Experimental strategy and validation of the FRET-based compound screen. (A) Response of nucleoBAS sensor-expressing cells to different TCDCA concentrations. White bars: cells only expressing the bile acid uptake transporter NA+-taurocholate co-transporting polypeptide (positive control). Blue bars: cells expressing NA+-taurocholate co-transporting polypeptide and OSTα-OSTβ (n = 4). (B) Experimental strategy used to determine which compounds inhibit OSTα-OSTβ. High FRET signal intensities represent compounds inhibiting OSTα-OSTβ–mediated transport activity. (C) Distribution of drug classes for inhibition of OSTα-OSTβ based on the top 25 hits. (D) Screen FACS plots of controls (dimethyl sulfoxide [DMSO], and 10 μmol/L GW4064), followed by FACS plots of the 6 selected compounds (10 μmol/L), bifonazole, bromhexine HCl, clofazimine, lovastatin, meclizine HCl, and simvastatin (n = 1, data are from a representative experiment replicated 2 times). (A) Data are presented as means ± SD. *P ≤ .05 (Student t test, 2-tailed).