Fig. 4
FA import into mitochondria is diverted into TG synthesis in BCAA-starved cells. a Routine or maximum respiration of intact cells (PaTu 8902) measured using high-resolution respirometry. Respiratory rates of BSA-palmitate (FA 16:0) with or without ETO addition demonstrate the difference between -BCAA and +BCAA treatment. The assay was performed in RPMI containing 1% FBS and BSA-palmitate (34 µM BSA, 200 µM palmitate). One-way ANOVA followed by Tukey’s multiple comparisons tests. N > 3, n ≥ 9. Criteria of significance: ***p < 0.001, ****p < 0.0001. b Confocal microscopy imaging using fluorescent FA conjugate (BODIPY FL C16, C16-BODIPY, green) and a mitochondrial network (Mitotracker™ Red) shows the import of fluorescently-labeled palmitate into mitochondria only with BCAA-containing treatment, which was augmented in DGAT1i-treated cells (inhibition of TG synthesis). No import of C16-BODIPY was observed under BCAA-depleted conditions. ETO treatment inhibits the import of C16-BODIPY into mitochondria and induces LD formation. c Log2 fold change of LC-CAR and FA species under designated conditions, namely -BCAA, +BCAA, ETO treatment, and DGAT1i treatment