In vivo exposure of the marine clam Ruditapes philippinarum to zinc oxide nanoparticles: responses in gills, digestive gland and haemolymph

Abstract

Potential nanoparticle (NP) toxicity poses a growing concern in marine coastal environments. Among NPs, zinc oxide nanoparticles (nZnO) are widely used in many common products that ultimately become deposited in coastal habitats from multiple non-point sources. In this study, we evaluated the in vivo effects of nZnO in the clam Ruditapes philippinarum. Animals were exposed to nZnO (1 and 10 μg/L) and ZnCl2 (10 μg/L) for 7 days. ZnCl2 was used to compare the effects of the NPs to those of Zn(2+) and to ascertain whether nZnO toxicity is attributable to the release of ions into the aquatic medium. At differing time intervals during the exposure, several biochemical and cellular responses were evaluated in the clam gills, digestive gland, and haemolymph. The results showed that nZnO, at concentrations close to the predicted environmental levels, significantly affected various parameters in clam tissues. Significant increases in catalase and superoxide dismutase activities and a decreasing trend of glutathione S-transferase activity indicated the involvement of oxidative stress in nZnO toxicity. In clams exposed to ZnCl2, slight variations in antioxidant enzyme activities were detected with respect to nZnO-treated clams. However, no damage to lipids, proteins or DNA was revealed in all exposure conditions, suggesting a protection of antioxidant enzymes in the tissues. Of the various haemolymph parameters measured, haemocyte proliferation increased significantly, in ZnCl2-treated clams in particular. Under nZnO (10 μg/L) and ZnCl2 exposure, DNA damage in haemocytes was also revealed, but it was lower in clams exposed to ZnCl2. A decreasing trend in gill AChE activity of treated clams proposed a possible role of zinc ions in nZnO toxicity. However, the dissimilar modulation of the responses in the nZnO- and ZnCl2-exposed clams suggested different mechanisms of action, with nZnO toxicity possibly depending not only on the release of zinc ions but also on NP-specific features. Changes in the biological parameters measured in the clams were consistent with Zn accumulation in their gills and digestive glands.

Impact of exposure time, particle size and uptake pathway on silver nanoparticle effects on circulating immune cells in mytilus galloprovincialis

“…Their exceptional broad-spectrum bactericidal properties and biocompatibility (i.e. as drug delivery agent) have also made AgNP extremely useful in a diverse range of consumer goods (Luoma 2008;Rainville et al 2014;Cozzari et al 2015;Katsumiti et al 2015;Marisa et al 2016).…”

“…Worldwide AgNP production is estimated at % 55 tonne/yr (Piccinno et al 2012). However, release of AgNP into aquatic environs can happen through wastewaters generated during AgNP synthesis and/or incorporation into goods and consumer products (Canesi et al 2012;Matranga & Corsi 2012;Katsumiti et al 2015;Marisa et al 2016). As such, AgNP have emerged as potential stressors that might enter marine environment (Luoma 2008).…”

“…Internalization of these NP subsequently impacted on morphologic/functional characteristics including immune responses (Canesi et al 2008(Canesi et al , 2010a(Canesi et al , b, 2012Katsumiti et al 2015;Marisa et al 2016). Various mussel hemocyte parameters, including total hemocyte count (THC), differential hemocyte count (DHC), hemocyte viability, phagocytic activity and lysosomal membrane stability, have been used as a tool for screening of immunomodulatory effects of differing NP (Matozzo et al 2007;Parisi et al 2008;Hoher et al 2013;Matozzo & Bailo 2015;Canesi & Corsi, 2016;Marisa et al 2016). Specifically, hyalinocytes and granulocytes have been assessed for morphological changes among hemocytes in Mytilus galloprovincialis (Pipe et al 1997;Chang et al 2005;Garcia-Garcia et al 2008).…”

Are the impacts of carbon nanotubes enhanced in Mytilus galloprovincialis submitted to air exposure?

“…In fact, ROS may promote the oxidation of proteins, a process known as protein carbonylation (PC) which constitutes the most common type of PTM triggered by oxidative stress (Cattaruzza and Hecker, 2008;Suzuki et al, 2010 In general, the present results showed no alteration on PC levels in ). mussels, with similar PC levels in non-contaminated and contaminated mussels exposed to submersion and tide conditions Similarly, Marisa et al (2016) showed no significant differences .…”

Evolutionary conserved pathway of the innate immune response after a viral insult in Paracentrotus lividus sea urchin

“…Moreover, an increase in the immune cell number was found in other marine invertebrates in response to different stimuli. For example, hemocytes increased in the mollusc Ruditapes philippinarum after treatment with zinc oxide nanoparticles (Marisa et al., ).…”