It seems incredible now that it was only in 1998 that it was conclusively proven that the podocyte plays a vital role in the prevention of albuminuria. At that time mutations in NPHS1, encoding nephrin, were found in 49 patients from Finland with congenital nephrotic syndrome. Up to that point, the podocyte was thought to play a secondary role in the glomerular filtration barrier. Since then, multiple mutations in different podocyte proteins have been identified in association with proteinuria. The table below (taken from a recent Nature Reviews Nephrology article ) summarizes the podocyte-related genes that have been associated with albuminuria (click to enlarge).
Orthodoxies continue to be challenged - the old model of podocytes that are fixed in place is being replaced by one where podocytes are constantly moving, being shed and replaced. The video below is from a remarkable paper where the authors have used GFP to visualize podocytes in mouse glomeruli. The pulsatile nature of glomerular contractions is notable and fascinating.