• 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.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2003.11a
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• pp.70-70
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• 2003

Estrogen receptor is a ligand-activated transcription factor. Its action depends on the receptor, its ligand, and its coactivator proteins. As a consequence, the concentration of the receptor is a major component that governs the magnitude of the estrogen response. Despite the extensive knowledge on mechanism of estrogen receptor action, regulation of estrogen receptor itself is not very well understood. Estrogen receptor is known to be downregulated under hypoxia leading to inhibition of estrogen receptor mediated transcription activation. We have studied mechanism of loss of estrogen responsiveness under hypoxia. We found that Hif-l${\alpha}$, a major transcription factor regulating hypoxic response, inhibited transcription of estrogen response element driven luciferase gene by expression of HIF-l${\alpha}$/vp16 construct designed to contain transcription activity under normoxia. This loss of estrogen responsiveness appears to be the result of ER${\alpha}$ downregulation. ER${\alpha}$was downregulated at the levels of ligand-biding and protein within l2-24h, and the response was blocked by the proteasome inhibitor MG132, protein synthesis inhibitor cyclohexamide, and tyrosine kinase inhibitor Genistein. These results demonstrate that Hif-l${\alpha}$ downregulates ER${\alpha}$ by proteasome dependent pathway.

• IMMUNE NETWORK
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• v.16 no.3
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• pp.176-182
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• 2016

CCR3 is a chemokine receptor that mediates the accumulation of allergic inflammatory cells, including eosinophils and Th2 cells, at inflamed sites. The regulatory sequence of the CCR3 gene, contains two Runt-related transcription factor (RUNX) 1 sites and two PU.1 sites, in addition to a functional GATA site for transactivation of the CCR3 gene. In the present study, we examined the effects of the cis-acting elements of RUNX1 and PU.1 on transcription of the gene in EoL-1 eosinophilic cells and Jurkat T cells, both of which expressed functional surface CCR3 and these two transcription factors. Introduction of RUNX1 siRNA or PU.1 siRNA resulted in a modest decrease in CCR3 reporter activity in both cell types, compared with transfection of GATA-1 siRNA. Cotransfection of the two siRNAs led to inhibition in an additive manner. EMSA analysis showed that RUNX1, in particular, bound to its binding motifs. Mutagenesis analysis revealed that all point mutants lacking RUNX1- and PU.1-binding sites exhibited reduced reporter activities. These results suggest that RUNX1 and PU.1 participate in transcriptional regulation of the CCR3 gene.

• Journal of Korean Medicine for Obesity Research
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• v.13 no.2
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• pp.74-83
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• 2013

Objectives: This study was performed to evaluate the effects of fermented lotus extracts on the inhibition of differentiation in 3T3-L1 preadipocytes. Methods: Extracts of lotus leaf and lotus root were fermented using 4 different probiotics separately, including Lactobacillus plantarum, Lactobacillus rhamnosus, Bifidobacterium breve, and Bifidobacterium longum. Inhibition of preadipocyte differentiation was examined by Oil red O dye staining. Expressions of adipogenic transcription factors including CCAAT/enhancer binding proteins (C/$EBP{\alpha}$) and peroxisome proliferators-activated receptor ${\gamma}$ ($PPAR{\gamma}$) were analyzed by real time polymerase chain reaction and Western blotting analysis. Results: Fermented lotus extracts inhibited adipogenic transcription factors by inhibiting preadipocytes differentiation. All of the groups fermented by 4 kinds of probiotics showed reduction in Oil Red O dye staining. Bifidobacterium breve showed the most effective inhibition of C/$EBP{\alpha}$. Bifidobacterium breve and Bifidobacterium longum showed the best downregulation of $PPAR{\gamma}$ expressions compared with the control and the unfermented lotus group. Conclusions: Fermented lotus extracts showed significant effects on inhibition of preadipocyte differentiation in 3T3-L1 preadipocytes showing correlation with insulin sensitivity and lipid metabolism related with obesity.

• Journal of Ginseng Research
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• v.41 no.3
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• pp.240-246
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• 2017

Background: Korean Red Ginseng (KRG) is a traditional herbal medicine made by steaming and drying fresh ginseng. It strengthens the endocrine and immune systems to ameliorate various inflammatory responses. The cyclooxygenase-2 (COX-2)/prostaglandin E2 pathway has important implications for inflammation responses and tumorigenesis. Peroxisome proliferator-activated receptor gamma ($PPAR{\gamma}$) is a transcription factor that regulates not only adipogenesis and lipid homeostasis, but also angiogenesis and inflammatory responses. Methods: The effects of the KRG on inhibition of hypoxia-induced COX-2 via $PPAR{\gamma}$ in A549 cells were determined by luciferase assay, Western blot, and/or quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The antimigration and invasive effects of KRG were evaluated on A549 cells using migration and matrigel invasion assays. Results and conclusion: We previously reported that hypoxia-induced COX-2 protein and mRNA levels were suppressed by KRG. This study examines the possibility of $PPAR{\gamma}$ as a cellular target of KRG for the suppression of hypoxia-induced COX-2. $PPAR{\gamma}$ protein levels and $PPAR{\gamma}$-responsive element (PPRE)-driven reporter activities were increased by KRG. Reduction of hypoxia-induced COX-2 by KRG was abolished by the $PPAR{\gamma}$ inhibitor GW9662. In addition, the inhibition of $PPAR{\gamma}$ abolished the effect of KRG on hypoxia-induced cell migration and invasion. Discussion: Our results show that KRG inhibition of hypoxia-induced COX-2 expression and cell invasion is dependent on $PPAR{\gamma}$ activation, supporting the therapeutic potential for suppression of inflammation under hypoxia. Further studies are required to demonstrate whether KRG activates directly $PPAR{\gamma}$ and to identify the constituents responsible for this activity.

• The Journal of Korean Medicine
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• v.29 no.5
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• pp.111-117
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• 2008

Objectives and methods : Previous mechanistic studies suggest the cyclooxygenase-2 (COX-2) inhibitors represent the good candidates against tumor progression. MeOH extract of the stem barks of Euonymus alatus induced the strong inhibition of COX-2. A phenolic compound responsible for the anti- COX-2 known to involve in tumor adhesion and invasion has been studied through the methanol extracts. The compound, rosmarinic acid (ROS-A) was an ester of caffeic acid and 3,4-dihydroxyphenyllactic acid. ROS-A showed a strong inhibitory effect of COX-2 activity in a concentration-dependent manner. Then we have measured the IL-1${\beta}$, IL-6 and TNF-${\alpha}$ production related the immune regulation, induction of inflammatory related genes. Results and Conclusions :Hep3B cells produce proinflammatory cytokines of IL-1${\beta}$, IL-6 and TNF-${\alpha}$ while ROS A inhibited the cytokines production. Since IL-1${\beta}$, IL-6 and TNF-${\alpha}$ need the transcription factors such as nuclear factor- ${\kappa}$B (NF-${\kappa}$B) and activated protein-1 (AP-1), we measured the transcription factors. ROS-A inhibited the activation of p65, p50, c-Rel subunits of NF-${\kappa}$B and AP-1 transcription factors. These findings indicate that ROS A from the stem bark of E. alatus inhibits proliferation in metastatic cancer cells. It was suggested that stem barks of E. alatus could be suitable for anti-cancer drugs.

• Microbiology and Biotechnology Letters
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• v.44 no.1
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• pp.89-97
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• 2016

Obesity is caused by excess accumulation of body fat and contributes to various pathological disorders such as diabetes, hypertension, cardiovascular disease, and cancer. In this study, we investigated the effect of a 30% ethanol extract of Fructus Rosae laevigata (RLE) on adipogenesis in 3T3-L1 adipocytes, measured by triglyceride accumulation and expression of adipogenesis-related transcription factors during differentiation of pre-adipocytes into adipocytes. RLE decreased the intracellular triglyceride contents (assessed by Oil Red-O staining) in a dose-dependent manner. It also downregulated the expression of adipogenic transcription factors and inhibited cell proliferation during the mitotic clonal expansion phase of adipocyte differentiation by inducing G1 phase arrest. We investigated the alterations in the levels of G1 phase arrest-related proteins. The expression of p21 protein significantly increased, while the levels of Cyclin E, Cdk2, and phospho-Rb decreased in a dose-dependent manner in 3T3-L1 cells treated with RLE. These results suggest that RLE inhibits the differentiation of 3T3-L1 adipocytes by suppressing the expression of adipogenic transcription factors and inducing G1 phase arrest in the early stages of adipocyte differentiation.

• Korean Journal of Poultry Science
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• v.50 no.4
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• pp.283-291
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• 2023

Long-chain fatty acids (LCFAs) are vital in cellular compartments, primarily regulating lipid metabolism. Fatty Acid-Binding Proteins (FABPs) facilitate LCFA transport, lipid synthesis, storage, and act as signaling molecules influencing various pathways, including inflammation. FABP4, in particular, is linked to vascular and cardio-related diseases, and it plays a role in macrophage-mediated inflammatory responses. Previous studies have identified FABP4 as not only a representative biomarker for lipogenesis but also as having correlations with immune responses. This study aims to investigate the regulation of the chicken FABP4 (chFABP4) gene by toll-like receptor 3 (TLR3) activation and determine the signaling pathways that are involved in chFABP4 transcriptional regulation. We analyzed the transcriptional regulation of chFABP4 in TLR3-stimulated DF-1 cells. The results showed that chFABP4 was up-regulated upon stimulation with polyinosinic-polycytidylic acid (PIC), a TLR3 ligand. Notably, chFABP4 transcription was independently regulated in the NF-κB signaling pathway. It was up-regulated in p38 inhibition, demonstrating that the p38 signaling pathway might suppress the transcription of chFABP4 within TLR3-activated DF-1 cells. In contrast, chFABP4 expression was down-regulated in JNK signaling pathway inhibition, suggesting the positive regulation of JNK signaling pathway for chFABP4 transcription in DF-1 cells in response to TLR3 activation, consistent with findings in macrophages. MEK pathway inhibition resulted in a similar regulation to NF-κB signaling. These results suggest that each MAPK contributes differentially to the transcriptional regulation of chFABP4 by in DF-1 cells in response to TLR3 activation.

• Animal cells and systems
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• v.13 no.3
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• pp.289-295
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• 2009

Cyclic AMP-mediated signaling pathways regulate a number of cellular functions. In this study, we examined the regulatory role of cAMP signaling pathways in chondrogenesis of chick limb bud mesenchymal cells in vitro. Forskolin, which increases cellular cAMP levels by the activation of adenylate cyclase, enhanced chondrogenic differentiation. Inhibition of PKA with specific inhibitors (H89 or KT5720) blocked pre-cartilage condensation stage, indicating that chondrogenesis is regulated by the increase in cellular cAMP level and subsequent activation of PKA. Downstream signaling pathway of PKA leading to gene expression was investigated by examination of several nuclear transcription factors. Forskolin treatment increased transcription level for a cartilage-specific marker gene Sox9. However, inhibition of PKA with H89 led to restore expression of Sox9, indicating PKA activity was required to regulate the expression of Sox9 in chondrogenesis. In addition, CREB was highly phosphorylated at early stage of mesenchyme culture, and followed by progressive dephosphorylation. CBP and ATF, another CRE related proteins were transiently expressed at the early stage of chondrogenesis with a pattern similar to CREB phosphorylation. Electrophoretic mobility shift assays confirmed that the binding activity of CREB to the CRE is closely correlated to the phosphorylation pattern of CREB. Therefore, cAMP-mediated signal transduction to nuclear events for the induction of genes appeared to be required at the early stage of chick limb bud chondrogenesis.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.22 no.2
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• pp.104-117
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• 2009

Objective : Melanin is one of the most important facor in skin color. Melanin protects human skin from ultraviolet radiation otherwise it causes melanin pigmentation. So this experiment is carried out for test whether Scutellaria baicalensis Georgi(SBG) inhibits melanin synthesis and tyrosinase activity in mouse B16 melanoma cells. Method : The melanin synthesis inhibition effects of SBG were examined by in vitro melanin production assay. We assessed inhibitory effects of SBG on melanin contents from B16F1 melanoma cell, on tyrosinase activity(cell and cell free system), effect of SBG on the expression tyrosinase, Microphthalmia-associated Transcription Factor(MITF), Extracellular signal-regulated Kinase(ERK). Result : SBG inhibited melanin synthesis induced $\alpha$-MSH($\alpha$-Melanin Stimulating Hormone) in B16F1. SBG inhibited tyrosinase activity and expression. And SBG down-regulates MITF and stimulated ERK activation in B16F1. Conclusion : According to above results, SBG was improved its suppression effect to the inhibition of melanin synthesis, tyrosinase activation, and tyrosinase promotor activation. So SBG is considered to be used for an strong source of skin whitening effect.