Fig. 5

Disruption of SphK2 localization within neurons in AD brain. a Representative confocal micrographs of SphK2 subcellular localization in fixed human frontal cortex tissue, in control (a1; n = 6) and AD (a2; n = 9) groups. Images were taken at 63× magnification (Scale bars indicate 10 μm). A TRITC-conjugated secondary antibody was used for SphK2 (red) and a FITC-conjugated secondary antibody was used for MAP2 (green). Nuclei were stained with DAPI (cyan). The confocal composite image (merge) was analyzed using ImageJ 1.51o software. The results are based on the evaluation of 493 neurons in AD group (frontal cortex: 187; entorhinal cortex: 150; CA1: 156) and 346 neurons in control group (frontal cortex: 133; entorhinal cortex: 90; CA1: 123). SphK2 staining was mainly observed in neurons and oligodendrocytes (asterisk). In neurons, the immunostaining of SphK2 was both nuclear and cytoplasmic. b Percentage of SphK2 staining surface was quantified in neurons. c SphK2 staining ratio between nuclear and cytoplasmic surface (%) in control and AD neurons for the three areas. d SphK2 staining intensity ratio (nuclear/cytoplasmic) in control and AD neurons for the three areas. Columns, mean; bars, SEM *p < 0.05, **p < 0.01, ***p < 0.001 vs control