Figure 5.

PAN injury results in internalization of surface nephrin and podocin. (A) Super-resolution structured illumination microscopy for nephrin (green) on kidney sections of control and PAN-injected rats on day 7 postinjection. Scale bar, 20 μm. (B) Isolated glomeruli from PAN-injected rats and controls were subject to surface biotinylation, followed by lysis, streptavidin agarose precipitation (Ppt), and nephrin immunoblotting (IB). A portion of the initial lysate was saved to represent the total input, and the supernatant postprecipitation contains nonbiotinylated (i.e., cytosolic) proteins. (C) Densitometric quantitation of streptavidin-precipitated biotinylated nephrin (surface) compared with total nephrin (input) from (B), showing a stepwise decrease in surface nephrin levels. All values were made relative to surface nephrin levels in control samples. *P<0.05 by two-tailed t test.