Forward RNAi screens in human stem cells.

Identifying the genes and pathways that regulate self-renewal and differentiation in somatic stem cells is a central goal in stem cell and cancer biology. Here, we describe a method for RNAi-based screens in primary human hematopoietic stem and progenitor cells. These cells are suitable targets for complex, selection-based screens using pooled lentiviral shRNA libraries. The screening approach is a promising new tool to dissect regulatory mechanisms in hematopoietic and somatic stem cells, in general, and may be particularly useful to identify gene targets and modifiers that can be further exploited in strategies for ex vivo stem cell expansion

FACS binding assay for analysing GDNF interactions.

Glial cell-line derived neurotrophic factor (GDNF) is a secreted protein with great therapeutic potential. However, in order to analyse the interactions between GDNF and its receptors, researchers have been mostly dependent of radioactive binding assays. We developed a FACS-based binding assay for GDNF as an alternative to current methods. We demonstrated that the FACS-based assay using TGW cells allowed readily detection of GDNF binding and displacement to endogenous receptors. The dissociation constant and half maximal inhibitory concentration obtained were comparable to other studies using standard binding assays. Overall, this FACS-based, simple to perform and adaptable to high throughput setup, provides a safer and reliable alternative to radioactive methods

RNAi screen identifies MAPK14 as a druggable suppressor of human hematopoietic stem cell expansion.

We report on a forward RNAi screen in primary human hematopoietic stem and progenitor cells, using pooled lentiviral shRNA libraries deconvoluted by next generation sequencing. We identify MAPK14/p38α as a modulator of ex vivo stem cell proliferation and show that pharmacological inhibition of p38 dramatically enhances the stem cell activity of cultured umbilical cord blood derived hematopoietic cells. p38 inhibitors should thus be considered in strategies aiming at expanding stem cells for clinical benefit

Temperature-mediated plasticity in the development of Palaemon serratus larvae from winter and summer laying

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Répercussions des dommages à l’ADN spermatique sur le développement embryo-larvaire chez la crevette bouquet, Palaemon serratus

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Effets de la disponibilité alimentaire et de la température sur la plasticité du développement larvaire et leurs conséquences sur la fitness des juvéniles chez Palaemon serratus

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Surface composition and micromasking effect during the etching of amorphous Ge-Sb-Se thin films in SF6 and SF6/Ar plasmas

International audienceA functional waveguide for photonic applications must fulfil some specific requirements in terms of dimension, shape, etch rate and roughness. In this study, Ge-Sb-Se thin films were etched using an Inductively Coupled Plasma reactor via fluorine-based chemistry. In a SF 6 plasma, etch rate and roughness highlight a micro masking effect which originates from the formation of SbF 3 , (Se)-Sb-F x and (Sb)-Se-F environments. The latter have been identified with in situ XPS. Systematically, a SF 6 plasma is associated with a quasi-isotropic profile and a rough surface. In a SF 6 /Ar plasma, the impact of pressure and the argon content has been investigated. The addition of argon affects directly the fluorine atom flux and the argon atom flux which were calculated using a global model. It was found that there is a strong coherence between the fluorine atom flux, the proportion of fluorine at the surface and the RMS roughness. A synergistic effect, between ion bombardment and reactive neutral species, is observed when varying both parameters. Surface is free of fluorinated products for a high percentage of argon (95%) and low-pressures (< 4mTorr). A smooth surface and a quasi-vertical profile were achieved in a SF 6 /Ar with a gas mixture ratio 5/95 and at a pressure of 1.5 mTorr

Pharmacogenomic analysis of acute promyelocytic leukemia cells highlights CYP26 cytochrome metabolism in differential all-trans retinoic acid sensitivity

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