Villejuif, France
Villejuif, France

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Hangen E.,French Institute of Health and Medical Research | Hangen E.,Institute Gustave Roussy | Hangen E.,University Paris - Sud | De Zio D.,University of Rome Tor Vergata | And 45 more authors.
Cell Death and Differentiation | Year: 2010

Apoptosis-inducing factor (AIF) has important supportive as well as potentially lethal roles in neurons. Under normal physiological conditions, AIF is a vital redox-active mitochondrial enzyme, whereas in pathological situations, it translocates from mitochondria to the nuclei of injured neurons and mediates apoptotic chromatin condensation and cell death. In this study, we reveal the existence of a brain-specific isoform of AIF, AIF2, whose expression increases as neuronal precursor cells differentiate. AIF2 arises from the utilization of the alternative exon 2b, yet uses the same remaining 15 exons as the ubiquitous AIF1 isoform. AIF1 and AIF2 are similarly imported to mitochondria in which they anchor to the inner membrane facing the intermembrane space. However, the mitochondrial inner membrane sorting signal encoded in the exon 2b of AIF2 is more hydrophobic than that of AIF1, indicating a stronger membrane anchorage of AIF2 than AIF1. AIF2 is more difficult to be desorbed from mitochondria than AIF1 on exposure to non-ionic detergents or basic pH. Furthermore, AIF2 dimerizes with AIF1, thereby preventing its release from mitochondria. Conversely, it is conceivable that a neuron-specific AIF isoform, AIF2, may have been designed to be retained in mitochondria and to minimize its potential neurotoxic activity. © 2010 Macmillan Publishers Limited All rights reserved.


Aguerri M.,IIS Fundacion Jimenez Diaz | Calzada D.,IIS Fundacion Jimenez Diaz | Montaner D.,Functional Genomic Unit | Mata M.,Hospital General Universitario | And 8 more authors.
Journal of Biological Regulators and Homeostatic Agents | Year: 2013

Analysis of gene-expression profiles by microarrays is useful for characterization of candidate genes, key regulatory networks, and to define phenotypes or molecular signatures which improve the diagnosis and/or classification of the allergic processes. We have used this approach in the study of olive pollen response in order to find differential molecular markers among responders and non-responders to this allergenic source. Five clinical groups, non-allergic, asymptomatic, allergic but not to olive pollen, untreated-olive-pollen allergic patients and olive-pollen allergic patients (under specific-immunotherapy), were assessed during and outside pollen seasons. Whole-genome gene expression analysis was performed in RNAs extracted from PBMCs. After assessment of data quality and principal components analysis (PCA), differential gene-expression, by multiple testing and, functional analyses by KEGG, for pathways and Gene-Ontology for biological processes were performed. Relevance was defined by fold change and corrected P values (<0.05). The most differential genes were validated by qRT-PCR in a larger set of individuals. Interestingly, gene-expression profiling obtained by PCA clearly showed five clusters of samples that correlated with the five clinical groups. Furthermore, differential gene expression and functional analyses revealed differential genes and pathways in the five clinical groups. The 93 most significant genes found were validated, and one set of 35 genes was able to discriminate profiles of olive pollen response. Our results, in addition to providing new information on allergic response, define a possible molecular signature for olive pollen allergy which could be useful for the diagnosis and treatment of this and other sensitizations. Copyright © by BIOLIFE, s.a.s.


Nanbakhsh A.,French Institute of Health and Medical Research | Visentin G.,French Institute of Health and Medical Research | Olive D.,French Institute of Health and Medical Research | Janji B.,CRP Sante | And 7 more authors.
OncoImmunology | Year: 2015

Although daunorubicin (DNR) is the most widely used anthracycline to treat acute myeloid leukemia (AML), resistance to this drug remains a critical problem. The aim of this study was to investigate the relationship between AML resistance to daunorubicin and susceptibility to natural killer (NK) cell-mediated cell lysis, and the putative expression of miRs. For this purpose, we used the parental AML cell lines U-937 and KG-1 and their equivalent resistant U937(R) and KG-1(R) cell lines. We demonstrate for the first time that the acquisition of resistance to DNR by the parental cell lines resulted in the acquisition of cross-resistance to NK cell-mediated cytotoxicity. miR microarray analysis revealed that this cross-resistance was associated with miR-181a downregulation and the subsequent regulation of MAP3K10 and MAP2K1 tyrosine kinases and the BCL-2 (BCL-2 and MCL-1) family. Overexpression of miR-181a in AML blasts resulted in the attenuation of their resistance to DNR and to NK-cell-mediated killing. These data point to a determinant role of miR-181a in the sensitization of leukemic resistant cells to DNR and NK cells and suggest that miR-181a may provide a promising option for the treatment of immuno- and chemo-resistant blasts. © 2015, Taylor & Francis Group, LLC.


PubMed | INSERM; Gustave Roussy Campus ; Villejuif, Functional Genomic Unit, Institute Paoli Calmettes, CNRS Gustave Roussy Institute and CRP Sante
Type: Journal Article | Journal: Oncoimmunology | Year: 2015

Although daunorubicin (DNR) is the most widely used anthracycline to treat acute myeloid leukemia (AML), resistance to this drug remains a critical problem. The aim of this study was to investigate the relationship between AML resistance to daunorubicin and susceptibility to natural killer (NK) cell-mediated cell lysis, and the putative expression of miRs. For this purpose, we used the parental AML cell lines U-937 and KG-1 and their equivalent resistant U937(R) and KG-1(R) cell lines. We demonstrate for the first time that the acquisition of resistance to DNR by the parental cell lines resulted in the acquisition of cross-resistance to NK cell-mediated cytotoxicity. miR microarray analysis revealed that this cross-resistance was associated with miR-181a downregulation and the subsequent regulation of MAP3K10 and MAP2K1 tyrosine kinases and the BCL

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