Secreted metalloprotease gene family of Microsporum canis

in Infection and Immunity (2002), 70(10), 5676-5683

Keratinolytic proteases secreted by dermatophytes are likely to be virulence-related factors. Microsporum canis, the main agent of dermatophytosis in dogs and cats, causes a zoonosis that is frequently ... [more ▼]

Keratinolytic proteases secreted by dermatophytes are likely to be virulence-related factors. Microsporum canis, the main agent of dermatophytosis in dogs and cats, causes a zoonosis that is frequently reported. Using Aspergillus fumigatus metalloprotease genomic sequence (MEP) as a probe, three genes (MEP1, MEP2, and MEP3) were isolated from an M. canis genomic library. They presented a quite-high percentage of identity with both A. fumigatus MEP and Aspergillus oryzae neutral protease I genes. At the amino acid level, they all contained an HEXXH consensus sequence, confirming that these M. canis genes (MEP genes) encode a zinc-containing metalloprotease gene family. Furthermore, MEP3 was found to be the gene encoding a previously isolated M. canis 43.5-kDa keratinolytic metalloprotease, and was successfully expressed as an active recombinant enzyme in Pichia pastoris. Reverse transcriptase nested PCR performed on total RNA extracted from the hair of M. canis-infected guinea pigs showed that at least MEP2 and MEP3 are produced during the infection process. This is the first report describing the isolation of a gene family encoding potential virulence-related factors in dermatophytes. [less ▲]

Secreted subtilisin Sub3 from Microsporum canis is required for adherence to but not for invasion of the epidermis

in British Journal of Dermatology (2010), 162(5), 990-997

Secreted subtilisins of Microsporum canis are involved in adhesion of arthroconidia to feline corneocytes

Poster (2008)

Microsporum canis is a pathogenic fungus that causes a superficial skin infection called dermatophytosis mainly in cats, dogs and humans. Like other dermatophytoses, the physiopathology of this dermatosis ... [more ▼]

Microsporum canis is a pathogenic fungus that causes a superficial skin infection called dermatophytosis mainly in cats, dogs and humans. Like other dermatophytoses, the physiopathology of this dermatosis remains largely unknown. From a fungal perspective, the infection process can be divided in three steps: adhesion of M. canis arthroconidia to corneocytes, conidial germination, and fungal invasion of the keratin network. The mechanisms involved in adherence of M. canis to epidermis have never been investigated. However, several previously characterized secreted fungal endoproteases like subtilisins (Sub), including the keratinolytic protease Sub3, are secreted in vivo and could be involved in the first pathogenic steps. The objective of this study were (1) to develop an in vitro model to study M. canis adherence to feline corneocytes and (2) to assess whether the Sub are involved in fungal adhesion. An arthroconidial suspension was spread over the surface of reconstituted feline epidermis (RFE). Co-cultures were incubated for varying lengths of time and adherent conidia were labelled using Calcofluor white and counted. In subsequent assays arthroconidia were exposed to the serine protease inhibitor chymostatin or a mixture of two anti-Sub3 monoclonal antibodies (Mabs) one hour prior to the adherence assay. In our model, adherence of M. canis arthroconidia to RFE is time-dependent, beginning within two hours and still increasing after six hours. Chymostatin and Mabs inhibit M. canis adherence to RFE by 53 and 23 % respectively, which suggests that subtilisins and particularly Sub3, are fungal virulence factors involved in the adherence process. [less ▲]

Secretion and maturation of conotoxins in the venom ducts of Conus textile

in Toxicon (2012), 60(8), 1370-1379

Secretion by Overexpression and Purification of the Water-Soluble Streptomyces K15 Dd-Transpeptidase/Penicillin-Binding Protein

in Biochemical Journal (1992), 288(1), 87-91

Though synthesized with a cleavable signal peptide and devoid of membrane anchors, the 262-amino-acid-residue Streptomyces K15 DD-transpeptidase/penicillin-binding protein is membrane-bound ... [more ▼]

Though synthesized with a cleavable signal peptide and devoid of membrane anchors, the 262-amino-acid-residue Streptomyces K15 DD-transpeptidase/penicillin-binding protein is membrane-bound. Overexpression in Streptomyces lividans resulted in the export of an appreciable amount of the synthesized protein (4 mg/litre of culture supernatant). The water-soluble enzyme was purified close to protein homogeneity with a yield of 75%. It requires the presence of 0.5 M-NaCl to remain soluble. It is indistinguishable from the detergent-extract wild-type enzyme with respect to molecular mass, thermostability, transpeptidase activity and penicillin-binding capacity. [less ▲]

Secretion of leukemia inhibitory factor (LIF) by human endometrium alone

in Human Reproduction (1996), 11

The secretions of oviduct epithelial cells increase the equine in vitro fertilization rate: are osteopontin, atrial natriuretic peptide A and oviductin involved?

in Reproductive biology and endocrinology (2009), 7(1), 129

ABSTRACT: BACKGROUND: Oviduct epithelial cells (OEC) co-culture promotes in vitro fertilization (IVF) in human, bovine and porcine species, but no data are available from equine species. Yet, despite ... [more ▼]

ABSTRACT: BACKGROUND: Oviduct epithelial cells (OEC) co-culture promotes in vitro fertilization (IVF) in human, bovine and porcine species, but no data are available from equine species. Yet, despite numerous attempts, equine IVF rates remain low. Our first aim was to verify a beneficial effect of the OEC on equine IVF. In mammals, oviductal proteins have been shown to interact with gametes and play a role in fertilization. Thus, our second aim was to identify the proteins involved in fertilization in the horse. Methods & results In the first experiment, we co-incubated fresh equine spermatozoa treated with calcium ionophore and in vitro matured equine oocytes with or without porcine OEC. We showed that the presence of OEC increases the IVF rates. In the subsequent experiments, we co-incubated equine gametes with OEC and we showed that the IVF rates were not significantly different between 1) gametes co-incubated with equine vs porcine OEC, 2) intact cumulus-oocyte complexes vs denuded oocytes, 3) OEC previously stimulated with human Chorionic Gonadotropin, Luteinizing Hormone and/or oestradiol vs non stimulated OEC, 4) in vivo vs in vitro matured oocytes. In order to identify the proteins responsible for the positive effect of OEC, we first searched for the presence of the genes encoding oviductin, osteopontin and atrial natriuretic peptide A (ANP A) in the equine genome. We showed that the genes coding for osteopontin and ANP A are present. But the one for oviductin either has become a pseudogene during evolution of horse genome or has been not well annotated in horse genome sequence. We then showed that osteopontin and ANP A proteins are present in the equine oviduct using a surface plasmon resonance biosensor, and we analyzed their expression during oestrus cycle by Western blot. Finally, we co-incubated equine gametes with or without purified osteopontin or synthesized ANP A. No significant effect of osteopontin or ANP A was observed, though osteopontin slightly increased the IVF rates. CONCLUSION: Our study shows a beneficial effect of homologous and heterologous oviduct cells on equine IVF rates, though the rates remain low. Furthers studies are necessary to identify the proteins involved. We showed that the surface plasmon resonance technique is efficient and powerful to analyze molecular interactions during fertilization. [less ▲]

Secretory phospholipase A2 pathway in various types of lung injury in neonates and infants: a multicentre translational study

in BMC Pediatrics (2011), 11(101),

Background Secretory phospholipase A2 (sPLA2) is a group of enzymes involved in lung tissue inflammation and surfactant catabolism. sPLA2 plays a role in adults affected by acute lung injury and seems a ... [more ▼]

Background Secretory phospholipase A2 (sPLA2) is a group of enzymes involved in lung tissue inflammation and surfactant catabolism. sPLA2 plays a role in adults affected by acute lung injury and seems a promising therapeutic target. Preliminary data allow foreseeing the importance of such enzyme in some critical respiratory diseases in neonates and infants, as well. Our study aim is to clarify the role of sPLA2 and its modulators in the pathogenesis and clinical severity of hyaline membrane disease, infection related respiratory failure, meconium aspiration syndrome and acute respiratory distress syndrome. sPLA2 genes will also be sequenced and possible genetic involvement will be analysed. Methods/Design Multicentre, international, translational study, including several paediatric and neonatal intensive care units and one coordinating laboratory. Babies affected by the above mentioned conditions will be enrolled: broncho-alveolar lavage fluid, serum and whole blood will be obtained at definite time-points during the disease course. Several clinical, respiratory and outcome data will be recorded. Laboratory researchers who perform the bench part of the study will be blinded to the clinical data. Discussion This study, thanks to its multicenter design, will clarify the role(s) of sPLA2 and its pathway in these diseases: sPLA2 might be the crossroad between inflammation and surfactant dysfunction. This may represent a crucial target for new anti-inflammatory therapies but also a novel approach to protect surfactant or spare it, improving alveolar stability, lung mechanics and gas exchange. [less ▲]

Les secrets de l'astrolabe - suite

Article for general public (2012)

Les Secrets du geste. Le jeu et la direction d’acteurs dans le cinéma des frères Dardenne

in Aubenas, Jacqueline (Ed.) Jean-Pierre et Luc Dardenne (2008)