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- 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.
- 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.
- Daily regulation of key metabolic pathways in two seagrasses under natural light conditionsPublication . Ruocco, Miriam; Barrote, Isabel; Hofman, Jan Dirk; Pes, Katia; Costa, Monya; Procaccini, Gabriele; Silva, João; Dattolo, EmanuelaThe circadian clock is an endogenous time-keeping mechanism that enables organisms to adapt to external environmental cycles. It produces rhythms of plant metabolism and physiology, and interacts with signaling pathways controlling daily and seasonal environmental responses through gene expression regulation. Downstream metabolic outputs, such as photosynthesis and sugar metabolism, besides being affected by the clock, can also contribute to the circadian timing itself. In marine plants, studies of circadian rhythms are still way behind in respect to terrestrial species, which strongly limits the understanding of how they coordinate their physiology and energetic metabolism with environmental signals at sea. Here, we provided a first description of daily timing of key core clock components and clock output pathways in two seagrass species, Cymodocea nodosa and Zostera marina (order Alismatales), cooccurring at the same geographic location, thus exposed to identical natural variations in photoperiod. Large differences were observed between species in the daily timing of accumulation of transcripts related to key metabolic pathways, such as photosynthesis and sucrose synthesis/transport, highlighting the importance of intrinsic biological, and likely ecological attributes of the species in determining the periodicity of functions. The two species exhibited a differential sensitivity to light-to-dark and dark-to-light transition times and could adopt different growth timing based on a differential strategy of resource allocation and mobilization throughout the day, possibly coordinated by the circadian clock. This behavior could potentially derive from divergent evolutionary adaptations of the species to their bio-geographical range of distributions.
- Glyphosate: a terrestrial threat to marine plants? a study on the seagrass zostera marinaPublication . Deguette, Alizé; Pes, Katia; Vasconcellos, Bernard; Costa, Monya; Silva, João; Barrote, IsabelGlyphosate-based herbicides (GBHs) are extensively used worldwide, raising concerns about their potential effect on non-target aquatic ecosystems. This study investigated the short-term physiological effects of a commercially available GBH on the seagrass Zostera marina under controlled mesocosm conditions. Z. marina individuals were exposed to three concentrations of glyphosate (0.165, 51, and 5100 mg L−1 ) for 4 days, and the impacts on photosynthetic performance, growth rate, photosynthetic pigments content and energy metabolism were assessed. Exposure to 5100 mg L−1 of glyphosate caused rapid water acidification and complete plant mortality within 24 h. Exposure to 51 mg L−1 of glyphosate significantly impaired photosynthetic efficiency and foliar growth rate. Energy availability, photosynthesis and photosynthetic pigments content were highly disrupted at both higher concentrations. Exposure to 0.165 mg L−1 of glyphosate decreased the foliar chlorophyll a/b ratio. These findings show that Z. marina can potentially be threatened by the presence of GBHs even at lower concentrations and underscore the necessity for monitoring herbicide pollution in coastal waters to protect seagrass habitats and associated ecosystems. Further research is needed to assess long-term effects and the role of herbicide formulations in mediating toxicity.
- Immunomodulatory inhibition of osteoclastogenesis by a marine microalgal ethanol fraction targeting T-cells, antigen presentation, and macrophage fatePublication . Carletti, Alessio; Pes, Katia; Tarasco, Marco; Rosa, Joana; Poudel, Sunil; Pereira, Hugo; Louro, Bruno; Cancela, M. Leonor; Laizé, Vincent; Gavaia, PauloBackground: Targeting immune pathways to prevent bone loss represents a promising, yet underexplored therapeutic strategy. Methods: An ethanol-soluble fraction derived from the freeze-dried biomass of the marine microalga Skeletonema costatum (SKLT) was tested for its ability to modulate immune responses and inhibit osteoclastogenesis. Its effects were evaluated in a zebrafish model of bone regeneration, a medaka model of RANKLinduced osteoporosis, and in vitro using murine RAW 264.7 macrophages. Transcriptomic profiling of regenerating fin blastemas at 24 hours postamputation was performed to identify the affected molecular pathways. Results: In zebrafish, SKLT treatment suppressed the recruitment of osteoclast precursors and altered mineralization dynamics. Transcriptomic profiling revealed downregulation of genes involved in inflammation, antigen presentation, T-cell activation, and macrophage commitment towards osteoclastogenesis, accompanied by reduced expression of chemokines and cytokines that promote osteoclast precursor recruitment and fusion. In medaka, SKLT significantly reduced vertebral bone loss and enhanced neural arch mineralization in larvae with high RANKL expression. In vitro, SKLT inhibited proliferation and osteoclastic differentiation of murine RAW 264.7 macrophages exposed to RANKL without inducing cytotoxicity. Conclusion: These findings identify S. costatum as a source of bioactive immunomodulatory compounds capable of interfering with key osteoimmune mechanisms. Beyond providing proof of concept for their therapeutic potential in bone erosive disorders, this work opens avenues for isolating and characterizing the active molecules, optimizing their delivery, and evaluating their efficacy in preclinical mammalian models. Such strategies could expand the repertoire of safe, nutraceutical-based or adjuvant therapies for osteoporosis and other inflammation-driven skeletal diseases, complementing and potentially enhancing current antiresorptive and anabolic treatments.
- Lipidomic fingerprinting of the red seaweed Asparagopsis spp. evidencing specific profiling in gametophyte and tetrasporophyte life stagesPublication . Lopes, Diana; Rey, Felisa; Melo, Tânia; Pinho, Marisa; Moreira, Ana S.P.; Pes, Katia; Mata, Leonardo; Domingues, M. RosárioIn recent years, there has been a growing interest in seaweed biomass for multiple industrial applications due to their broad spectrum of high-value nutrients and bioactive metabolites. Seaweed lipids, and particularly the polar lipids, are a source of polyunsaturated fatty acids (PUFA), which have been reported to possess various biological activities, and are a sustainable alternative to fish oils. However, the profile of polar lipids in seaweeds is still understudied and therefore it is crucial to expand the knowledge of the lipidome of seaweeds, particularly of those with commercial potential, including the invasive species such as Asparagopsis sp. These invasive species produce a large biomass, making it a sustainable strategy for reducing its abundance, which would result in both environmental and economic benefits. This study aimed to comprehensively characterize the fatty acids and polar lipid profile of the two Asparagopsis species (A. armata and A. taxiformis), across two life stages (gametophyte and tetrasporophyte) and two different origins (wild and cultivated), using highly sensitive mass spectrometry-based approaches. Our study provides the first detailed characterization of the polar lipidome of Asparagopsis species and revealed that the gametophyte stage exhibited a greater number of polar lipid species than the tetrasporophyte stage. The phosphatidylcholine and the sulfoquinovosyl-diacylglycerol classes are the most abundant in all the samples studied. Although the lipidome of A. armata and A. taxiformis from the gametophyte stage showed similar distributions, variations in the relative abundance of lipid molecular species were observed. The statistical analysis of all A. armata specimens revealed that the lipid profile of samples from the same life stage were similar, regardless of their distinct origin (i.e., wild and cultivated). Furthermore, several polar lipid species with reported bioactivity were identified in Asparagopsis spp., providing insights into the lipid composition of these invasive species and their potential for further biotechnological applications. However, given the low absolute content of lipids in Asparagopsis species, it is unlikely to be viable to use nuisance or farmed biomass as a source of lipids alone.