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- Gla portein localization and histological characterization of bone stuctures in relevant aquaculture fishPublication . Roberto, Vania Palma; Cancela, Maria Leonor; Gavaia, PauloOsteocalcin (Oc) and Matrix Gia Protein (MGP) are vitamin K-dependente proteins known for their Ca2" binding capacity. Considering the problem of skeletal malformations in Mediterranean fish aquaculture, we investigated a possible correlation between vertebral deformities and changes of Oc and Mgp accumulation sites. ln this work we proposed to characterize bony and cartilaginous tissues from important fish for aquaculture, using molecular tools. The sites of gene expression and accumulation of osteocalcin and Mgp were investigated throughout Northern blot analysis and immunohistochemistry, following the cloning of those cDNAs not yet available, together with histological analysis. ln Scophthalmus maximus, oc mRNA was detected in vertebrae and branchial arches while mgp mRNA was highly expressed in branchial arches, followed by vertebrae, kidney and heart. ln S. maximus and Diplodus sargus, Mgp accumulated in chondrocytes from cartilages, in the vertebral mineralizing fronts and in notochord cells. Mgp was also found in scales of D. sargus. Ocaccumulated mainly in bone tissues, like the ceratobranchial bone and vertebral bone matrix. ln cultured Sparus aurata, Mgp accumulated mainly in vertebrae growth zones and in notochord cells while Oc was immunodetected in bone matrix of vertebrae and vertebral arches, both in non-deformed and in deformed vertebrae. We also identified Oc in the non-calcified notochord cells of deformed vertebrae, suggesting that abnormal skeletal development resulted in modifications on sites of osteocalcin expression and/or accumulation. Accordingly, histological analysis of normal and deformed vertebrae revealed calcification in blood vessel walls and pathological formation of chondroid bone, in the affected area of deformed vertebrae.
- Mgp expression and accumulation in heart and kidney of turbot (Scophthalmus maximus)Publication . Roberto, Vania Palma; Cavaco, S.; Simes, D; Gavaia, Paulo J.; Cancela, LeonorMatrix γ-carboxyglutamic acid (Gla) protein (Mgp) is a vitamin K-dependent protein normally found associated with the organic matrix of cartilage and bone in vivo. After the discovery of Mgp in various soft tissues, this protein was proposed to act as a local inhibitor of mineralization although its molecular mechanisms of action remain incompletely understood.
- Matrix gla protein in turbot (Scophthalmus maximus): gene expression analysis and identification of sites of protein accumulationPublication . Roberto, Vania Palma; Cavaco, S.; S B Viegas, Carla; Simes, D; Ortiz-Delgado, J. B.; Sarasquete, C.; Gavaia, Paulo J.; Cancela, LeonorMatrix Gla protein (Mgp) is a secreted vitamin K-dependent extracellular matrix protein and a physiological inhibitor of calcification whose gene structure, amino acid sequence and tissue distribution have been conserved throughout evolution. In the present work, the turbot (Scophthalmus maximus) mgp cDNA was cloned and the sequence of the deduced protein compared to that of other vertebrates. As expected, it was closer to teleosts than to other vertebrate groups but there was a strict conservation of amino-acids thought to be important for protein function. Analysis of mgp gene expression indicated branchial arches as the site with higher levels of expression, followed by heart, vertebra and kidney. These results were confirmed by in situ hybridization with a strong mgp expression in branchial arch chondrocytes. Mgp was found to accumulate in gills where it appeared to be restricted to chondrocytes from branchial filaments, while in vertebrae it was localized in vertebral end plates, in growth zones, in vertebral arches and spines and in notochord cells. In the soft tissues analysed, Mgp was mainly detected in kidney and heart, consistent with previous data and providing further evidence for a role of Mgp as a calcification inhibitor and a modulator of the mineralization process. Our studies provide evidence that turbot, an important new species for aquaculture, is also a useful model to study function and expression of Mgp.
- Evidence for the conservation of miR-223 in zebrafish (Danio rerio): implications for functionPublication . Roberto, Vania Palma; Tiago, Daniel; Gautvik, K.; Cancela, M. LeonorMicroRNAs (miRNAs) are an abundant and conserved class of small RNAs, which play important regulatory functions by interacting with the 3' untranslated region (UTR) of target mRNAs. Through this mechanism, miR-223 was shown to regulate genes involved in mammalian haematopoiesis, both in physiological and pathological contexts. MiR-223 is essential for normal myelopoiesis in mammals, promoting granulocyte, osteoclast and megakaryocyte differentiation and suppressing erythropoiesis. However, there is a general lack of knowledge regarding miR-223 function in other vertebrates, which could help to clarify its role in other processes, such as development. In this work, we explored the functional conservation of miR-223 using zebrafish as a model. We show that miR-223 gene structure and genomic context have been maintained between human and zebrafish. In addition, we identified 22 novel sequences of miR-223 precursor and demonstrate that it contains domains highly conserved among vertebrates, suggesting function preservation throughout evolution. Furthermore, collected evidences show that miR-223 expression is highly correlated with haematopoietic events and osteoclastogenesis throughout zebrafish development. In adults, expression of miR-223 in zebrafish tissues mimics the distribution in mice, with high levels found in the major fish haematopoietic organ, the head kidney. These results suggest a conservation of miR-223 role in haematopoiesis, and osteoclastogenesis between zebrafish and human. Accordingly, validated targets of miR-223 in mammalian models were investigated and defined as putative targets in zebrafish, by in silico and gene expression analysis. Our data compiles critical evidence showing that miR-223, a highly conserved miRNA, appears to have kept similar regulatory functions throughout evolution.
- 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.
- Identification and molecular characterization of bone-related micrornas: functional implicationsPublication . Roberto, Vania Palma; Cancela, Leonor; Tiago, Daniel; Gautvik, KaareMicroRNAs (miRNAs) are a conserved class of small RNAs providing a post-transcriptional mechanism for fine-tuning of intricate physiological and pathological cellular processes, such as those affecting development. Skeletogenesis however, was so far poorly investigated and mainly focused on mammalian models, with a general lack of knowledge concerning other vertebrates. We aimed at the identification of bone-related miRNAs and their characterization from an evolutionary perspective, using fish (mostly zebrafish) as model, in comparison to mammalian systems. First, we focused on miR-223, a miRNA that was associated with bone remodelling. We demonstrated that miR-223 genomic organization/context and primary/secondary structures are largely maintained between human and zebrafish. As in mammals, miR-223 expression in zebrafish was highly correlated with hematopoietic events and osteoclastogenesis. Finally, miR-223 targets identified in mammals were also predicted in zebrafish, supporting a functional conservation of this miRNA. In a second set of experiments, we studied the biological role of miR-29a, a bone-related miRNA that was fairly investigated in mammals, but with no mineralogenic effects yet demonstrated. We took advantage of our fish bone-derived systems to explore miR-29a mineralogenic effects through gain-of-function experiments. We demonstrated a strong stimulation of this process through a mechanism probably involving the canonical Wnt signalling. Once more, through bioinformatics analysis, patterns of expression and target prediction/validation, we provided evidences for miR-29 conservation throughout evolution. Finally, we explored miR-214 putative roles on skeleton formation in vertebrates. Although our initial hypothesis of miR-214 involvement in osteogenesis was recently demonstrated by Wang et al. (2013), we proceeded with our investigation and finally showed that miR-214 is also associated with chondrogenesis. Overexpression of miR-214 in ATDC5 cells mitigated differentiation and down-regulated Mgp and Osteocalcin, probably by targeting Atf4. This work provides novel evidence that some miRNAs have conserved functions across vertebrates and, probably, conserved regulatory mechanisms of action.
- The TERT hypermethylated oncologic region predicts recurrence and survival in pancreatic cancerPublication . Faleiro, Inês; Apolónio, Joana; Price, Aryeh J.; De Mello, Ramon Andrade; Roberto, Vânia; Tabori, Uri; Castelo-Branco, PedroAim: We explore the biomarker potential of the TERT hypermethylated oncologic region (THOR) in pancreatic cancer. Materials & methods: We assessed the methylation status of THOR using the cancer genome atlas data on the cohort of pancreatic cancer (n = 193 patients). Results: THOR was significantly hypermethylated in pancreatic tumor tissue when compared with the normal tissue used as control (p < 0.0001). Also, THOR hypermethylation could distinguish early stage I disease from normal tissue and was associated with worse prognosis. Discussion: We found that THOR is hypermethylated in pancreatic tumor tissue when compared with normal tissue and that THOR methylation correlates with TERT expression in tumor samples. Conclusion: Our preliminary findings support the diagnostic and prognostic values of THOR in pancreatic cancer.
- Evidences for a new role of miR-214 in chondrogenesisPublication . Roberto, Vania Palma; Gavaia, Paulo; Nunes, Maria Joao; Rodrigues, Elsa; M. Leonor Cancela; Tiago, DanielmiR-214 is known to play a role in mammalian skeletal development through inhibition of osteogenesis and stimulation of osteoclastogenesis, but data regarding other vertebrates, as well as a possible role in chondrogenesis, remain unknown. Here, we show that miR-214 expression is detected in bone and cartilage of zebrafish skeleton, and is downregulated during murine ATDC5 chondrocyte differentiation. Additionally, we observed a conservation of the transcriptional regulation of miR-214 primary transcript Dnm3os in vertebrates, being regulated by Ets1 in ATDC5 chondrogenic cells. Moreover, overexpression of miR-214 in vitro and in vivo mitigated chondrocyte differentiation probably by targeting activating transcription factor 4 (Atf4). Indeed, miR-214 overexpression in vivo hampered cranial cartilage formation of zebrafish and coincided with downregulation of atf4 and of the key chondrogenic players sox9 and col2a1. We show that miR-214 overexpression exerts a negative role in chondrogenesis by impacting on chondrocyte differentiation possibly through conserved mechanisms.
- Circulating small non-coding RNAs provide new insights into vitamin K nutrition and reproductive physiology in teleost fishPublication . I, Fernández; Fernandes, Jorge M. O.; Roberto, Vânia; Kopp, Martina; Oliveira, Catarina; Riesco, Marta F.; Dias, Jorge; Cox, Cymon J.; Leonor Cancela, M.; Cabrita, Elsa; Gavaia, PauloBackground: Vitamin K (VK) is a fat-soluble vitamin known for its essential role in blood coagulation, but also on other biological processes (e.g. reproduction, brain and bone development) have been recently suggested. Nevertheless, the molecular mechanisms behind its particular function on reproduction are not yet fully understood. Methods: The potential role of VK on reproduction through nutritional supplementation in Senegalese sole (Solea senegalensis) was assessed by gonadal maturation and 11-ketosterone, testosterone and estriol plasma levels when fed with control or VK supplemented (1250 mg kg(-1) of VK,) diets along a six month trial. At the end, sperm production and quality (viability and DNA fragmentation) were evaluated. Circulating small non-coding RNAs (sncRNAs) in blood plasma from males were also studied through RNA-Seq. Results: Fish fed with dietary VK supplementation had increased testosterone levels and lower sperm DNA fragmentation. SncRNAs from blood plasma were found differentially expressed when nutritional and sperm quality conditions were compared. PiR-675//676//4794//5462 and piR-74614 were found up-regulated in males fed with dietary VK supplementation. Let-7g, let-7e(18nt), let-7a-1, let-7a-3//7a-2//7a-1, let-7e(23nt) and piR-675//676//4794//5462 were found to be up-regulated and miR-146a and miR-146a-1//146a-2//146a-3 down-regulated when fish with low and high sperm DNA fragmentation were compared. Bioinformatic analyses of predicted mRNAs targeted by sncRNAs revealed the potential underlying pathways. Conclusions: VK supplementation improves fish gonad maturation and sperm quality, suggesting an unexpected and complex regulation of the nutritional status and reproductive performance through circulating sncRNAs. General significance: The use of circulating sncRNAs as reliable and less-invasive physiological biomarkers in fish nutrition and reproduction has been unveiled.
- Antioxidant, mineralogenic and osteogenic activities of Spartina alterniflora and Salicornia fragilis extracts rich in polyphenolsPublication . Roberto, Vania Palma; Surget, Gwladys; Le Lann, Klervi; Mira, Sara; Tarasco, Marco; Guérard, Fabienne; Poupart, Nathalie; Laizé, Vincent; Stiger-Pouvreau, Valérie; Cancela, M. LeonorOsteoporosis is an aging-related disease and a worldwide health issue. Current therapeutics have failed to reduce the prevalence of osteoporosis in the human population, thus the discovery of compounds with bone anabolic properties that could be the basis of next generation drugs is a priority. Marine plants contain a wide range of bioactive compounds and the presence of osteoactive phytochemicals was investigated in two halophytes collected in Brittany (France): the invasive Spartina alterniflora and the native Salicornia fragilis. Two semi-purified fractions, prepared through liquid-liquid extraction, were assessed for phenolic and flavonoid contents, and for the presence of antioxidant, mineralogenic and osteogenic bioactivities. Ethyl acetate fraction (EAF) wasrich in phenolic compounds and exhibited the highest antioxidant activity. While S. fragilis EAF only triggered a weak proliferative effect in vitro, S. alterniflora EAF potently induced extracellular matrix mineralization (7-fold at 250µg/mL). A strong osteogenic effect was also observed in vivo using zebrafish operculum assay (2.5-fold at 10µg/mL in 9-dpf larvae). Results indicate that polyphenol rich EAF of S. alterniflora has both antioxidant and bone anabolic activities. As an invasive species, this marine plant may represent a sustainable source of molecules for therapeutic applications in bone disorders.