TiO2 nanoparticles induce omphalocele in chicken embryo by disrupting Wnt signaling pathway

Shweta Patel,Ranjitsinh Devkar,Man Singh,Sonal Thakore,Rajlakshmi Chetty,Sarmita Jana

doi:10.1038/s41598-018-23215-7

Shweta Patel, Ranjitsinh Devkar + Show 4 more

Open Access

https://doi.org/10.1038/s41598-018-23215-7

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Abstract

Titanium dioxide nanoparticles (TiO2 NPs) are among abundantly used metal oxide NPs but their interactions with biomolecules and subsequent embryonic toxicity in higher vertebrates is not extensively reported. Physicochemical interactions of TiO2 NPs with egg albumen reveals that lower doses of TiO2 NPs (10 and 25 µg/ml) accounted for higher friccohesity and activation energy but an increment in molecular radii was recorded at higher doses (50 and 100 µg/ml). FTIR analysis revealed conformational changes in secondary structure of egg albumen as a result of electrostratic interactions between egg albumen and TiO2 NPs. The morphometric data of chicken embryo recorded a reduction at all the doses of TiO2 NPs, but toxicity and developmental deformity (omphalocele and flexed limbs) were recorded at lower doses only. Inductively coupled plasma optical emission spectrometry (ICP-OES) confirmed presence of Ti in chicken embryos. mRNA levels of genes involved in canonical and non-canonical Wnt signaling were lowered following TiO2 NPs treatment resulting in free radical mediated disruption of lateral plate mesoderm and somite myogenesis. Conformational changes in egg albumen and subsequent developmental deformity in chicken embryo following TiO2 NPs treatment warrants detailed studies of NP toxicity at lower doses prior to their biomedical applications.

Highlights

Nanotechnology is a rapidly expanding field, with a wide range of applications in communications, robotics, medicine, clothes, sporting goods, etc[1,2]
Other studies had reported developmental toxicity of graphite[16], copper[17], carbon[18], platinum[19], pristine graphene[20] and silver[21] nanoparticles on chicken embryo, but their in ovo physicochemical interactions with biomolecules such as egg albumen have not been taken into account
We assess the interaction of TiO2 NPs with egg albumen and its subsequent impact on chicken embryonic development

Summary

Results

In DLS analysis, TiO2 NPs presented a single distribution with peak centered at 88.6 nm. A Similar trend of significant decrement was observed in cadmium treated embryos, whereas, TiO2 bulk treatment could not manifest any significant change (Fig. 4a–c). Expression levels of key genes of non-canonical Wnt/Ca2+ Wnt signaling (WNT11, PRKCA and CAMK2D) showed significantly lowered expression levels following TiO2 NPs or cadmium treatment. The TiO2 bulk treatment showed non-significant changes in the expression levels of the said genes (Fig. 4d–f). MRNA expression of key genes of Planar Cell Polarity pathway (ROCK1 and ROCK2) accounted for non-significant decrement following TiO2 NPs or cadmium treatment. It was observed that 10 μg/ml dose of TiO2 NPs accounted for 20% decrement in the number of somites after 24 h which was comparable to that of the cadmium treated group, whereas, TiO2 bulk treatment could not manifest any significant change (Fig. 4j)

Discussion

Conclusion

Materials and Methods