(a) Immunostaining for the Rap1 downstream effector
phospho-Erk1/2 was performed on paraffin-embedded human kidney sections.
Representative images are shown. Bar = low power, 100 μm; high power, 20
μm. (b) Quantification of glomerular staining intensity was
calculated and is shown as a fold change relative to MAGI2 CNS. Podocyte
phospho-Erk1/2 staining is severely reduced in patients with MAGI2 CNS
comparedwith control subjects but is only intermediately reduced in patients
with idiopathic focal segmental glomerulosclerosis (FSGS). The intensity of
total Erk1/2 staining is identical between the groups. Total number of glomeruli
analyzed: n = 60 control (20 glomeruli from each of 3
individual patients), n = 72 idiopathic FSGS (12 glomeruli from
each of 6 individual patients), n = 50 MAGI2 CNS (2 individual
patients, 32 glomeruli from nephrectomy sample, 18 glomeruli from biopsy sample;
*P < 0.001, **P < 0.002,
***P < 0.0001; NS, not significant).