Fig 2: The effect of FTO overexpression or silencing on inflammatory factor expression. (A–E) IL-1β, IL-6, IL-8, IL-4, and IL-10 mRNA levels in IPEC-J2 cells after treatment with 20 μg/mL CPB2 for 24 h. ** p < 0.01.

Fig 3: The effect of FTO on apoptosis in CPB2-treated IPEC-J2 cells. mRNA expression of Bax (A), Bcl-2 (B), caspase 3 (C), and caspase 8 (D) in cells treated with 20 μg/mL for 24 h. Flow cytometry analysis of apoptosis in FTO-overexpressing or silenced cells treated with CPB2 (E). ** p < 0.01.

Fig 4: YTHDC1 binds m6A modified FENDRR to decrease its stability. a SRAMP predicted m6A sites of FENDRR. b Western blotting was used to verify the expression of YTHDC1 and FTO under hypoxic conditions (n = 6). c qRT-PCR detection of FENDRR expression (n = 8). d FISH assay was performed to detect FENDRR expression. Scale bars = 50 µm. FENDRR probes were labeled with Cy3 (red) and nuclei were stained with DAPI (blue). e The m6A levels of FENDRR were quantified by MeRIP followed by qRT–PCR (n = 3). f and g EpiQuik m6A RNA Methylation Quantification Kit and Dot blot were used to detect global m6A modifications in total HPAECs RNAs (n = 5). h The qRT-PCR analysis of FENDRR levels after ActD (1 µg/mL) treatment at 0 h, 4 h, 8 h and 12 h (n = 4). i RNA RIP assay was performed to detect FENDRR interacts with the YTHDC1 protein (n = 4). j Colocalization of FENDRR and YTHDC1 in HPAECs. Scale bars = 50 µm. FENDRR probes were labeled with Cy3 (red), YTHDC1 were stained with FITC (green) and nuclei were stained with DAPI (blue). Pearson coefficient is 0.72121, indicating correlation. k After transfection with YTHDC1 siRNA, Western blotting was used to examine the protein levels of DRP1 (n = 6). Each datapoint in the figure represents a unique biological replicate. All values are presented as the mean ± SD. Statistical analysis was performed with one-way ANOVA or the Student’s t-test. NOR: normoxic; HYP: hypoxic; NC: negative control; ns: no significant. *P < 0.05, **P < 0.01, ***P < 0.001 compared with NOR + NC. ###p < 0.001, ##p < 0.01, #p < 0.05 compared with HYP + NC

Fig 5: FTO expression in jejunal and ileal tissue, and IPEC-J2 cells. FTO protein levels shown via Western blotting in the jejunum (A,B), ileum (C,D), and cells (E,F). (G) FTO mRNA levels in CPB2-treated IPEC-J2 cells, measured via qRT-PCR. Cells were incubated with 20 µg/mL CPB2 toxin for 24 h; control cells received no treatment. * p < 0.05; ** p < 0.01. Original western blot figures in Figure S1.