Up regulation of miR-96-5p is responsible for TiO2 NPs induced invasion dysfunction of human trophoblastic cells via disturbing Ezrin mediated cytoskeletons arrangement

Abstract

Titanium dioxide nanoparticles (TiO2 NPs) are used extensively in our daily lives, and their toxic effects on the placenta have been reported. Animal studies indicated that placental development is impaired after maternal exposure of TiO2 NPs, but the underlying mechanisms remain largely unknown. In the present study, we used a human trophoblast-derived cell, HTR8-SVneo, to determine how TiO2 NPs affected placental functions, and found out potential reversal targets. TEM was employed for TiO2 NPs morphology observation and uptake assessment. RT-PCR was used to detect the expression of both mRNA and miRNA, and western blotting was used for protein examination. Cell invasion ability was evaluated by Transwell assay, and cytoskeletons were observed by immunofluorescence combined with confocal microscope examination. We found that TiO2 NPs disrupted cytoskeletons and impaired cell invasion ability. Further investigations showed that TiO2 NPs increased the expression of a microRNA (miR-96-5p), which targeted and down-regulated the translation of EZR mRNA, a gene that encodes ezrin protein, and affected the cell cytoskeletons and ultimately cell invasion ability. When the expression of miR-96-5p was down-regulated, the expression level of ezrin protein was also reversed, and cell invasion ability was partially restored. Collectively, we determined how miR-96-5p mediates TiO2 NP-induced placental dysfunction, and provided a potential rescue target for future therapy.