Fig. 3: miRNAs differentially expressed by T. muris infection regulate fibrosis.

a Ingenuity pathway analysis was used to identify the top 16 enriched pathways of the mRNA targets of the faecal miRNAs differentially expressed on day 35 of chronic T. muris infection. Targets represent the number of mRNA targets of the differentially expressed miRNAs in each pathway. The mRNA targets were pre-filtered to only include those with a confidence level of ‘High predicted’ or ‘Experimentally observed’ prior to pathway analysis. P value is a result of Fisher’s exact test (right-tailed). b–d 3T3 fibroblasts were cultured in TGF-β in the presence of 50 nM of negative control miRNA (miR-ctrl), miR-29a mimic or inhibitor, miR-200c mimic or inhibitor, or miR-26b mimic or inhibitor for 36 h. b RNA was harvested and the expression of Col1 quantified by qPCR relative to the expression in the untreated untransfected cells in each biological replicate. Expression levels were normalised to Gapdh using the ∆∆CT method. Statistical significance was calculated by one-way ANOVA with Geisser-greenhouse correction and Dunnet’s multiple comparisons test. The mean and SD are displayed. n = 3 or n = 4 biological replicates for each condition. c Transfected fibroblasts were fixed after 36 h, stained for collagen I (yellow) and a nuclear stain (blue) and imaged by confocal microscopy using a 63x oil immersion objective. Scale bars are 50 µm. d Luminex cytokine profiling of fibroblast cell culture supernatant after 36 h of TGF-β treatment and transfections. Statistical analysis is a result of a one-way ANOVA with Holm–Šídák’s multiple comparisons test. The mean and SD are displayed. n = 3 biological replicates for each condition.