Figure 5.

Intracellular metabolism is required for palmitate-elicited ATF4 activation. A–D: AML-12 cells were pretreated with Triacsin C, an inhibitor of long fatty acid acyl-CoA synthetase, for 2 h before a 16-h palmitate exposure. ATF4 and CD36 expression was determined by real-time qPCR, Western blotting, and ELISA, respectively. Data were expressed as means ± SD, n = 4 separate experiments. Student’s t test was used for statistical evaluation (**P < 0.01). E–H: AML-12 cells were pretreated with GSK-1940029 (20 µM), a specific SCD-1 inhibitor, for 2 h before palmitate exposure for 16 more hours. ATF4 and CD36 expression was determined by real-time qPCR, Western blotting, and ELISA, respectively. Data were expressed as means ± SD, n = 4 separate experiments. Student’s t test was used for statistical evaluation (*P < 0.05; **P < 0.01; ***P < 0.001; ****P < 0.0001). ATF4, activating transcription factor 4; CD36, cluster of differentiation 36.