• Title/Summary/Keyword: $TNF{\alpha}$ signaling

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Effect of Samhwangsashimtang Extract on Lipopolysaccharide-Stimulated Inflammatory Response and Macrophage Activity (삼황사심탕(三黃瀉心湯) 추출물의 lipopolysaccharide 유도에 의한 염증 조절과 대식세포 활성에 대한 연구)

  • Kang, Hee;Kwon, Han-Al;So, Hyung-Jin;Lee, Jeong-Min;Lew, Jae-Hwan;Choi, Ho-Young
    • The Korea Journal of Herbology
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    • v.27 no.6
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    • pp.23-28
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    • 2012
  • Objectives : Samhwangsashim-tang(SHSST), a mixture of Rhei radix et rhizoma, Scutellariae radix, and Coptidis rhizoma, has been regarded as being able to treat bleeding, gastric discomfort, dry mouth, insomnia and purpura due to Blood Heat. Currently, this herbal formula is applied to gastritis, gastric ulcer, hypertension, atherosclerosis or other types of vascular inflammatory disorders. Methods : We extracted this herbal mixture with 30% ethanol and examined for its effects on systemic inflammatory responses and in vitro macrophage activity. Mice were orally given to SHSST for 7 days and then lipopolysaccharide(LPS) was intraperitoneally injected. Tumor necrosis factor-${\alpha}$(TNF-${\alpha}$) levels in serum were measured 1 h after LPS challenge. Peritoneal macrophages were isolated from thioglycollate-injected mice and used for in vitro cellular activity. Cell death was measured using the MTT method and annexin V/propidium iodide staining. LPS-stimulated signaling molecules necessary for TNF-${\alpha}$ expression were determined by Western blotting. Results : Oral administration of SHSST for 7 days resulted in a significant reduction in LPS-stimulated TNF-${\alpha}$ release into serum. In vitro treatment of SHSST was cytotoxic in a concentration-dependent manner. However, SHSST caused a concentration-dependent reduction in necrosis and increase in apoptosis in mouse peritoneal macrophages. SHSST inhibited the activation of NF-${\kappa}B$, p38 and JNK signaling molecules in response to LPS. Conclusion : Taken together, our results demonstrated that SHSST was effective in lowering LPS-stimulated TNF-${\alpha}$ serum levels, possibly through its modulation of NF-${\kappa}B$, p38 and JNK in macrophages.

Vitamin D maintains E-cadherin intercellular junctions by downregulating MMP-9 production in human gingival keratinocytes treated by TNF-α

  • Oh, Changseok;Kim, Hyun Jung;Kim, Hyun-Man
    • Journal of Periodontal and Implant Science
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    • v.49 no.5
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    • pp.270-286
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    • 2019
  • Purpose: Despite the well-known anti-inflammatory effects of vitamin D in periodontal health, its mechanism has not been fully elucidated. In the present study, the effect of vitamin D on strengthening E-cadherin junctions (ECJs) was explored in human gingival keratinocytes (HGKs). ECJs are the major type of intercellular junction within the junctional epithelium, where loose intercellular junctions develop and microbial invasion primarily occurs. Methods: HOK-16B cells, an immortalized normal human gingival cell line, were used for the study. To mimic the inflammatory environment, cells were treated with tumor necrosis factor-alpha ($TNF-{\alpha}$). Matrix metalloproteinases (MMPs) in the culture medium were assessed by an MMP antibody microarray and gelatin zymography. The expression of various molecules was investigated using western blotting. The extent of ECJ development was evaluated by comparing the average relative extent of the ECJs around the periphery of each cell after immunocytochemical E-cadherin staining. Vitamin D receptor (VDR) expression was examined via immunohistochemical analysis. Results: $TNF-{\alpha}$ downregulated the development of the ECJs of the HGKs. Dissociation of the ECJs by $TNF-{\alpha}$ was accompanied by the upregulation of MMP-9 production and suppressed by a specific MMP-9 inhibitor, Bay 11-7082. Exogenous MMP-9 decreased the development of ECJs. Vitamin D reduced the production of MMP-9 and attenuated the breakdown of ECJs in the HGKs treated with $TNF-{\alpha}$. In addition, vitamin D downregulated $TNF-{\alpha}$-induced nuclear factor kappa B ($NF-{\kappa}B$) signaling in the HGKs. VDR was expressed in the gingival epithelium, including the junctional epithelium. Conclusions: These results suggest that vitamin D may avert $TNF-{\alpha}$-induced downregulation of the development of ECJs in HGKs by decreasing the production of MMP-9, which was upregulated by $TNF-{\alpha}$. Vitamin D may reinforce ECJs by downregulating $NF-{\kappa}B$ signaling, which is upregulated by $TNF-{\alpha}$. Strengthening the epithelial barrier may be a way for vitamin D to protect the periodontium from bacterial invasion.

Wogonin inhibits Cytokine-induced TARC/CCL17 Expression by Suppression of NF-${\kappa}B$ activation via p38 MAP kinase Signalning Pathways in HaCaT Keratinocytes

  • Jang, Seon-Il
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.21 no.4
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    • pp.1017-1024
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    • 2007
  • Thymus and activation-regulated chemokine (TARC/CCL-17), produced by keratinocytes, is a CC chemokine known to selectively Th2 type T cells via $CCR4^+$ and is implicated in the development of atopic dermatitis (AD). TARC/CCL17 expression was induced by cytokines such as tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) and interferon-${\gamma}$ (IFN-${\gamma}$). We recently found that the wogonin, a flavone isolated from Scutellaria baicalensis, suppressed TARC expression via heme oxygenase 1 (HO1) in human keratinocytes induced with mite antigen. However, little is known about the inhibitory mechanism of wogonin on TARC/CCL-17 expression stimulated with cytokines. To investigate the inhibitory mechanism, I determined the inhibitory effects of wogonin on the activation of nuclear factor-${\kappa}B$ (NF-${\kappa}B$) and $I{\kappa}B{\alpha}$ phosphorylation, and also examined the activation of p38 MAP kainase in HaCaT keratinocytes stimulated with TNF-${\alpha}$ and IFN-${\gamma}$. Wogonin inhibited NF-${\kappa}B$-DNA complex, NF-${\kappa}B$ binding activity, and the phosphorylation of $I{\kappa}B{\alpha}$ in a dose dependent manner. Wogonin also inhibited the translocation of NF-${\kappa}B$ from cytosol to nucleus. Moreover, the phosphorylation of of p38 MAP kinase in the TNF-${\alpha}$ and IFN-${\gamma}$-stimulated HaCaT keratinocytes were suppressed by wogonin in a dose dependent manner. These results suggest that wogonin may inhibit cytokine-induced NF-${\kappa}B$ activation by $I{\kappa}B{\alpha}$ degradation via suppression of p38 MAP kinase signaling pathway in keratinocytes and modulation of wogonin signaling pathway may be beneficial for the treatment of AD.

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.

iRhoms; Its Functions and Essential Roles

  • Lee, Min-Young;Nam, Ki-Hoan;Choi, Kyung-Chul
    • Biomolecules & Therapeutics
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    • v.24 no.2
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    • pp.109-114
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    • 2016
  • In Drosophila, rhomboid proteases are active cardinal regulators of epidermal growth factor receptor (EGFR) signaling pathway. iRhom1 and iRhom2, which are inactive homologs of rhomboid intramembrane serine proteases, are lacking essential catalytic residues. These are necessary for maturation and trafficking of tumor necrosis factor-alpha (TNF-${\alpha}$) converting enzyme (TACE) from endoplasmic reticulum (ER) to plasma membrane through Golgi, and associated with the fates of various ligands for EGFR. Recent studies have clarified that the activation or downregulation of EGFR signaling pathways by alteration of iRhoms are connected to several human diseases including tylosis with esophageal cancer (TOC) which is the autosomal dominant syndrom, breast cancer, and Alzheimer's disease. Thus, this review focuses on our understanding of iRhoms and the involved mechanisms in the cellular processes.

Structural and Functional Roles of AIMP2 and TRAF2 in TNF-α Signaling (TNF-α 신호에서 AIMP2와 TRAF2의 구조적 및 기능적 역할)

  • Kim, Hyeon Jin;Jeong, Mi Suk;Jang, Se Bok
    • Journal of Life Science
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    • v.30 no.1
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    • pp.106-112
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    • 2020
  • Aminoacyl tRNA synthetase complex interacting multifunctional protein 2 (AIMP2) is a scaffolding protein required for the assembly of multi-tRNA synthetase, and it can exert pro-apoptotic activity in response to DNA damage. In the presence of DNA damage, AIMP2 binds to mouse double minute 2 homolog (MDM2) to protect p53 from MDM2 attack. TGF-β signaling results in the nuclear translocation of AIMP2, whereby AIMP2 interacts with FUSE-binding protein, and, thus, suppresses c-myc. TNF receptor-associated factor 2 (TRAF2) is an important mediator between TNF-receptors 1 and 2 which are involved in the signaling of c-Jun N-terminal kinase (JNK), nuclear factor κB (NF-κB), and p38 mitogen-activated protein kinases (MAPKs). TRAF2 is required for the activations of JNK and NF-κB via TNF-α and the mediation of anti-apoptosis signaling. AIMP2 can also enhance pro-apoptosis in the TNF-α signaling. During this signaling, AIMP2 assists the association of E3 ubiquitin ligase, the cellular inhibitor of apoptosis protein 1 (c-IAP1) which is well known and responsible for the degradation of TRAF2. The formation of a complex among AIMP2, TRAF2, and c-IAP1 results in proteasome-mediated TRAF2 degradation. AIMP2 can induce apoptosis via downregulation of TRAF2 to interact directly in TNF-α signaling. This review provides new insight into the molecular mechanism responsible for AIMP2 and TRAF2 complex formation and treatments for TNFα-associated diseases.

Combination of Nimbolide and TNF-α-Increases Human Colon Adenocarcinoma Cell Death through JNK-mediated DR5 Up-regulation

  • Boonyarat, Chantana;Yenjai, Chavi;Reubroycharoen, Prasert;Waiwut, Pornthip
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.5
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    • pp.2637-2641
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    • 2016
  • Tumor necrosis factor ($TNF-{\alpha}$), an inflammatory cytokine that plays an important role in the control of cell proliferation, differentiation, and apoptosis, has previously been used in anti-cancer therapy. However, the therapeutic applications of $TNF-{\alpha}$ are largely limited due to its general toxicity and anti-apoptotic influence. To overcome this problem, the present study focused on the effect of active constituents isolated from a medicinal plant on $TNF-{\alpha}$-induced apoptosis in human colon adenocarcinoma (HT-29) cells. Nimbolide from Azadirachta indica was evaluated for cytotoxicity by methyl tetrazolium 3-[4,5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide (MTT) assay and phase contrast microscopy. Effects on apoptotic signaling proteins were investigated using Western blot analysis. Nimbolide showed cytotoxicity against HT-29 cells that was significantly different from the control group (p<0.01), a concentration of $10{\mu}M$ significantly inducing cell death (p<0.01). In combination with $TNF-{\alpha}$, nimbolide significantly enhanced-induced cell death. In apoptotic pathway, nimbolide activated c-Jun N-terminal kinase (JNK) phosphorylation, BH3 interacting-domain death agonist (Bid) and up-regulated the death receptor 5 (DR5) level. In the combination group, nimbolide markedly sensitized $TNF-{\alpha}$-induced JNK, Bid, caspase-3 activation and the up-regulation of DR5. Our findings overall indicate that nimbolide may enhance $TNF-{\alpha}$-mediated cellular proliferation inhibition through increasing cell apoptosis of HT-29 cells by up-reglation of DR5 expression via the JNK pathway.

Inhibitory Effects of Lactobacillus plantarum Lipoteichoic Acid (LTA) on Staphylococcus aureus LTA-Induced Tumor Necrosis Factor-Alpha Production

  • Kim, Han-Geun;Lee, Seung-Yeon;Kim, Na-Ra;Ko, Mi-Yeon;Lee, Jung-Min;Yi, Tae-Hoo;Chung, Sung-Kyun;Chung, Dae-Kyun
    • Journal of Microbiology and Biotechnology
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    • v.18 no.6
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    • pp.1191-1196
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    • 2008
  • Staphylococcus aureus is a common etiologic agent for Gram-positive sepsis, and its lipoteichoic acid (LTA) may be important in causing Gram-positive bacterial septic shock. Here, we demonstrate that highly purified LTA (pLTA) isolated from Lactobacillus plantarum inhibited S. aureus LTA (aLTA)-induced TNF-${\alpha}$ production in THP-1 cells. Whereas pLTA scarcely induced TNF-${\alpha}$ production, aLTA induced excessive TNF-${\alpha}$ production. Interestingly, aLTA-induced TNF-${\alpha}$ production was inhibited by pLTA pretreatment. Compared with pLTA, aLTA induced a strong signal transduction through the MyD88, NF-${\kappa}B$, and MAP kinases. This signaling, however, was reduced by a pLTA pretreatment, and resulted in the inhibition of aLTA-induced TNF-${\alpha}$ production. Whereas dealanylated LTAs, as well as native LTAs, contributed to TNF-${\alpha}$ induction or TNF-${\alpha}$ reduction, deacylated LTAs did not, indicating that the acyl chain of LTA played an important role in the LTA-mediated immune regulation. These results suggest that pLTA may act as an antagonist for aLTA, and that an antagonistic pLTA may be a useful agent for suppressing the septic shock caused by Gram-positive bacteria.

The protective effect of Prunella vulgaris ethanol extract against vascular inflammation in TNF-α-stimulated human aortic smooth muscle cells

  • Park, Sun Haeng;Koo, Hyun Jung;Sung, Yoon Young;Kim, Ho Kyoung
    • BMB Reports
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    • v.46 no.7
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    • pp.352-357
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    • 2013
  • Atherosclerosis, which manifests as acute coronary syndrome, stroke, and peripheral arterial diseases, is a chronic inflammatory disease of the arterial wall. Prunella vulgaris, a perennial herb with a worldwide distribution, has been used as a traditional medicine in inflammatory disease. Here, we investigated the effects of P. vulgaris ethanol extract on TNF-${\alpha}$-induced inflammatory responses in human aortic smooth muscle cells (HASMCs). We found that P. vulgaris ethanol extract inhibited adhesion of monocyte/macrophage-like THP-1 cells to activated HASMCs. It also decreased expression of intercellular adhesion molecule-1, vascular cell adhesion molecule-1, E-selectin and ROS, No production in TNF-${\alpha}$-induced HASMCs and reduced NF-${\kappa}B$ activation. Furthermore, P. vulgaris extract suppressed TNF-${\alpha}$-induced phosphorylation of p38 mitogen-activated protein kinase (MAPK) and extracellular signal-regulated kinase (ERK). These results demonstrate that P. vulgaris possesses anti-inflammatory properties and can regulate TNF-${\alpha}$-induced expression of adhesion molecules by inhibiting the p38 MAPK/ERK signaling pathway.

NecroX-5 exerts anti-inflammatory and anti-fibrotic effects via modulation of the TNFα/Dcn/TGFβ1/Smad2 pathway in hypoxia/reoxygenation-treated rat hearts

  • Thu, Vu Thi;Kim, Hyoung Kyu;Long, Le Thanh;Thuy, To Thanh;Huy, Nguyen Quang;Kim, Soon Ha;Kim, Nari;Ko, Kyung Soo;Rhee, Byoung Doo;Han, Jin
    • The Korean Journal of Physiology and Pharmacology
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    • v.20 no.3
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    • pp.305-314
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    • 2016
  • Inflammatory and fibrotic responses are accelerated during the reperfusion period, and excessive fibrosis and inflammation contribute to cardiac malfunction. NecroX compounds have been shown to protect the liver and heart from ischemia-reperfusion injury. The aim of this study was to further define the role and mechanism of action of NecroX-5 in regulating inflammation and fibrosis responses in a model of hypoxia/reoxygenation (HR). We utilized HR-treated rat hearts and lipopolysaccharide (LPS)-treated H9C2 culture cells in the presence or absence of NecroX-5 ($10{\mu}mol/L$) treatment as experimental models. Addition of NecroX-5 significantly increased decorin (Dcn) expression levels in HR-treated hearts. In contrast, expression of transforming growth factor beta 1 ($TGF{\beta}1$) and Smad2 phosphorylation (pSmad2) was strongly attenuated in NecroX-5-treated hearts. In addition, significantly increased production of tumor necrosis factor alpha ($TNF{\alpha}$), $TGF{\beta}1$, and pSmad2, and markedly decreased Dcn expression levels, were observed in LPS-stimulated H9C2 cells. Interestingly, NecroX-5 supplementation effectively attenuated the increased expression levels of $TNF{\alpha}$, $TGF{\beta}1$, and pSmad2, as well as the decreased expression of Dcn. Thus, our data demonstrate potential antiinflammatory and anti-fibrotic effects of NecroX-5 against cardiac HR injuries via modulation of the $TNF{\alpha}/Dcn/TGF{\beta}1/Smad2$ pathway.