Figure 2.

AQP3 expression is reduced in the ileum of CD patients.

Notes: (A) 3D structural model of human AQP3. The model is drawn as a cartoon representation; only amino acids in the entrance and water selection region are shown as sticks. The numbering is consistent with the individual human AQP sequence. Complete sequence identities between bovine AQP1 (PDB ID 1J4N) and human AQP1, 3, and 7 are colored red, and nonidentical sequences are colored light blue. The water in the water channels is marked as W. (B) AQP3 mRNA levels relative to GAPDH in the ileum, right and left colon. **P<0.01. (C) Immunofluorescense staining with anti-AQP3 antibody (red) and DAPI staining of the cell nuclei (blue). Immunoreactivity of AQP3 was high in general. In the ileal biopsy of the control (upper panel) and the UC patient (lower panel), as well as in the sample from the colon of the control (upper panel), there was a distinct staining along the apical parts of the surface epithelium (arrows). The apical staining was reduced in the surface epithelium of the ileum biopsy from the CD patient (middle panel; arrowhead). Scale bar: 50 μm.

Abbreviations: 3D, three-dimensional; AQP, aquaporin; CD, Crohn’s disease; DAPI, 4′,6-diamidino-2-phenylindole; GAPDH, glyceraldehyde 3-phosphate dehydrogenase; ID, identification number; mRNA, messenger RNA; PDB, Protein Data Bank; UC, ulcerative colitis.