Figure 6. Hyperactivation of mTORC1 leads to mislocalization of slit diaphragm proteins.
(A) Nephrin expression at interpodocyte filtration slit area is diminished in PcKOTsc1 mice. Representative electron micrographs of immunogold nephrin staining in 3-week-old mice are shown. Number of immunogold particles for nephrin at the slit diaphragm was measured in 290 slit diaphragms from 2 wild-type and 170 slit diaphragms from 2 PcKOTsc1 mice. *P < 0.001 versus wild-type, mean ± SEM. (B) Nephrin and actin expression in the indicated glomeruli were determined by Western blotting. Levels of nephrin expression in the indicated genotypes were quantified (nephrin/actin). Data are expressed as fold increase. P = 0.67, mean ± SEM, n = 3. (C) Nephrin is mislocalized in PcKOTsc1 podocytes. Confocal microscopic analyses of nephrin and synaptopodin expression in the indicated animals (3 weeks old) are shown. Rapamycin treatment was performed for 1 week. Areas indicated by squares in the Merge column are shown at higher magnification in the right two columns. Original magnification, ×13,500 (A), ×400 (C).