• Title/Summary/Keyword: Hormone assay

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Inhibition of osteoclast formation by putative human cementoblasts

  • Kim, Mi-Ri;Yang, Won-Kyung;Grzesik, Wojciech;Ko, Hyun-Jung
    • International Journal of Oral Biology
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    • v.33 no.3
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    • pp.113-116
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    • 2008
  • Cementum is the mineralized tissue of the tooth. It is similar to bone in several aspects but it differs from bone. Human bone marrow stromal cells (BMSC) and human cementum derived cells (HCDC) (10,000 $cells/cm^2$) were plated in 6 well plates as feeder cells. The next day, mouse bone marrow cells (1.5 million $cells/cm^2$) were added. One group of these plates were incubated in serum-free conditioned medium (SFCM) generated from BMSC or HCDC supplemented with 2% FBS, parathyroid hormone (PTH), 1, 25 dihydroxyvitamin $D_3$ (Vit. $D_3$) and dexamethasone, or plain medium with the same supplements. Another group of plates were cocultured with BMSC or HCDC in plain medium supplemented with 2% FBS, PTH, Vit. $D_3$ and dexamethasone. Plates grown without SFCM or coculture were used as controls. After 10 days, the cells were stained for tartrate-resistant acid phosphatase (TRAP). BMSC were found to support osteoclast formation under normal conditions. This was inhibited however by both SFCM generated from HCDC and also by coculture with HCDC. In addition, HCDC themselves did not support osteoclast formation under any conditions. Our results thus indicate that HCDC do not support osteoclast formation in vitro and that soluble factor (s) from HCDC may inhibit this process. In addition, we show that this inhibition also involves an active mechanism that is independent of osteoprotegerin, a feature that may distinguish cementoblasts from other cells present in periodontium.

A Simple ELISA for Screening Ligands of Peroxisome Proliferator-activated Receptor γ

  • Cho, Min-Chul;Lee, Hae-Sook;Kim, Jae-Hwa;Choe, Yong-Kyung;Hong, Jin-Tae;Paik, Sang-Gi;Yoon, Do-Young
    • BMB Reports
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    • v.36 no.2
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    • pp.207-213
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    • 2003
  • Peroxisome proliferator-activated receptors (PPARs) are orphan nuclear hormone receptors that are known to control the expression of genes that are involved in lipid homeostasis and energy balance. PPARs activate gene transcription in response to a variety of compounds, including hypolipidemic drugs. Most of these compounds have high affinity to the ligand-binding domain (LBD) of PPARs and cause a conformational change within PPARs. As a result, the receptor is converted to an activated mode that promotes the recruitment fo co-activators such as the steroid receptor co-activator-1 (SRC-1). Based on the activation mechanism of PPARs (the ligand binding to $PPAR{\gamma}$ induces interactions of the receptor with transcriptional co-activators), we performed Western blot and ELISA. These showed that the indomethacin, a $PPAR{\gamma}$ ligand, increased the binding between $PPAR{\gamma}$ and SRC-1 in a ligand dose-dependent manner. These results suggested that the in vitro conformational change of $PPAR{\gamma}$ by ligands was also induced, and increased the levels of the ligand-dependent interaction with SRC-1. Collectively, we developed a novel and useful ELISA system for the mass screening of $PPAR{\gamma}$ ligands. This screening system (based on the interaction between $PPAR{\gamma}$ and SRC-1) may be a promising system in the development of drugs for metabolic disorders.

ARYL HYDROCARBON- AND ESTROGEN-MEDIATED SIGNALS POSSIBLY CROSS TALK TO REGULATE CYP1A1 GENE EXPRESSION

  • Joung, Ki-Eun;Kim, Yeo-Woon;Min, Kyung-Nan;Sheen, Yhun-Yhong
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 2001.11a
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    • pp.112-112
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    • 2001
  • 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is an environmental toxin that activates the aryl hydrocarbon receptor (AhR) and disrupts multiple endocrine signaling pathways by enhancing ligand metabolism, altering hormone synthesis, down regulating receptor levels, and interfering with gene transcription. And TCDD-mediated gene transactivation via the AhR has been shown to be dependent upon estrogen receptor (ER) expression in human breast cancer cells. In the present study, we have examined the effect of natural estrogen, phytoestrognes and environmental estrogens on the regulation of CYP1A1 gene expression in MCF-7 human breast cancer cell line. that ER and AhR are co-expressed. pCYP1A1 -luc reporter gene was transiently transfected into MCF-7 cells. These cells were treated with various chemicals and then luciferase assay was carried out. 17be1a-estradiol significantly inhibited TCDD stimulated luciferase activity dose dependently and this inhibition was partially recovered by concomitant treatment of tamoxifen. 17beta-estradiol metabolites, 2-hydroxyestradiol and 16alpha-estriol resulted in less potent inhibitory effect than estradiol and synthetic estrogen, diethylstilbestrol (DES) showed no effect on CYP1A1 gene expression. This study demonstrated that estrogen down-regulated TCDD stimulated CYP1A1 expression via ER mediation. And we have found out that several flavonoids such as genistein, kaempferol, daidzein, naringenin, and alkylphenols such as nonylphenol, 4-octylphenol and resveratrol also inhibited TCDD induced CYP1A1 expression like estrogen.

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Isolation and Identification of Endophytic Bacteria with Plant Growth Promoting Activity and Biocontrol Potential from Wild Pistachio Trees

  • Etminani, Faegheh;Harighi, Behrouz
    • The Plant Pathology Journal
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    • v.34 no.3
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    • pp.208-217
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    • 2018
  • In this study, samples were collected from the leaves and stems of healthy wild Pistachio trees (Pistacia atlantica L.) from various locations of Baneh and Marivan regions, Iran. In total, 61 endophytic bacteria were isolated and grouped according to phenotypic properties. Ten selected isolates from each group were further identified by partial sequencing of the 16S rRNA gene. Based on the results, isolates were identified as bacteria belonging to Pseudomonas, Stenotrophomonas, Bacillus, Pantoea and Serratia genus. The ability of these isolates was evaluated to phytohormone production such as auxin and gibberellin, siderophore production, phosphate solubilization, atmospheric nitrogen fixation, protease and hydrogen cyanide production. All strains were able to produce the plant growth hormone auxin and gibberellin in different amounts. The majority of strains were able to solubilize phosphate. The results of atmospheric nitrogen fixation ability, protease and siderophore production were varied among strains. Only Ba66 could produce a low amount of hydrogen cyanide. The results of biocontrol assay showed that Pb78 and Sp15 strains had the highest and lowest inhibition effects on bacterial plant pathogens, Pseudomonas syringae pv. syringae Pss20 and Pseudomonas tolaasii Pt18 under in vitro condition. Pb3, Pb24 and Pb71 strains significantly promote root formation on carrot slices. To our knowledge this is the first report of the isolation of endophytic bacterial strains belonging to Pantoea, Bacillus, Pseudomonas, Serratia and Stenotrophomonas genus from wild pistachio trees with plant growth promoting potential and biocontrol activity.

Influence of Antithyroid Antibodies in Euthyroid Women on IVF-ET Outcome (정상 갑상선기능을 가진 여성에서 항갑상선항체가 체외수정시술결과에 미치는 영향)

  • Kim, Chung-Hoon
    • Clinical and Experimental Reproductive Medicine
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    • v.24 no.1
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    • pp.143-151
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    • 1997
  • The present study was designed to investigate if antithyroid antibodies (ATA) could affect the pregnancy outcome in euthyroid women undergoing in vitro fertilization and embryo transfer (IVF-ET). From October 1995 to September 1996, 28 euthyroid women with ATA who underwent IVF-ET were studied. Fifty-one euthyroid women without ATA who underwent IVF-ET served as control. Thyroid peroxidase antibody (TPOA) and thyroglobulin antibody (TGA) were assayed using radio ligand assay kits as ATA. All patients included in study and control groups had only tubal factor in infertility. Long protocol of gonadotropin-releasing hormone agonist (GnRH-a) was used for controlled ovarian hyperstimulation (COH) in all patients. There were no significant differences between study and control groups in patient characteristics such as age, infertility duration and hormonal profile. There were also no significant differences between two groups with respect to the clinical response to COH and IVF results such as number of retrieved oocytes, fertilization rate, number of embryos frozen and number of embryos transfered. There were no correlations between ATA (TPOA and TGA) titers and fertilization rate. The clinical pregnancy rate per cycle seemed to be lower in the study group than in the control group (26.3% vs 39.3%), but the difference was not statistically significant. The biochemical pregnancy rate per cycle and miscarriage rate were significantly higher in the study group at 18.4% (7/38) and 40.0% (4/10) compared with 5.6% (5/89) and 11.4% (4/35) in the control group. In the study group, both TPOA and TGA titers were significantly higher in the biochemical pregnancy group than in the clinical pregnancy group or non-pregnancy group. In 10 women with ATA who achieved pregnancy following IVF-ET, both TPOA and TGA titers were significantly higher in the miscarriage group than in the ongoing or delivery group. In conclusion, euthyroid women with ATA appear to represent a less favorable subset within other tubal factor patients when treated with IVF-ET.

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Hexane Extract of Kaempferia galanga L. Suppresses Melanogenesis via p38, JNK and Akt

  • In, Myung-Hee;Jeon, Byoung Kook;Mun, Yeun-Ja;Woo, Won-Hong
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.30 no.1
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    • pp.47-53
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    • 2016
  • Kaempferia galanga L. is one of the plants in Zingiberaceae family. It is used by people in many regions of Asia and Africa for relieving toothache, abdominal pain, muscular swelling and rheumatism. Tyrosinase is a key enzyme for melanogenesis, and hyperpigmentation is associated with abnomal accumulation of melanin pigment. This study aimed to investigate the inhibition of melanogenesis by hexane extract of Kaempferia galanga L. (HKG) in B16F10 melanoma cells. Cell-free tyrosinase, melanin contents, intracellular tyrosinase activity and western blot analysis were performed to elucidate the effects on anti-melanogenesis. Cytotoxicity of the extracts was measured using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and determined the concentration of 12.5, 25 μg/ml. HKG significantly inhibited to activities of intracellular tyrosinase and melanin synthesis in the absence or presence of α-melanocyte stimulating hormone (α-MSH) with dose-dependent manner. And HKG inhibited the expression of tyrosinase, tyrosinase-related protein 1 (TRP-1) and tyrosinase-related protein 2 (TRP-2), regardless of the presence or absence of α-MSH. HKG also down-regulated phosphorylation of p38 and JNK, and up-regulated phosphorylation of Akt. These effects were not related to its cytotoxicity action. These results indicate that HKG has the potential to be a useful therapeutic agent for treating hyperpigmentation disorders and as a beneficial additive in whitening agents in cosmetics industry.

Inhibitory Effect of Fructus Ligustri Lucidi Hexane Extract on Melanin Biosynthesis (여정자 헥산추출물의 멜라닌합성 억제효과)

  • Kim, Dae-Sung;Han, Gyu-Su;Jeon, Byoung-Kook;Woo, Won-Hong;Mun, Yeun-Ja
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.24 no.4
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    • pp.674-680
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    • 2010
  • The purpose of this study was to investigate the effects of Fructus Ligustri Lucidi (FLL) on the process of melanogenesis. Cell viability of B16F10 cells was measured by MTT assay and melanin content was assessed using the method of Hosoi with some modifications. Methanol extract of Fructus Ligustri Lucidi (MFLL) significantly inhibited melanin synthesis in a concentration-dependent manner, and it reduced the activity of tyrosinase, the rate-limiting melanogenic enzyme. Additionally, $\alpha$-melanocyte stimulation hormone ($\alpha$-MSH)-induced hyperpigmentation was down-regulated by MFLL. MFLL was fractionated by organic solvent. In the present study, Hexane extract of Fructus Ligustri Lucidi (HFLL) inhibited tyrosinase activity and melanin production of B16F10 cells in the absence or presence of $\alpha$-MSH. Ethyl acetate, butanol and water layers did not affect tyrosinase activity and melanin production. Meanwhile ethyl acetate, butanol and water layers showed DPPH free radical scavenging activity. These results suggest that extract of FLL could be used as functional biomaterial in developing a skin whitening agent having the antioxidant activity.

Biological Activity of Human Dimeric Hyperglycosylated Erythropoietin (dHGEPO) Fusion Proteins

  • Naidansuren, Purevjargal;Min, Kwan-Sik
    • Reproductive and Developmental Biology
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    • v.34 no.4
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    • pp.289-297
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    • 2010
  • Erythropoietin (EPO) is a glycoprotein hormone secreted from primarily cells of the peritubular capillary endothelium of the kidney, and is responsible for the regulation of red blood cell production. We constructed and expressed dimeric cDNAs in Chinease hamster ovary (CHO) cells encoding a fusion protein consisting of 2 complete human EPO domains linked by a 2-amino acid linker (Ile-Asp). We described the activity of dimeric hyperglycosylated EPO (dHGEPO) mutants containing additional oligosaccharide chains and characterized the function of glycosylation. No dimeric proteins with mutation at the $105^{th}$ amino acid were found in the cell medium. Growth and differentiation of the human EPO-dependent leukemiae cell line (F36E) were used to measure cytokine dependency and in vitro bioactivity of dHGEPO proteins. MIT assay at 24 h increased due to the survival of F36E cells. The dHGEPO protein migrated as a broad band with an average molecular mass of 75 kDa. The mutant, dHGEPO, was slightly higher than the wild-type (WT) dimeri-EPO band. Enzymatic N-deglycosylation resulted in the formation of a narrow band with a molecular mass twice of that of of monomeric EPO digested with an N-glycosylation enzyme. Hematocrit values were remarkably increased in all treatment groups. Pharmacokinetic analysis was also affected when 2.5 IU of dHGEPO were intravenously injected into the tails of the mice. The biological activity and half-life of dHGEPO mutants were enhanced as compared to the corresponding items associated the WT dimeric EPO. These results suggest that recombinant dHGEPO may be attractive biological and therapeutic targets.

몇 가지 PBTs (Persistent, Bioaccumulative, Toxic Chemicals)가 생태계 곤충에 미치는 영향

  • Lee Seun Yeong;Kim Yong Gyun
    • Proceedings of the Korea Society of Environmental Biology Conference
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    • 2002.11a
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    • pp.123-126
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    • 2002
  • Pollutants that are persistent, bioaccurnulative, and toxic have been linked to numerous adverse effects in human and animals, PBTs include heavy metals, polychlorinated biphenyls (PCBs), dioxins, polycyclic aromatic compounds (PACs) in addition to pesticides. This study focuses on toxic effects of the PBTs except pesticides on insects. Eight PBTs were selected from subgroups: three heavy metals (Pb, Hg, and Cd), two PCB mixtures (Aroclor mixtures 1 and 2), 2,3,7,8-tetrachlorodibenzo-p-dioxin, two monophenols (4-octylphenol and 4-nonylphenol), and tetrabutyltin, Beet armyworm, Spodoptera exigua, was used as test target insect species. Three physiological markers (metamorphosis, immune reaction, and follicle patency) were assessed in each exposure to different doses of the PCBs. Heat-shock proteins as molecular markers were also analyzed in response to the PCBs. All tested PBTs were toxic to metamorphosis from larvae to pupae when they were applied with diet. Two PCB mixtures were the most toxic compounds in this assay by giving significant toxicity at 0.005 ppm, while others had from 10 to 1000 ppm. Dioxin (0.1 ppb), tetrabutyltin (0.1 ppb), Pb (10 ppb), and Hg (0,01 ppb) were potent to inhibit immune reactions analyzed by inducing phenoloxidase activity and blocked phospholipase $A_2$ enzyme, Tetrabutyltin and dioxin significantly induced follicle cell patency, but their effects were lower than that of endogenous juvenile hormone, Dioxin, Pb, Hg, and Cd could induce the expression of heat shock proteins that were detected by immunoblotting against human HSP70 monoclonal antibody. HSP78 and HSP80 were upregulated in response to the PBTs. This expression was detected from the fat body and epidermis at as fast as 4h after injection. All these results clearly suggest that PBTs give significant ecotoxicity to insects that are valuable organisms in our environment.

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In vitro Analysis of Glucocorticoid-induced Reporter Gene Expression Using Lentivirus System (Lentivirus System을 이용한 Glucocorticoid 유도 Reporter 유전자 발현의 분석)

  • Lee, Mi-Sook;Kim, Ji-Yeon;Her, Song
    • Journal of Marine Bioscience and Biotechnology
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    • v.2 no.2
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    • pp.81-85
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    • 2007
  • Glucocorticoid hormone regulates numerous physiological processes, such as regulation of metabolism, and anti-inflammatory and immunosuppressive actions via the activation and repression of gene expression. Here we described a lentivirus-based reporter vector system expressing red fluorescent protein (mRFP) or firefly luciferase (Luc) under the control of a glucocorticoid-responsive element that allows observation of the temporospatial pattern of glucocorticoid induced GR-mediated signaling on a cellular level. Moreover, usage of the chromatin insulator of the chicken ${\beta}$-globin locus induced a marked increase of sensitivity of glucocorticoid inducible promoter of a reporter gene. Use of this method will be applicable of screening for agonist and antagonist of GR in vitro, and also a reporter gene assay for the in vivo determination of the GR-mediated gene activation.

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