The SiO2NPs ingestion affects Xenopus laevis embryos development
Tussellino M1, Ronca R1, G. Benvenuto2, Manchisi E1, De Crescenzo S1, Cieri F1 Fusco S3, Netti PA3 and Carotenuto R1
1Department of Biology, University of Naples “Federico II”
2Stazione Zoologica “Anton Dohrn” Naples
3Center for Advanced Biomaterials for Health Care (IIT@CRIB), Italian Institute of Technology, Naples, Italy
The properties of nanoparticles (NPs) that make them useful in a wide range of industrial applications have led to concerns regarding their potential impact on human and environmental health. Synthetic amorphous silica (SiO2), is widely applied in food products and registered within the EU as a food additive (E551). It is mainly used to thicken pastes, as an anticaking agent to maintain flow properties in powdered products, and as a carrier for fragrances or flavors in food and nonfood products (Peters et al., 2012). Recent research showed that in powdered food materials containing E551 at least part of the silica is in the nano-size range (Dekkers et al., 2011). Xenopus laevis is an aquatic animal whose development takes place outside the mother's body, therefore allowing monitoring during embryonic morphogenesis. It is an organism that lends itself to different applications which help in understanding, for example, the pathways involved in its development; but it is also a valuable model for the study of factors that induce cancer (Lobikin et al., 2012). What makes Xenopus a convincing study model is, also, the ability to relate the data obtained at higher vertebrates including humans (Takagi et al., 2013; Tomlinson et al., 2005). Our aim is to evaluate the possible toxicity of commercial SiO2 nanoparticles of 20nm in diameter, on the embryogenesis of Xenopus laevis. These Nps is administered in culture medium and then they were uptakes via dietary also. We purchased our NPs from MKnano (Canada). Dynamic Light Scattering (DLS) was performed at 21°C to measure NPs size and Z-potential. The embryos were reared starting from st. 4/8 in FETAX containing 0.01, 1 and 5 mg / L nanoparticles. All embryos were harvested at stage 47/48. Various toxicity parameters as the mortality, morphology, length, heartbeat and pigment distribution were statistically analyzed as in Tussellino et al., 2015. Real Time-PCR for genes involved in early embryo development were carried out on RNA from embryos st. 46, see (Scudiero et al., 2015). Electronic images of intestine were carried out to verify the possible nanoparticles effects. Our data show that SiO2NPs aggregate in FETAX and do not cause mortality of Xenopus laevis but alter their development. They exert a toxic effect which is manifested by different phenotypes: alteration of length, dorsal pigmentation, heartbeat and alteration of intestinal brush border. Moreover our experiment show that they alter the expression of all the analyzed genes also at the lowest concentration. Finally we hypothesize that the ROS production could be responsible of the observed phenotypes.
Peters R, Kramer E, Oomen AG, Herrera Rivera ZE, Oegema G, Tromp PC, Fokkink R, Rietveld A, Marvin HJP, Weigel S, Peijnenburg AACM, and Bouwmeester H (2012) Presence of nano-sized silica during in vitro digestion of foods containing silica as a food additive. ACS Nano. 6(3):2441-51. doi: 10.1021/nn204728k
Dekkers, S.; Krystek, P.; Peters, R.J.; Lankveld, D.X.; Bokkers, B.G.; van Hoeven-Arentzen, P.H.;
Bouwmeester, H.; Oomen, A.G. (2011) Presence and risks of nanosilica in food products. Nanotoxicology 5, 393–405.
Lobikin M, Chernet B, Lobo D and Levin M (2012) Resting potential, oncogene-induced tumorigenesis, and metastasis: thebioelectric basis of cancer in vivo. Phys. Biol. 9 065002 (22pp)
Takagi C, Sakamaki K, Morita H, Hara Y, Suzuki M, Kinoshita N, Ueno N (2013) Transgenic Xenopus laevis for live imaging in cell and developmental biology. Develop Growth Differ 55(4):422–433
Tomlinson ML, Field RA, Wheeler GN (2005) Xenopus as a model organism in developmental chemical genetic screens. Mol BioSyst 1:223–228
Tussellino M, Ronca R, Formiggini F, De Marco N, Fusco S, Netti PA, Carotenuto R (2015) Polystyrene nanoparticles affect Xenopus laevis development. Journal of Nanoparticle Research 17 (2), 1-17
R. Scudiero, M. Tussellino, R. Carotenuto. (2015) Identification and expression of an atypical isoform of metallothionein in the African clawed frog Xenopus laevis. Comptes Rendus Biologies. pii: S1631-0691(15)00089-X. doi.org/10.1016/j.crvi.2015.03.011
