Extended Data Fig. 8: Effects of Trp metabolites do not depend on Gαi and β-arrestin signaling.
From: Dopamine receptor D2 confers colonization resistance via microbial metabolites
Caco-2 cells were pre-treated with (a–d) Gαi inhibitor pertussis toxin (PTx, 100 ng/mL) for 18 h or (e–h) β-arrestin inhibitor barbadin (100 μM) for 30 min, followed by Trp metabolite (I3A, IPyA, or IEt, 100 μM) for 24 h. The cells were then infected with EHEC (MOI 50) for 12 h, (a, e) fixed, and stained with DAPI and Alexa Fluor 647-phalloidin. Pedestal formation = # of pedestals per Caco-2 cell (PTx: I3A, n = 994; IPyA, n = 916; IEt, n = 905; barbadin: I3A, n = 934; IPyA, n = 993; IEt, n = 1087 cells examined over 3 independent experiments). For box plots, interquartile ranges (IQRs, boxes), median values (line within box), whiskers (lowest and highest values within 1.5 times IQR from the first and third quartiles), and outliers beyond whiskers (dots), are shown. b–d, f–h, Alternatively, cells were lysed and analyzed by Western blotting with the indicated antibodies. Source data are provided in Supplementary Fig. 9. (c–d, g–h) Densitometry was performed using FIJI. Data are representative of at least 3 independent experiments, n = 3 biological replicates, bars = mean, error bars = standard deviation. Statistical analysis was performed using one-way ANOVA, followed by post-hoc Tukey multiple comparison test.
