• Proceedings of the Korean Society of Applied Pharmacology
• /
• 2003.11a
• /
• pp.88-88
• /
• 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.

• Proceedings of the Korean Society of Toxicology Conference
• /
• 2002.05a
• /
• pp.105-105
• /
• 2002

A wide range of chemicals derived from plant and human-made xenobiotics are reported to have hormonal activity. The present studies were performed to examine the estrogenic effect of Kwao Keur, Pueraria mirifica (PM), that has been used a rejuvenating folk medicine from Thailand, using recombinant yeast, MCF-7 cell proliferation and HepG2 cell transient transfection assay.(omitted)

• Proceedings of the Korea Society of Environmental Toocicology Conference
• /
• 2003.10a
• /
• pp.178-178
• /
• 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.

• Animal cells and systems
• /
• v.15 no.1
• /
• pp.1-8
• /
• 2011

Perturbation of metabolism with increased expression of lipogenic enzymes is a common characteristic of human cancers, including prostate cancer. In the present work the overexpression of stearoyl-CoA desaturase (SCD) in LNCaP cells led to increased mRNA levels of fatty acid synthase (FAS) and acetyl-CoA-carboxylase-a, whereas micro RNA-mediated silencing of SCD inhibited the expression of these lipogenic genes in LNCaP cells. Treatment with the FAS-specific inhibitor cerulenin inhibited SCD induction of LNCaP cell proliferation. In addition, a transient transfection assay revealed the capability of cerulenin to suppress SCD and dihydrotestosterone induction of androgen receptor transcriptional activity. Furthermore, overexpression of SCD in LNCaP cells produced marked resistance to ceramide-induced cell death with reduced poly(ADP-ribose) polymerase (PARP) cleavage. In contrast, silencing of SCD expression increased Bax protein in LNCaP cells. Furthermore, addition of ceramide to SCD knockdown LNCaP cells increased cell death and caspase-3 activity with drastic increase of PARP cleavage. Together, the data indicate that SCD may provide resistance of prostate cancer cells to ceramide-induced cell death.

• Asian-Australasian Journal of Animal Sciences
• /
• v.29 no.10
• /
• pp.1383-1391
• /
• 2016

Bovine embryonic stem cells have potential for use in research, such as transgenic cattle generation and the study of developmental gene regulation. The Nanog may play a critical role in maintenance of the undifferentiated state of embryonic stem cells in the bovine, as in murine and human. Nevertheless, efforts to study the bovine Nanog for pluripotency-maintaining factors have been insufficient. In this study, in order to understand the mechanisms of transcriptional regulation of the bovine Nanog, the 5'-flanking region of the Nanog was isolated from ear cells of Hanwoo. Results of transient transfection using a luciferase reporter gene under the control of serially deleted 5'-flanking sequences revealed that the -134 to -19 region contained the positive regulatory sequences for the transcription of the bovine Nanog. Results from mutagenesis studies demonstrated that the Sp1-binding site that is located in the proximal promoter region plays an important role in transcriptional activity of the bovine Nanog promoter. The electrophoretic mobility shift assay with the Sp1 specific antibody confirmed the specific binding of Sp1 transcription factor to this site. In addition, significant inhibition of Nanog promoter activity by the Sp1 mutant was observed in murine embryonic stem cells. Furthermore, chromatin-immunoprecipitation assay with the Sp1 specific antibody confirmed the specific binding of Sp1 transcription factor to this site. These results suggest that Sp1 is an essential regulatory factor for bovine Nanog transcriptional activity.

• Archives of Pharmacal Research
• /
• v.27 no.8
• /
• pp.857-862
• /
• 2004

Naringenin, dietary flavonoid, is antioxidant constituents of many citrus fruits. In the present study, we investigated the effect of naringenin on 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-inducible CYP1 A 1 gene expression in mouse hepatoma Hepa-1c1c7 cells. Naringenin alone did not affect CYP1A1-specific 7-ethoxyresorufin O-deethylase (EROD) activity. In contrast, the TCDD-inducible EROD activities were markedly reduced upon concomitant treatment with TCDD and naringenin in a dose dependent manner. TCDD-induced CYP1A1 mRNA level was also markedly suppressed by naringenin. A transient transfection assay using dioxin-response element (DRE)-linked luciferase and electrophoretic mobility shift assay revealed that naringe-nin reduced transformation of the aryl hydrocarbons receptor(AhR) to a form capable of specif-ically binding to the DRE sequence in the promoter of the CYP1A1 gene. These results suggest the down regulation of the CYP1A1 gene expression by either naringenin in Hepa-1c1c7 cells might be antagonism of the DRE binding potential of nuclear AhR.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
• /
• v.20 no.2 s.33
• /
• pp.10-35
• /
• 2007

Objectives : To investigate the effects of Ohbaesangami (OBSGM) on mucosa and skin diseases, anti-microbial and anti-inflammatory tests were performed using several in vitro test models. Results : In anti-microbial test, OBSGM showed the slight inhibitory effect against Propionibacterium acnes (P. acnes) and Staphylococcus aureus (S. aureus). In anti-oxidant test, OBSGM showed the potent radical scavenging activity. In anti-inflammatory test, OBSGM weakly inhibited the lipopolysaccharide (LPS)-induced nitric oxide(NO) release from the RAW 264.7 macrophage cells. OBSGM also inhibited the LPS-induced $interleukin-1{\beta}(IL-1{\beta})$ and cyclooxygenase-2 (COX-2) expressions. The inhibitory effects of OBSGM on macrophage activation was via the inhibition of $NF-{\kappa}B$, evidenced by transient transfection assay. Furthermore, OBSGM markedly inhibited the activation of Jun-N-terminal kinase (JNK) and p38 MAP kinase in RAW 264.7 cells. In skin wrinkle formation assay, OBSGM strongly inhibited collagnease and elastase, whose activities are tightly related with the wrinkle formation. In addition, OBSGM inhibited the activities of MMP-1, MMP-2 on the mRNA levels in RAW 264.7 cells. However, OBSGM did not show an inhibitory potential on tyrosinase activity and melanin synthesis, indicating that it could not be applicable for skin whitening. Conclusion : These results suggest that the anti-inflammatory effect of OBSGM may be due to its inhibitory potentials on the macrophage activation. And, the anti-wrinkle effects of OBSGM may be due to its inhibitory potential on the collagnease and elastase activities. Therefore, OBSGM could be applicable for the treatment of mucosa and skin diseases.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.29 no.3
• /
• pp.337-344
• /
• 2002

Runx2, a Runt-related osteoblast-specific transcription factor, is essential for osteoblast differentiation and function. Runx2 was identified as a key regulator of osteoblast-specific gene expression through its binding to the OSE2 element present in these genes. However, little is known about the signaling mechanism regulating Runx2 activity. This study examines the role of protein kinase C (PKC) pathway and mitogen-activated protein kinase (MAPK) pathway in regulating Runx2 and bone marker genes (osteopontin; OP, osteocalcin; OC). Luciferase assay and Northern blot analysis suggested that the stimulation of PKC by PMA increased transcription activity of Runx2 and bone marker genes (OP and OC) and also increased expression of Runx2. The stimulation of MAPK by okadaic acid increased transcription activity of Runx2 and bone marker genes (OP and OC). Pretreatment with PD98059 (Erk pathway inhibitor) and SB203580 (P38 pathway inhibitor) prior to PMA treatment decreased PMA stimulated Runx2 activity. Together these results indicate that both PKC and MAPKs are involved in the regulation of Runx2 activity and also the stimulation of Runx2 transcriptional activity by the PKC pathway is through activation of MAPK pathway.

• Journal of Pharmacopuncture
• /
• v.19 no.1
• /
• pp.59-69
• /
• 2016

Objectives: The mushroom Ganoderma lucidum has been widely used as a traditional herbal medicine for many years. Although several studies have focused on the anti-oxidative activity of this mushroom, the molecular mechanisms underlying its activity have not yet been clearly established. The present study investigated the cytoprotective effect of ethanol extract of Ganoderma lucidum (EGL) against oxidative stress (hydrogen peroxide, $H_2O_2$) and elucidated the underlying mechanisms in a C2C12 myoblast cell line. Methods: Oxidative stress markers were determined by using the comet assay to measure reactive oxygen species (ROS) generation and deoxyribonucleic acid (DNA) damage. Cell viability and Western blotting analyses were employed to evaluate the cellular response to EGL and $H_2O_2$ in C2C12 cells. Transfection with nuclear factor erythroid 2-related factor 2 (Nrf2)-specific small interfering ribonucleic acid (siRNA) was conducted to understand the relationship between Nrf2 expression and $H_2O_2$-induced growth inhibition. Results: The results showed that EGL effectively inhibited $H_2O_2$-induced growth and the generation of ROS. EGL markedly suppressed $H_2O_2$-induced comet-like DNA formation and phosphorylation of histone H2AX at serine 139 ($p-{\gamma}H2AX$), a widely used marker of DNA damage, suggesting that EGL prevented $H_2O_2$-induced DNA damage. Furthermore, the EGL treatment effectively induced the expression of Nrf2, as well as heme oxygenase-1 (HO-1), with parallel phosphorylation and nuclear translocation of Nrf2 in the C2C12 myoblasts. However, zinc protoporphyrin IX, a HO-1 inhibitor, significantly abolished the protective effects of EGL against $H_2O_2$-induced accumulation of ROS and reduced cell growth. Notably, transient transfection with Nrf2-specific siRNA attenuated the cytoprotective effects and HO-1 induction by EGL, indicating that EGL induced the expression of HO-1 in an Nrf2-dependent manner. Conclusion: Collectively, these results demonstrate that EGL augments the cellular anti-oxidant defense capacity through activation of Nrf2/HO-1, thereby protecting C2C12 myoblasts from $H_2O_2$-induced oxidative cytotoxicity.

• Journal of Life Science
• /
• v.20 no.2
• /
• pp.275-280
• /
• 2010

Sulforaphane is a naturally occurring member of the iosothiocyanate family, which reveals chemopreventive capacities including anti-cancer, anti-inflammation and inhibition of MMP-9 activities. In this study, we investigated the effect of sulforaphane on the expression of matrix metalloproteinase-9 (MMP-9) in lipopolysaccharide (LPS)-induced Raw 264.7 cells. Sulforaphane strikingly suppressed the LPS-induced MMP-9 activity and mRNA expression in a dose-dependent manner. In addition, sulforaphane inhibited not only the LPS-induced MMP-9 promoter activity but also LPS-mediated activator protein-1 (AP-1) and nuclear factor-kB (NF-${\kappa}B$) promoter activity. Transient transfection by MMP-9 constructs, in which specific transcriptional factors were mutagenized, indicated that the effects of LPS and sulforaphane were mediated via AP-1 and NF-${\kappa}B$ response elements. We found that sulforaphane had the ability to suppress LPS-induced invasion in vitro. Taken together, these results demonstrated that sulforaphane effectively suppressed LPS-induced MMP-9 expression via modulation of promoter elements (AP-1 and NF-${\kappa}B$) in MMP-9 transcriptional activation.