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领域的应用呈指数级增长，这就要求对其与细胞和整个生物体的相互作用进行分析，以发展可持续的纳米技术。我们之前的研究表明，二氧化硅- nps在细胞培养和秀丽隐杆线虫中诱导神经退行性表型。在细胞培养中，二氧化硅- nps引起核内蛋白聚集体的形成。这些包涵体形成淀粉样结构，并精确地概括了发生在神经退行性疾病（如亨廷顿氏病）中的聚谷氨酰胺诱导的蛋白质聚集。二氧化硅- nps证明内源性核蛋白的聚集激活了泛素-蛋白酶体系统，淀粉样聚集体代表了蛋白质降解的位点。相比之下，二氧化钛- nps诱导的核包涵体与遗传毒性有关，而不是改变的蛋白质平衡。基于这些结果，本项目的主要目的是研究核内蛋白聚集对核功能的影响。为此，将分析np诱导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。与核功能相关的聚合谱试图填补核内包涵体形成之间的现有知识空白，导致异常的蛋白质-蛋白质相互作用和核功能改变，以及它们在神经退行性变中的作用。后者将通过秀丽隐杆线虫的体内分析得到加强。在这里，将讨论哪些神经元和神经内分泌信号通路是二氧化硅- np诱导的产蛋缺陷的目标，以及蛋白质稳态和蛋白质聚集的改变是否会导致产蛋回路的功能障碍，例如HSN神经元与外阴肌肉之间的相互作用。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行性过程中的作用，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.