• Journal of Microbiology and Biotechnology
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• 제24권1호
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• pp.127-131
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• 2014

While searching for lactic acid bacteria that can restore aging-impaired immune responses, we isolated the Toll-like receptor (TLR) 2/NF-${\kappa}B$-activating strain Lactobacillus plantarum HY7712 from kimchi and investigated its immunomodulating effect in whole-body ${\gamma}$-irradiated mice. Exposure to HY7712 strongly activated NF-${\kappa}B$ signaling in RAW264.7 cells, but inhibited lipopolysaccharide-stimulated NF-${\kappa}B$ activation. Moreover, HY7712 protected against the downregulation of interferon (IFN)-${\gamma}$ and upregulation of interleukin (IL)-13 caused by ${\gamma}$-irradiation in mice. In mice, ${\gamma}$-irradiation impaired NK-cell activity against YAC-1 tumor cells, but following HY7712 exposure, the activity of NK cells was restored to 91.5% of the level measured in control mice (p < 0.05). These findings suggest that HY7712 activates the TLR2/NF-${\kappa}B$ signaling pathway and protects against the impairment of NK-cell activity caused by ${\gamma}$-irradiation or aging.

• IMMUNE NETWORK
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• 제8권1호
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• pp.1-6
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• 2008

Apoptosis signal-regulating kinase 1 (ASK1), a mitogen- activated protein kinase kinase kinase, plays pivotal roles in stress responses. In addition, ASK1 has emerged as a key regulator of immune responses elicited by pathogen-associated molecular patterns (PAMPs) and endogenous danger signals. Recent studies have demonstrated that reactive oxygen species (ROS)-dependent activation of ASK1 is required for LPS-stimulated cytokine production as well as extracellular ATP-induced apoptosis in immune cells. The mechanism of ROS-dependent regulation of ASK1 activity by thioredoxin and TRAFs has been well characterized. In this review, we focus on the molecular details of the activation of ASK1 and its involvement in innate immunity.

• 대한의생명과학회지
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• 제19권2호
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• pp.168-172
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• 2013

Toll-like receptors (TLRs) play an important role for host defense against invading pathogens. TLR4 has been identified as the receptor for lipopolysaccharide (LPS), which is a cell wall component of gram-negative bacteria. The activation of TLR4 signaling by LPS leads to the activation of NF-${\kappa}B$ and the expression of pro-inflammatory gene products such as cytokines, inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2). To evaluate the therapeutic potential of (E)-1-(2-(2-nitrovinyl)phenyl)pyrrolidine (NVPP), previously synthesized in our laboratory, NF-${\kappa}B$ activation and iNOS and COX-2 expression induced by LPS were examined. NVPP inhibited the activation of NF-${\kappa}B$ induced by LPS. NVPP also suppressed the iNOS expression induced by LPS but it did not suppress COX-2 expression induced by LPS. These results suggest that NVPP has the specific mechanism for anti-inflammatory responses.

• BMB Reports
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• 제52권11호
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• pp.635-640
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• 2019

CpG-DNA triggers the proliferation and differentiation of B cells which results in the increased production of antibodies. The presence of bacteria-reactive IgM in normal serum was reported; however, the relevance of CpG-DNA with the production of bacteria-reactive IgM has not been investigated. Here, we proved the function of CpG-DNA for the production of bacteria-reactive IgM. CpG-DNA administration led to increased production of bacteria-reactive IgM both in the peritoneal fluid and serum through TLR9 signaling pathway. When we stimulated B cells with CpG-DNA, production of bacteria-reactive IgM was reproduced in vitro. We established a bacteria-reactive monoclonal IgM antibody using CpG-DNA stimulated-peritoneal B cells. The monoclonal IgM antibody enhanced the phagocytic activity of RAW 264.7 cells against S. aureus MW2 infection. Therefore, we suggest that CpG-DNA enhances the antibacterial activity of the immune system by triggering the production of bacteria-reactive IgM. We also suggest the possible application of the antibodies for the treatment of antibiotics-resistant bacterial infections.

• Biomolecules & Therapeutics
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• 제23권6호
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• pp.564-570
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• 2015

Peptidoglycan (PG), the gram positive bacterial pathogen-associated molecular patterns (PAMP), is detected in a high proportion in macrophage-rich atheromatous regions, and expression of chemokine CXCL8, which triggers monocyte arrest on early atherosclerotic endothelium, is elevated in monocytes/ macrophages in human atherosclerotic lesion. The aim of this study was to investigate whether PG induced CXCL8 expression in the cell type and to determine cellular signaling pathways involved in that process. Exposure of THP-1 cell, human monocyte/macrophage cell line, to PG not only enhanced CXCL8 release but also profoundly induced il8 gene transcription. PG-induced release of CXCL8 and induction of il8 gene transcription were blocked by OxPAPC, an inhibitor of TLR-2/4 and TLR4, but not by polymyxin B, an inhibitor of LPS. PG-mediated CXCL8 release was significantly attenuated by inhibitors of PI3K-Akt-mTOR pathways. PKC inhibitors, MAPK inhibitors, and ROS quenchers also significantly attenuated expression of CXCL8. The present study proposes that PG contributes to inflammatory reaction and progression of atherosclerosis by inducing CXCL8 expression in monocytes/macrophages, and that TLR-2, PI3K-Akt-mTOR, PKC, ROS, and MAPK are actively involved in the process.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제33권6호
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• pp.636-642
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• 2007

Background: CpG DNA plays an important role in immune cell function. This study examined whether the temporal control of toll-like receptor (TLR)9 by CpG DNA can regulate the expression of matrix metalloproteinase-9(MMP-9). Methods and materials: Macrophages were cultured in the presence of 10% FBS. For the various MMP genes analysis, RT-PCR and real-time PCR were performed. In addition, zymography assay performed for the MMP activity. The phosphorylation assay did for the ERK1/2 and NF${\kappa}B$ activation, and luciferase promoter assay was for the NF${\kappa}B$ activity. Results: CpG DNA induced the mRNA expression of MMP-2, MMP-9, and MMP-13, but not of MMP-7, MMP-8, and MMP-12, in a time-dependent manner. Especially, the mRNA expression of MMP-9 was strongly induced by CpG DNA using real-time RT-PCR. The TLR9 inhibitor, chloroquine, suppressed CpG DNA-induced MMP-9 expression and its activity. Moreover, CpG DNA induced the phosphorylation of ERK and the inhibition of ERK by U0126 suppressed CpG DNA-induced MMP-9 expression and its activity. CpG DNA stimulated $I{\kappa}B-{\alpha}$ degradation and luciferase activity. In addition, pretreatment of SN-50, the inhibitor of NF${\kappa}B$, strongly blocked the CpG DNA-induced MMP-9 expression and activity. Conclusion: These observations suggest that CpG DNA may play important roles in the activation of macrophages by regulating the production of MMP-9 via the sequential TLR9-ERK-NF${\kappa}B$ signaling pathway.

• Nutrition Research and Practice
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• 제7권6호
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• pp.460-465
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• 2013

The hepatoprotective activity of Acanthopanax koreanum Nakai extract (AE) was investigated against D-Galactosamine/Lipopolysaccharide (D-GalN/LPS)-induced liver failure rats compared with that of acanthoic acid (AA) isolated from AE. Although D-GalN/LPS (250 mg/kg body weight/$10{\mu}g/kg$ body weight, i.p.) induced hepatic damage, pretreatments with AE (1 and 3% AE/g day) and AA (0.037% AA, equivalent to 3% AE/g day) alleviated the hepatic damage. This effect was the result of a significant decrease in the activity of alanine transaminase. Concomitantly, both the nitric oxide and IL-6 levels in the plasma were significantly decreased by high-dose AE (AE3) treatment compared to the GalN/LPS control (AE0). This response resulted from the regulation of pro-inflammatory signaling via a decrease in TLR4 and CD14 mRNA levels in the liver. While a high degree of necrosis and hemorrhage were observed in the AE0, pretreatment with AE3 and AA reduced the extent of hepatocyte degeneration, necrosis, hemorrhage and inflammatory cell infiltrates compared to the AE0. In conclusion, these results suggest that especially high-dose AE are capable of alleviating D-GalN/LPS-induced hepatic injury by decreasing hepatic toxicity, thereby mitigating the TLR 4-dependent cytokine release. The anti-inflammatory effect of AE could be contributing to that of AA and AE is better than AA.

• Nutrition Research and Practice
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• 제15권5호
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• pp.591-603
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• 2021

BACKGROUND/OBJECTIVES: Unregulated inflammatory responses caused by hyperglycemia may induce diabetes complications. Hesperetin, a bioflavonoid, is a glycoside in citrus fruits and is known to have antioxidant and anticarcinogenic properties. However, the effect of inflammation on the diabetic environment has not been reported to date. In this study, we investigated the effect of hesperetin on proinflammatory cytokine secretion and its underlying mechanistic regulation in THP-1 macrophages with co-treatment LPS and hyperglycemic conditions. MATERIALS/METHODS: THP-1 cells differentiated by PMA (1 µM) were cultured for 48 h in the presence or absence of hesperetin under normoglycemic (5.5 mM/L glucose) or hyperglycemic (25 mM/L glucose) conditions and then treated with LPS (100 ng/mL) for 6 h before harvesting. Inflammation-related proteins and mRNA levels were evaluated by enzyme-linked immunosorbent assay, western blot, and quantitative polymerase chain reaction analyses. RESULTS: Hesperetin (0-100 µM, 48 h) treatment did not affect cell viability. The tumor necrosis factor-α and interleukin-6 levels increased in cells co-treated with LPS under hyperglycemic conditions compared to normoglycemic conditions, and these increases were decreased by hesperetin treatment. The TLR2/4 and MyD88 activity levels increased in cells co-treated with LPS under hyperglycemic conditions compared to normoglycemic conditions; however, hesperetin treatment inhibited the TLR2/4 and MyD88 activity increases. In addition, nuclear factor-κB (NF-κB) and Acetyl-NF-κB levels increased in response to treatment with LPS under hyperglycemic conditions compared to normoglycemic conditions, but those levels were decreased when treated with hesperetin. SIRT3 and SIRT6 expressions were increased by hesperetin treatment. CONCLUSIONS: Our results suggest that hesperetin may be a potential agent for suppressing inflammation in diabetes.

• Nutrition Research and Practice
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• 제15권6호
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• pp.798-806
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• 2021

BACKGROUND/OBJECTIVES: Obesity is associated with chronic inflammation. The spleen is the largest organ of the lymphatic system and has an important role in immunity. Obesity-induced inflammatory responses are triggered by Toll-like receptor (TLR)-myeloid differentiation primary response 88 (MyD88) pathway signaling. Phenethyl isothiocyanate (PEITC) and 3,3'-diindolylmethane (DIM), major dietary glucosinolates present in cruciferous vegetables, have been reported to produce anti-inflammatory effects on various diseases. However, the effects of PEITC and DIM on the obesity-induced inflammatory response in the spleen are unclear. The purpose of this study was to examine the anti-inflammatory effects of PEITC and DIM on the spleen and their mechanism in high fat/cholesterol diet (HFCD)-fed C57BL/6 mice. MATERIALS/METHODS: We established an animal model of HFCD-induced obesity using C57BL/6 mice. The mice were divided into six groups: normal diet with AIN-93G diet (CON), high fat diet (60% calories from fat) with 1% cholesterol (HFCD), HFCD with PEITC 30 mg/kg/day or 75 mg/kg/day (HFCD+P30, HFCD+P75), and HFCD with DIM 1.5 mg/kg/day or 7.5 mg/kg/day (HFCD+D1.5, HFCD+D7.5). Enzyme-linked immunosorbent assay was used to evaluate pro-inflammatory cytokine secretion. Western blot and quantitative polymerase chain reaction were used to analyze protein and mRNA levels of nuclear factor kappa B (NF-κB) p65, interleukin 6 (IL-6), cyclooxygenase 2 (COX-2), TLR2, TLR4, and MyD88 in spleen tissue. RESULTS: Serum IL-6 levels were significantly higher in the HFCD group than in groups fed a HFCD with PEITC or DIM. Levels of NF-κB p65 protein and TLR2/4, MyD88, NF-κB p65, IL-6, and COX-2 mRNA were significantly higher in the HFCD group than in the CON group and were reduced by the PEITC and DIM supplements. CONCLUSIONS: PEITC- and DIM-supplemented diets improved splenic inflammation by modulating the TLR2/4-MyD88 pathway in HFCD-fed mice. We suggest that dietary glucosinolates may at least partially improve obesity-induced inflammation of the spleen.

• Journal of Ginseng Research
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• 제46권1호
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• pp.156-166
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• 2022

Background: Panax ginseng Meyer (P. ginseng), a herb distributed in Korea, China and Japan, exerts benefits on diverse inflammatory conditions. However, the underlying mechanism and active ingredients remains largely unclear. Herein, we aimed to explore the active ingredients of P. ginseng against inflammation and elucidate underlying mechanisms. Methods: Inflammation model was constructed by lipopolysaccharide (LPS) in C57BL/6 mice and RAW264.7 macrophages. Molecular docking, molecular dynamics, surface plasmon resonance imaging (SPRi) and immunofluorescence were utilized to predict active component. Results: P. ginseng significantly inhibited LPS-induced lung injury and the expression of proinflammatory factors, including TNF-α, IL-6 and IL-1β. Additionally, P. ginseng blocked fluorescencelabeled LPS (LPS488) binding to the membranes of RAW264.7 macrophages, the phosphorylation of nuclear factor-κB (NF-κB) and mitogen-activated protein kinases (MAPKs). Furthermore, molecular docking demonstrated that ginsenoside Ro (GRo) docked into the LPS binding site of toll like receptor 4 (TLR4)/myeloid differentiation factor 2 (MD2) complex. Molecular dynamic simulations showed that the MD2-GRo binding conformation was stable. SPRi demonstrated an excellent interaction between TLR4/ MD2 complex and GRo (K_D value of 1.16 × 10^-9 M). GRo significantly inhibited LPS488 binding to cell membranes. Further studies showed that GRo markedly suppressed LPS-triggered lung injury, the transcription and secretion levels of TNF-α, IL-6 and IL-1β. Moreover, the phosphorylation of NF-κB and MAPKs as well as the p65 subunit nuclear translocation were inhibited by GRo dose-dependently. Conclusion: Our results suggest that GRo exerts anti-inflammation actions by direct inhibition of TLR4 signaling pathway.