• 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.88-88
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• 2003

Cytochrome P-450 3A4 (CYP3A4) is major enzyme in human liver, the role of this is detoxification and metabolizing more than 50% clinical drugs in use. Expression of CYP3A4 is transciptionally regulated by the Pregnenolone X receptor (PXR), of which human form is Steroid and Xenobiotics receptor (SXR). SXR is activated by wide range of endogenous and exogenous compounds, and then induces CYP3A4 gene expression. In the previous study, it has been known that proximal promoter (-864 to +64) does not response to chemical inducers such as pregnenolone 16a-carbonitrile (PCN), Rifampicin, Estrogen in terms of transcription of CYP 3A4 in cultured cells. Here, we developed luciferase reporter gene assay system to detect SXR-based CYP 3A4 transcriptional activity. We have used CYP3A4-Luc plasmid that contains proximal promoter of human CYP3A4 gene upstream of the luciferase gene. We did transient transfection of 3A4-luciferase gene and SXR. In the HepG2 cells transfected with CYP3A4-Luc, when rifampicin treatment was combined with histone deacetylase inhibitor (HDAC Inhibitor), such as Trichostatin A, Hc-toxin and IN 2001 of the luciferase activity was induced 10-20 fold over control.

• 한국축산식품학회지
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• 제31권3호
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• pp.398-404
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• 2011

TR4 has been suggested to play an important role in lipid metabolism in adipocytes. Although TR4 facilitates lipid accumulation during adipogenesis, the regulatory effect of TR4 on lipid storage in mature adipocytes remains unclear. We showed that TR4 inhibited the LXR agonist GW3965-mediated decrease of lipid accumulation in 3T3-L1 adipocytes. A reporter gene analysis revealed that TR4 suppressed LXR${\alpha}$ transcriptional activity, although LXR${\alpha}$ was unable to affect TR4 transcriptional activity. Moreover, adding TR4 resulted in reduced LXR${\alpha}$ binding to the LXR responsive element in a gel shift assay. Additionally, the suppressive effect of GW3965 on perilipin expression and lipid accumulation in 3T3-L1 adipocytes was abolished by TR4 overexpression. Taken together, our data demonstrate that TR4 plays an inhibitory role in LXR${\alpha}$-mediated suppression of lipid accumulation in 3T3-L1 adipocytes. This TR4 protective effect is mediated, in part, y blocking the suppressive effect of GW3965 on perilipin gene expression.

• 한국환경독성학회:학술대회논문집
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• 한국환경독성학회 2003년도 추계국제학술대회
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• pp.178-178
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• 2003

Cytochrome P-450 3A4 (CYP3A4) is major enzyme in human liver, the role of this Is detoxification and metabolizing more than 50% clinical drugs in use. Expression of CYP3A4 is transciptionally regulated by the Pregnenolone X receptor (PXR), of which human form is Steroid and Xenobiotics receptor (SXR). SXR is activated by wide range of endogenous and exogenous compounds, and then induces CYP3A4 gene expression. In the previous study, it has been known that proximal promoter (-864 to ＋64) does not response to chemical inducers such as pregnenolone 16a-carbonitrile (PCN), Rifampicin, Estrogen in terms of transcription of CYP 3A4 in cultured cells. Here, we developed luciferase reporter gene assay system to detect SXR-based CYP 3A4 transcriptional activity. We have used CYP3A4-Luc plasmid that contains proximal promoter of human CYP3A4 gene upstream of the luciferase gene. We did transient transfection of 3A4-luciferase gene and SXR. In the HepG2 cells transfected with CYP3A4-Luc, when rifampicin treatment was combined with histone deacetylase inhibitor (HDAC Inhibitor), such as Trichostatin A, Hc-toxin and IN 2001 of the luciferase activity was induced 10-20 fold over control.

• Natural Product Sciences
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• 제20권1호
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• pp.65-70
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• 2014

This study was carried out to investigate the potential effects of Gardenia jasminoides (GJ) extracts, on hepatic steatosis and lipid metabolism in mice fed with high-fat diet (HFD). GJ extracts (100 mg/kg, ${\times}10$ weeks) fed mice showed reduced body weight, adipose tissue weight, reduced aminotransferase level in plasma and hepatic lipid (triglyceride, total cholesterol) content. These effects were accompanied by decreased expression of lipogenic genes, sterol regulatory element binding protein-1c (SREBP-1c), liver X receptor (LXR), fatty acid synthase (FAS), acetyl-CoA carboxylase (ACC), cluster of differentiation 36 (CD36), lipoprotein lipase (LPL) and decreased lipogenic enzyme FAS and HMG-CoAR enzyme activities while elevating carnitine palmitoyltrasferase-1 (CPT) activity. Based on these results, we speculated that the inhibitory effect on hepatic steatosis of GJ extract containing geniposide is the result of suppression of lipid synthesis in mice fed with HFD, suggesting that GJ extract may be beneficial in preventing hepatic steatosis.

• Molecular & Cellular Toxicology
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• 제3권1호
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• pp.1-10
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• 2007

The persistent and ubiquitous environmental contaminant, tributyltin chloride (TBT), induces not only imposex in gastropods but also the differentiation of adipocytes in vitro and increases adipose mass in vivo in vertebrates. TBT is a nanomolar affinity ligand for retinoid X receptor (RXR) in the rock shell(Thais clavigera) and for both the RXR and the peroxisome proliferator activated receptor $\gamma(PPAR\gamma)$ in the amphibian (Xenopus laevis), mouse, and human. The molecular mechanisms underlying induction of imposex by TBT have not been clarified, though several hypotheses are proposed. TBT promotes adipogenesis in the murine 3T3-L1 cell model and perturbs key regulators of adipogenesis and lipogenic pathways in vivo primarily through activation of RXR and $PPAR\gamma$. Moreover, in utero exposure to TBT leads to strikingly elevated lipid accumulation in adipose depots, liver, and testis of neonate mice and results in increased adipose mass in adults. In X. laevis, ectopic adipocytes form in and around gonadal tissues following organotin, RXR or $PPAR\gamma$ ligand exposure. TBT represents the first example of an environmental endocrine disrupter that promotes adverse effects from gastropods to mammals.

• Molecules and Cells
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• 제26권4호
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• pp.409-414
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• 2008

The cholesteryl ester transfer protein (CETP), a key player in cholesterol metabolism, has been shown to promote the transfer of triglycerides from very low density lipoprotein (VLDL) and low density lipoprotein (LDL) to high density lipoprotein (HDL) in exchange for cholesterol ester. Here we demonstrate that farnesoid X receptor ${\alpha}$ ($FXR{\alpha}$; NR1H4) down-regulates CETP expression in HepG2 cells. A $FXR{\alpha}$ ligand, chenodeoxycholic acid (CDCA), suppressed basal mRNA levels of the CETP gene in HepG2 cells in a dose-dependent manner. Using gel shift and chromatin immunoprecipitation (ChIP) assays, we found that $FXR{\alpha}$ could bind to the liver X receptor ${\alpha}$ ( $LXR{\alpha}$; NR1H3) binding site (LXRE; DR4RE) located within the CETP 5' promoter region. $FXR{\alpha}$ suppressed $LXR{\alpha}$-induced DR4RE-luciferase activity and this effect was mediated by a binding competition between $FXR{\alpha}$ and $LXR{\alpha}$ for DR4RE. Furthermore, the addition of CDCA together with a $LXR{\alpha}$ ligand, GW3965, to HepG2 cells was shown to substantially decrease mRNA levels of hepatic CETP gene, which is typically induced by GW3965. Together, our data demonstrate that $FXR{\alpha}$ down-regulates CETP gene expression via binding to the DR4RE sequence within the CETP 5' promoter and this $FXR{\alpha}$ binding is essential for $FXR{\alpha}$ inhibition of $LXR{\alpha}$-induced CETP expression.

• Asian-Australasian Journal of Animal Sciences
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• 제31권4호
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• pp.595-606
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• 2018

Objective: The Fusarium mycotoxins of deoxynivalenol (DON) and zerolenone (ZEN) cause health hazards for both humans and farm animals. Therefore, the main intention of this study was to reveal DON and ZEN effects on the mRNA expression of pro-inflammatory cytokines and other immune related genes in the liver of piglets. Methods: In the present study, 15 six-week-old piglets were randomly assigned to the following three different dietary treatments for 4 weeks: control diet, diet containing 8 mg DON/kg feed, and diet containing 0.8 mg ZEN/kg feed. After 4 weeks, liver samples were collected and sequenced using RNA-Seq to investigate the effects of the mycotoxins on genes and gene networks associated with the immune systems of the piglets. Results: Our analysis identified a total of 249 differentially expressed genes (DEGs), which included 99 upregulated and 150 downregulated genes in both the DON and ZEN dietary treatment groups. After biological pathway analysis, the DEGs were determined to be significantly enriched in gene ontology terms associated with many biological pathways, including immune response and cellular and metabolic processes. Consistent with inflammatory stimulation due to the mycotoxin-contaminated diet, the following Kyoto encyclopedia of genes and genomes pathways, which were related to disease and immune responses, were found to be enriched in the DEGs: allograft rejection pathway, cell adhesion molecules, graft-versus-host disease, autoimmune thyroid disease (AITD), type I diabetes mellitus, human T-cell leukemia lymphoma virus infection, and viral carcinogenesis. Genome-wide expression analysis revealed that DON and ZEN treatments downregulated the expression of the majority of the DEGs that were associated with inflammatory cytokines (interleukin 10 receptor, beta, chemokine [C-X-C motif] ligand 9), proliferation (insulin-like growth factor 1, major facilitator superfamily domain containing 2A, insulin-like growth factor binding protein 2, lipase G, and salt inducible kinase 1), and other immune response networks (paired immunoglobulin-like type 2 receptor beta, Src-like-adaptor-1 [SLA1], SLA3, SLA5, SLA7, claudin 4, nicotinamide N-methyltransferase, thyrotropin-releasing hormone degrading enzyme, ubiquitin D, histone $H_2B$ type 1, and serum amyloid A). Conclusion: In summary, our results demonstrated that high concentrations DON and ZEN disrupt immune-related processes in the liver.

• Molecules and Cells
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• 제43권5호
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• pp.459-468
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• 2020

Nuclear receptor subfamily group H member 4 (NR1H4), also known as farnesoid X receptor, has been implicated in several cellular processes in the liver and intestine. Preclinical and clinical studies have suggested a role of NR1H4 in colon cancer development; however, how NR1H4 regulates colon cancer cell growth and survival remains unclear. We generated NR1H4 knockout (KO) colon cancer cells using clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein-9 nuclease (CAS9) technology and explored the effects of NR1H4 KO in colon cancer cell proliferation, survival, and apoptosis. Interestingly, NR1H4 KO cells showed impaired cell proliferation, reduced colony formation, and increased apoptotic cell death compared to control colon cancer cells. We identified MYC as an important mediator of the signaling pathway alterations induced by NR1H4 KO. NR1H4 silencing in colon cancer cells resulted in reduced MYC protein levels, while NR1H4 activation using an NR1H4 ligand, chenodeoxycholic acid, resulted in time- and dose-dependent MYC induction. Moreover, NR1H4 KO enhanced the anti-cancer effects of doxorubicin and cisplatin, supporting the role of MYC in the enhanced apoptosis observed in NR1H4 KO cells. Taken together, our findings suggest that modulating NR1H4 activity in colon cancer cells might be a promising alternative approach to treat cancer using MYC-targeting agents.

• 한방재활의학과학회지
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• 제30권1호
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• pp.13-29
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• 2020

Objectives This study was performed to decide the bone union effect of Hwaweo-jeon on tibia fractured mice. Methods In this study, laboratory experiments were implemented by the stage of in vitro and in vivo. In in vitro, MC3T3-E1 cells were treated with various concentration of Hwaweo-jeon extract (HWJ). To investigate effect of HWJ for osteoblast, relative mRNA expression of 5 substances (alkaline phosphatase [ALP], runt-related transcription factor 2 [Runx2], osteocalcin [OCN], osterix [OSX] and collagen type II alpha 1 chain [Col2a1]) was used as a marker of osteogenesis. In order to determine HWJ's effect for fracture healing, relative gene expression level of ALP, Runx2, OCN, OSX and Col2a1 were used to find out the influence to osteoblast. Furthermore, receptor activator of nuclear factor kappa-B ligand and osteoprotegerin relative mRNA expression were used to estimate the impact to osteoclast. Also, X-ray was used for the purpose of identifying bone union in tibia-fracture mouse model. Results In in vitro experiment, most part of relative mRNA expression were increased compared to control group. In in vivo and in vitro experiment, HWJ induced osteoblast activitation by verifying relative mRNA expression of 5 substances. And in vivo experiment, we can also identify that HWJ triggered osteoclast activation during early stage of tibia fracture. Furthermore, X-ray pictures show noticeable recovery of tibia fracture. Conclusions HWJ extract promotes bone union by facilitating the osteoblast. But, HWJ may occur liver & kidney toxicity over specific concentration. Therefore, when HWJ is applied to human body, doctors have to follow up the liver function test & renal function test of patient.

• Experimental and Molecular Medicine
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• 제50권11호
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• pp.14.1-14.14
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• 2018

The link between antibiotic treatment and IF-associated liver disease (IFALD) is unclear. Here, we study the effect of antibiotic treatment on bile acid (BA) metabolism and investigate the involved mechanisms. The results showed that pediatric IF patients with cholestasis had a significantly lower abundance of BA-biotransforming bacteria than patients without cholestasis. In addition, the BA composition was altered in the serum, feces, and liver of pediatric IF patients with cholestasis, as reflected by the increased proportion of primary BAs. In the ileum, farnesoid X receptor (FXR) expression was reduced in patients with cholestasis. Correspondingly, the serum FGF19 levels decreased significantly in patients with cholestasis. In the liver, the expression of the rate-limiting enzyme in bile salt synthesis, cytochrome P450 7a1 (CYP7A1), increased noticeably in IF patients with cholestasis. In mice, we showed that oral antibiotics (gentamicin, GM or vancomycin, VCM) reduced colonic microbial diversity, with a decrease in both Gram-negative bacteria (GM affected Eubacterium and Bacteroides) and Gram-positive bacteria (VCM affected Clostridium, Bifidobacterium and Lactobacillus). Concomitantly, treatment with GM or VCM decreased secondary BAs in the colonic contents, with a simultaneous increase in primary BAs in plasma. Moreover, the changes in the colonic BA profile especially that of tauro-beta-muricholic acid ($T{\beta}MCA$), were predominantly associated with the inhibition of the FXR and further altered BA synthesis and transport. In conclusion, the administration of antibiotics significantly decreased the intestinal microbiota diversity and subsequently altered the BA composition. The alterations in BA composition contributed to cholestasis in IF patients by regulating FXR signaling.