• Korean Journal of Veterinary Research
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• v.58 no.2
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• pp.95-98
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• 2018

Brucellosis is one of the common zoonoses caused by Brucella abortus (B. abortus). However, little has been reported on factors affecting invasion of B. abortus into host cells. To investigate cell-type dependent invasion of B. abortus, phagocytic RAW 264.7 and THP-1 cells and non-phagocytic HeLa cells were infected with wild-type and mutant B. abortus, and their invasion efficiencies were compared. The invasion efficiencies of the strains were cell-type dependent. Wild-type B. abortus invasion efficiency was greater in phagocytic cells than in epithelial cells. The results also indicated that there are different factors involved in the invasion of B. abortus into phagocytic cells.

• International Journal of Oral Biology
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• v.44 no.4
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• pp.160-164
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• 2019

Porphyromonas gingivalis (Pg), Aggregatibacter actinomycetemcomitans (Aa), Tannerella forsythia (Tf), Prevotella intermedia (Pi), and Fusobacterium nucleatum (Fn) are major periodontal pathogens. Lipopolysaccharides (LPSs) from periodontal bacteria play an important role in periodontal pathogenesis by stimulating host cells to produce inflammatory cytokines. In this study, highly pure LPSs from the five major periodontopathogens were prepared, and their monocyte chemoattractant protein-1 (MCP-1) and tumor necrosis factor-α (TNF-α)-inducing activities were compared in human umbilical vein endothelial cells (HUVECs) and THP-1 macrophagic cells, respectively. In HUVECs, LPSs from Aa and Fn were potent stimulators for MCP-1 induction; however, LPSs from Pg, Pi, and Tf were much weaker MCP-1 inducers. In THP-1 cells, LPSs from Pg, Aa, and Fn were relatively strong inducers of TNF-α, whereas LPSs from Pi and Tf produced little activity. The Toll-like receptor (TLR)2/TLR4 dependency of various LPSs was also determined by measuring NF-κB reporter activity in TLR2- or TLR4-expressing 293 cells. LPSs from Aa, Fn, and Tf stimulated only TLR4; however, LPSs from Pg and Pi stimulated both TLR2 and TLR4. These results suggest that LPSs from major periodontal bacteria differ considerably in their cell-stimulating activity.

• Parasites, Hosts and Diseases
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• v.46 no.3
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• pp.145-151
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• 2008

During Toxoplasma gondii infection, macrophages, dendritic cells, and neutrophils are important sources of pro-inflammatory cytokines from the host. To counteract the pro-inflammatory activities, T. gondii is known to have several mechanisms inducing down-regulation of the host immunity. In the present study, we analyzed the production of pro- and anti-inflammatory cytokines from a human myelomonocytic cell line, THP-1 cells, in response to treatment with T. gondii lysate or lipopolysaccharide (LPS). Treatment of THP-1 cells with LPS induced production of IL-12, TNF-$\alpha$, IL-8, and IL-10. Co-treatment of THP-1 cells with T. gondii lysate inhibited the LPS-induced IL-12, IL-8 and TNF-$\alpha$ expression, but increased the level of IL-10 synergistically. IL-12 and IL-10 production was down-regulated by anti-human toll-like receptor (TLR)-2 and TLR4 antibodies. T. gondii lysate triggered nuclear factor (NF)-${\kappa}B$-dependent IL-8 expression in HEK293 cells transfected with TLR2. It is suggested that immunosuppression induced by T. gondii lysate treatment might occur via TLR2-mediated NF-${\kappa}B$ activation.

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.6
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• pp.1305-1313
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• 2009

Saengjihwangeum-ja (SJHEJ) was recorded in DongEuiBoGam as being able to be used for treatment of Sogal whose concept had been applied to Diabetes Mellitus (DM). Modification of proteins by long term circulation of glucose leads to the formation of advanced glycation end product(AGE). Recent immunological studies demonstrated that ligation of AGE play an important role in the development of diabetic complications including atherosclerosis, which includes activation, adhesion, and migration of monocytes. Also, AGE and Maillard reaction product(MRP) could augment monocyte inflammatory responses via ligation of AGE receptor. In this study, the effects of SJHEJ extracts on the expression of inflammatory response-related genes such as tumor necrosis factor-$\alpha$, monocyte chemoattractant protein-1, interferon-g-inducible protein-10, and cyclooxygenase-2 in the human monocyte cell line, THP-1 cells. Reverse transcriptase-polymerase chain reaction revealed that SJHEJ had inhibitory effects on the expression of the TNF-a, MCP-1, IP-10, COX2, IL-1b genes in MRP-induced THP-1 cells. Treatment with SJHEJ had reduced reactive oxygen production in THP-1 cells stimulated by MRP. These inhibitory effects might be exerted via prevention of oxidative stress in activated monocytes. In addition, radical scavenging activity of SJHEJ was increased. These results suggest that SJHEJ has a beneficial effects for improve diabetic vascular complication.

• Journal of Life Science
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• v.22 no.12
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• pp.1637-1643
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• 2012

This study investigated the effects of PG on IL-$1{\beta}$ expression and determined cellular factors involved in PG-mediated IL-$1{\beta}$ up-regulation in mononuclear cells in order to understand the molecular mechanisms underlying inflammatory responses associated with bacterial pathogen-associated molecular patterns in the diseased artery. Exposure of human monocytic leukemia THP-1 cells to PG resulted in enhanced secretion of IL-$1{\beta}$ and also profound induction of the IL-$1{\beta}$ gene transcript. These effects were abrogated by OxPAPC, an inhibitor of TLR-2/4. Pharmacological inhibitors such as U0126, SP6001250, Akti IV, rapamycin, and DPI also significantly attenuated PG-mediated IL-$1{\beta}$ up-regulation. However, polymyxin B did not influence the IL-$1{\beta}$ expression. This study indicates that PG contributes to vascular inflammation in atherosclerotic plaques by up-regulating expression of IL-$1{\beta}$ via TLR-2, Akt, mTOR, MAPKs, and ROS.

• Nutrition Research and Practice
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• v.15 no.5
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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.

• Journal of Life Science
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• v.27 no.5
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• pp.553-560
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• 2017

Fermented garlic extract (FGE) is a well-known functional food containing cycloalliin. Here we tested if FGE has an effect on the vascular system. We found that FGE had an effect on monocytic adhesion to endothelial cells, which occurs at the initial step of processes of inflammation. From dose-dependent experiments, 0.1 to $1{\mu}g/ml$ of FGE appeared to inhibit lipopolysaccharide (LPS)-enhanced heterotypic cell adhesion between THP-1 and BAECs. This result indicates that FGE blocks vascular inflammation. Then we found that FGE activates eNOS and Akt in BAECs. The phosphorylation of eNOS was maximally elevated 10 min after FGE treatment. Parallely, the phosphorylation of Akt was also maximally increased 10 min after FGE treatment. Consistently, it was found that FGE enhanced the production of nitric oxide. We then examined whether NO mediates THP-1 cell adhesion to BAECs. Both Akt and eNOS inhibitors appeared to reverse an inhibitory effect of FGE. These findings indicate that FGE inhibits LPS-enhanced heterotypic cell adhesion via Akt and eNOS. In conclusion, FGE plays an important role in prevention of inflammatory diseases.

• Proceedings of the PSK Conference
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• 2001.04a
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• pp.168.1-168.1
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• 2001

• Biomolecules & Therapeutics
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• v.29 no.4
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• pp.410-418
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• 2021

Helicobacter pylori causes chronic gastritis through cag pathogenicity island (cagPAI), vacuolating cytotoxin A (VacA), lipopolysaccharides (LPS), and flagellin as pathogen-related molecular patterns (PAMPs), which, in combination with the pattern recognition receptors (PRRs) of host cells promotes the expression and secretion of inflammation-causing cytokines and activates innate immune responses such as inflammasomes. To identify useful compounds against H. pylori-associated gastric disorders, the effect of chalcone derivatives to activate the nucleotide-binding oligomerization domain (NOD)-like receptor family, pyrin domain-containing 3 (NLRP3) inflammasome was examined in an H. pylori-infected human monocytic THP-1 cell line in this study. Among the five synthetic structurally-related chalcone derivatives examined, 2'-hydroxy-4',6'-dimethoxychalcone (8) and 2'-hydroxy-3,4,5-trimethoxychalcone (12) strongly blocked the NLRP3 inflammasome in H. pylori-infected THP-1 cells. At 10 μM, these compounds inhibited the production of active IL-1β, IL-18, and caspase-1, and apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) oligomerization, but did not affect the expression levels of NLRP3, ASC, and pro-caspase-1. The interruption of NLRP3 inflammasome activation by these compounds was found to be mediated via the inhibition of the interleukin-1 receptor-associated kinase 4 (IRAK4)/IκBα/NF-κB signaling pathway. These compounds also inhibited caspase-4 production associated with non-canonical NLRP3 inflammasome activation. These results show for the first time that certain chalcones could interrupt the activation of the NLRP3 inflammasome in H. pylori-infected THP-1 cells. Therefore, these chalcones may be helpful in alleviating H. pylori-related inflammatory disorders including chronic gastritis.

• Nutrition Research and Practice
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• v.1 no.4
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• pp.285-290
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• 2007

The leukocyte recruitment and transmigration across the endothelial barrier into the vessel wall are crucial steps in atherosclerosis. Leukocyte trafficking on the endothelium is elicited by induction of endothelial adhesion molecules, and its transmigration is mediated by degradation of basement membrane proteins through enzymatic activity of matrix metalloproteinases (MMP). The current study investigated whether resveratrol, a polyphenol present in grapes and red wine, was capable of inhibiting leukocyte adhesion to tumor necrosis factor (TNF)-${\alpha}$-activated endothelium. It was found that resveratrol inhibited the TNF-${\alpha}$-activated endothelial expression of vascular cell adhesion molecule-1 in a dose-dependent manner. In addition, resveratrol hampered THP-1 monocyte adhesion to activated endothelial cells. This study further examined whether resveratrol interfered with transendothelial migration of leukocytes. The MMP-2 gelatinolytic activity of endothelial cells was enhanced by TNF-${\alpha}$, which was attenuated by an addition of ${\geq}25{\mu}M$ resveratrol. In addition, 25 ${\mu}M$ resveratrol mitigated the MMP-9 activity of THP-1 cells, followed by a marked inhibition of transendothelial migration. These results demonstrated that resveratrol suppressed monocyte adhesion and migration induced by TNF-${\alpha}$ through modulating expression of adhesion molecules and gelatinolytic activity of MMP. These findings suggest that dietary resveratrol may be therapeutic agent for inhibiting leukocyte recruitment into the subendothelium during inflammatory atherosclerosis.