Cell Biology, Faculty of Science and Engineering, Åbo Akademi University, Turku, Finland.
Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku, Finland.
Cell Stress Chaperones. 2019 Jul;24(4):735-748. doi: 10.1007/s12192-019-00999-9. Epub 2019 May 11.
The cellular stress response, which provides protection against proteotoxic stresses, is characterized by the activation of heat shock factor 1 and the formation of nuclear stress bodies (nSBs). In this study, we developed a computerized method to quantify the formation and size distribution of nSBs, as stress response induction is of interest in cancer research, neurodegenerative diseases, and in other pathophysiological processes. We employed an advanced bioimaging and analytics workflow to enable quantitative detailed subcellular analysis of cell populations even down to single-cell level. This type of detailed analysis requires automated single cell analysis to allow for detection of both size and distribution of nSBs. For specific induction of nSB we used mesoporous silica nanoparticles (MSNs) loaded with celastrol, a plant-derived triterpene with the ability to activate the stress response. To enable specific targeting, we employed folic acid functionalized nanoparticles, which yields targeting to folate receptor expressing cancer cells. In this way, we could assess the ability to quantitatively detect directed and spatio-temporal nSB induction using 2D and 3D confocal imaging. Our results demonstrate successful implementation of an imaging and analytics workflow based on a freely available, general-purpose software platform, BioImageXD, also compatible with other imaging modalities due to full 3D/4D and high-throughput batch processing support. The developed quantitative imaging analytics workflow opens possibilities for detailed stress response examination in cell populations, with significant potential in the analysis of targeted drug delivery systems related to cell stress and other cytoprotective cellular processes.
细胞应激反应可提供针对蛋白毒性应激的保护，其特征在于热休克因子 1 的激活和核应激体（nSB）的形成。在这项研究中，我们开发了一种计算机化方法来量化 nSB 的形成和大小分布，因为应激反应的诱导在癌症研究、神经退行性疾病和其他病理生理过程中很有意义。我们采用了先进的生物成像和分析工作流程，即使在单细胞水平，也能够对细胞群体进行定量详细的亚细胞分析。这种详细的分析需要自动化的单细胞分析，以检测 nSB 的大小和分布。为了特异性诱导 nSB，我们使用负载有雷公藤红素的介孔硅纳米颗粒（MSNs），雷公藤红素是一种具有激活应激反应能力的植物三萜。为了实现特异性靶向，我们使用叶酸功能化的纳米颗粒，它可以靶向表达叶酸受体的癌细胞。通过这种方式，我们可以评估使用 2D 和 3D 共聚焦成像来定量检测定向和时空 nSB 诱导的能力。我们的结果表明，成功实现了基于免费的、通用软件平台 BioImageXD 的成像和分析工作流程，由于完全支持 3D/4D 和高通量批处理，它还可以与其他成像模式兼容。开发的定量成像分析工作流程为细胞群体中的详细应激反应检查开辟了可能性，在与细胞应激和其他细胞保护过程相关的靶向药物输送系统分析方面具有重要的潜力。
