22 research outputs found
Predictive and motivational factors influencing anticipatory contrast: A comparison of contextual and gustatory predictors in food restricted and free-fed rats
In anticipation of palatable food, rats can learn to restrict consumption of a less rewarding food type resulting in an increased consumption of the preferred food when it is made available. This construct is known as anticipatory negative contrast (ANC) and can help elucidate the processes that underlie binge-like behavior as well as self-control in rodent motivation models. In the current investigation we aimed to shed light on the ability of distinct predictors of a preferred food choice to generate contrast effects and the motivational processes that underlie this behavior. Using a novel set of rewarding solutions, we directly compared contextual and gustatory ANC predictors in both food restricted and free-fed Sprague-Dawley rats. Our results indicate that, despite being food restricted, rats are selective in their eating behavior and show strong contextually-driven ANC similar to free-fed animals. These differences mirrored changes in palatability for the less preferred solution across the different sessions as measured by lick microstructure analysis. In contrast to previous research, predictive cues in both food restricted and free-fed rats were sufficient for ANC to develop although flavor-driven ANC did not relate to a corresponding change in lick patterning. These differences in the lick microstructure between context- and flavor-driven ANC indicate that the motivational processes underlying ANC generated by the two predictor types are distinct. Moreover, an increase in premature port entries to the unavailable sipper â a second measure of ANC â in all groups reveals a direct influence of response competition on ANC development
Altered DNA methylation and gene expression predict disease severity in patients with Aicardi-Goutieres syndrome
Aicardi-GoutiĂšres Syndrome (AGS) is a rare neuro-inflammatory disease characterized by increased expression of interferon-stimulated genes (ISGs). Disease-causing mutations are present in genes associated with innate antiviral responses. Disease presentation and severity vary, even between patients with identical mutations from the same family. This study investigated DNA methylation signatures in PBMCs to understand phenotypic heterogeneity in AGS patients with mutations in RNASEH2B. AGS patients presented hypomethylation of ISGs and differential methylation patterns (DMPs) in genes involved in "neutrophil and platelet activation". Patients with "mild" phenotypes exhibited DMPs in genes involved in "DNA damage and repair", whereas patients with "severe" phenotypes had DMPs in "cell fate commitment" and "organ development" associated genes. DMPs in two ISGs (IFI44L, RSAD2) associated with increased gene expression in patients with "severe" when compared to "mild" phenotypes. In conclusion, altered DNA methylation and ISG expression as biomarkers and potential future treatment targets in AGS
Characterization of the molecular dysfunctions occurring in Aicardi-GoutiĂšres syndrome patients with mutations in ADAR1
Metal-based gels: Synthesis, properties, and applications
This review covers various aspects of recent developments on the design, the synthesis, the characterization of gels that: (i) are formed in the presence of metal ions (metallogels); (ii) are based on coordination complexes as gelators. Particular attention is devoted to systems that show recognition and sensing properties towards different analytes
HPV insertional pattern as a personalized tumor marker for the optimized tumor diagnosis and follow-up of patients with HPV-associated carcinomas: a case report
Abstract Background In clinical oncology, only a few applications have been developed using HPV as a personalized tumor marker, a lack most probably related to the limited information obtained by the classical Polymerase Chain Reaction (PCR) approach. To overcome this limitation, we have recently developed the capture-based Next-Generation Sequencing (NGS) âCaptHPVâ assay, designed to provide an extensive and comprehensive molecular characterization of HPV DNA sequences associated with neoplasias, ie the sequence of the viral genome (245 genotypes), its physical state, viral load, integration site and genomic alterations at integration locus. These data correspond to highly specific tumor markers that can be used to improve diagnosis and patientâs follow-up. Case presentation We report here a case that is a straightforward and practical illustration of the power of the CaptHPV method. A patient developed successively a carcinoma of the anal canal and of the tongue. The two tumors were squamous cell carcinoma, found associated with HPV16 using PCR. In order to document a possible metastasis to the tongue from the anal cancer, we performed CaptHPV analysis on the two tumors. The analysis of the anal carcinoma found 55 viral/human hybrid reads allowing the identification of the HPV16 DNA integration in the 4q25 chromosomal band locus with a 178,808âbp deletion in the cell genome. Molecular analysis of the tongue tumor disclosed 6110 reads of HPV16, with a viral pattern strictly identical to that of the anal tumor. A total of 131 hybrid reads between HPV16 and the cell genome were found, corresponding exactly to the same locus of integration of viral DNA at the 4q25 site. The 178,808âbp genomic deletion was also found in the lingual tumor. The exact identity of HPV insertional signatures in the two tumors, demonstrates unambiguously that the tongue tumor derived from the anal cancer whereas neither histological immunophenotyping nor classical viral analysis using PCR could allow a definitive diagnosis. Conclusion Our observation indicates that the establishment of a detailed cartography of HPV DNA sequences in a tumor specimen provides crucial information for the design of specific biomarkers that can be used for diagnostic, prognostic or predictive purposes
Characterization of Mitochondrial Alterations in AicardiâGoutiĂšres Patients Mutated in <i>RNASEH2A</i> and <i>RNASEH2B</i> Genes
AicardiâGoutiĂšres syndrome (AGS) is a rare encephalopathy characterized by neurological and immunological features. Mitochondrial dysfunctions may lead to mitochondrial DNA (mtDNA) release and consequent immune system activation. We investigated the role of mitochondria and mtDNA in AGS pathogenesis by studying patients mutated in RNASEH2B and RNASEH2A genes. Lymphoblastoid cell lines (LCLs) from RNASEH2A- and RNASEH2B-mutated patients and healthy control were used. Transmission Electron Microscopy (TEM) and flow cytometry were used to assess morphological alterations, reactive oxygen species (ROS) production and mitochondrial membrane potential variations. Seahorse Analyzer was used to investigate metabolic alterations, and mtDNA oxidation and VDAC1 oligomerization were assessed by immunofluorescence. Western blot and RT-qPCR were used to quantify mtTFA protein and mtDNA release. Morphological alterations of mitochondria were observed in both mutated LCLs, and loss of physiological membrane potential was mainly identified in RNASEH2A LCLs. ROS production and 8-oxoGuanine levels were increased in RNASEH2B LCLs. Additionally, the VDAC1 signal was increased, suggesting a mitochondrial pore formation possibly determining mtDNA release. Indeed, higher cytoplasmic mtDNA levels were found in RNASEH2B LCLs. Metabolic alterations confirmed mitochondrial damage in both LCLs. Data highlighted mitochondrial alterations in AGS patientsâ LCLs suggesting a pivotal role in AGS pathogenesis
Archéologie du passé, mélancolie du présent - II
La problĂ©matique des sĂ©quences politiques Ă©mancipatrices est aujourdâhui structurellement et durablement inscrite dans un geste dâexploration du passĂ©. Le souci de la politique dâĂ©mancipation, de ses conditions et de ses limites, parvient de moins en moins Ă se formuler autrement que sous la forme dâun discours sur le passĂ©. Tout se passe, autrement dit, comme si la confrontation avec les mĂ©moires et les reconstructions, les bilans rĂ©trospectifs et les archives, Ă©tait la seule condition de possibilitĂ© dâune telle formulation. De quoi cette situation est donc le symptĂŽme ? Que rĂ©vĂšle-t-elle de lâĂ©conomie subjective du prĂ©sent ? LâhypothĂšse de ce Dossier des Cahiers du GRM est que cette condition relĂšve dâune impasse de la subjectivitĂ© « militante » ou « engagĂ©e » contemporaine, vue Ă la fois dans sa continuitĂ© « impossible » Ă lâĂ©gard de la sĂ©quence politique qui se referme catastrophiquement dans les annĂ©es 1970 et dans lâĂ©chec dâune nouvelle sĂ©quence de mobilisations dĂ©clenchĂ©e par la crise de 2007. Ce Dossier monographique essaie de se confronter au champ subjectif de la « mĂ©lancolie de gauche » que structure cette double impasse, et dâen contourner les piĂšges : il sâagit dâexplorer les maniĂšres dont des expĂ©riences et des consciences « militantes » ou « engagĂ©es » ont, entre les annĂ©es 1980 et aujourdâhui, essayĂ© dâĂ©laborer et de surmonter les impasses du prĂ©sent, les traumatismes du passĂ© et les ruptures brutales qui surviennent entre les temps historiques. Le Dossier vise ainsi Ă esquisser lâamorce dâune enquĂȘte sur des maniĂšres de survivre, en tant que subjectivitĂ© « engagĂ©e » ou « critique », par-delĂ le clivage qui nous sĂ©pare Ă la fois de la rĂ©conciliation avec le passĂ© et de lâefficacitĂ© dans le prĂ©sent
DNA Methylation Patterns in CD8(+) T Cells Discern Psoriasis From Psoriatic Arthritis and Correlate With Cutaneous Disease Activity
Background: Psoriasis is a T cell-mediated chronic autoimmune/inflammatory disease. While some patients experience disease limited to the skin (skin psoriasis), others develop joint involvement (psoriatic arthritis; PsA). In the absence of disease- and/or outcome-specific biomarkers, and as arthritis can precede skin manifestations, diagnostic and therapeutic delays are common and contribute to disease burden and damage accrual.Objective: Altered epigenetic marks, including DNA methylation, contribute to effector T cell phenotypes and altered cytokine expression in autoimmune/inflammatory diseases. This project aimed at the identification of disease-/outcome-specific DNA methylation signatures in CD8+ T cells from patients with psoriasis and PsA as compared to healthy controls.Method: Peripheral blood CD8+ T cells from nine healthy controls, 10 psoriasis, and seven PsA patients were collected to analyze DNA methylation marks using Illumina Human Methylation EPIC BeadChips (>850,000 CpGs per sample). Bioinformatic analysis was performed using R (minfi, limma, ChAMP, and DMRcate packages).Results: DNA methylation profiles in CD8+ T cells differentiate healthy controls from psoriasis patients [397 Differentially Methylated Positions (DMPs); 9 Differentially Methylated Regions (DMRs) when â„CpGs per DMR were considered; 2 DMRs for â„10 CpGs]. Furthermore, patients with skin psoriasis can be discriminated from PsA patients [1,861 DMPs, 20 DMRs (â„5 CpGs per region), 4 DMRs (â„10 CpGs per region)]. Gene ontology (GO) analyses considering genes with â„1 DMP in their promoter delivered methylation defects in skin psoriasis and PsA primarily affecting the BMP signaling pathway and endopeptidase regulator activity, respectively. GO analysis of genes associated with DMRs between skin psoriasis and PsA demonstrated an enrichment of GABAergic neuron and cortex neuron development pathways. Treatment with cytokine blockers associated with DNA methylation changes [2,372 DMPs; 1,907 DMPs within promoters, 7 DMRs (â„5 CpG per regions)] affecting transforming growth factor beta receptor and transmembrane receptor protein serine/threonine kinase signaling pathways. Lastly, a methylation score including TNF and IL-17 pathway associated DMPs inverse correlates with skin disease activity scores (PASI).Conclusion: Patients with skin psoriasis exhibit DNA methylation patterns in CD8+ T cells that allow differentiation from PsA patients and healthy individuals, and reflect clinical activity of skin disease. Thus, DNA methylation profiling promises potential as diagnostic and prognostic tool to be used for molecular patient stratification toward individualized treatment
Switching-on fluorescence by copper (II) and basic anions: A case study with a pyrene-functionalized squaramide
The new symmetric acyclic N,Nâ-bis(1-pyrenyl) squaramide (H2L) functionalized with the pyrene moiety as a fluorogenic fragment has been designed and its ability to selectively detect specific anions and metals investigated. H2L selectively binds Clâ both in solution (DMSO 0.5% H2O and MeCN) and in the solid state, and allows to selectively detect Cu2+ in MeCN with the formation of a 2:1 metal-receptor complex, with a green intense emission appreciable by naked eye under the UV lamp. The H2L copper complex preserves its emission properties in the presence of Clâ. The addition of basic anions (OHâ, CNâ, and Fâ) up to 10 equivalents caused the deprotonation of the squaramide NHs and a dramatic change of the emission properties of the H2L copper complex
Comparison between D-loop methylation and mtDNA copy number in patients with Aicardi-GoutiĂšres Syndrome
IntroductionAicardi-Goutieres Syndrome (AGS) is a rare encephalopathy with early onset that can be transmitted in both dominant and recessive forms. Its phenotypic covers a wide range of neurological and extraneurological symptoms. Nine genes that are all involved in nucleic acids (NAs) metabolism or signaling have so far been linked to the AGS phenotype. Recently, a link between autoimmune or neurodegenerative conditions and mitochondrial dysfunctions has been found. As part of the intricate system of epigenetic control, the mtDNA goes through various alterations. The displacement (D-loop) region represents one of the most methylated sites in the mtDNA. The term "mitoepigenetics" has been introduced as a result of increasing data suggesting that epigenetic processes may play a critical role in the control of mtDNA transcription and replication. Since we showed that RNASEH2B and RNASEH2A-mutated Lymphoblastoid Cell Lines (LCLs) derived from AGS patients had mitochondrial alterations, highlighting changes in the mtDNA content, the main objective of this study was to examine any potential methylation changes in the D-loop regulatory region of mitochondria and their relationship to the mtDNA copy number in peripheral blood cells of AGS patients with mutations in various AGS genes and healthy controls. Materials and methodsWe collected blood samples from 25 AGS patients and we performed RT-qPCR to assess the mtDNA copy number and pyrosequencing to measure DNA methylation levels in the D-loop region. ResultsComparing AGS patients to healthy controls, D-loop methylation levels and mtDNA copy number increased significantly. We also observed that in AGS patients, the mtDNA copy number increased with age at sampling, but not the D-loop methylation levels, and there was no relationship between sex and mtDNA copy number. In addition, the D-loop methylation levels and mtDNA copy number in the AGS group showed a non-statistically significant positive relation. ConclusionThese findings, which contradict the evidence for an inverse relationship between D-loop methylation levels and mtDNA copy number, show that AGS patients have higher D-loop methylation levels than healthy control subjects. Additional research is needed to identify the function of these features in the etiology and course of AGS