Histological Analysis of Murine Colitis

To make paraffin sections, the colon and Mes-WAT were fixed in Carnoy’s solution for 2 h or 4% paraformaldehyde, paraffin-embedded, and sectioned at 5 µm following hematoxylin and eosin (H&E) and alcian blue periodic acid Schiff (AB-PAS) staining. H&E staining was performed according to standard methods as we previously used [107 (link)], briefly, hematoxylin solution for 3 min and eosin solution for 1 min. For the histological score of colitis, H&E staining colon sections were scored by an individual blinded to the details using a previously published system as indicated [106 (link)] (range 0–3), including crypt architecture, degree of inflammatory cell infiltration, muscle thickening, and goblet cell depletion. The histological score of colitis is the sum of each mouse. For AB-PAS staining, sections were stained with an AB-PAS stain kit (Beijing Solarbio Science and Technology Co., Ltd., Beijing, China).