<i>Entamoeba histolytica</i> (<i>Eh</i>) in antibiotic-treated mice triggers robust mucus and Muc2 mRNA expression.

(A) Colonic loops from Muc2+/+ mice were fixed in Carnoy’s solution to preserve the mucus layers and stained with Periodic acid Schiff (PAS) reagent to visualize secreted and goblet cell mucus. Top left untreated control proximal colon with densely packed pear-shaped collection of goblet cells in the crypts filled with PAS+ material (arrow). Top right is the Abx- treated group showing similar morphology to the controls. Bottom left is Eh-inoculated colonic loops with secreted mucus is a watery exudate and less PAS+ cells in the crypts. Bottom right is the Abx treated mice inoculated with Eh showing fewer filled PAS+ cells in the crypts and with a dense mucus plugs on the surface of the mucosa (inset). (B) Quantification on the number of filled goblet cells per crypt. (C) Gene expression for Muc2, (D) Math1 and (E) Spdef. (F) Confocal microscopy using Muc2 specific antibody (red) and counterstained with DAPI (blue) to visualize Muc2 filled goblet cells in sections for A above. (G) Fluorescence quantification of Muc2 signal per crypt from images in F was analyzed using ImageJ software. Scale bar = 50 μm. n = 6. *P < 0.05, **P < 0.01, ***P < 0.001.