• Title/Summary/Keyword: Binding inhibitor

Search Result 535, Processing Time 0.033 seconds

Reduction of Dioxin-Induced Expression of cyplal Gene through Repression of AhR/Arnt DNA Binding by Mek-1 inhibitor PD98059

  • Park, Hyunsung
    • Proceedings of the Korean Society of Toxicology Conference
    • /
    • 2002.11b
    • /
    • pp.60-66
    • /
    • 2002
  • Aryl hydrocarbons, environmental contaminants accumulate in tissue and pose potential risk in human health. 2,3,7,8-Tertachlorodibenzo-p-dioxin (TCDD) is known as a most potent toxicant among aryl hydrocarbons. TCDD elicits numerous toxic responses in experimental animals and human, including hepatic carcinoma, pulmonary and skin tumor in adult rodents, craniofacial abnormality during mouse embryogenesis, chloracne, reproductive abnormality, immunotoxicity, endocrine effects in exposed humans.(omitted)

  • PDF

Effect of Cordycepin-Enriched WIB801C from Cordyceps militaris Suppressing Fibrinogen Binding to Glycoprotein IIb/IIIa

  • Lee, Dong-Ha;Kim, Hyun-Hong;Lim, Deok Hwi;Kim, Jong-Lae;Park, Hwa-Jin
    • Biomolecules & Therapeutics
    • /
    • v.23 no.1
    • /
    • pp.60-70
    • /
    • 2015
  • In this study, we investigated the effects of cordycepin-enriched (CE)-WIB801C, a n-butanol extract of Cordyceps militaris-hypha on collagen-stimulated platelet aggregation. CE-WIB801C dose dependently inhibited collagen-induced platelet aggregation, and had a synergistic effect together with cordycepin (W-cordycepin) from CE-WIB801C on the inhibition of collagen-induced platelet aggregation. CE-WIB801C and cordycepin stimulated the phosphorylation of VASP ($Ser^{157}$) and the dephosphorylation of PI3K and Akt, and inhibited the binding of fibrinogen to glycoprotein IIb/IIIa (${\alpha}IIb/{\beta}3$) and the release of ATP and serotonin in collagen-induced platelet aggregation. A-kinase inhibitor Rp-8-Br-cAMPS reduced CE-WIB801C-, and cordycepin-increased VASP ($Ser^{157}$) phosphorylation, and increased CE-WIB801C-, and cordycepin-inhibited the fibrinogen binding to ${\alpha}IIb/{\beta}3$. Therefore, we demonstrate that CE-WIB801C-, and cordycepin-inhibited fibrinogen binding to ${\alpha}IIb/{\beta}3$are due to stimulation of cAMP-dependent phosphorylation of VASP ($Ser^{157}$), and inhibition of PI3K/Akt phosphorylation. These results strongly indicate that CE-WIB801C and cordycepin may have preventive or therapeutic potential for platelet aggregation-mediated diseases, such as thrombosis, myocardial infarction, atherosclerosis, and ischemic cerebrovascular disease.

Manufacturing Protein-DNA Chip for Depigmenting Agent Screening (전사인자 저해제 통한 미백제 탐색용 단백질 칩 제작)

  • Han Jung-Sun;Kwak Eun-Young;Lee Hyang-Bok;Shin Jlung-Hyun;Baek Seung-Hak;Chung Bong-Hyun;Kim Eun-Ki
    • Journal of the Society of Cosmetic Scientists of Korea
    • /
    • v.30 no.4 s.48
    • /
    • pp.479-483
    • /
    • 2004
  • An attempt was made to develop a proteinchip for screening of MITF (microphthalmia transcription factor) inhibitor. Binding of MITF to E-box causes transcription of several pigmenting genes including tyrosinase gene. We investigated binding of MITF and its DNA binding site (E-box) using a protein-DNA chip with various detection methods including flurorescence (Cyt3). SPR (surface plasmon resonance) and SPRi (surface plasmon resonance imaging). A fusion protein (MITF-Maltose Binding Protein) was attached on the glass plate by chemical modification. An inhibitory synthetic DNA oligomer, artificially designed based on the E-box sequence, inhibited the binding of MITF and E-box. These results showed the potentials of flurorescence-based MITF protein chip as a microarray for high throughput screening (HTS) system of depigmenting agents.

The Effect of Dehydronifedipine on the Oxidation of Aflatoxin $B_1$ by Cytochrome P450 3A4 (Cytochrome P450 3A4에 의한 Aflatoxin $B_1$의 산화에 대한 Dehydronifedipine의 영향)

  • 김복량;권강범;김동현
    • Toxicological Research
    • /
    • v.15 no.1
    • /
    • pp.95-101
    • /
    • 1999
  • Cytochrome P450 (CYP) 3A4 metabolizes aflatoxin B1 (AFB1) to AFB1-exo-8,9-epoxide (8,9-epoxidation) and aflatoxin Q1 (AFQ1; 3$\alpha$-hydroxylation) simultaneously. We investigated whether each metabolite was formed via its own binding site of CAP3A4 active site. Kinetics of the formation of the two metabolites were sigmoidal and consistent with the kinetics of substrate activation. The HIll model predicted that two substrate binding wites are involved in the oxidationof AFB1 by CYP3A4. Dehydronifedipine, a metabolite of nifedipine generated by CYP3A4, inhibited the formation of AFQ1 without any inhibition in the formation of AFB1-exo-8,9-epoxidation. Dehydronifedipine was found to act as a reversible competitive inhibitor against 3$\alpha$-hydroxylation of AFB1. Vmax and S0.5 of the 8,9-epoxidation were not changed in the presence of 0, 50, or 100 $\mu\textrm{M}$ dehydronifedipine. S0.5 of 3$\alpha$-hydroxylation was increased from 58$\pm$4 $\mu\textrm{M}$ to 111$\pm$8 $\mu\textrm{M}$ in the presence of 100 $\mu\textrm{M}$ nifedipine whereas Vmax was not changed. These results suggest that there exist two independent binding sites in the active site of CAP3A4 . One binding site is responsible for AFB1-exo-8,9-epoxidation and the other is involved in 3$\alpha$-hydroxylation of AFB1. Dehydronifedipine might selectively bind to the site which is responsible for the formation of AFQ1 in the active site of CYP3A4.

  • PDF

EFFECT OF GINSENG SAPONIN ON THE VASCULAR SMOOTH MUSCLE

  • Lee Kwang Soo
    • Proceedings of the Ginseng society Conference
    • /
    • 1980.09a
    • /
    • pp.71-76
    • /
    • 1980
  • Aortic strips were prepared from rabbits, and the tensions were maintained by administration of norepinephrine into the incubation chamber. The application of diol or triol induced relaxation of the aortic strip, as indicated by the decreased aortic tension. Triol, in a concentration of $30\;mg\%\;causes\;approximately\;50\%$ of muscle relaxation, whereas a similar degree of relaxation is induced by $50\;mg\%$ of diol. This indicates that both triol and diol cause relaxation of the aorta, but that triol is about $170\%$ more potent than diol. It is well established that blood-vessel smooth-muscle tone is regulated by the available intracellular $Ca^{++}$ concentration, which in turn is profoundly influenced by interaction of the cellular membrane and sarcoplasmic reticulum in the smooth muscle. Thus, any agent which modifies the smooth-muscle tone is expected to interfere with the $Ca^{++}$ binding or uptake of sarcolemma and sarcoplasmic reticulum. In the following experiments sarcoplasmic reticulum and sarcolemma were prepared from the ventricle of rabbit heart, and the active $Ca^{++}$ uptake by these cellular components was measured employing $Ca^{45}$ in the presence of triol and diol. It was found that the active $Ca^{++}$ uptake in the presence of ATP by sarcoplasmic reticulum was inhibited by both triol and diol. Panaxatriol, in a concentration of $80\;mg\;\%,$ inhibited $Ca^{++}$ uptake by $30\%,$ whereas panaxatriol in the same concentration inhibited uptake by $20\%.$ It is clear that triol is a more potent inhibitor of active $Ca^{++}$ transport in sarcoplasmic reticulum than diol. The $Ca^{++}$ binding of the cellular membrane was also studied employing Ca45 and milipore techniques. It was found that triol in a concentration of $80\;mg\;\%,$ decreased $Ca^{++}$ binding by $29\%.$ Diol in the same concentration decreased the binding by $17\%.$ It is clear that both triol and diol inhibit $Ca^{++}$ binding to the cellular membrane, but triol is approximately $180\%$ more potent than diol.

  • PDF

Snail Promotes Cancer Cell Proliferation via Its Interaction with the BIRC3

  • Rho, Seung Bae;Byun, Hyun-Jung;Kim, Boh-Ram;Lee, Chang Hoon
    • Biomolecules & Therapeutics
    • /
    • v.30 no.4
    • /
    • pp.380-388
    • /
    • 2022
  • Snail is implicated in tumour growth and metastasis and is up-regulated in various human tumours. Although the role of Snails in epithelial-mesenchymal transition, which is particularly important in cancer metastasis, is well known, how they regulate tumour growth is poorly described. In this study, the possible molecular mechanisms of Snail in tumour growth were explored. Baculoviral inhibitor of apoptosis protein (IAP) repeat-containing protein 3 (BIRC3), a co-activator of cell proliferation during tumourigenesis, was identified as a Snail-binding protein via a yeast two-hybrid system. Since BIRC3 is important for cell survival, the effect of BIRC3 binding partner Snail on cell survival was investigated in ovarian cancer cell lines. Results revealed that Bax expression was activated, while the expression levels of anti-apoptotic proteins were markedly decreased by small interfering RNA (siRNA) specific for Snail (siSnail). siSnail, the binding partner of siBIRC3, activated the tumour suppressor function of p53 by promoting p53 protein stability. Conversely, BIRC3 could interact with Snail, for this reason, the possibility of BIRC3 involvement in EMT was investigated. BIRC3 overexpression resulted in a decreased expression of the epithelial marker and an increased expression of the mesenchymal markers. siSnail or siBIRC3 reduced the mRNA levels of matrix metalloproteinase (MMP)-2 and MMP-9. These results provide evidence that Snail promotes cell proliferation by interacting with BIRC3 and that BIRC3 might be involved in EMT via binding to Snail in ovarian cancer cells. Therefore, our results suggested the novel relevance of BIRC3, the binding partner of Snail, in ovarian cancer development.

Id3 mRNA Expression on Folliculogenesis in Rat Ovary (쥐 난소에서 난포 발달에 따른 Id3 mRNA의 발현)

  • Hwang, Seong-Soo;Ko, Yeoung-Gyu;Lim, Hyun-Joo;Seong, Hwan-Hoo;Yoon, Jong-Taek;Min, Kwan-Sik
    • Reproductive and Developmental Biology
    • /
    • v.31 no.3
    • /
    • pp.181-186
    • /
    • 2007
  • Inhibitor of DNA binding protein or inhibitor of differentiation(Id) is largely considered as positive and/or negative regulators of proliferation, differentiation, angiogeneisis, and apoptosis. The four Id genes(Id1, Id2, Id3, and Id4) were known in mammals. However, little is known about the expression and function of these genes in reproductive physiology. Among them, this study was conducted to analyze the expression pattern of Id3 mRNA on folliculogenesis in rat ovary. After PMSG administration, the ovaries were obtained at 3, 6, 12, 24, 36, and 48hrs, fixed, dehydrated, and paraffin embedded. For in situ hybridization, anti-sense and sense Id3 cRNA probes were prepared and applied to the ovarian section. The ovarian sections were coated with NTB-2 emulsion. After that, the slides were developed and counterstained with hematoxylin and eosin staining. The hybridization signal was estimated on a scale of 1+ to 4+. In oocyte, the intensity of Id3 mRNA in primordial and primary follicles was scored at ${\geq}2+$, but the intensity was less than 1+ in secondary, dominant, and preovulatory follicles. In granulosa cells, the Id3 mRNA was strongly expressed(3+ or 4+) in dominant and preovulatory follicles. Taken together, Id3 mRNA was expressed specifically at follicle stages and follicular tissue and might be closely related with follicle development.

Characterization of gene expression and genetic variation of horse ERBB receptor feedback inhibitor 1 in Thoroughbreds

  • Choi, Jae-Young;Jang, Hyun-Jun;Park, Jeong-Woong;Oh, Jae-Don;Shin, Donghyun;Kim, Nam Young;Oh, Jin Hyeog;Song, Ki-Duk;Cho, Byung-Wook
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.31 no.3
    • /
    • pp.309-315
    • /
    • 2018
  • Objective: This study aimed to test the expression patterns of ERBB receptor feedback inhibitor 1 (ERRFI1) before and after exercise and the association of non-synonymous single-nucleotide polymorphisms (nsSNPs) of horse ERRFI1 with racing traits in Thoroughbreds. Methods: We performed bioinformatics and gene expression analyses for horse ERRFI1. Transcription factor (TF) binding sites in the 5'-regulatory region of this gene were identified through a tool for prediction of TF-binding site (PROMO). A general linear model was used to detect the association between the nsSNP (LOC42830758 A to G) and race performance. Results: Quantitative polymerase chain reaction analysis showed that expression level of ERRFI1 after exercise was 1.6 times higher than that before exercise. Ten transcription factors were predicted from the ERRFI1 regulatory region. A novel nsSNP (LOC42830758 A to G) was found in ERRFI1, which was associated with three racing traits including average prize money, average racing index, and 3-year-old starts percentile ranking. Conclusion: Our analysis will be helpful as a basis for studying genes and SNPs that affect race performance in racehorses.

Valproic Acid Induces Transcriptional Activation of Human GD3 Synthase (hST8Sia I) in SK-N-BE(2)-C Human Neuroblastoma Cells

  • Kwon, Haw-Young;Dae, Hyun-Mi;Song, Na-Ri;Kim, Kyoung-Sook;Kim, Cheorl-Ho;Lee, Young-Choon
    • Molecules and Cells
    • /
    • v.27 no.1
    • /
    • pp.113-118
    • /
    • 2009
  • In this study, we have shown the transcriptional regulation of the human GD3 synthase (hST8Sia I) induced by valproic acid (VPA) in human neuroblastoma SK-N-BE(2)-C cells. To elucidate the mechanism underlying the regulation of hST8Sia I gene expression in VPA-stimulated SK-N-BE(2)-C cells, we characterized the promoter region of the hST8Sia I gene. Functional analysis of the 5'-flanking region of the hST8Sia I gene by the transient expression method showed that the -1146 to -646 region, which contains putative binding sites for transcription factors c-Ets-1, CREB, AP-1 and NF-${\kappa}B$, functions as the VPA-inducible promoter of hST8Sia I in SK-N-BE(2)-C cells. Site-directed mutagenesis and electrophoretic mobility shift assay indicated that the NF-${\kappa}B$ binding site at -731 to -722 was crucial for the VPA-induced expression of hST8Sia I in SK-N-BE(2)-C cells. In addition, the transcriptional activity of hST8Sia I induced by VPA in SK-N-BE(2)-C cells was strongly inhibited by SP600125, which is a c-Jun N-terminal kinase (JNK) inhibitor, and $G{\ddot{O}}6976$, which is a protein kinase C (PKC) inhibitor, as determined by RT-PCR (reverse transcription-polymerase chain reaction) and luciferase assays. These results suggest that VPA markedly modulated transcriptional regulation of hST8Sia I gene expression through PKC/JNK signal pathways in SK-N-BE(2)-C cells.