Browsing by Author "Sitjà-Bobadilla, Ariadna"
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- Disruption of gut integrity and permeability contributes to enteritis in a fish-parasite model: a story told from serum metabolomicsPublication . Sitjà-Bobadilla, Ariadna; Gil-Solsona, Rubén; Estensoro, Itziar; Piazzon, M. C; Martos-Sitcha, Juan A; Picard-Sánchez, Amparo; Fuentes, Juan; Sancho, Juan V; Calduch-Giner, Josep A; Hernández, Félix; Pérez-Sánchez, JaumeBackground In the animal production sector, enteritis is responsible for serious economic losses, and intestinal parasitism is a major stress factor leading to malnutrition and lowered performance and animal production efficiency. The effect of enteric parasites on the gut function of teleost fish, which represent the most ancient bony vertebrates, is far from being understood. The intestinal myxozoan parasite Enteromyxum leei dwells between gut epithelial cells and causes severe enteritis in gilthead sea bream (Sparus aurata), anorexia, cachexia, growth impairment, reduced marketability and increased mortality. Methods This study aimed to outline the gut failure in this fish-parasite model using a multifaceted approach and to find and validate non-lethal serum markers of gut barrier dysfunction. Intestinal integrity was studied in parasitized and non-parasitized fish by immunohistochemistry with specific markers for cellular adhesion (E-cadherin) and tight junctions (Tjp1 and Cldn3) and by functional studies of permeability (oral administration of FITC-dextran) and electrophysiology (Ussing chambers). Serum samples from parasitized and non-parasitized fish were analyzed using non-targeted metabolomics and some significantly altered metabolites were selected to be validated using commercial kits. Results The immunodetection of Tjp1 and Cldn3 was significantly lower in the intestine of parasitized fish, while no strong differences were found in E-cadherin. Parasitized fish showed a significant increase in paracellular uptake measured by FITC-dextran detection in serum. Electrophysiology showed a decrease in transepithelial resistance in infected animals, which showed a diarrheic profile. Serum metabolomics revealed 3702 ions, from which the differential expression of 20 identified compounds significantly separated control from infected groups in multivariate analyses. Of these compounds, serum inosine (decreased) and creatine (increased) were identified as relevant and validated with commercial kits. Conclusions The results demonstrate the disruption of tight junctions and the loss of gut barrier function, a metabolomic profile of absorption dysfunction and anorexia, which further outline the pathophysiological effects of E. leei.
- Sustainable fish meal-free diets for gilthead sea bream (Sparus aurata): integrated biomarker response to assess the effects on growth performance, lipid metabolism, antioxidant defense and immunological statusPublication . Fernandes, Ana M.; Calduch-Giner, Josep Àlvar; Pereira, Gabriella V.; Fachadas Gato Coelho Gonçalves, Ana Teresa; Dias, Jorge; Johansen, Johan; Silva, Tomé; Naya-Català, Fernando; Piazzon, Carla; Sitjà-Bobadilla, Ariadna; Costas, Benjamin; Conceição, Luís E. C.; Fernandes, Jorge M. O.; Pérez-Sánchez, JaumeThe growth of the aquaculture industry requires more sustainable and circular economy-driven aquafeed formulas. Thus, the goal of the present study was to assess in farmed gilthead sea bream (Sparus aurata L.) how different combinations of novel and conventional fish feed ingredients supported proper animal performance in terms of growth and physiological biomarkers of blood/liver/head kidney. A 77-day feeding trial was conducted with three experimental diets (PAP, with terrestrial processed animal protein from animal by-products; NOPAP, without processed animal protein from terrestrial animal by-products; MIX, a combination of alternative ingredients of PAP and NOPAP diets) and a commercial-type formulation (CTRL), and their effects on growth performance and markers of endocrine growth regulation, lipid metabolism, antioxidant defense and inflammatory condition were assessed at circulatory and tissue level (liver, head kidney). Growth performance was similar among all dietary treatments. However, fish fed the PAP diet displayed a lower feed conversion and protein efficiency, with intermediate values in MIX-fed fish. Such gradual variation in growth performance was supported by different biomarker signatures that delineated a lower risk of oxidation and inflammatory condition in NOPAP fish, in concurrence with an enhanced hepatic lipogenesis that did not represent a risk of lipoid liver degeneration.
- The influence of 17β-oestradiol on lymphopoiesis and immune system ontogenesis in juvenile sea bass, Dicentrarchus labraxPublication . Moreira, Catarina; Paiola, Matthieu; Duflot, Aurélie; Varó, Inma; Sitjà-Bobadilla, Ariadna; Knigge, Thomas; Pinto, P; Monsinjon, TiphaineThe female sex steroid 17β-oestradiol (E2) is involved in the regulation of numerous physiological functions, including the immune system development and performance. The role of oestrogens during ontogenesis is, however, not well studied. In rodents and fish, thymus maturation appears to be oestrogen-dependent. Never theless, little is known about the function of oestrogen in immune system development. To further the under standing of the role of oestrogens in fish immune system ontogenesis, fingerlings of European sea bass (Dicentrarchus labrax) were exposed for 30 days to 20 ng E2⋅L− 1 , at two ages tightly related to thymic maturation, i.e., 60 or 90 days post hatch (dph). The expression of nuclear and membrane oestrogen receptors was measured in the thymus and spleen, and the expression of several T cell-related gene markers was studied in both immune organs, as well as in the liver. Waterborne E2-exposure at 20.2 ± 2.1 (S.E.) ng⋅L− 1 was confirmed by radioimmunoassay, leading to significantly higher E2-contents in the liver of exposed fish. The majority of gene markers presented age-dependent dynamics in at least one of the organs, confirming thymus maturation, but also suggesting a critical ontogenetic window for the implementation of liver resident γδ and αβ T cells. The oestrogen receptors, however, remained unchanged over the age and treatment comparisons with the exception of esr2b, which was modulated by E2 in the younger cohort and increased its expression with age in the thymus of the older cohort, as did the membrane oestrogen receptor gpera. These results confirm that oestrogen-signalling is involved in thymus maturation in European sea bass, as it is in mammals. This suggests that esr2b and gpera play key roles during thymus ontogenesis, particularly during medulla maturation. In contrast, the spleen expressed low or non-detectable levels of oestrogen receptors. The E2-exposure decreased the expression of tcrγ in the liver in the cohort exposed from 93 to 122 dph, but not the expression of any other immune-related gene analysed. These results indicate that the proliferation/migration of these innate-like T cell populations is estrogensensitive. In regard to the apparent prominent role of oestrogen-signalling in the late thymus maturation stage, the thymic differentiation of the corresponding subpopulations of T cells might be regulated by oestrogen. To the best of our knowledge, this is the first study investigating the dynamics of both nuclear and membrane oestrogen receptors in specific immune organs in a teleost fish at very early stages of immune system development as well as to examine thymic function in sea bass after an exposure to E2 during ontogenesis.