Fig. 5

Intestinal epithelial cell-specific FXR activation of two bacterial metabolites. FXR-expressed or FXR-null SW480 cells were treated with bacterial culture supernatants (10 % v/v) for 24 h incubation before measurement of by administration of luciferase assay reagent. (a) The activation of FXR in each cell was measured by luciferase reporter construct FXRE-Luc (n = 2). The induction of FXR target gene by bacterial culture supernatants was determined with quantitative real-time reverse transcription-PCR analysis (n = 1): (b) Ibabp gene, (c) Ostα gene. (d, e) The culture supernatant derived from B. dorei transactivated FXR target gene (Ibabp) in Caco-2 cells (n = 1). Before the treatment with bacterial supernatants, cells were cultured for 7 days or 21 days. The induction of FXR target gene (Ibabp) by bacterial culture supernatant were determined in undifferentiated (d) or fully differentiated Caco-2 cells (e). (f) The FXR stimulatory potential of bacterial supernatants FXR in HepG2 cells. Shp gene expression levels in HepG2 cells treated with bacterial culture supernatant were determined (n = 1). mRNA levels were normalized to Gapdh mRNA levels via the relative standard curve method. Relative mRNA expression: Compared to DMEM medium group. Experiments were performed in triplicate. Values are the mean ± SD. Differences were calculated using Student’s t-test (*p < 0.05, **p < 0.01, ***p < 0.001)