels compared with those in controls, but indomethacin didn't affect the Zn-induced production of IL-2. These data, therefore, suggest that indomethacin significantly attenuated the in vivo and ex vivo IL-1$\beta$ production increased by excessive zinc and remarkedly enhanced the in vivo excessive zinc-suppressed production of IFN-${\gamma}$ but not IL-2.

• Biomolecules & Therapeutics
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• v.17 no.2
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• pp.175-180
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• 2009

Taurine is the most abundant free amino acid in the retina and transported into retina via taurine transporter (TauT) at the inner blood-retinal barrier (iBRB). In the present study, we investigated whether the taurine transport at the iBRB is regulated by oxidative stress or disease-like state in a conditionally immortalized rat retinal capillary endothelial cell line (TR-iBRB) used as an in vitro model of iBRB. First, [$^3H$]taurine uptake and efflux by TR-iBRB were regulated in the presence of extracellular $Ca^{2+}$. [$^3H$]Taurine uptake was inhibited and efflux was enhanced under $Ca^{2+}$ free condition in the cells. In addition, oxidative stress inducing agents such as tumor necrosis factor-$\alpha$ (TNF-$\alpha$), lipopolysaccharide (LPS), diethyl maleate (DEM) and glutamate increased [$^3H$]taurine uptake and decreased [$^3H$]taurine efflux in TR-iBRB cells. Whereas, 3-morpholinosydnonimine (SIN-1), which is known to NO donor decreased [$^3H$]taurine uptake. Lastly, TR-iBRB cells exposed to high glucose (25 mM) medium and the [$^3H$]taurine uptake was reduced about 20% at the condition. Also, [$^3H$]taurine uptake was decreased by cytochalasin B, which is known to glucose transport inhibitor. In conclusion, taurine transport in TR-iBRB cells is regulated diversely at extracellular $Ca^{2+}$, oxidative stress and hyperglycemic condition. It suggested that taurine would play a role as a retinal protector in diverse disease states.

• Biomedical Science Letters
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• v.27 no.4
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• pp.223-230
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• 2021

Tumor necrosis factor alpha (TNF-α) is a principal regulator of inflammation and immunity. The proinflammatory properties of TNF-α can be attributed to its ability to activate the enzyme cytosolic phospholipase A₂ (cPLA₂), which generates potent inflammatory lipid mediators, eicosanoids. L-glutamine (Gln) plays physiologically important roles in various metabolic processes. We have reported that Gln has a potent anti-inflammatory activity via rapid upregulation of mitogen-activated protein kinases (MAPKs) phosphatase (MKP)-1, which preferentially dephosphorylates the key proinflammatory enzymes, p38 MAPK and cytosolic phospholipase A₂ (cPLA₂). In this study, we have investigated whether Gln could inhibit TNF-α-induced cPLA₂ activation. Gln inhibited TNF-α-induced increases in cPLA₂ phosphorylation in the lungs and blood levels of the cPLA₂ metabolites, leukotrine B4 (LTB4) (lipoxygenase metabolite) and prostaglandin E2 (PGE2) (cyclooxygenase metabolite). TNF-α increased p38 and cPLA₂ phosphorylation and blood levels of LTB4 and PGE2, which were blocked by the p38 inhibitor SB202190. Gln inhibited TNF-α-induced p38 and cPLA₂ phosphorylation and production of the cPLA₂ metabolites. Such inhibitory activity of Gln was no longer observed in MKP-1 small interfering RNA-pretreated animals. Our data indicate that Gln inhibited TNF-α-induced cPLA₂ phosphorylation through MKP-1 induction/p38 inhibition, and suggest that the utility of Gln in inflammatory diseases in which TNF-α plays a major role in their pathogenesis.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.9
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• pp.1242-1247
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• 2012

Acer barbinerve Maxim belongs to the Aceraceae tree family and is often consumed as an Oriental medicine. In this study, we investigated whether or not ethanol extract from the bark of A. barbinerve Max. (EBA) inhibits lipopolysaccharide (LPS)-induced inflammatory responses in Raw264.7 macrophages. EBA was fractionated using n-hexane, $CH_2Cl_2$, ethyl acetate (EtOAc), and water. Raw264.7 cells were treated with 20 ${\mu}g/mL$ of EBA and the EBA fractions. EBA inhibited LPS-induced nitric oxide (NO) production. Among the three fractions, EtOAc fraction of EBA (EFEBA) was the most effective in inhibiting LPS-induced NO production without significant cytotoxicity in Raw264.7 cells. EFEBA futher reduced LPS-induced expression of inducible NO synthase (iNOS) proteins and its corresponding mRNA. Additionally, EFEBA decreased the mRNA levels of interleukin (IL)-6, IL-$1{\beta}$, and tumor necrosis factor-${\alpha}$ in LPS-treated Raw264.7 cells. Lastly, EFEBA inhibited LPS-induced degradation of the inhibitor of kappaBalpha ($I{\kappa}B{\alpha}$) as well as phosphorylation of p65 nuclear factor-${\kappa}B$ (NF-${\kappa}B$). These results indicate that EFEBA exhibits strong anti-inflammatory effects and can be developed as a potential anti-inflammatory agent.

• Biomolecules & Therapeutics
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• v.22 no.4
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• pp.295-300
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• 2014

The actin cytoskeleton plays an important role in macrophage-mediated inflammatory responses by modulating the activation of Src and subsequently inducing nuclear factor (NF)-${\kappa}B$ translocation. In spite of its critical functions, few papers have examined how the actin cytoskeleton can be regulated by the activation of toll-like receptor (TLR). Therefore, in this study, we further characterized the biological value of the actin cytoskeleton in the functional activation of macrophages using an actin cytoskeleton disruptor, cytochalasin B (Cyto B), and explored the actin cytoskeleton's involvement in morphological changes, cellular attachment, and signaling events. Cyto B strongly suppressed the TLR4-mediated mRNA expression of inflammatory genes such as cyclooxygenase (COX)-2, tumor necrosis factor (TNF)-${\alpha}$, and inducible nitric oxide (iNOS), without altering cell viability. This compound also strongly suppressed the morphological changes induced by lipopolysaccharide (LPS), a TLR4 ligand. Cyto B also remarkably suppressed NO production under non-adherent conditions but not in an adherent environment. Cyto B did not block the co-localization between surface glycoprotein myeloid differentiation protein-2 (MD2), a LPS signaling glycoprotein, and the actin cytoskeleton under LPS conditions. Interestingly, Cyto B and PP2, a Src inhibitor, enhanced the phagocytic uptake of fluorescein isothiocyanate (FITC)-dextran. Finally, it was found that Cyto B blocked the phosphorylation of vasodilator-stimulated phosphoprotein (VASP) at 1 min and the phosphorylation of heat shock protein 27 (HSP27) at 5 min. Therefore, our data suggest that the actin cytoskeleton may be one of the key components involved in the control of TLR4-mediated inflammatory responses in macrophages.

• Biomolecules & Therapeutics
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• v.20 no.1
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• pp.43-49
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• 2012

Stimulation of mast cells through the high affinity IgE receptor (Fc${\varepsilon}$RI) induces degranulation, lipid mediator release, and cytokine secretion leading to allergic reactions. Although various signaling pathways have been characterized to be involved in the Fc${\varepsilon}$RI-mediated responses, little is known about the precious mechanism for the expression of tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) in mast cells. Here, we report that rapamycin, a specific inhibitor of mammalian target of rapamycin (mTOR), reduces the expression of TNF-${\alpha}$ in rat basophilic leukemia (RBL-2H3) cells. IgE or specific antigen stimulation of RBL-2H3 cells increases the expression of TNF-${\alpha}$ and activates various signaling molecules including S6K1, Akt and p38 MAPK. Rapamycin specifically inhibits antigeninduced TNF-${\alpha}$ mRNA level, while other kinase inhibitors have no effect on TNF-${\alpha}$ mRNA level. These data indicate that mTOR signaling pathway is the main regulation mechanism for antigen-induced TNF-${\alpha}$ expression. TNF-${\alpha}$ mRNA stability analysis using reporter construct containing TNF-${\alpha}$ adenylate/uridylate-rich elements (AREs) shows that rapamycin destabilizes TNF-${\alpha}$ mRNA via regulating the AU-rich element of TNF-${\alpha}$ mRNA. The antigen-induced activation of S6K1 is inhibited by specific kinase inhibitors including mTOR, PI3K, PKC and $Ca^{2+}$chelator inhibitor, while TNF-${\alpha}$ mRNA level is reduced only by rapamycin treatment. These data suggest that the effects of rapamycin on the expression of TNF-${\alpha}$ mRNA are not mediated by S6K1 but regulated by mTOR. Taken together, our results reveal that mTOR signaling pathway is a novel regulation mechanism for antigen-induced TNF-${\alpha}$ expression in RBL-2H3 cells.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.16
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• pp.6813-6823
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• 2015

Glioblastoma, also known as glioblastoma multiforme (GBM), is the most aggressive of human brain tumors and has a stunning progression with a mean survival of one year from the date of diagnosis. High cell proliferation, angiogenesis and/or necrosis are histopathological features of this cancer, which has no efficient curative therapy. This aggressiveness is associated with particular heterogeneity of the tumor featuring multiple genetic and epigenetic alterations, but also with implications of aberrant signaling driven by growth factors. The transforming growth factor ${\beta}$ ($TGF{\beta}$) superfamily is a large group of structurally related proteins including $TGF{\beta}$ subfamily members Nodal, Activin, Lefty, bone morphogenetic proteins (BMPs) and growth and differentiation factor (GDF). It is involved in important biological functions including morphogenesis, embryonic development, adult stem cell differentiation, immune regulation, wound healing and inflammation. This superfamily is also considered to impact on cancer biology including that of GBM, with various effects depending on the member. The $TGF{\beta}$ subfamily, in particular, is overexpressed in some GBM types which exhibit aggressive phenotypes. This subfamily impairs anti-cancer immune responses in several ways, including immune cells inhibition and major histocompatibility (MHC) class I and II abolishment. It promotes GBM angiogenesis by inducing angiogenic factors such as vascular endothelial growth factor (VEGF), plasminogen activator inhibitor (PAI-I) and insulinlike growth factor-binding protein 7 (IGFBP7), contributes to GBM progression by inducing metalloproteinases (MMPs), "pro-neoplastic" integrins (${\alpha}v{\beta}3$, ${\alpha}5{\beta}1$) and GBM initiating cells (GICs) as well as inducing a GBM mesenchymal phenotype. Equally, Nodal promotes GICs, induces cancer metabolic switch and supports GBM cell proliferation, but is negatively regulated by Lefty. Activin promotes GBM cell proliferation while GDF yields immune-escape function. On the other hand, BMPs target GICS and induce differentiation and sensitivity to chemotherapy. This multifaceted involvement of this superfamily in GBM necessitates different strategies in anti-cancer therapy. While suppressing the $TGF{\beta}$ subfamily yields advantageous results, enhancing BMPs production is also beneficial.

• Fisheries and Aquatic Sciences
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• v.14 no.4
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• pp.267-274
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• 2011

Bacterial lipopolysaccharide (LPS) induces expression of pro-inflammatory cytokines and enzymes producing nitric oxide (NO) and prostaglandins (PGs) in immune cells. This process is mediated by the activation of nuclear factor kappaB (NF-${\kappa}B$). In this study, we investigated the anti-inflammatory characteristics of Codium fragile ethanolic extract (CFE) mediated by the regulation of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) using LPS-stimulated murine macrophage RAW 264.7 cells. CFE significantly inhibited LPS-induced NO and $PGE_2$ production in a dose-dependent manner and suppressed the expression of iNOS and COX-2 proteins in LPS-stimulated RAW 264.7 cells with no cytotoxicity. Pro-inflammatory cytokines, such as interleukin (IL)-$1{\beta}$, IL-6, and tumor necrosis factor-${\alpha}$, were significantly reduced by treatment of CFE in LPS-stimulated RAW 264.7 cells. CFE inhibited the promoter activity of (NF)-${\kappa}B$ in LPS-stimulated macrophages. Treatment with CFE suppressed translocation of the NF-${\kappa}B$ p65 subunit by preventing proteolytic degradation of inhibitor of ${\kappa}B-{\alpha}$. These results indicate that the CFE-mediated inhibition of NO and $PGE_2$ production in LPS-stimulated RAW 264.7 cells is mediated through the NF-${\kappa}B$-dependent transcriptional downregulation of iNOS and COX-2, suggesting the potential of CFE as a nutraceutical with anti-inflammatory activity.