Fig. 5.

IRE1α-XBP1 signaling in WT and PXR-null primary hepatocytes during exposure to EFV. (A) Representative XBP1 mRNA splicing PAGE images and densitometry quantification (mean ± S.D.) of XBP1 mRNA splicing from semiquantitative reverse transcriptase PCR for sXBP1 and uXBP1 in WT (n = 5) and PXR-null male (n = 5) mouse primary hepatocytes, as well as WT (n = 5) and PXR-null (n = 5) female hepatocytes treated with EFV and analogs of EFV at 50 μM for 4 hours. (B) Representative images for Western blotting of p-IRE1α, total IRE1α, and β-Actin and densitometry quantification ratios of p-IRE1α/total IRE1α for WT (n = 3) and PXR-null (n = 3) male mouse primary hepatocytes incubated with 50 μM EFV for 2 hours (mean ± S.D.). Ratios of sXBP1/uXBP1 and p-IRE1α/total IRE1α densitometry were log-transformed and the statistical significance of EFV treatments from DMSO (0.1%) control determined using an unpaired t test on transformed data, generating two-tailed P values (**P < 0.01; ***P < 0.001). n.s., not significant.