Stimulation of Wild-Type, F508del- and G551D-CFTR Chloride Channels by Non-Toxic Modified pyrrolo[2,3-b]pyrazine Derivatives

Cystic fibrosis (CF) is a major inherited disorder involving abnormalities of fluid and electrolyte transport in a number of different organs due to abnormal function of cystic fibrosis transmembrane conductance regulator (CFTR) protein. We recently identified a family of CFTR activators, which contains the hit: RP107 [7-n-butyl-6-(4-hydroxyphenyl)[5H]-pyrrolo[2,3-b]pyrazine]. Here, we further evaluated the effect of the chemical modifications of the RP107-OH radical on CFTR activation. The replacement of the OH radical by a fluorine atom at position 2 (RP193) or 4 (RP185) significantly decreased the toxicity of the compounds without altering the ability to activate CFTR, especially for RP193. The non-toxic compound RP193 has no effect on cAMP production but stimulates the channel activity of wild-type CFTR in stably transfected CHO cells, in human bronchial epithelial NuLi-1 cells, and in primary culture of human bronchial epithelial cells (HBEC). Whole-cell and single patch-clamp recordings showed that RP193 induced a linear, time- and voltage-independent current, which was fully inhibited by two different and selective CFTR inhibitors (CFTRinh-172 and GPinh5a). Moreover, RP193 stimulates CFTR in temperature-rescued CuFi-1 (F508del/F508del) HBEC and in CHO cells stably expressing G551D-CFTR. This study shows that it is feasible to reduce cytotoxicity of chemical compounds without affecting their potency to activate CFTR and to rescue the class 2 F508del-CFTR and class 3 G551D-CFTR CF mutant activities

The effects of age on objective and subjective recollection after visiting a virtual apartment

peer reviewedWhile aging has been associated with decreased retrieval of episodic memory details, subjective ratings about memory quality seem to remain stable. This suggests that subjective memory judgments are based on different information according to age. Here, we tested the hypothesis that older people would rather base their subjective judgments on the retrieval of personal elements (such as emotions and thoughts), whereas younger people would rather base their judgments on the retrieval of event-related elements (such as time, place, and perceptual details). Sixty participants (20 to 79 years old) performed eight actions in a virtual apartment and were then asked to verbally recall each action with a maximum of associated elements and to rate the subjective quality of their memories. The elements reported were classified into "person-related" and "event-related" categories. Executive functions, memory performance on traditional memory tasks, and subjects' perception of memory functioning were also evaluated. Results revealed that aging was associated with reduced retrieval of event-related elements, which was explained by decreasing executive resources. However, age did not affect the retrieval of person-related elements, and the subjective memory judgments of older people were not based on these elements to a greater extent than those of younger people. Finally, our results highlight the value of virtual reality (VR) in memory evaluations since subjects' perception of memory functioning was associated with their performance in the VR task but not in traditional memory tasks

Potential sites of CFTR activation by tyrosine kinases

The CFTR chloride channel is tightly regulated by phosphorylation at multiple serine residues. Recently it has been proposed that its activity is also regulated by tyrosine kinases, however the tyrosine phosphorylation sites remain to be identified. In this study we examined 2 candidate tyrosine residues near the boundary between the first nucleotide binding domain and the R domain, a region which is important for channel function but devoid of PKA consensus sequences. Mutating tyrosines at positions 625 and 627 dramatically reduced responses to Src or Pyk2 without altering the activation by PKA, suggesting they may contribute to CFTR regulation

Field-Based Metabolomics of Vitis vinifera L. Stems Provides New Insights for Genotype Discrimination and Polyphenol Metabolism Structuring

Grape accumulates numerous polyphenols with abundant health benefit and organoleptic properties that in planta act as key components of the plant defense system against diseases. Considerable advances have been made in the chemical characterization of wine metabolites particularly volatile and polyphenolic compounds. However, the metabotyping (metabolite-phenotype characterization) of grape varieties, from polyphenolic-rich vineyard by-product is unprecedented. As this composition might result from the complex interaction between genotype, environment and viticultural practices, a field experiment was setting up with uniform pedo-climatic factors and viticultural practices of growing vines to favor the genetic determinism of polyphenol expression. As a result, UPLC-MS-based targeted metabolomic analyses of grape stems from 8 Vitis vinifera L. cultivars allowed the determination of 42 polyphenols related to phenolic acids, flavonoids, procyanidins, and stilbenoids as resveratrol oligomers (degree of oligomerization 1–4). Using a partial least-square discriminant analysis approach, grape stem chemical profiles were discriminated according to their genotypic origin showing that polyphenol profile express a varietal signature. Furthermore, hierarchical clustering highlights various degree of polyphenol similarity between grape varieties that were in agreement with the genetic distance using clustering analyses of 22 microsatellite DNA markers. Metabolite correlation network suggested that several polyphenol subclasses were differently controlled. The present polyphenol metabotyping approach coupled to multivariate statistical analyses might assist grape selection programs to improve metabolites with both health-benefit potential and plant defense traits

Exhibition Architecture for Billets's 1/256-256/256

In de Sint-Lukasgalerie heeft Greet Billet samen met de architect Arnaud Hendrickx een tijdelijke, ruimtelijke constructie ontworpen in piepschuim. Die wordt belicht door drie felle spots, waarop een kleurenfilter werd gelegd in respectievelijk rood, blauw en groen. Het licht schijn door een spleet in de constructie en wordt vervolgens gebroken op een achterliggende muur. De drie kleuren geven samen een streep licht af in een roodachtige gloed. In een ruimte achteraan geeft Billet de drie boeken weer waarin de overgang van rood, groen en blauw wordt weergegeven naar zwart. De boeken liggen er imposant bij. Maar Billet heeft die, om de toeschouwer op zijn honger te laten, dichtgelaten en achter glas gezet.status: publishe

Relations structure-fonction du CFTR (étude de l'influence de l'extrémité C-terminale du NBD1 et de son environnement moléculaire sur l'adressage, l'activité et la pharmacologie des canaux)

La protéine transmembranaire CFTR (Cystic Fibrosis Transmembrane conductance Regulator), impliquée dans la mucoviscidose est un canal chlorure régulée par l'ATP et l'AMPc. Les mécanismes de régulation des processus d'ouverture/fermeture du canal ne sont pas encore clairement démontrés mais depuis quelques années, les nouvelles données sur la structure moléculaire de la protéine ont permis des avancés dans ce domaine. Les objectifs de ce travail de recherche ont été de caractériser, par une étude de relation structure/fonction, le rôle de l'extrémité C-terminale du NBD1 et de son environnement moléculaire dans la régulation de la maturation ou de l'activité du canal ainsi que dans sa pharmacologie. Certains résidus déterminés par l'exploration des modèles moléculaires ont été mutés par mutagenèse dirigée puis les conséquences de ces mutations ont été analysées par les techniques de western blot, de patch clamp et d'efflux d iodure. Nos travaux ont permis de mettre en évidence l'importance de l'intégrité de la structure en épingle à cheveux de l'extrémité C-terminale du NBD1 ainsi que de ses différentes liaisons, dans la maturation et l'activité du canal. Concernant le mécanisme d'action des composés MPB, composés à double action (activateur et correcteur de CFTR), nous avons montré que la perturbation directe de la structure de la b-hairpin rendait l'action des composés impossible alors que la perturbation de la liaison avec le Walker A du NBD2 induisait une meilleure action des MPB. Nos travaux ont donc permis de mettre en évidence un rôle important de l'extrémité C-terminale du NBD1 dans la régulation de l'adressage, de l'activité et de la pharmacologie du canal CFTR.Cystic fibrosis (CF) is caused by mutations of the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR). CFTR is a chloride channel regulated by ATP and cAMP. The regulation of the CFTR gating remains unclear. In this study we have investigated the role of the last b hairpin of NBD1 and its direct environment in the maturation, the activation and the pharmacology of the channel. We also performed a molecular dissection of CFTR by examining several CFTR mutants (constructed by site directed mutagenesis and tested by western blot, patch clamp recording and iodide efflux) located in the last b hairpin of NBD1 or in contact with it. Our results indicated that the integrity of the beta hairpin (and in particular the orientation of the two latest b strands) and its links with other domains is important for the maturation, the activity but also the pharmacology of the channel. All these results suggest an important influence of the C-terminus of the NBD1 for the control of CFTR channel gating and protein trafficking.POITIERS-BU Sciences (861942102) / SudocSudocFranceF

Comment formaliser une coordination en maison de santé pluri professionnelle ? (quel serait le profil de poste du coordinateur administratif ?)

La Bourgogne est une région pionnière en termes de développement de maisons de santé. Les professionnels de santé à l intérieur de ces structures ont un exercice regroupé et coordonné, facilitant ainsi une meilleure coopération pluri professionnelle. Ce cadre d organisation sanitaire nécessite la mise en place d un poste de coordinateur administratif indispensable pour faciliter la coordination, gérer les activités des acteurs de santé et libérer ceux-ci des tâches administratives. Objectifs : déterminer l utilité et l organisation d une coordination administrative et pluri professionnelle au sein des MSP de la région; établir un profil de poste de coordinateur administratif. Méthode : étude transversale à visée descriptive réalisée entre juillet et août 2013 à l aide d un questionnaire auto administré et envoyé par courriel par l Agence Régionale de Santé de Bourgogne. Ce questionnaire évalue :- l identité des MSP - la coordination du projet de santé - la coordination administrative. Résultats : la population générale étudiée compte 30 MSP .Le taux de participation est de 93,3%. 89,3% de ces maisons de santé se décrivent comme ayant une activité en secteur rural. Dans l ensemble de la population des MSP, on note que 78,6% des MSP ont un coordinateur administratif (n=22).L étude mesure l importance d un profil de poste qui énumère les activités et les missions d un coordinateur administratif au sein d une MSP. Conclusion :l intérêt du coordinateur administratif n étant plus à démontrer, il est essentiel d élaborer un référentiel de poste qui s appuie sur les compétences nécessaires pour exercer ce métier, en vue d une professionnalisation de cet exercice.DIJON-BU Médecine Pharmacie (212312103) / SudocSudocFranceF

Modulating the cystic fibrosis transmembrane regulator and the development of new precision drugs

International audienc

Development of Automated Patch Clamp Technique to Investigate CFTR Chloride Channel Function

International audienceThe chloride (Cl-) channel cystic fibrosis transmembrane conductance regulator (CFTR) is defective in cystic fibrosis (CF), and mutation of its encoding gene leads to various defects such as retention of the misfolded protein in the endoplasmic reticulum, reduced stability at the plasma membrane, abnormal channel gating with low open probability, and thermal instability, which leads to inactivation of the channel at physiological temperature. Pharmacotherapy is one major therapeutic approach in the CF field and needs sensible and fast tools to identify promising compounds. The high throughput screening assays available are often fast and sensible techniques but with lack of specificity. Few works used automated patch clamp (APC) for CFTR recording, and none have compared conventional and planar techniques and demonstrated their capabilities for different types of experiments. In this study, we evaluated the use of planar parallel APC technique for pharmacological search of CFTR-trafficking correctors and CFTR function modulators. Using optimized conditions, we recorded both wt- and corrected F508del-CFTR Cl- currents with automated whole-cell patch clamp and compared the data to results obtained with conventional manual whole-cell patch clamp. We found no significant difference in patch clamp parameters such as cell capacitance and series resistance between automated and manual patch clamp. Also, the results showed good similarities of CFTR currents recording between the two methods. We showed that similar stimulation protocols could be used in both manual and automatic techniques allowing precise control of temperature, classic I/V relationship, and monitoring of current stability in time. In conclusion, parallel patch-clamp recording allows rapid and efficient investigation of CFTR currents with a variety of tests available and could be considered as new tool for medium throughput screening in CF pharmacotherapy