Fig. 1

PDZD8 promotes fusion of LDs with lysosomes mediated by cholesterol. a Confocal fluorescence images of PC12 cells transfected with siControl or siPDZD8 as well as with expression vectors for EGFP-PLIN2 (green) and then metabolically labeled with LysoTracker (red). The boxed regions in the left panels are shown at higher magnification in those to the right. b TEM images of PC12 cells transfected with siControl or siPDZD8. Arrowheads in the images at higher magnification (enlarged-1) indicate LDs. Arrows in the enlarged-1 indicate organelles during lipophagy, which are shown at much higher magnification in those to the right (enlarged-2). LD and lysosome (Ly) are also indicated in the enlarged-2. c Confocal fluorescence images of PC12 cells transfected with siControl or siPDZD8 as well as with expression vectors for mCherry-PLIN2 (red) and then metabolically labeled with filipin (blue). The boxed regions in the left panels are shown at higher magnification in those to the right. Filipin is shown in gray scale in the enlarged images. d and e Intensity of filipin per cell (n = 17 and 16 cells for siControl and siPDZD8, respectively) (d) or per LD (n = 772 and 719 LDs for siControl and siPDZD8, respectively) (e) in images similar to those in (c). Quantitative data are presented with SEM values. n.s., not significant; ***P < 0.001