Fig. 2.

CPT1A-mediated fatty acid oxidation maintains mitochondrial homeostasis and helps sustain the TCA cycle and aspartate production. (A and B) WT or NK Cpt1a^−/− mice were infected with MCMV, and naive (d0) or activated (d2 PI) NK cells were stained with MitoTracker Orange CMTMRos (A) or MitoSOX Red (B). Representative histograms and summary graphs (for d2 PI) are shown. (C+D+G) ¹³C-labeled palmitate was incubated with WT or NK Cpt1a^−/− NK cells for 4 h, and incorporation of ¹³C into aspartate, citrate, and malate was measured. Relative abundance of isotopologues visualized as pie charts in (C). Comparison of aspartate (D+E) or citrate (F+G) isotopologue abundance between WT and NK Cpt1a^−/− NK cells following incubation with ¹³C-labeled palmitate (D+F) or glucose (E+G). *P < 0.05, **P < 0.01, and ***P < 0.001; Student’s t test. Data are representative of 1 to 3 independent experiments, 3 to 5 mice per condition.