LD-Stored Fatty Acids Released by Autophagy Move into Mitochondria for Energy Production
(A and B) Representative fluorescence images of U87 cells after culturing with BODIPY-labeled PA (C16:0; Cat# D3821, Life Technologies) (0.5 μM) for 12 h and then staining with Nile red and Hoechst 33342 (blue) (A) or with anti-TIP47 antibody (red) (B). Scale bar: 10 μm.
(C) U87 cells were cultured with BODIPY-PA (0.5 μM) for 12 h and then treated with/without CQ (5 μM) or ETO (100 μM) in the absence or presence of glucose (25 mM) for 8 h. Cells were then stained with MitoTracker (Red) and Hoechst 33342 (blue) and visualized by confocal microscopy. The co-localization of diffused BODIPY-PA and mitochondria was determined by the ratio of co-localized red and green signal (yellow) to total red signal using the ImageJ software (mean ± SEM, n = 30). Significance was determined by one-way ANOVA. ∗p < 0.01.
(D) U87 cells were transfected with shRNA-expressing lentivirus against ATG5 or CPT1A for 24 h and then cultured with BODIPY-labeled PA (0.5 μM) for 12 h. Cells were then placed into fresh medium without/with glucose (25 mM) for 8 h. Cell staining and quantification of the co-localization of BODIPY-PA and mitochondria were the same as in Panel C. Significance was determined by one-way ANOVA. ∗p < 0.01.