• Biomolecules & Therapeutics
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• 제23권1호
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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.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2003년도 Annual Meeting of KSAP : International Symposium on Pharmaceutical and Biomedical Sciences on Obesity
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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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• 제16권3호
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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.

• 한방비만학회지
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• 제13권2호
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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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• 제41권3호
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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.

• 대한한의학회지
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• 제29권5호
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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.

• 한국미생물·생명공학회지
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• 제44권1호
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• pp.89-97
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• 2016

비만은 체내 지방이 과도하게 축적되어 일어나는 현상으로, 당뇨, 고혈압, 심혈관 질환 및 암과 같은 질병의 원인이 된다. 본 연구는 RLE에 의해 지방전구세포에서 지방세포로 분화 시, 세포 내 축적되는 Triglyceride 저해 및 발현되는 전사인자들의 발현양상에 미치는 영향에 대하여 조사하였다. 그 결과, RLE는 Oil Red O 염색에서 세포 내 triglyceride의 축적을 농도 의존적으로 억제하였다. 또한 CCAAT/enhancer binding protein(C/EBP) ${\alpha}$, ${\beta}$와 peroxisome proliferator activated receptor ${\gamma}$($PPAR{\gamma}$)과 같은 지방세포 분화 관련 전사인자들의 발현을 억제하였다. RLE는 clonal expansion 단계의 지방세포를 G1기에서 세포 주기를 정지시켜 세포의 증식을 억제하였으며, RLE 처리에 의해 p21의 증가, Cyclin E, Cdk2, Phospho-Rb의 발현 저해 등 G1 arrest 관련 단백질의 발현 변화가 유도되었다. 따라서, RLE는 분화 관련 전사인자들의 발현을 조절하고 지방세포 분화 초기에 G1기의 세포 주기 정지를 억제함으로써 지방전구세포에서 지방세포로의 분화를 억제한다고 사료된다.

• 한국가금학회지
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• 제50권4호
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• pp.283-291
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• 2023

지방산 결합 단백질(FABP)은 LCFA 수송, 지질 합성, 저장을 용이하게 하고, 염증을 포함한 다양한 경로에 영향을 미치는 신호 분자로 작용한다. 특히 FABP4는 혈관 및 심장관련 질환과 관련이 있으며, 대식세포 매개 염증 반응에서 역할을 한다. 이전의 연구들은 FABP4를 지방 생성을 위한 대표적인 바이오 마커일 뿐만 아니라, 면역 반응과도 상관관계가 있는 것으로 확인하였다. 본 연구는 톨-유사 수용체 3(TLR3) 활성화에 의한 닭 FABP4(chFABP4) 유전자의조절을 조사하고 chFABP4 전사 조절에 관여하는 신호 경로를 결정하는 것을 목표로 한다. 우리는 TLR3 자극 DF-1 세포에서 chFABP4의 전사 조절을 분석하였다. 결과는 TLR3 리간드인 폴리이노신-폴리시티딜산(PIC)으로 자극 시 chFABP4가 상향 조절되었음을 보여주었다. 특히 chFABP4 전사는 NF-κB 신호 경로에서 독립적으로 조절되었다. p38 억제에서 상향 조절되어 p38 신호 경로가 TLR3 활성화 DF-1 세포 내에서 chFABP4 전사를 억제할 수 있음을 보여주었다. 이와는 대조적으로, JNK 신호 경로 억제에서는 chFABP4 발현이 하향 조절되었으며, 이는 대식세포의 연구 결과와 일치하며, TLR3 활성화에 반응하여 DF-1 세포에서 chFABP4 전사를 위한 JNK 신호 전달 경로의 긍정적인 조절을 시사한다. MEK 경로 억제는 NF-κB 신호 전달과 유사한 조절을 초래하였다. 이러한 결과는 각 MAPK가 TLR3 활성화에 반응하여 DF-1 세포에서 chFABP4의 전사 조절에 차별적으로 기여함을 시사한다.

• Animal cells and systems
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• 제13권3호
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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.

• 한방안이비인후피부과학회지
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• 제22권2호
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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.