Immunogenomics and Inflammation Research Unit EA 4130, Department of Immunology and Rheumatology, Edouard Herriot Hospital, Hospices Civils de Lyon, University of Lyon, Lyon, France.
Laboratory of Research and Development of Industrial Galenic Pharmacy and Laboratory of Tissue Biology and Therapeutic Engineering UMR-CNRS 5305, Pharmacy Department, FRIPHARM Platform, Edouard Herriot Hospital, Hospices Civils de Lyon, University of Lyon, Lyon, France.
Sci Rep. 2018 Aug 22;8(1):12614. doi: 10.1038/s41598-018-31077-2.
Characterization of cell death currently requires the use of indirect markers, which has largely limited the ability to monitor cell death processes inside the cell. Here, we introduce a new method for the characterization of cell death mechanisms using cadmium telluride quantum dots (CdTe-QDs). Using visible CdTe-QDs with mesenchymal cells (e.g. synoviocytes), live-stream imaging allowed for visualization of cadmium-induced cell death, combining characteristics of apoptosis and autophagy. Initially, similar anti-proliferative effect was observed between 10 µg/ml Cd and CdTe-QDs at 24 h (cell index/cell density ratio decreased from 0.6 to -16.6, p < 0.05) using techniques that do not require the capacity of CdTe-QDs. Apoptosis was confirmed by the quantification of morphological parameters (reduced surface area, increased cell thickness) and positive labeling with annexin V. Autophagy was confirmed by monodansylcadaverine staining, identifying similar autophagic vacuoles with both Cd and CdTe-QD. However, QD imaging allowed for visualization of cadmium elements inside cell structures and their kinetic changes leading to cell death. Cell death characteristics were similar in inflammatory and non-inflammatory environment but were induced up to 4 h earlier in the former. Therefore, live-stream imaging of a visible cytotoxic agent has useful applications not currently possible with indirect methods, including chronological monitoring of cell death.
目前，细胞死亡的特征需要使用间接标志物，这在很大程度上限制了监测细胞内细胞死亡过程的能力。在这里，我们介绍了一种使用碲化镉量子点（CdTe-QDs）来描述细胞死亡机制的新方法。使用具有间充质细胞（如滑膜细胞）的可见 CdTe-QD，可以进行实时成像，从而可视化镉诱导的细胞死亡，结合了细胞凋亡和自噬的特征。最初，使用不需要 CdTe-QDs 能力的技术，在 24 小时时观察到 10μg/ml Cd 和 CdTe-QDs 之间具有相似的抗增殖作用（细胞指数/细胞密度比从 0.6 降低至-16.6，p<0.05）。通过定量形态学参数（表面积减小，细胞厚度增加）和用膜联蛋白 V 进行阳性标记，证实了细胞凋亡。通过单丹磺酰尸胺染色证实了自噬，在 Cd 和 CdTe-QD 上均鉴定出相似的自噬空泡。然而，QD 成像可以可视化细胞结构内的镉元素及其导致细胞死亡的动力学变化。在炎症和非炎症环境中，细胞死亡特征相似，但前者的诱导时间提前了 4 小时。因此，可见细胞毒性剂的实时成像具有目前间接方法无法实现的有用应用，包括细胞死亡的时间监测。
