Figure 4.

Podocyte-specific loss of Klf15 abrogates DEX-mediated increase in podocyte differentiation markers. Primary podocytes were isolated from 12-week-old Podocin-Cre Klf15^flox/flox and Podocin-Cre Klf15^+/+ mice and cultured at 37°C for 1 week. Cells were subsequently treated with DEX or vehicle (VEH) for 12 hours. RNA was extracted, and real-time PCR was performed for (A) Klf15 mRNA expression (n=6). *P<0.05; **P<0.01 (Kruskal–Wallis test with Dunn post-test). (B) Immunostaining for Klf15 was performed. Representative images from three mice in each group are shown (left panel). Quantification for Klf15 expression in podocytes was determined by the ratio of Klf15+ and Wt1+ cells to W11+ cells (n=3). Magnification, ×20. **P<0.01; ***P<0.001 (Kruskal–Wallis test with Dunn post-test). (C) Phalloidin and hoechst staining was performed in isolated primary podocytes. The representative images from three independent experiments are shown. In total, 100 cells were selected in each group, and the cells were classified into type A (>90% of cell area filled with thick cables), type B (no thick cables but some cables present), and type C (no cables visible in the central area of the cell; n=3). **P<0.01; ***P<0.001 (unpaired t test). (D) Nephrin mRNA expression (n=6) and (E) Synaptopodin mRNA expression (n=6). *P<0.05; **P<0.01 (Kruskal–Wallis test with Dunn post-test).