An integrated study of molecular, cellular, tissue level and transgenerational effects of silver nanoparticles on dietarily exposed mussels at different seasons.

266 p.Las nanopartículas de plata (NPs de Ag) se encuentran en numerosos productos de consumo debido a sus propiedades antimicrobianas así como a otras propiedades únicas que presentan. Por ello, la preocupación acerca de su entrada en los ecosistemas acuáticos está creciendo. La toxicidad de las NPs de Ag ya se está estudiando en organismos acuáticos, sin embargo, apenas hay estudios que evalúen su posible toxicidad tras la ingestión a través de la dieta, especialmente a concentraciones ambientalmente relevantes. Además. la posibilidad de que estos efectos difieran dependiendo de la estación del año sigue siendo desconocida. Por tanto, el objetivo de la presente tesis doctoral ha sido ampliar el conocimiento sobre las respuestas a nivel molecular, celular y tisular, así como los efectos tr ansgeneracionales causados por las NPs de Ag inger idas a través de la dieta y a dosis cercanas a concentraciones ambientalmente relevantes en los mejillones de Mytilus galloprovincialis expuestos en dos estaciones del año diferentes (otoño y primavera). En general, considerando todas las respuestas medidas en los diferentes niveles de organización biológica tanto en otoño como en primavera, los efectos observados en los mejillones dependieron del tiempo de exposición, la concentración de NPs de Ag y la estación del año. Por lo tanto, para futuros estudios, la estación del año es un factor que debe ser considerado a la hora de evaluar los posibles efectos de NPs manufacturadas en bivalvos marinos. especialmente en hembras y especialmente en estudios a nivel de transcripción génica y expresión proteica

An integrated study of molecular, cellular, tissue level and transgenerational effects of silver nanoparticles on dietarily exposed mussels at different seasons.

266 p.Las nanopartículas de plata (NPs de Ag) se encuentran en numerosos productos de consumo debido a sus propiedades antimicrobianas así como a otras propiedades únicas que presentan. Por ello, la preocupación acerca de su entrada en los ecosistemas acuáticos está creciendo. La toxicidad de las NPs de Ag ya se está estudiando en organismos acuáticos, sin embargo, apenas hay estudios que evalúen su posible toxicidad tras la ingestión a través de la dieta, especialmente a concentraciones ambientalmente relevantes. Además. la posibilidad de que estos efectos difieran dependiendo de la estación del año sigue siendo desconocida. Por tanto, el objetivo de la presente tesis doctoral ha sido ampliar el conocimiento sobre las respuestas a nivel molecular, celular y tisular, así como los efectos tr ansgeneracionales causados por las NPs de Ag inger idas a través de la dieta y a dosis cercanas a concentraciones ambientalmente relevantes en los mejillones de Mytilus galloprovincialis expuestos en dos estaciones del año diferentes (otoño y primavera). En general, considerando todas las respuestas medidas en los diferentes niveles de organización biológica tanto en otoño como en primavera, los efectos observados en los mejillones dependieron del tiempo de exposición, la concentración de NPs de Ag y la estación del año. Por lo tanto, para futuros estudios, la estación del año es un factor que debe ser considerado a la hora de evaluar los posibles efectos de NPs manufacturadas en bivalvos marinos. especialmente en hembras y especialmente en estudios a nivel de transcripción génica y expresión proteica

Cell and tissue level responses in mussels Mytilus galloprovincialis dietarily exposed to PVP/PEI coated Ag nanoparticles at two seasons

Silver nanoparticles (Ag NPs) are present in numerous consumer products due to their antimicrobial and other unique properties, thus concerns about their potential input into aquatic ecosystems are increasing. Toxicity of Ag NPs in waterborne exposed aquatic organisms has been widely investigated, but studies assessing the potential toxic effects caused after ingestion through the food web, especially at low realistic concentrations, remain scarce. Moreover, it is not well known whether season may influence toxic effects of Ag NPs. The main objective of this study was to determine cell and tissue level responses in mussels Mytilus galloprovincialis dietarily exposed to poly-N-vinyl-2-pirrolidone/polyethyleneimine (PVP/PEI) coated 5 nm Ag NPs for 1, 7 and 21 days both in autumn and spring. Mussels were fed every day with microalgae Isochrysis galbana exposed for 24 h to a low dose (1 mu g Ag/L Ag NPs) in spring and to a higher dose (10 mu g Ag/L Ag NPs) in spring and autumn. Mussels fed with microalgae exposed to the high dose accumulated Ag significantly after 21 days in both seasons, higher levels being measured in autumn compared to spring. Intralysosomal metal accumulation measured in mussel digestive gland and time- and dose-dependent reduction of mussels health status was similar in both seasons. DNA strand breaks increased significantly in hemocytes at both exposure doses along the 21 days in spring and micronuclei frequency showed an increasing trend after 1 and 7 days of exposure to 1 mu g Ag/L Ag NPs in spring and to 10 mu g Ag/L in both seasons. Values decreased after 21 days of exposure in all the cases. In conclusion, PVP/PEI coated 5 nm Ag NPs ingested through the food web were significantly accumulated in mussel tissues and caused adverse cell and tissue level effects both in autumn and in spring.This work has been funded by the Spanish Ministry of Economy and Competitiveness (Nano Silver Omics project MAT2012-39372), Basque Government (SAIOTEK project S-PE13UN142 and Consolidated Research Group GIC IT810-13 and IT1302-19), the University of the Basque Country UPV/EHU (UFI 11/37 and PhD fellowship to N.D.) and French Ministry of Higher Education and Research (PhD fellowship to M.M.)

Changes in protein expression in mussels Mytilus galloprovincialis dietarily exposed to PVP/PEI coated silver nanoparticles at different seasons

Potential toxic effects of Ag NPs ingested through the food web and depending on the season have not been addressed in marine bivalves. This work aimed to assess differences in protein expression in the digestive gland of female mussels after dietary exposure to Ag NPs in autumn and spring. Mussels were fed daily with microalgae previously exposed for 24 hours to 10 µg/L of PVP/PEI coated 5 nm Ag NPs. After 21 days, mussels significantly accumulated Ag in both seasons and Ag NPs were found within digestive gland cells and gills. Two-dimensional electrophoresis distinguished 104 differentially expressed protein spots in autumn and 142 in spring. Among them, chitinase like protein-3, partial and glyceraldehyde-3-phosphate dehydrogenase, that are involved in amino sugar and nucleotide sugar metabolism, carbon metabolism, glycolysis/gluconeogenesis and the biosynthesis of amino acids KEGG pathways, were overexpressed in autumn but underexpressed in spring. In autumn, pyruvate metabolism, citrate cycle, cysteine and methionine metabolism and glyoxylate and dicarboxylate metabolism were altered, while in spring, proteins related to the formation of phagosomes and hydrogen peroxide metabolism were differentially expressed. Overall, protein expression signatures depended on season and Ag NPs exposure, suggesting that season significantly influences responses of mussels to NP exposure.This work has been funded by the Spanish Ministry of Economy and Competitiveness (NanoSilverOmics project MAT2012-39372), Basque Government (SAIOTEK project S-PE13UN142 and Consolidated Research Group GIC IT810-13) and the University of the Basque Country UPV/EHU (UFI 11/37 and PhD fellowship to N.D.). This study had also the support of Fundação para a Ciência e Tecnologia (FCT) from Portugal through the Strategic Project UID/MAH00350/2013 granted to CIMA. The contribution of K. Mehennaoui was possible within the project NanoGAM (AFR-PhD-9229040) and M. Mikolaczyk was supported by a PhD fellowship from the French Ministry of Higher Education and Research.info:eu-repo/semantics/acceptedVersio

Impacts of dietary exposure to different sized polystyrene microplastics alone and with sorbed benzo[a]pyrene on biomarkers and whole organism responses in mussels Mytilus galloprovincialis

Due to their hydrophobicity and relatively large surface area, microplastics (MPs) can act as carriers of hydrophobic pollutants in the ocean and may facilitate their transfer to organisms. This study examined effects of dietary exposure to polystyrene MPs of 0.5 and 45 mu m alone and with sorbed benzo[a]pyrene (BaP) on mussels Mytilus galloprovincialis in order to elucidate the effects of MP size and the presence of sorbed BaP on the organism. MPs were provided daily, mixed with algae, during 26 days at equivalent mass (0.058 mg/L), corresponding to 1000 particles/mL for 4.5 mu m MPs and to 7.44 x 10(5) particles/mL for 0.5 mu m MPs. Effects were determined on early cellular biomarkers in hemocytes, structure and cell type composition of digestive tubules (DTs), histopathology and whole organism responses (condition index (CI), clearance rate (CR), food absorption efficiency (AE), respiration rate (RR) and scope for growth (SFG)). BaP concentrations in mussels increased with time, in particular when sorbed to smaller MPs. Large MPs were abundant in the lumen of stomach and DTs, but were also occasionally found within epithelial cells. Effects in all treatments increased with exposure time. MPs with sorbed BaP were more toxic than MPs alone according to hemocyte viability and catalase activity and to the quantitative structure of DT epithelium. Higher toxicity of small MPs compared to larger ones was recorded for DNA damage and cell composition of DTs. At tissue level a slight increase in prevalence of inflammatory responses occurred in all exposed groups. At whole organism level a compensatory effect was observed on absorption efficiency across MP treatments at day 26, resulting in increased SFG in mussels exposed to small MPs with sorbed BaP. This could be related to an increased energy need to deal with stress observed in biomarkers. Further work is required to understand the Trojan horse effect of a variety of plastic type, size, shape combinations together with a wide variety of pollutants. (C) 2019 The Authors. Published by Elsevier B.V.This work was funded by Spanish MINECO (NACE project CTM2016-81130-R), Basque Government (consolidated group IT810-13) and predoctoral fellowship to NGS and UPV/EHU (UFI 11/37, VRI grant PLASTOX). Work carried out within EU project PLASTOX (JPI Oceans 005/2015)