Fig. 3.

Prednisone increases podocyte number in experimental FSGS. A–C: representative images of p57 staining (brown, nuclear) at 2 and 4 wk in normal mice (A-1, A-2), mice with FSGS given DMSO (B-1, B-2), and prednisone-treated mice with FSGS (C-1, C-2; ×630 original magnification). Arrows show examples of positive staining. D: staining is not detected in the negative control where the p57 primary antibody was omitted (×200 original magnification). E: podocyte number, measured as the number of p57-positive cells/glomerular cross section, was significantly depleted by day 3 of FSGS. Podocyte number remained low in mice with FSGS mice given DMSO at 2 and 4 wk (dotted line). Podocyte number increased significantly in mice with FSGS given prednisone (solid line) at 2 and 4 wk. These data show that when prednisone is administered following abrupt podocyte depletion, podocyte number increases compared with controls.