Figure 1.

Intestinal Smad4 loss associated with impaired barrier function in mice. A: seven Smad4^ΔLrig1 mice and eight control mice were administered 4 kDa fluorescein isothiocyanate-Dextran (FITC-D, FD4) by oral gavage. Blood was collected and colon was fresh frozen 4 h later. B: Smad4^ΔLrig1 mice demonstrated a 2.5-fold increase in plasma concentration of FD4 compared with control mice, suggesting an intestinal barrier defect (P = 0.029 by Mann–Whitney test). C: FITC molecules in preserved colon sections from eight Smad4^ΔLrig1 mice and eight control mice were detected using an anti-FITC antibody (red), demonstrating more FITC molecules per crypt in Smad4^ΔLrig1 mice compared with control (0.187 vs. 0.908, P = 0.007 by Mann–Whitney test). Statistical significance is designated as: *P < 0.05, **P < 0.01. Image created with BioRender.com.