FIG 3.

Butyrate induces a transcriptional program to increase P-gp expression independent of NRF2. (A) Fold change expression of ABCB1, NQO1, and HMOX1 in T84 cells treated with butyrate or sulforaphane for 4 h. One-way ANOVA with Dunnett’s multiple-comparison test, ns P > 0.05; **, P < 0.01; ***, P < 0.001; ****, P < 0.0001. (B) Densitometry analysis of P-gp protein expression by Western blot in T84 cells and Caco2 cells after 24 h incubation with sulforaphane. ns P > 0.05 by unpaired t test for each cell line. (C) Fold change expression of ABCB1 in T84 scrambled control and NRF2 knockdown cells after 4 h incubation with butyrate. ns P > 0.05 by one-way ANOVA. (D) Representative Western blot and densitometry for P-gp expression in T84 scrambled control and NRF2 knockdown cells after 24 h incubation with butyrate. ns P > 0.05 by one-way ANOVA. (E) Representative Western blot of NRF2 nuclear localization in T84 cells after incubation with butyrate (20 mM) or sulforaphane (20 μM) for 4 h and 24 h. GAPDH and Histone H3 detected as controls for cytoplasmic and nuclear lysate fractions, respectively. (A-E) All data representative of at least two independent experiments.