• Natural Product Sciences
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• v.23 no.4
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• pp.239-246
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• 2017

27-Hydroxycholesterol (27OHChol) has been reported to induce differentiation of monocytic cells into a mature dendritic cell phenotype. We examined the effect of methanol extract of Nardostachys chinensis (Nard) on 27OHChol-induced differentiation using THP-1, a human monocytic cell line. Treatment of monocytic cells with methanol extract of Nard resulted in decreased transcription and surface expression of CD80, CD83, and CD88 elevated by 27OHChol in a dose-dependent manner. Surface levels of MHC class I and II molecules elevated by 27OHChol were also reduced to basal levels by treatment with the Nard extract. Decreased endocytosis activity caused by 27OHChol was recovered by treatment with the Nard extract. CD197 expression and cell attachment were attenuated by the Nard extract. In addition, levels of transcription and surface expression of CD molecules involved in atherosclerosis, such as CD105, CD137, and CD166 upregulated by 27OHChol were significantly decreased by treatment with methanol extract of Nard. These results indicate that methanol extract of Nard down-regulates 27OHChol-induced differentiation of monocytic cells into a mature dendritic cell phenotype and expression of CD molecules associated with atherosclerosis. The current study suggests that biological activity of oxygenated cholesterol derivatives can be inhibited by herbal medication.

• Preventive Nutrition and Food Science
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• v.9 no.3
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• pp.265-269
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• 2004

Prunus mandshurica var. glabra Nakai (Rosaceae) is widely distributed in South Korea and bears a fruit with a bitter and astringent taste. An ethyl acetate-soluble extract of Prunus mandshurica was found to exhibit significant cytotoxicity against human leukemia cell lines. Bioassay-directed fractionation of this extract using an MTT(3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) cell proliferation assay as a monitor led to the isolation of the bioactive compounds. Two compounds, 1 and 2 were subsequently found to mediate cytotoxicity against U937, human monocytic leukemia cells. The 50% growth inhibitory concentrations ($IC_{50}$/) of compounds 1 and 2 on U937 were 40 and 62 $\mu\textrm{g}$/mL, respectively.

• International Journal of Oral Biology
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• v.31 no.1
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• pp.21-26
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• 2006

Periodontopathogens including Porphyromonas gingivalis interact with host periodontal cells and the excessive subsequent host responses contribute a major part to the development of periodontal diseases. Cyclooxygenase(COX)-2-synthesized $PGE_2$ has detrimental activities in terms of periodontal pathogenesis. The present study investigated induction of COX-2 expression by P. gingivalis in human monocytic THP-1 cells. Live P. gingivalis increased expression of COX-2, but not that of COX-1, which was demonstrated at both mRNA and protein levels. Elevated levels of $PGE_2$ were released from P. gingivalis-infected THP-1 cells. Pharma-cological inhibition of p38 mitogen-activated protein kinase(MAPK) and extracellular signal-regulated kinase(ERK) substantially attenuated P. gingivalis-induced COX-2 mRNA expression. Indeed, activation of p38 MAPK and ERK was observed in P. gingivalis-infected THP-1 cells. Also, P. gingivalis induced activation of nuclear $factor-{\kappa}B\;(NF-{\kappa}B)$ which is an important transcription factor for COX-2. These results suggest that COX-2 expression is up regulated in P. gingivalis-infected monocytic cells, at least in part, via p38 MAPK, ERK, and $NF-{\kappa}B$.

• Biomolecules & Therapeutics
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• v.23 no.1
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• pp.84-89
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• 2015

We investigated the question of whether 7-oxygenated cholesterol derivatives could affect inflammatory and/or immune responses in atherosclerosis by examining their effects on expression of IL-23 in monocytic cells. $7{\alpha}$-Hydroxycholesterol ($7{\alpha}OHChol$) induced transcription of the TLR6 gene and elevated the level of cell surface TLR6 protein in THP-1 monocytic cells. Addition of an agonist of TLR6, FSL-1, to TLR6-expressing cells by treatment with $7{\alpha}OHChol$ resulted in enhanced production of IL-23 and transcription of genes encoding the IL-23 subunit ${\alpha}$ (p19) and the IL-12 subunit ${\beta}$ (p40). However, treatment with 7-ketocholesterol (7K) and $7{\beta}$-hydroxycholesterol ($7{\beta}OHChol$) did not affect TLR6 expression, and addition of FSL-1 to cells treated with either 7K or $7{\beta}OHChol$ did not influence transcription of the genes. Pharmacological inhibition of ERK, Akt, or PI3K resulted in attenuated transcription of TLR6 induced by $7{\alpha}OHChol$ as well as secretion of IL-23 enhanced by $7{\alpha}OHChol$ plus FSL-1. Inhibition of p38 MAPK or JNK resulted in attenuated secretion of IL-23. These results indicate that a certain type of 7-oxygenated cholesterol like $7{\alpha}OHChol$ can elicit TLR6-mediated expression of IL-23 by monocytic cells via PI3K/Akt and MAPKs pathways.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.9
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• pp.4827-4834
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• 2012

Tumor suppressor genes have received much attention for their roles in the development of human malignancies. Gelsolin has been found to be down-regulated in several types of human cancers, including leukemias. It is, however, expressed in macrophages, which are the final differentiation derivatives for the monocytic myeloid lineage, implicating this protein in the differentiation process of such cells. In order to investigate the role of gelsolin in leukaemic cell differentiation, stable clones over-expressing ectopic gelsolin, and a control clone were established from U937 leukaemia cells. Unlike the control cells, both gelsolin-overexpressing clones displayed retarded growth, improved monocytic morphology, increased NADPH and NSE activities, and enhanced surface expression of the ${\beta}$-integrin receptor, CD11b, when compared with the parental U937 cells. Interestingly, RT-PCR and western blot analysis also revealed that gelsolin enhanced p21CIP1 mRNA and protein expression in the overexpressing clones. Moreover, transient transfection with siRNA silencing P21CIP1, but not the control siRNA, resulted in a reduction in monocytic differentiation, accompanied by an increase in proliferation. In conclusion, our work demonstrates that gelsolin, by itself, is capable of inducing monocytic differentiation in U937 leukaemia cells, most probably through p21CIP1 activation.

• YAKHAK HOEJI
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• v.52 no.1
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• pp.48-55
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• 2008

CD29 $({\beta}1-integrins)$ is one of major adhesion molecules involved in regulating cell adhesion, migration and morphological changes. In this study, we investigated the regulatory role of CD29 in monocytic functions using monocytic cell line U937 cells. CD29 was found to be one of highly expressed membrane proteins in U937 cells, according to flow cytometric analysis. The activation of CD29 by agonistic antibody MEM101A and extracellular matrix protein (ECM) fibronectin strongly induced cell-cell and cell-fibronectin adhesions. However, blocking antibodies to CD98 and CD147 showed different inhibitory features in these two adhesion events. Furthermore, U0126, an ERK inhibitor, only blocked cell-cell adhesion but not cell-fibronectin adhesion, indicating that cell-cell or cell-fibronectin adhesion events may be regulated by different molecular mechanisms. Meanwhile, CD29 activation also enhanced ROS generation but not phagocytic ability, and similarly radical scavenger N-acetyl-L-cysteine strongly blocked CD29-mediated cell-cell adhesion, implying that ROS may play a critical role in up-regulating cell-cell adhesion. Therefore, our data suggest that the activation of CD29 may be critically involved in regulating monocytic cell-mediated cell-cell adhesion and ROS generation.

• Parasites, Hosts and Diseases
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• v.51 no.1
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• pp.85-92
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• 2013

IL-23 and IL-12 are structurally similar and critical for the generation of efficient cellular immune responses. Toxoplasma gondii induces a strong cell-mediated immune response. However, little is known about IL-23 secretion profiles in T. gondii-infected immune cells in connection with IL-12. We compared the patterns of IL-23 and IL-12 production by THP-1 human monocytic cells in response to stimulation with live or heat-killed T. gondii tachyzoites, or with equivalent quantities of either T. gondii excretory/secretory proteins (ESP) or soluble tachyzoite antigen (STAg). IL-23 and IL-12 were significantly increased from 6 hr after stimulation with T. gondii antigens, and their secretions were increased with parasite dose-dependent manner. IL-23 concentrations were significantly higher than those of IL-12 at the same multiplicity of infection. IL-23 secretion induced by live parasites was significantly higher than that by heat-killed parasites, ESP, or STAg, whereas IL-12 secretion by live parasite was similar to those of ESP or STAg. However, the lowest levels of both cytokines were at stimulation with heat-killed parasites. These data indicate that IL-23 secretion patterns by stimulation with various kinds of T. gondii antigens at THP-1 monocytic cells are similar to those of IL-12, even though the levels of IL-23 induction were significantly higher than those of IL-12. The detailed kinetics induced by each T. gondii antigen were different from each other.

• Korean Journal of Microbiology
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• v.44 no.4
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• pp.299-304
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• 2008

Monocytic cells in myeloid lineage are known for latent site of HCMV Previous studies have suggested that HCMV regulates cell cycle progression in a variety of cells, but studies in monocytic cells are limited. In this study, we attempted to understand cell cycle changes after HCMV infection in the monocytic cell lines. Flow cytometric analyses using propidium iodide revealed that the proportion of G0-G1 phase was increased and the proportion of S phase decreased in HCMV-infected THP-1 cells, but not in HL-60 cells. BrdU-incorporation assay supported that cell proliferation was inhibited in HCMV-infected THP-1 cells by inhibition of de novo DNA synthesis. Western blot analysis revealed that p21, inhibitor of cell cycle progression from G1 phase to S phase, was induced in HCMV-infected THP-1 cells but not in HL-60 cells. Thus, HCMV inhibited cell pro-liferation by arresting the cell cycle at G0-G1 phase through induction of p21 protein in promocytic THP-1 cells.

• Biomedical Science Letters
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• v.19 no.1
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• pp.48-54
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• 2013

Atopic dermatitis is a recurrent or chronic eczematous skin disease with severe pruritus and has annually increased in Korea. In this study, we investigated whether Duchesnea chrysantha (Dc) extracts have an anti-inflammatory effect in human monocytic THP-1 cells and human eosinophilic EoL-1 cells. The dried and powdered whole plants of Dc were extracted with 80% EtOH (Dc-1). The residue was diluted with water, and then successively partitioned with n-hexane, EtOAc, and BuOH to produce the n-hexane (Dc-2), EtOAc (Dc-3), BuOH (Dc-4), and the water-soluble fractions (Dc-5), respectively. The mite extract and LPS increased the production of IL-6, IL-8 and MCP-1 in THP-1 cells and the increase was strongly suppressed by Dc-3 extract, as compare with other extracts. Dc-3 also inhibited the release of IL-6 increased by mite extract and LPS in EoL-1 cells. However, Dc-3 extract increased IL-8 production induced by the mite extract and LPS in EoL-1 cells. These results suggest that Dc extract may be used as anti-inflammatory agents in treating allergic disorders such as asthma and atopic dermatitis.

• Biomedical Science Letters
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• v.16 no.4
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• pp.341-347
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• 2010

In the present study, we investigated whether Houttuynia cordata Thumb (Saururaceae; HC) extracts have an anti-inflammatory effect in human monocytic THP-1 cells and human eosinophilic EoL-1 cells. The dried and powdered whole plants of HC were extracted with 80% EtOH. The combined extract (HC-1) was concentrated under reduced pressure. The residue was diluted with water, and then successively partitioned with n-hexane, EtOAc, and BuOH to produce the n-hexane (HC-2), EtOAc (HC-3), BuOH (HC-4), and the water-soluble fractions (HC-5), respectively. HC extracts have no cytotoxicity on THP-1 cells and EoL-1 cells at a high concentration of $10\;{\mu}g/ml$ for 24 h, except HC-2 extract ($10\;{\mu}g/ml$). Interleukin-6, Interleukin-8 and Monocyte chemoattractant protein-1 in THP-1 cells were increased after the treatment with the extract from house dust mite or LPS. The increase of cytokine production was strongly suppressed by HC-3 extract, in comparision with other extracts. HC-3 also had inhibitory effect on Interleukin-6 production increased by mite extract and LPS in EoL-1 cells. However, HC-3 extract increased Interleukin-8 production induced by mite extract and LPS in EoL-1 cells. These results suggest that HC extracts may be used as useful agents for treating allergic disorders such as asthma and atopic dermatitis.