The Glomerular Filtration Barrier (GFB) is composed of three functional units: the fenestrated endothelial cells of the intraglomerular capillaries, podocytes, and the glomerular basement membrane (GBM) formed by these two cell types. The GFB functions as a filtration interface that prevents plasma proteins—particularly albumin—from being lost into the urine, a pathological condition known as proteinuria or, more specifically, albuminuria.

Proteinuria is often associated with progressive kidney dysfunction, which, in many cases, ultimately necessitates renal replacement therapies such as dialysis or transplantation. It is now well established that podocyte injury is involved in approximately 80–90% of all glomerular diseases, positioning proteinuria primarily as a podocyte-related pathology.

These so-called podocytopathies encompass a spectrum of diseases ranging from rare genetic disorders (e.g., Finnish-type nephrotic syndrome) to more common conditions such as diabetic nephropathy. Both genetic predispositions and environmental factors significantly influence the onset and progression of these diseases.

Within our department of Molecular Nephrology, we investigate the genes and proteins that are critical for the development and function of podocytes, how these components interact, and the consequences of mutations or dysregulation affecting these elements.

Our research focuses in part on mutations in genes encoding proteins that are almost exclusively expressed in podocytes. Examples include nephrin (Nephrin Project) and Crumbs 2 (CRB2 Project).

Additional projects in our group address mutations in ubiquitously expressed proteins whose dysfunction selectively impairs podocyte-specific functions. These include genes/proteins involved in actin cytoskeleton dynamics (e.g., INF2 project or the C3Gproject), nuclear transport (e.g., the NUP complex), and protein biosynthesis (e.g., the KEOPS Project), as well as proteins that regulate podocyte-specific signaling pathways (e.g., WTIP, PALS1, and Ntrk3 Projects).

Lastly, we also study genetic variants associated with significantly increased risk of kidney disease. One notable example is the gene encoding apolipoprotein L1 (APOL1), which is found exclusively in humans and a few primate species (APOL1 Project).