17 research outputs found
Database model and specification of GermOnline Release 2.0, a cross-species community annotation knowledgebase on germ cell differentiation
Summary: GermOnline is a web-accessible relational database that enables life scientists to make a significant and sustained contribution to the annotation of genes relevant for the fields of mitosis, meiosis, germ line development and gametogenesis across species. This novel approach to genome annotation includes a platform for knowledge submission and curation as well as microarray data storage and visualization hosted by a global network of servers. Availability: The database is accessible at http://www.germonline.org/. For convenient world-wide access we have set up a network of servers in Europe (http://germonline.unibas.ch/; http://germonline.igh.cnrs.fr/), Japan (http://germonline.biochem.s.u-tokyo.ac.jp/) and USA (http://germonline.yeastgenome.org/). Supplementary information: Extended documentation of the database is available through the link ‘About GermOnline' at the website
Analysis of MEFV exon methylation and expression patterns in familial Mediterranean fever
<p>Abstract</p> <p>Background</p> <p>MEFV mutations and decreased expression level of the gene are related to FMF pathology. DNA methylation at CpG islands is a well-known mechanism for transcriptional silencing. MEFV has a CpG island, spanning a part of the first intron and the whole of the second exon of the gene covering 998 bp region. Here, we tested the hypothesis that the MEFV transcript level in FMF patients correlates with its methylation level, and methylation, by allowing transcription silencing, has a role in FMF ethiopathogenesis.</p> <p>Methods</p> <p>The study group was composed of pediatric FMF patients (N = 51) and age-gender matched healthy controls (N = 21). The relative expression level of MEFV was assessed via quantitative real-time PCR (qRT-PCR) and bisulfite sequencing (BS) was performed to analyse the methylation level quantitatively.</p> <p>Results</p> <p>MEFV expression in FMF patients were decreased compared to healthy controls (<it>P </it>= 0.031). Methylation level of exon 2 of MEFV was found to be slightly higher in FMF patients compared to healthy controls (76% versus 74%) (<it>P </it>= 0.049). The expression level of the MEFV was negatively correlated with the methylation level of the CpG island in both FMF and healthy controls groups (cor = -0.29, <it>P </it>= 0.041) but more so in the FMF only group (cor = -0.36, <it>P </it>= 0.035).</p> <p>Conclusions</p> <p>In this study, the relation between reduced MEFV expression level and FMF was confirmed. Observed slight increase in methylation in FMF patients, and correlation of methylation with expression might be indicative of its role in FMF, however a larger dataset is needed to confirm our preliminary findings.</p
Autoinflammatory periodic fever, immunodeficiency, and thrombocytopenia (PFIT) caused by mutation in actin-regulatory gene WDR1
The importance of actin dynamics in the activation of the inflammasome is becoming increasingly apparent. IL-1β, which is activated by the inflammasome, is known to be central to the pathogenesis of many monogenic autoinflammatory diseases. However, evidence from an autoinflammatory murine model indicates that IL-18, the other cytokine triggered by inflammasome activity, is important in its own right. In this model, autoinflammation was caused by mutation in the actin regulatory gene WDR1 We report a homozygous missense mutation in WDR1 in two siblings causing periodic fevers with immunodeficiency and thrombocytopenia. We found impaired actin dynamics in patient immune cells. Patients had high serum levels of IL-18, without a corresponding increase in IL-18-binding protein or IL-1β, and their cells also secreted more IL-18 but not IL-1β in culture. We found increased caspase-1 cleavage within patient monocytes indicative of increased inflammasome activity. We transfected HEK293T cells with pyrin and wild-type and mutated WDR1 Mutant protein formed aggregates that appeared to accumulate pyrin; this could potentially precipitate inflammasome assembly. We have extended the findings from the mouse model to highlight the importance of WDR1 and actin regulation in the activation of the inflammasome, and in human autoinflammation
First Report of Circulating MicroRNAs in Tumour Necrosis Factor Receptor-Associated Periodic Syndrome (TRAPS)
Tumor necrosis factor-receptor associated periodic syndrome (TRAPS) is a rare autosomal dominant autoinflammatory disorder characterized by recurrent episodes of long-lasting fever and inflammation in different regions of the body, such as the musculo-skeletal system, skin, gastrointestinal tract, serosal membranes and eye. Our aims were to evaluate circulating microRNAs (miRNAs) levels in patients with TRAPS, in comparison to controls without inflammatory diseases, and to correlate their levels with parameters of disease activity and/or disease severity. Expression levels of circulating miRNAs were measured by Agilent microarrays in 29 serum samples from 15 TRAPS patients carrying mutations known to be associated with high disease penetrance and from 8 controls without inflammatory diseases. Differentially expressed and clinically relevant miRNAs were detected using GeneSpring GX software. We identified a 6 miRNAs signature able to discriminate TRAPS from controls. Moreover, 4 miRNAs were differentially expressed between patients treated with the interleukin (IL)-1 receptor antagonist, anakinra, and untreated patients. Of these, miR-92a-3p and miR-150-3p expression was found to be significantly reduced in untreated patients, while their expression levels were similar to controls in samples obtained during anakinra treatment. MiR-92b levels were inversely correlated with the number of fever attacks/year during the 1st year from the index attack of TRAPS, while miR-377-5p levels were positively correlated with serum amyloid A (SAA) circulating levels. Our data suggest that serum miRNA levels show a baseline pattern in TRAPS, and may serve as potential markers of response to therapeutic intervention
ETUDES PHYSICO-CHIMIQUES DU GLUCAGON-LIKE PEPTIDE ET DE SON RECEPTEUR. OPTIQUE D'UNE NOUVELLE THERAPEUTIQUE POUR LE DIABETE DE TYPE II
Glucagon-Like Peptide-1 (GLP-1) represents an excellent candidate molecule for a novel therapeutical approach in the treatment of type II diabetes (NIDDM). Although its mode of action in vivo is well known, some fundamental problems remain to be addressed before GLP-1 might be used, and could substitute the drugs currently used in the treatment of NIDDM.In particular our understanding of the binding of GLP-1 to its receptor are insufficient and need to be extended by structural studies of both the peptide and its receptor. Moreover, GLP-1 cannot be used in therapy in its native form since it is highly sensitive to degradation by proteases.In order to define more stable forms of the peptide, several analogs of GLP-1-(7-37) were drawn and synthesized. According to the literature, amino acid positions previously described to play a key role for GLP-1 activity were respected. Amino acid changes were essentially introduced into the amino terminal region. Mutations were also introduced within the central region to corroborate certain hypotheses concerning conformation. Based on their in vitro binding and activity properties, certain analogs were further analyzed for their biological activity and in vivo stability. In such assays the analog [a8,desR36]GLP-1-(7-37) was found to display a remarkable stability and efficiency, superior to those of wild-type GLP-1-(7-37). Currently, this compound is further developed in pre-clinical trials.Additionally, the structure of each analogue was performed by biophysical studies (CD and IR-TF), and in view of the in vitro assays results, a potential bio-active structure is proposed.Finally, in order to gain a better understanding of its interaction(s) with GLP-1, molecular modeling of the receptor was performed. Based on these studies putative interaction sites are proposed. These theoretical considerations were sustained by biophysical analyses and synthesis of fragments of the receptor.Dans la perspective de trouver de nouvelles thérapies dans le traitement du diabète de type II, non insulino-dépendant, le Glucagon-Like Peptide-1 (GLP-1) constitue un excellent candidat. Si son mécanisme d'action est bien connu, il reste toutefois à résoudre de grands problèmes fondamentaux, avant de le substituer aux molécules utilisées pour une telle pathologie. En particulier, la compréhension de la liaison du GLP-1 à son récepteur demeure un point crucial. Une meilleure connaissance des structures du ligand et du récepteur sont nécessaires. De plus, ce peptide ne peut être utilisé dans sa forme native, dû à une inactivation rapide par les protéases.Pour essayer d'augmenter la stabilité du peptide, et en tenant compte des positions clés définies dans la littérature, plusieurs analogues du GLP-1-(7-37) sont conçus, et synthétisés. Ils possèdent principalement des pharmacomodulations au niveau de la partie N-terminale. Des substitutions sont également réalisées dans la partie centrale du peptide, permettant de vérifier certaines hypothèses concernant sa conformation. Considérant les résultats de liaison et d'efficacité in vitro, certains analogues sont sélectionnés pour des études in vivo d'activité et de stabilité métabolique. Le [a8,desR36]GLP-1-(7-37) se distingue des autres tant par sa grande stabilité que son efficacité, supérieure à la molécule native. Ce composé est en phase de développement pré-clinique.Parallèlement, la conformation de chaque analogue est étudiée (CD, IR) et ainsi, confrontée aux résultats in vitro, il est possible de proposer une conformation bioactive.Enfin, pour appréhender plus en avant les mécanismes de liaison du peptide avec son récepteur spécifique, la modélisation moléculaire du récepteur fait ressortir quelques hypothèses quant à la localisation probable de l'interaction hormone-récepteur. Des analyses biophysiques et la synthèse de fragments du récepteur, ont permis d'étayer de telles hypothèses
Restauration d’une plaque en faïence de Castelli
Sarrauste de Menthière Guy. Restauration d’une plaque en faïence de Castelli. In: Sèvres. Revue de la Société des Amis du musée national de Céramique, n°3, 1994. pp. 58-61
The technical and economic context of the use of herbicides in forestry
Quelle place pour les herbicides en forêt ? Une forte part de l'investissement forestier est consacrée à la maîtrise de la concurrence végétale naturelle. C'est pourquoi, depuis une vingtaine d'années, quelques forestiers novateurs, à la recherche d'économies, ont développé l'emploi des herbicides en forêt. Face aux techniques manuelles ou mécanisées, le nouvel outil ne s'est pas toujours révélé beaucoup plus économique mais il a permis de s'affranchir de difficiles problèmes de main-d'œuvre et il a fourni la solution à des problèmes jusque-là insolubles. Les caractéristiques de l'outil chimique (sélectivité, persistance des effets, modalités d'application strictes) ont conduit à une complète révision de la conception de chantiers qui avaient beaucoup hérité des dégagements manuels. On s'achemine progressivement vers un contrôle intégré de la végétation qui combine les avantages des différentes approches : pratiques sylvicoles préventives, travail du sol, contrôle manuel ou mécanique, protection individuelle des plants, herbicides. Mais l'utilisation d'herbicides, largement admise dans le monde agricole, est mal reçue par l'opinion publique lorsqu'il s'agit de forêt. On peut craindre qu'une méfiance générale insuffisamment raisonnée et/ou une réglementation par trop restrictive ne rendent cette utilisation impossible ; il appartient à l'ensemble des intervenants : fabricants, applicateurs, forestiers, de se rapprocher pour contribuer ensemble à la clarification du débat et à l'élaboration d'un cadre d'utilisation mûrement réfléchi.A major proportion of forestry investment is devoted to the control of natural plant competition. This is why for the past twenty years some innovative foresters, looking for ways of reducing costs, have been developing the use of herbicides in forestry. Compared with manual or mechanical techniques, the new tool has not always proved much more economic but it has made it possible to become independent of labour problems and has provided the solution to previously insoluble problems. The characteristics of the chemical method (selectivity, persistance of effects, and strict modes of application) have led to a complete reassessment of the control procedure which was largely based on manual cleaning. There is a gradual move towards integrated control of vegetation combining the advantages of the different methods : preventive silvicultural methods, tillage, manual or mechanical control, protection of individual plants, and herbicides. However, while the use of herbicides is widely accepted in agriculture, public opinion is against their use in forestry. There is a danger that widespread mistrust based on a lack of understanding and/or regulations which are too restrictive may make their use in forestry impossible. All the parties involved (manufacturers, users and foresters) should get together to help to clarify the matter and to develop a carefully considered framework for use