FIGURE 4.

Polyunsaturated fatty acids suppress UPR induced by SCD1 knockdown. HeLa cells were transfected with the indicated siRNA. 48 h after transfection cells were further incubated for 24 h in media supplemented with the indicated fatty acid (50 μm) and then harvested. A and B, expression of CHOP (A) and GRP78 (B) mRNAs detected by real-time PCR is shown. The expression level of each gene was normalized to the GAPDH gene and is represented as -fold induction over siControl. C, semiquantitative reverse transcription-PCR analysis of XBP1 spliced and unspliced mRNA. The positions of the unspliced form (u) and spliced form (s) are indicated. Thapsigargin-treated cells (Tg) were used as a positive control. The asterisks indicate significant differences compared with siControl-transfected cells (p < 0.01), and the number symbols indicate significant differences compared with siSCD1-transfected cells which were untreated (p < 0.01).