Low-Dose Ionizing Radiation Affects Mesenchymal Stem Cells via Extracellular Oxidized Cell-Free DNA: A Possible Mediator of Bystander Effect and Adaptive Response

Figure 1

Low-dose radiation causes a strong antiapoptotic response. (a) (1) Flow cytometric enumeration of cells with signs of early apoptosis by FL1 versus FSC. R: gated area, annexin V-positive cells in total population; (2) distribution of fluorescence intensities of cells stained with annexin V-FITC. (b) Signal intensity of FL1-R (1) and average signal intensity of FL1-annexin V-FITC (2) in irradiated (10 cGy, 15 min and 2 h after exposure) and exposed to cfDNAox and cfDNAoxR (50 ng/ml, 15 min and 2 h) cells (flow cytometry). (c) Fluorescence microscopy of irradiated and exposed to cfDNAox MSCs stained with BCL2 (anti-BCL2-antibody and secondary FITC-conjugated antibodies) and DAPI (40×), .

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