Fig 2: CYP1A1 deficiency promoted NF-?B activation in LPS-induced ALI. (A-C) CYP1A1+/+ and CYP1A1-/- mice were intraperitoneally injected with PBS or LPS (15 mg·kg-1) for 1, 2, or 6 h. (A) The phosphorylation and total levels of p65 and I?B-a in lung homogenates were analyzed by western blot after 1 and 2 h of LPS treatment and quantified by densitometry. (B) The DNA-binding activity of p65 was determined with a TransAM p65 transcription factor ELISA kit (n = 5 for each group). (C) The phosphorylation and total levels of STAT1 and AP-1 (jun and fos) in lung homogenates were examined at the indicated times and quantified by densitometry. Group means were compared by Student's t-test. Data shown are means ± SEM. *P < 0.05. ns, no statistical difference.

Fig 3: Supplementation with AHR agonists rescues DCA-induced damage to ISCs differentiation. (A–D) Relative mRNA expression levels of AHR (A), CYP1A1 (B), ATOH1 (C), and MUC2 (D) in isolated crypts cultured with different administrations for 24 h (n = 4). (E) Relative protein levels and analysis of MUC2 in isolated ileal tissue cultured with different treatments for 24 h (n = 6). (F) Representative images of intestinal enteroids and analysis of enteroid budding rates after culturing for 72 h in different groups (n = 3); scale bars, 100 µm. Data are shown as the mean ± SEM. AHR, aryl hydrocarbon receptor; ISCs, intestinal stem cells; ATOH1, atonal homologue 1; NC, negative control; DCA, deoxycholic acid; FICZ, 6-formylindolo[3,2-b]carbazole. * p < 0.05; ** p < 0.01; *** p < 0.001.

Fig 4: Effects of Ficz on the expression and activity of AhR-Notch1 signaling pathway in hypoxic Caco-2 cells. Caco-2 monolayers were administered with Ficz at five different concentrations (0, 1, 10, 100, 1,000 nM) respectively and then exposed to hypoxia for 12 h. (A) Western blotting of AhR, CYP1A1, NICD1, HES-1 and GAPDH protein levels. (B) Relative protein expressions determined by densitometry, GAPDH was used to verify equivalent loading. Data are presented as the mean ± standard deviation. *P<0.05, **P<0.01, ***P<0.001 vs. Ficz 0 nM group; n=3. Ficz, 6-formylindolo(3,2-b)carbazole; AhR, aryl hydrocarbon receptor; CYP1A1, cytochrome P450; NICD1, Notch1 intracellular domain; HES-1, hes family bHLH transcription factor 1.

Fig 5: AhR/CYP signal axis is required for NUPR1-mediated radioresistance in HCC. a Western blot analysis was utilized to examine the expression levels of AhR, CYP1A1, and CYP1B1 in different NUPR1 expressing cell lines transfected with AhR-overexpressing vector or control vector. b Relative ROS levels in different NUPR1 expressing cells with AhR overexpression or negative control were measured after exposure to 8 Gy of IR. c Quantification of cell death in indicated cells with AhR overexpression or negative control was measured after IR (8 Gy). d Cells with different NUPR1 expressions were pretreated with 5 µM FICZ or CH223191 for 24 h, followed by being exposed to 8 Gy of IR. The cells were collected to measure relative ROS levels. e, f Colony formation assays were performed in stably transfected NUPR1 overexpression or knockdown cell lines pretreated with FICZ or CH223191, followed by exposure to 6 Gy of IR. Data are the mean of biological triplicates and are shown as the mean ± SD. P values: *P < 0.05; **P < 0.01; ***P < 0.001 and ns, not significant by two-tailed Student’s t-test