Bio-plastic recognition by mussels hemocytes

The growing use of bio-polymers derivatives poses an increasingly pressing problem regarding their environmental sustainability. In particular, it should be still ascertained the claimed absence of direct and indirect influence on ecosystems and the health of living organisms, including humans. Our goal was about assessing the potential effects of poly-lactates and polyhydroxyalkanoates, the most widely used bio polymers classes with promising different applications for replacing conventional plastics on natural aquatic environments. We chose M. galloprovincialis as sentinel species since their extensive filter-feeding activity. When it is exposed to microparticles can bioaccumulate them in…

METHYLMERCURY EFFECTS ON Mytilus galloprovincialis HAEMOCYTES ACTIVITY

Bivalves, filter-feeding organisms, due to their wide distri-bution, are used by many countries in biomonitoring, particu-larly in the assessment of xenobiotics in the marine ecosystem.These sentinel organisms are able to accumulate trace metalsand other substances in their tissues. Haemocytes are effectorsof cellular immunity in bivalves and are capable of respond-ing to stressors through activities such as phagocytosis or cyto-toxicity. In order to identify cellular markers to investigate pol-lution, the effect of different concentrations of organic mercury(CH3HgCl) on the morphology and responses of Mytilus gal-loprovincialishaemocytes was studied in this work. Sublethalconcentrations of…

INFLAMMATION AND TENTACLE REGENERATION RESPONSES IN ANEMONIA VIRIDIS (ANTHOZOA, CNIDARIA)

Mesoglea Extracellular Matrix Reorganization during Regenerative Process in Anemonia viridis (Forskål, 1775)

Given the anatomical simplicity and the extraordinary ability to regenerate missing parts of the body, Cnidaria represent an excellent model for the study of the mechanisms regulating regenerative processes. They possess the mesoglea, an amorphous and practically acellular extracellular matrix (ECM) located between the epidermis and the gastrodermis of the body and tentacles and consists of the same molecules present in the ECM of vertebrates, such as collagen, laminin, fibronectin and proteoglycans. This feature makes cnidarians anthozoans valid models for understanding the ECM role during regenerative processes. Indeed, it is now clear that its role in animal tissues is not just tissue su…

Study of immunotoxicity responses of Sabella spallanzanii exposed to copper sulphate

Inflammation events occurring upon bacterial infection in Mytilus galloprovincialis

Bivalves, and in particular the Mediterranean Mytilus galloprovincialis are important sources of food in several countries in the world. Because of that, mussels farming has a strong economic impact. Due to their status as sessile and filter-feeding animals, bivalves accumulate in their tissues environmental pollutants and a larger amount of microorganisms and between these, a multitude of infective bacteria for higher vertebrates and humans, such as Vibrio species. Several immunological responses of M. galloprovincialis were investigated and described after Vibrio infection both, in vitro and in vivo conditions, such as hemocytes count and different cellular subpopulations. Particularly, i…

The multiple potentialities of anthozoans: analyses and comparisons between animal models

Anthozoans are the richest class of species of the phylum Cnidaria. They are a candidate group for studying the evolution of mutualisms and immunity and despite their morphological simplicity exhibit a repertoire of immunological components with large genomes and gene families similar to those of the Bilateria. Like other invertebrates, anthozoans immunity is based on self/non-self recognition mechanisms and allorecognition responses, therefore, maintaining their integrity and responding actively to selection pressures. Highlight and investigate the link between innate immunity, homeostasis maintenance, inflammation, tissue remodelling and regeneration in Anthozoa could be useful to elucida…

Actinins as novel broad-spectrum AMP isolated from the tentacle of Anthozoan Actinia equina (Linnaeus, 1758)

Capturing activities and defense mechanisms of Cnidarian are strongly associated with toxins and peptide with antimicrobial properties. AMP are an important component of many organisms’ innate immune system with a good inhibitory or killing effect against invaders pathogens. We investigated the AMP activity of acid extracts obtained from tentacle and body of Actinia equina (Cnidaria, Anthozoa) against Gram positive (Micrococcus lysodeikticus) and Gram negative (Escherichia coli, Vibrio alginolyticus) bacteria. The peptide fractions showed interesting minimum inhibitory concentrations (MIC) values (concentrations up to 0.125 μg/ml) against tested pathogens. Tentacle acid extracts exhibiting …

Effects of organic mercury on Mytilus galloprovincialis hemocyte function and morphology

Abstract Filter-feeding organisms accumulate xenobiotics and other substances in their tissues. They can be useful as sentinel organisms in biomonitoring of the marine compartment. Bivalve cellular immunity is ensured by phagocytosis and cytotoxic reactions carried out by hemocytes in a network with humoral responses. These can be affected by chemical contaminants in water that can be immunosuppressors also at a low concentration increasing the sensibility to pathogens. This work is an attempt to individuate cellular markers for pollution detection, investigating the effect of methylmercury (CH3HgCl) at different concentrations on the activity and hemocyte morphology of the Mediterranean m…

Step-by-Step Regeneration of Tentacles after Injury in Anemonia viridis—Morphological and Structural Cell Analyses

Benthic marine invertebrates, such as corals, are often subjected to injury caused by several sources. Here, the differences and characteristics in injured and health tissues in terms of cellular components are shown through a histological investigation of the soft coral Anemonia viridis at 0 h, 6 h, 24 h, and 7 days after injury caused by tentacle amputation. In addition, a new tool was used for the first time in invertebrates, positron emission tomography, in order to investigate the events that occur during regeneration within a longer time period (0 h, 24 h, and 14 days after the tentacles were cut). Higher integrated density values were measured through a densitometric analysis in sect…

F-type lectin from serum of the Antarctic teleost fish Trematomus bernacchii (Boulenger, 1902): Purification, structural characterization, and bacterial agglutinating activity.

Abstract The increasing availability of sequenced genomes has enabled a deeper understanding of the complexity of fish lectin repertoires involved in early development and immune recognition. The teleost fucose-type lectin (FTL) family includes proteins that preferentially bind fucose and display tandemly arrayed carbohydrate-recognition domains (CRDs) or are found in mosaic combinations with other domains. They function as opsonins, promoting phagocytosis and the clearance of microbial pathogens. The Antarctic fish Trematomus bernacchii is a Perciforme living at extremely low temperatures (−1.68 °C) which is considered a model for studying adaptability to the variability of environmental w…

Invertebrate Models in Innate Immunity and Tissue Remodeling Research

The aim of this Special Issue is to highlight the close functional and highly conserved link between innate immunity, homeostasis maintenance, inflammation, tissue remodeling and regeneration [...]

Response of Sabella spallanzanii to multiple stressors. The combined effect of infection and copper sulphate

The aim of this work is to study the immune responses of the polychaete Sabella spallanzanii after exposure to copper sulphate, an immunomodulating agent in marine organisms, and the multiple stresses caused by Escherichia coli infection, to validate the species as a model organism in marine-coastal biomonitoring programmes. Polychaetes were housed in laboratory and divided into five experimental groups: 1. Control (no microinjected), 2. filtered seawater + TBS injection (control of point 3), 3. filtered seawater + E. coli injection (control of point 4), 4. CuSO4 + TBS injection (control of point 5), and 5. CuSO4 + E. coli injection. The immune variables, esterase and alkaline phosphatase a…