Defective Autophagy, Mitochondrial Clearance and Lipophagy in Niemann-Pick Type B Lymphocytes
Fig 6
Evaluation of intracellular lipid content and lipophagy by BODIPY® 665/676 (BP).
(A) Single confocal optical sections (~0.8 μm thickness) showing overlay of LTG (green) and BP (red) and the relative merge with bright field (BF), from control, nutrient deprivation and rapamycin- treated tWT and tNP cells. Insets show lipid droplets bound to the outer cell surface, probably newly extruded from the cell, or just below the outer cell membrane, most likely about to be exocytosed by the cell. Bars: 10 μm; 5 μm for insets. (B) Pearson's colocalization coefficient (PCC) for LTG and BP in control and pathologic cells for control, nutrient deprivation and rapamycin administration. Pearson's coefficients were derived from three completely independent experiments with >10 fields per experiment contributing to the cumulative result. Each value is expressed as PCC ± SD; **P < 0.01 vs respective control. The difference between cell lines was determined to be significant by two-way ANOVA (***P < 0.001). Two-way ANOVA with Bonferroni post test revealed a P value < 0.01 (++P < 0.01) between tWT and tNP basal condition and rapamycin-treated cells. (C) Statistical histogram of MFI variation of intracellular BP in tWT and tNP cells for each experimental condition. Mean values were converted to arbitrary units (A.U.) setting control of wild-type cells as 100. Each value is expressed as a relative mean ± SD (Results from n ≥ 3 independent experiments); **P < 0.01 vs respective control.
