Retinoic acid regulates avian lung branching through a molecular network

Retinoic acid (RA) is of major importance during vertebrate embryonic development and its levels need to be strictly regulated otherwise congenital malformations will develop. Through the action of specific nuclear receptors, named RAR/RXR, RA regulates the expression of genes that eventually influence proliferation and tissue patterning. RA has been described as crucial for different stages of mammalian lung morphogenesis, and as part of a complex molecular network that contributes to precise organogenesis; nonetheless, nothing is known about its role in avian lung development. The current report characterizes, for the first time, the expression pattern of RA signaling members (stra6, raldh2, raldh3, cyp26a1, rar alpha, and rar beta) and potential RA downstream targets (sox2, sox9, meis1, meis2, tgf beta 2, and id2) by in situ hybridization. In the attempt of unveiling the role of RA in chick lung branching, in vitro lung explants were performed. Supplementation studies revealed that RA stimulates lung branching in a dose-dependent manner. Moreover, the expression levels of cyp26a1, sox2, sox9, rar beta, meis2, hoxb5, tgf beta 2, id2, fgf10, fgfr2, and shh were evaluated after RA treatment to disclose a putative molecular network underlying RA effect. In situ hybridization analysis showed that RA is able to alter cyp26a1, sox9, tgf beta 2, and id2 spatial distribution; to increase rar beta, meis2, and hoxb5 expression levels; and has a very modest effect on sox2, fgf10, fgfr2, and shh expression levels. Overall, these findings support a role for RA in the proximal-distal patterning and branching morphogenesis of the avian lung and reveal intricate molecular interactions that ultimately orchestrate branching morphogenesis.The authors would like to thank Ana Lima for slide sectioning and Rita Lopes for contributing to the initiation of this project. This work has been funded by FEDER funds, through the Competitiveness Factors Operational Programme (COMPETE), and by National funds, through the Foundation for Science and Technology (FCT), under the scope of the Project POCI-01-0145-FEDER-007038; and by the Project NORTE-01-0145- FEDER-000013, supported by the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (FEDER). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.info:eu-repo/semantics/publishedVersio

Regularity of the vibrational spectrum of the CS[sub 2] in the Σ[sub g][sup +] state: Our previous results revisited

International audienceIn previous experiments, a nearly complete vibrational spectrum of the CS2 molecule in the Σg+ state has been obtained using a laser induced fluorescence method. The statistical tests of the random matrix theory, applied on this spectrum, suggest a transition to quantum chaos. The aim of this letter is to show that these statistical results are biased because of a nonsingle excitation of the molecule. This is experimentally confirmed by high-resolution new experiments in supersonic jet, using the powerful laser chain of the french project for the isotopic separation of uranium by laser (SILVA project)

Isolation and characterization of a cDNA encoding a chicken actin-like protein

We report the isolation and characterization of a chicken cDNA which putatively encodes an actin-like protein (chACTL). This 394-amino-acid (aa) polypeptide shares sequence homology (81, 70 and 67% identical aa, respectively) with three actin-related proteins (ARP) described for Drosophila melanogaster (ARP14D), Caenorhabditis elegans (ACTL) and Saccharomyces cerevisiae (ACT2). At least six chACTL transcripts were detected in different tissues during chick embryogenesis. Sequence analysis suggests that at least three groups of ARP have been evolutionarily conserved

c-erbAalpha/T3R and RARs control commitment of hematopoietic self-renewing progenitor cells to apoptosis or differentiation and are antagonized by the v-erbA oncogene

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IR-UV double resonance experiment using a CO and a CuHBr (HyBrID) laser pumped dye laser: application to the spectroscopy of CS2

International audienceAn Infrared-Ultraviolet Double Resonance (IR-UV DR) experiment has been built in order to resolve and identify single rotational levels in dense molecular spectra. The system is based on a CO laser, working on the CO fundamental transition (Δ v=1), and a frequency doubled dye laser pumped by a recently developed copper vapor "HyBrID " or "CuHBr" laser. We demonstrate the promising nature of the CuHBr laser as a pump laser for high power dye lasers. Different excitation schemes can be used with this experiment in order to obtain information about excited electronic states. We also report here preliminary results on the spectroscopy of the carbon disulfide (CS 2) molecule

Characterization of the mesospheric sodium layer at La Palma

We present the results of a mesospheric sodium monitoring programme at La Palma carried out through five campaigns of one week each, from 1999 September to 2000 August. The yearly averaged parameters of the layer (the sodium column density and the width) are given. We show that the short time-scale dynamics of the layer are governed by the sporadic layers with an average frequency of one event per night. The influence of the short time-scale dynamics of the layer on an adaptive optics system working on the William Herschel Telescope is quantified. It appears that it is a small effect in terms of defocus error. Finally, we present data obtained during the Perseid meteor shower and show that the dynamics of the sodium layer undergoes a transition with the meteoric activity

The downregulation of miR-125b in chronic lymphocytic leukemias leads to metabolic adaptation of cells to a transformed state.

MiR-125b-1 maps at 11q24, a chromosomal region close to the epicenter of 11q23 deletions in chronic lymphocytic leukemias (CLLs). Our results establish that both aggressive and indolent CLL patients show reduced expression of miR-125b. Overexpression of miR-125b in CLL-derived cell lines resulted in the repression of many transcripts encoding enzymes implicated in cell metabolism. Metabolomics analyses showed that miR-125b overexpression modulated glucose, glutathione, lipid and glycerolipid metabolism. Changes on the same metabolic pathways were also observed in CLLs. We furthermore analyzed the expression of some of miR-125b-target transcripts that are potentially involved in the above metabolic pathways and defined a miR-125b-dependent CLL metabolism-related transcript signature. Thus, miR-125b acts as a master regulator for the adaptation of cell metabolism to a transformed state. MiR-125b and miR-125b-dependent metabolites therefore warrant further investigation as possible novel therapeutic approaches for CLLs