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See detailEtude de la diversité des pucerons et des auxiliaires adiphages relative à la présence d'orties en bordures de champ
Alhmedi, A.; Francis, Frédéric ULg; Bodson, Bernard ULg et al

in Notes Fauniques de Gembloux (2006), 59(2), 121-124

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See detailetude de la diversité enzymatique des microorganismes du sol par l'approche métagénomique
Berlemont, Renaud ULg

Doctoral thesis (2009)

Functional metagenomic approach was performed using total environmental DNA extracted from a temperate forest soil sample and from an Antarctica soil sample. Searching for clones harbouring phenotypes ... [more ▼]

Functional metagenomic approach was performed using total environmental DNA extracted from a temperate forest soil sample and from an Antarctica soil sample. Searching for clones harbouring phenotypes related to the production of new hydrolytic enzyme allows the isolation of several new enzymes. Amongst them, an esterase and a cellulase, named RBest1 and RBcel1 respectively, were characterized. By accurate description of their catalytic proprieties these two new enzymes appear to present interesting features. The RBest1 esterase is an enzyme whose activity is stabilised or improved in presence of non water-miscible organic solvent. By sequence analysis, RBest1 is related to other organic solvent tolerant enzyme. Moreover, in aqueous buffer, RBest1 is highly specific for butyrate compound but surprisingly its specificity appears to be shifted in presence of organic solvent. The RBcel1 cellulase, was thoroughly characterized for its involvement both in cellulose degradation and production. Our data highlight the requirement for such enzyme in the bacterial cellulose synthesis process. According to our results, the mining of metagenomic libraries by functional screening associated to detailed description of the isolated enzymes gives hints for both ecological and microbiological questions. [less ▲]

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See detailEtude de la diversité et des plantes hôtes des Coccinellidae de Belgique
Francis, Frédéric ULg

in Notes Fauniques de Gembloux (2001), 44

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See detailEtude de la diversité génétique de l'ulluco (Ullucus tuberosus Loz.) en conservation ex situ
Malice, Marie ULg; Villaroel Vogt, C. L.; Rochez, G. et al

Conference given outside the academic context (2006)

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See detailEtude de la diversité génétique et de l’état des stocks des populations de barbeaux et de hotus en Wallonie. Amélioration des techniques d’élevage en vue de repeuplements raisonnés et de transferts de connaissances vers les pisciculteurs
Gennotte, Vincent ULg; Prignon, Christian ULg; Dierckx, Arnaud ULg et al

Report (2015)

Nase (Chondrostoma nasus) and common barbel (Barbus barbus) are two rheophilic cyprinid fish naturally present in South Belgian rivers. During the last decades, the construction of dams together with ... [more ▼]

Nase (Chondrostoma nasus) and common barbel (Barbus barbus) are two rheophilic cyprinid fish naturally present in South Belgian rivers. During the last decades, the construction of dams together with changes in hydrological regimes, modifications of riverbed morphology and water pollution caused some local dramatic declines in their populations. However, recent improvements in terms of water quality and habitat fragmentation allow now to implement a rational restocking plan of locally endangered patrimonial fish species such as nase and common barbel. To reach this goal, this project (co-funded by the European Fisheries Fund and the Wallonia Public Service) proposed to develop five complementary parts with specific objectives: • Review of the knowledge on nase and barbel geographical distribution and stock health in Wallonia. This section presents the distribution and recent evolution of populations in Europe, and more specifically in Wallonia. Areas where population declines were reported are identified. Even if a weak population expansion was reported in some isolated cases, the global status of Walloon populations is still concerning. • Characterization of genetic structure and diversity of South Belgium populations. Restocking operations for a conservation purpose have to be based on the knowledge and the use of wild type genetic strains. Nase and barbel populations from South Belgium were genetically characterized by use of microsatellites. Globally, nase and barbel populations are structured on a basin scale. A slight genetic differentiation exists between populations from the Rhine basin and the Meuse basin, defining two conservation units, but no finer structure was observed among populations from the Meuse basin. Genetic variation was high within populations. Genetic structure of barbel populations is more complex due to past restocking operations with different genetic lineages. An analysis of mDNA identified 6 different haplotypes but was unable to categorize them as autochtone or allochtone. • Development of fish production techniques. The complete control of fish farming is necessary to produce high quality juveniles for restocking. All the steps of the production cycle were addressed: broodstock management and reproduction, egg incubation, larval rearing and grow-out. Production systems ranging from extensive pond culture to intensive RAS were tested and the optimal farming conditions were identified (temperature, density, feeding, tank volumes, …). • Adaptation assessment of farmed fingerlings to natural conditions. Growth and survival performances of captive farmed fish were assessed in an experimental environment that mimics natural conditions. The results suggested that the more efficient practice for restocking would be based on operations performed in spring with large juveniles (3 to 50 g). • Know-how diffusion toward fish farmers. All the breeding and grow-out techniques developed for nase and barbel production are the subject of two handbooks. These documents, attached to the report, will be published and distributed to fish producers. [less ▲]

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See detailEtude de la diversité génétique et de la structure d'une collection française de pommiers
Lassois, Ludivine ULg; Denancé, Caroline; Ravon, Elisa et al

Scientific conference (2012)

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See detailEtude de la diversité trophique des poissons demoiselles (Perciformes, Pomacentridae) par l'examen des variations du squelette céphalique à partir de leur vie récifale
Frederich, Bruno ULg

Doctoral thesis (2009)

Damselfishes (Pomacentridae) are among the most speciose coral reef fishes (>350 species). They are abundant, constituting a large proportion of the individuals at small spatial scale. Despite this ... [more ▼]

Damselfishes (Pomacentridae) are among the most speciose coral reef fishes (>350 species). They are abundant, constituting a large proportion of the individuals at small spatial scale. Despite this importance, few studies deal with their trophic and morphological diversity. As most coral reef fishes, damselfishes have a complex life-cycle with two distinct phases: (1) a potentially dispersive pelagic larval phase and (2) a sedentary adult phase associated to the coral reef environment. The larval phase ends at reef settlement. The pelagic environment offers a relatively homogeneous habitat for all pomacentrids larvae which exclusively feed on planktonic copepods. On the other hand, the variety of resources is higher in the coral reef. During ontogeny, damselfishes undergo a change in their lifestyle that involves an ontogenetic change in morphology, physiology and behavior in order to maximize survival in each environment. This thesis aims to test the hypothesis that a higher trophic diversity at the adult stage corresponds to a higher disparity level (measure of morphological diversity of a clade) than in larvae. To answer this question, the research has been divided into three main axis. Firstly, the stable isotope (δ15N and δ13C) and stomach content analyses in thirteen sympatric species of damselfishes have highlighted three main groups according to their foraging strategies: (1) the pelagic feeders which feed on planktonic copepods, (2) the benthic feeders which are mainly herbivorous grazing filamentous algae and (3) an intermediate group including species which pick up their prey in the pelagic and the benthic compartment in variable proportions (e.g. planktonic and benthic copepods, small vagile invertebrates and filamentous algae). Only two species are known to be exclusively coral polyp feeders. Secondly, an ecomorphological study has characterized the diversity of the adults head skeleton. Shape variations of four skeletal units (neurocranium, suspensorium and opercle, mandible and premaxilla) were explored in fourteen species using landmark-based geometric morphometrics. The results reveal a parallelism between the morphological diversity and the trophic variety at the adult stage. Generally speaking, the planktivorous damselfishes show skeletal shapes enhancing suction feeding (e.g. high suspensoria and opercles, a large supraoccipital crest, short mandibles forming a small mouth) The herbivorous species (grazers) have shapes improving the robustness of some skeletal parts (e.g. high and robust mandibles, broad hyomandibular). Among the planktivorous species, Chromis viridis and C. acares show divergent shapes from the species of the same trophic guild. Their skeletal characteristics suggest they could be considered as ram-suction feeders. The buccal dentition is not highly related to the diet. Thirdly, the post-settlement ontogeny and the variation of shape disparity were studied and compared among eight species having varied diets. The post-settlement growth is highly allometric in all species (40 – 87% of shape variations). For each skeletal unit, the morphological disparity is higher at the adult stage compared with the settlement stage. All studied developmental parameters were affected by evolutionary changes. At settlement, the larval shapes are already species-specific, probably due to differences in pelagic larval duration among species. The increasing of shape disparity during ontogeny is mainly related to the divergence of allometric patterns. The length of ontogenetic trajectories and the developmental rates appear as less variable parameters. Generally speaking, no correlation exist between the phylogenetic or ecological (diet, pelagic larval duration,..) data and the developmental parameters. Species of the genus Dascyllus were studied in a particular context: a study case of giantism. The geometric morphometric methods show that the small species and the giant ones share the same ontogenetic trajectories for the neurocranium and the mandible. A part of their diversification should result from heterochronic processes. The cephalic larval shapes suggest a mode of prey capture defined as ram-suction feeding. In all studied species, the morphological transformations reveal an optimization of the suction feeding system. During growth, the main shape changes include a heightening of the suspensoria and the opercles, an elevation of the supraoccipital crest, a shortening of the mandibles and a lengthening of the ascending process of the premaxilla. In the benthic feeders, other shape changes are related to an improved biting and grazing abilities (e.g. mandibles and suspensorium appear more robust at the adult stage). [less ▲]

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See detailEtude de la durabilité des hydrofuges de surface pour la conservation du patrimoine en béton
Lucquiaud, Vincent ULg; Courard, Luc ULg

Poster (2014)

La protection du patrimoine historique en béton est un challenge pour les années futures. Un traitement hydrofuge retarde l’apparition de pathologies du béton et apporte une protection contre la ... [more ▼]

La protection du patrimoine historique en béton est un challenge pour les années futures. Un traitement hydrofuge retarde l’apparition de pathologies du béton et apporte une protection contre la pénétration de l’eau. Les produits existants - essentiellement du silane et siloxane base - ont été soumis à différents processus de vieillissement, tels que la carbonatation accélérée, des rayons UV, des cycles d'humidification, des chocs thermiques, et des cycles de gel-dégel. Leur efficacité a été évaluée suivant la mesure de l’angle de contact, leur perméabilité à la vapeur d’eau et aux chlorures et leur absorption capillaire. Les résultats de l’étude montre un bon comportement de ces produits aux les principaux vieillissements étudiés. [less ▲]

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See detailETUDE DE LA DYNAMIQUE DE LA DESERTIFICATION DANS LE BASSIN VERSANT DE LA MOULOUYA EN INTEGRANT LES DONNEES ISSUES DE LA TELEDETECTION ET LES DONNEES SOCIO-ECONOMIQUES
Mokhtari, Noureddine ULg

Doctoral thesis (2016)

La recherche sur la désertification et la dégradation de l’environnement est très complexe et vise la mise en relation entre les ressources de l’environnement, leurs limites de durabilité et des usages ... [more ▼]

La recherche sur la désertification et la dégradation de l’environnement est très complexe et vise la mise en relation entre les ressources de l’environnement, leurs limites de durabilité et des usages qui se font de ces ressources par l’homme en tant qu’agent économique qui vise à améliorer son bien-être. Dans le bassin versant de la Moulouya caractérisé par un climat essentiellement aride à semi-aride, une augmentation sensible de la population et une forte hausse de la demande en ressources naturelles, le problème de la désertification se pose en termes d’adaptation des besoins de la population aux contraintes du milieu en vue de maintenir la durabilité des ressources. Dans ce sens, le challenge consiste en un double objectif, premièrement l’évaluation de la désertification à travers l’analyse de l’état de dégradation du milieu et deuxièmement, l’étude des causes de cette dégradation moyennant des enquêtes axées sur les pratiques agricoles et la formulation de propositions d’actions à entreprendre pouvant être utilisés de manière opérationnelle par les acteurs locaux et les pouvoirs publics. Ainsi, le suivi de la dynamique des phénomènes biophysiques liés à la désertification s’est fait essentiellement à travers l’étude de l’évolution du climat et de la qualité de la végétation à l’échelle de l’ensemble de la zone étudiée (NDVI) et au niveau d’une zone d’intérêt pour la recherche (occupation du sol). Pour la végétation, le suivi spatio-temporel de la végétation a montré pour les trois sources de données à basse résolution utilisées (GIMMS, MEDOKADS et SPOT) des évolutions similaires de l’indice de végétation NDVI. Malgré les différences entre les amplitudes de variation du NDVI, liées essentiellement aux spécificités des algorithmes de traitement, les trois séries données conservent la même tendance stationnaire au cours du temps. D’une manière générale, les fluctuations du NDVI mises en évidence à l’aide des données NDVI à basse résolution reflètent principalement les variations spatio-temporelles en quantité et en qualité des précipitations d’une année par rapport à une autre et ne montrent aucune tendance particulière concernant la qualité de la végétation. L’identification des zones sensibles à la désertification, réalisée sur la base de l’approche MEDALUS, a montré que les zones fragiles et critiques totalisent 61% de la superficie du bassin versant, soit une superficie d’environ 3,25 millions d’Ha. Spatialement, les zones sensibles à la dégradation se trouvent aussi bien dans la Basse Moulouya que dans les Hauts Plateaux et la vallée de Missour constitués essentiellement de parcours steppiques. L’analyse de la dynamique d’occupation du sol à travers l’utilisation des images satellites (LANDSAT) pour la commune de Tissaf, choisie comme zone d’intérêt pour la recherche, a révélé une dégradation qualitative de la végétation. En effet, de grandes superficies d’Alfa dense à très dense (végétation climacique) se sont dégradées pour se retrouver dans la classe d’Alfa faiblement dense, soit une diminution de l’ordre de 16.199 Ha sur 20 ans. L’analyse des causes de la dégradation des parcours au niveau de la commune de Tissaf à travers l’étude de la productivité des parcours et du système d’élevage pastoral a révélé que le capital, en tant que facteur de production, joue un rôle important dans les stratégies d’utilisation des ressources fourragères « gratuites » issues des parcours collectifs. Ainsi, les grands éleveurs sédentaires ou semi-nomades disposant d’importants fonds propres et grâce à une utilisation plus opportuniste des parcours collectifs paraissent profiter davantage de ces ressources (46.478,15 UF) par rapport aux petits éleveurs sédentaires et transhumants (5.148,70 UF et 18.714,40 UF). Les petits éleveurs qui adaptent l’effectif de leur cheptel en fonction des conditions du milieu (décapitalisation en période de sécheresse) semblent profiter moins en quantité et en qualité des ressources pastorales disponibles. En guise de conclusion, la thèse propose des scénarios d’adaptation des systèmes de production agricoles qui peuvent être utilisés d’une manière opérationnelle par les acteurs locaux et les pouvoirs publics en vue d’orienter les stratégies de développement et d’investissement vers les secteurs rentables économiquement et qui respectent en même temps l’environnement. [less ▲]

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See detailETUDE DE LA DYNAMIQUE DES ARN DANS LE NUCLÉOLE DES CELLULES DE REPTILES
Bartholomé, Odile ULg

Master's dissertation (2014)

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See detailEtude de la dynamique des populations d'insectes sur la culture du riz NERICA dans les conditions du Masuku, Sud-Est du Gabon (Franceville)
ONDO OVONO, Paul; GATARASI, Thaddée; OBAME MINKO, Daniel et al

in International Journal of Biological and Chemical Sciences (2014)

La dynamique des populations d’insectes sur la culture du riz a été étudiée durant toutes les phases de croissance. L’essai a été installé sur les parcelles pédagogiques de l’Institut National Supérieur ... [more ▼]

La dynamique des populations d’insectes sur la culture du riz a été étudiée durant toutes les phases de croissance. L’essai a été installé sur les parcelles pédagogiques de l’Institut National Supérieur d’Agronomie et de Biotechnologies à Franceville. Il s’inscrit dans le cadre de la poursuite des travaux d’évaluation de l’adaptabilité de nouvelles variétés de riz de type NERICA, introduites dans la province du Haut –Ogooué au Sud-Est du Gabon. L’objectif de la présente étude est de collecter des informations concernant les insectes susceptibles de s’attaquer au riz et de sélectionner les variétés NERICA qui résistent le mieux aux attaques. Chacune des six variétés de type NERICA (1, 4, 11, 12, 14 et 17) a été semée en utilisant un dispositif en blocs complètement randomisés avec trois répétitions, en 2010 et 2011. La collecte des insectes volants a été effectuée au moyen de pièges aériens et du filet entomologique. Au sol, la capture s’est faite au moyen de pièges. Les larves d’insectes foreurs des tiges, les chenilles et les pucerons des racines ont été capturés à la main. Au total, 46 familles appartenant à 9 ordres ont été recensées donc 29 renferment des espèces nuisibles et définies comme ravageuses du riz. Les 17 autres familles sont classées comme insectes utiles. Les stades de tallage, d’initiation paniculaire et d’épiaison ont été en général les plus visités par les différentes familles d’insectes. Les variétés NERICA 1 et NERICA 11 ont présenté les plus faibles taux d’infestation et de dégâts. Par ailleurs, la perte en biomasse a été considérable chez toutes les variétés. [less ▲]

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See detailEtude de la faculté des protéines MX porcines à conférer une résistance contre le virus influenza A et contribution à l'identification du mécanisme impliqué
Palm, Mélanie ULg

Doctoral thesis (2013)

La mise en œuvre d'une politique de sélection génétique spécifiquement dédiée à l'amélioration de la résistance des animaux domestiques aux maladies infectieuses constitue un projet prometteur, tant en ... [more ▼]

La mise en œuvre d'une politique de sélection génétique spécifiquement dédiée à l'amélioration de la résistance des animaux domestiques aux maladies infectieuses constitue un projet prometteur, tant en terme de santé publique (limitation de l'usage des antibiotiques) qu'en terme de bien-être animal et de rentabilité des élevages (diminution des intrants). Dans ce contexte, connaître un gène-candidat et disposer d'un jeu de variants alléliques à ce locus dans l'espèce visée sont des prérequis. En ce qui concerne la résistance aux virus influenza A, un gène-candidat était bien connu lorsque ce travail a débuté ; il s'agissait du gène mx1 de la souris dont l'un des variants (dit "A2G" du nom de la souche consanguine chez laquelle le trait de résistance qui lui est associé a été découvert) confère une résistance quasi-absolue contre les virus précités. J'ai d'abord participé à l'élucidation de l'organisation génomique du locus mx1 porcin. Après, je me suis lancée dans l'inventaire des variants alléliques éventuellement présents à ce locus. J'en ai identifié deux principaux. Ensuite, j'ai établi les fréquences de ces allèles dans les différentes races de porcs européens et chez le sanglier. La seconde partie de mes travaux suscite des questions de nature fonctionnelle. D'abord, j'ai mis en évidence que l'activité anti-influenza des deux allèles est significativement différente, l'allèle canonique (le plus ressemblant aux autres protéines Mx mammaliennes) conférant une meilleure résistance. Ensuite, j'ai entrepris les premières étapes d'une étude des mécanismes sous-jacents à la fonction antivirale. En associant diverses expériences, j'ai pu déterminer que la Mx1 porcine ralentit le trafic endosomal centripète qui amène les ribonucléoprotéines virales à proximité du noyau. [less ▲]

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See detailEtude de la fatigue dans l'analyse de la marche
Maquet, Didier ULg; Chapelier, D.; Bouquegneau, Adeline ULg et al

in Julia, M.; Perrey, S.; Dupeyron, A. (Eds.) et al Fatigue musculaire (2010)

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See detailEtude de la fiabilité d'un nouvel analyseur de lactate portable chez le cheval
Meynie, J.; Art, Tatiana ULg; Olaerts, J. et al

in Pratique Vétérinaire Equine (1996), 28(1), 37-40

A new portable lactate analyzer has been tested for its accuracy and reproducibility. Venous blood has been sampled on 12 horses while they were performing a treadmill exercise. A total of 134 samples ... [more ▼]

A new portable lactate analyzer has been tested for its accuracy and reproducibility. Venous blood has been sampled on 12 horses while they were performing a treadmill exercise. A total of 134 samples were obtained and analyzed either with the portable analyzer or with a reference method. The packed cell volume has been also determined for each sample. The results obtained with both methods were compared : the correlation between the two sets of data was satisfactory ((R2 = 0,86) but higher when the PCV was lower or equal to 55 % (R2 = 0,88). It was concluded that the portable analyzer is reliable for lactate determination in horses [less ▲]

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See detailEtude de la fiabilité du SMA 12/60.
Vos, A.; Ers, P.; Albert, Adelin ULg et al

in Expansion scientifique française (1973)

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See detailEtude de la fibrose pulmonaire idiopathique canine: analyse du transcriptome, investigation des voies du TGF beta 1 et recherche de biomarqueurs
Krafft, Emilie ULg

Doctoral thesis (2014)

Canine idiopathic pulmonary fibrosis (cIPF) is a fibrotic disease of the pulmonary parenchyma, mainly seen in the West Highland white terrier. It is characterized by exercise intolerance and cough with a ... [more ▼]

Canine idiopathic pulmonary fibrosis (cIPF) is a fibrotic disease of the pulmonary parenchyma, mainly seen in the West Highland white terrier. It is characterized by exercise intolerance and cough with a progressive deterioration until death from respiratory insufficiency. Clinical, tomodensitometric and histological characteristics of cIPF have been described recently. However, this disease remains largely unknown and the clinicians are dealing with two major challenges: confirmation of the diagnosis, which requires many complementary exams, and absence of effective treatment. Identification of a targeted therapy is difficult without having a good understanding of the mechanisms leading to pulmonary parenchyma fibrosis. A similar disease, the idiopathic pulmonary fibrosis (IPF) is recognized in humans and cIPF might be interesting as a spontaneous model. This project in dogs was undertaken to answer, at least partly, to these challenges. The aims were to elucidate some mechanisms involved in cIPF pathogenesis and to identify biomarkers that could be used in the diagnosis process. The hypotheses were first that analysis of the transcriptome through microarray experiment would identify altered biological functions in cIPF, highlight specific molecules with an altered expression and identify potential biomarkers. Another hypothesis was the transforming growth factor beta 1 (TGFB1) pathways, considered central in the pathogenesis of IPF, would also be modified in cIPF. Finally, ET1, a known biomarker in human IPF, might also be an interesting biomarker in dogs. Gene expression analysis through microarray analysis, combined with the use of IPA, a data analysis program, identified altered biological functions in cIPF: cellular growth and proliferation, developmental processes, cellular movement, cell to cell signaling and interaction and antigen presentation. Some genes highlighted in the microarray experiment were then analyzed individually. Quantitative RT-PCR analysis confirmed an upregulation of the expression of CCL2, CCL7, CXCL14, IL8 and FAP (fibroblast activation protein) as well as a downregulation of the expression of PLUNC (palate, lung and nasal epithelium associated). We then complete the gene expression analysis with a search for potential biomarkers. Thirty-four potential biomarkers were identified with 32 biomarkers potentially measurable in blood (including CCL2, serum amyloid 1, IL8) and 2 biomarkers measurable only in the bronchoalveolar lavage fluid (BALF) (PLUNC and mesothelin). This approach was validated by measurement in serum of one of this biomarker: CCL2. CCL2 serum concentration was higher in affected WHWT compared to healthy WHWT and also higher in dogs with cIPF compared to dogs with chronic bronchitis (CB) or eosinophilic bronchopneumopathy (EBP). Based on serum CCL2 determination, cIPF was diagnosed with a sensibility of 92% and a specificity of 80%. We then studied TGFB1 and part of its storage, activation and signaling pathways. TGFB1 gene expression was not significantly different in the pulmonary parenchyma between affected and control dogs. However, in affected dogs, increased TGFB1 protein levels were seen by immunohistochemistry in fibrotic areas. High expression of bothTGFB1 type I receptor and phosphorylated Smad2/3, markers of an active intracellular TGFB1 signal, were seen in epithelial cells. No difference in expression for the storage proteins LTBP1 and LTBP2 was seen while expression of LTBP4 was significantly decreased in dogs with cIPF. Concerning the proteins involved in TGFB1 activation, gene expression was decreased for integrin subunit β8, increased for thrombospondin-1 and not modified for integrin subunit β6. Expression of Smad 7, involved in intracellular TGFB1 signal inhibition, was not modified. No difference for TGFB1 serum concentration was seen between WHWT with cIPF and healthy WHWT. A multivariate analysis performed on healthy dogs showed no age effect but a significant breed effect with higher levels in predisposed breeds. We evaluated part of the serotonin pathway, as one of its receptor (5HTR2B) was highlighted during the gene expression analysis. Serotonin has also been involved in the pathogenesis of human IPF and described to be of potential use as a biomarker in degenerative mitral valve disease in dogs. Expression of 2 serotonin receptors (5HTR2A and 5HTR2B), evaluated by quantitative RT-PCR in pulmonary tissue, was not different between dogs with cIPF and control dogs while expression of the serotonin transporter (5HTT) was significantly lower in affected dogs. No difference in serotonin serum level was seen between affected and healthy WHWT or between dogs with cIPF, CB or EBP. ET1 was evaluated as a biomarker in serum and BALF. ET1 serum concentration was not different between healthy WHWT and Beagles. Covariance analysis did not reveal any significant age effect. Serum levels were significantly higher in dogs with cIPF compared to dogs with CB or EBP. ROC curve analysis was then used to evaluate its diagnostic performances. The area under the curve was 0,818 with a sensitivity of 91.7% and a specificity of 87.5%. ET1 was also measured in the BALF in a small number of dogs. Its concentration was measurable in all dogs with cIPF while it was below the detection limit in all other dogs tested (healthy and with CB). Even though cIPF and human IPF are not completely identical from clinical, tomodensitometric or histological points of view, these results show that both canine and human diseases share molecular pathways, supporting the idea that cIPF might have an interest as spontaneous model. This work allowed a better understanding of cIPF pathogenesis. Gene expression analysis in the pulmonary parenchyma of affected dogs first identified several altered biological functions that should be analyzed in details in further studies. A more targeted analysis of some genes confirmed an upregulated expression of CCL2, CCL7, CXCL14, IL8 and FAP. Such a positive regulation of the expression of various inflammatory cytokines tends to suggest that inflammation might have a role in cIPF pathogenesis. Some of these cytokines also have profibrotic properties. PLUNC was one of the top down-regulated genes. Roles of the protein are still largely unknown; it might have a role in the inflammatory response and in the innate immunity. Developmental pathways were also altered in cIPF and quantitative RT-PCR confirmed an upregulation of FAP, a protein normally expressed in areas of tissue remodeling during fetal development and also positively regulated in human IPF. This study has shown that there is an active TGFB1 signal in the lungs of dogs with cIPF, especially at the level of the pathological epithelium. TGFB1 storage and activation pathways also seemed to be altered. Elevated TGFB1 circulating levels were found in predisposed breeds, which might explain at least partly their susceptibility for cIPF. Because of these results and its well-known profibrotic properties, we can suggest that TGFB1 is probably involved in cIPF pathogenesis and that modulation of its storage, activation or intracellular signaling might offer potential therapeutic targets. Our preliminary results are not in favor of a significant modification of the serotonin pathways in cIPF, although a decreased expression of 5HTT was seen in affected dogs and might have an impact on the amount of serotonin present locally. However, other studies are needed to conclude. Finally, several potential biomarkers have been identified and some of them were evaluated in details. While serum measurements performed for TGFB1 and serotonin indicated that these molecules have no interest as diagnostic biomarkers, ET1 and CCL2 were identified as interesting candidates with good diagnostic performances. However these results need to be confirmed in an independent validation cohort and the interest of combining both biomarkers should be evaluated. [less ▲]

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