With the large-scale production and application of amorphous silica nanoparticles (aSiNPs), its adverse health effects are more worthy of our attention. Our previous research has demonstrated for the first time that aSiNPs induced cytokinesis failure, which resulted in abnormally high incidences of multinucleation in vitro, but the underlying mechanisms remain unclear. Therefore, the purpose of this study was firstly to explore whether aSiNPs induced multinucleation in vivo, and secondly to investigate the underlying mechanism of how aSiNPs caused abnormal cytokinesis and multinucleation. Male ICR mice with intratracheal instillation of aSiNPs were used as an experimental model in vivo. Human hepatic cell line (L-02) was introduced for further mechanism study in vitro. In vivo, histopathological results showed that the rate of multinucleation was significantly increased in the liver and lung tissue after aSiNPs treatment. In vitro, immunofluorescence results manifested that aSiNPs directly caused microfilaments aggregation. Following mechanism studies indicated that aSiNPs increased ROS levels. The accumulation of ROS further inhibited the PI3k 110β/Aurora B pathway, leading to a decrease in the expression of centralspindlin subunits MKLP1 and CYK4 as well as downstream cytokines regulation related proteins Ect2, Cep55, CHMP2A and RhoA. Meanwhile, the particles caused abnormal co-localization of the key mitotic regulatory kinase Aurora B and the centralspindlin complex by inhibiting the PI3k 110β/Aurora B pathway. PI3K activator IGF increased the phosphorylation level of Aurora B and improved the relative ratio of the centralspindlin cluster. And ROS inhibitors NAC reduced the ratio of multinucleation, alleviated the PI3k 110β/Aurora B pathway inhibition, and then increased the expression of MKLP1, CYK4 and cytokinesis-related proteins, whilst NAC restored the clustering of the centralspindlin. This study demonstrated that aSiNPs led to multinucleation formation both in vivo and in vitro. ASiNPs exposure caused microfilaments aggregation and inhibited the PI3k 110β/Aurora B pathway through excessive ROS, which then hindered the centralspindlin cluster as well as restrained the expression of centralspindlin subunits and cytokinesis-related proteins, which ultimately resulted in cytokinesis failure and the formation of multinucleation.

中文翻译：

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无定形二氧化硅纳米粒子通过中枢纺丝蛋白复合物和微丝的功能障碍导致异常胞质分裂和多核

随着无定形二氧化硅纳米粒子（aSiNPs）的大规模生产和应用，其对健康的不良影响更值得我们关注。我们前期的研究首次证明aSiNPs可诱导胞质分裂失败，从而导致体外多核发生率异常高，但其潜在机制仍不清楚。因此，本研究的目的首先是探讨aSiNPs是否在体内诱导多核，其次探讨aSiNPs如何引起异常胞质分裂和多核的潜在机制。使用气管内滴注aSiNPs的雄性ICR小鼠作为体内实验模型。引入人肝细胞系（L-02）进行进一步的体外机制研究。在体内，组织病理学结果表明，aSiNPs处理后，肝脏和肺组织中的多核率显着增加。体外免疫荧光结果表明aSiNPs直接引起微丝聚集。以下机制研究表明 aSiNPs 增加了 ROS 水平。ROS的积累进一步抑制PI3k 110β/Aurora B通路，导致中枢纺锤蛋白亚基MKLP1和CYK4以及下游细胞因子调节相关蛋白Ect2、Cep55、CHMP2A和RhoA的表达减少。同时，这些颗粒通过抑制 PI3k 110β/Aurora B 通路，引起关键有丝分裂调节激酶 Aurora B 和中枢纺锤蛋白复合体的异常共定位。PI3K激活剂IGF增加Aurora B的磷酸化水平并提高中枢纺锤蛋白簇的相对比例。ROS抑制剂NAC降低了多核比例，减轻了PI3k 110β/Aurora B通路抑制，进而增加了MKLP1、CYK4和胞质分裂相关蛋白的表达，同时NAC恢复了中枢纺锤体的聚集。这项研究表明，aSiNPs 在体内和体外均可导致多核形成。ASiNPs暴露引起微丝聚集，并通过过量的ROS抑制PI3k 110β/Aurora B通路，从而阻碍中枢纺锤蛋白簇，抑制中枢纺锤蛋白亚基和胞质分裂相关蛋白的表达，最终导致胞质分裂失败并形成多核。