Smoking hot news från Nature Scientific Reports

Klockan 11 i förmiddags publicerade Nature / Scientific Reports en forskningsrapport av 5 forskare från Frankrike.
Rapporten är intressant av flera anledningar, men främsta är de resultat man fått fram samt att forskarna INTE utgår från något av de 3 franska Uni som finns med på PHI,s sida över användare.
Dessa 5 forskare befinner sig nämligen på University of Lyon som alltså inte är upptagna på sidan.
Av det bör vi kunna dra slutsatsen att vi fått in ett fjärde Uni i Frankrike som användare. (Sale)

Rapporten som publicerades idag heter

Live-stream characterization of cadmium-induced cell death using visible CdTe-QDs

Received 17 January 2018 Accepted 02 August 2018 Published 22 August 2018
                         https://www.nature.com/articles/s41598-018-31077-2

Abstract

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 Cd²⁺ 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 Cd²⁺ 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.

Results

Satisfactory reproducibility of cell death between Cd²⁺ and CdTe-QDs

The proliferation of synoviocytes treated with QDs was evaluated qualitatively by imaging and quantitatively by cell impedance-based kinetics, enabling a real-time detection of cell death. For both Cd²⁺ and CdTe-QDs, a dose-response assay by imaging determined that a 10 µg/mL concentration induced a complete inhibition of synoviocyte proliferation at 24 hours and a lethal effect at 72 hours (Supplementary Figs 1 and 2). The cellular morphology and proliferation of synoviocytes treated with the negative control non-cytotoxic carbon fluoroxide quantum dots (CFO-QDs) were unchanged. Those indicated that an anti-proliferative effect was similar between Cd²⁺ and CdTe-QDs.

Imaging of CdTe-QDs-induced apoptosis

We characterized apoptosis with different methods (digital holographic microscopy, Annexin V staining, electron microscopy), and the results were compared to those obtained through QD imaging. Digital holographic microscopy showed significant changes in cell morphology at 24 h, including a significant decrease in surface area (mean ± standard error of the mean (SEM): 425 ± 35 µm² vs. 1008 ± 80 µm², p < 0.05) and a significant increase in cell thickness (mean ± SEM: 3.90 ± 0.26 µm vs. 1.56 ± 0.10 µm, p < 0.05), indicative of apoptosis (Supplementary Video 1, Fig. 1a). Classical Annexin V staining of fixed cells confirmed the induction of apoptosis by revealing phosphatidylserine labeling with both Cd²⁺ and CdTe-QDs (Fig. 1b). Moreover, Hoechst blue staining was used to confirm chromatin condensation (data not shown).

Methods

Digital holographic microscopy

The quantitative morphological parameters (cell area, volume, and thickness) were defined by analysis of cellular kinetics over 25 hours by HoloMonitor^® M4 (Phase Holographic Imaging AB, Lund, Sweden) with and without smallest CdTe-QDs.
The digital holographs were recorded every five minutes.

Conclusion

In conclusion, as compared to conventional methods, the use of CdTe-QDs enabled the direct and simultaneous visualization of different modes of Cd-induced cell death.  
Live-stream characterization of cell death showed that CdTe-QDs uptake by both the endocytic and non-endocytic pathways simultaneously led to apoptosis (with chromatin condensation and apoptotic bodies detectable) and autophagy (based on observation of autophagic vacuoles containing CdTe-QDs). This newly developed live-stream QD imaging method is a promising tool for the characterization and monitoring of the type of cell death but not to quantify the general toxicity of CdTe-QDs. This method has potentially useful applications, including monitoring of kinetic changes associated with cell death processes on other types of cells, through investigation of the homeostasis imbalance of the essential metals by other metals or with a combination of different metals on various type of cells. In the future, for the specific case of Cd²⁺, CdTe-QDs may be used in animal models to investigate the spread of Cd²⁺ and to define the cytotoxic effects of Cd²⁺-based QDs in different cell types toward clinical application.

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Min kommentar
Med den här rapporten visar dessa 5 forskare, efter en omfattande studie där PHI´s Holoteknik haft en betydande roll, att man nu fått NY kunskap i hur Apoptos (programmerad celldöd) kan förstås i ett bredare perspektiv.
Den kunskapen är oerhört värdefull som bas inom cellforskningen då dessa forskare nu med en helt ny metod, användning av kadmiumterulidkvantumpunkter (CdTe-QDs) lyckats övervaka celldödsprocesser inuti cellen.
Den möjligheten har tidigare varit begränsad då traditionell teknik med markörer inte medgett detta.
Här får vi nu i den respekterade Nature-editionen tämligen uppseväckande information (helt nya fakta som kontrollerats 3 gånger i forskarmiljö för att vidimera faktan man fått fram) som kommer ha signifikans för cellforskare världen över.
I denna studie har forskarna använt sig av den allra senaste och bästa tekniken för att kunna nå dessa sensationella upptäckter.
HoloMonitor har enligt mig fått ett maffigt erkännande.
                                                         
                                                                  Det är stort!