Browsing by Author "Fernández, Ignacio"
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- Biochemical and molecular responses of the Mediterranean mussel (Mytilus galloprovincialis) to short-term exposure to three commonly prescribed drugsPublication . Pes, Katia; Friese, Annika; Cox, Cymon J.; Laizé, Vincent; Fernández, IgnacioPharmaceuticals represent a group of emerging contaminants. The short-term effect (3 and 7 days) of warfarin (1 and 10 mg L-1), dexamethasone (0.392 and 3.92 mg L-1) and imidazole (0.013 and 0.13 mg L-1) exposure was evaluated on mussels (Mytilus galloprovincialis). Total antioxidant status, glutathione reductase, glutathione peroxidase (GPx) and superoxide dismutase enzyme activities, and the expression of genes involved in the xenobiotic response (ATP binding cassette subfamily B member 1 (abcb1) and several nuclear receptor family J (nr1j) isoforms), were evaluated. All nr1j isoforms are suggested to be the xenobiotic receptor orthologs of the NR1I family. All drugs increased GPx activity and altered the expression of particular nr1j isoforms. Dexamethasone exposure also decreased abcb1 expression. These findings raised some concerns regarding the release of these pharmaceuticals into the aquatic environment. Thus, further studies might be needed to perform an accurate environmental risk assessment of these 3 poorly studied drugs.
- Fish microbiome modulation and convenient storage of aquafeeds when supplemented with Vitamin K1Publication . Acosta, Marcos; Quiroz, Eduardo; Tovar-Ramírez, Dariel; Roberto, Vania Palma; Dias, Jorge; Gavaia, Paulo; Fernández, IgnacioVitamin K (VK), and particularly phylloquinone (VK1), is an essential micronutrient whose stability in aquafeeds has not been extensively evaluated. Losing stability can lead to nutritional deficiency, which is known to hamper fish development and physiology. Gut microbiota also plays a key role in host health through the interaction with several biological processes. The present study evaluated the best storing conditions of aquafeeds when supplemented in VK1 and intestinal microbiota modulation in Senegalese sole (Solea senegalensis) juveniles. Aquafeeds with a high level of VK1 supplementation required storage at −20 ◦C for short-term (up to 7 days) and at −80 ◦C for long-term (up to three months) to ensure optimal preservation. Furthermore, gut bacterial communities of Senegalese sole specimens fed with a commercial feed supplemented with VK1 showed a better-balanced population of microorganisms in the intestine, which might improve Senegalese sole health during the ongrowing phase. These results provide the practical guidelines for the proper storing of aquafeeds in the industry when supplemented with VK1 and highlight the potential benefits of dietary VK1 supplementation for a balanced intestinal microbiota and overall fish health.
- Kisspeptin influences the reproductive axis and circulating levels of microRNAs in Senegalese solePublication . Oliveira, Catarina; Fatsini, Elvira; Fernández, Ignacio; Anjos, Catarina; Chauvigné, François; Cerdà, Joan; Mjelle, Robin; Fernandes, Jorge M. O.; Cabrita, ElsaKisspeptin regulates puberty and reproduction onset, acting upstream of the brain-pituitary-gonad (HPG) axis. This study aimed to test a kisspeptin-based hormonal therapy on cultured Senegalese sole (G1) breeders, known to have reproductive dysfunctions. A single intramuscular injection of KISS2-10 decapeptide (250 µg/kg) was tested in females and males during the reproductive season, and gonad maturation, sperm motility, plasma levels of gonadotropins (Fsh and Lh) and sex steroids (11-ketotestosterone, testosterone and estradiol), as well as changes in small non-coding RNAs (sncRNAs) in plasma, were investigated. Fsh, Lh, and testosterone levels increased after kisspeptin injection in both sexes, while sperm analysis did not show differences between groups. Let7e, miR-199a-3p and miR-100-5p were differentially expressed in females, while miR-1-3p miRNA was up-regulated in kisspeptin-treated males. In silico prediction of mRNAs targeted by miRNAs revealed that kisspeptin treatment might affect paracellular transporters, regulate structural and functional polarity of cells, neural networks and intracellular trafficking in Senegalese sole females; also, DNA methylation and sphingolipid metabolism might be altered in kisspeptin-treated males. Results demonstrated that kisspeptin stimulated gonadotropin and testosterone secretion in both sexes and induced an unanticipated alteration of plasma miRNAs, opening new research venues to understand how this neuropeptide impacts in fish HPG axis.
- New insights on vitamin K metabolism in senegalese sole (Solea senegalensis) based on ontogenetic and tissue-specific vitamin K epoxide reductase molecular dataPublication . Beato, Silvia; Marques, Carlos; Laizé, Vincent; Gavaia, Paulo; Fernández, IgnacioVitamin K (VK) is a key nutrient for several biological processes (e.g., blood clotting and bone metabolism). To fulfill VK nutritional requirements, VK action as an activator of pregnane X receptor (Pxr) signaling pathway, and as a co-factor of γ-glutamyl carboxylase enzyme, should be considered. In this regard, VK recycling through vitamin K epoxide reductases (Vkors) is essential and should be better understood. Here, the expression patterns of vitamin K epoxide reductase complex subunit 1 (vkorc1) and vkorc1 like 1 (vkorc1l1) were determined during the larval ontogeny of Senegalese sole (Solea senegalensis), and in early juveniles cultured under different physiological conditions. Full-length transcripts for ssvkorc1 and ssvkorc1l1 were determined and peptide sequences were found to be evolutionarily conserved. During larval development, expression of ssvkorc1 showed a slight increase during absence or low feed intake. Expression of ssvkorc1l1 continuously decreased until 24 h post-fertilization, and remained constant afterwards. Both ssvkors were ubiquitously expressed in adult tissues, and highest expression was found in liver for ssvkorc1, and ovary and brain for ssvkorc1l1. Expression of ssvkorc1 and ssvkorc1l1 was differentially regulated under physiological conditions related to fasting and re-feeding, but also under VK dietary supplementation and induced deficiency. The present work provides new and basic molecular clues evidencing how VK metabolism in marine fish is sensitive to nutritional and environmental conditions.
- Retinoic acid differentially affects in vitro proliferation, differentiation and mineralization of two fish bone-derived cell lines: Different gene expression of nuclear receptors and ECM proteinsPublication . Fernández, Ignacio; Tiago, Daniel; Laizé, Vincent; Cancela, Leonor; Gisbert, EnricRetinoic acid (RA), the main active metabolite of vitamin A, regulates vertebrate morphogenesis through signaling pathways not yet fully understood. Such process involves the specific activation of retinoic acid and retinoid X receptors (RARs and RXRs), which are nuclear receptors of the steroid/thyroid hormone receptor superfamily. Teleost fish are suitable models to study vertebrate development, such as skeletogenesis. Cell systems capable of in vitro mineralization have been developed for several fish species and may provide new insights into the specific cellular and molecular events related to vitamin A activity in bone, complementary to in vivo studies. This work aims at investigating the in vitro effects of RA (0.5 and 12.5 μM) on proliferation, differentiation and extracellular matrix (ECM) mineralization of two gilthead seabream bone-derived cell lines (VSa13 and VSa16), and at identifying molecular targets of its action through gene expression analysis. RA induced phenotypic changes and cellular proliferation was inhibited in both cell lines in a cell type-dependent manner (36–59% in VSa13 and 17–46% in VSa16 cells). While RA stimulated mineral deposition in VSa13 cell cultures (50–62% stimulation), it inhibited the mineralization of extracellular matrix in VSa16 cells (11–57% inhibition). Expression of hormone receptor genes (rars and rxrs), and extracellular matrix-related genes such as matrix and bone Gla proteins (mgp and bglap), osteopontin (spp1) and type I collagen (col1a1) were differentially regulated upon exposure to RA in proliferating, differentiating and mineralizing cultures of VSa13 and VSa16 cells. Altogether, our results show: (i) RA affects proliferative and mineralogenic activities in two fish skeletal cell types and (ii) that during phenotype transitions, specific RA nuclear receptors and bone-related genes are differentially expressed in a cell type-dependent manner.
- Short-term exposure to pharmaceuticals negatively impacts marine flatfish species: Histological, biochemical and molecular clues for an integrated ecosystem risk assessmentPublication . Pes, Katia; Ortiz-Delgado, Juan B.; Sarasquete, Carmen; Laizé, Vincent; Fernández, IgnacioThe marine habitat and its biodiversity can be impacted by released pharmaceuticals. The short-term (7 days) effect of 3 commonly used drugs - warfarin, dexamethasone and imidazole - on Senegalese sole (Solea senegalensis) juveniles was investigated. Occurrence of hemorrhages, histopathological alterations, antioxidant status, activity of antioxidant enzymes and expression of genes involved in the xenobiotic response (pxr, abcb1 and cyp1a), were evaluated. The results showed a time and drug-dependent effect. Warfarin exposure induced hemorrhages, hepatocyte vacuolar degeneration, and altered the activity of glutathione peroxidase (GPx) and the expression of all the studied genes. Dexamethasone exposure increased liver glycogen content, altered antioxidant status, GPx and superoxide dismutase activities, as well as abcb1 and cyp1a expression. Imidazole induced hepatocyte vacuolar degeneration and ballooning, and altered the antioxidant status and expression of the tested genes. The present work anticipates a deeper impact of pharmaceuticals on the aquatic environment than previously reported, thus underlining the urgent need for an integrated risk assessment.
- Temporal and spatial expression patterns of pregnane X receptor and vitamin K epoxide reductase genes, two core molecular players on fish vitamin K homeostasis and skeletal development.Publication . Fernández, Ignacio; Cancela, Leonor; Gavaia, Paulo J.Vitamin K (VK) is a liposoluble vitamin known to be essential for bone metabolism by two different pathways: (i) by its role as a coenzyme in the gamma-carboxylation of some skeletal proteins (e.g. osteocalcin (OC) and matrix Gla protein (MGP); Price et al., 1998); and (ii) through its role in skeletal gene transcription via binding to the pregnane X receptor (PXR; Azuma et al., 2010).