Figure 9.

ATF2 and ATF7 are dispensable for intestinal barrier function under homeostatic conditions. (A) Four mice per group were induced by intraperitoneal injection with tamoxifen. Mice were fasted for 6 hours and then orally gavaged with FD4 (FITC dextran) dissolved in PBS. Four hours later, mice were killed (†) and cardiac puncture was performed to obtain blood. (B) Intestinal permeability assay measured by FITC fluorescence in serum. (C) E-cadherin immunofluorescence (green) in colon tissue with 4′,6-diamidino-2-phenylindole counterstain and (D) ZO-1 stain (green) in colon with 4′,6-diamidino-2-phenylindole counterstain (blue). (E) qRT-PCR for tight junction genes in mice under homeostatic conditions (n = 12 per group). (F) Electron microscopy of tight junctions in colon of control mice (left panel) and Atf2^-/-/7^ko/ko (rightpanel), and (G) small intestine of control mice (left panel) or ATF mutant mice (right panel). White asterisks indicate tight junctions. Scale bars: 200 nm. GAPDH, glyceraldehyde-3-phosphate dehydrogenase; ZO-1, Zonula Occludens-1.