Fig 1. EZH2 activity and expression in HT-5637 urothelial cells is increased by in vitro inoculation of uropathogenic E.coli (UPEC).

(A) H3K27me3 is a marker of EZH2 activity. H3K27me3 immunostaining in UPEC inoculated urothelial cells (10⁵ cells/ml) was significantly upregulated after 18 hours post-inoculation (p.i.) with UPEC (UTI89). Levels of the histone mark in nuclei were quantified by image analysis of confocal microscopy images. Fluorescence intensity was compared between HTB9 cells +/- UPEC inoculation at 18 hours p.i. (*, p<10⁻¹⁰, 2-tailed, student’s t-test). N = 5. (B) Expression of EZH2 isoform b mRNA increased after 18 hours p.i. in the UTI89 Fim H⁺ derivative as well as the point mutant Fim HΔ which is less able to invade host HT-5637 cells. N = 5. (C) Immunofluorescent staining reveals a similar rise in protein expression of EZH2 p.i. in Fim H⁺ inoculated cells. HT-5637 cells were inoculated with UPEC mutant strains complemented with Fim H⁺ or Fim HΔ plasmids. N = 6.