Generating a Podocyte-Specific Neonatal F Receptor (FcRn) Knockout Mouse.

Proteinuria is a widely used marker of renal disease and is strongly associated with renal and cardiovascular outcomes. The molecular mechanisms underlying filtration of serum proteins through the glomerular filtration barrier (GFB) remain to be determined. Since the GFB is a complex structure, studies of albumin or IgG trafficking in cultured cells in vitro may not fully recapitulate these processes in vivo. In other epithelial cells including renal proximal tubular cells, the neonatal Fc receptor (FcRn) is required to divert albumin and IgG from the degradative pathway which allows these proteins to be recycled or transcytosed. To examine the role of podocyte FcRn in albumin and IgG trafficking in vivo, we detail the creation of a podocyte-specific FcRn knockout mouse and describe methods for examining intraglomerular detection of albumin and IgG in these mice.