• The Journal of Korean Medicine
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• v.38 no.2
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• pp.53-60
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• 2017

Objectives: Beakdugu-tang (BDGT) consists of three medicinal herbs, and this prescription has long been used in treatment of various digestant problem in Korea. In this study, we designed to clarify mechanisms by which Korean traditional digestive medicine, BDGT, may exert anti-hepatic steatosis effects via improved insulin resistance cell model in human hepatocellular carcinoma (HepG2) and monocyte (THP-1). Materials and methods: The preparation of BDGT and constituents were extracted with 70% ethanol. HepG2 and THP-1 were treated with different concentrations of BDGT and constituents in the presence and absence of stimulants such as free fatty acids (FFAs) and oxidized low-density lipoprotein (ox-LDL), respectively. Results: The BDGT and its constituents inhibited the FFAs-stimulated lipid accumulation in HepG2 cells. Ethanol extracts of Amomum cardamomum (ACE) improved the ox-LDL induced insulin resistance in THP-1 cells. Also, treatment of monocytic cells with ACE increased anti-hepatic steatosis related gene levels including ABCA, ABCG and SR-B1. Conclusion: The results suggest that the ethanol extract of BDGT and its constituents potently inhibit the FFAs- and ox-LDL induced liver steatosis via improved insulin resistance.

• Smart Structures and Systems
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• v.31 no.3
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• pp.283-299
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• 2023

Structural stability of floating platforms has long since been a crucial issue in the field of marine engineering. Excessive motions would not only deteriorate the operating conditions but also seriously impact the safety, service life, and production efficiency. In recent decades, several control devices have been proposed to reduce unwanted motions, and an attractive one is the tuned heave plate (THP). However, the THP system may reduce or even lose its effectiveness when it is mistuned due to the shift of dominant wave frequency. In the present study, a novel adaptive tuned heave plate (ATHP) is proposed based on inerter by adjusting its inertance, which allows to overcome the limitation of the conventional THP and realize adaptations to the dominant wave frequencies in real time. Specifically, the analytical model of a representative semisubmersible platform (SSP) equipped with an ATHP is created, and the equations of motion are formulated accordingly. Two optimization strategies (i.e., J₁ and J₂ optimizations) are developed to determine the optimum design parameters of ATHP. The control effectiveness of the optimized ATHP is then examined in the frequency domain by comparing to those without control and controlled by the conventional THP. Moreover, parametric analyses are systematically performed to evaluate the influences of the pre-specified frequency ratio, damping ratio, heave plate sizes, peak periods and wave heights on the performance of ATHP. Furthermore, a Simulink model is also developed to examine the control performance of ATHP in the time domain. It is demonstrated that the proposed ATHP could adaptively adjust the optimum inertance-to-mass ratio by tracking the dominant wave frequencies in real time, and the proposed system shows better control performance than the conventional THP.

• BMB Reports
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• v.40 no.1
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• pp.130-134
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• 2007

Haptoglobin (Hp) is a glycoprotein that is produced by hepatic cells and secreted into the circulation. While studying the physiologic functions of Hp, we found that Hp synthesized in THP-1 monocytic cells was largely retained within cells, although Hp is considered a secretory protein. To investigate the molecular mechanism on Hp secretion in THP-1 cells, in the present study, we examined the effect of protein kinase C (PKC) on Hp secretion. When several inhibitors of PKC isoforms were tested, only Rottlerin, a specific inhibitor of PKC-$\delta$, completely blocked Hp secretion from cells to culture medium. To confirm the role of PKC-$\delta$ in Hp secretion, Hp-overexpressing COS7 cells were transiently transfected with a wild-type or a dominantnegative mutant of the PKC-$\delta$ gene. Mutant PKC-$\delta$ significantly inhibited Hp secretion, whereas the wild-type gene slightly increased Hp secretion. These results demonstrate that the PKC-$\delta$ signal is involved in Hp secretion.

• Journal of Microbiology and Biotechnology
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• v.33 no.5
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• pp.582-590
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• 2023

Stress granules (SGs) are cytoplasmic aggregates of RNA-protein complexes that form in response to various cellular stresses and are known to restrict viral access to host translational machinery. However, the underlying molecular mechanisms of SGs during viral infections require further exploration. In this study, we evaluated the effect of SG formation on cellular responses to coxsackievirus B3 (CVB3) infection. Sodium arsenite (AS)-mediated SG formation suppressed cell death induced by tumor necrosis factor-alpha (TNF-a)/cycloheximide (CHX) treatment in HeLa cells, during which G3BP1, an essential SG component, contributed to the modulation of apoptosis pathways. SG formation in response to AS treatment blocked CVB3-mediated cell death, possibly via the reduction of mitochondrial reactive oxygen species. Furthermore, we examined whether AS treatment would affect small extracellular vesicle (sEV) formation and secretion during CVB3 infection and modulate human monocytic cell (THP-1) response. CVB3-enriched sEVs isolated from HeLa cells were able to infect and replicate THP-1 cells without causing cytotoxicity. Interestingly, sEVs from AS-treated HeLa cells inhibited CVB3 replication in THP-1 cells. These findings suggest that SG formation during CVB3 infection modulates cellular response by inhibiting the release of CVB3-enriched sEVs.

• Journal of Mushroom
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• v.14 no.4
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• pp.155-161
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• 2016

A recent study reported that Pleurotus ostreatus has the potential to be used as a ${\beta}-glucan-based$ cream for supportive complementary therapy of atopic dermatitis. KH054 is a new herbal prescription consisting of P. ostreatus and Panax ginseng. The effects of atopic dermatitis-induced materials on the expression of cytokine genes in human monocytes (THP-1, EoL- 1) have been examined. Some reports demonstrated that P. ginseng augments the activity of natural killer cells, which plays an important role in innate immunity against infection and tumor development. Monocyte chemotactic protein 1 (MCP-1), interleukin (IL)-6, and IL-8 have important roles in mediating the infiltration of various cells into the skin of atopic dermatitis and psoriasis. The present study investigated whether KH054 on induced IL-6, IL-8, and MCP-1 secretion by house dust mite (Dermatophagoides pteronissinus) in THP-1 (human acute monocytic leukemia) and EoL-1(Human eosinophilic leukemia) cell. D. pteronissinus functions in the pathogenesis of allergic diseases, including atopic dermatitis and asthma. The inhibitory effect of KH054 on the induction of IL-6, IL-8, and MCP-1 secretion by D. pteronissinus extract in THP-1 and EoL-1 cells was examined. KH054 potently suppressed the elevated production of IL-6 and IL-8 induced by D. pteronissinus treatment in THP-1 and EoL-1 cells. Based on the present results, KH054 may be useful for developing functional foods to treat atopic dermatitis.

• Biomedical Science Letters
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• v.24 no.2
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• pp.134-137
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• 2018

S100A8 and S100A9 are involved in pathogenesis of cancer by induction or inhibition of cancer as well as inflammation. In this study, we investigated the association of S100A8 and S100A9 with pathogenesis of leukemia using human monocytic leukemia cells, THP-1. The expression of TLR4, which is a known receptor of S100A8 and S100A9, was examined by using flow cytometry and Western blotting. THP-1 cells have high surface and cytosol expression of TLR4. S100A8 and S100A9 suppressed the cell survival, and this suppression was found to be associated with apoptosis because they increased the number of apoptotic cells in a dose- and a time-dependent manners. However, S100A8 and S100A9 had no effect on the survival and apoptosis of monocytes isolated from the peripheral blood. We next examined the apoptotic effect of lipopolysaccharide (LPS) and monophosphoryl lipid A (MPLA), which are other ligands of TLR4, in THP-1 cells. Lipopolysaccharide had no effect on cell survival, but MPLA is effective on the cell apoptosis. These results suggest that S100A8 and S100A9 may regulate leukemia cell survival via TLR4, which is an essential receptor in the pro-apoptotic mechanism induced by S100A8 and S100A9. These findings may shed light on development of a possible therapeutic drug for leukemia treatment.

• IMMUNE NETWORK
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• v.10 no.5
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• pp.173-180
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• 2010

Background: APRIL, originally known as a cytokine involved in B cell survival, is now known to regulate the inflammatory activation of macrophages. Although the signal initiated from APRIL has been demonstrated, its role in cellular activation is still not clear due to the presence of BAFF, a closely related member of TNF superfamily, which share same receptors (TACI and BCMA) with APRIL. Methods: Through transfection of siRNA, BAFF-deficient THP-1 cells (human macrophage-like cells) were generated and APRIL-mediated inflammatory activities were tested. The expression patterns of APRIL were also tested in vivo. Results: BAFF-deficient THP-1 cells responded to APRIL-stimulating agents such as monoclonal antibody against APRIL and soluble form of TACI or BCMA. Furthermore, co-incubation of the siBAFF-deficient THP-1 cells with a human B cell line (Ramos) resulted in an activation of THP-1 cells which was dependent on interactions between APRIL and TACI/BCMA. Immunohistochemical analysis of human pathologic samples detected the expression of both APRIL and TACI in macrophage-rich areas. Additionally, human macrophage primary culture expressed APRIL on the cell surface. Conclusion: These observations indicate that APRIL, which is expressed on macrophages in pathologic tissues with chronic inflammation, may mediate activation signals through its interaction with its counterparts via cell-to-cell interaction.

• Korean Journal of Clinical Laboratory Science
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• v.52 no.3
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• pp.245-252
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• 2020

Macrophage cell death contributes to the formation of plaque, leading to the development of atherosclerosis. The accumulation of triglyceride (TG) is also associated with the pathogenesis of atherosclerosis. A previous study reported that TG induces the cell death of macrophages. This study examined whether the cytoplasmic release of cathepsin B from lysosome is associated with the TG-induced cell death of macrophage. The release of cathepsin B was increased in the TG-treated THP-1 macrophages, but the TG treatment did not affect cathepsin B expression. Furthermore, the inhibition of cathepsin B by its inhibitor, CA-074 Me, partially inhibited the TG-induced cell death of macrophage. TG-triggered macrophage cell death is mediated by the activation of caspase-1, -2, and apoptotic caspases. Therefore, this study investigated whether cathepsin B is implicated in the activation of these caspases. The inhibition of cathepsin B blocked the activation of caspase-7, -8, and -1 but did not affect the activity of caspase-3, -9, and -2. Overall, these results suggest that TG-induced cytoplasmic cathepsin B causes THP-1 macrophage cell death by activating caspase-1, leading to subsequent activation of the extrinsic apoptotic pathway.

• Nutritional Sciences
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• v.4 no.1
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• pp.26-33
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• 2001

Animal and clinical studies as well as epidemiological data have provided convincing evidence that n-3 polyunsaturated fatty acids can protect against atherosclerosis. However, the effects of the fatty acids on atherogenesis are contradictory. This discrepancy could derive from great susceptibility of the fatty acids to oxidation. We investigated the effect of eicosapentaenoic aced(EPA) on cellular atherogenesis via the scavenger receptor of THP-1 derived macrophages. THP-1 cells were fully differentiated into macrophages by incubating with phorbol 12-myristate 13-acetate for seven days. Atherogenic features of EPA were compared by subsitituting for linoleic acid (LA). Macrophages were also incubated without treatment of the fatty acids as controls. EPA (5-50 nmol/mL) was not cytotoxic and did not measurably induce cellular oxidation compared to bovine serum albumin (BSA) vehicle or identical doses of LA. EPA increased macrophage uptake and degradation of acetylated LDL(AcLDL) up to 14% and 88%, respectively. EPA increased markedly total cellular sterol synthesis and heparin-releasable lipoprotein lipase activity of macrophages, indicating that EPA may enhance accumulation of cellular cholesteryl ester and possibly facilitate formation of foam cells. These results demonstrate that EPA promotes the modified LDL-triggered atherosclerotic process by the modulation of the scavenger receptor and the activation of LPL in macrophages.

• The Journal of Korean Medicine
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• v.41 no.4
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• pp.12-26
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• 2020

Objectives: The aim of this study is to investigate the mechanisms involved in the anti-inflammatory and anti-tumor effects of Rhus verniciflua Stokes (RVS) on PMA-differentiated human monocytic leukemia THP-1 cells. Methods: Cells were treated with various concentrations of RVS decoction (0-300㎍/ml) for 24, 48, and 72h. Cell viability was evaluated by MTS/PMS assay. The expressions of MMP-2, MMP-9, TIMP-1, TIMP-2, iNOS and COX-2 mRNA and proteins were measured using RT-PCR and western blotting, respectively. Results: RVS suppressed expression of MMP-2 and MMP-9 mRNA. It also down-regulated iNOS and COX-2 mRNA and protein expression. RVS inhibited NF-𝜅B p65 activity and the phosphorylation of Akt and MAPK (ERK and p38 MAPK). Instead, the phosphorylation of JNK is increased at a very low concentration but decreased at higher concentrations. Conclusion: RVS is regarded to inhibit the expression of MMP and TIMP as well as iNOS and COX-2 gene expression via directly inhibiting the activation of NF-𝜅B and phosphorylation of MAPK pathway in THP-1 cells. This suggests RVS have potential to be used as a therapeutic agent for acute myeloid leukemia (AML).