• Journal of Applied Biological Chemistry
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• v.64 no.3
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• pp.263-268
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• 2021

7-Hydroxy-4-methylcoumarin (7H-4MC) inhibits hyaluronan production in multiple cell lines and tissue types both in vitro and in vivo. It is a commercially available drug approved for human use, called hymecromone, in European and Asian countries to prevent biliary spasms. Nevertheless, as the pharmacological efficacy of 7H-4MC has not yet been reported in macrophages, this study investigated its anti-inflammatory effects and mechanism of action using lipopolysaccharide (LPS)-induced RAW 264.7 macrophages. LPS-induced RAW 264.7 cells were treated with various concentrations of 7H-4MC (62.5, 125, 250, and 500 μM). The application of 7H-4MC significantly reduced nitric oxide and prostaglandin E₂ production without cytotoxic effects. Additionally, 7H-4MC strongly decreased the expression of inducible nitric oxide synthase and cyclooxygenase. Furthermore, 7H-4MC reduced the production of proinflammatory cytokines, such as tumor necrosis factor-α, interleukin (IL)-1β, and IL-6. Finally, 7H-4MC exerted its potent anti-inflammatory actions via the upregulation of IκB-α production, which led to the inhibition of nuclear factor-κB (NF-κB) activity. These results, obtained in macrophage cell lines, suggest that 7H-4MC prevents inflammatory diseases via the NF-κB signaling pathway and that its use could be beneficial for human health. Ultimately, this is the first report describing the anti-inflammatory activity of 7H-4MC in a macrophage cell line.

• Biomolecules & Therapeutics
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• v.32 no.3
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• pp.341-348
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• 2024

Endoplasmic reticulum (ER) stress plays a crucial role in liver diseases, affecting various types of hepatic cells. While studies have focused on the link between ER stress and hepatocytes as well as hepatic stellate cells (HSCs), the precise involvement of hepatic macrophages in ER stress-induced liver injury remains poorly understood. Here, we examined the effects of ER stress on hepatic macrophages and their role in liver injury. Acute ER stress led to the accumulation and activation of hepatic macrophages, which preceded hepatocyte apoptosis. Notably, macrophage depletion mitigated liver injury induced by ER stress, underscoring their detrimental role. Mechanistic studies revealed that ER stress stimulates macrophages predominantly via the PERK signaling pathway, regardless of its canonical substrate ATF4. hnRNPA1 has been identified as a crucial mediator of PERK-driven macrophage activation, as the overexpression of hnRNPA1 effectively reduced ER stress and suppressed pro-inflammatory activation. We observed that hnRNPA1 interacts with mRNAs that encode UPR-related proteins, indicating its role in the regulation of ER stress response in macrophages. These findings illuminate the cell type-specific responses to ER stress and the significance of hepatic macrophages in ER stress-induced liver injury. Collectively, the PERK-hnRNPA1 axis has been discovered as a molecular mechanism for macrophage activation, presenting prospective therapeutic targets for inflammatory hepatic diseases such as acute liver injury.

• Environmental Analysis Health and Toxicology
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• v.3 no.3_4
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• pp.29-37
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• 1988

Experiments were performed on mice to investigate the effect of panax ginseng extracts on the immunotoxicity of ethanol. Immune response were evaluated by antibody production, Arthus reaction, delayed type hypersensitivity (DTH), Rosette froming cell (RFC) and macrophage activity in mice, sensitized and challenged with sheep red blood cells. The weight of liver, spleen and thymus were measured. Following results obtained in this experiment. The exposure of ethanol decreased humoral and cellular immune response, the body weight and macrophage activity. Ginseng extracts such as ethanol extract, petroleum ether extract and n-butanol fraction were significantly increased the body weight. The administration of ginseng ethanol extract and ginseng petroleum ether extract were restored or increased humoral and cellular immune response. Macrophage activity was decreased by ethanol, but restored by the ginseng extracts.

• 대한치주과학회:학술대회논문집
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• 2004.11a
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• pp.138-138
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• 2004

• Proceedings of the PSK Conference
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• 2000.10a
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• pp.245.1-245.1
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• 2000

• IMMUNE NETWORK
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• v.24 no.2
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• pp.3.1-3.23
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• 2024

Cigarette smoke extract (CSE)-treated mouse airway epithelial cells (MAECs)-derived exosomes accelerate the progression of chronic obstructive pulmonary disease (COPD) by upregulating triggering receptor expressed on myeloid cells 1 (TREM-1); however, the specific mechanism remains unclear. We aimed to explore the potential mechanisms of CSE-treated MAECs-derived exosomes on M1 macrophage polarization and pyroptosis in COPD. In vitro, exosomes were extracted from CSE-treated MAECs, followed by co-culture with macrophages. In vivo, mice exposed to cigarette smoke (CS) to induce COPD, followed by injection or/and intranasal instillation with oe-TREM-1 lentivirus. Lung function and pathological changes were evaluated. CD68⁺ cell number and the levels of iNOS, TNF-α, IL-1β (M1 macrophage marker), and pyroptosis-related proteins (NOD-like receptor family pyrin domain containing 3, apoptosis-associated speck-like protein containing a caspase-1 recruitment domain, caspase-1, cleaved-caspase-1, gasdermin D [GSDMD], and GSDMD-N) were examined. The expression of maternally expressed gene 3 (MEG3), spleen focus forming virus proviral integration oncogene (SPI1), methyltransferase 3 (METTL3), and TREM-1 was detected and the binding relationships among them were verified. MEG3 increased N6-methyladenosine methylation of TREM-1 by recruiting SPI1 to activate METTL3. Overexpression of TREM-1 or METTL3 negated the alleviative effects of MEG3 inhibition on M1 polarization and pyroptosis. In mice exposed to CS, EXO^-CSE further aggravated lung injury, M1 polarization, and pyroptosis, which were reversed by MEG3 inhibition. TREM-1 overexpression negated the palliative effects of MEG3 inhibition on COPD mouse lung injury. Collectively, CSE-treated MAECs-derived exosomal long non-coding RNA MEG3 may expedite M1 macrophage polarization and pyroptosis in COPD via the SPI1/METTL3/TREM-1 axis.

• The Korean Journal of Physiology and Pharmacology
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• v.27 no.2
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• pp.157-165
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• 2023

Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer and current therapeutic strategies are limited in their effectiveness. The expressions of Rab5 and the M2 tumor-associated macrophage marker CD163 in tissues were detected by Western blot. The migration and invasion of cells were determined using a Transwell assay. The expressions of the exosome markers were evaluated by Western blot. The polarization of human macrophages (THP-1) was determined by incubation of THP-1 cells with conditioned medium or exosomes collected from MDA-MB-231 cells with indicated transfections or by a coculture system of THP-1 and MDA-MB-231 cells. The M1 and M2 macrophage markers were evaluated by qRT-PCR. The expression of Rab5 in TNBC was significantly higher than that in normal breast tissue. Rab5 expressions in triple-negative and luminal A breast cancer were higher than those in other molecular subtypes. Higher CD163 expression was observed in triple-negative breast cancer and in triple-negative and luminal B subtypes. Rab5 knockdown suppressed but Rab5 overexpression promoted the migration and invasion capacity of MDA-MB-231 cells. The levels of CD63 and CD9 in the medium of Rab5 knockdown cells were lower than those in control cells, whereas higher levels of CD63 and CD9 were observed in Rab5 overexpression cells. Rab5 knockdown decreased the excretion but did not alter the diameter of the exosomes. Knockdown of Rab5 facilitated the anti-tumor polarization of macrophages, which was partially reversed by Rab5 overexpression. Therefore, Rab5 is expected to be a potential therapeutic target for triple-negative breast cancer.

• Parasites, Hosts and Diseases
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• v.28 no.2
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• pp.85-90
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• 1990

This study was aimed to observe the direct and Iymphokine-activated cell mediated cytotoxic effects against Trichomenas waginalis by mouse peritoneal macrophages. Cytotoxicity was measured as release of 3H-thymidine from prelabeled protozoa, and tested in U-bottom microtiter plates. A 0.1 ml suspension of labeled protozoa (2{\times}10^5/ml$) was placed in each well, followed by 0.1 ml of a suspension containing increasing numbers of peritoneal cells. After a 24 hr incubation at $37^{\circ}C$, 0.1ml of the supernatant was collected and counted in liquid scintillation counter. Mouse peritoneal macrophages had appreciable level of spontaneous cytotoxicity against T. maginalis at the effector to target cell ratios from 5 : 1 to 50 : 1, Treatment of macrophages with Iymphokine, produced by PHA-stimulated spleen cells, increased the cytotoxicity in comparison with resident macrophages against T. vaginalis. The degree of macrophage activation for the killing was not dependent upon the Iymphokine concentration. Peritoneal cells adherent to plastic displayed significant levels of cytotoxicity against T. vaginalis. This study indicates that mouse peritoneal macrophages are spontaneously cytotoxic for T. waginalis and Iymphokine increases the cytotoxicity by activating macrophages to kill T. vaginalis.

• The Korean Journal of Physiology and Pharmacology
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• v.21 no.5
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• pp.547-554
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• 2017

Previous studies have demonstrated the role of hydroquinone (HQ), a hydroxylated benzene metabolite, in modulating various immune responses; however, its role in macrophage-mediated inflammatory responses is not fully understood. In this study, the role of HQ in inflammatory responses and the underlying molecular mechanism were explored in macrophages. HQ down-regulated the expression of interferon $(IFN)-{\beta}$ mRNA in LPS-stimulated RAW264.7 cells without any cytotoxicity and suppressed interferon regulatory factor (IRF)-3-mediated luciferase activity induced by TIR-domain-containing adapter-inducing interferon-${\beta}$ (TRIF) and TANK-binding kinase 1 (TBK1). A mechanism study revealed that HQ inhibited IRF-3 phosphorylation induced by lipopolysaccharide (LPS), TRIF, and AKT by suppressing phosphorylation of AKT, an upstream kinase of the IRF-3 signaling pathway. IRF-3 phosphorylation is highly induced by wild-type AKT and poorly induced by an AKT mutant, AKT C310A, which is mutated at an inhibitory target site of HQ. We also showed that HQ inhibited IRF-3 phosphorylation by targeting all three AKT isoforms (AKT1, AKT2, and AKT3) in RAW264.7 cells and suppressed IRF-3-mediated luciferase activities induced by AKT in HEK293 cells. Taken together, these results strongly suggest that HQ inhibits the production of a type I IFN, $IFN-{\beta}$, by targeting AKTs in the IRF-3 signaling pathway during macrophage-mediated inflammation.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.20 no.2 s.33
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• pp.10-35
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• 2007

Objectives : To investigate the effects of Ohbaesangami (OBSGM) on mucosa and skin diseases, anti-microbial and anti-inflammatory tests were performed using several in vitro test models. Results : In anti-microbial test, OBSGM showed the slight inhibitory effect against Propionibacterium acnes (P. acnes) and Staphylococcus aureus (S. aureus). In anti-oxidant test, OBSGM showed the potent radical scavenging activity. In anti-inflammatory test, OBSGM weakly inhibited the lipopolysaccharide (LPS)-induced nitric oxide(NO) release from the RAW 264.7 macrophage cells. OBSGM also inhibited the LPS-induced $interleukin-1{\beta}(IL-1{\beta})$ and cyclooxygenase-2 (COX-2) expressions. The inhibitory effects of OBSGM on macrophage activation was via the inhibition of $NF-{\kappa}B$, evidenced by transient transfection assay. Furthermore, OBSGM markedly inhibited the activation of Jun-N-terminal kinase (JNK) and p38 MAP kinase in RAW 264.7 cells. In skin wrinkle formation assay, OBSGM strongly inhibited collagnease and elastase, whose activities are tightly related with the wrinkle formation. In addition, OBSGM inhibited the activities of MMP-1, MMP-2 on the mRNA levels in RAW 264.7 cells. However, OBSGM did not show an inhibitory potential on tyrosinase activity and melanin synthesis, indicating that it could not be applicable for skin whitening. Conclusion : These results suggest that the anti-inflammatory effect of OBSGM may be due to its inhibitory potentials on the macrophage activation. And, the anti-wrinkle effects of OBSGM may be due to its inhibitory potential on the collagnease and elastase activities. Therefore, OBSGM could be applicable for the treatment of mucosa and skin diseases.