Figure 6.

CD36 expression is required for ATF4 activation upon palmitate exposure and ER stress induction in hepatocytes. A and B: AML-12 cells were transfected with either scramble siRNA (si-Ctrl) or Cd36 siRNA (si-Cd36) for 24 h before palmitate exposure (0.4 mM) for 16 h. Gene expression of Cd36 (A) and Atf4 (B) was determined by real-time qPCR and 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). C: AML-12 cells were transfected with either scramble siRNA (si-Ctrl) or Cd36 siRNA (si-Cd36) for 24 h before tunicamycin treatment (5 µM) for 16 h. Gene expression of Atf4 was determined by real-time qPCR and data were expressed as means ± SD, n = 4 separate experiments. Student’s t test was used for statistical evaluation (***P < 0.001; ****P < 0.0001). D: AML-12 cells were transfected with either scramble siRNA (si-Ctrl) or Cd36 siRNA (si-Cd36) for 24 h before palmitate exposure (0.4 mM) or tunicamycin treatment (5 µM) for 16 h. Protein abundance of ATF6 was detected by Western blotting. ATF4, activating transcription factor 4; CD36, cluster of differentiation 36; ER, endoplasmic reticulum.