Nitroxide Radical-Containing Redox Nanoparticles Protect Neuroblastoma SH-SY5Y Cells against 6-Hydroxydopamine Toxicity

Figure 2

Morphological changes in the cellular structure. Confocal images of SH-SY5Y 63× preexposed to NRNP1 or free nitroxides (TEMPO or 4-amino-TEMPO) for 2 h and treated with 6-OHDA for 24 h. Nuclei were stained with DAPI (blue), phalloidin conjugated with Atto-488 (green), and mitochondria with MitoTracker Deep Red FM (red). All scale bars (control, bottom right) are 20 μm (a). In ImageJ, the fluorescence intensity was expressed as a mean gray value separately for the red channel (from MitoTracker) and separately for the green channel (phalloidin). The ratio of MitoTracker to phalloidin fluorescence (i.e., the ratio of the signal from the mitochondria to the number of cells (actin skeleton)) was calculated. The calculated values were expressed as a percentage of untreated control (b).

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(b)