Numerous studies have proven that nano titanium dioxide (nano TiO₂) can accumulate in animal brains, where it damages the blood brain barrier (BBB); however, whether this process involves destruction of tight junction proteins in the mouse brain has not been adequately investigated. In this study, mice were exposed to nano TiO₂ for 30 consecutive days, and then we used transmission electron microscopy to observe the BBB ultrastructure and the Evans blue assay to evaluate the permeability of the BBB. Our data suggested that nano TiO₂ damaged the BBB ultrastructure and increased BBB permeability. Furthermore, we used immunofluorescence and Western blotting to examine the expression of key tight junction proteins, including Occludin, ZO-1, and Claudin-5 in the mouse brain. Our data showed that nano TiO₂ reduced Occludin, ZO-1 and Claudin-5 expression. Taken together, nano TiO₂-induced damage to the BBB structure and function may involve the destruction of key tight junction proteins.

中文翻译：

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纳米二氧化钛暴露对血脑屏障结构和功能的损害涉及破坏小鼠大脑中关键的紧密连接蛋白。

大量研究证明，纳米二氧化钛 (nano TiO₂) 会在动物大脑中积聚，从而破坏血脑屏障 (BBB)；然而，这一过程是否涉及破坏小鼠大脑中的紧密连接蛋白尚未得到充分研究。在这项研究中，小鼠连续接触纳米二氧化钛 30 天，然后我们使用透射电子显微镜观察 BBB 超微结构，并用埃文斯蓝法评估 BBB 的渗透性。我们的数据表明纳米二氧化钛破坏了血脑屏障的超微结构并增加了血脑屏障的渗透性。此外，我们使用免疫荧光和蛋白质印迹来检查关键紧密连接蛋白的表达，包括 Occludin、ZO-1 和 Claudin-5 在小鼠大脑中的表达。我们的数据显示纳米二氧化钛降低了 Occludin、ZO-1 和 Claudin-5 的表达。