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Sample records for 17beta-estradiol e2 plasmatico

  1. Occurrence and Pathways of Manure-borne 17beta-Estradiol in Vadose Zone Water

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Reproductive hormones, such as 17beta-estradiol (E2), can cause physiological and reproductive disorders in numerous species at low part per trillion concentrations. The persistence and transport pathways of manure-borne E2 in agricultural soils were determined by comparing the occurrence of E2 in t...

  2. Modeling of Coupled Degradation, Sorption, and Transport of 17beta-Estradiol in Undisturbed Soil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The presence of 17 beta-estradiol in the environment, even at part-per trillion concentrations, may raise significant concern regarding the health of aquatic organisms. Once 17 beta-estradiol is released into the environment from human and animal sources, its fate and transport is controlled by fact...

  3. O dealkylation and aliphatic and aromatic hydroxylation of 3-methoxy-17 beta-estradiol by Aspergillus alliaceus.

    PubMed Central

    Williamson, J S; Van Orden, D E; Rosazza, J P

    1989-01-01

    Aspergillus alliaceus UI 315 was examined for its ability to metabolize 3-methoxy-17 beta-estradiol. Preparative-scale incubations with this substrate afforded good yields of 6 beta-hydroxy-17 beta-estradiol, 4-hydroxy-17 beta-estradiol, and 4,6 beta-dihydroxy-17 beta-estradiol, which were identified by high-pressure liquid chromatography, 1H and 13C nuclear magnetic resonance, and high-resolution mass spectrometry. PMID:2624469

  4. Low-dosage micronized 17 beta-estradiol prevents bone loss in postmenopausal women

    NASA Technical Reports Server (NTRS)

    Ettinger, B.; Genant, H. K.; Steiger, P.; Madvig, P.

    1992-01-01

    With the use of a double-blind, randomized, dose-ranging design, we tested during an 18-month period the degree of protection against postmenopausal bone loss afforded by micronized 17 beta-estradiol in dosages of 0.5, 1.0, and 2.0 mg. All subjects received supplementation to ensure a minimum of 1500 mg calcium daily. Fifty-one subjects completed at least 1 year of follow-up bone density measurements by quantitative computed tomography and by single- and dual-photon absorptiometry. In the placebo group spinal trabecular bone density decreased 4.9% annually (p less than 0.001), whereas in those taking micronized 17 beta-estradiol bone density tended to increase (annual increases of 0.3% in the 0.5 mg micronized 17 beta-estradiol group, 1.8% in the 1.0 mg micronized 17 beta-estradiol group, and 2.5% in the 2.0 mg micronized 17 beta-estradiol group). After completing the double-blind phase, 41 subjects completed an additional 18 months of follow-up while taking 1.0 mg micronized 17 beta-estradiol. During this time one third of the subjects were randomly assigned to discontinue calcium supplements. Among those who previously received placebo, trabecular bone density increased 4.3% annually, whereas among those who had used micronized 17 beta-estradiol, trabecular bone density response was inversely related to the dosage previously used. Additionally and independently, the level of calcium intake showed a statistically significant correlation with the change in spinal trabecular bone density (r = 0.37, p = 0.02). We conclude that micronized 17 beta-estradiol has a continuous skeletal dose-response effect in the range of 0.5 to 2.0 mg and that calcium intake positively modifies the skeletal response to 1.0 mg micronized 17 beta-estradiol.

  5. Influence factor of 17beta-estradiol photodegradation by heterogeneous Fenton reaction.

    PubMed

    Zhao, Yaping; Huang, Minsheng; Ge, Ming; Tang, Xiaochun; Liu, Lu

    2010-01-01

    The photocatalytic degradation of 17beta-estradiol (E2), by Fenton like reaction was investigated as a function of E2 concentrations, organic co-solvents and co-existing estrogens, humic acid (HA) and other background anions. E2 degradation was effectively achieved by hydroxyl radicals that were generated in the heterogeneous photo-Fenton process. The degradation kinetics were fitted to Langmuir-Hinshelwood model with kr = 0.3140 microM/h and Kads = 2.2146L/micromol. The removal kinetics of E2 were initiated by a rapid decay and then followed by a much slower one in acetonitrile-water solutions while in methanol-water solutions they followed the first-kinetic model for the diffusion-control of hydroxyl radicals and competition between E2 and co-solvents. In addition, the lower level of co-existing substances did not significantly influence the oxidation efficiency of E2. The degradation rates of E2 were found to depend not only on the concentrations of hydrogen peroxide and iron content as reported before but also on pH, E2 concentrations and composition of co-solvents. Thus it is very important to look for the optimum conditions for the purpose of most efficiently eliminating E2 from drinking water. PMID:20082022

  6. 17beta-Estradiol releases thyroxine from the thyroid follicles of a teleost, Channa gachua (Ham. )

    SciTech Connect

    Bandyopadhyay, S.; Banerjee, P.P.; Bhattacharya, S. )

    1991-02-01

    To observe a direct effect of 17beta-estradiol (E2) on thyroid activity, thyroid follicles were isolated from hypobranchial muscles of a freshwater murrel, Channa gachua. Thyroid follicles were incubated (5 X 10{sup 6} follicles/well) in vitro at 30{degree}C for 2 hr without hormone and then 3 hr with E2 or bovine thyroid-stimulating hormone (bTSH). Addition of 10 and 100 ng of E2 to thyroid follicles resulted in 2- and 3-fold increases in thyroxine (T4) release. When 100 ng of bTSH was added to check the isolated follicular function, it stimulated T4 release to more than 3-fold. Increasing doses of E2 from 1 to 100 ng caused a dose-dependent stimulation of T4 release, while a 1000-ng dose reduced T4 release compared to 100 ng. When thyroid follicles of this experiment were lysed by sonication and T4 content was determined, it corroborated the profile of T4 release in response to varied E2 doses. E2 was ineffective in increasing {sup 125}I uptake by the follicles, while bTSH elevated it by 45% over the control. Incubation of varied concentrations of ({sup 3}H)estradiol with cytosol and nuclear fractions of thyroid follicles in the presence of a 100-fold excess of diethylstilbestrol showed saturable specific binding of E2.

  7. Biodegradation of endocrine disrupters: case of 17beta-estradiol and bisphenol A.

    PubMed

    Stavrakakis, C; Hequet, V; Faur, C; Andres, Y; Le Cloirec, P; Colin, R

    2008-03-01

    The biodegradation of 17 beta-estradiol (E2) and bisphenol A (BPA) was compared to that of a reference pollutant, sodium benzoate (SB), known for its high biodegradability. The biodegradation was measured using the Sturm test (ISO 9439 modified Sturm test). The susceptibility of the target pollutants to be degraded by microorganisms of activated sludge from a wastewater treatment plant (WWTP) was evaluated by the production of carbon dioxide (CO2). Sorption experiments onto inactivated sludge were carried out to assess the contribution of sorption in E2 and BPA removal during biological treatment in a WWTP. E2 was more adsorbed than BPA onto inactivated sludge, probably making it less accessible to assimilation by microorganisms. In fact, E2 was less biodegradable than BPA with 66% and 74% of theoretical CO2 formation (Th(co2)) in 28 days, respectively. However, E2 showed faster biodegradation than BPA due to the shorter adaptation time of the microorganisms to start the assimilation. Final concentrations were measured and revealed that, under Sturm test conditions, E2 was totally removed from the aqueous phase while some traces of BPA were detected. This result could be explained by the lower adsorbability of BPA observed in adsorption experiments onto inactivated sludge. To investigate competition in a bi-component solution, Sturm tests were carried out with BPA/SB and E2/SB. Moreover, the biodegradation curves obtained did not indicate a toxicity of the target compounds towards microorganisms, which rapidly degraded SB. In the case of BPA/SB, an inflection in the curve confirmed the adaptation time of 4-5 days for BPA to be degraded. PMID:18610788

  8. Toxicity of 17 {beta}-estradiol and dibutyl-n-phthalate to Japanese medaka (Oryzias latipes)

    SciTech Connect

    Patvna, P.J.; Cooper, K.R.

    1995-12-31

    Phthalate esters are ubiquitous environmental contaminants that are hypothesized to cause developmental toxicity in aquatic organisms via an estrogenic mechanism. Japanese medaka embryos and larvae provide an excellent model for the study of toxicant effects on embryonic development. The following groups were examined (N = 10--20): a non-treatment control, a vehicle control, 17 {beta}-estradiol and Dibutyl-n-phthalate, in individual glass vials. The medaka embryos were treated beginning at the blastula stage, for ten days. At day 10, embryos were changed into fresh rearing solution. The embryos were observed daily, until three days post-hatching, for toxic developmental effects. Exposure to 17 {beta}-estradiol caused urinary bladder lesions at the lowest doses tested. At concentrations {le} 3 {micro}M/0.82 ppm, 17 {beta}-estradiol caused inhibition of swim bladder inflation, pericardial edema, and marked cachexia. Dibutyl-n-phthalate caused pronounced enlargement of the urinary bladder. No other gross lesions were observed. Both 17 {beta}-estradiol and Dibutyl-n-phthalate caused effects on the urinary tract which will be characterized at the light microscopic level. The lesions observed in the embryo medaka following Dibutyl-n-phthalate exposure were at or below water solubility and are in agreement with previously reported toxic levels.

  9. Persistence and Fate of 17beta-estradiol and testosterone in agricultural soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Steroidal hormones are constantly released into the environment by man-made and natural sources. The goal of this study was to examine the persistence and fate of 17beta-estradiol and testosterone, the two primary natural hormones. Incubation experiments were conducted under aerobic and anaerobic co...

  10. An enriched environment and 17-beta estradiol produce similar pro-cognitive effects on ovariectomized rats.

    PubMed

    Ortiz-Pérez, A; Espinosa-Raya, J; Picazo, O

    2016-02-01

    Estrogen depletion due to aging, surgery or pathological events can cause a multitude of problems, including neurodegenerative alterations. In rodents without ovaries, 17-beta estradiol (E2) has been shown to produce beneficial effects on cognition, stimulating brain regions (e.g., the neocortex, hippocampus and amygdala) related to cognition and learning. Another treatment that stimulates these brain regions is an enriched environment (EE), which is a complex set of external factors in the immediate surroundings that facilitates greater stimulation of sensorial, cognitive and motor circuits of the brain. The aim of the present study was to test, using an animal model of ovariectomy-induced impairment of memory, the relative effect of E2 (with a time-released pellet; 1 μg/rat/day), EE exposure and a combination of both treatments. Experimental and control groups were submitted to two memory tests 18 weeks post-surgery: the autoshaping learning task (ALT) for measuring associative learning and the novel object recognition test (NORT) for evaluating short- and long-term memory. To assess potential motor impairments caused by treatments, all rats were tested after the ALT in an automatic activity counter. Results from ALT show that the ovariectomy blocked the conditioned responses displayed, an effect rescued by chronic treatment with estrogen or EE exposure. The combination of both treatments did not improve the results obtained separately. In the NORT, the exploration time for recognizing a novel object was similar in the short run with all groups, but greater in the long run with hormone administration or EE exposure. As with the ALT, in the NORT there was no improvement shown by the combination treatment. These data were not masked by changes in spontaneous activity because this parameter was not modified in the rats by either treatment. Possible action mechanisms are proposed, taking into account the role of corticosterone and BDNF on cognition. PMID:26872959

  11. 17beta-estradiol enhances the response of plasmacytoid dendritic cell to CpG.

    PubMed

    Li, Xiaoxi; Xu, Yixin; Ma, Ling; Sun, Lingyun; Fu, Gengfeng; Hou, Yayi

    2009-01-01

    Gender differences in immune capabilities suggest that sex hormones such as estrogens were involved in the regulation of the immunocompetence. Numerous studies also suggest that plasmacytoid dendritic cells (PDCs) play a pathogenic role in SLE. However, it is unclear whether estrogen can modulate the function of PDCs to influence the development of SLE. In the present study, PDCs from murine spleens were treated with 17beta-estradiol (E2) and CpG respectively or both in vitro, then cell viability, costimulatory molecule expression, cytokine secretion of PDCs, as well as stimulatory capacity of PDCs to B cells were analyzed. Results showed that E2 and CpG increased the cell viability and costimulatory molecule expression on PDCs synergistically. Moreover, the intracellular and extracellular secretion of IFN-alpha was increased by E2 or E2 plus CpG. In addition, E2 and CpG also increased the stimulatory capacity of PDCs to B cells, and the viability of B cells was decreased after neutralizing IFN-alpha significantly. In the experiments in vivo, mice received daily s.c. injections of E2 and CpG respectively or both, then we found that the plasma concentration of IgM were elevated by E2 and CpG synergistically and the expression of IFN-alpha/beta in spleens were noticeably increased by CpG plus E2 compared with the treatment of E2 or CpG only. This study indicates that E2 could exacerbate PDCs' activation with CpG, which further activates B cells to upregulate susceptibility to autoantigens. IFN-alpha plays an important role in the stimulatory effect of PDCs on B cells. E2 stimulation of IFN-alpha production may result in female prevalence in autoimmune diseases such as SLE through activation of PDCs. This study provides novel evidence of relationship between estrogen and SLE and also sheds light on gender biases among SLE patients. PMID:20037646

  12. Lycopene and other carotenoids inhibit estrogenic activity of 17beta-estradiol and genistein in cancer cells.

    PubMed

    Hirsch, Keren; Atzmon, Andrea; Danilenko, Michael; Levy, Joseph; Sharoni, Yoav

    2007-08-01

    Epidemiological evidence suggests that carotenoids prevent several types of cancer, including mammary and endometrial cancers. On the other hand, such studies have also shown that estrogens are the most important risk factors for these cancer types. Genistein, the phytoestrogen mainly found in soy, also shows significant estrogenic activity when tested at concentrations found in human blood. The aim of this study was to determine whether carotenoids inhibit signaling of steroidal estrogen and phytoestrogen which could explain their cancer preventive activity. Similar to the known effect of 17beta-estradiol (E(2)), treatment of breast (T47D and MCF-7) and endometrial (ECC-1) cancer cells with phytoestrogens induced cell proliferation, cell-cycle progression and transactivation of the estrogen response element (ERE). However, each of the tested carotenoids (lycopene, phytoene, phytofluene, and beta-carotene) inhibited cancer cell proliferation induced by either E(2) or genistein. The inhibition of cell growth by lycopene was accompanied by slow down of cell-cycle progression from G1 to S phase. Moreover, the carotenoids inhibited estrogen-induced transactivation of ERE that was mediated by both estrogen receptors (ERs) ERalpha and ERbeta. The possibility that this inhibition results from competition of carotenoid-activated transcription systems on a limited pool of shared coactivators with the ERE transcription system was tested. Although cotransfection of breast and endometrial cancer cells with four different coactivators (SRC-1, SRC-2, SRC-3, and DRIP) strongly stimulated ERE reporter gene activity, it did not oppose the inhibitory effect of carotenoids. These results suggest that dietary carotenoids inhibit estrogen signaling of both 17beta-estradiol and genistein, and attenuate their deleterious effect in hormone-dependent malignancies. PMID:17051425

  13. Activation of kinase pathways in MCF-7 cells by 17beta-estradiol and structurally diverse estrogenic compounds.

    PubMed

    Li, Xiangrong; Zhang, Shu; Safe, Stephen

    2006-02-01

    17beta-Estradiol (E2) activates non-genomic pathways in MCF-7 cells, and this study investigates the effects of structurally-diverse estrogenic compounds on activation of mitogen-activated protein kinase (MAPK), phosphatidylinositol-3-kinase (PI3-K), protein kinase C (PKC), PKA, and calcium calmodulin-dependent kinase IV (CaMKIV). Activation of kinases was determined by specific substrate phosphorylation and transactivation assays that were diagnostic for individual kinases. The compounds investigated in this study include E2, diethylstilbestrol (DES), the phytoestrogen resveratrol, and the following synthetic xenoestrogens, bisphenol-A (BPA), nonylphenol, octylphenol, endosulfan, kepone, 2,2-bis(p-hydroxyphenyl)-1,1,1-trichloroethane (HPTE), and 2',3',4',5'-tetrachloro-4-biphenylol (HO-PCB-Cl(4)). With the exception of resveratrol, all the compounds activated PI3-K and MAPK. Activation of PKC by the xenoestrogens was structure-dependent since resveratrol, kepone and HO-PCB-Cl(4) were inactive and only minimal activation of PKA was observed. CaMKIV was activated only by E2 and DES, and HO-PCB-Cl(4) was a potent inhibitor of CaMKIV-dependent activity. These results demonstrate that activation of estrogen receptor-alpha-mediated non-genomic pathways by estrogenic compounds in MCF-7 cells is structure-dependent and can result in activation or inhibition of kinase activities. PMID:16413991

  14. Signal pathway of 17beta-estradiol-induced MUC5B expression in human airway epithelial cells.

    PubMed

    Choi, Hye Joung; Chung, Yoo-Sam; Kim, Hyun Jik; Moon, Uk Yeol; Choi, Yeon Ho; Van Seuningen, Isabelle; Baek, Seung Joon; Yoon, Ho-Geun; Yoon, Joo-Heon

    2009-02-01

    MUC5B is a major mucin of the human respiratory tract, and it is not clear how MUC5B expression is regulated in various airway diseases. The goal of this study was to determine the mechanisms by which 17beta-estradiol induces MUC5B gene expression in airway epithelial cells. It was found that E2, a sex hormone, stimulates MUC5B gene overexpression by interaction with estrogen receptor alpha (ERalpha) and by acting through extracellular signal-regulated kinase 1/2 (ERK1/2)-mitogen-activated protein kinase (MAPK). Pretreatment with ER antagonist ICI 182,780 blocked both E2-induced ERK1/2-MAPK activation and MUC5B gene expression. It was also found that the activation of p90 ribosomal S 6 protein kinase 1 (RSK1), cAMP-response element-binding protein (CREB), and cAMP-response element (CRE) (-956 region of the MUC5B promoter)-responsive signaling cascades via ERK1/2 MAPK are crucial aspects of the intracellular mechanisms that mediate MUC5B gene expression. Taken together, these studies give additional insights into the molecular mechanism of hormone-induced MUC5B gene expression and enhance our understanding of abnormal mucin secretion in response to hormonal imbalances. PMID:18688042

  15. Development of magnetic particle-based chemiluminescence enzyme immunoassay for the detection of 17beta-estradiol in environmental water.

    PubMed

    Xin, Tian-Bing; Wang, Xu; Jin, Hui; Liang, Shu-Xuan; Lin, Jin-Ming; Li, Zhen-Jia

    2009-09-01

    In the present work, a simple, fast, and highly sensitive chemiluminescence enzyme immunoassay for 17beta-estradiol (E2) in environmental water samples was developed, using magnetic particles (MPs) labeled with secondary antibody as both the immobilization matrix and the separation tools. The specific anti-E2 polyclonal antibody (PcAb) was produced against a conjugate of estradiol-bovine serum albumin. The specificity of the anti-E2 antibody was studied. The results showed that the antibody did not cross-react with the structurally related endocrine-disrupting compounds, including estrone, ethinyl E2, estriol, E2-17-glucuronide, E2-3-sulfate-17-glucuronide, androstenedione, and dihydrotestosterone. The water samples were pretreated with solid-phase extraction using C18 cartridges for the removal of matrix effects. Several physicochemical parameters including the dilution ratios of E2-6-horseradish peroxidase conjugate and anti-E2 PcAb, immunoreaction time, volume of chemiluminescent substrate and MPs, chemiluminescence reaction time, and pH of assay solution were studied and optimized. At optimal experimental conditions, it was found that the proposed method exhibited high performance with detection limit of 2.0 pg/mL, linear range of 20-1,200 pg/mL, and total assay time of 45 min. Both inter- and intra-assay coefficient of variation were less than 10%. The average recoveries of three different spiked concentration samples ranged from 86.3% to 108%. The method was successfully applied to the determination of E2 in river, waste, and tap water, and showed a good correlation with the commercially available radioimmunoassay kit. PMID:18841499

  16. Effects of 17beta-estradiol and 4-nonylphenol on osmoregulation and hepatic enzymes in gilthead sea bream (Sparus auratus).

    PubMed

    Carrera, Erkuden Pérez; García-López, Angel; Martín del Río, María del Pilar; Martínez-Rodríguez, Gonzalo; Solé, Montserrat; Mancera, Juan Miguel

    2007-03-01

    Sexually immature Sparus auratus were injected intraperitoneally with coconut oil either alone (control) or containing 17beta-estradiol (E2, 10 microg/g body mass) or 4-nonyphenol (4-NP, 100 and 200 microg/g body mass) and sampled 10 days later. Gill and kidney Na(+),K(+)-ATPase activities, plasma levels of E2 and cortisol, plasma osmolites (osmolality, sodium and chloride) and metabolites (glucose, lactate, proteins and triglycerides) were examined. Livers were used for measuring hepatosomatic index (HSI) and determinations of the activities of antioxidant defences catalase (CAT) and total glutatione peroxidase (t-GPX), the CYP1A-dependent, 7-ethoxyresorufin O-deethylase (EROD) and glutathione S-transferase (GST). HSI and plasma levels of E2 were significantly increased in E2 -treated fish. E2 treatment enhanced plasma osmolality, glucose, triglycerides and proteins, but had no effect on plasma cortisol, and gill and kidney Na(+),K(+)-ATPase activities. Hepatic activities of EROD, GST and CAT were significantly decreased after E2 administration, whereas t-GPX remained unaffected. Treatment with 200 microg/g 4-NP caused a slight increase in plasma E2 relative to the control group. Plasma glucose and protein levels were not affected by 4-NP, while triglycerides were increased. Fish treated with the higher dose of 4-NP displayed a clear reduction in kidney Na(+),K(+)-ATPase activity, together with increases in plasma osmolality, relative to the control group. High 4-NP also caused a significant decrease in EROD and an increase in GST activity. Our results confirm the regulation of the natural estrogen E2 and the weak xenoestrogen 4-NP on osmoregulation and biotransformation enzymes in a partially similar manner. The actions of xenoestrogens on critical physiological processes may have an ecological significance as it can reduce adaptability and capacity to metabolise xenobiotics under stressful conditions. PMID:17251064

  17. 17beta-estradiol induces both up-regulation and processing of cyclin E in a calpain-dependent manner in MCF-7 breast cancer cells.

    PubMed

    Hou, Jianmei; Wang, Xudong; Li, Yang; Liu, Xiaohong; Wang, Zhuting; An, Jing; Yang, Li; He, Yan

    2012-03-23

    In the current study, we investigated whether 17beta-estradiol (E2) induces cyclin E expression and triggers cyclin E processing via calpain in MCF-7 breast cancer cells. We found that E2 induced increased expression of cyclin E in a slow and persistent manner, and a rapid yet sustained processing of cyclin E. In addition, estrogenic ethanol was able to stimulate cyclin E truncation. Calpeptin or ALLN greatly suppressed the E2-triggered cyclin E processing and its expression, suggesting a calpain-mediated action for E2. Finally, the E2-induced effects could also be significantly suppressed by BAPTA or U0126, indicating involvement of calcium/ERK signaling. Taken together, these results show that estrogen may contribute to both up-regulation and proteolysis of cyclin E through calpain in MCF-7 cells. PMID:22449977

  18. Effects of 17beta-estradiol on glutamate synaptic transmission and neuronal excitability in the rat medial vestibular nuclei.

    PubMed

    Grassi, S; Frondaroli, A; Scarduzio, M; Dutia, M B; Dieni, C; Pettorossi, V E

    2010-02-17

    We investigated the effects of the neurosteroid 17beta-estradiol (E(2)) on the evoked and spontaneous activity of rat medial vestibular nucleus (MVN) neurons in brainstem slices. E(2) enhances the synaptic response to vestibular nerve stimulation in type B neurons and depresses the spontaneous discharge in both type A and B neurons. The amplitude of the field potential, as well as the excitatory post-synaptic potential (EPSP) and current (EPSC), in type B neurons, are enhanced by E(2). Both effects are long-term phenomena since they outlast the drug washout. The enhancement of synaptic response is mainly due to facilitation of glutamate release mediated by pre-synaptic N-methyl-D-aspartate receptors (NMDARs), since the reduction of paired pulse ratio (PPR) and the increase of miniature EPSC frequency after E(2) are abolished under D-(-)-2-amino-5-phosphonopentanoic acid (AP-5). E(2) also facilitates post-synaptic NMDARs, but it does not affect directly alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) and group I-metabotropic glutamate receptors (mGluRs-I). In contrast, the depression of the spontaneous discharge of type A and type B neurons appears to depend on E(2) modulation of intrinsic ion conductances, as the effect remains after blockade of glutamate, GABA and glycine receptors (GlyRs). The net effect of E(2) is to enhance the signal-to-noise ratio of the synaptic response in type B neurons, relative to resting activity of all MVN neurons. These findings provide evidence for a novel potential mechanism to modulate the responsiveness of vestibular neurons to afferent inputs, and so regulate vestibular function in vivo. PMID:19944747

  19. 4-n-Nonylphenol and 17-beta estradiol may induce common DNA effects in developing barnacle larvae.

    PubMed

    Atienzar, Franck A; Billinghurst, Zoë; Depledge, Michael H

    2002-01-01

    There is a growing concern over the potential effects of environmental endocrine disrupters on both human and wildlife populations. However, to date, minimal research has been conducted to determine the effect of estrogens and xenoestrogens at the DNA level. In this study, we used the random amplified polymorphic DNA (RAPD) assay to evaluate the effects on the genomic DNA of barnacle larvae that had been exposed to 17beta-estradiol (E2) and low concentrations of 4-n-nonylphenol (NP). DNA effects include DNA damage as well as mutations and possibly other effects at the DNA level that can be induced by chemical or physical agents that directly and/or indirectly interact with genomic DNA. Not only did exposure to NP and E2 induce changes in RAPD profiles in the exposed barnacle larvae when compared to control patterns, but also, and more importantly, there were similarities in the RAPD modifications in the exposed populations that had been treated to either chemical. We propose that NP and E2 induced some common DNA effects in barnacle larvae and that these specific modifications in RAPD patterns may arise as a consequence of hot spot DNA damage (e.g. DNA adducts) and/or mutations (point mutations or genomic rearrangements). This could help to explain how xenoestrogens mimic the effects produced by natural estrogens. In conclusion, in the field of endocrine disruption, the study of DNA effects induced by estrogens and/or xenoestrogens warrants further investigation. Indeed, changes at the DNA levcl may be the precursors of some of the numerous effects reported at higher levels of biological organisation such as the feminization of males, developmental abnormalities, and infertility. PMID:12442797

  20. Dual derivatization-stir bar sorptive extraction--thermal desorption--gas chromatography-mass spectrometry for determination of 17beta-estradiol in water sample.

    PubMed

    Kawaguchi, Migaku; Ito, Rie; Sakui, Norihiro; Okanouchi, Noriya; Saito, Koichi; Nakazawa, Hiroyuki

    2006-02-10

    A novel method for the trace analysis of 17beta-estradiol (E2) in river water sample was developed, which involved stir bar sorptive extraction (SBSE) with in situ acylation (first derivatization) and thermal desorption (TD) with quartz wool assisted (QWA) in tube silylation (second derivatization), followed by gas chromatography-mass spectrometry (GC-MS), and is called the "dual derivatization method." The optimum conditions for SBSE with in situ acylation, such as the volume of acetic acid anhydride and the extraction time, were investigated. In addition, the optimum conditions for TD with QWA in tube silylation, such as the volume of N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) and the TD temperature and hold time, were investigated as well. The detection limit (S/N = 3) and the quantitation limit (S/N>10) of E2 in the river water sample were 0.5 and 2 pg ml(-1) (ppt), respectively, by the dual derivatization method. In addition, the detection limit was 0.1 pg ml(-1) by using dual derivatization method with multi-shot mode. The calibration curve for E2 was linear in the range of 0.002-10 ng ml(-1) with correlation coefficients >0.999. The average recoveries of E2 (n = 6) at the concentrations of 0.05 and 1.0 ng ml(-1) from the river water sample were 93.1 (RSD: 1.4%) and 98.4% (RSD: 0.8%), respectively, with correction using the added surrogate standard, 17beta-estradiol-(13)C(4). This simple, accurate, sensitive and selective analytical method may be applicable to the determination of trace amounts of E2 in water samples. PMID:16439260

  1. Elimination kinetic of 17beta-estradiol 3-benzoate and 17beta-nandrolone laureate ester metabolites in calves' urine.

    PubMed

    Pinel, Gaud; Rambaud, Lauriane; Cacciatore, Giuseppe; Bergwerff, Aldert; Elliott, Chris; Nielen, Michel; Le Bizec, Bruno

    2008-05-01

    Efficient control of the illegal use of anabolic steroids must both take into account metabolic patterns and associated kinetics of elimination; in this context, an extensive animal experiment involving 24 calves and consisting of three administrations of 17beta-estradiol 3-benzoate and 17beta-nandrolone laureate esters was carried out over 50 days. Urine samples were regularly collected during the experiment from all treated and non-treated calves. For sample preparation, a single step high throughput protocol based on 96-well C(18) SPE was developed and validated according to the European Decision 2002/657/EC requirements. Decision limits (CCalpha) for steroids were below 0.1 microg L(-1), except for 19-norandrosterone (CCalpha=0.7 microg L(-1)) and estrone (CCalpha=0.3 microg L(-1)). Kinetics of elimination of the administered 17beta-estradiol 3-benzoate and 17beta-nandrolone laureate were established by monitoring 17beta-estradiol, 17alpha-estradiol, estrone and 17beta-nandrolone, 17alpha-nandrolone, 19-noretiocholanolone, 19-norandrostenedione, respectively. All animals demonstrated homogeneous patterns of elimination both from a qualitative (metabolite profile) and quantitative point of view (elimination kinetics in urine). Most abundant metabolites were 17alpha-estradiol and 17alpha-nandrolone (>20 and 2 mg L(-1), respectively after 17beta-estradiol 3-benzoate and 17beta-nandrolone laureate administration) whereas 17beta-estradiol, estrone, 17beta-nandrolone, 19-noretiocholanolone and 19-norandrostenedione were found as secondary metabolites at concentration values up to the microg L(-1) level. No significant difference was observed between male and female animals. The effect of several consecutive injections on elimination profiles was studied and revealed a tendency toward a decrease in the biotransformation of administered steroid 17beta form. PMID:18356042

  2. 17beta-estradiol potently suppresses cAMP-induced insulin-like growth factor-I gene activation in primary rat osteoblast cultures

    NASA Technical Reports Server (NTRS)

    McCarthy, T. L.; Ji, C.; Shu, H.; Casinghino, S.; Crothers, K.; Rotwein, P.; Centrella, M.

    1997-01-01

    Insulin-like growth factor-I (IGF-I) is a key factor in bone remodeling. In osteoblasts, IGF-I synthesis is enhanced by parathyroid hormone and prostaglandin E2 (PGE2) through cAMP-activated protein kinase. In rats, estrogen loss after ovariectomy leads to a rise in serum IGF-I and an increase in bone remodeling, both of which are reversed by estrogen treatment. To examine estrogen-dependent regulation of IGF-I expression at the molecular level, primary fetal rat osteoblasts were co-transfected with the estrogen receptor (hER, to ensure active ER expression), and luciferase reporter plasmids controlled by promoter 1 of the rat IGF-I gene (IGF-I P1), used exclusively in these cells. As reported, 1 microM PGE2 increased IGF-I P1 activity by 5-fold. 17beta-Estradiol alone had no effect, but dose-dependently suppressed the stimulatory effect of PGE2 by up to 90% (ED50 approximately 0.1 nM). This occurred within 3 h, persisted for at least 16 h, required ER, and appeared specific, since 17alpha-estradiol was 100-300-fold less effective. By contrast, 17beta-estradiol stimulated estrogen response element (ERE)-dependent reporter expression by up to 10-fold. 17beta-Estradiol also suppressed an IGF-I P1 construct retaining only minimal promoter sequence required for cAMP-dependent gene activation, but did not affect the 60-fold increase in cAMP induced by PGE2. There is no consensus ERE in rat IGF-I P1, suggesting novel downstream interactions in the cAMP pathway that normally enhances IGF-I expression in skeletal cells. To explore this, nuclear extract from osteoblasts expressing hER were examined by electrophoretic mobility shift assay using the atypical cAMP response element in IGF-I P1. Estrogen alone did not cause DNA-protein binding, while PGE2 induced a characteristic gel shift complex. Co-treatment with both hormones caused a gel shift greatly diminished in intensity, consistent with their combined effects on IGF-I promoter activity. Nonetheless, hER did not bind IGF-I cAMP response element or any adjacent sequences. These results provide new molecular evidence that estrogen may temper the biological effects of hormones acting through cAMP to regulate skeletal IGF-I expression and activity.

  3. Antagonistic effects of 17 beta-estradiol, progesterone, and testosterone on Ca2+ entry mechanisms of coronary vasoconstriction.

    PubMed

    Crews, J K; Khalil, R A

    1999-04-01

    The clinical observation that coronary artery disease is more common in men and postmenopausal women than in premenopausal women has suggested cardioprotective effects of female sex hormones including hormone-mediated coronary vasodilation. The purpose of this study was to investigate whether the sex hormone-induced coronary relaxation is caused by inhibition of Ca2+ mobilization into coronary smooth muscle. The effects of 17beta-estradiol, progesterone, and testosterone on vascular reactivity and 45Ca2+ influx were tested in deendothelialized coronary artery strips isolated from castrated male pigs. Prostaglandin F2alpha (PGF2alpha) (10(-5) mol/L) caused significant, maintained contraction of coronary artery strips. Caffeine (25 mmol/L), an activator of Ca2+ release from intracellular stores, caused transient contraction in Ca2+-free solution whereas membrane depolarization by 96 mmol/L KCl, an activator of Ca2+ entry, caused maintained contraction in the presence of external Ca2+. The 3 sex hormones caused significant and concentration-dependent relaxation of PGF2alpha- and 96 mmol/L KCl-induced contractions with 17beta-estradiol being the most effective. The sex hormones did not significantly affect the transient caffeine contraction in Ca2+-free solution. In contrast, the sex hormones significantly inhibited the PGF2alpha- and KCl-induced 45Ca2+ influx. 17beta-Estradiol caused similar inhibition of PGF2alpha- and KCl-induced contractions, suggesting inhibition of the same Ca2+ entry mechanism. However, progesterone and testosterone caused greater relaxation of PGF2alpha-induced contraction than of KCl-induced contraction. We conclude that in coronary arteries of castrated male pigs, sex hormones inhibit Ca2+ entry from extracellular space but not Ca2+ release from intracellular stores. 17beta-Estradiol mainly inhibits Ca2+ entry, whereas progesterone and testosterone cause coronary relaxation by inhibiting other mechanisms in addition to Ca2+ entry. PMID:10195933

  4. Rapid vascular escape of arterially injected 16alpha-radioiodo, 17beta-estradiol

    SciTech Connect

    Scharl, A.; Holt, J.A. )

    1993-03-20

    The authors undertook this study because confirmation of a rapid vascular escape and slow release back into the circulatory system suggests that arterial injection of radiohalogenated steroid receptor ligands might provide an efficacious route of administration for imaging or treatment of receptor-rich malignant tumors in peripheral tissues. The authors injected radiolabeled 16alpha-iodo, 17beta-estradiol ([I]-E) into the femoral artery of swine in a solution that contained [[sup 125]I]-E in a known ratio to [[sup 99]Tc]-labeled red blood cells. Fractions of femoral venous blood were collected at short intervals during 10 min. They looked for changes in the ratio of the radiolabeles. [[sup 99m]Tc]-labeled red blood cells are known to remain in the vascular system for an hour or more. After passage of the injectate through the capillary bed of the swine leg, a dramatic decrease of the initial [sup 125]I:[sup 99m]Tc ratio to only 10% was observed in the femoral venous blood. This ratio increased gradually during the next 10 min to approximately 30% of that in the injectate, indicating that a significant portion (approximately 90%) of the [[sup 125]I]-E was initially trapped in the limb and then slowly re-entered the vascular system. To obtain visual confirmation of the rapid vascular escape of iodo-estrogen, they injected either an imageable form of [I]-E ([[sup 123]I]-E) or [[sup 99m]Tc]-labeled red blood cells into the dorsal aorta of superovulated rabbits, whose smaller size allowed whole-body imaging. The biodistributions of these radiopharmaceuticals were surveyed continuously by real-time planar gamma imaging. A large fraction of [I]-E escapes from the vascular system during the first pass through an organ or limb, without regard to the estrogen receptor content of the tissue. 28 refs., 3 figs., 1 tab.

  5. Decreased [Ca(2+)](i) during inhibition of coronary smooth muscle contraction by 17beta-estradiol, progesterone, and testosterone.

    PubMed

    Murphy, J G; Khalil, R A

    1999-10-01

    The clinical observation that coronary heart disease is more common in men and postmenopausal women than in premenopausal women has suggested cardiovascular protective effects of female sex hormones including hormone-mediated coronary vasodilation. We investigated whether the sex hormones induced coronary relaxation is due to a decrease in [Ca(2+)](i) as measured in single coronary smooth muscle cells isolated from gonadectomized male and female pigs. In the presence of external Ca(2+), prostaglandin F(2alpha) (PGF(2alpha); 10(-5) M) and membrane depolarization by 51 mM KCl caused significant cell contraction and maintained increase in [Ca(2+)](i) to 297 +/- 4 and 341 +/- 20 nM, respectively. At 10(-9) to 6 x 10(-7) M, 17beta-estradiol, progesterone, and testosterone caused inhibition of PGF(2alpha)- and KCl-induced contraction and [Ca(2+)](i) with 17beta-estradiol being most effective. 17alpha-Estradiol did not affect PGF(2alpha)-induced contraction, and the inhibition of PGF(2alpha) contraction by 17beta-estradiol, progesterone, or testosterone was abolished by tamoxifen and ICI 182, 780, RU-486, or flutamide, respectively. 17beta-Estradiol caused similar inhibition of PGF(2alpha)- and KCl-induced contraction and [Ca(2+)](i). Progesterone and testosterone caused greater inhibition of PGF(2alpha)-induced cell contraction and [Ca(2+)](i) compared with the KCl responses. In Ca(2+)-free (2 mM EGTA) solution, caffeine (10 mM) and carbachol (10(-5) M), which activate Ca(2+) release from intracellular stores, caused small cell contraction and transiently increased [Ca(2+)](i) to 256 +/- 53 and 262 +/- 32 nM, respectively. Sex hormones did not significantly affect caffeine- or carbachol-induced contraction or [Ca(2+)](i). Thus, 17beta-estradiol, progesterone, and testosterone cause relaxation of coronary smooth muscle cells and decrease [Ca(2+)](i) mainly by inhibiting Ca(2+) entry from extracellular space but not Ca(2+) release from intracellular stores. The differences in potency of sex hormones in reducing cell contraction and [Ca(2+)](i) suggest differences in the sensitivity of the PGF(2alpha)- and depolarization-activated Ca(2+) entry pathways to inhibition by sex hormones. PMID:10490885

  6. Upregulation of estrogen receptor subtypes and vitellogenin mRNA in cinnamon clownfish Amphiprion melanopus during the sex change process: profiles on effects of 17beta-estradiol.

    PubMed

    Kim, Na Na; Jin, Deuk-Hee; Lee, Jehee; Kil, Gyung-Suk; Choi, Cheol Young

    2010-10-01

    In the present study, we investigated the expression pattern of estrogen receptors (esr) and vitellogenin (vtg) mRNA in the gonads and liver during sex change in cinnamon clownfish by using quantitative polymerase chain reaction. We divided gonadal development during the sex change from male to female into 3 stages (mature male, male at 90days after removing female, and mature female) and investigated esr and vtg mRNA expressions during the sex change. With female, the esr and vtg mRNA expressions increased. In western blot analysis, Esr1 protein was detected only in the ovaries of female cinnamon clownfish. Also, to understand the effect of 17beta-estradiol (E(2)), we investigated the esr and vtg mRNA expression patterns in the gonads and liver, and the changes in plasma E(2) level after E(2) injection. E(2) treatment increased both mRNA expression levels of esr and vtg and plasma E(2) levels. The present study describes the molecular characterization of esr subtypes and the interactions between esr and vtg after E(2) treatment in cinnamon clownfish. PMID:20601066

  7. Oxidation products of stigmasterol interfere with the action of the female sex hormone 17beta-estradiol in cultured human breast and endometrium cell lines.

    PubMed

    Newill, Heike; Loske, Renate; Wagner, Jörg; Johannes, Christian; Lorenz, Reinhard L; Lehmann, Leane

    2007-07-01

    Phytosterols are constituents of plant membranes and are thus contained in low concentrations in vegetable products as well as at high concentrations in functional food designed to reduce serum cholesterol levels. Similar to ChOL, phytosterols are oxidized chemically in food and by biotransformation in vivo. Although oxyphytosterols have been detected in the serum of healthy human subjects, little is known of their biological activity. Therefore, the estrogenic and antiestrogenic activities of a mixture of six oxidation products of stigmasterol (oxy-StOL) were determined at the following endpoints: (i) the affinity to isolated human estrogen receptors (ER), (ii) the basal and 17beta-estradiol (E2)-induced expression of the alkaline phosphatase (AlP) in human endometrial adenocarcinoma (Ishikawa) cells, and (iii) the basal and E2-induced proliferation of human breast adenocarcinoma (MCF-7) cells. Oxy-StOL was able to replace E2 from human ERalpha and ERbeta and induced a weak estrogenic response in MCF-7 cells. Moreover, the E2-induced activity of the AlP in Ishikawa cells as well as the E2-induced proliferation of MCF-7 cells were decreased at noncytotoxic concentrations (up to 10 microM), indicating that at least one component of oxy-StOL represents an estrogen-active compound which might interfere with endogenous estrogens. PMID:17579897

  8. Arctic char (Salvelinus alpinus) metallothionein: cDNA sequence, expression, and tissue-specific inhibition of cadmium-mediated metallothionein induction by 17{beta}-estradiol, 4-OH-PCB 30, and PCB 104

    SciTech Connect

    Gerpe, M.; Kling, P.; Berg, A.H.; Olsson, P.E.

    2000-03-01

    In this study, the authors have examined the basal level expression and tissue-specific expression patterns of metallothionein (MT) in Arctic char following metal and E2 (17{beta}-estradiol) treatment. To study the gene regulation in Arctic char, the two MT isoforms were isolated from a lambda-ZAP hepatic cDNA library and characterized. Determination of basal MT and mRNA and MT expression for 10 different tissues revealed a lack of correlation between MT and mRNA and MT levels. The inducibility of MT mRNA and the correlation to resulting MT levels were then determined for liver and kidney. They found a more rapid and stronger induction of MT mRNA in liver than in kidney at day 1 and 3 postinjection, whereas the MT protein quantification showed higher MT levels in kidney than in liver at days 3 and 7 postinjection. These discrepancies indicate that differences in metal handling or posttranscriptional regulation of MT exists between tissues. Whereas metals induce MT synthesis, E2 inhibit the hepatic MT expression. To examine the tissue specificity of this inhibition, the authors determined the effect of 17{beta}-estradiol (E2) and two estrogenic PCBs (4{prime}-OH-PCB 30 and PCB 104) on Cd-mediated MT induction in liver and kidney. Although E2 and the estrogenic PCBs inhibited cadmium-mediated hepatic MT induction, these compounds did not interfere with renal MT induction.

  9. Gender-related effects of 17-{beta}-estradiol and B-hexachlorocyclohexane on liver tumor formation in medaka (Oryzias latipes)

    SciTech Connect

    Cooke, J.B.; Hinton, D.E.

    1994-12-31

    When medaka were acutely exposed to diethylnitrosamine (DEN), greater incidence of hepatocarcinoma was seen in female versus male fish. This is possibly related to elevated female endogenous estrogens, which increase liver weight and production of vitellogenin. To examine roles of estrogens in tumor modulation, 21-day old medaka were exposed to DEN (200 ppm for 24 hr.), then fed purified diets containing the estrogenic compound {beta}-hexachlorocyclohexane ({beta}-HCH) or 17-{beta}estradiol (E2) for 6 months. Incidences of basophilic preneoplastic foci of cellular alteration in females receiving DEN and 0.01, 0.1, or 1.0 ppm E2 were three times the incidences in similarly-treated males. Also, incidences of basophilic foci in DEN + 0.1 ppm E2 males were significantly increased over DEN-only males and were equal to incidences in DEN-only females. Liver weights and hepatosomatic indices of males given 0.1 ppm E2 were not significantly different than females fed control diet. Females fed 0.01-10.0 ppm {beta}-HCH after DEN had 4--5 times greater incidences of basophilic foci as males. Gender-related effects on kinetics of growth rates and volumes of foci are being examined.

  10. Progesterone and 17beta-estradiol, but not follicle stimulating hormone, alter the sex ratio of murine embryos fertilized in vitro.

    PubMed

    Zhang, L; Du, W; Lin, X; Zhang, A; Chen, H

    2008-05-01

    The objective was to determine the effects of adding progesterone, 17beta-estradiol (17beta-E2), and FSH during in vitro fertilization on development and sex ratio of murine embryos. Progesterone (33-330 pg/mL), 17beta-estradiol (17beta-E2); 10-70 pg/mL), and FSH (0.01-0.05 IU/mL), were added to human tubal fluid (HTF); this medium (with or without hormones) was used to pre-incubate sperm (2h) and to co-incubate sperm and oocytes (6h). Thereafter, the ova were washed and incubated in mM16 medium and embryo sex was determined (by PCR) on Day 4 (insemination=Day 0). There was no effect (P>0.05) of hormone treatments on rates of cleavage (6 h after cessation of co-incubation with sperm). The only significant effects of added hormones on development were a decrease in the rate of development to at least the morula stage in 165 pg/mL progesterone (0.46+/-0.03 vs. 0.54+/-0.05 in the control, mean+/-S.D.; P<0.05) and a decrease in the blastocyst rate in 0.03 IU/mL FSH (0.34+/-0.00 vs. 0.42+/-0.04 in the control, P<0.05). However, the ratio of male to female embryos was 1.61 and 2.90 following the addition of 99 pg/mL progesterone and 70 pg/mL 17beta-E2, respectively; both of these ratios were different (P<0.01) than in the control group (1.20). In contrast, the addition of FSH to the medium had no significant effect on this ratio (range, 0.78-1.02). We concluded that the addition of progesterone and estradiol to the media during in vitro fertilization did not enhance embryonic development, but significantly increased the proportion of male murine embryos. PMID:18359509

  11. Gender determination in the Paiche or Pirarucu (Arapaima gigas) using plasma vitellogenin, 17beta-estradiol, and 11-ketotestosterone levels.

    PubMed

    Chu-Koo, F; Dugu, R; Alvn Aguilar, M; Casanova Daza, A; Alcntara Bocanegra, F; Chvez Veintemilla, C; Duponchelle, F; Renno, J-F; Tello, Salvador; Nuez, J

    2009-03-01

    Arapaima gigas is an air-breathing giant fish of Amazonian rivers. Given its great economic and cultural importance, the aquaculture development of this species represents an evident solution to face the decline of wild populations. In captivity, reproduction occurs generally in large earthen ponds where stocks of a few tens of brooders are maintained together at the beginning of the rainy season (December-March in the Peruvian Amazon). Fry production relies on the spontaneous formation of male and female pairs, which build a nest, delimit a territory and guard the offspring for at least 20 days from other congeners and predators. However, as sex determination of A. gigas is not possible by morphological criteria, it is very difficult to optimize reproduction conditions and fry production in each pond, which seriously hampers the culture of this species. This situation prompted us to develop sexing methodologies based on (1) the detection of female specific plasma Vitellogenin (Vtg) using an enzyme immuno assay (EIA), and (2) the determination of plasma 17beta-estradiol and 11-ketotestosterone levels for immature specimens. The Vtg purification was performed by electro-elution after polyacrilamide gel electrophoresis (PAGE) from plasma of 17beta-estradiol treated A. gigas juveniles. Two different Vtg molecules were isolated, (Vtg(1) and Vtg(2)) with 184 and 112 kDa apparent molecular masses, respectively, and two antibodies were raised in rabbits for each Vtg molecule. Adult fish were 100% accurately sexed by Vtg EIA, while 100% of immature fish and 95% of adults were accurately sexed by 17beta-Estradiol and 11-Ketestosterone ratios. We also observed different color pattern development in male and female adult fish (6-year-olds) around the reproductive period. PMID:19189239

  12. Research note: effect of in ovo 17-beta-estradiol or tamoxifen administration on sexual differentiation of the external genitalia.

    PubMed

    Coco, C M; Hargis, B M; Hargis, P S

    1992-11-01

    The effect of in ovo administration of tamoxifen or 17 beta-estradiol on external sexual dimorphism in chickens was investigated. In two trials, fertile eggs were injected with either tamoxifen (200 micrograms per egg) or vehicle (100 microL corn oil) on Day 1 of incubation, or with 17 beta-estradiol (20 micrograms per egg) or vehicle on Day 11 of incubation. Sexes were determined by visual inspection of the external genitalia and by gonadal identification at Day 1 posthatch. Tamoxifen injection resulted in a significantly greater number of phenotypic male identifications, with male:female ratios of 76:24 (Trial 1) and 62:38 (Trial 2) based on external genitalia phenotype. Gonadal sexing corrected these ratios to 46:54 and 44:56, resulting in genital sexing errors of 27% (Trial 1) and 18% (Trial 2). These errors were significantly higher than genital sexing errors of the chicks treated with vehicle (2 and .6% for Trials 1 and 2, respectively). In ovo administration of 17 beta-estradiol resulted in an increased number of female identifications based on genital sex determination, with male:female ratios of 37:63 (Trial 1) and 46:54 (Trial 2). Gonadal sexing corrected these ratios to 54:46 and 51:49, resulting in genital sexing errors of 10 and 6% for Trials 1 and 2, respectively. These errors were significantly higher than genital sexing errors of vehicle-treated chicks (4 and .9% for Trials 1 and 2, respectively). The results of the present study indicate that early embryonic administration of estrogen or an estrogen antagonist alters chicken external sexual dimorphism near the time of hatch. PMID:1437983

  13. Research note: effect of in ovo 17-beta-estradiol or tamoxifen administration on sexual differentiation of the external genitalia.

    TOXLINE Toxicology Bibliographic Information

    Coco CM; Hargis BM; Hargis PS

    1992-11-01

    The effect of in ovo administration of tamoxifen or 17 beta-estradiol on external sexual dimorphism in chickens was investigated. In two trials, fertile eggs were injected with either tamoxifen (200 micrograms per egg) or vehicle (100 microL corn oil) on Day 1 of incubation, or with 17 beta-estradiol (20 micrograms per egg) or vehicle on Day 11 of incubation. Sexes were determined by visual inspection of the external genitalia and by gonadal identification at Day 1 posthatch. Tamoxifen injection resulted in a significantly greater number of phenotypic male identifications, with male:female ratios of 76:24 (Trial 1) and 62:38 (Trial 2) based on external genitalia phenotype. Gonadal sexing corrected these ratios to 46:54 and 44:56, resulting in genital sexing errors of 27% (Trial 1) and 18% (Trial 2). These errors were significantly higher than genital sexing errors of the chicks treated with vehicle (2 and .6% for Trials 1 and 2, respectively). In ovo administration of 17 beta-estradiol resulted in an increased number of female identifications based on genital sex determination, with male:female ratios of 37:63 (Trial 1) and 46:54 (Trial 2). Gonadal sexing corrected these ratios to 54:46 and 51:49, resulting in genital sexing errors of 10 and 6% for Trials 1 and 2, respectively. These errors were significantly higher than genital sexing errors of vehicle-treated chicks (4 and .9% for Trials 1 and 2, respectively). The results of the present study indicate that early embryonic administration of estrogen or an estrogen antagonist alters chicken external sexual dimorphism near the time of hatch.

  14. Effect of frying-meat emission particulate on 17beta-estradiol 2- and 4-hydroxylation in human lung adenocarcinoma CL5 cells.

    PubMed

    Wang, Hui-Wu; Ueng, Tzuu-Huei; Chen, Ta-Liang; Yang, Pan-Chyr

    2003-06-27

    The effect of airborne frying-meat emission particulate (FMEP) on metabolism of 17beta-estradiol (E(2)) to potentially toxic catechol estrogens 2- and 4-hydroxyestradiol (2- and 4-OH-E(2)) was determined using human lung adenocarcinoma CL5 cells treated with organic extracts of beef FMEP. E(2) was incubated with microsomes prepared from untreated CL5 cells or cells treated with 200 microg/ml FMEP extract for 6 h. E(2) metabolites formed were analyzed by high-performance liquid chromatography (HPLC). The results revealed that treatment with FMEP produced three-and twofold increases of 2- and 4-hydroxylation of E(2), respectively. Monooxygenase activity and immunoblot analyses showed that FMEP markedly induced microsomal 7-ethoxyresorufin O-deethylase (EROD) activity and cytochrome P-450 (CYP) IAI and CYPIBI protein levels. Similar increases in E(2) hydroxylation, EROD activity, and CYP protein levels were observed with HepG2 human hepatoma and MCF-7 human breast cancer cells treated with FMEP or 1 microM dibenz[a,h]anthracene. Cotreatment of CL5 cells with FMEP extract and 2 microM alpha-naphthoflavone, an arylhydrocarbon receptor antagonist, blocked the inductive effects of FMEP on E(2) hydroxylation and EROD activity. Additions of 0.01, 0.1, or 1 microM alpha-naphthoflavone, a CYP inhibitor, to microsomes produced concentration-dependent decreases in E(2) 2-hydroxylation and EROD activity of CL5 cells induced by dibenz[a,h]anthracene. The present finding demonstrates that FMEP can increase formation of 2-OH-E(2) and 4-OH-E(2) by human lung cells, and induction of CYP1A1 and CYP1B1 is a potential mechanism underlying increased E(2) metabolism. The toxicological significance of FMEP and estrogen interaction warrants further investigation. PMID:12791542

  15. Antioxidants J811 and 17beta-estradiol protect cerebellar granule cells from methylmercury-induced apoptotic cell death.

    PubMed

    Dar, E; Gtz, M E; Zhivotovsky, B; Manzo, L; Ceccatelli, S

    2000-11-15

    Cerebellar granule cells (CGC) have provided a reliable model for studying the toxicity of methylmercury (MeHg), a well-known neurotoxicant contaminating the environment. In the present study we report that doses of MeHg ranging from 0.1 microM to 1.5 microM activated apoptosis, as shown by cell shrinkage, nuclear condensation, and formation of high-molecular-weight DNA fragments. Nevertheless, caspase-3-like activity was not significantly induced, and the broad caspase inhibitor Z-VAD-FMK was not capable of protecting the cells. This argues for a minor role of caspases in the intracellular pathways leading to MeHg-induced cell death in CGC. Instead, proteolytic fragments obtained by specific calpain cleavage of procaspase-3 and alpha-fodrin were increased consistently in samples exposed to MeHg, pointing to a substantial activation of calpain. Notably, two antioxidants, 17beta-estradiol (10 microM) and the Delta(8,9)-dehydro derivative of 17alpha-estradiol J811 (10 microM), protected from MeHg damage, preventing morphological alterations, chromatin fragmentation, and activation of calpain. These findings underscore the key role of oxidative stress in MeHg toxicity, placing it upstream of calpain activation. The shielding effect of the 17beta-estradiol and the radical scavenger J811 is potentially relevant for the development of therapeutic strategies for MeHg intoxication. PMID:11070499

  16. The G protein-coupled receptor GPR30 mediates the proliferative effects induced by 17beta-estradiol and hydroxytamoxifen in endometrial cancer cells.

    PubMed

    Vivacqua, Adele; Bonofiglio, Daniela; Recchia, Anna Grazia; Musti, Anna Maria; Picard, Didier; And, Sebastiano; Maggiolini, Marcello

    2006-03-01

    The growth of both normal and transformed epithelial cells of the female reproductive system is stimulated by estrogens, mainly through the activation of estrogen receptor alpha (ERalpha), which is a ligand-regulated transcription factor. The selective ER modulator tamoxifen (TAM) has been widely used as an ER antagonist in breast tumor; however, long-term treatment is associated with an increased risk of endometrial cancer. To provide new insights into the potential mechanisms involved in the agonistic activity exerted by TAM in the uterus, we evaluated the potential of 4-hydroxytamoxifen (OHT), the active metabolite of TAM, to transactivate wild-type ERalpha and its splice variant expressed in Ishikawa and HEC1A endometrial tumor cells, respectively. OHT was able to antagonize only the activation of ERalpha by 17beta-estradiol (E2) in Ishikawa cells, whereas it up-regulated c-fos expression in a rapid manner similar to E2 and independently of ERalpha in both cell lines. This stimulation occurred through the G protein-coupled receptor named GPR30 and required Src-related and epidermal growth factor receptor tyrosine kinase activities, along with the activation of both ERK1/2 and phosphatidylinositol 3-kinase/AKT pathways. Most importantly, OHT, like E2, stimulated the proliferation of Ishikawa as well as HEC1A cells. Transfecting a GPR30 antisense expression vector in both endometrial cancer cell lines, OHT was no longer able to induce growth effects, whereas the proliferative response to E2 was completely abrogated only in HEC1A cells. Furthermore, in the presence of the inhibitors of MAPK and phosphatidylinositol 3-kinase pathways, PD 98059 and wortmannin, respectively, E2 and OHT did not elicit growth stimulation. Our data demonstrate a new mode of action of E2 and OHT in endometrial cancer cells, contributing to a better understanding of the molecular mechanisms involved in their uterine agonistic activity. PMID:16239258

  17. Effect of 17beta-estradiol and progesterone on the expression of FeLV in chronically infected cells.

    PubMed

    Tejerizo, German; Domenech, Ana; Illera, Juan C; Collado, Victorio M; Gomez-Lucia, Esperanza

    2005-08-30

    In a previous study, it was found that even though more male cats were infected by feline leukaemia virus (FeLV), females seemed to progress easier to overt disease. To study the effect of female hormones, 17beta-estradiol and progesterone were added in different concentrations (10(-3) M to 10(-12) M) to a culture of persistently FeLV-infected cells. The effect of both hormones was very similar. After 24 h the cell viability was very low at 10(-3) M and 10(-4) M but similar to controls at the remaining concentrations. Liberation of viral particles was estimated by the reverse transcriptase activity (RT), which was the lowest also at 10(-3) M and 10(-4) M. However, low viability could not account for this low RT, as when cells were lysed with lysis buffer RT was high. Thus, cells were dying without freeing viral particles, suggestive of apoptosis. This possibility was confirmed by staining hormone-treated cells with annexin V and propidium iodide. The FeLV antigen p27 measured in the cultures had a maximum at 10(-3) M and 10(-4) M, higher than controls and lysed cells, so the presence of p27 in the supernatant was not only due to cell lysis but a consequence of hormone effect. In conclusion, 17beta-estradiol and progesterone induce death of FeLV-infected cells at high concentrations, probably through a process of apoptosis, which might limit the spread of the infection, as infective viral particles would be hampered from budding. PMID:16023797

  18. Zearalenone induces chromosome aberrations in mouse bone marrow: preventive effect of 17beta-estradiol, progesterone and Vitamin E.

    PubMed

    Ouanes, Z; Ayed-Boussema, I; Baati, T; Creppy, E E; Bacha, H

    2005-01-01

    The cytogenetic effect of zearalenone (ZEN), a non-steroidal estrogenic mycotoxin, was evaluated in vivo, in mouse bone marrow cells, by assessing the percentage of cells bearing different chromosome aberrations. The studies included different conditions for animal treatment, as follows: (1) single intraperitoneal (ip) injection, (2) repeated ip injections, (3) pre-treatment for 24h with Vitamin E (Vit E), and (4) pre-treatment for 4h with 17beta-estradiol (17beta-Est) or progesterone (Prog). ZEN induced different types of chromosome aberrations, which was concentration-dependent (2-20 mg/kg bw). These doses corresponded to 0.4-4% of the LD50 in the mouse. Interestingly, when the dose of ZEN (40 mg/kg) was fractionated into four equivalent doses (4 x 10 mg/kg bw), into three doses (15 + 10 + 15 mg/kg bw), or into two equivalent doses (2 x 20 mg/kg bw), given every 24 h, the percentage of chromosome aberrations increased significantly. This finding suggests that ZEN proceeds by reversible binding on receptors that could become saturated, and that it damages the chromosomes in a 'hit and go' manner. Furthermore, pre-treatment of animals with 17beta-estradiol or progesterone significantly decreased the percentage of chromosome aberrations, suggesting that (i) these hormones bind to the same cytoplasmic receptors transported into the nucleus to elicit DNA damage, (ii) they may play a role in preventing chromosome aberrations induced by ZEN. Similarly, Vit E prevented these chromosome aberrations indicating that Vit E, previously reported to prevent most of the toxic effects induced by ZEN, may also bind to the same receptors. PMID:15661612

  19. Progesterone and 17beta-estradiol enhance regulatory responses to human papillomavirus type 16 virus-like particles in peripheral blood mononuclear cells from healthy women.

    PubMed

    Marks, Morgan A; Gravitt, Patti E; Burk, Robert D; Studentsov, Yevgeniy; Farzadegan, Homayoon; Klein, Sabra L

    2010-04-01

    Human papillomavirus (HPV) virus-like particle (VLP) vaccines are highly effective at preventing viral infections and the development of precancerous lesions through the induction of high-titer neutralizing antibodies and strong cell-mediated immune responses. Women taking combined oral contraceptives (COCs), however, show large variabilities in the magnitudes of their antibody responses. The goal of the present study was to determine the effects of 17beta-estradiol (E2) and progesterone (P4) alone and in combination on the cellular immune response to HPV type 16 (HPV-16) VLPs in vitro. Peripheral blood mononuclear cells (PBMCs) from healthy donor women were stimulated in vitro with HPV-16 VLPs (2.5 microg/ml) in the presence of E2 and P4 administered either alone or in combination; and lymphoproliferation, cytokine production, transcription factor expression, and steroid hormone receptor expression were analyzed. HPV-16 VLPs significantly increased the levels of lymphoproliferation, proinflammatory cytokine (gamma interferon [IFN-gamma], interleukin-1beta [IL-1beta], IL-2, IL-6, IL-8, IL-12p70, IL-17, tumor necrosis factor alpha [TNF-alpha]) production, anti-inflammatory cytokine (IL-1ra, IL-10) production, and the expression of Eralpha and Erbeta but decreased the levels of Foxp3 expression and production of transforming growth factor beta (TGF-beta). Exposure of PBMCs to E2 and P4 either alone or in combination significantly decreased the levels of lymphoproliferation and production of proinflammatory cytokines (IFN-gamma, IL-12p70, TNF-alpha) but increased the levels of production of IL-10 and TGF-beta and the expression of Foxp3 in response to HPV-16 VLPs. Treatment of cells with biologically relevant concentrations of sex steroid hormones suppressed the inflammatory response and enhanced the regulatory response to HPV-16 VLPs, which may have implications for predicting the long-term efficacy of HPV vaccines, adverse events, and cross-protection among women taking COCs. PMID:20130130

  20. Transport of 17beta-estradiol and testosterone in a field lysimeter

    Technology Transfer Automated Retrieval System (TEKTRAN)

    17ß-estradiol (E2) and testosterone (T) are present in sources such as waste treatment effluent and manures, and can potentially disrupt aquatic organisms at low concentrations. Laboratory studies consistently indicate limited mobility and rapid attenuation of E2 and T in soils; however, these hormo...

  1. Effect of 17beta-estradiol and testosterone on the expression of flavin-containing monooxygenase and the toxicity of aldicarb to Japanese medaka, Oryzias latipes.

    PubMed

    El-Alfy, Abir T; Schlenk, Daniel

    2002-08-01

    Previous studies in our laboratory indicated gender differences in salinity-enhanced acute toxicity of aldicarb in Japanese medaka with females being more susceptible. In the current study, the effects of the sex steroids, 17beta estradiol (E2) and testosterone (T) on aldicarb toxicity was examined. Adult Japanese medaka were separated by sex and exposed to 100 microg/l E2 or T for 6 days followed by exposure to the 96-h LC50 (0.5 mg/l) of aldicarb. The toxicity of aldicarb to adult males was significantly lowered by E2 and T whereby the mortality percentage was reduced to 23.3 +/- 5.8% and 3.3 +/- 5.8%, respectively, compared to the fish not receiving steroids (46.7 +/- 5.8% mortality). In females, T caused significant reduction in aldicarb toxicity to 16.7 +/- 5.8%, while E2 significantly enhanced the toxicity to 96.7 +/- 5.8% mortality. Since the flavin-containing monooxygenase (FMO) enzyme system had been shown to play a critical role in aldicarb toxicity, the effect of E2 and T on FMO expression was examined. Gill FMO activity showed a direct correlation with the overall toxicity of aldicarb in both male and female medaka. Expression of FMO1-like protein was significantly reduced by T in male livers and gills, and T did not affect the expression of FMOs in female tissues. In contrast, E2 significantly reduced FMO1-like protein expression in male gills and female livers, as well as FMO3 expression in both male and female livers, but significantly increased gill FMO1 expression in females. Since aldicarb acts by inhibiting the enzyme cholinesterase (ChE), the effect of sex hormones on the activity of this enzyme was also examined. In both male and female medaka, T counteracted the inhibitory effect of aldicarb on muscle ChE. In male fish, E2 had similar effects but did not seem to counteract the ChE inhibition in females. In conclusion, E2 and T modulation of aldicarb toxicity in Japanese medaka seems to be mediated via alteration of gill FMO and ChE actitivies. PMID:12151634

  2. Transformation of 17beta-estradiol mediated by lignin peroxidase: the role of veratryl alcohol.

    PubMed

    Mao, Liang; Lu, Junhe; Gao, Shixiang; Huang, Qingguo

    2010-07-01

    Lignin peroxidases (LiPs) are a group of extracellular enzymes excreted by certain fungi, e.g., Phanerochaete chrysosporium. These fungi also produce veratryl alcohol (VA) as a secondary metabolite to regulate the performance of LiP. 17ss-Estradiol (E2) is a natural female hormone that is strongly endocrine disruptive when released to the natural environment. The widespread occurrence of E2 and related hormonal chemicals in soil and water environments has been identified, representing an emerging contamination of concern. We report in this study that E2 can be effectively transformed and removed through reactions mediated by LiP and such reactions are significantly enhanced in the presence of VA. We systematically investigated LiP activity and enzymatic reaction kinetics in systems having VA absent or present. The results suggest that VA enhanced the transformation and removal of E2 by the combination of two effects: (i) mitigating LiP inactivation and (ii) modifying the enzyme catalytic kinetics. These findings provide insights into an important pathway that may govern the environmental transformation of E2 and other emerging endocrine-disrupting contaminants of similar nature in the environment, and provide a basis for potential development and optimization of enzyme-based processes for remediation and removal of these contaminants. PMID:20035325

  3. 17Beta-estradiol expands IgA-producing B cells in mice deficient for the mu chain.

    PubMed

    Lagerquist, M K; Erlandsson, M C; Islander, U; Svensson, L; Holmdahl, R; Carlsten, H

    2008-01-01

    Oestrogen is not only a sex hormone but also an important regulator of the immune system. Expression of the heavy chain of IgM (mu) is essential for B-cell differentiation. However, a small number of IgA-positive B cells can be found in mice lacking the mu chain (muMT-/-). The aim of this study was to investigate the effects of oestrogen on this alternative B-cell pathway in muMT-/- mice. Our results clearly demonstrate that oestrogen increases the frequency of IgA-producing B cells in muMT-/- mice in both bone marrow and spleen cells. We also show that mature IgM-producing B cells are not required for oestrogen-mediated suppression of granulocyte-mediated inflammation or thymic involution. In conclusion, we demonstrate that 17beta-estradiol benzoate increases the frequency of IgA-producing B cells in muMT-/- mice, suggesting that oestrogen can influence the alternative B-cell pathway found in muMT-/- mice. PMID:18021189

  4. Stimulation of catecholamine synthesis through unique estrogen receptors in the bovine adrenomedullary plasma membrane by 17{beta}-estradiol

    SciTech Connect

    Yanagihara, Nobuyuki . E-mail: yanagin@med.uoeh-u.ac.jp; Liu, Minhui; Toyohira, Yumiko; Tsutsui, Masato; Ueno, Susumu; Shinohara, Yuko; Takahashi, Kojiro; Tanaka, Kazumi

    2006-01-13

    Incubation of cultured bovine adrenal medullary cells with 17{beta}-estradiol (E{sub 2}) (0.3-100 nM) or membrane-impermeable E{sub 2}-bovine serum albumin (100 nM) acutely increased {sup 14}C-catecholamine synthesis from [{sup 14}C]tyrosine. The stimulatory effect of E{sub 2} was not inhibited by ICI182,780, a nuclear estrogen receptor inhibitor. E{sub 2} also increased tyrosine hydroxylase activity and p44/42MAPK phosphorylation, the former of which was attenuated by U0126, an inhibitor of p44/42MAPK kinase. The plasma membrane isolated from the gland showed two classes of specific binding sites of [{sup 3}H]E{sub 2} with apparent K {sub d}s of 3.2 and 106 nM, and B {sub max}s of 0.44 and 8.5 pmol/mg protein, respectively. The high-affinity binding of [{sup 3}H]E{sub 2} was most strongly inhibited by E{sub 2} and phytoestrogens, and to lesser extents by other steroid hormones, while it was enhanced by ICI182,780 and environmental estrogenic pollutants. These findings suggest that E{sub 2} acutely stimulates catecholamine synthesis via activation of p44/42MAPK through unique estrogen receptors in the plasma membrane of bovine adrenal medulla.

  5. Maternally derived testosterone and 17beta-estradiol in the eggs of Arctic-breeding glaucous gulls in relation to persistent organic pollutants.

    PubMed

    Verboven, Nanette; Verreault, Jonathan; Letcher, Robert J; Gabrielsen, Geir W; Evans, Neil P

    2008-08-01

    It is largely unknown if and how persistent organic pollutants (POPs) affect the transfer of maternal hormones to eggs. This occurs despite an increasing number of studies relating environmental conditions experienced by female birds at the time of egg formation to maternal hormonal effects. Here we report the concentrations of maternal testosterone, 17beta-estradiol and major classes of POPs (organochlorines, brominated flame retardants and metabolically-derived products) in the yolk of unincubated, third-laid eggs of the glaucous gull (Larus hyperboreus), a top-predator in the Arctic marine environment. Controlled for seasonal and local variation, positive correlations were found between the concentrations of certain POPs and testosterone. Contaminant-related changes in the relative concentrations of testosterone and 17beta-estradiol were also observed. In addition, yolk steroid concentrations were associated with contaminant profiles describing the proportions of different POPs present in the yolk. Eggs from nests in which two sibling eggs hatched or failed to hatch differed in POP profiles and in the relative concentrations of testosterone and 17beta-estradiol. Although the results of this correlative study need to be interpreted with caution, they suggest that contaminant-related changes in yolk steroids may occur, possibly affecting offspring performance over and above toxic effects brought about by POPs in eggs. PMID:18550446

  6. Affinity chromatography of human estrogen receptor-alpha expressed in Saccharomyces cerevisiae. Combination of heparin- and 17beta-estradiol-affinity chromatography.

    PubMed

    Feng, W; Graumann, K; Hahn, R; Jungbauer, A

    1999-08-01

    Estrogen receptor-alpha is a member of the nuclear hormone receptor superfamily and is considered as a very important regulatory protein. Human estrogen receptor-alpha has been cloned into Saccharomyces cerevisiae as a fusion to ubiquitin and expression is controlled by a metallothionin promotor. Pilot scale quantities of receptor have been produced by a yeast strain transformed with expression plasmid YEpE13 [Graumann et al., J. Steroid Biochem. Mol. Biol. 57 (1996) 293] in a 14 l stirred tank reactor. The yeast extract contained 2-4 pmol of receptor protein per mg total protein. A purification scheme has been developed using heparin-affinity chromatography combined with affinity chromatography with immobilized 17beta-estradiol 17-hemisuccinate. Heparin-affinity chromatography was very efficient to remove host cell protein. Accompanying proteins that stabilize unoccupied receptor have not been dissociated during elution. The receptor could be purified 5-10-fold in ligand-free state. In contrast to previous reports, we did not find a difference of the binding affinity of liganded and unliganded receptor for heparin immobilized onto Sepharose. The unoccupied receptor could be further purified 100-fold with ligand-affinity chromatography using 17beta-estradiol 17-hemisuccinate-bovine serum albumin-Sepharose. The receptor could be kept in its native state, although saturated with 17beta-estradiol. The purification sequence allows an efficient production of receptor. Further improvement of productivity can be only accomplished by increasing the expression level. PMID:10480241

  7. Influence of 17beta-estradiol and insulin on type II collagen and protein synthesis of articular chondrocytes.

    PubMed

    Claassen, Horst; Schlter, Matthias; Schnke, Michael; Kurz, Bodo

    2006-08-01

    Clinical observations have suggested a relationship between osteoarthritis and a changed estrogen metabolism in menopausal women. Type II collagen is one main structural protein of articular cartilage matrix and its synthesis is increased by insulin in growth plate cartilage. Therefore, it was investigated if [(3)H]-proline incorporation and type II collagen synthesis (immunocytochemistry, ELISA) in female bovine articular chondrocytes are affected by 17beta-estradiol and/or insulin. Articular chondrocytes were cultured in monolayers at 5% O(2) in medium containing serum for 5-9 days, followed by application of 10(-13) to 10(-9) M estradiol or 5 microg/ml insulin during a serum-free culture phase of 2-3 days. Immunostaining for type II collagen was strong in the serum-free culture phase whereas it was negative for type I collagen, indicating that cells did not dedifferentiate to fibroblast-like cells during culture in serum-free medium. Whereas insulin raised the proline incorporation and the type II collagen synthesis significantly, physiological doses of estradiol did not show significant effects. The stimulating effect of insulin on the [(3)H]-proline incorporation or the type II collagen synthesis was significantly suppressed after preincubation of cells with 10(-11) to 10(-9) M estradiol resembling an unfavorable effect for articular cartilage. The suppression was reversed if cells were incubated with 10(-11) to 10(-7) M tamoxifen or ICI 182,780 combined with 10(-11) or 10(-9) M estradiol followed by incubation with 5 microg/ml insulin, indicating an estrogen receptor-mediated process. Because the articular cartilage of diabetic patients is biomechanically less stable, further experiments are needed to clarify the role of estradiol and insulin in the metabolism of articular chondrocytes. PMID:16631425

  8. Cosupplementation of isoflavones, prenylflavonoids, and lignans alters human exposure to phytoestrogen-derived 17beta-estradiol equivalents.

    PubMed

    Bolca, Selin; Wyns, Ciska; Possemiers, Sam; Depypere, Herman; De Keukeleire, Denis; Bracke, Marc; Verstraete, Willy; Heyerick, Arne

    2009-12-01

    The microbial metabolism of dietary phytoestrogens varies considerably among individuals and influences the final exposure to bioactive compounds. In view of the increasing number of food supplements combining several classes of phytoestrogens, the microbial potential to activate various proestrogens within an individual was evaluated in 3 randomized dietary crossovers. Treatment allocation was based on participants' eligibility (>45% in vitro bioactivation of >or=2 separate proestrogens by fecal cultures; n = 40/100). After a run-in of >or=4 d, participants were given soy-, hop-, and/or flax-based food supplements dosed either separately (SOY: 2.83 mg daidzein aglycone equivalents/supplement, HOP: 1.20 mg isoxanthohumol (IX)/supplement, or FLAX: 2.08 mg secoisolariciresinol (SECO) aglycone equivalents/supplement; reference intervention) or simultaneously (MIX; test intervention) 3 times/d for 5 d, followed by a wash-out period (>or=7 d) and the second intervention. Before and after each (co)supplementation, spot urine and serum were collected. In total, 22 equol, 19 8-prenylnaringenin (8-PN), and 21 enterolactone (ENL) producers completed the SOY+MIX, HOP+MIX, and FLAX+MIX trials, respectively. The microbial bioactivation of daidzein, IX, and SECO, generally decreased upon coincubation in vitro (equol: 4.4%, P = 0.164; 8-PN: 20.5%, P < 0.001; ENL: 44.3%, P < 0.001) and cosupplementation in vivo (equol: 28.3%, P = 0.009; 8-PN: 35.4%, P = 0.107; ENL: 35.9%, P = 0.003). Although the bioavailabilities of total isoflavones, prenylflavonoids, and lignans were not significantly affected upon coadministration, participants were exposed to lower phytoestrogen-derived 17beta-estradiol equivalents. In conclusion, the bioavailability of phytoestrogens, especially when given in mixtures, is subject to high interindividual variation. These findings support the importance of personalized screening when assessing the efficacy of such products and mixtures. PMID:19864398

  9. Effects of 17 beta-estradiol and medroxyprogesterone acetate upon MtTW15 mammosomatotropic pituitary tumor growth and hormone production in male and female rats.

    PubMed

    Winneker, R C; Parsons, J A

    1981-05-01

    The purpose of this study was to characterize the effects of two functionally diverse steroids, 17 beta-estradiol and medroxyprogesterone acetate (MPA), on MtTW15 rat mammosomatotropic pituitary tumor growth and hormone production. Steroid responsiveness, as well as the hormonally autonomous nature of the tumor, was studied by treating both male and female tumor-bearing rats for 7 weeks with weekly injections of either 17 beta-estradiol (600 ng/g body weight/week) or MPA (200 microgram/g body weight/week) and, subsequently, comparing both the tumor weights and the in vivo production of growth hormone (GH) and prolactin (PRL) among the treatment groups. Large tumors (6 to 20 gm) were obtained in all treatment groups, indicating hormonal autonomy; however, tumors were markedly smaller, on the average, in untreated males an ovariectomized females. Treatment of such rats with 17 beta-estradiol stimulated tumor growth. Radioimmunoassay of tumor and serum GH and PRL levels in all treatment groups indicated the following: (a) tumors from untreated male or female hosts did not favor the production of one hormone over the other to any great extent; (b) MPA, however, promoted significant increases (p less than 0.05) in GH production in both male and female tumor-bearing rats while having little effect on the production of PRL; and (c) 17 beta-estradiol significantly inhibited (p less than 0.05) GH production and promoted PRL production by tumors borne by either sex. Selected studies utilizing multiple doses of MPA (1 to 500 microgram per gm body weight per week) and 17 beta-estradiol (10 to 800 ng per gm body weight per week) were accomplished and demonstrated that hormone production can be influenced in a dose-related manner. These results indicated that the estrogen-induced MtTW15 rat pituitary tumor is hormonally autonomous, yet divergently responsive to two different classes of steroidal compounds, thus making this tumor line an appropriate model for the study of hormonally responsive pituitary tumor cells. PMID:7214344

  10. Regulation of preprosomatostatin 1 (PSS1) gene expression by 17beta-estradiol and identification of the PSS1 promoter region in orange-spotted grouper (Epinephelus coioides).

    PubMed

    Zhang, Li; Li, Wensheng; Hong, Xun; Lin, Haoran

    2009-11-13

    In the present paper the effects of 17beta-estradiol on the expression of the preprosomatostatin 1 (PSS1) in the orange-spotted grouper hypothalamus and ovary were investigated. Results from in vivo of intraperitoneal injection and in vitro static cultures showed that estradiol increased the mRNA expression of PSS1 gene in both hypothalamus and ovary. To investigate the molecular basis of the estrogen regulation on PSS1 gene expression, we cloned the upstream region of 848bp from the translation initiation codon of the grouper PSS1 gene. The TATA-box and putative transcription factor binding sites were identified using computer analysis. Transient transfections with promoter-luciferase reporter constructs together with hER expression vector were carried out in MCF-7 cell line. The results suggest that the region from -848 to -373bp, containing five putative ERE half sites, may contribute to the promoter activity induced by estradiol. These results represent the first demonstration at the molecular level of the regulation of PSS1 gene by 17beta-estradiol in fish. PMID:19559750

  11. 17Beta-estradiol protects against oxidative stress-induced cell death through the glutathione/glutaredoxin-dependent redox regulation of Akt in myocardiac H9c2 cells.

    PubMed

    Urata, Yoshishige; Ihara, Yoshito; Murata, Hiroaki; Goto, Shinji; Koji, Takehiko; Yodoi, Junji; Inoue, Satoshi; Kondo, Takahito

    2006-05-12

    The GSH/glutaredoxin (GRX) system is involved in the redox regulation of certain enzyme activities, and this system protects cells from H2O2-induced apoptosis by regulating the redox state of Akt (Murata, H., Ihara, Y., Nakamura, H., Yodoi, J., Sumikawa, K., and Kondo, T. (2003) J. Biol. Chem. 278, 50226-50233). Estrogens, such as 17beta-estradiol (E2), play an important role in development, growth, and differentiation and appear to have protective effects on oxidative stress mediated by estrogen receptor alpha (ERalpha). However, the role of the ERbeta-mediated pathway in this cytoprotection and the involvement of E2 in the redox regulation are not well understood. In the present study, we demonstrated that E2 protected cardiac H9c2 cells, expressing ERbeta from H2O2-induced apoptosis concomitant with an increase in the activity of Akt. E2 induced the expression of glutaredoxin (GRX) as well as gamma-glutamylcysteine synthetase, a rate-limiting enzyme for the synthesis of GSH. Inhibitors for both gamma-glutamylcysteine synthetase and GRX and ICI182,780, a specific inhibitor of ERs, abolished the protective effect of E2 on cell survival as well as the activity of Akt, suggesting that ERbeta is involved in the cytoprotection and redox regulation by E2. Transcription of the GRX gene was enhanced by E2. The promoter activity of GRX was up-regulated by an ERbeta-dependent element. These results suggest that the GRX/GSH system is involved in the cytoprotective and genomic effects of E2 on the redox state of Akt, a pathway that is mediated, at least in part, by ERbeta. This mechanism may also play an antiapoptotic role in cancer cells during carcinogenesis or chemotherapy. PMID:16549430

  12. Up-regulation of PI3K/Akt signaling by 17{beta}-estradiol through activation of estrogen receptor-{alpha}, but not estrogen receptor-{beta}, and stimulates cell growth in breast cancer cells

    SciTech Connect

    Lee, Young-Rae; Park, Jinny; Kim, Jong-Suk; Youn, Hyun Jo; Jung, Sung Hoo . E-mail: shjung@chonbuk.ac.kr

    2005-11-04

    Estrogen stimulates cell proliferation in breast cancer. The biological effects of estrogen are mediated through two intracellular receptors, estrogen receptor-{alpha} (ER{alpha}) and estrogen receptor-{beta} (ER{beta}). However, the role of ERs in the proliferative action of estrogen is not well established. Recently, it has been known that ER activates phosphatidylinositol-3-OH kinase (PI3K) through binding with the p85 regulatory subunit of PI3K. Therefore, possible mechanisms may include ER-mediated phosphoinositide metabolism with subsequent formation of phosphatidylinositol-3,4,5-trisphosphate (PIP{sub 3}), which is generated from phosphatidylinositol 4,5-bisphosphate via PI3K activation. The present study demonstrates that 17{beta}-estradiol (E2) up-regulates PI3K in an ER{alpha}-dependent manner, but not ER{beta}, and stimulates cell growth in breast cancer cells. In order to study this phenomenon, we have treated ER{alpha}-positive MCF-7 cells and ER{alpha}-negative MDA-MB-231 cells with 10 nM E2. Treatment of MCF-7 cells with E2 resulted in a marked increase in PI3K (p85) expression, which paralleled an increase in phospho-Akt (Ser-473) and PIP{sub 3} level. These observations also correlated with an increased activity to E2-induced cell proliferation. However, these effects of E2 on breast cancer cells were not observed in the MDA-MB-231 cell line, indicating that the E2-mediated up-regulation of PI3K/Akt pathway is ER{alpha}-dependent. These results suggest that estrogen activates PI3K/Akt signaling through ER{alpha}-dependent mechanism in MCF-7 cells.

  13. [Percentage of plasma protein-bound and free 17-beta-estradiol, progesterone and testosterone during the sexual cycle and during pregnancy in cows].

    PubMed

    Kunchev, L

    1977-01-01

    Examined were 12 cows with normal sexual cycle and other 12 cows in the last 20 days of pregnancy, all animals belonging to the Black-Pied breed. It was found that plasma protein bound 17-beta estradiol, progesteron, and testosteron during the sexual cycle were 94.726 +/- 0.076, 94-500 +/- 0.125 and 94.122 +/- 0.066 per cent, respectively. In the last twenty days of pregnancy these values rose - 96.911 +/- 0.058, 96.124 +/- 0.074, and 96.040 +/- 0.115, respectively. In testing the binding capacity of the bovine serum albumin it was found that it fixed almost 100 per cent the three ovarial hormones, while the bovine alpha, beta- and gamma-globulin's capacity in this respect was expressed in a negligible percent. PMID:75605

  14. Cytochrome P450 inhibition profile in liver of veal calves administered a combination of 17beta-estradiol, clenbuterol, and dexamethasone for growth-promoting purposes.

    PubMed

    Cantiello, Michela; Carletti, Monica; Dacasto, Mauro; Martin, Pascal G P; Pineau, Thierry; Capolongo, Francesca; Gardini, Giulia; Nebbia, Carlo

    2008-08-01

    The effects of the administration of a combination of 17beta-estradiol (10mg i.m. for three times at 17 days intervals), dexamethasone (4 mg/day for 6 days and 5mg/day for further 6 days, dissolved in milk), and clenbuterol (20 microg/kg b.w./day, dissolved in milk, for the last 40 days before slaughtering) for growth-promoting (GP) purposes on liver drug metabolising capacity were studied in crossbred Friesian male calves. Compared to controls, liver preparations from GP-treated calves showed an overall reduction in the extent of the in vitro ability to metabolize testosterone and a number of substrates, most notably those associated with CYP 2C or CYP 3A, which also displayed a reduced expression on western blotting. By contrast, the tested hydrolytic and conjugative pathways were not significantly affected. As measured by northern blot, the lack of significant differences in CYP mRNA abundance point to a post-transcriptional effect of the GP combination. The remarkable involvement of the affected hepatic CYPs in the biotransformation of both steroid hormones and a large array of commonly used drugs may result in the further accumulation of undesirable residues in meat and offals of illegally treated calves. PMID:18602204

  15. Alterations in the subcellular distribution of 17 beta-estradiol dehydrogenase in porcine endometrial cells over the course of the estrous cycle.

    PubMed

    Husen, B; Adamski, J; Szendro, P I; Jungblut, P W

    1994-11-01

    The uteri of German landrace gilts slaughtered at different days of the cycle were processed for immunocytochemistry and biochemical analyses. Plasma was collected for hormone assays. The monoclonal antibody F1 against the structure-bound 17 beta-estradiol dehydrogenase of porcine endometrial epithelium was applied to rehydrated paraffin sections either as a direct, peroxidase-linked probe or in combination with a fluorescing secondary antibody. The oxidation of estradiol was measured in homogenates of tissue powdered in liquid nitrogen. Immunoreactivity was restricted to endometrial epithelium. In the glandular epithelium, faint dots of fluorescence became visible at day 4, which apparently coalesced to spherical structures of 2-4 microns diameter at the cell basis between days 11 through 17 before disappearing by day 18. A similar distribution was observed for the oxidation products of diaminobenzidine beginning with a faint uniform staining and followed by the appearance of intensely stained basal bodies persisting until day 17. Essentially the same time course was seen in the luminal epithelium but with a different distribution. Immunoreactive material amassed in the apical region of the cells, but the conspicuous aggregations were absent. Time course and intensities of the immunological responses are matched by the enzymatic activity measured in parallel. Both correlate with the plasma progesterone levels, suggesting an induction of the enzyme by the hormone. An involvement of the cytoskeleton in the sequence of subcellular distribution patterns is discussed. PMID:8001078

  16. Rainfall and tillage effects on transport of fecal bacteria and sex hormones 17beta-estradiol and testosterone from broiler litter applications to a Georgia Piedmont Ultisol.

    PubMed

    Jenkins, Michael B; Truman, Clint C; Siragusa, Gregory; Line, Eric; Bailey, J Stan; Frye, Jonathan; Endale, Dinku M; Franklin, Dorcas H; Schomberg, Harry H; Fisher, Dwight S; Sharpe, Ronald R

    2008-09-15

    Poultry litter provides nutrients for crop and pasture production; however, it also contains fecal bacteria, sex hormones (17beta-estradiol and testosterone) and antibiotic residues that may contaminate surface waters. Our objective was to quantify transport of fecal bacteria, estradiol, testosterone and antibiotic residues from a Cecil sandy loam managed since 1991 under no-till (NT) and conventional tillage (CT) to which either poultry litter (PL) or conventional fertilizer (CF) was applied based on the nitrogen needs of corn (Zea mays L) in the Southern Piedmont of NE Georgia. Simulated rainfall was applied for 60 min to 2 by 3-m field plots at a constant rate in 2004 and variable rate in 2005. Runoff was continuously measured and subsamples taken for determining flow-weighted concentrations of fecal bacteria, hormones, and antibiotic residues. Neither Salmonella, nor Campylobacter, nor antimicrobial residues were detected in litter, soil, or runoff. Differences in soil concentrations of fecal bacteria before and after rainfall simulations were observed only for Escherichia coli in the constant rainfall intensity experiment. Differences in flow-weighted concentrations were observed only for testosterone in both constant and variable intensity rainfall experiments, and were greatest for treatments that received poultry litter. Total loads of E. coli and fecal enterococci, were largest for both tillage treatments receiving poultry litter for the variable rainfall intensity. Load of testosterone was greatest for no-till plots receiving poultry litter under variable rainfall intensity. Poultry litter application rates commensurate for corn appeared to enhance only soil concentrations of E. coli, and runoff concentrations of testosterone above background levels. PMID:18571694

  17. Beneficial effect of 17{beta}-estradiol on hyperglycemia and islet {beta}-cell functions in a streptozotocin-induced diabetic rat model

    SciTech Connect

    Yamabe, Noriko; Kang, Ki Sung; Zhu Baoting

    2010-11-15

    The modulating effect of estrogen on glucose homeostasis remains a controversial issue at present. In this study, we sought to determine the beneficial effect of 17{beta}-estradiol (E{sub 2}) on hyperglycemia and islet {beta}-cell functions in streptozotocin (STZ)-induced diabetic rats. Male Sprague-Dawley rats were injected i.p. with STZ to induce a relatively mild diabetic condition. The rats were then treated with E{sub 2} orally at 500 {mu}g/kg body weight/day for 15 days to evaluate the modulating effect on hyperglycemia, insulin secretion, and islet {beta}-cell proliferation. E{sub 2} administration for 10 days significantly lowered plasma glucose levels, increased plasma insulin levels, and improved glucose tolerance by attenuating insulin response to oral glucose loading. These beneficial effects of E{sub 2} were accompanied by increases in islet number and volume, rate of islet cell proliferation, and the amount of insulin secreted. The growth-stimulatory effect of E{sub 2} on islet cells was linked to the functions of the estrogen receptor {alpha}. Notably, these protective effects of E{sub 2} on diabetic conditions were basically not observed when the STZ-treated rats had a more severe degree of islet damage and hyperglycemia. Taken together, we conclude that E{sub 2} can promote the regeneration of damaged pancreatic islets by stimulating {beta}-cell proliferation in diabetic rats, and this effect is accompanied by improvements in glucose tolerance and a decrease in plasma glucose levels. These findings suggest that oral administration of E{sub 2} may be beneficial in diabetic patients with an accelerated loss of islet {beta}-cells.

  18. Hepatic estrogen receptor and plasma 17{beta}-estradiol concentrations as biomarkers of 2,3,7,8-TCDD exposure in avian hatchlings

    SciTech Connect

    Janz, D.M.; Bellward, G.D.

    1995-12-31

    The authors have been investigating the sensitivity of various toxicologically relevant endpoints as environmental biomarkers in avian hatchlings exposed in ovo to 2,3,7,8-TCDD. Potential biomarkers included various endocrine endpoints such as plasma 17{beta}-estradiol (E{sub 2}), hepatic estrogen receptor (ER) affinities and concentrations, and plasma thyroid hormones, which were compared to hepatic ethoxyresorufin O-deethylase (EROD) induction. The animal models used were domestic chickens and pigeons, and great blue herons. An experiment conducted in pigeon hatchlings compared ``early`` (embryonic day 4; E4) vs. ``late`` (E14) in ovo exposure to 1 {micro}g/kg and 3 {micro}g/kg of TCDD, respectively. Birds were sacrificed on day of hatch (H) and day 7 after hatch (D7). In the late exposure experiment, plasma E{sub 2} concentrations were reduced at H and elevated at D7 in the TCDD-exposed birds (p < 0.05). Hepatic ER concentrations were elevated at H (p < 0.01). Although EROD was half-maximally induced at H and D7 in the early exposure experiment in pigeons, there was no effect of TCDD treatment on E, or ER levels. The nominal TCDD concentration in these pigeons (1 {micro}g/kg egg) was within the range observed in wild piscivorous bird eggs collected from aquatic systems contaminated with TCDD and related chemicals (approx. 0.5--2 ng TEQ/g egg). In herons exposed to 2 {micro}g/kg of TCDD at the midpoint of incubation, hepatic ER affinities (Kd) and concentrations (Bmax) were elevated in treated birds at H (p < 0.05); however there was no effect on plasma E, levels. Liver [{sup 3}H]-TCDD concentrations were 11.3 {+-} 0.8 ng/g at H, and 0.8 {+-} 0.1 ng/g at D7, representing 9.9% and 4.9% of the nominal TCDD dose, respectively.

  19. Long-term dysregulation of circadian and 17-beta estradiol-induced LH, prolactin and corticosterone secretion after dimethylbenz (a) anthracene administration in the Sprague-Dawley female rat.

    PubMed

    Yon de Jonage-Canonico, M Beau; Lenoir, V; Scholler, R; Kerdelhué, B

    2005-07-01

    A single intragastric administration of 7,12-dimethylbenz (a) anthracene (DMBA) has been shown, when given at 55-60 days of age, to induce mammary tumors in young cycling female Sprague-Dawley rats. The appearance of the tumors is preceded by a series of neuroendocrine disturbances of the hypothalamo-pituitary-gonadal (HPG) axis, including attenuation of the preovulatory Luteinizing Hormone (LH) and Gonadotropin-Releasing Hormone (GnRH) release and amplification of the preovulatory 17beta-Estradiol (E(2)) surge. In this study, we examined the hypothesis that a single administration of DMBA could also, in the long range, induce disturbances of others neuroendocrine axis, like the Hypothalamic-Pituitary-Adrenal (HPA) axis and/or the Lactotroph axis. Sprague-Dawley rats, 55-60 days of age, received, on the day of Estrous of the Estrous cycle, a single administration of 15 mg of DMBA delivered by intragastric intubation. Then, they were ovariectomized 5 days later. One month later, (1) Two groups of animal were sacrificed by decapitation at 09:00 a.m. and 05:00 p.m. to record the circadian rhythm of plasma LH, Prolactin (PRL) and corticosterone, (2) Three other groups of animal were sacrificed by decapitation at three different times after a morning subcutaneous administration of 50 microg/kg of Estradiol Benzoate (EB), to induce a negative and positive feed-back of the secretion of LH. Then, plasma LH, PRL and corticosterone concentrations were measured. After DMBA administration, (1) the negative--but not the positive--LH feed-back was seen, (2) the PRL circadian rhythm was blunted and the corticosterone circadian rhythm was almost absent, (3) the increase in PRL or Corticosterone plasma concentration was significantly reduced. In conclusion, a single administration of DMBA provokes a long-term dysregulation of not only the HPG axis but also of the lactotroph and HPA axis. These dysregulations, along with the already evidenced long-term inhibition of DMBA upon Melatonin secretion from the pineal gland, might accelerate the promotion of mammary tumors induced by the mammary carcinogen. PMID:15980990

  20. Effects of 17beta-estradiol and testosterone on hepatic mRNA/protein levels and catalytic activities of CYP2M1, CYP2K1, and CYP3A27 in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Buhler, D R; Miranda, C L; Henderson, M C; Yang, Y H; Lee, S J; Wang-Buhler, J L

    2000-10-15

    There is growing concern that exposure to chemicals in the environment can disrupt the endocrine systems of wildlife and humans, causing reproductive problems or other adverse effects. The expression of many cytochrome P450s (CYPs) is under hormonal control, hence, levels of these enzymes can be affected by exposure to endocrine-disrupting chemicals. Previous research has reported that treatment of fish and other animals with the estrogenic and androgenic hormones 17beta-estradiol (E2) and testosterone (T) alters the P450 content or enzyme activities in the treated animals. However, the results of many of these studies are either incomplete or in disagreement and in most cases the effect on specific P450 forms has not been determined. Therefore, to better understand the effects of gonadal hormones on the expression of P450s and their associated enzyme activities, it was of interest to undertake a comprehensive investigation of the transcriptional and translational expression of three constitutive hepatic P450s in the rainbow trout (Oncorhynchus mykiss) following hormone exposure. Accordingly, juvenile trout were injected intraperitoneally with propylene glycol vehicle and the most active estrogenic and androgenic hormones E2 (3 mg/kg) or T (3 mg/kg) on days 1, 4, 7, 13, and 15 and euthanized on day 19. After treatment with E2, hepatic microsomes showed significantly lower levels (percentage of control) in total P450 contents (52%), lauric acid hydroxylase (32%), and 6beta-progesterone hydroxylase activities (27%), [(3)H]aflatoxin-DNA binding (31%), and the protein levels of individual cytochrome P450s (CYPs) LMC1 (CYP2M1), LMC2, (CYP2K1), and LMC5 (CYP3A27) (average for three isoforms a reduction to 29% of control values) with only minor differences between sexes. Treatment with T had either no effect or resulted in small increases in total P450 in males (42%), in lauric acid hydroxylase in females (24%), and in 6beta-progesterone hydroxylase activity in males (21%). Biological variabilities among fish were high and a polymorphic or new LMC2-like form was detected at about 52 kDa in some liver microsomal samples after exposure of fish to either hormone. Female liver RNAs were analyzed through Northern blots and an average decrease of 94% in CYP2 M1, CYP2K1, and CYP3A27 mRNA levels occurred in the E2-treated trout. In livers from T-treated trout, the changes of mRNA levels of CYP2M1 and CYP3A27 were negligible, but CYP2K1 mRNA level decreased by about 60%. Additional CYP2K1 cDNA hybridizable mRNAs were seen in some fish as faint bands at about 2.8 kb for both hormone treatments. Results of this study, therefore, indicated that E2 down-regulated while T produced small but variable effects on the hepatic mRNA/protein levels of CYP2K1, CYP2M1, and CYP3A27 in juvenile rainbow trout. This study, therefore, suggests that exposure of fish and other wildlife to environmental endocrine disruptors, especially estrogen mimics, can adversely affect a number of physiological processes through mechanisms involving altered levels of expression of specific P450 isozymes. PMID:11032764

  1. Comparison of the effects of an aqueous extract of Physalis alkekengi fruits and/or various doses of 17-beta-estradiol on rat estrous cycle and uterine glucose 6-phosphate dehydrogenase activity.

    PubMed

    Vessal, M; Yazdanian, M

    1995-10-01

    Intraperitoneal injections of an aqueous extract of winter cherry fruits (Physalis alkekengi) to adult normal cycling female rats produced 100% diestrus and diminished uterine glucose 6-P dehydrogenase activity (an estrogen-induced protein) by 52%. Daily doses of 1.88, 3.75 and 7.5 micrograms 17-beta-estradiol administered intraperitoneally to adult female rats for a period of 6-8 days prolonged proestrus or estrus and increased uterine glucose 6-P dehydrogenase activity by 11.5%, 26.9% and 82.1%, respectively. Combined intraperitoneal injections of a given dose of the aqueous extract together with the above doses of 17-beta-estradiol for 8 consecutive days shortened the time spent in diestrus proportional to the dose employed and proportionately reduced the uterine glucose 6-P dehydrogenase inhibitory power of the aqueous extract (1.88 micrograms estradiol, 33.9% inhibition; 3.75 micrograms estradiol, 27% inhibition; and 7.5 micrograms estradiol, 6.0% activation). The data obtained clearly demonstrate the presence of an estrogen antagonist in the aqueous extract of Physalis alkekengi fruits. PMID:8788592

  2. Environmental Technology Verification Report for Abraxis 17?-Estradiol (E2) Magnetic Particle Enzyme-Linked Immunosorbent Assay (ELISA) Test Kits

    EPA Science Inventory

    The EPA's National Risk Management Research Laboratory (NRMRL) and its verification organization partner, Battelle, operate the Advanced Monitoring Systems (AMS) Center under ETV. The AMS Center recently evaluated the performance of the Abraxis 17(beta)-estradiol (E2) magnetic p...

  3. Divergent effects of 17-{beta}-estradiol on human vascular smooth muscle and endothelial cell function diminishes TNF-{alpha}-induced neointima formation

    SciTech Connect

    Nintasen, Rungrat; Multidisciplinary Cardiovascular Research Center , University of Leeds, Leeds LS2 9JT; Department of Tropical Pathology, Faculty of Tropical Medicine, Mahidol University ; Riches, Kirsten; Mughal, Romana S.; Multidisciplinary Cardiovascular Research Center , University of Leeds, Leeds LS2 9JT ; Viriyavejakul, Parnpen; Chaisri, Urai; Maneerat, Yaowapa; Turner, Neil A.; Multidisciplinary Cardiovascular Research Center , University of Leeds, Leeds LS2 9JT ; Porter, Karen E.

    2012-04-20

    Highlights: Black-Right-Pointing-Pointer TNF-{alpha} augments neointimal hyperplasia in human saphenous vein. Black-Right-Pointing-Pointer TNF-{alpha} induces detrimental effects on endothelial and smooth muscle cell function. Black-Right-Pointing-Pointer Estradiol exerts modulatory effects on TNF-induced vascular cell functions. Black-Right-Pointing-Pointer The modulatory effects of estradiol are discriminatory and cell-type specific. -- Abstract: Coronary heart disease (CHD) is a condition characterized by increased levels of proinflammatory cytokines, including tumor necrosis factor-{alpha} (TNF-{alpha}). TNF-{alpha} can induce vascular endothelial cell (EC) and smooth muscle cell (SMC) dysfunction, central events in development of neointimal lesions. The reduced incidence of CHD in young women is believed to be due to the protective effects of estradiol (E2). We therefore investigated the effects of TNF-{alpha} on human neointima formation and SMC/EC functions and any modulatory effects of E2. Saphenous vein (SV) segments were cultured in the presence of TNF-{alpha} (10 ng/ml), E2 (2.5 nM) or both in combination. Neointimal thickening was augmented by incubation with TNF-{alpha}, an effect that was abolished by co-culture with E2. TNF-{alpha} increased SV-SMC proliferation in a concentration-dependent manner that was optimal at 10 ng/ml (1.5-fold increase), and abolished by E2 at all concentrations studied (1-50 nM). Surprisingly, E2 itself at low concentrations (1 and 5 nM) stimulated SV-SMC proliferation to a level comparable to that of TNF-{alpha} alone. SV-EC migration was significantly impaired by TNF-{alpha} (42% of control), and co-culture with E2 partially restored the ability of SV-EC to migrate and repair the wound. In contrast, TNF-{alpha} increased SV-SMC migration by 1.7-fold, an effect that was completely reversed by co-incubation with E2. Finally, TNF-{alpha} potently induced ICAM-1 and VCAM-1 expression in both SV-EC and SV-SMC. However there was no modulation by E2 in either cell-type. In conclusion, TNF-{alpha} induced SV neointima formation, increased SMC proliferation and migration, impaired SV-EC migration and increased expression of adhesion molecules. E2 exerted distinct cell-type and function-specific modulation, the mechanisms underlying which are worthy of further detailed study.

  4. An inter-laboratory study on the variability in measured concentrations of 17Beta-estradiol, testosterone and 11-ketotestosterone in white sucker: implications and recommendations

    EPA Science Inventory

    Endocrine-disrupting chemicals (EDCs) are exogenous substances that can lead to impacts on the reproduction of fish sometimes by altering circulating concentrations of 17â-estradiol (E2), testosterone (T) and 11-ketotestosterone (11-KT). Common methods to measure steroids in pla...

  5. An inter-laboratory study on the variability in measured concentrations of 17Beta-estradiol, testosterone and 11-ketotestosterone in white sucker: implications and recommendations

    EPA Science Inventory

    Endocrine-disrupting chemicals (EDCs) are exogenous substances that can lead to impacts on the reproduction of fish sometimes by altering circulating concentrations of 17-estradiol (E2), testosterone (T) and 11-ketotestosterone (11-KT). Common methods to measure steroids in pla...

  6. FoxM1 influences embryo implantation and is regulated by 17 beta-estradiol and progesterone in mouse uteri and endometrium cells

    PubMed Central

    Xie, Yunpeng; Cui, Dan; Kong, Ying

    2014-01-01

    To be a successful implantation, endometrial receptivity should be established. Forkhead box M1 (FoxM1) is described as a major oncogenic transcription factor in tumor initiation, promotion, and progression. FoxM1 regulates the expression of lots of targeted genes important to cell differentiation, proliferation and apoptosis; cell-cycle progression; and tumor angiogenesis, migration, invasion, and metastasis. According to these functions, we believe that FoxM1 should also play an essential role in embryo implantation. To test our hypothesis, we observed the expression and distribution of FoxM1 during the early pregnancy of mouse. Then, we used Immunohistochemistry to examine the expression of FoxM1 induced by E2 and/or P4 in the ovariectomized mouse uterus and human endometrium cells. This study further investigated whether FoxM1 was an important factor in the implantation. Our results showed that FoxM1 expressed in the mouse uterus during early pregnancy (Day 1 to 5). The expression of FoxM1 gradually increased along pregnancy process; FoxM1 expression could be increased by E2. On the contrary, FoxM1 expression could be decreased by P4 and E2 plus P4. We also detected the proliferation of human endometrium cells. We found that E2 might promote cells proliferation, while P4 and E2 plus P4 inhibited cells proliferation; Inhibiting FoxM1 could interfere the embryo implantation of mouse. Amplification or inhibiting of FoxM1 in JAR cells can increase or decrease the adhesion rate to Rl95-2 and HEC-1A cells separately. Our data indicate that FoxM1 might play an important role during the process of mouse embryo implantation. PMID:25400737

  7. FoxM1 influences embryo implantation and is regulated by 17 beta-estradiol and progesterone in mouse uteri and endometrium cells.

    PubMed

    Xie, Yunpeng; Cui, Dan; Kong, Ying

    2014-01-01

    To be a successful implantation, endometrial receptivity should be established. Forkhead box M1 (FoxM1) is described as a major oncogenic transcription factor in tumor initiation, promotion, and progression. FoxM1 regulates the expression of lots of targeted genes important to cell differentiation, proliferation and apoptosis; cell-cycle progression; and tumor angiogenesis, migration, invasion, and metastasis. According to these functions, we believe that FoxM1 should also play an essential role in embryo implantation. To test our hypothesis, we observed the expression and distribution of FoxM1 during the early pregnancy of mouse. Then, we used Immunohistochemistry to examine the expression of FoxM1 induced by E2 and/or P4 in the ovariectomized mouse uterus and human endometrium cells. This study further investigated whether FoxM1 was an important factor in the implantation. Our results showed that FoxM1 expressed in the mouse uterus during early pregnancy (Day 1 to 5). The expression of FoxM1 gradually increased along pregnancy process; FoxM1 expression could be increased by E2. On the contrary, FoxM1 expression could be decreased by P4 and E2 plus P4. We also detected the proliferation of human endometrium cells. We found that E2 might promote cells proliferation, while P4 and E2 plus P4 inhibited cells proliferation; Inhibiting FoxM1 could interfere the embryo implantation of mouse. Amplification or inhibiting of FoxM1 in JAR cells can increase or decrease the adhesion rate to Rl95-2 and HEC-1A cells separately. Our data indicate that FoxM1 might play an important role during the process of mouse embryo implantation. PMID:25400737

  8. 17beta-estradiol induced vitellogenesis is inhibited by cortisol at the post-transcriptional level in Arctic char (Salvelinus alpinus)

    PubMed Central

    Berg, Hakan; Modig, Carina; Olsson, Per-Erik

    2004-01-01

    This study was performed to investigate stress effects on the synthesis of egg yolk precursor, vitellogenin (Vtg) in Arctic char (Salvelinus alpinus). In particular the effect of cortisol (F) was determined since this stress hormone has been suggested to interfere with vitellogenesis and is upregulated during sexual maturation in teleosts. Arctic char Vtg was purified and polyclonal antibodies were produced in order to develop tools to study regulation of vitellogenesis. The Vtg antibodies were used to develop an enzyme-linked immunosorbent assay. The corresponding Vtg cDNA was cloned from a hepatic cDNA library in order to obtain DNA probes to measure Vtg mRNA expression. Analysis of plasma from juvenile Arctic char, of both sexes, exposed to different steroids showed that production of Vtg was induced in a dose dependent fashion by 17?-estradiol (E2), estrone and estriol. Apart from estrogens a high dose of F also upregulated Vtg. In addition, F, progesterone (P) and tamoxifen were tested to determine these compounds ability to modulate E2 induced Vtg synthesis at both the mRNA and protein level. Tamoxifen was found to inhibit E2 induced Vtg mRNA and protein upregulation. P did not alter the Vtg induction while F reduced the Vtg protein levels without affecting the Vtg mRNA levels. Furthermore the inhibition of Vtg protein was found to be dose dependent. Thus, the inhibitory effect of F on Vtg appears to be mediated at the post-transcriptional level. PMID:15345061

  9. Reconnaissance of 17 beta-estradiol, 11-ketotestosterone, vitellogenin, and gonad histopathology in common carp of United States streams; potential for contaminant-induced endocrine disruption

    USGS Publications Warehouse

    Goodbred, Steven L.; Gilliom, Robert J.; Gross, Timothy S.; Denslow, Nancy P.; Bryant, Wade B.; Schoeb, Trenton R.

    1997-01-01

    A reconnaissance of sex steroid hormones and other biomarkers in common carp was used to assess whether endocrine disruption may be occurring in fish in United States streams, to evaluate relations between endocrine disruption and contaminant levels, and to determine requirements for further studies. 17?-estradiol, 11-ketotestosterone, vitellogenin, and gonadal histopathology were measured in adult carp (usually 10--15 for each sex) at 25 sites (647 fish), representing a wide range of environmental settings typical of major regions of the nation. Fish were collected during August--December 1994, a period of gonadal maturation after spawning. Contaminants evaluated were organochlorine pesticides and polychlorinated biphenyls in tissue; phthalates, phenols, and polycyclic aromatic hydrocarbons in bed sediment; and dissolved pesticides in water. Mean site concentrations of steroid hormones spanned two orders of magnitude for both sexes. No significant regional differences in steroid hormones were detected for males, but females from the Northern and Southern Midcontinent were significantly different from other regions of the country in one or both hormones. Within all regions there were significant differences between sites in one or both hormones for both sexes. Most correlation coefficients between biomarkers and contaminants were negative. Contaminants that had significant (a=0.05) correlations with biomarkers were organochlorine pesticides, phenols, and dissolved pesticides. The strongest pattern common to both males and females was a negative correlation between the hormone ratio (E2/11-KT) and dissolved pesticides. The significant site-to-site differences in biomarkers, and the presence of significant correlations between biomarkers and contaminants, are evidence that fish in some streams may be experiencing endocrine disruption. Improved information is needed to evaluate whether endocrine disruption is actually occurring and if there are reproductive effects on individual or populations of carp or other species. Future studies should shift to more intensive study of fewer sites, including reference and contaminated sites, in order to address these additional questions.

  10. Land-cover effects on the fate and transport of surface-applied antibiotics and 17-beta-estradiol on a sandy outwash plain, Anoka County, Minnesota, 2008–09

    USGS Publications Warehouse

    Trost, Jared J.; Kiesling, Richard L.; Erickson, Melinda L.; Rose, Peter J.; Elliott, Sarah M.

    2013-01-01

    A plot-scale field experiment on a sandy outwash plain in Anoka County in east-central Minnesota was used to investigate the fate and transport of two antibiotics, sulfamethazine (SMZ) and sulfamethoxazole (SMX), and a hormone, 17-beta-estradiol (17BE), in four land-cover types: bare soil, corn, hay, and prairie. The SMZ, SMX, and 17BE were applied to the surface of five plots of each land-cover type in May 2008 and again in April 2009. The cumulative application rate was 16.8 milligrams per square meter (mg/m2) for each antibiotic and 0.6 mg/m2 for 17BE. Concentrations of each chemical in plant-tissue, soil, soil-water, and groundwater samples were determined by using enzyme-linked immunosorbent assay (ELISA) kits. Soil-water and groundwater sampling events were scheduled to capture the transport of SMZ, SMX, and 17BE during two growing seasons. Soil and plant-tissue sampling events were scheduled to identify the fate of the parent chemicals of SMZ, SMX, and 17BE in these matrices after two chemical applications. Areal concentrations (mg/m2) of SMZ and SMX in soil tended to decrease in prairie plots in the 8 weeks after the second chemical application, from April 2009 to June 2009, but not in other land-cover types. During these same 8 weeks, prairie plots produced more aboveground biomass and had extracted more water from the upper 125 centimeters of the soil profile compared to all other land-cover types. Areal concentrations of SMZ and SMX in prairie plant tissue did not explain the temporal changes in areal concentrations of these chemicals in soil. The areal concentrations of SMZ and SMX in the aboveground plant tissues in June 2009 and August 2009 were much lower, generally two to three orders of magnitude, than the areal concentrations of these chemicals in soil. Pooling all treatment plot data, the median areal concentration of SMZ and SMX in plant tissues was 0.01 and 0.10 percent of the applied chemical mass compared to 22 and 12 percent in soil, respectively. Furthermore, areal concentrations of SMZ and SMX in plant-tissue samples were variable, and did not differ significantly between control and treatment plots within each land-cover type. SMZ was detected in 23 percent of soil-water samples and in 16 percent of groundwater samples collected between October 2008 and October 2009 in treatment plots, indicating that surface-applied SMZ leached below the rooting zone and reached groundwater. SMX was detected in only 1 percent of soil-water and groundwater samples during this same time period. In contrast to the antibiotics, 17BE was not reliably detected in soil samples. Additionally, ELISA-determined 17BE concentrations in plant-tissue, soil-water, and groundwater samples indicated the presence of chemicals that were not applied as part of this experiment [17BE from an external source or other chemical(s) that interfered with the 17BE ELISA kits].

  11. Water-compatible magnetic imprinted nanoparticles served as solid-phase extraction sorbents for selective determination of trace 17beta-estradiol in environmental water samples by liquid chromatography.

    PubMed

    Hao, Yi; Gao, Ruixia; Shi, Lu; Liu, Dechun; Tang, Yuhai; Guo, Zengjun

    2015-05-29

    Endocrine disrupting compounds (EDCs) are a potential risk for wildlife and humans for their existence in water. The efficient extraction and clean-up steps are required before detection of low concentration levels of EDCs. In this work, a novel water-compatible magnetic molecularly imprinted nanoparticles is synthesized for the selective extraction of 17?-estradiol (E2) in environmental water samples. The preparation is carried out by introducing aldehyde groups to the surface of amino-functionalized magnetic nanoparticles through a simple one-step modification, followed by copolymerization of functional monomer gelatin and template E2 via surface imprinting technique. The gelatin with abundant active groups could not only act as functional monomer reacting with template, but also assemble covalently at the surface of magnetic nanoparticles. At the same time, gelatin would improve the water-compatibility of imprinted materials for attaining high extraction efficiency. To obtain high imprinting effect, the preparation conditions are optimized in detail using Central composite design-response surface methodology. The resultant polymers have uniform spherical shape with a shell thickness of about 8nm, stable crystalline form, and super-paramagnetic property. Meanwhile, the obtained polymers have high capacity of 12.87mgg(-1) and satisfactory selectivity to template molecule. To testify the feasibility of the magnetic imprinted polymers in sample pretreatment, a method for determination of trace E2 in environmental water samples was set up by combination of solid-phase extraction (SPE) using the prepared polymers as sorbents and HPLC for rapid isolation and determination of E2. The limit of detection of proposed method is 0.04ngmL(-1), the intra- and inter-day relative standard deviations (RSDs) are less than 4.6% and 5.7%, respectively. The recoveries of E2 from environmental water samples are in the range from 88.3% to 99.1% with the RSDs less than 7.2%. PMID:25890441

  12. 17beta-estradiol downregulates beta3-integrin expression in differentiating and mature human osteoclasts.

    PubMed

    Saintier, D; Burde, M-A; Rey, J M; Maudelonde, T; de Vernejoul, M C; Cohen-Solal, M E

    2004-02-01

    The increased bone resorption observed after estrogen withdrawal is responsible for bone loss and may lead to osteoporosis. The mechanism by which estradiol inhibits bone resorption is known to involve decreased osteoclastogenesis, however, the effect on osteoclast adhesion remains unclear. We examined the in vitro effect of estradiol and raloxifene on human osteoclast differentiation and function. Human peripheral blood mononuclear cells were cultured with M-CSF/RANK-L for 18 days, and we evaluated bone resorption, the expression of the protein and mRNA of the integrins, c-jun and c-fos in the presence or absence of estradiol. In this human model, beta3-integrin expression increased at the mRNA and protein levels during osteoclast differentiation, whereas that of beta5-integrin did not. We found that estradiol and raloxifene directly inhibited bone resorption on bone slices by 50%, and decreased the expression of beta3-integrin mRNA (60%) and protein (20%) in a time-dependent manner. Moreover, the mRNAs of c-fos and c-jun were both diminished by estradiol and raloxifene, particularly in early osteoclasts, but also to a lesser extent in mature cells. These findings suggest that the direct inhibitory action of estradiol on bone resorption may affect human osteoclast differentiation through downregulation of c-fos and c-jun and adhesion through modulation of beta3-integrin. PMID:14603529

  13. Assessing the effects of exposure timing on biomarker expression using 17beta-estradiol

    EPA Science Inventory

    Temporal and spatial variability in estrogenicity has been documented for many treated wastewater effluents with the consequences of this variability on the expression of biomarkers of endocrine disruption being largely unknown. Laboratory exposure studies usually utilize constan...

  14. Lipocalin 2: a "sexy" adipokine that regulates 17Beta-estradiol and obesity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this article we review the findings of Guo et. al. (Endocrinology, 153: 1183-1193) that the protein, Lipocalin 2 is more highly expressed in subcutaneous adipose tissue than in gondal tissue of female mice. Of particular interest is that the paper by Guo et. al. observed that ablation of the Lip...

  15. Development of a rapid and confirmatory procedure to detect 17beta-estradiol 3-benzoate treatments in bovine hair.

    PubMed

    Regal, Patricia; Vzquez, Beatriz I; Franco, Carlos M; Cepeda, Alberto; Fente, Cristina A

    2008-12-24

    A high-performance liquid chromatography-tandem mass spectrometry method (LC-MS/MS) was developed for efficient and confirmatory surveillance of illegal use of estradiol benzoate, even when this substance is used in reproductive control. After cryogenic grinding, estradiol benzoate was extracted from hair with acetonitrile for 24 h on a rocking table. The validation of the method was based on Commission Decision 2002/657/EC using the deuterated analogue of estradiol benzoate as internal standard. Decision limit (0.81 ng/g), detection capability (1.38 ng/g), repeatability CV% (13.7), within in laboratory reproducibility CV% (15.6%), and trueness (99.3%) were calculated. Using the proposed methodology the presence of estradiol benzoate in samples obtained from animals treated to synchronize their estrous cycles can be confirmed. PMID:19090709

  16. 17Beta-estradiol induces nuclear translocation of CrkL at the window of embryo implantation.

    PubMed

    Nautiyal, Jaya; Kumar, Pradeep G; Laloraya, Malini

    2004-05-21

    Crk family adaptors are widely expressed and mediate the timely formation of signal transduction protein complexes upon a variety of extracellular stimuli, including various growth and differentiation factors. The window of implantation is the favorable time period when the uterus develops a receptive approach to the invading embryo. Various signaling cascades are likely to become active at the window of implantation both in the uterus and the embryo. This helps create maternal embryo dialogue leading to successful embryo implantation. In this study we report for the first time the presence and nuclear translocation of the adaptor molecule CrkL both in the uterine and embryonic partners at the window of implantation. We also report that estrogen, which initiates and guides crucial changes in the uterus and the embryo at the window of receptivity, causes a massive surge in the expression and subsequent nuclear translocation of CrkL. We have also identified the existence of one LXXLL motif in the CrkL amino acid sequence and a single LXD is sufficient for activation by the estrogen receptor. This is suggestive that CrkL can bind to estrogen receptors and act as a coactivator. PMID:15110759

  17. 17beta-estradiol counteracts neuropathic pain: a behavioural, immunohistochemical, and proteomic investigation on sex-related differences in mice.

    PubMed

    Vacca, Valentina; Marinelli, Sara; Pieroni, Luisa; Urbani, Andrea; Luvisetto, Siro; Pavone, Flaminia

    2016-01-01

    Sex differences play a role in pain sensitivity, efficacy of analgesic drugs and prevalence of neuropathic pain, even if the underlying mechanisms are far from being understood. We demonstrate that male and female mice react differently to structural and functional changes induced by sciatic nerve ligature, used as model of neuropathic pain. Male mice show a gradual decrease of allodynia and a complete recovery while, in females, allodynia and gliosis are still present four months after neuropathy induction. Administration of 17?-estradiol is able to significantly attenuate this difference, reducing allodynia and inducing a complete recovery also in female mice. Parallel to pain attenuation, 17?-estradiol treated-mice show a functional improvement of the injured limb, a faster regenerative process of the peripheral nerve and a decreased neuropathy-induced gliosis. These results indicate beneficial effects of 17?-estradiol on neuropathic pain and neuronal regeneration and focuses on the importance of considering gonadal hormones also in clinical studies. PMID:26742647

  18. PROMOTION BY 17BETA-ESTRADIOL AND BETA-HEXACHLOROCYCLOHEXANE OF HEPATOCELLULAR TUMORS IN MEDAKA, ORYZIAS LATIPES. (R825298)

    EPA Science Inventory

    Abstract

    A feature common to many laboratory and field studies with various fish species is a higher prevalence of hepatocellular neoplasia in females than in males. During female sexual maturation, endogenous estrogens stimulate substantial increases in synthetic acti...

  19. The effect of 17beta estradiol withdrawal on the level of brain and peripheral neurosteroids in ovarectomized rats.

    PubMed

    Maayan, Rachel; Strous, Rael D; Abou-Kaoud, Machmoud; Weizman, Abraham

    Dehydroepiandrosterone (DHEA), pregnenolone (P) and their sulfate derivatives are neuroactive neurosteroids synthesized endogenously in the brain and in steroidogenic organs and influence or are influenced by a variety of physiological processes. Since parturition is followed by a rapid drop in estrogen levels in serum and brain it may be hypothesized that the drastic drop in the brain exposure to estrogens may cause a disturbance in the neurosteroid-to-neurosteroid-sulfate equilibrium with clinical relevance. In order to develop a rat animal model for human postpartum rapid estrogen decline conditions, the present study investigated effects of sudden withdrawal of hyperphysiological estrogens levels on levels of DHEA, DHEAS, P and PS in peripheral blood and brain tissue as well as cortical sulfatase activity. Twenty-four 3-month-old female rats were ovarectomized followed by either no estrogen, high levels of estrogen alone, or followed by sudden withdrawal after high-administered estrogen levels. Results indicated elevated brain cortical DHEA-S and reduced cortical sulfatase in ovarectomized rats following sudden estrogen withdrawal. No significant alterations in DHEA, P or PS were noted. Study observations suggest the marked influence estrogen withdrawal states may have on cortical DHEA-S levels in particular, the precise mechanism of which remains unknown but which may be related to the paralleled decrease in sulfatase activity. This DHEA-S increase may lead to attenuated GABAergic tone and may be relevant to post-natal behavioral disturbances (e.g. depression, anxiety). PMID:15927368

  20. The effect of 17 beta-estradiol on cholesterol in human macrophages is influenced by the lipoprotein milieu

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Estrogen and testosterone are thought to modulate coronary heart disease (CHD) risk. To examine how these hormones affect human macrophage cholesterol transport, a key factor in atherogenesis, we obtained monocytes from healthy male and postmenopausal female donors (age 50-70 y). Cells were allowe...

  1. 17beta-estradiol counteracts neuropathic pain: a behavioural, immunohistochemical, and proteomic investigation on sex-related differences in mice

    PubMed Central

    Vacca, Valentina; Marinelli, Sara; Pieroni, Luisa; Urbani, Andrea; Luvisetto, Siro; Pavone, Flaminia

    2016-01-01

    Sex differences play a role in pain sensitivity, efficacy of analgesic drugs and prevalence of neuropathic pain, even if the underlying mechanisms are far from being understood. We demonstrate that male and female mice react differently to structural and functional changes induced by sciatic nerve ligature, used as model of neuropathic pain. Male mice show a gradual decrease of allodynia and a complete recovery while, in females, allodynia and gliosis are still present four months after neuropathy induction. Administration of 17β-estradiol is able to significantly attenuate this difference, reducing allodynia and inducing a complete recovery also in female mice. Parallel to pain attenuation, 17β-estradiol treated-mice show a functional improvement of the injured limb, a faster regenerative process of the peripheral nerve and a decreased neuropathy-induced gliosis. These results indicate beneficial effects of 17β-estradiol on neuropathic pain and neuronal regeneration and focuses on the importance of considering gonadal hormones also in clinical studies. PMID:26742647

  2. Effects of 17Beta-estradiol on cognitive performance of ovariectomized female rats exposed to 56Fe particles

    Technology Transfer Automated Retrieval System (TEKTRAN)

    On exploratory class missions to other planets astronauts will be exposed to types and doses of radiation (HZE particles) that are not experienced in low earth orbit. While it is likely that the crew will consist of both male and female astronauts, there has been little research on the effects of ...

  3. Effect of ovariectomy and 17 beta-estradiol implantation on bone metabolism in female rats fed 1,25 dihydroxyvitamin D/sub 3/

    SciTech Connect

    Osborne, M.; Sherman, S.; Soares, J.H. Jr.

    1986-03-01

    Eight-week old Sprague-Dawley female rats were used in two experiments to test the effects of 17-B estradiol (E/sub 2/) via silastic tubing implants on /sup 3/H-labelled tetracycline (TC) incorporation into bone. 1,25(OH)/sub 2/D/sub 3/ was the dietary source of vitamin D in a low calcium (.2%) semipurified eggwhite diet. In experiment I, the Ovx + E/sub 2/ animals showed a significantly (p < .01) higher /sup 3/H TC uptake in scapula during a 2-week labelling experiment. An increase in /sup 3/H TC content resulted (p < .01) when E/sub 2/ was implanted in 1,25(OH)/sub 2/D/sub 3/ fed Ovx rats. However, the calcium content was not significantly different. The effect of dietary 1,25(OH)/sub 2/D/sub 3/ and E/sub 2/ implantation appears to be additive. Optimal action of the Vitamin D endocrine system may be dependent on presence of E/sub 2/.

  4. Identification of two Isoforms of Vitelline Envelope Protein as Complementary Biomarkers to Vitellogenin in the Plasma of Rainbow Trout Exposed to 17beta-estradiol

    EPA Science Inventory

    In the present study, protein markers of estrogenic exposure in rainbow trout (Oncorhynchus mykiss) were isolated and identified using innovative sample preparation techniques followed by advanced MS and bioinformatics approaches. Juvenile trout were administered 17ß-estradiol t...

  5. Modulation of vitellogenin synthesis through estrogen receptor beta-1 in goldfish (Carassius auratus) juveniles exposed to 17-beta estradiol and nonylphenol.

    PubMed

    Soverchia, L; Ruggeri, B; Palermo, F; Mosconi, G; Cardinaletti, G; Scortichini, G; Gatti, G; Polzonetti-Magni, A M

    2005-12-15

    Many synthetic chemicals, termed xenoestrogens, have been shown to interact as agonists with the estrogen receptor (ER) to elicit biological responses similar to those of natural hormones. To date, the regulation of vitellogenesis in oviparous vertebrates has been widely used for evaluation of estrogenic effects. Therefore, Carassius auratus juveniles were chosen as a fish model for studying the effects of estradiol-17beta and different concentrations (10(-6) and 10(-7) M) of 4-nonylphenol (4-NP) on the expression of liver ERbeta-1 subtype; plasma vitellogenin and sex steroids (androgens and estradiol-17beta) were also evaluated together with the bioaccumulation process, through mass-spectrometry. C. auratus is a species widespread in the aquatic environment and, on the toxicological point of view, can be considered a good "sentinel" species. Juveniles of goldfish were maintained in tanks with only tap water or water with different concentrations (10(-6) and 10(-7) M) of 4-nonylphenol (4-NP), or 10(-7) M of estradiol-17beta. After 3 weeks of treatment, animals were anesthetized within 5 min after capture, and blood was immediately collected into heparinized syringes by cardiac puncture and stored at -70 degrees C; the gonads were fixed, then frozen and stored at -70 degrees C; the whole fish, liver, and muscle tissues were harvested and immediately stored at -70 degrees C for molecular biology experiments and bioaccumulation measurements. The estrogenic effects of 4-NP were evidenced by the presence of plasma vitellogenin in juveniles exposed both to estradiol-17beta and the two doses of 4-NP; moreover, exposure to 4-NP also increased aromatization of androgens, as suggested by decreasing androgens and increasing estradiol-17beta plasma levels. The changes of these parameters were in agreement with the increasing transcriptional rate of ERbeta-1 mRNA in the liver, demonstrating that both estradiol-17beta and 4-NP modulate the vitellogenin rate through interaction with the ERbeta-1 subtype. The present study also suggests that 4-NP at the concentration of 10(-6) M bioaccumulates in the liver. PMID:15921715

  6. Identification of two Isoforms of Vitelline Envelope Protein as Complementary Biomarkers to Vitellogenin in the Plasma of Rainbow Trout Exposed to 17beta-estradiol

    EPA Science Inventory

    In the present study, protein markers of estrogenic exposure in rainbow trout (Oncorhynchus mykiss) were isolated and identified using innovative sample preparation techniques followed by advanced MS and bioinformatics approaches. Juvenile trout were administered 17-estradiol t...

  7. A Computational Model of the Hypothalamic-pituitary-gonadal Axis in Male Fathead Minnows Exposed to 17 | *alpha* | -ethinylestradiol and 17 | *beta* | -estradiol

    EPA Science Inventory

    Estrogenic chemicals in the aquatic environment have been shown to cause a variety of reproductive anomalies in fish including full sex reversal, intersex, and altered population sex ratios. Two estrogens found in the aquatic environment, 17-ethinylestradiol and 17-estradiol, h...

  8. DNA ARRAYS TO MONITOR GENE EXPRESSION IN RAT BLOOD AND UTERUS FOLLOWING 17-BETA-ESTRADIOL EXPOSURE: BIOMONITORING ENVIRONMENTAL EFFECTS USING SURROGATE TISSUES

    EPA Science Inventory

    DNA arrays to monitor gene expression in rat blood and uterus following 17-b-estradiol exposure - biomonitoring environmental effects using surrogate tissues
    John C. Rockett, Robert J. Kavlock, Christy R. Lambright, Louise G. Parks, Judith E. Schmid, Vickie S. Wilson, Carmen W...

  9. PROMOTION BY 17&BETA;-ESTRADIOL AND &BETA;-HEXACHLOROCYCLOHEXANE OF HEPATOCELLULAR TUMORS IN MEDAKA, ORYZIAS LATIPES. AQUAT. (R828676C002)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  10. Activation of growth factor secretion in tumorigenic states of breast cancer induced by 17. beta. -estradiol or v-Ha-ras oncogene

    SciTech Connect

    Dickson, R.B.; Kasid, A.; Huff, K.K.; Bates, S.E.; Knabbe, C.; Bronzert, D.; Gelmann, E.P.; Lippman, M.E.

    1987-02-01

    The MCF-7 human breast cancer cell line responds to estrogen stimulation in vitro by increased secretion of growth factors and proliferation and in vivo by tumor formation in the nude mouse. To test a possible role of growth factor secretion in expression of the tumorigenic phenotype, the authors stably transfected MCF-7 cells with the v-Ha-ras oncogene to produce the MCF-7ras cell line. The MCF-7ras cell line was tumorigenic in the absence of estrogens and secreted 3- to 5-fold elevated levels of a high molecular weight form of a type ..cap alpha.. transforming growth factor-like growth factor, type ..beta.. transforming growth factor, and insulin-like growth factor I. MCF-7ras cells, in contrast to MCF-7, were less sensitive to further growth stimulation by estrogen, type ..cap alpha.. transforming growth factor, and insulin-like growth factor I and showed little change in receptor levels for these hormones. Conditioned medium from MCF-7ras cells as well as two of its component growth factors replaced estrogen in stimulating MCF-7 colony formation in vitro. A coordinate increase in growth factor secretion by human breast cancer may contribute to its escape from estrogen dependence.

  11. Uterine physiological responses and global gene expression in ovariectomized (ovx) rats treated with soy protein isolate (spi) or 17Beta-estradiol

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Concerns regarding increased endometrial cancer risk have been raised in women who consume soy products as the result of the estrogenicity of phytochemical components such as the isoflavones genistein and daidzein. Female Sprague-Dawley rats (N = 20/group) were fed AIN-93G diets with casein or SPI a...

  12. In vitro fertilization and primary embryonic cleavage are possible in 17 alpha-hydroxylase deficiency despite extremely low intrafollicular 17 beta-estradiol.

    PubMed

    Rabinovici, J; Blankstein, J; Goldman, B; Rudak, E; Dor, Y; Pariente, C; Geier, A; Lunenfeld, B; Mashiach, S

    1989-03-01

    Congenital adrenal hyperplasia due to 17 alpha-hydroxylase deficiency in genotypic females is characterized by primary amenorrhea and the absence of sexual maturation due to inadequate biosynthesis of ovarian androgens and estrogens. We induced ovarian follicular development in a woman with this syndrome. Ovum pick-up, in vitro fertilization, and primary embryonic development were achieved despite undetectable plasma estradiol and extremely low ovarian androgen concentrations and minute concentrations of these hormones in the ovarian follicular fluid. PMID:2493041

  13. SPE-LC/ESI/MS: a simple and reproducible method for detection and quantification of 17beta-estradiol in aqueous samples

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Steroid estrogens contained in wastewater discharge from sewage treatment plants and agricultural run-off can alter endocrine function in exposed wildlife at part per trillion (ng/L) levels. Detection and quantification of estrogens in the environment at these levels pose numerous analytical challen...

  14. A Computational Model of the Hypothalamic-pituitary-gonadal Axis in Male Fathead Minnows Exposed to 17 | *alpha* | -ethinylestradiol and 17 | *beta* | -estradiol

    EPA Science Inventory

    Estrogenic chemicals in the aquatic environment have been shown to cause a variety of reproductive anomalies in fish including full sex reversal, intersex, and altered population sex ratios. Two estrogens found in the aquatic environment, 17-ethinylestradiol and 17â-estradiol, h...

  15. Modulation of vitellogenin synthesis through estrogen receptor beta-1 in goldfish (Carassius auratus) juveniles exposed to 17-{beta} estradiol and nonylphenol

    SciTech Connect

    Soverchia, L.; Ruggeri, B.; Palermo, F.; Mosconi, G.; Cardinaletti, G.; Scortichini, G.; Gatti, G.; Polzonetti-Magni, A.M. . E-mail: alberta.polzonetti@unicam.it

    2005-12-15

    Many synthetic chemicals, termed xenoestrogens, have been shown to interact as agonists with the estrogen receptor (ER) to elicit biological responses similar to those of natural hormones. To date, the regulation of vitellogenesis in oviparous vertebrates has been widely used for evaluation of estrogenic effects. Therefore, Carassius auratus juveniles were chosen as a fish model for studying the effects of estradiol-17{beta} and different concentrations (10{sup -6} and 10{sup -7} M) of 4-nonylphenol (4-NP) on the expression of liver ER{beta}-1 subtype; plasma vitellogenin and sex steroids (androgens and estradiol-17{beta}) were also evaluated together with the bioaccumulation process, through mass-spectrometry. C. auratus is a species widespread in the aquatic environment and, on the toxicological point of view, can be considered a good 'sentinel' species. Juveniles of goldfish were maintained in tanks with only tap water or water with different concentrations (10{sup -6} and 10{sup -7} M) of 4-nonylphenol (4-NP), or 10{sup -7} M of estradiol-17{beta}. After 3 weeks of treatment, animals were anesthetized within 5 min after capture, and blood was immediately collected into heparinized syringes by cardiac puncture and stored at -70 deg. C; the gonads were fixed, then frozen and stored at -70 deg. C; the whole fish, liver, and muscle tissues were harvested and immediately stored at -70 deg. C for molecular biology experiments and bioaccumulation measurements. The estrogenic effects of 4-NP were evidenced by the presence of plasma vitellogenin in juveniles exposed both to estradiol-17{beta} and the two doses of 4-NP; moreover, exposure to 4-NP also increased aromatization of androgens, as suggested by decreasing androgens and increasing estradiol-17{beta} plasma levels. The changes of these parameters were in agreement with the increasing transcriptional rate of ER{beta}-1 mRNA in the liver, demonstrating that both estradiol-17{beta} and 4-NP modulate the vitellogenin rate through interaction with the ER{beta}-1 subtype. The present study also suggests that 4-NP at the concentration of 10{sup -6} M bioaccumulates in the liver.

  16. Hepatic gene expression following consumption of soy protein isolate in female sprague-dawley rats differs from that produced by 17beta-estradiol treatment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although soy foods have been recognized as an excellent source of protein, there have been recent concerns regarding potential adverse effects of isoflavone phytochemicals found in soy products, which are known to bind and activate estrogen receptors. Here we used global hepatic gene expression prof...

  17. Mammary gland morphology and gene expression differ in female rats treated with 17 beta-estradiol or fed soy protein isolate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soy foods have been suggested to have both positive health benefits and potentially adverse effects as a result of their content of phytoestrogens. However, studies on the estrogenicity of soy foods are lacking. Here we directly compared the effects of soy protein isolate (SPI), the protein in soy i...

  18. Estradiol coupling to human monocyte nitric oxide release is dependent on intracellular calcium transients: evidence for an estrogen surface receptor.

    PubMed

    Stefano, G B; Prevot, V; Beauvillain, J C; Fimiani, C; Welters, I; Cadet, P; Breton, C; Pestel, J; Salzet, M; Bilfinger, T V

    1999-10-01

    We tested the hypothesis that estrogen acutely stimulates constitutive NO synthase (cNOS) activity in human peripheral monocytes by acting on an estrogen surface receptor. NO release was measured in real time with an amperometric probe. 17beta-estradiol exposure to monocytes stimulated NO release within seconds in a concentration-dependent manner, whereas 17alpha-estradiol had no effect. 17beta-estradiol conjugated to BSA (E2-BSA) also stimulated NO release, suggesting mediation by a membrane surface receptor. Tamoxifen, an estrogen receptor inhibitor, antagonized the action of both 17beta-estradiol and E2-BSA, whereas ICI 182,780, a selective inhibitor of the nuclear estrogen receptor, had no effect. We further showed, using a dual emission microfluorometry in a calcium-free medium, that the 17beta-estradiol-stimulated release of monocyte NO was dependent on the initial stimulation of intracellular calcium transients in a tamoxifen-sensitive process. Leeching out the intracellular calcium stores abolished the effect of 17beta-estradiol on NO release. RT-PCR analysis of RNA obtained from the cells revealed a strong estrogen receptor-alpha amplification signal and a weak beta signal. Taken together, a physiological dose of estrogen acutely stimulates NO release from human monocytes via the activation of an estrogen surface receptor that is coupled to increases in intracellular calcium. PMID:10490972

  19. Pathogenic infection confounds induction of the estrogenic biomarker vitellogenin in rainbow trout

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To examine the behavior of the estrogenic biomarker vitellogenin (VTG) under the combined impact of estrogens and pathogens, parasite-infected or noninfected rainbow trout were exposed to two doses of 17 beta-estradiol (E2). Infected and E2-exposed fish showed significantly lower hepatic VTG mRNA le...

  20. Sorption, fate, and transport of endogenous steroid hormones in soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The natural hormones 17 beta-estradiol (E2) and testosterone (T) are present in animal manures that are applied to agricultural land as fertilizer and, potentially, may act as endocrine disruptors. Laboratory incubation, batch, and column experiments have been conducted on a series of soils and wer...

  1. The E(2) particle

    SciTech Connect

    Ghosh, Subir; Pal, Probir

    2009-12-15

    Recently it has been advocated [A. G. Cohen and S. L. Glashow, Phys. Rev. Lett. 97, 021601 (2006)] that for describing nature within the minimal symmetry requirement, certain subgroups of the Lorentz group may play a fundamental role. One such group is E(2) which induces a Lie algebraic noncommutative spacetime [M. M. Sheikh-Jabbari and A. Tureanu, Phys. Rev. Lett. 101, 261601 (2008); arXiv:0811.3670] where translation invariance is not fully maintained. We have constructed a consistent structure of noncommutative phase space for this system, and furthermore we have studied an appropriate point particle action on it. Interestingly, the Einstein dispersion relation p{sup 2}=m{sup 2} remains intact. The model is constructed by exploiting a dual canonical phase space following the scheme developed by us earlier [S. Ghosh and P. Pal, Phys. Rev. D 75, 105021 (2007)].

  2. The Papillomavirus E2 proteins

    SciTech Connect

    McBride, Alison A.

    2013-10-15

    The papillomavirus E2 proteins are pivotal to the viral life cycle and have well characterized functions in transcriptional regulation, initiation of DNA replication and partitioning the viral genome. The E2 proteins also function in vegetative DNA replication, post-transcriptional processes and possibly packaging. This review describes structural and functional aspects of the E2 proteins and their binding sites on the viral genome. It is intended to be a reference guide to this viral protein. - Highlights: • Overview of E2 protein functions. • Structural domains of the papillomavirus E2 proteins. • Analysis of E2 binding sites in different genera of papillomaviruses. • Compilation of E2 associated proteins. • Comparison of key mutations in distinct E2 functions.

  3. Properties of the estrogen receptors contained in the MtTF4 tumor whose growth is inhibited by estradiol: 17 beta-estradiol, 17 alpha-estradiol and DNA bindings.

    PubMed

    Albaladejo, V; Pharaboz, M O; Morel, Y; Andre, J

    1986-07-01

    The steroid and the DNA bindings of the estrogen receptor of the MtTF4 tumor whose growth is inhibited by estradiol where characterized and compared to those of uterine estrogen receptors. In the tumor cytosol: E protects its binding sites against thermal denaturation, depending on the effects of sodium molybdate upon the dissociation rate of [3H]E at 20 degrees C and the ability of receptor to bind to DNA, the activation (or transformation) process, supposed to be necessary for the full action of estrogen ligand, occurs on estrogen receptor complexes and the calf thymus DNA interacts with estrogen receptor with an affinity similar to that of uterine estrogen receptor. Kinetic and equilibrium studies with 17 alpha-[3H]E both in uterus and tumor indicate that this ligand is fast-associating, fast-dissociating and that its affinity for ER is 2- to 4-fold lower than that of 17 beta-[3H]estradiol one. Competition experiments between 17 beta-[3H]estradiol and the unlabelled 17 alpha epimer reveal, in both uterus and tumor, a time-dependent decrease of the apparent potency of 17 alpha-E to inhibit the binding of [3H]E. It is concluded that the estrogen receptors are very similar in MtTF4 tumor and uterus and the diversity of the response of cell growth to E is due rather to differences at the post-receptor level. PMID:3747513

  4. DIFFERENTIAL EFFECTS OF 17-BETA-ESTRADIOL AND 1,25-DIHYDROXYVITAMIN D ON CAT1 AND CALBINDIN D GENE EXPRESSION AND TRANSEPITHELIAL CALCIUM TRANSPORT IN CACO2 CELLS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Estrogen deficiency has been associated with low intestinal calcium (Ca) absorption and increased bone loss. Studies in experimental animals and humans have shown that estrogen treatment has a positive effect on calcium absorption. However, it is unclear whether estrogen has a direct effect on calci...

  5. E2f2 induces cone photoreceptor apoptosis independent of E2f1 and E2f3

    PubMed Central

    Chen, D; Chen, Y; Forrest, D; Bremner, R

    2013-01-01

    The activating' E2fs (E2f1-3) are transcription factors that potently induce quiescent cells to divide. Work on cultured fibroblasts suggested they were essential for division, but in vivo analysis in the developing retina and other tissues disproved this notion. The retina, therefore, is an ideal location to assess other in vivo adenovirus E2 promoter binding factor (E2f) functions. It is thought that E2f1 directly induces apoptosis, whereas other activating E2fs only induce death indirectly by upregulating E2f1 expression. Indeed, mouse retinoblastoma (Rb)-null retinal neuron death requires E2f1, but not E2f2 or E2f3. However, we report an entirely distinct mechanism in dying cone photoreceptors. These neurons survive Rb loss, but undergo apoptosis in the cancer-prone retina lacking both Rb and its relative p107. We show that while E2f1 killed Rb/p107 null rod, bipolar and ganglion neurons, E2f2 was required and sufficient for cone death, independent of E2f1 and E2f3. Moreover, whereas E2f1-dependent apoptosis was p53 and p73-independent, E2f2 caused p53-dependent cone death. Our in vivo analysis of cone photoreceptors provides unequivocal proof that E2f-induces apoptosis independent of E2f1, and reveals distinct E2f1- and E2f2-activated death pathways in response to a single tumorigenic insult. PMID:23558950

  6. 26 CFR 1.367(e)-2 - Distributions described in section 367(e)(2).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 4 2014-04-01 2014-04-01 false Distributions described in section 367(e)(2). 1.367(e)-2 Section 1.367(e)-2 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES (CONTINUED) Effects on Corporation 1.367(e)-2...

  7. 26 CFR 1.367(e)-2 - Distributions described in section 367(e)(2).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 4 2013-04-01 2013-04-01 false Distributions described in section 367(e)(2). 1.367(e)-2 Section 1.367(e)-2 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES (CONTINUED) Effects on Corporation 1.367(e)-2...

  8. 26 CFR 1.367(e)-2 - Distributions described in section 367(e)(2).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 4 2011-04-01 2011-04-01 false Distributions described in section 367(e)(2). 1.367(e)-2 Section 1.367(e)-2 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES Effects on Corporation 1.367(e)-2 Distributions...

  9. 26 CFR 1.367(e)-2 - Distributions described in section 367(e)(2).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 4 2012-04-01 2012-04-01 false Distributions described in section 367(e)(2). 1.367(e)-2 Section 1.367(e)-2 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES (Continued) Effects on Corporation 1.367(e)-2...

  10. Colicin E2 is DNA endonuclease.

    PubMed Central

    Schaller, K; Nomura, M

    1976-01-01

    Colicin E2 purified by conventional methods contains a tightly bound low-molecular-weight protein, as has been found with purified colicin E3 [Jakes,N.&Zinder,N.D.(1974) Proc. Natl. Acad. Sci. USA 71, 3380-3384]. Such E2 preparations do not cause DNA cleavage in vitro. After separation from the low-molecular-weight protein, colicin E2 retained the original in vivo killing activity, and in addition showed a high activity in vitro in cleaving various DNA molecules, such as a ColE1 hybrid plasmid and DNAs from Escherichia coli, lambda phage, chiX174 phage, and simian virus 40. The low-molecular-weight protein ("E2-immunity protein") specifically prevented this in vitro DNA cleavage reaction, i.e., had an "immunity function." The results demonstrate that colicin E2 itself is a DNA endonuclease and explain the in vivo effects caused by E2 in sensitive cells as well as the mechanism of immunity in E2-colicinogenic cells. Images PMID:1069283

  11. The Astro-E2 Mission

    NASA Technical Reports Server (NTRS)

    Kelley, Richard L.

    2004-01-01

    The Astro-E2 observatory is a rebuild of the original Astro-E observatory that was lost during launch in February 2000. It is scheduled for launch into low earth orbit on a Japanese M-V rocket in early 2005. The Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, is developing the observatory with major contributions from the US. The three instruments on the observatory are the high-resolution x-ray spectrometer (the XRS) featuring a 30-pixel x-ray microcalorimeter array, a set of four CCD cameras (the XIS) and a combination photo-diode/scintillator detector system (the HXD) that will extend the band pass up to nearly 700 keV. A significant feature of Astro-E2 is that all of the instruments are coaligned and operated simultaneously. With its high spectral resolution and collecting area for spectroscopy above 1 keV, Astro-E2 should enable major discovery space and pioneer new technology for use in space. Prime areas for investigation are supernova remnants, active galaxies and the measurement of black hole properties via relativistically-broadened Fe-K emission galaxies. A number of enhancements have been made for the Astro-E2/XRS, including a higher resolution microcalorimeter array, ii mechanical cooler for longer cryogen life, and an improved in-flight calibration system. The Astro-E2/XIS has also been improved to include two back-side-illuminated CCDs to enhance the low energy response. Improvements have also been made to the x-ray mirrors used for both the XRS and XIS to sharpen the point spread function and reduce the effects of stray light. In this talk we will present the essential features of Astro-E2, paying particular attention to the enhancements, and describe the major scientific strengths of the observatory.

  12. Vortices in (e,2e) momentum distributions

    NASA Astrophysics Data System (ADS)

    Macek, J. H.; Ovchinnikov, S. Y.; Sternberg, J. B.

    2010-03-01

    Complete experiments measure all variables associated with atomic processes. Momentum distributions of ejected electrons in pure states, as for (e,2e) measurements, are examples of such complete experiments. All structures seen in such distributions are listed by Briggs and co-workersootnotetextJ. Berakdar and J. S. Briggs, J. Phys. B, 27, 4271 (1994). in 1994. Recently, we pointed out that there is a type of structure not included in the list. It has been shown that momentum distributions image time-dependent wave functions, and such wave functions may contain vortices owing to angular momentum transfer between species involved in the dynamical processes. The vortices are associated with exact zeros at single, isolated points. We have found such zeros in calculated momentum distributions for ion-atom collisions, photoionization, and (e,2e) distributions. By mapping distributions that image time-dependent wave functions we find velocity fields that circulate about exact zeros confirming their vortex structure. The vortices appear as unexpected holes in the (e,2e) momentum distributions. Our calculations suggest that one particular vortex has been observed.ootnotetextA. J. Murray and F. H. Read, Phys. Rev. A, 47, 3724 (1993).

  13. Ultrafast Electron Pulse (e,2e) Processes

    NASA Astrophysics Data System (ADS)

    Shao, Hua-Chieh; Starace, Anthony; Madsen, Lars

    2012-06-01

    Techniques for producing ultrafast electron pulses have been proposedootnotetextP. Baum and A.H. Zewail, Proc. Natl. Acad. Sci. U.S.A. 104, 18409 (2007); S.A. Hilbert, C. Ulterwaal, B. Barwick, H. Betalaan, and A.H. Zewail, ibid. 106, 10558 (2009). and prospects for using such pulses to image electron dynamics in the H atom and the hydrogen molecular ion have been theoretically demonstrated.ootnotetextH.-C. Shao and A.F. Starace, Phys. Rev. Lett. 105, 263201 (2010). The (e,2e) process provides a means to directly image the momentum distribution of the target.ootnotetextM.A. Coplan, J.H. Moore, and J.P. Doering, Rev. Mod. Phys. 66, 985 (1994). We explore here the possibility of observing the time dependence of a coherent superposition of target orbitals by means of the (e,2e) process with ultrafast incident electron pulses. Using scattering theory for a longitudinally coherent beam,ootnotetextF. Robicheaux, Phys. Rev. A 62, 062706 (2000). we find that the momentum distribution of a coherent state of the H atom can be retrieved.

  14. Anik-E2 recovery mission

    NASA Astrophysics Data System (ADS)

    Wang, D.; Martens, N.

    1993-09-01

    Anik-E2 was launched from Kourou on an Ariane 44P on 4 April 1991. Upon a successful completion of a series of apogee burns, the satellite reached the predicted drift orbit. Subsequently, two anomalies on deployment occurred. The first anomaly was the delay in deploying the Ku-band reflector. The full deployment did not occur until 2 days after the tie-down pyro firing. The second anomaly was noticed in connection with the deployment of the C-band reflector which did not deploy. An intensive investigation was immediately organized by Telesat and supported by Spar Aerospace and GE Astro to identify the possible cause(s) of the C-band antenna deployment failure. The investigations were focused on possible causes of failure which included the wiring of the pyro harness, freezing of the hinge damper, structural failure of the struts supporting the reflectors, alignment of the reflector tie-downs and interference of the thermal blankets surrounding the tie-down mechanisms. Due to some outstanding logistic planning effort and execution of a number of Anik-E2 flight manoeuvres and Anik-E1 ground testing, it was soon concluded that the most likely cause for the C-band reflector deployment failure was an interference resulting from the loosening of the thermal blankets surrounding the tie-down mechanisms. Based on the results of ground testing on Anik-E1, the required breakaway force for the snag was determined. This force requirement created a reflector deployment environment which was much more severe than the nominal design environment. In order to safely deploy the C-band reflector, another series of non-stop activities were performed by Telesat and its contractors to define a more dynamic satellite maneuver, e.g. high degree of nutation, coupled with a cold soak for the hinge dampers in order to provide a high breakaway force and efficient energy absorption during deployment to reduce the force at impact. A series of complex maneuvers with gradually increasing nutation was performed and the C-band reflector was eventually safely deployed on 3 July 1991 which was 3 months after the launch. Due to the constraints of the omni antenna coverage and the battery capacity, Telesat had conducted a large number of maneuvers which were never envisaged and rarely if ever carried out before. This paper will detail all the fault investigation events and mission maneuvers which led to the final recovery of the Anik-E2 satellite, and briefly describe the modification implemented on Anik-E1 which was subsequently launched and on which all deployments were executed flawlessly.

  15. Contrasting roles of E2F2 and E2F3 in endothelial cell growth and ischemic angiogenesis.

    PubMed

    Zhou, Junlan; Cheng, Min; Wu, Min; Boriboun, Chan; Jujo, Kentaro; Xu, Shiyue; Zhao, Ting C; Tang, Yao-Liang; Kishore, Raj; Qin, Gangjian

    2013-07-01

    The growth of new blood vessels after ischemic injury requires endothelial cells (ECs) to divide and proliferate, and the E2F transcription factors are key regulators of the genes responsible for cell-cycle progression; however, the specific roles of individual E2Fs in ECs are largely unknown. To determine the roles of E2F2 and E2F3 in EC proliferation and the angiogenic response to ischemic injury, hind-limb ischemia was surgically induced in E2F2(-/-) mice, endothelial-specific E2F3-knockout (EndoE2F3(?/?)) mice, and their littermates with wild-type E2F2 and E2F3 expression. Two weeks later, Laser-Doppler perfusion measurements, capillary density, and endothelial proliferation were significantly greater in E2F2(-/-) mice and significantly lower in EndoE2F3(?/?) mice than in their littermates, and EndoE2F3(?/?) mice also developed toe and limb necrosis. The loss of E2F2 expression was associated with increases in the proliferation and G1/S-phase gene expression of isolated ECs, while the loss of E2F3 expression led to declines in these parameters. Thus E2F2 impairs, and endothelial E2F3 promotes, the angiogenic response to peripheral ischemic injury through corresponding changes in EC cell-cycle progression. PMID:23603666

  16. An adenovirus E4 gene product trans-activates E2 transcription and stimulates stable E2F binding through a direct association with E2F.

    PubMed Central

    Neill, S D; Hemstrom, C; Virtanen, A; Nevins, J R

    1990-01-01

    The adenovirus E4 gene encodes a trans-activating function that can stimulate the E2 promoter. E2 promoter sequences required for E4 trans-activation are identical to those required for E1A trans-activation, and these principally are the E2 promoter binding factor (E2F) binding sites. Furthermore, full activation of E2F DNA binding activity requires both E1A and E4 action. Analysis of a series of mutant E4 viruses identifies open reading frame (orf) 6/7 of the E4 transcription unit as that required for activation of E2F binding activity. In addition, the assay of various E4 cDNAs demonstrates that the E4 orf 6/7 also is responsible for the trans-activation of E2 transcription. Translation of the E4 orf 6/7 mRNA, but not a control mRNA, in a reticulocyte extract generates an activity that can stimulate cooperative binding of E2F in vitro, consistent with recent in vivo assays that demonstrate a role for the E4 gene in E2F stable complex formation. This stimulation is due to a direct interaction of the E4 protein with E2F since an antibody that recognizes the E4 orf 6/7 polypeptide detects this E4 protein in the E2F-DNA complex. We conclude that the E4 orf 6/7 product interacts with the E2F factor altering binding to allow formation of a stable complex that results in a stimulation of transcription. Images PMID:2137929

  17. 26 CFR 1.503(e)-2 - Requirements.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 7 2010-04-01 2010-04-01 true Requirements. 1.503(e)-2 Section 1.503(e)-2...) INCOME TAXES (CONTINUED) Exempt Organizations 1.503(e)-2 Requirements. (a) In general. The requirements which must be met under section 503(e) for an obligation not to be treated as a loan made without...

  18. 26 CFR 1.503(e)-2 - Requirements.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 7 2014-04-01 2013-04-01 true Requirements. 1.503(e)-2 Section 1.503(e)-2 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES (CONTINUED) Exempt Organizations 1.503(e)-2 Requirements. (a) In general. The requirements which must be met under section 503(e)...

  19. 26 CFR 1.503(e)-2 - Requirements.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 7 2012-04-01 2012-04-01 false Requirements. 1.503(e)-2 Section 1.503(e)-2...) INCOME TAXES (CONTINUED) Exempt Organizations 1.503(e)-2 Requirements. (a) In general. The requirements which must be met under section 503(e) for an obligation not to be treated as a loan made without...

  20. 26 CFR 1.503(e)-2 - Requirements.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 7 2013-04-01 2013-04-01 false Requirements. 1.503(e)-2 Section 1.503(e)-2...) INCOME TAXES (CONTINUED) Exempt Organizations 1.503(e)-2 Requirements. (a) In general. The requirements which must be met under section 503(e) for an obligation not to be treated as a loan made without...

  1. E2f4 and E2f5 are essential for the development of the male reproductive system.

    PubMed

    Danielian, Paul S; Hess, Rex A; Lees, Jacqueline A

    2016-01-17

    The E2F transcription factors are primarily implicated in the regulation of entry and exit from the cell cycle. However, in vivo studies have established additional roles for E2Fs during organ development and homeostasis. With the goal of addressing the intestinal requirements of E2f4 and E2f5, we crossed mice carrying Vil-cre, E2f4 conditional and E2f5 germline alleles. E2f4 deletion had no detectable effect on intestinal development. However, E2f4f/f;E2f5+/-;Vil-cre males, but not E2f4f/f;Vil-cre littermates, were unexpectedly sterile. This defect was not due to defective spermatogenesis. Instead, the seminiferous tubules and rete testes showed significant dilation, and spermatozoa accumulated aberrantly in the rete testis and efferent ducts. Our data show that these problems result from defective efferent ducts, a tissue whose primary function is to concentrate sperm through fluid absorption. First, Vil-cre expression, and consequent E2F4 loss, was specific to the efferent ducts and not other reproductive tract tissues. Second, the E2f4f/f;E2f5+/-;Vil-cre efferent ducts had completely lost multiciliated cells and greatly reduced levels of critical absorptive cell proteins: aquaporin1, a water channel protein, and clusterin, an endocytic marker. Collectively, the observed testis phenotypes suggest a fluid flux defect. Remarkably, we observed rete testis dilation prior to the normal time of seminiferous fluid production, arguing that the efferent duct defects promote excessive secretory activity within the reproductive tract. Finally, we also detect key aspects of these testis defects in E2f5-/- mice. Thus, we conclude that E2f4 and E2f5 display overlapping roles in controlling the normal development of the male reproductive system. PMID:26825228

  2. E2F transcription factor-1 regulates oxidative metabolism

    PubMed Central

    Lagarrigue, Sylviane; Aguilar, Victor; Clap, Cyrielle; Chavey, Carine; Fritz, Vanessa; Casas, Franois; Apparailly, Florence; Auwerx, Johan; Fajas, Lluis

    2013-01-01

    Cells respond to stress by coordinating proliferative and metabolic pathways. Starvation restricts cell proliferative (glycolytic) and activates energy productive (oxidative) pathways. Conversely, cell growth and proliferation require increased glycolytic and decreased oxidative metabolism1. E2F transcription factors regulate both proliferative and metabolic genes2,3. E2Fs have been implicated in the G1/S cell cycle transition, DNA repair, apoptosis, development, and differentiation2-4. In pancreatic ?-cells, E2F1 gene regulation facilitated glucose-stimulated insulin secretion5,6. Moreover, mice lacking E2F1 (E2f1?/?) were resistant to diet-induced obesity4. Here, we show that E2F1 coordinates cellular responses by acting as a regulatory switch between cell proliferation and metabolism. In basal conditions, E2F1 repressed key genes that regulate energy homeostasis and mitochondrial functions in muscle and brown adipose. Consequently, E2f1?/? mice had a marked oxidative phenotype An association between E2F1 and pRb was required for repression of genes implicated in oxidative metabolism. This repression was alleviated in a constitutive active CDK4 (CDK4R24C) mouse model or when adaptation to energy demand was required. Thus, E2F1 represents a metabolic switch from oxidative to glycolytic metabolism that responds to stressful conditions. PMID:21841792

  3. E2F1 and E2F2 prevent replicative stress and subsequent p53-dependent organ involution.

    PubMed

    Iglesias-Ara, A; Zenarruzabeitia, O; Buelta, L; Merino, J; Zubiaga, A M

    2015-10-01

    Tissue homeostasis requires tight regulation of cellular proliferation, differentiation and apoptosis. E2F1 and E2F2 transcription factors share a critical role in tissue homeostasis, since their combined inactivation results in overall organ involution, specially affecting the pancreatic gland, which subsequently triggers diabetes. We have examined the mechanism by which these E2Fs regulate tissue homeostasis. We show that pancreas atrophy in E2F1/E2F2 double-knockout (DKO) mice is associated with mitochondrial apoptosis and activation of the p53 pathway in young animals, before the development of diabetes. A deregulated expression of E2F target genes was detected in pancreatic cells of young DKO animals, along with unscheduled DNA replication and activation of a DNA damage response. Importantly, suppression of DNA replication in vivo with aphidicolin led to a significant inhibition of the p53 pathway in DKO pancreas, implying a causal link between DNA replication stress and p53 activation in this model. We further show that activation of the p53 pathway has a key role in the aberrant phenotype of DKO mice, since targeted inactivation of p53 gene abrogated cellular apoptosis and prevented organ involution and insulin-dependent diabetes in mice lacking E2F1/E2F2. Unexpectedly, p53 inactivation unmasked oncogenic features of E2F1/E2F2-depleted cells, as evidenced by an accelerated tumor development in triple-knockout mice compared with p53(-/-) mice. Collectively, our data reveal a role for E2F1 and E2F2 as suppressors of replicative stress in differentiating cells, and uncover the existence of a robust E2F-p53 regulatory axis to enable tissue homeostasis and prevent tumorigenesis. These findings have implications in the design of approaches targeting E2F for cancer therapy. PMID:25656653

  4. 26 CFR 1.503(e)-2 - Requirements.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 7 2011-04-01 2009-04-01 true Requirements. 1.503(e)-2 Section 1.503(e)-2 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED... Commission, it must be purchased through such an exchange or in an over-the-counter transaction at a...

  5. Estrogen and xenoestrogens in breast cancer.

    PubMed

    Fernandez, S V; Russo, J

    2010-01-01

    There is growing concern that estrogenic environmental compounds that act as endocrine-disrupting chemicals might potentially have adverse effects on hormone-sensitive organs such as the breast. This concern is further fueled by evidence indicating that natural estrogens, specifically 17beta-estradiol, are important factors in the initiation and progression of breast cancer. We have developed an in vitro-in vivo model in which we have demonstrated the carcinogenicity of E2 in human breast epithelial cells MCF-10F. Hypermethylation of NRG1, STXBP6, BMP6, CSS3, SPRY1, and SNIP were found at different progression stages in this model. The use of this powerful and unique model has provided a tool for exploring whether bisphenol A and butyl benzyl phthalate have relevance in the initiation of breast cancer. These studies provide firsthand evidence that the natural estrogen 17beta-estradiol and xenoestrogenic substances like bisphenol A are able to induce neoplastic transformation in human breast epithelial cells. PMID:19933552

  6. Tax1BP1 interacts with papillomavirus E2 and regulates E2-dependent transcription and stability.

    PubMed

    Wang, Xiaoyu; Naidu, Samisubbu R; Sverdrup, Francis; Androphy, Elliot J

    2009-03-01

    The papillomavirus E2 proteins regulate viral replication, gene transcription, and genome maintenance by interacting with other viral and host proteins. From a yeast two-hybrid screen, we identified the cellular protein Tax1BP1 as a novel binding partner of human papillomavirus type 18 (HPV18) E2. Tax1BP1 also interacts with the HPV16 and bovine papillomavirus type 1 (BPV1) E2 proteins, with the C-terminal region of Tax1BP1 interacting with the N-terminal transactivation domain of BPV1 E2. Tax1BP1 complexes with p300 and acts synergistically as a coactivator with p300 to enhance E2-dependent transcription. Using chromatin immunoprecipitation assays, we show that Tax1BP1 and E2 localize to the long control region on the BPV1 genome. Tax1BP1 was recently reported to bind ubiquitin and to function as an essential component of an A20 ubiquitin-editing complex. We demonstrate that Tax1BP1 plays a role in the regulation of the steady-state level of E2 by preventing its proteasomal degradation. These studies provide new insights into the regulation of E2 functions. PMID:19109394

  7. Tax1BP1 Interacts with Papillomavirus E2 and Regulates E2-Dependent Transcription and Stability▿

    PubMed Central

    Wang, Xiaoyu; Naidu, Samisubbu R.; Sverdrup, Francis; Androphy, Elliot J.

    2009-01-01

    The papillomavirus E2 proteins regulate viral replication, gene transcription, and genome maintenance by interacting with other viral and host proteins. From a yeast two-hybrid screen, we identified the cellular protein Tax1BP1 as a novel binding partner of human papillomavirus type 18 (HPV18) E2. Tax1BP1 also interacts with the HPV16 and bovine papillomavirus type 1 (BPV1) E2 proteins, with the C-terminal region of Tax1BP1 interacting with the N-terminal transactivation domain of BPV1 E2. Tax1BP1 complexes with p300 and acts synergistically as a coactivator with p300 to enhance E2-dependent transcription. Using chromatin immunoprecipitation assays, we show that Tax1BP1 and E2 localize to the long control region on the BPV1 genome. Tax1BP1 was recently reported to bind ubiquitin and to function as an essential component of an A20 ubiquitin-editing complex. We demonstrate that Tax1BP1 plays a role in the regulation of the steady-state level of E2 by preventing its proteasomal degradation. These studies provide new insights into the regulation of E2 functions. PMID:19109394

  8. Recruitment of Pontin/Reptin by E2f1 amplifies E2f transcriptional response during cancer progression.

    PubMed

    Tarangelo, Amy; Lo, Nathanael; Teng, Rebecca; Kim, Eunsun; Le, Linh; Watson, Deborah; Furth, Emma E; Raman, Pichai; Ehmer, Ursula; Viatour, Patrick

    2015-01-01

    Changes in gene expression during tumorigenesis are often considered the consequence of de novo mutations occurring in the tumour. An alternative possibility is that the transcriptional response of oncogenic transcription factors evolves during tumorigenesis. Here we show that aberrant E2f activity, following inactivation of the Rb gene family in a mouse model of liver cancer, initially activates a robust gene expression programme associated with the cell cycle. Slowly accumulating E2f1 progressively recruits a Pontin/Reptin complex to open the chromatin conformation at E2f target genes and amplifies the E2f transcriptional response. This mechanism enhances the E2f-mediated transactivation of cell cycle genes and initiates the activation of low binding affinity E2f target genes that regulate non-cell-cycle functions, such as the Warburg effect. These data indicate that both the physiological and the oncogenic activities of E2f result in distinct transcriptional responses, which could be exploited to target E2f oncogenic activity for therapy. PMID:26639898

  9. Recruitment of Pontin/Reptin by E2f1 amplifies E2f transcriptional response during cancer progression

    PubMed Central

    Tarangelo, Amy; Lo, Nathanael; Teng, Rebecca; Kim, Eunsun; Le, Linh; Watson, Deborah; Furth, Emma E.; Raman, Pichai; Ehmer, Ursula; Viatour, Patrick

    2015-01-01

    Changes in gene expression during tumorigenesis are often considered the consequence of de novo mutations occurring in the tumour. An alternative possibility is that the transcriptional response of oncogenic transcription factors evolves during tumorigenesis. Here we show that aberrant E2f activity, following inactivation of the Rb gene family in a mouse model of liver cancer, initially activates a robust gene expression programme associated with the cell cycle. Slowly accumulating E2f1 progressively recruits a Pontin/Reptin complex to open the chromatin conformation at E2f target genes and amplifies the E2f transcriptional response. This mechanism enhances the E2f-mediated transactivation of cell cycle genes and initiates the activation of low binding affinity E2f target genes that regulate non-cell-cycle functions, such as the Warburg effect. These data indicate that both the physiological and the oncogenic activities of E2f result in distinct transcriptional responses, which could be exploited to target E2f oncogenic activity for therapy. PMID:26639898

  10. 17?-estradiol (E2) in membranes: Orientation and dynamic properties.

    PubMed

    Guo, Jason J; Yang, De-Ping; Tian, Xiaoyu; Vemuri, V Kiran; Yin, Dali; Li, Chen; Duclos, Richard I; Shen, Lingling; Ma, Xiaoyu; Janero, David R; Makriyannis, Alexandros

    2016-02-01

    Non-genomic membrane effects of estrogens are of great interest because of the diverse biological activities they may elicit. To further our understanding of the molecular features of the interaction between estrogenic hormones and membrane bilayers, we have determined the preferred orientation, location, and dynamic properties of 17?-estradiol (E2) in two different phospholipid membrane environments using (2)H-NMR and 2D (1)H-(13)C HSQC in conjunction with molecular dynamics simulations. Unequivocal spectral assignments to specific (2)H labels were made possible by synthesizing six selectively deuterated E2 molecules. The data allow us to conclude that the E2 molecule adopts a nearly "horizontal" orientation in the membrane bilayer with its long axis essentially perpendicular to the lipid acyl-chains. All four rings of the E2 molecule are located near the membrane interface, allowing both the E2 3-OH and the 17?-OH groups to engage in hydrogen bonding and electrostatic interactions with polar phospholipid groups. The findings augment our knowledge of the molecular interactions between E2 and membrane bilayer and highlight the asymmetric nature of the dynamic motions of the rigid E2 molecule in a membrane environment. PMID:26607010

  11. Canonical and Atypical E2Fs Regulate the Mammalian Endocycle

    PubMed Central

    Chen, Hui-Zi; Ouseph, Madhu M.; Li, Jing; Pcot, Thierry; Chokshi, Veda; Kent, Lindsey; Bae, Sooin; Byrne, Morgan; Duran, Camille; Comstock, Grant; Trikha, Prashant; Mair, Markus; Senapati, Shantibhusan; Martin, Chelsea K.; Gandhi, Sagar; Wilson, Nicholas; Liu, Bin; Huang, Yi-Wen; Thompson, John C.; Raman, Sundaresan; Singh, Shantanu; Leone, Marcelo; Machiraju, Raghu; Huang, Kun; Mo, Xiaokui; Fernandez, Soledad; Kalaszczynska, Ilona; Wolgemuth, Debra J.; Sicinski, Piotr; Huang, Tim; Jin, Victor; Leone, Gustavo

    2012-01-01

    SUMMARY The endocycle is a variant cell cycle consisting of successive DNA synthesis and Gap phases that yield highly polyploid cells. Although essential for metazoan development, relatively little is known about its control or physiologic role in mammals. Using novel lineage-specific cre mice we identified two opposing arms of the E2F program, one driven by canonical transcription activation (E2F1, E2F2 and E2F3) and the other by atypical repression (E2F7 and E2F8), that converge on the regulation of endocycles in vivo. Ablation of canonical activators in the two endocycling tissues of mammals, trophoblast giant cells in the placenta and hepatocytes in the liver, augmented genome ploidy, whereas ablation of atypical repressors diminished ploidy. These two antagonistic arms coordinate the expression of a unique G2/M transcriptional program that is critical for mitosis, karyokinesis and cytokinesis. These results provide in vivo evidence for a direct role of E2F family members in regulating non-traditional cell cycles in mammals. PMID:23064266

  12. Gamma-ray spectrometer onboard Chang'E-2

    NASA Astrophysics Data System (ADS)

    Ma, T.; Chang, J.; Zhang, N.; Jian, W.; Cai, M. S.; Gong, Y. Z.; Tang, H. S.; Zhang, R. J.; Wang, N. S.; Yu, M.; Mao, J. P.; Hu, Y. M.; Xu, A. A.; Zhu, M. H.

    2013-10-01

    Chang'E-2 gamma-ray spectrometer (GRS) is included in the payload of Chinese second lunar mission Chang'E-2 that has been launched in October 2010. Specific objectives of the GRS are to map abundance of O, Si, Fe, Ti, U, Th, K, and, perhaps, Mg, Al, and Ca, to depth of about 20 cm. The energy resolution and detection efficiency were improved compared with Chang'E-1 GRS. We will describe the design of GRS, which used LaBr3 for its main detector, and present its performance in this paper. Moreover, the initial result of Chang'E-2 GRS is reported.

  13. 17?-Estradiol and Inflammation: Implications for Ischemic Stroke

    PubMed Central

    Petrone, Ashley B.; Simpkins, James W.; Barr, Taura L.

    2014-01-01

    Although typically associated with maintenance of female reproductive function, estrogens mediate physiological processes in nearly every body tissue, including the central nervous system. Numerous pre-clinical studies have shown that estrogen, specifically 17-beta-estradiol (17?-E2), protects the brain from ischemic injury following stroke. There are multiple mechanisms of 17?-E2s neuroprotection, including activation of several neuroprotective pathways in the brain, but 17?-E2 also mediates the local and systemic immune response to ischemic stroke. This review summarizes the immune response to stroke, sex differences in stroke pathophysiology, and the role of estrogen as an immunomodulator. This review will focus almost entirely on the role of 17?-E2; however, there will be a brief review and comparison to other forms of estrogen. Understanding the immunomodulatory action of estrogens may provide an opportunity for the use of estrogens in treatment of stroke and other inflammatory disease. PMID:25276492

  14. Cezanne regulates E2F1-dependent HIF2? expression.

    PubMed

    Moniz, Sonia; Bandarra, Daniel; Biddlestone, John; Campbell, Kirsteen J; Komander, David; Bremm, Anja; Rocha, Sonia

    2015-08-15

    Mechanisms regulating protein degradation ensure the correct and timely expression of transcription factors such as hypoxia inducible factor (HIF). Under normal O2 tension, HIF? subunits are targeted for proteasomal degradation, mainly through vHL-dependent ubiquitylation. Deubiquitylases are responsible for reversing this process. Although the mechanism and regulation of HIF? by ubiquitin-dependent proteasomal degradation has been the object of many studies, little is known about the role of deubiquitylases. Here, we show that expression of HIF2? (encoded by EPAS1) is regulated by the deubiquitylase Cezanne (also known as OTUD7B) in an E2F1-dependent manner. Knockdown of Cezanne downregulates HIF2? mRNA, protein and activity independently of hypoxia and proteasomal degradation. Mechanistically, expression of the HIF2? gene is controlled directly by E2F1, and Cezanne regulates the stability of E2F1. Exogenous E2F1 can rescue HIF2? transcript and protein expression when Cezanne is depleted. Taken together, these data reveal a novel mechanism for the regulation of the expression of HIF2?, demonstrating that the HIF2? promoter is regulated by E2F1 directly and that Cezanne regulates HIF2? expression through control of E2F1 levels. Our results thus suggest that HIF2? is controlled transcriptionally in a cell-cycle-dependent manner and in response to oncogenic signalling. PMID:26148512

  15. An (e,2e) Measurement of the Xe Photoelectron ? Parameter

    NASA Astrophysics Data System (ADS)

    Childers, J. G.; Martin, N. L. S.; Thompson, D. B.

    2000-06-01

    We have carried out (e,2e) experiments on Xe in the autoionizing region between the ^2P_3/2 and ^2P_1/2 ionic limits. (e,2e) spectra were taken at 150 eV incident electron energy and 0^circ scattering angle corresponding to a momentum transfer of 0.14 au. The spectral range covered the (^2P_1/2)nd,ms (n>=6,m>=8) autoionizing resonances which have ejected electron energies between 0 and 1.3 eV. The (e,2e) spectrometer has two ejected electron detectors configured to allow the simultaneous collection of (e,2e) ejected-electron spectra 180^circ apart. The summation of these spectra eliminates the non-dipole effects due to dipole-monopole and dipole-quadrupole interference, leaving a spectrum that mimics a pure dipole photoelectron experiment. Two separate (e,2e) experiments, at ejected electron directions 60^circ (the minimum possible) and 90^circ away from the momentum transfer axis, enable the determination of the Xe ? parameter. Our results are in quite good agreement with the true photoelectron experiments.(J.Z. Wu, S.B. Whitfield, C.D. Caldwell, M.O. Krause, P. van der Meulen and A. Fahlman, Phys.Rev.A 42), 1350 (1990).

  16. Large Scale Genotype Comparison of Human Papillomavirus E2-Host Interaction Networks Provides New Insights for E2 Molecular Functions

    PubMed Central

    Muller, Mandy; Jacob, Yves; Jones, Louis; Weiss, Amlie; Brino, Laurent; Chantier, Thibault; Lotteau, Vincent; Favre, Michel; Demeret, Caroline

    2012-01-01

    Human Papillomaviruses (HPV) cause widespread infections in humans, resulting in latent infections or diseases ranging from benign hyperplasia to cancers. HPV-induced pathologies result from complex interplays between viral proteins and the host proteome. Given the major public health concern due to HPV-associated cancers, most studies have focused on the early proteins expressed by HPV genotypes with high oncogenic potential (designated high-risk HPV or HR-HPV). To advance the global understanding of HPV pathogenesis, we mapped the virus/host interaction networks of the E2 regulatory protein from 12 genotypes representative of the range of HPV pathogenicity. Large-scale identification of E2-interaction partners was performed by yeast two-hybrid screenings of a HaCaT cDNA library. Based on a high-confidence scoring scheme, a subset of these partners was then validated for pair-wise interaction in mammalian cells with the whole range of the 12 E2 proteins, allowing a comparative interaction analysis. Hierarchical clustering of E2-host interaction profiles mostly recapitulated HPV phylogeny and provides clues to the involvement of E2 in HPV infection. A set of cellular proteins could thus be identified discriminating, among the mucosal HPV, E2 proteins of HR-HPV 16 or 18 from the non-oncogenic genital HPV. The study of the interaction networks revealed a preferential hijacking of highly connected cellular proteins and the targeting of several functional families. These include transcription regulation, regulation of apoptosis, RNA processing, ubiquitination and intracellular trafficking. The present work provides an overview of E2 biological functions across multiple HPV genotypes. PMID:22761572

  17. Hepatitis C virus E2 envelope glycoprotein core structure.

    PubMed

    Kong, Leopold; Giang, Erick; Nieusma, Travis; Kadam, Rameshwar U; Cogburn, Kristin E; Hua, Yuanzi; Dai, Xiaoping; Stanfield, Robyn L; Burton, Dennis R; Ward, Andrew B; Wilson, Ian A; Law, Mansun

    2013-11-29

    Hepatitis C virus (HCV), a Hepacivirus, is a major cause of viral hepatitis, liver cirrhosis, and hepatocellular carcinoma. HCV envelope glycoproteins E1 and E2 mediate fusion and entry into host cells and are the primary targets of the humoral immune response. The crystal structure of the E2 core bound to broadly neutralizing antibody AR3C at 2.65 angstroms reveals a compact architecture composed of a central immunoglobulin-fold ? sandwich flanked by two additional protein layers. The CD81 receptor binding site was identified by electron microscopy and site-directed mutagenesis and overlaps with the AR3C epitope. The x-ray and electron microscopy E2 structures differ markedly from predictions of an extended, three-domain, class II fusion protein fold and therefore provide valuable information for HCV drug and vaccine design. PMID:24288331

  18. Hepatitis C Virus E2 Envelope Glycoprotein Core Structure

    SciTech Connect

    Kong, Leopold; Giang, Erick; Nieusma, Travis; Kadam, Rameshwar U.; Cogburn, Kristin E.; Hua, Yuanzi; Dai, Xiaoping; Stanfield, Robyn L.; Burton, Dennis R.; Ward, Andrew B.; Wilson, Ian A.; Law, Mansun

    2014-08-26

    Hepatitis C virus (HCV), a Hepacivirus, is a major cause of viral hepatitis, liver cirrhosis, and hepatocellular carcinoma. HCV envelope glycoproteins E1 and E2 mediate fusion and entry into host cells and are the primary targets of the humoral immune response. The crystal structure of the E2 core bound to broadly neutralizing antibody AR3C at 2.65 angstroms reveals a compact architecture composed of a central immunoglobulin-fold β sandwich flanked by two additional protein layers. The CD81 receptor binding site was identified by electron microscopy and site-directed mutagenesis and overlaps with the AR3C epitope. The x-ray and electron microscopy E2 structures differ markedly from predictions of an extended, three-domain, class II fusion protein fold and therefore provide valuable information for HCV drug and vaccine design.

  19. B (e 2 ;21+?01+) value in 90Kr

    NASA Astrophysics Data System (ADS)

    Rgis, J.-M.; Jolie, J.; Saed-Samii, N.; Warr, N.; Pfeiffer, M.; Blanc, A.; Jentschel, M.; Kster, U.; Mutti, P.; Soldner, T.; Simpson, G. S.; Drouet, F.; Vancraeyenest, A.; de France, G.; Clment, E.; Stezowski, O.; Ur, C. A.; Urban, W.; Regan, P. H.; Podolyk, Zs.; Larijani, C.; Townsley, C.; Carroll, R.; Wilson, E.; Fraile, L. M.; Mach, H.; Paziy, V.; Olaizola, B.; Vedia, V.; Bruce, A. M.; Roberts, O. J.; Smith, J. F.; Krll, T.; Hartig, A.-L.; Ignatov, A.; Ilieva, S.; Thrauf, M.; Lalkovski, S.; Ivanova, D.; Kisyov, S.; Korten, W.; Salsac, M.-D.; Zieli?ska, M.; M?rginean, N.; Ghit?, D. G.; Lic?, R.; Petrache, C. M.; Astier, A.; Leguillon, R.

    2014-12-01

    A smooth onset of collectivity in 88 ,92 ,94 ,96Kr has been determined from reported B (E 2 ;21+?01+) and E (21+) values. This is in contrast to the sudden onset in even-even Zr, Mo, and Sr isotopes. Our objective was to complete the systematics by determining the B (E 2 ;21+?01+) value in 90Kr, which was produced by cold-neutron-induced fission of 235U . The lifetime of the 21+ state in 90Kr was measured via the electronic ? -? timing technique using the EXILL and FATIMA spectrometers. Based on the measured mean lifetime of ? = 15(10) ps, the B (E 2 ;21+?01+) value of 13 -5+26 W.u. in 90Kr is determined for the first time and the smooth onset of deformation in the even-even Kr isotopes beyond neutron number N =50 is confirmed.

  20. Reproductive responses of common carp (Cyprinus carpio) exposed in cages to influent of the Las Vegas Wash in Lake Mead, Nevada, from late winter to early spring.

    PubMed

    Snyder, Erin M; Snyder, Shane A; Kelly, Kevin L; Gross, Timothy S; Villeneuve, Daniel L; Fitzgerald, Scott D; Villalobos, Sergio A; Giesy, John P

    2004-12-01

    The Las Vegas Wash (LW) delivers tertiary-treated municipal wastewater effluent, nonpotable shallow groundwater seepage, and runoff from the urbanized Las Vegas Valley to Las Vegas Bay (LX) of Lake Mead. To investigate the potential for contaminants in LW influent to produce effects indicative of endocrine disruption in vivo, adult male and female common carp (Cyprinus carpio) were exposed in cages for 42-48 d at four sites in Lake Mead: LW, LX, and two reference locations in the lake. End points examined included gonadosomatic index; gonad histology; concentrations of plasma vitellogenin (VTG) and plasma sex steroids (17beta-estradiol (E2), testosterone (T), 11-ketotestosterone (11-KT)); plasma estrogen:androgen ratios (E2:T, E2:11-KT), in vitro production of T by gonad tissue, and hepatopancreas ethoxyresorufin O-deethylase activity. Few differences among fish caged at different sites were potentially attributable to exposure to contaminants PMID:15597896

  1. 26 CFR 31.3231(e)-2 - Contribution base.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 15 2010-04-01 2010-04-01 false Contribution base. 31.3231(e)-2 Section 31.3231... Contribution base. The term compensation does not include any remuneration paid during any calendar year by an employer to an employee for services rendered in excess of the applicable contribution base. For...

  2. 26 CFR 31.3231(e)-2 - Contribution base.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 15 2011-04-01 2011-04-01 false Contribution base. 31.3231(e)-2 Section 31.3231... Contribution base. The term compensation does not include any remuneration paid during any calendar year by an employer to an employee for services rendered in excess of the applicable contribution base. For...

  3. E-2C Loads Calibration in DFRC Flight Loads Lab

    NASA Technical Reports Server (NTRS)

    Schuster, Lawrence S.

    2008-01-01

    Objectives: a) Safely and efficiently perform structural load tests on NAVAIR E-2C aircraft to calibrate strain gage instrumentation installed by NAVAIR; b) Collect load test data and derive loads equations for use in NAVAIR flight tests; and c) Assist flight test team with use of loads equations measurements at PAX River.

  4. ENVIRONMENTAL EFFECTS OF DREDGING AND DISPOSAL (E2-D2)

    EPA Science Inventory

    US Army Corps of Engineers public web site for the "Environmental Effects of Dredging and Disposal" ("E2-D2") searchable database of published reports and studies about environmental impacts associated with dredging and disposal operations. Many of the reports and studies are ava...

  5. Chang'e-2 spacecraft observations of asteroid 4179 Toutatis

    NASA Astrophysics Data System (ADS)

    Ji, Jianghui; Jiang, Yun; Zhao, Yuhui; Wang, Su; Yu, Liangliang

    2016-01-01

    On 13 December 2012, Chang'e-2 completed a successful flyby of the near-Earth asteroid 4179 Toutatis at a closest distance of 770 meters from the asteroid's surface. The observations show that Toutatis has an irregular surface and its shape resembles a ginger-root of a smaller lobe (head) and a larger lobe (body). Such bilobate shape is indicative of a contact binary origin for Toutatis. In addition, the high-resolution images better than 3 meters provide a number of new discoveries about this asteroid, such as an 800-meter depression at the end of the large lobe, a sharply perpendicular silhouette near the neck region, boulders, indicating that Toutatis is probably a rubble-pile asteroid. Chang'e-2 observations have significantly revealed new insights into the geological features and the formation and evolution of this asteroid. In final, we brief the future Chinese asteroid mission concept.

  6. Endoatmospheric/Exoatmospheric Interceptor (E2 I) Program

    SciTech Connect

    Sherer, A.D.; Reeves, W.C. Jr. )

    1992-05-01

    An overview is given of the Endoatmospheric/Exoatmospheric Interceptor (E2 I) Program. The overall objective of the program is to develop an interceptor to support the endoatmospheric mission of SDI Organization National Missile Defense, while its primary technical objective is to develop the hardware and software required to demonstrate the deployable interceptor that can perform onboard target cluster track and target selection. The background, modes of operation, concept of operation, basis for onboard target selection, and program acquisition are discussed.

  7. Advanced Stirling Convertor (ASC-E2) Characterization Testing

    NASA Technical Reports Server (NTRS)

    Williams, Zachary D.; Oriti, Salvatore M.

    2012-01-01

    Testing has been conducted on Advanced Stirling Convertor (ASC-E2) convertors at NASA Glenn Research Center in support of the Advanced Stirling Radioisotope Generator (ASRG) Project. This testing has been conducted to understand sensitivities of convertor parameters due to environmental and operational changes during operation of the ASRG in missions to space. This paper summarizes test results and explains in terms of operation of the ASRG during space missions.

  8. Advanced Stirling Convertor (ASC-E2) Characterization Testing

    NASA Technical Reports Server (NTRS)

    Williams, Zachary D.; Oriti, Salvatore M.

    2012-01-01

    Testing has been conducted on Advanced Stirling Convertors (ASCs)-E2 at NASA Glenn Research Center in support of the Advanced Stirling Radioisotope Generator (ASRG) project. This testing has been conducted to understand sensitivities of convertor parameters due to environmental and operational changes during operation of the ASRG in missions to space. This paper summarizes test results and explains the operation of the ASRG during space missions

  9. Formulation of Ames 24E2 IR-black coating

    NASA Technical Reports Server (NTRS)

    Smith, Sheldon M.

    1991-01-01

    The formulation of Ames 24E2 IR-black coating and a rationale for the selection of its components are given. The objective was to make a very rough, very thick, and highly absorbing coating to attenuate the specular reflectance of telescope baffles at far-IR wavelengths. Application and curing instructions are also given. Outgassing measurements are quite low following a 24-hour radiative cure.

  10. The ancient function of RB-E2F Pathway: insights from its evolutionary history

    PubMed Central

    2010-01-01

    Background The RB-E2F pathway is conserved in most eukaryotic lineages, including animals and plants. E2F and RB family proteins perform crucial functions in cycle controlling, differentiation, development and apoptosis. However, there are two kinds of E2Fs (repressive E2Fs and active E2Fs) and three RB family members in human. Till now, the detail evolutionary history of these protein families and how RB-E2F pathway evolved in different organisms remain poorly explored. Results We performed a comprehensive evolutionary analysis of E2F, RB and DP (dimerization partners of E2Fs) protein family in representative eukaryotic organisms. Several interesting facts were revealed. First, orthologues of RB, E2F, and DP family are present in several representative unicellular organisms and all multicellular organisms we checked. Second, ancestral E2F, RB genes duplicated before placozoans and bilaterians diverged, thus E2F family was divided into E2F4/5 subgroup (including repressive E2Fs: E2F4 and E2F5) and E2F1/2/3 subgroup (including active E2Fs: E2F1, E2F2 and E2F3), RB family was divided into RB1 subgroup (including RB1) and RBL subgroup (including RBL1 and RBL2). Third, E2F4 and E2F5 share more sequence similarity with the predicted E2F ancestral sequence than E2F1, E2F2 and E2F3; E2F4 and E2F5 also possess lower evolutionary rates and higher purification selection pressures than E2F1, E2F2 and E2F3. Fourth, for RB family, the RBL subgroup proteins possess lower evolutionary rates and higher purification selection pressures compared with RB subgroup proteins in vertebrates, Conclusions Protein evolutionary rates and purification selection pressures are usually linked with protein functions. We speculated that function conducted by E2F4/5 subgroup and RBL subgroup proteins might mainly represent the ancient function of RB-E2F pathway, and the E2F1/2/3 subgroup proteins and RB1 protein might contribute more to functional diversification in RB-E2F pathway. Our results will enhance the current understanding of RB-E2F pathway and will also be useful to further functional studies in human and other model organisms. Reviewers This article was reviewed by Dr. Pierre Pontarotti, Dr. Arcady Mushegian and Dr. Zhenguo Lin (nominated by Dr. Neil Smalheiser). PMID:20849664

  11. Developing a Biosensor for Estrogens in Water Samples: Study ofthe Real-time Response of Live Cells of the Estrogen-sensitive YeastStrain RMY/ER-ERE using Fluorescence Microscopy

    SciTech Connect

    Wozei, E.; Hermanowicz, S.W.; Holman, H-Y.N.

    2005-07-13

    Using a fluorescein di-{beta}-D-galactopyranoside (FDG) substrate we show that in live cells of an estrogen-sensitive yeast strain RMY/ER-ERE with human estrogen receptor (ER{alpha}) gene and the lacZ gene which encodes {beta}-galactosidase, the uptake of 17 {beta}-estradiol (E2) and the subsequent production of {beta}-galactosidase enzyme occur quite rapidly, with maximal enzyme-catalyzed product formation evident after about 30 minutes of exposure to E2. This finding which agrees with the well-known rates of enzyme-catalyzed reactions could have implications for shortening the duration of environmental sample screening and monitoring regimes using yeast-based estrogen assays, and the development of biosensors for environmental estrogens to complement quantification methods.

  12. Developing a Biosensor for Estrogens in Water Samples: Study ofthe Real-time Response of Live Cells of the Estrogen-sensitive YeastStrain RMY/ER-ERE using Fluorescence Microscopy

    SciTech Connect

    Wozei, E.; Hermanowicz, S.W.; Holman, H-Y.N.

    2006-01-01

    Using a fluorescein di-{beta}-d-galactopyranoside (FDG) substrate we show that in live cells of an estrogen-sensitive yeast strain RMY/ER-ERE with human estrogen receptor (ER{alpha}) gene and the lacZ gene which encodes {beta}-galactosidase, the uptake of 17{beta}-estradiol (E2) and the subsequent production of {beta}-galactosidase enzyme occur quite rapidly, with maximal enzyme-catalyzed product formation evident after about 30 min of exposure to E2. This finding which agrees with the well-known rates of enzyme-catalyzed reactions could have implications for shortening the duration of environmental sample screening and monitoring regimes using yeast-based estrogen assays, and the development of biosensors for environmental estrogens to complement quantification methods.

  13. An E2 accessory domain increases affinity for the anaphase-promoting complex and ensures E2 competition.

    PubMed

    Girard, Juliet R; Tenthorey, Jeanette L; Morgan, David O

    2015-10-01

    The anaphase-promoting complex/cyclosome (APC/C) is a member of the RING family of E3 ubiquitin ligases, which promote ubiquitin transfer from an E2 ubiquitin-conjugating enzyme to a substrate. In budding yeast, the APC/C collaborates with two E2s, Ubc4 and Ubc1, to promote the initiation and elongation, respectively, of polyubiquitin chains on the substrate. Ubc4 and Ubc1 are thought to compete for the same site on the APC/C, but it is not clear how their affinities are balanced. Here, we demonstrate that a C-terminal ubiquitin-associated (UBA) domain enhances the affinity of Ubc1 for the APC/C. Deletion of the UBA domain reduced apparent APC/C affinity for Ubc1 and decreased polyubiquitin chain length. Surprisingly, the positive effect of the UBA domain was not due to an interaction with the acceptor ubiquitin attached to the APC/C substrate or the donor ubiquitin attached to Ubc1 itself. Instead, our evidence suggests that the UBA domain binds to a site on the APC/C core, thereby increasing Ubc1 affinity and enhancing its ability to compete with Ubc4. The UBA domain is required for normal Ubc1 function and E2 competition in vivo. Thus, the UBA domain of Ubc1 ensures efficient polyubiquitination of substrate by balancing Ubc1 affinity with that of Ubc4. PMID:26306044

  14. Astro-E2 Magnesium Diboride High Current Leads

    NASA Technical Reports Server (NTRS)

    Panek, J. S.; Tuttle, J. G.; Riall, S.; Mustafi, S.; Gray, A.; Edmonds, R.; Marrero, V.

    2003-01-01

    The recent discovery of superconducting properties in MgB_2 and rapid development of small diameter steel-clad wires has opened up the possibility of enhancing the design of the baseline Astro-E2 high current lead assembly. Replacing YBCO filaments with MgB_2 wires and modifying the heat sink location can give much higher margins against quench from temperature oscillations of the 4 K heat sink, although wih some overall thermal penalty. The design and performance of a new lead assembly during flight qualification is discussed, with emphasis on thermal, structural, and electrical test results.

  15. E-2-Benzylidenebenzocycloalkanones. Stereostructure and NMR spectroscopic investigation

    NASA Astrophysics Data System (ADS)

    Perjsi, P.; Nusser, T.; Tarczay, Gy.; Sohr, P.

    1999-04-01

    Series of E-2-benzylideneindanones ( a), -tetralones ( b) and -benzosuberones ( c) with OCH 3 ( 2- 4), NO 2 ( 5- 7) and F ( 8- 10) substitutions ( ortho, meta and para) on their benzylidene moiety were synthesized by aldol condensation of the appropriate aldehydes and benzocyclanones. The stereostructure (configuration and conformation) and the electronic properties (conjugation of the enone moiety with the aromatic rings) of the compounds were studied by IR, 1H and 13C NMR spectroscopy including also 2D-HSC, DNOE and DEPT measurements. Ab initio calculations were carried out to corroborate the experimental findings.

  16. HPV 16 E2 binding sites 1 and 2 become more methylated than E2 binding site 4 during cervical carcinogenesis.

    PubMed

    Leung, Tsin-Wah; Liu, Stephanie S; Leung, Rebecca C Y; Chu, Mandy M Y; Cheung, Annie N Y; Ngan, Hextan Y S

    2015-06-01

    E2 protein binding to the four E2 binding sites (E2BSs) at the long control region of Human Papillomavirus (HPV) 16/18 genome may exert either transcriptional activation/repression on E6 and E7 oncoproteins. Methylation status at the E2BSs may affect the relative binding of E2 protein to them. In this study, methylation percentage at E2BS 1, 2 (promoter-proximal), and 4 (promoter-distal) were assessed by pyrosequencing and compared among HPV 16/18-positive cervical cancer, high-grade, and low-grade Cervical Intraepithelial Neoplasia, Atypical Squamous Cells of Undetermined Significance, and normal cervical epithelium. HPV 16 E2BS1&2 were more methylated than HPV 16 E2BS4 in cervical cancer whereas in cervical premalignant lesions and normal epithelium, HPV 16 E2BS1&2 were less methylated than HPV 16 E2BS4. HPV 18 E2BS1&2 remained more methylated than E2BS4 in all histological groups. HPV 16 E2BS1&2 methylation increased from high-grade lesions to cervical cancer (P?E2BS4 methylation increased from low-grade to high-grade premalignant lesions (P?=?0.041). Both HPV 18 E2BS1&2 and E2BS4 methylation increased from low-grade to high-grade Cervical Intraepithelial Neoplasia (P?=?0.019 and 0.001 respectively) and further increased form high-grade lesions to cervical cancer (P?E2BS1&2 (for transcriptional repression of E6/E7 oncoproteins) became more heavily methylated than E2BS4 (for transcriptional activation of E6/E7) in cervical cancer, favouring the differential binding of E2 protein to E2BS4. Increasing methylation at HPV 16/18 E2BSs are potentially useful adjunctive molecular markers for predicting progression from low-grade to high-grade cervical premalignant lesions and from high-grade lesions to cervical cancer. PMID:25648229

  17. Estrogens in streams associated with a concentrated animal feeding operation in upstate New York, USA.

    PubMed

    Zhao, Sherry; Zhang, Pengfei; Melcer, Michael E; Molina, John F

    2010-04-01

    Estrogens (estrone, 17 alpha-estradiol, 17beta-estradiol, and estriol) in three headwater streams within a concentrated animal feed operation (CAFO) site were monitored on a monthly base for a year (November 2006-October 2007). This CAFO is certified as organic (no growth promoters are administrated) and uses many Whole Farm Planning practices (e.g., 12-month-capacity waste storage lagoons). In general, estrogen concentrations in the streams are low (<1 ng L(-1)), and appeared to increase in spring, likely due to the mobilization of estrogens from soils upon snow melting/precipitation. Estrogens were detected in the streams during dry periods, indicating the contribution of estrogens from groundwater. The low concentrations of estrogens in stream water were probably the result of the long residence time (approximately 8 months) of the manure in the lagoons where most of the estrogens were degraded during storage. An analysis of liquid manure at the beginning of manure application season (after approximately 8 months storage) showed that over 99.8% of the estrogens potentially excreted by the cows were degraded. Moreover, about 90% of the estrogens in the liquid manure were associated with particulates larger than 0.7 microm. Batch experiments with spiked deuterium-labeled 17beta-estradiol-16,16,17-d(3) (d(3)-E2 beta) in the liquid manure demonstrated sorption of d(3)-E2 beta onto particulates in the liquid manure, and rapid degradation of d(3)-E2 beta in the aqueous phase and on particulates of the liquid manure under aerobic conditions. PMID:20172589

  18. The Astro-E2/XRS-2 helium insert system

    NASA Astrophysics Data System (ADS)

    Shirron, P. J.; DiPirro, M. J.; Panek, J.; Kelley, R.; Mitsuda, K.; Fujimoto, R.; Hirabayashi, M.; McCammon, D.

    2006-04-01

    The X-ray Spectrometer (XRS-2) instrument on the Japanese Space Agency (JAXA) Astro-E2 spacecraft will measure faint X-ray emissions in the energy range of 0.2-10 keV. A square array of 32 X-ray microcalorimeters used will be able to distinguish individual photons to better than 10 eV at 6 keV, with a quantum efficiency near 100%. The detectors are cooled to 60 mK by means of an adiabatic demagnetization refrigerator (ADR). The ADR rejects heat to a 1.3 K superfluid helium tank, which is surrounded by a 17 K solid neon tank. A Stirling cycle cryocooler precools an outer shield around the neon tank. This system will provide an estimated 3 years of on-orbit lifetime. This paper describes the helium insert, the ADR, the high temperature superconducting leads, and early on-orbit performance.

  19. Inflammatory mediator prostaglandin E2 in colorectal cancer

    PubMed Central

    Wang, Dingzhi; DuBois, Raymond N.

    2016-01-01

    It is widely accepted that dietary fats and chronic inflammation are risk factors for developing colorectal cancer. Arachidonic acid is a major component of animal fats and the bioactive lipids produced from this substrate play critical roles in a variety of biologic processes, including cancer. Cyclooxygenase-derived prostaglandin E2 (PGE2) is a known pro-inflammatory lipid mediator and promotes tumor progression. Metabolism of arachidonic acid by the cyclooxygenase pathway provides one mechanism for the contribution of dietary fats and chronic inflammation to carcinogenesis. In this review, we highlight recent advances in our understanding of how pro-inflammatory mediator PGE2 promotes colorectal cancer immune evasion. These findings may provide a rationale for the development of new therapeutic approaches to subvert tumor-induced immunosuppression. PMID:24270349

  20. Ionization excitation of helium by the (e,2e) reaction

    SciTech Connect

    Ren, X.G.; Ning, C.G.; Deng, J.K.; Su, G.L.; Zhang, S.F.; Huang, Y.R.; Li, G.Q.

    2005-10-15

    The (e,2e) cross sections for transitions to the n=1, 2, and 3 final state of He{sup +} have been measured at impact energies of 1000 and 1600 eV by using a newly developed energy and momentum dispersive spectrometer. Binding energy spectra in the range of 8 to 86 eV and momentum profiles for the transitions to the ground and excited ion states of He{sup +} are reported at different impact energies, and the experimental results are compared with plane wave impulse approximation calculations. The impact energy dependence of cross section ratios for the He{sup +} n=1, 2, and 3 final states are obtained. Some discrepancies are observed between experimental data and theoretical calculations.

  1. Triply differential (e,2e) studies of phenol

    SciTech Connect

    Silva, G. B. da; Neves, R. F. C.; Chiari, L.; Jones, D. B.; Ali, E.; Madison, D. H.; Ning, C. G.; Nixon, K. L.; Lopes, M. C. A.; Brunger, M. J.

    2014-09-28

    We have measured (e,2e) triple differential cross sections (TDCS) for the electron-impact ionisation of phenol with coplanar asymmetrical kinematics for an incident electron energy of 250 eV. Experimental measurements of the angular distribution of the slow outgoing electrons at 20 eV are obtained when the incident electron scatters through angles of −5°, −10°, and −15°, respectively. The TDCS data are compared with calculations performed within the molecular 3-body distorted wave model. In this case, a mixed level of agreement, that was dependent on the kinematical condition being probed, was observed between the theoretical and experimental results in the binary peak region. The experimental intensity of the recoil features under all kinematical conditions was relatively small, but was still largely underestimated by the theoretical calculations.

  2. Dynamical (e,2e) studies of tetrahydrofurfuryl alcohol.

    PubMed

    Bellm, S M; Builth-Williams, J D; Jones, D B; Chaluvadi, Hari; Madison, D H; Ning, C G; Wang, F; Ma, X G; Lohmann, B; Brunger, M J

    2012-06-28

    Cross section data for electron scattering from DNA are important for modelling radiation damage in biological systems. Triply differential cross sections for the electron impact ionization of the highest occupied outer valence orbital of tetrahydrofurfuryl alcohol, which can be considered as an analogue to the deoxyribose backbone molecule in DNA, have been measured using the (e,2e) technique. The measurements have been performed with coplanar asymmetric kinematics at an incident electron energy of 250 eV, an ejected electron energy of 20 eV, and at scattered electron angles of -5°, -10°, and -15°. Experimental results are compared with corresponding theoretical calculations performed using the molecular 3-body distorted wave model. Some important differences are observed between the experiment and calculations. PMID:22755568

  3. Triply differential (e,2e) studies of phenol

    NASA Astrophysics Data System (ADS)

    da Silva, G. B.; Neves, R. F. C.; Chiari, L.; Jones, D. B.; Ali, E.; Madison, D. H.; Ning, C. G.; Nixon, K. L.; Lopes, M. C. A.; Brunger, M. J.

    2014-09-01

    We have measured (e,2e) triple differential cross sections (TDCS) for the electron-impact ionisation of phenol with coplanar asymmetrical kinematics for an incident electron energy of 250 eV. Experimental measurements of the angular distribution of the slow outgoing electrons at 20 eV are obtained when the incident electron scatters through angles of -5, -10, and -15, respectively. The TDCS data are compared with calculations performed within the molecular 3-body distorted wave model. In this case, a mixed level of agreement, that was dependent on the kinematical condition being probed, was observed between the theoretical and experimental results in the binary peak region. The experimental intensity of the recoil features under all kinematical conditions was relatively small, but was still largely underestimated by the theoretical calculations.

  4. Three body effects in low energy (e,2e) processes

    SciTech Connect

    Rasch, J.; Whelan, Colm T.

    1999-06-10

    Within the last two years a number of highly refined measurements have been performed on H targets which have yielded accurate absolute data for a range of energies and geometries and it would appear that the experimental situation for this, the simplest of atomic targets is now resolved. The theoretical situation is however far from satisfactory and in this paper we will analysis some of the main approaches and characterize their strengths and their weaknesses. We have developed a numerical method which allows us to evaluate triple differential cross sections (TDCS) using the most complex position dependent analytic ansatz wave function and we will present results, using this for low energy (e,2e) processes. We will see that this approach fails when incident channel effects, such as target polarization are likely to be strong.

  5. Cigarette smoking reduces human gastric luminal prostaglandin E2.

    PubMed Central

    McCready, D R; Clark, L; Cohen, M M

    1985-01-01

    The effect of smoking three cigarettes on the release of prostaglandin E2 (PGE2) by the gastric mucosa was studied in seven healthy smokers. Smoking caused the expected increases in pulse rate, blood pressure, plasma glucose, and carboxyhaemoglobin. In addition, smoking resulted in a significant (p less than 0.05) reduction in the volume of pentagastrin stimulated gastric juice from 76.1 +/- 4.4 to 54.1 +/- 4.6 ml/15 min and PGE2 output from 22.8 +/- 4.9 to 12.2 +/- 3.8 ng/15 min but did not alter acid output. It is concluded that smoking reduces the amount of PGE2 in the gastric lumen and that this may explain why it is a risk factor for peptic ulcer. PMID:3864718

  6. Spectrin's chimeric E2/E3 enzymatic activity.

    PubMed

    Goodman, Steven R; Petrofes Chapa, Rachel; Zimmer, Warren E

    2015-08-01

    In this minireview, we cover the discovery of the human erythrocyte ? spectrin E2/E3 ubiquitin conjugating/ligating enzymatic activity and the specific cysteines involved. We then discuss the consequences when this activity is partially inhibited in sickle cell disease and the possibility that the same attenuation is occurring in multiple organ dysfunction syndrome. We finish by discussing the reasons for believing that nonerythroid ? spectrin isoforms (I and II) also have this activity and the importance of testing this hypothesis. If correct, this would suggest that the nonerythroid spectrin isoforms play a major role in protein ubiquitination in all cell types. This would open new fields in experimental biology focused on uncovering the impact that this enzymatic activity has upon protein-protein interactions, protein turnover, cellular signaling, and many other functions impacted by spectrin, including DNA repair. PMID:26283706

  7. E-2D Advanced Hawkeye: primary flight display

    NASA Astrophysics Data System (ADS)

    Paolillo, Paul W.; Saxena, Ragini; Garruba, Jonathan; Tripathi, Sanjay; Blanchard, Randy

    2006-05-01

    This paper is a response to the challenge of providing a large area avionics display for the E-2D AHE aircraft. The resulting display design provides a pilot with high-resolution visual information content covering an image area of almost three square feet (Active Area of Samsung display = 33.792cm x 27.0336 cm = 13.304" x 10.643" = 141.596 square inches = 0.983 sq. ft x 3 = 2.95 sq. ft). The avionics display application, design and performance being described is the Primary Flight Display for the E-2D Advanced Hawkeye aircraft. This cockpit display has a screen diagonal size of 17 inches. Three displays, with minimum bezel width, just fit within the available instrument panel area. The significant design constraints of supporting an upgrade installation have been addressed. These constraints include a display image size that is larger than the mounting opening in the instrument panel. This, therefore, requires that the Electromagnetic Interference (EMI) window, LCD panel and backlight all fit within the limited available bezel depth. High brightness and a wide dimming range are supported with a dual mode Cold Cathode Fluorescent Tube (CCFT) and LED backlight. Packaging constraints dictated the use of multiple U shaped fluorescent lamps in a direct view backlight design for a maximum display brightness of 300 foot-Lamberts. The low intensity backlight levels are provided by remote LEDs coupled through a fiber optic mesh. This architecture generates luminous uniformity within a minimum backlight depth. Cross-cockpit viewing is supported with ultra-wide field-of-view performance including contrast and the color stability of an advanced LCD cell design supports. Display system design tradeoffs directed a priority to high optical efficiency for minimum power and weight.

  8. E2F mediates enhanced alternative polyadenylation in proliferation

    PubMed Central

    2012-01-01

    Background The majority of mammalian genes contain multiple poly(A) sites in their 3' UTRs. Alternative cleavage and polyadenylation are emerging as an important layer of gene regulation as they generate transcript isoforms that differ in their 3' UTRs, thereby modulating genes' response to 3' UTR-mediated regulation. Enhanced cleavage at 3' UTR proximal poly(A) sites resulting in global 3' UTR shortening was recently linked to proliferation and cancer. However, mechanisms that regulate this enhanced alternative polyadenylation are unknown. Results Here, we explored, on a transcriptome-wide scale, alternative polyadenylation events associated with cellular proliferation and neoplastic transformation. We applied a deep-sequencing technique for identification and quantification of poly(A) sites to two human cellular models, each examined under proliferative, arrested and transformed states. In both cell systems we observed global 3' UTR shortening associated with proliferation, a link that was markedly stronger than the association with transformation. Furthermore, we found that proliferation is also associated with enhanced cleavage at intronic poly(A) sites. Last, we found that the expression level of the set of genes that encode for 3'-end processing proteins is globally elevated in proliferation, and that E2F transcription factors contribute to this regulation. Conclusions Our results comprehensively identify alternative polyadenylation events associated with cellular proliferation and transformation, and demonstrate that the enhanced alternative polyadenylation in proliferative conditions results not only in global 3' UTR shortening but also in enhanced premature cleavage in introns. Our results also indicate that E2F-mediated co-transcriptional regulation of 3'-end processing genes is one of the mechanisms that links enhanced alternative polyadenylation to proliferation. PMID:22747694

  9. The human papillomavirus type 16 L1 protein directly interacts with E2 and enhances E2-dependent replication and transcription activation

    PubMed Central

    Siddiqa, Abida; Léon, Karen Campos; James, Claire D.; Bhatti, Muhammad Faraz; Roberts, Sally

    2015-01-01

    The human papillomavirus (HPV) E2 protein is a multifunctional protein essential for the control of virus gene expression, genome replication and persistence. E2 is expressed throughout the differentiation-dependent virus life cycle and is functionally regulated by association with multiple viral and cellular proteins. Here, we show for the first time to our knowledge that HPV16 E2 directly associates with the major capsid protein L1, independently of other viral or cellular proteins. We have mapped the L1 binding region within E2 and show that the α-2 helices within the E2 DNA-binding domain mediate L1 interaction. Using cell-based assays, we show that co-expression of L1 and E2 results in enhanced transcription and virus origin-dependent DNA replication. Upon co-expression in keratinocytes, L1 reduces nucleolar association of E2 protein, and when co-expressed with E1 and E2, L1 is partially recruited to viral replication factories. Furthermore, co-distribution of E2 and L1 was detected in the nuclei of upper suprabasal cells in stratified epithelia of HPV16 genome-containing primary human keratinocytes. Taken together, our findings suggest that the interaction between E2 and L1 is important for the regulation of E2 function during the late events of the HPV life cycle. PMID:25911730

  10. The human papillomavirus type 16 L1 protein directly interacts with E2 and enhances E2-dependent replication and transcription activation.

    PubMed

    Siddiqa, Abida; Léon, Karen Campos; James, Claire D; Bhatti, Muhammad Faraz; Roberts, Sally; Parish, Joanna L

    2015-08-01

    The human papillomavirus (HPV) E2 protein is a multifunctional protein essential for the control of virus gene expression, genome replication and persistence. E2 is expressed throughout the differentiation-dependent virus life cycle and is functionally regulated by association with multiple viral and cellular proteins. Here, we show for the first time to our knowledge that HPV16 E2 directly associates with the major capsid protein L1, independently of other viral or cellular proteins. We have mapped the L1 binding region within E2 and show that the α-2 helices within the E2 DNA-binding domain mediate L1 interaction. Using cell-based assays, we show that co-expression of L1 and E2 results in enhanced transcription and virus origin-dependent DNA replication. Upon co-expression in keratinocytes, L1 reduces nucleolar association of E2 protein, and when co-expressed with E1 and E2, L1 is partially recruited to viral replication factories. Furthermore, co-distribution of E2 and L1 was detected in the nuclei of upper suprabasal cells in stratified epithelia of HPV16 genome-containing primary human keratinocytes. Taken together, our findings suggest that the interaction between E2 and L1 is important for the regulation of E2 function during the late events of the HPV life cycle. PMID:25911730

  11. Direct coating of culture medium from cells secreting classical swine fever virus E2 antigen on ELISA plates for detection of E2-specific antibodies.

    PubMed

    Cheng, Ta-Chun; Pan, Chu-Hsiang; Chen, Chien-Shu; Chuang, Kuo-Hsiang; Chuang, Chih-Hung; Huang, Chien-Chaio; Chu, Yu-Yi; Yang, Ya-Chun; Chu, Pei-Yu; Kao, Chien-Han; Hsieh, Yuan-Chin; Cheng, Tian-Lu

    2015-07-01

    The envelope glycoprotein E2 of classical swine fever virus (CSFV) is widely used as a marker for measuring vaccine efficacy and antibody titer. The glycosylation profile of E2 may affect the immunogenicity of the vaccine and the timing of re-vaccination. In this study, a human embryonic kidney cell line was used to secrete fully-glycosylated CSFV E2, which was then coated onto ELISA plates without purification or adjustment. The resulting E2-secreting medium-direct-coating (E2-mDc) ELISA was successfully used to measure anti-E2 antibody titers in vaccinated and field pig sera samples. Compared with a virus neutralization test (as standard), the E2-mDc ELISA was found to be more accurate (90%) than a commercial CSFV antibody diagnostic kit (62%). In conclusion, the mammalian cell-secreted antigen can provide cheap, accurate and effective assays for vaccine efficacy and disease diagnoses. PMID:25975854

  12. Cesium vacancy ordering in phase-separated C sxF e2 -yS e2

    NASA Astrophysics Data System (ADS)

    Taddei, K. M.; Sturza, M.; Chung, D. Y.; Cao, H. B.; Claus, H.; Kanatzidis, M. G.; Osborn, R.; Rosenkranz, S.; Chmaissem, O.

    2015-09-01

    By simultaneously displaying magnetism and superconductivity in a single phase, the iron-based superconductors provide a model system for the study of magnetism's role in superconductivity. The class of intercalated iron selenide superconductors is unique among these in having the additional property of phase separation and coexistence of two distinct phasesone majority phase with iron vacancy ordering and strong antiferromagnetism, and the other a poorly understood minority microscopic phase with a contested structure. Adding to the intrigue, the majority phase has never been found to show superconductivity on its own while the minority phase has never been successfully synthesized separate from the majority phase. In order to better understand this minority phase, a series of high-quality C sxF e2 -yS e2 single crystals with (0.8 ?x ?1 ; 0 ?y ?0.3 ) were grown and studied. Neutron and x-ray powder diffraction performed on ground crystals show that the average I 4 /m m m structure of the minority phase is distinctly different from the high-temperature I 4 /m m m parent structure. Moreover, single-crystal diffraction reveals the presence of discrete superlattice reflections that remove the degeneracy of the Cs sites in both the majority and minority phases and reduce their structural symmetries from body centered to primitive. Group theoretical analysis in conjunction with structural modeling shows that the observed superlattice reflections originate from three-dimensional Cs vacancy ordering. This model predicts a 25 % vacancy of the Cs site in the minority phase which is consistent with the site's refined occupancy. Magnetization measurements performed in tandem with neutron single-crystal diffraction provide evidence that the minority phase is the host of superconductivity. Our results also reveal a superconducting dome in which the superconducting transition temperature varies as a function of the nominal valence of iron.

  13. Structure of the Rb C-Terminal Domain Bound to E2F1-DP1: A Mechanism for Phosphorylation-Induced E2F Release

    SciTech Connect

    Rubin,S.; Gall, A.; Zheng, N.; Pavletich, N.

    2005-01-01

    The retinoblastoma (Rb) protein negatively regulates the G1-S transition by binding to the E2F transcription factors, until cyclin-dependent kinases phosphorylate Rb, causing E2F release. The Rb pocket domain is necessary for E2F binding, but the Rb C-terminal domain (RbC) is also required for growth suppression. Here we demonstrate a high-affinity interaction between RbC and E2F-DP heterodimers shared by all Rb and E2F family members. The crystal structure of an RbC-E2F1-DP1 complex reveals an intertwined heterodimer in which the marked box domains of both E2F1 and DP1 contact RbC. We also demonstrate that phosphorylation of RbC at serines 788 and 795 destabilizes one set of RbC-E2F-DP interactions directly, while phosphorylation at threonines 821 and 826 induces an intramolecular interaction between RbC and the Rb pocket that destabilizes the remaining interactions indirectly. Our findings explain the requirement of RbC for high-affinity E2F binding and growth suppression and establish a mechanism for the regulation of Rb-E2F association by phosphorylation.

  14. Giant biquadratic interaction-induced magnetic anisotropy in the iron-based superconductor AxF e2 -yS e2

    NASA Astrophysics Data System (ADS)

    Zhu, Hai-Feng; Cao, Hai-Yuan; Xie, Yun; Hou, Yu-Sheng; Chen, Shiyou; Xiang, Hongjun; Gong, Xin-Gao

    2016-01-01

    The emergence of the electron-pocket-only iron-based superconductor AxF e2 -yS e2 (A =alkali metal ) challenges the Fermi-surface nesting picture established in iron pnictides. It was widely believed that magnetism is correlated with the superconductivity in AxF e2 -yS e2 . Unfortunately, the highly anisotropic exchange parameters and the disagreement between theoretical calculations and experimental results triggered a fierce debate on the nature of magnetism in AxF e2 -yS e2 . Here we find that the strong magnetic anisotropy is from the anisotropic biquadratic interaction. In order to accurately obtain the magnetic interaction parameters, we propose a universal method, which does not need to include other high-energy configurations as in the conventional energy-mapping method. We show that our model successfully captures the magnetic interactions in AxF e2 -yS e2 and correctly predicts the spin-wave spectrum, in quantitative agreement with the experimental observation. These results suggest that the local moment picture, including the biquadratic term, can describe accurately the magnetic properties and spin excitations in AxF e2 -yS e2 , which sheds new light on the future study of the high-Tc iron-based superconductors.

  15. Prostaglandin E2(PGE2) induces headache in healthy subjects.

    PubMed

    Wienecke, T; Olesen, J; Oturai, P S; Ashina, M

    2009-05-01

    The role of prostanoids in nociception is well established. The headache-eliciting effects of prostaglandin E(2) (PGE(2)) and its possible mechanisms have previously not been systematically studied in man. We hypothesized that infusion of PGE(2) might induce headache and vasodilation of cranial vessels. PGE(2) (0.40 microg kg(-1) min(-1)) or saline was infused for 25 min into 11 healthy subjects in a cross-over, double-blind study. Headache intensity was scored on a verbal rating scale from 0 to 10. In addition, we recorded mean flow in the middle cerebral artery (V(MCA)) by transcranial Doppler and diameter of the superficial temporal artery (STA) by high-resolution ultrasonography. All 11 subjects reported headache on the PGE(2) day and no subjects reported headache on the placebo day (P = 0.001). During the immediate phase (0-30 min) (P = 0.005) and the postinfusion phase (30-90 min) (P = 0.005), the area under the curve for headache score was significantly larger on the PGE(2) day compared with the placebo day. PGE(2) caused dilatation of the STA (23.5%; 95% CI 14.0, 37.8) and the MCA (8.3%; 95% CI 4.0, 12.6). We suggest that PGE(2) induces headache by activation and sensitization of cranial perivascular sensory afferents. PMID:19187340

  16. Parametrization of a spin-polarized (e,2e) experiment

    NASA Astrophysics Data System (ADS)

    Mazevet, S.; McCarthy, I. E.; Weigold, E.

    1998-03-01

    We use the density-matrix formalism to parametrize a spin-polarized (e,2e) experiment where a p electron is ejected from a closed-shell system and the fine structure of the ion is resolved experimentally. This formulation allows a definition from general principles of the recently observed spin up-down asymmetry [X. Guo and co-workers, Phys. Rev. Lett. 76, 1228 (1996); J. Phys. B 30, 4097 (1997)] due to the fine-structure effect [S. Jones et al., Phys. Rev. Lett. 72, 2554 (1994); G. F. Hanne, in Abstracts of Contributed Papers, XVIIth International Conference on the Physics of Electronic and Atomic Collisions, edited by W. R. MacGillivray, I. E. McCarthy, and M. C. Standage (Hilger, Bristol, 1992), p. 199] and the complete definition of potentially observable quantities such as the polarization of the fast- and slow-emitted-electron beams and the orientation of the ion beam after the collision. These parameters are defined for the general case where the incoming-electron beam has an arbitrary polarization P=(Px,Py,Pz) and calculated in an asymmetric kinematic for the case where the initial-electron beam is, respectively, unpolarized and polarized perpendicular to the scattering plane.

  17. Differential Stem and Progenitor Cell Trafficking by Prostaglandin E2

    PubMed Central

    Hoggatt, Jonathan; Mohammad, Khalid S.; Singh, Pratibha; Hoggatt, Amber F.; Chitteti, Brahmananda Reddy; Speth, Jennifer M.; Hu, Peirong; Poteat, Bradley A.; Stilger, Kayla N.; Ferraro, Francesca; Silberstein, Lev; Wong, Frankie K.; Farag, Sherif S.; Czader, Magdalena; Milne, Ginger L.; Breyer, Richard M.; Serezani, Carlos H.; Scadden, David T.; Guise, Theresa; Srour, Edward F.; Pelus, Louis M.

    2013-01-01

    SUMMARY To maintain lifelong production of blood cells, hematopoietic stem cells (HSC) are tightly regulated by inherent programs and extrinsic regulatory signals received from their microenvironmental niche. Long-term repopulating HSC (LT-HSC) reside in several, perhaps overlapping, niches that produce regulatory molecules/signals necessary for homeostasis and increased output following stress/injury 1–5. Despite significant advances in specific cellular or molecular mechanisms governing HSC/niche interactions, little is understood about regulatory function within the intact mammalian hematopoietic niche. Recently, we and others described a positive regulatory role for Prostaglandin E2 (PGE2) on HSC function ex vivo 6,7. While exploring the role of endogenous PGE2 we unexpectedly observed hematopoietic egress after nonsteroidal anti-inflammatory drug (NSAID) treatment. Surprisingly, this was independent of the SDF-1/CXCR4 axis. Stem and progenitor cells were found to have differing mechanisms of egress, with HSC transit to the periphery dependent on niche attenuation and reduction in the retentive molecule osteopontin (OPN). Hematopoietic grafts mobilized with NSAIDs had superior repopulating ability and long-term engraftment. Treatment of non-human primates and healthy human volunteers confirmed NSAID-mediated egress in higher species. PGE2 receptor knockout mice demonstrated that progenitor expansion and stem/progenitor egress resulted from reduced EP4 receptor signaling. These results not only uncover unique regulatory roles for EP4 signaling in HSC retention in the niche but also define a rapidly translatable strategy to therapeutically enhance transplantation. PMID:23485965

  18. STS-70 Launch - Nikon E-2 Digital Image

    NASA Technical Reports Server (NTRS)

    1995-01-01

    This test image was taken with a Nikon E-2 Digital Imaging System camera and are provided courtesy of Nikon (GIF 450x450 JPEG 1280x1000): The second Shuttle launch in 16 days hurtles off the pad into a sweltering summer sky. The unstable weather typical to Florida in the summertime didn't have a chance to coalesce and impact this morning's launch window, and the Space Shuttle Discovery began its planned seven-day, 22-hour flight on Mission STS-70 from Launch Pad 39B at 9:41:55.078 a.m. EDT, just seconds off schedule. On board for Discovery's 21st spaceflight are a crew of five: Commander Terence 'Tom' Henricks; Pilot Kevin R. Kregel; and Mission Specialists Nancy Jane Currie, Donald A. Thomas and Mary Ellen Weber. The crew's primary objective during the 70th Shuttle flight is to deploy the Tracking and Data Relay Satellite (TDRS-G), which will join a constellation of other TDRS spacecraft already on orbit. TDRS-G is destined to become an on- orbit, fully operational 'ready reserve' satellite, available along with one other ready reserve TDRS spacecraft to back up the two primary TDRS satellites positions, TDRS East over the Atlantic Ocean and TDRS West over the Pacific. Assured capability of the TDRS communications network is essential for linking Earth-orbiting spacecraft such as the Shuttle and the Hubble Space Telescope with the ground.

  19. STS-70 Launch - Nikon E-2 Digital Image

    NASA Technical Reports Server (NTRS)

    1995-01-01

    This test images was taken with a Nikon E-2 Digital Imaging System camera and are provided courtesy of Nikon (GIF 450x450 JPEG 1280x1000): The second Shuttle launch in 16 days hurtles off the pad into a sweltering summer sky. The unstable weather typical to Florida in the summertime didn't have a chance to coalesce and impact this morning's launch window, and the Space Shuttle Discovery began its planned seven-day, 22-hour flight on Mission STS-70 from Launch Pad 39B at 9:41:55.078 a.m. EDT, just seconds off schedule. On board for Discovery's 21st spaceflight are a crew of five: Commander Terence 'Tom' Henricks; Pilot Kevin R. Kregel; and Mission Specialists Nancy Jane Currie, Donald A. Thomas and Mary Ellen Weber. The crew's primary objective during the 70th Shuttle flight is to deploy the Tracking and Data Relay Satellite (TDRS-G), which will join a constellation of other TDRS spacecraft already on orbit. TDRS-G is destined to become an on- orbit, fully operational 'ready reserve' satellite, available along with one other ready reserve TDRS spacecraft to back up the two primary TDRS satellites positions, TDRS East over the Atlantic Ocean and TDRS West over the Pacific. Assured capability of the TDRS communications network is essential for linking Earth-orbiting spacecraft such as the Shuttle and the Hubble Space Telescope with the ground.

  20. Prostaglandin E2 Prevents Disuse-Induced Cortical Bone Loss

    NASA Technical Reports Server (NTRS)

    Jee, Webster S. S.; Akamine, T.; Ke, Hua Zhu; Li, Xiao Jian; Tang, L. Y.; Zeng, Q. Q.

    1992-01-01

    The object of this study was to determine whether prostaglandin E2 (PGE2) can prevent disuse (underloaded)-induced cortical bone loss as well as add extra bone to underloaded bones. Thirteen-month-old retired female Sprague-Dawley breeders served as controls or were subjected to simultaneous right hindlimb immobilization by bandaging and daily subcutaneous doses of 0, 1, 3, or 6 mg PGE2/kg/d for two and six weeks. Histomorphometric analyses were performed on double-fluorescent labeled undecalcified tibial shaft sections (proximal to the tibiofibular junction). Disuse-induced cortical bone loss occurred by enlarging the marrow cavity and increasing intracortical porosity. PGE2 treatment of disuse shafts further increased intracortical porosity above that in disuse alone controls. This bone loss was counteracted by enhancement of periosteal and corticoendosteal bone formation. Stimulation of periosteal and corticoendosteal bone formation slightly enlarged the total tissue (cross-sectional) area and inhibited marrow cavity enlargement. These PGE2-induced activities netted the same percentage of cortical bone with a different distribution than the beginning and age related controls. These findings indicate the PGE2-induced increase in bone formation compensated for the disuse and PGE2-induced bone loss, and thus prevented immobilization induced bone loss.

  1. Feedback regulation between atypical E2Fs and APC/CCdh1 coordinates cell cycle progression.

    PubMed

    Boekhout, Michiel; Yuan, Ruixue; Wondergem, Annelotte P; Segeren, Hendrika A; van Liere, Elsbeth A; Awol, Nesibu; Jansen, Imke; Wolthuis, Rob Mf; de Bruin, Alain; Westendorp, Bart

    2016-03-01

    E2F transcription factors control the oscillating expression pattern of multiple target genes during the cell cycle. Activator E2Fs, E2F1-3, induce an upswing of E2F targets, which is essential for the G1-to-S phase transition, whereas atypical E2Fs, E2F7 and E2F8, mediate a downswing of the same targets during late S, G2, and M phases. Expression of atypical E2Fs is induced by E2F1-3, but it is unknown how atypical E2Fs are inactivated in a timely manner. Here, we demonstrate that E2F7 and E2F8 are substrates of the anaphase-promoting complex/cyclosome (APC/C). Removal of CDH1, or mutating the CDH1-interacting KEN boxes, stabilized E2F7/8 from anaphase onwards and during G1. Expressing KEN mutant E2F7 during G1 impairs S phase entry and eventually results in cell death. Furthermore, we show that E2F8, but not E2F7, interacts also with APC/C(C) (dc20). Importantly, atypical E2Fs can activate APC/C(C) (dh1) by repressing its inhibitors cyclin A, cyclin E, and Emi1. In conclusion, we discovered a feedback loop between atypical E2Fs and APC/C(C) (dh1), which ensures balanced expression of cell cycle genes and normal cell cycle progression. PMID:26882548

  2. Apoptosis Associated with Deregulated E2F Activity Is Dependent on E2F1 and Atm/Nbs1/Chk2

    PubMed Central

    Rogoff, Harry A.; Pickering, Mary T.; Frame, Fiona M.; Debatis, Michelle E.; Sanchez, Yolanda; Jones, Stephen; Kowalik, Timothy F.

    2004-01-01

    The retinoblastoma protein (Rb)/E2F pathway links cellular proliferation control to apoptosis and is critical for normal development and cancer prevention. Here we define a transcription-mediated pathway in which deregulation of E2F1 by ectopic E2F expression or Rb inactivation by E7 of human papillomavirus type 16 signals apoptosis by inducing the expression of Chk2, a component of the DNA damage response. E2F1- and E7-mediated apoptosis are compromised in cells from patients with the related disorders ataxia telangiectasia and Nijmegen breakage syndrome lacking functional Atm and Nbs1 gene products, respectively. Both Atm and Nbs1 contribute to Chk2 activation and p53 phosphorylation following deregulation of normal Rb growth control. E2F2, a related E2F family member that does not induce apoptosis, also activates Atm, resulting in phosphorylation of p53. However, we found that the key commitment step in apoptosis induction is the ability of E2F1, and not E2F2, to upregulate Chk2 expression. Our results suggest that E2F1 plays a central role in signaling disturbances in the Rb growth control pathway and, by upregulation of Chk2, may sensitize cells to undergo apoptosis. PMID:15024084

  3. Prostaglandin E2 increases the skeletal response to mechanical loading

    NASA Technical Reports Server (NTRS)

    Tang, L. Y.; Cullen, D. M.; Yee, J. A.; Jee, W. S.; Kimmel, D. B.

    1997-01-01

    The study tested the influence of prostaglandin E2 (PGE2) on the skeletal response to increased in vivo mechanical loading through a four-point bending device. One hundred and twenty Sprague-Dawley female rats (6 months old, 354 +/- 34 g) were divided into 12 groups to accommodate all possible combinations of doses of loads (25, 30, or 35 N) and PGE2 (0, 0.1, 0.3, or 1 mg/kg). Rats received subcutaneous injections of PGE2 daily and in vivo loading of the right tibia every Monday, Wednesday, and Friday for four weeks. Histomorphometric analysis of the periosteal and endocortical surfaces following in vivo dual fluorochrome labeling was performed on both the loaded region of the right tibial diaphysis and a similar region of the left tibial diaphysis. Without PGE2, the threshold for loading to stimulate bone formation was 30 N (peak strain 1360 mu epsilon) at the periosteal surface and 25 N (peak strain 580 mu epsilon) at the endocortical surface. Without loading, the minimum dose of PGE2 to stimulate bone formation at all surfaces was 1 mg/kg/day. When 1 mg/kg/day PGE2 was combined with the minimum effective load, an additive effect of PGE2 and loading on bone formation was observed at the endocortical surface, but a synergistic effect was noted at the periosteal surface. No combined effect of ineffective doses of loading and PGE2 was found. A synergistic effect at peak strains of approximately 1625 mu epsilon on the periosteal surface could suggest either the involvement of locally produced growth factors or autoregulation of endogenous synthesis of PGE2 by exogenously administered PGE2.

  4. Urinary prostaglandin E2 metabolite and breast cancer risk

    PubMed Central

    Cui, Yong; Shu, Xiao-Ou; Gao, Yu-Tang; Cai, Qiuyin; Ji, Bu-Tian; Li, Hong-Lan; Rothman, Nathaniel; Wu, Jie; Yang, Gong; Xiang, Yong-Bing; Zheng, Wei

    2014-01-01

    Background Levels of the cyclooxygenase 2 (COX-2) enzyme are elevated in breast cancer tissue, and most COX-2 effects are believed to be mediated through overproduction of prostaglandin-E2 (PGE2). We evaluated associations between the primary urinary metabolite of PGE2 (PGE-M) and breast cancer risk. Methods A nested case-control study of 504 cases and 1,082 controls was conducted using data from the Shanghai Womens Health Study, a large population-based prospective cohort study of 74,941 Chinese women. Urinary PGE-M was measured using a liquid chromatography/tandem mass spectrometric method. Logistic regression estimated odds ratios (OR) and 95% confidence intervals (95%CI), with adjustment for potential confounders. Results Overall, no association between urinary PGE-M and breast cancer was detected. However, a suggestive positive association was found among postmenopausal women. In particular, a clear dose-response relationship between urinary PGE-M and breast cancer was observed among postmenopausal women with a BMI<25 kg/m2 (P for linear trend = 0.005). Among these women, risk of breast cancer increased from 1.00 (reference) to 1.06 (95% CI: 0.561.99), 1.50 (95% CI: 0.792.83), and 2.32 (95% CI: 1.244.41) for the lowest to highest quartiles of PGE-M, and such associations were stronger among those who were diagnosed with cancer within the first 4 years of sample collection. No apparent association was observed among overweight postmenopausal women (BMI?25 kg/m2). Conclusion High urinary PGE-M level was associated with elevated risk of breast cancer among normal weight, postmenopausal women. Impact Urinary PGE-M level may be useful for breast cancer risk assessment among normal weight, postmenopausal women. PMID:25214156

  5. Structural models of the membrane anchors of envelope glycoproteins E1 and E2 from pestiviruses

    SciTech Connect

    Wang, Jimin Li, Yue; Modis, Yorgo

    2014-04-15

    The membrane anchors of viral envelope proteins play essential roles in cell entry. Recent crystal structures of the ectodomain of envelope protein E2 from a pestivirus suggest that E2 belongs to a novel structural class of membrane fusion machinery. Based on geometric constraints from the E2 structures, we generated atomic models of the E1 and E2 membrane anchors using computational approaches. The E1 anchor contains two amphipathic perimembrane helices and one transmembrane helix; the E2 anchor contains a short helical hairpin stabilized in the membrane by an arginine residue, similar to flaviviruses. A pair of histidine residues in the E2 ectodomain may participate in pH sensing. The proposed atomic models point to Cys987 in E2 as the site of disulfide bond linkage with E1 to form E1E2 heterodimers. The membrane anchor models provide structural constraints for the disulfide bonding pattern and overall backbone conformation of the E1 ectodomain. - Highlights: Structures of pestivirus E2 proteins impose constraints on E1, E2 membrane anchors. Atomic models of the E1 and E2 membrane anchors were generated in silico. A snorkeling arginine completes the short helical hairpin in the E2 membrane anchor. Roles in pH sensing and E1E2 disulfide bond formation are proposed for E1 residues. Implications for E1 ectodomain structure and disulfide bonding pattern are discussed.

  6. DNA-binding and trans-activation properties of Drosophila E2F and DP proteins.

    PubMed Central

    Dynlacht, B D; Brook, A; Dembski, M; Yenush, L; Dyson, N

    1994-01-01

    The temporal activation of E2F transcriptional activity appears to be an important component of the mechanisms that prepare mammalian cells for DNA replication. Regulation of E2F activity appears to be a highly complex process, and the dissection of the E2F pathway will be greatly facilitated by the ability to use genetic approaches. We report the isolation of two Drosophila genes that can stimulate E2F-dependent transcription in Drosophila cells. One of these genes, dE2F, contains three domains that are highly conserved in the human homologs E2F-1, E2F-2, and E2F-3. Interestingly, one of these domains is highly homologous to the retinoblastoma protein (RB)-binding sequences of human E2F genes. The other gene, dDP, is closely related to the human DP-1 and DP-2 genes. We demonstrate that dDP and dE2F interact and cooperate to give sequence-specific DNA binding and optimal trans-activation. These features suggest that endogenous Drosophila E2F, like human E2F, may be composed of heterodimers and may be regulated by RB-like proteins. The isolation of these genes will provide important reagents for the genetic analysis of the E2F pathway. Images PMID:8022787

  7. A potential oncogenic role of the commonly observed E2F5 overexpression in hepatocellular carcinoma

    PubMed Central

    Jiang, Yuzhu; Yim, Seon-Hee; Xu, Hai-Dong; Jung, Seung-Hyun; Yang, So Young; Hu, Hae-Jin; Jung, Chan-Kwon; Chung, Yeun-Jun

    2011-01-01

    AIM: To explore the expression pattern of E2F5 in primary hepatocellular carcinomas (HCCs) and elucidate the roles of E2F5 in hepatocarcinogenesis. METHODS: E2F5 expression was analyzed in 120 primary HCCs and 29 normal liver tissues by immunohistochemistry analysis. E2F5-small interfering RNA was transfected into HepG2, an E2F5-overexpressed HCC cell line. After E2F5 knockdown, cell growth capacity and migrating potential were examined. RESULTS: E2F5 was significantly overexpressed in primary HCCs compared with normal liver tissues (P = 0.008). The E2F5-silenced cells showed significantly reduced proliferation (P = 0.004). On the colony formation and soft agar assays, the number of colonies was significantly reduced in E2F5-silenced cells (P = 0.004 and P = 0.009, respectively). E2F5 knockdown resulted in the accumulation of G0/G1 phase cells and a reduction of S phase cells. The number of migrating/invading cells was also reduced after E2F5 knockdown (P = 0.021). CONCLUSION: To our knowledge, this is the first evidence that E2F5 is commonly overexpressed in primary HCC and that E2F5 knockdown significantly repressed the growth of HCC cells. PMID:21274376

  8. Transformation properties of the E2a-Pbx1 chimeric oncoprotein: fusion with E2a is essential, but the Pbx1 homeodomain is dispensable.

    PubMed Central

    Monica, K; LeBrun, D P; Dedera, D A; Brown, R; Cleary, M L

    1994-01-01

    The t(1;19) chromosomal translocation in acute lymphoblastic leukemias creates chimeric E2a-Pbx1 oncoproteins that can act as DNA-binding activators of transcription. A structural analysis of the functional domains of E2a-Pbx1 showed that portions of both E2a and Pbx1 were essential for transformation of NIH 3T3 cells and transcriptional activation of synthetic reporter genes containing PBX1 consensus binding sites. Hyperexpression of wild-type or experimentally truncated Pbx1 proteins was insufficient for transformation, consistent with their inability to activate transcription. When fused with E2a, the Pbx-related proteins Pbx2 and Pbx3 were also transformation competent, demonstrating that all known members of this highly similar subfamily of homeodomain proteins have latent oncogenic potential. The oncogenic contributions of E2a to the chimeras were localized to transactivation motifs AD1 and AD2, as their mutation significantly impaired transformation. Either the homeodomain or Pbx1 amino acids flanking this region could mediate transformation when fused to E2a. However, the homeodomain was not essential for transformation, since a mutant E2a-Pbx1 protein (E2a-Pbx delta HD) lacking the homeodomain efficiently transformed fibroblasts and induced malignant lymphomas in transgenic mice. Thus, transformation mediated by the chimeric oncoprotein E2a-Pbx1 is absolutely dependent on motifs acquired from E2a but the Pbx1 homeodomain is optional. The latter finding suggests that E2a-Pbx1 may interact with cellular proteins that assist or mediate alterations in gene expression responsible for oncogenesis even in the absence of homeodomain-DNA interactions. Images PMID:7969166

  9. MPN patients harbor recurrent truncating mutations in transcription factor NF-E2

    PubMed Central

    Jutzi, Jonas S.; Bogeska, Ruzhica; Nikoloski, Gorica; Schmid, Corina A.; Seeger, Thalia S.; Stegelmann, Frank; Schwemmers, Sven; Grnder, Albert; Peeken, Jan C.; Gothwal, Monika; Wehrle, Julius; Aumann, Konrad; Hamdi, Kamar; Dierks, Christine; Wang, Wei; Dhner, Konstanze; Jansen, Joop H.

    2013-01-01

    The molecular etiology of myeloproliferative neoplasms (MPNs) remains incompletely understood, despite recent advances incurred through the discovery of several different mutations in MPN patients. We have recently described overexpression of the transcription factor NF-E2 in MPN patients and shown that elevated NF-E2 levels in vivo cause an MPN phenotype and predispose to leukemic transformation in transgenic mice. We report the presence of acquired insertion and deletion mutations in the NF-E2 gene in MPN patients. These result in truncated NF-E2 proteins that enhance wild-type (WT) NF-E2 function and cause erythrocytosis and thrombocytosis in a murine model. NF-E2 mutant cells acquire a proliferative advantage, witnessed by clonal dominance over WT NF-E2 cells in MPN patients. Our data underscore the role of increased NF-E2 activity in the pathophysiology of MPNs. PMID:23589569

  10. Differential expression of members of the E2F family of transcription factors in rodent testes

    PubMed Central

    El-Darwish, Kame S; Parvinen, Martti; Toppari, Jorma

    2006-01-01

    Background The E2F family of transcription factors is required for the activation or repression of differentially expressed gene programs during the cell cycle in normal and abnormal development of tissues. We previously determined that members of the retinoblastoma protein family that interacts with the E2F family are differentially expressed and localized in almost all the different cell types and tissues of the testis and in response to known endocrine disruptors. In this study, the cell-specific and stage-specific expression of members of the E2F proteins has been elucidated. Methods We used immunohistochemical (IHC) analysis of tissue sections and Western blot analysis of proteins, from whole testis and microdissected stages of seminiferous tubules to study the differential expression of the E2F proteins. Results For most of the five E2F family members studied, the localizations appear conserved in the two most commonly studied rodent models, mice and rats, with some notable differences. Comparisons between wild type and E2F-1 knockout mice revealed that the level of E2F-1 protein is stage-specific and most abundant in leptotene to early pachytene spermatocytes of stages IX to XI of mouse while strong staining of E2F-1 in some cells close to the basal lamina of rat tubules suggest that it may also be expressed in undifferentiated spermatogonia. The age-dependent development of a Sertoli-cell-only phenotype in seminiferous tubules of E2F-1 knockout males corroborates this, and indicates that E2F-1 is required for spermatogonial stem cell renewal. Interestingly, E2F-3 appears in both terminally differentiated Sertoli cells, as well as spermatogonial cells in the differentiative pathway, while the remaining member of the activating E2Fs, E2F-2 is most concentrated in spermatocytes of mid to late prophase of meiosis. Comparisons between wildtype and E2F-4 knockout mice demonstrated that the level of E2F-4 protein displays a distinct profile of stage-specificity compared to E2F-1, which is probably related to its prevalence and role in Sertoli cells. IHC of rat testis indicates that localization of E2F-5 is distinct from that of E2F-4 and overlaps those of E2F-1 and E2F-2. Conclusion The E2F-1 represents the subfamily of transcription factors required during stages of DNA replication and gene expression for development of germ cells and the E2F-4 represents the subfamily of transcription factors that help maintain gene expression for a terminally differentiated state within the testis. PMID:17147820

  11. E2 protein cage as a multifunctional nanoplatform

    NASA Astrophysics Data System (ADS)

    Dalmau Mallorqui, Merce

    Caged protein systems such as viral capsids, heat shock proteins, and ferritin are spherical structures that occur naturally in living organisms and are a growing class of biomimetic templates used to create new materials in nanotechnology. Such systems have been proposed as general drug carriers since they form highly symmetric nanoscale architectures that offer the potential to be tailored according to the desired application. Within this framework, this dissertation focuses on the design and development of a new drug delivery nanoplatform based on the E2 subunit of the pyruvate dehydrogenase protein from Bacillus stearothermophilus. This scaffold forms a 25-nm nanocapsule structure with a hollow cavity. We produced a variant of this protein consisting only of the structural core, and found the thermostability of this self-assembled scaffold to be unusually high, with an onset unfolding temperature of 81.1 +/- 0.9°C and an apparent midpoint unfolding temperature of 91.4 +/- 1.4°C. To evaluate the potential of this scaffold for encapsulation of guest molecules in the internal cavity, we made variants which altered the physicochemical properties of the hollow internal surface. These mutants, yielding up to 240 mutations within this cavity, assembled into correct architectures and exhibited high thermostability that was also comparable to the wild-type scaffold. To show the applicability of this scaffold we coupled two drug-like small molecules to the internal cavity. We also developed a new strategy for encapsulation of small hydrophobic drug molecules. This method is based on hydrophobic differences between the interior cavity and the external buffer to nucleate drug-like agents inside the protein cage. We demonstrate that internal mutations can introduce non-native functionality and enable molecular encapsulation within the cavity while still retaining the dodecahedral structure. Another surface amenable to modifications is the interface between subunits. Such a region was modified to introduce pH-dependent scaffold disassembly ability to assist drug release upon endocytosis inside the cells. Moreover, we demonstrated that modulation of the pH at which disassembly occurs can be achieved by modulation of electrostatic interactions through mutagenesis or changing ionic strength. Together, these results demonstrate the potential of our scaffold as a robust nanoscale platform for biomedical applications.

  12. The E2F transcription factor family regulates CENH3 expression in Arabidopsis thaliana.

    PubMed

    Heckmann, Stefan; Lermontova, Inna; Berckmans, Barbara; De Veylder, Lieven; Bumlein, Helmut; Schubert, Ingo

    2011-11-01

    To elucidate the epigenetic maintenance mechanism for functional plant centromeres, we studied transcriptional regulation of the centromere-specific histone H3 variant CENH3 in Arabidopsis thaliana. We focused on the structure and activity of the CENH3 promoter (CENH3pro) and its regulation by E2F transcription factors. Use of CENH3pro::GUS reporter gene constructs showed that CENH3pro is active in dividing tissues, and that full expression in root meristems depends on intragenic regulatory elements within the second intron. Chromatin immunoprecipitation identified CENH3 as an E2F target gene. Transient co-expression of a CENH3pro::GUS reporter gene construct with various E2F transcription factors in A.thaliana protoplasts showed that E2Fa and E2Fb (preferentially with dimerization protein DPb) activate CENH3pro. Stable over-expression of E2Fa and E2Fb increased the CENH3 transcript level in planta, whereas over-expression of E2Fc decreased the CENH3 transcript level. Surprisingly, mutation of the two E2F binding sites of CENH3pro, in particular the more upstream one (E2F2), caused an increase in CENH3pro activity, indicating E2F-dependent transcriptional repression. CENH3pro repression may be triggered by the interplay of typical and atypical E2Fs in a cell cycle-dependent manner, and/or by interaction of typical E2Fs with retinoblastoma-related (RBR) protein. We speculate that E2Fs are involved in differential transcriptional regulation of CENH3 versus H3, as H3 promoters lack E2F binding motifs. E2F binding motifs are also present in human and Drosophila CENH3pro regions, thus cell cycle-dependent transcriptional regulation of CENH3 may be highly conserved. PMID:21771121

  13. Modulation of the E2F1-driven cancer cell fate by the DNA damage response machinery and potential novel E2F1 targets in osteosarcomas.

    PubMed

    Liontos, Michalis; Niforou, Katerina; Velimezi, Georgia; Vougas, Konstantinos; Evangelou, Konstantinos; Apostolopoulou, Kalliopi; Vrtel, Radek; Damalas, Alexandros; Kontovazenitis, Panayiotis; Kotsinas, Athanassios; Zoumpourlis, Vassilis; Tsangaris, George Th; Kittas, Christos; Ginsberg, Doron; Halazonetis, Thanos D; Bartek, Jiri; Gorgoulis, Vassilis G

    2009-07-01

    Osteosarcoma is the most common primary bone cancer. Mutations of the RB gene represent the most frequent molecular defect in this malignancy. A major consequence of this alteration is that the activity of the key cell cycle regulator E2F1 is unleashed from the inhibitory effects of pRb. Studies in animal models and in human cancers have shown that deregulated E2F1 overexpression possesses either "oncogenic" or "oncosuppressor" properties, depending on the cellular context. To address this issue in osteosarcomas, we examined the status of E2F1 relative to cell proliferation and apoptosis in a clinical setting of human primary osteosarcomas and in E2F1-inducible osteosarcoma cell line models that are wild-type and deficient for p53. Collectively, our data demonstrated that high E2F1 levels exerted a growth-suppressing effect that relied on the integrity of the DNA damage response network. Surprisingly, induction of p73, an established E2F1 target, was also DNA damage response-dependent. Furthermore, a global proteome analysis associated with bioinformatics revealed novel E2F1-regulated genes and potential E2F1-driven signaling networks that could provide useful targets in challenging this aggressive neoplasm by innovative therapies. PMID:19541929

  14. Inhibition of the entomopathogenic fungus Metarhizium anisopliae in vitro by the bed bug defensive secretions (E)-2-hexenal and (E)-2-octenal

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The two major aldehydes (E)-2-hexenal and (E)-2-octenal emitted as defensive secretions by bed bugs Cimex lectularius L. (Hemiptera: Cimicidae), inhibit the in vitro growth of Metarhizium anisopliae (Metsch.) Sokorin (Hypocreales: Clavicipitaceae). These chemicals inhibit fungal growth by direct con...

  15. Curcumin blocks prostaglandin E2 biosynthesis through direct inhibition of the microsomal prostaglandin E2 synthase-1.

    PubMed

    Koeberle, Andreas; Northoff, Hinnak; Werz, Oliver

    2009-08-01

    Prostaglandin E(2) (PGE(2)) plays a crucial role in the apparent link between tumor growth and chronic inflammation. Cyclooxygenase (COX)-2 and microsomal PGE(2) synthase-1, which are overexpressed in many cancers, are functionally coupled and thus produce massive PGE(2) in various tumors. Curcumin, a polyphenolic beta-diketone from tumeric with anti-carcinogenic and anti-inflammatory activities, was shown to suppress PGE(2) formation and to block the expression of COX-2 and of microsomal PGE(2) synthase-1. Here, we identified microsomal PGE(2) synthase-1 as a molecular target of curcumin and we show that inhibition of microsomal PGE(2) synthase-1 activity is the predominant mechanism of curcumin to suppress PGE(2) biosynthesis. Curcumin reversibly inhibited the conversion of PGH(2) to PGE(2) by microsomal PGE(2) synthase-1 in microsomes of interleukin-1beta-stimulated A549 lung carcinoma cells with an IC(50) of 0.2 to 0.3 micromol/L. Closely related polyphenols (e.g., resveratrol, coniferyl alcohol, eugenol, rosmarinic acid) failed in this respect, and isolated ovine COX-1 and human recombinant COX-2 were not inhibited by curcumin up to 30 micromol/L. In lipopolysaccharide-stimulated human whole blood, curcumin inhibited COX-2-derived PGE(2) formation from endogenous or from exogenous arachidonic acid, whereas the concomitant formation of COX-2-mediated 6-keto PGF(1)alpha and COX-1-derived 12(S)-hydroxy-5-cis-8,10-trans-heptadecatrienoic acid was suppressed only at significant higher concentrations. Based on the key function of PGE(2) in inflammation and carcinogenesis, inhibition of microsomal PGE(2) synthase-1 by curcumin provides a molecular basis for its anticarcinogenic and anti-inflammatory activities. PMID:19671757

  16. 26 CFR 48.4216(e)-2 - Limitation on aggregate of exclusions and price readjustments.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 16 2011-04-01 2011-04-01 false Limitation on aggregate of exclusions and price readjustments. 48.4216(e)-2 Section 48.4216(e)-2 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE... Applicable to Manufacturers Taxes § 48.4216(e)-2 Limitation on aggregate of exclusions and...

  17. 17 CFR 270.6e-2 - Exemptions for certain variable life insurance separate accounts.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 17 Commodity and Securities Exchanges 3 2013-04-01 2013-04-01 false Exemptions for certain variable life insurance separate accounts. 270.6e-2 Section 270.6e-2 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION (CONTINUED) RULES AND REGULATIONS, INVESTMENT COMPANY ACT OF 1940 270.6e-2 Exemptions for certain variable...

  18. Structural insights into the DNA-binding specificity of E2F family transcription factors

    PubMed Central

    Morgunova, Ekaterina; Yin, Yimeng; Jolma, Arttu; Dave, Kashyap; Schmierer, Bernhard; Popov, Alexander; Eremina, Nadejda; Nilsson, Lennart; Taipale, Jussi

    2015-01-01

    The mammalian cell cycle is controlled by the E2F family of transcription factors. Typical E2Fs bind to DNA as heterodimers with the related dimerization partner (DP) proteins, whereas the atypical E2Fs, E2F7 and E2F8 contain two DNA-binding domains (DBDs) and act as repressors. To understand the mechanism of repression, we have resolved the structure of E2F8 in complex with DNA at atomic resolution. We find that the first and second DBDs of E2F8 resemble the DBDs of typical E2F and DP proteins, respectively. Using molecular dynamics simulations, biochemical affinity measurements and chromatin immunoprecipitation, we further show that both atypical and typical E2Fs bind to similar DNA sequences in vitro and in vivo. Our results represent the first crystal structure of an E2F protein with two DBDs, and reveal the mechanism by which atypical E2Fs can repress canonical E2F target genes and exert their negative influence on cell cycle progression. PMID:26632596

  19. 29 CFR 2584.8477(e)-2 - Allocation of fiduciary duties.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 9 2010-07-01 2010-07-01 false Allocation of fiduciary duties. 2584.8477(e)-2 Section 2584.8477(e)-2 Labor Regulations Relating to Labor (Continued) EMPLOYEE BENEFITS SECURITY ADMINISTRATION... AND REGULATIONS FOR THE ALLOCATION OF FIDUCIARY RESPONSIBILITY 2584.8477(e)-2 Allocation...

  20. Suppression of newborn natural killer cell activity by prostaglandin E2

    SciTech Connect

    Milch, P.O.; Salvatore, W.; Luft, B.; Baker, D.A.

    1988-10-01

    The effect of prostaglandin E2 on natural killer cell activity of cord blood was examined. Natural killer cell activity, determined by chromium 51 release, was significantly reduced after prostaglandin E2 (1 microgram/ml) treatment. Prostaglandin E2 has been found to enhance the cellular spread of herpesvirus. Thus prostaglandins may enhance viral infections indirectly by suppressing natural killer cell activity.

  1. E2F Activators Signal and Maintain Centrosome Amplification in Breast Cancer Cells

    PubMed Central

    Lee, Mi-Young; Moreno, Carlos S.

    2014-01-01

    Centrosomes ensure accurate chromosome segregation by directing spindle bipolarity. Loss of centrosome regulation results in centrosome amplification, multipolar mitosis and aneuploidy. Since centrosome amplification is common in premalignant lesions and breast tumors, it is proposed to play a central role in breast tumorigenesis, a hypothesis that remains to be tested. The coordination between the cell and centrosome cycles is of paramount importance to maintain normal centrosome numbers, and the E2Fs may be responsible for regulating these cycles. However, the role of E2F activators in centrosome amplification is unclear. Because E2Fs are deregulated in Her2+ cells displaying centrosome amplification, we addressed whether they signal this abnormal process. Knockdown of E2F1 or E2F3 in Her2+ cells decreased centrosome amplification without significantly affecting cell cycle progression, whereas the overexpression of E2F1, E2F2, or E2F3 increased centrosome amplification in MCF10A mammary epithelial cells. Our results revealed that E2Fs affect the expression of proteins, including Nek2 and Plk4, known to influence the cell/centrosome cycles and mitosis. Downregulation of E2F3 resulted in cell death and delays/blocks in cytokinesis, which was reversed by Nek2 overexpression. Nek2 overexpression enhanced centrosome amplification in Her2+ breast cancer cells silenced for E2F3, revealing a role for the E2F activators in maintaining centrosome amplification in part through Nek2. PMID:24797070

  2. Subunit affinities and stoichiometries of the human papillomavirus type 11 E1:E2:DNA complex.

    PubMed

    Chao, S F; Rocque, W J; Daniel, S; Czyzyk, L E; Phelps, W C; Alexander, K A

    1999-04-01

    The association between the papillomavirus E1 and E2 proteins is an important regulatory interaction, imparting coordinated control of viral transcription and replication. Using fluorescence polarization, we have characterized the interactions between HPV-11 E1, HPV-11 E2, and DNA in solution at equilibrium. For these studies, two double-stranded fluorescein-labeled oligonucleotides were prepared. The first fluorescent oligonucleotide, designated Fl-E2BS and containing a single E2 binding-site palindrome (ACCGN6CGGT), was used to determine the affinity of E2 for its DNA binding site. HPV-11 E2 bound Fl-E2BS with an apparent Kd of 0.84 nM. Binding was saturable and consistent with a single class of noninteracting sites. The second oligonucleotide, designated Fl-E1E2BS, contained both E1 and E2 sites in sequence derived directly from the HPV-11 origin of replication. Under titration conditions identical to those used for Fl-E2BS, the E2 protein exhibited reduced affinity for Fl-E1E2BS (Kd > 100 nM). E1 binding to Fl-E1E2BS was of very low affinity. Addition of excess HPV-11 E1 to Fl-E1E2BS lowered the dissociation constant for the E2:Fl-E1E2BS interaction to 2 nM. This effect was not dependent upon ATP or magnesium ion. Fluorescence polarization and other data suggest formation of a complex containing six E1 molecules and a single dimer of E2 bound to a single Fl-E1E2BS oligonucleotide; E2 dissociation from the final complex did not occur. In summary, physical interaction between E1 and E2 increases the DNA binding affinity of each. The role of this energy coupling may be to promote origin-specific binding of both E1 and E2 to DNA. PMID:10194380

  3. The role of E2F1 in the development of hypertrophic cardiomyopathy

    PubMed Central

    Wolfram, Julie A; Liner, Anna; Richardson, Sandy L; Zhu, Xiongwei; Smith, Mark A; Hoit, Brian D; Lee, Hyoung-gon

    2011-01-01

    The overexpression of the transcription factor, E2F1, induces hypertrophy and apoptosis with cell cycle re-entry in cardiomyocytes in vitro and in vivo, suggesting that targeting E2F1 may have therapeutic potential. Accordingly, we tested the hypothesis that blocking the E2F1-mediated signal transduction pathway prevents cardiac hypertrophy by treating E2F1 knockout mice (E2F1-/-) with either isoproterenol (ISO) or Angiotensin II (ANG). Echocardi-ography was used to measure left ventricular mass index and myocardial performance index, a measure of combined systolic and diastolic left ventricular function. In control mice (E2F1+/+) both ISO and ANG treatments induced cardiac hypertrophy, and impaired ventricular function in ANG treated mice. In contrast to previously published work, E2F1-/- mice also demonstrated a similar pattern of cardiac hypertrophy and function after either treatment. Atrial natriuretic peptide, a molecular marker of hypertrophy and necropsy-determined body weight-normalized left ventricle mass were similarly increased in ISO and ANG treated E2F1+/+ and E2F-/- mice, supporting the echocardiographic data. These data indicate that E2F1 is not necessary for the development of cardiac hypertrophy although studies using an overexpression approach suggest a causal role of E2F1. The reason for this discrepancy is unclear, although it is possible that other E2F-family members (e.g., E2F2) may play a compensatory role. In conclusion, our data demonstrate that cardiac hypertrophy can be induced in an E2F1-independent fashion and suggest that in contrast to previous reports, targeting E2F1 may not be a good therapeutic approach. PMID:21738823

  4. [The effect of E2 and progesterone on the receptor status in endometrial carcinoma].

    PubMed

    Gorchev, G; Milkov, V; Tanchev, S; Popov, I

    1992-01-01

    The authors study the plasma levels of E2 and progesterone in 62 women with EC. Parallelly the ER and PR in the same number of cases have been studied. The values of E2 in the plasma of ER+ are much lower than those of E2 in ER-. The quantity of E2 and progesterone influence the values of ER and PR in cancers of women in pre and postmenopausal age. In positive ER and PR patients the level of E2 and progesterone is lower in comparison of ER- and PR-. PMID:1342552

  5. The banana E2 gene family: Genomic identification, characterization, expression profiling analysis.

    PubMed

    Dong, Chen; Hu, Huigang; Jue, Dengwei; Zhao, Qiufang; Chen, Hongliang; Xie, Jianghui; Jia, Liqiang

    2016-04-01

    The E2 is at the center of a cascade of Ub1 transfers, and it links activation of the Ub1 by E1 to its eventual E3-catalyzed attachment to substrate. Although the genome-wide analysis of this family has been performed in some species, little is known about analysis of E2 genes in banana. In this study, 74 E2 genes of banana were identified and phylogenetically clustered into thirteen subgroups. The predicted banana E2 genes were distributed across all 11 chromosomes at different densities. Additionally, the E2 domain, gene structure and motif compositions were analyzed. The expression of all of the banana E2 genes was analyzed in the root, stem, leaf, flower organs, five stages of fruit development and under abiotic stresses. All of the banana E2 genes, with the exception of few genes in each group, were expressed in at least one of the organs and fruit developments, which indicated that the E2 genes might involve in various aspects of the physiological and developmental processes of the banana. Quantitative RT-PCR (qRT-PCR) analysis identified that 45 E2s under drought and 33 E2s under salt were induced. To the best of our knowledge, this report describes the first genome-wide analysis of the banana E2 gene family, and the results should provide valuable information for understanding the classification, cloning and putative functions of this family. PMID:26940488

  6. Comprehensive ubiquitin E2 profiling of ten ubiquitin E3 ligases.

    PubMed

    Marblestone, Jeffrey G; Butt, Samir; McKelvey, Devin M; Sterner, David E; Mattern, Michael R; Nicholson, Benjamin; Eddins, Michael J

    2013-09-01

    The ubiquitin pathway regulates diverse functions including protein localization and stability. The complexity of the pathway involving nearly 40 identified E2 conjugating enzymes and over 600 E3 ligases raises the issue of specificity. With the E2s and E3s fitting into a limited number of classes based on bioinformatics, structures, and proven activities, there is not a clear picture as to what would determine which E2/E3 enzyme pair would be functional. There have been many reports of limited E2/E3 activity profiling with a small number of E2s and E3s. We have expanded on this to investigate the activity of ubiquitin E2s covering the majority of the reported classes/families in concert with a number of E3s implicated in a variety of diseases. Using an ELISA-based assay we screened 10 E3 ligases against a panel of 11 E2s to determine which E2/E3 pairs exhibited E3 autoubiquitylation activity. In addition, the ubiquitin chain linkage preference by certain E2/E3 pairs was investigated. Finally, substrate ubiquitylation was assayed for the E3 ligase MuRF1 using various E2/MuRF1 pairs. These studies demonstrate the utility of identifying the correct E2/E3 pair to monitor specific substrate ubiquitylation. PMID:23695783

  7. E2F7 overexpression leads to tamoxifen resistance in breast cancer cells by competing with E2F1 at miR-15a/16 promoter

    PubMed Central

    Chu, Junjun; Zhu, Yinghua; Liu, Yujie; Sun, Lijuan; Lv, Xiaobin; Wu, Yanqin; Hu, Pengnan; Su, Fengxi; Gong, Chang; Song, Erwei; Liu, Bodu; Liu, Qiang

    2015-01-01

    About 50–70% of breast cancers are estrogen receptor α (ERα) positive and most of them are sensitive to endocrine therapy including tamoxifen. However, one third of these patients will eventually develop resistance and relapse. We found that the expression of miR-15a and miR-16 were significantly decreased in tamoxifen resistant ER positive breast cancer cell lines. Exogenous expression of miR-15a/16 mimics re-sensitized resistant cells to tamoxifen by inhibiting Cyclin E1 and B cell lymphoma-2 (Bcl-2) to induce cell growth arrest and apoptosis respectively. Further, we identified that a repressive member of E2F family, E2F7, was responsible for the suppression of miR-15a/16 cluster by competing with E2F1 for E2F binding site at the promoter of their host gene DLEU2. Moreover, high expression of E2F7 is correlated with high risk of relapse and poor prognosis in breast cancer patients receiving tamoxifen treatment. Together, our results suggest that overexpression of E2F7 represses miR-15a/16 and then increases Cyclin E1 and Bcl-2 that result in tamoxifen resistance. E2F7 may be a valuable prognostic marker and a therapeutic target of tamoxifen resistance in breast cancer. PMID:26397135

  8. The swine CD81 enhances E2-based DNA vaccination against classical swine fever.

    PubMed

    Li, Wenliang; Mao, Li; Zhou, Bin; Liu, Xia; Yang, Leilei; Zhang, Wenwen; Jiang, Jieyuan

    2015-07-01

    Classical swine fever (CSF) is a highly contagious and economically important viral disease that affects the pig industry worldwide. The glycoprotein E2 of CSFV can induce neutralizing antibodies and protective immunity, and is widely used for novel vaccine development. The objective of this study was to explore whether a tetraspanin molecule CD81 could improve the immune responses of an E2-based DNA vaccine. Plasmids pVAX-CD81, pVAX-E2 and pVAX-CD81-E2 were constructed and the expression of target proteins was confirmed in BHK-21 cells by indirect immunofluorescence assay. BALB/c mice were divided into 5 groups and immunized with different plasmids (pVAX-E2, pVAX-CD81-E2, pVAX-E2+pVAX-CD81, pVAX-CD81 and PBS) three times with two weeks interval. The results showed that the introduction of CD81 promoted higher humoral and cellular immune responses than E2 expression alone (P<0.05). In addition, immunization with pVAX-CD81-E2 induced stronger immune responses than pVAX-E2+pVAX-CD81. Furthermore, four groups of pigs were immunized with pVAX-E2, pVAX-CD81-E2, pVAX-CD81 and PBS, respectively. Humoral and cellular immune responses detection showed similar results with those in mice. Compared to pVAX-E2, pVAX-CD81-E2 induced higher titers of neutralizing antibodies after viral challenge and conferred stronger protection. These results confirmed the capacity of swine CD81 enhancing the humoral and cellular responses with an adjuvant effect on CSFV DNA vaccine. This is the first report demonstrating the adjuvant effect of CD81 to enhance the DNA vaccination for swine pathogen. PMID:26051512

  9. Regulation of E2F1-induced apoptosis by poly(ADP-ribosyl)ation

    PubMed Central

    Kumari, A; Iwasaki, T; Pyndiah, S; Cassimere, E K; Palani, C D; Sakamuro, D

    2015-01-01

    The transcription factor adenovirus E2 promoter-binding factor (E2F)-1 normally enhances cell-cycle progression, but it also induces apoptosis under certain conditions, including DNA damage and serum deprivation. Although DNA damage facilitates the phosphorylation and stabilization of E2F1 to trigger apoptosis, how serum starvation renders cells vulnerable to E2F1-induced apoptosis remains unclear. Because poly(ADP-ribose) polymerase 1 (PARP1), a nuclear enzyme essential for genomic stability and chromatin remodeling, interacts directly with E2F1, we investigated the effects of PARP1 on E2F1-mediated functions in the presence and absence of serum. PARP1 attenuation, which increased E2F1 transactivation, induced G2/M cell-cycle arrest under normal growth conditions, but enhanced E2F1-induced apoptosis in serum-starved cells. Interestingly, basal PARP1 activity was sufficient to modify E2F1 by poly(ADP-ribosyl)ation, which stabilized the interaction between E2F1 and the BIN1 tumor suppressor in the nucleus. Accordingly, BIN1 acted as an RB1-independent E2F1 corepressor. Because E2F1 directly activates the BIN1 gene promoter, BIN1 curbed E2F1 activity through a negative-feedback mechanism. Conversely, when the BIN1E2F1 interaction was abolished by PARP1 suppression, E2F1 continuously increased BIN1 levels. This is functionally germane, as PARP1-depletion-associated G2/M arrest was reversed by the transfection of BIN1 siRNA. Moreover, PARP-inhibitor-associated anti-transformation activity was compromised by the coexpression of dominant-negative BIN1. Because serum starvation massively reduced the E2F1 poly(ADP-ribosyl)ation, we conclude that the release of BIN1 from hypo-poly(ADP-ribosyl)ated E2F1 is a mechanism by which serum starvation promotes E2F1-induced apoptosis. PMID:25257171

  10. Transcriptional regulation of human RANK ligand gene expression by E2F1

    SciTech Connect

    Hu Yan; Sun Meng; Nadiminty, Nagalakshmi; Lou Wei; Pinder, Elaine; Gao, Allen C.

    2008-06-06

    Receptor activator of nuclear factor kappa B ligand (RANKL) is a critical osteoclastogenic factor involved in the regulation of bone resorption, immune function, the development of mammary gland and cardiovascular system. To understand the transcriptional regulation of RANKL, we amplified and characterized a 1890 bp 5'-flanking sequence of human RANKL gene (-1782 bp to +108 bp relative to the transcription start site). Using a series of deletion mutations of the 1890 bp RANKL promoter, we identified a 72 bp region (-172 to -100 bp) mediating RANKL basal transcriptional activity. Sequence analysis revealed a putative E2F binding site within this 72 bp region in the human RANKL promoter. Overexpression of E2F1 increased RANKL promoter activity, while down-regulation of E2F1 expression by small interfering RNA decreased RANKL promoter activity. RT-PCR and enzyme linked immunosorbent assays (ELISA) further demonstrated that E2F1 induced the expression of RANKL. Electrophoretic gel mobility shift assays (EMSA) and antibody competition assays confirmed that E2F1 proteins bind to the consensus E2F binding site in the RANKL promoter. Mutation of the E2F consensus binding site in the RANKL promoter profoundly reduced the basal promoter activity and abolished the transcriptional modulation of RANKL by E2F1. These results suggest that E2F1 plays an important role in regulating RANKL transcription through binding to the E2F consensus binding site.

  11. Regulation of VEGF receptors by Rb and E2F1: Role of acetylation

    PubMed Central

    Pillai, Smitha; Kovacs, Michelle; Chellappan, Srikumar

    2010-01-01

    E2F transcription factors regulate a variety of cellular processes but their role in angiogenesis is not clear. We find that many genes involved in angiogenesis like FLT-1, KDR and angiopoietin 2 have potential E2F1 binding sites in their promoter. ChIP assays showed that E2F1 can associate with these promoters and the recruitment of E2F1 was enhanced upon VEGF stimulation with concomitant dissociation of Rb leading to the transcriptional activation of these promoters. Transient transfection experiments showed that these promoters were induced by E2F1 and repressed by Rb while depletion of E2F1 decreased their expression. The increased binding of E2F1 to these promoters upon VEGF stimulation correlated with acetylation of histones and E2F1; this required VEGFR function, as seen in ChIP-re-ChIP experiments. This suggests the existence of a positive feedback loop regulating E2F1 acetylation and VEGFR expression. Acetylation associated with VEGF signaling appears to be predominantly mediated by PCAF and depletion of histone acetyl transferases disrupted the formation of angiogenic tubules. These results suggest a novel role for E2F1 and acetylation in the angiogenic process. PMID:20516113

  12. E2F function in muscle growth is necessary and sufficient for viability in Drosophila

    PubMed Central

    Zappia, Maria Paula; Frolov, Maxim V.

    2016-01-01

    The E2F transcription factor is a key cell cycle regulator. However, the inactivation of the entire E2F family in Drosophila is permissive throughout most of animal development until pupation when lethality occurs. Here we show that E2F function in the adult skeletal muscle is essential for animal viability since providing E2F function in muscles rescues the lethality of the whole-body E2F-deficient animals. Muscle-specific loss of E2F results in a significant reduction in muscle mass and thinner myofibrils. We demonstrate that E2F is dispensable for proliferation of muscle progenitor cells, but is required during late myogenesis to directly control the expression of a set of muscle-specific genes. Interestingly, E2f1 provides a major contribution to the regulation of myogenic function, while E2f2 appears to be less important. These findings identify a key function of E2F in skeletal muscle required for animal viability, and illustrate how the cell cycle regulator is repurposed in post-mitotic cells. PMID:26823289

  13. A functionally distinct member of the DP family of E2F subunits.

    PubMed

    Milton, A; Luoto, K; Ingram, L; Munro, S; Logan, N; Graham, A L; Brummelkamp, T R; Hijmans, E M; Bernards, R; La Thangue, N B

    2006-05-25

    E2F transcription factors regulate genes involved in cell-cycle progression. In mammalian cells, physiological E2F exists as an E2F/DP heterodimer. Currently, eight E2F and two DP subunits have been characterized. We report here the characterization of a new member of the DP family, DP-4. While DP-4 exhibits certain similarities with members of the DP family, it also possesses a number of significant differences. Thus, DP-4 forms a heterodimer with E2F subunits, binds to the E2F site and associates with pocket proteins including pRb. In contrast to DP-1, however, DP-4/E2F-1 complexes exhibit reduced DNA binding activity. Furthermore, DP-4 interferes with E2F-1-dependent transcription and delays cell-cycle progression. These results highlight an emerging complexity in the DP family of E2F subunits, and suggest that DP-4 may endow E2F heterodimers with distinct transcription properties. PMID:16418725

  14. Amplification of the E2F1 transcription factor gene in the HEL erythroleukemia cell line

    SciTech Connect

    Saito, M.; Valentine, M.B.; Look, A.T.

    1995-01-01

    The E2F transcription factor plays an important regulatory role in cell proliferation, mediating the expression of genes whose products are essential for inducing resting cells to enter the cell cycle and synthesize DNA. To investigate the possible involvement of E2F in hematopoietic malignancies, we isolated genomic clones encompassing the human E2F1 gene. We then used fluorescence in situ hybridization to localize E2F1 to human chromosome 20q11, telomeric to the p107 locus, a gene whose product is related to the retinoblastoma gene product (pRb). This finding contrasts with the 1p36 and 6q22 chromosomal locations previously assigned E2F2 and E2F3, two additional members of the E2F family. Although deletions or structural rearrangements of E2F1 were not detected in 14 primary acute leukemia or myelodysplasia samples with structural abnormalities of chromosome 20q11, the gene was amplified and overexpressed in HEL erythroleukemia cells and translocated to other chromosomes in several established human leukemia cell lines. This study provides the first evidence of gene amplification involving a member of the E2F family of transcription factors. We propose that E2F1 overexpression in erythroid progenitors may stimulate abnormal cell proliferation by overriding negative regulatory signals mediated by tumor suppressor proteins such as pRb. 76 refs., 5 figs., 2 tabs.

  15. E2F function in muscle growth is necessary and sufficient for viability in Drosophila.

    PubMed

    Zappia, Maria Paula; Frolov, Maxim V

    2016-01-01

    The E2F transcription factor is a key cell cycle regulator. However, the inactivation of the entire E2F family in Drosophila is permissive throughout most of animal development until pupation when lethality occurs. Here we show that E2F function in the adult skeletal muscle is essential for animal viability since providing E2F function in muscles rescues the lethality of the whole-body E2F-deficient animals. Muscle-specific loss of E2F results in a significant reduction in muscle mass and thinner myofibrils. We demonstrate that E2F is dispensable for proliferation of muscle progenitor cells, but is required during late myogenesis to directly control the expression of a set of muscle-specific genes. Interestingly, E2f1 provides a major contribution to the regulation of myogenic function, while E2f2 appears to be less important. These findings identify a key function of E2F in skeletal muscle required for animal viability, and illustrate how the cell cycle regulator is repurposed in post-mitotic cells. PMID:26823289

  16. Inhibition of E2F-mediated transcription by p202.

    PubMed Central

    Choubey, D; Li, S J; Datta, B; Gutterman, J U; Lengyel, P

    1996-01-01

    Many of the antimicrobial, immunomodulatory and cell growth inhibitory activities of the interferons are mediated by interferon-inducible proteins. Earlier we characterized an interferon-inducible murine protein, p202, whose expression in transfected cells inhibits cell proliferation and which can form a complex with retinoblastoma protein (pRb). Here we report that in transfected cells expression of p202 inhibits E2F-stimulated transcription of a reporter gene and of endogenous genes. Inhibition of the transcriptional activity of E2F by p202 does not depend on fully functional pRb and is correlated with inhibition of the sequence-specific DNA binding of E2F. p202 interacts with the transcription factor E2F (E2F-1/DP-1) in vitro and in vivo. Inhibition of E2F activity by p202 may contribute to growth inhibition by the interferons. Images PMID:8896460

  17. [Codon optimization and expression in Pichia pastoris of E2 gene of classical swine fever virus].

    PubMed

    Han, Xueqing; Liu, Xiangtao; Zhang, Yongguo; Zhangyong; Xie, Qingge

    2003-10-01

    Codon bias was one of the important parameter which influence heterogenous gene expression, optimizing codon sequence could improve expression level of heterogenous gene. In the preview study, wildtype E2 gene was expressed poorly in Pichia pastoris, in order to improve the expression level of E2 gene in Pichia pastoris, the low usage codons of E2 gene were mutated into high usage codons in Pichia pastoris by directed-mutagenesis based on PCR. The result showed that, compared with the results reported in preview study, the expression level of E2 gene in Pichia pastoris was improved observably by substituting 24 low usage codons of E2 gene for the high usage synonymous codons. It suggested the stragety to improve the expression of E2 gene in Pichia pastoris by codon optimization was successful. PMID:16281552

  18. Structure of a RING E3 ligase and ubiquitin-loaded E2 primed for catalysis

    PubMed Central

    Plechanovová, Anna; Jaffray, Ellis; Tatham, Michael H.; Naismith, James H.; Hay, Ronald T.

    2012-01-01

    SUMMARY Ubiquitin modification is mediated by a large family of specificity determining ubiquitin E3 ligases. To facilitate ubiquitin transfer, RING E3 ligases bind both substrate and a ubiquitin E2 conjugating enzyme linked to ubiquitin via a thioester bond, but the mechanism of transfer has remained elusive. Here we report the crystal structure of the dimeric RING of RNF4 in complex with E2 (UbcH5a) linked by an isopeptide bond to ubiquitin. While the E2 contacts a single protomer of the RING, ubiquitin is folded back onto the E2 by contacts from both RING protomers. The C-terminal tail of ubiquitin is locked into an active site groove on the E2 by an intricate network of interactions, resulting in changes at the E2 active site. This arrangement is primed for catalysis as it can deprotonate the incoming substrate lysine residue and stabilise the consequent tetrahedral transition state intermediate. PMID:22842904

  19. Cumulative Effect of Phosphorylation of pRB on Regulation of E2F Activity

    PubMed Central

    Brown, Vivette D.; Phillips, Robert A.; Gallie, Brenda L.

    1999-01-01

    The product of the retinoblastoma susceptibility gene, pRB, is a nuclear phosphoprotein that controls cell growth by binding to and suppressing the activities of transcription factors such as the E2F family. Transactivation activity is inhibited when E2F is bound to hypophosphorylated pRB and released when pRB is phosphorylated by cyclin-dependent kinases (CDKs). To determine which of 16 potential CDK phosphorylation sites regulated the pRB-E2F interaction, mutant pRB proteins produced by site-directed mutagenesis were tested for the ability to suppress E2F-mediated transcription in a reporter chloramphenicol acetyltransferase assay. Surprisingly, no one CDK site regulated the interaction of pRB with E2F when E2F was bound to DNA. Instead, disruption of transcriptional repression resulted from accumulation of phosphate groups on the RB molecule. PMID:10207050

  20. Functional impact of colorectal cancer-associated mutations in the transcription factor E2F4.

    PubMed

    Paquin, Marie-Christine; Leblanc, Caroline; Lemieux, Etienne; Bian, Benjamin; Rivard, Nathalie

    2013-12-01

    The transcription factor E2F4 plays a critical role in cell cycle progression of normal and cancerous intestinal epithelial cells. Contrary to other E2Fs, the coding region of the E2F4 gene contains a longer spacer segment of a CAG trinucleotide repeat sequence encoding 13 consecutive serine residues, which is highly vulnerable to frameshift mutations in situations of genetic instability. Mutations in this region of the E2F4 gene have been observed in colorectal tumors with microsatellite instability. However, the effect of these changes on its function in colorectal cancer cells is currently unknown. We generated E2F4(CAG)?? and E2F4(CAG)?? mutants and compared their activity to the E2F4 wild-type, E2F4(CAG)??. Luciferase assays with the thymidine kinase-luc reporter gene revealed that the mutants were more transcriptionally active than wild-type E2F4. The mechanism of increased activity of E2F4 was primarily related to protein stability, due to a significantly enhanced half-life of E2F4 mutants comparatively to that of wild-type E2F4. However, the association with the pocket protein p130/RBL2 did not account for this increased protein stability. Sequencing analysis of the endogenous E2F4 gene in a series of colorectal cancer cell lines showed that the microsatellite-unstable cell line SW48 exhibited a serine deletion in this gene. Accordingly, E2F4 half-life was much more elevated in SW48 cells in comparison to Caco-2/15, a microsatellite-stable cell line. Notably, in soft-agar assays, both mutants more potently increased anchorage-independent growth in comparison to wild-type E2F4. In conclusion, our data demonstrate that cancer-associated E2F4 mutations enhance the capacity of colorectal cancer cells to grow without anchorage, thereby contributing to tumor progression. PMID:24100580

  1. Characterization of the nuclear localization signal of high risk HPV16 E2 protein

    SciTech Connect

    Klucevsek, Kristin; Wertz, Mary; Lucchi, John; Leszczynski, Anna; Moroianu, Junona . E-mail: moroianu@bc.edu

    2007-03-30

    The E2 protein of high risk human papillomavirus type 16 (HPV16) contains an amino-terminal (N) domain, a hinge (H) region and a carboxyl-terminal (C) DNA-binding domain. Using enhanced green fluorescent protein (EGFP) fusions with full length E2 and E2 domains in transfection assays in HeLa cells, we found that the C domain is responsible for the nuclear localization of E2 in vivo, whereas the N and H domains do not contain additional nuclear localization signals (NLSs). Deletion analysis of EGFP-E2 and EGFP-cE2 determined that the C domain contains an {alpha} helix cNLS that overlaps with the DNA-binding region. Mutational analysis revealed that the arginine and lysine residues in this cNLS are essential for nuclear localization of HPV16 E2. Interestingly, these basic amino acid residues are well conserved among the E2 proteins of BPV-1 and some high risk HPV types but not in the low risk HPV types, suggesting that there are differences between the NLSs and corresponding nuclear import pathways between these E2 proteins.

  2. The Mdm2 Ubiquitin Ligase Enhances Transcriptional Activity of Human Papillomavirus E2?

    PubMed Central

    Gammoh, Noor; Gardiol, Daniela; Massimi, Paola; Banks, Lawrence

    2009-01-01

    The regulation of human papillomavirus (HPV) gene expression by the E2 protein is a critical feature of the viral life cycle. Previous studies have shown an important role in transcription for the ubiquitin-proteasome pathway, but its role in HPV gene expression has not been addressed. We now show that HPV E2 requires an active proteasome for its optimal transcriptional activator function. This involves an interaction with the Mdm2 ubiquitin ligase, which together with E2 acts synergistically to activate the HPV type 16 promoter. We also show that HPV E2 recruits Mdm2 onto HPV promoter sequences, providing an explanation for this cooperative activity. PMID:19004934

  3. The Mdm2 ubiquitin ligase enhances transcriptional activity of human papillomavirus E2.

    PubMed

    Gammoh, Noor; Gardiol, Daniela; Massimi, Paola; Banks, Lawrence

    2009-02-01

    The regulation of human papillomavirus (HPV) gene expression by the E2 protein is a critical feature of the viral life cycle. Previous studies have shown an important role in transcription for the ubiquitin-proteasome pathway, but its role in HPV gene expression has not been addressed. We now show that HPV E2 requires an active proteasome for its optimal transcriptional activator function. This involves an interaction with the Mdm2 ubiquitin ligase, which together with E2 acts synergistically to activate the HPV type 16 promoter. We also show that HPV E2 recruits Mdm2 onto HPV promoter sequences, providing an explanation for this cooperative activity. PMID:19004934

  4. AMF-1/Gps2 binds p300 and enhances its interaction with papillomavirus E2 proteins.

    PubMed

    Peng, Y C; Breiding, D E; Sverdrup, F; Richard, J; Androphy, E J

    2000-07-01

    The cellular protein AMF-1 (Gps2) positively modulates gene expression by the papillomavirus E2 protein (D. E. Breiding et al., Mol. Cell. Biol. 17:7208-7219, 1997). We show here that AMF-1 also binds the transcriptional coactivator p300 in vitro and in vivo. E2 interacted weakly with p300. These observations led to a model in which AMF-1 recruits p300 into a complex with E2. Cotransfection of AMF-1 or p300 stimulated levels of E2-dependent transcription, while cotransfection of both AMF-1 and p300 showed an additive effect. The functional significance of p300 recruitment for E2 transactivation was evidenced by repression of E2-activated transcription by adenovirus E1A, which inhibits both coactivator and acetylase activities of p300. Antibodies to AMF-1 or E2 immunoprecipitated histone acetylase activity from cell lysates. Western blotting using antibody against acetyl-lysine failed to detect acetylation of AMF-1 or E2 in complex with p300. These results suggest that AMF-1 facilitates the recruitment of p300 and its histone acetylase activity into complexes with E2 and represents a novel mechanism of transcriptional activation. PMID:10846067

  5. RNAi-mediated knockdown of E2F2 inhibits tumorigenicity of human glioblastoma cells

    PubMed Central

    NAKAHATA, ADRIANA M.; SUZUKI, DANIELA E.; RODINI, CAROLINA O.; FIUZA, MAYARA L.; OKAMOTO, OSWALDO K.

    2014-01-01

    In a previous genome-wide expression profiling study, we identified E2F2 as a hyperexpressed gene in stem-like cells of distinct glioblastoma multiforme (GBM) specimens. Since the encoded E2F2 transcription factor has been implicated in both tumor suppression and tumor development, we conducted a functional study to investigate the pertinence of E2F2 to human gliomagenesis. E2F2 expression was knocked down by transfecting U87MG cells with plasmids carrying a specific silencing shRNA. Upon E2F2 silencing, in vitro cell proliferation was significantly reduced, as indicated by a time-course analysis of viable tumor cells. Anchorage-independent cell growth was also significantly inhibited after E2F2 silencing, based on cell colony formation in soft agar. Subcutaneous and orthotopic xenograft models of GBM in nude mice also indicated inhibition of tumor development in vivo, following E2F2 silencing. As expression of the E2F2 gene is associated with glioblastoma stem cells and is involved in the transformation of human astrocytes, the present findings suggest that E2F2 is involved in gliomagenesis and could be explored as a potential therapeutic target in malignant gliomas. PMID:25202354

  6. UHMWPE carrying estradiol to treat the particle-induced osteolysis-Processing and characterizing.

    PubMed

    Liu, Aiqin; Qu, Shuxin; Chao, Mengmeng; Zhu, Minhao; Weng, Jie; Zhou, Zhongrong

    2009-08-01

    The objective of this study was to explore the possibility of UHMWPE implant used as the drug carrier to treat particle-induced osteolysis. 17beta-estradiol (E2), which had the potential application on osteolysis treatment and the high melting point, was added into UHMWPE powder to produce UHMWPE-E2 composites through hot press processing. The hydrophobicity, crystallinity, mechanical properties, and wear performance of the UHMWPE-E2 were characterized compared with the control UHMWPE. The thermal analysis and Fourier Transform Infrared Spectroscopy results demonstrated that the hot press processing would not alter the functional groups of E2 in this study. There were no significant differences in the hydrophobicity and crystallinity between the UHMWPE-E2 and UHMWPE. The UHMWPE-E2 showed satisfying mechanical properties, including ultimate tensile strength (47.2 +/- 3.6 MPa), yield strength (25.0 +/- 0.6 MPa) and elongation at break (320 +/- 25.5 %), which were similar with the control UHMWPE. The friction coefficients and worn scars were similar between the UHMWPE-E2 and the control UHMWPE. The wear mechanism of the UHMWPE-E2 and UHMWPE both were abrasive wear under dry friction. The UHMWPE-E2 possesses the approving mechanical properties and wear performance compared with the control UHMWPE, which might be used as the potential implanted drug carrier to prevent the particle-induced osteolysis in joint replacements. PMID:18563828

  7. The First Human Epitope Map of the Alphaviral E1 and E2 Proteins Reveals a New E2 Epitope with Significant Virus Neutralizing Activity

    PubMed Central

    Hunt, Ann R.; Frederickson, Shana; Maruyama, Toshiaki; Roehrig, John T.; Blair, Carol D.

    2010-01-01

    Background Venezuelan equine encephalitis virus (VEEV) is responsible for VEE epidemics that occur in South and Central America and the U.S. The VEEV envelope contains two glycoproteins E1 (mediates cell membrane fusion) and E2 (binds receptor and elicits virus neutralizing antibodies). Previously we constructed E1 and E2 epitope maps using murine monoclonal antibodies (mMAbs). Six E2 epitopes (E2c,d,e,f,g,h) bound VEEV-neutralizing antibody and mapped to amino acids (aa) 182–207. Nothing is known about the human antibody repertoire to VEEV or epitopes that engage human virus-neutralizing antibodies. There is no specific treatment for VEE; however virus-neutralizing mMAbs are potent protective and therapeutic agents for mice challenged with VEEV by either peripheral or aerosol routes. Therefore, fully human MAbs (hMAbs) with virus-neutralizing activity should be useful for prevention or clinical treatment of human VEE. Methods We used phage-display to isolate VEEV-specific hFabs from human bone marrow donors. These hFabs were characterized by sequencing, specificity testing, VEEV subtype cross-reactivity using indirect ELISA, and in vitro virus neutralization capacity. One E2-specific neutralizing hFAb, F5n, was converted into IgG, and its binding site was identified using competitive ELISA with mMAbs and by preparing and sequencing antibody neutralization-escape variants. Findings Using 11 VEEV-reactive hFabs we constructed the first human epitope map for the alphaviral surface proteins E1 and E2. We identified an important neutralization-associated epitope unique to the human immune response, E2 aa115–119. Using a 9 Å resolution cryo-electron microscopy map of the Sindbis virus E2 protein, we showed the probable surface location of this human VEEV epitope. Conclusions The VEEV-neutralizing capacity of the hMAb F5 nIgG is similar to that exhibited by the humanized mMAb Hy4 IgG. The Hy4 IgG has been shown to limit VEEV infection in mice both prophylactically and therapeutically. Administration of a cocktail of F5n and Hy4 IgGs, which bind to different E2 epitopes, could provide enhanced prophylaxis or immunotherapy for VEEV, while reducing the possibility of generating possibly harmful virus neutralization-escape variants in vivo. PMID:20644615

  8. The E2F2 Transcription Factor Sustains Hepatic Glycerophospholipid Homeostasis in Mice

    PubMed Central

    Maldonado, Eduardo N.; Delgado, Igotz; Furland, Natalia E.; Buqué, Xabier; Iglesias, Ainhoa; Aveldaño, Marta I.; Zubiaga, Ana; Fresnedo, Olatz; Ochoa, Begoña

    2014-01-01

    Increasing evidence links metabolic signals to cell proliferation, but the molecular wiring that connects the two core machineries remains largely unknown. E2Fs are master regulators of cellular proliferation. We have recently shown that E2F2 activity facilitates the completion of liver regeneration after partial hepatectomy (PH) by regulating the expression of genes required for S-phase entry. Our study also revealed that E2F2 determines the duration of hepatectomy-induced hepatic steatosis. A transcriptomic analysis of normal adult liver identified “lipid metabolism regulation” as a major E2F2 functional target, suggesting that E2F2 has a role in lipid homeostasis. Here we use wild-type (E2F2+/+) and E2F2 deficient (E2F2−/−) mice to investigate the in vivo role of E2F2 in the composition of liver lipids and fatty acids in two metabolically different contexts: quiescence and 48-h post-PH, when cellular proliferation and anabolic demands are maximal. We show that liver regeneration is accompanied by large triglyceride and protein increases without changes in total phospholipids both in E2F2+/+ and E2F2−/− mice. Remarkably, we found that the phenotype of quiescent liver tissue from E2F2−/− mice resembles the phenotype of proliferating E2F2+/+ liver tissue, characterized by a decreased phosphatidylcholine to phosphatidylethanolamine ratio and a reprogramming of genes involved in generation of choline and ethanolamine derivatives. The diversity of fatty acids in total lipid, triglycerides and phospholipids was essentially preserved on E2F2 loss both in proliferating and non-proliferating liver tissue, although notable exceptions in inflammation-related fatty acids of defined phospholipid classes were detected. Overall, our results indicate that E2F2 activity sustains the hepatic homeostasis of major membrane glycerolipid components while it is dispensable for storage glycerolipid balance. PMID:25396754

  9. Transcription factor E2F3 overexpressed in prostate cancer independently predicts clinical outcome.

    PubMed

    Foster, Christopher S; Falconer, Alison; Dodson, Andrew R; Norman, Andrew R; Dennis, Nening; Fletcher, Anne; Southgate, Christine; Dowe, Anna; Dearnaley, David; Jhavar, Sameer; Eeles, Rosalind; Feber, Andrew; Cooper, Colin S

    2004-08-01

    E2F transcription factors, including E2F3, directly modulate expression of EZH2. Recently, overexpression of the EZH2 gene has been implicated in the development of human prostate cancer. In tissue microrarray studies we now show that expression of high levels of nuclear E2F3 occurs in a high proportion (98/147, 67%) of human prostate cancers, but is a rare event in non-neoplastic prostatic epithelium suggesting a role for E2F3 overexpression in prostate carcinogenesis. Patients with prostate cancer exhibiting immunohistochemically detectable nuclear E2F3 expression have poorer overall survival (P=0.0022) and cause-specific survival (P=0.0047) than patients without detectable E2F3 expression. When patients are stratified according to the maximum percentage of E2F3-positive nuclei identified within their prostate cancers (up to 20, 21-40%, etc.), there is an increasingly significant association between E2F3 staining and risk of death both for overall survival (P=0.0014) and for cause-specific survival (P=0.0004). Multivariate analyses select E2F3 expression as an independent factor predicting overall survival (unstratified P=0.0103, stratified P=0.0086) and cause-specific survival (unstratified P=0.0288, stratified P=0.0072). When these results are considered together with published data on EZH2 and on the E2F3 control protein pRB, we conclude that the pRB-E2F3-EZH2 control axis may have a critical role in modulating aggressiveness of individual human prostate cancer. PMID:15184867

  10. Clinical significance of E2F1 protein expression in non-small cell lung cancer

    PubMed Central

    2012-01-01

    Background The transcription factor E2F1 has been implicated in cell cycle control and DNA damage response. Paradoxically, E2F1 can promote apoptosis and function as tumor suppressor. In non-small cell lung cancer (NSCLC), there are conflicting data for clinical significance of E2F1 expression. In this study, we investigated the protein expression of E2F1 in patients with stage I-III NSCLC, and its correlation with clinical outcome. Results 56 paired adjacent non-tumor/tumor matched samples were prospectively obtained from patients undergoing surgery for stage I-III NSCLC at Taipei Veterans General Hospital. The protein expression of E2F1 was determined by Western blot analysis. The levels of E2F1 protein were significantly higher in tumor samples than in non-tumor lung specimens (P = 0.008). Overexpression of E2F1 was defined as a more than 2-fold expression in the tumorous sample compared with the corresponding nontumorous one, and was noted in 21 patients (37.5%). There was no significant difference in overall survival (P = 0.44) or probability of freedom from recurrence (P = 0.378) between patients with E2F1 overexpression vs. non-overexpressors. Additionally, there was no significant association between E2F1 overexpression and any clinicopathologic parameter such as histological type, stage, or angiolymphatic invasion of tumor. Conclusion E2F1 protein is frequently overexpressed in NSCLC. There is no correlation between E2F1 protein expression and clinical outcome such as survival and freedom from progression. PMID:23210897

  11. Destructive interference of E2 matrix elements in a triaxial rotor model

    SciTech Connect

    Allmond, James M; Wood, J. L.; Kulp, W. D.

    2010-01-01

    A triaxial rotor model with independent inertia and electric quadrupole tensors is applied to nuclei that have certain E2 matrix elements equal to zero. It is shown that such vanishing E2 matrix elements are explained by the model as a destructive interference effect. The example of 196Pt is considered.

  12. 17 CFR 270.6e-2 - Exemptions for certain variable life insurance separate accounts.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... to the lesser of 20 years or the anticipated life expectancy of the insured named in the contract... extent necessary with Rule 7d-1 (17 CFR 270.7d-1) under the Act; (2) The assets of the separate account... variable life insurance separate accounts. 270.6e-2 Section 270.6e-2 Commodity and Securities...

  13. 17 CFR 270.6e-2 - Exemptions for certain variable life insurance separate accounts.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... to the lesser of 20 years or the anticipated life expectancy of the insured named in the contract... extent necessary with Rule 7d-1 (17 CFR 270.7d-1) under the Act; (2) The assets of the separate account... variable life insurance separate accounts. 270.6e-2 Section 270.6e-2 Commodity and Securities...

  14. Insights into the mechanism of human papillomavirus E2-induced procaspase-8 activation and cell death

    PubMed Central

    Singh, Nitu; Senapati, Sanjib; Bose, Kakoli

    2016-01-01

    High-risk human papillomavirus (HR-HPV) E2 protein, the master regulator of viral life cycle, induces apoptosis of host cell that is independent of its virus-associated regulatory functions. E2 protein of HR-HPV18 has been found to be involved in novel FADD-independent activation of caspase-8, however, the molecular basis of this unique non-death-fold E2-mediated apoptosis is poorly understood. Here, with an interdisciplinary approach that involves in silico, mutational, biochemical and biophysical probes, we dissected and characterized the E2-procasapse-8 binding interface. Our data demonstrate direct non-homotypic interaction of HPV18 E2 transactivation domain (TAD) with α2/α5 helices of procaspase-8 death effector domain-B (DED-B). The observed interaction mimics the homotypic DED-DED complexes, wherein the conserved hydrophobic motif of procaspase-8 DED-B (F122/L123) occupies a groove between α2/α3 helices of E2 TAD. This interaction possibly drives DED oligomerization leading to caspase-8 activation and subsequent cell death. Furthermore, our data establish a model for E2-induced apoptosis in HR-HPV types and provide important clues for designing E2 analogs that might modulate procaspase-8 activation and hence apoptosis. PMID:26906543

  15. 26 CFR 48.4216(e)-2 - Limitation on aggregate of exclusions and price readjustments.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 16 2010-04-01 2010-04-01 true Limitation on aggregate of exclusions and price readjustments. 48.4216(e)-2 Section 48.4216(e)-2 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) MISCELLANEOUS EXCISE TAXES MANUFACTURERS AND RETAILERS EXCISE TAXES Special Provisions Applicable to...

  16. Localization of E2A mRNA expression in developing and adult rat tissues.

    PubMed Central

    Roberts, V J; Steenbergen, R; Murre, C

    1993-01-01

    E2A helix-loop-helix proteins are involved in the control of various developmental pathways. We show here by in situ hybridization that E2A transcripts are present in most embryonic and adult tissues. However, no E2A expression is detectable in heart and nonproliferative regions of the brain and spinal cord. Highest levels of E2A expression are found in the ependyma cell layer surrounding the cerebral ventricles in the embryonic rat brain. In addition, in the embryo, E2A transcripts were found in secretory cells of the pancreas, the bronchial tubes of the lung, glomeruli of the kidney, and the lining of the stomach. Interestingly, high levels of E2A transcripts are selectively found in the germinal center of the lymphatic nodules in the adult rat spleen. Thus, E2A, like its Drosophila homolog daughterless, is expressed in most tissues. The most notable feature of the E2A expression pattern is its high levels of expression in some areas of rapid cell proliferation and differentiation and in certain epithelial cell types. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:8356060

  17. Functional characterization of the Sindbis virus E2 glycoprotein by transposon linker-insertion mutagenesis

    SciTech Connect

    Navaratnarajah, Chanakha K.; Kuhn, Richard J. . E-mail: kuhnr@purdue.edu

    2007-06-20

    The glycoprotein envelope of alphaviruses consists of two proteins, E1 and E2. E1 is responsible for fusion and E2 is responsible for receptor binding. An atomic structure is available for E1, but one for E2 has not been reported. In this study, transposon linker-insertion mutagenesis was used to probe the function of different domains of E2. A library of mutants, containing 19 amino acid insertions in the E2 glycoprotein sequence of the prototype alphavirus, Sindbis virus (SINV), was generated. Fifty-seven independent E2 insertions were characterized, of which more than half (67%) gave rise to viable virus. The wild-type-like mutants identify regions that accommodate insertions without perturbing virus production and can be used to insert targeting moieties to direct SINV to specific receptors. The defective and lethal mutants give insight into regions of E2 important for protein stability, transport to the cell membrane, E1-E2 contacts, and receptor binding.

  18. Rb/E2F Regulates Expression of Neogenin during Neuronal Migration?

    PubMed Central

    Andrusiak, Matthew G.; McClellan, Kelly A.; Dugal-Tessier, Delphie; Julian, Lisa M.; Rodrigues, Sonia P.; Park, David S.; Kennedy, Timothy E.; Slack, Ruth S.

    2011-01-01

    The Rb/E2F pathway has long been appreciated for its role in regulating cell cycle progression. Emerging evidence indicates that it also influences physiological events beyond regulation of the cell cycle. We have previously described a requirement for Rb/E2F mediating neuronal migration; however, the molecular mechanisms remain unknown, making this an ideal system to identify Rb/E2F-mediated atypical gene regulation in vivo. Here, we report that Rb regulates the expression of neogenin, a gene encoding a receptor involved in cell migration and axon guidance. Rb is capable of repressing E2F-mediated neogenin expression while E2F3 occupies a region containing E2F consensus sites on the neogenin promoter in native chromatin. Absence of Rb results in aberrant neuronal migration and adhesion in response to netrin-1, a known ligand for neogenin. Increased expression of neogenin through ex vivo electroporation results in impaired neuronal migration similar to that detected in forebrain-specific Rb deficiency. These findings show direct regulation of neogenin by the Rb/E2F pathway and demonstrate that regulation of neogenin expression is required for neural precursor migration. These studies identify a novel mechanism through which Rb regulates transcription of a gene beyond the classical E2F targets to regulate events distinct from cell cycle progression. PMID:21059867

  19. Cell cycle-related transformation of the E2F4-p130 repressor complex

    SciTech Connect

    Popov, Boris . E-mail: popov_478@hotmail.com; Chang, L.-S.; Serikov, Vladimir

    2005-10-28

    During G0 phase the p130, member of the pRb tumor suppressor protein family, forms a repressor complex with E2F4 which is inactivated in G1/S by hyperphosphorylation of the p130. The role of p130 after G1/S remains poorly investigated. We found that in nuclear extracts of T98G cells, the p130-E2F4-DNA (pp-E2F4) complex does not dissociate at G1/S transition, but instead reverts to the p130-E2F4-cyclin E/A-cdk2 (cyc/cdk-pp-E2F4) complex, which is detected in S and G2/M phases of the cell cycle. Hyperphosphorylation of the p130 at G1/S transition is associated with a decrease of its total amount; however, this protein is still detected during the rest of the cell cycle, and it is increasingly hyperphosphorylated in the cytosol, but continuously dephosphorylated in the nucleus. Both nuclear and cytosol cell fractions in T98G cells contain a hyperphosphorylated form of p130 in complex with E2F4 at S and G2/M cell cycle phases. In contrast to T98G cells, transformation of the p130 containing cyc/cdk-pp-E2F4 complex into the p130-pp-E2F4 repressor does not occur in HeLa cells under growth restriction conditions.

  20. NRIP enhances HPV gene expression via interaction with either GR or E2

    SciTech Connect

    Chang, Szu-Wei; Lu, Pei-Yu; Guo, Jih-Huong; Tsai, Tzung-Chieh; Tsao, Yeou-Ping; Chen, Show-Li

    2012-02-05

    We previously identified a gene, nuclear receptor-interaction protein (NRIP), which functions as a transcription cofactor in glucocorticoid receptor (GR) and human papillomavirus E2 (HPV E2)-driven gene expression. Here, we comprehensively evaluated the role of NRIP in HPV-16 gene expression. NRIP acts as a transcription cofactor to enhance GR-regulated HPV-16 gene expression in the presence of hormone. NRIP also can form complex with E2 that caused NRIP-induced HPV gene expression via E2-binding sites in a hormone-independent manner. Furthermore, NRIP can associate with GR and E2 to form tri-protein complex to activate HPV gene expression via GRE, not the E2-binding site, in a hormone-dependent manner. These results indicate that NRIP and GR are viral E2-binding proteins and that NRIP regulates HPV gene expression via GRE and/or E2 binding site in the HPV promoter in a hormone-dependent or independent manner, respectively.

  1. Increased prostaglandin F2 alpha and E2 production in late passage WI38 diploid fibroblasts.

    PubMed

    Mets, T; Korteweg, M; Verdonk, G

    1979-11-01

    The prostaglandin (PG) F2alpha and E2 concentrations in the culture medium of WI38 cells were determined at various passage levels. It was found that late passage cells produce significantly higher amounts of both PG F2alpha and PG E2. PMID:509542

  2. The Spectrum of E2F in Liver Disease-Mediated Regulation in Biology and Cancer.

    PubMed

    Huntington, Justin T; Tang, Xing; Kent, Lindsey N; Schmidt, Carl R; Leone, Gustavo

    2016-07-01

    Uncoordinated cell growth is one of the fundamental concepts in carcinogenesis and occurs secondary to dysregulation of the cell cycle. The E2Fs are a large family of transcription factors and are key regulators of the cell cycle. The activation of E2Fs is intimately regulated by retinoblastoma 1 (RB1). The RB pathway has been implicated in almost every human malignancy. Recently there have been exciting developments in the E2F field using animal models to better understand the role of E2Fs in vivo. Genetic mouse models have proven essential in implicating E2Fs in hepatocellular carcinoma (HCC) and liver disease. In this review, the general structure and function of E2Fs as well as the role for E2Fs in the development of HCC and liver disease is evaluated. Specifically, what is known about E2Fs in human disease is explored in depth, and future directions are discussed. J. Cell. Physiol. 231: 1438-1449, 2016. © 2015 Wiley Periodicals, Inc. PMID:26566968

  3. Overexpression of E2F3 promotes proliferation of functional human ? cells without induction of apoptosis

    PubMed Central

    Rady, Brian; Chen, Yanmei; Vaca, Pilar; Wang, Qian; Wang, Yong; Salmon, Patrick; Oberholzer, Jos

    2013-01-01

    The mechanisms that control proliferation, or lack thereof, in adult human ? cells are poorly understood. Controlled induction of proliferation could dramatically expand the clinical application of islet cell transplantation and represents an important component of regenerative approaches to a functional cure of diabetes. Adult human ? cells are particularly resistant to common proliferative targets and often dedifferentiate during proliferation. Here we show that expression of the transcription factor E2F3 has a role in regulating ?-cell quiescence and proliferation. We found human islets have virtually no expression of the pro-proliferative G1/S transcription factors E2F13, but an abundance of inhibitory E2Fs 46. In proliferative human insulinomas, inhibitory E2Fs were absent, while E2F3 is expressed. Using this pattern as a roadmap for proliferation, we demonstrated that ectopic expression of nuclear E2F3 induced significant expansion of insulin-positive cells in both rat and human islets. These cells did not undergo apoptosis and retained their glucose-responsive insulin secretion, showing the ability to reverse diabetes in mice. Our results suggest that E2F46 may help maintain quiescence in human ? cells and identify E2F3 as a novel target to induce proliferation of functional ? cells. Refinement of this approach may increase the islets available for cell-based therapies and research and could provide important cues for understanding in vivo proliferation of ? cells. PMID:23907129

  4. Insights into the mechanism of human papillomavirus E2-induced procaspase-8 activation and cell death.

    PubMed

    Singh, Nitu; Senapati, Sanjib; Bose, Kakoli

    2016-01-01

    High-risk human papillomavirus (HR-HPV) E2 protein, the master regulator of viral life cycle, induces apoptosis of host cell that is independent of its virus-associated regulatory functions. E2 protein of HR-HPV18 has been found to be involved in novel FADD-independent activation of caspase-8, however, the molecular basis of this unique non-death-fold E2-mediated apoptosis is poorly understood. Here, with an interdisciplinary approach that involves in silico, mutational, biochemical and biophysical probes, we dissected and characterized the E2-procasapse-8 binding interface. Our data demonstrate direct non-homotypic interaction of HPV18 E2 transactivation domain (TAD) with α2/α5 helices of procaspase-8 death effector domain-B (DED-B). The observed interaction mimics the homotypic DED-DED complexes, wherein the conserved hydrophobic motif of procaspase-8 DED-B (F122/L123) occupies a groove between α2/α3 helices of E2 TAD. This interaction possibly drives DED oligomerization leading to caspase-8 activation and subsequent cell death. Furthermore, our data establish a model for E2-induced apoptosis in HR-HPV types and provide important clues for designing E2 analogs that might modulate procaspase-8 activation and hence apoptosis. PMID:26906543

  5. E2F1 mediates sustained lipogenesis and contributes to hepatic steatosis.

    PubMed

    Denechaud, Pierre-Damien; Lopez-Mejia, Isabel C; Giralt, Albert; Lai, Qiuwen; Blanchet, Emilie; Delacuisine, Brigitte; Nicolay, Brandon N; Dyson, Nicholas J; Bonner, Caroline; Pattou, Franois; Annicotte, Jean-Sbastien; Fajas, Lluis

    2016-01-01

    E2F transcription factors are known regulators of the cell cycle, proliferation, apoptosis, and differentiation. Here, we reveal that E2F1 plays an essential role in liver physiopathology through the regulation of glycolysis and lipogenesis. We demonstrate that E2F1 deficiency leads to a decrease in glycolysis and de novo synthesis of fatty acids in hepatocytes. We further demonstrate that E2F1 directly binds to the promoters of key lipogenic genes, including Fasn, but does not bind directly to genes encoding glycolysis pathway components, suggesting an indirect effect. In murine models, E2F1 expression and activity increased in response to feeding and upon insulin stimulation through canonical activation of the CDK4/pRB pathway. Moreover, E2F1 expression was increased in liver biopsies from obese, glucose-intolerant humans compared with biopsies from lean subjects. Finally, E2f1 deletion completely abrogated hepatic steatosis in different murine models of nonalcoholic fatty liver disease (NAFLD). In conclusion, our data demonstrate that E2F1 regulates lipid synthesis and glycolysis and thus contributes to the development of liver pathology. PMID:26619117

  6. The CDK4-pRB-E2F1 pathway controls insulin secretion

    PubMed Central

    Annicotte, Jean-Sbastien; Blanchet, Emilie; Chavey, Carine; Iankova, Irena; Costes, Safia; Assou, Said; Teyssier, Jacques; Dalle, Stphane; Sardet, Claude; Fajas, Lluis

    2009-01-01

    CDK4-pRB-E2F1 cell cycle regulators are robustly expressed in non-proliferating ?-cells, suggesting that besides the control of ?-cell number the CDK4-pRB-E2F1 pathway has a role in ?-cell function. We show here that E2F1 directly regulates the expression of Kir6.2, which is a key component of the KATP channel involved in the regulation of glucose-induced insulin secretion. We demonstrate, by in tissue chromatin immunoprecipitation analysis that Kir6.2 expression is regulated at the promoter level by the CDK4-pRB-E2F1 pathway. Consistently, inhibition of CDK4, or genetic inactivation of E2F1 results in decreased expression of Kir6.2, impaired insulin secretion, and glucose intolerance in mice. Furthermore we show that rescue of Kir6.2 expression restores insulin secretion in E2f1 ?/? ?-cells. Finally, we demonstrate that CDK4 is activated by glucose through the insulin pathway, ultimately resulting in E2F1 activation and consequently in Kir6.2 increased expression. In summary we provide evidence that the CDK4-pRB-E2F1 regulatory pathway is involved in glucose homeostasis, defining a new link between cell proliferation and metabolism. PMID:19597485

  7. Phosphorylation-Dependent SUMOylation of the Transcription Factor NF-E2

    PubMed Central

    Su, Yee-Fun; Shyu, Yu-Chiau; Shen, Che-Kun James; Hwang, Jaulang

    2012-01-01

    Nuclear factor erythroid-derived 2 (NF-E2), a heterodimer composed of p45 and p18, is a transcriptional activator in hematopoietic progenitors. The transcriptional activity of NF-E2 is not only upregulated by SUMOylation but also stimulated by the cAMP-dependent protein kinase A (PKA). However, the relationship between SUMOylation and phosphorylation in the activation of NF-E2 is unclear. In the present studies, we have demonstrated that PKA enhances NF-E2 SUMOylation in an in vitro system using purified proteins, suggesting a possible mechanism for PKA-dependent activation of the NF-E2 transcription factor through SUMOylation. PMID:22970264

  8. Tables of E2 transition probabilities from the first 2+ states in even-even nuclei

    NASA Astrophysics Data System (ADS)

    Pritychenko, B.; Birch, M.; Singh, B.; Horoi, M.

    2016-01-01

    Experimental results of E2 transition probabilities or B(E2) values for the known first 2+ states in 447 even-even nuclei have been compiled and evaluated. The evaluation policies for the analysis of experimental data have been described and new results are discussed. The recommended B(E2) values have been compared with comprehensive shell model calculations for a selected set of nuclei, where such theoretical procedures are amenable. The present work was motivated by a rapid increase in the number of new B(E2) measurements for the first 2+ states since the previous evaluation of such data by S. Raman etal. published in 2001. Future plans to investigate the systematics of B(E2) ? values, and intercomparison of different experimental techniques to obtain these data are outlined.

  9. Survival signals generated by estrogen and phospholipase D in MCF-7 breast cancer cells are dependent on Myc.

    PubMed

    Rodrik, Vanessa; Zheng, Yang; Harrow, Faith; Chen, Yuhong; Foster, David A

    2005-09-01

    Estrogens, which have been strongly implicated in the development of breast cancer, enhance proliferation of mammary epithelial cells and, importantly, estrogen receptor (ER)-positive breast cancer cells. In the absence of serum growth factors, the ER-positive MCF-7 breast cancer cell line undergoes apoptosis. Estrogens, most commonly 17-beta-estradiol (E2), can suppress apoptosis in MCF-7 cells deprived of serum. While E2 stimulated a short-term transient increase in Myc expression, E2 stimulated a sustained increase in Myc expression that was detectable at 48 h and pronounced at 5 days, the point where increased proliferation of MCF-7 cells in the absence of serum could be detected. The delayed increase in Myc expression was not dependent upon transcription of the Myc gene. Suppression of Myc expression reversed the survival effects of E2. The Myc-dependent survival signal generated by E2 was dependent upon basal levels of mTOR (mammalian target of rapamycin) and two upstream regulators of mTOR, phosphatidylinositol 3-kinase and phospholipase D (PLD). Stable elevated expression of PLD2 also increased Myc expression and provided a Myc-dependent survival signal in the absence of E2. These data provide evidence that E2 promotes survival signals in breast cancer cells through an mTOR-dependent increase in Myc expression. The data also suggest that elevated PLD expression, which is common in breast cancer, confers E2 independence. PMID:16107734

  10. Measurement of the optical dielectric function of monolayer transition-metal dichalcogenides: MoS2, Mo S e2 , WS2, and WS e2

    NASA Astrophysics Data System (ADS)

    Li, Yilei; Chernikov, Alexey; Zhang, Xian; Rigosi, Albert; Hill, Heather M.; van der Zande, Arend M.; Chenet, Daniel A.; Shih, En-Min; Hone, James; Heinz, Tony F.

    2014-11-01

    We report a determination of the complex in-plane dielectric function of monolayers of four transition-metal dichalcogenides: Mo S2 , Mo S e2 , W S2 , and WS e2 , for photon energies from 1.5 to 3 eV. The results were obtained from reflection spectra using a Kramers-Kronig constrained variational analysis. From the dielectric functions, we obtain the absolute absorbance of the monolayers. We also provide a comparison of the dielectric function for the monolayers with the corresponding bulk materials.

  11. In vivo delivery of bovine viral diahorrea virus, E2 protein using hollow mesoporous silica nanoparticles

    NASA Astrophysics Data System (ADS)

    Mahony, D.; Cavallaro, A. S.; Mody, K. T.; Xiong, L.; Mahony, T. J.; Qiao, S. Z.; Mitter, N.

    2014-05-01

    Our work focuses on the application of mesoporous silica nanoparticles as a combined delivery vehicle and adjuvant for vaccine applications. Here we present results using the viral protein, E2, from bovine viral diarrhoea virus (BVDV). BVDV infection occurs in the target species of cattle and sheep herds worldwide and is therefore of economic importance. E2 is a major immunogenic determinant of BVDV and is an ideal candidate for the development of a subunit based nanovaccine using mesoporous silica nanoparticles. Hollow type mesoporous silica nanoparticles with surface amino functionalisation (termed HMSA) were characterised and assessed for adsorption and desorption of E2. A codon-optimised version of the E2 protein (termed Opti-E2) was produced in Escherichia coli. HMSA (120 nm) had an adsorption capacity of 80 μg Opti-E2 per mg HMSA and once bound E2 did not dissociate from the HMSA. Immunisation studies in mice with a 20 μg dose of E2 adsorbed to 250 μg HMSA was compared to immunisation with Opti-E2 (50 μg) together with the traditional adjuvant Quillaja saponaria Molina tree saponins (QuilA, 10 μg). The humoral responses with the Opti-E2/HMSA nanovaccine although slightly lower than those obtained for the Opti-E2 + QuilA group demonstrated that HMSA particles are an effective adjuvant that stimulated E2-specific antibody responses. Importantly the cell-mediated immune responses were consistently high in all mice immunised with Opti-E2/HMSA nanovaccine formulation. Therefore we have shown the Opti-E2/HMSA nanoformulation acts as an excellent adjuvant that gives both T-helper 1 and T-helper 2 mediated responses in a small animal model. This study has provided proof-of-concept towards the development of an E2 subunit nanoparticle based vaccine.Our work focuses on the application of mesoporous silica nanoparticles as a combined delivery vehicle and adjuvant for vaccine applications. Here we present results using the viral protein, E2, from bovine viral diarrhoea virus (BVDV). BVDV infection occurs in the target species of cattle and sheep herds worldwide and is therefore of economic importance. E2 is a major immunogenic determinant of BVDV and is an ideal candidate for the development of a subunit based nanovaccine using mesoporous silica nanoparticles. Hollow type mesoporous silica nanoparticles with surface amino functionalisation (termed HMSA) were characterised and assessed for adsorption and desorption of E2. A codon-optimised version of the E2 protein (termed Opti-E2) was produced in Escherichia coli. HMSA (120 nm) had an adsorption capacity of 80 μg Opti-E2 per mg HMSA and once bound E2 did not dissociate from the HMSA. Immunisation studies in mice with a 20 μg dose of E2 adsorbed to 250 μg HMSA was compared to immunisation with Opti-E2 (50 μg) together with the traditional adjuvant Quillaja saponaria Molina tree saponins (QuilA, 10 μg). The humoral responses with the Opti-E2/HMSA nanovaccine although slightly lower than those obtained for the Opti-E2 + QuilA group demonstrated that HMSA particles are an effective adjuvant that stimulated E2-specific antibody responses. Importantly the cell-mediated immune responses were consistently high in all mice immunised with Opti-E2/HMSA nanovaccine formulation. Therefore we have shown the Opti-E2/HMSA nanoformulation acts as an excellent adjuvant that gives both T-helper 1 and T-helper 2 mediated responses in a small animal model. This study has provided proof-of-concept towards the development of an E2 subunit nanoparticle based vaccine. Electronic supplementary information (ESI) available: Desorption studies of Opti-E2 bound HMSA. See DOI: 10.1039/c4nr01202j

  12. E2F Transcription Factors Control the Roller Coaster Ride of Cell Cycle Gene Expression.

    PubMed

    Thurlings, Ingrid; de Bruin, Alain

    2016-01-01

    Initially, the E2F transcription factor was discovered as a factor able to bind the adenovirus E2 promoter and activate viral genes. Afterwards it was shown that E2F also binds to promoters of nonviral genes such as C-MYC and DHFR, which were already known at that time to be important for cell growth and DNA metabolism, respectively. These findings provided the first clues that the E2F transcription factor might be an important regulator of the cell cycle. Since this initial discovery in 1987, several additional E2F family members have been identified, and more than 100 targets genes have been shown to be directly regulated by E2Fs, the majority of these are important for controlling the cell cycle. The progression of a cell through the cell cycle is accompanied with the increased expression of a specific set of genes during one phase of the cell cycle and the decrease of the same set of genes during a later phase of the cell cycle. This roller coaster ride, or oscillation, of gene expression is essential for the proper progression through the cell cycle to allow accurate DNA replication and cell division. The E2F transcription factors have been shown to be critical for the temporal expression of the oscillating cell cycle genes. This review will focus on how the oscillation of E2Fs and their targets is regulated by transcriptional, post-transcriptional and post-translational mechanism in mammals, yeast, flies, and worms. Furthermore, we will discuss the functional impact of E2Fs on the cell cycle progression and outline the consequences when E2F expression is disturbed. PMID:26254918

  13. Dual mechanisms of repression of E2F1 activity by the retinoblastoma gene product.

    PubMed Central

    Zacksenhaus, E; Jiang, Z; Phillips, R A; Gallie, B L

    1996-01-01

    The retinoblastoma gene product, pRb, negatively regulates cell proliferation by modulating the activity of the transcription factor E2F1 that controls expression of S-phase genes. To dissect transcriptional regulation of E2F1 by pRb, we developed a means to control the subcellular localization of pRb by exchanging its constitutive nuclear localization signal (NLS) with an inducible nuclear targeting domain from the glucocorticoid receptor (GR). In co-transfection experiments in hormone-free media, pRb delta NLS-GR sequestered E2F1 in the cytoplasm; addition of steroid hormones induced co-translocation of pRb delta NLS-GR and E2F1 to the nucleus. A pRb allele lacking a NLS, pRb delta NLS, also sequestered E2F1 in the cytoplasm. Both nuclear and cytoplasmic pRb delta NLS-GR repressed transcription from a simple, E2F1-activated, promoter equally well. pRb delta NLS-GR exerted differential effects on complex promoters containing an activator and E2F sites that acted as either positive or negative elements. We propose a dual mechanism of transcriptional repression by pRb which allows tight control of E2F1-responsive genes: a pRb-E2F1 repressor unit is assembled off DNA to pre-empt transcriptional activation by E2F1; recruitment of this repressor unit to cognate binding sites on promoters allows silencing of adjacent promoter elements. Images PMID:8918469

  14. E2F4 Program Is Predictive of Progression and Intravesical Immunotherapy Efficacy in Bladder Cancer

    PubMed Central

    Cheng, Chao; Varn, Frederick S.; Marsit, Carmen J.

    2016-01-01

    Bladder cancer is a common malignant disease, with nonmuscle-invasive bladder cancer (NMIBC) representing the majority of tumors. This cancer subtype is typically treated by transurethral resection. In spite of treatment, up to 70% of patients show local recurrences. Intravesical BCG (Bacillus Calmette-Guerin) immunotherapy has been widely used to treat NMIBC, but it fails to suppress recurrence of bladder tumors in up to 40% of patients. Therefore, the development of prognostic markers is needed to predict the progression of bladder cancer and the efficacy of intravesical BCG treatment. This study demonstrates the effectiveness of an E2F4 signature for prognostic prediction of bladder cancer. E2F4 scores for each sample in a bladder cancer expression dataset were calculated by summarizing the relative expression levels of E2F4 target genes identified by ChIP-seq, and then the scores were used to stratify patients into good- and poor-outcome groups. The molecular signature was investigated in a single bladder cancer dataset and then its effectiveness was confirmed in two meta-bladder datasets consisting of specimens from multiple independent studies. These results were consistent in different datasets and demonstrate that the E2F4 score is predictive of clinical outcomes in bladder cancer, with patients whose tumors exhibit an E2F4 score >0 having significantly shorter survival times than those with an E2F4 score <0, in both nonmuscle-invasive, and muscle-invasive bladder cancer. Furthermore, although intravesical BCG immunotherapy can significantly improve the clinical outcome of NMIBC patients with positive E2F4 scores (E2F4>0 group), it does not show significant treatment effect for those with negative scores (E2F4<0 group). Implications The E2F4 signature can be applied to predict the progression/recurrence and the responsiveness of patients to intravesical BCG immunotherapy in bladder cancer. PMID:26032289

  15. Identification of a viral kinase that phosphorylates specific E2Fs and pocket proteins.

    PubMed

    Pajovic, S; Wong, E L; Black, A R; Azizkhan, J C

    1997-11-01

    The transcription factor E2F and its regulation by pRB and related pocket proteins are central to cell cycle control in higher eukaryotes. Much of our knowledge of this regulation has come from studies using immediate-early proteins of DNA tumor viruses. Previously, we reported that the 72-kDa immediate-early region 1 gene product of the human cytomegalovirus, IE72, transactivates the dihydrofolate reductase promoter through the E2F site and that it physically interacts with E2F1 (M. J. Margolis, S. Pajovic, E. L. Wong, M. Wade, R. Jupp, J. A. Nelson, and J. C. Azizkhan, J. Virol. 69:7759-7767, 1995). In this study, we further characterized the mechanism by which IE72 modulates E2F-dependent transcription. In vitro phosphorylation reactions using gel-purified bacterially expressed proteins revealed that IE72 is a kinase that autophosphorylates and phosphorylates E2F1, -2, and -3 (but not E2F4 or -5) and the RB-related pocket proteins p130 and p107 (but not pRB). The region of IE72 spanning amino acids 173 to 197 shows a high level of homology to the ATP binding sites in over 500 kinases. The kinase-negative protein IE72deltaATP, from which this region has been deleted, cannot activate E2F-dependent transcription. The kinase activity of IE72 is also required for its ability to reduce the association of E2F4 with p107 and p130. Taken together, these data suggest that the kinase activity of IE72 is required for E2F-dependent transcriptional activation and that this is likely to result from phosphorylation of specific members of the E2F and pocket protein families by IE72. PMID:9343408

  16. Materials characterization activities for %E2%80%9CTake Our Sons&Daughters to Work Day%E2%80%9D 2013.

    SciTech Connect

    Mowry, Curtis Dale; Pimentel, Adam S.; Sparks, Elizabeth Schares; Hanlon, Brittany Paula

    2013-09-01

    We created interactive demonstration activities for Take Our Daughters&Sons to Work Day (TODSTWD) 2013 in order to promote general interest in chemistry and also generate awareness of the type of work our laboratories can perform. %E2%80%9CCurious about Mars Rover Curiosity?%E2%80%9D performed an elemental analysis on rocks brought to our lab using the same technique utilized on the planet Mars by the NASA robotic explorer Curiosity. %E2%80%9CFood is Chemistry?%E2%80%9D utilized a mass spectrometer to measure, in seconds, each participant's breath in order to identify the food item consumed for the activity. A total of over 130 children participated in these activities over a 3 hour block, and feedback was positive. This document reports the materials (including handouts), experimental procedures, and lessons learned so that future demonstrations can benefit from the baseline work performed. We also present example results used to prepare the Food activity and example results collected during the Curiosity demo.

  17. The Arabidopsis her1 mutant implicates GABA in E-2-hexenal responsiveness.

    PubMed

    Mirabella, Rossana; Rauwerda, Han; Struys, Eduard A; Jakobs, Cornelis; Triantaphylids, Christian; Haring, Michel A; Schuurink, Robert C

    2008-01-01

    When wounded or attacked by herbivores or pathogens, plants produce a blend of six-carbon alcohols, aldehydes and esters, known as C6-volatiles. Undamaged plants, when exposed to C6-volatiles, respond by inducing defense-related genes and secondary metabolites, suggesting that C6-volatiles can act as signaling molecules regulating plant defense responses. However, to date, the molecular mechanisms by which plants perceive and respond to these volatiles are unknown. To elucidate such mechanisms, we decided to isolate Arabidopsis thaliana mutants in which responses to C6-volatiles were altered. We observed that treatment of Arabidopsis seedlings with the C6-volatile E-2-hexenal inhibits root elongation. Among C6-volatiles this response is specific to E-2-hexenal, and is not dependent on ethylene, jasmonic and salicylic acid. Using this bioassay, we isolated 18 E-2-hexenal-response (her) mutants that showed sustained root growth after E-2-hexenal treatment. Here, we focused on the molecular characterization of one of these mutants, her1. Microarray and map-based cloning revealed that her1 encodes a gamma-amino butyric acid transaminase (GABA-TP), an enzyme that degrades GABA. As a consequence of the mutation, her1 plants accumulate high GABA levels in all their organs. Based on the observation that E-2-hexenal treatment induces GABA accumulation, and that high GABA levels confer resistance to E-2-hexenal, we propose a role for GABA in mediating E-2-hexenal responses. PMID:17971036

  18. OTUB1 co-opts Lys48-linked ubiquitin recognition to suppress E2 enzyme function

    PubMed Central

    Juang, Yu-Chi; Landry, Marie-Claude; Sanches, Mario; Vittal, Vinayak; Leung, Charles; Ceccarelli, Derek F.; Mateo, Abigail-Rachele F.; Pruneda, Jonathan N.; Mao, Dan; Szilard, Rachel K.; Orlicky, Stephen; Munro, Meagan; Brzovic, Peter S.; Klevit, Rachel E.; Sicheri, Frank; Durocher, Daniel

    2012-01-01

    SUMMARY Ubiquitylation entails the concerted action of E1, E2 and E3 enzymes. We recently reported that OTUB1, a deubiquitylase, inhibits the DNA damage response independently of its isopeptidase activity. OTUB1 does so by blocking ubiquitin transfer by UBC13, the cognate E2 enzyme for RNF168. OTUB1 also inhibits E2s of the UBE2D and UBE2E families. Here we elucidate the structural mechanism by which OTUB1 binds E2s to inhibit ubiquitin transfer. OTUB1 recognizes ubiquitin-charged E2s through contacts with both donor ubiquitin and the E2 enzyme. Surprisingly, free ubiquitin associates with the canonical distal ubiquitin-binding site on OTUB1 to promote formation of the inhibited E2 complex. Lys48 of donor ubiquitin lies near the OTUB1 catalytic site and the C-terminus of free ubiquitin, a configuration that mimics the products of Lys48-linked ubiquitin chain cleavage. OTUB1 therefore co-opts Lys48-linked ubiquitin chain recognition to suppress ubiquitin conjugation and the DNA damage response. PMID:22325355

  19. Oncogenic ETS fusions deregulate E2F3 target genes in Ewing sarcoma and prostate cancer

    PubMed Central

    Bilke, Sven; Schwentner, Raphaela; Yang, Fan; Kauer, Maximilian; Jug, Gunhild; Walker, Robert L.; Davis, Sean; Zhu, Yuelin J.; Pineda, Marbin; Meltzer, Paul S.; Kovar, Heinrich

    2013-01-01

    Deregulated E2F transcription factor activity occurs in the vast majority of human tumors and has been solidly implicated in disturbances of cell cycle control, proliferation, and apoptosis. Aberrant E2F regulatory activity is often caused by impairment of control through pRB function, but little is known about the interplay of other oncoproteins with E2F. Here we show that ETS transcription factor fusions resulting from disease driving rearrangements in Ewing sarcoma (ES) and prostate cancer (PC) are one such class of oncoproteins. We performed an integrative study of genome-wide DNA-binding and transcription data in EWSR1/FLI1 expressing ES and TMPRSS2/ERG containing PC cells. Supported by promoter activity and mutation analyses, we demonstrate that a large fraction of E2F3 target genes are synergistically coregulated by these aberrant ETS proteins. We propose that the oncogenic effect of ETS fusion oncoproteins is in part mediated by the disruptive effect of the E2F–ETS interaction on cell cycle control. Additionally, a detailed analysis of the regulatory targets of the characteristic EWSR1/FLI1 fusion in ES identifies two functionally distinct gene sets. While synergistic regulation in concert with E2F in the promoter of target genes has a generally activating effect, EWSR1/FLI1 binding independent of E2F3 is predominantly associated with repressed differentiation genes. Thus, EWSR1/FLI1 appears to promote oncogenesis by simultaneously promoting cell proliferation and perturbing differentiation. PMID:23940108

  20. Functional interaction of a novel cellular protein with the papillomavirus E2 transactivation domain.

    PubMed

    Breiding, D E; Sverdrup, F; Grossel, M J; Moscufo, N; Boonchai, W; Androphy, E J

    1997-12-01

    The transactivation domain (AD) of bovine papillomavirus type 1 E2 stimulates gene expression and DNA replication. To identify cellular proteins that interact with this 215-amino-acid domain, we used a transactivation-defective mutant as bait in the yeast two-hybrid screen. In vitro and in vivo results demonstrate that the cDNA of one plasmid isolated in this screen encodes a 37-kDa nuclear protein that specifically binds to an 82-amino-acid segment within the E2 AD. Mutants with point mutations within this E2 domain were isolated based on their inability to interact with AMF-1 and were found to be unable to stimulate transcription. These mutants also exhibited defects in viral DNA replication yet retained binding to the viral E1 replication initiator protein. Overexpression of AMF-1 stimulated transactivation by both wild-type E2 and a LexA fusion to the E2 AD, indicating that AMF-1 is a positive effector of the AD of E2. We conclude that interaction with AMF-1 is necessary for the transcriptional activation function of the E2 AD in mammalian cells. PMID:9372953

  1. A BIPOLAR OUTFLOW FROM THE MASSIVE PROTOSTELLAR CORE W51e2-E

    SciTech Connect

    Shi Hui; Han, J. L.; Zhao Junhui E-mail: hil@nao.cas.c

    2010-08-01

    We present high-resolution images of the bipolar outflow from W51e2, which are produced from the Submillimeter Array archival data observed for CO(3-2) and HCN(4-3) lines with angular resolutions of 0.''8 x 0.''6 and 0.''3 x 0.''2, respectively. The images show that the powerful outflow originates from the protostellar core W51e2-E rather than from the ultracompact H II region W51e2-W. The kinematic timescale of the outflow from W51e2-E is about 1000 yr, younger than the age ({approx}5000 yr) of the ultracompact H II region W51e2-W. A large mass-loss rate of {approx}1 x 10{sup -3} M{sub sun} yr{sup -1} and a high mechanical power of 120 L{sub sun} are inferred, suggesting that an O star or a cluster of B stars are forming in W51e2-E. The observed outflow activity along with the inferred large accretion rate indicates that at present W51e2-E is in a rapid phase of star formation.

  2. Citrullination-acetylation interplay guides E2F-1 activity during the inflammatory response

    PubMed Central

    Ghari, Fatemeh; Quirke, Anne-Marie; Munro, Shonagh; Kawalkowska, Joanna; Picaud, Sarah; McGouran, Joanna; Subramanian, Venkataraman; Muth, Aaron; Williams, Richard; Kessler, Benedikt; Thompson, Paul R.; Fillipakopoulos, Panagis; Knapp, Stefan; Venables, Patrick J.; La Thangue, Nicholas B.

    2016-01-01

    Peptidyl arginine deiminase 4 (PAD4) is a nuclear enzyme that converts arginine residues to citrulline. Although increasingly implicated in inflammatory disease and cancer, the mechanism of action of PAD4 and its functionally relevant pathways remains unclear. E2F transcription factors are a family of master regulators that coordinate gene expression during cellular proliferation and diverse cell fates. We show that E2F-1 is citrullinated by PAD4 in inflammatory cells. Citrullination of E2F-1 assists its chromatin association, specifically to cytokine genes in granulocyte cells. Mechanistically, citrullination augments binding of the BET (bromodomain and extra-terminal domain) family bromodomain reader BRD4 (bromodomain-containing protein 4) to an acetylated domain in E2F-1, and PAD4 and BRD4 coexist with E2F-1 on cytokine gene promoters. Accordingly, the combined inhibition of PAD4 and BRD4 disrupts the chromatin-bound complex and suppresses cytokine gene expression. In the murine collagen-induced arthritis model, chromatin-bound E2F-1 in inflammatory cells and consequent cytokine expression are diminished upon small-molecule inhibition of PAD4 and BRD4, and the combined treatment is clinically efficacious in preventing disease progression. Our results shed light on a new transcription-based mechanism that mediates the inflammatory effect of PAD4 and establish the interplay between citrullination and acetylation in the control of E2F-1 as a regulatory interface for driving inflammatory gene expression. PMID:26989780

  3. Rendezvous with Toutatis from the Moon: The Chang'e-2 mission

    NASA Astrophysics Data System (ADS)

    Huang, J.; Tang, X.; Meng, L.

    2014-07-01

    Chang'e-2 probe was the second lunar probe of China, with the main objectives to demonstrate some key features of the new lunar soft landing technology, and its applications to future exploration missions. After completing the planned mission successfully, Chang'e-2 flew away from the Moon and entered into the interplanetary space. Later, at a distance of 7 million km from the Earth, Chang'e-2 encountered asteroid (4179) Toutatis with a very close fly-by distance and obtained colorful images with a 3-m resolution. Given some surplus velocity increment as well as the promotion of autonomous flight ability and improvement of control, propulsion, and thermal systems in the initial design, Chang'e-2 had the capabilities necessary for escaping from the Moon. By taking advantage of the unique features of the Lagrangian point, the first close fly-by of asteroid Toutatis was realized despite the tight constraints of propellant allocation, spacecraft-Earth communication, and coordination of execution sequences. Chang'e-2 realized the Toutatis flyby with a km-level distance at closest approach. In the absence of direct measurement method, based on the principle of relative navigation and through the use of the sequence of target images, we calculated the rendezvous parameters such as relative distance and image resolution. With the help of these parameters, some fine and new scientific discoveries about the asteroid were obtained by techniques of optical measurements and image processing. Starting with an innovative design, followed by high-fidelity testing and demonstration, elaborative implementation, and optimal usage of residual propellant, Chang'e-2 has for the first time successfully explored the Moon, L2 point and an asteroid, while achieving the purpose of 'faster, better, cheaper'. What Chang'e-2 has accomplished was far beyond our expectations. *J. Huang is the chief designer (PI) of Chang'e-2 probe, planned Chang'e-2's multi-objective and multitasking exploration mission.

  4. E2F1 controls germ cell apoptosis during the first wave of spermatogenesis.

    PubMed

    Rotgers, E; Nurmio, M; Pietil, E; Cisneros-Montalvo, S; Toppari, J

    2015-09-01

    Cell cycle control during spermatogenesis is a highly complex process owing to the control of the mitotic expansion of the spermatogonial cell population and following meiosis, induction of DNA breaks during meiosis and the high levels of physiological germ-cell apoptosis. We set out to study how E2F1, a key controller of cell cycle, apoptosis, and DNA damage responses, functions in the developing and adult testis. We first analyzed the expression pattern of E2f1 during post-natal testis development using RNA insitu hybridization, which showed a differential expression pattern of E2f1 in the adult and juvenile mouse testes. To study the function of E2f1, we took advantage of the E2F1(-/-) mouse line, which was back-crossed to C57Bl/6J genetic background. E2f1 loss led to a severe progressive testicular atrophy beginning at the age of 20days. Spermatogonial apoptosis during the first wave of spermatogenesis was decreased. However, already in the first wave of spermatogenesis an extensive apoptosis of spermatocytes was observed. In the adult E2F1(-/-) testes, the atrophy due to loss of spermatocytes was further exacerbated by loss of spermatogonial stem cells. Surprisingly, only subtle changes in global gene expression array profiling were observed in E2F1(-/-) testis at PND20. To dissect the changes in each testicular cell type, an additional comparative analysis of the array data was performed making use of previously published data on transcriptomes of the individual testicular cell types. Taken together, our data indicate that E2F1 has a differential role during first wave of spermatogenesis and in the adult testis, which emphasizes the complex nature of cell cycle control in the developing testis. PMID:26311345

  5. Erythropoiesis and globin gene expression in mice lacking the transcription factor NF-E2.

    PubMed Central

    Shivdasani, R A; Orkin, S H

    1995-01-01

    Previous studies in transgenic mice and cultured cells have indicated that the major enhancer function for erythroid cell expression of the globin genes is provided by the heterodimeric basic-leucine zipper transcription factor NF-E2. Globin gene expression within cultured mouse erythroleukemia cells is highly dependent on NF-E2. To examine the requirement for this factor in vivo, we used homologous recombination in embryonic stem cells to generate mice lacking the hematopoietic-specific subunit, p45 NF-E2. The most dramatic aspect of the homozygous mutant mice was an absence of circulating platelets, which led to the death of most animals due to hemorrhage. In contrast, the effect of loss of NF-E2 on the erythroid lineage was surprisingly mild. Although neonates exhibited severe anemia and dysmorphic red-cell changes, probably compounded by concomitant bleeding, surviving adults exhibited only mild changes consistent with a small decrease in the hemoglobin content per cell. p45 NF-E2-null mice responded to anemia with compensatory reticulocytosis and splenomegaly. Globin chain synthesis was balanced, and switching from fetal to adult globins progressed normally. Although these findings are consistent with the substitution of NF-E2 function in vivo by one or more compensating proteins, gel shift assays using nuclear extracts from p45 NF-E2-null mice failed to reveal novel complexes formed on an NF-E2 binding site. Thus, regulation of globin gene transcription through NF-E2 binding sites in vivo is more complex than has been previously appreciated. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:7567998

  6. The Retinoblastoma Tumor Suppressor Protein (pRb)/E2 Promoter Binding Factor 1 (E2F1) Pathway as a Novel Mediator of TGF?-induced Autophagy.

    PubMed

    Korah, Juliana; Canaff, Lucie; Lebrun, Jean-Jacques

    2016-01-29

    TGF? is a multifunctional cytokine that regulates cell proliferation, cell immortalization, and cell death, acting as a key homeostatic mediator in various cell types and tissues. Autophagy is a programmed mechanism that plays a pivotal role in controlling cell fate and, consequently, many physiological and pathological processes, including carcinogenesis. Although autophagy is often considered a pro-survival mechanism that renders cells viable in stressful conditions and thus might promote tumor growth, emerging evidence suggests that autophagy is also a tumor suppressor pathway. The relationship between TGF? signaling and autophagy is context-dependent and remains unclear. TGF?-mediated activation of autophagy has recently been suggested to contribute to the growth inhibitory effect of TGF? in hepatocarcinoma cells. In the present study, we define a novel process of TGF?-mediated autophagy in cancer cell lines of various origins. We found that autophagosome initiation and maturation by TGF? is dependent on the retinoblastoma tumor suppressor protein/E2 promoter binding factor (pRb/E2F1) pathway, which we have previously established as a critical signaling axis leading to various TGF? tumor suppressive effects. We further determined that TGF? induces pRb/E2F1-dependent transcriptional activation of several autophagy-related genes. Together, our findings reveal that TGF? induces autophagy through the pRb/E2F1 pathway and transcriptional activation of autophagy-related genes and further highlight the central relevance of the pRb/E2F1 pathway downstream of TGF? signaling in tumor suppression. PMID:26598524

  7. 26 CFR 301.6223(e)-2 - Elections if Internal Revenue Service fails to provide timely notice.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... years beginning prior to October 4, 2001, see 301.6223(e)-2T contained in 26 CFR part 1, revised April... provide timely notice. 301.6223(e)-2 Section 301.6223(e)-2 Internal Revenue INTERNAL REVENUE SERVICE... In General 301.6223(e)-2 Elections if Internal Revenue Service fails to provide timely notice....

  8. 26 CFR 301.6223(e)-2 - Elections if Internal Revenue Service fails to provide timely notice.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... years beginning prior to October 4, 2001, see 301.6223(e)-2T contained in 26 CFR part 1, revised April... provide timely notice. 301.6223(e)-2 Section 301.6223(e)-2 Internal Revenue INTERNAL REVENUE SERVICE... In General 301.6223(e)-2 Elections if Internal Revenue Service fails to provide timely notice....

  9. 26 CFR 301.6223(e)-2 - Elections if Internal Revenue Service fails to provide timely notice.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... years beginning prior to October 4, 2001, see 301.6223(e)-2T contained in 26 CFR part 1, revised April... provide timely notice. 301.6223(e)-2 Section 301.6223(e)-2 Internal Revenue INTERNAL REVENUE SERVICE... In General 301.6223(e)-2 Elections if Internal Revenue Service fails to provide timely notice....

  10. 26 CFR 301.6223(e)-2 - Elections if Internal Revenue Service fails to provide timely notice.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... years beginning prior to October 4, 2001, see 301.6223(e)-2T contained in 26 CFR part 1, revised April... provide timely notice. 301.6223(e)-2 Section 301.6223(e)-2 Internal Revenue INTERNAL REVENUE SERVICE... In General 301.6223(e)-2 Elections if Internal Revenue Service fails to provide timely notice....

  11. 26 CFR 301.6223(e)-2 - Elections if Internal Revenue Service fails to provide timely notice.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... years beginning prior to October 4, 2001, see 301.6223(e)-2T contained in 26 CFR part 1, revised April... provide timely notice. 301.6223(e)-2 Section 301.6223(e)-2 Internal Revenue INTERNAL REVENUE SERVICE... In General 301.6223(e)-2 Elections if Internal Revenue Service fails to provide timely notice....

  12. Silencing of E2F3 suppresses tumor growth of Her2+ breast cancer cells by restricting mitosis

    PubMed Central

    Lee, Miyoung; Oprea-Ilies, Gabriela; Saavedra, Harold I.

    2015-01-01

    The E2F transcriptional activators E2F1, E2F2 and E2F3a regulate many important cellular processes, including DNA replication, apoptosis and centrosome duplication. Previously, we demonstrated that silencing E2F1 or E2F3 suppresses centrosome amplification (CA) and chromosome instability (CIN) in Her2+ breast cancer cells without markedly altering proliferation. However, it is unknown whether and how silencing a single E2F activator, E2F3, affects malignancy of human breast cancer cells. Thus, we injected HCC1954 Her2+ breast cancer cells silenced for E2F3 into mammary fat pads of immunodeficient mice and demonstrated that loss of E2F3 retards tumor growth. Surprisingly, silencing of E2F3 led to significant reductions in mitotic indices relative to vector controls, while the percentage of cells undergoing S phase were not affected. Nek2 is a mitotic kinase commonly upregulated in breast cancers and a critical regulator of Cdk4- or E2F- mediated CA. In this report, we found that Nek2 overexpression rescued back the CA caused by silencing of shE2F3. However, the effects of Nek2 overexpression in affecting tumor growth rates of shE2F3 and shE2F3; GFP cells were inconclusive. Taken together, our results indicate that E2F3 silencing decreases mammary tumor growth by reducing percentage of cells undergoing mitosis. PMID:26512919

  13. Estradiol prevents olfactory dysfunction induced by A-β 25–35 injection in hippocampus

    PubMed Central

    2013-01-01

    Background Some neurodegenerative diseases, such as Alzheimer and Parkinson, present an olfactory impairment in early stages, and sometimes even before the clinical symptoms begin. In this study, we assess the role of CA1 hippocampus (structure highly affected in Alzheimer disease) subfield in the rats’ olfactory behavior, and the neuroprotective effect of 17 beta estradiol (E2) against the oxidative stress produced by the injection of amyloid beta 25–35. Results 162 Wistar rats were ovariectomized and two weeks after injected with 2 μl of amyloid beta 25–35 (A-β25–35) in CA1 subfield. Olfactory behavior was evaluated with a social recognition test, odor discrimination, and search tests. Oxidative stress was evaluated with FOX assay and Western Blot against 4-HNE, Fluoro Jade staining was made to quantify degenerated neurons; all these evaluations were performed 24 h, 8 or 15 days after A-β25–35 injection. Three additional groups treated with 17 beta estradiol (E2) were also evaluated. The injection of A-β25–35 produced an olfactory impairment 24 h and 8 days after, whereas a partial recovery of the olfactory behavior was observed at 15 days. A complete prevention of the olfactory impairment was observed with the administration of E2 two weeks before the amyloid injection (A-β25–35 24 h + E2) and one or two weeks after (groups 8 A-β +E2 and 15 A-β +E2 days, respectively); a decrease of the oxidative stress and neurodegeneration were also observed. Conclusions Our finding shows that CA1 hippocampus subfield plays an important role in the olfactory behavior of the rat. The oxidative stress generated by the administration of A-β25–35 is enough to produce an olfactory impairment. This can be prevented with the administration of E2 before and after amyloid injection. This suggests a possible therapeutic use of estradiol in Alzheimer’s disease. PMID:24059981

  14. Degradation of estradiol and ethinyl estradiol by activated sludge and by a defined mixed culture.

    PubMed

    Weber, Stefanie; Leuschner, Prisca; Kmpfer, Peter; Dott, Wolfgang; Hollender, Juliane

    2005-04-01

    The aerobic degradation of the natural hormone 17-beta-estradiol (E2) and the synthetic hormone 17-alpha-ethinyl estradiol (EE2) was investigated in batch experiments with activated sludge from a conventional and a membrane sewage treatment plant. E2 was converted to estrone (E1), the well known metabolite, and further completely transformed within 3 days. The turnover rates of E2 did not differ greatly between conventional and membrane activated sludge. EE2 was persistent in both sludges. By several transfers into fresh E2-medium an enrichment culture could be selected that used E2 as growth substrate. Further enrichment and isolation led to a defined mixed culture consisting of two strains, which were identified by a polyphasic approach as Achromobacter xylosoxidans and Ralstonia sp., respectively. The culture used E2 and E1 as growth substrates and transformed estriol (E3) and 16-alpha-hydroxyestrone but not the xenoestrogens bisphenol A, alpha-zearalenol, mestranol or EE2. The turnover rates of E2 were 0.025-0.1 microg h(-1) cfu(-1) and did not depend on the steroid concentration. PMID:15290133

  15. In vitro effect of vitellogenin on steroid production by ovarian follicles of greenback flounder Rhombosolea tapirina.

    PubMed

    Sun, B; Pankhurst, N W

    2006-05-01

    Ovarian follicles from vitellogenic greenback flounder (Rhombosolea tapirina) were incubated in L15 medium alone, or containing human chorionic gonadotropin (hCG), dibutyryl cyclic AMP (dbcAMP) or the steroid precursors testosterone (T), 17-hydroxyprogesterone (17P) and androstenedione (A) in the presence of vitellogenin (Vtg) at 0.1-5.0mg mL(-)(1). Medium concentrations of 17beta-estradiol (E(2)) and T were measured by radioimmunoassay. HCG generally stimulated follicular E(2) but not T production, whereas 17P, A and T stimulated production of E(2), T, and E(2) respectively. Treatment of follicles with dbcAMP inhibited follicular E(2) production, but increased follicular T production at high doses. The effect of low concentrations of Vtg on follicular steroid production was variable; however, higher doses of Vtg significantly suppressed basal, hCG-, dbcAMP- and steroid precursor-stimulated follicular E(2) and T production. The results of this study show that high concentrations of Vtg may suppress follicular steroid production by interfering in the steroidogenic pathway. This suggests that Vtg may regulate its own production by limiting the ovarian production of E(2). PMID:16580856

  16. Estrogen suppresses MLK3-mediated apoptosis sensitivity in ER+ breast cancer cells.

    PubMed

    Rangasamy, Velusamy; Mishra, Rajakishore; Mehrotra, Suneet; Sondarva, Gautam; Ray, Rajarshi S; Rao, Arundhati; Chatterjee, Malay; Rana, Basabi; Rana, Ajay

    2010-02-15

    Little knowledge exists about the mechanisms by which estrogen can impede chemotherapy-induced cell death of breast cancer cells. 17beta-Estradiol (E(2)) hinders cytotoxic drug-induced cell death in estrogen receptor-positive (ER(+)) breast cancer cells. We noted that the activity of the proapoptotic mixed lineage kinase 3 (MLK3) kinase was relatively higher in estrogen receptor-negative (ER(-)) breast tumors, suggesting that E(2) might inhibit MLK3 activity. The kinase activities of MLK3 and its downstream target, c-Jun NH(2)-terminal kinase, were rapidly inhibited by E(2) in ER(+) but not in ER(-) cells. Specific knockdown of AKT1/2 prevented MLK3 inhibition by E(2), indicating that AKT mediated this event. Furthermore, MLK3 inhibition by E(2) involved phosphorylation of MLK3 Ser(674) by AKT, attenuating the proapoptotic function of MLK3. We found that a pan-MLK inhibitor (CEP-11004) limited Taxol-induced cell death and that E(2) accentuated this limitation. Taken together, our findings indicate that E(2) inhibits the proapoptotic function of MLK3 as a mechanism to limit cytotoxic drug-induced death of ER(+) breast cancer cells. PMID:20145118

  17. Estradiol uptake, toxicity, metabolism, and adverse effects on cadmium-treated amphibian embryos.

    PubMed Central

    Fridman, Osvaldo; Corró, Lucrecia; Herkovits, Jorge

    2004-01-01

    The exposure of Bufo arenarum embryos to 25 micromol/L 17beta-estradiol (E2) resulted in 100% lethality within 48 hr, whereas 10 micromol//L E2 was the no observed effect concentration value for short-term chronic (7 days) exposure. The toxicity profile curves show that lethal effects were proportional to the E2 concentration and the time of exposure. The E2 uptake resulted in 20.1 ng E2/mg embryo at 8 hr posttreatment, but 67.3% of this value was achieved during the first 30 min of incubation with this estrogen. Regarding metabolism, the embryos synthesize estrone (E1) from E2 by means of 17beta-hydroxysteroid dehydrogenase. Simultaneous treatments of Bufo arenarum embryos with 1 mg/L Cd2+ and 0.1, 1, or 10 micromol/L E2 enhanced the lethality exerted by cadmium in 76.7, 80, and 83.3% of embryos, respectively. The results indicate that estrogenic endocrine disruptors could have an adverse effect on amphibian embryos and enhance the toxic effect of Cd on amphibian embryos. This study points to the possibility of using the AMPHITOX test as a screening method for potential endocrine disruption as well as the combined effects of chemical mixtures. PMID:15175173

  18. The dark side of E2F1: in transit beyond apoptosis.

    PubMed

    Engelmann, David; Ptzer, Brigitte M

    2012-02-01

    E2F1 plays a critical role in cell-cycle progression and the induction of apoptosis in response to DNA damage. The latest evidence has uncovered that this tumor suppressor is most relevant for cancer progression and chemoresistance. Increased abundance of E2F1 triggers invasion and metastasis by activating growth receptor signaling pathways, which in turn promote an antiapoptotic tumor environment. The data shed light on the molecular mechanisms underlying E2F1-induced prometastatic activity and predict its radical switch from a mediator of cell death toward an accelerator of tumor progression. This raises the perspective of new drug targets at late-stage cancer. PMID:22298593

  19. Acute Hemoperitoneum after Administration of Prostaglandin E2 for Induction of Labour

    PubMed Central

    Zhang, Zhenyu; Lou, Jiangyan

    2015-01-01

    Prostaglandin E2 is widely used in obstetrics and is thought to be relatively safe for cervical ripening and induction of labour. Here we present a case in which acute hemoperitoneum was observed after administration of prostaglandin E2 in a pregnant woman. The patient had a history of endometriosis, and a severe pelvic adhesion (ASRM stage IV) was found during her last laparoscopic surgery 3 years previously. In cases with endometriosis, use of prostaglandin E2 for induction of labour in pregnant women must be done cautiously. PMID:26495145

  20. Anisotropic magnetotransport and exotic longitudinal linear magnetoresistance in WT e2 crystals

    NASA Astrophysics Data System (ADS)

    Zhao, Yanfei; Liu, Haiwen; Yan, Jiaqiang; An, Wei; Liu, Jun; Zhang, Xi; Wang, Huichao; Liu, Yi; Jiang, Hua; Li, Qing; Wang, Yong; Li, Xin-Zheng; Mandrus, David; Xie, X. C.; Pan, Minghu; Wang, Jian

    2015-07-01

    The WT e2 semimetal, as a typical layered transition-metal dichalcogenide, has recently attracted much attention due to an extremely large, nonsaturating parabolic magnetoresistance in the perpendicular field. Here, we report a systematic study of the angular dependence of the magnetoresistance in a WT e2 single crystal. The significant anisotropic magnetotransport behavior in different magnetic field directions and violation of the Kohler's rule are observed. Unexpectedly, when the applied field and excitation current are both parallel to the tungsten chains of WT e2 , an exotic large longitudinal linear magnetoresistance as high as 1200 % at 15 T and 2 K is identified. Our results imply that the WT e2 semimetal, due to its balanced hole and electron populations, seems to be the first material for which a large longitudinal linear magnetoresistance appears when the external magnetic field is parallel to the applied current. Our work may stimulate studies of double-carrier correlated materials and the corresponding quantum physics.

  1. Incompatibility Exhibited by Colicin Plasmids E1, E2, and E3 in Escherichia coli

    PubMed Central

    Inselburg, Joseph

    1974-01-01

    Escherichia coli strains were made multiply colicinogenic for the colicin plasmids E1, E2, or E3 (Col E1, Col E2, or Col E3, respectively) by both a deoxyribonucleic acid transformation system and bacterial conjugation. The multiply colicinogenic bacteria constructed exhibited an immunity to the colicins produced by all the plasmids they carried and also produced colicins corresponding to all the plasmids they carried. An incompatibility was observed among the plasmids. In doubly colicinogenic cells where the presence of two plasmids was established, Col E2 was lost more frequently than Col E3. In triply colicinogenic cells, Col E1, Col E2, and Col E3 were lost, with Col E3 being lost least frequently. A significant reduction in the acquisition of a conjugationally transferred Col E1 plasmid by cells colicinogenic for Col E1 was demonstrated. PMID:4604597

  2. The RB/E2F pathway and regulation of RNA processing

    SciTech Connect

    Ahlander, Joseph; Bosco, Giovanni

    2009-07-03

    The retinoblastoma tumor suppressor protein (RB) is inactivated in a majority of cancers. RB restricts cell proliferation by inhibiting the E2F family of transcription factors. The current model for RB/E2F function describes its role in regulating transcription at gene promoters. Whether the RB or E2F proteins might play a role in gene expression beyond transcription initiation is not well known. This review describes evidence that points to a novel role for the RB/E2F network in the regulation of RNA processing, and we propose a model as a framework for future research. The elucidation of a novel role of RB in RNA processing will have a profound impact on our understanding of the role of this tumor suppressor family in cell and developmental biology.

  3. Identification of New Functional Regions in Hepatitis C Virus Envelope Glycoprotein E2?

    PubMed Central

    Albecka, Anna; Montserret, Roland; Krey, Thomas; Tarr, Alexander W.; Diesis, Eric; Ball, Jonathan K.; Descamps, Vronique; Duverlie, Gilles; Rey, Felix; Penin, Franois; Dubuisson, Jean

    2011-01-01

    Little is known about the structure of the envelope glycoproteins of hepatitis C virus (HCV). To identify new regions essential for the function of these glycoproteins, we generated HCV pseudoparticles (HCVpp) containing HCV envelope glycoproteins, E1 and E2, from different genotypes in order to detect intergenotypic incompatibilities between these two proteins. Several genotype combinations were nonfunctional for HCV entry. Of interest, a combination of E1 from genotype 2a and E2 from genotype 1a was nonfunctional in the HCVpp system. We therefore used this nonfunctional complex and the recently described structural model of E2 to identify new functional regions in E2 by exchanging protein regions between these two genotypes. The functionality of these chimeric envelope proteins in the HCVpp system and/or the cell-cultured infectious virus (HCVcc) was analyzed. We showed that the intergenotypic variable region (IgVR), hypervariable region 2 (HVR2), and another segment in domain II play a role in E1E2 assembly. We also demonstrated intradomain interactions within domain I. Importantly, we also identified a segment (amino acids [aa] 705 to 715 [segment 705-715]) in the stem region of E2, which is essential for HCVcc entry. Circular dichroism and nuclear magnetic resonance structural analyses of the synthetic peptide E2-SC containing this segment revealed the presence of a central amphipathic helix, which likely folds upon membrane binding. Due to its location in the stem region, segment 705-715 is likely involved in the reorganization of the glycoprotein complexes taking place during the fusion process. In conclusion, our study highlights new functional and structural regions in HCV envelope glycoprotein E2. PMID:21147916

  4. E2F-1 represses transcription of the human telomerase reverse transcriptase gene

    PubMed Central

    Crowe, David L.; Nguyen, Dan C.; Tsang, Kenneth J.; Kyo, Satoru

    2001-01-01

    The ends of human chromosomes (telomeres) lose up to 200 bp of DNA per cell division. Chromosomal shortening ultimately leads to senescence and death in normal cells. Many human carcinoma lines are immortal in vitro, suggesting that these cells have a mechanism for maintaining the ends of their chromosomes. Telomerase is a ribonucleoprotein complex that synthesizes telomeric DNA onto chromosomes using its RNA component as template. Telomerase activity is found in most tumor cells, but is absent from normal cells. Little is known about how normal human cells repress telomerase (hTERT) gene expression. Mice carrying an E2F-1 null mutation develop a variety of malignant tumors, suggesting that this transcription factor has a tumor suppressor function. To determine mechanisms by which E2F-1 suppresses tumor formation, we examined the role of this transcription factor in regulation of the hTERT promoter in human cells. We identified two putative E2F-1-binding sites proximal to the transcriptional start site of the hTERT promoter. Mutation of these sites produced dramatic increases in promoter activity. Overexpression of E2F-1 but not a mutant E2F-1 repressed hTERT promoter activity in reporter gene assays. This repression was abolished by mutation of the E2F-1-binding sites in the hTERT promoter. Human cancer cell lines stably overexpressing E2F-1 exhibited decreased hTERT mRNA expression and telomerase activity. We conclude that E2F-1 has an atypical function as a transcriptional repressor of the hTERT gene in human cells. PMID:11433024

  5. Regression of human papillomavirus intraepithelial lesions is induced by MVA E2 therapeutic vaccine.

    PubMed

    Rosales, Ricardo; Lpez-Contreras, Mario; Rosales, Carlos; Magallanes-Molina, Jose-Roberto; Gonzalez-Vergara, Roberto; Arroyo-Cazarez, Jose Martin; Ricardez-Arenas, Antonio; Del Follo-Valencia, Armando; Padilla-Arriaga, Santiago; Guerrero, Miriam Veronica; Pirez, Miguel Angel; Arellano-Fiore, Claudia; Villarreal, Freddy

    2014-12-01

    Human papilloma viruses can induce warts, condylomas, and other intraepithelial cervical lesions that can progress to cancer. Cervical cancer is a serious problem in developing countries because early detection is difficult, and thus proper early treatment is many times missing. In this phase III clinical trial, we evaluated the potential use of MVA E2 recombinant vaccinia virus to treat intraepithelial lesions associated with papillomavirus infection. A total of 1176 female and 180 male patients with intraepithelial lesions were studied. They were injected with 10(7) MVA E2 virus particles directly into their uterus, urethra, vulva, or anus. Patients were monitored by colposcopy and cytology. Immune response was determined by measuring the antibody titer against MVA E2 virus and by analyzing the cytotoxic activity against cancer cells bearing papillomavirus DNA. Papillomavirus was determined by the Hybrid Capture method or by polymerase chain reaction analysis. By histology, 1051 (89.3%) female patients showed complete elimination of lesions after treatment with MVA E2. In 28 (2.4%) female patients, the lesion was reduced to CIN 1. Another 97 (8.3%) female patients presented isolated koilocytes after treatment. In men, all lesions were completely eliminated. All MVA E2-treated patients developed antibodies against the MVA E2 vaccine and generated a specific cytotoxic response against papilloma-transformed cells. Papillomavirus DNA was not detected after treatment in 83% of total patients treated. MVA E2 did not generate any apparent side effects. These data suggest that therapeutic vaccination with MVA E2 vaccine is an excellent candidate to stimulate the immune system and generate regression in intraepithelial lesions when applied locally. PMID:25275724

  6. Increased metastasis with loss of E2F2 in Myc-driven tumors

    PubMed Central

    Yuwanita, Inez; Barnes, Danielle; Monterey, Michael D.; O'Reilly, Sandra; Andrechek, Eran R.

    2015-01-01

    In human breast cancer, mortality is associated with metastasis to distant sites. Therefore, it is critical to elucidate the biological mechanisms that underlie tumor progression and metastasis. Using signaling pathway signatures we previously predicted a role for E2F transcription factors in Myc induced tumors. To test this role we interbred MMTV-Myc transgenic mice with E2F knockouts. Surprisingly, we observed that the loss of E2F2 sharply increased the percentage of lung metastasis in MMTV-Myc transgenic mice. Examining the gene expression profile from these tumors, we identified genetic components that were potentially involved in mediating metastasis. These genes were filtered to uncover the genes involved in metastasis that also impacted distant metastasis free survival in human breast cancer. In order to elucidate the mechanism by which E2F2 loss enhanced metastasis we generated knockdowns of E2F2 in MDA-MB-231 cells and observed increased migration in vitro and increased lung colonization in vivo. We then examined genes that were differentially regulated between tumors from MMTV-Myc, MMTV-Myc E2F2−/−, and lung metastases samples and identified PTPRD. To test the role of PTPRD in E2F2-mediated breast cancer metastasis, we generated a knockdown of PTPRD in MDA-MB-231 cells. We noted that decreased levels of PTPRD resulted in decreased migration in vitro and decreased lung colonization in vivo. Taken together, these data indicate that E2F2 loss results in increased metastasis in breast cancer, potentially functioning through a PTPRD dependent mechanism. PMID:26474282

  7. Regression of Human Papillomavirus Intraepithelial Lesions Is Induced by MVA E2 Therapeutic Vaccine

    PubMed Central

    López-Contreras, Mario; Rosales, Carlos; Magallanes-Molina, Jose-Roberto; Gonzalez-Vergara, Roberto; Arroyo-Cazarez, Jose Martin; Ricardez-Arenas, Antonio; del Follo-Valencia, Armando; Padilla-Arriaga, Santiago; Guerrero, Miriam Veronica; Pirez, Miguel Angel; Arellano-Fiore, Claudia; Villarreal, Freddy

    2014-01-01

    Abstract Human papilloma viruses can induce warts, condylomas, and other intraepithelial cervical lesions that can progress to cancer. Cervical cancer is a serious problem in developing countries because early detection is difficult, and thus proper early treatment is many times missing. In this phase III clinical trial, we evaluated the potential use of MVA E2 recombinant vaccinia virus to treat intraepithelial lesions associated with papillomavirus infection. A total of 1176 female and 180 male patients with intraepithelial lesions were studied. They were injected with 107 MVA E2 virus particles directly into their uterus, urethra, vulva, or anus. Patients were monitored by colposcopy and cytology. Immune response was determined by measuring the antibody titer against MVA E2 virus and by analyzing the cytotoxic activity against cancer cells bearing papillomavirus DNA. Papillomavirus was determined by the Hybrid Capture method or by polymerase chain reaction analysis. By histology, 1051 (89.3%) female patients showed complete elimination of lesions after treatment with MVA E2. In 28 (2.4%) female patients, the lesion was reduced to CIN 1. Another 97 (8.3%) female patients presented isolated koilocytes after treatment. In men, all lesions were completely eliminated. All MVA E2–treated patients developed antibodies against the MVA E2 vaccine and generated a specific cytotoxic response against papilloma-transformed cells. Papillomavirus DNA was not detected after treatment in 83% of total patients treated. MVA E2 did not generate any apparent side effects. These data suggest that therapeutic vaccination with MVA E2 vaccine is an excellent candidate to stimulate the immune system and generate regression in intraepithelial lesions when applied locally. PMID:25275724

  8. Transcriptional control of stem cell fate by E2Fs and pocket proteins

    PubMed Central

    Julian, Lisa M.; Blais, Alexandre

    2015-01-01

    E2F transcription factors and their regulatory partners, the pocket proteins (PPs), have emerged as essential regulators of stem cell fate control in a number of lineages. In mammals, this role extends from both pluripotent stem cells to those encompassing all embryonic germ layers, as well as extra-embryonic lineages. E2F/PP-mediated regulation of stem cell decisions is highly evolutionarily conserved, and is likely a pivotal biological mechanism underlying stem cell homeostasis. This has immense implications for organismal development, tissue maintenance, and regeneration. In this article, we discuss the roles of E2F factors and PPs in stem cell populations, focusing on mammalian systems. We discuss emerging findings that position the E2F and PP families as widespread and dynamic epigenetic regulators of cell fate decisions. Additionally, we focus on the ever expanding landscape of E2F/PP target genes, and explore the possibility that E2Fs are not simply regulators of general ‘multi-purpose’ cell fate genes but can execute tissue- and cell type-specific gene regulatory programs. PMID:25972892

  9. Identification of Aptamer-Binding Sites in Hepatitis C Virus Envelope Glycoprotein E2

    PubMed Central

    Chen, Fan; Chen, Si-Chong; Zhou, Jing; Chen, Zhi-De; Chen, Fang

    2015-01-01

    Hepatitis C Virus (HCV) encodes two envelope glycoproteins, E1 and E2. Our previous work selected a specific aptamer ZE2, which could bind to E2 with high affinity, with a great potential for developing new molecular probes as an early diagnostic reagents or therapeutic drugs targeting HCV. In this study, the binding sites between E2 and aptamer ZE2 were further explored. E2 was truncated to 15 peptides (P1 to P15) and these peptides were used to detect the affinity with ZE2 by ELISA respectively. The peptide with high affinity was then further truncated, detected and compared with six kinds of HCV genotypes. The basic amino acid in 500 aa bound to ZE2 with high affinity, while acidic amino acid in 501 aa reduced the reaction between E2 and ZE2. The results showed the 500 aa and 501 aa of E2 were the key sites that bound to ZE2. PMID:25648186

  10. Physical and functional interactions of human papillomavirus E2 protein with nuclear receptor coactivators

    SciTech Connect

    Wu, M.-H.; Huang, C.-J.; Liu, S.-T.; Liu, P.-Y.; Ho, C.-L. . E-mail: shihming@ndmctsgh.edu.tw

    2007-05-11

    In addition to the human papillomavirus (HPV)-induced immortalization of epithelial cells, which usually requires integration of the viral DNA into the host cell genome, steroid hormone-activated nuclear receptors (NRs) are thought to bind to specific DNA sequences within transcriptional regulatory regions on the long control region to either increase or suppress transcription of dependent genes. In this study, our data suggest that the NR coactivator function of HPV E2 proteins might be mediated through physical and functional interactions with not only NRs but also the NR coactivators GRIP1 (glucocorticoid receptor-interacting protein 1) and Zac1 (zinc-finger protein which regulates apoptosis and cell cycle arrest 1), reciprocally regulating their transactivation activities. GRIP1 and Zac1 both were able to act synergistically with HPV E2 proteins on the E2-, androgen receptor-, and estrogen receptor-dependent transcriptional activation systems. GRIP1 and Zac1 might selectively function with HPV E2 proteins on thyroid receptor- and p53-dependent transcriptional activation, respectively. Hence, the transcriptional function of E2 might be mediated through NRs and NR coactivators to regulate E2-, NR-, and p53-dependent transcriptional activations.

  11. The HPV E2-Host Protein-Protein Interactions: A Complex Hijacking of the Cellular Network

    PubMed Central

    Muller, Mandy; Demeret, Caroline

    2012-01-01

    Over 100 genotypes of human papillomaviruses (HPVs) have been identified as being responsible for unapparent infections or for lesions ranging from benign skin or genital warts to cancer. The pathogenesis of HPV results from complex relationships between viral and host factors, driven in particular by the interplay between the host proteome and the early viral proteins. The E2 protein regulates the transcription, the replication as well as the mitotic segregation of the viral genome through the recruitment of host cell factors to the HPV regulatory region. It is thereby a pivotal factor for the productive viral life cycle and for viral persistence, a major risk factor for cancer development. In addition, the E2 proteins have been shown to engage numerous interactions through which they play important roles in modulating the host cell. Such E2 activities are probably contributing to create cell conditions appropriate for the successive stages of the viral life cycle, and some of these activities have been demonstrated only for the oncogenic high-risk HPV. The recent mapping of E2-host protein-protein interactions with 12 genotypes representative of HPV diversity has shed some light on the large complexity of the host cell hijacking and on its diversity according to viral genotypes. This article reviews the functions of E2 as they emerge from the E2/host proteome interplay, taking into account the large-scale comparative interactomic study. PMID:23341853

  12. Temperature Dependent E2 Raman Modes in the ZnCoO Ternary Alloy

    NASA Technical Reports Server (NTRS)

    Samanta, K.; Bhattacharya, P.; Katiyar, R. S.

    2007-01-01

    The anharmonic properties of low and high frequency E2 modes of ZnO and Co doped ZnO were investigated using Raman scattering spectroscopy. We have determined the behavior of frequency, linewidths, and lifetime of E2 modes in the temperature range from 80 to 800 K. In the case of E2(high) mode the frequency shift towards the lower energy side was analyzed in light of the theory of anharmonic phonon-phonon interaction and thermal expansion of the lattice, and the linewidth behavior was analyzed in terms of anharmonic effect of three-phonon decay mechanism. But in the case of E2(low), the linewidth and frequency behaved practically harmonic with respect to temperature and independent of Co substitutions. It is found that the E2(high) phonon anharmonicity is higher for ZnCoO alloys than in pure ZnO and it increases with the compositional disorder. The low temperature lifetime of E2 phonon in ZnO, 1 % and 3% Co doped ZnO were found to be 1.S2, 1.74, and 1.54 ps, respectively.

  13. NATURE OF W51e2: MASSIVE CORES AT DIFFERENT PHASES OF STAR FORMATION

    SciTech Connect

    Shi Hui; Han, J. L.; Zhao Junhui E-mail: hjl@nao.cas.c

    2010-02-10

    We present high-resolution continuum images of the W51e2 complex processed from archival data of the Submillimeter Array (SMA) at 0.85 and 1.3 mm and the Very Large Array at 7 and 13 mm. We also made line images and profiles of W51e2 for three hydrogen radio recombination lines (RRLs; H26alpha, H53alpha, and H66alpha) and absorption of two molecular lines of HCN(4-3) and CO(2-1). At least four distinct continuum components have been detected in the 3'' region of W51e2 from the SMA continuum images at 0.85 and 1.3 mm with resolutions of 0.''3 x 0.''2 and 1.''4 x 0.''7, respectively. The west component, W51e2-W, coincides with the ultracompact H II region reported from previous radio observations. The H26alpha line observation reveals an unresolved hyper-compact ionized core (<0.''06 or <310 AU) with a high electron temperature of 1.2 x 10{sup 4} K, with the corresponding emission measure EM>7 x 10{sup 10} pc cm{sup -6} and the electron density N{sub e} >7 x 10{sup 6} cm{sup -3}. The inferred Lyman continuum flux implies that the H II region W51e2-W requires a newly formed massive star, an O8 star or a cluster of B-type stars, to maintain the ionization. W51e2-E, the brightest component at 0.85 mm, is located 0.''9 east from the hyper-compact ionized core. It has a total mass of {approx}140 M{sub sun} according to our spectral energy distribution analysis and a large infall rate of >1.3 x 10{sup -3} M{sub sun} yr{sup -1} inferred from the absorption of HCN. W51e2-E appears to be the accretion center in W51e2. Given the fact that no free-free emission and no RRLs have been detected, the massive core of W51e2-E appears to host one or more growing massive proto-stars. Located 2'' northwest from W51e2-E, W51e2-NW is detected in the continuum emission at 0.85 and 1.3 mm. No continuum emission has been detected at lambda>= 7 mm. Along with the maser activities previously observed, our analysis suggests that W51e2-NW is at an earlier phase of star formation. W51e2-N is located 2'' north of W51e2-E and has only been detected at 1.3 mm with a lower angular resolution ({approx}1''), suggesting that it is a primordial, massive gas clump in the W51e2 complex.

  14. Formation mechanism of superconducting phase and its three-dimensional architecture in pseudo-single-crystal KxF e2 -yS e2

    NASA Astrophysics Data System (ADS)

    Liu, Yong; Xing, Qingfeng; Straszheim, Warren E.; Marshman, Jeff; Pedersen, Pal; McLaughlin, Richard; Lograsso, Thomas A.

    2016-02-01

    We report how the superconducting phase forms in pseudo-single-crystal KxF e2 -yS e2 . In situ scanning electron microscopy (SEM) observation reveals that, as an order-disorder transition occurs, on cooling, most of the high-temperature iron-vacancy-disordered phase gradually changes into the iron-vacancy-ordered phase, whereas a small quantity of the high-temperature phase retains its structure and aggregates to the stripes with more iron concentration but less potassium concentration compared to the iron-vacancy-ordered phase. The stripes that are generally recognized as the superconducting phase are actually formed as a remnant of the high-temperature phase with a compositional change after an "imperfect" order-disorder transition. It should be emphasized that the phase separation in pseudo-single-crystal KxF e2 -yS e2 is caused by the iron-vacancy order-disorder transition. The shrinkage of the high-temperature phase and the expansion of the newly created iron-vacancy-ordered phase during the phase separation rule out the mechanism of spinodal decomposition proposed in an early report [Z. Wang et al., Phys. Rev. B 91, 064513 (2015), 10.1103/PhysRevB.91.064513]. Since the formation of the superconducting phase relies on the occurrence of the iron-vacancy order-disorder transition, it is impossible to synthesize a pure superconducting phase by a conventional solid state reaction or melt growth. By focused ion beam scanning electron microscopy, we further demonstrate that the superconducting phase forms a contiguous three-dimensional architecture composed of parallelepipeds that have a coherent orientation relationship with the iron-vacancy-ordered phase.

  15. 17?-estradiol regulates giant vesicle formation via estrogen receptor-alpha in human breast cancer cells

    PubMed Central

    Wright, Paul K; Jones, Sarah Bowen; Ardern, Nicholas; Ward, Rebecca; Clarke, Robert B; Sotgia, Federica; Lisanti, Michael P; Landberg, Goran; Lamb, Rebecca

    2014-01-01

    A significant proportion of the genes regulated by 17-beta-estradiol (E2) via estrogen receptor alpha (ER?) have roles in vesicle trafficking in breast cancer. Intracellular vesicle trafficking and extracellular vesicles have important roles in tumourigenesis. Here we report the discovery of giant (3-42?m) intracellular and extracellular vesicles (GVs) and the role of E2 on vesicle formation in breast cancer (BC) cell lines using three independent live cell imaging techniques. Large diameter vesicles, GVs were also identified in a patient-derived xenograft BC model, and in invasive breast carcinoma tissue. ER?-positive (MCF-7 and T47D) BC cell lines demonstrated a significant increase in GV formation after stimulation with E2 which was reversed by tamoxifen. ER?-negative (MDA-MB-231 and MDA-MB-468) BC cell lines produced GVs independently of E2 and tamoxifen. These results indicate the existence of both intracellular and extracellular vesicles with considerably larger dimensions than generally recognised with BC cells and suggest that the GVs are regulated by E2 via ER? in ER?-positive BC but by E2-independent mechanisms in ER-ve BC. PMID:24931391

  16. 17?-estradiol regulates giant vesicle formation via estrogen receptor-alpha in human breast cancer cells.

    PubMed

    Wright, Paul K; Jones, Sarah Bowen; Ardern, Nicholas; Ward, Rebecca; Clarke, Robert B; Sotgia, Federica; Lisanti, Michael P; Landberg, Goran; Lamb, Rebecca

    2014-05-30

    A significant proportion of the genes regulated by 17-beta-estradiol (E2) via estrogen receptor alpha (ER?) have roles in vesicle trafficking in breast cancer. Intracellular vesicle trafficking and extracellular vesicles have important roles in tumourigenesis. Here we report the discovery of giant (3-42?m) intracellular and extracellular vesicles (GVs) and the role of E2 on vesicle formation in breast cancer (BC) cell lines using three independent live cell imaging techniques. Large diameter vesicles, GVs were also identified in a patient-derived xenograft BC model, and in invasive breast carcinoma tissue. ER?-positive (MCF-7 and T47D) BC cell lines demonstrated a significant increase in GV formation after stimulation with E2 which was reversed by tamoxifen. ER?-negative (MDA-MB-231 and MDA-MB-468) BC cell lines produced GVs independently of E2 and tamoxifen. These results indicate the existence of both intracellular and extracellular vesicles with considerably larger dimensions than generally recognised with BC cells and suggest that the GVs are regulated by E2 via ER? in ER?-positive BC but by E2-independent mechanisms in ER-ve BC. PMID:24931391

  17. Estradiol affects liver mitochondrial function in ovariectomized and tamoxifen-treated ovariectomized female rats

    SciTech Connect

    Moreira, Paula I.; Custodio, Jose B.A.; Nunes, Elsa; Moreno, Antonio; Seica, Raquel; Oliveira, Catarina R.; Santos, Maria S. . E-mail: mssantos@ci.uc.pt

    2007-05-15

    Given the tremendous importance of mitochondria to basic cellular functions as well as the critical role of mitochondrial impairment in a vast number of disorders, a compelling question is whether 17{beta}-estradiol (E2) modulates mitochondrial function. To answer this question we exposed isolated liver mitochondria to E2. Three groups of rat females were used: control, ovariectomized and ovariectomized treated with tamoxifen. Tamoxifen has antiestrogenic effects in the breast tissue and is the standard endocrine treatment for women with breast cancer. However, under certain circumstances and in certain tissues, tamoxifen can also exert estrogenic agonist properties. We observed that at basal conditions, ovariectomy and tamoxifen treatment do not induce any statistical alteration in oxidative phosphorylation system and respiratory chain parameters. Furthermore, tamoxifen treatment increases the capacity of mitochondria to accumulate Ca{sup 2+} delaying the opening of the permeability transition pore. The presence of 25 {mu}M E2 impairs respiration and oxidative phosphorylation system these effects being similar in all groups of animals studied. Curiously, E2 protects against lipid peroxidation and increases the production of H{sub 2}O{sub 2} in energized mitochondria of control females. Our results indicate that E2 has in general deleterious effects that lead to mitochondrial impairment. Since mitochondrial dysfunction is a triggering event of cell degeneration and death, the use of exogenous E2 must be carefully considered.

  18. Time course of the estradiol-dependent induction of oxytocin receptor binding in the ventromedial hypothalamic nucleus of the rat

    SciTech Connect

    Johnson, A.E.; Ball, G.F.; Coirini, H.; Harbaugh, C.R.; McEwen, B.S.; Insel, T.R. )

    1989-09-01

    Oxytocin (OT) transmission is involved in the steroid-dependent display of sexual receptivity in rats. One of the biochemical processes stimulated by the ovarian steroid 17 beta-estradiol (E2) that is relevant to reproduction is the induction of OT receptor binding in the ventromedial hypothalamic nucleus (VMN). The purpose of these experiments was to determine if E2-induced changes in OT receptor binding in the VMN occur within a time frame relevant to cyclic changes in ovarian steroid secretion. OT receptor binding was measured in the VMN of ovariectomized rats implanted for 0-96 h with E2-containing Silastic capsules. The rate of decay of OT receptor binding was measured in another group of animals 6-48 h after capsule removal. Receptors were labeled with the specific OT receptor antagonist ({sup 125}I)d(CH2)5(Tyr(Me)2,Thr4,Tyr-NH2(9))OVT, and binding was measured with quantitative autoradiographic methods. In addition, plasma E2 levels and uterine weights were assessed in animals from each treatment condition. Significant increases in E2-dependent OT receptor binding and uterine weight occurred within 24 h of steroid treatment. After E2 withdrawal, OT receptor binding and uterine weight decreased significantly within 24 h. These results are consistent with the hypothesis that steroid modulation of OT receptor binding is necessary for the induction of sexual receptivity.

  19. Estrogen inhibits the response-to-injury in a mouse carotid artery model.

    PubMed Central

    Sullivan, T R; Karas, R H; Aronovitz, M; Faller, G T; Ziar, J P; Smith, J J; O'Donnell, T F; Mendelsohn, M E

    1995-01-01

    The atheroprotective effects of estrogen are well documented, but the mechanisms responsible for these effects are not well understood. To study the role of physiologic (nanomolar) estrogen levels on the arterial response-to-injury, we applied a mouse carotid artery injury model to ovariectomized C57BL/6J mice. Mice were treated with vehicle (-E2, n = 10) or 17 beta-estradiol (+E2, n = 10) for 7 d, subjected to unilateral carotid injury, and 14 d later contralateral (normal = NL) and injured carotids from -E2 and +E2 animals were pressure fixed, harvested, and analyzed by quantitative morphometry. E2 levels in +E2 mice were consistently in the nanomolar range (2.1-2.5 nM) at days 0, 7, and 14. At 14 d, measures of both intimal and medial area were markedly increased in the -E2 group: (-E2 vs NL, P < 0.05 for both), but were unchanged from normal levels in the +E2 group (+E2 vs NL, P = NS and +E2 vs -E2, P < 0.05 for both). Cellular proliferation, as assessed by bromodeoxyuridine (BrdU) labeling, was significantly increased over NL in the -E2 mice, but this increase was markedly attenuated in the estrogen replacement group (total BrdU positive cells/section: NL = 6.4 +/- 4.5; -E2 = 113 +/- 26, +E2 = 40 +/- 3.7; -E2 vs NL, P < 0.05; +E2 vs NL, P = NS; -E2 vs +E2, P < 0.05). These data (a) demonstrate significant suppression of the mouse carotid response-to-injury by physiologic levels of estrogen replacement; (b) support the utility of this model in the study of the biologic effects of estrogen on the vascular-injury response; and (c) suggest a direct effect of estrogen on vascular smooth muscle cell proliferation in injured vessels. Images PMID:7593638

  20. Hp-41CV flight performance advisory system (FPAS) for the E-2c, E-2B, and C-2A aircraft. Final technical report Apr-Jun 82

    SciTech Connect

    Ferrell, D.R.

    1982-06-01

    This report describes follow-on work performed under the auspices of AE 4900, Directed Studies in Aeronautical Engineering at the Naval Postgraduate School, to complement the original design of a Flight Performance Advisory System (FPAS) for the E-2C aircraft. The original design fulfilled the requirements of AE 3001, Aircraft Energy Conservation. AE 3001, offered in the Fall Quarter 1981, and conducted by Professor Allen E. Fuhs, was sponsored in part by the Naval Air Development Center (NADC). NADC desired to obtain the input of several fleet experienced aviators in order to design program code for the HP-41CV handheld, programmable calculator that would benefit pilots by providing them with fuel efficiency parameters in flight. Calculators were made available to the participants with the proviso that a completed and operable code for each aircraft be submitted by the end of the academic quarter, September 1981. Upon completion of the E-2C program, attempts were made to use the calculator in flight. One test was conducted informally in an E-2C at RVAW-110, NAS Miramar. Unfortunately, the voltage field induced in the cockpit by the main lobe of the radar passing over the cockpit caused the calculator to cease functioning. The need to devise shielding for the calculator, plus the desire to simplify and improve the existing code lead to this effort.

  1. E2F-1-deficient NOD/SCID mice developed showing decreased saliva production.

    PubMed

    Matsui-Inohara, Hikaru; Uematsu, Hiroshi; Narita, Takanori; Satoh, Keitaro; Yonezawa, Hideo; Kuroda, Koichiro; Ito, Tatsuro; Yoneda, Saori; Kawarai, Taketo; Sugiya, Hiroshi; Watanabe, Haruo; Senpuku, Hidenobu

    2009-12-01

    The non-obese diabetic mouse (NOD) is the most characterized model used to study insulin-dependent type 1 diabetes mellitus (IDDM) and Sjogren's syndrome (SS). In a previous report, we found NOD.E2f1(-/-) mice show a greater progressive development to IDDM and SS compared to NOD mice. Our previous data indicated a progressive decrease in regulatory T cells (CD4(+)CD25(+)) and a decrease in the systemic secretion systems for insulin, and saliva was associated with the progression of IDDM and SS. Therefore, to define the mechanism of early-onset IDDM SS in E2F-1 deficient NOD mice required further investigation by producing E2F-1 deficient NOD/SCID mice in which the T and B cells do not develop. The purpose here was to analyze the essential function of the E2F-1 molecule in the development of IDDM and SS; and the dysfunction of the pancreas islet and salivary gland in the NOD background using NOD/SCID mice. We produced NOD/SCID.E2f1(-/-) mice using homologous recombination; determined diabetes development; measured saliva and insulin production; and performed a histological analysis. The deficient mice showed a decreasing volume of saliva; no infiltration of lymphocytes into salivary glands; no development of diabetes; and no protein localization of FGFR-2b in the ducts of the salivary gland that regulates submandibular gland proliferation and morphogenesis. Therefore, we considered a deficiency in E2F-1 induces a decrease in regulatory T cells and an increase in auto-reactive T cells; however, the E2F-1 deficiency is not associated with T and B cells-independent dysfunction of pancreatic beta cell in insulin secretion. Further, the E2F-1 deficiency is associated with T and B cells-independent dysfunction of the salivary gland exhibits a decrease in saliva production volume. We suggest E2F-1 may be also associated with the differentiation of exocrine cells in the duct where FGFR-2b is expressed in the salivary gland. The E2F-1 deficient NOD/SCID mouse model is useful for showing the development of the salivary gland; and is also useful for various experiments in humanized mice. PMID:19934373

  2. Tissue-specific targeting of cell fate regulatory genes by E2f factors.

    PubMed

    Julian, L M; Liu, Y; Pakenham, C A; Dugal-Tessier, D; Ruzhynsky, V; Bae, S; Tsai, S-Y; Leone, G; Slack, R S; Blais, A

    2016-04-01

    Cell cycle proteins are important regulators of diverse cell fate decisions, and in this capacity have pivotal roles in neurogenesis and brain development. The mechanisms by which cell cycle regulation is integrated with cell fate control in the brain and other tissues are poorly understood, and an outstanding question is whether the cell cycle machinery regulates fate decisions directly or instead as a secondary consequence of proliferative control. Identification of the genes targeted by E2 promoter binding factor (E2f) transcription factors, effectors of the pRb/E2f cell cycle pathway, will provide essential insights into these mechanisms. We identified the promoter regions bound by three neurogenic E2f factors in neural precursor cells in a genome-wide manner. Through bioinformatic analyses and integration of published genomic data sets we uncovered hundreds of transcriptionally active E2f-bound promoters corresponding to genes that control cell fate processes, including key transcriptional regulators and members of the Notch, fibroblast growth factor, Wnt and Tgf-β signaling pathways. We also demonstrate a striking enrichment of the CCCTC binding factor transcription factor (Ctcf) at E2f3-bound nervous system-related genes, suggesting a potential regulatory co-factor for E2f3 in controlling differentiation. Finally, we provide the first demonstration of extensive tissue specificity among E2f target genes in mammalian cells, whereby E2f3 promoter binding is well conserved between neural and muscle precursors at genes associated with cell cycle processes, but is tissue-specific at differentiation-associated genes. Our findings implicate the cell cycle pathway as a widespread regulator of cell fate genes, and suggest that E2f3 proteins control cell type-specific differentiation programs by regulating unique sets of target genes. This work significantly enhances our understanding of how the cell cycle machinery impacts cell fate and differentiation, and will importantly drive further discovery regarding the mechanisms of cell fate control and transcriptional regulation in the brain, as well as in other tissues. PMID:25909886

  3. Structure-function analysis of hepatitis C virus envelope glycoproteins E1 and E2.

    PubMed

    Nayak, Aparajita; Pattabiraman, Nagarajan; Fadra, Numrah; Goldman, Radoslav; Kosakovsky Pond, Sergei L; Mazumder, Raja

    2015-01-01

    Hepatitis C virus (HCV) is the leading cause of chronic liver disease in humans. The envelope proteins of HCV are potential candidates for vaccine development. The absence of three-dimensional (3D) structures for the functional domain of HCV envelope proteins [E1.E2] monomer complex has hindered overall understanding of the virus infection, and also structure-based drug design initiatives. In this study, we report a 3D model containing both E1 and E2 proteins of HCV using the recently published structure of the core domain of HCV E2 and the functional part of E1, and investigate immunogenic implications of the model. HCV [E1.E2] molecule is modeled by using aa205-319 of E1 to aa421-716 of E2. Published experimental data were used to further refine the [E1.E2] model. Based on the model, we predict 77 exposed residues and several antigenic sites within the [E1.E2] that could serve as vaccine epitopes. This study identifies eight peptides which have antigenic propensity and have two or more sequentially exposed amino acids and 12 singular sites are under negative selection pressure that can serve as vaccine or therapeutic targets. Our special interest is 285FLVGQLFTFSPRRHW299 which has five negatively selected sites (L286, V287, G288, T292, and G303) with three of them sequential and four amino acids exposed (F285, L286, T292, and R296). This peptide in the E1 protein maps to dengue envelope vaccine target identified previously by our group. Our model provides for the first time an overall view of both the HCV envelope proteins thereby allowing researchers explore structure-based drug design approaches. PMID:25245635

  4. Mutations in the endodomain of Sindbis virus glycoprotein E2 define sequences critical for virus assembly.

    PubMed

    West, John; Hernandez, Raquel; Ferreira, Davis; Brown, Dennis T

    2006-05-01

    Envelopment of Sindbis virus at the plasma membrane is a multistep process in which an initial step is the association of the E2 protein via a cytoplasmic endodomain with the preassembled nucleocapsid. Sindbis virus is vectored in nature by blood-sucking insects and grows efficiently in a number of avian and mammalian vertebrate hosts. The assembly of Sindbis virus, therefore, must occur in two very different host cell environments. Mammalian cells contain cholesterol which insect membranes lack. This difference in membrane composition may be critical in determining what requirements are placed on the E2 tail for virus assembly. To examine the interaction between the E2 tail and the nucleocapsid in Sindbis virus, we have produced substitutions and deletions in a region of the E2 tail (E2 amino acids 408 to 415) that is initially integrated into the endoplasmic reticulum. This sequence was identified as being critical for nucleocapsid binding in an in vitro peptide protection assay. The effects of these mutations on virus assembly and function were determined in both vertebrate and invertebrate cells. Amino acid substitutions (at positions E2: 408, 410, 411, and 413) reduced infectious virus production in a position-dependent fashion but were not efficient in disrupting assembly in mammalian cells. Deletions in the E2 endodomain (delta406-407, delta409-411, and delta414-417) resulted in the failure to assemble virions in mammalian cells. Electron microscopy of BHK cells transfected with these mutants revealed assembly of nucleocapsids that failed to attach to membranes. However, introduction of these deletion mutants into insect cells resulted in the assembly of virus-like particles but no assayable infectivity. These data help define protein interactions critical for virus assembly and suggest a fundamental difference between Sindbis virus assembly in mammalian and insect cells. PMID:16611906

  5. Glucocorticoid regulation of branched-chain alpha-ketoacid dehydrogenase E2 subunit gene expression.

    PubMed Central

    Costeas, P A; Chinsky, J M

    2000-01-01

    Regulation of the mammalian branched-chain alpha-ketoacid dehydrogenase complex (BCKAD) occurs under a variety of stressful conditions associated with changes in circulating glucocorticoids. Multiple levels of regulation in hepatocytes, including alteration of the levels of the structural subunits available for assembly (E1, alpha-ketoacid decarboxylase; E2, dihydrolipoamide acyltransferase; and E3, dihydrolipoamide dehydrogenase), as well as BCKAD kinase, which serves to phosphorylate the E1alpha subunit and inactivate complex activity, have been proposed. The direct role of glucocorticoids in regulating the expression of the murine gene encoding the major BCKAD subunit E2, upon which the other BCKAD subunits assemble, was therefore examined. Deletion analysis of the 5' proximal 7.0 kb of the murine E2 promoter sequence, using E2 promoter/luciferase expression minigene plasmids introduced into the hepatic H4IIEC3 cell line, suggested a promoter proximal region responsive to glucocorticoid regulation. Linker-scanning mutagenesis combined with deletion analysis established this functional glucocorticoid-responsive unit (GRU) to be located near the murine E2 proximal promoter site at -140 to -70 bp upstream from the transcription initiation site. The presence of this region in plasmid minigenes, containing varying amounts of the murine genomic sequence 5' upstream from proximal E2 promoter sequences, conferred 2-10 fold increases in luciferase reporter gene expression in H4IIEC3 cells, whether introduced by transient transfection or following co-selection for stable transfectants. The GRU region itself appeared to contain multiple interacting elements that combine to regulate overall E2 promoter activity in response to changing physiological conditions associated with varying concentrations of glucocorticoids and likely other hormonal effectors. PMID:10749674

  6. ModelE2-TOMAS development and evaluation using aerosol optical depths, mass and number concentrations

    NASA Astrophysics Data System (ADS)

    Lee, Y. H.; Adams, P. J.; Shindell, D. T.

    2014-09-01

    The TwO-Moment Aerosol Sectional microphysics model (TOMAS) has been integrated into the state-of-the-art general circulation model, GISS ModelE2. TOMAS has the flexibility to select a size resolution as well as the lower size cutoff. A computationally efficient version of TOMAS is used here, which has 15 size bins covering 3 nm to 10 ?m aerosol dry diameter. For each bin, it simulates the total aerosol number concentration and mass concentrations of sulphate, pure elementary carbon (hydrophobic), mixed elemental carbon (hydrophilic), hydrophobic organic matter, hydrophilic organic matter, sea salt, mineral dust, ammonium, and aerosol-associated water. This paper provides a detailed description of the ModelE2-TOMAS model and evaluates the model against various observations including aerosol precursor gas concentrations, aerosol mass and number concentrations, and aerosol optical depths. Additionally, global budgets in ModelE2-TOMAS are compared with those of other global aerosol models, and the TOMAS model is compared to the default aerosol model in ModelE2, which is a bulk aerosol model. Overall, the ModelE2-TOMAS predictions are within the range of other global aerosol model predictions, and the model has a reasonable agreement with observations of sulphur species and other aerosol components as well as aerosol optical depth. However, ModelE2-TOMAS (as well as the bulk aerosol model) cannot capture the observed vertical distribution of sulphur dioxide over the Pacific Ocean possibly due to overly strong convective transport. The TOMAS model successfully captures observed aerosol number concentrations and cloud condensation nuclei concentrations. Anthropogenic aerosol burdens in the bulk aerosol model running in the same host model as TOMAS (ModelE2) differ by a few percent to a factor of 2 regionally, mainly due to differences in aerosol processes including deposition, cloud processing, and emission parameterizations. Larger differences are found for naturally emitted aerosols such as sea salt and mineral dust. With TOMAS, ModelE2 has three different aerosol models (the bulk aerosol model and modal-based aerosol microphysics model, MATRIX) and allows exploration of the uncertainties associated with aerosol modelling within the same host model, NASA GISS ModelE2.

  7. Detergent-Resistant Membrane Association of NS2 and E2 during Hepatitis C Virus Replication

    PubMed Central

    Shanmugam, Saravanabalaji; Saravanabalaji, Dhanaranjani

    2015-01-01

    ABSTRACT Previously, we demonstrated that the efficiency of hepatitis C virus (HCV) E2-p7 processing regulates p7-dependent NS2 localization to putative virus assembly sites near lipid droplets (LD). In this study, we have employed subcellular fractionations and membrane flotation assays to demonstrate that NS2 associates with detergent-resistant membranes (DRM) in a p7-dependent manner. However, p7 likely plays an indirect role in this process, since only the background level of p7 was detectable in the DRM fractions. Our data also suggest that the p7-NS2 precursor is not involved in NS2 recruitment to the DRM, despite its apparent targeting to this location. Deletion of NS2 specifically inhibited E2 localization to the DRM, indicating that NS2 regulates this process. Treatment of cells with methyl-?-cyclodextrin (M?CD) significantly reduced the DRM association of Core, NS2, and E2 and reduced infectious HCV production. Since disruption of the DRM localization of NS2 and E2, either due to p7 and NS2 defects, respectively, or by M?CD treatment, inhibited infectious HCV production, these proteins' associations with the DRM likely play an important role during HCV assembly. Interestingly, we detected the HCV replication-dependent accumulation of ApoE in the DRM fractions. Taking into consideration the facts that ApoE was shown to be a major determinant for infectious HCV particle production at the postenvelopment step and that the HCV Core protein strongly associates with the DRM, recruitment of E2 and ApoE to the DRM may allow the efficient coordination of Core particle envelopment and postenvelopment events at the DRM to generate infectious HCV production. IMPORTANCE The biochemical nature of HCV assembly sites is currently unknown. In this study, we investigated the correlation between NS2 and E2 localization to the detergent-resistant membranes (DRM) and HCV particle assembly. We determined that although NS2's DRM localization is dependent on p7, p7 was not targeted to these membranes. We then showed that NS2 regulates E2 localization to the DRM, consistent with its role in recruiting E2 to the virus assembly sites. We also showed that short-term treatment with the cholesterol-extracting agent methyl-?-cyclodextrin (M?CD) not only disrupted the DRM localization of Core, NS2, and E2 but also specifically inhibited intracellular virus assembly without affecting HCV RNA replication. Thus, our data support the role of the DRM as a platform for particle assembly process. PMID:25673706

  8. Relationship between vitamin D, IFN-?, and E2 levels in systemic lupus erythematosus.

    PubMed

    Kokic, V; Martinovic Kaliterna, D; Radic, M; Perkovic, D; Cvek, M; Capkun, V

    2016-03-01

    In this study, we investigated the relationship between vitamin D, interferon-gamma (IFN-?), and estradiol (E2) in females of childbearing age with inactive systemic lupus erythematosus (SLE). The study included 22 SLE patients, and 21 age- and gender-matched healthy individuals. Serum concentrations of 25-hydroxyvitamin D3 (25(OH)D3), E2, and IFN-? were measured by radioimmunoassay using the gamma-counter and ELISA. Patients and control subjects were divided into two groups based on their vitamin D levels (25(OH)D3???20?ng/mL; 25(OH)D3?>?20?ng/mL). The median values of IFN-? and E2 were higher in SLE patients compared to the controls, irrespective of vitamin D level (p?=?0.001, p?=?0.009, p?=?0.003, and p?=?0.003, respectively). In SLE patients, there was a negative correlation between IFN-? and 25(OH)D3 (rs?=?-0.330; p?=?0.03) and a positive correlation between IFN-? and E2 (rs?=?0.404; p?=?0.007). This study demonstrates an interesting interplay between vitamin D, INF-?, and E2 in SLE patients with inactive disease. PMID:26405019

  9. Role of E2-Ub-conjugating enzymes during skeletal muscle atrophy

    PubMed Central

    Polge, Cecile; Attaix, Didier; Taillandier, Daniel

    2015-01-01

    The Ubiquitin Proteasome System (UPS) is a major actor of muscle wasting during various physio-pathological situations. In the past 15 years, increasing amounts of data have depicted a picture, although incomplete, of the mechanisms implicated in myofibrillar protein degradation, from the discovery of muscle-specific E3 ligases to the identification of the signaling pathways involved. The targeting specificity of the UPS relies on the capacity of the system to first recognize and then label the proteins to be degraded with a poly-ubiquitin (Ub) chain. It is fairly assumed that the recognition of the substrate is accomplished by the numerous E3 ligases present in mammalian cells. However, most E3s do not possess any catalytic activity and E2 enzymes may be more than simple Ub-providers for E3s since they are probably important actors in the ubiquitination machinery. Surprisingly, most authors have tried to characterize E3 substrates, but the exact role of E2s in muscle protein degradation is largely unknown. A very limited number of the 35 E2s described in humans have been studied in muscle protein breakdown experiments and the vast majority of studies were only descriptive. We review here the role of E2 enzymes in skeletal muscle and the difficulties linked to their study and provide future directions for the identification of muscle E2s responsible for the ubiquitination of contractile proteins. PMID:25805999

  10. Apolipoprotein E ?4 is superior to apolipoprotein E ?2 in predicting cognitive scores over 30 months

    PubMed Central

    Regal, Paul; Nair, Balakrishnan; Hetherington, Eileen

    2013-01-01

    Background The purpose of this study was to compare apolipoprotein E ?4 (Apo E ?4) and apolipoprotein E ?2 (Apo E ?2) as predictors of cognitive and functional trajectories over 30 months. Methods This prospective cohort study included 287 community-dwelling memory clinic patients with dementia, mild cognitive impairment, or no cognitive impairment. The Addenbrooke Cognitive Examination, Mini-Mental State Examination, Montreal Cognitive Assessment, Delirium Index, and Nottingham Instrumental Activities of Daily Living tests were administered to each subject. Results One hundred and nine subjects (40%) carried Apo E ?4 and 48 (16.7%) carried Apo E ?2. One hundred and nine ?4-positive subjects differed significantly from 178 ?4-negative subjects in 19/52 comparisons (36.5%), whereas 46 Apo E ?2-positive subjects had 0/52 significant differences from 239 ?2-negative subjects (P < 0.0001). The variables most affected by ?4 were the Delirium Index and Mini-Mental State Examination. Instrumental Activities of Daily Living score and residence were unrelated to Apo E ?4 or ?2. Conclusion Apo E ?4 positivity predicted four cognitive scores measured every 6 months over 30 months. Apo E ?2 scores predicted none of 52 comparisons. PMID:24204131

  11. E2F1 and telomerase: alliance in the dark side.

    PubMed

    Alonso, Marta M; Fueyo, Juan; Yung, W K Alfred; Gomez-Manzano, Candelaria

    2006-05-01

    Cancer arises from a stepwise accumulation of genetic changes. Among these changes, deregulation of the Rb/E2F1 pathway and constitutively active telomerase are pivotal milestones for the attainment of immortality and maintaining the neoplastic phenotype. We recently showed the Rb/E2F1 pathway to be a direct modulator of telomerase activity in normal and cancer cells, specifically in malignant gliomas. In addition, we reported that the correlation between the levels of expression of E2F1 and hTERT -the catalytic subunit of telomerase- in a subset of patients with glioblastoma multiforme confers clinical relevance to the role of E2F1 in triggering or maintaining hTERT expression. Here we review the evidence supporting the mechanistic linkage between E2F1 and telomerase activation. We also consider the clinical implications of this association in terms of prognostic significance and opportunities for the development of new and more rational therapeutic strategies. PMID:16628012

  12. Redeployment of Myc and E2f1-3 drives Rb deficient cell cycles

    PubMed Central

    Liu, Huayang; Tang, Xing; Srivastava, Arunima; Pécot, Thierry; Daniel, Piotr; Hemmelgarn, Benjamin; Reyes, Stephan; Fackler, Nicholas; Bajwa, Amneet; Kladney, Raleigh; Koivisto, Christopher; Chen, Zhong; Wang, Qianben; Huang, Kun; Machiraju, Raghu; Sáenz-Robles, Maria Teresa; Cantalupo, Paul; Pipas, James M.; Leone, Gustavo

    2015-01-01

    Robust mechanisms to control cell proliferation have evolved to maintain the integrity of organ architecture. Here, we investigated how two critical proliferative pathways, Myc and E2f, are integrated to control cell cycles in normal and Rb deficient cells using a murine intestinal model. We show that Myc and E2f1-3 have little impact on normal G1-S transitions. Instead, they synergistically control an S-G2 transcriptional program required for normal cell divisions and maintaining crypt-villus integrity. Surprisingly, Rb deficiency results in the Myc-dependent accumulation of E2f3 protein and chromatin repositioning of both Myc and E2f3, leading to the ‘super activation’ of a G1-S transcriptional program, ectopic S phase entry and rampant cell proliferation. These findings reveal that Rb deficient cells hijack and redeploy Myc and E2f3 from an S-G2 program essential for normal cell cycles to a G1-S program that re-engages ectopic cell cycles, exposing an unanticipated addiction of Rb-null cells on Myc. PMID:26192440

  13. Early thymocyte development is regulated by modulation of E2A protein activity.

    PubMed

    Engel, I; Johns, C; Bain, G; Rivera, R R; Murre, C

    2001-09-17

    The E2A gene encodes the E47 and E12 basic helix-loop-helix (bHLH) transcription factors. T cell development in E2A-deficient mice is partially arrested before lineage commitment. Here we demonstrate that E47 expression becomes uniformly high at the point at which thymocytes begin to commit towards the T cell lineage. E47 protein levels remain high until the double positive developmental stage, at which point they drop to relatively moderate levels, and are further downregulated upon transition to the single positive stage. However, stimuli that mimic pre-T cell receptor (TCR) signaling in committed T cell precursors inhibit E47 DNA-binding activity and induce the bHLH inhibitor Id3 through a mitogen-activated protein kinase kinase-dependent pathway. Consistent with these observations, a deficiency in E2A proteins completely abrogates the developmental block observed in mice with defects in TCR rearrangement. Thus E2A proteins are necessary for both initiating T cell differentiation and inhibiting development in the absence of pre-TCR expression. Mechanistically, these data link pre-TCR mediated signaling and E2A downstream target genes into a common pathway. PMID:11560990

  14. Genes for E1, E2, and E3 small nucleolar RNAs.

    PubMed Central

    Nag, M K; Thai, T T; Ruff, E A; Selvamurugan, N; Kunnimalaiyaan, M; Eliceiri, G L

    1993-01-01

    We have found earlier three small nucleolar RNA (snoRNA) species, named E1, E2, and E3, that have unique nucleotide sequences and may participate in ribosome formation. The present report shows that there is a monophosphate at the 5' end of each of these three snoRNAs, suggesting that their 5' termini are formed by RNA processing. E1, E2, and E3 human genomic sequences were isolated. Apparently, the E2 and E3 loci are genes for the main E2 and E3 RNA species, based on their full homology, while the E1 locus is a gene for an E1 RNA sequence variant in HeLa cells. These loci do not have any of the intragenic or flanking sequences known to be functional in other genes. The E1 gene is located within the first intron of the gene for RCC1, a protein that regulates onset of mitosis. There is substantial sequence homology between the human E3 gene and flanking regions, and intron 8 and neighboring exons of the gene for mouse translation initiation factor 4AII. Injection of the human E1, E2, and E3 genes into Xenopus oocytes generated sequence-specific transcripts of the approximate sizes of the respective snoRNAs. We discuss why the available results are compatible with specific transcription and processing occurring in frog oocytes. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 PMID:8415643

  15. Redeployment of Myc and E2f1-3 drives Rb-deficient cell cycles.

    PubMed

    Liu, Huayang; Tang, Xing; Srivastava, Arunima; Pcot, Thierry; Daniel, Piotr; Hemmelgarn, Benjamin; Reyes, Stephan; Fackler, Nicholas; Bajwa, Amneet; Kladney, Raleigh; Koivisto, Christopher; Chen, Zhong; Wang, Qianben; Huang, Kun; Machiraju, Raghu; Senz-Robles, Maria Teresa; Cantalupo, Paul; Pipas, James M; Leone, Gustavo

    2015-08-01

    Robust mechanisms to control cell proliferation have evolved to maintain the integrity of organ architecture. Here, we investigated how two critical proliferative pathways, Myc and E2f, are integrated to control cell cycles in normal and Rb-deficient cells using a murine intestinal model. We show that Myc and E2f1-3 have little impact on normal G1-S transitions. Instead, they synergistically control an S-G2 transcriptional program required for normal cell divisions and maintaining crypt-villus integrity. Surprisingly, Rb deficiency results in the Myc-dependent accumulation of E2f3 protein and chromatin repositioning of both Myc and E2f3, leading to the 'super activation' of a G1-S transcriptional program, ectopic S phase entry and rampant cell proliferation. These findings reveal that Rb-deficient cells hijack and redeploy Myc and E2f3 from an S-G2 program essential for normal cell cycles to a G1-S program that re-engages ectopic cell cycles, exposing an unanticipated addiction of Rb-null cells on Myc. PMID:26192440

  16. Identification of E2F1 as a positive transcriptional regulator for {delta}-catenin

    SciTech Connect

    Kim, Kwonseop; Oh, Minsoo; Ki, Hyunkyoung; Wang Tao; Bareiss, Sonja; Fini, M. Elizabeth.; Li Dawei; Lu Qun

    2008-05-02

    {delta}-Catenin is upregulated in human carcinomas. However, little is known about the potential transcriptional factors that regulate {delta}-catenin expression in cancer. Using a human {delta}-catenin reporter system, we have screened several nuclear signaling modulators to test whether they can affect {delta}-catenin transcription. Among {beta}-catenin/LEF-1, Notch1, and E2F1, E2F1 dramatically increased {delta}-catenin-luciferase activities while {beta}-catenin/LEF-1 induced only a marginal increase. Rb suppressed the upregulation of {delta}-catenin-luciferase activities induced by E2F1 but did not interact with {delta}-catenin. RT-PCR and Western blot analyses in 4 different prostate cancer cell lines revealed that regulation of {delta}-catenin expression is controlled mainly at the transcriptional level. Interestingly, the effects of E2F1 on {delta}-catenin expression were observed only in human cancer cells expressing abundant endogenous {delta}-catenin. These studies identify E2F1 as a positive transcriptional regulator for {delta}-catenin, but further suggest the presence of strong negative regulator(s) for {delta}-catenin in prostate cancer cells with minimal endogenous {delta}-catenin expression.

  17. Allosteric regulation of E2:E3 interactions promote a processive ubiquitination machine

    PubMed Central

    Das, Ranabir; Liang, Yu-He; Mariano, Jennifer; Li, Jess; Huang, Tao; King, Aaren; Tarasov, Sergey G; Weissman, Allan M; Ji, Xinhua; Byrd, R Andrew

    2013-01-01

    RING finger proteins constitute the large majority of ubiquitin ligases (E3s) and function by interacting with ubiquitin-conjugating enzymes (E2s) charged with ubiquitin. How low-affinity RING–E2 interactions result in highly processive substrate ubiquitination is largely unknown. The RING E3, gp78, represents an excellent model to study this process. gp78 includes a high-affinity secondary binding region for its cognate E2, Ube2g2, the G2BR. The G2BR allosterically enhances RING:Ube2g2 binding and ubiquitination. Structural analysis of the RING:Ube2g2:G2BR complex reveals that a G2BR-induced conformational effect at the RING:Ube2g2 interface is necessary for enhanced binding of RING to Ube2g2 or Ube2g2 conjugated to Ub. This conformational effect and a key ternary interaction with conjugated ubiquitin are required for ubiquitin transfer. Moreover, RING:Ube2g2 binding induces a second allosteric effect, disrupting Ube2g2:G2BR contacts, decreasing affinity and facilitating E2 exchange. Thus, gp78 is a ubiquitination machine where multiple E2-binding sites coordinately facilitate processive ubiquitination. PMID:23942235

  18. Identification of E2F1 as a positive transcriptional regulator for ?-catenin

    PubMed Central

    Kim, Kwonseop; Oh, Minsoo; Ki, Hyunkyoung; Wang, Tao; Bareiss, Sonja; Fini, M. Elizabeth; Li, Dawei; Lu, Qun

    2008-01-01

    ?-Catenin is upregulated in human carcinomas. However, little is known about the potential transcriptional factors that regulate ?-catenin expression in cancer. Using a human ?-catenin reporter system, we have screened several nuclear signaling modulators to test whether they can affect ?-catenin transcription. Among ?-catenin/LEF-1, Notch1, and E2F1, E2F1 dramatically increased ?-catenin-luciferase activities while ?-catenin/LEF-1 induced only a marginal increase. Rb suppressed the upregulation of ?-catenin-luciferase activities induced by E2F1 but did not interact with ?-catenin. RT-PCR and Western blot analyses in 4 different prostate cancer cell lines revealed that regulation of ?-catenin expression is controlled mainly at the transcriptional level. Interestingly, the effects of E2F1 on ?-catenin expression were observed only in human cancer cells expressing abundant endogenous ?-catenin. These studies identify E2F1 as a positive transcriptional regulator for ?-catenin, but further suggest the presence of strong negative regulator(s) for ?-catenin in prostate cancer cells with minimal endogenous ?-catenin expression. PMID:18302937

  19. Transcriptome regulation and chromatin occupancy by E2F3 and MYC in mice

    PubMed Central

    Tang, Xing; Liu, Huayang; Srivastava, Arunima; Pécot, Thierry; Chen, Zhong; Wang, Qianben; Huang, Kun; Sáenz-Robles, Maria Teresa; Cantalupo, Paul; Pipas, James; Leone, Gustavo

    2016-01-01

    E2F3 and MYC are transcription factors that control cellular proliferation. To study their mechanism of action in the context of a regenerating tissue, we isolated both proliferating (crypts) and non-dividing (villi) cells from wild-type and Rb depleted small intestines of mice and performed ChIP-exo-seq (chromatin immunoprecipitation combined with lambda exonuclease digestion followed by high-throughput sequencing). The genome-wide chromatin occupancy of E2F3 and MYC was determined by mapping sequence reads to the genome and predicting preferred binding sites (peaks). Binding sites could be accurately identified within small regions of only 24 bp-28 bp long, highlighting the precision to which binding peaks can be identified by ChIP-exo-seq. Forty randomly selected E2F3- and MYC-specific binding sites were validated by ChIP-PCR. In addition, we also presented gene expression data sets from wild type, Rb-, E2f3- and Myc-depleted crypts and villi within this manuscript. These represent comprehensive and validated datasets that can be integrated to identify putative direct targets of E2F3 and MYC involved in the control of cellular proliferation in normal and Rb-deficient small intestines. PMID:26881867

  20. Synergistic cooperation of MDM2 and E2F1 contributes to TAp73 transcriptional activity

    SciTech Connect

    Kasim, Vivi; Huang, Can; Zhang, Jing; Jia, Huizhen; Wang, Yunxia; Yang, Li; Miyagishi, Makoto; Wu, Shourong

    2014-07-04

    Highlights: • MDM2 is a novel positive regulator of TAp73 transcriptional activity. • MDM2 colocalizes together and physically interacts with E2F1. • Synergistic cooperation of MDM2 and E2F1 is crucial for TAp73 transcription. • MDM2 regulates TAp73 transcriptional activity in a p53-independent manner. - Abstract: TAp73, a structural homologue of p53, plays an important role in tumorigenesis. E2F1 had been reported as a transcriptional regulator of TAp73, however, the detailed mechanism remains to be elucidated. Here we reported that MDM2-silencing reduced the activities of the TAp73 promoters and the endogenous TAp73 expression level significantly; while MDM2 overexpression upregulated them. We further revealed that the regulation of TAp73 transcriptional activity occurs as a synergistic effect of MDM2 and E2F1, most probably through their physical interaction in the nuclei. Furthermore, we also suggested that MDM2 might be involved in DNA damage-induced TAp73 transcriptional activity. Finally, we elucidated that MDM2-silencing reduced the proliferation rate of colon carcinoma cells regardless of the p53 status. Our data show a synergistic effect of MDM2 and E2F1 on TAp73 transcriptional activity, suggesting a novel regulation pathway of TAp73.

  1. E2~Ub Conjugates Regulate the Kinase Activity of Shigella Effector OspG During Pathogenesis

    SciTech Connect

    Pruneda, Jonathan N.; Smith, F Donelson; Daurie, Angela; Swaney, Danielle L.; Villen, Judit; Scott, John D.; Stadnyk, Andrew W.; Le Trong, Isolde; Stenkamp, Ronald E.; Klevit, Rachel E.; Rohde, John R.; Brzovic, Peter S.

    2014-03-03

    Pathogenic bacteria introduce effector proteins directly into the cytosol of eukaryotic cells to promote invasion and colonization. OspG, a Shigella spp. effector kinase, plays a role in this process by helping to suppress the host inflammatory response. OspG has been reported to bind host E2 ubiquitin-conjugating enzymes activated with ubiquitin (E2~Ub), a key enzyme complex in ubiquitin transfer pathways. A cocrystal structure of the OspG/UbcH5c~Ub complex reveals that complex formation has important ramifications for the activity of both OspG and the UbcH5c~Ub conjugate. OspG is a minimal kinase domain containing only essential elements required for catalysis. UbcH5c~Ub binding stabilizes an active conformation of the kinase, greatly enhancing OspG kinase activity. In contrast, interaction with OspG stabilizes an extended, less reactive form of UbcH5c~Ub. Recognizing conserved E2 features, OspG can interact with at least ten distinct human E2s~Ub. Mouse oral infection studies indicate that E2~Ub conjugates act as novel regulators of OspG effector kinase function in eukaryotic host cells.

  2. Aberrant Retinoblastoma (RB)-E2F Transcriptional Regulation Defines Molecular Phenotypes of Osteosarcoma.

    PubMed

    Scott, Milcah C; Sarver, Aaron L; Tomiyasu, Hirotaka; Cornax, Ingrid; Van Etten, Jamie; Varshney, Jyotika; O'Sullivan, M Gerard; Subramanian, Subbaya; Modiano, Jaime F

    2015-11-20

    We previously identified two distinct molecular subtypes of osteosarcoma through gene expression profiling. These subtypes are associated with distinct tumor behavior and clinical outcomes. Here, we describe mechanisms that give rise to these molecular subtypes. Using bioinformatic analyses, we identified a significant association between deregulation of the retinoblastoma (RB)-E2F pathway and the molecular subtype with worse clinical outcomes. Xenotransplantation models recapitulated the corresponding behavior for each osteosarcoma subtype; thus, we used cell lines to validate the role of the RB-E2F pathway in regulating the prognostic gene signature. Ectopic RB resets the patterns of E2F regulated gene expression in cells derived from tumors with worse clinical outcomes (molecular phenotype 2) to those comparable with those observed in cells derived from tumors with less aggressive outcomes (molecular phenotype 1), providing a functional association between RB-E2F dysfunction and altered gene expression in osteosarcoma. DNA methyltransferase and histone deacetylase inhibitors similarly reset the transcriptional state of the molecular phenotype 2 cells from a state associated with RB deficiency to one seen with RB sufficiency. Our data indicate that deregulation of RB-E2F pathway alters the epigenetic landscape and biological behavior of osteosarcoma. PMID:26378234

  3. Physiological consequences of membrane-initiated estrogen signaling in the brain

    PubMed Central

    Roepke, Troy A.; Ronnekleiv, Oline K.; Kelly, Martin J.

    2011-01-01

    Many of the actions of 17beta-estradiol (E2) in the central nervous system (CNS) are mediated via the classical nuclear steroid receptors, ERalpha and ERbeta, which interact with the estrogen response element to modulate gene expression. In addition to the nuclear-initiated estrogen signaling, E2 signaling in the brain can occur rapidly within minutes prior to any sufficient effects on transcription of relevant genes. These rapid, membrane-initiated E2 signaling mechanisms have now been characterized in many brain regions, most importantly in neurons of the hypothalamus and hippocampus. Furthermore, our understanding of the physiological effects of membrane-initiated pathways is now a major field of interest in the hypothalamic control of reproduction, energy balance, thermoregulation and other homeostatic functions as well as the effects of E2 on physiological and pathophysiological functions of the hippocampus. Membrane signaling pathways impact neuronal excitability, signal transduction, cell death, neurotransmitter release and gene expression. This review will summarize recent findings on membrane-initiated E2 signaling in the hypothalamus and hippocampus and its contribution to the control of physiological and behavioral functions. PMID:21196248

  4. Functional Interactions between 17?-Estradiol and Progesterone Regulate Autophagy during Acini Formation by Bovine Mammary Epithelial Cells in 3D Cultures

    PubMed Central

    Zielniok, Katarzyna; Motyl, Tomasz

    2014-01-01

    Mammary gland epithelium forms a network of ducts and alveolar units under control of ovarian hormones: 17-beta-estradiol (E2) and progesterone (P4). Mammary epithelial cells (MECs) cultured on reconstituted basement membrane (rBM) form three-dimensional (3D) acini composed of polarized monolayers surrounding a lumen. Using the 3D culture of BME-UV1 bovine MECs we previously demonstrated that autophagy was induced in the centrally located cells of developing spheroids, and sex steroids increased this process. In the present study we showed that E2 and P4 enhanced the expression of ATG3, ATG5, and BECN1 genes during acini formation, and this effect was accelerated in the presence of both hormones together. The stimulatory action of E2 and P4 was also reflected by increased levels of Atg5, Atg3, and LC3-II proteins. Additionally, the activity of kinases involved in autophagy regulation, Akt, ERK, AMPK, and mTOR, was examined. E2 + P4 slightly increased the level of phosphorylated AMPK but diminished phosphorylated Akt and mTOR on day 9 of 3D culture. Thus, the synergistic actions of E2 and P4 accelerate the development of bovine mammary acini, which may be connected with stimulation of ATGs expression, as well as regulation of signaling pathways (PI3K/Akt/mTOR; AMPK/mTOR) involved in autophagy induction. PMID:24895572

  5. Failure of estradiol to improve spontaneous or rehabilitation-facilitated recovery after hemorrhagic stroke in rats.

    PubMed

    Nguyen, Angela P; Arvanitidis, Anastasia P; Colbourne, Frederick

    2008-02-01

    Estrogen influences not only the incidence of stroke, but also the amount of injury sustained from a stroke including intracerebral hemorrhage (ICH). In this study we tested whether delayed 17beta-estradiol (E2) treatment affects recovery following striatal ICH. Female rats were trained and tested on several behavioral tests to assess skilled reaching, spontaneous forelimb usage and walking ability. Two weeks following ovariectomy, rats were subjected to a moderate-sized ICH via infusion of collagenase into the striatum. One week later they were implanted with either an E2 pellet (0.36 mg; 60-day release) or they underwent a sham procedure. They were further divided into groups that received either environmental enrichment (EE) rehabilitation therapy (group housing in a complex cage with ramps, tunnels, etc.) or a control condition (group housing in a standard cage). Rats were then behaviorally evaluated out to 8 weeks post-ICH and then euthanized. Neither EE nor E2 affected lesion size, which averaged 62.8 mm(3) across all groups. The EE therapy improved recovery on some tests (e.g., traversing a horizontal ladder) whereas E2 treatment did not notably affect either spontaneous or EE-facilitated recovery. Thus, E2 fails to improve recovery or protect against brain injury when given after a 1-week delay in contrast to its clear neuroprotective effects when given before or soon after ICH. PMID:18178174

  6. Decreased brain infarct following focal ischemia in mice lacking the transcription factor E2F1.

    PubMed

    MacManus, J P; Koch, C J; Jian, M; Walker, T; Zurakowski, B

    1999-09-01

    E2F1+/- mice subjected to 2 h middle cerebral artery occlusion developed an infarct of 77.0 +/- 3.2 mm3 (mean +/- s.e.m., n = 15) in the ischemic hemisphere after 24 h reperfusion. A significantly smaller infarct of 58.8 +/- 4.8 mm3 (n = 15; p < 0.01) was found in E2F1-/- animals. Both deficient and normal mice had similar cerebral angioarchitecture and intra-ischemic decreases in regional blood flow. Similar areas of hypoxia in both groups of ischemic animals were demonstrated directly by immunohistochemical detection of nitroimidazole adducts. It was concluded that all animals received the same ischemic insult, yet the subsequent damage was different in the mutant mice. This is the first indication that the E2F1 gene plays a role in ischemic death of post-mitotic neurons. PMID:10511428

  7. Purification, crystallization and initial crystallographic characterization of brazil-nut allergen Ber e 2

    SciTech Connect

    Guo, Feng; Jin, Tengchuan; Howard, Andrew; Zhang, Yu-Zhu

    2007-11-01

    The crystallization of the brazil nut allergen Ber e 2 is reported. Peanut and tree-nut allergies have attracted considerable attention because of their frequency and their lifelong persistence. Brazil-nut (Bertholletia excelsa) allergies have been well documented and the 11S legumin-like seed storage protein Ber e 2 (excelsin) is one of the two known brazil-nut allergens. In this study, Ber e 2 was extracted from brazil-nut kernels and purified to high purity by crystalline precipitation and gel-filtration chromatography. Well diffracting single crystals were obtained using the hanging-drop vapour-diffusion method. A molecular-replacement structural solution has been obtained. Refinement of the structure is currently under way.

  8. Release of deuterated (E)-2-nonenal during beer aging from labeled precursors synthesized before boiling.

    PubMed

    Ligeois, Catherine; Meurens, Nicolas; Badot, Camille; Collin, Sonia

    2002-12-18

    Although lipid autoxidation in the boiling kettle is a key determinant of the cardboard flavor of aged beers, recent results show that mashing is another significant source of wort nonenal potential, the well-known indicator of how a beer will release (E)-2-nonenal during storage. Although unstable, deuterated (E)-2-nonenal nitrogen adducts created during mashing can in some cases partially persist in the pitching wort, to release deuterated (E)-2-nonenal during beer aging. In the experiment described here, the relative contributions of mashing and boiling were estimated at 30 and 70%, respectively. The presence of oxygen during mashing and, to a lesser extent, high lipoxygenase activity can intensify the stale cardboard flavor. PMID:12475282

  9. Production and Actions of the Anandamide Metabolite Prostamide E2 in the Renal Medulla

    PubMed Central

    Li, Cao; Xia, Min; Poklis, Justin L.; Lichtman, Aron H.; Abdullah, Rehab A.; Dewey, William L.; Li, Pin-Lan

    2012-01-01

    Medullipin has been proposed to be an antihypertensive lipid hormone released from the renal medulla in response to increased arterial pressure and renal medullary blood flow. Because anandamide (AEA) possesses characteristics of this purported hormone, the present study tested the hypothesis that AEA or one of its metabolites represents medullipin. AEA was demonstrated to be enriched in the kidney medulla compared with cortex. Western blotting and enzymatic analyses of renal cortical and medullary microsomes revealed opposite patterns of enrichment of two AEA-metabolizing enzymes, with fatty acid amide hydrolase higher in the renal cortex and cyclooxygenase-2 (COX-2) higher in the renal medulla. In COX-2 reactions with renal medullary microsomes, prostamide E2, the ethanolamide of prostaglandin E2, was the major product detected. Intramedullarily infused AEA dose-dependently increased urine volume and sodium and potassium excretion (1560 nmol/kg/min) but had little effect on mean arterial pressure (MAP). The renal excretory effects of AEA were blocked by intravenous infusion of celecoxib (0.1 ?g/kg/min), a selective COX-2 inhibitor, suggesting the involvement of a prostamide intermediate. Plasma kinetic analysis revealed longer elimination half-lives for AEA and prostamide E2 compared with prostaglandin E2. Intravenous prostamide E2 reduced MAP and increased renal blood flow (RBF), actions opposite to those of angiotensin II. Coinfusion of prostamide E2 inhibited angiotensin II effects on MAP and RBF. These results suggest that AEA and/or its prostamide metabolites in the renal medulla may represent medullipin and function as a regulator of body fluid and MAP. PMID:22685343

  10. RNF126 promotes homologous recombination via regulation of E2F1-mediated BRCA1 expression.

    PubMed

    Wang, Y; Deng, O; Feng, Z; Du, Z; Xiong, X; Lai, J; Yang, X; Xu, M; Wang, H; Taylor, D; Yan, C; Chen, C; Difeo, A; Ma, Z; Zhang, J

    2016-03-17

    RNF126 is an E3 ubiquitin ligase. The deletion of RNF126 gene was observed in a wide range of human cancers and is correlated with improved disease-free and overall survival. These data highlight the clinical relevance of RNF126 in tumorigenesis and cancer therapy. However, the specific functions of RNF126 remain largely unknown. Homologous recombination (HR)-mediated DNA double-strand break repair is important for tumor suppression and cancer therapy resistance. Here, we demonstrate that RNF126 facilitates HR by promoting the expression of BRCA1, in a manner independent of its E3 ligase activity but depending on E2F1, a well-known transcription factor of BRCA1 promoter. In support of this result, RNF126 promotes transactivation of BRCA1 promoter by directly binding to E2F1. Most importantly, an RNF126 mutant lacking 11 amino acids that is responsible for the interaction with E2F1 has a dominant-negative effect on BRCA1 expression and HR by suppressing E2F1-mediated transactivation of BRCA1 promoter and blocking the enrichment of E2F1 on BRCA1 promoter. Lastly, RNF126 depletion leads to the increased sensitivity to ionizing radiation and poly (ADP-ribose) polymerase inhibition. Collectively, our results suggest a novel role of RNF126 in promoting HR-mediated repair through positive regulation on BRCA1 expression by direct interaction with E2F1. This study not only offers novel insights into our current understanding of the biological functions of RNF126 but also provides a potential therapeutic target for cancer treatment. PMID:26234677

  11. Comparative genomics reveals multistep pathogenesis of E2A-PBX1 acute lymphoblastic leukemia

    PubMed Central

    Duque-Afonso, Jesús; Feng, Jue; Scherer, Florian; Lin, Chiou-Hong; Wong, Stephen H.K.; Wang, Zhong; Iwasaki, Masayuki; Cleary, Michael L.

    2015-01-01

    Acute lymphoblastic leukemia (ALL) is the most common childhood cancer; however, its genetic diversity limits investigation into the molecular pathogenesis of disease and development of therapeutic strategies. Here, we engineered mice that conditionally express the E2A-PBX1 fusion oncogene, which results from chromosomal translocation t(1;19) and is present in 5% to 7% of pediatric ALL cases. The incidence of leukemia in these mice varied from 5% to 50%, dependent on the Cre-driving promoter (Cd19, Mb1, or Mx1) used to induce E2A-PBX1 expression. Two distinct but highly similar subtypes of B cell precursor ALLs that differed by their pre–B cell receptor (pre-BCR) status were induced and displayed maturation arrest at the pro-B/large pre–B II stages of differentiation, similar to human E2A-PBX1 ALL. Somatic activation of E2A-PBX1 in B cell progenitors enhanced self-renewal and led to acquisition of multiple secondary genomic aberrations, including prominent spontaneous loss of Pax5. In preleukemic mice, conditional Pax5 deletion cooperated with E2A-PBX1 to expand progenitor B cell subpopulations, increasing penetrance and shortening leukemia latency. Recurrent secondary activating mutations were detected in key signaling pathways, most notably JAK/STAT, that leukemia cells require for proliferation. These data support conditional E2A-PBX1 mice as a model of human ALL and suggest targeting pre-BCR signaling and JAK kinases as potential therapeutic strategies. PMID:26301816

  12. Small molecule regulators of Rb-E2F pathway as modulators of transcription

    PubMed Central

    Singh, Sandeep; Johnson, Jackie; Chellappan, Srikumar

    2010-01-01

    The retinoblastoma tumor suppressor protein, Rb, plays a major role in the regulation of mammalian cell cycle progression. It has been shown that Rb function is essential for the proper modulation of G1/S transition and inactivation of Rb contributes to deregulated cell proliferation. Rb exerts its cell cycle regulatory functions mainly by targeting the E2F family of transcription factors and Rb has been shown to physically interact with E2Fs1, 2 and 3, repressing their transcriptional activity. Multiple genes involved in DNA synthesis and cell cycle progression are regulated by E2Fs, and Rb prevents their expression by inhibiting E2F activity, inducing growth arrest. It has been established that inactivation of Rb by phosphorylation, mutation, or by the interaction of viral oncoproteins lead to a release of the repression of E2F activity, facilitating cell cycle progression. Rb-mediated repression of E2F activity involves the recruitment of a variety of transcriptional co-repressors and chromatin remodeling proteins, including histone deacetylases, DNA methyl transferases and Brg1/Brm chromatin remodeling proteins. Inactivation of Rb by sequential phosphorylation events during cell cycle progression leads to a dissociation of these co-repressors from Rb, facilitating transcription. It has been found that small molecules that prevent the phosphorylation of Rb prevents the dissociation of certain co-repressors from Rb, especially Brg1, leading to the maintenance of Rb mediated transcriptional repression and cell cycle arrest. Such small molecules have anti-cancer activities and will also act as valuable probes to study chromatin remodeling and transcriptional regulation. PMID:20637913

  13. Membrane-initiated actions of estradiol (E2) in the regulation of LH secretion in ovariectomized (OVX) ewes

    PubMed Central

    2010-01-01

    Background We demonstrated that E2 conjugated to BSA (E2BSA) induces a rapid membrane-initiated inhibition of LH secretion followed hours later by a slight increase in LH secretion. Whether these actions of E2BSA are restricted to the pituitary gland and whether the membrane-initiated pathway of E2BSA contributes to the up-regulation of the number of GnRH receptors during the positive feedback effect of E2 were evaluated here. We have shown that the suppression of LH secretion induced by E2 and E2BSA is the result of a decreased responsiveness of the pituitary gland to GnRH. In this study we further tested the ability of E2BSA to decrease the responsiveness of the pituitary gland to GnRH under the paradigm of the preovulatory surge of LH induced by E2. Methods For the first experiment GnRH and LH secretions were determined in samples of pituitary portal and jugular blood, respectively, in ewes treated with 12 mg E2BSA. In the second experiment, the number of GnRH receptors was quantified in ewes 12 h after administration of 25 micrograms E2 (the expected time for the increase in the number of GnRH receptors and the positive feedback effect of E2 in LH secretion) or 12 mg E2BSA. In the third experiment, the preovulatory-like surge of LH was characterized in ewes injected with 25 micrograms E2 alone or followed 8 h later (before the beginning of the LH surge) with 60 mg E2BSA. Results a) the decrease in LH secretion induced by E2BSA was not accompanied by changes in the pulsatile pattern of GnRH, b) E2BSA increased the number of GnRH receptors, and c) the presence of E2BSA in E2-treated ewes delayed the onset, reduced the length, and decreased the amount of LH released during the preovulatory surge of LH. Conclusions a) the rapid suppression of LH secretion induced by E2BSA is mediated only via a direct action on the pituitary gland, b) E2 acting via a membrane-initiated pathway contributes to increase the number of GnRH receptors and, c) administration of E2BSA near the beginning of the pre-ovulatory surge of LH delays and reduces the magnitude of the surge. PMID:20459750

  14. Global identification of genes regulated by estrogen signaling and demethylation in MCF-7 breast cancer cells

    SciTech Connect

    Putnik, Milica; Zhao, Chunyan; Gustafsson, Jan-Ake; Department of Biology and Biochemistry, Science and Engineering Research Center Bldg, University of Houston, Houston, TX 77204-5056 ; Dahlman-Wright, Karin

    2012-09-14

    Highlights: Black-Right-Pointing-Pointer Estrogen signaling and demethylation can both control gene expression in breast cancers. Black-Right-Pointing-Pointer Cross-talk between these mechanisms is investigated in human MCF-7 breast cancer cells. Black-Right-Pointing-Pointer 137 genes are influenced by both 17{beta}-estradiol and demethylating agent 5-aza-2 Prime -deoxycytidine. Black-Right-Pointing-Pointer A set of genes is identified as targets of both estrogen signaling and demethylation. Black-Right-Pointing-Pointer There is no direct molecular interplay of mediators of estrogen and epigenetic signaling. -- Abstract: Estrogen signaling and epigenetic modifications, in particular DNA methylation, are involved in regulation of gene expression in breast cancers. Here we investigated a potential regulatory cross-talk between these two pathways by identifying their common target genes and exploring underlying molecular mechanisms in human MCF-7 breast cancer cells. Gene expression profiling revealed that the expression of approximately 140 genes was influenced by both 17{beta}-estradiol (E2) and a demethylating agent 5-aza-2 Prime -deoxycytidine (DAC). Gene ontology (GO) analysis suggests that these genes are involved in intracellular signaling cascades, regulation of cell proliferation and apoptosis. Based on previously reported association with breast cancer, estrogen signaling and/or DNA methylation, CpG island prediction and GO analysis, we selected six genes (BTG3, FHL2, PMAIP1, BTG2, CDKN1A and TGFB2) for further analysis. Tamoxifen reverses the effect of E2 on the expression of all selected genes, suggesting that they are direct targets of estrogen receptor. Furthermore, DAC treatment reactivates the expression of all selected genes in a dose-dependent manner. Promoter CpG island methylation status analysis revealed that only the promoters of BTG3 and FHL2 genes are methylated, with DAC inducing demethylation, suggesting DNA methylation directs repression of these genes in MCF-7 cells. In a further analysis of the potential interplay between estrogen signaling and DNA methylation, E2 treatment showed no effect on the methylation status of these promoters. Additionally, we show that the ER{alpha} recruitment occurs at the FHL2 promoter in an E2- and DAC-independent fashion. In conclusion, we identified a set of genes regulated by both estrogen signaling and DNA methylation. However, our data does not support a direct molecular interplay of mediators of estrogen and epigenetic signaling at promoters of regulated genes.

  15. Discovery and Classification of the z=1.86 SLSNe: DES15E2mlf

    NASA Astrophysics Data System (ADS)

    Pan, Y.-C.; Foley, R. J.; Galbany, L.; Gonzalez-Gaitan, S.; Forster, F.; Hamuy, M.; Prieto, J. L.; Yuan, F.; Tucker, B. E.; Lidman, C.; Martini, P.; Gshwend, Julia; Moller, A.; Zhang, B.; Desai, S.; Paech, K.; Smith, R. C.; Schubnell, M.; Kessler, R.; Lasker, J.; Scolnic, D.; Brout, D. J.; Gladney, L.; Sako, M.; Wolf, R. C.; Brown, P. J.; Krisciunas, K.; Suntzeff, N.; Nichol, R.; Papadopoulos, A.; Childress, M.; D'Andrea, C.; Prajs, S.; Smith, M.; Sullivan, M.; Maartens, R.; Gupta, R.; Kovacs, E.; Kuhlmann, S.; Spinka, H.; Ahn, E.; Finley, D. A.; Frieman, J.; Marriner, J.; Wester, W.; Aldering, G.; Kim, A. G.; Thomas, R. C.; Barbary, K.; Bloom, J. S.; Goldstein, D.; Nugent, P.; Perlmutter, S.; Casas, R.; Castander, F. J.

    2015-12-01

    We report the spectroscopic classification of DES15E2mlf as a superluminous supernova (SLSN) discovered by the Dark Energy Survey (ATEL #4668). DES15E2mlf was discovered on 7 November 2015 at R.A. = 00:41:33.40, Decl = -43:27:17.2 with r = 24.1 mag. We obtained spectra using GMOS on Gemini-South (520-990nm) on 06 December 2015 which indicated a redshift of z = 1.86 from Mg II 2800 absorption.

  16. Update on e+e- -->?+?- ? (2 S) via Initial State Radiation at Belle

    NASA Astrophysics Data System (ADS)

    Wang, Xiaolong

    2014-03-01

    Using the 980fb-1 full data sample taken with the Belle detector, the cross section of e+e- -->?+?- ? (2 S) between 4.0 and 5.5 GeV is measured via initial state radiation. The properties of the Y (4360) and Y (4660) are updated. Fitting the mass spectrum of e+e- -->?+?- ? (2 S) with two coherent Breit-Wigner functions yields two equivalent solutions with either constructive or destructive interference. We also search for a possible charged charmoniumlike structure in the ?+/- ? (2 S) intermediate state.

  17. Second-order Born effect in coplanar doubly symmetric (e,2e) collisions for sodium

    NASA Astrophysics Data System (ADS)

    Wang, Yang; Jiao, Liguang; Zhou, Yajun

    2012-06-01

    The second-order distorted wave Born approximation (DWBA) method is employed to investigate the triple differential cross sections (TDCS) of coplanar doubly symmetric (e,2e) collisions for alkali target sodium at excess energies of 6-60 eV. Comparing with the first-order DWBA calculations, the inclusion of second-order Born term in the scattering amplitude improves the degree of agreement with experiments, especially for backward scattering region of TDCS. This indicates the present second-order Born term is capable to give a reasonable correction to DWBA model in studying coplanar symmetric (e,2e) problems in low and intermediate energy range.

  18. Theory of Deep Minima in (e,2e) Measurements of Triply Differential Cross Sections

    NASA Astrophysics Data System (ADS)

    Macek, J. H.; Sternberg, J. B.; Ovchinnikov, S. Y.; Briggs, J. S.

    2010-01-01

    Deep minima in He(e,2e)He+ triply differential cross sections are traced to vortices in atomic wave functions. Such vortices have been predicted earlier, but the present calculations show that they have also been observed experimentally, although not recognized as vortices. Their observation in (e,2e) measurements shows that vortices play an important role in electron correlations related to the transfer of angular momentum between incident and ejected electrons. The vortices significantly extend the list of known features that summarize the general picture of electron correlations in impact ionization.

  19. Loss of E2F1 Extends Survival and Accelerates Oral Tumor Growth in HPV-Positive Mice.

    PubMed

    Zhong, Rong; Bechill, John; Spiotto, Michael T

    2015-01-01

    The Human Papillomavirus (HPV) is associated with several human cancers, including head and neck squamous cell carcinomas (HNSCCs). HPV expresses the viral oncogene E7 that binds to the retinoblastoma protein (RB1) in order to activate the E2F pathway. RB1 can mediate contradictory pathways-cell growth and cell death via E2F family members. Here, we assessed the extent to which E2F1 mediates lethality of HPV oncogenes. Ubiquitous expression of the HPV oncogenes E6 and E7 caused lethality in mice that was associated with focal necrosis in hepatocytes and pancreatic tissues. Furthermore, all organs expressing HPV oncogenes displayed up-regulation of several E2F1 target genes. The E2F1 pathway mediated lethality in HPV-positive mice because deletion of E2F1 increased survival of mice ubiquitously expressing HPV oncogenes. E2F1 similarly functioned as a tumor suppressor in HPV-positive oral tumors as tumors grew faster with homozygous loss of E2F1 compared to tumors with heterozygous loss of E2F1. Re-expression of E2F1 caused decreased clonogenicity in HPV-positive cancer cells. Our results indicate that HPV oncogenes activated the E2F1 pathway to cause lethality in normal mice and to suppress oral tumor growth. These results suggest that selective modulation of the E2F1 pathway, which is activated in HPV tumors, may facilitate tumor regression. PMID:26670255

  20. Loss of E2F1 Extends Survival and Accelerates Oral Tumor Growth in HPV-Positive Mice

    PubMed Central

    Zhong, Rong; Bechill, John; Spiotto, Michael T.

    2015-01-01

    The Human Papillomavirus (HPV) is associated with several human cancers, including head and neck squamous cell carcinomas (HNSCCs). HPV expresses the viral oncogene E7 that binds to the retinoblastoma protein (RB1) in order to activate the E2F pathway. RB1 can mediate contradictory pathwayscell growth and cell death via E2F family members. Here, we assessed the extent to which E2F1 mediates lethality of HPV oncogenes. Ubiquitous expression of the HPV oncogenes E6 and E7 caused lethality in mice that was associated with focal necrosis in hepatocytes and pancreatic tissues. Furthermore, all organs expressing HPV oncogenes displayed up-regulation of several E2F1 target genes. The E2F1 pathway mediated lethality in HPV-positive mice because deletion of E2F1 increased survival of mice ubiquitously expressing HPV oncogenes. E2F1 similarly functioned as a tumor suppressor in HPV-positive oral tumors as tumors grew faster with homozygous loss of E2F1 compared to tumors with heterozygous loss of E2F1. Re-expression of E2F1 caused decreased clonogenicity in HPV-positive cancer cells. Our results indicate that HPV oncogenes activated the E2F1 pathway to cause lethality in normal mice and to suppress oral tumor growth. These results suggest that selective modulation of the E2F1 pathway, which is activated in HPV tumors, may facilitate tumor regression. PMID:26670255

  1. 40 CFR Table E-2 to Subpart E of... - Spectral Energy Distribution and Permitted Tolerance for Conducting Radiative Tests

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Permitted Tolerance for Conducting Radiative Tests E Table E-2 to Subpart E of Part 53 Protection of... Reference Methods and Class I and Class II Equivalent Methods for PM2.5 or PM10â2.5 Pt. 53, Subpt. E, Table E-2 Table E-2 to Subpart E of Part 53—Spectral Energy Distribution and Permitted Tolerance...

  2. 40 CFR Table E-2 to Subpart E of... - Spectral Energy Distribution and Permitted Tolerance for Conducting Radiative Tests

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Permitted Tolerance for Conducting Radiative Tests E Table E-2 to Subpart E of Part 53 Protection of... Reference Methods and Class I and Class II Equivalent Methods for PM2.5 or PM10â2.5 Pt. 53, Subpt. E, Table E-2 Table E-2 to Subpart E of Part 53—Spectral Energy Distribution and Permitted Tolerance...

  3. An E2F1-Dependent Gene Expression Program That Determines the Balance Between Proliferation and Cell Death

    PubMed Central

    Hallstrom, Timothy C.; Mori, Seiichi; Nevins, Joseph R.

    2008-01-01

    Summary The Rb/E2F pathway regulates the expression of genes essential for cell proliferation but that also trigger apoptosis. During normal proliferation, PI3K/Akt signaling blocks E2F1 induced apoptosis, thus serving to balance proliferation and death. We now identify a subset of E2F1 target genes that are specifically repressed by PI3K/Akt signaling, thus distinguishing the E2F1 proliferative or apoptotic function. RNAi-mediated inhibition of several of these PI3K-repressed E2F1 target genes, including AMPK?2, impairs apoptotic induction by E2F1. Activation of AMPK?2 with an AMP analog further stimulates E2F1 induced apoptosis. We also show that the presence of the E2F1 apoptotic expression program in breast and ovarian tumors coincides with good prognosis, emphasizing the importance of the balance in the E2F1 proliferation/apoptotic program. Significance E2F1 has been shown to induce both proliferation and apoptosis. We now show that PI3K/Akt signaling regulates the balance of these events by specifically blocking expression of genes in the E2F1 apoptotic program but not the proliferative program. We further show that an alteration in the balance of the E2F1 program coincides with poor prognosis in both breast and ovarian cancer emphasizing the importance of these events for a clinical cancer phenotype. PMID:18167336

  4. TGF{beta}-mediated formation of pRb-E2F complexes in human myeloid leukemia cells

    SciTech Connect

    Hu Xiaotang

    2008-05-02

    TGF{beta} is well known for its inhibitory effect on cell cycle G1 checkpoint kinases. However, its role in the control of pRb-E2F complexes is not well established. TGF{beta} inhibits phosphorylation of pRb at several serine and threonine residues and regulates the association of E2F transcription factors with pRb family proteins. Recent studies found that predominantly E2F-4, p130, and histone deacetylase (HDAC) are found to bind to corresponding E2F-responsive promoters in G0/G1 phase. As cells progress through mid-G1, p130-E2F4 complex are replaced by p107-E2F4 followed by activators E2F1, 2, and 3. pRb was not detectable in the promoters containing the E2F-responsive site in cycling cells but was associated with E2F4-p130 complexes or E2F4-p107 complexes during G0/G1 phase. In human myeloid leukemia cell line, MV4-11, TGF{beta} upregulated pRb-E2F-4 and p130-E2F-4, and downregulated p107-E2F-4 complexes. However, pRB-E2F1 and pRb-E2F3 complexes were found in proliferating cells but not in TGF{beta} arrested G1 cells. In addition, electrophoretic gel mobility shift assay (EMSA) could not detect pRb-E2F DNA-binding activities either in S or G1 phase but exhibited the existence of p107-E2F4 in proliferating cells and p130-E2F4 complexes in TGF{beta}-arrested G1 cells, respectively. Our data suggest that p107 and p130, but not pRb, and the repressor E2F, but not activator E2Fs, play a critical role in regulating E2F-responsive gene expression in TGF{beta}-mediated cell cycle control in human myeloid leukemia cells.

  5. Interaction of the Arabidopsis E2F and DP Proteins Confers Their Concomitant Nuclear Translocation and Transactivation

    PubMed Central

    Kosugi, Shunichi; Ohashi, Yuko

    2002-01-01

    E2F transcription factors are required for the progression and arrest of the cell cycle in animals. Like animals, plants have evolved to conserve the E2F family. The Arabidopsis genome encodes E2F and DP proteins that share a high similarity with the animal E2F and DP families. Here, we show that Arabidopsis E2F and DP proteins are not predominantly localized to the nucleus in analyses with green fluorescent protein, and that the complete nuclear localization of some members is driven by the co-expression of their specific partner proteins. Both AtE2F1 and AtE2F3 were translocated to the nucleus and transactivate an E2F reporter gene when co-expressed with DPa but not DPb. In contrast, AtE2F2 was inactive for both nuclear translocation and transactivation even when Dpa or DPb was co-expressed. Because the DNA binding activities of the three E2Fs are equally stimulated by the interaction with DPa or DPb in vitro, the observed transactivation of AtE2F1 and AtE2F3 is DPa specific and nuclear import dependent. A green fluorescent protein fusion with an AtE2F3 mutant, in which a conserved nuclear export signal-like sequence in the dimerization domain was deleted, was localized to the nucleus. Thus, the concomitant nuclear translocation seems to be conferred by the DPa interaction to release an activity that inhibits an intrinsic nuclear import activity of AtE2Fs. Furthermore, the nuclear translocation of AtE2F3 stimulated by DPa was abolished by the deletion of the N-terminal region of AtE2F3, which is conserved among all the E2F proteins identified in plants to date. Replacement of the N-terminal region of AtE2F3 with a canonical nuclear localization signal only partially mimicked the effect of the DPa co-expression, demonstrating the function of plant E2F distinct from that observed for animal E2Fs. These observations suggest that the function of plant E2F and DP proteins is primarily controlled by their nuclear localization mediated by the interaction with specific partner proteins. PMID:11891240

  6. DOE Challenge Home Case Study: e2 Homes – Winter Park, Florida

    SciTech Connect

    none,

    2013-01-01

    This Challenge Home case study describes the first certified DOE Challenge Home as constructed by e2 Homes. Completed in May 2012, the “Wilson Residence” in Winter Park, Florida, is a 4,305-ft2 custom home that scores a HERS 57 without solar and a better than zero net-energy HERS -7 with solar.

  7. Use of Prostaglandin E2 in the Management of Missed Abortion, Missed Labour, and Hydatidiform Mole

    PubMed Central

    Karim, S. M. M.

    1970-01-01

    Treatment of six cases of missed abortion and one case of hydatidiform mole with intravenous infusion of prostaglandin E2 resulted in complete abortion in all cases. Of 15 patients with missed labour, 14 were delivered successfully with similar treatment. The technique appears to be a safe, reliable, and rapid method of managing missed abortion, missed labour, and hydatidiform mole. PMID:5448780

  8. Staining of keratin and keratohyalin with the reactive dye levafix red violet E-2BL.

    PubMed

    Waldrop, F S; Puchtler, H; Akamatsu, Y

    1976-07-01

    Demonstration of keratin in Zenker-fixed skin and in tissues stored in formalin can be difficult because such material is unsuitable for histochemical studies. A reactive dye, Levafix red violet E-2BL, proved useful for demonstration of keratohyalin and some types of keratin. Formalin-, Zenker- and methacarn-fixed sections were pretreated with alkaline alcohol, stained one hour at 60 C in an aqueous solution containing 0.25% Levafix red violet E-2BL plus 0.25% NaCl, rinsed in buffer solution pH 9, dehydrated and mounted. Keratohyalin granules and stratum corneum were colored red violet; hair and tonofibrils remained unstained. In sections prestained with Mayer's acid hemalum, keratohyalin was dark blue. Sulfonated monoazo dyes without reactive groups colored no tissue structures under the conditions of this technic; apparently, Levafix red violet E-2BL is bound via its reactive group. Polarization microscopic studies suggest binding of Levafix red violet E-2BL by an amorphous matrix of keratin. Correlations with chemical data indicate that the staining patterns parallel the distribution of proteins formed in the stratum granulosum. PMID:60802

  9. The nuclear factor ?B inhibitor (E)-2-fluoro-4?-methoxystilbene inhibits firefly luciferase

    PubMed Central

    Braeuning, Albert; Vetter, Silvia

    2012-01-01

    Photinus pyralis (firefly) luciferase is widely used as a reporter system to monitor alterations in gene promoter and/or signalling pathway activities in vitro. The enzyme catalyses the formation of oxyluciferin from D-luciferin in an ATP-consuming reaction involving photon emission. The purpose of the present study was to characterize the luciferase-inhibiting potential of (E)-2-fluoro-4?-methoxystilbene, which is known as a potent inhibitor of the NF-?B (nuclear factor ?B) signalling pathway that is used to modulate the NF-?B signalling pathway in vitro. Results show that (E)-2-fluoro-4?-methoxystilbene effectively inhibits firefly luciferase activity in cell lysates and living cells in a non-competitive manner with respect to the luciferase substrates D-luciferin and ATP. By contrast, the compound has no effect on Renilla and Gaussia luciferases. The mechanism of firefly luciferase inhibition by (E)-2-fluoro-4?-methoxystilbene, as well as its potency is comparable to its structure analogue resveratrol. The in vitro use of trans-stilbenes such as (E)-2-fluoro-4?-methoxystilbene or resveratrol compromises firefly luciferase reporter assays as well as ATP/luciferase-based cell viability assays. PMID:22789175

  10. Synthesis of monoclinic IrT e2 under high pressure and its physical properties

    NASA Astrophysics Data System (ADS)

    Li, X.; Yan, J.-Q.; Singh, D. J.; Goodenough, J. B.; Zhou, J.-S.

    2015-10-01

    In a pressure-temperature (P -T ) diagram for synthesizing IrT e2 compounds, the well-studied trigonal (H ) phase with the Cd I2 -type structure is stable at low pressures. The superconducting cubic (C ) phase can be synthesized under higher temperatures and pressures. A rhombohedral phase with the crystal structure similar to the C phase can be made at ambient pressure; but the phase contains a high concentration of Ir deficiency. In this paper we report that a rarely studied monoclinic (M ) phase can be stabilized in narrow ranges of pressure and temperature in this P -T diagram. The peculiar crystal structure of the M -IrT e2 eliminates the tendency to form Ir-Ir dimers found in the H phase. The M phase has been fully characterized by structural determination and measurements of electrical resistivity, thermoelectric power, DC magnetization, and specific heat. These physical properties have been compared with those in the H and C phases of I r1 -xT e2 . Moreover, magnetic and transport properties and specific heat of the M -IrT e2 can be fully justified by calculations with the density-functional theory presented in this paper.

  11. 76 FR 75774 - Targeted Populations Under Section 45D(e)(2)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-05

    ... advance notice of proposed rulemaking (ANPRM) (70 FR 29658) to seek comments from the public with respect... proposed rulemaking (NPRM) (REG-142339-05) was published in the Federal Register (73 FR 54990). Written and... Internal Revenue Service 26 CFR Part 1 RIN 1545-BE89 Targeted Populations Under Section 45D(e)(2)...

  12. 40 CFR Figure E-2 to Subpart E of... - Product Manufacturing Checklist

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Sections of 40 CFR Part 53 or 40 CFR Part 50, Appendix L Verification Comments (Includes documentation of... 40 Protection of Environment 5 2010-07-01 2010-07-01 false Product Manufacturing Checklist E Figure E-2 to Subpart E of Part 53 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY...

  13. 40 CFR Figure E-2 to Subpart E of... - Product Manufacturing Checklist

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Sections of 40 CFR Part 53 or 40 CFR Part 50, Appendix L Verification Comments (Includes documentation of... 40 Protection of Environment 5 2011-07-01 2011-07-01 false Product Manufacturing Checklist E Figure E-2 to Subpart E of Part 53 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY...

  14. pRb-Independent Growth Arrest and Transcriptional Regulation of E2F Target Genes1

    PubMed Central

    McCabe, Michael T; Azih, Odinaka J; Day, Mark L

    2005-01-01

    Abstract The retinoblastoma tumor suppressor (pRb) has traditionally been studied as a negative regulator of cell cycle progression through its interactions with the E2F family of transcription factors. Utilizing prostate epithelial cell lines established from Rb+/+ and Rb-/- prostate tissues, we previously demonstrated that Rb-/- epithelial cells were not transformed and retained the ability to differentiate in vivo despite the lack of pRb. To further study the effects of pRb loss in an epithelial cell population, we utilized oligonucleotide microarrays to identify any pRb-dependent transcriptional regulation during serum depletion-induced growth arrest. These studies identified 120 unique transcripts regulated by growth arrest in Rb+/+ cells. In these wild-type cells, the majority (80%) of altered transcripts were downregulated, including 40 previously identified E2F target genes. Although the transcriptional repression of E2F target genes is characteristic of pRb pocket protein family activity, further analysis revealed that, compared to Rb+/+ cells, Rb-/- cells exhibited a nearly identical response for all transcripts including those of E2F target genes. These findings demonstrate that pRb is not strictly required for the vast majority of transcriptional alterations associated with growth arrest. PMID:15802019

  15. "Expectations to Change" ((E2C): A Participatory Method for Facilitating Stakeholder Engagement with Evaluation Findings

    ERIC Educational Resources Information Center

    Adams, Adrienne E.; Nnawulezi, Nkiru A.; Vandenberg, Lela

    2015-01-01

    From a utilization-focused evaluation perspective, the success of an evaluation is rooted in the extent to which the evaluation was used by stakeholders. This paper details the "Expectations to Change" (E2C) process, an interactive, workshop-based method designed to engage primary users with their evaluation findings as a means of

  16. The E2 Domains of APP and APLP1 Share a Conserved Mode of Dimerization

    SciTech Connect

    S Lee; Y Xue; J Hulbert; Y Wang; X Liu; B Demeler; Y Ha

    2011-12-31

    Amyloid precursor protein (APP) is genetically linked to Alzheimer's disease. APP is a type I membrane protein, and its oligomeric structure is potentially important because this property may play a role in its function or affect the processing of the precursor by the secretases to generate amyloid {beta}-peptide. Several independent studies have shown that APP can form dimers in the cell, but how it dimerizes remains controversial. At least three regions of the precursor, including a centrally located and conserved domain called E2, have been proposed to contribute to dimerization. Here we report two new crystal structures of E2, one from APP and the other from APLP1, a mammalian APP homologue. Comparison with an earlier APP structure, which was determined in a different space group, shows that the E2 domains share a conserved and antiparallel mode of dimerization. Biophysical measurements in solution show that heparin binding induces E2 dimerization. The 2.1 {angstrom} resolution electron density map also reveals phosphate ions that are bound to the protein surface. Mutational analysis shows that protein residues interacting with the phosphate ions are also involved in heparin binding. The locations of two of these residues, Arg-369 and His-433, at the dimeric interface suggest a mechanism for heparin-induced protein dimerization.

  17. "Expectations to Change" ((E2C): A Participatory Method for Facilitating Stakeholder Engagement with Evaluation Findings

    ERIC Educational Resources Information Center

    Adams, Adrienne E.; Nnawulezi, Nkiru A.; Vandenberg, Lela

    2015-01-01

    From a utilization-focused evaluation perspective, the success of an evaluation is rooted in the extent to which the evaluation was used by stakeholders. This paper details the "Expectations to Change" (E2C) process, an interactive, workshop-based method designed to engage primary users with their evaluation findings as a means of…

  18. E2A Antagonizes PU.1 Activity through Inhibition of DNA Binding

    PubMed Central

    Rogers, Jason H.; Owens, Kristin S.; Kurkewich, Jeffrey; Klopfenstein, Nathan; Iyer, Sangeeta R.; Simon, M. Celeste; Dahl, Richard

    2016-01-01

    Antagonistic interactions between transcription factors contribute to cell fate decisions made by multipotent hematopoietic progenitor cells. Concentration of the transcription factor PU.1 affects myeloid/lymphoid development with high levels of PU.1 directing myeloid cell fate acquisition at the expense of B cell differentiation. High levels of PU.1 may be required for myelopoiesis in order to overcome inhibition of its activity by transcription factors that promote B cell development. The B cell transcription factors, E2A and EBF, are necessary for commitment of multipotential progenitors and lymphoid primed multipotential progenitors to lymphocytes. In this report we hypothesized that factors required for early B cell commitment would bind to PU.1 and antagonize its ability to induce myeloid differentiation. We investigated whether E2A and/or EBF associate with PU.1. We observed that the E2A component, E47, but not EBF, directly binds to PU.1. Additionally E47 represses PU.1-dependent transactivation of the MCSFR promoter through antagonizing PU.1's ability to bind to DNA. Exogenous E47 expression in hematopoietic cells inhibits myeloid differentiation. Our data suggest that E2A antagonism of PU.1 activity contributes to its ability to commit multipotential hematopoietic progenitors to the lymphoid lineages. PMID:26942192

  19. Transcriptional activation function is not required for stimulation of DNA replication by bovine papillomavirus type 1 E2.

    PubMed

    Grossel, M J; Sverdrup, F; Breiding, D E; Androphy, E J

    1996-10-01

    Bovine papillomavirus type 1 replication was previously shown to require both the E1 initiator protein and the E2 transactivator protein. We show here that E1, in the absence of E2, is sufficient for low-level bovine papillomavirus type 1 DNA replication in C-33A cells. In addition, studies of genetically isolated E2 point mutants demonstrate that enhancement of replication by E2 does not require its transcriptional activation function. The uncoupling of the E2 functions suggests that stimulation of transcription and replication by enhancer proteins occurs via divergent mechanisms. PMID:8794380

  20. Catalytic diesel particulate filters reduce the in vitro estrogenic activity of diesel exhaust.

    PubMed

    Wenger, Daniela; Gerecke, Andreas C; Heeb, Norbert V; Naegeli, Hanspeter; Zenobi, Renato

    2008-04-01

    An in vitro reporter gene assay based on human breast cancer T47D cells (ER-CALUX) was applied to examine the ability of diesel exhaust to induce or inhibit estrogen receptor (ER)-mediated gene expression. Exhaust from a heavy-duty diesel engine was either treated by iron- or copper/iron-catalyzed diesel particulate filters (DPFs) or studied as unfiltered exhaust. Collected samples included particle-bound and semivolatile constituents of diesel exhaust. Our findings show that all of the samples contained compounds that were able to induce ER-mediated gene expression as well as compounds that suppressed the activity of the endogenous hormone 17beta-estradiol (E2). Estrogenic activity prevailed over antiestrogenic activity. We found an overall ER-mediated activity of 1.63 +/- 0.31 ng E2 CALUX equivalents (E2-CEQs) per m(3) of unfiltered exhaust. In filtered exhaust, we measured 0.74 +/- 0.07 (iron-catalyzed DPF) and 0.55 +/- 0.09 ng E2-CEQ m(-3) (copper/iron-catalyzed DPF), corresponding to reductions in estrogenic activity of 55 and 66%, respectively. Our study demonstrates that both catalytic DPFs lowered the ER-mediated endocrine-disrupting potential of diesel exhaust. PMID:18264702

  1. The influence of endocrine disrupting chemicals on the proliferation of ERalpha knockdown-human breast cancer cell line MCF-7; new attempts by RNAi technology.

    PubMed

    Miyakoshi, Takashi; Miyajima, Katsuhiro; Takekoshi, Susumu; Osamura, Robert Yoshiyuki

    2009-04-28

    Bisphenol A (BPA) is a monomer use in manufacturing a wide range of chemical products which include epoxy resins and polycarbonate. It has been reported that BPA increases the cell proliferation activity of human breast cancer MCF-7 cells as well as 17-beta estradiol (E2) and diethylstilbestrol (DES). However, BPA induces target genes through ER-dependent and ER-independent manners which are different from the actions induced by E2. Therefore, BPA may be unique in estrogen-dependent cell proliferation compared to other endocrine disrupting chemicals (EDCs). In the present study, to test whether ERalpha is essential to the BPA-induced proliferation on MCF-7 cells, we suppressed the ERalpha expression of MCF-7 cells by RNA interference (RNAi). Proliferation effects in the presence of E2, DES and BPA were not observed in ERalpha-knockdown MCF-7 cells in comparison with control MCF-7. In addition, a marker of proliferative potential, MIB-1 labeling index (LI), showed no change in BPA-treated groups compared with vehicle-treated groups on ERalpha-knockdown MCF-7 cells. In conclusion, we demonstrated that ERalpha has a role in BPA-induced cell proliferation as well as E2 and DES. Moreover, this study indicated that the direct knockdown of ERalpha using RNAi serves as an additional tool to evaluate, in parallel with MCF-7 cell proliferation assay, for potential EDCs. PMID:19492024

  2. Modulation of the cytosolic androgen receptor in striated muscle by sex steroids

    NASA Technical Reports Server (NTRS)

    Rance, N. E.; Max, S. R.

    1984-01-01

    The effects of orchiectomy (GDX) and of subsequent administration of testosterone propionate (TP) or 17(beta)-estradiol (E2) on the maximum binding (Bmax) and apparent Kd of the cytosolic androgen receptor in levator ani (LA) and skeletal muscles of adult male Sprague-Dawley rats are investigated experimentally. The results are presented in graphs and discussed. In LA, BMAX is found to rise from a control level of 2.5 fmol/mg protein to 280, 600, 478, and 133 percent of control at 12 h, 14 d, 30 d, and 44 d after GDX, respectively, while Kd increased only insignificantly (from 680 to 960 fM); Bmax is held at control levels for 6 h by cycloheximide given at GDX, is unaffected by TP given at 30 d, and is further increased (by 480 percent at 44 d) by administration of E2 at 30 d. Bmax in skeletal muscles is found to increase to 139, 212, 220, and 158 percent of control at 12 h, 14 d, 30 d, and 44 d, respectively; Bmax is returned to control at 44 d by TP at 30 d but is not affected by E2. The effect of E2 in LA is attributed to either induction of the cytosolic receptor or a decreased rate of receptor degradation.

  3. The use of primary hepatocytes from brown trout (Salmo trutta lacustris) and the fish cell lines RTH-149 and ZF-L for in vitro screening of (anti)estrogenic activity of wood extractives.

    PubMed

    Christianson-Heiska, I; Isomaa, B

    2008-04-01

    Wood extractives are constituents of wood present in pulp and paper mill effluents, which may cause reproductive disturbances in fish. In the present study, we examined three cellular in vitro bioassays in order to assess (anti)estrogenic potencies of the wood extractives dehydroabietic acid (DHAA), isopimaric acid (IPA), betulinol (BET), hydroxymatairesinol (HMR), a phytosterol preparation (ULT), an oxidized phytosterol preparation (OX) and the model estrogen 17beta-estradiol (E2). The test systems used were primary hepatocyte cultures from brown trout and two piscine liver cell lines, RTH-149 and ZF-L. Estrogenicity was measured as vitellogenin (Vtg) secretion in cell culture medium. The primary hepatocytes cultures responded to E2 in a dose-dependent way. Vtg induction was inhibited with a simultaneous exposure to 4-hydroxytamoxifen (4-HT) indicating an estrogen receptor mediated response. DHAA and ULT induced a weak statistically non-significant Vtg production, and weak additive effects were found in some combination treatments of wood extractives and E2. Additionally, a pulp mill effluent tested on primary hepatocytes induced Vtg production when exposed at a 1% dilution. The cell lines secreted negligible amounts of Vtg upon E2 stimulation, which was neither dose-dependent nor inhibited by 4-HT. In conclusion, trout primary hepatocytes could be useful for assessing (anti)estrogenic potencies of compounds, and the wood extractives and a pulp mill effluent showed only weak or no estrogenic activity in this model system. PMID:18206344

  4. VirE2: a unique ssDNA-compacting molecular machine.

    PubMed

    Grange, Wilfried; Duckely, Myriam; Husale, Sudhir; Jacob, Susan; Engel, Andreas; Hegner, Martin

    2008-02-01

    The translocation of single-stranded DNA (ssDNA) across membranes of two cells is a fundamental biological process occurring in both bacterial conjugation and Agrobacterium pathogenesis. Whereas bacterial conjugation spreads antibiotic resistance, Agrobacterium facilitates efficient interkingdom transfer of ssDNA from its cytoplasm to the host plant cell nucleus. These processes rely on the Type IV secretion system (T4SS), an active multiprotein channel spanning the bacterial inner and outer membranes. T4SSs export specific proteins, among them relaxases, which covalently bind to the 5' end of the translocated ssDNA and mediate ssDNA export. In Agrobacterium tumefaciens, another exported protein-VirE2-enhances ssDNA transfer efficiency 2000-fold. VirE2 binds cooperatively to the transferred ssDNA (T-DNA) and forms a compact helical structure, mediating T-DNA import into the host cell nucleus. We demonstrated-using single-molecule techniques-that by cooperatively binding to ssDNA, VirE2 proteins act as a powerful molecular machine. VirE2 actively pulls ssDNA and is capable of working against 50-pN loads without the need for external energy sources. Combining biochemical and cell biology data, we suggest that, in vivo, VirE2 binding to ssDNA allows an efficient import and pulling of ssDNA into the host. These findings provide a new insight into the ssDNA translocation mechanism from the recipient cell perspective. Efficient translocation only relies on the presence of ssDNA binding proteins in the recipient cell that compacts ssDNA upon binding. This facilitated transfer could hence be a more general ssDNA import mechanism also occurring in bacterial conjugation and DNA uptake processes. PMID:18303950

  5. Neutralizing activities of caprine antibodies towards conserved regions of the HCV envelope glycoprotein E2

    PubMed Central

    2011-01-01

    Anti HCV vaccine is not currently available and the present antiviral therapies fail to cure approximately half of the treated HCV patients. This study was designed to assess the immunogenic properties of genetically conserved peptides derived from the C-terminal region of HVR-1 and test their neutralizing activities in a step towards developing therapeutic and/or prophylactic immunogens against HCV infection. Antibodies were generated by vaccination of goats with synthetic peptides derived from HCV E2. Viral neutralizing capacity of the generated anti E2 antibodies was tested using in vitro assays. Goats immunized with E2 synthetic peptides termed p412 [a.a 412-419], p430 [a.a 430-447] and p517 [a.a 517-531] generated high titers of antibody responses 2 to 4.5 fold higher than comparable titers of antibodies to the same epitopes in chronic HCV patients. In post infection experiments of native HCV into cultured Huh7.5 cells anti p412 and anti p 517 were proven to be neutralizing to HCV genotype 4a from patients' sera (87.5% and 75% respectively). On the contrary anti p430 exhibited weak viral neutralization capacity on the same samples (31.25%). Furthermore Ab mixes containing anti p430 exhibited reduced viral neutralization properties. From these experiments one could predict that neutralization by Abs towards different E2-epitopes varies considerably and success in the enrichment of neutralization epitope-specific antibodies may be accompanied by favorable results in combating HCV infection. Also, E2 conserved peptides p517 and p412 represent potential components of a candidate peptide vaccine against HCV infection. PMID:21819575

  6. Identifying the Role of E2 Domains on Alphavirus Neutralization and Protective Immune Responses

    PubMed Central

    Weger-Lucarelli, James; Aliota, Matthew T.; Kamlangdee, Attapon; Osorio, Jorge E.

    2015-01-01

    Background Chikungunya virus (CHIKV) and other alphaviruses are the etiologic agents of numerous diseases in both humans and animals. Despite this, the viral mediators of protective immunity against alphaviruses are poorly understood, highlighted by the lack of a licensed human vaccine for any member of this virus genus. The alphavirus E2, the receptor-binding envelope protein, is considered to be the predominant target of the protective host immune response. Although envelope protein domains have been studied for vaccine and neutralization in flaviviruses, their role in alphaviruses is less characterized. Here, we describe the role of the alphavirus E2 domains in neutralization and protection through the use of chimeric viruses. Methodology/Principal Findings Four chimeric viruses were constructed in which individual E2 domains of CHIKV were replaced with the corresponding domain from Semliki Forest virus (SFV) (ΔDomA/ΔDomB/ΔDomC/ ΔDomA+B). Vaccination studies in mice (both live and inactivated virus) revealed that domain B was the primary determinant of neutralization. Neutralization studies with CHIKV immune serum from humans were consistent with mouse studies, as ΔDomB was poorly neutralized. Conclusions/Significance Using chimeric viruses, it was determined that the alphavirus E2 domain B was the critical target of neutralizing antibodies in both mice and humans. Therefore, chimeric viruses may have more relevance for vaccine discovery than peptide-based approaches, which only detect linear epitopes. This study provides new insight into the role of alphavirus E2 domains on neutralization determinants and may be useful for the design of novel therapeutic technologies. PMID:26473963

  7. E2F decoy oligodeoxynucleotides on neointimal hyperplasia in canine vein graft.

    PubMed

    Cho, W H; Lee, S O; Kim, H T; Ahn, J D; Lee, I K

    2005-01-01

    Double-stranded DNA with high affinity to E2F as a decoy cis-element blocks the activation of genes mediating the cell cycle, resulting in effective suppression of the smooth muscle cell proliferation that causes intimal hyperplasia. To evaluate the effect of the E2F decoy to suppress neointimal hyperplasia autogenous venous bypass grafts were performed in dogs after incubation with heparin (group 1), with E2F decoy oligodeoxynucleotides (ODN) (groups 2 and 3), or with a random ODN (group 4) using a Japan-liposomeal method based on a hemagglutinating virus. The intimal and medial cross-sectional surface area of the anastomotic site was measured at 4 months after bypass surgery in groups 1, 3, and 4 by computerized planimetry and at 4 weeks in group 2 to compare the intimal/medial (I/M) area ratios. Autogenous vein grafts treated with E2F decoy showed a significant reduction in I/M area ratio (0.26 +/- 0.11) compared with the heparin-treated control group (1.49 +/- 0.29) or the mismatched ODN-treated group (1.61 +/- 0.28; P = .000). There was no difference in the I/M area ratio according to experimental periods (groups 2 vs 3: 0.26 +/- 0.11 vs 0.37 +/- 0.32; P = .446) or the anastomotic sites (proximal vs distal; P = .934). In conclusion, an E2F decoy can suppress neointimal hyperplasia in autogenous vein grafts, which may prolong patency by reducing graft stenosis. PMID:15808553

  8. Phenol hydroxylase cloned from Ralstonia eutropha strain E2 exhibits novel kinetic properties.

    PubMed

    Hino, S; Watanabe, K; Takahashi, N

    1998-07-01

    Ralstonia eutropha strain E2 (previously Alcaligenes sp.) is a phenol-degrading bacterium expressing phenol-oxygenating activity with a low Ks (the apparent half-saturation constant in Haldane's equation) and an extremely high KSI (the apparent inhibition constant). To identify the molecular basis for these novel cellular kinetic properties, a 9.5 kb DNA fragment that allowed Pseudomonas aeruginosa PAO1c (Phl- Cat+) to grow on phenol as the sole carbon source was cloned from strain E2 into plasmid pRO1614. PAO1c harbouring this plasmid (designated pROE217) transformed phenol to catechol, indicating that this fragment contains gene(s) for phenol hydroxylase. The cloned genes consist of eight complete ORFs, designated poxRABCDEFG. The products are homologous to those of dmpRKLMNOPQ of Pseudomonas sp. CF600, sharing 30-65% identity: this suggests that the phenol hydroxylase is a multicomponent enzyme. The kinetic constants for phenol-oxygenating activity of PAO1c(pROE217) were determined, and these were compared with those of strain E2. The kinetic constants of PAO1c derivatives expressing different phenol hydroxylases were also determined. A comparison of these kinetic data suggests that phenol hydroxylase, the first enzyme in the phenol-degradative pathway, determines Ks and KSI values for the cellular phenol-oxygenating activity. It is thus suggested that the phenol hydroxylase cloned from strain E2 exhibits the novel kinetic properties that were observed with intact cells of strain E2. PMID:9695910

  9. Single Cell Analysis to locate the Restriction Point with respect to E2F Expression

    NASA Astrophysics Data System (ADS)

    Pimienta, R.; Johnson, A.

    2011-12-01

    The restriction point is a G1-phase checkpoint that regulates passage through the cell cycle and is misregulated in all known types of cancer. The Rb-E2F switch is thought to be one of the most relevant molecular mechanisms which regulate the restriction point in mammalian cells. However, recent experiments have brought the timing of the restriction point into question. In previous studies, cells were analyzed as populations and this prevented an accurate determination of the restriction point. By creating and analyzing an E2F-GFP reporter in single cells, we can pinpoint the timing of E2F activation and determine whether it coincides with the restriction point. Using calcium phosphate and Fugene,we transfected human embryonic kidney (293T) cells with a CMV-GFP plasmid and an E2F-GFP reporter. Based on our results, it appears that calcium phosphate is more effective than Fugene at transfecting mammalian cells. The calcium phosphate transfection had 9.59% more fluorescent cells than Fugene. However, this result only occurred with the CMV-GFP plasmid and not the E2F-GFP reporter, which was not properly expressed in human embryonic kidney (293T) cells. We will continue troubleshooting to fix this reporter as we proceed with our research. Once the reporter is properly cloned, we will transfect it into retinal pigmented epithelial (RPE1-hTERT) cells using the calcium phosphate method. RPE1-hTERT cells are an immortalized with telomerase and are more close to normal cells than tumor-derived cell lines. Through this research we will better comprehend commitment to the mammalian cell cycle.

  10. Evaluation of Emerging Contaminants of Concern at the South District Wastewater Treatment Plant Based on Seasonal Events, Miami-Dade County, Florida, 2004

    USGS Publications Warehouse

    Lietz, Arthur C.; Meyer, Michael T.

    2006-01-01

    The Comprehensive Everglades Restoration Plan has identified highly treated wastewater as a possible water source for the restoration of natural water flows and hydroperiods in selected coastal areas, including the Biscayne Bay coastal wetlands. One potential source of reclaimed wastewater for the Biscayne Bay coastal wetlands is the effluent from the South District Wastewater Treatment Plant in southern Miami-Dade County. The U.S. Geological Survey, in cooperation with the Comprehensive Everglades Restoration Plan Wastewater Reuse Technology Pilot Project Delivery Team, initiated a study to assess the presence of emerging contaminants of concern in the South District Wastewater Treatment Plant influent and effluent using current wastewater-treatment methods. As part of the study, 24-hour composite and discrete samples were collected at six locations (influent at plants 1 and 2, effluent pump, reuse train, chlorine dioxide unit, and ultraviolet pilot unit) at the plant during: (1) a dry-season, low-flow event on March 2-3, 2004, with an average inflow rate of 83.7 million gallons per day; (2) a wet-season, average-flow event on July 20-21, 2004, with an average inflow rate of 89.7 million gallons per day; and (3) high-rate disinfection tests on October 5 and 20, 2004, with average flow rates of 84.1 and 119.6 million gallons per day, respectively. During these four sampling events, 26, 27, 29, and 35 constituents were detected, respectively. The following transformations in concentration were determined in the waste stream: -100 to 180 percent at the effluent pump and -100 to 85 percent at the reuse train on March 2-3, 2004, and -100 to 1,609 percent at the effluent pump and -100 to 832 percent at the reuse train on July 20-21, 2004; -100 to -37 percent at the effluent pump, -100 to -62 percent at the reuse train, -100 to -56 percent at the chlorine dioxide unit, and -100 to -40 percent at the ultraviolet pilot unit on October 5, 2004; and -100 to -4 percent at the effluent pump, -100 to 17 percent at the reuse train, -100 to -40 percent at the chlorine dioxide unit, and -100 to -14 percent at the ultraviolet pilot unit on October 20, 2004. Samples were tested for detection of household and industrial (organic) wastewater compounds, pharmaceutical compounds, antibiotic compounds, and hormones in influent. Two 'known' endocrine disrupting compounds?17 beta-estradiol (E2) and diethoxynonylphenol? and four 'suspected' endocrine-disrupting compounds?1,4-dichlorobenzene, benzophenone, tris(2-chloroethyl) phosphate, and tris(dichloroisopropyl) phosphate?were detected during these sampling events. Phenanthrene and indole showed the greatest concentration ranges and highest concentrations for the organic wastewater compounds. Acetaminophen showed the greatest concentration range and highest concentration, and warfarin showed the smallest concentration range for the pharmaceutical compounds. Sulfamethoxazole (a sulfonamide) showed the greatest concentration range and highest concentration, and sulfathiozole (also a sulfonamide) showed the smallest concentration range for the antibiotic compounds. Two hormones, 17 beta-estradiol (E2) and estrone (E1), were detected in influent. Samples were also tested for detection of organic wastewater compounds, pharmaceutical compounds, antibiotic compounds, and hormones in effluent. Indole showed the greatest concentration range and highest concentration, and triphenyl phosphate showed the smallest concentration range for the organic wastewater compounds. Dehydronifedipine showed the greatest concentration range and highest concentration, and warfarin had the smallest concentration range for the pharmaceutical compounds. Anhydro-erythromycin (a macrolide degradation product) showed the greatest concentration range, and sulfadiazine (a sulfonamide) and tetracycline showed the lowest concentration ranges for the antibiotic compounds. One hormone, 17 beta-estradiol (E2), was det

  11. The E2F transcription factors regulate tumor development and metastasis in a mouse model of metastatic breast cancer.

    PubMed

    Hollern, Daniel P; Honeysett, Jordan; Cardiff, Robert D; Andrechek, Eran R

    2014-09-01

    While the E2F transcription factors (E2Fs) have a clearly defined role in cell cycle control, recent work has uncovered new functions. Using genomic signature methods, we predicted a role for the activator E2F transcription factors in the mouse mammary tumor virus (MMTV)-polyomavirus middle T oncoprotein (PyMT) mouse model of metastatic breast cancer. To genetically test the hypothesis that the E2Fs function to regulate tumor development and metastasis, we interbred MMTV-PyMT mice with E2F1, E2F2, or E2F3 knockout mice. With the ablation of individual E2Fs, we noted alterations of tumor latency, histology, and vasculature. Interestingly, we noted striking reductions in metastatic capacity and in the number of circulating tumor cells in both the E2F1 and E2F2 knockout backgrounds. Investigating E2F target genes that mediate metastasis, we found that E2F loss led to decreased levels of vascular endothelial growth factor (Vegfa), Bmp4, Cyr61, Nupr1, Plod 2, P4ha1, Adamts1, Lgals3, and Angpt2. These gene expression changes indicate that the E2Fs control the expression of genes critical to angiogenesis, the remodeling of the extracellular matrix, tumor cell survival, and tumor cell interactions with vascular endothelial cells that facilitate metastasis to the lungs. Taken together, these results reveal that the E2F transcription factors play key roles in mediating tumor development and metastasis in addition to their well-characterized roles in cell cycle control. PMID:24934442

  12. Assessment of the role of in situ generated (E)-2,4-diene-valproic acid in the toxicity of valproic acid and (E)-2-ene-valproic acid in sandwich-cultured rat hepatocytes

    SciTech Connect

    Surendradoss, Jayakumar; Chang, Thomas K.H.; Abbott, Frank S.

    2012-11-01

    Valproic acid (VPA) undergoes cytochrome P450-mediated desaturation to form 4-ene-VPA, which subsequently yields (E)-2,4-diene-VPA by β-oxidation. Another biotransformation pathway involves β-oxidation of VPA to form (E)-2-ene-VPA, which also generates (E)-2,4-diene-VPA by cytochrome P450-mediated desaturation. Although the synthetic form of (E)-2,4-diene-VPA is more hepatotoxic than VPA as shown in various experimental models, there is no conclusive evidence to implicate the in situ generated (E)-2,4-diene-VPA in VPA hepatotoxicity. The present study investigated the effects of modulating the in situ formation of (E)-2,4-diene-VPA on markers of oxidative stress (formation of 2′,7′-dichlorofluorescein; DCF), steatosis (accumulation of BODIPY 558/568 C{sub 12}), necrosis (release of lactate dehydrogenase; LDH), and on cellular total glutathione (GSH) levels in sandwich-cultured rat hepatocytes treated with VPA or (E)-2-ene-VPA. Treatment with either of these chemicals alone increased each of the toxicity endpoints. In VPA-treated hepatocytes, (E)-2,4-diene-VPA was detected only at trace levels, even after phenobarbital (PB) pretreatment and there was no effect on the toxicity of VPA. Furthermore, pretreatment with a cytochrome P450 enzyme inhibitor, 1-aminobenzotriazole (1-ABT), did not influence the extent of VPA toxicity in both PB-pretreated and vehicle-pretreated hepatocytes. However, in (E)-2-ene-VPA-treated hepatocytes, PB pretreatment greatly enhanced the levels of (E)-2,4-diene-VPA and this was accompanied by a further enhancement of the effects of (E)-2-ene-VPA on DCF formation, BODIPY accumulation, LDH release, and GSH depletion. Pretreatment with 1-ABT reduced the concentrations of (E)-2,4-diene-VPA and the extent of (E)-2-ene-VPA toxicity; however, this occurred in PB-pretreated hepatocytes, but not in control hepatocytes. In conclusion, in situ generated (E)-2,4-diene-VPA is not responsible for the hepatocyte toxicity of VPA, whereas it contributes to the toxicity of (E)-2-ene-VPA in PB-pretreated rat hepatocytes. -- Highlights: ► (E)-2,4-diene-valproic acid is a reactive and toxic metabolite of valproic acid (VPA). ► In situ, this metabolite is not responsible for VPA toxicity in rat hepatocytes. ► This metabolite enhances (E)-2-ene-VPA toxicity in PB-pretreated hepatocytes.

  13. E2 superfamily of ubiquitin-conjugating enzymes: constitutively active or activated through phosphorylation in the catalytic cleft

    PubMed Central

    Valimberti, Ilaria; Tiberti, Matteo; Lambrughi, Matteo; Sarcevic, Boris; Papaleo, Elena

    2015-01-01

    Protein phosphorylation is a modification that offers a dynamic and reversible mechanism to regulate the majority of cellular processes. Numerous diseases are associated with aberrant regulation of phosphorylation-induced switches. Phosphorylation is emerging as a mechanism to modulate ubiquitination by regulating key enzymes in this pathway. The molecular mechanisms underpinning how phosphorylation regulates ubiquitinating enzymes, however, are elusive. Here, we show the high conservation of a functional site in E2 ubiquitin-conjugating enzymes. In catalytically active E2s, this site contains aspartate or a phosphorylatable serine and we refer to it as the conserved E2 serine/aspartate (CES/D) site. Molecular simulations of substrate-bound and -unbound forms of wild type, mutant and phosphorylated E2s, provide atomistic insight into the role of the CES/D residue for optimal E2 activity. Both the size and charge of the side group at the site play a central role in aligning the substrate lysine toward E2 catalytic cysteine to control ubiquitination efficiency. The CES/D site contributes to the fingerprint of the E2 superfamily. We propose that E2 enzymes can be divided into constitutively active or regulated families. E2s characterized by an aspartate at the CES/D site signify constitutively active E2s, whereas those containing a serine can be regulated by phosphorylation. PMID:26463729

  14. Api5 Contributes to E2F1 Control of the G1/S Cell Cycle Phase Transition

    PubMed Central

    Garcia-Jove Navarro, Marina; Basset, Cline; Arcondguy, Tania; Touriol, Christian; Perez, Guillaume; Prats, Herv; Lacazette, Eric

    2013-01-01

    Background The E2f transcription factor family has a pivotal role in controlling the cell fate in general, and in particular cancer development, by regulating the expression of several genes required for S phase entry and progression through the cell cycle. It has become clear that the transcriptional activation of at least one member of the family, E2F1, can also induce apoptosis. An appropriate balance of positive and negative regulators appears to be necessary to modulate E2F1 transcriptional activity, and thus cell fate. Methodology/Principal Findings In this report, we show that Api5, already known as a regulator of E2F1 induced-apoptosis, is required for the E2F1 transcriptional activation of G1/S transition genes, and consequently, for cell cycle progression and cell proliferation. Api5 appears to be a cell cycle regulated protein. Removal of Api5 reduces cyclin E, cyclin A, cyclin D1 and Cdk2 levels, causing G1 cell cycle arrest and cell cycle delay. Luciferase assays established that Api5 directly regulates the expression of several G1/S genes under E2F1 control. Using protein/protein and protein/DNA immunoprecipitation studies, we demonstrate that Api5, even if not physically interacting with E2F1, contributes positively to E2F1 transcriptional activity by increasing E2F1 binding to its target promoters, through an indirect mechanism. Conclusion/Significance The results described here support the pivotal role of cell cycle related proteins, that like E2F1, may act as tumor suppressors or as proto-oncogenes during cancer development, depending on the behavior of their positive and negative regulators. According to our findings, Api5 contributes to E2F1 transcriptional activation of cell cycle-associated genes by facilitating E2F1 recruitment onto its target promoters and thus E2F1 target gene transcription. PMID:23940755

  15. How Does (E)-2-(Acetamidomethylene)succinate Bind to Its Hydrolase? From the Binding Process to the Final Result

    PubMed Central

    Zhang, Ji-Long; Zheng, Qing-Chuan; Li, Zheng-Qiang; Zhang, Hong-Xing

    2013-01-01

    The binding of (E)-2-(acetamidomethylene)succinate (E-2AMS) to E-2AMS hydrolase is crucial for biological function of the enzyme and the last step reaction of vitamin B6 biological degradation. In the present study, several molecular simulation methods, including molecular docking, conventional molecular dynamics (MD), steered MD (SMD), and free energy calculation methods, were properly integrated to investigate the detailed binding process of E-2AMS to its hydrolase and to assign the optimal enzyme-substrate complex conformation. It was demonstrated that the substrate binding conformation with trans-form amide bond is energetically preferred conformation, in which E-2AMS's pose not only ensures hydrogen bond formation of its amide oxygen atom with the vicinal oxyanion hole but also provides probability of the hydrophobic interaction between its methyl moiety and the related enzyme's hydrophobic cavity. Several key residues, Arg146, Arg167, Tyr168, Arg179, and Tyr259, orientate the E-2AMS's pose and stabilize its conformation in the active site via the hydrogen bond interaction with E-2AMS. Sequentially, the binding process of E-2AMS to E-2AMS hydrolase was studied by SMD simulation, which shows the surprising conformational reversal of E-2AMS. Several important intermediate structures and some significant residues were identified in the simulation. It is stressed that Arg146 and Arg167 are two pivotal residues responsible for the conformational reversal of E-2AMS in the binding or unbinding. Our research has shed light onto the full binding process of the substrate to E-2AMS hydrolase, which could provide more penetrating insight into the interaction of E-2AMS with the enzyme and would help in the further exploration on the catalysis mechanism. PMID:23308285

  16. E2 enzyme inhibition by stabilization of a low affinity interface with ubiquitin

    PubMed Central

    St-Cyr, Daniel J.; Ziemba, Amy; Garg, Pankaj; Plamondon, Serge; Auer, Manfred; Sidhu, Sachdev; Marinier, Anne; Kleiger, Gary; Tyers, Mike; Sicheri, Frank

    2014-01-01

    Weak protein interactions between ubiquitin and the ubiquitin-proteasome system (UPS) enzymes that mediate its covalent attachment to substrates serve to position ubiquitin for optimal catalytic transfer. We show that a small molecule inhibitor of the E2 ubiquitin conjugating enzyme Cdc34A, called CC0651, acts by trapping a weak interaction between ubiquitin and the E2 donor ubiquitin binding site. A structure of the ternary CC0651-Cdc34A-ubiquitin complex reveals that the inhibitor engages a composite binding pocket formed from Cdc34A and ubiquitin. CC0651 also suppresses the spontaneous hydrolysis rate of the Cdc34A-ubiquitin thioester, without overtly affecting the interaction between Cdc34A and the RING domain subunit of the E3 enzyme. Stabilization of the numerous other weak interactions between ubiquitin and UPS enzymes by small molecules may be a feasible strategy to selectively inhibit different UPS activities. PMID:24316736

  17. Structural insights into E2-E3 interaction for LC3 lipidation.

    PubMed

    Metlagel, Zoltan; Otomo, Chinatsu; Ohashi, Kazuto; Takaesu, Giichi; Otomo, Takanori

    2014-03-01

    The members of the LC3/Atg8 family of proteins are covalently attached to phagophore and autophagosomal membranes. At the last step of the LC3 lipidation cascade, LC3 is transferred from the E2 enzyme ATG3 to phosphatidylethanolamine (PE). This transfer is stimulated by the ATG12-ATG5-ATG16L1 E3 complex, but the mechanism is not fully understood. We recently found that ATG12 of the E3 binds to a short sequence in the flexible region (FR) of ATG3 with high affinity, and that this interaction is critical for E2-E3 complex formation. These findings, together with detailed structural analyses of this interaction, define the properties of ATG12 and provide new insights of how LC3 transfer begins with ATG3 recruitment by ATG12. PMID:24413923

  18. Purification, crystallization and initial crystallographic characterization of brazil-nut allergen Ber?e?2

    PubMed Central

    Guo, Feng; Jin, Tengchuan; Howard, Andrew; Zhang, Yu-Zhu

    2007-01-01

    Peanut and tree-nut allergies have attracted considerable attention because of their frequency and their lifelong persistence. Brazil-nut (Bertholletia excelsa) allergies have been well documented and the 11S legumin-like seed storage protein Ber?e?2 (excelsin) is one of the two known brazil-nut allergens. In this study, Ber?e?2 was extracted from brazil-nut kernels and purified to high purity by crystalline precipitation and gel-filtration chromatography. Well diffracting single crystals were obtained using the hanging-drop vapour-diffusion method. A molecular-replacement structural solution has been obtained. Refinement of the structure is currently under way. PMID:18007055

  19. Vitexin inhibits polyubiquitin synthesis by the ubiquitin-conjugating enzyme E2-25K.

    PubMed

    Helms, Kimberli M; Wilson, Randall C; Ogungbe, Ifedayo V; Setzer, William N; Twigg, Pamela D

    2011-10-01

    An extract of bark from the tropical rainforest plant Byrsonima crassifolia was screened for inhibition of diubiquitin formation by the human ubiquitin-conjugating enzyme E2-25K. Activity assays with both the full-length enzyme and a truncated, active catalytic UBC domain revealed that the extract contained inhibitory properties. Separation of the extract into individual components and additional screens identified vitexin as the active inhibitor. An IC50 for vitexin was calculated to be approximately 0.5 mM. Molecular modeling simulations were used to predict the mode of inhibition and NMR spectra were used to confirm the binding site of vitexin to E2-25K. PMID:22164771

  20. Second-order Born calculation of coplanar symmetric (e, 2e) process on Mg

    NASA Astrophysics Data System (ADS)

    Zhang, Yong-Zhi; Wang, Yang; Zhou, Ya-Jun

    2014-06-01

    The second-order distorted wave Born approximation (DWBA) method is employed to investigate the triple differential cross sections (TDCS) of coplanar doubly symmetric (e, 2e) collisions for magnesium at excess energies of 6 eV-20 eV. Comparing with the standard first-order DWBA calculations, the inclusion of the second-order Born term in the scattering amplitude improves the degree of agreement with experiments, especially for backward scattering region of TDCS. This indicates that the present second-order Born term is capable to give a reasonable correction to DWBA model in studying coplanar symmetric (e, 2e) problems of two-valence-electron target in low energy range.

  1. Identification of a Drosophila Myb-E2F2/RBF transcriptional repressor complex

    PubMed Central

    Lewis, Peter W.; Beall, Eileen L.; Fleischer, Tracey C.; Georlette, Daphne; Link, Andrew J.; Botchan, Michael R.

    2004-01-01

    The Drosophila Myb complex has roles in both activating and repressing developmentally regulated DNA replication. To further understand biochemically the functions of the Myb complex, we fractionated Drosophila embryo extracts relying upon affinity chromatography. We found that E2F2, DP, RBF1, RBF2, and the Drosophila homolog of LIN-52, a class B synthetic multivulva (synMuv) protein, copurify with the Myb complex components to form the Myb-MuvB complex. In addition, we found that the transcriptional repressor protein, lethal (3) malignant brain tumor protein, L(3)MBT, and the histone deacetylase, Rpd3, associated with the Myb-MuvB complex. Members of the Myb-MuvB complex were localized to promoters and were shown to corepress transcription of developmentally regulated genes. These and other data now link together the Myb and E2F2 complexes in higher-order assembly to specific chromosomal sites for the regulation of transcription. PMID:15545624

  2. M1-E2 interference in the Zeeman spectra of Bi I

    SciTech Connect

    Werbowy, S.; Kwela, J.

    2008-02-15

    Studies of the M1-E2 interference effect in the mixed-type forbidden lines 461.5, 647.6, and 875.5 nm of Bi I are reported. A special computer program considering the interference effect was designed to obtain the predicted contours of the Zeeman structures of the lines. By variation of free parameters describing the line shapes and the electric-quadrupole admixtures, the calculated profiles were fitted to the recorded spectra. The E2 admixtures found are (7.84{+-}0.14)%, (17.5{+-}0.4)%, and (0.70{+-}0.11)% for the 461.5, 647.6, and 875.5 nm lines, respectively. Our results are compared with recent theories and other experiments.

  3. Advanced Stirling Convertor (ASC-E2) Performance Testing at NASA Glenn Research Center

    NASA Technical Reports Server (NTRS)

    Oriti, Salvatore; Wilson, Scott

    2011-01-01

    The National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) has been supporting development of the Advanced Stirling Radioisotope Generator (ASRG) since 2006. A key element of the ASRG Project is providing life, reliability, and performance testing of the Advanced Stirling Convertor (ASC). For this purpose, four pairs of ASCs capable of operating to 850 C and designated with the model number ASC-E2, were delivered by Sunpower of Athens, Ohio, to GRC in 2010. The ASC-E2s underwent a series of tests that included workmanship vibration testing, performance mapping, and extended operation. Workmanship vibration testing was performed following fabrication of each convertor to verify proper hardware build. Performance mapping consisted of operating each convertor at various conditions representing the range expected during a mission. Included were conditions representing beginning-of-mission (BOM), end-of-mission (EOM), and fueling. This same series of tests was performed by Sunpower prior to ASC-E2 delivery. The data generated during the GRC test were compared to performance before delivery. Extended operation consisted of a 500-hr period of operation with conditions maintained at the BOM point. This was performed to demonstrate steady convertor performance following performance mapping. Following this initial 500-hr period, the ASC-E2s will continue extended operation, controller development and special durability testing, during which the goal is to accumulate tens of thousands of hours of operation. Data collected during extended operation will support reliability analysis. Performance data from these tests is summarized in this paper.

  4. Genetic Variation in the Prostaglandin E2 Pathway Is Associated with Primary Graft Dysfunction

    PubMed Central

    Akimova, Tatiana; Kazi, Altaf; Shah, Rupal J.; Cantu, Edward; Feng, Rui; Levine, Matthew H.; Kawut, Steven M.; Meyer, Nuala J.; Lee, James C.; Hancock, Wayne W.; Aplenc, Richard; Ware, Lorraine B.; Palmer, Scott M.; Bhorade, Sangeeta; Lama, Vibha N.; Weinacker, Ann; Orens, Jonathan; Wille, Keith; Crespo, Maria; Lederer, David J.; Arcasoy, Selim; Demissie, Ejigayehu; Christie, Jason D.

    2014-01-01

    Rationale: Biologic pathways with significant genetic conservation across human populations have been implicated in the pathogenesis of primary graft dysfunction (PGD). The evaluation of the role of recipient genetic variation in PGD has thus far been limited to single, candidate gene analyses. Objectives: We sought to identify genetic variants in lung transplant recipients that are responsible for increased risk of PGD using a two-phase large-scale genotyping approach. Methods: Phase 1 was a large-scale candidate gene association study of the multicenter, prospective Lung Transplant Outcomes Group cohort. Phase 2 included functional evaluation of selected variants and a bioinformatics screening of variants identified in phase 1. Measurements and Main Results: After genetic data quality control, 680 lung transplant recipients were included in the analysis. In phase 1, a total of 17 variants were significantly associated with PGD, four of which were in the prostaglandin E2 family of genes. Among these were a coding variant in the gene encoding prostaglandin E2 synthase (PTGES2; P = 9.3 10?5) resulting in an arginine to histidine substitution at amino acid position 298, and three variants in a block containing the 5? promoter and first intron of the PTGER4 gene (encoding prostaglandin E2 receptor subtype 4; all P < 5 10?5). Functional evaluation in regulatory T cells identified that rs4434423A in the PTGER4 gene was associated with differential suppressive function of regulatory T cells. Conclusions: Further research aimed at replication and additional functional insight into the role played by genetic variation in prostaglandin E2 synthetic and signaling pathways in PGD is warranted. PMID:24467603

  5. Advanced Stirling Convertor (ASC-E2) Performance Testing at NASA Glenn Research Center

    NASA Technical Reports Server (NTRS)

    Oriti, Salvatore; Wilson, Scott

    2011-01-01

    The National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) has been supporting development of the Advanced Stirling Radioisotope Generator (ASRG) since 2006. A key element of the ASRG Project is providing life, reliability, and performance testing of the Advanced Stirling Convertor (ASC). For this purpose, four pairs of ASCs capable of operating to 850 C and designated with the model number ASC-E2, were delivered by Sunpower of Athens, OH, to GRC in 2010. The ASC-E2s underwent a series of tests that included workmanship vibration testing, performance mapping, and extended operation. Workmanship vibration testing was performed following fabrication of each convertor to verify proper hardware build. Performance mapping consisted of operating each convertor at various conditions representing the range expected during a mission. Included were conditions representing beginning-of-mission (BOM), end-of-mission (EOM), and fueling. This same series of tests was performed by Sunpower prior to ASC-E2 delivery. The data generated during the GRC test were compared to performance before delivery. Extended operation consisted of a 500-hour period of operation with conditions maintained at the BOM point. This was performed to demonstrate steady convertor performance following performance mapping. Following this initial 500-hour period, the ASC-E2s will continue extended operation, controller development and special durability testing, during which the goal is to accumulate tens of thousands of hours of operation. Data collected during extended operation will support reliability analysis. Performance data from these tests is summarized in this paper.

  6. Electrophile-modified lipoic derivatives of PDC-E2 elicits anti-mitochondrial antibody reactivity.

    PubMed

    Naiyanetr, Phornnop; Butler, Jeffrey D; Meng, Liping; Pfeiff, Janice; Kenny, Thomas P; Guggenheim, Kathryn G; Reiger, Roman; Lam, Kit; Kurth, Mark J; Ansari, Aftab A; Coppel, Ross L; Lpez-Hoyos, Marcos; Gershwin, M Eric; Leung, Patrick S C

    2011-11-01

    Our laboratory has hypothesized that xenobiotic modification of the native lipoyl moiety of the major mitochondrial autoantigen, the E2 subunit of the pyruvate dehydrogenase complex (PDC-E2), may lead to loss of self-tolerance in primary biliary cirrhosis (PBC). This thesis is based on the finding of readily detectable levels of immunoreactivity of PBC sera against extensive panels of protein microarrays containing mimics of the inner lipoyl domain of PDC-E2 and subsequent quantitative structure-activity relationships (QSARs). Importantly, we have demonstrated that murine immunization with one such mimic, 2-octynoic acid coupled to bovine serum albumin (BSA), induces anti-mitochondrial antibodies (AMAs) and cholangitis. Based upon these data, we have focused on covalent modifications of the lipoic acid disulfide ring and subsequent analysis of such xenobiotics coupled to a 15mer of PDC-E2 for immunoreactivity against a broad panel of sera from patients with PBC and controls. Our results demonstrate that AMA-positive PBC sera demonstrate marked reactivity against 6,8-bis(acetylthio)octanoic acid, implying that chemical modification of the lipoyl ring, i.e. disruption of the S-S disulfide, renders lipoic acid to its reduced form that will promote xenobiotic modification. This observation is particularly significant in light of the function of the lipoyl moiety in electron transport of which the catalytic disulfide constantly opens and closes and, thus, raises the intriguing thesis that common electrophilic agents, i.e. acetaminophen or non-steroidal anti-inflammatory drugs (NSAIDs), may lead to xenobiotic modification in genetically susceptible individuals that results in the generation of AMAs and ultimately clinical PBC. PMID:21763105

  7. Rapid estrogenic regulation of extracellular signal- regulated kinase 1/2 signaling in cerebellar granule cells involves a G protein- and protein kinase A-dependent mechanism and intracellular activation of protein phosphatase 2A.

    PubMed

    Belcher, Scott M; Le, Hoa H; Spurling, Lynda; Wong, Jeremy K

    2005-12-01

    In neonatal rat cerebellar neurons, 17beta-estradiol (E(2)) rapidly stimulates ERK1/2 phosphorylation through a membrane-associated receptor. Here the mechanism of rapid E(2)-induced ERK1/2 signaling in primary cultured granule cells was investigated in more detail. The results of these studies show that E(2) and ICI182,780, a steroidal antagonist of estrogen receptor transactivation, rapidly increased ERK signaling with a time course similar to the transient activation induced by epidermal growth factor (EGF). However, EGF receptor (EGFR) autophosphorylation was not increased by E(2), and blockade of EGFR tyrosine kinase activity did not abrogate the rapid actions of E(2). The involvement of Src-tyrosine kinase activity was demonstrated by detection of increased c-Src phosphorylation in response to E(2) and by blockade of E(2)-induced ERK1/2 activation by inhibition of Src-family tyrosine kinase activity. Inhibition of Galphai signaling or protein kinase A (PKA) activity blocked the ability of ICI182,780 to rapidly stimulate ERK signaling. Under those conditions, E(2) treatment induced a rapid and transient suppression of basal ERK1/2 phosphorylation. Protein phosphatase 2A (PP2A) activity was rapidly increased by E(2) but not by E(2) covalently linked to BSA. Rapid E(2)-induced increases in PP2A activity were insensitive to pertussis toxin. The presented evidence indicates that the rapid effects of estrogens on ERK signaling in cerebellar granule cells are induced through a novel G protein-coupled receptor mechanism that requires PKA and Src-kinase activity to link E(2) to the ERK/MAPK signaling module. Along with stimulating ERK signaling, E(2) rapidly activates PP2A via an independent signaling mechanism that may serve as a cell-specific regulator of signal duration. PMID:16123167

  8. Broadly Neutralizing Alphavirus Antibodies Bind an Epitope on E2 and Inhibit Entry and Egress.

    PubMed

    Fox, Julie M; Long, Feng; Edeling, Melissa A; Lin, Hueylie; van Duijl-Richter, Mareike K S; Fong, Rachel H; Kahle, Kristen M; Smit, Jolanda M; Jin, Jing; Simmons, Graham; Doranz, Benjamin J; Crowe, James E; Fremont, Daved H; Rossmann, Michael G; Diamond, Michael S

    2015-11-19

    We screened a panel of mouse and human monoclonal antibodies (MAbs) against chikungunya virus and identified several with inhibitory activity against multiple alphaviruses. Passive transfer of broadly neutralizing MAbs protected mice against infection by chikungunya, Mayaro, and O'nyong'nyong alphaviruses. Using alanine-scanning mutagenesis, loss-of-function recombinant proteins and viruses, and multiple functional assays, we determined that broadly neutralizing MAbs block multiple steps in the viral lifecycle, including entry and egress, and bind to a conserved epitope on the B domain of the E2 glycoprotein. A 16 Å resolution cryo-electron microscopy structure of a Fab fragment bound to CHIKV E2 B domain provided an explanation for its neutralizing activity. Binding to the B domain was associated with repositioning of the A domain of E2 that enabled cross-linking of neighboring spikes. Our results suggest that B domain antigenic determinants could be targeted for vaccine or antibody therapeutic development against multiple alphaviruses of global concern. PMID:26553503

  9. Two hepatitis C virus glycoprotein E2 products with different C termini.

    PubMed Central

    Mizushima, H; Hijikata, M; Asabe, S; Hirota, M; Kimura, K; Shimotohno, K

    1994-01-01

    Processing of the boundary region between the putative structural and nonstructural regions of the hepatitis C virus precursor polyprotein was analyzed by in vitro translation using reticulocyte lysate in the presence of canine microsomal membranes. At this boundary in the precursor polyprotein, the most carboxy-terminal of the structural proteins, gp70 (E2), is proximal to the amino terminal of the nonstructural protein p21 (NS2). The presence of a novel microsomal membrane-dependent cleavage site was observed at the region upstream of the amino-terminal end of p21 (NS2) in the precursor polyprotein. The cleavage site was assigned to amino acid residues 746/747 in the hepatitis C virus precursor polyprotein. Inefficient cleavage of this site resulted in the production of two forms of E2 products with different sizes of peptide backbones. Translation and cleavage of various C-terminal deletion constructs established the significance of the C-terminal hydrophobic amino acid sequences of E2 products in membrane anchoring. Images PMID:8083961

  10. New observations of asteroid (4179) Toutatis as closely observed by Chang’e-2

    NASA Astrophysics Data System (ADS)

    Ji, Jianghui; Jiang, Yun; Zhao, Yuhui

    2015-08-01

    Toutatis, as an Apollo near-Earth asteroid in an eccentric orbit, was successfully visited by Chang'e-2 on December 13th 2012 after the spacecraft completed its lunar exploration and an extended mission of space-environment exploration at the Sun-Earth Lagrangian point. This flyby as close as a distance of 770 m away from the asteroid’s surface, reveals many geological features on Toutatis’ surface, like concavities, boulders, lineaments and regolith, particularly an ~ 800 m giant basin at the end of the large lobe as well as a sharply perpendicular silhouette near the neck region, indicating that Toutatis is probably a rubble-pile asteroid (Huang et al. 2013). We further identify more than 200 boulders over the imaged area of Toutatis, and infer that most boulders cannot solely be generated by impact cratering, but probably originate from the fragments of parent body of Toutatis. Incorporation with ground-based radar observations over the last two decades, we investigate the orientation and the rotational parameters of Toutatis based on the images captured by Chang'e-2. Hence, Chang'e-2's flyby enables us to have an in-depth understanding of the formation and evolution of this asteroid.

  11. A specific subset of E2 ubiquitin-conjugating enzymes regulate Parkin activation and mitophagy differently.

    PubMed

    Fiesel, Fabienne C; Moussaud-Lamodire, Elisabeth L; Ando, Maya; Springer, Wolfdieter

    2014-08-15

    Loss-of-function mutations in the genes encoding PINK1 and Parkin (also known as PARK2) are the most common causes of recessive Parkinson's disease. Both together mediate the selective degradation of mitochondrial proteins and whole organelles via the proteasome and the autophagy-lysosome pathway (mitophagy). The mitochondrial kinase PINK1 activates and recruits the E3 ubiquitin ligase Parkin to de-energized mitochondria. However, the cognate E2 co-enzymes of Parkin in this ubiquitin-dependent pathway have not been investigated. Here, we discovered a total of four E2s that either positively or negatively regulate the activation, translocation and enzymatic functions of Parkin during mitochondrial quality control. UBE2D family members and UBE2L3 redundantly charged the RING-HECT hybrid ligase Parkin with ubiquitin, resulting in its initial activation and translocation to mitochondria. UBE2N, however, primarily operated through a different mechanism in order to mediate the proper clustering of mitochondria, a prerequisite for degradation. Strikingly, in contrast to UBE2D, UBE2L3 and UBE2N, depletion of UBE2R1 resulted in enhanced Parkin translocation and clustering upon mitochondrial uncoupling. Our study uncovered redundant, cooperative or antagonistic functions of distinct E2 enzymes in the regulation of Parkin and mitophagy that might suggest a putative role in Parkinson's disease pathogenesis. PMID:24928900

  12. A novel E2 box-GATA element modulates Cdc6 transcription during human cells polyploidization

    PubMed Central

    Vilaboa, Nuria; Bermejo, Rodrigo; Martinez, Pilar; Bornstein, Rafael; Cals, Carmela

    2004-01-01

    Cdc6 is a key regulator of the strict alternation of S and M phases during the mitotic cell cycle. In mammalian and plant cells that physiologically become polyploid, cdc6 is transcriptionally and post-translationally regulated. We have recently reported that Cdc6 levels are maintained in megakaryoblastic HEL cells, but severely downregulated by ectopic expression of transcriptional repressor Drosophila melanogaster escargot. Here, we show that cdc6 promoter activity is upregulated during megakaryocytic differentiation of HEL endoreplicating cells, and that Escargot interferes with such activation. Transactivation experiments showed that a 1.7 kb region located at 2800 upstream cdc6 transcription initiation site behaved as a potent enhancer in endoreplicating cells only. This activity was mainly dependent on a novel cis-regulatory element composed by an E2 box overlapping a GATA motif. Ectopic Escargot could bind this regulatory element in vitro and endogenous GATA-1 and E2A formed specific complexes in megakaryoblastic cells as well as in primary megakaryocytes. Chromatin Immunoprecipitation analysis revealed that both transcription factors were occupying the E2 box/GATA site in vivo. Altogether, these data suggest that cdc6 expression could be actively maintained during megakaryocytic differentiation through transcriptional mechanisms involving specific cis- and trans-regulatory elements. PMID:15590906

  13. CMIP5 historical simulations (1850-2012) with GISS ModelE2

    NASA Astrophysics Data System (ADS)

    Miller, Ron L.; Schmidt, Gavin A.; Nazarenko, Larissa S.; Tausnev, Nick; Bauer, Susanne E.; DelGenio, Anthony D.; Kelley, Max; Lo, Ken K.; Ruedy, Reto; Shindell, Drew T.; Aleinov, Igor; Bauer, Mike; Bleck, Rainer; Canuto, Vittorio; Chen, Yonghua; Cheng, Ye; Clune, Thomas L.; Faluvegi, Greg; Hansen, James E.; Healy, Richard J.; Kiang, Nancy Y.; Koch, Dorothy; Lacis, Andy A.; LeGrande, Allegra N.; Lerner, Jean; Menon, Surabi; Oinas, Valdar; Prez Garca-Pando, Carlos; Perlwitz, Jan P.; Puma, Michael J.; Rind, David; Romanou, Anastasia; Russell, Gary L.; Sato, Makiko; Sun, Shan; Tsigaridis, Kostas; Unger, Nadine; Voulgarakis, Apostolos; Yao, Mao-Sung; Zhang, Jinlun

    2014-06-01

    Observations of climate change during the CMIP5 extended historical period (1850-2012) are compared to trends simulated by six versions of the NASA Goddard Institute for Space Studies ModelE2 Earth System Model. The six models are constructed from three versions of the ModelE2 atmospheric general circulation model, distinguished by their treatment of atmospheric composition and the aerosol indirect effect, combined with two ocean general circulation models, HYCOM and Russell. Forcings that perturb the model climate during the historical period are described. Five-member ensemble averages from each of the six versions of ModelE2 simulate trends of surface air temperature, atmospheric temperature, sea ice and ocean heat content that are in general agreement with observed trends, although simulated warming is slightly excessive within the past decade. Only simulations that include increasing concentrations of long-lived greenhouse gases match the warming observed during the twentieth century. Differences in twentieth-century warming among the six model versions can be attributed to differences in climate sensitivity, aerosol and ozone forcing, and heat uptake by the deep ocean. Coupled models with HYCOM export less heat to the deep ocean, associated with reduced surface warming in regions of deepwater formation, but greater warming elsewhere at high latitudes along with reduced sea ice. All ensembles show twentieth-century annular trends toward reduced surface pressure at southern high latitudes and a poleward shift of the midlatitude westerlies, consistent with observations.

  14. E2-2 Dependent Plasmacytoid Dendritic Cells Control Autoimmune Diabetes

    PubMed Central

    Hansen, Lisbeth; Schmidt-Christensen, Anja; Gupta, Shashank; Fransén-Pettersson, Nina; Hannibal, Tine D.; Reizis, Boris; Santamaria, Pere; Holmberg, Dan

    2015-01-01

    Autoimmune diabetes is a consequence of immune-cell infiltration and destruction of pancreatic β-cells in the islets of Langerhans. We analyzed the cellular composition of the insulitic lesions in the autoimmune-prone non-obese diabetic (NOD) mouse and observed a peak in recruitment of plasmacytoid dendritic cells (pDCs) to NOD islets around 8–9 weeks of age. This peak coincides with increased spontaneous expression of type-1-IFN response genes and CpG1585 induced production of IFN-α from NOD islets. The transcription factor E2-2 is specifically required for the maturation of pDCs, and we show that knocking out E2-2 conditionally in CD11c+ cells leads to a reduced recruitment of pDCs to pancreatic islets and reduced CpG1585 induced production of IFN-α during insulitis. As a consequence, insulitis has a less aggressive expression profile of the Th1 cytokine IFN-γ and a markedly reduced diabetes incidence. Collectively, these observations demonstrate a disease-promoting role of E2-2 dependent pDCs in the pancreas during autoimmune diabetes in the NOD mouse. PMID:26624013

  15. CMIP5 Historical Simulations (1850-2012) with GISS ModelE2

    NASA Technical Reports Server (NTRS)

    Miller, Ronald Lindsay; Schmidt, Gavin A.; Nazarenko, Larissa S.; Tausnev, Nick; Bauer, Susanne E.; DelGenio, Anthony D.; Kelley, Max; Lo, Ken K.; Ruedy, Reto; Shindell, Drew T.; Aleinov, Igor; Bauer, Mike; Bleck, Rainer; Canuto, Vittorio; Chen, Yonghua; Cheng, Ye; Clune, Thomas L.; Faluvegi, Greg; Healy, Richard J.; Kiang, Nancy Y.; Lacis, Andy A.; LeGrande, Allegra N.; Lerner, Jean; Rind, David; Russell, Gary L.

    2014-01-01

    Observations of climate change during the CMIP5 extended historical period (1850-2012) are compared to trends simulated by six versions of the NASA Goddard Institute for Space Studies ModelE2 Earth System Model. The six models are constructed from three versions of the ModelE2 atmospheric general circulation model, distinguished by their treatment of atmospheric composition and the aerosol indirect effect, combined with two ocean general circulation models, HYCOM and Russell. Forcings that perturb the model climate during the historical period are described. Five-member ensemble averages from each of the six versions of ModelE2 simulate trends of surface air temperature, atmospheric temperature, sea ice and ocean heat content that are in general agreement with observed trends, although simulated warming is slightly excessive within the past decade. Only simulations that include increasing concentrations of long-lived greenhouse gases match the warming observed during the twentieth century. Differences in twentieth-century warming among the six model versions can be attributed to differences in climate sensitivity, aerosol and ozone forcing, and heat uptake by the deep ocean. Coupled models with HYCOM export less heat to the deep ocean, associated with reduced surface warming in regions of deepwater formation, but greater warming elsewhere at high latitudes along with reduced sea ice. All ensembles show twentieth-century annular trends toward reduced surface pressure at southern high latitudes and a poleward shift of the midlatitude westerlies, consistent with observations.

  16. A specific subset of E2 ubiquitin-conjugating enzymes regulate Parkin activation and mitophagy differently

    PubMed Central

    Fiesel, Fabienne C.; Moussaud-Lamodière, Elisabeth L.; Ando, Maya; Springer, Wolfdieter

    2014-01-01

    ABSTRACT Loss-of-function mutations in the genes encoding PINK1 and Parkin (also known as PARK2) are the most common causes of recessive Parkinson's disease. Both together mediate the selective degradation of mitochondrial proteins and whole organelles via the proteasome and the autophagy-lysosome pathway (mitophagy). The mitochondrial kinase PINK1 activates and recruits the E3 ubiquitin ligase Parkin to de-energized mitochondria. However, the cognate E2 co-enzymes of Parkin in this ubiquitin-dependent pathway have not been investigated. Here, we discovered a total of four E2s that either positively or negatively regulate the activation, translocation and enzymatic functions of Parkin during mitochondrial quality control. UBE2D family members and UBE2L3 redundantly charged the RING-HECT hybrid ligase Parkin with ubiquitin, resulting in its initial activation and translocation to mitochondria. UBE2N, however, primarily operated through a different mechanism in order to mediate the proper clustering of mitochondria, a prerequisite for degradation. Strikingly, in contrast to UBE2D, UBE2L3 and UBE2N, depletion of UBE2R1 resulted in enhanced Parkin translocation and clustering upon mitochondrial uncoupling. Our study uncovered redundant, cooperative or antagonistic functions of distinct E2 enzymes in the regulation of Parkin and mitophagy that might suggest a putative role in Parkinson's disease pathogenesis. PMID:24928900

  17. Studies on orientation and rotation parameters of 4179 Toutatis from Chang'e-2 mission

    NASA Astrophysics Data System (ADS)

    Zhao, Yuhui; Ji, Jianghui; Hu, Shoucun

    The ginger-shaped near-Earth asteroid 4179 Toutatis is close to a 4:1 orbital resonance with the Earth and has made close Earth flybys approximately every four years in the recent 20 years. China’s lunar probe Chang’e-2 achieved a successful flyby the Toutatis on 13th Dec 2012 during its most recent flyby of Earth. During the mission, a series of image with high resolution has been obtained. Combined with the radar model of Toutatis, these figures show the attitude of the asteroid from the camera’s point of view and the orientation of it is then deduced based on the attitude of the camera and the relative position between 4179 Toutatis and Chang'e-2 in our works. According to the previous ground-based observations and works on the rotation parameters of Toutatis, this paper studies the rotating rate of the asteroid in accordance with the imaging result of Toutatis by Chang’e-2 and puts forward a correction to the spin rate parameters.

  18. Lysine Activation and Functional Analysis of E2-Mediated Conjugation in the SUMO Pathway

    SciTech Connect

    Yunus,A.; Lima, C.

    2006-01-01

    E2 conjugating proteins that transfer ubiquitin and ubiquitin-like modifiers to substrate lysine residues must first activate the lysine nucleophile for conjugation. Genetic complementation revealed three side chains of the E2 Ubc9 that were crucial for normal growth. Kinetic analysis revealed modest binding defects but substantially lowered catalytic rates for these mutant alleles with respect to wild-type Ubc9. X-ray structures for wild-type and mutant human Ubc9-RanGAP1 complexes showed partial loss of contacts to the substrate lysine in mutant complexes. Computational analysis predicted pK perturbations for the substrate lysine, and Ubc9 mutations weakened pK suppression through improper side chain coordination. Biochemical studies with p53, RanGAP1 and the Nup358/RanBP2 E3 were used to determine rate constants and pK values, confirming both structural and computational predictions. It seems that Ubc9 uses an indirect mechanism to activate lysine for conjugation that may be conserved among E2 family members.

  19. Biocontrol of Salmonella Typhimurium in RTE foods with the virulent bacteriophage FO1-E2.

    PubMed

    Guenther, Susanne; Herzig, Oliver; Fieseler, Lars; Klumpp, Jochen; Loessner, Martin J

    2012-03-01

    Foodborne Salmonella infections are a major public health concern worldwide. Bacteriophages offer highly specific and effective biocontrol of such pathogens. We evaluated the broad host range, virulent phage FO1-E2 for reduction of Salmonella Typhimurium in different RTE foods. Samples were spiked with 110 Salmonella cells and treated with 310? pfu/g phage, and incubated for 6 days at 8 C or 15 C. At 8 C, no viable cells remained following FO1-E2 application, corresponding to a more than 3 log?? unit reduction. At 15 C, application of phage lowered S. Typhimurium counts by 5 log units on turkey deli meat and in chocolate milk, and by 3 logs on hot dogs and in seafood. In egg yolk, an effect was observed only after 2 days, but not after 6 days. Phage particles retained their infectivity, although they were readily immobilized by the food matrix, resulting in loss of their ability to diffuse and infect target cells. At the end of the incubation period, phage-resistant Salmonella strains appeared which, however, were not able to compensate for the initial killing effect. Altogether, our data show that virulent phages such as FO1-E2 offer an effective biocontrol measure for Salmonella in foods. PMID:22244192

  20. Sertoli-Leydig cell tumors: hormonal profile after dynamic test with GnRH analogue: triptorelin represents a useful tool to evaluate tumoral hyperandrogenism.

    PubMed

    Turra, J; Granzotto, M; Gallea, M; Faggian, D; Conte, L; Litta, P; Vettor, R; Mioni, R

    2015-01-01

    We report the case of a 15-year-old woman with signs of hyperandrogenism affected by a Sertoli-Leydig cell tumor (SLCT). In our patient, blood analysis showed a high testosterone (T) level (T: 8.53?nmol/L; nv?17-beta estradiol (E2) and T, from 2 to 18 times higher than healthy women. When we compared our patient with healthy men, we differently observed a comparable response of T. The response of our patient was also comparable with that observed in the PCOS group for E2. During the post-surgical follow up, the GnRH-analogue test of our patient showed a response of OHP, T, and E2 comparable with that of the PCOS group. The GnRH-analogue test is a useful tool to characterize steroidogenesis in SLCT. PMID:25299229

  1. Antiestrogenic effects of marijuana smoke condensate and cannabinoid compounds.

    PubMed

    Lee, Soo Yeun; Oh, Seung Min; Lee, Sang Ki; Chung, Kyu Hyuck

    2005-12-01

    The antiestrogenic effects of marijuana smoke condensate (MSC) and three major cannabinoids, ie., delta9-tetrahydrocannabinol (THC), cannabidiol (CBD), and cannabinol (CBN), were evaluated using in vitro bioassays, viz., the human breast cancer cell proliferation assay, the recombinant human estrogen receptor (ER) competitive binding assay, and the reporter gene assay. The inhibitory effects on estrogen were also examined using the ethoxyresorufin-O-deethylase (EROD) assay, the aromatase assay, and the 17beta-estradiol (E2) metabolism assay. The results showed that MSC induced the antiestrogenic effect via the ER-mediated pathway, while THC, CBD, and CBN did not have any antiestrogenic activity. This suggests that the combined effects of the marijuana smoke components are responsible for the antiestrogenicity of marijuana use. In addition, MSC induced the CYP1A activity and the E2 metabolism, but inhibited the aromatase activity, suggesting that the antiestrogenic activity of MSC is also related to the indirect ER-dependent pathway, as a result of the depletion of the in situ E2 level available to bind to the ER. In conclusion, pyrogenic products including polycyclic aromatic hydrocarbons (PAHs) in the non-polar fraction, which is the most biologically active fraction among the seven fractions of MSC, might be responsible for the antiestrogenic effect. PMID:16392670

  2. Regulation of mitochondrial respiratory chain biogenesis by estrogens/estrogen receptors and physiological, pathological and pharmacological implications.

    PubMed

    Chen, Jin-Qiang; Cammarata, Patrick R; Baines, Christopher P; Yager, James D

    2009-10-01

    There has been increasing evidence pointing to the mitochondrial respiratory chain (MRC) as a novel and important target for the actions of 17beta-estradiol (E(2)) and estrogen receptors (ER) in a number of cell types and tissues that have high demands for mitochondrial energy metabolism. This novel E(2)-mediated mitochondrial pathway involves the cooperation of both nuclear and mitochondrial ERalpha and ERbeta and their co-activators on the coordinate regulation of both nuclear DNA- and mitochondrial DNA-encoded genes for MRC proteins. In this paper, we have: 1) comprehensively reviewed studies that reveal a novel role of estrogens and ERs in the regulation of MRC biogenesis; 2) discussed their physiological, pathological and pharmacological implications in the control of cell proliferation and apoptosis in relation to estrogen-mediated carcinogenesis, anti-cancer drug resistance in human breast cancer cells, neuroprotection for Alzheimer's disease and Parkinson's disease in brain, cardiovascular protection in human heart and their beneficial effects in lens physiology related to cataract in the eye; and 3) pointed out new research directions to address the key questions in this important and newly emerging area. We also suggest a novel conceptual approach that will contribute to innovative regimens for the prevention or treatment of a wide variety of medical complications based on E(2)/ER-mediated MRC biogenesis pathway. PMID:19559056

  3. Effects of postoperative adjuvant chemotherapy and radiotherapy on ovarian function in women undergoing treatment for soft tissue sarcoma

    SciTech Connect

    Shamberger, R.C.; Sherins, R.J.; Ziegler, J.L.; Glatstein, E.; Rosenberg, S.A.

    1981-12-01

    Ovarian function was evaluated in 11 women 16 to 43 years of age at treatment who received doxorubicin, cyclophosphamide, and high doses of methotrexate with or without radiotherapy in adjuvant therapy of soft tissue sarcoma. Five women (16-33 yr old) who received chemotherapy alone or combined with radiotherapy only at sites distant from the ovaries (chest wall, thigh, and leg) had minimal menstrual irregularities or temporary cessation of menses during therapy; cyclic menses returned promptly after therapy. Gonadotropin levels (expressed as means +/- SD (follicle-stimulating hormone (FSH), 10 +/- 5 mlU/ml; luteinizing hormone (LH), 10 +/- 4 mlU/ml) and 17 beta-estradiol (E2) levels (means +/- SD, 208 +/- 147 pg/ml) were normal. By contrast, 4 older women (ages 36-43 yr) who received similar treatment developed persistent amenorrhea with postmenopausal levels of gonadotropin (FSH, 108 +/- 29 mlU/ml; LH, 72 +/- 19 mlU/ml) and E2 (19 +/- 8 pg/ml). Two additional women (ages 21 and 39 yr) who received radiation (7,000 rad) to the pelvis plus chemotherapy developed prompt cessation of menses and became functional castrates (FSH, 77 and 80 mlU/ml; LH, 40 and 58 mlU/ml; E2, 10 and 19 pg/ml). However, this result would be expected from the radiation dose alone. The data demonstrated that ovarian dysfunction may follow the use of doxorubicin, cyclophosphamide, and high doses of methotrexate and that the injury is age related.

  4. Induction of osteoblast differentiation by selective activation of kinase-mediated actions of the estrogen receptor.

    PubMed

    Kousteni, Stavroula; Almeida, Maria; Han, Li; Bellido, Teresita; Jilka, Robert L; Manolagas, Stavros C

    2007-02-01

    Estrogens control gene transcription by cis or trans interactions of the estrogen receptor (ER) with target DNA or via the activation of cytoplasmic kinases. We report that selective activation of kinase-mediated actions of the ER with 4-estren-3alpha,17beta-diol (estren) or an estradiol-dendrimer conjugate, each a synthetic compound that stimulates kinase-mediated ER actions 1,000 to 10,000 times more potently than direct DNA interactions, induced osteoblastic differentiation in established cell lines of uncommitted osteoblast precursors and primary cultures of osteoblast progenitors by stimulating Wnt and BMP-2 signaling in a kinase-dependent manner. In sharp contrast, 17beta-estradiol (E(2)) suppressed BMP-2-induced osteoblast progenitor commitment and differentiation. Consistent with the in vitro findings, estren, but not E(2), stimulated Wnt/beta-catenin-mediated transcription in T-cell factor-lacZ transgenic mice. Moreover, E(2) stimulated BMP signaling in mice in which ERalpha lacks DNA binding activity and classical estrogen response element-mediated transcription (ERalpha(NERKI/-)) but not in wild-type controls. This evidence reveals for the first time the existence of a large signalosome in which inputs from the ER, kinases, bone morphogenetic proteins, and Wnt signaling converge to induce differentiation of osteoblast precursors. ER can either induce it or repress it, depending on whether the activating ligand (and presumably the resulting conformation of the receptor protein) precludes or accommodates ERE-mediated transcription. PMID:17158928

  5. Lack of activity of cadmium in in vitro estrogenicity assays

    SciTech Connect

    Silva, Elisabete . E-mail: elisabete.silva@pharmacy.ac.uk; Lopez-Espinosa, Maria Jose; Molina-Molina, Jose-Manuel; Fernandez, Marieta; Olea, Nicolas; Kortenkamp, Andreas

    2006-10-01

    Prompted by reports about strong estrogenic effects of cadmium, attempts were made to reproduce these observations using the yeast estrogen screen (YES) and the E-Screen assays. For the first time, possible activation of the Src/MAPK pathway was also investigated. In the YES, only a slight activation (10% of a maximal effect) of the estrogen receptor alpha (ER{alpha}) was observed at cadmium concentrations between 5 x 10{sup -7} M and 5 x 10{sup -6} M. In the E-Screen assay, carried out by two laboratories, the heavy metal was without observable cell proliferative effects when tested in the range between 6 x 10{sup -11} M and 1 x 10{sup -5} M. However, in both assays, cadmium led to a reduction of the effects of 17{beta}-estradiol (E2). Treatment of MCF-7 human breast cancer cells with 1 x 10{sup -7} M cadmium failed to induce phosphorylation of Src and the MAP kinases Erk1 and Erk2-effects shown to occur with E2 and epidermal growth factor (EGF). In summary, we were unable to confirm the strong estrogenicity of cadmium reported recently by a number of laboratories. This apparent absence of effects in our hands is not due to a lack of uptake of the metal or to effective protection against cadmium by high levels of glutathione or metallothionein, since toxicity and an antagonism of E2 responses were observed both in the YES and the E-Screen.

  6. Effect of sex hormones on human T cell activation by concanavalin A.

    PubMed

    Yron, I; Langer, A; Weinstein, T; Sahar, E; Lidor, Y; Pardo, Y; Katz, I; Shohat, L; Kalechman, Y; Ovadia, J

    1991-01-01

    The effect of sex hormones on concanavalin A (Con A)-activated human T cells was studied. We show that neither 17 beta-estradiol (E2) nor progesterone, in concentrations of up to 10(-6) M, alters the proliferative response of peripheral-blood mononuclear cells (PBMC) of healthy postmenopausal women. Furthermore, the hormones had no effect on the composition of T cell populations and on the expression of activation markers. We extended our study to a unique T cell population that is characterized by the ability to form rosettes with human erythrocytes, following Con A activation (designated autorosette-forming cells; ARFC) and known to manifest suppressive activity. Indeed, the in vitro addition of E2 (neither progesterone nor testosterone) to Con A-stimulated PBMC brought an about 2- to 4-fold increase in the frequency of ARFC. Tamoxifen, an antiestrogen drug, reduced the frequency of estrogen-stimulated ARFC to the original low level. Furthermore, the inhibitory effect of growth medium from ARFC cultures originally stimulated with Con A + E2 was found to be higher than that of ARFC cultures originally stimulated with Con A alone. PMID:2057020

  7. Metabolism of testosterone by human granulosa cells in culture: influence of follicle-stimulating hormone and luteinizing hormone

    SciTech Connect

    Moon, Y.S.; Duleba, A.; Leung, P.C.; Gomel, V.

    1982-03-15

    Human granulosa cells were isolated from follicles (8 to 15 mm) and cultivated for 24 hours in the presence or absence of follicle-stimulating hormone (NIH-FSH-HS-1, 1 microgram/ml) and luteinizing hormone (NIAMDD-hLH-1, 1 microgram/ml). Testosterone -4-14C was added subsequently to all cultures for 4-, 6-, and 24-hour periods. Of the seven metabolites of testosterone studied, 17 beta-estradiol (E2) and estrone (E1) were the major products. In all patients, levels of E2 were three to ten times higher than those of E1. Production of E2, but not E1, was stimulated by either follicle-stimulating hormone (FSH) or luteinizing hormone (LH). The cells of the largest follicle (15 mm) showed greater response to LH than to FSH. Production of the other C19 and C18 metabolites was very low or negligible. These results further suggest that FSH regulates the aromatization of testosterone in human granulosa cells, and that LH may have the same effect on the matured follicle during the preovulatory period.

  8. Disrupted Organization of RFamide Pathways in the Hypothalamus Is Associated with Advanced Puberty in Female Rats Neonatally Exposed to Bisphenol A1

    PubMed Central

    Losa-Ward, Sandra M.; Todd, Karina L.; McCaffrey, Katherine A.; Tsutsui, Kazuyoshi; Patisaul, Heather B.

    2012-01-01

    ABSTRACT Hypothalamic neurons, which produce the kisspeptin family of peptide hormones (Kp), are critical for initiating puberty and maintaining estrous cyclicity by stimulating gonadotropin-releasing hormone (GnRH) release. Conversely, RFamide-related peptide-3 (RFRP3) neurons inhibit GnRH activity. It has previously been shown that neonatal exposure to bisphenol A (BPA) can alter the timing of female pubertal onset and induce irregular estrous cycles or premature anestrus. Here we tested the hypothesis that disrupted ontogeny of RFamide signaling pathways may be a mechanism underlying advanced puberty. To test this, we used a transgenic strain of Wistar rats whose GnRH neurons express enhanced green fluorescent protein. Pups were exposed by daily subcutaneous injection to vehicle, 17beta-estradiol (E2), 50 μg/kg BPA, or 50 mg/kg BPA, from Postnatal Day (PND) 0 through PND 3, and then cohorts were euthanized on PNDs 17, 21, 24, 28, and 33 (5–8 animals per age per exposure; males were collected on PNDs 21 and 33). Vaginal opening was advanced by E2 and 50 μg/kg BPA. On PND 28, females exposed to E2 and 50 μg/kg BPA had decreased RFRP-3 fiber density and contacts on GnRH neurons. RFRP3 perikarya were also decreased in females exposed to 50 μg/kg BPA. Data suggest that BPA-induced premature puberty results from decreased inhibition of GnRH neurons. PMID:22572997

  9. Structure Determination and Characterization of the Vitamin B[superscript 6] Degradative Enzyme (E)-2-(Acetamidomethylene)succinate Hydrolase

    SciTech Connect

    McCulloch, Kathryn M.; Mukherjee, Tathagata; Begley, Tadhg P.; Ealick, Steven E.

    2010-06-22

    The gene identification and kinetic characterization of (E)-2-(acetamidomethylene)succinate (E-2AMS) hydrolase has recently been described. This enzyme catalyzes the final reaction in the degradation of vitamin B{sub 6} and produces succinic semialdehyde, acetate, ammonia, and carbon dioxide from E-2AMS. The structure of E-2AMS hydrolase was determined to 2.3 {angstrom} using SAD phasing. E-2AMS hydrolase is a member of the {alpha}/{beta} hydrolase superfamily and utilizes a serine/histidine/aspartic acid catalytic triad. Mutation of either the nucleophilic serine or the aspartate resulted in inactive enzyme. Mutation of an additional serine residue in the active site causes the enzyme to be unstable and is likely structurally important. The structure also provides insight into the mechanism of hydrolysis of E-2AMS and identifies several potential catalytically important residues.

  10. Targeted gene mutation of E2F1 evokes age-dependent synaptic disruption and behavioral deficits

    PubMed Central

    Ting, Jenhao H.; Marks, David R.; Schleidt, Stephanie S.; Wu, Joanna N.; Zyskind, Jacob W.; Lindl, Kathryn A.; Blendy, Julie A.; Pierce, R. Christopher; Jordan-Sciutto, Kelly L.

    2014-01-01

    Aberrant expression and activation of the cell cycle protein E2F1 in neurons has been implicated in many neurodegenerative diseases. As a transcription factor regulating G1 to S phase progression in proliferative cells, E2F1 is often upregulated and activated in models of neuronal death. However, despite its well studied functions in neuronal death, little is known regarding the role of E2F1 in the mature brain. In the present study, we used a combined approach to study the effect of E2F1 gene disruption on mouse behavior and brain biochemistry. We identified significant age-dependent olfactory and memory related deficits in E2f1 mutant mice. In addition, we found that E2F1 exhibits punctated staining and localizes closely to the synapse. Furthermore, we found a mirroring age-dependent loss of postsynaptic protein-95 in the hippocampus and olfactory bulb as well as a global loss of several other synaptic proteins. Coincidently, E2F1 expression is significantly elevated at the ages in which behavioral and synaptic perturbations were observed. Lastly, we show that deficits in adult neurogenesis persist late in aged E2f1 mutant mice which may partially contribute to the behavior phenotypes. Taken together, our data suggest that the disruption of E2F1 function leads to specific age-dependent behavioral deficits and synaptic perturbations. PMID:24460902

  11. Characterization of a peptide domain within the GB virus C envelope glycoprotein (E2) that inhibits HIV replication.

    PubMed

    Xiang, Jinhua; McLinden, James H; Kaufman, Thomas M; Mohr, Emma L; Bhattarai, Nirjal; Chang, Qing; Stapleton, Jack T

    2012-08-15

    GB virus C (GBV-C) infection is associated with prolonged survival in HIV-infected cohorts, and GBV-C E2 protein inhibits HIV entry when added to CD4+ T cells. To further characterize E2 effects on HIV replication, stably transfected Jurkat cell lines expressing GBV-C E2 or control sequences were infected with HIV and replication was measured. HIV replication (all 6 isolates studied) was inhibited in all cell lines expressing a region of 17 amino acids of GBV-C E2, but not in cell lines expressing E2 without this region. In contrast, mumps and yellow fever virus replication was not inhibited by E2 protein expression. Synthetic GBV-C E2 17mer peptides did not inhibit HIV replication unless they were fused to a tat-protein-transduction-domain (TAT) for cellular uptake. These data identify the region of GBV-C E2 protein involved in HIV inhibition, and suggest that this GBV-C E2 peptide must gain entry into the cell to inhibit HIV. PMID:22608061

  12. Enhancing expression of the classical swine fever virus glycoprotein E2 in yeast and its application to a blocking ELISA.

    PubMed

    Cheng, Chih-Yuan; Wu, Ching-Wei; Lin, Guang-Jan; Lee, Wei-Cheng; Chien, Maw-Sheng; Huang, Chienjin

    2014-03-20

    Classical swine fever virus (CSFV) infection is a severe swine disease, often causing large economic losses. A Pichia pastoris yeast-expressed CSFV glycoprotein E2 (yE2) has been shown to induce a protective immune response against the virus. To improve the expression level of yE2, the first codon of E2 gene, Arg (CGG), which is the least used in P. pastoris, was optimized to the most favorite codon AGA. The yield of E2 protein was remarkably increased in the codon optimized strain (N342). Three truncated E2 subunits encoding the N-terminal 330 (N330), 301 (N301), and 190 (N190) residues, respectively, were also constructed. The immunogenicity of each recombinant E2 subunits was confirmed by immunization of pigs, and all immunized groups demonstrated high neutralizing antibody titers after boost immunization, which lasted for a long period of time. In addition, a monoclonal antibody (MAb), 1B6, specific to yE2, was generated and shown to recognize CSFV-infected cells. A panel of swine sera were tested by peroxidase-conjugated MAb 1B6-based blocking enzyme-linked immunosorbent assay (ELISA) using N330 as coated antigen, and the assay demonstrated high sensitivity and specificity. The recombinant yE2 subunits may provide potential subunit vaccine candidates and useful diagnostic reagents for CSFV with easy manipulation and low cost. PMID:24468422

  13. Involvement of G protein-coupled receptor 30 (GPR30) in rapid action of estrogen in primate LHRH neurons.

    PubMed

    Noel, Sekoni D; Keen, Kim L; Baumann, David I; Filardo, Edward J; Terasawa, Ei

    2009-03-01

    Previously, we have reported that 17beta-estradiol (E(2)) induces an increase in firing activity of primate LH-releasing hormone (LHRH) neurons. The present study investigates whether E(2) alters LHRH release as well as the pattern of intracellular calcium ([Ca(2+)](i)) oscillations and whether G protein-coupled receptor 30 (GPR30) plays a role in mediating the rapid E(2) action in primate LHRH neurons. Results are summarized: 1) E(2), the nuclear membrane-impermeable estrogen, estrogen-dendrimer conjugate, and the plasma membrane-impermeable estrogen, E(2)-BSA conjugate, all stimulated LHRH release within 10 min of exposure; 2) whereas the estrogen receptor antagonist, ICI 182,780, did not block the E(2)-induced LHRH release, E(2) application to cells treated with pertussis toxin failed to induce LHRH release; 3) GPR30 mRNA was expressed in olfactory placode cultures, and GPR30 protein was expressed in a subset of LHRH neurons; 4) pertussis toxin treatment blocked the E(2)-induced increase in [Ca(2+)](i) oscillations; 5) knockdown of GPR30 in primate LHRH neurons by transfection with small interfering RNA (siRNA) for GPR30 completely abrogated the E(2)-induced changes in [Ca(2+)](i) oscillations, whereas transfection with control siRNA did not; 6) the estrogen-dendrimer conjugate-induced increase in [Ca(2+)](i) oscillations also did not occur in LHRH neurons transfected with GPR30 siRNA; and 7) G1, a GPR30 agonist, resulted in changes in [Ca(2+)](i) oscillations, similar to those observed with E(2). Collectively, E(2) induces a rapid excitatory effect on primate LHRH neurons, and this rapid action of E(2) appears to be mediated, in part, through GPR30. PMID:19131510

  14. Hyperforin, an Anti-Inflammatory Constituent from St. John's Wort, Inhibits Microsomal Prostaglandin E2 Synthase-1 and Suppresses Prostaglandin E2 Formation in vivo

    PubMed Central

    Koeberle, Andreas; Rossi, Antonietta; Bauer, Julia; Dehm, Friederike; Verotta, Luisella; Northoff, Hinnak; Sautebin, Lidia; Werz, Oliver

    2010-01-01

    The acylphloroglucinol hyperforin (Hyp) from St. John's wort possesses anti-inflammatory and anti-carcinogenic properties which were ascribed among others to the inhibition of 5-lipoxygenase. Here, we investigated whether Hyp also interferes with prostanoid generation in biological systems, particularly with key enzymes participating in prostaglandin (PG)E2 biosynthesis, i.e., cyclooxygenases (COX)-1/2 and microsomal PGE2 synthase (mPGES)-1 which play key roles in inflammation and tumorigenesis. Similar to the mPGES-1 inhibitors MK-886 and MD-52, Hyp significantly suppressed PGE2 formation in whole blood assays starting at 0.03–1 μM, whereas the concomitant generation of COX-derived 12(S)-hydroxy-5-cis-8,10-trans-heptadecatrienoic acid, thromboxane B2, and 6-keto PGF1α was not significantly suppressed up to 30 μM. In cell-free assays, Hyp efficiently blocked the conversion of PGH2 to PGE2 mediated by mPGES-1 (IC50 = 1 μM), and isolated COX enzymes were not (COX-2) or hardly (COX-1) suppressed. Intraperitoneal (i.p.) administration of Hyp (4 mg kg−1) to rats impaired exudate volume and leukocyte numbers in carrageenan-induced pleurisy associated with reduced PGE2 levels, and Hyp (given i.p.) inhibited carrageenan-induced mouse paw edema formation (ED50 = 1 mg kg−1) being superior over indomethacin (ED50 = 5 mg kg−1). We conclude that the suppression of PGE2 biosynthesis in vitro and in vivo by acting on mPGES-1 critically contributes to the anti-inflammatory efficiency of Hyp. PMID:21687502

  15. Evaluation of the global aerosol microphysical ModelE2-TOMAS model against satellite and ground-based observations

    NASA Astrophysics Data System (ADS)

    Lee, Y. H.; Adams, P. J.; Shindell, D. T.

    2015-03-01

    The TwO-Moment Aerosol Sectional (TOMAS) microphysics model has been integrated into the state-of-the-art general circulation model, GISS ModelE2. This paper provides a detailed description of the ModelE2-TOMAS model and evaluates the model against various observations including aerosol precursor gas concentrations, aerosol mass and number concentrations, and aerosol optical depths. Additionally, global budgets in ModelE2-TOMAS are compared with those of other global aerosol models, and the ModelE2-TOMAS model is compared to the default aerosol model in ModelE2, which is a one-moment aerosol (OMA) model (i.e. no aerosol microphysics). Overall, the ModelE2-TOMAS predictions are within the range of other global aerosol model predictions, and the model has a reasonable agreement (mostly within a factor of 2) with observations of sulfur species and other aerosol components as well as aerosol optical depth. However, ModelE2-TOMAS (as well as ModelE2-OMA) cannot capture the observed vertical distribution of sulfur dioxide over the Pacific Ocean, possibly due to overly strong convective transport and overpredicted precipitation. The ModelE2-TOMAS model simulates observed aerosol number concentrations and cloud condensation nuclei concentrations roughly within a factor of 2. Anthropogenic aerosol burdens in ModelE2-OMA differ from ModelE2-TOMAS by a few percent to a factor of 2 regionally, mainly due to differences in aerosol processes including deposition, cloud processing, and emission parameterizations. We observed larger differences for naturally emitted aerosols such as sea salt and mineral dust, as those emission rates are quite different due to different upper size cutoff assumptions.

  16. E6AP/UBE3A Ubiquitin Ligase Harbors Two E2?ubiquitin Binding Sites*

    PubMed Central

    Ronchi, Virginia P.; Klein, Jennifer M.; Haas, Arthur L.

    2013-01-01

    By exploiting 125I-polyubiquitin chain formation as a functional readout of enzyme activity, we have quantitatively examined the mechanism of human E6AP/UBE3A for the first time. Initial rate studies identify UbcH7 as the cognate E2 carrier protein for E6AP, although related Ubc5 isoforms and the ISG15-specific UbcH8 paralog also support E6AP with reduced efficacy due to impaired binding and catalytic competence. Initial rates of polyubiquitin chain formation displayed hyperbolic kinetics with respect to UbcH7 concentration (Km = 57.6 5.7 nm and kcat = 0.032 0.001 s?1) and substrate inhibition above 2 ?m. Competitive inhibition by an isosteric UbcH7C86S-ubiquitin oxyester substrate analog (Ki = 64 18 nm) demonstrates that Km reflects intrinsic substrate affinity. In contrast, noncompetitive inhibition by a UbcH7C86A product analog (Ki = 7 0.7 ?m) and substrate inhibition at high concentrations require two functionally distinct E2?ubiquitin substrate binding sites. The kinetics of polyubiquitin chain formation reflect binding at a cryptic Site 1 not previously recognized that catalyzes E6AP?ubiquitin thioester formation. Subsequent binding of E2?ubiquitin at the canonical Site 2 present in the extant crystal structure is responsible for polyubiquitin chain elongation. Other rate studies show that the conserved ?4 Phe849 residue is required for polyubiquitin chain formation rather than target protein conjugation as originally suggested. The present studies unambiguously preclude earlier models for the mechanism of Hect domain-catalyzed conjugation through the canonical binding site suggested by the crystal structure and define a novel two-step mechanism for formation of the polyubiquitin degradation signal. PMID:23439649

  17. Electronic, magnetic, transport, and thermal properties of single-crystalline UF e2A l10

    NASA Astrophysics Data System (ADS)

    Tro?, R.; Samsel-Czeka?a, M.; Talik, E.; Wawryk, R.; Gajek, Z.; Pasturel, M.

    2015-09-01

    The valence and core-level x-ray photoemission spectra (XPS), performed on an UF e2A l10 single crystal, were measured using the Al K? radiation. The results of valence XPS show practically two separate regions of spectral intensity, one just at the Fermi level (EF) and the other one being a wide content with its maximum at about 0.8 eV below EF. These give rise to two electronic configurations of the 5 f states in the studied aluminide, itinerant and localized ones, i.e., their dual character. In such a situation the corresponding valence spectra, calculated within the local density approximation (LDA), well explain the former configuration, being responsible for a metallic behavior of the studied compound. Moreover, this behavior is confirmed clearly also by our results of magnetotransport measurements. On the other hand, the obtained magnetic susceptibility, specific heat, electrical resistivity, and thermoelectric power data support very well the local character of the 5 f2 -electron configuration of the U4 + ion in UF e2A l10 having the orthorhombic and cage-type crystal structure. Based on that configuration, the magnetic and thermal characteristics of the compound were modeled by the effective crystal field (CF) potential in the intermediate coupling scheme using initial parameters obtained by the angular overlap model (AOM). The obtained final CF parameters yielded the CF level scheme, composed of only singlets, proper for orthorhombic symmetry. Such a set of singlets reproduces in a satisfactory way both the strongly anisotropic temperature variations of the magnetic susceptibility, measured along the three main crystallographic directions, as well as the Schottky anomaly, evaluated using specific heat results of isomorphic ThF e2A l10 as a phonon reference. Also, the strongly anisotropic behavior of the Seebeck coefficient and its low temperature maxima observed for the compound studied here have been explained roughly by the CF effect.

  18. Comparative analysis of the replicon regions of eleven ColE2-related plasmids.

    PubMed Central

    Hiraga, S; Sugiyama, T; Itoh, T

    1994-01-01

    The incA gene product of ColE2-P9 and ColE3-CA38 plasmids is an antisense RNA that regulates the production of the plasmid-coded Rep protein essential for replication. The Rep protein specifically binds to the origin and synthesizes a unique primer RNA at the origin. The IncB incompatibility is due to competition for the Rep protein among the origins of the same binding specificity. We localized the regions sufficient for autonomous replication of 15 ColE plasmids related to ColE2-P9 and ColE3-CA38 (ColE2-related plasmids), analyzed their incompatibility properties, and determined the nucleotide sequences of the replicon regions of 9 representative plasmids. The results suggest that all of these plasmids share common mechanisms for initiation of DNA replication and its control. Five IncA specificity types, 4 IncB specificity types, and 9 of the 20 possible combinations of the IncA and IncB types were found. The specificity of interaction of the Rep proteins and the origins might be determined by insertion or deletion of single nucleotides and substitution of several nucleotides at specific sites in the origins and by apparently corresponding insertion or deletion and substitution of amino acid sequences at specific regions in the C-terminal portions of the Rep proteins. For plasmids of four IncA specificity types, the nine-nucleotide sequences at the loop regions of the stem-loop structures of antisense RNAs are identical, suggesting an evolutionary significance of the sequence. The mosaic structures of the replicon regions with homologous and nonhomologous segments suggest that some of them were generated by exchanging functional parts through homologous recombination. PMID:7525540

  19. A study of autoionization phenomena in helium using (e, 2e) spectroscopy

    NASA Astrophysics Data System (ADS)

    Brunger, M. J.; Samardzic, O.; Kheifets, A. S.; Weigold, E.

    1997-07-01

    Results are presented for the triple differential (e, 2e) cross sections in the region encompassing the helium n = 2 autoionization resonances at the respective incident energies 94.6, 96.6 and 99.6 eV. The scattered-electron angle in each case is 0953-4075/30/14/017/img1 and the range of ejected-electron angles are between 0953-4075/30/14/017/img2 and 0953-4075/30/14/017/img3. The measured coincidence ejected-electron spectra are analysed in terms of the Shore - Balashov parametrization to obtain the direct (e, 2e) cross section 0953-4075/30/14/017/img4 and the resonance parameters 0953-4075/30/14/017/img5 and 0953-4075/30/14/017/img6 for the 0953-4075/30/14/017/img7 and 0953-4075/30/14/017/img8 resonances as a function of ejected-electron momentum. These derived parameters are compared against the results of a calculation where configuration-interaction expansions for the resonances and helium ground state, which employed hydrogenic and multiconfiguration Hartree - Fock orbitals, respectively, were used. Here the distorted-wave Born approximation was employed for the (e, 2e) cross section calculation. The calculated parameters agree quite well with the experimental results indicating that the theoretical description of the reaction mechanism is physically realistic. Further, both experiment and theory show strong correlations between the resonance amplitudes and the direct ionization amplitudes. Finally, we report and discuss our results of an experimental investigation into the post-collision interaction effects for the present kinematical conditions.

  20. GPR30 FORMS AN INTEGRAL PART OF E2-PROTECTIVE PATHWAY IN EXPERIMENTAL AUTOIMMUNE ENCEPHALOMYELITIS

    PubMed Central

    Bodhankar, Sheetal; Offner, Halina

    2011-01-01

    A major focus of our laboratory has been an in-depth evaluation as to how estrogens exert a pronounced protective effect on clinical and histological disease in the animal model of multiple sclerosis (MS), experimental autoimmune encephalomyelitis (EAE). An important issue regarding their therapeutic application has been the undesirable estrogenic side effects thought to be mediated primarily through 17β-estradiol (E2) binding to intracellular estrogen receptor alpha (ERα). With the discovery and characterization of GPR30 as the putative membrane estrogen receptor, we sought to study whether signaling through GPR30 was sufficient to mediate protection against EAE without engagement of ERα. Treatment of EAE in WT mice with G-1, a selective GPR30 agonist, retained estradiol’s ability to protect against clinical and histological EAE without estrogenic side effects. G-1 treatment deviated cytokine profiles and enhanced suppressive activity of CD4+Foxp3+ Treg cells through a GPR30- and programmed death 1 (PD-1)-dependent mechanism. This novel finding was indicative of the protective effect of GPR30 activation in EAE and provides a strong foundation for the clinical application of GPR30 agonists such as G-1 in MS. However, future studies are needed to elucidate cross-signaling and evaluate possible additive effects of combined signaling through both GPR30 and ER-α. Deciphering the possible mechanism of involvement of GPR30 in estrogen-mediated protection against EAE may result in lowering treatment doses of E2 and GPR30 agonists that could minimize risks and maximize immunoregulation and therapeutic effects in MS. Alternatively, one might envision using E2 derivatives with reduced estrogenic activity alone or in combination with GPR30 agonists as therapies for both male and female MS patients. PMID:22247749

  1. (e, 2e) electron momentum spectrometer with high sensitivity and high resolution

    SciTech Connect

    Ren, X.G.; Ning, C.G.; Deng, J.K.; Zhang, S.F.; Su, G.L.; Huang, F.; Li, G.Q.

    2005-06-15

    A high sensitivity and high resolution (e, 2e) electron momentum spectrometer with simultaneous detection in energy and momentum are constructed. The design and performance of the spectrometer are reported. The orbital electron density distributions are obtained accurately and rapidly by using this spectrometer equipped with a double toroidal analyzer. The experimental results on argon and helium exhibit the significant improvements in coincidence count rates, resolution, sensitivity and obtainment of a wide range of adjustable experimental impact energies, which are crucial for further electron momentum spectroscopy studying electronic structure and electron correlation in complex systems.

  2. Future climate change under RCP emission scenarios with GISS ModelE2

    DOE PAGESBeta

    Nazarenko, L.; Schmidt, G. A.; Miller, R. L.; Tausnev, N.; Kelley, M.; Ruedy, R.; Russell, G. L.; Aleinov, I.; Bauer, M.; Bauer, S.; et al

    2015-02-24

    We examine the anthropogenically forced climate response for the 21st century representative concentration pathway (RCP) emission scenarios and their extensions for the period 2101–2500. The experiments were performed with ModelE2, a new version of the NASA Goddard Institute for Space Sciences (GISS) coupled general circulation model that includes three different versions for the atmospheric composition components: a noninteractive version (NINT) with prescribed composition and a tuned aerosol indirect effect (AIE), the TCAD version with fully interactive aerosols, whole-atmosphere chemistry, and the tuned AIE, and the TCADI version which further includes a parameterized first indirect aerosol effect on clouds. Each atmosphericmore » version is coupled to two different ocean general circulation models: the Russell ocean model (GISS-E2-R) and HYCOM (GISS-E2-H). By 2100, global mean warming in the RCP scenarios ranges from 1.0 to 4.5° C relative to 1850–1860 mean temperature in the historical simulations. In the RCP2.6 scenario, the surface warming in all simulations stays below a 2 °C threshold at the end of the 21st century. For RCP8.5, the range is 3.5–4.5° C at 2100. Decadally averaged sea ice area changes are highly correlated to global mean surface air temperature anomalies and show steep declines in both hemispheres, with a larger sensitivity during winter months. By the year 2500, there are complete recoveries of the globally averaged surface air temperature for all versions of the GISS climate model in the low-forcing scenario RCP2.6. TCADI simulations show enhanced warming due to greater sensitivity to CO₂, aerosol effects, and greater methane feedbacks, and recovery is much slower in RCP2.6 than with the NINT and TCAD versions. All coupled models have decreases in the Atlantic overturning stream function by 2100. In RCP2.6, there is a complete recovery of the Atlantic overturning stream function by the year 2500 while with scenario RCP8.5, the E2-R climate model produces a complete shutdown of deep water formation in the North Atlantic.« less

  3. Future climate change under RCP emission scenarios with GISS ModelE2

    NASA Astrophysics Data System (ADS)

    Nazarenko, L.; Schmidt, G. A.; Miller, R. L.; Tausnev, N.; Kelley, M.; Ruedy, R.; Russell, G. L.; Aleinov, I.; Bauer, M.; Bauer, S.; Bleck, R.; Canuto, V.; Cheng, Y.; Clune, T. L.; Del Genio, A. D.; Faluvegi, G.; Hansen, J. E.; Healy, R. J.; Kiang, N. Y.; Koch, D.; Lacis, A. A.; LeGrande, A. N.; Lerner, J.; Lo, K. K.; Menon, S.; Oinas, V.; Perlwitz, J.; Puma, M. J.; Rind, D.; Romanou, A.; Sato, M.; Shindell, D. T.; Sun, S.; Tsigaridis, K.; Unger, N.; Voulgarakis, A.; Yao, M.-S.; Zhang, Jinlun

    2015-03-01

    We examine the anthropogenically forced climate response for the 21st century representative concentration pathway (RCP) emission scenarios and their extensions for the period 2101-2500. The experiments were performed with ModelE2, a new version of the NASA Goddard Institute for Space Sciences (GISS) coupled general circulation model that includes three different versions for the atmospheric composition components: a noninteractive version (NINT) with prescribed composition and a tuned aerosol indirect effect (AIE), the TCAD version with fully interactive aerosols, whole-atmosphere chemistry, and the tuned AIE, and the TCADI version which further includes a parameterized first indirect aerosol effect on clouds. Each atmospheric version is coupled to two different ocean general circulation models: the Russell ocean model (GISS-E2-R) and HYCOM (GISS-E2-H). By 2100, global mean warming in the RCP scenarios ranges from 1.0 to 4.5C relative to 1850-1860 mean temperature in the historical simulations. In the RCP2.6 scenario, the surface warming in all simulations stays below a 2C threshold at the end of the 21st century. For RCP8.5, the range is 3.5-4.5C at 2100. Decadally averaged sea ice area changes are highly correlated to global mean surface air temperature anomalies and show steep declines in both hemispheres, with a larger sensitivity during winter months. By the year 2500, there are complete recoveries of the globally averaged surface air temperature for all versions of the GISS climate model in the low-forcing scenario RCP2.6. TCADI simulations show enhanced warming due to greater sensitivity to CO2, aerosol effects, and greater methane feedbacks, and recovery is much slower in RCP2.6 than with the NINT and TCAD versions. All coupled models have decreases in the Atlantic overturning stream function by 2100. In RCP2.6, there is a complete recovery of the Atlantic overturning stream function by the year 2500 while with scenario RCP8.5, the E2-R climate model produces a complete shutdown of deep water formation in the North Atlantic.

  4. Dynamical (e, 2e) studies using tetrahydrofuran as a DNA analog.

    PubMed

    Colyer, C J; Bellm, S M; Lohmann, B; Hanne, G F; Al-Hagan, O; Madison, D H; Ning, C G

    2010-09-28

    Triple differential cross sections for the electron-impact ionization of the outer valence orbital of tetrahydrofuran have been measured using the (e, 2e) technique. The measurements have been performed with coplanar asymmetric kinematics, at an incident electron energy of 250 eV and at an ejected electron energy of 10 eV, over a range of momentum transfers. The experimental results are compared with theoretical calculations carried out using the molecular three-body distorted wave model. The results obtained are important for gaining an understanding of electron driven processes at a molecular level and for modeling energy deposition in living tissue. PMID:20886927

  5. On-orbit calibration of soft X-ray detector on Chang'E-2 satellite

    NASA Astrophysics Data System (ADS)

    Xiao, Hong; Peng, Wen-Xi; Wang, Huan-Yu; Cui, Xing-Zhu; Guo, Dong-Ya

    2015-10-01

    The X-ray spectrometer is one of the satellite payloads on the Chang'E-2 satellite. The soft X-ray detector is one of the devices on the X-ray spectrometer, designed to detect the major rock-forming elements within the 0.5-10 keV range on the lunar surface. In this paper, energy linearity and energy resolution calibration is done using a weak 55Fe source. Temperature and time effects are found not to give a large error. The total uncertainty of calibration is estimated to be within 5% after correction. Supported by National Science Foundation of Ministry of Education

  6. Development of an (e,2e) electron momentum spectroscopy apparatus using an ultrashort pulsed electron gun

    SciTech Connect

    Yamazaki, M.; Kasai, Y.; Oishi, K.; Nakazawa, H.; Takahashi, M.

    2013-06-15

    An (e,2e) apparatus for electron momentum spectroscopy (EMS) has been developed, which employs an ultrashort-pulsed incident electron beam with a repetition rate of 5 kHz and a pulse duration in the order of a picosecond. Its instrumental design and technical details are reported, involving demonstration of a new method for finding time-zero. Furthermore, EMS data for the neutral Ne atom in the ground state measured by using the pulsed electron beam are presented to illustrate the potential abilities of the apparatus for ultrafast molecular dynamics, such as by combining EMS with the pump-and-probe technique.

  7. A new photon counting imaging detector for the Chinese ChangE-2 EUV explorer mission

    NASA Astrophysics Data System (ADS)

    Zhu, Xiangping; Zhao, Baosheng; Liu, Yongan; Zhang, Xinghua; Miao, Zhenhua; Wei, Yonglin

    2008-11-01

    This paper describes the preliminary design and performances of a new developed photon counting imaging detector for Chinese ChangE-2 EUV explorer mission. The detector consists of microchannel plate (MCP) stacks and wedge and strip anode and corresponding data read out electronics. The experimental results shows that the new developed detector has a spatial resolution of about 75μm, image distortions are small and dark noise count rate less than 0.4 counts cm-2s-1. The pulse height distribution vs MCP operating voltages and the flat field performances are also discussed.

  8. Future climate change under RCP emission scenarios with GISS ModelE2

    SciTech Connect

    Nazarenko, L.; Schmidt, G. A.; Miller, R. L.; Tausnev, N.; Kelley, M.; Ruedy, R.; Russell, G. L.; Aleinov, I.; Bauer, M.; Bauer, S.; Bleck, R.; Canuto, V.; Cheng, Y.; Clune, T. L.; Del Genio, A. D.; Faluvegi, G.; Hansen, J. E.; Healy, R. J.; Kiang, N. Y.; Koch, D.; Lacis, A. A.; LeGrande, A. N.; Lerner, J.; Lo, K. K.; Menon, S.; Oinas, V.; Perlwitz, J.; Puma, M. J.; Rind, D.; Romanou, A.; Sato, M.; Shindell, D. T.; Sun, S.; Tsigaridis, K.; Unger, N.; Voulgarakis, A.; Yao, M. -S.; Zhang, Jinlun

    2015-02-24

    We examine the anthropogenically forced climate response for the 21st century representative concentration pathway (RCP) emission scenarios and their extensions for the period 2101–2500. The experiments were performed with ModelE2, a new version of the NASA Goddard Institute for Space Sciences (GISS) coupled general circulation model that includes three different versions for the atmospheric composition components: a noninteractive version (NINT) with prescribed composition and a tuned aerosol indirect effect (AIE), the TCAD version with fully interactive aerosols, whole-atmosphere chemistry, and the tuned AIE, and the TCADI version which further includes a parameterized first indirect aerosol effect on clouds. Each atmospheric version is coupled to two different ocean general circulation models: the Russell ocean model (GISS-E2-R) and HYCOM (GISS-E2-H). By 2100, global mean warming in the RCP scenarios ranges from 1.0 to 4.5° C relative to 1850–1860 mean temperature in the historical simulations. In the RCP2.6 scenario, the surface warming in all simulations stays below a 2 °C threshold at the end of the 21st century. For RCP8.5, the range is 3.5–4.5° C at 2100. Decadally averaged sea ice area changes are highly correlated to global mean surface air temperature anomalies and show steep declines in both hemispheres, with a larger sensitivity during winter months. By the year 2500, there are complete recoveries of the globally averaged surface air temperature for all versions of the GISS climate model in the low-forcing scenario RCP2.6. TCADI simulations show enhanced warming due to greater sensitivity to CO₂, aerosol effects, and greater methane feedbacks, and recovery is much slower in RCP2.6 than with the NINT and TCAD versions. All coupled models have decreases in the Atlantic overturning stream function by 2100. In RCP2.6, there is a complete recovery of the Atlantic overturning stream function by the year 2500 while with scenario RCP8.5, the E2-R climate model produces a complete shutdown of deep water formation in the North Atlantic.

  9. Surface plasmon resonance imaging reveals multiple binding modes of Agrobacterium transformation mediator VirE2 to ssDNA.

    PubMed

    Kim, Sanghyun; Zbaida, David; Elbaum, Michael; Leh, Herv; Nogues, Claude; Buckle, Malcolm

    2015-07-27

    VirE2 is the major secreted protein of Agrobacterium tumefaciens in its genetic transformation of plant hosts. It is co-expressed with a small acidic chaperone VirE1, which prevents VirE2 oligomerization. After secretion into the host cell, VirE2 serves functions similar to a viral capsid in protecting the single-stranded transferred DNA en route to the nucleus. Binding of VirE2 to ssDNA is strongly cooperative and depends moreover on protein-protein interactions. In order to isolate the protein-DNA interactions, imaging surface plasmon resonance (SPRi) studies were conducted using surface-immobilized DNA substrates of length comparable to the protein-binding footprint. Binding curves revealed an important influence of substrate rigidity with a notable preference for poly-T sequences and absence of binding to both poly-A and double-stranded DNA fragments. Dissociation at high salt concentration confirmed the electrostatic nature of the interaction. VirE1-VirE2 heterodimers also bound to ssDNA, though by a different mechanism that was insensitive to high salt. Neither VirE2 nor VirE1-VirE2 followed the Langmuir isotherm expected for reversible monomeric binding. The differences reflect the cooperative self-interactions of VirE2 that are suppressed by VirE1. PMID:26044711

  10. THE E2/FRB PATHWAY REGULATION OF DNA REPLICATION AND PROTEIN BIOSYNTHESIS

    EPA Science Inventory

    The E2F/Rb pathway plays a pivotal role in the control of cell cycle progression and regulates the expression of genes required for Gl/S transition. Our study examines the genomic response in Drosophila embryos after overexpression and mutation of E2F/Rb pathway molecules. Hierar...

  11. HPV-18 E2circumflexE4 chimera: 2 new spliced transcripts and proteins induced by keratinocyte differentiation

    SciTech Connect

    Tan, Chye Ling; Gunaratne, Jayantha; Lai, Deborah; Carthagena, Laetitia; Wang, Qian; Xue, Yue Zhen; Quek, Ling Shih; Doorbar, John; Bachelerie, Francoise; Thierry, Francoise; Bellanger, Sophie

    2012-07-20

    The Human Papillomavirus (HPV) E4 is known to be synthesized as an E1circumflexE4 fusion resulting from splice donor and acceptor sites conserved across HPV types. Here we demonstrate the existence of 2 HPV-18 E2circumflexE4 transcripts resulting from 2 splice donor sites in the 5 Prime part of E2, while the splice acceptor site is the one used for E1circumflexE4. Both E2circumflexE4 transcripts are up-regulated by keratinocyte differentiation in vitro and can be detected in clinical samples containing low-grade HPV-18-positive cells from Pap smears. They give rise to two fusion proteins in vitro, E2circumflexE4-S and E2circumflexE4-L. Whereas we could not differentiate E2circumflexE4-S from E1circumflexE4 in vivo, E2circumflexE4-L could be formally identified as a 23 kDa protein in raft cultures in which the corresponding transcript was also found, and in a biopsy from a patient with cervical intraepithelial neoplasia stage I-II (CINI-II) associated with HPV-18, demonstrating the physiological relevance of E2circumflexE4 products.

  12. Hepatitis C Virus E1 and E2 Proteins Used as Separate Immunogens Induce Neutralizing Antibodies with Additive Properties

    PubMed Central

    Beaumont, Elodie; Roch, Emmanuelle; Chopin, Lucie; Roingeard, Philippe

    2016-01-01

    Various strategies involving the use of hepatitis C virus (HCV) E1 and E2 envelope glycoproteins as immunogens have been developed for prophylactic vaccination against HCV. However, the ideal mode of processing and presenting these immunogens for effective vaccination has yet to be determined. We used our recently described vaccine candidate based on full-length HCV E1 or E2 glycoproteins fused to the heterologous hepatitis B virus S envelope protein to compare the use of the E1 and E2 proteins as separate immunogens with their use as the E1E2 heterodimer, in terms of immunogenetic potential and the capacity to induce neutralizing antibodies. The specific anti-E1 and anti-E2 antibody responses induced in animals immunized with vaccine particles harboring the heterodimer were profoundly impaired with respect to those in animals immunized with particles harboring E1 and E2 separately. Moreover, the anti-E1 and anti-E2 antibodies had additive neutralizing properties that increase the cross-neutralization of heterologous strains of various HCV genotypes, highlighting the importance of including both E1 and E2 in the vaccine for an effective vaccination strategy. Our study has important implications for the optimization of HCV vaccination strategies based on HCV envelope proteins, regardless of the platform used to present these proteins to the immune system. PMID:26966906

  13. 40 CFR Table E-2 to Subpart E of... - Spectral Energy Distribution and Permitted Tolerance for Conducting Radiative Tests

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 6 2012-07-01 2012-07-01 false Spectral Energy Distribution and... E-2 Table E-2 to Subpart E of Part 53Spectral Energy Distribution and Permitted Tolerance for Conducting Radiative Tests Characteristic Spectral Region Ultraviolet Visible Infrared Bandwidth (m) 0.28...

  14. 40 CFR Table E-2 to Subpart E of... - Spectral Energy Distribution and Permitted Tolerance for Conducting Radiative Tests

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 6 2014-07-01 2014-07-01 false Spectral Energy Distribution and..., Table E-2 Table E-2 to Subpart E of Part 53Spectral Energy Distribution and Permitted Tolerance for Conducting Radiative Tests Characteristic Spectral Region Ultraviolet Visible Infrared Bandwidth (m) 0.28...

  15. 40 CFR Table E-2 to Subpart E of... - Spectral Energy Distribution and Permitted Tolerance for Conducting Radiative Tests

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 6 2013-07-01 2013-07-01 false Spectral Energy Distribution and..., Table E-2 Table E-2 to Subpart E of Part 53Spectral Energy Distribution and Permitted Tolerance for Conducting Radiative Tests Characteristic Spectral Region Ultraviolet Visible Infrared Bandwidth (m) 0.28...

  16. Surface plasmon resonance imaging reveals multiple binding modes of Agrobacterium transformation mediator VirE2 to ssDNA

    PubMed Central

    Kim, Sanghyun; Zbaida, David; Elbaum, Michael; Leh, Herv; Nogues, Claude; Buckle, Malcolm

    2015-01-01

    VirE2 is the major secreted protein of Agrobacterium tumefaciens in its genetic transformation of plant hosts. It is co-expressed with a small acidic chaperone VirE1, which prevents VirE2 oligomerization. After secretion into the host cell, VirE2 serves functions similar to a viral capsid in protecting the single-stranded transferred DNA en route to the nucleus. Binding of VirE2 to ssDNA is strongly cooperative and depends moreover on proteinprotein interactions. In order to isolate the proteinDNA interactions, imaging surface plasmon resonance (SPRi) studies were conducted using surface-immobilized DNA substrates of length comparable to the protein-binding footprint. Binding curves revealed an important influence of substrate rigidity with a notable preference for poly-T sequences and absence of binding to both poly-A and double-stranded DNA fragments. Dissociation at high salt concentration confirmed the electrostatic nature of the interaction. VirE1VirE2 heterodimers also bound to ssDNA, though by a different mechanism that was insensitive to high salt. Neither VirE2 nor VirE1VirE2 followed the Langmuir isotherm expected for reversible monomeric binding. The differences reflect the cooperative self-interactions of VirE2 that are suppressed by VirE1. PMID:26044711

  17. E2F1 Localizes to Sites of UV-induced DNA Damage to Enhance Nucleotide Excision Repair*

    PubMed Central

    Guo, Ruifeng; Chen, Jie; Zhu, Feng; Biswas, Anup K.; Berton, Thomas R.; Mitchell, David L.; Johnson, David G.

    2010-01-01

    The E2F1 transcription factor is a well known regulator of cell proliferation and apoptosis, but its role in the DNA damage response is less clear. Using a local UV irradiation technique and immunofluorescence staining, E2F1 is shown to accumulate at sites of DNA damage. Localization of E2F1 to UV-damaged DNA requires the ATM and Rad3-related (ATR) kinase and serine 31 of E2F1 but not an intact DNA binding domain. E2F1 deficiency does not appear to affect the expression of nucleotide excision repair (NER) factors, such as XPC and XPA. However, E2F1 depletion does impair the recruitment of NER factors to sites of damage and reduces the efficiency of DNA repair. E2F1 mutants unable to bind DNA or activate transcription retain the ability to stimulate NER. These findings demonstrate that E2F1 has a direct, non-transcriptional role in DNA repair involving increased recruitment of NER factors to sites of damage. PMID:20413589

  18. Two distinct regions of the BPV1 E1 replication protein interact with the activation domain of E2.

    PubMed

    Moscufo, N; Sverdrup, F; Breiding, D E; Androphy, E J

    1999-12-15

    Papillomavirus E1 and E2 proteins co-operation in viral DNA replication is mediated by protein-protein interactions that lead to formation of an E1-E2 complex. To identify the domains involved, portions of the two proteins were expressed as fusions to the DNA-binding protein LexA or the transactivation domain of VP16 and analyzed by the yeast two-hybrid system. The C-terminal 266 amino acids of BPV1 E1 (E1C266) interacted strongly with E2 in the yeast system and in a mammalian two-hybrid assay. VP16-E1C266 interacted with a region encompassing amino acids 1-200 of the transactivation domain of E2 that was fused to LexA. The interaction between E1 full length and E2 was clearly observed only when E1 was expressed as LexA-E1 chimera. In addition, we found that in the LexA context also the N-terminal region encompassing the first 340 amino acids of E1 (E1N340) interacted with E2 full length. The interactions of E1N340 and E1C266 with E2 were confirmed also by in vitro binding studies. These observations demonstrate that two distinct regions of E1 mediate the interaction with E2 in vivo. PMID:10581387

  19. Interaction of CSFV E2 protein with swine host factors as detected by yeast two-hybrid system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    E2 is one of the envelope glycoproteins of pestiviruses, including classical swine fever virus (CSFV) and bovine viral diarrhea virus (BVDV). E2 is involved in several critical functions, including virus entry into target cells, induction of a protective immune response and virulence in swine. Howev...

  20. Role of the transcription factor E2F1 in CXCR4-mediated neurotoxicity and HIV neuropathology

    PubMed Central

    Shimizu, Saori; Khan, Muhammad Z.; Hippensteel, Randi L; Parkar, Anjum; Raghupathi, Ramesh; Meucci, Olimpia

    2006-01-01

    This study sought to determine the role of the transcription factor E2F1 in CXCR4-mediated neurotoxicity and HIV neuropathology. We studied the effect of the HIV envelope protein gp120 on the expression of E2F1-dependent apoptotic proteins in human and rodent neurons and examined the expression pattern of E2F1 in the brain of HIV-infected individuals. Our findings suggest that in cultured neurons gp120 increased E2F1 levels in the nucleus, stimulated its transcriptional activity, and enhanced the expression of the E2F1 target proteins Cdc2 and Puma. Studies with neuronal cultures from E2F1 deficient mice demonstrated that the transcription factor is required for gp120-induced neurotoxicity and up-regulation of Cdc2 and Puma. Levels of E2F1 protein were greater in the nucleus of neurons in brains of HIV-infected patients exhibiting dementia when compared to HIV-negative subjects or HIV-positive neurologically normal patients. Overall, these studies indicate that E2F1 is primarily involved in CXCR4-mediated neurotoxicity and HIV neuropathogenesis. PMID:17011204

  1. 37 CFR 1.760 - Interim extension of patent term under 35 U.S.C. 156(e)(2).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... term under 35 U.S.C. 156(e)(2). 1.760 Section 1.760 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE, DEPARTMENT OF COMMERCE GENERAL RULES OF PRACTICE IN PATENT CASES Adjustment... extension of patent term under 35 U.S.C. 156(e)(2). An applicant who has filed a formal application...

  2. 37 CFR 1.760 - Interim extension of patent term under 35 U.S.C. 156(e)(2).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... term under 35 U.S.C. 156(e)(2). 1.760 Section 1.760 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE, DEPARTMENT OF COMMERCE GENERAL RULES OF PRACTICE IN PATENT CASES Adjustment... extension of patent term under 35 U.S.C. 156(e)(2). An applicant who has filed a formal application...

  3. 37 CFR 1.760 - Interim extension of patent term under 35 U.S.C. 156(e)(2).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... term under 35 U.S.C. 156(e)(2). 1.760 Section 1.760 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE, DEPARTMENT OF COMMERCE GENERAL RULES OF PRACTICE IN PATENT CASES Adjustment... extension of patent term under 35 U.S.C. 156(e)(2). An applicant who has filed a formal application...

  4. 37 CFR 1.760 - Interim extension of patent term under 35 U.S.C. 156(e)(2).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... term under 35 U.S.C. 156(e)(2). 1.760 Section 1.760 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE, DEPARTMENT OF COMMERCE GENERAL RULES OF PRACTICE IN PATENT CASES Adjustment... extension of patent term under 35 U.S.C. 156(e)(2). An applicant who has filed a formal application...

  5. 37 CFR 1.760 - Interim extension of patent term under 35 U.S.C. 156(e)(2).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... term under 35 U.S.C. 156(e)(2). 1.760 Section 1.760 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE, DEPARTMENT OF COMMERCE GENERAL RULES OF PRACTICE IN PATENT CASES Adjustment... extension of patent term under 35 U.S.C. 156(e)(2). An applicant who has filed a formal application...

  6. Structure of an E3:E2~Ub Complex Reveals an Allosteric Mechanism Shared among RING/U-box Ligases

    SciTech Connect

    Pruneda, Jonathan N.; Littlefield, Peter J.; Soss, Sarah E.; Nordquist, Kyle A.; Chazin, Walter J.; Brzovic, Peter S.; Klevit, Rachel E.

    2012-09-28

    Despite the widespread importance of RING/U-box E3 ubiquitin ligases in ubiquitin (Ub) signaling, the mechanismby which this class of enzymes facilitates Ub transfer remains enigmatic. Here, we present a structural model for a RING/U-box E3:E2~Ub complex poised for Ub transfer. The model and additional analyses reveal that E3 binding biases dynamic E2~Ub ensembles toward closed conformations with enhanced reactivity for substrate lysines. We identify a key hydrogen bond between a highly conserved E3 side chain and an E2 backbone carbonyl, observed in all structures of active RING/ U-Box E3/E2 pairs, as the linchpin for allosteric activation of E2~Ub. The conformational biasing mechanism is generalizable across diverse E2s and RING/U-box E3s, but is not shared by HECT-type E3s. The results provide a structural model for a RING/ U-box E3:E2~Ub ligase complex and identify the long sought-after source of allostery for RING/UBox activation of E2~Ub conjugates.

  7. 26 CFR 1.927(e)-2T - Temporary regulations; effect of boycott participation on FSC and small FSC benefits.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 10 2011-04-01 2011-04-01 false Temporary regulations; effect of boycott participation on FSC and small FSC benefits. 1.927(e)-2T Section 1.927(e)-2T Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES (CONTINUED) Earned Income of Citizens of United States...

  8. N-LINKED GLYCOSYLATION STATUS OF CLASSICAL SWINE FEVER VIRUS STRAIN BRECIA E2 GLYCOPROTEIN INFLUENCES VIRULENCE IN SWINE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    E2 is one of the three envelope glycoproteins of Classical Swine Fever Virus (CSFV). Although E2 have been involved in virus attachment to target cells, the induction of a protective immune response as well in the process of viral pathogenesis, the role of glycosylation in the functionality of the p...

  9. 17 CFR 240.14e-2 - Position of subject company with respect to a tender offer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... with respect to a tender offer. 240.14e-2 Section 240.14e-2 Commodity and Securities Exchanges... subject company with respect to a tender offer. (a) Position of subject company. As a means reasonably... 14(e) of the Act, the subject company, no later than 10 business days from the date the tender...

  10. 17 CFR 240.14e-2 - Position of subject company with respect to a tender offer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... with respect to a tender offer. 240.14e-2 Section 240.14e-2 Commodity and Securities Exchanges... subject company with respect to a tender offer. (a) Position of subject company. As a means reasonably... 14(e) of the Act, the subject company, no later than 10 business days from the date the tender...

  11. 17 CFR 240.14e-2 - Position of subject company with respect to a tender offer.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... with respect to a tender offer. 240.14e-2 Section 240.14e-2 Commodity and Securities Exchanges... subject company with respect to a tender offer. (a) Position of subject company. As a means reasonably... 14(e) of the Act, the subject company, no later than 10 business days from the date the tender...

  12. 17 CFR 240.14e-2 - Position of subject company with respect to a tender offer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... with respect to a tender offer. 240.14e-2 Section 240.14e-2 Commodity and Securities Exchanges... subject company with respect to a tender offer. (a) Position of subject company. As a means reasonably... 14(e) of the Act, the subject company, no later than 10 business days from the date the tender...

  13. 17 CFR 240.14e-2 - Position of subject company with respect to a tender offer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... with respect to a tender offer. 240.14e-2 Section 240.14e-2 Commodity and Securities Exchanges... subject company with respect to a tender offer. (a) Position of subject company. As a means reasonably... 14(e) of the Act, the subject company, no later than 10 business days from the date the tender...

  14. N-Linked Glycosylation Status Of Classical Swine Fever Virus Strain Brescia E2 Glycoprotein Influences Virulence In Swine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    E2 is one of the three envelope glycoproteins of Classical Swine Fever Virus (CSFV). Previous studies indicate that E2 is involved in several functions including virus attachment and entry to target cells, production of antibodies, induction of protective immune response in swine, and virulence. Her...

  15. e2f1 Gene is a new member of Wnt/beta-catenin/Tcf-regulated genes.

    PubMed

    Abramova, Maria V; Zatulovskiy, Evgeny A; Svetlikova, Svetlana B; Kukushkin, Alexander N; Pospelov, Valery A

    2010-01-01

    HDAC inhibitors induce cell cycle arrest of E1A+Ras-transformed cells accompanied by e2f1 gene down-regulation and activation of Wnt pathway. Here we show that e2f1 expression is regulated through the Wnt/Tcf-pathway: e2f1 promoter activity is inhibited by sodium butyrate (NaB) and by overexpression of beta-catenin/Tcf. The e2f1 promoter was found to contain two putative Tcf-binding elements: the proximal one competes well with canonical Tcf element in DNA-binding assay. Being inserted into luciferase reporter vector, the identified element provides positive transcriptional regulation in response to beta-catenin/Tcf co-transfection and NaB treatment. Thus we have firstly demonstrated that e2f1 belongs to genes regulated through Wnt/beta-catenin/Tcf pathway. PMID:19900401

  16. E2 transition probabilities for decays of isomers observed in neutron-rich odd Sn isotopes

    SciTech Connect

    Iskra, Ł. W.; Broda, R.; Janssens, R. V.F.; Wrzesiński, J.; Chiara, C. J.; Carpenter, M. P.; Fornal, B.; Hoteling, N.; Kondev, F. G.; Królas, W.; Lauritsen, T.; Pawłat, T.; Seweryniak, D.; Stefanescu, I.; Walters, W. B.; Zhu, S.

    2015-01-01

    High-spin states were investigated with gamma coincidence techniques in neutron-rich Sn isotopes produced in fission processes following ⁴⁸Ca + ²⁰⁸Pb, ⁴⁸Ca + ²³⁸U, and ⁶⁴Ni + ²³⁸U reactions. By exploiting delayed and cross-coincidence techniques, level schemes have been delineated in odd ¹¹⁹⁻¹²⁵Sn isotopes. Particular attention was paid to the occurrence of 19/2⁺ and 23/2⁺ isomeric states for which the available information has now been significantly extended. Reduced transition probabilities, B(E2), extracted from the measured half-lives and the established details of the isomeric decays exhibit a striking regularity. This behavior was compared with the previously observed regularity of the B(E2) amplitudes for the seniority ν = 2 and 3, 10⁺ and 27/2⁻ isomers in even- and odd-Sn isotopes, respectively.

  17. E2 transition probabilities for decays of isomers observed in neutron-rich odd Sn isotopes

    DOE PAGESBeta

    Iskra, Ł. W.; Broda, R.; Janssens, R. V.F.; Wrzesiński, J.; Chiara, C. J.; Carpenter, M. P.; Fornal, B.; Hoteling, N.; Kondev, F. G.; Królas, W.; et al

    2015-01-01

    High-spin states were investigated with gamma coincidence techniques in neutron-rich Sn isotopes produced in fission processes following ⁴⁸Ca + ²⁰⁸Pb, ⁴⁸Ca + ²³⁸U, and ⁶⁴Ni + ²³⁸U reactions. By exploiting delayed and cross-coincidence techniques, level schemes have been delineated in odd ¹¹⁹⁻¹²⁵Sn isotopes. Particular attention was paid to the occurrence of 19/2⁺ and 23/2⁺ isomeric states for which the available information has now been significantly extended. Reduced transition probabilities, B(E2), extracted from the measured half-lives and the established details of the isomeric decays exhibit a striking regularity. This behavior was compared with the previously observed regularity of the B(E2) amplitudesmore » for the seniority ν = 2 and 3, 10⁺ and 27/2⁻ isomers in even- and odd-Sn isotopes, respectively.« less

  18. Detection of ethylene glycol - toward W51/e2 and G34.3+0.02

    NASA Astrophysics Data System (ADS)

    Lykke, Julie M.; Favre, Ccile

    2014-07-01

    Ethylene glycol (HOCH2CH2OH), also commenly known as antifreeze, is the reduced alcohol version of glycolaldehyde (CH2OHCHO). Glycoladehyde - the simplest possible aldehyde sugar (Marstokk and Mllendal 1973) - is the first intermediate step in the path toward forming more complex and biologically relevant molecules through the the formose reaction, which begins with formaldehyde (H2CO) and ends with the formation of sugars and ultimately ribose, the backbone of RNA (e.g., Larralde et al. 1995). The presence of glycolaldehyde is therefore an important indication that processes leading to biologically relevant molecules are taking place. It is however, still unclear as to how glycolaldehyde and ethylene glycol are formed in the ISM. It has been proposed that they share a common formation pathway through UV-irradiation of methanol (CH3OH) ices mixed with CO (berg et al. 2009). So far, ethylene glycol, in its lower energy con-former (gGa(CH2OH)2), has been detected toward SgrB2 (N) by Hollis et al. (2002), tentatively toward IRAS 16293-2422 (Jrgensen et al. 2012) and marginally by Kalenskii and Johansson (2010) toward W51 e1/e2. Here we present a firm detection of ethylene glycol toward W51/e2 as well as a first detection toward G34.3+0.02 at 1mm and 3mm using the IRAM 30m telescope.

  19. NOAO E2E Integrated Data Cache Initiative Using iRODS

    NASA Astrophysics Data System (ADS)

    Barg, I.; Scott, D.; Timmermann, E.

    2011-07-01

    The NOAO Mass Storage System (MSS) holds astronomical data collected from about two dozen different scientific instruments at eleven telescopes on three mountain tops in two different countries both north and south of the Equator. Data are transferred via the net, from each mountain to Data Centers in La Serena, Chile and Tucson, Arizona. Then replicated across both hemispheres. A third copy is saved on tape at NCSA. This system is collectively called the End-to-End system (E2E). The data flow and file repository management is accomplished using a collection of custom code built on top of the Storage Resource Broker (SRB) developed by Data Intensive Cyber Environments (DICE) research group at the University of North Carolina at Chapel Hill, and the Institute for Neural Computation at the University of California, San Diego. iRODS, the Integrated Rule-Oriented Data System, is a data grid software system developed by DICE and collaborators and the successor to SRB. Both SRB and iRODS provide the ability to manage large amounts of data which can be distributed across data centers. This paper will describe why NOAO Science Data Management (SDM) chose iRODS as the next generation file repository management system for the E2E data management system.

  20. Structural Code for DNA Recognition Revealed in Crystal Structures of Papillomavirus E2-DNA Targets

    NASA Astrophysics Data System (ADS)

    Rozenberg, Haim; Rabinovich, Dov; Frolow, Felix; Hegde, Rashmi S.; Shakked, Zippora

    1998-12-01

    Transcriptional regulation in papillomaviruses depends on sequence-specific binding of the regulatory protein E2 to several sites in the viral genome. Crystal structures of bovine papillomavirus E2 DNA targets reveal a conformational variant of B-DNA characterized by a roll-induced writhe and helical repeat of 10.5 bp per turn. A comparison between the free and the protein-bound DNA demonstrates that the intrinsic structure of the DNA regions contacted directly by the protein and the deformability of the DNA region that is not contacted by the protein are critical for sequence-specific protein/DNA recognition and hence for gene-regulatory signals in the viral system. We show that the selection of dinucleotide or longer segments with appropriate conformational characteristics, when positioned at correct intervals along the DNA helix, can constitute a structural code for DNA recognition by regulatory proteins. This structural code facilitates the formation of a complementary protein-DNA interface that can be further specified by hydrogen bonds and nonpolar interactions between the protein amino acids and the DNA bases.

  1. Pure E2 transitions: A test for BRICC Internal Conversion Coefficients

    NASA Astrophysics Data System (ADS)

    Gerl, J.; Sai, K. Vijay; Sainath, M.; Gowrishankar, R.; Venkataramaniah, K.

    2009-01-01

    The most widely used theoretical internal conversion coefficient (ICC) tables are of Hager and Seltzer (HS), Rosel et al. and BRICC (Band et al. tables using BRICC interpolation code). A rigorous comparison of experimental ICCs with various theoretical tabulations is possible only when a large data on experimental ICCs is available at one place. For this reason, a compilation of all the available experimental ICCs, αT, αK, αL of E2 transitions for a number of elements in the range of 24⩽Z⩽94 is presented. Listing of experimental data includes 595 datasets corresponding to 505 E2 transitions in 165 nuclei across the nuclear chart. Data with less than 10% experimental uncertainty have been selected for comparison with the theoretical values of Hager and Seltzer, Rosel et al. and BRICC. The relative percentage deviation (%Δ) have been calculated for each of the above theories and the average (%Δ¯) are estimated. The Band et al. tables, using the BRICC interpolation code are seen to give theoretical ICCs closest to experimental values.

  2. Levels of the E2 interacting protein TopBP1 modulate papillomavirus maintenance stage replication

    PubMed Central

    Kanginakudru, Sriramana; DeSmet, Marsha; Thomas, Yanique; Morgan, Iain M.; Androphy, Elliot J.

    2015-01-01

    The evolutionarily conserved DNA topoisomerase II beta-binding protein 1 (TopBP1) functions in DNA replication, DNA damage response, and cell survival. We analyzed the role of TopBP1 in human and bovine papillomavirus genome replication. Consistent with prior reports, TopBP1 co-localized in discrete nuclear foci and was in complex with papillomavirus E2 protein. Similar to E2, TopBP1 is recruited to the region of the viral origin of replication during G1/S and early S phase. TopBP1 knockdown increased, while over-expression decreased transient virus replication, without affecting cell cycle. Similarly, using cell lines harboring HPV-16 or HPV-31 genome, TopBP1 knockdown increased while over-expression reduced viral copy number relative to genomic DNA. We propose a model in which TopBP1 serves dual roles in viral replication: it is essential for initiation of replication yet it restricts viral copy number. PMID:25666521

  3. A dynamic Asp-Arg interaction is essential for catalysis in microsomal prostaglandin E2 synthase.

    PubMed

    Brock, Joseph S; Hamberg, Mats; Balagunaseelan, Navisraj; Goodman, Michael; Morgenstern, Ralf; Strandback, Emilia; Samuelsson, Bengt; Rinaldo-Matthis, Agnes; Haeggstrm, Jesper Z

    2016-01-26

    Microsomal prostaglandin E2 synthase type 1 (mPGES-1) is responsible for the formation of the potent lipid mediator prostaglandin E2 under proinflammatory conditions, and this enzyme has received considerable attention as a drug target. Recently, a high-resolution crystal structure of human mPGES-1 was presented, with Ser-127 being proposed as the hydrogen-bond donor stabilizing thiolate anion formation within the cofactor, glutathione (GSH). We have combined site-directed mutagenesis and activity assays with a structural dynamics analysis to probe the functional roles of such putative catalytic residues. We found that Ser-127 is not required for activity, whereas an interaction between Arg-126 and Asp-49 is essential for catalysis. We postulate that both residues, in addition to a crystallographic water, serve critical roles within the enzymatic mechanism. After characterizing the size or charge conservative mutations Arg-126-Gln, Asp-49-Asn, and Arg-126-Lys, we inferred that a crystallographic water acts as a general base during GSH thiolate formation, stabilized by interaction with Arg-126, which is itself modulated by its respective interaction with Asp-49. We subsequently found hidden conformational ensembles within the crystal structure that correlate well with our biochemical data. The resulting contact signaling network connects Asp-49 to distal residues involved in GSH binding and is ligand dependent. Our work has broad implications for development of efficient mPGES-1 inhibitors, potential anti-inflammatory and anticancer agents. PMID:26755582

  4. The High Resolution X-ray Spectrometer on the Astro-E2 mission

    NASA Astrophysics Data System (ADS)

    Porter, F. S.; Mitsuda, K.; Astro-E2/XRS Collaboration

    2003-03-01

    The X-ray Spectrometer (XRS) instrument on the Astro-E2 mission is based on a high resolution non-dispersive cryogenic x-ray detector system. The detector system consists of a 32 pixel x-ray microcalorimeter array with an inherent resolving power of 1000 at 6 keV, with very high throughput, and a bandpass of <300 eV to 10 keV. The spectral resolving power represents a factor of two improvement over the detector system delivered for the original Astro-E. The flight detector system for Astro-E2 has been fabricated, qualified, and is currently undergoing functional and pre-calibration testing. Thus flight-like performance data for this new spectrometer will be presented here. In addition we will discuss measured and projected mission parameters including instrument lifetime, bandpass, effective area, ground and in-flight calibration plans and their impact on the science mission. The XRS will build on the results from Chandra and XMM, adding extended source spectroscopy, a much larger collecting area and higher resolving power at the Fe K complex, and complete spectral coverage from C K to 10 keV.

  5. Global Carbon Cycle Modeling in GISS ModelE2 GCM

    NASA Astrophysics Data System (ADS)

    Aleinov, I. D.; Kiang, N. Y.; Romanou, A.; Romanski, J.

    2014-12-01

    Consistent and accurate modeling of the Global Carbon Cycle remains one of the main challenges for the Earth System Models. NASA Goddard Institute for Space Studies (GISS) ModelE2 General Circulation Model (GCM) was recently equipped with a complete Global Carbon Cycle algorithm, consisting of three integrated components: Ent Terrestrial Biosphere Model (Ent TBM), Ocean Biogeochemistry Module and atmospheric CO2 tracer. Ent TBM provides CO2 fluxes from the land surface to the atmosphere. Its biophysics utilizes the well-known photosynthesis functions of Farqhuar, von Caemmerer, and Berry and Farqhuar and von Caemmerer, and stomatal conductance of Ball and Berry. Its phenology is based on temperature, drought, and radiation fluxes, and growth is controlled via allocation of carbon from labile carbohydrate reserve storage to different plant components. Soil biogeochemistry is based on the Carnegie-Ames-Stanford (CASA) model of Potter et al. Ocean biogeochemistry module (the NASA Ocean Biogeochemistry Model, NOBM), computes prognostic distributions for biotic and abiotic fields that influence the air-sea flux of CO2 and the deep ocean carbon transport and storage. Atmospheric CO2 is advected with a quadratic upstream algorithm implemented in atmospheric part of ModelE2. Here we present the results for pre-industrial equilibrium and modern transient simulations and provide comparison to available observations. We also discuss the process of validation and tuning of particular algorithms used in the model.

  6. Association of the Apolipoprotein E 2 Allele with Concurrent Occurrence of Endometrial Hyperplasia and Endometrial Carcinoma

    PubMed Central

    Ivanova, Tatiana I.; Krikunova, Ludmila I.; Ryabchenko, Nikolay I.; Mkrtchyan, Liana S.; Khorokhorina, Vera A.; Salnikova, Lyubov E.

    2015-01-01

    Genes encoding proteins with antioxidant properties may influence susceptibility to endometrial hyperplasia (EH) and endometrial carcinoma (ECa). Patients with EH (n = 89), EH concurrent with ECa (n = 76), ECa (n = 186), and healthy controls (n = 1110) were genotyped for five polymorphic variants in the genes involved in metabolism of lipoproteins (APOE Cys112Arg and Arg158Cys), iron (HFE Cys282Tyr and His63Asp), and catecholamines (COMT Val158Met). Patients and controls were matched by ethnicity (all Caucasians), age, body mass index (BMI), and incidence of hypertension and diabetes. The frequency of the APOE E 2 allele (158Cys) was higher in patients with EH + ECa than in controls (P = 0.0012, PBonferroni = 0.018, OR = 2.58, 95% CI 1.49–4.45). The APOE E 4 allele (112Arg) was more frequently found in patients with EH than in controls and HFE minor allele G (63Asp) had a protective effect in the ECa group, though these results appeared to be nonsignificant after correction for multiple comparisons. The results of the study indicate that E 2 allele might be associated with concurrent occurrence of EH and ECa. PMID:25741405

  7. A dynamic Asp–Arg interaction is essential for catalysis in microsomal prostaglandin E2 synthase

    PubMed Central

    Brock, Joseph S.; Hamberg, Mats; Balagunaseelan, Navisraj; Goodman, Michael; Morgenstern, Ralf; Strandback, Emilia; Samuelsson, Bengt; Rinaldo-Matthis, Agnes; Haeggström, Jesper Z.

    2016-01-01

    Microsomal prostaglandin E2 synthase type 1 (mPGES-1) is responsible for the formation of the potent lipid mediator prostaglandin E2 under proinflammatory conditions, and this enzyme has received considerable attention as a drug target. Recently, a high-resolution crystal structure of human mPGES-1 was presented, with Ser-127 being proposed as the hydrogen-bond donor stabilizing thiolate anion formation within the cofactor, glutathione (GSH). We have combined site-directed mutagenesis and activity assays with a structural dynamics analysis to probe the functional roles of such putative catalytic residues. We found that Ser-127 is not required for activity, whereas an interaction between Arg-126 and Asp-49 is essential for catalysis. We postulate that both residues, in addition to a crystallographic water, serve critical roles within the enzymatic mechanism. After characterizing the size or charge conservative mutations Arg-126–Gln, Asp-49–Asn, and Arg-126–Lys, we inferred that a crystallographic water acts as a general base during GSH thiolate formation, stabilized by interaction with Arg-126, which is itself modulated by its respective interaction with Asp-49. We subsequently found hidden conformational ensembles within the crystal structure that correlate well with our biochemical data. The resulting contact signaling network connects Asp-49 to distal residues involved in GSH binding and is ligand dependent. Our work has broad implications for development of efficient mPGES-1 inhibitors, potential anti-inflammatory and anticancer agents. PMID:26755582

  8. New insights of asteroid 4179 Toutatis using China Chang'e-2 close flyby optical measurements

    SciTech Connect

    Bu, Yanlong; Tang, Geshi; Cao, Jianfeng; Hu, Songjie; Yang, Cheng; Liu, Chuankai; Di, KaiChang; Xu, Bin; Liu, Bin; Fa, Wenzhe; Hu, Tianjiang; Ding, Chibiao E-mail: tanggeshi@bacc.org.cn

    2015-01-01

    The mysteries of near-Earth asteroid 4179 Toutatis have been more comprehensively unveiled by analyzing the optical images taken during the Chang'e-2 flyby in 2012. Compared with previous works, this paper concentrates on the photogrammetric relation between the Chang'e-2 spacecraft and Toutatis and the imaging shadow effect during the flyby. Accurate models of imaging and optical measurements are developed to study Toutatis's dimensions and rotational state at the time of imaging. As the illumination study shows, the shadowed region perpendicular to the long axis accounts for 27.78% of the Toutatis images, while the long axis of the body is fully captured. With a compensation on the shadow effect, the optical measurements reveal that Toutatis's long axis is 4354 ± 56 m, the maximum length is 4391 ± 56 m, and the spatial orientation described with the angles of direction cosine during the flyby is (126.°13 ± 0.°29, 122.°98 ± 0.°21, 126.°63 ± 0.°46). Furthermore, a new triaxial ellipsoid of 4354 × 1835 × 2216 m and a volume of 7.5158 km{sup 3} are proposed based on the previous Toutatis shape model. The effectiveness of the proposed method is validated, since typical features such as the neck and endpoints agree well with the results simultaneously observed by the ground radar. Moreover, it also potentially provides a feasible approach to precisely calculate the spin period of Toutatis.

  9. Overexpression of E2F1 Promotes Tumor Malignancy And Correlates with TNM Stages in Clear Cell Renal Cell Carcinoma

    PubMed Central

    Fan, Yang; Ni, Dong; Zhang, Yu; Chen, Weihao; Zhang, Peng; Song, Erlin; Huang, Qingbo; Ai, Qing; Li, Hongzhao; Wang, Baojun; Zheng, Tao; Shi, Taoping; Zhang, Xu

    2013-01-01

    Background Transcription factor E2F1 exerts effects on many types of cancers. As an upstream regulator of a host of genes, E2F1 can trigger diverse aberrant transcription processes that may dominate malignancy. Clear cell renal cell carcinoma (ccRCC) is the most common subtype in renal cell carcinoma which displays high malignancy and has a shortage of biomarkers in clinics. Our study aimed to explore the function of E2F1 in ccRCC and its correlation with clinicopathological parameters. Methodology/Principle Findings Transcription factor E2F1 was mainly distributed in cancer cell nucleus and mRNA expression significantly increased in 72 cases of clear cell renal cell carcinoma (ccRCC) tissues compared with adjacent non-cancerous kidney tissues (p<0.001). The protein expression was