Figure 1.

Podocyte Sema3a gain-of-function induces proteinuria. A: Western blotting indicates that Sema3a⁺ mice overexpress kidney Sema3a approximately twofold after doxycycline-induction for 1 month. Smaller molecular weight bands represent cleaved Sema3a. Quantitation is based on at least three independent experiments. B: Dual immunofluorescence reveals Sema3a (red) and podocin (green) expression in developing mouse glomeruli; colocalization (yellow) indicates Sema3a expression in podocytes. C and D: Western blotting (C) and Coomassie Blue gel (D) indicate that excess Sema3a induces reversible proteinuria, based on albumin detected in urine samples corrected for creatinine. E and F: Excess Sema3a does not alter creatinine clearance (E) or blood pressure (F) within 1 month. Data are expressed as means ± SEM. White bars, control (−dox); black bars, Sema3a excess (+dox); gray bars, reversibility (+/−dox). ^∗P < 0.05. bwt, body weight. Original magnification, ×400 (E).