201. Titanium dioxide nanoparticles impair the inner blood-retinal barrier and retinal electrophysiology through rapid ADAM17 activation and claudin-5 degradation.
- Author
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Chan YJ, Liao PL, Tsai CH, Cheng YW, Lin FL, Ho JD, Chen CY, and Li CH
- Subjects
- Animals, Blood-Retinal Barrier, Claudin-5, Electrophysiology, Endothelial Cells, Mice, Mice, Inbred C57BL, Nanoparticles, Metal Nanoparticles toxicity, Titanium toxicity
- Abstract
Background: Depending on their distinct properties, titanium dioxide nanoparticles (TiO
2 -NPs) are manufactured extensively and widely present in our daily necessities, with growing environmental release and public concerns. In sunscreen formulations, supplementation of TiO2 -NPs may reach up to 25% (w/w). Ocular contact with TiO2 -NPs may occur accidentally in certain cases, allowing undesirable risks to human vision. This study aimed to understand the barrier integrity of retinal endothelial cells in response to TiO2 -NP exposure. bEnd.3 cells and human retinal endothelial cells (HRECs) were exposed to TiO2 -NP, followed by examination of their tight junction components and functions., Results: TiO2-NP treatment apparently induced a broken structure of the junctional plaques, conferring decreased transendothelial electrical resistance, a permeable paracellular cleft, and improved cell migration in vitro. This might involve rapid activation of metalloproteinase, a disintegrin and metalloproteinase 17 (ADAM17), and ADAM17-mediated claudin-5 degradation. For the in vivo study, C57BL/6 mice were administered a single dose of TiO2-NP intravitreally and then subjected to a complete ophthalmology examination. Fluorescein leakage and reduced blood flow at the optical disc indicated a damaged inner blood-retinal barrier induced by TiO2 -NPs. Inappreciable change in the thickness of retinal sublayers and alleviated electroretinography amplitude were observed in the TiO2 -NP-treated eyes., Conclusions: Overall, our data demonstrate that TiO2-NP can damage endothelial cell function, thereby affecting retinal electrophysiology.- Published
- 2021
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