Fig. 1.
Collecting duct (CD)-specific overexpression of periostin. A: we generated a transgenic mouse (Postntg) carrying a full-length periostin cDNA construct downstream of a floxed mCherry STOP cassette that was inserted in front of the Rosa26 promoter. These mice were bred to Pkhd1-Cre mice to specifically overexpress periostin in the CD. B: to confirm Cre-mediated transgene expression, protein lysates from Postntg mice with or without Pkhd1-Cre were immunoblotted for periostin. Conditioned media (CM) from M1 cells transfected with full-length mouse periostin cDNA was used as a positive control for periostin expression. We crossed Postntg;Pkhd1-Cre (PostnCD) mice to pcy mice to generate Postntg;Pkhd1-Cre;pcy mice (PostnCD pcy). Sections were stained for periostin (green), AQP-2 (CD marker, red), and DAPI (nuclear stain, blue). Wild-type (C), PostnCD (D), pcy (E), and PostnCD pcy (F). C and D are the same magnification. A lower magnification was used of E and F to visualize multiple cysts. Scale bars: 5 µm.