Tetrastatin, the NC1 Domain of the α4(IV) Collagen Chain: A Novel Potent Anti-Tumor Matrikine

BACKGROUND: NC1 domains from α1, α2, α3 and α6(IV) collagen chains were shown to exert anti-tumor or anti-angiogenic activities, whereas the NC1 domain of the α4(IV) chain did not show such activities so far. METHODOLOGY/PRINCIPAL FINDINGS: We demonstrate in the present paper that the NC1 α4(IV) domain exerts a potent anti-tumor activity both in vitro and in an experimental human melanoma model in vivo. The overexpression of NC1 α4(IV) in human UACC-903 melanoma cells strongly inhibited their in vitro proliferative (-38%) and invasive (-52%) properties. MT1-MMP activation was largely decreased and its cellular distribution was modified, resulting in a loss of expression at the migration front associated with a loss of migratory phenotype. In an in vivo xenograft model in athymic nude mice, the subcutaneous injection of NC1 α4(IV)-overexpressing melanoma cells induced significantly smaller tumors (-80% tumor volume) than the Mock cells, due to a strong inhibition of tumor growth. Exogenously added recombinant human NC1 α4(IV) reproduced the inhibitory effects of NC1 α4(IV) overexpression in UACC-903 cells but not in dermal fibroblasts. An anti-αvβ3 integrin blocking antibody inhibited cell adhesion on recombinant human NC1 α4(IV) substratum. The involvement of αvβ3 integrin in mediating NC1 α4(IV) effect was confirmed by surface plasmon resonance (SPR) binding assays showing that recombinant human NC1 α4(IV) binds to αvβ3 integrin (K(D) = 148 ± 9.54 nM). CONCLUSION/SIGNIFICANCE: Collectively, our results demonstrate that the NC1 α4(IV) domain, named tetrastatin, is a new endogenous anti-tumor matrikine

MOSAIC: an online database dedicated to the comparative genomics of bacterial strains at the intra-species level

BACKGROUND: The recent availability of complete sequences for numerous closely related bacterial genomes opens up new challenges in comparative genomics. Several methods have been developed to align complete genomes at the nucleotide level but their use and the biological interpretation of results are not straightforward. It is therefore necessary to develop new resources to access, analyze, and visualize genome comparisons. DESCRIPTION: Here we present recent developments on MOSAIC, a generalist comparative bacterial genome database. This database provides the bacteriologist community with easy access to comparisons of complete bacterial genomes at the intra-species level. The strategy we developed for comparison allows us to define two types of regions in bacterial genomes: backbone segments (i.e., regions conserved in all compared strains) and variable segments (i.e., regions that are either specific to or variable in one of the aligned genomes). Definition of these segments at the nucleotide level allows precise comparative and evolutionary analyses of both coding and non-coding regions of bacterial genomes. Such work is easily performed using the MOSAIC Web interface, which allows browsing and graphical visualization of genome comparisons. CONCLUSION: The MOSAIC database now includes 493 pairwise comparisons and 35 multiple maximal comparisons representing 78 bacterial species. Genome conserved regions (backbones) and variable segments are presented in various formats for further analysis. A graphical interface allows visualization of aligned genomes and functional annotations. The MOSAIC database is available online at http://genome.jouy.inra.fr/mosaic

Assessment of Verticillium flax inoculum in agroecosystem soils using real-time PCR assay: from diagnosis to evaluation of crop system.

Verticillium wilt, due to the soilborne fungus Verticillium dahliae, is a persistent disease affecting flax crops in Normandy. This pathology has increased since the last decade, leading to yield losses for flax producers. In part due to the long survival of V. dahliae in soil and the difficulty of early diagnosis, Verticillium flax wilt management remains problematic. Pathogen avoidance and the reduction of soil inoculum through adapted cultural practices are the two best alternatives to fight against Verticillium wilt. Here, the objectives were to develop a rapid and specific assay to measure V. dahliae density in soil. A real-time PCR assay was optimized and validated to provide a sensitive and reliable quantification of V. dahliae in a range of artificially inoculated soils with known inoculum density. This assay was then successfully applied to study the in situ relationship between pathogen density and disease development in flax fields. Some studies have already reported the direct relationship between Verticillium densities in soil and disease severity on several important crops (potato, cauliflower …). But this link appeared to be more complex for flax. The importance of soil receptivity, linked to chemical and microbial characteristics, have to be particularly consider.Finally, the real-time PCR assay was also used to evaluate and compare pathogen load in fields from diverse management systems: conventional, integrated and organic. Verticillium densities appeared to be impacted by agricultural practices, and particularly tillage. The influence of the previous crop on pathogen load had also to be considered with attention to manage efficiently this disease through crop rotation. Measured V. dahliae densities in all fields presented an intra-parcel heterogeneity, emphasizing the importance of an adapted sampling strategy to assess pathogen density. Such knowledge of pathogen density in soils could provide critical information for stakeholders to identify infested fields and predict disease development

The CEDRES++ equilibrium code and its application to ITER, JT-60SA and Tore Supra.

International audienceFree-boundary equilibrium codes are an essential tool for tokamak design studies and scenario development. In this contribution, the CEDRES++ code is presented and applications to ITER, JT-60SA and Tore Supra are reported on. A satisfactory benchmark of CEDRES++ with the DINA code was performed on an ITER Scenario 2 case at 32 different times across the discharge, both in direct and inverse mode. Ongoing design studies for the poloidal field coils system of JT-60SA, performed in the frame of the Broader Approach,werecross checkedwithCEDRES++.Finally,adimensioningstudywascarriedoutforthecoils and power supplies for plasma vertical control in the frame of a feasibility study for the implementation of a divertor in Tore Supr

Cholesterol 24-hydroxylase defect is implicated in memory impairments associated with Alzheimer-like Tau pathology

International audienc

NC1 α4(IV) overexpression decreases MT1-MMP activation and modifies MT1-MMP distribution.

<p>(A): Mock or NC1 α4(IV)-overexpressing cells were incubated for 48 h without FBS. MT1-MMP expression and activation in whole cell extracts were analyzed by Western blot with an antibody directed against the hinge region of MT1-MMP. The membrane was dehybridized and reprobed with an anti-actin antibody. Quantifications were performed by densitometry using the Bio-1D software. Results were expressed as arbitrary units (AU). NS: Non significant. ***: p<0.001. (B): Cells were cultured on glass slides, fixed with paraformaldehyde and labelled with an anti-MT1-MMP directed against both the pro and the active form (green), anti-caveolin 1 (red). Yellow staining corresponds to areas where proMT1-MMP and caveolin-1 colocalized and white arrows in the insert underline the colocalization at the migration front at a higher magnification. Nuclei were conterstained with DAPI (blue). Scale bar: 5 µm.</p

Selection of NC1 α4(IV) overexpressing cell clones.

<p>UACC-903 cells were transfected with either p3xFLAG-CMV-9 (Mock 1, 2, 3) or p3xFLAG-NC1[α4(IV)] (NC1 α4(IV) 1, 2, 3). (A): RT-PCR: Total RNA was isolated from clones selected for G418 resistance and analyzed by RT-PCR using p3xFLAG-CMV-9 (1) and GAPDH specific primers (2). (B): Western-blot: Three clones were selected by RT-PCR for their high gene expression of FLAG epitope and FLAG-NC1[α4(IV)] fusion protein. Supernatant from Mock cells and from cells stably transfected with FLAG-NC1[α4(IV)] were tested for the 28 kDa fusion protein secretion by Western blot using an anti-FLAG monoclonal antibody or an anti-NC1 α4(IV) polyclonal antibody.</p