New stably transfected bioluminescent cells expressing FLAG epitope-tagged estrogen receptors to study their chromatin recruitment

International audienceBACKGROUND: Biological actions of estrogens are mediated by the two specific estrogen receptors ERalpha and ERbeta. However, due to the absence of adequate cellular models, their respective transcriptional activities are still poorly understood. For instance, the evaluation of such differing properties on the transcription of responsive genes using ChIP experiments was hindered by the deficiency of cells exhibiting the same genotypic background and properties but expressing only one of the ERs. We describe here the generation of such cells, using an estrogen receptor negative HELN cell line that was derived from HeLa cells stably transfected with an ERE-driven luciferase plasmid. These HELN-Falpha and HELN-Fbeta cell lines stably express either the alpha or beta (full length) estrogen receptor tagged with the FLAG epitope. The use of antibodies directed against the FLAG epitope allowed a direct comparative evaluation of the respective actions of both ERs using ChIP. RESULTS: HELN-Falpha and HELN-Fbeta cell lines were found to express comparable levels of their corresponding tagged receptors with a Kd for estradiol binding of 0.03 and 0.27 nM respectively. The presence of a stably transfected ERE-driven luciferase plasmid in these cells allowed the direct evaluation of the transcriptional activity of both tagged receptors, using natural or synthetic estrogens. FLAG-ERalpha and FLAG-ERbeta were found to exhibit similar transcriptional activity, as indicated by a kinetic evaluation of the transcriptional activation of the luciferase gene during 10 hrs of treatment with estradiol. The validity of these model cells was further confirmed by the predictable transcriptional regulations measured upon treatments with ERalpha or ERbeta specific ligands. The similar immunoprecipitation efficiency of both tagged receptors by an anti-FLAG antibody allowed the assessment of their kinetic recruitment on the synthetic luciferase promoter (containing an estrogen response element) by ChIP assays during 8 hours. A biphasic curve was obtained for both FLAG-ERalpha and FLAG-ERbeta, with a peak occurring either at 2 hr or at 1 hr, respectively, and a second one following 4 hr of E2 stimulation in both cases. In MCF-7 cells, the recruitment of ERalpha also exhibited a biphasic behaviour; with the second peak however not so important than in the HeLa cell lines. CONCLUSION: In HELN derived cell lines, no fundamental differences between kinetics were observed during 8 hours for FLAG-ERalpha and FLAG-ERbeta, as well as for polymerase II recruitment. However, the relative importance of recruitment between 1 hr and 4 hr was found to be different in HeLa cell line expressing exogenous tagged ERalpha and in MCF-7 cell line expressing endogenous ER

Long QT syndrome provoked by induction of general anesthesia -A case report-

Long QT syndrome (LQTS) is an arrhythmogenic cardiovascular disorder resulting from mutations in cardiac ion channels. LQTS is characterized by prolonged ventricular repolarization and frequently manifests itself as QT interval prolongation on the electrocardiogram (ECG). A variety of commonly prescribed anesthetic drugs possess the adverse property of prolonging cardiac repolarization and may provoke serious ventricular tachyarrhythmia called 'torsades de pointes', ventricular fibrillation, and sudden death. We experienced a case of ventricular tachycardia and ventricular fibrillation after anesthetic induction and it came out into the open that anesthetic induction provoked long QT syndrome

Profiling of benzophenone derivatives using fish and human estrogen receptor-specific in vitro bioassays.

International audienceBenzophenone (BP) derivatives, BP1 (2,4-dihydroxybenzophenone), BP2 (2,2',4,4'-tetrahydroxybenzophenone), BP3 (2-hydroxy-4-methoxybenzophenone), and THB (2,4,4'-trihydroxybenzophenone) are UV-absorbing chemicals widely used in pharmaceutical, cosmetics, and industrial applications, such as topical sunscreens in lotions and hair sprays to protect skin and hair from UV irradiation. Studies on their endocrine disrupting properties have mostly focused on their interaction with human estrogen receptor alpha (hERalpha), and there has been no comprehensive analysis of their potency in a system allowing comparison between hERalpha and hERbeta activities. The objective of this study was to provide a comprehensive ER activation profile of BP derivatives using ER from human and fish origin in a battery of in vitro tests, i.e., competitive binding, reporter gene based assays, vitellogenin (Vtg) induction in isolated rainbow trout hepatocytes, and proliferation based assays. The ability to induce human androgen receptor (hAR)-mediated reporter gene expression was also examined. All BP derivatives tested except BP3 were full hERalpha and hERbeta agonists (BP2>THB>BP1) and displayed a stronger activation of hERbeta compared with hERalpha, the opposite effect to that of estradiol (E2). Unlike E2, BPs were more active in rainbow trout ERalpha (rtERalpha) than in hERalpha assay. All four BP derivatives showed anti-androgenic activity (THB>BP2>BP1>BP3). Overall, the observed anti-androgenic potencies of BP derivatives, together with their proposed greater effect on ERbeta versus ERalpha activation, support further investigation of their role as endocrine disrupters in humans and wildlife

Money for writing: Screenplay development and screenwriters earnings in French cinema

The funds allocated to developing screenplays currently constitute on average 2 to 3% of the overall budget of a film in France. Producers are more than ever dependent on presenting attractive draft screenplays to find their financial partners. As a result, screenwriters undoubtedly are active economic partners of production planning, but they do not seem to receive much professional recognition for this vital role. Moreover, their earnings often fail to reflect the amount of work produced and do not reward adequately the risks taken, including the possibility that production could stop after the screenplay is written. This article investigates the place of screenplay development within the economics of French cinema. Using recently published official reports and interviews, the author identifies different types of screenwriters – freestanding screenwriters, writing teams and screenwriters co-writing with the director – and addresses their working conditions. She surveys some of the contract modalities for the remuneration of professional screenwriters. Finally, she reviews the proposals made by different professional bodies to improve the remuneration of screenwriters and reform the financing of screenwriting

Variable Nav1.5 Protein Expression from the Wild-Type Allele Correlates with the Penetrance of Cardiac Conduction Disease in the Scn5a+/− Mouse Model

BACKGROUND: Loss-of-function mutations in SCN5A, the gene encoding Na(v)1.5 Na+ channel, are associated with inherited cardiac conduction defects and Brugada syndrome, which both exhibit variable phenotypic penetrance of conduction defects. We investigated the mechanisms of this heterogeneity in a mouse model with heterozygous targeted disruption of Scn5a (Scn5a(+/-) mice) and compared our results to those obtained in patients with loss-of-function mutations in SCN5A. METHODOLOGY/PRINCIPAL FINDINGS: Based on ECG, 10-week-old Scn5a(+/-) mice were divided into 2 subgroups, one displaying severe ventricular conduction defects (QRS interval>18 ms) and one a mild phenotype (QRS53 weeks), ajmaline effect was larger in the severely affected subgroup. These data matched the clinical observations on patients with SCN5A loss-of-function mutations with either severe or mild conduction defects. Ventricular tachycardia developed in 5/10 old severely affected Scn5a(+/-) mice but not in mildly affected ones. Correspondingly, symptomatic SCN5A-mutated Brugada patients had more severe conduction defects than asymptomatic patients. Old severely affected Scn5a(+/-) mice but not mildly affected ones showed extensive cardiac fibrosis. Mildly affected Scn5a(+/-) mice had similar Na(v)1.5 mRNA but higher Na(v)1.5 protein expression, and moderately larger I(Na) current than severely affected Scn5a(+/-) mice. As a consequence, action potential upstroke velocity was more decreased in severely affected Scn5a(+/-) mice than in mildly affected ones. CONCLUSIONS: Scn5a(+/-) mice show similar phenotypic heterogeneity as SCN5A-mutated patients. In Scn5a(+/-) mice, phenotype severity correlates with wild-type Na(v)1.5 protein expression

USE OF CERTAIN TRANSITION METAL HYPERACCUMULATOR PLANTS FOR REDUCING ORGANIC COMPOUNDS IN A GREEN MANNER

The invention relates to a method for reducing organic compounds using catalysts containing nickel (O) from metal hyperaccumulator plants. Said method can be implemented in a green manner and is advantageous compared to methods using the known catalysts

Use of compositions obtained by calcing particular metal-accumulating plants for implementing catalytical reactions

The invention relates to the use of compositions derived from metal-accumulating plants, wherein the metals are more particularly zinc, nickel and copper, for implementing chemical reactions especially catalytical reactions, a method for the preparation of specific Ni-containing composition, and said Ni-containing composition

REDUCING THE CARBONYL FUNCTIONS OF CARBOHYDRATES AND CARBOHYDRATE DERIVATIVES IN AN AQUEOUS MEDIUM BY MEANS OF SODIUM DITHIONITE

The present invention relates to the use of sodium dithionite to reduce at least one aldehyde or ketone function of a carbohydrate, C-glycoside, oligosaccharide, or water-soluble polysaccharide in the absence of a water-immiscible organic solvent and in the absence of a phase transfer agent. The invention also relates to a preparation method that includes treating a carbohydrate, a C-glycoside, an oligosaccharide, or a water-soluble polysaccharide with sodium dithionite