ESPN 51th Annual Meeting

ESPN 2018


 
PAN disrupts podocyte cytoskeleton via oxidative stress
TAE-SUN HA 2

1- CHUNGBUK NATIONAL UNIVERSITY
2- Chungbuk National University Hospital
 
Introduction:

Puromycin aminonucleoside (PAN)-induced nephrosis is a widely used animal model for studying human idiopathic nephrotic syndrome because PAN injection into rats results in increased glomerular permeability with the characteristic ultrastructural changes in glomerular epithelial cells (GEpC; podocytes) similar to human nephrosis. We previously found that PAN treatment increased oxidative stress level of podocytes significantly with the induction of Nox4. In this study, we investigated the phenotypical changes of podocyte cytoskeletal proteins induced by PAN in vitro.

Material and methods:

Rat GEpCs and mouse podocytes were incubated in media containing various concentrations of PAN. The phenotypical changes of podocyte F-actin and alpha-actinin-4 were analyzed by confocal imaging and western blotting, in the view of oxidative injury mechanism. SiRNA for Nox4 was applied.

Results:

Morphological assessment revealed that in vitro PAN not only induced the ultrastructural changes of GEpC, such as shortening and fusion of microvilli, but also separated the intercellular gaps. PAN induced the polymerization of F-actin in a dose-dependent manner, which was reversed by the antioxidative effect of vitamin C and probucol. PAN induced the peripheral concentration of alpha-actinin-4 and reduced its protein amount. Such changes were also reversed by the antioxidant vitamin C. SiRNA for Nox4 improved the ultrastructural changes of podocytes, and also recovered the distributional changes of F-actin and -actinin-4 and the protein amount of alpha-actinin-4.

Conclusions:

Our findings suggest that podocyte cytoskeletal changes induced by PAN via oxidative stress would be the mechanism of foot process changes in experimental PAN-induced nephrosis.