Figure 3.

mTORC1 activation upon palmitate exposure contributes to NNMT upregulation. A: AML12 cells were pretreated with or without Torin1 (0.25 µM) or rapamycin (Rapa at 50 nM) for 2 h before palmitate (0.4 mM) exposure for 16 h. Total protein was extracted. Protein abundance of phosphorylated (p-)S6, total-S6, and actin were detected by Western blotting. The signal of p-S6 protein band was measured by densitometry and then divided by the signal of its corresponding actin abundance in the same sample. Data are expressed as means ± SD, n = 3 separate experiments. Student’s t test was used for statistical evaluation (***P < 0.001 vs. control). B and C: AML12 cells were pretreated with or without Torin1 (0.25 µM) (B) or rapamycin (Rapa at 50 nM) (C) for 2 h before palmitate (0.4 mM) exposure for 16 h. Total RNA was extracted. NNMT gene expressions were detected by real time-qPCR. Data are expressed as means ± SD, n = 3 separate experiments. Differences between the two groups were determined using Student’s t test (**P < 0.01; ***P < 0.001 vs. control). NNMT, nicotinamide N-methyltransferase.