Figure 2.

Inhibiting β-Oxidation Improves ER Ultrastructure

(A) Primary hepatocytes were treated with vehicle, 250 ng/mL TM, 25 μg/mL ET, or TM and ET for 8 h and fixed in 2.5% glutaraldehyde. Fixed cells were imaged by transmission electron microscopy. Inset panels are indicated and shown on the right. Blue arrowheads represent areas of structurally normal ER, whereas orange arrowheads represent dysmorphic ER. Scale bars, 2 μm.

(B) Images were scored blindly based on an approximation of the percentage of “dilated” ER in each image. Normal (blue): <25% of ER in an image dilated, moderate (gray): 25%–75% dilated, and severe (orange): >75% dilated. Thus, the graph represents the percentage of images falling into each category. n = 9–10 cell images per group.

(C) Primary hepatocytes were treated with 25 μg/mL ET in the presence of 0.5, 2, or 10 μg/ml TM for 8 h, and expression of Bip and Chop was detected by qRT-PCR. Note that the relative magnitude of UPR activation upon TM treatment varied from experiment to experiment, which is why induction of CHOP was less robust at even the highest dose of TM in this experiment than in response to 0.25 μg/mL TM in Figure 1A.

See also Figure S2.