Nanovirus-alphasatellite complex identified in Vicia cracca in the Rhône delta region of France

BGPI : équipe 2 / 7International audienceNanoviruses are multi-component plant-infecting single-stranded DNA viruses. Using a viral metagenomics-informed approach, a new nanovirus and two associated alphasatellite molecules have been identified in an uncultivated asymptomatic Vicia cracca plant in the Rhône region of France. This novel nanovirus genome includes eight genomic components (named DNA-R, DNA-S, DNA-M, DNA-C, DNA-N, DNA-U1, DNA-U2 and DNA-U4) and, across all components, shares < 66% pairwise sequence identity with other nanovirus genomes. The two associated alphasatellites share 62% identity with each other and < 81% identity will all other nanovirus-associated alphasatellites

Glycosylation-related gene expression is linked to differentiation status in glioblastomas undifferentiated cells.

Chantier qualité GAInternational audienceGlioblastoma Multiforme (GBM) is the most frequent malignant brain tumor with still poor prognosis. Tumor initiation, growth and recurrences might depend on Brain Tumor Stem Cells (BTSCs) which can promote tumor aggressiveness and potentially affords new therapeutic target. Recent works emphasized aberrant cell-surface glyco-conjugate expression in brain tumors suggesting that altered glycosylation is closely linked to cancer tumor metastasis and invasive process. Post-translational changes might play a key role in determining the fates of most aggressive and undifferentiated cells such as self-renewal, proliferation and differentiation. In order to characterize the glycosylation-related genes involved in differentiation status of the BTSCs, two glioblastoma cell lines, U87-MG and U251 have been cultured according to two conditions leading to undifferentiated floating cells or differentiated adherent cells. The expression level of 559 glycosylation related genes has been analyzed by Taqman Low Density Array (TLDA) analysis and allowed to isolate eight up-regulated genes specific of a subpopulation of undifferentiated cells. Protein expression has been confirmed. Among main selected genes, five are also over-expressed in the undifferentiated condition in primary cultures provided by three GBM freshly isolated from patient. This work suggests that new Glycosylation-related gene signature might improve the characterization of the most aggressive and undifferentiated cells and supports that in future, N-linked glycosylation might provide new target to develop therapeutic strategy for inhibiting tumor growth

Selective iron chelation in Friedreich ataxia: biologic and clinical implications.

International audienceGenetic disorders of iron metabolism and chronic inflammation often evoke local iron accumulation. In Friedreich ataxia, decreased iron-sulphur cluster and heme formation leads to mitochondrial iron accumulation and ensuing oxidative damage that primarily affects sensory neurons, the myocardium, and endocrine glands. We assessed the possibility of reducing brain iron accumulation in Friedreich ataxia patients with a membrane-permeant chelator capable of shuttling chelated iron from cells to transferrin, using regimens suitable for patients with no systemic iron overload. Brain magnetic resonance imaging (MRI) of Friedreich ataxia patients compared with age-matched controls revealed smaller and irregularly shaped dentate nuclei with significantly (P < .027) higher H-relaxation rates R2*, indicating regional iron accumulation. A 6-month treatment with 20 to 30 mg/kg/d deferiprone of 9 adolescent patients with no overt cardiomyopathy reduced R2* from 18.3 s(-1) (+/- 1.6 s(-1)) to 15.7 s(-1) (+/- 0.7 s(-1); P < .002), specifically in dentate nuclei and proportionally to the initial R2* (r = 0.90). Chelator treatment caused no apparent hematologic or neurologic side effects while reducing neuropathy and ataxic gait in the youngest patients. To our knowledge, this is the first clinical demonstration of chelation removing labile iron accumulated in a specific brain area implicated in a neurodegenerative disease. The use of moderate chelation for relocating iron from areas of deposition to areas of deprivation has clinical implications for various neurodegenerative and hematologic disorders

Les luttes anti-seigneuriales

La Jacquerie française de 1358 et la révolte des paysans anglais de 1381 ont durablement marqué les mémoires, révélant une aspiration manifeste dès le Moyen Âge : le désir de libération des masses populaires. Du Nord au Midi de l’Europe, la paysannerie s’est engagée dans des luttes ouvertes contre les pouvoirs en place, contre les princes et les seigneurs. Mais ces combats ont été parfois plus feutrés et la résistance à l’autorité s’est souvent exprimée par la voie de la justice ou de l’arbitrage. Comprendre les causes et les enjeux de ces résistances à l’autorité constitue un chantier historiographique en plein renouveau. Les pistes explorées dans cet ouvrage mettent en lumière le rôle sociopolitique de la noblesse, le poids des redevances seigneuriales, l’oppression des officiers locaux, l’essor de la fiscalité étatique, la genèse de l’État moderne et l’impact de la Réforme - permettant d’appréhender les mobilisations populaires dans leur diversité