Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
This work relates to the characterisation of the predominant gill protein of the white clam, Codakia orbicularis (Linné, 1758), which harbours endosymbiotic sulphur-oxidising chemoautotrophic bacteria. Total RNA was extracted from the clam to perform 3'rapid amplification of cDNA ends (3'RACE) using degenerate oligonucleotides prepared from a partial sequence of a predominant protein of about 14kDa, termed codakine. The partial peptide sequence was obtained by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and Edman degradation. Clones isolated from the cDNA library and containing the gene of interest were used in polymerase chain reaction (PCR). The PCR and RACE-PCR products were sequenced to determine the entire coding DNA sequence of codakine. BLAST analysis revealed about 23% to 29% sequence identity between codakine and various animal C-type lectins that are often involved in symbiosis and immune defences. Codakine also contains the motifs and domains of Ca(2+)-dependent C-type lectins, and in particular the tripeptide EPN motif frequently found in mannose-binding lectins (MBLs). Analysis of the protein by affinity chromatography on a mannose-agarose column is consistent with the findings that codakine is a dimeric Ca(2+)-dependent MBL of about 29kDa. Based on the present results, it is hypothesised that this novel C. orbicularis gill protein is involved in the recognition of symbiotic and pathogenic bacteria.
ISSN: 1050-4648

hal-00746015
https://hal.univ-antilles.fr/hal-00746015
DOI : 10.1016/j.fsi.2006.06.013
PUBMED : 17169576

Éditeur(s) : HAL CCSD IOS Press
Résumé : The main objectives of the present work were to test the effects of heat stress on blood rheology and to determine whether the responses can change according to the pig breeds. Thirty-six pigs from three pig's lines (n = 12 for each line) with assumed different tolerance to heat stress were compared: Large White (LW, little tolerance), Creole (CR, good tolerance) and LW × CR pigs (produced from a cross between LW and CR lines). In a first period, all pigs were exposed to a 9-d period of thermo-neutral environment (24°C; d-9 to d-1; P0). At the end of P0, six pigs from each line were slaughtered (n = 18). Then in a second period, the remaining pigs (6/breed; n = 18) were exposed to a 5-d period of heat stress (32°C; d + 1 -d + 5; P1) and thereafter slaughtered at d + 5. Rectal and skin temperatures, as well as respiratory rate, were recorded on d-1 and d + 5. At slaughter, blood was sampled for hematological and hemorheological measurements. Heat stress caused a rise of the skin temperature and respiratory rate without any changes in the rectal temperature or on the hematological and hemorheological parameters when all pigs' lines were considered. We observed a pig line effect on blood viscosity at high shear rate (375 s-1) and red blood cell deformability at 30 Pa with CR pigs having lower blood viscosity and higher red blood cell deformability than LW pigs. While the changes of blood viscosity under heat stress did not reach statistical significance in LW and CR lines, blood viscosity (at 375 s-1) increased above the temperate values in the LW × CR line. Red blood cell deformability at 30 Pa was higher in CR pigs exposed to heat stress compared to LW pigs in the same condition. In conclusion, thermal loading caused physiological stress but did not widely change the hematological and hemorheological profiles. Although some blood rheological parameters seem to vary with the pig breeds, the responses to heat stress are very similar.
ISSN: 1386-0291

hal-01210926
https://hal.archives-ouvertes.fr/hal-01210926
DOI : 10.3233/CH-131722
PRODINRA : 286489
PUBMED : 23603327

Éditeur(s) : HAL CCSD Wiley Open Access
Résumé : International audience
Estetrol (E4) is a natural estrogen with a long half-life produced only by the human fetal liver during pregnancy. The crystal structures of the estrogen receptor α (ERα) ligand-binding domain bound to 17β-estradiol (E2) and E4 are very similar, as well as their capacity to activate the two activation functions AF-1 and AF-2 and to recruit the coactivator SRC3. In vivo administration of high doses of E4 stimulated uterine gene expression, epithelial proliferation, and prevented atheroma, three recognized nuclear ERα actions. However, E4 failed to promote endothelial NO synthase activation and acceleration of endothelial healing, two processes clearly dependent on membrane-initiated steroid signaling (MISS). Furthermore, E4 antagonized E2 MISS-dependent effects in endothelium but also in MCF-7 breast cancer cell line. This profile of ERα activation by E4, uncoupling nuclear and membrane activation, characterizes E4 as a selective ER modulator which could have medical applications that should now be considered further.
ISSN: 1757-4676

hal-01118028
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01118028
PUBMED : 25214462
PUBMEDCENTRAL : PMC4287935
DOI : 10.15252/emmm.201404112