The Role of the Cephalopod Digestive Gland in the Storage and Detoxification of Marine Pollutants

COST Action FA1301 "A network for improvement of cephalopod welfare and husbandry in research, aquaculture and fisheries (CephsInAction)" The Portuguese Foundation for Science and Technology (FCT) MARE through the strategic programme (UID/MAR/04292/2013; SFRH/BD/109462/2015; IF/00265/2015) GreenTech (PTDC/MARBIO/0113/2014) FCTThe relevance of cephalopods for fisheries and even aquaculture, is raising concerns on the relationship between these molluscs and environmental stressors, from climate change to pollution. However, how these organisms cope with environmental toxicants is far less understood than for other molluscs, especially bivalves, which are frontline models in aquatic toxicology. Although, sharing the same basic body plan, cephalopods hold distinct adaptations, often unique, as they are active predators with high growth and metabolic rates. Most studies on the digestive gland, the analog to the vertebrate liver, focused on metal bioaccumulation and its relation to environmental concentrations, with indication for the involvement of special cellular structures (like spherulae) and proteins. Although the functioning of phase I and II enzymes of detoxification in molluscs is controversial, there is evidence for CYP-mediated bioactivation, albeit with lower activity than vertebrates, but this issue needs yet much research. Through novel molecular tools, toxicology-relevant genes and proteins are being unraveled, from metallothioneins to heat-shock proteins and phase II conjugation enzymes, which highlights the importance of increasing genomic annotation as paramount to understand toxicant-specific pathways. However, little is known on how organic toxicants are stored, metabolized and eliminated, albeit some evidence from biomarker approaches, particularly those related to oxidative stress, suggesting that these molluscs' digestive gland is indeed responsive to chemical aggression. Additionally, cause-effect relationships between pollutants and toxicopathic effects are little understood, thus compromising, if not the deployment of these organisms for biomonitoring, at least understanding how they are affected by anthropogenically-induced global change.publishersversionpublishe

An integrative assessment to determine the genotoxic hazard of estuarine sediments: combining cell and whole-organism responses

The application of the Comet assay in environmental monitoring remains challenging in face of the complexity of environmental stressors, e.g., when dealing with estuarine sediments, that hampers the drawing of cause-effect relationships. Although the in vitro Comet assay may circumvent confounding factors, its application in environmental risk assessment (ERA) still needs validation. As such, the present work aims at integrating genotoxicity and oxidative DNA damage induced by sediment-bound toxicants in HepG2 cells with oxidative stress-related effects observed in three species collected from an impacted estuary. Distinct patterns were observed in cells exposed to crude mixtures of sediment contaminants from the urban/industrial area comparatively to the ones from the rural/riverine area of the estuary, with respect to oxidative DNA damage and oxidative DNA damage. The extracts obtained with the most polar solvent and the crude extracts caused the most significant oxidative DNA damage in HepG2 cells, as measured by the formamidopyrimidine-DNA glycosylase (FPG)-modified Comet assay. This observation suggests that metals and unknown toxicants more hydrophilic than polycyclic aromatic hydrocarbons may be important causative agents, especially in samples from the rural part of the estuary, where oxidative DNA damage was the most significant. Clams, sole, and cuttlefish responded differentially to environmental agents triggering oxidative stress, albeit yielding results accordant with the oxidative DNA damage observed in HepG2 cells. Overall, the integration of in vivo biomarker responses and Comet assay data in HepG2 cells yielded a comparable pattern, indicating that the in vitro FPG-modified Comet assay may be an effective and complementary line-of-evidence in ERA even in particularly challenging, natural, scenarios such as estuarine environments

A Transcriptomic Approach to the Recruitment of Venom Proteins in a Marine Annelid

CEECIND/02699/2017The growing number of known venomous marine invertebrates indicates that chemical warfare plays an important role in adapting to diversified ecological niches, even though it remains unclear how toxins fit into the evolutionary history of these animals. Our case study, the Polychaeta Eulalia sp., is an intertidal predator that secretes toxins. Whole-transcriptome sequencing revealed proteinaceous toxins secreted by cells in the proboscis and delivered by mucus. Toxins and accompanying enzymes promote permeabilization, coagulation impairment and the blocking of the neuromuscular activity of prey upon which the worm feeds by sucking pieces of live flesh. The main neurotoxins ("phyllotoxins") were found to be cysteine-rich proteins, a class of substances ubiquitous among venomous animals. Some toxins were phylogenetically related to Polychaeta, Mollusca or more ancient groups, such as Cnidaria. Some toxins may have evolved from non-toxin homologs that were recruited without the reduction in molecular mass and increased specificity of other invertebrate toxins. By analyzing the phylogeny of toxin mixtures, we show that Polychaeta is uniquely positioned in the evolution of animal venoms. Indeed, the phylogenetic models of mixed or individual toxins do not follow the expected eumetazoan tree-of-life and highlight that the recruitment of gene products for a role in venom systems is complex.publishersversionpublishe

Assessment of sediment contamination in an impacted estuary: differential effects and adaptations of sentinel organisms and implications for biomonitoring

Conferência realizada em Lisboa, de 6-9 November de 2013Estuarine pollution is reflected in the concentration of toxicants in sediments, depending on their geochemical properties, since sediments trap substances from the water column, either dissolved or bound to suspended matter. However, determining risk of sediment contaminants to biota has many constraints. For such reason, integrative approaches are keystone. Taking the Sado estuary (SW Portugal) as a case study, contrasted to a reference estuary (the Mira) within the same geographical location, the present study aimed at integrating sediment contamination with the effects and responses to pollutants in distinct benthic organisms with commercial and ecological value

A Plot for the Visualization of Missing Value Patterns in Multivariate Data.

Missing data patterns are the combinations in which the variables with missing values occur. Exploring these patterns in multivariate data can be very useful but there are few specialized tools. The current paper presents a plot that includes relevant information for visualizing these patterns. The plot is also dynamic-interactive; so, selecting elements in it permits the highlighting of those that are more relevant according to certain criteria. An example, based on college data, is used for the purposes of illustrating the capabilities of the plo

A transcriptomic approach to the metabolism of tetrapyrrolic photosensitizers in a marine annelid

Funding Information: Funding: The authors also acknowledge DPGM (the Portuguese General Directorate for Marine Policy) for funding the MARVEN project (ref. FA_05_2017_007). The Portuguese Foundation for Science and Technology (FCT) funded project WormALL (PTDC/BTA-BTA/28650/2017), which includes the contract attributed to M.D. and the fellowship attributed to A.P.R. UCIBIO and LAQV are financed by national funds from FCT, UID/Multi/04378/2020 and UID/QUI/50006/2020, respectively. Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.The past decade has seen growing interest in marine natural pigments for biotechnological applications. One of the most abundant classes of biological pigments is the tetrapyrroles, which are prized targets due their photodynamic properties; porphyrins are the best known examples of this group. Many animal porphyrinoids and other tetrapyrroles are produced through heme metabolic pathways, the best known of which are the bile pigments biliverdin and bilirubin. Eulalia is a marine Polychaeta characterized by its bright green coloration resulting from a remarkably wide range of greenish and yellowish tetrapyrroles, some of which have promising photodynamic properties. The present study combined metabolomics based on HPLC-DAD with RNA-seq transcriptomics to investigate the molecular pathways of porphyrinoid metabolism by comparing the worm’s proboscis and epidermis, which display distinct pigmentation patterns. The results showed that pigments are endogenous and seemingly heme-derived. The worm possesses homologs in both organs for genes encoding enzymes involved in heme metabolism such as ALAD, FECH, UROS, and PPOX. However, the findings also indicate that variants of the canonical enzymes of the heme biosynthesis pathway can be species-and organ-specific. These differences between molecular networks contribute to explain not only the differential pigmentation patterns between organs, but also the worm’s variety of novel endogenous tetrapyrrolic compounds.publishersversionpublishe

Strength Training Prevents Hyperinsulinemia, Insulin Resistance, And Inflammation Independent Of Weight Loss In Fructose-fed Animals

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)The aim of this study was to compare the effects of aerobic, strength, and combined training on metabolic disorders induced by a fructose-rich diet. Wistar rats (120 days old) were randomized into five groups (n = 8-14): C (control diet and sedentary), F (fed the fructose-rich diet and sedentary), FA (fed the fructose-rich diet and subject to aerobic exercise), FS (fed the fructose-rich diet and subject to strength exercise), and FAS (fed the fructose-rich diet and subject to combined aerobic and strength exercises). After the 8-week experiment, glucose homeostasis, blood biochemistry, tissue triglycerides, and inflammation were evaluated and analyzed. The strength protocol exerted greater effects on glucose homeostasis, insulin sensitivity, and liver lipid contents than other protocols (all P < 0.05). All three exercise protocols induced a remarkable reduction in inflammation, tissue triglyceride content, and inflammatory pathways, which was achieved through c-Jun NH2-terminal kinase (JNK) phosphorylation and factor nuclear kappa B (NFkB) activation in both the liver and the muscle. Our data suggest that strength training reduced the severity of most of the metabolic disorders induced by a fructose-rich diet and could be the most effective strategy to prevent or treat fructose-induced metabolic diseases.6Brazilian foundation FAPESP [2013/20293-2, 2013/21491-2, 2016/14380-8]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Specific Antiproliferative Properties of Proteinaceous Toxin Secretions from the Marine Annelid Eulalia sp. onto Ovarian Cancer Cells

The Portuguese Foundation for Science and Technology (FCT) funded project WormALL (PTDC/BTA-BTA/28650/2017) plus the grants SFRH/BD/109462/2015 to A.P.R., and CEECIND/02699/2017 to A.R.G. The Applied Molecular Biosciences Unit-UCIBIO is financed by national funds from FCT, ref. UIDB/04378/2020. FCT, along with the European Regional Development Fund (ERDF) through the COMPETE 2020-Operational Programme for Competitiveness and Internationalisation also funded the projects: POCI-01-0145-FEDER-007440 (UID/NEU/04539/2019), POCI-01-0145-FEDER-016428 (SAICTPAC/0010/2015), POCI-01-0145-FEDER-029311 (PTDC/BTM-TEC/29311/2017), POCI-01-0145-FEDER-30943 (PTDC/MEC-PSQ/30943/2017) and PTDC/MED-NEU/27946/2017. The work was also funded by the National Mass Spectrometry Network (RNEM) under the contract POCI-01-0145-FEDER-402-022125 (ref.: ROTEIRO/0028/2013).As Yondelis joins the ranks of approved anti-cancer drugs, the benefit from exploring the oceans' biodiversity becomes clear. From marine toxins, relevant bioproducts can be obtained due to their potential to interfere with specific pathways. We explored the cytotoxicity of toxin-bearing secretions of the polychaete Eulalia onto a battery of normal and cancer human cell lines and discovered that the cocktail of proteins is more toxic towards an ovarian cancer cell line (A2780). The secretions' main proteins were identified by proteomics and transcriptomics: 14-3-3 protein, Hsp70, Rab3, Arylsulfatase B and serine protease, the latter two being known toxins. This mixture of toxins induces cell-cycle arrest at G2/M phase after 3h exposure in A2780 cells and extrinsic programmed cell death. These findings indicate that partial re-activation of the G2/M checkpoint, which is inactivated in many cancer cells, can be partly reversed by the toxic mixture. Protein-protein interaction networks partake in two cytotoxic effects: cell-cycle arrest with a link to RAB3C and RAF1; and lytic activity of arylsulfatases. The discovery of both mechanisms indicates that venomous mixtures may affect proliferating cells in a specific manner, highlighting the cocktails' potential in the fine-tuning of anti-cancer therapeutics targeting cell cycle and protein homeostasis.publishersversionpublishe

Topological Superconductor from the Quantum Hall Phase: Effective Field Theory Description

We derive low-energy effective field theories for the quantum anomalous Hall and topological superconducting phases. The quantum Hall phase is realized in terms of free fermions with nonrelativistic dispersion relation, possessing a global $U(1)$ symmetry. We couple this symmetry with a background gauge field and compute the effective action by integrating out the gapped fermions. In spite of the fact that the corresponding Dirac operator governing the dynamics of the original fermions is nonrelativistic, the leading contribution in the effective action is a usual Abelian $U(1)$ Chern-Simons term. The proximity to a conventional superconductor induces a pairing potential in the quantum Hall state, favoring the formation of Cooper pairs. When the pairing is strong enough, it drives the system to a topological superconducting phase, hosting Majorana fermions. Even though the continuum $U(1)$ symmetry is broken down to a $\mathbb{Z}_2$ one, we can forge fictitious $U(1)$ symmetries that enable us to derive the effective action for the topological superconducting phase, also given by a Chern-Simons theory. To eliminate spurious states coming from the artificial symmetry enlargement, we demand that the fields in the effective action are $O(2)$ instead of $U(1)$ gauge fields. In the $O(2)$ case we have to sum over the $\mathbb{Z}_2$ bundles in the partition function, which projects out the states that are not $\mathbb{Z}_2$ invariants. The corresponding edge theory is the $U(1)/\mathbb{Z}_2$ orbifold, which contains Majorana fermions in its operator content.Comment: 40 pages, 5 figures, journal versio