Figure 3. Bacterial colonization results in a transient increase in epithelial proliferation and the maturation of enterocytes.
(A) Representative confocal micrographs of HIOs injected with PBS or 104 CFU E. coli str. ECOR2 at 24–96 hr post-microinjection and stained with fluorescent indicators for for EdUDNA, E-cadherin, or nuclei (DAPI) as indicated in the figure labels . All HIOs were exposed to 10 M EdU at 22 hr post-microinjection and EdU was removed at 24 hr. Panels are representative of 4 HIOs per timepoint per treatment condition. (B) Quantification of the number of EdU-positive and Ki67-positive epithelial cells (E-cadherin cells) per 10X confocal microscopy field. One 10X confocal microscopy field consisting of 200–1000 epithelial cells was collected from each of 4 HIOs per timepoint per treatment group. The error bars represent the standard error of the mean and the p-values reflect the results of an unpaired two-tailed Student’s t-test comparing the PBS-injected HIOs to the E. coli-injected HIOs at that timepoint. (C) Representative confocal micrographs of HIOs injected with PBS or 104 CFU E. coli str. ECOR2 at 24–96 hr post-microinjection and stained with fluorescent antibodies for Sox9, E-cadherin, or nuclei (DAPI) as indicated in the figure labels. Panels are representative of 4 HIOs per timepoint per treatment condition.
Figure 3—figure supplement 1. Pathview (Luo and Brouwer, 2013) plot of the KEGG (Kanehisa and Goto, 2000) pathway showing the Cell mitotic cycle ('HSA 04110') superimposed with RNA-seq expression data corresponding to the log2 -transformed fold change in expression of cell cycle transcripts from HIOs microinjected with E. coli relative to PBS-injected HIOs at 48 h post-microinjection.
