Effects of nanoparticles on structure and function of the cell nucleus: Analysis of nuclear protein aggregation and neurodegeneration.

纳米粒子在工程和生物医学中的应用呈指数级增长，为了发展可持续的纳米技术，需要分析它们与细胞和整个生物体的相互作用。我们以前已经在细胞培养和线虫秀丽线虫中发现了二氧化硅纳米颗粒诱导神经退行性变的表型。在细胞培养中，二氧化硅-纳米颗粒会导致核内蛋白质聚集体的形成。这些包涵体形成淀粉样结构，并准确地概括了多谷氨酰胺诱导的蛋白质聚集，这种聚集发生在神经退行性疾病中，如亨廷顿病。二氧化硅纳米颗粒证明了内源核蛋白的聚集激活了泛素-蛋白酶体系统，而淀粉样聚集体代表了蛋白质降解的位置。相比之下，二氧化钛-纳米颗粒诱导的核内含物与遗传毒性有关，而不是与蛋白平衡改变有关。根据这些结果，拟议项目的主要目的是研究核内蛋白质聚集对核功能的影响。为此，将分析NP诱导的聚集体的生化特性与复制、DNA损伤、修复、转录和细胞死亡等过程的相关性。与核功能相关的聚集图谱试图填补现有的知识空白，即核内包涵体的形成，导致蛋白质-蛋白质相互作用的异常和核内功能的改变，以及它们在神经退行性变中的作用。后者将通过对秀丽隐杆线虫的体内分析而得到加强。在这里，我们将讨论在二氧化硅-NP诱导的产卵缺陷中，哪些神经元和神经内分泌信号通路是靶点，以及蛋白平衡和蛋白质聚集的改变是否导致产卵回路的故障，例如HSN神经元和外阴肌之间的相互作用。预期的发现能够促进两者，更好地理解蛋白质聚集在神经退化过程中的作用，以及NPs的细胞相互作用。

The exponentially growing application of nanoparticles (NPs) in engineering and biomedicine calls for analysis of their interactions with cells and whole organisms in order to develop sustainable nanotechnologies. We showed previously that silica-NPs induce neurodegenerative phenotypes in cell culture and the nematode Caenorhabditis elegans. In cell culture silica-NPs cause formation of intranuclear protein aggregates. These inclusions form amyloid-like structures and recapitulate exactly polyglutamine-induced protein aggregation that occurs in neurodegenerative disorders such as Huntington's disease. Silica-NPs enabled demonstration that aggregation of endogenous nuclear proteins activates the ubiquitin-proteasome system, and amyloid-like aggregates represent sites of protein degradation. In contrast, titanium dioxide-NPs induce nuclear inclusions which are correlated with genotoxicity rather than altered proteostasis. Based on these results the main aim of the proposed project is to study the consequences of intranuclear protein aggregation for nuclear function. To this end, biochemical properties of NP-induced aggregates will be analysed in correlation with processes such as replication, DNA damage, repair, transcription, and cell death. Aggregate profiling in correlation with nuclear function seeks to fill the existing gap of knowledge between formation of intranuclear inclusions, resulting aberrant protein-protein interactions and altered function in the nucleus as well as their role in neurodegeneration. The latter will be reinforced by in vivo analyses in Caenorhabditis elegans. Here, the questions will be addressed which neurons and neuroendocrine signalling pathways are targeted in silica-NP-induced defects of egg-laying, and if altered proteostasis and protein aggregation contributes to the malfunction of the egg-laying circuit, e.g. interaction between HSN neurons and vulval muscles. The expected findings are capable to promote both, a better understanding of the role of protein aggregation in neurodegenerative processes, and cellular interactions of NPs.