Occludin is regulated by Epac1. Panel A shows occludin levels in REC grown in NG, HG, HG + Compound 49b, HG + scrambled siRNA (HG + Sc), HG + Compound49b + scrambled siRNA (Sc + 49b), HG + Epac1 siRNA, or HG + Compound 49b + Epac1 siRNA (Epac1 siRNA + 49b). N = 4 for each group of cells. *P < 0.05 versus NG, #P < 0.05 versus HG, %P < 0.05 versus HG + Compound 49b. A representative blot is provided for each group. Panel B shows representative immunostaining of occludin in Epac1 floxed mouse retina versus cdh5/Epac1 Cre-Lox mice retina. Red staining is occludin and Isolectin B4 is green. Arrows point to gaps along the vessel with no occludin staining. Staining is representative of four mice in each group. Panel C provides Western blot results for occludin levels in the Epac1 floxed and Cre-Lox mice. N = 4, *P < 0.05 versus floxed.