Éditeur(s) : Université des Antilles AREBio Groupe de recherche BIOSPHERES : BIOlogie, Sciences Physiques & Humaines pour les énergies Renouvelables, l
Extrait de : 1er colloque international BIOSPHERES, du 18 au 20 juin 2019. Université des Antilles
Description : Drosophila often offers many advantages as an experimental organism. The dead ringer (dri) gene of drosophila melanogaster is a member of the recently discovered ARID-box family of eukaryotic genes that encodes proteins with a conserved DNA-binding domain. dri itself is highly well conserved with specific orthologs from human to yeast genomes. This family include ARID3A, 3B and 3C with have role in embryonic pattening, cell lineage gene regulation, cell cycle control, transcriptional regulation and chromatin structure modification. We first showed that the gene encoding ARID3A also known as Bright (B cell regulator of immunoglobulin heavy chain transcription) play critical roles in B-cell development and SATB1 in T-cell transcription regulation. In this international workshops we will expose a comprehensive understanding of these molecules and better knowledge of their specific targets and function-interactions in controlling cell fate decisions and development. In addition, dri have homology with the Aedes aegypti mosquitoes which had ability to carry and spread disease to human. More than half of the world?s population live in areas where this mosquito species is present, including Martinique. Sustained mosquito control efforts are important to prevent outbreaks from Dengue, Chikungunya, malaria, zika diseases. Discovering the functions of AT-rich genes in preventing illness from mosquito is the central goal for raising working progress hypothesis.

Droits : CC-BY-NC-ND - Attribution - Pas d'utilisation commerciale - Pas de modification
Permalien : http://www.manioc.org/fichiers/V19077
V19077

Éditeur(s) : National Shellfisheries Association
Résumé : The subcellular fractionation of the digestive gland cells of the common cuttlefish Sepia officinalis was performed to investigate the distribution of metals between organelles and cytosol and the different cytosolic fractions separated by gel-filtration chromatography. Total metal concentrations vary over 3 orders of magnitude, ranging from dwt for Pb to dwt for Zn. With the exception of Cd, Co, and Cu, metals were mostly bound to the organelles. Whereas no specific organelle compartment was found for Mn, Ph, and Zn, Fe was mainly associated with nucleus, brown body, and "boule" fraction (i.e., 52%) and 44% of the total Ag was contained in the lysosomal and mitochondria enriched fraction. The link of metals with hydrosoluble proteins in the cytosolic fraction was investigated at 254 and 280 not. Direct relationship between cytosolic metal and metallothioneins could only be established for Ag and Cu, whereas Cd and Zn seem to mainly bind high (> 70 kDa) and low (< 4 kDa) molecular weight proteins.
The Journal of Shellfish Research (0730-8000) (National Shellfisheries Association), 2006-12 , Vol. 25 , N. 3 , P. 987-993

Droits : 2006 NSA
http://archimer.ifremer.fr/doc/2006/publication-2532.pdf
http://archimer.ifremer.fr/doc/00000/2532/

Éditeur(s) : HAL CCSD Endocrine Society
Résumé : International audience
Transcriptional regulation by the estrogen receptor-alpha(ER) has been investigated mainly in breast cancer cell lines, but estrogens such as 17 beta-estradiol (E2) exert numerous extrareproductive effects, particularly in the liver, where E2 exhibits both protective metabolic and deleterious thrombotic actions. To analyze the direct and early transcriptional effects of estrogens in the liver, we determined the E2-sensitive transcriptome and ER cistrome in mice after acute administration of E2 or placebo. These analyses revealed the early induction of genes involved in lipid metabolism, which fits with the crucial role of ER in the prevention of liver steatosis. Characterization of the chromatin state of ER binding sites (BSs) in mice expressing or not ER demonstrated that ER is not required per se for the establishment and/or maintenance of chromatin modifications at the majority of its BSs. This is presumably a consequence of a strong overlap between ER and hepatocyte nuclear factor 4 alpha BSs. In contrast, 40% of the BSs of the pioneer factor forkhead box protein a (Foxa2) were dependent upon ER expression, and ER expression also affected the distribution of nucleosomes harboring dimethylated lysine 4 of Histone H3 around Foxa2 BSs. We finally show that, in addition to a network of liver-specific transcription factors including CCAAT/enhancer-binding protein and hepatocyte nuclear factor 4 alpha, ER might be required for proper Foxa2 function in this tissue.
ISSN: 0888-8809

hal-01357623
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01357623
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01357623/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01357623/file/Changes%20in%20gene%20expression%201%20and%20Estrogen%20Receptor_accepted.pdf
DOI : 10.1210/me.2015-1311

Résumé : En Guadeloupe, la prévalence du diabète est deux fois plus élevée qu'en France hexagonale, avec une prédominance féminine. En dehors des facteurs environnementaux, la vitamine D et certains polymorphismes de gènes impliqués dans son métabolisme seraient associés à un risque de pathologies métaboliques. Les androgènes sont également associés aux anomalies du métabolisme glucidique, soit directement, soit via leur transporteur SHBG (Sex Hormone Binding Protein). Nous avons émis les hypothèses de recherche suivantes: 11 le statut en vitamine D et les polymorphismes des gènes impliqués dans son métabolisme pourraient être associés aux paramètres métaboliques chez des sujets Afro-Caribéens (AC). Ils expliqueraient l'importance des pathologies cardiométaboliques en Guadeloupe. 2/ la SHBG pourrait être associée aux anomalies du métabolisme glucidique, indépendamment des stéroïdes sexuels. Nos travaux sont présentés dans 4 études. Nous avons mis en évidence une prévalence élevée du déficit en vitamine D chez les sujets AC diabétiques de type 2. Nous avons trouvé une association significative entre le statut vitaminique D et le risque cardiométabolique chez ces sujets, mais aussi dans une population de sujets en hémodialyse chronique. Les polymorphismes des gènes impliqués dans le métabolisme de la vitamine D sont aussi associés à ce risque. Chez les sujets dysmétaboliques, une relation entre la SHBG, la graisse intra-hépatique, les hépatokines et les paramètres métaboliques a été mise en évidence, indépendamment des stéroïdes sexuels. En conclusion, la vitamine D et la SHBG pourraient être des marqueurs d'intérêt pour le dépistage des sujets à haut risque cardiométabolique.
In Guadeloupe, the prevalence of diabetes is two times higher than in Metropolitan France, with a female predominance. Apart from environmental factors, vitamin D and polymorphisms of genes involved in vitamin D metabolism would be associated with increased risk of metabolic diseases. Androgens are also associated with abnormal glucose metabolism, directly or through the Sex Hormone Binding Protein (SHBG). Our main hypotheses were: 11 Vitamin D status and polymorphisms of genes involved in its metabolism may be associated with metabolic pammeters in Afro-Caribbean (AC). They could explain the importance of cardiometabolic diseases in Guadeloupe. 2/ SHBG may be associated with abnormal glucose metabolism, independently of sex steroids. Our research is presente
http://www.theses.fr/2012AGUY0536/document

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
BOI1 and BOI2 are paralogs important for the actin cytoskeleton andpolar growth. BOI1 encodes a meiotic transcript isoform with an extended5-untranslated region predicted to impair protein translation. It is,however, unknown how the isoform is repressed during mitosis, and ifBoi1 is present during sporulation. By interpreting microarray data fromMATa cells, MATa/ cells, a starving MAT/ control, and a meiosis-impairedrrp6 mutant, we classified BOI1's extended isoform as earlymeiosis-specific. These results were confirmed by RNA-Sequencing, andextended by a 5-RACE assay and Northern blotting, showing that meioticcells induce the long isoform while the mitotic isoform remainsdetectable during meiosis. We provide evidence via motif predictions, anin vivo binding assay and genetic experiments that the Rpd3/Sin3/Ume6histone deacetylase complex, which represses meiotic genes duringmitosis, also prevents the induction of BOI1's 5-extended isoform inmitosis by direct binding of Ume6 to its URS1 target. Finally, we findthat Boi1 protein levels decline when cells switch from fermentation torespiration and sporulation. The histone deacetylase Rpd3 is conserved,and eukaryotic genes frequently encode transcripts with variable 5-UTRs.Our findings are therefore relevant for regulatory mechanisms involvedin the control of transcript isoforms in multi-cellular organisms.
ISSN: 0950-382X

hal-01122120
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01122120
DOI : 10.1111/mmi.12976
PUBMED : 25708805

Éditeur(s) : HAL CCSD
Résumé : International audience
The Duffy Antigen/Receptor for Chemokine (DARC) is a seven segment transmembrane protein. It was firstly discovered as a blood group antigen and was the first specific gene locus assigned to a specific autosome in man. It became more famous as an erythrocyte receptor for malaria parasites (Plasmodium vivax and Plasmodium knowlesi), and finally for chemokines. DARC is an unorthodox chemokine receptor as (i) it binds chemokines of both CC and CXC classes and (ii) it lacks the Asp-Arg-Tyr consensus motif in its second cytoplasmic loop hence cannot couple to G proteins and activate their signaling pathways. DARC had also been associated to cancer progression, numerous inflammatory diseases, and possibly to AIDS. In this review, we will summarize important biological data on DARC. Then we shall focus on recent development of the elaboration and analyzes of structural models of DARC. We underline the difficulty to propose pertinent structural models of transmembrane protein using comparative modeling process, and other dedicated approaches as the Protein Blocks. The chosen structural models encompass most of the biochemical data known to date. Finally, we present recent development of protein - protein docking between DARC structural models and CXCL-8 structures. We propose a hierarchal search based on separated rigid and flexible docking.
Infectious disorders drug targets

Droits : info:eu-repo/semantics/OpenAccess
inserm-00366309
http://www.hal.inserm.fr/inserm-00366309
http://www.hal.inserm.fr/inserm-00366309/document
http://www.hal.inserm.fr/inserm-00366309/file/de_Brevern_Autin_Bertrand_Colin_Etchebest.pdf
http://www.hal.inserm.fr/inserm-00366309/file/inserm-00366309_edited.pdf

Éditeur(s) : HAL CCSD BioMed Central
Résumé : International audience
BACKGROUND: Homologous recombination is the key process that generates genetic diversity and drives evolution. SPO11 protein triggers recombination by introducing DNA double stranded breaks at discreet areas of the genome called recombination hotspots. The hotspot locations are largely determined by the DNA binding specificity of the PRDM9 protein in human, mice and most other mammals. In budding yeast Saccharomyces cerevisae, which lacks a Prdm9 gene, meiotic breaks are formed opportunistically in the regions of accessible chromatin, primarily at gene promoters. The genome-wide distribution of hotspots in this organism can be altered by tethering Spo11 protein to Gal4 recognition sequences in the strain expressing Spo11 attached to the DNA binding domain of the Gal4 transcription factor. To establish whether similar re-targeting of meiotic breaks can be achieved in PRDM9-containing organisms we have generated a Gal4BD-Spo11 mouse that expresses SPO11 protein joined to the DNA binding domain of yeast Gal4. RESULTS: We have mapped the genome-wide distribution of the recombination initiation sites in the Gal4BD-Spo11 mice. More than two hundred of the hotspots in these mice were novel and were likely defined by Gal4BD, as the Gal4 consensus motif was clustered around the centers in these hotspots. Surprisingly, meiotic DNA breaks in the Gal4BD-Spo11 mice were significantly depleted near the ends of chromosomes. The effect is particularly striking at the pseudoautosomal region of the X and Y chromosomes -- normally the hottest region in the genome. CONCLUSIONS: Our data suggest that specific, yet-unidentified factors influence the initiation of meiotic recombination at subtelomeric chromosomal regions.
ISSN: 1471-2164

inserm-00849779
http://www.hal.inserm.fr/inserm-00849779
http://www.hal.inserm.fr/inserm-00849779/document
http://www.hal.inserm.fr/inserm-00849779/file/1471-2164-14-493.pdf
DOI : 10.1186/1471-2164-14-493

Éditeur(s) : HAL CCSD Oxford University Press (OUP)
Résumé : International audience
BACKGROUND: Mammalian spermatogenesis is a process that involves a complex expression program in both somatic and germ cells present in the male gonad. A number of studies have attempted to define the transcriptome of male meiosis and gametogenesis in rodents and primates. Few human transcripts, however, have been associated with testicular somatic cells and germ cells at different post-natal developmental stages and little is known about their level of germline-specificity compared with non-testicular tissues. METHODS: We quantified human transcripts using GeneChips and a total of 47 biopsies from prepubertal children diagnosed with undescended testis, infertile adult patients whose spermatogenesis is arrested at consecutive stages and fertile control individuals. These results were integrated with data from enriched normal germ cells, non-testicular expression data, phenotype information, predicted regulatory DNA-binding motifs and interactome data. RESULTS: Among 3580 genes for which we found differential transcript concentrations in somatic and germ cells present in human testis, 933 were undetectable in 45 embryonic and adult non-testicular tissues, including many that were corroborated at protein level by published gene annotation data and histological high-throughput protein immunodetection assays. Using motif enrichment analyses, we identified regulatory promoter elements likely involved in germline development. Finally, we constructed a regulatory disease network for human fertility by integrating expression signals, interactome information, phenotypes and functional annotation data. CONCLUSIONS: Our results provide broad insight into the post-natal human testicular transcriptome at the level of cell populations and in a global somatic tissular context. Furthermore, they yield clues for genetic causes of male infertility and will facilitate the identification of novel cancer/testis genes as targets for cancer immunotherapies.
ISSN: 0268-1161

hal-00877243
https://hal.archives-ouvertes.fr/hal-00877243
DOI : 10.1093/humrep/des301
PUBMED : 22926843

Éditeur(s) : HAL CCSD Cold Spring Harbor Laboratory Press
Résumé : International audience
Meiotic recombination is required for the segregation of homologous chromosomes and is essential for fertility. In most mammals, the DNA double-strand breaks (DSBs) that initiate meiotic recombination are directed to a subset of genomic loci (hot spots) by sequence-specific binding of the PRDM9 protein. Rapid evolution of the DNA-binding specificity of PRDM9 and gradual erosion of PRDM9-binding sites by gene conversion will alter the recombination landscape over time. To better understand the evolutionary turnover of recombination hot spots and its consequences, we mapped DSB hot spots in four major subspecies of Mus musculus with different Prdm9 alleles and in their F1 hybrids. We found that hot spot erosion governs the preferential usage of some Prdm9 alleles over others in hybrid mice and increases sequence diversity specifically at hot spots that become active in the hybrids. As crossovers are disfavored at such hot spots, we propose that sequence divergence generated by hot spot turnover may create an impediment for recombination in hybrids, potentially leading to reduced fertility and, eventually, speciation
ISSN: 0890-9369

hal-01281480
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01281480
DOI : 10.1101/gad.270009.115
PUBMED : 26833728

Éditeur(s) : HAL CCSD Oxford University Press (OUP)
Résumé : International audience
STUDY QUESTION: Is prenatal exposure to persistent organic pollutants (POPs) associated with variations of sex hormone levels in cord blood? SUMMARY ANSWER: Prenatal exposure to a number of POPs is associated with a disruption of hormone levels in cord blood, with sex specificities. WHAT IS KNOWN ALREADY: Epidemiological studies have reported disorders of reproductive health, in relation with POPs exposure during early life and the endocrine disruption properties of these chemicals have been suggested as possible mechanisms. STUDY DESIGN, SIZE, DURATION: A subset of 282 mother-child pairs was selected from the prospective population-based PELAGIE birth cohort (n = 3421, 2002-2006, Brittany, France). Pregnant women were recruited before 19 weeks of gestation and followed until delivery. PARTICIPANTS/MATERIALS, SETTING, METHODS: Sex hormone levels including sex hormone-binding globulin (SHBG), estradiol (E2), total testosterone (T), free testosterone (fT = T/SHBG) and the aromatase index (AI = T/E2) were measured in 282 cord blood samples. Anti-Müllerian hormone (AMH) was measured in male newborns only. Pesticide concentrations of α-endosulfan, β-hexachlorocyclohexane (β-HCH), γ-HCH, dieldrin, pp'-dichlorodiphenyldichloroethylene (p,p'-DDE), hexachlorobenzene (HCB), heptachlor epoxide (HCE), as well as PCBs (congeners 153, 187 and the sum of anti-estrogenic PCBs 118, 138, and 170) and decabrominated diphenyl ether (BDE209) were also measured in cord blood. Associations between sex hormones and POPs exposure were explored using multiple linear regressions adjusted for potential confounders. MAIN RESULTS AND THE ROLE OF CHANCE: High PCB levels were associated with an increase of SHBG (P-trend extless 0.01) and AMH (P-trend extless 0.05) and a decrease of fT (P-trend extless 0.05) and AI (P-trend extless 0.01). High pesticide levels, particularly α-endosulfan and HCE, were associated with an increase of SHBG (P extless 0.05) and E2 (P extless 0.01) and a decrease of fT (P extless 0.05) and AI (P extless 0.01). Several of these associations were stronger, or specific, among male or female newborns. The associations were not altered in the sensitivity analyses. LIMITATIONS, REASONS FOR CAUTION: The study population was of relatively small sample size, and some compounds rarely detected in cord blood. The high level of correlation between POPs makes it difficult to identify the most contributing POPs. Hormone measurements were performed at birth (in cord blood) and may not adequately represent the infant endocrine system. Multiple statistical testing may have led to false-positive associations. WIDER IMPLICATIONS OF THE FINDINGS: Our results are in discordance with those reported in the only published study of the kind but in accordance with studies about prenatal exposure to other endocrine disruptors such as phthalates. These findings may help understanding the pathways involved in adverse reproductive outcomes associated with POPs exposure. STUDY FUNDING/COMPETING INTERESTS: The PELAGIE cohort is funded by Inserm, French Ministry of Health, French Ministry of Labor, InVS, ANR, ANSES, and French Ministry of Ecology. None of the authors has any competing interest to declare
ISSN: 0268-1161

hal-01220641
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01220641
DOI : 10.1093/humrep/dev260
PUBMED : 26493407

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The discerning behavior of living systems relies on accurate interactions selected from the lot of molecular collisions occurring in the cell. To ensure the reliability of interactions, binding partners are classically envisioned as finely preadapted molecules, selected on the basis of their affinity in one-step associations. But the counterselection of inappropriate interactions can in fact be much more efficiently obtained through difficult multi-step adjustment, whose final high energy state is locked by a fluctuation ratchet. The progressive addition of molecular bonds during stereo-adjustment can be modeled as a predominantly backward random walk whose first arrival is frozen by a micro-irreversible transition. A new criterion of ligand specificity is presented, that is based on the ratio rejection/incorporation. In addition to its role in the selectivity of interactions, this generic recipe can underlie other important biological phenomena such as the regular synthesis at low level of supramolecular complexes, monostable kinetic bimodality, substrate concentration thresholds or the preparation of rapidly depolymerizable structures with stored energy, like microtubules
ISSN: 0079-6107

hal-01274234
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01274234
DOI : 10.1016/j.pbiomolbio.2016.02.001
PUBMED : 26867859

Éditeur(s) : HAL CCSD
Résumé : International audience
Among infertile couples, approximately half have to face with male infertility. In men with non-obstructive azoospermia, surgical retrieval testicular sperm extraction (TESE) of spermatozoa can be attempted, but with low success rates. A specific biomarker that could predict residual spermatogenesis would obviously be of interest before performing TESE. Thus, our aim was to identify biomarkers of residual spermatogenesis in seminal plasma of patients with non-obstructive azoospermia (NOA) using an isotope-coded protein label (ICPL)-based proteomic strategy coupled with conventional protein assay. This retrospective study was conducted in 40 men with NOA at the University Hospital of Nantes and Proteomics Core facility Biogenouest - Inserm U1085 - IRSET, Rennes, France. Comparative ICPL proteomic screening of frozen seminal plasma and correlation with TESE outcome allowed the identification of some differentially expressed proteins. Among them, lectin galactoside-binding, soluble 3 binding protein (LGALS3BP) expression was further confirmed using conventional protein assay, and its interest as a predictor of TESE outcome was then evaluated and compared with conventional clinical and hormonal markers of residual spermatogenesis. Among the 12 differentially expressed proteins identified with comparative ICPL proteomic strategy, seminal LGALS3BP expression was found to be significantly higher in men with successful TESE. Finally, comparative ICPL proteomic screening of seminal plasma appears to be a promising approach for the identification of biomarkers of residual spermatogenesis. LGALS3BP, associated with clinical and hormonal markers, could potentially be used as a predictive marker of successful TESE outcome in patients with NOA.
Andrology

inserm-00818514
http://www.hal.inserm.fr/inserm-00818514
DOI : 10.1111/j.2047-2927.2012.00059.x
PUBMED : 23427166

Éditeur(s) : HAL CCSD Cold Spring Harbor Laboratory Press
Résumé : International audience
The genome of male germ cells is actively transcribed during spermatogenesis to produce phase-specific protein-coding mRNAs and a considerable amount of different noncoding RNAs. Ribonucleoprotein (RNP) granule-mediated RNA regulation provides a powerful means to secure the quality and correct expression of the requisite transcripts. Haploid spermatids are characterized by a unique, unusually large cytoplasmic granule, the chromatoid body (CB), which emerges during the switch between the meiotic and post-meiotic phases of spermatogenesis. To better understand the role of the CB in male germ cell differentiation, we isolated CBs from mouse testes and revealed its full RNA and protein composition. We showed that the CB is mainly composed of RNA-binding proteins and other proteins involved RNA regulation. The CB was loaded with RNA, including pachytene piRNAs, a diverse set of mRNAs, and a number of uncharacterized long noncoding transcripts. The CB was demonstrated to accumulate nascent RNA during all the steps of round spermatid differentiation. Our results revealed the CB as a large germ cell-specific RNP platform that is involved in the control of the highly complex transcriptome of haploid male germ cells.
ISSN: 1355-8382

hal-00985894
https://hal-univ-rennes1.archives-ouvertes.fr/hal-00985894
DOI : 10.1261/rna.043729.113
PUBMED : 24554440

Éditeur(s) : HAL CCSD Oxford University Press
Résumé : International audience
It was recently reported that the sizes of many mRNAs change when budding yeast cells exit mitosis and enter the meiotic differentiation pathway. These differences were attributed to length variations of their untranslated regions. The function of UTRs in protein translation is well established. However, the mechanism controlling the expression of distinct transcript isoforms during mitotic growth and meiotic development is unknown. In this study, we order developmentally regulated transcript isoforms according to their expression at specific stages during meiosis and gametogenesis, as compared to vegetative growth and starvation. We employ regulatory motif prediction, in vivo protein-DNA binding assays, genetic analyses and monitoring of epigenetic amino acid modification patterns to identify a novel role for Rpd3 and Ume6, two components of a histone deacetylase complex already known to repress early meiosis-specific genes in dividing cells, in mitotic repression of meiosis-specific transcript isoforms. Our findings classify developmental stage-specific early, middle and late meiotic transcript isoforms, and they point to a novel HDAC-dependent control mechanism for flexible transcript architecture during cell growth and differentiation. Since Rpd3 is highly conserved and ubiquitously expressed in many tissues, our results are likely relevant for development and disease in higher eukaryotes.
ISSN: 0305-1048

Droits : http://creativecommons.org/licenses/by/
hal-01122128
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01122128
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01122128/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01122128/file/The%20conserved%20histone%20deacetylase.pdf
DOI : 10.1093/nar/gku1185

Éditeur(s) : HAL CCSD Portland Press
Résumé : International audience
CP12 is a small chloroplastic protein involved in the Calvin cycle that was shown to bind copper, a metal ion involved in modulation of its transition from reduced to oxidized state. In order to describe CP12 copper binding properties, copper-IMAC experiments and site-directed mutagenesis based on computational modeling, were coupled to top-down mass spectrometry (ESI-MS and MSMS). Copper-IMAC experiments allowed the primary characterization of mutation effects upon copper binding. Top-down MSMS experiments carried out under non-denaturing conditions on wild-type and mutant CP12/Cu2+ complexes then allowed fragment ions specifically liganding the copper ion to be determined. Comparison of MSMS datasets defined three regions involved in metal ion binding: residues D16 to D23, D38 to K50 and D70 to E76, with the two first regions containing selected residues for mutation. These data confirmed that copper ligands involved glutamic and aspartic residues in contrast to typical protein copper chelators. We propose that copper might play a role in regulation of CP12 biological activity.
ISSN: 0264-6021

hal-00479106
https://hal.archives-ouvertes.fr/hal-00479106
https://hal.archives-ouvertes.fr/hal-00479106/document
https://hal.archives-ouvertes.fr/hal-00479106/file/PEER_stage2_10.1042%252FBJ20082004.pdf
DOI : 10.1042/BJ20082004

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Metalloproteases involved in extracellular matrix remodeling play a pivotal role in cell response by regulating the bioavailability of cytokines and growth factors. Recently, the disintegrin and metalloprotease, ADAMTS1 has been demonstrated to be able to activate the transforming growth factor TGF-β, a major factor in fibrosis and cancer. The KTFR sequence from ADAMTS1 is responsible for the interaction with the LSKL peptide from the latent form of TGF-β, leading to its activation. While the atomic details of the interaction site can be the basis of the rational design of efficient inhibitory molecules, the binding mode of interaction is totally unknown. In this study, we show that recombinant fragments of human ADAMTS1 containing KTFR sequence keep the ability to bind the latent form of TGF-β. The recombinant fragment with the best affinity is modeled to investigate the binding mode of LSKL peptide with ADAMTS1 at the atomic level. Using a combined approach with molecular docking and multiple independent molecular dynamics (MD) simulations, we provide the binding mode of LSKL peptide with ADAMTS1. The MD simulations starting with the two lowest energy model predicted by molecular docking shows stable interactions characterized by 3 salt bridges (K3-NH3+ with E626-COO−; L4-COO− with K619-NH3+; L1-NH3+ with E624-COO−) and 2 hydrogen bonds (S2-OH with E623-COO−; L4-NH with E623-COO−). The knowledge of this interaction mechanism paves the way to the design of more potent and more specific inhibitors against the inappropriate activation of TGF-β by ADAMTS1 in liver diseases
ISSN: 1476-9271

hal-01269916
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01269916
DOI : 10.1016/j.compbiolchem.2016.01.012
PUBMED : 26878129

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
Cytochrome P450 aromatase (P450arom; aromatase) is a microsomal enzyme involved in the production of endogeneous sex steroids by converting testosterone into oestradiol. Aromatase is the product of the cyp19a1 gene and plays a crucial role in the sexual differentiation of the brain and in the regulation of reproductive functions. In the brain of mammals and birds, expression of cyp19a1 has been demonstrated in neuronal populations of the telencephalon and diencephalon. By contrast, a wealth of evidence established that, in teleost fishes, aromatase expression in the brain is restricted to radial glial cells. The present study investigated the precise neuroanatomical distribution of cyp19a1 mRNA during brain development in Xenopus laevis (late embryonic to juvenile stages). For this purpose, we used in situ hybridisation alone or combined with the detection of a proliferative (proliferating cell nuclear antigen), glial (brain lipid binding protein, Vimentin) or neuronal (acetylated tubulin; HuC/D; NeuroβTubulin) markers. We provide evidence that cyp19a1 expression in the brain is initiated from the very early larval stage and remains strongly detected until the juvenile and adult stages. At all stages analysed, we found the highest expression of cyp19a1 in the preoptic area and the hypothalamus compared to the rest of the brain. In these two brain regions, cyp19a1-positive cells were never detected in the ventricular layers. Indeed, no co-labelling could be observed with radial glial (brain lipid binding protein, Vimentin) or dividing progenitors (proliferating cell nuclear antigen) markers. By contrast, cyp19a1-positive cells perfectly matched with the distribution of post-mitotic neurones as shown by the use of specific markers (HuC/D, acetylated tubulin and NeuroβTubulin). These data suggest that, similar to that found in other tetrapods, aromatase in the brain of amphibians is found in post-mitotic neurones and not in radial glia as reported in teleosts.
ISSN: 0953-8194

hal-00994513
https://hal-univ-rennes1.archives-ouvertes.fr/hal-00994513
DOI : 10.1111/jne.12142
PUBMED : 24612124

Éditeur(s) : HAL CCSD Ferrata Storti Foundation
Résumé : International audience
BACKGROUND: Abnormal interactions between red blood cells, leukocytes and endothelial cells play a critical role in the occurrence of the painful vaso-occlusive crises associated with sickle cell disease. We investigated the interaction between circulating leukocytes and red blood cells which could lead to aggregate formation, enhancing the incidence of vaso-occlusive crises. DESIGN AND METHODS: Blood samples from patients with sickle cell disease (n=25) and healthy subjects (n=5) were analyzed by imaging and classical flow cytometry after density gradient separation. The identity of the cells in the peripheral blood mononuclear cell layer was determined using antibodies directed specifically against white (anti-CD45) or red (anti-glycophorin A) blood cells. RESULTS: Aggregates between red blood cells and peripheral blood mononuclear cells were visualized in whole blood from patients with sickle cell disease. The aggregation rate was 10-fold higher in these patients than in control subjects. Both mature red blood cells and reticulocytes were involved in these aggregates through their interaction with mononuclear cells, mainly with monocytes. The size of the aggregates was variable, with one mononuclear cell binding to one, two or several red blood cells. Erythroid Lu/basal cell adhesion molecule and α(4)β(1) integrin were involved in aggregate formation. The aggregation rate was lower in patients treated with hydroxycarbamide than in untreated patients. CONCLUSIONS: Our study gives visual evidence of the existence of circulating red blood cell-peripheral blood mononuclear cell aggregates in patients with sickle cell disease and shows that these aggregates are decreased during hydroxycarbamide treatment. Our results strongly suggest that erythroid Lu/basal cell adhesion molecule proteins are implicated in these aggregates through their interaction with α(4)β(1) integrin on peripheral blood mononuclear cells.
ISSN: 0390-6078

inserm-00821120
http://www.hal.inserm.fr/inserm-00821120
http://www.hal.inserm.fr/inserm-00821120/document
http://www.hal.inserm.fr/inserm-00821120/file/1841.full.pdf
DOI : 10.3324/haematol.2010.026294

Éditeur(s) : HAL CCSD
Résumé : International audience
Necroptosis is a regulated form of cell death involved in several disease models including in particular liver diseases. Receptor-interacting protein kinases, RIPK1 and RIPK3, are the main serine/threonine kinases driving this cell death pathway. We screened a noncommercial, kinase-focused chemical library which allowed us to identify Sibiriline as a new inhibitor of necroptosis induced by tumor necrosis factor (TNF) in Fas-associated protein with death domain (FADD)-deficient Jurkat cells. Moreover, Sib inhibits necroptotic cell death induced by various death ligands in human or mouse cells while not protecting from caspase-dependent apoptosis. By using competition binding assay and recombinant kinase assays, we demonstrated that Sib is a rather specific competitive RIPK1 inhibitor. Molecular docking analysis shows that Sib is trapped closed to human RIPK1 adenosine triphosphate-binding site in a relatively hydrophobic pocket locking RIPK1 in an inactive conformation. In agreement with its RIPK1 inhibitory property, Sib inhibits both TNF-induced RIPK1-dependent necroptosis and RIPK1-dependent apoptosis. Finally, Sib protects mice from concanavalin A-induced hepatitis. These results reveal the small-molecule Sib as a new RIPK1 inhibitor potentially of interest for the treatment of immune-dependent hepatitis. © 2017 Federation of European Biochemical Societies
ISSN: 1742464X

hal-01616420
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01616420
DOI : 10.1111/febs.14176
PUBMED : 28715128

Éditeur(s) : HAL CCSD MDPI
Résumé : International audience
Drug transporters are now recognized as major actors in pharmacokinetics, involved notably in drug-drug interactions and drug adverse effects. Factors that govern their activity, localization and expression are therefore important to consider. In the present review, the implications of protein kinases C (PKCs) in transporter regulations are summarized and discussed. Both solute carrier (SLC) and ATP-binding cassette (ABC) drug transporters can be regulated by PKCs-related signaling pathways. PKCs thus target activity, membrane localization and/or expression level of major influx and efflux drug transporters, in various normal and pathological types of cells and tissues, often in a PKC isoform-specific manner. PKCs are notably implicated in membrane insertion of bile acid transporters in liver and, in this way, are thought to contribute to cholestatic or choleretic effects of endogenous compounds or drugs. The exact clinical relevance of PKCs-related regulation of drug transporters in terms of drug resistance, pharmacokinetics, drug-drug interactions and drug toxicity remains however to be precisely determined. This issue is likely important to consider in the context of the development of new drugs targeting PKCs-mediated signaling pathways, for treating notably cancers, diabetes or psychiatric disorders.
ISSN: 1422-0067

hal-01516024
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01516024
DOI : 10.3390/ijms18040764
PUBMED : 28375174