Figure 1.
SREBP target gene activation and lipid accumulation in cells with erlin depletion. (A) Silencing of erlin-1 and -2 with siRNA. HeLa cells were transfected with erlin-targeting or control (ctrl) siRNAs and incubated in complete medium or with LD, and were analyzed by q-RT-PCR (left and middle) and Western blotting (right) for erlin mRNA and protein levels. (B) q-RT-PCR of SREBP target genes. P-values for all comparisons to control <0.031; n = 5. (C) Oil Red O (ORO) staining of siRNA-transfected cells. Overlays of phase contrast (blue) and red fluorescence (left) and quantification of Oil Red O staining (right). *, P < 10−4; n = 3. (D) Quantification of cellular lipids in erlin-depleted cells. (left) Esterified cholesterol (gray sections) is the difference between total cholesterol and free cholesterol (black). Values were normalized to phosphoglyceride levels and expressed relative to control. **, P < 10−4; *, P < 4 × 10−4; #, P > 0.36; n = 3. Error bars indicate standard deviations.