Perfluorooctanesulfonic acid (PFOS) exacerbates intestinal-specific expression of proinflammatory cytokines during TNBS-induced inflammation in zebrafish larvae. (A) Zebrafish larvae were exposed to TNBS (70 µg/ml) and/or PFOS, perfluorooctanoic acid (PFOA) or perfluorohexanesulfonic acid (PFHxS) (200 nM) from 72 hpf until 120 hpf. Violin plots showing the relative expression of il1b, tnfa, il17a/f3 and il22 in whole larvae at 120 hpf following exposure to TNBS and PFOS, PFOA or PFHxS. n=7-9, three experiments. Each dot represents a pool of ten zebrafish larvae. Values for the UT and TNBS groups for the experiment with each individual polyfluoroalkyl substance (PFAS) in A have previously been presented as a pool in Fig. 1D. (B) Panel of PFASs tested. (C,D) Scheme of dissection of intestines from zebrafish larvae (C, left) and violin plots showing relative expression of an intestine-specific gene, cldn15la (C, right), and proinflammatory cytokines, tnfa (D, left) and il1b (D, right), analyzed by qPCR in dissected intestines or carcasses at 120 hpf following exposure to TNBS (70 µg/ml) and PFOS (200 nM). n=11-12, four experiments. Data show transcript levels as A.U. with respect to eef1l1a1. Each dot represents a pool of ten intestines or carcasses. The black line represents the median. *P<0.05, **P<0.01, ***P<0.001. One-way ANOVA with Fisher's LSD test for all plots, except in C, for which an unpaired Student's t-test was used.