Mesangial cell integrin αvβ8 provides glomerular endothelial cell cytoprotection by sequestering TGF-β and regulating PECAM-1.

Integrins are heterodimeric receptors that regulate cell adhesion, migration, and apoptosis. Integrin αvβ8 is most abundantly expressed in kidney and brain, and its major ligand is latent transforming growth factor-β (TGF-β). Kidney αvβ8 localizes to mesangial cells, which appose glomerular endothelial cells and maintain glomerular capillary structure by mechanical and poorly understood paracrine mechanisms.

A WT1 co-regulator controls podocyte phenotype by shuttling between adhesion structures and nucleus.

Glomerular podocyte differentiation state is critical for filtration barrier function and is regulated by WT1, a zinc finger transcription factor. A yeast two-hybrid assay identified a novel, WT1-interacting protein (WTIP) that maps to human chromosome 19q13.1, a region with genes linked to familial focal segmental glomerulosclerosis.