Manganese: A New Emerging Contaminant in the Environment

Physiolog

Dosi citotossiche di manganese ed effetti sullo sviluppo embrionale. Modello sperimentale: Riccio di mare Paracentrotus lividus

DOSI CITOTOSSICHE DI MANGANESE ED EFFETTI SULLO SVILUPPO EMBRIONALE. MODELLO SPERIMENTALE: RICCIO DI MARE PARACENTROTUS LIVIDUS Annalisa Pinsino1, Francesca Trinchella2, Maria Carmela Roccheri1 1 Dipartimento di Biologia Cellulare e dello Sviluppo “A. Monroy”, Università degli Studi di Palermo, Italia 2 Dipartimento delle Scienze Biologiche, Università degli Studi di Napoli Federico II, Italia Il manganese (Mn) è uno degli elementi più abbondanti in natura, presente nelle rocce, nel suolo e nelle acque. E’ un elemento in traccia appartenente alla categoria dei nutrienti o metalli essenziali; utilizzato ed accumulato da tutte le forme di vita, è coinvolto nel normale funzionamento di meccanismi cellulari come la replicazione, la mineralizzazione e la protezione cellulare. D’altro canto, se la sua presenza è fondamentale per la vita, l’esposizione di cellule/organismi ad elevate concentrazioni di Mn causa tossicità. Il manganese rappresenta oggi, un “nuovo” importante fattore di contaminazione ambientale, conseguenza dell’intensa attività antropica dell’ultimo secolo. Il trattamento di embrioni di riccio di mare della specie Paracentrotus lividus con dosi citotossiche di Mn influisce sullo sviluppo embrionale producendo un alternativo morfotipo di sviluppo, attivando le principali MAPK (ERK e p38) coinvolte sia nella regolazione dello sviluppo che nello stress, provocando una modulazione nei livelli di sintesi delle principali proteine da stress HSC70 e HSC60. Nello specifico, troviamo che dosi crescenti di Mn (da 7,7 a 61,6 mg/L) provocano ritardi e malformazioni nello sviluppo embrionale secondo un andamento dose-effetto, chiaramente caratterizzato dall’aumento in frequenza del numero di embrioni con totale assenza o ridotto allungamento dello scheletro di CaCO3 (spicole). Il processo di spicologenesi sembra comunque ripristinarsi quando il Mn viene allontanato dal mezzo di coltura, per i diversi tempi di trattamento/ sviluppo, anche se dopo 40 ore di trattamento gli embrioni non riescono a recuperare il corretto disegno della struttura scheletrica. Mediante l’uso di marcatori territorio-specifici per i tre foglietti embrionali già differenziati in ecto-, meso- ed endoderma (anticorpi monoclonali Ecto V, UH2-95, 1D5) è stato osservato che tutti gli antigeni specifici per i vari territori sono presenti, sia negli embrioni controllo che negli embrioni trattati (61,6 mg Mn/L), in una posizione spaziale e per un tempo di sviluppo appropriato. Invece, le ibridazioni in situ per i trascritti codificanti per msp130, sm30 ed sm50 (geni espressi esclusivamente nelle cellule deputate alla secrezione delle spicole, PMC), hanno messo in evidenza, per i trattati, una forte inibizione nei livelli di espressione di sm30, l’unico dei tre geni che risponde a segnali mediati dalla matrice extracellulare. Inoltre, ERK e p38 rimangono nella forma fosforilata per tutto lo sviluppo degli embrioni trattati: questo risultato potrebbe dipendere da una quantità di calcio fisiologico non sufficiente a regolare gli eventi di fosfo-/defosforilazione delle MAPK, dovuto all’accumulo di Mn negli embrioni (AAS analisi). Per concludere l’accumulo di Mn negli embrioni di P. lividus stimola una duplice soluzione adattativa: attivazione di una risposta da stress e regolazione di pathways alternativi per consentire il proseguo dello sviluppo. http://www.unisi.it/eventi/gei/programma.pd

Immunomodulatory Function of Polyvinylpyrrolidone (PVP)-Functionalized Gold Nanoparticles in Vibrio -Stimulated Sea Urchin Immune Cells

We investigated the role of the gold nanoparticles functionalized with polyvinylpyrrolidone (PVP-AuNPs) on the innate immune response against an acute infection caused by Vibrio anguillarum in an in vitro immunological nonmammalian next-generation model, the sea urchin Paracentrotus lividus. To profile the immunomodulatory function of PVP-AuNPs (0.1 μg mL −1) in sea urchin immune cells stimulated by Vibrio (10 μg mL −1) for 3 h, we focused on the baseline immunological state of the donor, and we analysed the topography, cellular metabolism, and expression of human cell surface antigens of the exposed cells, as well as the signalling leading the interaction between PVP-AuNPs and the Vibrio -stimulated cells. PVP-AuNPs are not able to silence the inflammatory signalling (TLR4/p38MAPK/NF-κB signalling) that involves the whole population of P. lividus immune cells exposed to Vibrio. However, our findings emphasise the ability of PVP-AuNPs to stimulate a subset of rare cells (defined here as Group 3) that express CD45 and CD14 antigens on their surface, which are known to be involved in immune cell maturation and macrophage activation in humans. Our evidence on how PVP-AuNPs may stimulate sea urchin immune cells represents an important starting point for planning new research work on the topic

Methodological Approaches To Assess Innate Immunity and Innate Memory in Marine Invertebrates and Humans

open8Assessing the impact of drugs and contaminants on immune responses requires methodological approaches able to represent real-life conditions and predict long-term effects. Innate immunity/inflammation is the evolutionarily most widespread and conserved defensive mechanism in living organisms, and therefore we will focus here on immunotoxicological methods that specifically target such processes. By exploiting the conserved mechanisms of innate immunity, we have examined the most representative immunotoxicity methodological approaches across living species, to identify common features and human proxy models/assays. Three marine invertebrate organisms are examined in comparison with humans, i.e., bivalve molluscs, tunicates and sea urchins. In vivo and in vitro approaches are compared, highlighting common mechanisms and species-specific endpoints, to be applied in predictive human and environmental immunotoxicity assessment. Emphasis is given to the 3R principle of Replacement, Refinement and Reduction of Animals in Research and to the application of the ARRIVE guidelines on reporting animal research, in order to strengthen the quality and usability of immunotoxicology research data.openAuguste, Manon; Melillo, Daniela; Corteggio, Annunziata; Marino, Rita; Canesi, Laura; Pinsino, Annalisa; Italiani, Paola; Boraschi, DianaAuguste, Manon; Melillo, Daniela; Corteggio, Annunziata; Marino, Rita; Canesi, Laura; Pinsino, Annalisa; Italiani, Paola; Boraschi, Dian

Titanium dioxide nanoparticles temporarily influence the sea urchin immunological state suppressing inflammatory-relate gene transcription and boosting antioxidant metabolic activity.

Abstract Titanium dioxide nanoparticles (TiO2NPs) are revolutionizing biomedicine due to their potential application as diagnostic and therapeutic agents. However, the TiO2NP immune-compatibility remains an open issue, even for ethical reasons. In this work, we investigated the immunomodulatory effects of TiO2NPs in an emergent proxy to human non-mammalian model for in vitro basic and translational immunology: the sea urchin Paracentrotus lividus. To highlight on the new insights into the evolutionarily conserved intracellular signaling and metabolism pathways involved in immune-TiO2NP recognition/interaction we applied a wide-ranging approach, including electron microscopy, biochemistry, transcriptomics and metabolomics. Findings highlight that TiO2NPs interact with immune cells suppressing the expression of genes encoding for proteins involved in immune response and apoptosis (e.g. NF-κB, FGFR2, JUN, MAPK14, FAS, VEGFR, Casp8), and boosting the immune cell antioxidant metabolic activity (e.g. pentose phosphate, cysteine-methionine, glycine-serine metabolism pathways). TiO2NP uptake was circumscribed to phagosomes/phagolysosomes, depicting harmless vesicular internalization. Our findings underlined that under TiO2NP-exposure sea urchin innate immune system is able to control inflammatory signaling, excite antioxidant metabolic activity and acquire immunological tolerance, providing a new level of understanding of the TiO2NP immune-compatibility that could be useful for the development in Nano medicines

Stem Cells and Innate Immunity in Aquatic Invertebrates: Bridging Two Seemingly Disparate Disciplines for New Discoveries in Biology

The scopes related to the interplay between stem cells and the immune system are broad and range from the basic understanding of organism's physiology and ecology to translational studies, further contributing to (eco)toxicology, biotechnology, and medicine as well as regulatory and ethical aspects. Stem cells originate immune cells through hematopoiesis, and the interplay between the two cell types is required in processes like regeneration. In addition, stem and immune cell anomalies directly affect the organism's functions, its ability to cope with environmental changes and, indirectly, its role in ecosystem services. However, stem cells and immune cells continue to be considered parts of two branches of biological research with few interconnections between them. This review aims to bridge these two seemingly disparate disciplines towards much more integrative and transformative approaches with examples deriving mainly from aquatic invertebrates. We discuss the current understanding of cross-disciplinary collaborative and emerging issues, raising novel hypotheses and comments. We also discuss the problems and perspectives of the two disciplines and how to integrate their conceptual frameworks to address basic equations in biology in a new, innovative way

Addressing nanomaterial immunosafety by evaluating innate immunity across living species

The interaction of a living organism with external foreign agents is a central issue for its survival and adaptation to the environment. Nanosafety should be considered within this perspective, and it should be examined that how different organisms interact with engineered nanomaterials (NM) by either mounting a defensive response or by physiologically adapting to them. Herein, the interaction of NM with one of the major biological systems deputed to recognition of and response to foreign challenges, i.e., the immune system, is specifically addressed. The main focus is innate immunity, the only type of immunity in plants, invertebrates, and lower vertebrates, and that coexists with adaptive immunity in higher vertebrates. Because of their presence in the majority of eukaryotic living organisms, innate immune responses can be viewed in a comparative context. In the majority of cases, the interaction of NM with living organisms results in innate immune reactions that eliminate the possible danger with mechanisms that do not lead to damage. While in some cases such interaction may lead to pathological consequences, in some other cases beneficial effects can be identified

Probing the immune responses to nanoparticles across environmental species. A perspective of the EU Horizon 2020 project PANDORA

Understanding how engineered nanomaterials affect immune responses of living organisms requires a strong collaborative effort between immunologists, toxicologists, ecologists, physiologists, inorganic chemists, nanomaterial scientists and experts in law and risk management. This perspective aims to provide a new viewpoint on the interaction between engineered nanomaterials and the immune defensive systems across living species, gained within the EU Horizon 2020 project PANDORA. We consider the effects of nanoparticle exposure on immune functions in plants, marine and terrestrial invertebrates and their relation to the current state of knowledge for vertebrates (in particular humans). These studies can shed light on the broader perspective of defensive and homeostatic mechanisms (immunity, inflammation, stress responses, microbiota, stem cell differentiation) suggesting ways to: i) perform a comparative analysis of the nanoparticle impact on immunity across model organisms; ii) inspire best practices in experimental methodologies for nanosafety/nanotoxicity studies; iii) regroup and harmonise fragmented research activities; iv) improve knowledge transfer strategies and nano-security; v) propose innovative tools and realistic solutions, thereby helping in identifying future research needs and tackling their challenges