• Title/Summary/Keyword: TLR-4

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Curcumin Inhibits MHCC97H Liver Cancer Cells by Activating ROS/TLR-4/Caspase Signaling Pathway

  • Li, Pei-Min;Li, Yu-Liang;Liu, Bin;Wang, Wu-Jie;Wang, Yong-Zheng;Li, Zheng
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.5
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    • pp.2329-2334
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    • 2014
  • Curcumin can inhibit proliferation of liver cancer cells by inducing apoptosis, but the specific signaling pathways involved are not completely clear. Here, we report that curcumin inhibited proliferation of MHCC97H liver cancer cells by induction of apoptosis in a concentration dependent manner via stimulating intracellular reactive oxygen species (ROS) generation. Also, we showed that increased intracellular ROS formation activated the TLR-4/MyD-88 signaling pathway, resulting in activation of caspase-8 and caspase-3, which eventually led to apoptosis in MHCC97H cells. These results showed that as an prooxidant, curcumin exerts anti-cancer effects by inducing apoptosis via the TLR-4/MyD-88 signaling pathway.

Shigyungbanha-tang Exhibits Anti-inflammatory Effects by Inhibiting $I{\kappa}B-{\alpha}$ Degradation in LPS-stimulated Peritoneal Macrophages (LPS로 유도한 복강대식세포에서 $I{\kappa}B-{\alpha}$ 분해억제에 의한 시경반하탕(柴梗半夏湯)의 항염증효과)

  • Shin, Jo-Young;Lee, Si-Hyeong;Lee, Seung-Eon
    • The Journal of Internal Korean Medicine
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    • v.28 no.3
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    • pp.442-452
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    • 2007
  • Objectives : The purpose of this study was to investigate the toll-like receptor (TLR)-4 mediated anti-inflammatory effects of extract from Shigyungbanha-tang (SBT) on the peritoneal macrophage. Methods : To evaluate of TLR-4 mediated inflammatory of SBT. we examined NO and cytokine production in TRL-4 ligand (LPS : lipopolysaccharide) induced macrophages. Furthermore, we examined its molecular mechanism using western blot. Results : Extract from SBT itself does not have any cytotoxic effect in the peritoneal macrophages. Extract from SBT reduced LPS-induced nitric oxide (NO). tumor necrosis factor-alpha ($TNF-{\alpha}$), interleukin (IL)-6 and IL-12 production in peritoneal macrophages. SBT inhibited degradation of inhibitor kappa B-alpha ($I{\kappa}B-{\alpha}$) in the TLR-4 mediated peritoneal macrophages. Conclusions : These results suggest that SBT inhibits NO and cytokines production through inhibiting nuclear factor-kappaB (NF-${\kappa}$B) activation in peritoneal macrophage and that SBT may be beneficial oriental medicine for inflammation.

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Echinacea purpurea extract inhibits LPS-induced inflammatory response by interfering with TLR4-mediated NF-κB and MAPKs signaling pathways

  • Kim, Hae Lim;Min, Daeun;Lee, Sung-Kwon;Choi, Bong-Keun;Lee, Hae Jin;Lee, Dong-Ryung
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.36 no.1
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    • pp.28-34
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    • 2022
  • Echinacea purpurea (Asteraceae family) is widely used in the European countries and the United States due to its proven immune enhancement and anti-inflammatory effects. Echinacea purpurea has been reported prevent and treat upper respiratory tract infections and common cold, but the underlying molecular mechanisms are not well understood. In the present study, we examined the anti-inflammatory effects and molecular mechanisms of Echinacea purpurea (EP) extract using lipopolysaccharide (LPS)-stimulated signal pathways in RAW264.7 cells. Our results suggest that EP extract exerts anti-inflammatory effects by down-regulating the expression of LPS-induced toll-like receptor 4 (TLR4), subsequently inhibiting the activation of nuclear factor (NF)-κB and mitogen-activated protein kinase (MAPK) signaling pathways and suppression of the release of pro-inflammatory cytokines. These results suggest that EP extract is a potential therapeutic agent for inflammatory diseases.

Study on the Immunomodulatory Effects of Ellagic Acid and their Mechanisms Related to Toll-like Receptor 4 in Macrophages (Ellagic acid가 대식세포의 면역조절작용에 미치는 영향과 Toll-like receptor 4 관련 작용기전 연구)

  • NamKoong, Seung;Kim, Ye-Jin;Kim, Taeseong;Sohn, Eun-Hwa
    • Korean Journal of Plant Resources
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    • v.25 no.5
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    • pp.561-567
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    • 2012
  • Ellagic acid (EA) is a phenolic compound in fruits and nuts including raspberries, strawberries, grapes and walnuts. Previous studies have indicated that EA possesses antioxidant activity, growth-inhibition and apoptosis-promoting activity in cancer cells. However, macrophage mediated cytotoxicity and immunomodulating effects on cancer cells have not been clarified. In the present study, we show that EA increased effects on macrophage mediated tumoricidal activity and NO production without direct tumor cell cytotoxicity. To further determine whether TLR4 (toll like receptor 4) is involved in anti-tumor activity, cells were treated TLR4 signaling inhibitor, CLI-095 in the presence of EA. CLI-095 treatment partially reduced macrophage-mediated tumoridial activity. EA also has inhibitory effects of NO production induced by LPS, whereas phagocytic activity was not changed. These results suggest that EA induces macrophage mediated tumoricidal activity which is partially related to TLR4 signaling and has a potential adjuvant in cancer therapy.

Immunostimulatory activity and intracellular signaling pathways of a rhamnogalcaturonan II polysaccharide isolated from ginseng berry (인삼열매로부터 분리한 Rhamnogalacturonan II 다당의 면역활성과 세포 내 신호전달 기작 규명)

  • Cha, Ha Young;Son, Seung-U;Shin, Kwang-Soon
    • Korean Journal of Food Science and Technology
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    • v.53 no.6
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    • pp.722-730
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    • 2021
  • In this study, we aimed to elucidate the intracellular signaling pathways for macrophage activation by the polysaccharide GBW-II purified from ginseng berry. GBW-II consists of 14 different sugars, including rarely observed sugars such as 2-O-methyl-xylose, apiose, aceric acid, 2-keto-3-deoxy-D-manno-2-octulosonic acid, and 2-keto-3-deoxy-D-lyxo-2-heptulosaric acid, which are typical RG-II component sugars. GBW-II enhanced the production of IL-6 and TNF-α in RAW 264.7 cells. In experiments evaluating specific inhibitor activity, it was found that the production of IL-6 was suppressed by inhibitors of SB, PD, and BAY, and the production of TNF-α was suppressed by PD and BAY. The experiments with neutralizing antibodies showed that TLR4 was involved in the stimulation of IL-6 production by GBW-II in RAW 264.7 cells, whereas TNF-α production was regulated through SR and TLR2. These results suggest that GBW-II activates the MAPK and NF-κB pathways via several macrophage receptors, including SR, TLR2, and TLR4, and subsequently induces the secretion of IL-6 and TNF-α.

Involvement of Multiple Signaling Molecules in Peptidoglycan-induced Expression of Interleukin-1α in THP-1 Monocytes/Macrophages (THP-1 단핵구의 펩티도글리칸 유래 인터루킨-1 알파 발현에서 TLR2, PI3K/Akt/mTOR, MAPKs의 역할)

  • Heo, Weon;Son, Yonghae;Cho, Hyok-rae;Kim, Koanhoi
    • Journal of Life Science
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    • v.32 no.6
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    • pp.421-429
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    • 2022
  • The expression of interleukin-1α (IL-1α) is elevated in monocytic cells, such as monocytes and macro-phages, within atherosclerotic arteries, yet the cellular molecules involved in cytokine upregulation remain unclear. Because peptidoglycan (PG), a major component of gram-positive bacterial cell walls, is detected within the inflammatory cell-rich regions of atheromatous plaques, it was investigated if PG contributes to IL-1α expression in monocytes/macrophages. Exposure of THP-1 monocytic cells to PG resulted in elevated levels of IL-1α gene transcripts and increased secretion of IL-1α protein. The transcription and secretion of IL-1α were abrogated by OxPAPC, an inhibitor of TLR2/4, but not by polymyxin B that inhibits lipopolysaccharide-induced TLR4 activation. To understand the molecular mechanisms of the inflammatory responses due to bacterial pathogen-associated molecular patterns (PAMPs) in diseased arteries, we attempted to determine the cellular factors involved in the PG-induced upregulation of IL-1α expression. Pharmacological inhibition of cell signaling pathways with LY294002 (a PI3K inhibitor), Akti IV (an inhibitor of Akt activation), rapamycin (an mTOR inhibitor), U0126 (a MEK inhibitor), SB202190 (a p38 MAPK inhibitor), SP6001250 (a JNK inhibitor), and DPI (a NOX inhibitor) also significantly attenuated the PG-mediated expression of IL-1α. These results suggest that PG induces the monocytic or macrophagic expression of IL-1α, thereby contributing to vascular inflammation, via multiple signaling molecules, including TLR2, PI3K/Akt/mTOR, and MAPKs.

Long-Term Clinical Outcomes of Iliac Artery Endovascular Therapy in the Korean Vascular Intervention Society Endovascular Therapy in Lower Limb Artery Diseases (K-VIS ELLA) Registry

  • Ji Woong Roh;Sanghoon Shin;Young-Guk Ko;Nak-Hoon Son;Chul-Min Ahn;Pil-Ki Min;Jae-Hwan Lee;Chang-Hwan Yoon;Cheol Woong Yu;Seung Whan Lee;Sang-Rok Lee;Seung Hyuk Choi;In-Ho Chae;Donghoon Choi
    • Korean Circulation Journal
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    • v.52 no.7
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    • pp.529-540
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    • 2022
  • Background and Objectives: Limited data are available regarding long-term clinical outcomes of iliac artery endovascular therapy (EVT) in real-world practice. This study investigated long-term outcomes according to Trans-Atlantic Inter-Society Consensus (TASC) classifications. Methods: We analyzed data from 1,705 limbs of 1,364 patients from the retrospective cohort of the multicenter Korean Vascular Intervention Society Endovascular Therapy in Lower Limb Artery Disease registry. The primary endpoint was target lesion revascularization (TLR)-free survival. Results: TASC A, B, C, and D lesions were present in 19.4%, 26.2%, 28.7%, and 25.7% of the treated limbs, respectively. The technical success rate was 96.2% and did not differ between TASC lesion types. Complications occurred in 6.8% of cases and more occurred in TASC D (11.8%). Iliac artery EVT showed a 5-year TLR-free survival of 89.2%. The TASC D group had the lowest TLR-free rate of 79.3%. TASC D (hazard ratio [HR], 1.75; 95% confidence interval [CI], 1.12-2.73; p=0.014), plain old balloon angioplasty (HR, 4.25; 95% CI, 2.03-8.88; p<0.001), current smoker (HR, 1.89; 95% CI, 1.26-2.83; p=0.002), previous bypass surgery (HR, 3.04; 95% CI, 1.28-7.19; p=0.011), combined femoropopliteal treatment (HR, 4.89; 95% CI, 3.19-7.50; p<0.001), combined below the knee treatment (HR, 2.20; 95% CI, 1.25-3.89; p=0.007), and complications (HR, 1.86; 95% CI, 1.07-3.24; p=0.028) were predictors for TLR. Conclusions: Iliac artery EVT achieved excellent technical success and 5-year TLR-free survival. TASC D showed a favorable but lower 5-year TLR-free survival rate and higher complication rate compared with other TASC groups.

Immune-Enhancing Effects of Green Lettuce (Lactuca sativa L.) Extracts through the TLR4-MAPK/NF-κB Signaling Pathways in RAW264.7 Macrophage Cells

  • Seo, Hyun-Ju;Jeong, Jin Boo
    • Korean Journal of Plant Resources
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    • v.33 no.3
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    • pp.183-193
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    • 2020
  • Recently, as a natural substance has been emphasized interest in research to enhance the immune function. Green lettuce (Lactuca sativa L.) is a popular vegetable used fresh and it contains various phytochemicals and antioxidant compounds, and has been reported to have various physiological activities such as antibacterial, antioxidant, antitumor and anti-mutagenic. However, only a few studies have investigated on the mechanism of action of immune-enhancing activity of lettuce. Therefore, in this study, the immunomodulatory activities and potential mechanism of action of Green lettuce extracts (GLE) were evaluated in the murine macrophage cell line RAW264.7. GLE significantly increased NO levels by RAW264.7 cells, as well as expressions of immunomodulators such as iNOS, COX-2, IL-1β, IL-6, IL-12, TNF-α and MCP-1. Although GLE activated ERK1/2, p38, JNK and NF-κB, GLE-mediated expressions of immunomodulators was dependent on p38, JNK and NF-κB. In addition, TLR4 inhibition blocked GLE-mediated expressions of immunomodulators and activation of p38, JNK and NF-κB. Taken together, these results demonstrated that TLR4-MAPK/NF-κB signalling pathways participated in GLE-induced macrophage activation and GLE could be developed as a potential immunomodulating functional food.

Oak Wood Vinegar Suppresses the Expression of Cyclooxygenase-2 Induced by TLR4 Agonist

  • Yun, Sae-Mi;Park, Se-Jeong;Lee, A-Neum;Ahn, Sang-Il;Youn, Hyung-Sun
    • Biomedical Science Letters
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    • v.15 no.3
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    • pp.257-260
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    • 2009
  • Toll-like receptors (TLRs) recognize molecular structures derived from microbes including bacteria, viruses, yeast, and fungi. TLRs have emerged as a major signaling component of the mammalian host defense. TLR4 is a member of the Toll family that senses lipopolysaccharide (LPS), a cell wall component of gram negative bacteria. LPS recognition by TLR4 requires an additional accessory molecule, MD-2. LPS induces the activation of NF-${\kappa}B$ and IRF3 through MyD88 or TRIF-dependent pathways. The activation of NF-${\kappa}B$ leads to the induction of inflammatory gene products including cytokines and cyclooxygenase-2 (COX-2). This study was carried out to investigate the anti-inflammatory effects of oak wood vinegar. Oak wood vinegar inhibits the NF-${\kappa}B$ activation and COX-2 expression induced by LPS. These results provide new ideas to understand the mechanism of oak wood vinegar for its anti-bacterial and anti-inflammatory activities.

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Thymol Ameliorates Aspergillus fumigatus Keratitis by Downregulating the TLR4/ MyD88/ NF-kB/ IL-1β Signal Expression and Reducing Necroptosis and Pyroptosis

  • Limei Wang;Haijing Yan;Xiaomeng Chen;Lin Han;Guibo Liu;Hua Yang;Danli Lu;Wenting Liu;Chengye Che
    • Journal of Microbiology and Biotechnology
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    • v.33 no.1
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    • pp.43-50
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    • 2023
  • Fungal keratitis is a refractory kind of keratopathy. We attempted to investigate the antiinflammatory role of thymol on Aspergillus fumigatus (A. fumigatus) keratitis. Wound healing and fluorescein staining of the cornea were applied to verify thymol's safety. Mice models of A. fumigatus keratitis underwent subconjunctival injection of thymol. The anti-inflammatory roles of thymol were verified by hematoxylin-eosin (HE) staining, slit lamp observation, quantitative real-time polymerase chain reaction (qRT-PCR), and Western blotting. In contrast with the DMSO group, more transparent corneas and less inflammatory cells infiltration were detected in mice treated with 50 ㎍/ml thymol. Thymol downregulated the synthesis of TLR4, MyD88, NF-kB, IL-1β, NLRP3, caspase 1, caspase 8, GSDMD, RIPK3 and MLKL. In summary, we proved that thymol played a protective part in A. fumigatus keratitis by cutting down inflammatory cells aggregation, downregulating the TLR4/ MyD88/ NF-kB/ IL-1β signal expression and reducing necroptosis and pyroptosis.