• Title/Summary/Keyword: Macrophages

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Cell to Cell Interaction Can Activate Membrane-bound APRIL Which Are Expressed on Inflammatory Macrophages

  • Lee, Sang-Min;Kim, Won-Jung;Suk, Kyoung-Ho;Lee, Won-Ha
    • IMMUNE NETWORK
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    • v.10 no.5
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    • pp.173-180
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    • 2010
  • Background: APRIL, originally known as a cytokine involved in B cell survival, is now known to regulate the inflammatory activation of macrophages. Although the signal initiated from APRIL has been demonstrated, its role in cellular activation is still not clear due to the presence of BAFF, a closely related member of TNF superfamily, which share same receptors (TACI and BCMA) with APRIL. Methods: Through transfection of siRNA, BAFF-deficient THP-1 cells (human macrophage-like cells) were generated and APRIL-mediated inflammatory activities were tested. The expression patterns of APRIL were also tested in vivo. Results: BAFF-deficient THP-1 cells responded to APRIL-stimulating agents such as monoclonal antibody against APRIL and soluble form of TACI or BCMA. Furthermore, co-incubation of the siBAFF-deficient THP-1 cells with a human B cell line (Ramos) resulted in an activation of THP-1 cells which was dependent on interactions between APRIL and TACI/BCMA. Immunohistochemical analysis of human pathologic samples detected the expression of both APRIL and TACI in macrophage-rich areas. Additionally, human macrophage primary culture expressed APRIL on the cell surface. Conclusion: These observations indicate that APRIL, which is expressed on macrophages in pathologic tissues with chronic inflammation, may mediate activation signals through its interaction with its counterparts via cell-to-cell interaction.

Mechanisms Underlying Enterococcus faecalis-Induced Tumor Necrosis Factor-$\alpha$ Production in Macrophages

  • Choi, Eun-Kyoung;Kim, Dae-Eob;Oh, Won-Mann;Paek, Yun-Woong;Kang, In-Chol
    • International Journal of Oral Biology
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    • v.35 no.2
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    • pp.43-49
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    • 2010
  • Enterococcus faecalis, a gram-positive bacterium, has been implicated in endodontic infections, particularly in chronic apical periodontitis. Proinflammatory cytokines, including tumor necrosis factor-$\alpha$ (TNF-$\alpha$), are involved in the pathogenesis of these apical lesions. E. faecalis has been reported to stimulate macrophages to produce TNF-$\alpha$. The present study investigated the mechanisms involved in TNF-$\alpha$ production by a murine macrophage cell line, RAW 264.7 in response to exposure to E. faecalis. Both live and heat-killed E. faecalis induced high levels of gene expression and protein release of TNF-$\alpha$. Treatment of RAW 264.7 cells with cytochalasin D, an inhibitor of endocytosis, prevented the mRNA up-regulation of TNF-$\alpha$ by E. faecalis. In addition, antioxidant treatment reduced TNF-$\alpha$ production to baseline levels. Inhibition of extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein (MAP) kinase also significantly attenuated E. faecalis-induced TNF-$\alpha$ expression by RAW 264.7 cells. Furthermore, activation of NF-${\kappa}B$ and AP-1 in RAW 264.7 cells was also stimulated by E. faecalis. These results suggest that the phagocytic uptake of bacteria is necessary for the induction of TNF-$\alpha$ in E. faecalis-stimulated macrophages, and that the underlying intracellular signaling pathways involve reactive oxygen species, ERK, p38 MAP kinase, NF-${\kappa}B$, and AP-1.

Scrophularia Buergeriana inhibits the Production of NO through the Suppression of NF-kB adivity in LPS-stimulated Mouse Peritoneal Macrophages

  • Ha Mi Suk;Kim Young Hee;Ko Woo Shin;Kim Han Do
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.16 no.6
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    • pp.1284-1290
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    • 2002
  • Scrophularia buergeriana Miquel (Scrophulariaceae) has been used as an anti-inflammatory drug in the folk medicine recipe and been proved its anti-inflammatory effect in the oriental medicine. Since nitric oxide (NO) and superoxide anion (O/sub 2//sup -/) are ones of the major inflammatory parameters, we studied the effect of aqueous extracts of Scrophularia buergeriana (SB) on NO and O/sub 2//sup -/ production in lipopolysaccharide (LPS)-stimulated mouse peritoneal macrophages. NO, O/sub 2//sup -/production and inducible NO synthase (iNOS) level were significantly reduced in LPS-activated macrophages by SB compared to those without. Electrophoretic mobility shift assay (EMSA) indicated that SB blocked the activation of NF-kB, which was considered to be a potential transcription factor for the iNOS expression. SB also blocked degradation of IkBα. Furthermore, IkB kinase alpha (IKKα), which phosphorylates serine residues of IkB directly, is inhibited by SB. These results suggest that SB could exert its anti-inflammatory actions by suppressing the activation of NF-kB through inhibition of IKK activity.

Effects of Water-Extracted Cyperus Rotundus on the Nitric Oxide Production and Cytokine gene Expression (향부자 열수추출물의 Nitric oxide 생성 및 iNOS 유전자 발현에 미치는 영향)

  • Lee Young Sun;Han Ok Kyung;Shin Sang Woo;Park Jong Hyun;Kwon Young Kyu
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.17 no.3
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    • pp.771-776
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    • 2003
  • The present study was conducted to evaluate the regulation mechanism of nitric oxide(NO) by water-extracted Cyperus rotundus (WCR) in RAW 264.7 macrophages. We investigated the effects of cell proliferation in mouse spleen cell and RAW 264.7 macrophages cells. WCR enhanced mitogenic activity in the dose-response manner in mouse spleen cells and RAW 264.7 macrophages cells. In nitric oxide (NO) synthesis by WCR, WCR alone had an effect on NO synthesis. It was found that the production of NO of RAW 264.7 cells stimulated with lipopolysaccharide (LPS) could be markedly inhibited by WCR. Inhibition of NO production was achieved by reducing inducible nitric oxide syntheses(iNOS) mRNA expression. The expression of IL-I gene by WCR was investigated using reverse transcription polymerase chain reaction (RT-PCR). In RT-PCR, IL-1 family(IL-1 α, IL-1β) expressions were induced by WCR. These finding suggested that regulation of NO production by WCR may be, at least in part, associated with the regulation of iNOS mRNA expression and IL-1 family gene expression.

Effect of Anisi Stellati Fructus Water Extract on Hydrogen Peroxide Production in RAW 264.7 Mouse Macrophages (대회향(大茴香) 물추출물이 마우스 대식세포주(RAW 264.7 cell line)의 hydrogen peroxide 생성에 미치는 영향)

  • Lee, Ji-Young;Kim, Young-Jin;Kim, Hyung-Joo;Lee, Min-Woo;Park, Wan-Su
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.26 no.3
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    • pp.301-305
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    • 2012
  • The purpose of this study is to investigate effects of Anisi stellati Fructus Water Extract on hydrogen peroxide production in RAW 264.7 mouse macrophages. Anisi stellati Fructus were extracted by hot water. Effects of Anisi stellati Fructus water extract (AS) on hydrogen peroxide production in RAW 264.7 were measured by dihydrorhodamine 123 assay after 20, 24, 28, 44, 48, and 52 h incubation at the concentrations of 10, 25, 50, and $100{\mu}g/mL$. For 20 h incubation, AS significantly increased hydrogen peroxide production in RAW 264.7 cells by $108.6{\pm}1.56%$, $109.5{\pm}1.94%$, $108.4{\pm}1.14%$, and $107.3{\pm}3.06%$ at the concentrations of 10, 25, 50, and $100{\mu}g/mL$ (P < 0.05) respectively. For 24, 28, 44, 48, and 52 h incubation, AS also significantly increased hydrogen peroxide production in RAW 264.7 cells at the concentrations of 10, 25, 50, and $100{\mu}g/mL$ (P < 0.05). These results suggest that Anisi stellati Fructus has the immune - enhancing property related with its increase of hydrogen peroxide production in macrophages.

Involvement of MAPK activation in chemokine or COX-2 productions by Toxoplasma gondii

  • Kim Ji-Young;Ahn Myoung-Hee;Song Hyun-Ouk;Choi Jong-Hak;Ryu Jae-Sook;Min Duk-Young;Cho Myung-Hwan
    • Parasites, Hosts and Diseases
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    • v.44 no.3
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    • pp.197-207
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    • 2006
  • This experiment focused on MAPK activation in host cell invasion and replication of T. gondii, as well as the expression of CC chemokines, MCP-1 and $MIP-1\alpha$, and enzyme, COX-2/prostaglandin $E_2(PGE_2)$ in infected cells via western blot, $[^3H]-uracil$ incorporation assay, ELISA and RT-PCR. The phosphorylation of ERK1/2 and p38 in infected HeLa cells was detected at 1 hr and/or 6 hr postinfection (PI). Tachyzoite proliferation was reduced by p38 or JNK MAPK inhibitors. MCP-1 secretion was enhanced in infected peritoneal macrophages at 6 hr PI. $MIP-1\alpha$ mRNA was increased in macrophages at 18 hr PI. MCP-1 and $MIP-1\alpha$ were reduced after treatment with inhibitors of ERK1/2 and JNK MAPKs. COX-2 mRNA gradually increased in infected RAW 264.7 cells and the secretion of COX-2 peaked at 6 hr PI. The inhibitor of JNK suppressed COX-2 expression. $PGE_2$ from infected RAW 264.7 cells was increased and synthesis was suppressed by PD98059, SB203580, and SP600125. In this study, the activation of p38, JNK and/or ERK1/2 MAPKs occurred during the invasion and proliferation of T. gondii tachyzoites in HeLa cells. Also, increased secretion and expression of MCP-1, $MIP-1\alpha$, COX-2 and $PGE_2$ were detected in infected macrophages, and appeared to occur via MAPK signaling pathways.

Anti-Inflammatory Effect of Rosa rugosa Flower Extract in Lipopolysaccharide-Stimulated RAW264.7 Macrophages

  • Tursun, Xirali;Zhao, Yongxin;Talat, Zulfiya;Xin, Xuelei;Tursun, Adila;Abdulla, Rahima;AkberAisa, Haji
    • Biomolecules & Therapeutics
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    • v.24 no.2
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    • pp.184-190
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    • 2016
  • Rosa rugosa Thunb, a deciduous shrub of the genus Rosa, has been widely used to treat stomach aches, diarrhoea, pain, and chronic inflammatory disease in eastern Asia. In recent years, our research team has extensively studied the Rosa rugosa flower extract, and specifically undertook pharmacological experiments which have optimized the extraction process. Our methods have yielded a standard extract enriched in phenolic compounds, named PRE. Herein, we expand our efforts and evaluated the anti-inflammatory activity of PRE on lipopolysaccharide (LPS)-induced inflammation in RAW 264.7 macrophages. PRE significantly inhibited production of nitric oxide (NO), prostaglandin $E_2(PGE_2)$, tumor necrosis factor (TNF)-${\alpha}$, interleukin (IL)-6, and interleukin $1{\beta}$ (IL-$1{\beta}$), as well as expression of their synthesizing enzymes, inducible nitric oxide synthase (iNOS) and cyclooxygenase2 (COX-2). Furthermore, PRE inhibited activity of mitogen-activated protein kinases (MAPK) as well as nuclear factor-kappa B (NF-${\kappa}B$) signaling pathway. Our findings are the first to explain the anti-inflammatory mechanism by PRE in LPS-stimulated macrophages. Given these results, we propose that PRE has therapeutic potential in the prevention of inflammatory disorders.

Cytochalasin B Modulates Macrophage-Mediated Inflammatory Responses

  • Kim, Mi-Yeon;Kim, Jong-Hoon;Cho, Jae Youl
    • 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.

Production of IL-1β and Inflammasome with Up-Regulated Expressions of NOD-Like Receptor Related Genes in Toxoplasma gondii-Infected THP-1 Macrophages

  • Chu, Jia-Qi;Shi, Ge;Fan, Yi-Ming;Choi, In-Wook;Cha, Guang-Ho;Zhou, Yu;Lee, Young-Ha;Quan, Juan-Hua
    • Parasites, Hosts and Diseases
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    • v.54 no.6
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    • pp.711-717
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    • 2016
  • Toxoplasma gondii is an obligate intracellular parasite that stimulates production of high levels of proinflammatory cytokines, which are important for innate immunity. NLRs, i.e., nucleotide-binding oligomerization domain (NOD)-like receptors, play a crucial role as innate immune sensors and form multiprotein complexes called inflammasomes, which mediate caspase-1-dependent processing of $pro-IL-1{\beta}$. To elucidate the role of inflammasome components in T. gondiiinfected THP-1 macrophages, we examined inflammasome-related gene expression and mechanisms of inflammasome-regulated cytokine $IL-1{\beta}$ secretion. The results revealed a significant upregulation of $IL-1{\beta}$ after T. gondii infection. T. gondii infection also upregulated the expression of inflammasome sensors, including NLRP1, NLRP3, NLRC4, NLRP6, NLRP8, NLRP13, AIM2, and NAIP, in a time-dependent manner. The infection also upregulated inflammasome adaptor protein ASC and caspase-1 mRNA levels. From this study, we newly found that T. gondii infection regulates NLRC4, NLRP6, NLRP8, NLRP13, AIM2, and neuronal apoptosis inhibitor protein (NAIP) gene expressions in THP-1 macrophages and that the role of the inflammasome-related genes may be critical for mediating the innate immune responses to T. gondii infection.

Cimicifuga heracleifolia Extract Induces iNOS Expression via a Nuclear Factor-${\kappa}B$-dependent Pathway in Mouse Peritoneal Macrophages

  • Lee, Kyoung-In;Tabassum, Nadia;Pyo, Byoung-Sik;Kim, Sun-Min;Lee, Ik-Soo;Jung, Da-Woon;Yim, Soon-Ho
    • Natural Product Sciences
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    • v.20 no.4
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    • pp.227-231
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    • 2014
  • Cimicifuga heracleifolia extract (CHE) was investigated for its effects on the release of nitric oxide (NO) and at the level of inducible nitric oxide synthase (iNOS) gene expression in mouse macrophages. We found that C. heracleifolia elicited a dose-dependent increase in NO production and the level of iNOS mRNA. Since, iNOS transcription has been shown to be under the control of the transcription factor $NF-{\kappa}B$, the effects of CHE on $NF-{\kappa}B$ activation were examined. Transient expression assays with $NF-{\kappa}B$ binding sites linked to the luciferase gene revealed that the increased level of iNOS mRNA, induced by CHE, was mediated by the $NF-{\kappa}B$ transcription factor complex. By using DNA fragments containing the $NF-{\kappa}B$ binding sequence, CHE was shown to activate the protein/DNA binding of $NF-{\kappa}B$ to its cognate site, as measured by electrophoretic mobility shift assay. These results demonstrate that C. heracleifolia stimulates NO production and is able to up-regulate iNOS expression through $NF-{\kappa}B$ transactivation.