Transferrin receptor 1 mRNA is downregulated in placenta of hepcidin transgenic embryos

AbstractWe have previously shown that hepcidin transgenic embryos are severely anemic and die around birth. Here, we report that embryonic hepcidin transgene expression decreases transferrin receptor 1 (TfR1) mRNA level in placenta, as shown by cDNA microarray analysis and quantitative RT-PCR, by a mechanism which is independent of placenta iron content and iron responsive element/iron regulatory protein (IRE/IRP) activity. On the contrary, iron injections into pregnant mothers result in increased placenta iron and ferritin content, and reduced IRE binding activity of IRP1 leading to decreased TfR1 mRNA level. Taken together, these results suggest that hepcidin action on placenta is mostly through transcriptional downregulation of the iron uptake machinery

Influence of insulators on transgene expression from integrating and non-integrating lentiviral vectors.

International audienceBACKGROUND: The efficacy and biosafety of lentiviral gene transfer is influenced by the design of the vector. To this end, properties of lentiviral vectors can be modified by using cis-acting elements such as the modification of the U3 region of the LTR, the incorporation of the central flap (cPPT-CTS) element, or post-transcriptional regulatory elements such as the woodchuck post-transcriptional regulatory element (WPRE). Recently, several studies evaluated the influence of the incorporation of insulators into the integrating lentiviral vector genome on transgene expression level and position effects. METHODS: In the present study, the influence of the matrix attachment region (MAR) of the mouse immunoglobulin-κ (Ig-κ) or the chicken lysozyme (ChL) gene was studied on three types of HIV-1-derived lentiviral vectors: self-inactivating (SIN) lentiviral vectors (LV), double-copy lentiviral vectors (DC) and non-integrating lentiviral vectors (NILVs) in different cell types: HeLa, HEK293T, NIH-3T3, Raji, and T Jurkat cell lines and primary neural progenitors. RESULTS AND DISCUSSION: Our results demonstrate that the Ig-κ MAR in the context of LV slightly increases transduction efficiency only in Hela, NIH-3T3 and Jurkat cells. In the context of double-copy lentiviral vectors, the Ig-κ MAR has no effect or even negatively influences transduction efficiency. In the same way, in the context of non-integrating lentiviral vectors, the Ig-κ MAR has no effect or even negatively influences transduction efficiency, except in differentiated primary neural progenitor cells.The ChL MAR in the context of integrating and non-integrating lentiviral vectors shows no effect or a decrease of transgene expression in all tested conditions. CONCLUSIONS: This study demonstrates that MAR sequences not necessarily increase transgene expression and that the effect of these sequences is probably context dependent and/or vector dependent. Thus, this study highlights the importance to consider a MAR sequence in a given context. Moreover, other recent reports pointed out the potential effects of random integration of insulators on the expression level of endogenous genes. Taken together, these results show that the use of an insulator in a vector for gene therapy must be well assessed in the particular therapeutic context that it will be used for, and must be balanced with its potential genotoxic effects

Inactive matriptase-2 mutants found in IRIDA patients still repress hepcidin in a transfection assay despite having lost their serine protease activity.

L'article final de l'éditeur contient 9 pages. Le manuscrit accepté contient 32 pages.International audienceMutations of the TMPRSS6 gene, which encodes Matriptase-2, are responsible for iron-refractory iron-deficiency anemia. Matriptase-2 is a transmembrane protease that downregulates hepcidin expression. We report one frameshift (p.Ala605ProfsX8) and four novel missense mutations (p.Glu114Lys, p.Leu235Pro, p.Tyr418Cys, p.Pro765Ala) found in IRIDA patients. These mutations lead to changes in both the catalytic and noncatalytic domains of Matriptase-2. Analyses of the mutant proteins revealed a reduction of autoactivating cleavage and the loss of N-Boc-Gln-Ala-Arg-p-nitroanilide hydrolysis. This resulted either from a direct modification of the active site or from the lack of the autocatalytic cleavage that transforms the zymogen into an active protease. In a previously described transfection assay measuring the ability of Matriptase-2 to repress the hepcidin gene (HAMP) promoter, all mutants retained some, if not all, of their transcriptional repression activity. This suggests that caution is called for in interpreting the repression assay in assessing the functional relevance of Matriptase-2 substitutions. We propose that Matriptase-2 activity should be measured directly in the cell medium of transfected cells using the chromogenic substrate. This simple test can be used to determine whether a sequence variation leading to an amino acid substitution is functionally relevant or not

Heavy quarkonia in a medium as a quantum dissipative system: Master-equation approach

The problem of the evolution of a heavy quarkonium in a medium can be recast as that of a quantum dissipative system. Within the framework of the master-equation approach to open quantum systems, we consider the real-time dynamics of quarkonia. We find that in a plasma at fixed temperature, the populations of the various quarkonium states evolve together, while their momentum distribution satisfies a Fokker-Planck equation.Comment: 12 pages, 8 figures. Version 2 matches the published versio

Alternative Oxidase Expression in the Mouse Enables Bypassing Cytochrome c Oxidase Blockade and Limits Mitochondrial ROS Overproduction

Peer reviewe

Développement de nouveaux vecteurs lentiviraux à intégration spécifique via la recombinase du phage C31

PARIS7-Bibliothèque centrale (751132105) / SudocSudocFranceF

Weighted Monte Carlo: A New Technique for Calibrating Asset-Pricing Models

A general approach for calibrating Monte Carlo models to the market prices of benchmark securities is presented. Starting from a given model for market dynamics (price diffusion, rate diffusion, etc.), the algorithm corrects for price-misspecifications and finite-sample effects in the simulation by assigning "probability weights" to the simulated paths. The choice of weights is done by minimizing the Kullback-Leibler relative entropy distance of the posterior measure to the empirical measure. The resulting ensemble prices the given set of benchmark instruments exactly or in the sense of least-squares. We discuss pricing and hedging in the context of these weighted Monte Carlo models. A significant reduction of variance is demonstrated theoretically as well as numerically. Concrete applications to the calibration of stochastic volatility models and term-structure models with up to forty benchmark instruments are presented. The construction of implied volatility surfaces and forward-rate..

Austrittsrezepte: pharmazeutische Interventionen in der Offizin

Die Versorgungskontinuität oder Continuity of Care stellt eine grosse Herausforderung im Gesundheitsbereich dar. Der Spitalaustritt ist ein heikler Schritt mit Optimierungsbedarf, um eine angemessene Arzneimittelsicherheit zu gewährleisten. Die Apotheke der Spitäler der Region Ost-Waadtland (Pharmacie des Hôpitaux de l’Est Lémanique; PHEL), die Offizinapotheker:innen der Waadt- länder Riviera und das Riviera-Chablais Spital, Waadt-Wallis (Hôpital Riviera- Chablais; HRC) haben eine Studie durchgeführt, um den Versorgungs- übergang beim Spitalaustritt zu beurteilen. Vorschläge, wie die pharma-zeutische Betreuung optimiert werden könnte, liegen auf dem Tisch.La continuité des soins représente un enjeu de santé majeur, et la sortie d’hôpital est une étape délicate qui a besoin d’être optimisée pour assurer une sécurité médicamenteuse adéquate. Une étude pour évaluer la transition des soins lors de la sortie d’hôpital a été réalisée par la Pharmacie des Hôpitaux de l’Est Lémanique (PHEL), les pharmaciens d’officine de la Riviera vaudoise et l’Hôpital Riviera-Chablais,Vaud-Valais (HRC). Avec à la clé des suggestions pouvant optimiser le suivi pharmaceutique

Molecular Analysis of Uroporphyrinogen Decarboxylase Deficiency in a Family with Two Cases of Hepatoerythropoietic Porphyria

Abstract In order to determine the molecular basis of uroporphyrinogen (URO) decarboxylase deficiency responsible for hepatoerythropoietic porphyria (HEP) and familial porphyria cutanea tarda, we used a human URO decarboxylase cDNA to analyze the organization and expression of the URO decarboxylase gene in lymphoblastoid cells from normal individuals and from two patients with HEP. We could detect neither deletions nor rearrangements in the URO decarboxylase gene. Synthesis, processing, and cell-free translation of the specific transcripts appeared to be normal. The half-life of the abnormal protein was 12 times shorter than that of the normal enzyme. The results indicate that the enzyme defect is due to a rapid degradation of the protein in vivo. This study is the first to provide information regarding the molecular mechanism responsible for the URO decarboxylase deficiency in HEP